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. it was a saturday, so the radiation safety technician on call didn't arrive for half an hour — at which point i was clean, so the detective questions began. i had spent the day sitting on a plastic step stool. the tech looked at it, said that radon's decay products are concentrated by static electricity, and told me ... | https://api.stackexchange.com |
how long would it take for this super - material to convert to the stuff i scribble with? no, despite the fact that james bond said " diamonds are forever ", that is not exactly the case. although bond's statement is a fair approximation of reality it is not a scientifically accurate description of reality. as we will ... | https://api.stackexchange.com |
is very small the activation energy for the forward reaction is almost the same ) at 367 kj / mol. so at least our rough approximation was in the right ballpark, off by about a factor of 2. however, it appears that the transition state is even further from the midpoint ( closer to starting material ) than we might have... | https://api.stackexchange.com |
in general, all krylov methods essentially seek a polynomial that is small when evaluated on the spectrum of the matrix. in particular, the $ n $ th residual of a krylov method ( with zero initial guess ) can be written in the form $ $ r _ n = p _ n ( a ) b $ $ where $ p _ n $ is some monic polynomial of degree $ n $. ... | https://api.stackexchange.com |
this polynomial, they ought to be quite similar ( the candidate polynomial values are smaller than the gmres residual because $ \ | b \ | _ 2 > 1 $ ) : | https://api.stackexchange.com |
it's undecidable because a law book can include arbitrary logic. a silly example censorship law would be " it is illegal to publicize any computer program that does not halt ". the reason results for mtg exist and are interesting is because it has a single fixed set of ( mostly ) unambiguous rules, unlike law which is ... | https://api.stackexchange.com |
yes, if you can come up with any of the following : deterministic finite automaton ( dfa ), nondeterministic finite automaton ( nfa ), regular expression ( regexp of formal languages ) or regular grammar for some language $ l $, then $ l $ is regular. there are more equivalent models, but the above are the most common.... | https://api.stackexchange.com |
sure, you can combine prngs like this, if you want, assuming they are seeded independently. however, it will be slower and it probably won't solve the most pressing problems that people have. in practice, if you have a requirement for a very high - quality prng, you use a well - vetted cryptographic - strength prng and... | https://api.stackexchange.com |
as suggested, here ’ s an example showing the relevant lines from a description file from a cran / github hosted project that has bioconductor dependencies ( truncated ) : depends : r ( > = 3. 3. 0 ) biocviews : imports : methods, snpstats, dplyr the relevant bit is the empty biocviews : declaration, which allows the b... | https://api.stackexchange.com |
i'm not aware of any recent overview articles, but i am actively involved in the development of the pfasst algorithm so can share some thoughts. there are three broad classes of time - parallel techniques that i am aware of : across the method — independent stages of rk or extrapolation integrators can be evaluated in ... | https://api.stackexchange.com |
kutta, extrapolation, and deferred correction methods ; ketcheson and waheed. this paper also shows a nice way of parallelizing across the method, and introduces the ridc algorithm : parallel high - order integrators ; christlieb, macdonald, ong. this paper introduces the pita algorithm : a time - parallel implicit met... | https://api.stackexchange.com |
that molecule is called geosmin. it is mainly produced 1 by actinomycetes such as streptomyces which are filamentous bacteria that live in soil. other organisms also produce geosmin : cyanobacteria certain fungi an amoeba called vanella a liverwort it is an intracellular metabolite and cell damage is the primary reason... | https://api.stackexchange.com |
