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https://en.wikipedia.org/wiki/Mammalian%20Genome | Mammalian Genome is a peer-reviewed journal that publishes research and review articles in the fields of genetics and genomics in mouse, human and related organisms. As of July 2009 its editors-in-chief are Joseph H. Nadeau and Stephen D. M. Brown. Mammalian Genome has been published by Springer since the journal was launched in 1991, and is the official journal of the International Mammalian Genome Society. In 1998 the journal Mouse Genome was merged into Mammalian Genome. Authors are allowed to self-archive, and can pay extra for open access for an article. |
https://en.wikipedia.org/wiki/Pairwise%20summation | In numerical analysis, pairwise summation, also called cascade summation, is a technique to sum a sequence of finite-precision floating-point numbers that substantially reduces the accumulated round-off error compared to naively accumulating the sum in sequence. Although there are other techniques such as Kahan summation that typically have even smaller round-off errors, pairwise summation is nearly as good (differing only by a logarithmic factor) while having much lower computational cost—it can be implemented so as to have nearly the same cost (and exactly the same number of arithmetic operations) as naive summation.
In particular, pairwise summation of a sequence of n numbers xn works by recursively breaking the sequence into two halves, summing each half, and adding the two sums: a divide and conquer algorithm. Its worst-case roundoff errors grow asymptotically as at most O(ε log n), where ε is the machine precision (assuming a fixed condition number, as discussed below). In comparison, the naive technique of accumulating the sum in sequence (adding each xi one at a time for i = 1, ..., n) has roundoff errors that grow at worst as O(εn). Kahan summation has a worst-case error of roughly O(ε), independent of n, but requires several times more arithmetic operations. If the roundoff errors are random, and in particular have random signs, then they form a random walk and the error growth is reduced to an average of for pairwise summation.
A very similar recursive structure of summation is found in many fast Fourier transform (FFT) algorithms, and is responsible for the same slow roundoff accumulation of those FFTs.
The algorithm
In pseudocode, the pairwise summation algorithm for an array of length ≥ 0 can be written:
s = pairwise(x[1…n])
if n ≤ N base case: naive summation for a sufficiently small array
s = 0
for i = 1 to n
s = s + x[i]
else divide and conquer: recursively sum two halves |
https://en.wikipedia.org/wiki/Two-graph | In mathematics, a two-graph is a set of (unordered) triples chosen from a finite vertex set X, such that every (unordered) quadruple from X contains an even number of triples of the two-graph. A regular two-graph has the property that every pair of vertices lies in the same number of triples of the two-graph. Two-graphs have been studied because of their connection with equiangular lines and, for regular two-graphs, strongly regular graphs, and also finite groups because many regular two-graphs have interesting automorphism groups.
A two-graph is not a graph and should not be confused with other objects called 2-graphs in graph theory, such as 2-regular graphs.
Examples
On the set of vertices {1,...,6} the following collection of unordered triples is a two-graph:
123 124 135 146 156 236 245 256 345 346
This two-graph is a regular two-graph since each pair of distinct vertices appears together in exactly two triples.
Given a simple graph G = (V,E), the set of triples of the vertex set V whose induced subgraph has an odd number of edges forms a two-graph on the set V. Every two-graph can be represented in this way. This example is referred to as the standard construction of a two-graph from a simple graph.
As a more complex example, let T be a tree with edge set E. The set of all triples of E that are not contained in a path of T form a two-graph on the set E.
Switching and graphs
A two-graph is equivalent to a switching class of graphs and also to a (signed) switching class of signed complete graphs.
Switching a set of vertices in a (simple) graph means reversing the adjacencies of each pair of vertices, one in the set and the other not in the set: thus the edge set is changed so that an adjacent pair becomes nonadjacent and a nonadjacent pair becomes adjacent. The edges whose endpoints are both in the set, or both not in the set, are not changed. Graphs are switching equivalent if one can be obtained from the other by switching. An equivalence c |
https://en.wikipedia.org/wiki/Chern%E2%80%93Weil%20homomorphism | In mathematics, the Chern–Weil homomorphism is a basic construction in Chern–Weil theory that computes topological invariants of vector bundles and principal bundles on a smooth manifold M in terms of connections and curvature representing classes in the de Rham cohomology rings of M. That is, the theory forms a bridge between the areas of algebraic topology and differential geometry. It was developed in the late 1940s by Shiing-Shen Chern and André Weil, in the wake of proofs of the generalized Gauss–Bonnet theorem. This theory was an important step in the theory of characteristic classes.
Let G be a real or complex Lie group with Lie algebra and let denote the algebra of -valued polynomials on (exactly the same argument works if we used instead of Let be the subalgebra of fixed points in under the adjoint action of G; that is, the subalgebra consisting of all polynomials f such that , for all g in G and x in ,
Given a principal G-bundle P on M, there is an associated homomorphism of -algebras,
,
called the Chern–Weil homomorphism, where on the right cohomology is de Rham cohomology. This homomorphism is obtained by taking invariant polynomials in the curvature of any connection on the given bundle. If G is either compact or semi-simple, then the cohomology ring of the classifying space for G-bundles, , is isomorphic to the algebra of invariant polynomials:
(The cohomology ring of BG can still be given in the de Rham sense:
when and are manifolds.)
Definition of the homomorphism
Choose any connection form ω in P, and let Ω be the associated curvature form; i.e., the exterior covariant derivative of ω. If is a homogeneous polynomial function of degree k; i.e., for any complex number a and x in then, viewing f as a symmetric multilinear functional on (see the ring of polynomial functions), let
be the (scalar-valued) 2k-form on P given by
where vi are tangent vectors to P, is the sign of the permutation in the symmetric group on 2k numbers |
https://en.wikipedia.org/wiki/Pure%204D%20N%20%3D%201%20supergravity | In supersymmetry, pure 4D supergravity describes the simplest four-dimensional supergravity, with a single supercharge and a supermultiplet containing a graviton and gravitino. The action consists of the Einstein–Hilbert action and the Rarita–Schwinger action. The theory was first formulated by Daniel Z. Freedman, Peter van Nieuwenhuizen, and Sergio Ferrara and independently by Stanley Deser and Bruno Zumino in 1976. The only consistent extension to spacetimes with a cosmological constant is to anti-de Sitter space, first formulated by Paul Townsend in 1977.
Flat spacetime
To describe the coupling between gravity and particles of arbitrary spin, it is useful to use the vielbein formalism of general relativity. This replaces the metric by a set of vector fields indexed by flat indices such that
In a sense the vielbeins are the square root of the metric. This introduces a new local Lorentz symmetry on the vielbeins , together with the usual diffeomorphism invariance associated with the spacetime indices . This has an associated connection known as the spin connection defined through , a generalization of the Christoffel connection that works for arbitrary spin fields. For example, for spinors the covariant derivative is given by
where , and . The spin connection has an explicit expression in terms of the vielbein and an additional torsion tensor which can arise when there is matter present in the theory. A vanishing torsion is equivalent to the Levi-Civita connection.
The pure supergravity action in four dimensions is the combination of the Einstein–Hilbert action and the Rarita–Schwinger action
Here is the Planck mass, , and is the Majorana gravitino with its spinor index left implicit. Treating this action within the first-order formalism where both the vielbein and spin connection are independent fields allows one to solve for the spin connections equation of motion, showing that it has the torsion . The second-order formalism action is then acquired |
https://en.wikipedia.org/wiki/InterBase | InterBase is a relational database management system (RDBMS) currently developed and marketed by Embarcadero Technologies. InterBase is distinguished from other RDBMSs by its small footprint, close to zero administration requirements, and multi-generational architecture. InterBase runs on the Microsoft Windows, macOS, Linux, Solaris operating systems as well as iOS and Android.
Technology
InterBase is a SQL-92-compliant relational database and supports standard interfaces such as JDBC, ODBC, and ADO.NET.
Small footprint
A full InterBase server installation requires around 40 MB on disk. A minimum InterBase client install requires about 400 KB of disk space.
Embedded or server
InterBase can be run as an embedded database or regular server.
Data controller friendly inbuilt encryption
Since InterBase XE, InterBase includes 256-bit AES-strength encryption that offers full database, table or column data encryption. This assists data controllers conform with data protection laws around at-rest data by separating encryption and access to the database, ensuring the database file is encrypted wherever it resides. The separation of the encryption also enables developers to just develop the application rather than worry about the data visible from a specific user login.
Multi-generational architecture
Concurrency control
To avoid blocking during updates, Interbase uses multiversion concurrency control instead of locks. Each transaction will create a version of the record. Upon the write step, the update will fail rather than be blocked initially.
Rollbacks and recovery
InterBase also uses multi-generational records to implement rollbacks rather than transaction logs.
Drawbacks
Certain operations are more difficult to implement in a multi-generational architecture, and hence perform slowly relative to a more traditional implementation. One example is the SQL COUNT verb. Even when an index is available on the column or columns included in the COUNT, all records must be |
https://en.wikipedia.org/wiki/List%20of%20Microsoft%20software | Microsoft is a developer of personal computer software. It is best known for its Windows operating system, the Internet Explorer and subsequent Microsoft Edge web browsers, the Microsoft Office family of productivity software plus services, and the Visual Studio IDE. The company also publishes books (through Microsoft Press) and video games (through Xbox Game Studios), and produces its own line of hardware. The following is a list of the notable Microsoft software Applications.
Software development
Azure DevOps
Azure DevOps Server (formerly Team Foundation Server and Visual Studio Team System)
Azure DevOps Services (formerly Visual Studio Team Services, Visual Studio Online and Team Foundation Service)
BASICA
Bosque
CLR Profiler
GitHub
Atom
GitHub Desktop
GitHub Copilot
npm
Spectrum
Dependabot
GW-BASIC
IronRuby
IronPython
JScript
Microsoft Liquid Motion
Microsoft BASIC, also licensed as:
Altair BASIC
AmigaBASIC
Applesoft BASIC
Commodore BASIC
Color BASIC
MBASIC
Spectravideo Extended BASIC
TRS-80 Level II BASIC
Microsoft MACRO-80
Microsoft Macro Assembler
Microsoft Small Basic
Microsoft Visual SourceSafe
Microsoft XNA
Microsoft WebMatrix
MSX BASIC
NuGet
QBasic and QuickBASIC
TASC (The AppleSoft Compiler)
TypeScript
VBScript
Visual Studio
Microsoft Visual Studio Express
Visual Basic
Visual Basic .NET
Visual Basic for Applications
Visual C++
C++/CLI
Managed Extensions for C++
Visual C#
Visual FoxPro
Visual J++
Visual J#
Visual Studio Code
Visual Studio Lab Management
Visual Studio Tools for Applications
Visual Studio Tools for Office
VSTS Profiler
Windows API
Windows SDK
WordBASIC
Xbox Development Kit
3D
3D Builder
3D Scan (requires a Kinect for Xbox One sensor)
3D Viewer
AltspaceVR
Bing Maps for Enterprise (formerly "Bing Maps Platform" and "Microsoft Virtual Earth")
Direct3D
Havok
HoloStudio
Kinect for Windows SDK
Microsoft Mesh
Paint 3D
Simplygon
Educational
Bing
Bing Bar
Browstat
Creative Writ |
https://en.wikipedia.org/wiki/Wind%20transducer | A wind transducer is a device used by sailors to receive a real-time measurement of wind speed and direction. A wind transducer is usually mounted on the masthead of a sailing boat and is occasionally used by power boats too. The wind speed and direction measurements are more critical to sailing boats than to power boats. Sailors rely on the wind speed and direction to help with navigation and pilotage. These devices can be calibrated to measure the true wind speed and the apparent wind speed (speed that a sailor would 'feel'). Sailing boats can sail at a maximum of 45 degrees close to the wind and will sail faster on a reach than when at closest to the wind.
Wind transducers are usually wired to the cock or head, although 'wireless' versions are becoming steadily more popular due to the reduced installation time required. |
https://en.wikipedia.org/wiki/Authbind | authbind is an open-source system utility written by Ian Jackson and is distributed under the GNU General Public License. The authbind software allows a program that would normally require superuser privileges to access privileged network services to run as a non-privileged user. authbind allows the system administrator to permit specific users and groups access to bind to TCP and UDP ports below 1024. Ports 0 - 1023 are normally privileged and reserved for programs that are run as the root user. Allowing regular users limited access to privileged ports helps prevent possible privilege escalation and system compromise if the software happens to contain software bugs or is found to be vulnerable to unknown exploits.
authbind achieves this by defining the LD_PRELOAD environment variable which loads a libauthbind library. This library overrides the bind() call with a version that executes a setuid helper program (/usr/lib/authbind/helper) with the socket as file descriptor 0. The helper validates its arguments and checks its configuration, calls the real bind() system call on file descriptor 0 (which also affects the original process's socket), and exits, allowing the original process to continue with the socket bound to the requested address and port.
authbind is currently distributed with the Debian and Ubuntu Linux distributions.
Alternatives
The Linux kernel's implementation of POSIX capabilities includes the CAP_NET_BIND_SERVICE which allows either explicitly enabled binaries (with "setcap CAP_NET_BIND_SERVICE+ep /path/to/binary") or binaries configured to accept the capability from the invoking user's capability set ("setcap CAP_NET_BIND_SERVICE+ei /path/to/binary") if available, making userland software unnecessary for binding to lower numeral ports. Linux capabilities, however were not introduced until the latter half of 1999, more than a year after authbind's release, and (similar to setuid/setgid) cannot be set on scripts. Both these explain why the so |
https://en.wikipedia.org/wiki/Soil%20conservation | Soil conservation is the prevention of loss of the topmost layer of the soil from erosion or prevention of reduced fertility caused by over usage, acidification, salinization or other chemical soil contamination.
Slash-and-burn and other unsustainable methods of subsistence farming are practiced in some lesser developed areas. A consequence of deforestation is typically large-scale erosion, loss of soil nutrients and sometimes total desertification. Techniques for improved soil conservation include crop rotation, cover crops, conservation tillage and planted windbreaks, affect both erosion and fertility. When plants die, they decay and become part of the soil. Code 330 defines standard methods recommended by the U.S. Natural Resources Conservation Service. Farmers have practiced soil conservation for millennia. In Europe, policies such as the Common Agricultural Policy are targeting the application of best management practices such as reduced tillage, winter cover crops, plant residues and grass margins in order to better address soil conservation. Political and economic action is further required to solve the erosion problem. A simple governance hurdle concerns how we value the land and this can be changed by cultural adaptation. Soil carbon is a carbon sink, playing a role in climate change mitigation.
Contour ploughing
Contour ploughing orients furrows following the contour lines of the farmed area. Furrows move left and right to maintain a constant altitude, which reduces runoff. Contour plowing was practiced by the ancient Phoenicians for slopes between two and ten percent. Contour plowing can increase crop yields from 10 to 50 percent, partially as a result of greater soil retention.
Terrace farming
Terracing is the practice of creating nearly level areas in a hillside area. The terraces form a series of steps each at a higher level than the previous. Terraces are protected from erosion by other soil barriers. Terraced farming is more common on small far |
https://en.wikipedia.org/wiki/Proth%20prime | A Proth number is a natural number N of the form where k and n are positive integers, k is odd and . A Proth prime is a Proth number that is prime. They are named after the French mathematician François Proth. The first few Proth primes are
3, 5, 13, 17, 41, 97, 113, 193, 241, 257, 353, 449, 577, 641, 673, 769, 929, 1153, 1217, 1409, 1601, 2113, 2689, 2753, 3137, 3329, 3457, 4481, 4993, 6529, 7297, 7681, 7937, 9473, 9601, 9857 ().
It is still an open question whether an infinite number of Proth primes exist. It was shown in 2022 that the reciprocal sum of Proth primes converges to a real number near 0.747392479, substantially less than the value of 1.093322456 for the reciprocal sum of Proth numbers.
The primality of Proth numbers can be tested more easily than many other numbers of similar magnitude.
Definition
A Proth number takes the form where k and n are positive integers, is odd and . A Proth prime is a Proth number that is prime. Without the condition that , all odd integers larger than 1 would be Proth numbers.
Primality testing
The primality of a Proth number can be tested with Proth's theorem, which states that a Proth number is prime if and only if there exists an integer for which
This theorem can be used as a probabilistic test of primality, by checking for many random choices of whether If this fails to hold for several random , then it is very likely that the number is composite.
This test is a Las Vegas algorithm: it never returns a false positive but can return a false negative; in other words, it never reports a composite number as "probably prime" but can report a prime number as "possibly composite".
In 2008, Sze created a deterministic algorithm that runs in at most time, where Õ is the soft-O notation. For typical searches for Proth primes, usually is either fixed (e.g. 321 Prime Search or Sierpinski Problem) or of order (e.g. Cullen prime search). In these cases algorithm runs in at most , or time for all . There is |
https://en.wikipedia.org/wiki/Morchella%20snyderi | Morchella snyderi is a species of fungus in the family Morchellaceae. Described as new to science in 2012, it occurs in the montane forests of western North America, including California, Idaho, Montana, Oregon and Washington. It produces fruit bodies up to tall with ridged and pitted conical caps, and stipes that become pitted in maturity. The color of the morel is yellow to tan when young, but the cap ridges become brown to black in maturity or when dried.
Taxonomy
Morchella snyderi was described as new to science in 2012, along with 13 other morels from the United States and Canada. The study, published in the journal Mycologia, resulted from the Morel Data Collection Project, which aimed to help clarify the taxonomy, biology, and distribution of morel species in North America. The specific epithet honors Leon C. Snyder, who described similar morels in Washington state in the 1930s. According to Michael Kuo, who coauthored the species description, the morel should have been named Morchella crassistipa, as it was previously described by Snyder in 1938, from collections made in Washington. However, molecular analysis determined that Snyder's type collection contained two distinct species, rendering the validity of the taxon dubious. M. snyderi was also previously identified as phylogenetic species Mel-12 (i.e., defined by DNA sequence) in a 2011 study.
Despite the light coloration of young fruit bodies, Morchella snyderi groups in the elata clade (named after the European black morel M. elata) along with other "black" morels such as M. angusticeps and M. tomentosa. Morphological characteristics of morels in this clade include pits on the cap that are usually elongated vertically in mature fruit bodies, and often the presence of a sinus (a space or indentation) where the cap attaches to the stipe.
