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https://en.wikipedia.org/wiki/Protosteroid | A protosteroid or primordial fat is a lipid precursor, which can be transformed during subsequent biochemical reactions and finally become steroid. The protosteroids are biomarkers that are produced by ancient eukaryotes belonged to the microorganisms in the protosterol biota. The intermediate compounds created by these eukaryotes while making crown sterol molecules.
For the first time, the German biochemist and Nobel laureate Konrad Emil Bloch thought that instead of today's sterols, earlier life forms could have used chemical intermediates in their cells. He called these intermediates protosteroids. Later researchers synthesized protosteroids called lanosterol, cycloartenol, and 24-methylene cycloartenol. Then researchers from the Australian National University and the University of Bremen found protosteroids in rocks that formed 1.6 billion years ago in the Barney Creek Formation in Northern Australia. The researchers also found derivatives that matched the pattern produced by 24-methylene cycloartenol in 1.3-billion-year-old rocks. |
https://en.wikipedia.org/wiki/Hemogenic%20endothelium | Hemogenic endothelium is a special subset of endothelial cells scattered within blood vessels that can differentiate into haematopoietic cells.
The development of hematopoietic cells in the embryo proceeds sequentially from mesoderm through the hemangioblast to the hemogenic endothelium and hematopoietic progenitors.
See also
Hemangioblast |
https://en.wikipedia.org/wiki/Camera%20module | A camera module is an image sensor integrated with a lens, control electronics
, and an interface like CSI, Ethernet or plain raw low-voltage differential signaling.
See also
IP camera
Mobile Industry Processor Interface (MIPI)
Elphel - multi-sensor camera based on FPGA and Ethernet interface. Previous camera models were used with Google Books and street view |
https://en.wikipedia.org/wiki/Set%20splitting%20problem | In computational complexity theory, the set splitting problem is the following decision problem: given a family F of subsets of a finite set S, decide whether there exists a partition of S into two subsets S1, S2 such that all elements of F are split by this partition, i.e., none of the elements of F is completely in S1 or S2. Set Splitting is one of Garey & Johnson's classical NP-complete problems. The problem is sometimes called hypergraph 2-colorability.
Variants
The optimization version of this problem is called max set splitting and requires finding the partition which maximizes the number of split elements of F. It is an APX-complete problem and hence in NPO.
The set k-splitting problem is stated as follows: given S, F, and an integer k, does there exist a partition of S which splits at least k subsets of F? The original formulation is the restricted case with k equal to the cardinality of F. The Set k-Splitting is fixed-parameter tractable, i.e., if k taken to be a fixed parameter, rather than a part of the input, then a polynomial algorithm exists for any fixed k. Dehne, Fellows and Rosamond presented an algorithm that solves it in time
for some function f and constant c.
When each element of F is restricted to be of cardinality exactly k, the decision variant is called Ek-set splitting and the optimization version max Ek-set splitting. For k > 2 the former remains NP complete, and for k ≥ 2 the latter remains APX complete. For k ≥ 4, Ek-Set Splitting is approximation resistant. That is, unless P=NP, there is no polynomial-time (factor) approximation algorithm which does essentially better than a random partition.
The weighted set splitting is a variant in which the subsets in F have weights and the objective is to maximize the total weight of the split subsets.
Connection to other problems
Set splitting is special case of the not-all-equal satisfiability problem without negated variables. Additionally, Ek-set splitting equals non-monochromatic gr |
https://en.wikipedia.org/wiki/Intrinsic%20flat%20distance | In mathematics, the intrinsic flat distance is a notion for distance between two Riemannian manifolds which is a generalization of Federer and Fleming's flat distance between submanifolds and integral currents lying in Euclidean space.
Overview
The Sormani–Wenger intrinsic flat (SWIF) distance is a distance between compact oriented Riemannian manifolds of the same dimension. More generally it defines the distance between two integral current spaces, (X,d,T), of the same dimension (see below). This class of spaces and this distance were first announced by mathematicians Sormani and Wenger at the Geometry Festival in 2009 and the detailed development of these notions appeared in the Journal of Differential Geometry in 2011.
The SWIF distance is an intrinsic notion based upon the (extrinsic) flat distance between submanifolds and integral currents in Euclidean space developed by Federer and Fleming. The definition imitates Gromov's definition of the Gromov–Hausdorff distance in that it involves taking an infimum over all distance-preserving maps of the given spaces into all possible ambient spaces Z. Once in a common space Z, the flat distance between the images is taken by viewing the images of the spaces as integral currents in the sense of Ambrosio–Kirchheim.
The rough idea in both intrinsic and extrinsic settings is to view the spaces as the boundary of a third space or region and to find the smallest weighted volume of this third space. In this way, spheres with many splines that contain increasingly small amounts of volume converge "SWIF-ly" to spheres.
Riemannian setting
Given two compact oriented Riemannian manifolds, Mi, possibly with boundary:
dSWIF(M1, M2) = 0
iff there is an orientation preserving isometry from M1 to M2. If Mi converge in the Gromov–Hausdorff sense to a metric space Y then a subsequence of the Mi converge SWIF-ly to an integral current space contained in Y but not necessarily equal to Y. For example, the GH limit of a se |
https://en.wikipedia.org/wiki/Cartesian%20tree | In computer science, a Cartesian tree is a binary tree derived from a sequence of distinct numbers. To construct the Cartesian tree, set its root to be the minimum number in the sequence, and recursively construct its left and right subtrees from the subsequences before and after this number. It is uniquely defined as a min-heap whose symmetric (in-order) traversal returns the original sequence.
Cartesian trees were introduced by in the context of geometric range searching data structures. They have also been used in the definition of the treap and randomized binary search tree data structures for binary search problems, in comparison sort algorithms that perform efficiently on nearly-sorted inputs, and as the basis for pattern matching algorithms. A Cartesian tree for a sequence can be constructed in linear time.
Definition
Cartesian trees are defined using binary trees, which are a form of rooted tree. To construct the Cartesian tree for a given sequence of distinct numbers, set its root to be the minimum number in the sequence, and recursively construct its left and right subtrees from the subsequences before and after this number, respectively. As a base case, when one of these subsequences is empty, there is no left or right child.
It is also possible to characterize the Cartesian tree directly rather than recursively, using its ordering properties. In any tree, the subtree rooted at any node consists of all other nodes that can reach it by repeatedly following parent pointers. The Cartesian tree for a sequence of distinct numbers is defined by the following properties:
The Cartesian tree for a sequence is a binary tree with one node for each number in the sequence.
A symmetric (in-order) traversal of the tree results in the original sequence. Equivalently, for each node, the numbers in its left subtree are earlier than it in the sequence, and the numbers in the right subtree are later.
The tree has the min-heap property: the parent of any non-root node ha |
https://en.wikipedia.org/wiki/Track%20%28disk%20drive%29 | A disk drive track is a circular path on the surface of a disk or diskette on which information is magnetically recorded and from which recorded information is read.
A track is a physical division of data in a disk drive, as used in the Cylinder-Head-Record (CCHHR) addressing mode of a CKD disk. The concept is concentric, through the physical platters, being a data circle per each cylinder of the whole disk drive. In other words, the number of tracks on a single surface in the drive exactly equals the number of cylinders of the drive.
Tracks are subdivided into blocks (or sectors, pages) (see: Storage block and Virtual page).
The term track is sometimes prefaced with the word logical (i.e. "3390-9 has 3 logical tracks per physical track") to emphasize that it is used as an abstract concept, not a track in the physical sense.
See also
Hard disk drive
Disk sector
Cylinder
Computer storage devices
Rotating disc computer storage media |
https://en.wikipedia.org/wiki/Rogers%E2%80%93Ramanujan%20continued%20fraction | The Rogers–Ramanujan continued fraction is a continued fraction discovered by and independently by Srinivasa Ramanujan, and closely related to the Rogers–Ramanujan identities. It can be evaluated explicitly for a broad class of values of its argument.
Definition
Given the functions and appearing in the Rogers–Ramanujan identities, and assume ,
and,
with the coefficients of the q-expansion being and , respectively, where denotes the infinite q-Pochhammer symbol, j is the j-function, and 2F1 is the hypergeometric function. The Rogers–Ramanujan continued fraction is then,
denotes the Jacobi symbol.
One should be careful with notation since the formulas employing the j-function will be consistent with the other formulas only if (the square of the nome) is used throughout this section since the q-expansion of the j-function (as well as the well-known Dedekind eta function) uses . However, Ramanujan, in his examples to Hardy and given below, used the nome instead.
Special values
If q is the nome or its square, then and , as well as their quotient , are related to modular functions of . Since they have integral coefficients, the theory of complex multiplication implies that their values for involving an imaginary quadratic field are algebraic numbers that can be evaluated explicitly.
Examples of R(q)
Given the general form where Ramanujan used the nome ,
when ,
when ,
when ,
when ,
when ,
when ,
when ,
and is the golden ratio. Note that is a positive root of the quartic equation,
while and are two positive roots of a single octic,
(since has a square root) which explains the similarity of the two closed-forms. More generally, for positive integer m, then and are two roots of the same equation as well as,
The algebraic degree k of for is ().
Incidentally, these continued fractions can be used to solve some quintic equations as shown in a later section.
Examples of G(q) and H(q)
Interestingly, there are explicit formulas for |
https://en.wikipedia.org/wiki/Ecomorphology | Ecomorphology or ecological morphology is the study of the relationship between the ecological role of an individual and its morphological adaptations. The term "morphological" here is in the anatomical context. Both the morphology and ecology exhibited by an organism are directly or indirectly influenced by their environment, and ecomorphology aims to identify the differences. Current research places emphasis on linking morphology and ecological niche by measuring the performance of traits (i.e. sprint speed, bite force, etc.) associated behaviours, and fitness outcomes of the relationships.
Current ecomorphological research focuses on a functional approach and application to the science. A broadening of this field welcomes further research in the debate regarding differences between both the ecological and morphological makeup of an organism.
Development of ecomorphology
The roots of ecomorphology date back to the late 19th century. Then, description and comparison of morphological form, primarily for use in avian classification, was focal point of morphological research. However, during the 1930s and 40s morphology as a field shrank. This was likely due to the emergence of new areas of biological inquiry enabled by new techniques. The 1950s brought about not only a change in the approach of morphological studies, resulting in the development of evolutionary morphology in the form of theoretical questions, and a resurgence of interest in the field. High-speed cinematography and x-ray cinematography began to allow for observations of movements of parts while electromyography allowed for observation of the integration of muscle activities. Together, these methodologies allowed morphologists to better delve into the intricacies of their study. It was then, in the 1950s and 60s, that ecologists began to use morphological measures to study evolutionary and ecological questions. This culminated in Karr and James coining the term "ecomorphology" in 1975. The follo |
https://en.wikipedia.org/wiki/Snap%21%20%28programming%20language%29 | Snap! (formerly Build Your Own Blocks) is a free block-based educational graphical programming language and online community allowing students to explore, create, and remix interactive animations, games, stories, and more, while learning about mathematical and computational ideas. While inspired by Scratch, Snap! has many advanced features. The Snap! editor, and programs created in it, are web applications that run in the browser (like Scratch 3) without requiring installation. It is built on top of Morphic.js, a Morphic GUI, written by Jens Mönig as 'middle layer' between Snap! itself and 'bare' JavaScript.
User interface
In Snap!, the screen is organized in three resizable columns containing five regions: the block group selector (top of left column), the blocks palette (left column), the main area (middle column), and the stage area (top of right column) with the sprite selector (also called the sprite corral) showing sprite thumbnails below it.
In the interactively resizable stage area are shown the graphical results of the scripts running in the script area and/or interactively double-clicked individual blocks in any palette. Individual blocks can be dragged from the palette onto the scripts area to be associated with the selected sprite.
Snap!'''s blocks are divided into eight groups: Motion, Looks, Sound, Pen, Control, Sensing, Operators, and Variables. The layout of these groups in the block group selector is shown in the table below.
The central area can show scripts, costumes/backdrops, or sounds associated with the selected sprite. What that area shows depends on the selected tab.
Features
The most important features that Snap! offers, but Scratch does not, include:
Expressions using anonymous functions, represented by a block inside a gray ring, having one or more empty slot(s)/argument(s) that are filled by a "higher order function" (the one that is calling the anonymous one). (Their computer-science theoretical basis is first class functions, whi |
https://en.wikipedia.org/wiki/Hawaiian%20Islands | The Hawaiian Islands (Hawaiian: Nā Moku o Hawai‘i) are an archipelago of eight major volcanic islands, several atolls, and numerous smaller islets in the North Pacific Ocean, extending some from the island of Hawaiʻi in the south to northernmost Kure Atoll. Formerly called the Sandwich Islands, the present name for the archipelago is derived from the name of its largest island, Hawaiʻi.
The archipelago sits on the Pacific Plate. The islands are exposed peaks of a great undersea mountain range known as the Hawaiian–Emperor seamount chain, formed by volcanic activity over a hotspot in the Earth's mantle. The islands are about from the nearest continent and are part of the Polynesia subregion of Oceania.
The U.S. state of Hawaii occupies the archipelago almost in its entirety (including the mostly uninhabited Northwestern Hawaiian Islands), with the sole exception of Midway Atoll (a United States Minor Outlying Island). Hawaii is the only U.S. state that is situated entirely on an archipelago, and the only state not geographically connected with North America. The Northwestern islands (sometimes called the Leeward Islands) and surrounding seas are protected as a National Monument and World Heritage Site.
Islands and reefs
The date of the first settlements of the Hawaiian Islands is a topic of continuing debate. Archaeological evidence seems to indicate a settlement as early as 124 AD.
Captain James Cook, RN, visited the islands on January 18, 1778, and named them the "Sandwich Islands" in honor of The 4th Earl of Sandwich, who as the First Lord of the Admiralty was one of his sponsors. This name was in use until the 1840s, when the local name "Hawaii" gradually began to take precedence.
The Hawaiian Islands have a total land area of . Except for Midway, which is an unincorporated territory of the United States, these islands and islets are administered as Hawaii—the 50th state of the United States.
Major islands
The eight major islands of Hawaii (Windward Is |
https://en.wikipedia.org/wiki/ATM%20%28computer%29 | The ATM Turbo (ru: "АТМ-ТУРБО"), also known simply as ATM (from ru: "Ассоциация Творческой Молодёжи", meaning "Association of Creative Youth") is a ZX Spectrum clone, developed in Moscow in 1991, by two firms, MicroArt and ATM.
It offers enhanced characteristics, compared to the original Spectrum, such as a , RAM, ROM, AY-8910 (two chips in upgraded models), 8-bit DAC, 8-bit 8-channel ADC, RS-232, parallel port, Beta Disk Interface, IDE interface, AT/XT keyboard, text mode (, , ), and three new graphics modes.
The ATM can be emulated in Unreal Speccy v0.27 and higher.
History
ATM was developed in 1991 based on the Pentagon, a ZX Spectrum clone popular in Russia. In 1992 an upgraded model was introduced, named ATM Turbo 2. Up to 1994 the computer was produced by ATM and MicroArt; later the firms separated and production ended.
In 2004 NedoPC from Moscow resumed production. New versions called ATM Turbo 2+ and ZX Evolution were introduced.
Characteristics
Graphics modes
For compatibility purposes, the original ZX Spectrum mode is available.
New graphics modes offer expanded abilities:
mode, with 2 out of 16 colors per 8x1 pixels. The Profi offers a similar mode, but the ATM can use the full set for both ink and paper.
mode with a raster mode (a two-pixel chunky mode, not planar like EGA). Two games for this mode were converted directly from PC: Prince of Persia and Goblins, and one from Sony PlayStation: Time Gal. Other games that use this mode exist, like Ball Quest, released in August, 2006.
Palette:
from a 64 color palette (6-bit RGB) can be set for all modes.
Operating systems
48K Sinclair BASIC, 128K Sinclair BASIC, TR-DOS, CP/M, iS-DOS, TASiS, DNA OS, Mr Gluk Reset Service.
Software
ATM Turbo
Virtual TR-DOS
Models
Many models exist. Models before version 6.00 are called ATM 1, later models are called ATM 2(2+) or ATM Turbo 2(2+) or simply Turbo 2+. A IDE interface is available since v6.00.JIO0UBH9BY8B9T7GVC6R (the latest model is 7.18 |
https://en.wikipedia.org/wiki/Domination%20analysis | Domination analysis of an approximation algorithm is a way to estimate its performance, introduced by Glover and Punnen in 1997. Unlike the classical approximation ratio analysis, which compares the numerical quality of a calculated solution with that of an optimal solution, domination analysis involves examining the rank of the calculated solution in the sorted order of all possible solutions. In this style of analysis, an algorithm is said to have dominance number or domination number K, if there exists a subset of K different solutions to the problem among which the algorithm's output is the best. Domination analysis can also be expressed using a domination ratio, which is the fraction of the solution space that is no better than the given solution; this number always lies within the interval [0,1], with larger numbers indicating better solutions. Domination analysis is most commonly applied to problems for which the total number of possible solutions is known and for which exact solution is difficult.
For instance, in the Traveling salesman problem, there are (n-1)! possible solutions for a problem instance with n cities. If an algorithm can be shown to have dominance number close to (n-1)!, or equivalently to have domination ratio close to 1, then it can be taken as preferable to an algorithm with lower dominance number.
If it is possible to efficiently find random samples of a problem's solution space, as it is in the Traveling salesman problem, then it is straightforward for a randomized algorithm to find a solution that with high probability has high domination ratio: simply construct a set of samples and select the best solution from among them. (See, e.g., Orlin and Sharma.)
The dominance number described here should not be confused with the domination number of a graph, which refers to the number of vertices in the smallest dominating set of the graph.
Recently, a growing number of articles in which domination analysis has been applied to assess the |
https://en.wikipedia.org/wiki/Coding%20strand | When referring to DNA transcription, the coding strand (or informational strand) is the DNA strand whose base sequence is identical to the base sequence of the RNA transcript produced (although with thymine replaced by uracil). It is this strand which contains codons, while the non-coding strand contains anticodons. During transcription, RNA Pol II binds to the non-coding template strand, reads the anti-codons, and transcribes their sequence to synthesize an RNA transcript with complementary bases.
By convention, the coding strand is the strand used when displaying a DNA sequence. It is presented in the 5' to 3' direction.
Wherever a gene exists on a DNA molecule, one strand is the coding strand (or sense strand), and the other is the noncoding strand (also called the antisense strand, anticoding strand, template strand or transcribed strand).
