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there are several things which affect the time to first fix ( ttfx ). getting the almanac and ephemeris. these two things are technically a little different from each other, but for our purposes we'll treat them as the same. they are the locations of the satellites, and you need a to know where they are in order to wor... | https://api.stackexchange.com |
is always better, but more does increase cost and power consumption. some phones and modules have more than others. signal and antennas. the correlators will do their job faster if you have a good signal - to - noise going into them. very poor signals might not work at all. a good antenna design, amplifier, sky view, a... | https://api.stackexchange.com |
via gencode and bedops convert2bed : $ wget - qo - ftp : / / ftp. ebi. ac. uk / pub / databases / gencode / gencode _ human / release _ 28 / gencode. v28. annotation. gff3. gz \ | gunzip - - stdout - \ | awk'$ 3 = = " gene "'- \ | convert2bed - i gff - \ > genes. bed you can modify the awk statement to get exons, by re... | https://api.stackexchange.com |
this question is usually posed as the length of the diagonal of a unit square. you start going from one corner to the opposite one following the perimeter and observe the length is $ 2 $, then take shorter and shorter stair - steps and the length is $ 2 $ but your path approaches the diagonal. so $ \ sqrt { 2 } = 2 $. ... | https://api.stackexchange.com |
( i assume for the purposes of this answer that the data has been preprocessed to have zero mean. ) simply put, the pca viewpoint requires that one compute the eigenvalues and eigenvectors of the covariance matrix, which is the product $ \ frac { 1 } { n - 1 } \ mathbf x \ mathbf x ^ \ top $, where $ \ mathbf x $ is th... | https://api.stackexchange.com |
forming the covariance matrix to begin with, since the formation of $ \ mathbf x \ mathbf x ^ \ top $ can cause loss of precision. this is detailed in books on numerical linear algebra, but i'll leave you with an example of a matrix that can be stable svd'd, but forming $ \ mathbf x \ mathbf x ^ \ top $ can be disastro... | https://api.stackexchange.com |
practically, what limits cpu speed is both the heat generated and the gate delays, but usually, the heat becomes a far greater issue before the latter kicks in. recent processors are manufactured using cmos technology. every time there is a clock cycle, power is dissipated. therefore, higher processor speeds means more... | https://api.stackexchange.com |
perform just as fast, or you need an immense cache. | https://api.stackexchange.com |
combustion is a gas phase reaction. the heat of the flame vapourises the substrate and it's the vapour that reacts with the air. that's why heat is needed to get combustion started. anyhow, wood contains lots of relatively volatile compounds so it's not too hard to get combustion started. once combustion has started th... | https://api.stackexchange.com |
i always hesitate to jump into a thread with as many excellent responses as this, but it strikes me that few of the answers provide any reason to prefer the logarithm to some other transformation that " squashes " the data, such as a root or reciprocal. before getting to that, let's recapitulate the wisdom in the exist... | https://api.stackexchange.com |
##um that does not fit some parsimonious, relatively simple description of the data. changing one's description in order to make outliers look better is usually an incorrect reversal of priorities : first obtain a scientifically valid, statistically good description of the data and then explore any outliers. don't let ... | https://api.stackexchange.com |
i'm a physicist, so apologies if the answer below is in a foreign language ; but this was too interesting of a problem to pass up. i'm going to focus on a particular question : if we have oxygen and nothing else in a box, how strong does the magnetic field need to be to concentrate the gas in a region? the tl ; dr is t... | https://api.stackexchange.com |
cause the oxygen to diffuse out of the region of higher magnetic field. so how high does this have to be? the $ \ alpha $ we have defined above is approximately related to the molar magnetic susceptibility by $ \ chi _ \ text { mol } \ approx \ mu _ 0 n _ \ mathrm a \ alpha $ ; and so we have1 $ $ \ chi _ \ text { mol ... | https://api.stackexchange.com |
yes, it has a lot to do with mass. since deuterium has a higher mass than protium, simple bohr theory tells us that the deuterium 1s electron will have a smaller orbital radius than the 1s electron orbiting the protium nucleus ( see " note " below for more detail on this point ). the smaller orbital radius for the deut... | https://api.stackexchange.com |