Description
The fruit bodies are high. The conical cap is high and wide at the widest point. The cap surface features pits and ridges, formed by the intersection o |
https://en.wikipedia.org/wiki/Bottom%20type | In type theory, a theory within mathematical logic, the bottom type of a type system is the type that is a subtype of all other types.
Where such a type exists, it is often represented with the up tack (⊥) symbol.
When the bottom type is empty, a function whose return type is bottom cannot return any value, not even the lone value of a unit type. In such a language, the bottom type may therefore be known as the zero, void or never type. In the Curry–Howard correspondence, an empty type corresponds to falsity.
Computer science applications
In subtyping systems, the bottom type is a subtype of all types. It is dual to the top type, which spans all possible values in a system.
If a type system is sound, the bottom type is uninhabited and a term of bottom type represents a logical contradiction. In such systems, typically no distinction is drawn between the bottom type and the empty type, and the terms may be used interchangeably.
If the bottom type is inhabited, its terms[s] typically correspond to error conditions such as undefined behavior, infinite recursion, or unrecoverable errors.
In Bounded Quantification with Bottom, Pierce says that "Bot" has many uses:
In a language with exceptions, a natural type for the raise construct is raise ∈ exception -> Bot, and similarly for other control structures. Intuitively, Bot here is the type of computations that do not return an answer.
Bot is useful in typing the "leaf nodes" of polymorphic data structures. For example, List(Bot) is a good type for nil.
Bot is a natural type for the "null pointer" value (a pointer which does not point to any object) of languages like Java: in Java, the null type is the universal subtype of reference types. null is the only value of the null type; and it can be cast to any reference type. However, the null type is not a bottom type as described above, it is not a subtype of int and other primitive types.
A type system including both Top and Bot seems to be a natural target for t |
https://en.wikipedia.org/wiki/12th%20meridian%20west | The meridian 12° west of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, Greenland, the Atlantic Ocean, Africa, the Southern Ocean, and Antarctica to the South Pole.
The 12th meridian west forms a great circle with the 168th meridian east.
Part of the border between Western Sahara and Mauritania is defined by the meridian.
From Pole to Pole
Starting at the North Pole and heading south to the South Pole, the 12th meridian west passes through:
{| class="wikitable plainrowheaders"
! scope="col" width="125" | Co-ordinates
! scope="col" | Country, territory or sea
! scope="col" | Notes
|-
| style="background:#b0e0e6;" |
! scope="row" style="background:#b0e0e6;" | Arctic Ocean
| style="background:#b0e0e6;" |
|-
|
! scope="row" |
|
|-
| style="background:#b0e0e6;" |
! scope="row" style="background:#b0e0e6;" | Atlantic Ocean
| style="background:#b0e0e6;" |
|-
|
! scope="row" |
|
|-
|
! scope="row" | Western Sahara
| Claimed by and the Sahrawi Arab Democratic Republic
|-valign="top"
|
! scope="row" | Western Sahara / border
|
|-
|
! scope="row" |
|
|-
|
! scope="row" |
|
|-
|
! scope="row" |
| For about 13 km
|-
|
! scope="row" |
| For about 11 km
|-
|
! scope="row" |
|
|-
|
! scope="row" |
|
|-
|
! scope="row" |
|
|-
|
! scope="row" |
|
|-
|
! scope="row" |
|
|-valign="top"
| style="background:#b0e0e6;" |
! scope="row" style="background:#b0e0e6;" | Atlantic Ocean
| style="background:#b0e0e6;" | Passing just east of the island of Tristan da Cunha, (at )
|-
| style="background:#b0e0e6;" |
! scope="row" style="background:#b0e0e6;" | Southern Ocean
| style="background:#b0e0e6;" |
|-
|
! scope="row" | Antarctica
| Queen Maud Land, claimed by
|-
|} |
https://en.wikipedia.org/wiki/Paper%20composite%20panels | Paper composite panels are a phenolic resin/cellulose composite material made from partially recycled paper and phenolic resin. Multiple layers of paper are soaked in phenolic resin, then molded and baked into net shape in a heated form or press. Originally distributed as a commercial kitchen surface in the 1950s, it has recently been adapted for use in skateboard parks as well as various other applications, such as residential counters, cabinetry, fiberglass cores, guitar fingerboards, signage, exterior wall cladding, and a variety of architectural applications.
Composition
There are several manufacturers in North America who use a different composition of materials to form the final product. One composition is cellulose fiber and phenolic resin (a type of polymer) which is combined and baked for a smooth hard surface. The natural fibers are made from plant, animal and mineral sources. However most natural fibers are predominantly cellulosic.
Cellulose derived from tree pulp is turned into large rolls of paper.
The paper is then soaked in phenolic resin and goes up to a heating chamber to be dried out before being rolled back up.
Then hundreds of these sheets are laid on top of each other and with the use of compression molding the stack is compacted.
Because of the resin's thermoset properties the resulting cooled material is hard.
Applications
It was used for the Boeing 747 for their air tables, hydroforming dyes, vacuum chuck faces, work holders, and proofing materials. Architecturally, it is used for countertops. It has also been used for whaleboard in fiberglass boat building. Other commercial uses include cutting boards, prep tables, pizza peels, and the dashboard of a pickup truck prototype vehicle.
Since the last quarter of the 20th century, phenolic resin and cellulose based compound materials have been used as an alternative to ebony and rosewood to make stringed instrument fingerboards. From 2012 to 2018 guitarmaker Gibson used Richlite, |
https://en.wikipedia.org/wiki/Karloff%E2%80%93Zwick%20algorithm | The Karloff–Zwick algorithm, in computational complexity theory, is a randomised approximation algorithm taking an instance of MAX-3SAT Boolean satisfiability problem as input. If the instance is satisfiable, then the expected weight of the assignment found is at least 7/8 of optimal. There is strong evidence (but not a mathematical proof) that the algorithm achieves 7/8 of optimal even on unsatisfiable MAX-3SAT instances. Howard Karloff and Uri Zwick presented the algorithm in 1997.
The algorithm is based on semidefinite programming. It can be derandomized using, e.g., the techniques from to yield a deterministic polynomial-time algorithm with the same approximation guarantees.
Comparison to random assignment
For the related MAX-E3SAT problem, in which all clauses in the input 3SAT formula are guaranteed to have exactly three literals, the simple randomized approximation algorithm which assigns a truth value to each variable independently and uniformly at random satisfies 7/8 of all clauses in expectation, irrespective of whether the original formula is satisfiable. Further, this simple algorithm can also be easily derandomized using the method of conditional expectations. The Karloff–Zwick algorithm, however, does not require the restriction that the input formula should have three literals in every clause.
Optimality
Building upon previous work on the PCP theorem, Johan Håstad showed that, assuming P ≠ NP, no polynomial-time algorithm for MAX 3SAT can achieve a performance ratio exceeding 7/8, even when restricted to satisfiable instances of the problem in which each clause contains exactly three literals. Both the Karloff–Zwick algorithm and the above simple algorithm are therefore optimal in this sense. |
https://en.wikipedia.org/wiki/False%20sharing | In computer science, false sharing is a performance-degrading usage pattern that can arise in systems with distributed, coherent caches at the size of the smallest resource block managed by the caching mechanism. When a system participant attempts to periodically access data that is not being altered by another party, but that data shares a cache block with data that is being altered, the caching protocol may force the first participant to reload the whole cache block despite a lack of logical necessity. The caching system is unaware of activity within this block and forces the first participant to bear the caching system overhead required by true shared access of a resource.
Multiprocessor CPU caches
By far the most common usage of this term is in modern multiprocessor CPU caches, where memory is cached in lines of some small power of two word size (e.g., 64 aligned, contiguous bytes). If two processors operate on independent data in the same memory address region storable in a single line, the cache coherency mechanisms in the system may force the whole line across the bus or interconnect with every data write, forcing memory stalls in addition to wasting system bandwidth. In some cases, the elimination of false sharing can result in order-of-magnitude performance improvements. False sharing is an inherent artifact of automatically synchronized cache protocols and can also exist in environments such as distributed file systems or databases, but current prevalence is limited to RAM caches.
Example
#include <iostream>
#include <thread>
#include <new>
#include <atomic>
#include <chrono>
#include <latch>
#include <vector>
using namespace std;
using namespace chrono;
#if defined(__cpp_lib_hardware_interference_size)
// default cacheline size from runtime
constexpr size_t CL_SIZE = hardware_constructive_interference_size;
#else
// most common cacheline size otherwise
constexpr size_t CL_SIZE = 64;
#endif
int main()
{
vector<jthread> threads;
int hc = thread::hard |
https://en.wikipedia.org/wiki/Computer-automated%20design | Design Automation usually refers to electronic design automation, or Design Automation which is a Product Configurator. Extending Computer-Aided Design (CAD), automated design and Computer-Automated Design (CAutoD) are more concerned with a broader range of applications, such as automotive engineering, civil engineering, composite material design, control engineering, dynamic system identification and optimization, financial systems, industrial equipment, mechatronic systems, steel construction, structural optimisation, and the invention of novel systems.
The concept of CAutoD perhaps first appeared in 1963, in the IBM Journal of Research and Development, where a computer program was written.
to search for logic circuits having certain constraints on hardware design
to evaluate these logics in terms of their discriminating ability over samples of the character set they are expected to recognize.
More recently, traditional CAD simulation is seen to be transformed to CAutoD by biologically-inspired machine learning, including heuristic search techniques such as evolutionary computation, and swarm intelligence algorithms.
Guiding designs by performance improvements
To meet the ever-growing demand of quality and competitiveness, iterative physical prototyping is now often replaced by 'digital prototyping' of a 'good design', which aims to meet multiple objectives such as maximised output, energy efficiency, highest speed and cost-effectiveness. The design problem concerns both finding the best design within a known range (i.e., through 'learning' or 'optimisation') and finding a new and better design beyond the existing ones (i.e., through creation and invention). This is equivalent to a search problem in an almost certainly, multidimensional (multivariate), multi-modal space with a single (or weighted) objective or multiple objectives.
Normalized objective function: cost vs. fitness
Using single-objective CAutoD as an example, if the objective function, either |
https://en.wikipedia.org/wiki/Elliptic%20Curve%20Digital%20Signature%20Algorithm | In cryptography, the Elliptic Curve Digital Signature Algorithm (ECDSA) offers a variant of the Digital Signature Algorithm (DSA) which uses elliptic-curve cryptography.
Key and signature-size
As with elliptic-curve cryptography in general, the bit size of the private key believed to be needed for ECDSA is about twice the size of the security level, in bits. For example, at a security level of 80 bits—meaning an attacker requires a maximum of about operations to find the private key—the size of an ECDSA private key would be 160 bits. On the other hand, the signature size is the same for both DSA and ECDSA: approximately bits, where is the exponent in the formula , that is, about 320 bits for a security level of 80 bits, which is equivalent to operations.
Signature generation algorithm
Suppose Alice wants to send a signed message to Bob. Initially, they must agree on the curve parameters . In addition to the field and equation of the curve, we need , a base point of prime order on the curve; is the multiplicative order of the point .
The order of the base point must be prime. Indeed, we assume that every nonzero element of the ring is invertible, so that must be a field. It implies that must be prime (cf. Bézout's identity).
Alice creates a key pair, consisting of a private key integer , randomly selected in the interval ; and a public key curve point . We use to denote elliptic curve point multiplication by a scalar.
For Alice to sign a message , she follows these steps:
Calculate . (Here HASH is a cryptographic hash function, such as SHA-2, with the output converted to an integer.)
Let be the leftmost bits of , where is the bit length of the group order . (Note that can be greater than but not longer.)
Select a cryptographically secure random integer from .
Calculate the curve point .
Calculate . If , go back to step 3.
Calculate . If , go back to step 3.
The signature is the pair . (And is also a valid signature.)
As the standa |
https://en.wikipedia.org/wiki/Grant%20Olney | Grant Olney Passmore (born October 18, 1983) is a singer-songwriter who has recorded on the Asian Man Records label. He is considered part of the New Weird America movement along with David Dondero, Devendra Banhart, Bright Eyes, and CocoRosie. His latest full-length album, Hypnosis for Happiness, was released in July 2013 on the Friendly Police UK label. His previous full-length album, Brokedown Gospel, was released on the Asian Man Records label in July 2004. He also releases music under the pseudonym Scout You Devil and as part of the songwriting duo Olney Clark.
Alongside his music, Passmore is also a mathematician and theoretical computer scientist, formerly a student at the University of Texas at Austin, the Mathematical Research Institute in the Netherlands, and the University of Edinburgh, where he earned his PhD. He is a Life Member of Clare Hall, University of Cambridge and is cofounder of the artificial intelligence company Imandra Inc. (formerly known as Aesthetic Integration) which produces technology for the formal verification of algorithms. He was paired with artist Hito Steyerl in the 2016 Rhizome Seven on Seven.
As a young child and early teenager, Passmore was involved in the development of the online Bulletin Board system scene, and under the name skaboy he was the author of many applications of importance to the Bulletin Board System community, including the Infusion Bulletin Board System, Empathy Image Editor, Avenger Packer Pro, and Impulse Tracker Tosser. Passmore was head programmer for ACiD Productions while working on many of these applications.
Personal life
Passmore married Barbara Galletly in 2014. They have three children.
Discography
Albums
Hypnosis for Happiness – Grant Olney – (2013 · Friendly Police UK)
Olney Clark – Olney Clark – (2010 · Friendly Police UK)
Let Love Be (single) – Grant Olney – (2006 · Asian Man Records)
Brokedown Gospel – Grant Olney – (2004 · Asian Man Records)
Sweet Wine – Grant Olney – (2003 · MyAutomat |
https://en.wikipedia.org/wiki/Primitive%20element%20theorem | In field theory, the primitive element theorem is a result characterizing the finite degree field extensions that can be generated by a single element. Such a generating element is called a primitive element of the field extension, and the extension is called a simple extension in this case. The theorem states that a finite extension is simple if and only if there are only finitely many intermediate fields. An older result, also often called "primitive element theorem", states that every finite separable extension is simple; it can be seen as a consequence of the former theorem. These theorems imply in particular that all algebraic number fields over the rational numbers, and all extensions in which both fields are finite, are simple.
Terminology
Let be a field extension. An element is a primitive element for if i.e. if every element of can be written as a rational function in with coefficients in . If there exists such a primitive element, then is referred to as a simple extension.
If the field extension has primitive element and is of finite degree , then every element x of E can be written uniquely in the form
where for all i. That is, the set
is a basis for E as a vector space over F.
Example
If one adjoins to the rational numbers the two irrational numbers and to get the extension field of degree 4, one can show this extension is simple, meaning for a single . Taking , the powers 1, α, α2, α3 can be expanded as linear combinations of 1, , , with integer coefficients. One can solve this system of linear equations for and over , to obtain and . This shows that α is indeed a primitive element:
The theorems
The classical primitive element theorem states:
Every separable field extension of finite degree is simple.
This theorem applies to algebraic number fields, i.e. finite extensions of the rational numbers Q, since Q has characteristic 0 and therefore every finite extension over Q is separable.
The following primitive element the |
https://en.wikipedia.org/wiki/Elette%20Boyle | Elette Boyle is an American and Israeli computer scientist and cryptographer, known for her research on secret sharing, digital signatures, and obfuscation. She is a professor of computer science at the Interdisciplinary Center Herzliya, where she directs the Center for Foundations and Applications of Cryptographic Theory.
Education and career
Boyle is originally from Yamhill, Oregon. She studied mathematics at the California Institute of Technology, competed for Caltech in the high jump, and was named Caltech's female scholar-athlete of the year for 2007–2008. After graduating in 2008, she completed her Ph.D. at the Massachusetts Institute of Technology, under the joint supervision of Shafi Goldwasser and Yael Tauman Kalai. Before joining the IDC Herzliya faculty, she was a postdoctoral researcher at the Technion – Israel Institute of Technology and at Cornell University.
Recognition
A paper by Boyle on secret sharing using homomorphic encryption was given the best paper award at the 2016 International Cryptology Conference (Crypto). She was an invited plenary speaker at Public Key Cryptography 2018. |
https://en.wikipedia.org/wiki/Southern%20Dispersal | In the context of the recent African origin of modern humans, the Southern Dispersal scenario (also the coastal migration or great coastal migration hypothesis) refers to the early migration along the southern coast of Asia, from the Arabian Peninsula via Persia and India to Southeast Asia and Oceania. Alternative names include the "southern coastal route" or "rapid coastal settlement", with later descendants of those migrations eventually colonizing the rest of Eurasia, the remainder of Oceania, and the Americas.
The coastal route theory is primarily used to describe the initial peopling of West Asia, India, Southeast Asia, New Guinea, Australia, Near Oceania, and East Asia beginning between roughly 70,000 and 50,000 years ago.
It is linked with the presence and dispersal of mtDNA haplogroup M and haplogroup N, as well as the specific distribution patterns of Y-DNA haplogroup F (ancestral to O, N, R, Q), haplogroup C and haplogroup D, in these regions.
The theory proposes that early modern humans, some of the bearers of mitochondrial haplogroup L3, arrived in the Arabian peninsula about 70,000-50,000 years ago, crossing from East Africa via the Bab-el-Mandeb strait. It has been estimated that from a population of 2,000 to 5,000 individuals in Africa, only a small group, possibly as few as 150 to 1,000 people, crossed the Red Sea. The group would have travelled along the coastal route around Arabia and Persia to India relatively rapidly, within a few thousand years. From India, they would have spread to Southeast Asia ("Sundaland") and Oceania ("Sahul").
A review paper by Melinda A. Yang (in 2022) summarized and concluded that a distinctive "Basal-East Asian population" referred to as 'East- and Southeast Asian lineage' (ESEA); which is ancestral to modern East Asians, Southeast Asians, Polynesians, and Siberians, originated in Mainland Southeast Asia at ~50,000BC, and expanded through multiple migration waves southwards and northwards respectively. This ESEA li |
https://en.wikipedia.org/wiki/Kidamycin | Kidamycin is an anthracycline antibiotic with anticancer activity. It was first synthesized from a strain of streptomyces bacteria isolated from a soil sample. In clinical trials, Kindamycin showed high effect against gram positive bacteria as well as multiple cancer models including Ehrlich ascites carcinoma, Sarcoma 180, NF-sarcoma, and Yoshida sarcoma. |
https://en.wikipedia.org/wiki/Miklos%20Udvardy | Miklos Dezso Ferenc Udvardy (March 23, 1919–January 27, 1998) was a Hungarian-American biologist and university instructor. He made significant contributions to various fields, including biogeography, evolutionary biology, ornithology, and vegetation classification. Throughout his career, Udvardy published 191 papers, authored 8 books, and created 3 maps that have been recognized in the scientific literature.
