Shape coding is a method of design of a control that allows the control s function to be signified by the shape of the control. It was used successfully by Alphonse Chapanis on airplane controls to improve aviation safety . External links http ergo.human.cornell.edu studentdownloads DEA325pdfs controls.pdf A paper on the design of controls pdf file MPEG 4 Video Object Plane Decoder and the functionality The shape information is referred to as alpha planes. The techniques to be adopted by the standard will provide lossless coding of alpha planes and lossy coding of shapes and transparency information since the shape size scalable, thus allowing a tradeoffs between bit rate and accuracy of shape representation. Furthermore, intra and inter shape prediction is envisioned so as to allow both efficient random access operations as well as efficient compression of shape and transparency information. Alpha planes Binary each pixel is either 0 or 255 . Grey scale each pixel is 8 bit . Category Design design stub ... more details
. Disadvantages of cowboy coding In cowboy coding, the lack of formal software project management ... developers Cowboy coding can be common at the hobbyist or student level where developers may initially ... more than just the basic coding a software project requires. This can result in time required ... with the client concerning requirements. Cowboy coding can accentuate this problem by not scaling ... an incomplete project unusable. Advantages of cowboy coding Developers maintain a free form working ... can begin with cowboy coding techniques before later selling them to commercial use or creating ... cowboy coding removes this burden. By coding in their own time, a hobby project may come to fruition ... cgi wiki?CowboyCoding Cowboy Coding definition at Wards Wiki http cowboyprogramming.com 2007 01 11 delving ... Coding Category Software development philosophies it Cowboy coding uk ... more details
cleanup rewrite date February 2010 Coding theory is the study of the properties of code s and their fitness ... and more recently also for network coding . Codes are studied by various scientific disciplines ... two aspects to Coding theory Data compression or, source coding Error correction code Error correction or, channel coding . These two aspects may be Joint source and channel coding studied in combination ... channel. The ordinary user may not be aware of many applications using channel coding ... also use coding techniques to correct for the fading and noise of high frequency radio transmission. Data modems, telephone transmissions, and NASA all employ channel coding techniques to get the bits through, for example the turbo code and LDPC code s. Source coding main data compression The aim of source coding is to take the source data and make it smaller. Principle Entropy information theory ... assumed probability model is called entropy encoding . Various techniques used by source coding ... bitrate , and C x is the bitrate after compression. In particular, no source coding scheme can ... encoding run length code . Source coding includes also removal of all data that superfluous the need of transmitter, this decreases the bandwidth required for the transmission process. Channel coding main Forward error correction The aim of channel coding theory is to find codes which transmit quickly ... algebraic coding theory denotes the sub field of coding theory where the properties of codes are expressed in algebraic terms and then further researched. Citation needed date July 2008 Algebraic coding ... is the dimensions refer to the length of the codeword as defined above. The theory of coding ... coding author Christian Schlegel and Lance P rez publisher Wiley IEEE year 2004 isbn 9780471227557 ... coding Convolutional codes Main Convolutional code The idea behind a convolutional code is to make ... communication devices. Other applications of coding theory misleading Another concern of coding ... more details
Unary coding , sometimes called thermometer code , is an entropy encoding that represents a natural number , n , with n ones followed by a zero if natural number is understood as non negative integer or with n &minus 1 ones followed by a zero if natural number is understood as strictly positive integer . For example 5 is represented as 111110 or 11110. Some representations use n or n &minus 1 zeros followed by a one. The ones and zeros are interchangeable without loss of generality. table border 1 cellpadding 2 tr th n non negative th n strictly positive th Unary code th Alternative tr td 0 td 1 td 0 td 1 tr td 1 td 2 td 10 td 01 tr td 2 td 3 td 110 td 001 tr td 3 td 4 td 1110 td 0001 tr td 4 td 5 td 11110 td 00001 tr td 5 td 6 td 111110 td 000001 tr td 6 td 7 td 1111110 td 0000001 tr td 7 td 8 td 11111110 td 00000001 tr td 8 td 9 td 111111110 td 000000001 tr td 9 td 10 td 1111111110 td 0000000001 table Unary coding is an optimally efficient encoding for the following discrete probability distribution math operatorname P n 2 n , math for math n 1,2,3,... math . In symbol by symbol coding, it is optimal for any geometric distribution math operatorname P n k 1 k n , math for which k &ge &phi 1.61803398879&hellip , the golden ratio , or, more generally, for any discrete distribution for which math operatorname P n ge operatorname P n 1 operatorname P n 2 , math for math n 1,2,3,... math . Although it is the optimal symbol by symbol coding for such probability distributions, Golomb coding achieves better compression capability for the geometric distribution because it does not consider input symbols independently, but rather implicitly groups the inputs ... index schemes like the Golomb Rice code . Unary coding is Prefix free code prefix free , and can ... ed, Morgan Kaufmann. Professor K.R Rao, EE5359 Principles of Digital Video Coding . Compression Methods Category Coding theory Category Data compression Category Lossless compression algorithms es C digo ... more details