\ frac { m _ \ mathrm { e } \ times m _ \ text { nucleus } } { m _ \ mathrm { e } + m _ \ text { nucleus } } $ $ now the equation for the bohr radius becomes $ $ r _ { n } = { n ^ 2 \ hbar ^ 2 \ over zk _ \ mathrm { c } e ^ 2 \ mu _ \ mathrm { e } } $ $ since the reduced mass of an electron orbiting a heavy nucleus is ... | https://api.stackexchange.com |
the two primary factors that describe a window function are : width of the main lobe ( i. e., at what frequency bin is the power half that of the maximum response ) attenuation of the side lobes ( i. e., how far away down are the side lobes from the mainlobe ). this tells you about the spectral leakage in the window. a... | https://api.stackexchange.com |
i'd like to find genes that were not expressed in a group of samples and were expressed in another group. this is, fundamentally, a differential expression analysis, with a twist. to solve this, you ’ d first use a differential expression library of your choice ( e. g. deseq2 ) and perform a one - tailed test of differ... | https://api.stackexchange.com |
it's simpler than you think. when we discretize frequencies, we get frequency bins. so, when you discretize your fourier transform : $ $ e ^ { - j \ omega } \ rightarrow e ^ { - j { 2 \ pi k } / { n } } $ $ our continuous frequencies become $ n $ discrete bins. this is exactly why the following is true : $ $ n ^ { th }... | https://api.stackexchange.com |
first, a note on spelling. both " ortholog " and " orthologue " are correct, one is the american and the other the british spelling. the same is true for homolog / homologue and paralog / paralogue. on to the biology. homology is the blanket term, both ortho - and paralogs are homologs. so, when in doubt use " homologs... | https://api.stackexchange.com |
gene duplication or a speciation event, then you cannot know if it is a case of paralogy or orthology. references r. a. jensen, orthologs and paralogs - we need to get it right, genome biology, 2 ( 8 ), 2001 suggested reading : i highly recommend the jensen article referenced above. i read it when i was first starting ... | https://api.stackexchange.com |
ftensor is a lightweight, header only, fully templated library that includes ergonomic summation notation. it has been tested extensively in 2, 3, and 4 dimensions, but should work fine for any number of dimensions. | https://api.stackexchange.com |
a standard linear model ( e. g., a simple regression model ) can be thought of as having two'parts '. these are called the structural component and the random component. for example : $ $ y = \ beta _ 0 + \ beta _ 1x + \ varepsilon \ \ \ text { where } \ varepsilon \ sim \ mathcal { n } ( 0, \ sigma ^ 2 ) $ $ the first... | https://api.stackexchange.com |
that can be acceptable, often there is one that is special. without wanting to get too far into the weeds ( this can get very technical ) the predicted mean, $ \ mu $, will not necessarily be mathematically the same as the response distribution's canonical location parameter ; the link function that does equate them is... | https://api.stackexchange.com |
), nonetheless, clinicians dichotomized it during the study ( that is, they only recorded'high - bp'or'normal'). in this case, probit would be preferable a - priori for theoretical reasons. this is what @ elvis meant by " your binary outcome depends on a hidden gaussian variable ". another consideration is that both lo... | https://api.stackexchange.com |
##ly, the logit's $ \ beta _ 1 $ must be $ \ approx 1. 7 $ times the corresponding slope value for the probit. in addition, i could have shifted the cloglog over slightly so that they would lay on top of each other more, but i left it to the side to keep the figure more readable. ) notice that the cloglog is asymmetric... | https://api.stackexchange.com |
that you shouldn't use the probit, because it can't be interpreted. this is not true, although the interpretation of the betas is less intuitive. with logistic regression, a one unit change in $ x _ 1 $ is associated with a $ \ beta _ 1 $ change in the log odds of'success'( alternatively, an $ \ exp ( \ beta _ 1 ) $ - ... | https://api.stackexchange.com |
the central issue is the length of the critical path $ c $ relative to the total amount of computation $ t $. if $ c $ is proportional to $ t $, then parallelism offers at best a constant speed - up. if $ c $ is asymptotically smaller than $ t $, there is room for more parallelism as the problem size increases. for alg... | https://api.stackexchange.com |
sequential " and cannot be sped up significantly by parallelism. | https://api.stackexchange.com |
let $ v $ be a vector space ( over any field, but we can take it to be $ \ mathbb r $ if you like, and for concreteness i will take the field to be $ \ mathbb r $ from now on ; everything is just as interesting in that case ). certainly one of the interesting concepts in linear algebra is that of a hyperplane in $ v $.... | https://api.stackexchange.com |