Early life and career
Udvardy was born on March 23, 1919, in Debrecen, Hungary, to a family of noble descent. His father, Miklos Udvardy de Udvardy et Básth, held a noble title, and his mother was Elizabeth Komlossy de Komlos. Although Udvardy initially developed an interest in birds, his father encouraged him to pursue a legal education. However, he eventually obtained a doctorate in biology from the University of Debrecen in 1942. He began his career as a research biologist at the Tihanyi Biological Station, located on Lake Balaton in western Hungary.
In 1948, Udvardy left Hungary and obtained a postdoctoral fellowship at Helsinki University in Finland under the guidance of Professor Pontus Palmgren, an esteemed ornithologist and zoologist. It was during this time that he met his future wife, Maud Björklund, in 1950. Subsequently, Udvardy relocated to Uppsala, Sweden. He briefly served as the curator of marine invertebrates at the Swedish Museum of Natural History in Stockholm.
Later career
Miklos and Maud were married in 1951 and immigrated to Canada. In 1952, Udvardy joined the University of British Columbia in Vancouver, British Columbia, where he assumed the position of assistant professor in the department of zoology. From 1953 to 1966, he taught courses on comparative anatomy and ornithology. During the academic year 1958–1959, he served as a visiting professor at the University of Hawaii, and in the academic year 1963–1964, he was the Lida Scott Brown Lecturer in Ornithology at the University of California, Los Angeles.
Between 1967 and 1991, Udvar |
https://en.wikipedia.org/wiki/List%20of%20military%20flags | This is a list of currently flags flown by military powers worldwide. All flags in this list are for specific use for a branch of or the whole national military of a given state.
Albania
Algeria
Antigua and Barbuda
Argentina
Australia
Bangladesh
Belarus
Belgium
Brazil
Canada
Former flags
Colombia
People’s Republic of China
Egypt
Finland
France
Estonia
Georgia
Former flags
Germany
Former flags
India
Former flags
Iran
Iraq
Former flags
Ireland
Israel
Italy
Japan
Jordan
Kenya
Korea (North)
Former flags
Korea (South)
Lithuania
Malaysia
Mexico
Mongolia
Morocco
Myanmar (Burma)
Namibia
Netherlands
New Zealand
Nigeria
Pakistan
Peru
Philippines
Poland
Russia
Former flags
Saudi Arabia
Serbia
Former flags
Slovenia
Somalia
South Africa
Former flags
Sri Lanka
Sweden
Republic of China (Taiwan)
Thailand
Turkmenistan
Turkey
United Arab Emirates
Ukraine
United Kingdom
United States
Former flags
Uruguay
Venezuela
Vietnam
Former flags |
https://en.wikipedia.org/wiki/Composition%20operator | In mathematics, the composition operator with symbol is a linear operator defined by the rule
where denotes function composition.
The study of composition operators is covered by AMS category 47B33.
In physics
In physics, and especially the area of dynamical systems, the composition operator is usually referred to as the Koopman operator (and its wild surge in popularity is sometimes jokingly called "Koopmania"), named after Bernard Koopman. It is the left-adjoint of the transfer operator of Frobenius–Perron.
In Borel functional calculus
Using the language of category theory, the composition operator is a pull-back on the space of measurable functions; it is adjoint to the transfer operator in the same way that the pull-back is adjoint to the push-forward; the composition operator is the inverse image functor.
Since the domain considered here is that of Borel functions, the above describes the Koopman operator as it appears in Borel functional calculus.
In holomorphic functional calculus
The domain of a composition operator can be taken more narrowly, as some Banach space, often consisting of holomorphic functions: for example, some Hardy space or Bergman space. In this case, the composition operator lies in the realm of some functional calculus, such as the holomorphic functional calculus.
Interesting questions posed in the study of composition operators often relate to how the spectral properties of the operator depend on the function space. Other questions include whether is compact or trace-class; answers typically depend on how the function behaves on the boundary of some domain.
When the transfer operator is a left-shift operator, the Koopman operator, as its adjoint, can be taken to be the right-shift operator. An appropriate basis, explicitly manifesting the shift, can often be found in the orthogonal polynomials. When these are orthogonal on the real number line, the shift is given by the Jacobi operator. When the polynomials are orthogonal o |
https://en.wikipedia.org/wiki/When%20the%20Weather%20Is%20Fine%20%28song%29 | "When the Weather Is Fine" is the fourth and final single released from Australian pop rock band Thirsty Merc's debut album, Thirsty Merc (2004). The song only appears on the 2005 re-packaged version of the album.
Music video
The music video features Thirsty Merc playing the song in a theatre and there's water shallowly covering the stage (to ankle height) intercut with scenes from the audience where a young man and woman appear to be having relationship troubles, reflecting the lyrical content of the song.
Track listing
Australian CD single
"When the Weather Is Fine" – 3:24
"Baby Tell Me I'm the Only One" – 3:25
"Crystal Striker" – 3:51
"Someday, Someday" (video)
"Wasting Time" (video)
Charts |
https://en.wikipedia.org/wiki/Partial%20veil | In mycology, a partial veil (also called an inner veil, to differentiate it from the "outer", or universal veil) is a temporary structure of tissue found on the fruiting bodies of some basidiomycete fungi, typically agarics. Its role is to isolate and protect the developing spore-producing surface, represented by gills or tubes, found on the lower surface of the cap. A partial veil, in contrast to a universal veil, extends from the stem surface to the cap edge. The partial veil later disintegrates, once the fruiting body has matured and the spores are ready for dispersal. It might then give rise to a stem ring, or fragments attached to the stem or cap edge. In some mushrooms, both a partial veil and a universal veil may be present.
Structure
In the immature fruit bodies of some basidiomycete fungi, the partial veil extends from the stem surface to the cap margin and shields the gills during development, and later breaks to expose the mature gills. The presence, absence, or structure of the partial veil is an aid to identification of mushrooms. Some fruit bodies may have both a universal and partial veil, others may have only one or the other, while many lack both types of veils. The partial veil may be membranous or cobwebby, and may have multiple layers. Various adjectives are commonly used to describe the texture of partial veils, such as: membranous, like a membrane; cottony, where the veil tissue is made of separate fibers that may be easily separated like a cotton ball; fibrillose, composed of thin strands and glutinous, with a slimy consistency. Some mushrooms have partial veils which are evanescent, which are so thin and delicate that they disappear after they rupture, or leave merely a faint trace on the stem known as an annular zone or ring zone. Others may leave a persistent annulus (ring). Occasionally, the partial veil adheres to the edge of the cap as shreds of tissue, forming an appendiculate margin.
The cobweb-like, fragile partial veil of some mus |
https://en.wikipedia.org/wiki/Function%20series | In calculus, a function series is a series, where the summands are not just real or complex numbers but functions.
Examples
Examples of function series include power series, Laurent series, Fourier series, etc.
Convergence
There exist many types of convergence for a function series, such as uniform convergence, pointwise convergence, almost everywhere convergence, etc.
The Weierstrass M-test is a useful result in studying convergence of function series.
See also
Function space |
https://en.wikipedia.org/wiki/Bilinear%20transform | The bilinear transform (also known as Tustin's method, after Arnold Tustin) is used in digital signal processing and discrete-time control theory to transform continuous-time system representations to discrete-time and vice versa.
The bilinear transform is a special case of a conformal mapping (namely, a Möbius transformation), often used to convert a transfer function of a linear, time-invariant (LTI) filter in the continuous-time domain (often called an analog filter) to a transfer function of a linear, shift-invariant filter in the discrete-time domain (often called a digital filter although there are analog filters constructed with switched capacitors that are discrete-time filters). It maps positions on the axis, , in the s-plane to the unit circle, , in the z-plane. Other bilinear transforms can be used to warp the frequency response of any discrete-time linear system (for example to approximate the non-linear frequency resolution of the human auditory system) and are implementable in the discrete domain by replacing a system's unit delays with first order all-pass filters.
The transform preserves stability and maps every point of the frequency response of the continuous-time filter, to a corresponding point in the frequency response of the discrete-time filter, although to a somewhat different frequency, as shown in the Frequency warping section below. This means that for every feature that one sees in the frequency response of the analog filter, there is a corresponding feature, with identical gain and phase shift, in the frequency response of the digital filter but, perhaps, at a somewhat different frequency. This is barely noticeable at low frequencies but is quite evident at frequencies close to the Nyquist frequency.
Discrete-time approximation
The bilinear transform is a first-order Padé approximant of the natural logarithm function that is an exact mapping of the z-plane to the s-plane. When the Laplace transform is performed on a discret |
https://en.wikipedia.org/wiki/Anochetus%20intermedius | Anochetus intermedius is an extinct species of ant in the subfamily Ponerinae known from two possibly Miocene fossils found on Hispaniola. A. intermedius is one of eight species in the ant genus Anochetus to have been described from fossils found in Dominican amber and is one of a number of Anochetus species found in the Greater Antilles.
History and classification
Anochetus intermedius is known from a solitary fossil insect which, along with two flies, three other ants, and two springtails, is an inclusion in a transparent yellow chunk of Dominican amber. The amber was produced by the extinct Hymenaea protera, which formerly grew on Hispaniola, across northern South America and up to southern Mexico. The specimen was collected from an undetermined amber mine in fossil bearing rocks of the Cordillera Septentrional mountains of northern Dominican Republic. The amber dates from at least the Burdigalian stage of the Miocene, based on studying the associated fossil foraminifera and may be as old as the Middle Eocene, based on the associated fossil coccoliths. This age range is due to the host rock being secondary deposits for the amber, and the Miocene the age range is only the youngest that it might be.
At the time of description, the holotype specimen was preserved in the Natural History Museum, London amber collections in London, England. The holotype fossil was first studied by entomologist Maria L. De Andrade of the University of Basle with her 1991 type description of the new species being published in the journal Stuttgarter Beiträge zur Naturkunde. Serie B (Geologie und Paläontologie). The specific epithet is derived from the Latin intermedius meaning "intermediate".
The species is one of eight Anochetus which have been described from Dominican amber. Two species were described prior to A. intermedius, A. corayi in 1980 and A. brevidentatus in 1991. The remaining five species; A. ambiguus, A. conisquamis, A. dubius, A. exstinctus, and A. lucidus were a |
https://en.wikipedia.org/wiki/Cyber%20Essentials | Cyber Essentials is a United Kingdom certification scheme designed to show an organisation has a minimum level of protection in cyber security through annual assessments to maintain certification.
Backed by the UK government and overseen by the National Cyber Security Centre (NCSC). It encourages organisations to adopt good practices in information security. Cyber Essentials also includes an assurance framework and a simple set of security controls to protect information from threats coming from the internet.
The certification underwent substantial changes in January 2022 which included bringing all cloud services into scope and changes to the requirements on multi-factor authentication, passwords and pins.
Certification
The Cyber Essentials program provides two levels, the first is self-certification and the second requires independent validation of claims made:
Cyber Essentials
Commonly referred to as mark your own homework, organisations self-assess their systems, and then complete an online assessment. The online assessment is marked by a Cyber Essentials Assessor who provides feedback on any areas where improvements could be made.
There is no independent validation of the accuracy of the answers at this level.
The cost for Cyber Essentials starts from £300 and is subject to VAT in the UK. The pricing model is tiered based on the number of employees and more information can be found on the IASME website.
Cyber Essentials Plus
The same as the basic but with independent validation by an accredited third party.
Systems are independently tested, and Cyber Essentials is integrated into the organisation's information risk management.
The cost for the Plus accreditation is dependent on the complexity of the environment but for a simple SME would typically cost around £1,400 and subject to VAT within the UK.
IASME has incorporated the Cyber Essentials into the wider IASME information assurance standard.
As with ISO/IEC 27001, organisations may choose to li |
https://en.wikipedia.org/wiki/Berkeley%20RISC | Berkeley RISC is one of two seminal research projects into reduced instruction set computer (RISC) based microprocessor design taking place under the Defense Advanced Research Projects Agency VLSI Project. RISC was led by David Patterson (who coined the term RISC) at the University of California, Berkeley between 1980 and 1984. The other project took place a short distance away at Stanford University under their MIPS effort starting in 1981 and running until 1984.
Berkeley's project was so successful that it became the name for all similar designs to follow; even the MIPS would become known as a "RISC processor". The Berkeley RISC design was later commercialized by Sun Microsystems as the SPARC architecture, and inspired the ARM architecture.
The RISC concept
Both RISC and MIPS were developed from the realization that the vast majority of programs did not use the vast majority of a processor's instructions. In a famous 1978 paper, Andrew S. Tanenbaum demonstrated that a complex 10,000 line high-level program could be represented using a simplified instruction set architecture using an 8-bit fixed-length opcode. This was roughly the same conclusion reached at IBM, whose studies of their own code running on mainframes like the IBM 360 used only a small subset of all the instructions available. Both of these studies suggested that one could produce a much simpler CPU that would still run the vast majority of real-world code. Another finding, not fully explored at the time, was Tanenbaum's note that 81% of the constants were either 0, 1, or 2.
These realizations were taking place as the microprocessor market was moving from 8 to 16-bit with 32-bit designs about to appear. These processors were designed on the premise of trying to replicate some of the more well-respected ISAs from the mainframe and minicomputer world. For instance, the National Semiconductor NS32000 started out as an effort to produce a single-chip implementation of the VAX-11, which had a rich inst |
https://en.wikipedia.org/wiki/Port%20Revel | The Port Revel Shiphandling Training Centre is a French maritime pilotage school that trains pilots, masters, and officers on large ships like supertankers, container ships, LNG carriers and cruise ships . The facility uses manned models at a 1:25 scale on a man-made lake designed to simulate natural conditions including harbours, canals, and open seas. It was the first such facility in the world. The Centre was created in 1967 near Grenoble, France, by Laboratoire Dauphinois d'Hydraulique (now Artelia).
The courses are given by former maritime pilots. Since 1967, the Centre has trained over 6 500 maritime pilots, captains and officers from all over the world. French, European, Australian, Brazilian and North American pilots make up 90% of the Centre's students.
The manned model training regime is now recommended by the International Maritime Organization under Resolution A 960 (23) of December 2005.
The facility was written about by John McPhee in an October, 1998 article for The Atlantic Monthly, later republished as Chapter Two in his book Uncommon Carriers (2006).
History
The centre's origin goes back to the fifties, when Port Revel's mother company, Sogreah, was studying bank erosion on the Suez Canal using model ships sailing on a scale model with a movable bed (i.e. granular material subjected to erosion by turbulent water movement).
At the end of the sixties this experience with free sailing model ships was used by Esso to anticipate the manoeuvring behaviour of the new, much larger, oil tankers.
After three years spent with Esso captains between 1967 and 1970, the Centre was taken over by Sogreah in 1970.
During the 1970s, most students were captains, while the first maritime pilots came to discover the centre.
In the 1990s, the first refresher courses were organised for pilots, who returned every 5 years. These courses are less directive and leave more room for customisation, which is a way of optimising port operations to increase port accessibi |
https://en.wikipedia.org/wiki/Lynx%20Software%20Technologies | Lynx Software Technologies, Inc. (formerly LynuxWorks) is a San Jose, California software company founded in 1988. Lynx specializes in secure virtualization and open, reliable, certifiable real-time operating systems (RTOSes). Originally known as Lynx Real-Time Systems, the company changed its name to LynuxWorks in 2000 after acquiring, and merging with, ISDCorp (Integrated Software & Devices Corporation), an embedded systems company with a strong Linux background. In May 2014, the company changed its name to Lynx Software Technologies.
Over 30 years of processor evolution, Lynx has crafted and adapted platform architectures for builders of safety- and security-critical software systems. Lynx embraced open standards from its inception, with its original RTOS, LynxOS, featuring a UNIX-like user model and standard POSIX interfaces to embedded developers. LynxOS-178 is developed and certified to the FAA DO-178C DAL A safety standard and received the first and only FAA Reusable Software Component certificate for an RTOS. It supports ARINC API and FACE standards.
Lynx has created technology that has been deployed in thousands of designs and millions of products made by leading communications, industrial, transportation, avionics, aerospace/defense and consumer electronics companies. In 1989, LynxOS, the company's flagship RTOS, was selected for use in the NASA/IBM Space Station Freedom project. Lynx Software Technologies operating systems are also used in medical, industrial and communications systems around the world.
In early 2020, Lynx announced that the TR3 modernization program for the joint strike fighter had adopted Lynx’s LYNX MOSA.ic software development framework. The F-35 Lightning II Program (also known as the Joint Strike Fighter Program) is the US Department of Defense's focal point for defining affordable next generation strike aircraft weapon systems It is intended to replace a wide range of existing fighter, strike, and ground attack aircraft for the |
https://en.wikipedia.org/wiki/Summer%20Bummer | "Summer Bummer" is a song by American singer and songwriter Lana Del Rey featuring American rappers ASAP Rocky and Playboi Carti featured on her fifth studio album Lust For Life. The song was released for digital download on July 12, 2017, alongside "Groupie Love" featuring ASAP Rocky, as a promotional single with the pre-order of the album. The song was written by the artists, alongside producers BigWhiteBeatz., Boi-1da, Jahaan Sweet, and T-Minus, with additional production credits going to Rick Nowels.
Background and composition
The song was written by Lana Del Rey in collaboration with songwriters such as ASAP Rocky , Boi-1da, Playboi Carti, Matthew Samuels, and Tyler Williams in the summer of 2016.
On June 2, 2017, Del Rey revealed that she and ASAP Rocky had collaborated on a track for the album by posting a snippet of the song on Instagram with the caption: "We made a lot of good ones but I think we picked the best ones for the record".