Strands in transcription bubble
During transcription, RNA polymerase unwinds a short section of the DNA double helix near the start of the gene (the transcription start site). This unwound section is known as the transcription bubble. The RNA polymerase, and with it the transcription bubble, travels along the noncoding strand in the opposite, 3' to 5', direction, as well as polymerizing a newly synthesized strand in 5' to 3' or downstream direction. The DNA double helix is rewound by RNA polymerase at the rear of the transcription bubble. Like how two adjacent zippers work, when pulled together, they unzip and rezip as they proceed in a particular direction. Various factors can cause double-stranded DNA to break; thus, reorder genes or cause cell death.
RNA-DNA hybrid
Where the helix is unwound, the coding strand consists of unpaired bases, while the template strand consists of an RNA:DNA composite, followed by a number of unpaired bases at the rear. This hybrid consists of the most recently added nucleotides of the RNA transcript, complementary base-paired to the template strand. The number of base-pairs in the hybrid is |
https://en.wikipedia.org/wiki/DSSP%20%28imaging%29 | DSSP stands for digital shape sampling and processing. It is an alternative and often preferred way of describing "reverse engineering" software and hardware. The term originated in a 2005 Society of Manufacturing Engineers' "Blue Book" on the topic, which referenced numerous suppliers of both scanning hardware and processing software.
DSSP employs various 3D scanning methods, including laser scanners, to acquire thousands to millions of points on the surface of a form and then software from a variety of suppliers to convert the resulting "point cloud" into forms useful for inspection, computer-aided design, visualization and other applications. It may also employ volumetric methods of scanning, such as digital tomography.
Some common applications include CAI (computer-aided inspection), creation of 3D CAD models from scanned data, medical applications, 3D imaging for Web 2.0 applications, and the restoration of culturally significant artifacts; as well as conventional reverse engineering for creating replacement parts.
The term 'reverse engineering' itself has acquired some notoriety when the technology has been used to copy others' designs.
The term 'laser scanning' has also been used somewhat interchangeably for DSSP. However, there are two problems with the term as a broad description of the field. First, it is only one of many alternative scanning technologies. Second, it misses the essential role of processing software in converting point cloud data into useful forms.
In some ways, DSSP is a 3D analog to DSP (digital signal processing) in that the software attempts to extract a clear and accurate 3D image from point data that may include noise. The notion of 'shape sampling' embedded in the term also acknowledges that, as in many measurement processes, the accuracy of the 3D data will depend upon the number and accuracy of points sampled.
The speed and accuracy of both scanners to acquire data and software algorithms to extract useful data has dramatical |
https://en.wikipedia.org/wiki/Servo%20control | Servo control is a method of controlling many types of RC/hobbyist servos by sending the servo a PWM (pulse-width modulation) signal, a series of repeating pulses of variable width where either the width of the pulse (most common modern hobby servos) or the duty cycle of a pulse train (less common today) determines the position to be achieved by the servo. The PWM signal might come from a radio control receiver to the servo or from common microcontrollers such as the Arduino.
Small hobby servos (often called radio control, or RC servos) are connected through a standard three-wire connection: two wires for a DC power supply and one for control, carrying the control pulses.
The parameters for the pulses are the minimal pulse width, the maximal pulse width, and the repetition rate. Given the rotation constraints of the servo, neutral is defined to be the center of rotation. Different servos will have different constraints on their rotation, but the neutral position is always around 1.5 milliseconds (ms) pulse width.
Pulse duration
In modern RC servos the angle of mechanical rotation is determined by the width of an electrical pulse that is applied to the control wire. This is a form of pulse-width modulation. The typical RC servo expects to see a pulse every 20 ms, however this can vary within a wide range that differs from servo to servo. The width of the pulse will determine how far the motor turns. For example, in many RC servos a 1.5 ms pulse will make the motor turn to the 90° position (neutral position). The low time (and the total period) can vary over a wide range, and vary from one pulse to the next, without any effect on the position of the servo motor.
Modern RC servo position is not defined by the PWM duty cycle (i.e., ON vs OFF time) but only by the width of the pulse. (This is different from the PWM used, for example, in some DC motor speed control). Most RC servos move to the same position when they receive a 1.5 ms pulse every 6 ms (a duty cycle o |
https://en.wikipedia.org/wiki/Pose%20%28computer%20vision%29 | In the fields of computing and computer vision, pose (or spatial pose) represents the position and orientation of an object, usually in three dimensions. Poses are often stored internally as transformation matrices. The term “pose” is largely synonymous with the term “transform”, but a transform may often include scale, whereas pose does not.
In computer vision, the pose of an object is often estimated from camera input by the process of pose estimation. This information can then be used, for example, to allow a robot to manipulate an object or to avoid moving into the object based on its perceived position and orientation in the environment. Other applications include skeletal action recognition.
Pose estimation
The specific task of determining the pose of an object in an image (or stereo images, image sequence) is referred to as pose estimation. Pose estimation problems can be solved in different ways depending on the image sensor configuration, and choice of methodology. Three classes of methodologies can be distinguished:
Analytic or geometric methods: Given that the image sensor (camera) is calibrated and the mapping from 3D points in the scene and 2D points in the image is known. If also the geometry of the object is known, it means that the projected image of the object on the camera image is a well-known function of the object's pose. Once a set of control points on the object, typically corners or other feature points, has been identified, it is then possible to solve the pose transformation from a set of equations which relate the 3D coordinates of the points with their 2D image coordinates. Algorithms that determine the pose of a point cloud with respect to another point cloud are known as point set registration algorithms, if the correspondences between points are not already known.
Genetic algorithm methods: If the pose of an object does not have to be computed in real-time a genetic algorithm may be used. This approach is robust especially when |
https://en.wikipedia.org/wiki/Assimilation%20%28biology%29 | ' is the process of absorption of vitamins, minerals, and other chemicals from food as part of the nutrition of an organism. In humans, this is always done with a chemical breakdown (enzymes and acids) and physical breakdown (oral mastication and stomach churning).chemical alteration of substances in the bloodstream by the liver or cellular secretions. Although a few similar compounds can be absorbed in digestion bio assimilation, the bioavailability of many compounds is dictated by this second process since both the liver and cellular secretions can be very specific in their metabolic action (see chirality). This second process is where the absorbed food reaches the cells via the liver.
Most foods are composed of largely indigestible components depending on the enzymes and effectiveness of an animal's digestive tract. The most well-known of these indigestible compounds is cellulose; the basic chemical polymer in the makeup of plant cell walls. Most animals, however, do not produce cellulase; the enzyme needed to digest cellulose. However some animal and species have developed symbiotic relationships with cellulase-producing bacteria (see termites and metamonads.) This allows termites to use the energy-dense cellulose carbohydrate. Other such enzymes are known to significantly improve bio-assimilation of nutrients. Because of the use of bacterial derivatives, enzymatic dietary supplements now contain such enzymes as amylase, glucoamylase, protease, invertase, peptidase, lipase, lactase, phytase, and cellulase.
Examples of biological assimilation
Photosynthesis, a process whereby carbon dioxide and water are transformed into a number of organic molecules in plant cells.
Nitrogen fixation from the soil into organic molecules by symbiotic bacteria which live in the roots of certain plants, such as Leguminosae.
Magnesium supplements orotate, oxide, sulfate, citrate, and glycerate are all structurally similar. However, oxide and sulfate are not water-soluble |
https://en.wikipedia.org/wiki/Battery%20eliminator%20circuit | In battery-powered equipment, a battery eliminator circuit (BEC) is an electronic voltage regulator used to power a subsystem at a different voltage without the need for a supplemental battery. BECs are commonly used in radio-controlled models, which need separate voltages to power the motor and the R/C equipment.
Radio-controlled (R/C) models
In an electric-powered radio-controlled model, the BEC is typically part of the electronic speed control (ESC). BEC allows such a model to carry only one battery (the motive power battery) instead of two (motive power, and a separate battery to operate the R/C equipment). A BEC-equipped ESC meant for airplane use often incorporates a low-voltage-cutoff (LVC) circuit which can sense the voltage drop caused when the battery has little charge left. It then cuts the power to the 'drive' motor in order to provide the 'steering' servo(s) with enough power to be able to bring the model safely back to the operator. The power to the propeller is cut but the operation of the control surfaces would be maintained in order to perform a dead-stick landing. Without this feature, all control would be lost when the battery expired, probably resulting in the destruction of the model. In some cases, the BEC is part of the radio control receiver, instead of being part of the ESC.
R/C BECs in their simplest form use a linear fixed voltage regulator with its standard circuit suggested in the manufacturer's datasheet – usually the power supply of the receiver needs 5 V. Low-dropout types are preferred – especially for batteries with only a few cells. For small models, 1.5 to 2 A are enough; for mid-size models a 3 A type needs to be considered. BECs for large models have to provide current of 5 A or more. In this case, a more complicated switching mode regulator should be used, as the switching mode BECs are more electrically efficient than linear regulator BECs. The power dissipation losses in a linear regulator BEC are a product of the differen |
https://en.wikipedia.org/wiki/Bicomplex%20number | In abstract algebra, a bicomplex number is a pair of complex numbers constructed by the Cayley–Dickson process that defines the bicomplex conjugate , and the product of two bicomplex numbers as
Then the bicomplex norm is given by
a quadratic form in the first component.
The bicomplex numbers form a commutative algebra over C of dimension two, which is isomorphic to the direct sum of algebras .
The product of two bicomplex numbers yields a quadratic form value that is the product of the individual quadratic forms of the numbers:
a verification of this property of the quadratic form of a product refers to the Brahmagupta–Fibonacci identity. This property of the quadratic form of a bicomplex number indicates that these numbers form a composition algebra. In fact, bicomplex numbers arise at the binarion level of the Cayley–Dickson construction based on with norm z2.
The general bicomplex number can be represented by the matrix , which has determinant . Thus, the composing property of the quadratic form concurs with the composing property of the determinant.
Bicomplex numbers feature two distinct imaginary units. Multiplication being associative and commutative, the product of these imaginary units must have positive one for its square. Such an element as this product has been called a hyperbolic unit.
As a real algebra
Bicomplex numbers form an algebra over C of dimension two, and since C is of dimension two over R, the bicomplex numbers are an algebra over R of dimension four. In fact the real algebra is older than the complex one; it was labelled tessarines in 1848 while the complex algebra was not introduced until 1892.
A basis for the tessarine 4-algebra over R specifies z = 1 and z = −i, giving the matrices
, which multiply according to the table given. When the identity matrix is identified with 1, then a tessarine t = w + z j .
History
The subject of multiple imaginary units was examined in the 1840s. In a long series "On quaternions, or on a new |
https://en.wikipedia.org/wiki/Security%20Account%20Manager | The Security Account Manager (SAM) is a database file in Windows XP, Windows Vista, Windows 7, 8.1, 10 and 11 that stores users' passwords. It can be used to authenticate local and remote users. Beginning with Windows 2000 SP4, Active Directory authenticates remote users. SAM uses cryptographic measures to prevent unauthenticated users accessing the system.
The user passwords are stored in a hashed format in a registry hive either as an LM hash or as an NTLM hash. This file can be found in %SystemRoot%/system32/config/SAM and is mounted on HKLM/SAM and SYSTEM privileges are required to view it.
In an attempt to improve the security of the SAM database against offline software cracking, Microsoft introduced the SYSKEY function in Windows NT 4.0. When SYSKEY is enabled, the on-disk copy of the SAM file is partially encrypted, so that the password hash values for all local accounts stored in the SAM are encrypted with a key (usually also referred to as the "SYSKEY"). It can be enabled by running the syskey program. As of Windows 10 version 1709, syskey was removed due to a combination of insecure security and misuse by bad actors to lock users out of systems.
Cryptanalysis
In 2012, it was demonstrated that every possible 8-character NTLM password hash permutation can be cracked in under 6 hours.
In 2019, this time was reduced to roughly 2.5 hours by using more modern hardware.
In the case of online attacks, it is not possible to simply copy the SAM file to another location. The SAM file cannot be moved or copied while Windows is running, since the Windows kernel obtains and keeps an exclusive filesystem lock on the SAM file, and will not release that lock until the operating system has shut down or a "Blue Screen of Death" exception has been thrown. However, the in-memory copy of the contents of the SAM can be dumped using various techniques (including pwdump), making the password hashes available for offline brute-force attack.
Removing LM hash
LM hash is a com |
https://en.wikipedia.org/wiki/National%20Institute%20for%20Astrophysics | The National Institute for Astrophysics (, or INAF) is an Italian research institute in astronomy and astrophysics, founded in 1999. INAF funds and operates twenty separate research facilities, which in turn employ scientists, engineers and technical staff. The research they perform covers most areas of astronomy, ranging from planetary science to cosmology.
Research facilities
INAF coordinates the activities of twenty research units, nineteen in Italy and one in Spain:
Bologna Observatory
Istituto di Astrofisica Spaziale e Fisica cosmica di Bologna
Istituto di Radioastronomia di Bologna
Cagliari Observatory
Catania Observatory
Arcetri Observatory (Florence)
Brera Observatory (Milan)
Istituto di Astrofisica Spaziale e Fisica cosmica di Milano
Capodimonte Observatory (Naples)
Osservatorio Astronomico di Padova
Palermo Observatory
Istituto di Astrofisica Spaziale e Fisica cosmica di Palermo
Rome Observatory
Istituto di Astrofisica Spaziale e Fisica cosmica di Roma
Istituto di Fisica dello Spazio Interplanetario di Roma
Collurania-Teramo Observatory
Turin Observatory
Istituto di Fisica dello Spazio Interplanetario di Torino
Trieste Observatory
Telescopio Nazionale Galileo (Canary Islands, Spain)
Sardinia Radio Telescope (San Basilio, Sardinia)
Noto Radio Observatory (Noto, Sicily)
International partnerships
INAF is involved in scientific collaborations with several international institutions, including:
the European Southern Observatory (Italy has been an ESO member since 1982)
the astronomical observatories located in Canary Islands (Teide Observatory and Roque de los Muchachos Observatory)
the Large Binocular Telescope, in partnership with the United States and Germany
the Very Long Baseline Interferometry consortium
the European Space Agency (ESA)
the American National Aeronautic and Space Administration (NASA)
Notable figures
Giampaolo Vettolani, scientific director
Stefano Cristiani, board member
Nicolò D'Amico, president in 2015-2020
Projects
Projects i |
https://en.wikipedia.org/wiki/Perry%20O.%20Simons | Perry Oveitt Simons (October 6, 1869 – 1901) was an American scientific collector. He predominantly worked in the Neotropics.
Early life and education
Simons was born on October 6, 1869, in Mineral Point, Wisconsin. He had at least one brother, Luther B. Simons. In 1886 he left Wisconsin for Riverside, California, where he graduated from Riverside High School in 1893. He spent four years at Stanford University as an electrical engineering major.
Career
His first job in the natural sciences was working for William W. Price as a scientific collector in Mexico from 1896 to 1897. He was joined by his brother, Luther. The mammal specimens collected on this 10-month expedition were purchased by the British Museum. British Museum zoologist Oldfield Thomas was so pleased by the quality of the specimens, he offered Simons a job collecting additional specimens in South America. Luther accompanied Perry for the first two years of the expedition before sailing back to San Francisco.
Death
While crossing the Argentinean Andes around the end of December 1901, Simons was murdered by his guide. The guide struck him in the back of the head before driving a spike through his forehead. His body was found, and it was buried nearby. The motive was said to be robbery, and the guide was captured and imprisoned in Mendoza, Argentina. After Simons's death, Oldfield Thomas called him "the most successful mammal collector that I have ever had to deal with", noting, "we shall not easily find his like again".
Namesake species
Several species were named after Simons:
Reptiles:
Simons's whorltail iguana (Stenocercus simonsii)
Simons's green racer (Philodryas simonsi)
Simons's sun tegu (Euspondylus simonsii)
Amphibians:
Paramo robber frog (Pristimantis simonsii)
Sucre water frog (Telmatobius simonsi)
Birds:
Puna tapaculo (Scytalopus simonsi)
Mammals:
Simons's spiny rat (Proechimys simonsi)
Fish:
Astroblepus simonsii
Another species of reptile in the genus Liolaemus was named L. simonsi |
https://en.wikipedia.org/wiki/Garde%20manger | A (; French) is a cool, well-ventilated area where cold dishes (such as salads, , appetizers, canapés, pâtés, and terrines) are prepared and other foods are stored under refrigeration. The person in charge of this area is known as the "" or "pantry chef". Larger hotels and restaurants may have staff to perform additional duties, such as creating decorative elements of buffet presentation like ice carving and edible centerpieces.
History
The term originated in pre-Revolutionary France, where large, wealthy households designated a kitchen manager to supervise the use and storage of large amounts of foodstuffs. The term literally means 'keeping to eat'.
The term is also related to the cold rooms inside castles and manor houses where the food was stored. These food storage areas were usually located in the lower levels, since the cool basement-like environment was ideal for storing food. These cold storage areas developed over time into the modern cold kitchen.
Most merchants who worked outside noble manors at this time were associated with a guild, an association of persons of the same trade formed for their mutual aid and protection. Guilds would develop training programs for their members, thereby preserving their knowledge and skills. was the name of a guild that prepared and sold cooked items made from pigs. Through this organization, the methods of preparing hams, bacon, sausages, pâtés, and terrines were preserved. When the guild system was abolished in 1791 following the French Revolution of 1789, took on the responsibility for tasks that had formerly been performed by , who had difficulty competing with the versatile garde mangers due to the limited range of skills involved.
The position of "butcher" first developed as a specialty within the garde manger kitchen. As both the cost of and demand for animal meats increased, more space was required for the task of fabricating and portioning the raw meats. This increased need for space was due not only |
https://en.wikipedia.org/wiki/Exocytosis | Exocytosis () is a form of active transport and bulk transport in which a cell transports molecules (e.g., neurotransmitters and proteins) out of the cell (exo- + cytosis). As an active transport mechanism, exocytosis requires the use of energy to transport material. Exocytosis and its counterpart, endocytosis, are used by all cells because most chemical substances important to them are large polar molecules that cannot pass through the hydrophobic portion of the cell membrane by passive means. Exocytosis is the process by which a large amount of molecules are released; thus it is a form of bulk transport. Exocytosis occurs via secretory portals at the cell plasma membrane called porosomes. Porosomes are permanent cup-shaped lipoprotein structure at the cell plasma membrane, where secretory vesicles transiently dock and fuse to release intra-vesicular contents from the cell.