) = b \ } $ $ is a hyperplane in $ v $, and all hyperplanes in $ v $ arise this way. so this gives a reasonable justification for introducing the elements of the dual space to $ v $ ; they generalize the notion of linear equation in several variables from the case of $ \ mathbb r ^ n $ to the case of an arbitrary vecto... | https://api.stackexchange.com |
if you want to normalize your data, you can do so as you suggest and simply calculate the following : $ $ z _ i = \ frac { x _ i - \ min ( x ) } { \ max ( x ) - \ min ( x ) } $ $ where $ x = ( x _ 1,..., x _ n ) $ and $ z _ i $ is now your $ i ^ { th } $ normalized data. as a proof of concept ( although you did not ask... | https://api.stackexchange.com |
i think your question implicates another question ( which is also mentioned in some comments here ), namely : why are all energy eigenvalues of states with a different angular momentum quantum number $ \ ell $ but with the same principal quantum number $ n $ ( e. g., $ \ mathrm { 3s } $, $ \ mathrm { 3p } $, $ \ mathrm... | https://api.stackexchange.com |
back to a symmetry, the $ so ( 4 ) $ symmetry. the system's $ so ( 4 ) $ symmetry is not a geometric symmetry like the one explored before but a so called dynamical symmetry which follows from the form of the schroedinger equation for the kepler potential. ( it corresponds to rotations in a four - dimensional cartesian... | https://api.stackexchange.com |
varphi ) $ \ begin { equation } \ bigg ( \ frac { - \ hbar ^ { 2 } } { 2 m _ { \ mathrm { e } } } \ frac { \ mathrm { d } ^ { 2 } } { \ mathrm { d } r ^ { 2 } } + \ underbrace { \ frac { \ hbar ^ { 2 } } { 2 m _ { \ mathrm { e } } } \ frac { \ ell ( \ ell + 1 ) } { r ^ { 2 } } } - \ frac { z e ^ { 2 } } { 2 m _ { \ mat... | https://api.stackexchange.com |
than the outer ones, the core repulsion is weakened whereas the effects due to the centrifugal force remain unchanged. the reduced core repulsion in turn stabilizes the states with lower angular momenta, i. e. lower $ \ ell $ values. so, $ \ mathrm { 3s } $ states are lower in energy than $ \ mathrm { 3p } $ states whi... | https://api.stackexchange.com |
i'm not sure about the existence of molecules with bridges through rings. however, there are several publications of synthesis of molecules mimicking wheels and axles ( [ 2 ] rotaxanes ; the “ [ 2 ] ” refers to the number of interlocked components ) as one shown below ( ref. 1 ) : ( the diagram is from reference 1 ) th... | https://api.stackexchange.com |
i think the ( first order ) right thing to do is look at the ratio of flops to bytes needed in the algorithm, which i call $ \ beta $. let $ f _ { \ mathrm { max } } $ be the maximum flop rate of the processor, and $ b _ { \ mathrm { max } } $ the maximum bandwidth. if $ \ frac { f _ { \ mathrm { max } } } { \ beta } >... | https://api.stackexchange.com |
$ $ x ^ 2 = \ underbrace { x + x + \ cdots + x } _ { ( x \ text { times } ) } $ $ $ $ \ frac { d } { dx } x ^ 2 = \ frac { d } { dx } [ \ underbrace { x + x + \ cdots + x } _ { ( x \ text { times } ) } ] $ $ $ $ 2x = 1 + 1 + \ cdots + 1 = x $ $ $ $ 2 = 1 $ $ | https://api.stackexchange.com |
short answer : no, you don't have to do integration for certain fems. but in your case, you have to do that. long answer : let's say $ u _ h $ is the finite element solution. if you choose piecewise linear polynomial as your basis, then taking $ \ delta $ on it will give you an order 1 distribution ( think taking deriv... | https://api.stackexchange.com |
integration by parts can be traced back to the sobolev theory for elliptic pde using smooth function, where the $ w ^ { k, p } $ - spaces are all closure of smooth functions under the $ w ^ { k, p } $ type of integral norm. then people say what is the minimum regularity here that we can perform inner product. also bear... | https://api.stackexchange.com |
it depends a lot on the size of your matrix, in the large - scale case also on whether it is sparse, and on the accuracy you want to achieve. if your matrix is too large to allow a single factorization, and you need high accuracy, the lanczsos algorithm is probably the fastest way. in the nonsymmetric case, the arnoldi... | https://api.stackexchange.com |
it is a result from the insecticide you are using. from this excerpt from the 10th edition of the mallis handbook on pest control : neurotoxic insecticides cause tremors and muscle spasms, flipping the cockroach on its back. a healthy cockroach can easily right itself, but without muscle coordination, the cockroach die... | https://api.stackexchange.com |
the odour threshold for hydrogen cyanide $ ( \ ce { hcn } ) $ is in fact quite a bit lower than the lethal toxicity threshold. data for $ \ ce { hcn } $ can be found in many places, but here and here are a couple of good references. that subset of the human population that can detect bitter almonds do so at a threshold... | https://api.stackexchange.com |