According to the sheet music published at Musicnotes.com by Universal Music Publishing Group, "Summer Bummer" is composed in time and the key of E-flat minor, with a relaxed trap/hip hop and electronica tempo of 67 beats per minute. "Summer Bummer" was labeled a hip hop song by Alexa Camp of Slant Magazine, while Ryan Reed of Rolling Stone described the sound of the song as "dark noir-pop style over a rattling trap beat".
Critical reception
"Summer Bummer" received generally positive reviews from critics. Anna Gaca of Spin stated "Even as it widens—slightly—the range of her catalog, 'Summer Bummer' is best viewed as a classically Lana Del Rey set piece: a heavily stylized soundtrack for drugs, pools, and high-contrast monochromes. 'White lies'—or maybe that's, ahem, 'white lines'—'and black beaches/And blood red sangrias', she sings later, mirroring a color scheme that dates back to 'Off to the Races'. Sonically, 'Bummer' is like a trap-inspired take on Honeymoons High by the Beach, and thematically, it doesn't go anywhere |
https://en.wikipedia.org/wiki/Gordana%20Jovanovic%20Dolecek | Gordana Jovanovic Dolecek is an electronics engineer specializing in digital filters. Originally from Yugoslavia, she works in Mexico as a professor and researcher at the National Institute of Astrophysics, Optics and Electronics (INAOE) in Puebla.
Education and career
Dolecek earned a bachelor's degree in electrical engineering from the University of Sarajevo in 1969. After a master's degree from the University of Belgrade in 1975, she returned to the University of Sarajevo for her Ph.D., completed in 1981.
She worked as a research assistant at Energoinvest in 1969 and 1971 became a teaching and research assistant at the University of Sarajevo. She became an assistant professor there in 1977, one of the founding members of the Department of Telecommunications. She was promoted to associate professor in 1985 and full professor in 1991. She alternately chaired the telecommunications and communications systems departments from 1980 to 1993.
In 1993 she moved to the Mihajlo Pupin Institute of the University of Belgrade, and in 1995 she took her present position in Mexico at INAOE.
Books
Dolecek is the author of the book Random Signals and Processes Primer with MATLAB (Springer, 2012). Her edited volumes include Multirate Systems: Design and Applications (Idea Group, 2002) and Advances in Multirate Systems (Springer, 2017).
Recognition
Dolecek is a member of the Mexican Academy of Sciences, elected in 2005.
Personal life
Dolecek was married to mechanical engineering professor Vlatko Doleček. Their daughter, coding theorist Lara Dolecek, is a professor in California at the UCLA Henry Samueli School of Engineering and Applied Science. |
https://en.wikipedia.org/wiki/Numerical%20range | In the mathematical field of linear algebra and convex analysis, the numerical range or field of values of a complex matrix A is the set
where denotes the conjugate transpose of the vector . The numerical range includes, in particular, the diagonal entries of the matrix (obtained by choosing x equal to the unit vectors along the coordinate axes) and the eigenvalues of the matrix (obtained by choosing x equal to the eigenvectors).
In engineering, numerical ranges are used as a rough estimate of eigenvalues of A. Recently, generalizations of the numerical range are used to study quantum computing.
A related concept is the numerical radius, which is the largest absolute value of the numbers in the numerical range, i.e.
Properties
The numerical range is the range of the Rayleigh quotient.
(Hausdorff–Toeplitz theorem) The numerical range is convex and compact.
for all square matrix and complex numbers and . Here is the identity matrix.
is a subset of the closed right half-plane if and only if is positive semidefinite.
The numerical range is the only function on the set of square matrices that satisfies (2), (3) and (4).
(Sub-additive) , where the sum on the right-hand side denotes a sumset.
contains all the eigenvalues of .
The numerical range of a matrix is a filled ellipse.
is a real line segment if and only if is a Hermitian matrix with its smallest and the largest eigenvalues being and .
If is a normal matrix then is the convex hull of its eigenvalues.
If is a sharp point on the boundary of , then is a normal eigenvalue of .
is a norm on the space of matrices.
, where denotes the operator norm.
Generalisations
C-numerical range
Higher-rank numerical range
Joint numerical range
Product numerical range
Polynomial numerical hull
See also
Spectral theory
Rayleigh quotient
Workshop on Numerical Ranges and Numerical Radii
Bibliography
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"Functional Characterizations of the Field of Values and the Convex Hull of |
https://en.wikipedia.org/wiki/Adenylyl%20cyclase | Adenylate cyclase (EC 4.6.1.1, also commonly known as adenyl cyclase and adenylyl cyclase, abbreviated AC) is an enzyme with systematic name ATP diphosphate-lyase (cyclizing; 3′,5′-cyclic-AMP-forming). It catalyzes the following reaction:
ATP = 3′,5′-cyclic AMP + diphosphate
It has key regulatory roles in essentially all cells. It is the most polyphyletic known enzyme: six distinct classes have been described, all catalyzing the same reaction but representing unrelated gene families with no known sequence or structural homology. The best known class of adenylyl cyclases is class III or AC-III (Roman numerals are used for classes). AC-III occurs widely in eukaryotes and has important roles in many human tissues.
All classes of adenylyl cyclase catalyse the conversion of adenosine triphosphate (ATP) to 3',5'-cyclic AMP (cAMP) and pyrophosphate. Magnesium ions are generally required and appear to be closely involved in the enzymatic mechanism. The cAMP produced by AC then serves as a regulatory signal via specific cAMP-binding proteins, either transcription factors, enzymes (e.g., cAMP-dependent kinases), or ion transporters.
Classes
Class I
The first class of adenylyl cyclases occur in many bacteria including E. coli (as CyaA [unrelated to the Class II enzyme]). This was the first class of AC to be characterized. It was observed that E. coli deprived of glucose produce cAMP that serves as an internal signal to activate expression of genes for importing and metabolizing other sugars. cAMP exerts this effect by binding the transcription factor CRP, also known as CAP. Class I AC's are large cytosolic enzymes (~100 kDa) with a large regulatory domain (~50 kDa) that indirectly senses glucose levels. , no crystal structure is available for class I AC.
Some indirect structural information is available for this class. It is known that the N-terminal half is the catalytic portion, and that it requires two Mg2+ ions. S103, S113, D114, D116 and W118 are the five absolut |
https://en.wikipedia.org/wiki/Hyperharmonic%20number | In mathematics, the n-th hyperharmonic number of order r, denoted by , is recursively defined by the relations:
and
In particular, is the n-th harmonic number.
The hyperharmonic numbers were discussed by J. H. Conway and R. K. Guy in their 1995 book The Book of Numbers.
Identities involving hyperharmonic numbers
By definition, the hyperharmonic numbers satisfy the recurrence relation
In place of the recurrences, there is a more effective formula to calculate these numbers:
The hyperharmonic numbers have a strong relation to combinatorics of permutations. The generalization of the identity
reads as
where is an r-Stirling number of the first kind.
Asymptotics
The above expression with binomial coefficients easily gives that for all fixed order r>=2 we have.
that is, the quotient of the left and right hand side tends to 1 as n tends to infinity.
An immediate consequence is that
when m>r.
Generating function and infinite series
The generating function of the hyperharmonic numbers is
The exponential generating function is much more harder to deduce. One has that for all r=1,2,...
where 2F2 is a hypergeometric function. The r=1 case for the harmonic numbers is a classical result, the general one was proved in 2009 by I. Mező and A. Dil.
The next relation connects the hyperharmonic numbers to the Hurwitz zeta function:
Integer hyperharmonic numbers
It is known, that the harmonic numbers are never integers except the case n=1. The same question can be posed with respect to the hyperharmonic numbers: are there integer hyperharmonic numbers? István Mező proved that if r=2 or r=3, these numbers are never integers except the trivial case when n=1. He conjectured that this is always the case, namely, the hyperharmonic numbers of order r are never integers except when n=1. This conjecture was justified for a class of parameters by R. Amrane and H. Belbachir. Especially, these authors proved that is not integer for all r<26 and n=2,3, |
https://en.wikipedia.org/wiki/Apple%20Pascal | Apple Pascal is an implementation of Pascal for the Apple II and Apple III computer series. It is based on UCSD Pascal.
Just like other UCSD Pascal implementations, it ran on its own operating system (Apple Pascal Operating System, a derivative of UCSD p-System with graphical extensions).
Originally released for the Apple II in August 1979, just after Apple DOS 3.2, Apple Pascal pioneered a number of features that would later be incorporated into DOS 3.3, as well as others that would not be seen again until the introduction of ProDOS.
The Apple Pascal software package also included disk maintenance utilities, and an assembler meant to complement Apple's built-in "monitor" assembler. A FORTRAN compiler (written by Silicon Valley Software, Sunnyvale California) compiling to the same p-code as Pascal was also available.
Comparison of Pascal OS with DOS 3.2
Apple Pascal Operating System introduced a new disk format. Instead of dividing the disk into 256-byte sectors as in DOS 3.2, Apple Pascal divides it into "blocks" of 512 bytes each. The p-System also introduced a different method for saving and retrieving files. Under Apple DOS, files were saved to any available sector that the OS could find, regardless of location. Over time, this could lead to file system fragmentation, slowing access to the disk. Apple Pascal attempted to rectify this by saving only to consecutive blocks on the disk.
Other innovations introduced in the file system included the introduction of a timestamp feature. Previously only a file's name, basic type, and size would be shown. Disks could also be named for the first time.
Limitations of the p-System included new restrictions on the naming of files.
Writing files only on consecutive blocks also created problems, because over time free space tended to become too fragmented to store new files. A utility called Krunch was included in the package to consolidate free space.
The biggest problem with the Apple Pascal system was that it wa |
https://en.wikipedia.org/wiki/Uterine%20artery%20embolization | Uterine artery embolization (UAE) is a procedure in which an interventional radiologist uses a catheter to deliver small particles that block the blood supply to the uterine body. The procedure is primarily done for the treatment of uterine fibroids and adenomyosis. However, it may also be used to treat postpartum hemorrhage and uterine arteriovenous fistulas. Since this minimally invasive procedure is commonly used in the treatment of uterine fibroids and is also called uterine fibroid embolization.
Medical uses
Uterine fibroids are the most common type of benign uterine tumor and are composed of smooth muscle. They often cause bulk-related symptoms, which can be characterized by back pain, heaviness in the pelvic area, abdominal bloating. UAE may be used to treat these bothersome bulk-related symptoms as well as abnormal or heavy uterine bleeding due to uterine fibroids. Fibroid size, number, and location are three potential predictors of a successful outcome. UAE may also be appropriate for the treatment of adenomyosis, which is when the lining of the uterus aberrantly grows into the muscle of the uterus. Symptoms of adenomyosis include heavy or prolonged menstrual bleeding and painful menstrual periods.
Long-term patient satisfaction outcomes are similar to that of surgery. There is tentative evidence that traditional surgery may result in better fertility. UAE also appears to require more repeat procedures than if surgery was done initially.
It has shorter recovery times. UAE is thought to work because uterine fibroids have abnormal vasculature together with aberrant responses to hypoxia (inadequate oxygenation to tissues).
UAE can also be used to control heavy uterine bleeding for reasons other than fibroids, such as postpartum obstetrical hemorrhage. and adenomyosis.
According to the American Journal of Gynecology, UAE costs 12% less than hysterectomy and 8% less than myomectomy.
Adverse effects
The rate of serious complications is comparable to that of |
https://en.wikipedia.org/wiki/Midas%20XL8 | The Midas XL8 was the first digital mixing console produced by Midas, previously a leading manufacturer of analogue mixing consoles for live sound. The introduction of the console came after years of digital console competition by Yamaha, Digidesign, and DiGiCo. |
https://en.wikipedia.org/wiki/Computed%20tomography%20of%20the%20head | Computed tomography of the head uses a series of X-rays in a CT scan of the head taken from many different directions; the resulting data is transformed into a series of cross sections of the brain using a computer program. CT images of the head are used to investigate and diagnose brain injuries and other neurological conditions, as well as other conditions involving the skull or sinuses; it used to guide some brain surgery procedures as well. CT scans expose the person getting them to ionizing radiation which has a risk of eventually causing cancer; some people have allergic reactions to contrast agents that are used in some CT procedures.
Uses
Computed tomography (CT) has become the diagnostic modality of choice for head trauma due to its accuracy, reliability, safety, and wide availability. The changes in microcirculation, impaired auto-regulation, cerebral edema, and axonal injury start as soon as head injury occurs and manifest as clinical, biochemical, and radiological changes. Proper therapeutic management of brain injury is based on correct diagnosis and appreciation of the temporal course of the disease process. CT scan detects and precisely localizes the intracranial hematomas, cerebral contusions, edema and foreign bodies.
Even in emergency situations, when a head injury is minor as determined by a physician's evaluation and based on established guidelines, CT of the head should be avoided for adults and delayed pending clinical observation in the emergency department for children. Many people visit emergency departments for minor head injuries. CT scans of the head can confirm a diagnosis of skull fracture or brain bleeding, but even in the emergency department, such things are uncommon and not minor injuries, so CT of the head is usually not necessary. Clinical trials have shown the efficacy and safety of using CT of the head in emergency settings only when indicated, which would be at the indication of evidence-based guidelines following the physic |
https://en.wikipedia.org/wiki/Breaking%20the%20Spell%20%28Stork%20book%29 | Breaking the Spell: My Life as a Rajneeshee and the Long Journey Back to Freedom is a non-fiction book by Catherine Jane Stork about her experiences as a Rajneeshee, a follower of Indian guru Bhagwan Shree Rajneesh (now known as Osho). It was published in April 2009 by Pan Macmillan. Stork was raised in Western Australia in a Catholic upbringing, and met her first husband while at university in Perth, Australia. After a psychotherapist introduced Stork to teachings of Rajneesh, she became involved in the movement and moved with her husband to an ashram in Poona, India. Stork later moved to the Rajneesh commune in Rajneeshpuram, Oregon. She became involved in criminal activities while at Rajneeshpuram, participated in an attempted murder against Rajneesh's doctor, and an assassination plot against the U.S. Attorney for Oregon, Charles H. Turner. Stork served time in jail but later lived in exile in Germany for 16 years, after a German court had denied extradition to the United States. She returned to the U.S. to face criminal charges after learning of her son's terminal cancer condition. Stork discusses her process of reevaluating the effects her actions within the Rajneesh organization had on other people and on her family.
The book received generally positive reception in the press and media. The Australian Associated Press commented that Stork "provides an insight into the mind of the Bhagwan and his mouthpiece Ma Sheela", and The Sunday Mail called the book "An amazing story of self-delusion, followed by self-determination and redemption." The Sunday Telegraph highlighted the book in the newspaper's "Must Read" section, and The Gold Coast Bulletin called it "Shattering". A review in The Age commented that the book exposes "the ultimately selfish nature of apparently selfless fanaticism".
Background
Born in 1945, Catherine Jane Stork was raised in Western Australia, in a family of five children. She is the daughter of a math teacher from Albany, Western Australi |
https://en.wikipedia.org/wiki/Logo%20of%20Argentina | The logo of Argentina refers to the official logo of the Marca País (MP), a State policy of nation branding that aims to promote tourism, boost exports, attract investments and spread Argentine culture.
The first logo came from the Contest for the Visual Identity of the Argentina Brand, which took place in 2006 and included some of the best designers in the country. Through the presidential decree 1372/2008, published on August 29 in the official gazette, the national government created the Intersectoral Commission on the Argentine Country Brand Strategy, formed by the Ministry of Foreign Affairs and International Trade, the Secretariat of Tourism, and the Secretariat of Media for Communication. Under the same decree, the logo representing Argentina abroad became official.
In 2018, Mauricio Macri's government renewed the Marca País and unveiled a new logo. |
https://en.wikipedia.org/wiki/Journal%20of%20Automated%20Reasoning | The Journal of Automated Reasoning was established in 1983 by Larry Wos, who was its editor in chief until 1992. It covers research and advances in automated reasoning, mechanical verification of theorems, and other deductions in classical and non-classical logic.
The journal is published by Springer Science+Business Media. As of 2021, the editor-in-chief is Jasmin Blanchette, an associate professor of computer science at the Vrije Universiteit Amsterdam. The journal's 2019 impact factor is 1.431, and it is indexed by several science indexing services, including the Science Citation Index Expanded and Scopus. |
https://en.wikipedia.org/wiki/Ten15 | Ten15 is an algebraically specified abstract machine. It was developed by Foster, Currie et al. at the Royal Signals and Radar Establishment at Malvern, Worcestershire, during the 1980s. It arose from earlier work on the Flex machine, which was a capability computer implemented via microcode. Ten15 was intended to offer an intermediate language common to all implementations of the Flex architecture for portability purposes. It had the side effect of making the benefits of that work available on modern processors lacking a microcode facility.
Ten15 served as an intermediate language for compilers, but with several unique features, some of which have still to see the light of day in everyday systems. Firstly, it was strongly typed, yet wide enough in application to support most languages — C being an exception, chiefly because C deliberately treats an array similar to a pointer to the first element of that array. This ultimately led to Ten15's development into TDF, which in turn formed the basis for ANDF. Secondly, it offered a persistent, write-only filestore mechanism, allowing arbitrary data structures to be written and retrieved without conversion into an external representation.
Historical note
Why 'Ten15'? Nic Peeling reports that during early discussions of the concepts of Ten15, it was agreed that this was important and should have a name - but what? Ian Currie looked up at the clock and said 'Why not call it 10:15?'
See also
Virtual machine
TenDRA Compiler |
https://en.wikipedia.org/wiki/Measurable%20Riemann%20mapping%20theorem | In mathematics, the measurable Riemann mapping theorem is a theorem proved in 1960 by Lars Ahlfors and Lipman Bers in complex analysis and geometric function theory. Contrary to its name, it is not a direct generalization of the Riemann mapping theorem, but instead a result concerning quasiconformal mappings and solutions of the Beltrami equation. The result was prefigured by earlier results of Charles Morrey from 1938 on quasi-linear elliptic partial differential equations.