In exocytosis, membrane-bound secretory vesicles are carried to the cell membrane, where they dock and fuse at porosomes and their contents (i.e., water-soluble molecules) are secreted into the extracellular environment. This secretion is possible because the vesicle transiently fuses with the plasma membrane. In the context of neurotransmission, neurotransmitters are typically released from synaptic vesicles into the synaptic cleft via exocytosis; however, neurotransmitters can also be released via reverse transport through membrane transport proteins.
Exocytosis is also a mechanism by which cells are able to insert membrane proteins (such as ion channels and cell surface receptors), lipids, and other components into the cell membrane. Vesicles containing these membrane components fully fuse with and become part of the outer cell membrane.
History
The term was proposed by De Duve in 1963.
Types
In eukaryotes there are two types of exocytosis:
1) Ca2+ triggered non-constitutive (i.e., regulated exocytosis) and
2) non-Ca2+ triggered constitutive (i.e., non-regulated).
Ca2+ triggered non-const |
https://en.wikipedia.org/wiki/Penman%20equation | The Penman equation describes evaporation (E) from an open water surface, and was developed by Howard Penman in 1948. Penman's equation requires daily mean temperature, wind speed, air pressure, and solar radiation to predict E. Simpler Hydrometeorological equations continue to be used where obtaining such data is impractical, to give comparable results within specific contexts, e.g. humid vs arid climates.
Details
Numerous variations of the Penman equation are used to estimate evaporation from water, and land. Specifically the Penman–Monteith equation refines weather based potential evapotranspiration (PET) estimates of vegetated land areas. It is widely regarded as one of the most accurate models, in terms of estimates.
The original equation was developed by Howard Penman at the Rothamsted Experimental Station, Harpenden, UK.
The equation for evaporation given by Penman is:
where:
m = Slope of the saturation vapor pressure curve (Pa K−1)
Rn = Net irradiance (W m−2)
ρa = density of air (kg m−3)
cp = heat capacity of air (J kg−1 K−1)
δe = vapor pressure deficit (Pa)
ga = momentum surface aerodynamic conductance (m s−1)
λv = latent heat of vaporization (J kg−1)
γ = psychrometric constant (Pa K−1)
which (if the SI units in parentheses are used) will give the evaporation Emass in units of kg/(m2·s), kilograms of water evaporated every second for each square meter of area.
Remove λ to obviate that this is fundamentally an energy balance. Replace λv with L to get familiar precipitation units ETvol, where Lv=λvρwater. This has units of m/s, or more commonly mm/day, because it is flux m3/s per m2=m/s.
This equation assumes a daily time step so that net heat exchange with the ground is insignificant, and a unit area surrounded by similar open water or vegetation so that net heat & vapor exchange with the surrounding area cancels out. Some times people replace Rn with and A for total net available energy when a situation warrants account of additional heat fluxes.
|
https://en.wikipedia.org/wiki/Multiple%20instruction%2C%20multiple%20data | In computing, multiple instruction, multiple data (MIMD) is a technique employed to achieve parallelism. Machines using MIMD have a number of processors that function asynchronously and independently. At any time, different processors may be executing different instructions on different pieces of data.
MIMD architectures may be used in a number of application areas such as computer-aided design/computer-aided manufacturing, simulation, modeling, and as communication switches. MIMD machines can be of either shared memory or distributed memory categories. These classifications are based on how MIMD processors access memory. Shared memory machines may be of the bus-based, extended, or hierarchical type. Distributed memory machines may have hypercube or mesh interconnection schemes.
Examples
An example of MIMD system is Intel Xeon Phi, descended from Larrabee microarchitecture. These processors have multiple processing cores (up to 61 as of 2015) that can execute different instructions on different data.
Most parallel computers, as of 2013, are MIMD systems.
Shared memory model
In shared memory model the processors are all connected to a "globally available" memory, via either software or hardware means. The operating system usually maintains its memory coherence.
From a programmer's point of view, this memory model is better understood than the distributed memory model. Another advantage is that memory coherence is managed by the operating system and not the written program. Two known disadvantages are: scalability beyond thirty-two processors is difficult, and the shared memory model is less flexible than the distributed memory model.
There are many examples of shared memory (multiprocessors): UMA (uniform memory access), COMA (cache-only memory access).
Bus-based
MIMD machines with shared memory have processors which share a common, central memory. In the simplest form, all processors are attached to a bus which connects them to memory. This means that every |
https://en.wikipedia.org/wiki/Cerberus%20Privy | The Cerberus Privy, at Gayhurst House, Buckinghamshire, England, is a communal lavatory built for the male servants of the house. It was constructed between 1859-1860 and was designed by William Burges. Now converted to a private home, it is a Grade II* listed building.
History
Gayhurst House was built in the early sixteenth-century on the site of a Roman villa and Norman manor. It was expanded in 1597 by William Moulsoe. The house was completed by his son-in-law, Sir Everard Digby, one of the conspirators involved in the Gunpowder Plot. In 1704 the estate was sold to Sir Nathan Wrighte.
The house was extensively refurbished, 1858–72, by William Burges for Robert Carrington, 2nd Baron Carrington, and his son. Lord Carrington was Burges' first significant patron. In total, some £30,000 was spent which did not include the costs of construction for Burges' planned main staircase that was never built. However, a minor stair, the Caliban Stair, was constructed.
The Cerberus Privy was built as a communal lavatory for the male servants of the house. Burges's biographer, J. Mordaunt Crook, considers it "one of Burges's happiest inventions." The Gayhurst estate was broken up in the twentieth century and the house was converted into flats, and the estate buildings including the privy were developed into houses, between 1971 and 1979. The estate is privately owned and is not open to the public, although the house can be seen from the footpath to the adjacent Church of St Peter.
Architecture and description
Nikolaus Pevsner and Elizabeth Williamson, in their 2003 revised edition, Buckinghamshire, of the Pevsner Buildings of England suggest Burges's main design influence for the privy was the Abbot's Kitchen, Glastonbury. The building is circular and consists of a main storey, with a dormer attic above. Atop this is a statue of Cerberus, which originally had eyes made of red glass. Crook calls it; "a picturesque convenience, dedicated to a cloacal demon with billiard ball |
https://en.wikipedia.org/wiki/Postorgasmic%20illness%20syndrome | Postorgasmic illness syndrome (POIS) is a syndrome in which people have chronic physical and cognitive symptoms following ejaculation. The symptoms usually onset within seconds, minutes, or hours, and last for up to a week. The cause and prevalence are unknown; it is considered a rare disease.
Signs and symptoms
The distinguishing characteristics of POIS are:
the rapid onset of symptoms after ejaculation;
the presence of an overwhelming systemic reaction.
POIS symptoms, which are called a "POIS attack", can include some combination of the following: cognitive dysfunction, aphasia, severe muscle pain throughout the body, severe fatigue, weakness, and flu-like or allergy-like symptoms, such as sneezing, itchy eyes, and nasal irritation. Additional symptoms include headache, dizziness, lightheadedness, extreme hunger, sensory and motor problems, intense discomfort, irritability, anxiety, gastrointestinal disturbances, craving for relief, susceptibility to nervous system stresses (e.g. common cold), depressed mood, and difficulty communicating, remembering words, reading and retaining information, concentrating, and socializing. Affected individuals may also experience intense warmth or cold. An online anonymous self-report study found that 80% of respondents always experienced the symptom cluster involving fatigue, insomnia, irritation, and concentration difficulties.
The symptoms usually begin within 30 minutes of ejaculation, and can last for several days, sometimes up to a week. In some cases, symptoms may be delayed by 2 to 3 days or may last up to 2 weeks.
In some men, the onset of POIS is in puberty, while in others, the onset is later in life. POIS that is manifest from the first ejaculations in adolescence is called primary type; POIS that starts later in life is called secondary type.
Many individuals with POIS report lifelong premature ejaculation, with intravaginal ejaculation latency time (IELT) of less than one minute.
The 7 clusters of symptoms |
https://en.wikipedia.org/wiki/Ball%20tree | In computer science, a ball tree, balltree or metric tree, is a space partitioning data structure for organizing points in a multi-dimensional space. A ball tree partitions data points into a nested set of balls. The resulting data structure has characteristics that make it useful for a number of applications, most notably nearest neighbor search.
Informal description
A ball tree is a binary tree in which every node defines a D-dimensional ball containing a subset of the points to be searched. Each internal node of the tree partitions the data points into two disjoint sets which are associated with different balls. While the balls themselves may intersect, each point is assigned to one or the other ball in the partition according to its distance from the ball's center. Each leaf node in the tree defines a ball and enumerates all data points inside that ball.
Each node in the tree defines the smallest ball that contains all data points in its subtree. This gives rise to the useful property that, for a given test point outside the ball, the distance to any point in a ball in the tree is greater than or equal to the distance from to the surface of the ball. Formally:
Where is the minimum possible distance from any point in the ball to some point .
Ball-trees are related to the M-tree, but only support binary splits, whereas in the M-tree each level splits to fold, thus leading to a shallower tree structure, therefore need fewer distance computations, which usually yields faster queries. Furthermore, M-trees can better be stored on disk, which is organized in pages. The M-tree also keeps the distances from the parent node precomputed to speed up queries.
Vantage-point trees are also similar, but they binary split into one ball, and the remaining data, instead of using two balls.
Construction
A number of ball tree construction algorithms are available. The goal of such an algorithm is to produce a tree that will efficiently support queries of the desir |
https://en.wikipedia.org/wiki/Trottolino | Trottolino is the title character of an Italian humorous comics magazine.
Background
Trottolino was created in 1952 by Giorgio Rebuffi under the pen name "O'Layne" and was the title character of a comics magazine published between 1952 and 1990. It was the first comics magazine published by Renato Bianconi, a former collaborator of publisher Alpe; released without any marketing hype, it got an immediate commercial success and launched the career of Bianconi as a publisher.
The comics magazine, similar in its digest-sized format to Topolino, featured the adventures of an anthropomorphic squirrel. His sidekick in many stories was the anthropomorphic duck Papy Papero, a character created by Luciano Bottaro who was also the leading character of independent stories and later of a western-themed spin-off comic book series, Papys Bill. The magazine also included comics featuring different characters created by the same Rebuffi, Nicola Del Principe (who later also cured, for several decades, the stories of Trottolino), Giovan Battista Carpi, Luciano Gatto, Tiberio Colantuoni. From 1982 until the end of publications, it stopped the release of original comics and just republished old stories.
Several spin-off magazines were published, notably between 1959 and 1978 Super Trottolino and between 1980 and 1983 Gran Trottolino; they substantially were collections of old stories already published in the main publication. |
https://en.wikipedia.org/wiki/Topological%20homomorphism | In functional analysis, a topological homomorphism or simply homomorphism (if no confusion will arise) is the analog of homomorphisms for the category of topological vector spaces (TVSs).
This concept is of considerable importance in functional analysis and the famous open mapping theorem gives a sufficient condition for a continuous linear map between Fréchet spaces to be a topological homomorphism.
Definitions
A topological homomorphism or simply homomorphism (if no confusion will arise) is a continuous linear map between topological vector spaces (TVSs) such that the induced map is an open mapping when which is the image of is given the subspace topology induced by
This concept is of considerable importance in functional analysis and the famous open mapping theorem gives a sufficient condition for a continuous linear map between Fréchet spaces to be a topological homomorphism.
A TVS embedding or a topological monomorphism is an injective topological homomorphism. Equivalently, a TVS-embedding is a linear map that is also a topological embedding.
Characterizations
Suppose that is a linear map between TVSs and note that can be decomposed into the composition of the following canonical linear maps:
where is the canonical quotient map and is the inclusion map.
The following are equivalent:
is a topological homomorphism
for every neighborhood base of the origin in is a neighborhood base of the origin in
the induced map is an isomorphism of TVSs
If in addition the range of is a finite-dimensional Hausdorff space then the following are equivalent:
is a topological homomorphism
is continuous
is continuous at the origin
is closed in
Sufficient conditions
Open mapping theorem
The open mapping theorem, also known as Banach's homomorphism theorem, gives a sufficient condition for a continuous linear operator between complete metrizable TVSs to be a topological homomorphism.
Examples
Every continuous linear functional on a TVS is a to |
https://en.wikipedia.org/wiki/Copiale%20cipher | The Copiale cipher is an encrypted manuscript consisting of 75,000 handwritten characters filling 105 pages in a bound volume. Undeciphered for more than 260 years, the document was decrypted in 2011 with computer assistance. An international team consisting of Kevin Knight of the University of Southern California Information Sciences Institute and Viterbi School of Engineering, along with Beáta Megyesi and Christiane Schaefer of Uppsala University in Sweden, found the cipher to be an encrypted German text. The manuscript is a homophonic cipher that uses a complex substitution code, including symbols and letters, for its text and spaces.
Previously examined by scientists at the German Academy of Sciences at Berlin in the 1970s, the cipher was thought to date from between 1760 and 1780. Decipherment revealed that the document had been created in the 1730s by a secret society called the "high enlightened (Hocherleuchtete) oculist order" of Wolfenbüttel, or Oculists. The Oculists used sight as a metaphor for knowledge.
The manuscript is in a private collection. A parallel manuscript is kept at the Staatsarchiv Wolfenbüttel.
The Copiale cipher includes abstract symbols, as well as letters from Greek and most of the Roman alphabet. The only plain text in the book is "Copiales 3" at the end and "Philipp 1866" on the flyleaf. Philipp is thought to have been an owner of the manuscript. The plain-text letters of the message were found to be encoded by accented Roman letters, Greek letters and symbols, with unaccented Roman letters serving only to represent spaces.
The researchers found that the initial 16 pages describe an Oculist initiation ceremony. The manuscript portrays, among other things, an initiation ritual in which the candidate is asked to read a blank piece of paper and, on confessing inability to do so, is given eyeglasses and asked to try again, and then again after washing the eyes with a cloth, followed by an "operation" in which a single eyebrow hair |
https://en.wikipedia.org/wiki/Missing%20fundamental | A harmonic sound is said to have a missing fundamental, suppressed fundamental, or phantom fundamental when its overtones suggest a fundamental frequency but the sound lacks a component at the fundamental frequency itself.
The brain perceives the pitch of a tone not only by its fundamental frequency, but also by the periodicity implied by the relationship between the higher harmonics; we may perceive the same pitch (perhaps with a different timbre) even if the fundamental frequency is missing from a tone.
For example, when a note (that is not a pure tone) has a pitch of 100 Hz, it will consist of frequency components that are integer multiples of that value (e.g. 100, 200, 300, 400, 500.... Hz). However, smaller loudspeakers may not produce low frequencies, so in our example, the 100 Hz component may be missing. Nevertheless, a pitch corresponding to the fundamental may still be heard.
Explanation
A low pitch (also known as the pitch of the missing fundamental or virtual pitch) can sometimes be heard when there is no apparent source or component of that frequency. This perception is due to the brain interpreting repetition patterns that are present.
It was once thought that this effect was because the missing fundamental was replaced by distortions introduced by the physics of the ear. However, experiments subsequently showed that when a noise was added that would have masked these distortions had they been present, listeners still heard a pitch corresponding to the missing fundamental, as reported by J. C. R. Licklider in 1954. It is now widely accepted that the brain processes the information present in the overtones to calculate the fundamental frequency. The precise way in which it does so is still a matter of debate, but the processing seems to be based on an autocorrelation involving the timing of neural impulses in the auditory nerve. However, it has long been noted that any neural mechanisms which may accomplish a delay (a necessary operation of a true |
https://en.wikipedia.org/wiki/Semi-elliptic%20operator | In mathematics — specifically, in the theory of partial differential equations — a semi-elliptic operator is a partial differential operator satisfying a positivity condition slightly weaker than that of being an elliptic operator. Every elliptic operator is also semi-elliptic, and semi-elliptic operators share many of the nice properties of elliptic operators: for example, much of the same existence and uniqueness theory is applicable, and semi-elliptic Dirichlet problems can be solved using the methods of stochastic analysis.
Definition
A second-order partial differential operator P defined on an open subset Ω of n-dimensional Euclidean space Rn, acting on suitable functions f by
is said to be semi-elliptic if all the eigenvalues λi(x), 1 ≤ i ≤ n, of the matrix a(x) = (aij(x)) are non-negative. (By way of contrast, P is said to be elliptic if λi(x) > 0 for all x ∈ Ω and 1 ≤ i ≤ n, and uniformly elliptic if the eigenvalues are uniformly bounded away from zero, uniformly in i and x.) Equivalently, P is semi-elliptic if the matrix a(x) is positive semi-definite for each x ∈ Ω. |
https://en.wikipedia.org/wiki/Conformal%20field%20theory | A conformal field theory (CFT) is a quantum field theory that is invariant under conformal transformations. In two dimensions, there is an infinite-dimensional algebra of local conformal transformations, and conformal field theories can sometimes be exactly solved or classified.
Conformal field theory has important applications to condensed matter physics, statistical mechanics, quantum statistical mechanics, and string theory. Statistical and condensed matter systems are indeed often conformally invariant at their thermodynamic or quantum critical points.
Scale invariance vs conformal invariance
In quantum field theory, scale invariance is a common and natural symmetry, because any fixed point of the renormalization group is by definition scale invariant. Conformal symmetry is stronger than scale invariance, and one needs additional assumptions to argue that it should appear in nature. The basic idea behind its plausibility is that local scale invariant theories have their currents given by where is a Killing vector and is a conserved operator (the stress-tensor) of dimension exactly . For the associated symmetries to include scale but not conformal transformations, the trace has to be a non-zero total derivative implying that there is a non-conserved operator of dimension exactly .
Under some assumptions it is possible to completely rule out this type of non-renormalization and hence prove that scale invariance implies conformal invariance in a quantum field theory, for example in unitary compact conformal field theories in two dimensions.
While it is possible for a quantum field theory to be scale invariant but not conformally invariant, examples are rare. For this reason, the terms are often used interchangeably in the context of quantum field theory.
Two dimensions vs higher dimensions
The number of independent conformal transformations is infinite in two dimensions, and finite in higher dimensions. This makes conformal symmetry much more constraini |
https://en.wikipedia.org/wiki/Montini%20%28toy%29 | Montini was a Dutch brand of Lego-like building bricks, manufactured between 1961 and 1969.
Montini blocks were produced by Berco Lux in Tiel. The bricks were compatible with Lego bricks, though the studs on the bricks were taller. The blocks were moulded in a flexible tough polypropylene, making them softer than Lego blocks.