was xkcd, so time for dilbert : source : | https://api.stackexchange.com |
if you are not well - acquainted with special relativity, there is no way to truly explain this phenomenon. the best one could do is give you rules steeped in esoteric ideas like " electromagnetic field " and " lorentz invariance. " of course, this is not what you're after, and rightly so, since physics should never be... | https://api.stackexchange.com |
force in the positive $ x $ - direction, away from the axis, over and above what we would have predicted from just sitting in the lab frame. basically, coulomb's law is the only force law acting on a charge, but only the charge's rest frame is valid for using this law to determine what force the charge feels. rather th... | https://api.stackexchange.com |
you tend to use the covariance matrix when the variable scales are similar and the correlation matrix when variables are on different scales. using the correlation matrix is equivalent to standardizing each of the variables ( to mean 0 and standard deviation 1 ). in general, pca with and without standardizing will give... | https://api.stackexchange.com |
% $ ). notice also that the outlying individuals ( in this data set ) are outliers regardless of whether the covariance or correlation matrix is used. | https://api.stackexchange.com |
this is a really interesting question. it turns out that your body is reasonably conductive ( think salt water, more on that in the answer to this question ), and that it can couple to rf sources capacitively. referring to the wikipedia article on keyless entry systems ; they typically operate at an rf frequency of $ 3... | https://api.stackexchange.com |
/ / gcc impredictivepropositionallogic1. c - o impredictivepropositionallogic1. exe - std = c99 - wall - o3 / * which answer in this list is the correct answer to this question? ( a ) all of the below. ( b ) none of the below. ( c ) all of the above. ( d ) one of the above. ( e ) none of the above. ( f ) none of the ab... | https://api.stackexchange.com |
satisfying assignment. for example consider the question : which of the following is true? ( a ) both of these ( b ) both of these you might be tempted to say that both ( a ) and ( b ) are true. but it is also consistent that both ( a ) and ( b ) are false. the tendency to assume singularity from definitions isn't corr... | https://api.stackexchange.com |
error estimates usually have the form $ $ \ | u - u _ h \ | \ leq c ( h ), $ $ where $ u $ is the exact solution you are interested in, $ u _ h $ is a computed approximate solution, $ h $ is an approximation parameter you can control, and $ c ( h ) $ is some function of $ h $ ( among other things ). in finite element m... | https://api.stackexchange.com |
you want to make the error smaller by a factor of four, you need to halve $ h $. in a posteriori estimates, the right - hand side depends on $ h $ and $ u _ h $, but not on $ u $. a simple residual - based a posterior estimate for poisson's equation would be $ $ \ | u - u _ h \ | _ { l ^ 2 } \ leq c h \ | f + \ delta u... | https://api.stackexchange.com |
i used to implement everything myself, but lately have begun using libraries much more. i think there are several very important advantages of using a library, beyond just the issue of whether you have to write a routine yourself or not. if you use a library, you get code that has been tested by hundreds / thousands / ... | https://api.stackexchange.com |
pedagogical dimension due to its simplicity lomuto's partitioning method might be easier to implement. there is a nice anecdote in jon bentley's programming pearl on sorting : “ most discussions of quicksort use a partitioning scheme based on two approaching indices [... ] [ i. e. hoare's ]. although the basic idea of ... | https://api.stackexchange.com |
ldots, n \ } $ is equally likely to become pivot ( namely with prob. $ \ frac1n $ ), so we have $ $ \ frac1n \ sum _ { x = 1 } ^ n ( x - 1 ) = \ frac n2 - \ frac12 \ ;. $ $ swaps on average to partition an array of length $ n $ with lomuto's method. hoare's method here, the analysis is slightly more tricky : even fixin... | https://api.stackexchange.com |
. t. caching. equal elements and already sorted lists as already mentioned by wandering logic, the performance of the algorithms differs more drastically for lists that are not random permutations. on an array that is already sorted, hoare's method never swaps, as there are no misplaced pairs ( see above ), whereas lom... | https://api.stackexchange.com |
for pseudocode of the desirable implementation analyzed above, see my master's thesis, algorithm 1. ( that code is due to robert sedgewick ). | https://api.stackexchange.com |