what's the big deal? when quantum mechanics was being discovered and formalized, in the 1920s and 1930s, our view of physics was deeply rooted in the macroscopic world. we understood that microscopic entities like atoms and molecules existed, and we arrived reasonably quickly at a good understanding of their basic stru... | https://api.stackexchange.com |
fast, first faster than a microsecond ( $ 10 ^ { - 6 } \ : \ rm s $ ) and then faster than a nanosecond ( $ 10 ^ { - 9 } \ : \ rm s $ ), respectively, and work in the 1970s and 1980s allowed us to create pulses as short as a picosecond ( $ 10 ^ { - 12 } \ : \ rm s $ ) and shorter. if you really push a laser system, usi... | https://api.stackexchange.com |
of magnitude. and that means, in turn, that those dynamics might seem completely out of reach, because the period of oscillation of optical light is still rather slower than this. ( for light of wavelength $ 550 \ : \ rm nm $, the period is of about $ 2 \ : \ rm fs $. ) so that might make you think that a direct observ... | https://api.stackexchange.com |
2018 ) in essence, the laser can be thought of as a constant force ( and therefore a linear ramp in potential energy ) which slowly oscillates and tilts around the potential well that the atomic electron sits in. at the maximum of field intensity, this is enough to yank the electron away ( though more on this later ), ... | https://api.stackexchange.com |
\ rm as $, which is very, very short. ( another cool record is how high you can push the order of nonlinearity in the process, for which, if i understand correctly, a 2012 classic still holds the prize with a minimal order of nonlinearity of 4, 500. ) what can you use these pulses for? we're now down to the most intere... | https://api.stackexchange.com |
##p $ levels, the charge density in the atom will oscillate over time : mathematica source through import [ " this is not a hypothetical or purely theoretical construct, and we can directly observe it in experiment. the first landmark test, reported in real - time observation of valence electron motion. e. goulielmakis... | https://api.stackexchange.com |
##ky, nontrivial shape in the absorption spectrum. however, if we have short pulses of radiation, we are able to control how long we let the electron to sit in that autoionizing state, before we come in with a second pulse of light to disrupt it, and kill the interference : and indeed, when we do this, the build - up o... | https://api.stackexchange.com |
zair. advanced photonics 5, 060501 ( 2023 ) | https://api.stackexchange.com |
this is not an answer to your question, but an extended comment on the issue that has been raised here in comments by different people, namely : are machine learning " tensors " the same thing as tensors in mathematics? now, according to the cichoki 2014, era of big data processing : a new approach via tensor networks ... | https://api.stackexchange.com |
wikipedia : in principle, one could define a " tensor " simply to be an element of any tensor product. however, the mathematics literature usually reserves the term tensor for an element of a tensor product of a single vector space $ v $ and its dual, as above. one example of a real tensor in statistics would be a cova... | https://api.stackexchange.com |
superoxide, o2− is created by the immune system in phagocytes ( including neutrophils, monocytes, macrophages, dendritic cells, and mast cells ) which use nadph oxidase to produce it from o2 for use against invading microorganisms. however, under normal conditions, the mitochondrial electron transport chain is a major ... | https://api.stackexchange.com |
intriguing question. first, the best yield would be achieved by selectively producing one enantiomer instead of the other. in this case, white wants d - methamphetamine ( powerful psychoactive drug ), not l - methamphetamine ( vicks vapor inhaler ). reaction processes designed to do this are known as " asymmetric synth... | https://api.stackexchange.com |
for the non - chemists, that each enantiomer molecule prefers to crystallize with others of the same chiral species, so as the solution cools and the solvent is evaporated off, the d - methamphetamine will form one set of homogeneous crystals and the l - methamphetamine will form another set. this means that all white ... | https://api.stackexchange.com |