Ongoing patent litigation by Lego led to Montini stopping production in 1969. |
https://en.wikipedia.org/wiki/Fukuppy | was the short-lived English name of a mascot of the Japanese company Fukushima Industries. The mascot has the form of a genderless anthropomorphic egg with red feet, little blue wings, and a happy smiling face.
Fukushima Industries (now known as Fukushima Galilei) is based in Osaka, and manufactures industrial cooling systems, particularly for the food industry. It has offices throughout Japan and in many parts of Asia, including China, Hong Kong, Malaysia, Singapore, and Taiwan.
It launched its new mascot in April 2013, to little attention. The name "Fukuppy" was a portmanteau of "Fukushima", the surname of the founder of the company, and the English word "happy". According to Fukushima Industries, Fukuppy says,
In mid-October 2013, Fukuppy was noticed by English-speakers who spotted the inadvertent similarity to the English word "fuckup". Fukuppy rapidly attracted publicity not only in English (including in Japan), but also in Afrikaans, Catalan, Dutch, French, German and Swedish. Some early reports wrongly associated Fukuppy with Fukushima Prefecture, or with the cleanup efforts after the 2011 Fukushima Daiichi nuclear disaster. Fukushima Industries speedily published an apology and announced that it would be withdrawing the English name of its mascot.
Fukuppy has been cited as an example of the risks associated with , Japanese-language expressions based on English words that do not exist in standard English.
Explanatory notes |
https://en.wikipedia.org/wiki/Adaptive%20quality%20of%20service%20multi-hop%20routing | In multi-hop networks, Adaptive Quality of Service routing (AQoS or AQR) protocols have become increasingly popular and have numerous applications. One application in which it may be useful is in Mobile ad hoc networking (MANET).
Adaptive QoS routing is a cross-layer optimization adaptive routing mechanism. The cross-layer mechanism provides up-to-date local QoS information for the adaptive routing algorithm, by considering the impacts of node mobility and lower-layer link performance. The multiple QoS requirements are satisfied by adaptively using forward error correction and multipath routing mechanisms, based on the current network status. The complete routing mechanism includes three parts: (1) a modified dynamic source routing algorithm that handles route discovery and the collection of QoS related parameters; (2) a local statistical computation and link monitoring function located in each node; and (3) an integrated
decision-making system to calculate the number of routing paths, coding parity length, and traffic distribution rates.
Introduction
A wireless ad hoc network consists of a collection of mobile nodes interconnected by multihop wireless paths with wireless transmitters and receivers. Such networks can be spontaneously created and operated in a self-organized manner, because they do not rely upon any preexisting network infrastructure.
The emergence of multimedia applications in communications has generated the need to provide
mobile quality-of-service (QoS) support in ad hoc networks, and such applications require a stable path to guarantee QoS requirements. However, the topology of ad hoc networks is highly dynamic due to the unpredictable node mobility. In addition, wireless channel bandwidth is limited. So, QoS provisioning in such networks is complex and challenging.
QoS routing usually involves two tasks: collecting and maintaining up-to-date state information about the network and finding feasible paths for a connection based on its QoS |
https://en.wikipedia.org/wiki/Robert%20Brunner | Robert Brunner (born 1958) is an American industrial designer. Brunner was the Director of Industrial Design for Apple Computer from 1989 to 1996, and is a founder and current partner at Ammunition Design Group.
Biography
Brunner received a Bachelor of Science degree in Industrial Design from San José State University in 1981.
After working as a designer and project manager at several high technology companies, Brunner went on to co-found Lunar Design in 1984. In 1989, Brunner accepted the position of Director of Industrial Design at Apple Computer, where he provided design and direction for all Apple product lines, including the PowerBook. He was succeeded by Jonathan Ive in 1997. Brunner claims that while with Apple, he hired Ive three times.
In January 1996, he became a partner in the San Francisco office of Pentagram. In 2006, Brunner partnered Alex Siow, founder of San Francisco-based Zephyr Ventilation, to launch outdoor grill design firm Fuego. Emblematic of his relationship with Siow, he designed the Arc Collection of modern range-hoods for Zephyr Ventilation.
By mid-2007 Brunner left Pentagram to start Ammunition Design Group. In 2008, former MetaDesign leaders Brett Wickens and Matt Rolandson joined Ammunition LLC as partners. In 2008, Brunner collaborated with Jimmy Iovine and Dr. Dre to launch Beats by Dre, and is responsible for the design of the company's lines of headphones and speakers including Beats Studio, Powerbeats, Mixr, Solo and Solo Pro as well as the Pill wireless speaker, among others.
Brunner's work has been widely published in North America, Europe, Asia and Australia. His product designs have won 23 IDSA Awards from the Industrial Designers Society of America and Business Week, including 6 best of category awards. His work is included in the permanent collections of the Museum of Modern Art (MoMA), Cooper Hewitt, Smithsonian Design Museum, Indianapolis Museum of Art (IMA), and the San Francisco Museum of Modern Art (SFMoMA).
See |
https://en.wikipedia.org/wiki/Solenodonsaurus | Solenodonsaurus ("single-tooth lizard") is an extinct genus of reptiliomorphs that lived in what is now Czech Republic, during the Westphalian stage.
Description
Solenondosaurus had snout-vent length with a skull length .
Solenodonsaurus shows a curious mix of characters making it difficult to place phylogenetically. The teeth lack labyrinthodont folding of the enamel, and it skull has a much smaller otic notch than seen in other reptiliomorph amphibians. Yet general build ties it in with the Diadectomorpha.
Paleobiology
Solenodonsaurus was likely best adapted to life on land, as opposed to living in an aquatic environment like many other early tetrapods. The limbs and pelvis are incomplete in all known specimens of Solenodonsaurus, making it difficult to infer how the animal may have moved. One feature that suggests a terrestrial lifestyle is the 90° rotation of the ends of the humerus, which orients the forelimb forward rather than out to the side. Several presumably terrestrial groups of Paleozoic tetrapods, including amphibamid temnospondyls, microsaurs, and the first amniotes, have a similar degree of rotation in their humeri. The short, triangular shape of the skull of Solenodonsaurus distinguishes it from most aquatic forms, which have either long and narrow or broad and parabolic heads.
Solenodonsaurus was once believed to have had an impedance matching hearing system like those of modern tetrapods, with an eardrum-like membrane called a tympanum that covered a notch in the squamosal bone at the back of the skull. Evidence for a tympanum is seen in a ridge that runs along the squamosal notch, which may have been an attachment point for the membrane. However, since the otic notch is very small, the presence of a tympanum is now considered unlikely.
Phylogeny
Solenodonsaurus is traditionally classified as a close relative of amniotes (vertebrates that lay eggs on land). However, a 2012 phylogenetic analysis of Solenodonsaurus and other early tetrapods |
https://en.wikipedia.org/wiki/NeXtProt | neXtProt is an on-line knowledge platform on human proteins.
It strives to be a comprehensive resource that provides a variety of
types of information on human proteins, such as their function,
subcellular location, expression, interactions and role in diseases.
The major part of the information in neXtProt
is obtained from the UniProt Swiss-Prot database but it is complemented by data originating from high-throughput studies with an emphasis on proteomics. neXtProt offers also an advanced search capacity based on the SPARQL technology as well as an API that allows to programatically extract the data stored in the resource. It is developed by the CALIPHO group directed by Amos Bairoch and Lydie Lane of the Swiss Institute of Bioinformatics (SIB). |
https://en.wikipedia.org/wiki/Thin%20shrink%20small%20outline%20package | The Thin Shrink Small Outline Package (TSSOP) is a rectangular surface mount plastic integrated circuit (IC) package with gull-wing leads.
Application
They are suited for applications requiring 1 mm or less mounted height and are commonly used in analog and operation amplifiers, controllers and Drivers, Logic, Memory, and RF/Wireless, Disk drives, video/audio and consumer electronics.
Physical properties
The Thin shrink small outline package has a smaller body and smaller lead pitch than the standard SOIC package. It is also smaller and thinner than a TSOP with the same lead count. Body widths are 3.0 mm, 4.4 mm and 6.1 mm. The lead counts range from 8 to 80 pins. The lead pitches are 0.5 or 0.65 mm.
Exposed Pad
Some TSSOP packages have an exposed pad. This is a rectangular metal pad on the bottom side of the package. The exposed pad will be soldered on the pcb to transfer heat from the package to the pcb. In most applications, the exposed pad is connected to ground.
HTSSOP
The Heat sink thin shrink small outline package (HTSSOP) is Texas Instruments name for a TSSOP with an exposed pad on the bottom side. There are some other manufacturers who use the same name.
See also
List of integrated circuit packaging types
Small outline integrated circuit
Similar package types
Shrink Small Outline Package
Mini Small Outline Package
Small outline integrated circuit |
https://en.wikipedia.org/wiki/Haven%20%28graph%20theory%29 | In graph theory, a haven is a certain type of function on sets of vertices in an undirected graph. If a haven exists, it can be used by an evader to win a pursuit–evasion game on the graph, by consulting the function at each step of the game to determine a safe set of vertices to move into. Havens were first introduced by as a tool for characterizing the treewidth of graphs. Their other applications include proving the existence of small separators on minor-closed families of graphs, and characterizing the ends and clique minors of infinite graphs.
Definition
If is an undirected graph, and is a set of vertices, then an -flap is a nonempty connected component of the subgraph of formed by deleting . A haven of order in is a function that assigns an -flap to every set of fewer than vertices. This function must also satisfy additional constraints which are given differently by different authors.
The number is called the order of the haven.
In the original definition of Seymour and Thomas, a haven is required to satisfy the property that every two flaps and must touch each other: either they share a common vertex or there exists an edge with one endpoint in each flap. In the definition used later by Alon, Seymour, and Thomas, havens are instead required to satisfy a weaker monotonicity property: if , and both and have fewer than vertices, then . The touching property implies the monotonicity property, but not necessarily vice versa. However, it follows from the results of Seymour and Thomas that, in finite graphs, if a haven with the monotonicity property exists, then one with the same order and the touching property also exists.
Havens with the touching definition are closely related to brambles, families of connected subgraphs of a given graph that all touch each other. The order of a bramble is the minimum number of vertices needed in a set of vertices that hits all of the subgraphs in the family. The set of flaps for a haven of order (with the |
https://en.wikipedia.org/wiki/Forkhead-associated%20domain | In molecular biology, the forkhead-associated domain (FHA domain) is a phosphopeptide recognition domain found in many regulatory proteins. It displays specificity for phosphothreonine-containing epitopes but will also recognise phosphotyrosine with relatively high affinity. It spans approximately 80-100 amino acid residues folded into an 11-stranded beta sandwich, which sometimes contains small helical insertions between the loops connecting the strands.
To date, genes encoding FHA-containing proteins have been identified in eubacterial, eukaryotic and archaeal genomes. The domain is present in a diverse range of proteins, such as kinases, phosphatases, kinesins, transcription factors, RNA-binding proteins and metabolic enzymes which partake in many different cellular processes - DNA repair, signal transduction, vesicular transport and protein degradation are just a few examples.
DNA repair
The forkhead associated (FHA) domain of polynucleotide kinase phosphatase (PNKP) is necessary for the recruitment of PNKP to damage sites in DNA. PNKP is active in the repair of DNA damage by the processes of base excision repair, single-strand break repair and non-homologous end joining in the case of double strand breaks. In these activities PNKP acts both as a kinase and a phosphatase in the ligation of DNA ends. The kinase domain phosphorylates 5' hydroxyl ends, and the phosphatase domain removes phosphates from 3' ends. These activities, acting together, prepare single-strand breaks with damaged termini for ligation. |
https://en.wikipedia.org/wiki/Total%20least%20squares | In applied statistics, total least squares is a type of errors-in-variables regression, a least squares data modeling technique in which observational errors on both dependent and independent variables are taken into account. It is a generalization of Deming regression and also of orthogonal regression, and can be applied to both linear and non-linear models.
The total least squares approximation of the data is generically equivalent to the best, in the Frobenius norm, low-rank approximation of the data matrix.
Linear model
Background
In the least squares method of data modeling, the objective function, S,
is minimized, where r is the vector of residuals and W is a weighting matrix. In linear least squares the model contains equations which are linear in the parameters appearing in the parameter vector , so the residuals are given by
There are m observations in y and n parameters in β with m>n. X is a m×n matrix whose elements are either constants or functions of the independent variables, x. The weight matrix W is, ideally, the inverse of the variance-covariance matrix of the observations y. The independent variables are assumed to be error-free. The parameter estimates are found by setting the gradient equations to zero, which results in the normal equations
Allowing observation errors in all variables
Now, suppose that both x and y are observed subject to error, with variance-covariance matrices and respectively. In this case the objective function can be written as
where and are the residuals in x and y respectively. Clearly these residuals cannot be independent of each other, but they must be constrained by some kind of relationship. Writing the model function as , the constraints are expressed by m condition equations.
Thus, the problem is to minimize the objective function subject to the m constraints. It is solved by the use of Lagrange multipliers. After some algebraic manipulations, the result is obtained.
or alternatively
where M is the v |
https://en.wikipedia.org/wiki/Pre-play%20attack | In the field of security engineering, a pre-play attack is a cryptographic attack in which an attacker prepares for the attack in advance by carrying out a simulated transaction while pretending to be the device to be attacked, and then repeats the attack a second time with the real device at a time when it is likely to carry out the same series of operations as in the simulation. The technique relies on being able to guess the content of the transaction in advance, something usually made possible by a poor choice of unpredictability within the system. The name is a play on "replay attack". Pre-play attacks are not very effective and chances of success are slim. |
https://en.wikipedia.org/wiki/Karl%20H.%20Pribram | Karl H. Pribram (; ; February 25, 1919 – January 19, 2015) was a professor at Georgetown University, in the United States, an emeritus professor of psychology and psychiatry at Stanford University and distinguished professor at Radford University. Board-certified as a neurosurgeon, Pribram did pioneering work on the definition of the limbic system, the relationship of the frontal cortex to the limbic system, the sensory-specific "association" cortex of the parietal and temporal lobes, and the classical motor cortex of the human brain. He worked with Karl Lashley at the Yerkes Primate Center of which he was to become director later. He was professor at Yale University for ten years and at Stanford University for thirty years.
To the general public, Pribram is best known for his development of the holonomic brain model of cognitive function and his contribution to ongoing neurological research into memory, emotion, motivation and consciousness. He was married to American author Katherine Neville.
Holonomic model
Pribram's holonomic model of brain processing is described in his 1991 Brain and Perception, which contains the extension of his work with David Bohm. It states that, in addition to the circuitry accomplished by the large fiber tracts in the brain, processing also occurs in webs of fine fiber branches (for instance, dendrites) that form webs, as well as in the dynamic electrical fields that surround these dendritic "trees". In addition, the processing occurring around these dendritic trees can influence that occurring in those trees of nearby neurons whose dendrites are entangled but not in direct contact (known as ephaptic signaling). In this way, processing in the brain can occur in a non-localized manner. This type of processing is properly described by Dennis Gabor, the inventor of holography, as quanta of information he called a "holon", an energy-based concept of information. These wavelets are used in quantum holography, the basis of MRI, PET scans |
https://en.wikipedia.org/wiki/Angular%20frequency | In physics, angular frequency (symbol ω), also called angular speed and angular rate, is a scalar measure of the angle rate (the angle per unit time) or the temporal rate of change of the phase argument of a sinusoidal waveform or sine function (for example, in oscillations and waves).
Angular frequency (or angular speed) is the magnitude of the pseudovector quantity angular velocity.
Angular frequency can be obtained multiplying rotational frequency, ν (or ordinary frequency, f) by a full turn (2 radians): ω2radν.
It can also be formulated as ωdθ/dt, the instantaneous rate of change of the angular displacement, θ, with respect to time, t.
Units
In SI units, angular frequency is normally presented in radians per second, even when it does not express a rotational value. The unit hertz (Hz) is dimensionally equivalent, but by convention it is only used for frequency f, never for angular frequency ω. This convention is used to help avoid the confusion that arises when dealing with quantities such as frequency and angular quantities because the units of measure (such as cycle or radian) are considered to be one and hence may be omitted when expressing quantities in SI units.
In digital signal processing, the frequency may be normalized by the sampling rate, yielding the normalized frequency.
Examples
Circular motion
In a rotating or orbiting object, there is a relation between distance from the axis, , tangential speed, , and the angular frequency of the rotation. During one period, , a body in circular motion travels a distance . This distance is also equal to the circumference of the path traced out by the body, . Setting these two quantities equal, and recalling the link between period and angular frequency we obtain:
Oscillations of a spring
An object attached to a spring can oscillate. If the spring is assumed to be ideal and massless with no damping, then the motion is simple and harmonic with an angular frequency given by
where
k is the spring consta |
https://en.wikipedia.org/wiki/NuFW | NuFW is a software package that extends Netfilter, the Linux kernel-internal packet filtering firewall module. NuFW adds authentication to filtering rules. NuFW is also provided as a hardware firewall, in the EdenWall firewalling appliance. NuFW has been restarted by the FFI and renamed into UFWI.
Introduction
NuFW / UFWI is an extension of Netfilter which brings the notion of user to IP filtering.
NuFW / UFWI can :
Authenticate any connection that goes through your gateway or only from/to a chosen subset or a specific protocol (iptables is used to select the connections to authenticate).
Perform accounting, routing and Quality of service (QOS) based on users and not simply on IPs.
Filter packets with criteria such as application and OS used by distant users.
Be the key of a secure and simple Single Sign On system.
Principles
NuFW / UFWI refuses the idea of IP == user as an IP address can easily be spoofed. It thus uses
its own algorithm to perform authentication. It depends on two subsystems: Nufw which is connected to Netfilter and Nuauth
which is connected to clients and Nufw.
The algorithm is the following:
A standard application sends a packet.
The Nufw client sees that a connection is being initiated and sends a user request packet.
The Nufw server queues the packet and sends an auth request packet to the Nuauth server.
The Nuauth server sums the auth request and the user request packet and checks this against an authentication authority.
The Nuauth server sends answer back to the Nufw server
The Nufw server transmits the packet following the answer given to its request.
This algorithm realizes an A Posteriori authentication of the connection. As there is no time-based association, this ensures the identity of the user who sent the packet.
NuFW is the only real Authentication firewall, as it never associates a user with his machine.