i can't tell you which to learn, but here's some contrasting points ( from a very vhdl - centric user, but i've tried to be as fair as possible! ), which may help you make a choice based on your own preferences in terms of development style : and keep in mind the famous quote which goes along the lines of " i prefer wh... | https://api.stackexchange.com |
for many years i was under the misapprehension that i didn't have enough time to write unit tests for my code. when i did write tests, they were bloated, heavy things which only encouraged me to think that i should only ever write unit tests when i knew they were needed. then i started to use test driven development an... | https://api.stackexchange.com |
a great question, and since a textbook could probably be written to answer it, there's probably not going to be any single answer. i want to provide a general answer tailored to hobbyists, and hope that people more knowledgeable can come in and tie up specifics. summary solder is basically metal wire with a " low " mel... | https://api.stackexchange.com |
as long as you keep your parts clean and don't let them sit around too long, a flux core isn't necessary. however, if you are looking for solder then you probably should pick up something with a rosin core. the only reason you wouldn't use a flux core solder as a hobbyist is if you knew exactly why you didn't need the ... | https://api.stackexchange.com |
a common error i think is to use greedy algorithms, which is not always the correct approach, but might work in most test cases. example : coin denominations, $ d _ 1, \ dots, d _ k $ and a number $ n $, express $ n $ as a sum of $ d _ i $ : s with as few coins as possible. a naive approach is to use the largest possib... | https://api.stackexchange.com |
you're attempting to take a limit. $ $ x _ { n + 1 } = 1 - \ frac { 1 } { x _ n } $ $ this recurrence actually never converges, from any real starting point. indeed, $ $ x _ 2 = 1 - \ frac { 1 } { x _ 1 } ; \ \ x _ 3 = 1 - \ frac { 1 } { 1 - 1 / x _ 1 } = 1 - \ frac { x _ 1 } { x _ 1 - 1 } = \ frac { 1 } { 1 - x _ 1 } ... | https://api.stackexchange.com |
the reason is simple : chocolate contains cocoa which contains theobromine. the darker the chocolate is ( meaning the more cocoa it contains ) the more theobromine it contains. this is a bitter alkaloid which is toxic to dogs ( and also cats ), but can be tolerated by humans. the reason for this is the much slower meta... | https://api.stackexchange.com |
can i predict the products of any chemical reaction? in theory, yes! every substance has characteristic reactivity behavior. likewise pairs and sets of substances have characteristic behavior. for example, the following combinations of substances only have one likely outcome each : $ $ \ ce { hcl + naoh - > nacl + h2o ... | https://api.stackexchange.com |
. 4 \ times 10 ^ { 27 } $ bytes of data, or $ 2. 4 \ times 10 ^ 7 $ zb ( zettabytes ) or $ 2. 4 \ times 10 ^ 4 $ trillion terabytes. the total digital data generated by the human species was estimated recently ( nov. 2015 ) to be 4. 4 zb. we need $ 5. 5 \ times 10 ^ 5 $ times more data in the world to hold such a datab... | https://api.stackexchange.com |
, but they are not few in number. there are too many classes of compounds to list here. likewise even one class, like primary alcohols ( an hydroxyl group at the end of a hydrocarbon chain ) has too many characteristic reactions to list here. if there are 30 classes of compounds ( an underestimate ) and 30 types of rea... | https://api.stackexchange.com |
the correct answer is because the ethernet specification requires it. although you didn't ask, others may wonder why this method of connection was chosen for that type of ethernet. keep in mind that this applies only to the point - to - point ethernet varieties, like 10base - t and 100base - t, not to the original ethe... | https://api.stackexchange.com |
is perfectly fine and within the standard to have one node riding on a power line phase with the other referenced to the neutral. | https://api.stackexchange.com |
adapted from an answer to a different question ( as mentioned in a comment ) in the hope that this question will not get thrown up repeatedly by community wiki as one of the top questions.... there is no " flipping " of the impulse response by a linear ( time - invariant ) system. the output of a linear time - invarian... | https://api.stackexchange.com |
& \ cdots & n & n + 1 & \ cdots \ \ \ hline x [ 0 ] & x [ 0 ] h [ 0 ] & x [ 0 ] h [ 1 ] & x [ 0 ] h [ 2 ] & \ cdots & x [ 0 ] h [ n ] & x [ 0 ] h [ n + 1 ] & \ cdots \ \ \ hline x [ 1 ] & 0 & x [ 1 ] h [ 0 ] & x [ 1 ] h [ 1 ] & \ cdots & x [ 1 ] h [ n - 1 ] & x [ 1 ] h [ n ] & \ cdots \ \ \ hline x [ 2 ] & 0 & 0 & x [ ... | https://api.stackexchange.com |