i'll translate an entry in the blog gaussianos ( " gaussians " ) about polya's conjecture, titled : a belief is not a proof. we'll say a number is of even kind if in its prime factorization, an even number of primes appear. for example $ 6 = 2 \ cdot 3 $ is a number of even kind. and we'll say a number is of odd kind i... | https://api.stackexchange.com |
trust intuition or what happens for a finite number of cases, no matter how large the number is. until the result is proved for the general case, we have no certainty that it is true. | https://api.stackexchange.com |
a rolling hash function for dna sequences called nthash has recently been published in bioinformatics and the authors dealt with reverse complements : using this table, we can easily compute the hash value for the reverse - complement ( as well as the canonical form ) of a sequence efficiently, without actually reverse... | https://api.stackexchange.com |
s [ i + 1, i + k ] ) = rol ( f ( s [ i, i + k - 1 ] ), 1 ) ^ rol ( h ( s [ i ] ), k ) ^ h ( s [ i + k ] ) r ( s [ i + 1, i + k ] ) = ror ( r ( s [ i, i + k - 1 ] ), 1 ) ^ ror ( h ( ~ s [ i ] ), 1 ) ^ rol ( h ( ~ s [ i + k ] ), k - 1 ) in other words, for the forward kmer for each additional base, xor the following thre... | https://api.stackexchange.com |
as willie wong observed, including an expression of the form $ \ displaystyle \ frac { | \ alpha | } { \ alpha } $ is a way of ensuring that $ \ alpha > 0 $. ( as $ \ sqrt { | \ alpha | / \ alpha } $ is $ 1 $ if $ \ alpha > 0 $ and non - real if $ \ alpha < 0 $. ) the ellipse $ \ displaystyle \ left ( \ frac { x } { 7 ... | https://api.stackexchange.com |
| \ left | x \ right | - 2 \ right | - 1 \ right ) ^ { 2 } } $, the upper halves of the four circles $ \ left ( \ left | \ left | x \ right | - 2 \ right | - 1 \ right ) ^ 2 + y ^ 2 = 1 $ : the third factor $ 9 \ sqrt { \ frac { \ left ( \ left | \ left ( 1 - \ left | x \ right | \ right ) \ left ( \ left | x \ right |... | https://api.stackexchange.com |
left | x \ right | \ right ) \ ; - \ ; \ frac { \ left ( 6 \ sqrt { 10 } \ right ) } { 14 } \ sqrt { 4 - \ left ( \ left | x \ right | - 1 \ right ) ^ { 2 } } \ ; - \ ; y \ ; = \ ; 0 $ looks like : so the sixth factor $ \ frac { 6 \ sqrt { 10 } } { 7 } \ ; + \ ; \ left ( 1. 5 \ ; - \ ;. 5 \ left | x \ right | \ right )... | https://api.stackexchange.com |
look carefully, it's ( distorted ) tetrahedral - - four groups at nearly symmetrically positions in 3d space { * }. so the hybridization is $ sp ^ 3 $. as you can see, the shape is distorted, but it's tetrahedral. technically, the banana bonds can be said to be made up of orbitals similar to $ sp ^ 3 $ but not exactly ... | https://api.stackexchange.com |
. additionally, $ \ ce { al } $ is an iffy case - - it like both covalent and ionic bonds. also, for this geometry ( either by banana bonds or by dative bonds ), i suppose the relative sizes matter as well - - since $ \ ce { bcl3 } $ is a monomer even though $ \ ce { cl } $ has a lone pair and can form a dative bond. *... | https://api.stackexchange.com |
the global alliance for genomics and health has been working on the issue of representing sequencing data and metadata for storage and sharing for quite some time, though with mixed results. they do offer a model and api for storing ngs data in their github repository, but it can be a bit of a pain to get a high - leve... | https://api.stackexchange.com |
what follows is taken ( mostly ) from more extensive discussions in the following sci. math posts : [ 23 january 2000 ] [ 6 november 2006 ] [ 20 december 2006 ] note : the term interval is restricted to nondegenerate intervals ( i. e. intervals containing more than one point ). the continuity set of a derivative on an ... | https://api.stackexchange.com |
nowhere else prior to 1966 ( including goffman's ph. d. dissertation ). interestingly, in a certain sense most derivatives have the property that $ d $ is large in all of the ways listed above ( # 1 through # 7 ). in 1977 cliff weil [ 8 ] published a proof that, in the space of derivatives with the sup norm, all but a ... | https://api.stackexchange.com |