The theorem of Ahlfors and Bers states that if μ is a bounded measurable function on C with , then there is a
unique solution f of the Beltrami equation
for which f is a quasiconformal homeomorphism of C fixing the points 0, 1 and ∞. A similar result is true with C replaced by the unit disk D. Their proof used the Beurling transform, a singular integral operator. |
https://en.wikipedia.org/wiki/Level%20shifter | In digital electronics, a level shifter, also called level converter or logic level shifter, or voltage level translator, is a circuit used to translate signals from one logic level or voltage domain to another, allowing compatibility between integrated circuits with different voltage requirements, such as TTL and CMOS. Modern systems use level shifters to bridge domains between processors, logic, sensors, and other circuits. In recent years, the three most common logic levels have been 1.8V, 3.3V, and 5V, though levels above and below these voltages are also used.
Types of level shifter
Uni-directional – All input pins are dedicated to one voltage domain, all output pins are dedicated to the other.
Bi-directional with Dedicated ports – Each voltage domain has both input and output pins, but the data direction of a pin does not change.
Bi-directional with external direction indicator – When an external signal is changed, inputs become outputs and vice versa.
Bi-directional, auto-sensing – A pair of I/O spanning voltage domains can act as either inputs or outputs depending on external stimulus without the need for a dedicated direction control pin.
Hardware implementation
Fixed function level shifter ICs - These ICs provide several different types of level shift in fixed function devices. Often lumped into 2-bit, 4-bit, or 8-bit level shift configurations offered with various VDD1 and VDD2 ranges, these devices translate logic levels without any additional integrated logic or timing adjustment.
Configurable mixed-signal ICs (CMICs) – Level shifter circuitry can also be implemented in a CMIC. The no-code programmable nature of CMICs allows designers to implement fully customizable level shifters with the added option to integrate configurable logic or timing adjustments in the same device.
Applications of level shifters
Since level shifters are used to resolve the voltage incompatibility between various parts of a system, they have a wide range of applic |
https://en.wikipedia.org/wiki/%CE%9434S | {{DISPLAYTITLE:δ34S}}
The δ34S (pronounced delta 34 S) value is a standardized method for reporting measurements of the ratio of two stable isotopes of sulfur, 34S:32S, in a sample against the equivalent ratio in a known reference standard. Presently, the most commonly used standard is Vienna-Canyon Diablo Troilite (VCDT). Results are reported as variations from the standard ratio in parts per thousand, per mil or per mille, using the ‰ symbol. Heavy and light sulfur isotopes fractionate at different rates and the resulting δ34S values, recorded in marine sulfate or sedimentary sulfides, have been studied and interpreted as records of the changing sulfur cycle throughout the earth's history.
Calculation
Of the 25 known isotopes of sulfur, four are stable. In order of their abundance, those isotopes are 32S (94.93%), 34S (4.29%), 33S (0.76%), and 36S (0.02%). The δ34S value refers to a measure of the ratio of the two most common stable sulfur isotopes, 34S:32S, as measured in a sample against that same ratio as measured in a known reference standard. The lowercase delta character is used by convention, to be consistent with use in other areas of stable isotope chemistry. That value can be calculated in per mil (‰, parts per thousand) as:
‰
Less commonly, if the appropriate isotope abundances are measured, similar formulae can be used to quantify ratio variations between 33S and 32S, and 36S and 32S, reported as δ33S and δ36S, respectively.
Reference standard
Sulfur from meteorites was determined in the early 1950s to be an adequate reference standard because it exhibited a small variability in isotopic ratios. It was also believed that because of their extraterrestrial provenances, meteors represented primordial terrestrial isotopic conditions. During a meeting of the National Science Foundation in April 1962, troilite from the Canyon Diablo meteorite found in Arizona, US, was established as the standard with which δ34S values (and other sulfur stable isotopic |
https://en.wikipedia.org/wiki/Wolstenholme%20number | A Wolstenholme number is a number that is the numerator of the generalized harmonic number Hn,2.
The first such numbers are 1, 5, 49, 205, 5269, 5369, 266681, 1077749, ... .
These numbers are named after Joseph Wolstenholme, who proved Wolstenholme's theorem on modular relations of the generalized harmonic numbers. |
https://en.wikipedia.org/wiki/Neuromechanics | Neuromechanics is an interdisciplinary field that combines biomechanics and neuroscience to understand how the nervous system interacts with the skeletal and muscular systems to enable animals to move. In a motor task, like reaching for an object, neural commands are sent to motor neurons to activate a set of muscles, called muscle synergies. Given which muscles are activated and how they are connected to the skeleton, there will be a corresponding and specific movement of the body. In addition to participating in reflexes, neuromechanical process may also be shaped through motor adaptation and learning.
Neuromechanics underlying behavior
Walking
The inverted pendulum theory of gait is a neuromechanical approach to understand how humans walk. As the name of the theory implies, a walking human is modeled as an inverted pendulum consisting of a center of mass (COM) suspended above the ground via a support leg (Fig. 2). As the inverted pendulum swings forward, ground reaction forces occur between the modeled leg and the ground. Importantly, the magnitude of the ground reaction forces depends on the COM position and size. The velocity vector of the center of mass is always perpendicular to the ground reaction force.
Walking consists of alternating single-support and double-support phases. The single-support phase occurs when one leg is in contact with the ground while the double-support phase occurs when two legs are in contact with the ground.
Neurological influences
The inverted pendulum is stabilized by constant feedback from the brain and can operate even in the presence of sensory loss. In animals who have lost all sensory input to the moving limb, the variables produced by gait (center of mass acceleration, velocity of animal, and position of the animal) remain constant between both groups.
During postural control, delayed feedback mechanisms are used in the temporal reproduction of task-level functions such as walking. The nervous system takes into a |
https://en.wikipedia.org/wiki/Sampled%20data%20system | In systems science, a sampled-data system is a control system in which a continuous-time plant is controlled with a digital device. Under periodic sampling, the sampled-data system is time-varying but also periodic; thus, it may be modeled by a simplified discrete-time system obtained by discretizing the plant. However, this discrete model does not capture the inter-sample behavior of the real system, which may be critical in a number of applications.
The analysis of sampled-data systems incorporating full-time information leads to challenging control problems with a rich mathematical structure. Many of these problems have only been solved recently. |
https://en.wikipedia.org/wiki/State%E2%80%93action%E2%80%93reward%E2%80%93state%E2%80%93action | State–action–reward–state–action (SARSA) is an algorithm for learning a Markov decision process policy, used in the reinforcement learning area of machine learning. It was proposed by Rummery and Niranjan in a technical note with the name "Modified Connectionist Q-Learning" (MCQ-L). The alternative name SARSA, proposed by Rich Sutton, was only mentioned as a footnote.
This name reflects the fact that the main function for updating the Q-value depends on the current state of the agent "S1", the action the agent chooses "A1", the reward "R" the agent gets for choosing this action, the state "S2" that the agent enters after taking that action, and finally the next action "A2" the agent chooses in its new state. The acronym for the quintuple (st, at, rt, st+1, at+1) is SARSA. Some authors use a slightly different convention and write the quintuple (st, at, rt+1, st+1, at+1), depending on which time step the reward is formally assigned. The rest of the article uses the former convention.
Algorithm
A SARSA agent interacts with the environment and updates the policy based on actions taken, hence this is known as an on-policy learning algorithm. The Q value for a state-action is updated by an error, adjusted by the learning rate alpha. Q values represent the possible reward received in the next time step for taking action a in state s, plus the discounted future reward received from the next state-action observation.
Watkin's Q-learning updates an estimate of the optimal state-action value function based on the maximum reward of available actions. While SARSA learns the Q values associated with taking the policy it follows itself, Watkin's Q-learning learns the Q values associated with taking the optimal policy while following an exploration/exploitation policy.
Some optimizations of Watkin's Q-learning may be applied to SARSA.
Hyperparameters
Learning rate (alpha)
The learning rate determines to what extent newly acquired information overrides old information. A |
https://en.wikipedia.org/wiki/Atransferrinemia | Atransferrinemia is an autosomal recessive metabolic disorder in which there is an absence of transferrin, a plasma protein that transports iron through the blood.
Atransferrinemia is characterized by anemia and hemosiderosis in the heart and liver. The iron damage to the heart can lead to heart failure. The anemia is typically microcytic and hypochromic (the red blood cells are abnormally small and pale). Atransferrinemia was first described in 1961 and is extremely rare, with only ten documented cases worldwide.
Symptoms and signs
The presentation of this disorder entails anemia, arthritis, hepatic anomalies, and recurrent infections are clinical signs of the disease. Iron overload occurs mainly in the liver, heart, pancreas, thyroid, and kidney.
Genetics
In terms of genetics of atransferrinemia researchers have identified mutations in the TF gene as a probable cause of this genetic disorder in affected people.
Transferrin is a serum transport protein that transports iron to the reticuloendothelial system for utilization and erythropoiesis, since there is no transferrin in atransferrinemia, serum free iron cannot reach reticuloendothelial cells and there is microcytic anemia. Also, this excess iron deposits itself in the heart, liver and joints, and causes damage. Ferritin, the storage form of iron gets secreted more into the bloodstream so as to bind with the excessive free iron and hence serum ferritin levels rise in this condition
Diagnosis
The diagnosis of atransferrinemia is done via the following means to ascertain if an individual has the condition:
Blood test(for anemia)
TF level
Physical exam
Genetic test
Types
There are two forms of this condition that causes an absence of transferrin in the affected individual:
Acquired atransferrinemia
Congenital atransferrinemia
Treatment
The treatment of atransferrinemia is apotransferrin. The missing protein without iron. Iron treatment is detrimental as it does not correct the anemia and is a cause o |
https://en.wikipedia.org/wiki/Triphalangeal%20thumb | Triphalangeal thumb (TPT) is a congenital malformation where the thumb has three phalanges instead of two. The extra phalangeal bone can vary in size from that of a small pebble to a size comparable to the phalanges in non-thumb digits. The true incidence of the condition is unknown, but is estimated at 1:25,000 live births. In about two-thirds of the patients with triphalangeal thumbs, there is a hereditary component. Besides the three phalanges, there can also be other malformations. It was first described by Columbi in 1559.
Signs and symptoms
The triphalangeal thumb has a different appearance than normal thumbs. The appearance can differ widely; the thumb can be a longer thumb, it can be deviated in the radio-ulnar plane (clinodactyly), or thumb strength can be diminished. In the case of a five-fingered hand it has a finger-like appearance, with the position in the plane of the four fingers, thenar muscle deficiency, and additional length. There is often a combination with radial polydactyly.
Complications
Generally, triphalangeal thumbs are non-opposable. In contrast to most people with opposable thumbs, a person suffering from TPT cannot easily place his or her thumb opposite the other four digits of the same hand. The opposable thumb's ability to effortlessly utilize fingers in a "pinch" formation is critical in precision gripping. For the thumb to adequately grip, certain thumb criteria must be met (e.g. suitable position and length, stable joints and good thenar muscle strength). Because triphalangeal thumbs cannot easily oppose and do not possess many of the optimal qualities found in most opposable thumbs, they tend to cause the hand to be less effective in use and, therefore, prove to be more problematic in daily life.
Cause
Malformations of the upper extremities can occur in the third to seventh embryonic week. In some cases the TPT is hereditary. In these cases, there is a mutation on chromosome 7q36. If the TPT is hereditary, it is mostly inherite |
https://en.wikipedia.org/wiki/Crataegus%20pinnatifida | Crataegus pinnatifida, also known as mountain hawthorn, Chinese haw, Chinese hawthorn or Chinese hawberry, refers to a small to medium-sized tree, as well as the fruit of the tree. The fruit is bright red, in diameter.
Use
Culinary use
In northern Chinese cuisine, ripe C. pinnatifida fruits are used in the desserts tanghulu and shanzhagao. It is also used to make the traditional candies haw flakes and haw rolls, as well as candied fruit slices, jam, jelly, and wine. It is also traditionally used as a finishing ingredient in Cantonese sweet and sour sauce, although it has since been partially supplanted by ketchup.
Traditional medicine
In traditional Chinese medicine, the dried fruits of C. pinnatifida have been used as a digestive aid.
See also
List of culinary fruits
Phytotherapy |
https://en.wikipedia.org/wiki/Bruno%20Murari | Bruno Murari is an Italian inventor. During his career he has patented about 200 inventions in the field of circuit design, power technologies and MEMS (Micro Electro Mechanical Systems) devices. He is the only Italian to have received the Elmer A. Sperry Award., which is awarded to those who have distinguished themselves with proven engineering contributions to advance the field of transport. He was defined "legendary analog engineer" and "father" of the BCD technology
Early years
Murari grew up in Venice, on the island of San Giorgio and, after earning a diploma in electrical engineering, in 1955 at the Technical Institute "A. Pacinotti" in Mestre, he began working for Edison Volta, for which he designed substations and power lines in Val Camonica.
In 1961 he was hired at the Somiren (Nuclear Energy Radioactive Minerals Society) of San Donato Milanese, a small company of the Agip Nuclear group. After work, he attended evening classes at the Aurelio Beltrami Radiotechnical Institute and obtained an electronic expert's diploma two years later.
STMicroelectronics
In November 1961 Murari transferred to SGS (General semiconductor company) of Agrate Brianza, today STMicroelectronics, a startup founded by Adriano Olivetti and Virgilio Floriani, founder of Telettra, first at the Applications Laboratory and then in the linear integrated circuits design group. Thanks to the partnership with the semiconductor company Fairchild Semiconductor, he began collaborating with Bob Widlar, one of the pioneers of integrated circuit design.
At the end of the 1960s he developed the first audio amplifier integrated circuit for TVs and portable radios. Then he adapted the technology for integrated circuits, initially developed in the consumer electronics field, to the automotive market, obtaining the first voltage regulator with metal casing for automotive alternators, made with the STMicroelectronics bipolar process.
In 1972 he took on responsibility for the design of linear integra |
https://en.wikipedia.org/wiki/Freivalds%27%20algorithm | Freivalds' algorithm (named after Rūsiņš Mārtiņš Freivalds) is a probabilistic randomized algorithm used to verify matrix multiplication. Given three n × n matrices , , and , a general problem is to verify whether . A naïve algorithm would compute the product explicitly and compare term by term whether this product equals . However, the best known matrix multiplication algorithm runs in time. Freivalds' algorithm utilizes randomization in order to reduce this time bound to
with high probability. In time the algorithm can verify a matrix product with probability of failure less than .
The algorithm
Input
Three n × n matrices , , and .
Output
Yes, if ; No, otherwise.
Procedure
Generate an n × 1 random 0/1 vector .
Compute .
Output "Yes" if ; "No," otherwise.
Error
If , then the algorithm always returns "Yes". If , then the probability that the algorithm returns "Yes" is less than or equal to one half. This is called one-sided error.
By iterating the algorithm k times and returning "Yes" only if all iterations yield "Yes", a runtime of and error probability of is achieved.
Example
Suppose one wished to determine whether:
A random two-element vector with entries equal to 0 or 1 is selected say and used to compute:
This yields the zero vector, suggesting the possibility that AB = C. However, if in a second trial the vector is selected, the result becomes:
The result is nonzero, proving that in fact AB ≠ C.
There are four two-element 0/1 vectors, and half of them give the zero vector in this case ( and ), so the chance of randomly selecting these in two trials (and falsely concluding that AB=C) is 1/22 or 1/4. In the general case, the proportion of r yielding the zero vector may be less than 1/2, and a larger number of trials (such as 20) would be used, rendering the probability of error very small.
Error analysis
Let p equal the probability of error. We claim that if A × B = C, then p = 0, and if A × B ≠ C, then p ≤ 1/2.
Case A × B = C
This is re |
https://en.wikipedia.org/wiki/Pullulan%20bioconjugate | Pullulan bioconjugates are systems that use pullulan as a scaffold to attach biological materials to, such as drugs. These systems can be used to enhance the delivery of drugs to specific environments or the mechanism of delivery. These systems can be used in order to deliver drugs in response to stimuli, create a more controlled and sustained release, and provide a more targeted delivery of certain drugs.
Pullulan formulation
Pullulan is generated by the microbial A. pullulans through the processing mainly of glucose, but can also be produced from maltose, fructose, galactose, sucrose, and mannose. In a commercial setting, pullulan is obtained from a strain of A. pullulans that is non-toxic, non-pathogenic, and unmodified genetically that is given a liquid form of starch in a set environment. The pullulan produced can be modified by different conditions such as the nutrients provided, temperature, pH, oxygen content, and other supplements. The microbial needs to be provided with a source of carbon and nitrogen in order to produce pullulan and the ratio of carbon to nitrogen needs to be precise in order to maximize pullulan production. Higher levels of nitrogen than carbon are required as excess carbon can decrease the efficiency of the enzymes and excess nitrogen can increase the production of biomass, but does not affect the pullulan production. Oxygen is also important for the proliferation of the A. pullulans cells and the production of pullulan. Further supplements can be used in order to increase the level of pullulan production, such as olive oil and tween 80.
While the manufacturing conditions of pullulan can be altered in order to increase yield, chemical modifications of pullulan can also be used to alter the properties of the pullulan. The unmodified structure of pullulan contains nine hydroxyl groups attached to the backbone of the molecule, and these hydroxyl groups can be replaced with other functional groups. Some examples of processes that can mo |
https://en.wikipedia.org/wiki/Maria%20Colombo%20%28mathematician%29 | Maria Colombo (born 25 May 1989) is an Italian mathematician specializing in mathematical analysis. She is a professor at the EPFL (École Polytechnique Fédérale de Lausanne) in Switzerland, where she holds the chair for mathematical analysis, calculus of variations and partial differential equations.
Education and career
Colombo was born in Luino, near the Swiss border of Italy. She competed for Italy in the 2005, 2006, and 2007 International Mathematical Olympiads, earning bronze, gold, and silver medals respectively.
She earned bachelor's and master's degrees in mathematics at the University of Pisa in 2010 and 2011, and completed a Ph.D. in 2015 at the Scuola Normale Superiore di Pisa, under the joint supervision of Luigi Ambrosio and Alessio Figalli. Her dissertation, Flows of non-smooth vector fields and degenerate elliptic equations: With applications to the Vlasov-Poisson and semigeostrophic systems, was published as a book in 2017 by Edizioni della Normale.
After postdoctoral research with Camillo De Lellis at the University of Zurich, she joined the EPFL as an assistant professor in 2018, and was promoted to full professor in 2021.