Awards
2007 : Lutèce d'Or (Paris, France), Best Innovation
2005 : Les Trophées du Libre (Soissons, Franc |
https://en.wikipedia.org/wiki/Rosiwal%20scale | The Rosiwal scale is a hardness scale in mineralogy, with its name given in memory of the Austrian geologist August Karl Rosiwal. The Rosiwal scale attempts to give more quantitative values of scratch hardness, unlike the Mohs scale which is a qualitative measurement with relative values.
The Rosiwal method (also called the Delesse-Rosiwal method) is a method of petrographic analysis and is performed by scratching a polished surface under a known load using a scratch-tip with a known geometry. The hardness is calculated by finding the volume of removed material, but this measurement can be difficult and must sample a large enough number of grain in order to have statistical significance.
Rosiwal scale values
Measures the scratch hardness of a mineral expressed on a quantitative scale. These measurements must be performed in a laboratory, since the surfaces must be flat and smooth. The base value of the Rosiwal scale is defined as corundum set to 1000 (unitless).
See also
Hardness
August Karl Rosiwal
Friedrich Mohs |
https://en.wikipedia.org/wiki/Morchella%20pulchella | Morchella pulchella is a species of fungus in the family Morchellaceae that was described as new to science in 2012. It is found in France, where it grows on calcareous soil under Buddleja davidii. |
https://en.wikipedia.org/wiki/Extendible%20cardinal | In mathematics, extendible cardinals are large cardinals introduced by , who was partly motivated by reflection principles. Intuitively, such a cardinal represents a point beyond which initial pieces of the universe of sets start to look similar, in the sense that each is elementarily embeddable into a later one.
Definition
For every ordinal η, a cardinal κ is called η-extendible if for some ordinal λ there is a nontrivial elementary embedding j of Vκ+η into Vλ, where κ is the critical point of j, and as usual Vα denotes the αth level of the von Neumann hierarchy. A cardinal κ is called an extendible cardinal if it is η-extendible for every nonzero ordinal η (Kanamori 2003).
Properties
For a cardinal , say that a logic is -compact if for every set of -sentences, if every subset of or cardinality has a model, then has a model. (The usual compactness theorem shows -compactness of first-order logic.) Let be the infinitary logic for second-order set theory, permitting infinitary conjunctions and disjunctions of length . is extendible iff is -compact.
Variants and relation to other cardinals
A cardinal κ is called η-C(n)-extendible if there is an elementary embedding j witnessing that κ is η-extendible (that is, j is elementary from Vκ+η to some Vλ with critical point κ) such that furthermore, Vj(κ) is Σn-correct in V. That is, for every Σn formula φ, φ holds in Vj(κ) if and only if φ holds in V. A cardinal κ is said to be C(n)-extendible if it is η-C(n)-extendible for every ordinal η. Every extendible cardinal is C(1)-extendible, but for n≥1, the least C(n)-extendible cardinal is never C(n+1)-extendible (Bagaria 2011).
Vopěnka's principle implies the existence of extendible cardinals; in fact, Vopěnka's principle (for definable classes) is equivalent to the existence of C(n)-extendible cardinals for all n (Bagaria 2011). All extendible cardinals are supercompact cardinals (Kanamori 2003).
See also
List of large cardinal properties
Reinhardt cardinal |
https://en.wikipedia.org/wiki/Sexual%20dimorphism%20in%20Carnivorans | Sexual dimorphism is the condition where sexes of the same species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. Sexual dimorphism in carnivorans, in which males are larger than females, is common among carnivorans. Sexual selection is frequently cited as the cause of the intraspecific divergence in body proportions and craniomandibular morphology between the sexes within the Carnivora order. It is anticipated that animals with polygynous mating systems and high levels of territoriality and solitary behavior will exhibit the highest levels of sexual size dimorphism. Pinnipeds offer an illustration for this.
Different types
Body size
Sexual size dimorphism is the difference in body size between the sexes within a group of some sort or another. Carnivorans exhibit high levels of sexual size dimorphism with males generally being larger than females.
Canine tooth
Males have larger, longer and more powerful canines than their female counterparts. A study of skull and tooth size in 45 species of Carnivorans showed that sexual dimorphism was most pronounced in the size of the canine tooth. Breeding systems seems to be the most reasonable explanation for the finding. Social species like lions, in which males have a canine teeth 25% larger than females are the most sexual dimorphic of felids.
Skeletal structure
In terms of skeletal structure,
Carnivorans are highly sexually dimorphic. Males have more robust and larger skulls which promotes a stronger biteforce, larger necks to permit more powerful neck muscles that work to prevent torsional loading of the neck and improve the ability to rend with the teeth and jerk the skull. Males also have larger scapulae that enable more muscle to transmit force from the trunk to the forelimbs and stabilize the shoulder joint and stronger limbs with better mechanical advantages due to anatomy.
Mechanisms
A secondary factor that propels the evolution of se |
https://en.wikipedia.org/wiki/Pinole | Pinole, also called pinol or pinolillo, is roasted ground maize, which is then mixed with a combination of cocoa, agave, cinnamon, chia seeds, vanilla, or other spices. The resulting powder is then used as a nutrient-dense ingredient to make different foods, such as cereals, baked goods, tortillas, and beverages. The name comes from the Nahuatl word pinolli, meaning cornmeal. Today, pinole is generally made by hand using wood-burning adobe ovens and a stone and pestle, and is still consumed in certain, often rural, parts of Latin America. Pinole is considered the national beverage of Nicaragua and Honduras.
Nutrient content
Depending on the type of pinole and the quality of its ingredients, pinole can be high in key vitamins and nutrients, including protein, amino acids, fiber, and antioxidants. Due to the large amount of fiber and the slow digestion of the maize, pinole also has a very high satiety effect, leaving those who consume it feeling full for a longer period of time. For many indigenous peoples of Mexico and Central America, it is relied upon as a key source of nutrition and sustenance.
Use by Tarahumara people
Along with chia, pinole is a staple food of the Tarahumara Indians, a reclusive indigenous people living in the Copper Canyon of Mexico who call themselves Rarámuri, meaning "footrunners". Noted for physical stamina and their ability to run extraordinarily long distances wearing only huarache sandals with soles made of recycled tire treads and their traditional garb of a white cotton loincloth with a woven belt., the Rarámuri consume bajíachi (corn beer) and pinole before races.
Other folklore
The recorded history of Pinole, California dates back to the early 1700s when a Spanish commandant, Don Pedro Fages, led an exploration through the Contra Costa shoreline of California. With a small band of soldiers and an Indian guide, Don Pedro Fages left Monterey and traveled northward until he reached the area known today as Pinole. According |
https://en.wikipedia.org/wiki/Cobalt | Cobalt is a chemical element with the symbol Co and atomic number 27. As with nickel, cobalt is found in the Earth's crust only in a chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, produced by reductive smelting, is a hard, lustrous, silvery metal.
Cobalt-based blue pigments (cobalt blue) have been used since ancient times for jewelry and paints, and to impart a distinctive blue tint to glass, but the color was for a long time thought to be due to the known metal bismuth. Miners had long used the name kobold ore (German for goblin ore) for some of the blue pigment-producing minerals; they were so named because they were poor in known metals and gave off poisonous arsenic-containing fumes when smelted. In 1735, such ores were found to be reducible to a new metal (the first discovered since ancient times), and this was ultimately named for the kobold.
Today, some cobalt is produced specifically from one of a number of metallic-lustered ores, such as cobaltite (CoAsS). The element is, however, more usually produced as a by-product of copper and nickel mining. The Copperbelt in the Democratic Republic of the Congo (DRC) and Zambia yields most of the global cobalt production. World production in 2016 was (according to Natural Resources Canada), and the DRC alone accounted for more than 50%.
Cobalt is primarily used in lithium-ion batteries, and in the manufacture of magnetic, wear-resistant and high-strength alloys. The compounds cobalt silicate and cobalt(II) aluminate (CoAl2O4, cobalt blue) give a distinctive deep blue color to glass, ceramics, inks, paints and varnishes. Cobalt occurs naturally as only one stable isotope, cobalt-59. Cobalt-60 is a commercially important radioisotope, used as a radioactive tracer and for the production of high-energy gamma rays. Cobalt is also used in the petroleum industry as a catalyst when refining crude oil. This is to clean it of its sulfur content, which is very po |
https://en.wikipedia.org/wiki/VGA%20connector | The Video Graphics Array (VGA) connector is a standard connector used for computer video output. Originating with the 1987 IBM PS/2 and its VGA graphics system, the 15-pin connector went on to become ubiquitous on PCs, as well as many monitors, projectors and high-definition television sets.
Other connectors have been used to carry VGA-compatible signals, such as mini-VGA or BNC, but "VGA connector" typically refers to this design.
Devices continue to be manufactured with VGA connectors, although newer digital interfaces such as DVI, HDMI and DisplayPort are increasingly displacing VGA, and many modern computers and other devices do not include it.
Physical design
The VGA connector is a three-row, 15-pin D-subminiature connector referred to variously as DE-15, HD-15 or erroneously DB-15(HD). DE-15 is the accurate nomenclature under the D-sub specifications: an "E" size D-sub connector, with 15 pins in three rows.
Electrical design
All VGA connectors carry analog RGBHV (red, green, blue, horizontal sync, vertical sync) video signals. Modern connectors also include VESA DDC pins, for identifying attached display devices.
In both its modern and original variants, VGA utilizes multiple scan rates, so attached devices such as monitors are multisync by necessity.
The VGA interface includes no affordances for hot swapping, the ability to connect or disconnect the output device during operation, although in practice this can be done and usually does not cause damage to the hardware or other problems. The VESA DDC specification does, however, include a standard for hot-swapping.
PS/2 signaling
In the original IBM VGA implementation, refresh rates were limited to two vertical (60 and 70 Hz) and three horizontal frequencies, all of which were communicated to the monitor using combinations of different polarity H and V sync signals.
Some pins on the connector were also different: pin 9 was keyed by plugging the female connector hole, and four pins carried the monitor |
https://en.wikipedia.org/wiki/M%C3%B6ller%E2%80%93Trumbore%20intersection%20algorithm | The Möller–Trumbore ray-triangle intersection algorithm, named after its inventors Tomas Möller and Ben Trumbore, is a fast method for calculating the intersection of a ray and a triangle in three dimensions without needing precomputation of the plane equation of the plane containing the triangle. Among other uses, it can be used in computer graphics to implement ray tracing computations involving triangle meshes.
Calculation
Definitions
The ray is defined by an origin point and a direction vector .
Every point on the ray can be expressed by , where the parameter ranges from zero to infinity.
The triangle is defined by three vertices, named , , .
The plane that the triangle is on, which is needed to calculate the ray-triangle intersection, is defined by a point on the plane, such as , and a vector that is orthogonal to every point on that plane, such as the cross product between the vector from to and the vector from to :
, where , and and are any points on the plane.
Check if the ray is parallel to the triangle
First, find out if the ray intersects with the plane that the triangle is on, and if it does, find the coordinates of that intersection. The only way that the ray will not intersect the plane is if the ray's direction vector is parallel to the plane. When this happens, the dot product between the ray's direction vector and the plane's normal vector will be zero. Otherwise, the ray does intersect the plane somewhere, but not necessarily within the triangle.
Check if the ray-plane intersection lies outside the triangle
Using barycentric coordinates, any point on the triangle can be expressed as a convex combination of the triangle's vertices:
The coefficients must be non-negative and sum to 1, so w can be replaced with :
, where is any point on the plane.
Observe that and are vectors on the edge of the triangle, and together, they span a plane (which goes through the origin). Each point on that plane can be written as and can be translate |
https://en.wikipedia.org/wiki/Spaghetti%20sort | Spaghetti sort is a linear-time, analog algorithm for sorting a sequence of items, introduced by A. K. Dewdney in his Scientific American column. This algorithm sorts a sequence of items requiring O(n) stack space in a stable manner. It requires a parallel processor.
Algorithm
For simplicity, assume we are sorting a list of natural numbers. The sorting method is illustrated using uncooked rods of spaghetti:
For each number x in the list, obtain a rod of length x. (One practical way of choosing the unit is to let the largest number m in the list correspond to one full rod of spaghetti. In this case, the full rod equals m spaghetti units. To get a rod of length x, break a rod in two so that one piece is of length x units; discard the other piece.)
Once you have all your spaghetti rods, take them loosely in your fist and lower them to the table, so that they all stand upright, resting on the table surface. Now, for each rod, lower your other hand from above until it meets with a rod—this one is clearly the longest. Remove this rod and insert it into the front of the (initially empty) output list (or equivalently, place it in the last unused slot of the output array). Repeat until all rods have been removed.
Analysis
Preparing the n rods of spaghetti takes linear time. Lowering the rods on the table takes constant time, O(1). This is possible because the hand, the spaghetti rods and the table work as a fully parallel computing device. There are then n rods to remove so, assuming each contact-and-removal operation takes constant time, the worst-case time complexity of the algorithm is O(n). |
https://en.wikipedia.org/wiki/COPS%20%28software%29 | The Computer Oracle and Password System (COPS) was the first vulnerability scanner for Unix operating systems to achieve widespread use. It was created by Dan Farmer while he was a student at Purdue University. Gene Spafford helped Farmer start the project in 1989.
Features
COPS is a software suite comprising at least 12 small vulnerability scanners, each programmed to audit one part of the operating system:
File permissions, including device permissions/nodes
Password strength
Content, format, and security of password and group files (e.g., passwd)
Programs and files run in /etc/rc* and cron(tab) files
Root-SUID files: Which users can modify them? Are they shell scripts?
A cyclic redundancy check of important files
Writability of users' home directories and startup files
Anonymous FTP configuration
Unrestricted TFTP, decode alias in sendmail, SUID uudecode problems, hidden shells inside inetd.conf, rexd in inetd.conf
Various root checks: Is the current directory in the search path? Is there a plus sign ("+") in the /etc/host.equiv file? Are NFS mounts unrestricted? Is root in /etc/ftpusers?
Compare the modification dates of crucial files with dates of advisories from the CERT Coordination Center
Kuang expert system
After COPS, Farmer developed another vulnerability scanner called SATAN (Security Administrator Tool for Analyzing Networks).
COPS is generally considered obsolete, but it is not uncommon to find systems which are set up in an insecure manner that COPS will identify. |
https://en.wikipedia.org/wiki/Tesla%20Roadster%20%28second%20generation%29 | The Tesla Roadster is an upcoming battery electric four-seater sports car to be built by Tesla, Inc. The company has said that it will be capable of accelerating from 0 to 60 mph in 1.9 seconds. The Roadster is the successor to Tesla's first production car, the 2008 Roadster.
Tesla CEO Elon Musk has said that the Roadster should ship in 2024. Musk said in a tweet that higher-performance trim levels will be available beyond the base specifications, including a SpaceX package that would "include ~10 small rocket cold air thrusters arranged seamlessly around the car" which would supposedly allow for dramatic improvements in "acceleration, top speed, braking & cornering" such as a claimed 1.1 second 0–60 mph (0–97 km/h) time.
Overview
History
In 2011, at the end of the production run of the original Tesla Roadster, Elon Musk suggested that a new version of the Roadster, without the Lotus chassis, would return to production by 2014. The new Roadster was first teased in 2014. At the time, it was also referred to as the Tesla Model R.
In 2015, Musk suggested a new Roadster, capable of faster acceleration. A tweet by Elon Musk in December 2016 reconfirmed a second Roadster was in the works, but still "some years away". The second Roadster was designed by Franz von Holzhausen.
A prototype of the Roadster was shown in a surprise moment at the end of the Tesla Semi event on November 16, 2017, with an announced availability in the year 2020 at the starting price of US$200,000. Musk explained the concept as: "The point of doing this is to give a hardcore smackdown to gasoline cars. Driving a gasoline sports car is going to feel like a steam engine with a side of quiche." Test rides were given at the event for those who immediately paid the first $5,000 of a $50,000 deposit to pre-order the vehicle. Additional information followed after the teaser, such as the various world-record speeds Tesla said it will break.
In June 2018, Elon Musk revealed a potential feature called |
https://en.wikipedia.org/wiki/Tactile%20transducer | A tactile transducer or "bass shaker" is a device which is made on the principle that low bass frequencies can be felt as well as heard. They can be compared with a common loudspeaker, just that the diaphragm is missing. Instead, another object is used as a diaphragm. A shaker transmits low-frequency vibrations into various surfaces so that they can be felt by people. This is called tactile sound. Tactile transducers may augment or in some cases substitute for a subwoofer. One benefit of tactile transducers is they produce little or no noise, if properly installed, as compared with a subwoofer speaker enclosure.
Applications
A bass-shaker is meant to be firmly attached to some surface such as a seat, couch or floor. The shaker houses a small weight which is driven by a voice coil similar to those found in dynamic loudspeakers. The voice-coil is driven by a low-frequency audio signal from an amplifier; common shakers typically handle 25 to 50 watts of amplifier power. The voice coil exerts force on both the weight and the body of the shaker, with the latter forces being transmitted into the mounting surface. Tactile transducers may be used in a home theater, a video gaming chair or controller, a commercial movie theater, or for special effects in an arcade game, amusement park ride or other application.
Related to bass shakers are a newer type of transducer referred to as linear actuators. These piston-like electromagnetic devices transmit motion in a direct fashion by lifting home theater seating in the vertical plane rather than transferring vibrations (by mounting within a seat, platform or floor). This technology is said to transmit a high-fidelity sound-motion augmentation, whereas "Shakers" may require heavy equalization and/or multiple units to approach a realistic effect.
Virtual reality
There are other products which employ hydraulic (long-throw) linear actuators and outboard motion processors for home applications as popularized in "virtual reality" ride |
https://en.wikipedia.org/wiki/Combinatorial%20Theory%20%28journal%29 | Combinatorial Theory is a peer-reviewed diamond open access mathematical journal specializing in the field of combinatorics. It was established in 2021, when the vast majority of the editorial board of the Elsevier-published Journal of Combinatorial Theory left to create a new journal.
Operations
Combinatorial Theory operates on a diamond open access model, in which publication costs are underwritten by voluntary contributions from universities, foundations, and other organizations. Authors do not pay submission fees or article processing charges, and the journal belongs to the Free Journal Network. All content is published under a Creative Commons license.
The journal's editorial board consists of approximately 50 mathematicians, and includes Timothy Gowers and June Huh. It follows a doubly-anonymous review process, in which author names are not disclosed to reviewers.