5, american mathematical society, 1994, xii + 195 pages. [ the first edition was published in 1978 as springer - verlag's lecture notes in mathematics # 659. the second edition is essentially unchanged from the first edition with the exception of a new chapter on recent developments ( 23 pages ) and 94 additional bibli... | https://api.stackexchange.com |
five point summary yes, the idea is to give a quick summary of the distribution. it should be roughly symmetrical about mean, the median should be close to 0, the 1q and 3q values should ideally be roughly similar values. coefficients and $ \ hat { \ beta _ i } s $ each coefficient in the model is a gaussian ( normal )... | https://api.stackexchange.com |
) : > 2 * pt ( abs ( tstats ), df = df. residual ( mod ), lower. tail = false ) ( intercept ) petal. width 1. 835999e - 98 4. 073229e - 06 so we compute the upper tail probability of achieving the $ t $ values we did from a $ t $ distribution with degrees of freedom equal to the residual degrees of freedom of the model... | https://api.stackexchange.com |
residuals 148 24. 5124 0. 1656 - - - signif. codes : 0 ‘ * * * ’ 0. 001 ‘ * * ’ 0. 01 ‘ * ’ 0. 05 ‘. ’ 0. 1 ‘ ’ 1 the $ f $ s are the same in the anova output and the summary ( mod ) output. the mean sq column contains the two variances and $ 3. 7945 / 0. 1656 = 22. 91 $. we can compute the probability of achieving an ... | https://api.stackexchange.com |
theorem ( false ) : one can arbitrarily rearrange the terms in a convergent series without changing its value. | https://api.stackexchange.com |
it's difficult to get this to go massively quicker i think - as with this question working with large gzipped fastq files is mostly io - bound. we could instead focus on making sure we are getting the right answer. people deride them too often, but this is where a well - written parser is worth it's weight in gold. hen... | https://api.stackexchange.com |
##5. 112s ( by the way, just zcat - ing the data file to / dev / null ) : real 0m38. 736s user 0m38. 356s sys 0m0. 308s so, i get pretty close in speed, but am likely to be more standards compliant. also this solution gives you more flexibility with what you can do with the data. and my horrible c can almost certainly ... | https://api.stackexchange.com |
the name " ring " is derived from hilbert's term " zahlring " ( number ring ), introduced in his zahlbericht for certain rings of algebraic integers. as for why hilbert chose the name " ring ", i recall reading speculations that it may have to do with cyclical ( ring - shaped ) behavior of powers of algebraic integers.... | https://api.stackexchange.com |
$, $ b $, $ c $ are relatively prime. for example, $ x ^ 2 - 45y ^ 2 $ has $ d = 4 \ cdot45 $. the $ 4 $ was ignored for the reason that $ 4 | d $ necessarily by virtue of gauss's requirement that $ b $ be even, but the factor of $ 3 ^ 2 $ in $ d $ caused gauss to refer to the form as one of " order $ 3 $. " eventually... | https://api.stackexchange.com |
ok, my bad. the error is in the last equation : \ begin { align } kl ( p, q ) & = - \ int p ( x ) \ log q ( x ) dx + \ int p ( x ) \ log p ( x ) dx \ \ \ \ & = \ frac { 1 } { 2 } \ log ( 2 \ pi \ sigma _ 2 ^ 2 ) + \ frac { \ sigma _ 1 ^ 2 + ( \ mu _ 1 - \ mu _ 2 ) ^ 2 } { 2 \ sigma _ 2 ^ 2 } - \ frac { 1 } { 2 } ( 1 + ... | https://api.stackexchange.com |
in practice, most people stick to relatively low orders, usually first or second order. this view is often challenged by more theoretical researchers that believe in more accurate answers. the rate of convergence for simple smooth problems is well documented, for example see bill mitchell's comparison of hp adaptivity.... | https://api.stackexchange.com |
there are some cases of bio - metallic materials, as hinted at by the comments. but these are relatively small amount of metal. it's not that there is a lack of metal available. iron in particular is the fourth most common element in the earth's crust. most soil that has a reddish color has iron in it. there are severa... | https://api.stackexchange.com |
biological materials actually perform as well as or better than metal when they need to. spider silk has a greater tensile strength than steel ( along the direction of the thread ). mollusk shells are models for tank armor - they are remarkably resistant to puncture and breakage. bone is durable for most purposes and f... | https://api.stackexchange.com |