Recognition
The Accademia dei Lincei gave Colombo their Gioacchino Iapichino Prize for 2016. She was the 2017 winner of the Carlo Miranda Prize of the , and the 2019 winner of the Bartolozzi Prize of the Italian Mathematical Union. She is the 2022 winner of the biennial Peter Lax Award, to be given at the International Conference on Hyperbolic Problems, and the 2023 winner of the Collatz Prize of the International Council for Industrial and Applied Mathematics, "for her fundamental contributions to regularity theory and the analysis of singularities in elliptic partial differential equations, geometric variational problems, transport equations, and incompressible fluid dynamics". |
https://en.wikipedia.org/wiki/Analytic%20function%20of%20a%20matrix | In mathematics, every analytic function can be used for defining a matrix function that maps square matrices with complex entries to square matrices of the same size.
This is used for defining the exponential of a matrix, which is involved in the closed-form solution of systems of linear differential equations.
Extending scalar function to matrix functions
There are several techniques for lifting a real function to a square matrix function such that interesting properties are maintained. All of the following techniques yield the same matrix function, but the domains on which the function is defined may differ.
Power series
If the analytic function has the Taylor expansion
then a matrix function can be defined by substituting by a square matrix: powers become matrix powers, additions become matrix sums and multiplications by coefficients become scalar multiplications. If the series converges for , then the corresponding matrix series converges for matrices such that for some matrix norm that satisfies .
Diagonalizable matrices
A square matrix is diagonalizable, if there is an invertible matrix such that is a diagonal matrix, that is, has the shape
As it is natural to set
It can be verified that the matrix does not depend on a particular choice of .
For example, suppose one is seeking for
One has
for
Application of the formula then simply yields
Likewise,
Jordan decomposition
All complex matrices, whether they are diagonalizable or not, have a Jordan normal form , where the matrix J consists of Jordan blocks. Consider these blocks separately and apply the power series to a Jordan block:
This definition can be used to extend the domain of the matrix function
beyond the set of matrices with spectral radius smaller than the radius of convergence of the power series.
Note that there is also a connection to divided differences.
A related notion is the Jordan–Chevalley decomposition which expresses a matrix as a sum of a diagonalizable and a |
https://en.wikipedia.org/wiki/Intel%208237 | Intel 8237 is a direct memory access (DMA) controller, a part of the MCS 85 microprocessor family. It enables data transfer between memory and the I/O with reduced load on the system's main processor by providing the memory with control signals and memory address information during the DMA transfer.
The 8237 is a four-channel device that can be expanded to include any number of DMA channel inputs. The 8237 is capable of DMA transfers at rates of up to per second. Each channel is capable of addressing a full 64k-byte section of memory and can transfer up to 64k bytes with a single programming.
A single 8237 was used as the DMA controller in the original IBM PC and IBM XT. The IBM PC AT added another 8237 in master-slave configuration, increasing the number of DMA channels from four to seven. Later IBM-compatible personal computers may have chip sets that emulate the functions of the 8237 for backward compatibility. The Intel 8237 was actually designed by AMD (called Am9517). It was part of a cross licensing agreement, allowing AMD to manufacture Intel processors, that made the design available for Intel as well. This is why the Intel package has "(C) AMD 1980" printed on it.
Modes
The 8237 operates in four different modes, depending upon the number of bytes transferred per cycle and number of ICs used:
Single - One DMA cycle, one CPU cycle interleaved until address counter reaches zero.
Block - Transfer progresses until the word count reaches zero or the EOP signal goes active.
Demand - Transfers continue until TC or EOP goes active or DRQ goes inactive. The CPU is permitted to use the bus when no transfer is requested.
Cascade - Used to cascade additional DMA controllers. DREQ and DACK is matched with HRQ and HLDA from the next chip to establish a priority chain. Actual bus signals is executed by cascaded chip.
Memory-to-memory transfer can be performed. This means data can be transferred from one memory device to another memory device. The channel 0 Curre |
https://en.wikipedia.org/wiki/HDMI | High-Definition Multimedia Interface (HDMI) is a proprietary audio/video interface for transmitting uncompressed video data and compressed or uncompressed digital audio data from an HDMI-compliant source device, such as a display controller, to a compatible computer monitor, video projector, digital television, or digital audio device. HDMI is a digital replacement for analog video standards.
HDMI implements the ANSI/CTA-861 standard, which defines video formats and waveforms, transport of compressed and uncompressed LPCM audio, auxiliary data, and implementations of the VESA EDID. CEA-861 signals carried by HDMI are electrically compatible with the CEA-861 signals used by the Digital Visual Interface (DVI). No signal conversion is necessary, nor is there a loss of video quality when a DVI-to-HDMI adapter is used. The Consumer Electronics Control (CEC) capability allows HDMI devices to control each other when necessary and allows the user to operate multiple devices with one handheld remote control device.
Several versions of HDMI have been developed and deployed since the initial release of the technology, occasionally introducing new connectors with smaller form factors, but all versions still use the same basic pinout and are compatible with all connector types and cables. Other than improved audio and video capacity, performance, resolution and color spaces, newer versions have optional advanced features such as 3D, Ethernet data connection, and CEC extensions.
Production of consumer HDMI products started in late 2003. In Europe, either DVI-HDCP or HDMI is included in the HD ready in-store labeling specification for TV sets for HDTV, formulated by EICTA with SES Astra in 2005. HDMI began to appear on consumer HDTVs in 2004 and camcorders and digital still cameras in 2006. , nearly 10 billion HDMI devices have been sold.
History
The HDMI founders were Hitachi, Panasonic, Philips, Silicon Image, Sony, Thomson, and Toshiba. Digital Content Protection, LLC provi |
https://en.wikipedia.org/wiki/Data%20center%20bridging | Data center bridging (DCB) is a set of enhancements to the Ethernet local area network communication protocol for use in data center environments, in particular for use with clustering and storage area networks.
Motivation
Ethernet is the primary network protocol in data centers for computer-to-computer communications. However, Ethernet is designed to be a best-effort network that may experience packet loss when the network or devices are busy.
In IP networks, transport reliability under the end-to-end principle is the responsibility of the transport protocols, such as the Transmission Control Protocol (TCP). One area of evolution for Ethernet is to add extensions to the existing protocol suite to provide reliability without requiring the complexity of TCP. With the move to 10 Gbit/s and faster transmission rates, there is also a desire for finer granularity in control of bandwidth allocation and to ensure it is used more effectively. These enhancements are particularly important to make Ethernet a more viable transport for storage and server cluster traffic. A primary motivation is the sensitivity of Fibre Channel over Ethernet to frame loss. The higher level goal is to use a single set of Ethernet physical devices or adapters for computers to talk to a Storage Area Network, Local Area network and InfiniBand fabric.
Approach
DCB aims, for selected traffic, to eliminate loss due to queue overflow (sometimes called lossless Ethernet) and to be able to allocate bandwidth on links. Essentially, DCB enables, to some extent, the treatment of different priorities as if they were different pipes. To meet these goals new standards are being (or have been) developed that either extend the existing set of Ethernet protocols or emulate the connectivity offered by Ethernet protocols. They are being (or have been) developed respectively by two separate standards bodies:
The Institute of Electrical and Electronics Engineers (IEEE) Data Center Bridging Task Group of the IE |
https://en.wikipedia.org/wiki/Symmetry%20in%20Mechanics | Symmetry in Mechanics: A Gentle, Modern Introduction is an undergraduate textbook on mathematics and mathematical physics, centered on the use of symplectic geometry to solve the Kepler problem. It was written by Stephanie Singer, and published by Birkhäuser in 2001.
Topics
The Kepler problem in classical mechanics is a special case of the two-body problem in which two point masses interact by Newton's law of universal gravitation (or by any central force obeying an inverse-square law). The book starts and ends with this problem, the first time in an ad hoc manner that represents the problem using a system of twelve variables for the positions and momentum vectors of the two bodies, uses the conservation laws of physics to set up a system of differential equations obeyed by these variables, and solves these equations. The second time through, it describes the positions and variables of the two bodies as a single point in a 12-dimensional phase space, describes the behavior of the bodies as a Hamiltonian system, and uses symplectic reductions to shrink the phase space to two dimensions before solving it to produce Kepler's laws of planetary motion in a more direct and principled way.
The middle portion of the book sets up the machinery of symplectic geometry needed to complete this tour. Topics covered in this part include manifolds, vector fields and differential forms, pushforwards and pullbacks, symplectic manifolds, Hamiltonian energy functions, the representation of finite and infinitesimal physical symmetries using Lie groups and Lie algebras, and the use of the moment map to relate symmetries to conserved quantities. In these topics, as well, concrete examples are central to the presentation.
Audience and reception
The book is written as a textbook for undergraduate mathematics and physics students, with many exercises, and it assumes that the students are already familiar with multivariable calculus and linear algebra, a significantly lower level of backgr |
https://en.wikipedia.org/wiki/GeoSpy | GeoSpy was an outdoor recreational activity which combines geographic locations and maps with photography in a location-based game. To play the game requires a camera and a mobile Global Positioning System (GPS) device.
There are several goals in the game, but the primary one is to find and create objects through pictures of objects and places which are uploaded to the game's website.
To create an object the participant requires a complete knowledge about the object, and the GPS coordinates and photos of the object that the participant has taken. Similarly, existing objects can be secured by visiting and photographing the object and posting the photo on the game’s website as proof that the competitor visited the object. The objects are divided into different categories namely Civil, Religious & Historical, Natural, Technical and Military objects with further sub-categories such as hospitals, museums, factories, memorials, etc.
Participants in the game are called spies.
See also
Augmented reality
Benchmarking (geolocating)
Encounter (game)
Geocaching
Geohashing
Location-based game
Munzee
Orienteering
Puzzlehunt
Questing
Transmitter hunting
Waymarking |
https://en.wikipedia.org/wiki/Vulnerability%20index | A vulnerability index is a measure of the exposure of a population to some hazard. Typically, the index is a composite of multiple quantitative indicators that via some formula, delivers a single numerical result. Through such an index "diverse issues can be combined into a standardised framework...making comparisons possible". For instance, indicators from the physical sciences can be combined with social, medical and even psychological variables to evaluate potential complications for disaster planning.
The origin of vulnerability indexes as a policy planning tool began with the United Nations Environmental Program. One of the participants in the early task forces has also conducted secondary research documenting the evolution of the analytic tool through various stages. The term and methodology then expanded through medical literature and social work as discussed by Dr. James O'Connell of Boston Healthcare for the Homeless.
Basic methodology
The basic methodology of constructing a vulnerability index is described by University of Malta researcher Lino Briguglio. The individual measures are weighted according to their relative importance. A cumulative score is then generated, typically by adding the weighted values. Decision trees can evaluate alternative policy options. Much of the original research has been evaluated by Lino Briguglio and presenters at Oxford, providing a body of secondary source material.
Earlier use
A composite vulnerability index grew out of the work of South Pacific Applied Geoscience Commission (SOPAC), Fiji, and the Expert Group on Vulnerability Indexes affiliated with the United Nations, in response to a call made in the Barbados Plan of Action, the Alliance of Small Island States (AOSIS).
Bruguglio participated in development of the vulnerability index model for international organizations of small island developing states. University of Malta also hosts the Islands and Small States Institute, Foundation for International Studies. |
https://en.wikipedia.org/wiki/Edyth%20May%20Sliffe%20Award | The Edyth May Sliffe Award is given annually to (roughly) 20 teachers in the United States by the Mathematical Association of America (MAA). The awards are funded by a bequest from a retired high school mathematics teacher named Edyth May Sliffe, of Emeryville, California. Her purpose was to award high school teachers whose students have done well on the AHSME, now the AMC 12. She felt students who won in math competitions received honors, but their teachers never received any recognition.
Edyth May Sliffe and her Award
(1901 - 1986)
Edyth May Sliffe, a retired teacher who taught at Emery High School, felt that teachers also needed recognition for their contributions toward the students' success. In 1978 she contacted the Governor of the Northern California Section of the MAA, Professor Kenneth Rebman. Kenneth Rebman then told the President of the MAA, Professor Henry Alder, and arranged a meeting with Sliffe. She decided to use her estate to recognize 20 teachers of the highest scoring teams annually. Edyth Sliffe died on December 11, 1986. In accordance with her will, over $250,000 was donated to the MAA. Since 1989, about 20 high school teachers from the top 60 American and Canadian schools have received the award annually. In 1995, the MAA Committee extended the award to middle school teachers. Five teachers are selected from each of the ten American Mathematics Competition Regions.
Nomination of a Teacher
Three students from each of the top 60 highest scoring teams in the AMC 12 are asked to nominate a teacher they felt contributed most to their success.
Award
Award-winning teachers win a cash prize of $350-$750, a letter from the president of the MAA, a certificate signed by the president of MAA, Chair of the Committee on the AMC 12, and the Executive Director of the American Mathematics Competitions. In addition, they get one year free membership in the MAA, and recognition in national and regional professional publications. The award ceremony is arran |
https://en.wikipedia.org/wiki/Cyber%20manufacturing | Cyber manufacturing is a concept derived from cyber-physical systems (CPS) that refers to a modern manufacturing system that offers an information-transparent environment to facilitate asset management, provide reconfigurability, and maintain productivity. Compared with conventional experience-based management systems, cyber manufacturing provides an evidence-based environment to keep equipment users aware of networked asset status, and transfer raw data into possible risks and actionable information. Driving technologies include design of cyber-physical systems, combination of engineering domain knowledge and computer sciences, as well as information technologies. Among them, mobile applications for manufacturing is an area of specific interest to industries and academia.
Motivation
The idea of cyber manufacturing originates from the fact that Internet-enabled services have added business value in economic sectors such as retail, music, consumer products, transportation, and healthcare; however, compared to existing Internet-enabled sectors, manufacturing assets are less connected and less accessible in real-time. Besides, current manufacturing enterprises make decisions following a top-down approach: from overall equipment effectiveness to assignment of production requirements, without considering the condition of machines. This usually leads to inconsistency in operation management due to lack of linkage between factories, possible overstock in spare part inventory, as well as unexpected machine downtime. Such situation calls for connectivity between machines as a foundation, and analytics on top of that as a necessity to translate raw data into information that actually facilitates user decision making. Expected functionalities of cyber manufacturing systems include machine connectivity and data acquisition, machine health prognostics, fleet-based asset management, and manufacturing reconfigurability.
Technology
Several technologies are involved in developing |
https://en.wikipedia.org/wiki/Network%20Science%20CTA | The Network Science Collaborative Technology Alliance (NS CTA) is a collaborative research alliance funded by the US Army Research Laboratory (ARL) and focused on fundamental research on the critical scientific and technical challenges that emerge from the close interdependence of several genres of networks such as social/cognitive, information, and communications networks. The primary goal of the NS CTA is to deeply understand the underlying commonalities among these intertwined networks, and, by understanding, improve our ability to analyze, predict, design, and influence complex systems interweaving many kinds of networks.
This emerging research domain, termed network science,
also has the potential to accelerate understanding of each
genre of network by cross-fertilization of insights, theories,
algorithms, and approaches and by expanding their study
into the larger context of the multi-genre (or composite) network environments
within which each must act.
The NS CTA is an alliance between ARL, other government
researchers, and a consortium of four research centers: an
Academic Research Center (ARC) focused on social/cognitive
networks (the SCNARC), an ARC focused on information
networks (the INARC), an ARC focused on communications
networks (the CNARC), and an Interdisciplinary Research Center
(the IRC) focused on interdisciplinary research and technology transition. Overall, these centers include roughly one hundred
PhD-level researchers from about 30 universities and industrial
research labs, engaged with as many graduate students and interns.
The Alliance unites research across organizations and research
disciplines to address the critical technical challenges faced by
the Army in a world where all missions are embedded in and
depend upon many genres of networks. The expected impact
of its transdisciplinary research includes greatly enhanced
human performance for network-embedded missions and
greatly enhanced speed and precision for complex military
operati |
https://en.wikipedia.org/wiki/Radio%20resource%20management | Radio resource management (RRM) is the system level management of co-channel interference, radio resources, and other radio transmission characteristics in wireless communication systems, for example cellular networks, wireless local area networks, wireless sensor systems, and radio broadcasting networks. RRM involves strategies and algorithms for controlling parameters such as transmit power, user allocation, beamforming, data rates, handover criteria, modulation scheme, error coding scheme, etc. The objective is to utilize the limited radio-frequency spectrum resources and radio network infrastructure as efficiently as possible.
RRM concerns multi-user and multi-cell network capacity issues, rather than the point-to-point channel capacity. Traditional telecommunications research and education often dwell on channel coding and source coding with a single user in mind, but when several users and adjacent base stations share the same frequency channel it may not be possible to achieve the maximum channel capacity. Efficient dynamic RRM schemes may increase the system spectral efficiency by an order of magnitude, which often is considerably more than what is possible by introducing advanced channel coding and source coding schemes. RRM is especially important in systems limited by co-channel interference rather than by noise, for example cellular systems and broadcast networks homogeneously covering large areas, and wireless networks consisting of many adjacent access points that may reuse the same channel frequencies.
The cost for deploying a wireless network is normally dominated by base station sites (real estate costs, planning, maintenance, distribution network, energy, etc.) and sometimes also by frequency license fees. So, the objective of radio resource management is typically to maximize the system spectral efficiency in bit/s/Hz/area unit or Erlang/MHz/site, under some kind of user fairness constraint, for example, that the grade of service should be above |
https://en.wikipedia.org/wiki/Effective%20stress | The effective stress can be defined as the stress, depending on the applied tension and pore pressure , which controls the strain or strength behaviour of soil and rock (or a generic porous body) for whatever pore pressure value or, in other terms, the stress which applied over a dry porous body (i.e. at ) provides the same strain or strength behaviour which is observed at ≠ 0. In the case of granular media it can be viewed as a force that keeps a collection of particles rigid. Usually this applies to sand, soil, or gravel, as well as every kind of rock and several other porous materials such as concrete, metal powders, biological tissues etc. The usefulness of an appropriate ESP formulation consists in allowing to assess the behaviour of a porous body for whatever pore pressure value on the basis of experiments involving dry samples (i.e. carried out at zero pore pressure).