we could have written $ $ \ begin { align * } y [ n ] & = x [ n ] h [ 0 ] + x [ n - 1 ] h [ 1 ] + x [ n - 2 ] h [ 2 ] + \ cdots + x [ 0 ] h [ n ] + \ cdots \ \ & = \ sum _ { m = 0 } ^ { \ infty } x [ n - m ] h [ m ], \ end { align * } $ $ so that it is the input that seems " flipped over " or running backwards in time!... | https://api.stackexchange.com |
historical perspective it is really impossible to say what the new paradigms will be like in the future, for example a good historical perspective i suggest reading ken kennedy's rise and fall of hpf. kennedy gives an account of two emerging patterns, mpi versus a smart compiler, and details how mpi had the right amoun... | https://api.stackexchange.com |
clear winner right now, but pgas languages such as upc and chapel are making headways into the space. one good indication is the hpc benchmark challenge. pgas languages are giving very elegant implementations of the benchmarks. the most interesting point here is that while this model currently only works at the node le... | https://api.stackexchange.com |
mic, cell acclerators ) has taken hold. it is becoming clear that no path to exascale will be complete without them. at sc11, every bell prize contestent used them very effectively to get to the low petaflops. while cuda and opencl have dominated the current market, i have hopes for openacc and pgas compilers entering ... | https://api.stackexchange.com |
" data - intensive " machines being funded by the nsf, but these machines are on a different track than the 2019 exascale grand challenge. this became longer than expected ask for references where you need them in the comments | https://api.stackexchange.com |
this is really a footnote to the accepted answer. light cannot escape from an event horizon. but how can you check that light can never escape? you can watch the surface for some time $ t $, but all you have proved is that light can't escape in the time $ t $. this is what we mean by an apparent horizon, i. e. it is a ... | https://api.stackexchange.com |
$ \ text { error = bias + variance } $ boosting is based on weak learners ( high bias, low variance ). in terms of decision trees, weak learners are shallow trees, sometimes even as small as decision stumps ( trees with two leaves ). boosting reduces error mainly by reducing bias ( and also to some extent variance, by ... | https://api.stackexchange.com |
i can tell you why i don't believe in it. i think my reasons are different from most physicists'reasons, however. regular quantum mechanics implies the existence of quantum computation. if you believe in the difficulty of factoring ( and a number of other classical problems ), then a deterministic underpinning for quan... | https://api.stackexchange.com |
i believe this can also be solved using double integrals. it is possible ( if i remember correctly ) to justify switching the order of integration to give the equality : $ $ \ int _ { 0 } ^ { \ infty } \ bigg ( \ int _ { 0 } ^ { \ infty } e ^ { - xy } \ sin x \, dy \ bigg ) \, dx = \ int _ { 0 } ^ { \ infty } \ bigg ( ... | https://api.stackexchange.com |
{ 0 } ^ { \ infty } \ big ( \ frac { \ sin x } { x } \ big ) \, dx = \ int _ { 0 } ^ { \ infty } \ frac { 1 } { 1 + y ^ 2 } \, dy = \ frac { \ pi } { 2 }. $ $ | https://api.stackexchange.com |
all three are so - called " meta - algorithms " : approaches to combine several machine learning techniques into one predictive model in order to decrease the variance ( bagging ), bias ( boosting ) or improving the predictive force ( stacking alias ensemble ). every algorithm consists of two steps : producing a distri... | https://api.stackexchange.com |
essentially, os is slightly more efficient since it does not require the addition of the overlapping transients. however, you may want to use oa if you need to reuse the ffts with zero - padding rather than repeated samples. here is a quick overview from an article i wrote a while ago fast convolution refers to the blo... | https://api.stackexchange.com |
i think possibly the problem here is the way you're approaching the issue. you're considering improvement as anything that increases the abilities or complexity of the organism — that isn't necessarily what an improvement is though. the outcome of natural selection is that the organism best equipped to survive / reprod... | https://api.stackexchange.com |
gravitational waves are qualitatively different from other detections. as much as we have tested gr before, it's still reassuring to find a completely different test that works just as well. the most notable tests so far have been the shifting of mercury's orbit, the correct deflection of light by massive objects, and ... | https://api.stackexchange.com |