in a svm you are searching for two things : a hyperplane with the largest minimum margin, and a hyperplane that correctly separates as many instances as possible. the problem is that you will not always be able to get both things. the c parameter determines how great your desire is for the latter. i have drawn a small ... | https://api.stackexchange.com |
it is not possible to produce white light without an efficient blue led, either using rgb leds or a blue led + yellow phosphor. the breakthrough was the invention of the high - brightness gallium - nitride blue led by shuji nakamura at nichia in the early 1990s. it still took a while to get the overall efficiency up to... | https://api.stackexchange.com |
there is a very different mechanism for generation ( and detection ) of ultraviolet, visible and infrared light vs radio waves. for the first, it is possible to generate it using chemical reactions ( that is, chemiluminescence, bioluminescence ) with a typical energy of order of 2 ev ( electronovolts ). also, it is eas... | https://api.stackexchange.com |
simulators designed specifically for oxford nanopore : nanosim nanosim - h silico readsim deepsimulator general long read simulators : loresim loresim 2 fastqsim longislnd for an exhaustive list of existing read simulators, see page 15 of my thesis, novel computational techniques for mapping and classifying next - gene... | https://api.stackexchange.com |
yes, you can. and you do not even need to leave the earth to do it. you are always viewing things in the past, just as you are always hearing things in the past. if you see someone do something, who is 30 meters away, you are seeing what happened $ ( 30 \ ; \ mathrm { m } ) / ( 3 \ times10 ^ 8 \ ; \ mathrm { m } / \ ma... | https://api.stackexchange.com |
in general terms, there are the $ o ( n ^ 2 ) $ sorting algorithms, such as insertion sort, bubble sort, and selection sort, which you should typically use only in special circumstances ; quicksort, which is worst - case $ o ( n ^ 2 ) $ but quite often $ o ( n \ log n ) $ with good constants and properties and which ca... | https://api.stackexchange.com |
the " stuff " sticks to itself better than it sticks to the cookie. now if you pull the cookies apart, you create a region of local stress, and one of the two interfaces will begin to unstick. at that point, you get something called " stress concentration " at the tip of the crack ( red arrow ) - where the tensile forc... | https://api.stackexchange.com |
you are right that the two algorithms of dijkstra ( shortest paths from a single start node ) and prim ( minimal weight spanning tree starting from a given node ) have a very similar structure. they are both greedy ( take the best edge from the present point of view ) and build a tree spanning the graph. the value they... | https://api.stackexchange.com |
the power spectral density describes the density of power in a stationary random process $ x ( t ) $ per unit of frequency. by the wiener - khinchin theorem, it can be calculated as follows for a wide - sense stationary random process : $ $ s _ { xx } ( f ) = \ int _ { - \ infty } ^ { \ infty } r _ { xx } ( \ tau ) e ^... | https://api.stackexchange.com |
it does. you would find the average percentage of the atmosphere that is argon is very slightly higher at the floor of valleys. however, bear in mind first of all it wouldn't be anywhere near a complete stratification - - a layer of pure argon, then another of pure n2, and so on. a mixture of nearly ideal gases doesn't... | https://api.stackexchange.com |
here's a video of physicist richard feynman discussing this question. imagine a blue dot and a red dot. they are in front of you, and the blue dot is on the right. behind them is a mirror, and you can see their image in the mirror. the image of the blue dot is still on the right in the mirror. what's different is that ... | https://api.stackexchange.com |
you can think of the dct as a compression step. typically with mfccs, you will take the dct and then keep only the first few coefficients. this is basically the same reason that the dct is used in jpeg compression. dcts are chosen because their boundary conditions work better on these types of signals. let's contrast t... | https://api.stackexchange.com |