Abstracting and indexing
The journal is abstracted and indexed in the Directory of Open Access Journals, the Free Journal Network, Mathematical Reviews, and Zentralblatt Math. |
https://en.wikipedia.org/wiki/Six%20nines%20in%20pi | A sequence of six consecutive nines occurs in the decimal representation of the number pi (), starting at the 762nd decimal place. It has become famous because of the mathematical coincidence, and because of the idea that one could memorize the digits of up to that point, and then suggest that is rational. The earliest known mention of this idea occurs in Douglas Hofstadter's 1985 book Metamagical Themas, where Hofstadter states
This sequence of six nines is sometimes called the "Feynman point", after physicist Richard Feynman, who allegedly stated this same idea in a lecture. However it is not clear when, or even if, Feynman made such a statement. It is not mentioned in published biographies or in his autobiographies, and is unknown to his biographer, James Gleick.
Related statistics
is conjectured, but not known, to be a normal number. For a normal number sampled uniformly at random, the probability of a specific sequence of six digits occurring this early in the decimal representation is about 0.08%.
The early string of six 9's is also the first occurrence of four and five consecutive identical digits. The next sequence of six consecutive identical digits is again composed of 9's, starting at position 193,034. The next distinct sequence of six consecutive identical digits after that starts with the digit 8 at position 222,299.
The positions of the first occurrence of a string of 1, 2, 3, 4, 5, 6, 7, 8, and 9 consecutive 9's in the decimal expansion are 5; 44; 762; 762; 762; 762; 1,722,776; 36,356,642; and 564,665,206, respectively .
Decimal expansion
The first 1,001 digits of (1,000 decimal places), showing consecutive runs of three or more digits including the consecutive six 9's underlined, are as follows:
See also
0.999...
9 (number)
Mathematical coincidence
Repdigit
Ramanujan's constant |
https://en.wikipedia.org/wiki/Free%20energy%20principle | The free energy principle is a theoretical framework suggesting that the brain reduces surprise or uncertainty by making predictions based on internal models and updating them using sensory input. It highlights the brain's objective of aligning its internal model with the external world to enhance prediction accuracy. This principle integrates Bayesian inference with active inference, where actions are guided by predictions and sensory feedback refines them. It has wide-ranging implications for comprehending brain function, perception, and action.
Overview
In biophysics and cognitive science, the free energy principle is a mathematical principle describing a formal account of the representational capacities of physical systems: that is, why things that exist look as if they track properties of the systems to which they are coupled.
It establishes that the dynamics of physical systems minimise a quantity known as surprisal (which is just the negative log probability of some outcome); or equivalently, its variational upper bound, called free energy. The principle is used especially in Bayesian approaches to brain function, but also some approaches to artificial intelligence; it is formally related to variational Bayesian methods and was originally introduced by Karl Friston as an explanation for embodied perception-action loops in neuroscience.
The free energy principle models the behaviour of systems that are distinct from, but coupled to, another system (e.g., an embedding environment), where the degrees of freedom that implement the interface between the two systems is known as a Markov blanket. More formally, the free energy principle says that if a system has a "particular partition" (i.e., into particles, with their Markov blankets), then subsets of that system will track the statistical structure of other subsets (which are known as internal and external states or paths of a system).
The free energy principle is based on the Bayesian idea of the brain as |
https://en.wikipedia.org/wiki/Reusability | In computer science and software engineering, reusability is the use of existing assets in some form within the software product development process; these assets are products and by-products of the software development life cycle and include code, software components, test suites, designs and documentation. The opposite concept of reusability is leverage, which modifies existing assets as needed to meet specific system requirements. Because reuse implies the creation of a , it is preferred over leverage.
Subroutines or functions are the simplest form of reuse. A chunk of code is regularly organized using modules or namespaces into layers. Proponents claim that objects and software components offer a more advanced form of reusability, although it has been tough to objectively measure and define levels or scores of reusability.
The ability to reuse relies in an essential way on the ability to build larger things from smaller parts, and being able to identify commonality among those parts. Reusability is often a required characteristic of platform software. Reusability brings several aspects to software development that do not need to be considered when reusability is not required.
Reusability implies some explicit management of build, packaging, distribution, installation, configuration, deployment, maintenance and upgrade issues. If these issues are not considered, software may appear to be reusable from design point of view, but will not be reused in practice.
Software reusability more specifically refers to design features of a software element (or collection of software elements) that enhance its suitability for reuse.
Many reuse design principles were developed at the WISR workshops.
Candidate design features for software reuse include:
Adaptable
Brief: small size
Consistency
Correctness
Extensibility
Fast
Flexible
Generic
Localization of volatile (changeable) design assumptions (David Parnas)
Modularity
Orthogonality
Parameterization
Simple: |
https://en.wikipedia.org/wiki/Virtual%20metrology | In semiconductor manufacturing, virtual metrology refers to methods to predict the properties of a wafer based on machine parameters and sensor data in the production equipment, without performing the (costly) physical measurement of the wafer properties. Statistical methods such as classification and regression are used to perform such a task. Depending on the accuracy of this virtual data, it can be used in modelling for other purposes, such as predicting yield, preventative analysis, etc. This virtual data is helpful for modelling techniques that are adversely affected by missing data. Another option to handle missing data is to use imputation techniques on the dataset, but virtual metrology in many cases, can be a more accurate method.
Examples of virtual metrology include:
the prediction of the silicon nitride () layer thickness in the chemical vapor deposition process (CVD), using multivariate regression methods;
the prediction of critical dimension in photolithography, using multi-level and regularization approaches;
the prediction of layer width in etching. |
https://en.wikipedia.org/wiki/Vibrionaceae | The Vibrionaceae are a family of Pseudomonadota given their own order, Vibrionales. Inhabitants of fresh or salt water, several species are pathogenic, including the type species Vibrio cholerae, which is the agent responsible for cholera. Most bioluminescent bacteria belong to this family, and are typically found as symbionts of deep-sea animals.
Vibrionaceae are Gram-negative organisms and facultative anaerobes, capable of fermentation. They contain oxidase and have one or more flagella, which are generally polar. Originally, these characteristics defined the family, which was divided into four genera. Two of these, Vibrio and Photobacterium, correspond to the modern group, although several new genera have been defined. Genetic studies have shown the other two original members—Aeromonas and Plesiomonas—belong to separate families. The family Vibrionaceae currently comprises eight validly published genera: Aliivibrio, Catenococcus, Enterovibrio, Grimontia, Listonella, Photobacterium, Salinivibrio, and Vibrio; although the status of Listonella has been questioned.
Members of this family also synthesize tetrodotoxin (TTX), an ancient marine alkaloid and powerful neurotoxin (Na+ pump inhibitor, 1 mg can kill an adult) that serves to protect members of an order of fishes, the Tetraodontiformes (tetras-four and odontos-tooth), which include the puffer fish (see fugu, raw puffer fish served in Japan). As mentioned above, Vibrionaceae bacteria are in symbiosis with many marine organisms. In the case of the puffer fish, and other marine organisms harboring TTX-producing Vibrionaceae, the symbiosis is an ancient and powerful one, providing protection against predation for the marine organisms that harbor these bacteria, while providing the bacteria a protected environment with plenty of nutrients for growth. TTX and saxitoxin provide good examples of convergent biochemical evolution: both toxins are extremely toxic at low levels, both are Na+ pump inhibitors and both |
https://en.wikipedia.org/wiki/Amplitude%20amplification | Amplitude amplification is a technique in quantum computing which generalizes the idea behind Grover's search algorithm, and gives rise to a family of quantum algorithms.
It was discovered by Gilles Brassard and Peter Høyer in 1997, and independently rediscovered by Lov Grover in 1998.
In a quantum computer, amplitude amplification can be used to obtain a quadratic speedup over several classical algorithms.
Algorithm
The derivation presented here roughly follows the one given by Brassard et al. in 2000.
Assume we have an -dimensional Hilbert space representing the state space of a quantum system, spanned by the orthonormal computational basis states .
Furthermore assume we have a Hermitian projection operator .
Alternatively, may be given in terms of a Boolean oracle function
and an orthonormal operational basis
,
in which case
.
can be used to partition into a direct sum of two mutually orthogonal subspaces, the good subspace and the bad subspace :In other words, we are defining a "good subspace" via the projector . The goal of the algorithm is then to evolve some initial state into a state belonging to .
Given a normalized state vector with nonzero overlap with both subspaces, we can uniquely decompose it as
,
where ,
and
and are the normalized projections of into the subspaces and , respectively. This decomposition defines a two-dimensional subspace
, spanned by the vectors
and .
The probability of finding the system in a good state when measured is .
Define a unitary operator , where
flips the phase of the states in the good subspace, whereas
flips the phase of the initial state .
The action of this operator on is given by
and
.
Thus in the subspace corresponds to a rotation by the angle :
.
Applying times on the state
gives
,
rotating the state between the good and bad subspaces.
After iterations the probability of finding the
system in a good state is .The probability is maximized if we choose
.
Up until this point each itera |
https://en.wikipedia.org/wiki/CC41 | The CC41 Utility logo was an identifying mark of products produced and sold as part of the British Government's Second World War Utility Clothing Scheme.
The CC41 mark indicated that the item met the standards of the Government's Utility regulations, and could be sold as a product of the Utility Scheme. Easily recognisable, the CC41 symbol was useful to manufacturers, retailers, and the civilian consumer public.
Therefore, the Board of Trade stipulated the CC41 marks was applied to all Utility products, which included clothing, footwear, furniture, and fabrics and textiles, from the implementation of the Utility Clothing Scheme in 1941, until its end in 1952.
The CC41 mark could be attached to a Utility product as a label, printed directly onto cloth, or impressed mark, as on furniture and early examples of Utility footwear.
The symbol, colloquially referred to as ‘cheeses’ was designed by Reginald Shipp, and is understood to represent ‘Civilian Clothing 1941’.
Second World War
By 1941, with the need to produce clothing and other war essentials for the expanding armed services during the Second World War, many items were rationed. Certain raw materials could no longer be imported, and those that could were directed towards the war effort. Food rationing had already been reintroduced in January 1940. Non-rationed items saw their price surge, and clothing saw large mark-ups in price, well above the cost of living.
The government introduced Limitation of Supply Orders that forced manufacturers to produce only a fraction of their pre-war amounts. By April 1940, the limits on cloth were having a major impact with a 25% cut in wool and rayon, and a 75% cut in linen. As a consequence, manufacturers ended the production of any loss-making lines which led to calls for clothing rationing to be introduced. The prime minister, Winston Churchill, believed that the general public would not accept this change.
In June 1941 Oliver Lyttleton, the President of the Board o |
https://en.wikipedia.org/wiki/Protocol%20engineering | Protocol engineering is the application of systematic methods to the development of communication protocols. It uses many of the principles of software engineering, but it is specific to the development of distributed systems.
History
When the first experimental and commercial computer networks were developed in the 1970s, the concept of protocols was not yet well developed. These were the first distributed systems. In the context of the newly adopted layered protocol architecture (see OSI model), the definition of the protocol of a specific layer should be such that any entity implementing that specification in one computer would be compatible with any other computer containing an entity implementing the same specification, and their interactions should be such that the desired communication service would be obtained. On the other hand, the protocol specification should be abstract enough to allow different choices for the implementation on different computers.
It was recognized that a precise specification of the expected service provided by the given layer was important. It is important for the verification of the protocol, which should demonstrate that the communication service is provided if both protocol entities implement the protocol specification correctly. This principle was later followed during the standardization of the OSI protocol stack, in particular for the transport layer.
It was also recognized that some kind of formalized protocol specification would be useful for the verification of the protocol and for developing implementations, as well as test cases for checking the conformance of an implementation against the specification. While initially mainly finite-state machine were used as (simplified) models of a protocol entity, in the 1980s three formal specification languages were standardized, two by ISO and one by ITU. The latter, called SDL, was later used in industry and has been merged with UML state machines.
Principles
The followi |
https://en.wikipedia.org/wiki/St-connectivity | In computer science, st-connectivity or STCON is a decision problem asking, for vertices s and t in a directed graph, if t is reachable from s.
Formally, the decision problem is given by
.
Complexity
On a sequential computer, st-connectivity can easily be solved in linear time by either depth-first search or breadth-first search. The interest in this problem in computational complexity concerns its complexity with respect to more limited forms of computation. For instance, the complexity class of problems that can be solved by a non-deterministic Turing machine using only a logarithmic amount of memory is called NL. The st-connectivity problem can be shown to be in NL, as a non-deterministic Turing machine can guess the next node of the path, while the only information which has to be stored is the total length of the path and which node is currently under consideration. The algorithm terminates if either the target node t is reached, or the length of the path so far exceeds n, the number of nodes in the graph.
The complement of st-connectivity, known as st-non-connectivity, is also in the class NL, since NL = coNL by the Immerman–Szelepcsényi theorem.
In particular, the problem of st-connectivity is actually NL-complete, that is, every problem in the class NL is reducible to connectivity under a log-space reduction. This remains true for the stronger case of first-order reductions . The log-space reduction from any language in NL to STCON proceeds as follows: Consider the non-deterministic log-space Turing machine M that accepts a language in NL. Since there is only logarithmic space on the work tape, all possible states of the Turing machine (where a state is the state of the internal finite state machine, the position of the head and the contents of the work tape) are polynomially many. Map all possible states of the deterministic log-space machine to vertices of a graph, and put an edge between u and v if the state v can be reached from u within one step o |
https://en.wikipedia.org/wiki/Radon%E2%80%93Riesz%20property | The Radon–Riesz property is a mathematical property for normed spaces that helps ensure convergence in norm. Given two assumptions (essentially weak convergence and continuity of norm), we would like to ensure convergence in the norm topology.
Definition
Suppose that (X, ||·||) is a normed space. We say that X has the Radon–Riesz property (or that X is a Radon–Riesz space) if whenever is a sequence in the space and is a member of X such that converges weakly to and , then converges to in norm; that is, .
Other names
Although it would appear that Johann Radon was one of the first to make significant use of this property in 1913, M. I. Kadets and V. L. Klee also used versions of the Radon–Riesz property to make advancements in Banach space theory in the late 1920s. It is common for the Radon–Riesz property to also be referred to as the Kadets–Klee property or property (H). According to Robert Megginson, the letter H does not stand for anything. It was simply referred to as property (H) in a list of properties for normed spaces that starts with (A) and ends with (H). This list was given by K. Fan and I. Glicksberg (Observe that the definition of (H) given by Fan and Glicksberg includes additionally the rotundity of the norm, so it does not coincide with the Radon-Riesz property itself). The "Riesz" part of the name refers to Frigyes Riesz. He also made some use of this property in the 1920s.
It is important to know that the name "Kadets-Klee property" is used sometimes to speak about the coincidence of the weak topologies and norm topologies in the unit sphere of the normed space.
Examples
1. Every real Hilbert space is a Radon–Riesz space. Indeed, suppose that H is a real Hilbert space and that is a sequence in H converging weakly to a member of H. Using the two assumptions on the sequence and the fact that
and letting n tend to infinity, we see that
Thus H is a Radon–Riesz space.
2. Every uniformly convex Banach space is a Radon-Riesz space. See Sect |
https://en.wikipedia.org/wiki/Ultrawide%20formats | Ultrawide formats refers to photos, videos, and displays with aspect ratios greater than 2. There were multiple moves in history towards wider formats, including one by Disney, with some of them being more successful than others.
Cameras usually capture ultra-wide photos and videos using an anamorphic format lens, which shrinks the extended horizontal field-of-view (FOV) while saving on film or disk.
Historic displays
Before computer monitors became a separate product line, televisions were used as displays for computers such as Timex Sinclair 1000.
4:3
4:3 was the aspect ratio used by 35 mm silent films. By having televisions match this aspect ratio, movies originally filmed in 4:3 could be satisfactorily viewed on standard-definition television (SDTV).
Monitors around the turn of the century would often use resolutions like 640x480, 800x600, 1024x768 or 1200x900 in an 4:3 aspect ratio.
NTSC (480i)
National Television System Committee (NTSC) broadcasts were analogue and intended for analogue NTSC displays. The standard was developed and implemented by the NTSC in the United States in 1954. It also saw widespread international adoption by trade partners of the US. When converted to the Digital Video format, DV NTSC has a 3:2 aspect ratio, a resolution of 720x480i, and a refresh rate of 60 Hz.
PAL (576i)
Phase Alternating Line (PAL) broadcasts were analogue broadcasts meant for PAL analogue displays. The standard was developed in 1967 by the United Kingdom and Germany, and implemented in most countries. When converted to Digital Video format, DV PAL has a 5:4 resolution of 720×576i running at 50 Hz.
32:27
32:27 was originally developed for compressed video storage in cameras, meant to be displayed in anamorphic x1.5 as 16:9. 640×540i was such a 32:27 resolution running at 50 Hz and 100 Hz, meant for cameras.
Panasonic's DVCPRO HD with a resolution of 1280×1080i was latest in the line of 32:27 video formats for cameras. Hitachi's 42" and 50" 1280×1080i tel |
https://en.wikipedia.org/wiki/Google%20Moderator | Google Moderator was a Google service that used crowdsourcing to rank user-submitted questions, suggestions and ideas. It was launched on September 25, 2008 and shut down on June 30, 2015. The service allowed the management of feedback from a large number of people, who could vote for questions they thought should be posed from a pool of questions submitted by others or submit their own to be asked and voted on. The service aimed to ensure that every question was considered, let the audience see others' questions, and helped the moderator of a team or event address the questions that the audience most cared about. The service was nicknamed Dory internally by Google, a reference to "the fish who asked questions all the time in ''Finding Nemo".
Google Moderator was developed by Google engineers Dave S. Young, Taliver Heath, and Colby Ranger in their 20% time, led by project manager Katie Jacobs Stanton.
In December 2008, Google Moderator was used by the President-elect Barack Obama's transition team in a public series called "Open for Questions", in which they answered questions from the general public. The first series ran for less than 48 hours and attracted 1 million votes from 20,000 people on 10,000 questions. The second series ran for just over a week and attracted 4.7 million votes from 100,000 people on 76,000 questions. In January 2009, Obama appointed Stanton to the newly created position of Director of Citizen Participation.
Google Moderator was shut down on June 30, 2015 because the usage did not match Google's expectations. The site remained available as read-only until August 15, 2015, at which time it closed completely. Content will remain available for a minimum of two years via Google's Takeout tool. Since the shutdown, the term has been used to refer to Google Moderators, an advanced permission given to certain accounts to allow the user to monitor certain aspects of Google and take administrative action(s) when needed. |
https://en.wikipedia.org/wiki/Vacuum%20packing | Vacuum packing is a method of packaging that removes air from the package prior to sealing. This method involves placing items in a plastic film package, removing air from inside and sealing the package. Shrink film is sometimes used to have a tight fit to the contents. The intent of vacuum packing is usually to remove oxygen from the container to extend the shelf life of foods and, with flexible package forms, to reduce the volume of the contents and package.