sometimes, especially in introductory courses the instructor will try to keep things " focused " in order to promote learning. still, it's unfortunate that the instructor couldn't respond in a more positive and stimulating way to your question. these reactions do occur at $ \ ce { sp ^ 2 } $ hybridized carbon atoms, th... | https://api.stackexchange.com |
it stabilizes them because the more s character in an orbital the lower its energy ; conversely, in the absence of electrons, an orbital prefers to have high p character and mix the remaining s character into other bonding orbitals that do contain electrons in order to lower their energy ). | https://api.stackexchange.com |
a schematic is a visual representation of a circuit. as such, its purpose is to communicate a circuit to someone else. a schematic in a special computer program for that purpose is also a machine - readable description of the circuit. this use is easy to judge in absolute terms. either the proper formal rules for descr... | https://api.stackexchange.com |
are commonly placed in different orientations, horizontal and vertical in the case of resistors for example. diodes can be placed in at least 4 orientations since they have direction too. the placement of text around a part, like the component designator and value, probably won't work in other orientations than it was ... | https://api.stackexchange.com |
similarly most of the time. once you get more experience looking at schematics, these will pop out at you and you will appreciate this. if stuff is drawn every which way, then these common circuits will look visually different every time and it will take others longer to understand your schematic. what's this mess, for... | https://api.stackexchange.com |
the schematic you are drawing, you'll probably do alright. you should be trying to help people understand the circuit easily, not make them figure it out despite the schematic. design for regular size paper the days of electrical engineers having drafting tables and being set up to work with d size drawings are long go... | https://api.stackexchange.com |
to myself screw this and gone on to answer someone else's question. label key nets schematic capture programs generally let you give nets nicely readable names. all nets probably have names inside the software, just that they default to some gobbledygook unless you explicitly set them. if a net is broken up into visual... | https://api.stackexchange.com |
" 8 mhz clock to my pic ", when simply " clock ", " clk ", or " 8mhz " would convey the same information. see this ansi / ieee standard for recommended pin name abbreviations. upper case symbol names use all caps for net names and pin names. pin names are almost always shown upper case in datasheets and schematics. var... | https://api.stackexchange.com |
##hematics were routinely photocopied or otherwise optically reproduced, junction dots could disappear after a few generations, or could sometimes even appear at crosses when they weren't there originally. this is less important now that schematics are generally in a computer, but it's not a bad idea to be extra carefu... | https://api.stackexchange.com |
this method has worked well for me ( but what works well for one person won't necessarily work well for everyone ). i take it in several passes : read 0 : don't read the book, read the wikipedia article or ask a friend what the subject is about. learn about the big questions asked in the subject, and the basics of the ... | https://api.stackexchange.com |
if you can assign the total electron geometry ( geometry of all electron domains, not just bonding domains ) on the central atom using vsepr, then you can always automatically assign hybridization. hybridization was invented to make quantum mechanical bonding theories work better with known empirical geometries. if you... | https://api.stackexchange.com |
an electron domain for determining total electron geometry. since the sample question says $ \ ce { nh3 } $ is $ \ ce { sp ^ 3 } $, then $ \ ce { nh3 } $ must be tetrahedral. make sure you can figure out how $ \ ce { nh3 } $ has tetrahedral electron geometry. for $ \ ce { h2co } $ start by drawing the lewis structure. ... | https://api.stackexchange.com |
the fundamental difference between discriminative models and generative models is : discriminative models learn the ( hard or soft ) boundary between classes generative models model the distribution of individual classes to answer your direct questions : svms ( support vector machines ) and dts ( decision trees ) are d... | https://api.stackexchange.com |
what we're seeing is arithmetic progressions ( not prime - producing polynomials ) of primes, combined with a classical phenomenon about rational approximations. when the integers ( or any subset of them ) are represented by the polar points $ ( n, n ) $, of course integers that are close to a multiple of $ 2 \ pi $ ap... | https://api.stackexchange.com |
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