magnitudes themselves would probably not be as good because the particular amplitude at different frequencies are less important than the general shape of the spectrum. | https://api.stackexchange.com |
here is my favourite " wow " proof. theorem there exist two positive irrational numbers $ s, t $ such that $ s ^ t $ is rational. proof if $ \ sqrt2 ^ \ sqrt 2 $ is rational, we may take $ s = t = \ sqrt 2 $. if $ \ sqrt 2 ^ \ sqrt 2 $ is irrational, we may take $ s = \ sqrt 2 ^ \ sqrt 2 $ and $ t = \ sqrt 2 $ since $ ... | https://api.stackexchange.com |
edit : i now think that this list is long enough that i shall be maintaining it over time - - updating it whenever i use a new book / learn a new subject. while every suggestion below should be taken with a grain of salt - - i will say that i spend a huge amount of time sifting through books to find the ones that confo... | https://api.stackexchange.com |
tom dieck et. al - - sepanski ( linear ) algebraic groups : springer - - humphreys " elementary " number theory : niven et. al - - ireland et. al algebraic number theory : ash - - lorenzini - - neukirch - - marcus - - washington fourier analysis - - katznelson modular forms : diamond and shurman - - stein local fields ... | https://api.stackexchange.com |
shafarevich - - hartshorne - - griffiths and harris - - mumford | https://api.stackexchange.com |
ok, this question appears to have generated some controversy. on the one hand is the answer by niels nielsen ( currently accepted ), which implies that the orange color is from sodium. on the other hand is the answer by stessenj, which implies that the orange is normal black body radiation from the soot. plus there are... | https://api.stackexchange.com |
with 5 - point moving average before plotting. the spectrometer has lower sensitivity near uv and ir, so disregard the noise there. ( click the image for a larger version. ) what's worth noting is that not only the sodium 590 nm line is present in the orange flame, but also two potassium lines – 766 nm and 770 nm. edit... | https://api.stackexchange.com |
as an extension to moyner's answer, the on - chip sqrt is usually an rsqrt, i. e. a reciprocal square root that computes $ a \ rightarrow 1 / \ sqrt { a } $. so if in your code you're only going to use $ 1 / r $ ( if you're doing molecular dynamics, you are ), you can compute r = rsqrt ( r2 ) directly and save yourself... | https://api.stackexchange.com |
each other. although no interaction is computed for such pairs, accessing the particle data and computing the spurious pairwise distance carries a large cost. my own work in this area ( here, here, and here ), as well as that of others ( e. g. here ), show how these spurious computations can be avoided. these neighbour... | https://api.stackexchange.com |
edit : i am rewriting the answer in response to updates to the original question. tl ; dr : use cram background 1 : quality binning and fastq compression in the old days, base callers outputted base quality at full resolution – you could see quality from q2 to q40 in full range. as a result, quality strings were like s... | https://api.stackexchange.com |
slower than bam. not any more. the latest htslib implementation of cram is faster than bam on encoding and only slightly slower on decoding. the poor performance of igv on cram could be that the java cram decoder is not as optimized. it is true that cram is not as widely supported as bam. however, all the other alterna... | https://api.stackexchange.com |
since general relativity is a local theory just like any good classical field theory, the earth will respond to the local curvature which can change only once the information about the disappearance of the sun has been communicated to the earth's position ( through the propagation of gravitational waves ). so yes, the ... | https://api.stackexchange.com |
pca computes eigenvectors of the covariance matrix ( " principal axes " ) and sorts them by their eigenvalues ( amount of explained variance ). the centered data can then be projected onto these principal axes to yield principal components ( " scores " ). for the purposes of dimensionality reduction, one can keep only ... | https://api.stackexchange.com |