Vacuum packing reduces atmospheric oxygen, limiting the growth of aerobic bacteria or fungi, and preventing the evaporation of volatile components. It is also commonly used to store dry foods over a long period of time, such as cereals, nuts, cured meats, cheese, smoked fish, coffee, and potato chips (crisps). On a more short-term basis, vacuum packing can also be used to store fresh foods, such as vegetables, meats, and liquids, because it inhibits bacterial growth.
Vacuum packing greatly reduces the bulk of non-food items. For example, clothing and bedding can be stored in bags evacuated with a domestic vacuum cleaner or a dedicated vacuum sealer. This technique is sometimes used to compact household waste, for example where a charge is made for each full bag collected.
Vacuum packaging products, using plastic bags, canisters, bottles, or mason jars, are available for home use.
For delicate food items that might be crushed by the vacuum packing process (such as potato chips), an alternative is to replace the interior gas with nitrogen. This has the same effect of inhibiting deterioration due to the removal of oxygen.
Type of Vacuum Sealers or Vacuum Packaging Machines
Edge, Suction, and External Vacuum Sealers
External vacuum sealers involve a bag being attached to the vacuum-sealing machine externally. The machine will remove the air and seal the bag, which is all done outside the machine. A heat sealer is often used to seal the pack. Typically these units use a dry piston vacuum pump which is often |
https://en.wikipedia.org/wiki/Relativistic%20angular%20momentum | In physics, relativistic angular momentum refers to the mathematical formalisms and physical concepts that define angular momentum in special relativity (SR) and general relativity (GR). The relativistic quantity is subtly different from the three-dimensional quantity in classical mechanics.
Angular momentum is an important dynamical quantity derived from position and momentum. It is a measure of an object's rotational motion and resistance to changes in its rotation. Also, in the same way momentum conservation corresponds to translational symmetry, angular momentum conservation corresponds to rotational symmetry – the connection between symmetries and conservation laws is made by Noether's theorem. While these concepts were originally discovered in classical mechanics, they are also true and significant in special and general relativity. In terms of abstract algebra, the invariance of angular momentum, four-momentum, and other symmetries in spacetime, are described by the Lorentz group, or more generally the Poincaré group.
Physical quantities that remain separate in classical physics are naturally combined in SR and GR by enforcing the postulates of relativity. Most notably, the space and time coordinates combine into the four-position, and energy and momentum combine into the four-momentum. The components of these four-vectors depend on the frame of reference used, and change under Lorentz transformations to other inertial frames or accelerated frames.
Relativistic angular momentum is less obvious. The classical definition of angular momentum is the cross product of position x with momentum p to obtain a pseudovector , or alternatively as the exterior product to obtain a second order antisymmetric tensor . What does this combine with, if anything? There is another vector quantity not often discussed – it is the time-varying moment of mass polar-vector (not the moment of inertia) related to the boost of the centre of mass of the system, and this combines with t |
https://en.wikipedia.org/wiki/Lawn | A lawn () is an area of soil-covered land planted with grasses and other durable plants such as clover which are maintained at a short height with a lawn mower (or sometimes grazing animals) and used for aesthetic and recreational purposes—it is also commonly referred to as part of a garden. Lawns are usually composed only of grass species, subject to weed and pest control, maintained in a green color (e.g., by watering), and are regularly mowed to ensure an acceptable length. Lawns are used around houses, apartments, commercial buildings and offices. Many city parks also have large lawn areas. In recreational contexts, the specialised names turf, pitch, field or green may be used, depending on the sport and the continent.
The term "lawn", referring to a managed grass space, dates to at least the 16th century. With suburban expansion, the lawn has become culturally ingrained in some areas of the world as part of the desired household aesthetic. However, awareness of the negative environmental impact of this ideal is growing. In some jurisdictions where there are water shortages, local government authorities are encouraging alternatives to lawns to reduce water use. Researchers in the United States have noted that suburban lawns are "biological deserts" that are contributing to a "continental-scale ecological homogenization." Lawn maintenance practices also cause biodiversity loss in surrounding areas.
Etymology
Lawn is a cognate of Welsh llan which is derived from the Common Brittonic word landa () that originally meant
heath, barren land, or clearing.
History
Origins
Lawns may have originated as grassed enclosures within early medieval settlements used for communal grazing of livestock, as distinct from fields reserved for agriculture. The word "laune" is first attested in 1540 from the Old French lande "heath, moor, barren land; clearing".
Lawns became popular with the aristocracy in northern Europe from the Middle Ages onward. In medieval Europe, open expan |
https://en.wikipedia.org/wiki/Museum%20informatics | Museum informatics is an interdisciplinary field of study that refers to the theory and application of informatics by museums. It represents a convergence of culture, digital technology, and information science. In the context of the digital age facilitating growing commonalities across museums, libraries and archives, its place in academe has grown substantially and also has connections with digital humanities.
In all ages, museums are responsible for obtaining, storing, and exhibiting objects of different kinds of objects from art, cultural heritage, natural history, science, to technological inventions. However, modern museums are not only repositories of objects; they are repositories of knowledge. They are more like an information service organization, store information and share knowledge.
After years of studies, the museum professionals and visitors have found their understanding of roles museums play largely changed by the introduction of new information technologies in museums. Today's visitors to museums expect instant access to a large amount of information about every object in the museum's collections.
As the needs and expectations change, the users of museum information resources are galvanizing museums to make appropriate changes. Besides, museum researchers and professionals have begun to explore the impact of information science and technology on the people who use museum resources.
Overview
Museum informatics is an emerging field of academic study focused on the intersection between information technologies, museums and their staff members, and online museum data and services. The more general cultural informatics deals with, for example, information design and interaction, digital curation, cultural heritage description and access, social media, and the application of digital tools. Museums have embraced the application of museum informatics, which has been supported by US federal grants and in particular, by the Institute of Museum and Librar |
https://en.wikipedia.org/wiki/Smoothened%20agonist | Smoothened agonist (SAG) was one of the first small-molecule agonists developed for the protein Smoothened, a key part of the hedgehog signaling pathway, which is involved in brain development as well as having a number of other functions in the body.
Smoothened agonist has been shown to aid proliferation and survival of developing neurons, and prevent drug-induced brain injury. When injected into the cerebellum of newborn mice with an induced Down syndrome-like condition, Smoothened agonist was able to stimulate normal cerebellum development, resulting in significant behavioural improvement once the mice had grown to adulthood.
Smoothened Agonist was capable of inducing androgen production in both prostate and bone stromal cells that was significantly greater than even similarly treated prostate cancer cells.
Some analogues of piperazines as a novel class of Smoothened agonists modulates Hedgehog signaling in the crypts of the small intestines by binding to Smoothened and thereby leading to intestinal stem cell compartment expansion, improved intestinal recovery, and survival of lethally irradiated animals. |
https://en.wikipedia.org/wiki/MSX | MSX is a standardized home computer architecture, announced by ASCII Corporation on June 16, 1983. It was initially conceived by Microsoft as a product for the Eastern sector, and jointly marketed by Kazuhiko Nishi, the director at ASCII Corporation. Microsoft and Nishi conceived the project as an attempt to create unified standards among various home computing system manufacturers of the period, in the same fashion as the VHS standard for home video tape machines. The first MSX computer sold to the public was a Mitsubishi ML-8000, released on October 21, 1983, thus marking its official release date.
MSX systems were popular in Japan and several other countries. There are differing accounts of MSX sales. One source claims 9 million MSX units were sold worldwide, including in Japan alone, whereas ASCII corporation founder Kazuhiko Nishi claims that 3 million were sold in Japan, and 1 million overseas. Despite Microsoft's involvement, few MSX-based machines were released in the United States.
The meaning of the acronym MSX remains a matter of debate. In 2001, Kazuhiko Nishi recalled that many assumed that it was derived from "Microsoft Extended", referring to the built-in Microsoft Extended BASIC (MSX BASIC). Others believed that it stood for "Matsushita-Sony". Nishi said that the team's original definition was "Machines with Software eXchangeability", although in 1985 he said it was named after the MX missile. According to his book in 2020, he considered the name of the new standard should consist of three letters, like VHS. He felt "MSX" was fit because it means "the next of Microsoft", and it also contains the first letters of Matsushita (Panasonic) and Sony.
Before the success of Nintendo's Family Computer, the MSX was the platform that major Japanese game studios such as Konami and Hudson Soft developed for. The Metal Gear series, for example, was first written for MSX hardware.
History
In the early 1980s, most home computers manufactured in Japan such as t |
https://en.wikipedia.org/wiki/Postmortem%20studies | Postmortem studies are a type of neurobiological research, which provides information to researchers and individuals who will have to make medical decisions in the future. Postmortem researchers conduct a longitudinal study of the brain of an individual, who has some sort of phenomenological condition (i.e. cannot speak, trouble moving left side of body, Alzheimer's, etc.) that is examined after death. Researchers look at certain lesions in the brain that could have an influence on cognitive or motor functions. These irregularities, damage, or other cerebral anomalies observed in the brain are attributed to an individual's pathophysiology and their environmental surroundings. Postmortem studies provide a unique opportunity for researchers to study different brain attributes that would be unable to be studied on a living person.
Postmortem studies allow researchers to determine causes and cure for certain diseases and functions. It is critical for researchers to develop hypotheses, in order to discover the characteristics that are meaningful to a particular disorder. The results that the researcher discovers from the study will help the researcher trace the location in the brain to specific behaviors.
When tissue from a postmortem study is obtained it is imperative that the researcher ensures the quality is adequate to study. This is specifically important when an individual is researching gene expression (i.e. DNA, RNA, and proteins). Some key ways researchers monitor the quality are by determining the pain level/time of death of the individual, pH of the tissue, refrigeration time and temperature of storage, time until the brain tissue is frozen, and the thawing conditions. As well as finding out specific information about the individual's life such as: age, sex, legal/illegal substance use, and a treatment analysis of the individual.
Background
Postmortem studies have been used to further the understanding of the brain for centuries. Before the time of the MRI, |
https://en.wikipedia.org/wiki/Computational%20steering | Computational steering is the practice of manually intervening with an otherwise autonomous computational process, to change its outcome. The term is commonly used within the numerical simulation community, where it more specifically refers to the practice of interactively guiding a computational experiment into some region of interest.
Examples
A simple, but contrived, example of computational steering is:
In a simulated chess match with two automated players: manually forcing a certain move at a particular time for one player, to change the evolution of the game.
Some real examples of computational steering are:
In a population dynamics simulation: changing selection pressures exerted between hosts and parasites, to examine the effect on their coevolution.
In a fluid dynamics simulation: resetting the phase state of an immiscible fluid, to speed the search for its critical separation temperature.
System design
Computational steering systems are a manner of feedback control system, where some or all of the feedback is provided interactively by the operator.
All computational steering mechanisms have three fundamental components:
A target system that is being studied
A representation of the target system, typically a graphical visualization, that can be perceived by the investigator
A set of controls that the investigator can use to provide feedback that modifies the state, behavior, or product of the system being studied
Disambiguation
There appears to be a distinction that the term computational steering is used only when referring to interaction with simulated systems, not operational ones. Further clarification on this point is needed. For example: Vetter (who is apparently well acquainted with the computational steering field
) refers to the following practice as interactive steering.
In a grid computing framework: adjusting the cache size of a computational process, to examine the effect on its performance.
Computational steering softwa |
https://en.wikipedia.org/wiki/EnvZ/OmpR%20two-component%20system | EnvZ/OmpR is a two-component regulatory system widely distributed in bacteria and particularly well characterized in Escherichia coli. Its function is in osmoregulation, responding to changes in environmental osmolality by regulating the expression of the outer membrane porins OmpF and OmpC. EnvZ is a histidine kinase which also possesses a cytoplasmic osmosensory domain, and OmpR is its corresponding response regulator protein.
Overview
EnvZ is a sensor-transmitter that spans the inner cytoplasmic membrane and has historically been divided into two domains, the sensory and the transmitter domain. The protein is composed of a short N-terminal tail in the periplasm, two transmembrane regions with an intervening periplasmic loop, and a cytoplasmic domain containing the autophosphorylated histidine residue, which is located in a dimeric four-helix bundle. Variations in osmolality trigger conformational changes in EnvZ which have been localized to the cytoplasmic four-helix bundle and which effects phosphoryl transfer to OmpR. Upon phosphorylation, OmpR becomes an active dimer that exhibits enhanced DNA-binding ability specific for both the ompC and ompF genes. The signaling cascade can be elucidated as follows:
Activation of the inner membrane sensor histidine kinase EnvZ,
Autophosphorylation of EnvZ at His243,
Phosphate transfer to OmpR at Asp 55,
Binding of OmpR-P to upstream sites on the ompF and ompC porin promoters to differentially modulate their transcription.
Dephosphorylation of OmpR-P via the phosphatase function of EnvZ.
It is important to note that ompF and ompC are expressed at all times at constant levels; however, the individual porins OmpF and OmpC are present in various relative abundances based on medium osmolarity. Also, the amount of OmpF and OmpC are each controlled by a variety of mechanisms; for example, synthesis of OmpF is also repressed by high temperature. Likewise, the EnvZ-OmpR pair is involved in tripeptide permease system that is comple |
https://en.wikipedia.org/wiki/Subhash%20Kak | Subhash Kak is an Indian-American computer scientist and historical revisionist. He is the Regents Professor of Computer Science Department at Oklahoma State University–Stillwater, an honorary visiting professor of engineering at Jawaharlal Nehru University, and a member of the Indian Prime Minister's Science, Technology and Innovation Advisory Council (PM-STIAC).
Kak has published on the history of science, the philosophy of science, ancient astronomy, and the history of mathematics. Kak has also published on archaeoastronomy, and advocated the idea of Indigenous Aryans. Many scholars have rejected his theories on these topics in entirety, and his writings have been heavily criticized.
In 2019, the Government of India awarded him the Padma Shri, the fourth highest civilian award in India, for his contributions on the history of mathematics, science, ancient astronomy and philosophy of science.
Early life and education
Kak was born to Ram Nath Kak, a government veterinary doctor and Sarojini Kak in Srinagar, India. His brother is the computer scientist Avinash Kak and his sister is the literary theorist Jaishree Odin.
Kak received a Bachelor of Engineering degree from the Regional Engineering College, Srinagar (now the National Institute of Technology, Srinagar) and a Ph.D. from the Indian Institute of Technology Delhi in 1970.
Academic career
During 1975–1976, Kak was a visiting faculty at Imperial College, London, and a guest researcher at Bell Laboratories, Murray Hill. In 1977, he was a visiting researcher at the Tata Institute of Fundamental Research, Bombay. In 1979, he joined Louisiana State University, Baton Rouge, where he was appointed the Donald C. and Elaine T. Delaune Distinguished Professor of Electrical and Computer Engineering. In 2007, he joined the Computer Science department at Oklahoma State University–Stillwater.
Kak proposed an efficient three-layer feed-forward neural network architecture and developed four corner classification algorith |
https://en.wikipedia.org/wiki/Human%20brain | The human brain is the central organ of the human nervous system, and with the spinal cord makes up the central nervous system. The brain consists of the cerebrum, the brainstem and the cerebellum. It controls most of the activities of the body, processing, integrating, and coordinating the information it receives from the sense organs, and making decisions as to the instructions sent to the rest of the body. The brain is contained in, and protected by, the skull bones of the head.
The cerebrum, the largest part of the human brain, consists of two cerebral hemispheres. Each hemisphere has an inner core composed of white matter, and an outer surface – the cerebral cortex – composed of grey matter. The cortex has an outer layer, the neocortex, and an inner allocortex. The neocortex is made up of six neuronal layers, while the allocortex has three or four. Each hemisphere is conventionally divided into four lobes – the frontal, temporal, parietal, and occipital lobes. The frontal lobe is associated with executive functions including self-control, planning, reasoning, and abstract thought, while the occipital lobe is dedicated to vision. Within each lobe, cortical areas are associated with specific functions, such as the sensory, motor and association regions. Although the left and right hemispheres are broadly similar in shape and function, some functions are associated with one side, such as language in the left and visual-spatial ability in the right. The hemispheres are connected by commissural nerve tracts, the largest being the corpus callosum.
The cerebrum is connected by the brainstem to the spinal cord. The brainstem consists of the midbrain, the pons, and the medulla oblongata. The cerebellum is connected to the brainstem by three pairs of nerve tracts called cerebellar peduncles. Within the cerebrum is the ventricular system, consisting of four interconnected ventricles in which cerebrospinal fluid is produced and circulated. Underneath the cerebral cortex |
https://en.wikipedia.org/wiki/Joel%20Emer | Joel S. Emer (born March 2, 1954) is a pioneer in computer performance analysis techniques and a microprocessor architect. He is currently a researcher at Nvidia, and a Professor of the Practice at MIT,
and was formerly an Intel Fellow. He was the 2009 recipient of the Eckert–Mauchly Award, an ACM/IEEE joint award for contributions to computer and digital systems architecture.
Emer received his Ph.D. degree from the University of Illinois, Urbana-Champaign under the supervision of Prof. Edward S. Davidson. His first job immediately after graduation was at Digital Equipment Corporation where he initially worked on VAX performance evaluation and then on Alpha performance evaluation. As a consequence of his performance evaluation work, he became a pioneer in the quantitative approach to computer architecture. In conjunction with the development and application of various performance analysis techniques, he contributed a variety of research and advanced development ideas that were incorporated into various VAX and Alpha designs.
He is well known, along with his co-author Douglas W. Clark, for a seminal paper on the quantitative analysis of processor architectures, which was published in the 11th International Symposium on Computer Architecture. That paper also contained the result that the VAX-11/780's performance was actually 0.5 MIPS instead of 1 MIPS as was previously claimed by DEC. That result helped popularize what Clark called the iron law of processor performance that related cycles per instruction (CPI), frequency and number of instructions to computer performance.
Emer has also contributed to simultaneous multithreading (SMT), memory dependence prediction via store sets, and soft error analysis, and led the development of the Asim simulator.