History
Karl von Terzaghi first proposed the relationship for effective stress in 1925. For him, the term "effective" meant the calculated stress that was effective in moving soil, or causing displacements. It has been often interpreted as the average stress carried by the soil skeleton. Afterwards, different formulations have been proposed for the effective stress. Maurice Biot fully developed the three-dimensional soil consolidation theory, extending the one-dimensional model previously developed by Terzaghi to more general hypotheses and introducing the set of basic equations of Poroelasticity. Alec Skempton in his work in 1960, has carried out an extensive review of available formulations and experimental data in literature about effective stress valid in soil, concrete and rock, in order to reject some of these expressions, as well as clarify what expression was appropriate according to several work hypotheses, such as stress–strain or strength behaviour, saturated or nonsaturated media, rock/concrete or soil behaviour, etc.
Description
Effective stress (σ') acting on a soil is calcula |
https://en.wikipedia.org/wiki/Scientific%20pitch%20notation | Scientific pitch notation (SPN), also known as American standard pitch notation (ASPN) and international pitch notation (IPN), is a method of specifying musical pitch by combining a musical note name (with accidental if needed) and a number identifying the pitch's octave.
Although scientific pitch notation was originally designed as a companion to scientific pitch (see below), the two are not synonymous. Scientific pitch is a pitch standard—a system that defines the specific frequencies of particular pitches (see below). Scientific pitch notation concerns only how pitch names are notated, that is, how they are designated in printed and written text, and does not inherently specify actual frequencies. Thus, the use of scientific pitch notation to distinguish octaves does not depend on the pitch standard used.
Nomenclature
The notation makes use of the traditional tone names (A to G) which are followed by numbers showing which octave they are part of.
For standard A440 pitch equal temperament, the system begins at a frequency of 16.35160 Hz, which is assigned the value C0.
The octave 0 of the scientific pitch notation is traditionally called the sub-contra octave, and the tone marked C0 in SPN is written as ,,C or C,, or CCC in traditional systems, such as Helmholtz notation. Octave 0 of SPN marks the low end of what humans can actually perceive, with the average person being able to hear frequencies no lower than 20 Hz as pitches.
The octave number increases by 1 upon an ascension from B to C. Thus, A0 refers to the first A above C0 and middle C (the one-line octave's C or simply ) is denoted as C4 in SPN. For example, C4 is one note above B3, and A5 is one note above G5.
The octave number is tied to the alphabetic character used to describe the pitch, with the division between note letters ‘B’ and ‘C’, thus:
"B3" and all of its possible variants (B, B, B, B, B) would properly be designated as being in octave "3".
"C4" and all of its possible variants (C, |
https://en.wikipedia.org/wiki/Ydc2%20protein%20domain | In molecular biology, the protein domain, Ydc2 (also known as SpCce1), is a Holliday junction resolvase from the fission yeast Schizosaccharomyces pombe that is involved in the maintenance of mitochondrial DNA.
Function
In molecular biology, the Ydc2 domains are enzymes, or in other words biological catalysts, capable of resolving Holliday junctions into separate DNA duplexes by cleaving DNA after 5'-CT-3, and 5'-TT-3, sequences.
Properties
The junction resolving enzymes are very diverse, but have the following properties in common:
high structure specificity for binding
metal dependent, sequence specific cleavage activity
Essentially, they are highly specific.
Limiting factors
Furthermore, the cleavage efficiency is affected by:
strand type (continuous or exchange)
nucleotide sequence at cleavage site
Structure
This protein domain forms a ribonuclease H fold consisting of two beta sheets and one alpha helix, arranged as a beta-alpha-beta motif. Each beta sheet has five strands, arranged in a 32145 order, with the second strand being antiparallel to the rest. |
https://en.wikipedia.org/wiki/Grip%20%28raven%29 | Grip was a talking raven kept as a pet by Charles Dickens. She was the basis for a character of the same name in Dickens's novel Barnaby Rudge and is generally considered to have inspired the eponymous bird from Edgar Allan Poe's poem "The Raven".
Grip lived with the Dickens family in their home at 1 Devonshire Terrace, Marylebone. She could repeat several phrases, she buried coins and cheese in the garden, and she often bit people, including the coachman and the children. Following an incident where Grip bit one of the Dickens children, she was banished to the shed.
Grip died in 1841, possibly from lead poisoning after consuming a large amount of lead paint. After a necropsy, Dickens had her stuffed and mounted. She was displayed above the desk in his study and he replaced her with another raven he also named Grip. Her remains passed through the hands of several collectors after Dickens's death and are now on display in the Rare Book Department of the Parkway Central Library in Philadelphia.
Life in London
Grip was a female common raven (Corvus corax), hatched in England 1839. Charles Dickens may have been considering including a raven as a character in his novel Barnaby Rudge as early as 1839. After he announced to his neighbours that he had a fancy for ravens, Grip was discovered in a "modest retirement" in London by Frederick Ash and gifted to Dickens.
Dickens named the raven Grip and she lived with the Dickens family at 1 Devonshire Terrace, in Marylebone near Regent's Park. The earliest mention of Grip was in a letter from Dickens to his friend Daniel Maclise on 13 February 1840 in which he joked, "I love nobody here but the Raven, and I only love him because he seems to have no feeling in common with anybody."
Grip was treated as a family pet in the Dickens household, allowed to roam freely like a cat or a dog. She grew to be 18 inches in length and her wingspan was at least 25 inches.
She was a talking bird and knew several phrases, her favourite bein |
https://en.wikipedia.org/wiki/169%20%28number%29 | 169 (one hundred [and] sixty-nine) is the natural number following 168 and preceding 170.
In mathematics
169 is an odd number, a composite number, and a deficient number.
169 is a square number: 13 × 13 = 169, and if each number is reversed the equation is still true: 31 × 31 = 961. 144 shares this property: 12 × 12 = 144, 21 × 21 = 441.
169 is one of the few squares to also be a centered hexagonal number. Like all odd squares, it is a centered octagonal number. 169 is an odd-indexed Pell number, thus it is also a Markov number, appearing in the solutions (2, 169, 985), (2, 29, 169), (29, 169, 14701), etc. 169 is the sum of seven consecutive primes: 13 + 17 + 19 + 23 + 29 + 31 + 37. 169 is a difference in consecutive cubes, equaling
In astronomy
169 Zelia is a bright main belt asteroid
Gliese 169 is an orange, main sequence (K7 V) star in the constellation Taurus
QSO B0307+169 is a quasar in the constellation Aries
Sayh al Uhaymir 169 is a 206g lunar meteorite found in Sultanate of Oman
In the military
was a United States Navy technical research ship during the 1960s
was a United States Navy during World War II
was a United States Navy during World War II
was a United States Navy following World War I
was a United States Navy during World War II
was a United States Navy submarine during World War II
169th Battalion, CEF unit in the Canadian Expeditionary Force during the World War I
169th Fires Brigade the US Army National Guard artillery brigade, a part of the Colorado Army National Guard
The United States Air Force's 169th Fighter Wing fighter unit at McEntire Joint National Guard Station, South Carolina
169 or 169th Squadrons
169th Airlift Squadron, a unit of the U.S. Air Force
Marine Light Attack Helicopter Squadron 169, United States Marine Corps Light Attack Helicopter Squadron
No. 169 Squadron RAF, a unit of the United Kingdom Royal Air Force
In transportation
Metro Transit Route 169 in Seattle
169th Street station on the I |
https://en.wikipedia.org/wiki/Leading%20zero | A leading zero is any 0 digit that comes before the first nonzero digit in a number string in positional notation. For example, James Bond's famous identifier, 007, has two leading zeros. Any zeroes appearing to the left of the first non-zero digit (of any integer or decimal) do not affect its value, and can be omitted (or replaced with blanks) with no loss of information. Therefore, the usual decimal notation of integers does not use leading zeros except for the zero itself, which would be denoted as an empty string otherwise. However, in decimal fractions strictly between −1 and 1, the leading zeros digits between the decimal point and the first nonzero digit are necessary for conveying the magnitude of a number and cannot be omitted, while trailing zeros – zeros occurring after the decimal point and after the last nonzero digit – can be omitted without changing the meaning.
Occurrence
Often, leading zeros are found on non-electronic digital displays or on such electronic ones as seven-segment displays, that contain fixed sets of digits. These devices include manual counters, stopwatches, odometers, and digital clocks. Leading zeros are also generated by many older computer programs when creating values to assign to new records, accounts and other files, and as such are likely to be used by utility billing systems, human resources information systems and government databases. Many digital cameras and other electronic media recording devices use leading zeros when creating and saving new files to make names of the equal length.
Leading zeros are also present whenever the number of digits is fixed by the technical system (such as in a memory register), but the stored value is not large enough to result in a non-zero most significant digit. The count leading zeros operation efficiently determines the number of leading zero bits in a machine word.
A leading zero appears in roulette in the United States, where "00" is distinct from "0" (a wager on "0" will not win |
https://en.wikipedia.org/wiki/Salvage%20enzyme | Salvage enzymes are enzymes, nucleoside kinases, required during cell division to "salvage" nucleotides, present in body fluids, for the manufacture of DNA. They catalyze the phosphorylation of nucleosides to nucleoside - 5'-phosphates, that are further phosphorylated to triphosphates, that can be built into the growing DNA chain. The salvage enzymes are synthesized during the G1 phase in anticipation of DNA synthesis. After the cell division has been completed, the salvage enzymes, no longer required, are degraded. During interphase the cell derives its requirement of nucleoside-5'-phosphates by de novo synthesis, that leads directly to the 5'-monophosphate nucleotides.
Cell cycle
Enzymes |
https://en.wikipedia.org/wiki/Pwdump | pwdump is the name of various Windows programs that outputs the LM and NTLM password hashes of local user accounts from the Security Account Manager (SAM) database and from the Active Directory domain's users cache on the operating system.
It is widely used, to perform both the famous pass-the-hash attack, or also can be used to brute-force users' password directly. In order to work, it must be run under an Administrator account, or be able to access an Administrator account on the computer where the hashes are to be dumped. Pwdump could be said to compromise security because it could allow a malicious administrator to access user's passwords.
History
The initial program called pwdump was written by Jeremy Allison. He published the source code in 1997 (see open-source). Since then there have been further developments by other programmers:
pwdump (1997) — original program by Jeremy Allison.
pwdump2 (2000) — by Todd Sabin of Bindview (GPL), uses DLL injection.
pwdump3 — by Phil Staubs (GPL), works over the network.
pwdump3e — by Phil Staubs (GPL), sends encrypted over network.
pwdump4 — by bingle (GPL), improvement on pwdump3 and pwdump2.
pwdump5 — by AntonYo! (freeware).
pwdump6 (c. 2006) — by fizzgig (GPL), improvement of pwdump3e. No source code.
fgdump (2007) — by fizzgig, improvement of pwdump6 w/ addons. No source code.
pwdump7 — by Andres Tarasco (freeware), uses own filesystem drivers. No source code.
pwdump8 — by Fulvio Zanetti and Andrea Petralia, supports AES128 encrypted hashes (Windows 10 and later). No source code.
Notes |
https://en.wikipedia.org/wiki/Classification%20of%20electromagnetic%20fields | In differential geometry and theoretical physics, the classification of electromagnetic fields is a pointwise classification of bivectors at each point of a Lorentzian manifold. It is used in the study of solutions of Maxwell's equations and has applications in Einstein's theory of relativity.
The classification theorem
The electromagnetic field at a point p (i.e. an event) of a Lorentzian spacetime is represented by a real bivector defined over the tangent space at p.
The tangent space at p is isometric as a real inner product space to E1,3. That is, it has the same notion of vector magnitude and angle as Minkowski spacetime. To simplify the notation, we will assume the spacetime is Minkowski spacetime. This tends to blur the distinction between the tangent space at p and the underlying manifold; fortunately, nothing is lost by this specialization, for reasons we discuss as the end of the article.
The classification theorem for electromagnetic fields characterizes the bivector F in relation to the Lorentzian metric by defining and examining the so-called "principal null directions". Let us explain this.
The bivector Fab yields a skew-symmetric linear operator defined by lowering one index with the metric. It acts on the tangent space at p by . We will use the symbol F to denote either the bivector or the operator, according to context.
We mention a dichotomy drawn from exterior algebra. A bivector that can be written as , where v, w are linearly independent, is called simple. Any nonzero bivector over a 4-dimensional vector space either is simple, or can be written as , where v, w, x, and y are linearly independent; the two cases are mutually exclusive. Stated like this, the dichotomy makes no reference to the metric η, only to exterior algebra. But it is easily seen that the associated skew-symmetric linear operator Fab has rank 2 in the former case and rank 4 in the latter case.
To state the classification theorem, we consider the eigenvalue problem fo |
https://en.wikipedia.org/wiki/Not%20evaluated | A not evaluated (NE) species is one which has been categorized under the IUCN Red List of threatened species as not yet having been assessed by the International Union for Conservation of Nature.
This conservation category is one of nine IUCN threat assessment categories for species to indicate their risk of global extinction. The categories range from 'extinct' (EX) at one end of the spectrum, to 'least concern' (LC) at the other. The categories 'data deficient' and 'not evaluated' (NE) are not on the spectrum, because they indicate species that have not been reviewed enough to assign to a category.
The category of 'not evaluated' does not indicate that a species is not at risk of extinction, but simply that the species has not yet been studied for any risk to be quantified and published. The IUCN advises that species categorised as 'not evaluated' "...should not be treated as if they were non-threatened. It may be appropriate ... to give them the same degree of attention as threatened taxa, at least until their status can be assessed."
By 2015, the IUCN had assessed and allocated conservation statuses to over 76,000 species worldwide. From these it had categorised some 24,000 species as globally threatened at one conservation level or another. However, despite estimates varying widely as to the number of species existing on Earth (ranging from 3 million up to 30 million), this means the IUCN's 'not evaluated' (NE) category is by far the largest of all nine extinction risk categories.
Other applications
The global IUCN assessment and categorization process has subsequently been applied at country and sometimes at regional levels as the basis for assessing conservation threats and for establishing individual Red Data lists for those areas.
Assessment criteria have also begun to be applied as a way of categorizing threats to ecosystems, with every ecosystem falling into the IUCN category 'not evaluated' prior to the start of the assessment process.
See also
Dat |
https://en.wikipedia.org/wiki/UNIX%20System%20III | UNIX System III (or System 3) is a discontinued version of the Unix operating system released by AT&T's Unix Support Group (USG).
AT&T announced System III in late 1981, and it was first released outside of Bell Labs in 1982. UNIX System III was a mix of various AT&T Unix systems: Version 7 Unix, PWB/UNIX 2.0, CB UNIX 3.0, UNIX/RT and UNIX/32V. System III supported the DEC PDP-11 and VAX computers.
The system was apparently called System III because it was considered the outside release of UNIX/TS 3.0.1 and CB UNIX 3 which were internally supported Bell Labs Unices; its manual refers to it as UNIX Release 3.0 and there were no Unix versions called System I or System II. There was no official release of UNIX/TS 4.0 (which would have been System IV) either, so System III was succeeded by System V, based on UNIX/TS 5.0.
System III introduced new features such as named pipes, the uname system call and command, and the run queue. It also combined various improvements to Version 7 Unix by outside organizations. However, it did not include notable additions made in BSD such as the C shell (csh) and screen editing.
Third-party variants of System III include (early versions of) HP-UX, IRIX, IS/3 and PC/IX, PC-UX, PNX, SINIX, Venix and Xenix. |
https://en.wikipedia.org/wiki/Congruence%20lattice%20problem | In mathematics, the congruence lattice problem asks whether every algebraic distributive lattice is isomorphic to the congruence lattice of some other lattice. The problem was posed by Robert P. Dilworth, and for many years it was one of the most famous and long-standing open problems in lattice theory; it had a deep impact on the development of lattice theory itself. The conjecture that every distributive lattice is a congruence lattice is true for all distributive lattices with at most ℵ1 compact elements, but F. Wehrung provided a counterexample for distributive lattices with ℵ2 compact elements using a construction based on Kuratowski's free set theorem.
Preliminaries
We denote by Con A the congruence lattice of an algebra A, that is, the lattice of all congruences of A under inclusion.
The following is a universal-algebraic triviality. It says that for a congruence, being finitely generated is a lattice-theoretical property.
Lemma.
A congruence of an algebra A is finitely generated if and only if it is a compact element of Con A.
As every congruence of an algebra is the join of the finitely generated congruences below it (e.g., every submodule of a module is the union of all its finitely generated submodules), we obtain the following result, first published by Birkhoff and Frink in 1948.
Theorem (Birkhoff and Frink 1948).
The congruence lattice Con A of any algebra A is an algebraic lattice.
While congruences of lattices lose something in comparison to groups, modules, rings (they cannot be identified with subsets of the universe), they also have a property unique among all the other structures encountered yet.
Theorem (Funayama and Nakayama 1942).
The congruence lattice of any lattice is distributive.
This says that α ∧ (β ∨ γ) = (α ∧ β) ∨ (α ∧ γ), for any congruences α, β, and γ of a given lattice. The analogue of this result fails, for instance, for modules, as , as a rule, for submodules A, B, C of a given module.
Soon after this result, Dilworth p |
https://en.wikipedia.org/wiki/Van%20de%20Graaff%20generator | A Van de Graaff generator is an electrostatic generator which uses a moving belt to accumulate electric charge on a hollow metal globe on the top of an insulated column, creating very high electric potentials. It produces very high voltage direct current (DC) electricity at low current levels. It was invented by American physicist Robert J. Van de Graaff in 1929.
The potential difference achieved by modern Van de Graaff generators can be as much as 5 megavolts. A tabletop version can produce on the order of 100 kV and can store enough energy to produce visible electric sparks. Small Van de Graaff machines are produced for entertainment, and for physics education to teach electrostatics; larger ones are displayed in some science museums.
The Van de Graaff generator was originally developed as a particle accelerator for physics research, as its high potential can be used to accelerate subatomic particles to great speeds in an evacuated tube. It was the most powerful type of accelerator until the cyclotron was developed in the early 1930s. Van de Graaff generators are still used as accelerators to generate energetic particle and X-ray beams for nuclear research and nuclear medicine.
The voltage produced by an open-air Van de Graaff machine is limited by arcing and corona discharge to about 5 MV. Most modern industrial machines are enclosed in a pressurized tank of insulating gas; these can achieve potentials as large as about 25 MV.