eigenvectors } ^ \ top + \ text { mean } } $ $ note that one can go directly from the first subplot to the third one by multiplying $ \ mathbf x $ with the $ \ mathbf { vv } ^ \ top $ matrix ; it is called a projection matrix. if all $ p $ eigenvectors are used, then $ \ mathbf { vv } ^ \ top $ is the identity matrix (... | https://api.stackexchange.com |
##a on it and compute $ \ hat { \ mathbf x } _ \ text { raw } $ using the first 50 principal components. the result is displayed on the right. reverting svd pca is very closely related to singular value decomposition ( svd ), see relationship between svd and pca. how to use svd to perform pca? for more details. if a $ ... | https://api.stackexchange.com |
= scale ( xhat, center = - mu, scale = false ) xhat [ 1, ] output : sepal. length sepal. width petal. length petal. width 5. 0830390 3. 5174139 1. 4032137 0. 2135317 for worked out r example of pca reconstruction of images see also this answer. python import numpy as np import sklearn. datasets, sklearn. decomposition ... | https://api.stackexchange.com |
i prefer to treat software tools and computers in a similar fashion to laboratory equipment, and in some sense biology in general. biologists are used to unexpected things happening in their experiments, and it's not uncommon for a new discovery to change the way that people look at something. things break down, cells ... | https://api.stackexchange.com |
you have some very strong color and geometry cues you can leverage. i would try the following : extract the green channel & apply watershed type algorithm on it, followed by connected components. subsequently compute component statistics ( area & bounding box ) for each component. retain only the components with area ~... | https://api.stackexchange.com |
the problem with equispaced points is that the interpolation error polynomial, i. e. $ $ f ( x ) - p _ n ( x ) = \ frac { f ^ { ( n + 1 ) } ( \ xi ) } { ( n + 1 )! } \ prod _ { i = 0 } ^ n ( x - x _ i ), \ quad \ xi \ in [ x _ 0, x _ n ] $ $ behaves differently for different sets of nodes $ x _ i $. in the case of equi... | https://api.stackexchange.com |
no - one mentioned the inverse hyperbolic sine transformation. so for completeness i'm adding it here. this is an alternative to the box - cox transformations and is defined by \ begin { equation } f ( y, \ theta ) = \ text { sinh } ^ { - 1 } ( \ theta y ) / \ theta = \ log [ \ theta y + ( \ theta ^ 2y ^ 2 + 1 ) ^ { 1 ... | https://api.stackexchange.com |
without a transformer the live wire is live relative to ground. if you are at " ground " potential then touching the live wire makes you part of the return path. { this image taken from an excellent discussion here with a transformer the output voltage is not referenced to ground - see diagram ( a ) below. there is no ... | https://api.stackexchange.com |
the probabilistic way : this is $ p [ n _ n \ leqslant n ] $ where $ n _ n $ is a random variable with poisson distribution of parameter $ n $. hence each $ n _ n $ is distributed like $ x _ 1 + \ cdots + x _ n $ where the random variables $ ( x _ k ) $ are independent and identically distributed with poisson distribut... | https://api.stackexchange.com |
2n } }. $ $ likewise, the function $ t \ mapsto u ( t ) \ mathrm e ^ { t ^ 2 / 2 } $ is decreasing on $ t \ geqslant0 $ hence $ u ( t ) \ geqslant c _ n \ mathrm e ^ { - t ^ 2 / 2 } $ on $ t \ leqslant1 / n ^ { 1 / 4 } $, with $ c _ n = u ( 1 / n ^ { 1 / 4 } ) \ mathrm e ^ { - 1 / ( 2 \ sqrt { n } ) } $, hence $ $ j _ ... | https://api.stackexchange.com |
it's a rather rough algorithm, but i'd use the following procedure for a crude estimate : if, as you say, the purported $ f ( x ) $ that represents your $ ( x _ i, y _ i ) $ is already almost linear as $ x $ increases, what i'd do is to take differences $ \ dfrac { y _ { i + 1 } - y _ i } { x _ { i + 1 } - x _ i } $, a... | https://api.stackexchange.com |
1 } ] ; res = { res, ep [ if [ oddq [ k ], 1, 2 ] ] } ;, { k, n } ] ; flatten [ res ] ] last [ wynnepsilon [ differences [ ydata ] / differences [ xdata ] ] ] 1. 99966 this implementation is adapted from weniger's paper. | https://api.stackexchange.com |