In 2020, Emer was elected as a member into the National Academy of Engineering for quantitative analysis of computer architecture and its application to architectural innovation in commercial microprocessors. |
https://en.wikipedia.org/wiki/Physiology%20of%20dinosaurs | The physiology of dinosaurs has historically been a controversial subject, particularly their thermoregulation. Recently, many new lines of evidence have been brought to bear on dinosaur physiology generally, including not only metabolic systems and thermoregulation, but on respiratory and cardiovascular systems as well.
During the early years of dinosaur paleontology, it was widely considered that they were sluggish, cumbersome, and sprawling cold-blooded lizards. However, with the discovery of much more complete skeletons in western United States, starting in the 1870s, scientists could make more informed interpretations of dinosaur biology and physiology. Edward Drinker Cope, opponent of Othniel Charles Marsh in the Bone Wars, propounded at least some dinosaurs as active and agile, as seen in the painting of two fighting Laelaps produced under his direction by Charles R. Knight.
In parallel, the development of Darwinian evolution, and the discoveries of Archaeopteryx and Compsognathus, led Thomas Henry Huxley to propose that dinosaurs were closely related to birds. Despite these considerations, the image of dinosaurs as large reptiles had already taken root, and most aspects of their paleobiology were interpreted as being typically reptilian for the first half of the twentieth century. Beginning in the 1960s and with the advent of the Dinosaur Renaissance, views of dinosaurs and their physiology have changed dramatically, including the discovery of feathered dinosaurs in Early Cretaceous age deposits in China, indicating that birds evolved from highly agile maniraptoran dinosaurs.
History
Early interpretations
The study of dinosaurs began in the 1820s in England. Pioneers in the field, such as William Buckland, Gideon Mantell, and Richard Owen, interpreted the first, very fragmentary remains as belonging to large quadrupedal beasts. Their early work can be seen today in the Crystal Palace Dinosaurs, constructed in the 1850s, which present known dinosaurs a |
https://en.wikipedia.org/wiki/Reference%20circuit | A reference circuit is a hypothetical electric circuit of specified equivalent length and configuration, and having a defined transmission characteristic or characteristics, used primarily as a reference for measuring the performance of other, i.e., real, circuits or as a guide for planning and engineering of circuits and networks.
Normally, several types of reference circuits are defined, with different configurations, because communications are required over a wide range of distances. Another type of reference circuit shows how to configure integrated circuits into function blocks, which Analog Devices provides for electrical design engineers. Analog Devices' Circuits from the Lab reference circuits are fully tested and come with the schematics, evaluation boards, and device drivers necessary for system integration. A group of related reference circuits is also called a reference system. |
https://en.wikipedia.org/wiki/Nonnegative%20matrix | In mathematics, a nonnegative matrix, written
is a matrix in which all the elements are equal to or greater than zero, that is,
A positive matrix is a matrix in which all the elements are strictly greater than zero. The set of positive matrices is a subset of all non-negative matrices. While such matrices are commonly found, the term is only occasionally used due to the possible confusion with positive-definite matrices, which are different. A matrix which is both non-negative and is positive semidefinite is called a doubly non-negative matrix.
A rectangular non-negative matrix can be approximated by a decomposition with two other non-negative matrices via non-negative matrix factorization.
Eigenvalues and eigenvectors of square positive matrices are described by the Perron–Frobenius theorem.
Properties
The trace and every row and column sum/product of a nonnegative matrix is nonnegative.
Inversion
The inverse of any non-singular M-matrix is a non-negative matrix. If the non-singular M-matrix is also symmetric then it is called a Stieltjes matrix.
The inverse of a non-negative matrix is usually not non-negative. The exception is the non-negative monomial matrices: a non-negative matrix has non-negative inverse if and only if it is a (non-negative) monomial matrix. Note that thus the inverse of a positive matrix is not positive or even non-negative, as positive matrices are not monomial, for dimension .
Specializations
There are a number of groups of matrices that form specializations of non-negative matrices, e.g. stochastic matrix; doubly stochastic matrix; symmetric non-negative matrix.
See also
Metzler matrix
Bibliography
Abraham Berman, Robert J. Plemmons, Nonnegative Matrices in the Mathematical Sciences, 1994, SIAM. .
A. Berman and R. J. Plemmons, Nonnegative Matrices in the Mathematical Sciences, Academic Press, 1979 (chapter 2),
R.A. Horn and C.R. Johnson, Matrix Analysis, Cambridge University Press, 1990 (chapter 8).
Henryk Minc, N |
https://en.wikipedia.org/wiki/Duplex%20perception | Duplex perception refers to the linguistic phenomenon whereby "part of the acoustic signal is used for both a speech and a nonspeech percept." A listener is presented with two simultaneous, dichotic stimuli. One ear receives an isolated third-formant transition that sounds like a nonspeech chirp. At the same time the other ear receives a base syllable. This base syllable consists of the first two formants, complete with formant transitions, and the third formant without a transition. Normally, there would be peripheral masking in such a binaural listening task but this does not occur. Instead, the listener's percept is duplex, that is, the completed syllable is perceived and the nonspeech chirp is heard at the same time. This is interpreted as being due to the existence of a special speech module.
The phenomenon was discovered in 1974 by Timothy C. Rand at the Haskins Laboratories associated with Yale University.
Duplex perception was argued as evidence for the existence of distinct systems for general auditory perception and speech perception. It is also notable that this same phenomenon can be obtained with slamming doors.
See also
McGurk effect |
https://en.wikipedia.org/wiki/Maxillary%20nerve | In neuroanatomy, the maxillary nerve (V) is one of the three branches or divisions of the trigeminal nerve, the fifth (CN V) cranial nerve. It comprises the principal functions of sensation from the maxilla, nasal cavity, sinuses, the palate and subsequently that of the mid-face, and is intermediate, both in position and size, between the ophthalmic nerve and the mandibular nerve.
Structure
It begins at the middle of the trigeminal ganglion as a flattened plexiform band then it passes through the lateral wall of the cavernous sinus. It leaves the skull through the foramen rotundum, where it becomes more cylindrical in form, and firmer in texture. After leaving foramen rotundum it gives two branches to the pterygopalatine ganglion. It then crosses the pterygopalatine fossa, inclines lateralward on the back of the maxilla, and enters the orbit through the inferior orbital fissure. It then runs forward on the floor of the orbit, at first in the infraorbital groove and then in the infraorbital canal remaining outside the periosteum of the orbit. It then emerges on the face through the infraorbital foramen and terminates by dividing into inferior palpebral, lateral nasal and superior labial branches. The nerve is accompanied by the infraorbital branch of (the third part of) the maxillary artery and the accompanying vein.
Branches
Its branches may be divided into four groups, depending upon where they branch off: in the cranium, in the pterygopalatine fossa, in the infraorbital canal, or on the face.
In the cranium
Middle meningeal nerve in the meninges
From the pterygopalatine fossa
Zygomatic nerve (zygomaticotemporal nerve, zygomaticofacial nerve), through the Inferior orbital fissure
Nasopalatine nerve, through the sphenopalatine foramen
Posterior superior alveolar nerve
Greater and lesser palatine nerves
Pharyngeal nerve
In the infraorbital canal
Middle superior alveolar nerve
Anterior superior alveolar nerve
Infraorbital nerve
On the face
Inferior pa |
https://en.wikipedia.org/wiki/Reactive%20planning | In artificial intelligence, reactive planning denotes a group of techniques for action selection by autonomous agents. These techniques differ from classical planning in two aspects. First, they operate in a timely fashion and hence can cope with highly dynamic and unpredictable environments. Second, they compute just one next action in every instant, based on the current context. Reactive planners often (but not always) exploit reactive plans, which are stored structures describing the agent's priorities and behaviour. The term reactive planning goes back to at least 1988, and is synonymous with the more modern term dynamic planning.
Reactive plan representation
There are several ways to represent a reactive plan. All require a basic representational unit and a means to compose these units into plans.
Condition-action rules (productions)
A condition action rule, or if-then rule, is a rule in the form: if condition then action. These rules are called productions. The meaning of the rule is as follows: if the condition holds, perform the action. The action can be either external (e.g., pick something up and move it), or internal (e.g., write a fact into the internal memory, or evaluate a new set of rules). Conditions are normally boolean and the action either can be performed, or not.
Production rules may be organized in relatively flat structures, but more often are organized into a hierarchy of some kind. For example, subsumption architecture consists of layers of interconnected behaviors, each actually a finite state machine which acts in response to an appropriate input. These layers are then organized into a simple stack, with higher layers subsuming the goals of the lower ones. Other systems may use trees, or may include special mechanisms for changing which goal / rule subset is currently most important. Flat structures are relatively easy to build, but allow only for description of simple behavior, or require immensely complicated conditions to |
https://en.wikipedia.org/wiki/Cloudant | Cloudant is an IBM software product, which is primarily delivered as a cloud-based service. Cloudant is a non-relational, distributed database service of the same name. Cloudant is based on the Apache-backed CouchDB project and the open source BigCouch project.
Cloudant's service provides integrated data management, search, and analytics engine designed for web applications. Cloudant scales databases on the CouchDB framework and provides hosting, administrative tools, analytics and commercial support for CouchDB and BigCouch. Cloudant's distributed CouchDB service is used the same way as standalone CouchDB, with the added advantage of data being redundantly distributed over multiple machines.
Cloudant was acquired by IBM from the start-up company of the same name. The acquisition was announced on February 24, 2014, The acquisition was completed on March 4 of that year.
By March 31, 2018, Cloudant Shared Plan will be retired and migrated to IBM Cloud.
History
Cloudant was founded by Alan Hoffman, Adam Kocoloski, and Michael Miller. The three met in the physics department at MIT where they worked with large data sets from experiments such as the Large Hadron Collider and the Relativistic Heavy Ion Collider. In early 2008 their ideas for fixing the "big data problem" caught the attention of Silicon Valley-based Y Combinator, which resulted in $20,000 seed funding. The company also received an early seed round of $1 million from Avalon Ventures in August 2010.
Cloudant was designed for cloud computing, automatically distributing data across multiple servers in addition to scaling the database to accommodate web applications.
In August 2010, Cloudant released free BigCouch under an Apache License(2.0). Cloudant offered services including support, consulting services and training.
Cloudant delivered their first product in the third quarter of 2010. Cloudant has over 2500 customers for its hosted service as of January 2011.
In November 2010, Cloudant was recognize |
https://en.wikipedia.org/wiki/Royal%20Institute%20of%20Public%20Health | Royal Institute of Public Health merged in 2008 with the Royal Society for Health to form Royal Society for Public Health (RSPH).
History
The institute was the amalgamation of a few societies. The Metropolitan Association of Medical Officers of Health was an English society of metropolitan Medical Officer for Health established on 3 April 1856. In 1869 "Metropolitan" was dropped from the title, and in 1873 it became the Society of Medical Officers of Health, and in 1989 it became the Society of Public Health.
Timeline
Presidents
Past presidents include:
John Simon, first president
Lawson Soulsby, Baron Soulsby of Swaffham Prior
Nora Wattie
Publications
Public Health (journal), now owned by Royal Society for Public Health.
Previous publications
Journal of State Medicine
Health & Hygiene |
https://en.wikipedia.org/wiki/Wholesome%20Meat%20Act | The Wholesome Meat Act (also called "Equal To" law) is a United States federal law passed by the 90th United States Congressional session and enacted into law by United States President Lyndon B. Johnson on December 15, 1967, amending the Federal Meat Inspection Act of 1906 which established a statute for federal meat inspection programs. It requires that states have inspection programs "equal to" that of the federal government which are administered by the Food Safety and Inspection Service (FSIS) of the United States Department of Agriculture (USDA).
See also
Humane Slaughter Act |
https://en.wikipedia.org/wiki/Online%20Centres%20Network | The Online Centres Network is a UK-based network which helps communities tackle social and digital exclusion.
Good Things Foundation coordinates the Online Centres Network of 5,000 community partners, who provide free or low-cost access to computers and the internet. The organisation also provide training and support to hundreds of volunteers, centre staff and community leaders, helping them to work within their own communities.
Over 2 million people have been helped to improve their skills through the Online Centres Network to date, with many learners also going on to further learning and increased employment opportunities.
In 2011 the management of the Online Centres Network (then known as UK online centres) was taken over by Good Things Foundation (formerly known as Tinder Foundation), a staff-owned mutual and social enterprise formed by the Sheffield-based team previously managing the UK online centres contract on behalf of Ufi Ltd. In July 2013, Online Centres Foundation became known as Tinder Foundation. Tinder Foundation officially received charity status in early 2016. In November 2016 Tinder Foundation rebranded as Good Things Foundation.
Good Things Foundation Chief Executive, Helen Milner, was inducted into the BIMA Digital Hall of Fame in 2012 alongside Sir Tim Berners Lee, Stephen Fry, and others noted for their work in the digital arena.
Online learning
In April 2011, Good Things Foundation (then known as Online Centres Foundation) launched a brand new learning platform Go ON, which was renamed Learn My Way in 2012 (http://www.learnmyway.com/). The website was developed by Good Things Foundation with the aim of bringing together all of the resources on the market for internet beginners, including those developed specifically by Good Things Foundation, and from other providers including the BBC and Digital Unite.
The new website contains four main sections:
Get ready, to tackle those basic literacy and numeracy skills before tackling any online |
https://en.wikipedia.org/wiki/William%20Skinner%20Cooper | William Skinner Cooper (25 August 1884 – 8 October 1978) was an American ecologist. Cooper received his B.S. in 1906 from Alma College in Michigan. In 1909, he entered graduate school at the University of Chicago, where he studied with Henry Chandler Cowles, and completed his Ph.D. in 1911. His first major publication, "The Climax Forest of Isle Royale, Lake Superior, and Its Development" appeared in 1913.
Cooper served briefly in 1914-1915 as a lecturer in plant ecology at Stanford University before beginning his long career in the botany department at the University of Minnesota, where he taught from 1915 to 1951. Among his students at Minnesota were Henry J. Oosting, Murray Fife Buell, Rexford F. Daubenmire, Frank Edwin Egler and Arnold M. Schultz; the latter went on to teach "Ecosystemology" at U.C. Berkeley, and received U.C. Berkeley's "Distinguished Teaching Award" in 1992. Cooper was the president of the Ecological Society of America in 1936 and the president of the Minnesota Academy of Science in 1937. Other professional accolades included receipt of the Botanical Society of America's Merit Award in 1956 and the Eminent Ecologist Award from the Ecological Society of America in 1963.
Cooper's travels in Glacier Bay, Alaska, compelled him to lead scientists in nominating it as a national park or monument. He also established the oldest permanent plot network in post-glacial areas in the world in 1916 in the Glacier Bay basin, now maintained by Brian Buma at the University of Colorado. At the Ecological Society of America's 1922 meeting, Cooper headed a committee that drafted a resolution adopted by the organization and sent to President Calvin Coolidge asking him to name the bay a monument. His 1935 monograph on the late glacial and postglacial environment of the Glacier Bay Basin is considered a classic. Mount Cooper in Glacier Bay is named in his honor.
The Ecological Society of America recognizes Cooper's work in the discipline by bestowing its a |
https://en.wikipedia.org/wiki/Paleoethnobotany%20of%20the%20Mapuche | The paleoethnobotany of the Mapuche focuses on archaeological evidence supporting plant use by past and present Mapuche populations collected from multiple sites in southern Chile and the Patagonia region of Argentina. Paleoethnobotany is the study of fossil and material remains from plants, mostly seeds and residues that can be analyzed from material remains. Data can be collected from archaeological sites with a particular interest in learning about the history of agriculture in a region or the use of plants for either subsistence or medicinal use. The Mapuche are an indigenous culture native to South America. The archaeological record has revealed that the Mapuche were present in modern-day south-central Chile and southwestern Argentina from at least 500-600 BC. It is also noteworthy, that while collectively the Mapuche (Picunche, Huilliche and Moluche or Nguluche) use this endonym, there are often subsets of the culture that have more specific names based on geographic location as well as different ecological niches (See Mapuche: Etymology).
Regional sites in South America
Central and Southern Chile
Cerro del Inga
The Promaucaes, a Mapuche group, were the last group of indigenous peoples to occupy this site in modern-day Chile in the Cachapoal Valley. Archeobotanical analysis was conducted at these sites in relation to pre-Hispanic cultures dominated by the Incan civilization. This site serves as a point of resistance to both Incan occupation as well as Spanish colonization. Analysis of seeds and macromaterials from soil reveal the following plants were present at this site. Culitivated plants included: Maize (Zea mays), Madi (Madia chilensis), Quinoa (Chenopodium quinua), Sunflower (Helianthus sp. cf. tuberosum), Gourd (Lagenaria sp.). Fruiting bushes and trees included: Guillave (Echinopsis chilensis) Michay (Berberis sp.), Boldo (Peumus boldus), Quilo (Muehlenbeckia hastulata) Grape (Vitis sp.), Blackberry (Rubus sp.), Cocito, Palm Nut (Jubaea chilensi |
https://en.wikipedia.org/wiki/Pressure%20drop | Pressure drop (often abbreviated as "dP" or "ΔP") is defined as the difference in total pressure between two points of a fluid carrying network. A pressure drop occurs when frictional forces, caused by the resistance to flow, act on a fluid as it flows through a conduit (such as a channel, pipe, or tube). This friction converts some of the fluid’s hydraulic energy to thermal energy (i.e., internal energy). Since the thermal energy cannot be converted back to hydraulic energy, the fluid experiences a drop in pressure, as is required by conservation of energy.
The main determinants of resistance to fluid flow are fluid velocity through the pipe and fluid viscosity. Pressure drop increases proportionally to the frictional shear forces within the piping network. A piping network containing a high relative roughness rating as well as many pipe fittings and joints, tube convergence, divergence, turns, surface roughness, and other physical properties will affect the pressure drop. High flow velocities or high fluid viscosities result in a larger pressure drop across a pipe section, valve, or elbow joint. Low velocity will result in less (or no) pressure drop. The fluid may also be biphasic as in pneumatic conveying with a gas and a solid; in this case, the friction of the solid must also be taken into consideration for calculating the pressure drop.
Applications
Fluid in a system will always flow from a region of higher pressure to a region of lower pressure, assuming it has a path to do so. All things being equal, a higher pressure drop will lead to a higher flow (except in cases of choked flow).
The pressure drop of a given system will determine the amount of energy needed to convey fluid through that system. For example, a larger pump could be required to move a set amount of water through smaller-diameter pipes (with higher velocity and thus higher pressure drop) as compared to a system with larger-diameter pipes (with lower velocity and thus lower pressure drop).
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