History
Background
The concept of an electrostatic generator in which charge is mechanically transported in small amounts into the interior of a high-voltage electrode originated with the Kelvin water dropper, invented in 1867 by William Thomson (Lord Kelvin), in which charged drops of water fall into a bucket with the same polarity charge, adding to the charge.
In a machine of this type, the gravitational force moves the drops against the opposing electrostatic field of the bucket. Kelvin himself first suggested using a belt to carry |
https://en.wikipedia.org/wiki/Quantization%20%28music%29 | In digital music processing technology, quantization is the studio-software process of transforming performed musical notes, which may have some imprecision due to expressive performance, to an underlying musical representation that eliminates the imprecision. The process results in notes being set on beats and on exact fractions of beats.
The purpose of quantization in music processing is to provide a more beat-accurate timing of sounds. Quantization is frequently applied to a record of MIDI notes created by the use of a musical keyboard or drum machine. Additionally, the phrase "pitch quantization" can refer to pitch correction used in audio production, such as using Auto-Tune.
Description
A frequent application of quantization in this context lies within MIDI application software or hardware. MIDI sequencers typically include quantization in their manifest of edit commands. In this case, the dimensions of this timing grid are set beforehand. When one instructs the music application to quantize a certain group of MIDI notes in a song, the program moves each note to the closest point on the timing grid. Quantization in MIDI is usually applied to Note On messages and sometimes Note Off messages; some digital audio workstations shift the entire note by moving both messages together. Sometimes quantization is applied in terms of a percentage, to partially align the notes to a certain beat. Using a percentage of quantization allows for the subtle preservation of some natural human timing nuances.
The most difficult problem in quantization is determining which rhythmic fluctuations are imprecise or expressive (and should be removed by the quantization process) and which should be represented in the output score. For instance, a simple children's song should probably have very coarse quantization, resulting in few different notes in output. On the other hand, quantizing a performance of a piano piece by Arnold Schoenberg, for instance, should result in many smaller no |
https://en.wikipedia.org/wiki/Chasing%20Shadows%3A%20My%20Life%20Tracking%20the%20Great%20White%20Shark | Chasing Shadows: My Life Tracking the Great White Shark is a memoir written by Greg Skomal that chronicles his decades long career as an Atlantic shark researcher. It was published in July 2023 by William Morrow, an imprint of HarperCollins. Ret Talbot, a science writer and independent journalist, co-authored this book. Talbot collaborated with Skomal so that the book would appeal to a general audience. The goal for Skomal is to educate and share insights with readers about the Great white shark.
Other books
Close to Shore by Michael Capuzzo about the Jersey Shore shark attacks of 1916
Twelve Days of Terror by Richard Fernicola about the same events
The Devil's Teeth by Canadian born journalist Susan Casey. |
https://en.wikipedia.org/wiki/Inorganic%20phosphate%20transporter%20family | The inorganic phosphate transporter (PiT) family is a group of carrier proteins derived from Gram-negative and Gram-positive bacteria, archaea, and eukaryotes.
Function
Functionally-characterized members of the family appear to catalyze inorganic phosphate (Pi) or inorganic sulfate uptake either by H+ or Na+ symport. Both PitA (TC# 2.A.20.1.1) and PitB (TC# 2.A.20.1.2) of E. coli probably catalyze metal ion·phosphate:H+ symport, where Mg2+, Ca2+ or Zn2+ (and probably other divalent cations) can complex with Pi. The mammalian proteins (i.e., TC# 2.A.20.2.7) have been reported to function as viral receptors, but they undoubtedly function as transport proteins as well. For numerous gammaretroviruses, such as the gibbon ape leukemia virus, woolly monkey virus, feline leukemia virus subgroup B, feline leukemia virus subgroup T, and 10A1 murine leukemia virus, this receptor is the human type III sodium-dependent inorganic phosphate transporter, SLC20A1, also known as PiT1.
The malaria parasite, Plasmodium falciparum, grows within its host erythrocyte and induces an increase in the permeability of the erythrocyte membrane to a range of solutes including Na+ and K+. This results in a progressive increase in the concentration of Na+ in the erythrocyte cytosol. The parasite cytosol has a relatively low Na+ concentration, generating a large inward Na+ gradient across the parasite plasma membrane. Saliba et al. (2006) showed that the parasite exploits the Na+ electrochemical gradient to energize the uptake of inorganic phosphate (Pi) with a stoichiometry of 2Na+:1Pi and with an apparent preference for the monovalent over the divalent form of Pi (see TC #2.A.20.2.5).
The generalized transport reactions possibly catalyzed by members of the PiT family are:
(out) + [nH+ or Na+] (out) → (in) + [nH+ or Na+] (in)
Me2+ · (out) + nH+ (out) → Me2+ · (in) + nH+ (in)
(out) + nH+ (out) → (in) + nH+ (in).
Structure
The molecular sizes of Pit family members are reported to var |
https://en.wikipedia.org/wiki/Wood%20Green%20ricin%20plot | The Wood Green ricin plot was an alleged bioterrorism plot to attack the London Underground with ricin poison. The Metropolitan Police Service arrested six suspects on 5 January 2003, with one more arrested two days later.
Within two days, the Biological Weapon Identification Group at the Defence Science and Technology Laboratory in Porton Down were sure that there was no trace of ricin on any of the articles that were found. This fact was initially misreported to other government departments as well as to the public, who only became aware of this in 2005. Reporting restrictions were in place before the public's perceptions could be corrected.
The only subsequent conviction was of Kamel Bourgass, sentenced to 17 years imprisonment for conspiring "together with other persons unknown to commit public nuisance by the use of poisons and/or explosives to cause disruption, fear or injury" on the basis of five pages of his hand-written notes on how to make ricin, cyanide and botulinum. Bourgass had already been sentenced to life imprisonment for the murder of detective Stephen Oake, whom he stabbed to death during his arrest in Manchester. Bourgass also stabbed three other police officers in that incident; they all survived. All other suspects were either released without charge, acquitted, or had their trials abandoned. Bourgass had attended meetings of Al-Muhajiroun leading up to the plot.
Public reaction
Prime Minister Tony Blair referred to the case in a speech shortly after the arrests, in breach of the principle of sub judice which prevents politicians prejudicing impending court cases.
Physicians throughout the United Kingdom were warned to watch for signs that patients had been poisoned by ricin, and the public health director for London urged the public not to be alarmed following some media reports. Britain's largest circulation tabloid newspaper, The Sun, reported the discovery of a "factory of death", and other newspapers warned on their front pages "250,0 |
https://en.wikipedia.org/wiki/Corona%20radiata%20%28embryology%29 | The corona radiata is the innermost layer of the cells of the cumulus oophorus and is directly adjacent to the zona pellucida, the inner protective glycoprotein layer of the ovum. Cumulus oophorus are the cells surrounding corona radiata, and are the cells between corona radiata and follicular antrum. Its main purpose in many animals is to supply vital proteins to the cell. It is formed by follicle cells adhering to the oocyte before it leaves the ovarian follicle, and originates from the squamous granulosa cells present at the primordial stage of follicular development. The corona radiata is formed when the granulosa cells enlarge and become cuboidal, which occurs during the transition from the primordial to primary stage. These cuboidal granulosa cells, also known as the granulosa radiata, form more layers throughout the maturation process, and remain attached to the zona pellucida after the ovulation of the Graafian follicle. For fertilization to occur, sperm cells rely on hyaluronidase (an enzyme found in the acrosome of spermatozoa) to disperse the corona radiata from the zona pellucida of the secondary (ovulated) oocyte, thus permitting entry into the perivitelline space and allowing contact between the sperm cell and the nucleus of the oocyte. |
https://en.wikipedia.org/wiki/Messenger%20of%20Mathematics | The Messenger of Mathematics is a defunct British mathematics journal. The founding editor-in-chief was William Allen Whitworth with Charles Taylor and volumes 1–58 were published between 1872 and 1929. James Whitbread Lee Glaisher was the editor-in-chief after Whitworth. In the nineteenth century, foreign contributions represented 4.7% of all pages of mathematics in the journal.
History
The journal was originally titled Oxford, Cambridge and Dublin Messenger of Mathematics. It was supported by mathematics students and governed by a board of editors composed of members of the universities of Oxford, Cambridge and Dublin (the last being its sole constituent college, Trinity College Dublin). Volumes 1–5 were published between 1862 and 1871. It merged with The Quarterly Journal of Pure and Applied Mathematics to form the Quarterly Journal of Mathematics. |
https://en.wikipedia.org/wiki/Chemocline | A chemocline is a type of cline, a layer of fluid with different properties, characterized by a strong, vertical chemistry gradient within a body of water. In bodies of water where chemoclines occur, the cline separates the upper and lower layers, resulting in different properties for those layers. The lower layer shows a change in the concentration of dissolved gases and solids compared to the upper layer.
Chemoclines most commonly occur where local conditions favor the formation of anoxic bottom water — deep water deficient in oxygen, where only anaerobic forms of life can exist. Common anaerobic organisms that live in these conditions include phototrophic purple sulfur bacteria and green sulfur bacteria. The Black Sea is an example of a body of water with a prominent chemocline, though similar bodies (classified as meromictic lakes) exist across the globe. Meromictic lakes are the result of meromixis, which is a circumstance where a body of water does not fully mix and circulate, causing stratification.
In any body of water in which oxygen-rich surface waters are well-mixed (holomictic), no chemocline will exist, as there is no stratification of layers. Chemoclines can become unstable when dissolved gases become supersaturated, such as H2S, due to mixing associated with bubbling or boiling (ebullition).
Chemocline structure
Containing the largest chemical gradient, the chemocline is a thin boundary layer that separates a meromictic lake into two parts: the upper mixolimnion and the lower monimolimnion. The mixolimnion is a region that is accessed by the wind where the water can be fully mixed and circulated. However, the monimolimnion is dense and cannot interact with the wind in the same manner, preventing mixing. Furthermore, the chemocline's variability in density determines the degree to which the body of water will experience mixing and circulation. Since the chemocline acts as a barrier between the mixed and non-mixed layers, the deeper monimolimnion l |
https://en.wikipedia.org/wiki/Bistorta%20vivipara | Bistorta vivipara (synonym Persicaria vivipara) is a perennial herbaceous flowering plant in the knotweed and buckwheat family Polygonaceae, commonly known as alpine bistort. Scientific synonyms include Bistorta vivipara and Polygonum viviparum. It is common all over the high Arctic through Europe, North America, incl. Greenland, and temperate and tropical Asia. Its range stretches further south in high mountainous areas such as the Alps, Carpathians, Pyrenees, Caucasus, Alaska and the Tibetan Plateau.
Taxonomy
Molecular phylogenetic work has demonstrated that the genus Bistorta represents a distinct lineage within the family Polygonaceae. The genus Bistorta contains at least 42 accepted species.
Description
Alpine bistort is a perennial herb that grows to tall. It has a thick rhizomatous rootstock and an erect, unbranched, hairless stem. The leaves are hairless on the upper surfaces, but hairy and greyish-green below. The basal ones are longish-elliptical with long stalks and rounded bases; the upper ones are few and are linear and stalkless. The tiny flowers are white or pink in the upper part of the spike with five perianth segments, eight stamens with purple anthers and three fused carpels. The lower ones are replaced by bulbils. Flowers rarely produce viable seeds and reproduction is normally by the bulbils, which are small bulb-like structures that develop in the axils of the leaves and may develop into new plants. Very often, a small leaf develops when the bulbil is still attached to the mother plant. The bulbils are rich in starch and are a preferred food for rock ptarmigans (Lagopus mutus) and reindeer; they are also occasionally used by Arctic peoples. Alpine bistort flowers in June and July.
Habitat
Alpine bistort grows in many different plant communities, very often in abundance. Typical habitats include moist short grassland, yards, the edges of tracks, and nutrient-rich fens.
As with many other alpine plants, Alpine bistort is slow-growing and |
https://en.wikipedia.org/wiki/R%C3%B8mer%27s%20determination%20of%20the%20speed%20of%20light | Rømer's determination of the speed of light was the demonstration in 1676 that light has an apprehensible, measurable speed and so does not travel instantaneously. The discovery is usually attributed to Danish astronomer Ole Rømer, who was working at the Royal Observatory in Paris at the time.
By timing the eclipses of the Jovian moon Io, Rømer estimated that light would take about 22 minutes to travel a distance equal to the diameter of Earth's orbit around the Sun. Using modern orbits, this would imply a speed of light of 226,663 kilometres per second, 24.4% lower than the true value of 299,792 km/s. In his calculations Rømer used the idea and observations that the apparent time between eclipses would be greater when the Earth relatively moves away from Jupiter and lesser while moving closer.
Rømer's theory was controversial at the time that he announced it and he never convinced the director of the Paris Observatory, Giovanni Domenico Cassini, to fully accept it. However, it quickly gained support among other natural philosophers of the period such as Christiaan Huygens and Isaac Newton. It was finally confirmed nearly two decades after Rømer's death, with the explanation in 1729 of stellar aberration by the English astronomer James Bradley.
Background
The determination of east-west positioning (longitude) was a significant practical problem in cartography and navigation before the 1700s. In 1598 Philip III of Spain had offered a prize for a method to determine the longitude of a ship out of sight of land. Galileo proposed a method of establishing the time of day, and thus longitude, based on the times of the eclipses of the moons of Jupiter, in essence using the Jovian system as a cosmic clock; this method was not significantly improved until accurate mechanical clocks were developed in the eighteenth century. Galileo proposed this method to the Spanish crown in 1616–1617 but it proved to be impractical, not least because of the difficulty of observing the e |
https://en.wikipedia.org/wiki/Morgan%20Holmes | Morgan Holmes is a Canadian sociologist, author, and a professor at Wilfrid Laurier University, Ontario. She is also an intersex activist and writer, and former member of Intersex Society of North America. Holmes participated in the first public demonstration by intersex people, now marked by Intersex Awareness Day.
Early life
Holmes underwent a clitorectomy, described as a "clitoral recession", at age 7, at The Hospital for Sick Children in Toronto. This surgery was undertaken because her clitoris "could become erect", and the surgery has affected her life ever since, including repeated pelvic exams, adolescent sexual experiences, fear of intimacy, and feelings of difference and embarrassment. Holmes describes how clinician "promises of sexual normalcy are not being met" by surgical intervention.
Holmes refers to herself as "still intersexual" after medical intervention.
Career
Activism
A member of the (now defunct) Intersex Society of North America, Holmes participated with Max Beck and others in the first North American demonstration about intersex issues, a 1996 demonstration as Hermaphrodites with Attitude outside the Annual Meeting of the American Academy of Pediatrics in Boston. The event is now commemorated internationally as Intersex Awareness Day. She participated in the second International Intersex Forum in 2012.
Academia
Holmes is a professor of sociology at Wilfrid Laurier University, Ontario, where she describes her academic interests as sexuality and queer theory, feminist thought; qualitative health research and law related to sexuality and health. Holmes has also extended her interest in intersex issues to other forms of bodily diversity, including disability.
Works
Holmes is widely published, including works that link intersex to queer theory and ideas of compulsory heterosexuality. In Re-membering a Queer Body''' (1994), Holmes describes how surgery on intersex infants is undertaken to make bodies conform to heterosexual norms:
Holmes |
https://en.wikipedia.org/wiki/Privacy%20policy | A privacy policy is a statement or legal document (in privacy law) that discloses some or all of the ways a party gathers, uses, discloses, and manages a customer or client's data. Personal information can be anything that can be used to identify an individual, not limited to the person's name, address, date of birth, marital status, contact information, ID issue, and expiry date, financial records, credit information, medical history, where one travels, and intentions to acquire goods and services. In the case of a business, it is often a statement that declares a party's policy on how it collects, stores, and releases personal information it collects. It informs the client what specific information is collected, and whether it is kept confidential, shared with partners, or sold to other firms or enterprises. Privacy policies typically represent a broader, more generalized treatment, as opposed to data use statements, which tend to be more detailed and specific.
The exact contents of a certain privacy policy will depend upon the applicable law and may need to address requirements across geographical boundaries and legal jurisdictions. Most countries have own legislation and guidelines of who is covered, what information can be collected, and what it can be used for. In general, data protection laws in Europe cover the private sector, as well as the public sector. Their privacy laws apply not only to government operations but also to private enterprises and commercial transactions.
California Business and Professions Code, Internet Privacy Requirements (CalOPPA) mandate that websites collecting Personally Identifiable Information () from California residents must conspicuously post their privacy policy.x (See also Online Privacy Protection Act)
History
In 1968, the Council of Europe began to study the effects of technology on human rights, recognizing the new threats posed by computer technology that could link and transmit in ways not widely available before. |
https://en.wikipedia.org/wiki/Adnan%20Abdallat | Adnan Al Abdallat (1943 – 9 March 2021) was a Jordanian neurologist. He participated in the discovery of Abdallat Davis Farrage syndrome in 1980.
Dr. Adnan Al Abdallat served in King Hussein Medical Center, a military hospital in Amman, Jordan. Abdallat held the position of head of the Neurologist Department in the hospital until he retired and opened his private research and clinic center.
Death
Abdallat died on 9 March 2021, of an infection and complication with COVID-19. |
https://en.wikipedia.org/wiki/New%20York%20Pathological%20Society | The New York Pathological Society is a professional organization for pathologists in New York State. It was organized in 1844 and incorporated in 1886. In 1908, its membership was approximately 215. It published the journal Proceedings of the New York Pathological Society at various times from 1875 until 1955.
Presidents of the Society
The first president of the society was Dr. John A. Swett in 1844. Other notable presidents include James R. Wood (1848, 1857), William H. Van Buren (1850), Edmund Randolph Peaslee (1858), John C. Dalton (1859), Alfred C. Post (1861), Abraham Jacobi (1864), Gurdon Buck (1865), Lewis Albert Sayre (1869), Alfred L. Loomis (1871, 1872), Hermann Knapp (1874), Francis Delafield (1875), Edward G. Janeway (1877), Edward L. Keyes (1879), George Frederick Shrady, Sr. (1883, 1884), John A. Wyeth (1885, 1886),
T. Mitchell Prudden (1887), Hermann Biggs (1891), William H. Park (1903), James Ewing (1921), and Virginia Kneeland Frantz (1949, 1950). |
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