all models are wrong, but some are useful. ( george e. p. box ) reference : box & draper ( 1987 ), empirical model - building and response surfaces, wiley, p. 424. also : g. e. p. box ( 1979 ), " robustness in the strategy of scientific model building " in robustness in statistics ( launer & wilkinson eds. ), p. 202. | https://api.stackexchange.com |
the exact mechanism is unclear. here are some possible causes : rapid collapsing of cavities inside the joint [ 1 ] ; rapid ligament stretching [ 1 ] ; breaking of intra - articular adhesions [ 1 ] ; escaping gases from synovial fluid [ 2 ] ; movements of joints, tendons and ligaments [ 2 ] ; mechanic interaction betwe... | https://api.stackexchange.com |
( this is a fairly long answer, there is a summary at the end ) you are not wrong in your understanding of what nested and crossed random effects are in the scenario that you describe. however, your definition of crossed random effects is a little narrow. a more general definition of crossed random effects is simply : ... | https://api.stackexchange.com |
have 6 schools ( labelled i - vi ) and 4 classes within each school ( labelled a to d ) : > dt < - read. table ( " header = true, sep = ", ", na. strings = " na ", dec = ". ", strip. white = true ) > # update 1 : data was previously publicly available from > # > # but the link is now broken. > # update 2 : the link is ... | https://api.stackexchange.com |
, 6 ; class, 4 fixed effects : estimate std. error t value ( intercept ) 60. 198841 4. 212974 14. 289 open 0. 010834 0. 008349 1. 298 agree - 0. 005420 0. 009605 - 0. 564 social - 0. 001762 0. 003107 - 0. 567 as expected, the results differ because m0 is a nested model while m1 is a crossed model. now, if we introduce ... | https://api.stackexchange.com |
( intercept ) 8. 2043 2. 8643 school ( intercept ) 93. 8419 9. 6872 residual 0. 9684 0. 9841 number of obs : 1200, groups : classid : school, 24 ; school, 6 fixed effects : estimate std. error t value ( intercept ) 60. 2378227 4. 0117882 15. 015 open 0. 0061065 0. 0049636 1. 230 agree - 0. 0076659 0. 0056986 - 1. 345 s... | https://api.stackexchange.com |
items are not nested within subjects or vice - versa. again, we say that subjects and items are crossed. summary : tl ; dr the difference between crossed and nested random effects is that nested random effects occur when one factor ( grouping variable ) appears only within a particular level of another factor ( groupin... | https://api.stackexchange.com |
there is considerable overlap among these, but some distinctions can be made. of necessity, i will have to over - simplify some things or give short - shrift to others, but i will do my best to give some sense of these areas. firstly, artificial intelligence is fairly distinct from the rest. ai is the study of how to c... | https://api.stackexchange.com |
the answer - - discovery ) or'supervised'( we know the answer - - prediction ). note that the goal is generally not to develop a more sophisticated understanding of the underlying data generating process. common data mining techniques would include cluster analyses, classification and regression trees, and neural netwo... | https://api.stackexchange.com |
" touch not the cat, bot a glove " dttah / acnr / ianal / ymmv * equipment : high impedance voltmeter / oscilloscope with hv probe. high voltage low capacitance capacitors ( 1 10 100 1000 pf ) x 2 of each. pretest - charge capacitors to some semi known high voltage and measure with voltmeter to determine measurement ab... | https://api.stackexchange.com |
& oe........ errors & omissions excepted. | https://api.stackexchange.com |
it's an interesting question and one that has been asked before. npr did a story in 2013 on this topic, but their question was a bit more focused than just " why are so many black people good runners? " the observation that led to their story wasn't just that black people in general were over - represented among long -... | https://api.stackexchange.com |
why do we age is a classical question in evolutionary biology. there are several things to consider when we think of how genes that cause disease, aging, and death to evolve. one explanation for the evolution of aging is the mutation accumulation ( ma ) hypothesis. this hypothesis by p. medawar states that mutations ca... | https://api.stackexchange.com |
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