In optics and signal processing , wavefront coding refers to the use of a cubic phase modulating element in conjunction with deconvolution to extend the depth of field of a digital imaging system such as a video camera. Wavefront coding falls under the broad category of computational photography as a technique to enhance the depth of field. Encoding Linear phase mask Wavefront Coding with linear phase masks works by creating an optical transfer function that encodes distance information. ref name LinearPhasePatent http www.patentstorm.us patents 7218448 description.html US Patent 7218448 Extended depth of field optical systems ref Cubic phase mask Wavefront Coding with cubic phase masks works to blur the image uniformly using a cubic shaped waveplate so that the intermediate image, the optical transfer function, is out of Focus optics focus by a constant amount. Digital image processing then removes the blur and introduces noise depending upon the physical characteristics of the processor. Dynamic range is sacrificed to extend the depth of field depending upon the type of filter used. It can also correct optical aberration . ref name StanfordPaper http graphics.stanford.edu courses cs448a 06 winter dowski wavefront coding optics95.pdf Extended depth of field through wave front coding ref The mask was developed by using the ambiguity function and the stationary phase method History The technique was pioneered by radar engineer Edward Dowski and his thesis adviser Thomas Cathey at the University of Colorado at Boulder University of Colorado in the United States in the 1990s. After the university showed little interest in the research ref name KeepingFocus http optics.org cws article articles 18342 Wavefront coding keeps a focus on applications ref they have since founded a company ... Technologies , which has released wavefront coding based mobile camera chips as TrueFocus sensors ... Display.cfm?Section ARTCL&ARTICLE ID 197348&VERSION NUM 1 Wavefront coding finds increasing use Laser ... more details
Unreferenced stub auto yes date December 2009 In computing , hand coding means editing the underlying representation of a document or a computer program , when tools that allow working on more sophisticated representation also exist. Typically this means editing the source code , or the textual representation of a document or a program, instead of using a WYSIWYG editor that always displays an approximation of the final product. It may also mean translating the whole or parts of the source code into machine language manually instead of using a compiler or an automatic translator. The reasons to use hand coding include the ability to Use features or refinements not supported by the graphical editor or compiler Control the semantics of a document beyond that allowed by the graphical editor Produce more elegant source code to help maintenance and integration Produce better performing machine code than that produced by the compiler see optimization computer science optimization Avoid having to pay for expensive WYSIWYG Editors. Note that there are some open source editors available on the web, however. Develop an understanding of the methods underlying a common level of abstraction. For example, although it has become rare in real life scenarios, computer science students may be required to write a program in an assembly language to get a notion of processor register s and other basal elements of computer architecture . Escape abstractions and templated code. Hand coding allows more refined control of code, which may improve efficiency, or add functionality that is otherwise unavailable. Hand coding may require more expertise and time than using automatic tools. See also HTML Markup language DEFAULTSORT Hand Coding Category Computer programming Comp sci stub ... more details
orphan date February 2009 Axial coding is the disaggregation of core themes during qualitative data analysis . Axial coding in Grounded Theory is the process of relating codes categories and concepts to each other, via a combination of inductive and deductive thinking. The basic framework of generic relationships is understood, according to Strauss and Corbin 1990, 1998 who propose the use of a coding paradigm , to include categories related to 1 the phenomenon under study, 2 the conditions related to that phenomenon context conditions, intervening structural conditions or causal conditions , 3 the actions and interactional strategies directed at managing or handling the phenomenon and 4 the consequences of the actions interactions related to the phenomenon. As Kelle underlines, the implicit or explicit theoretical framework necessary to identify categories in empirical data is derived, in the procedures explicited by Strauss and Corbin 1990 , from a general model of action rooted in pragmatist and interactionist social theory Kelle, 2005, para. 16 . This model or theoretical framework underlines the importance of analysing and modelling action and interaction strategies of the actors para. 16 . Axial coding is a cornerstone of Strauss and Corbin s 1990, 1998 approach but is regarded by Charmaz 2006 as highly structured and optional. References Charmaz, K. 2006 . Constructing grounded theory A practical guide through qualitative analysis . London Sage. Gatrell, A.C. 2002 Geographies of Health an Introduction , Oxford Blackwell. Kelle, Udo 2005 . Emergence vs. forcing of empirical data? A crucial problem of grounded theory reconsidered 52 paragraphs . Forum Qualitative Sozialforschung Forum Qualitative Social Research, 6 2 , Art. 27, http nbn resolving.de urn nbn de 0114 fqs0502275. Strauss, A. L., & Corbin, J. M. 1990 . Basics of qualitative research grounded theory procedures ... Axial Coding Category Qualitative research ... more details
In digital communications , differential coding is a technique used to provide unambiguous signal reception when using some types of modulation . It makes data to be transmitted to depend not only on the current bit or symbol , but also on the previous one. The common types of modulation that require differential coding include phase shift keying and quadrature amplitude modulation . Purposes of differential coding To demodulate BPSK one needs to make a local oscillator synchronous with the remote one. This is accomplished by a carrier recovery circuit. However, a carrier can be recovered in different ways, depending upon a valid phases count 2 for BPSK . For this coding, if a carrier is recovered incorrectly, the received data are inverted. Assuming that math x i math is a bit intended for transmission, and math y i math is a bit actually transmitted differentially encoded , if math y i y i 1 oplus x i, qquad 1 math is transmitted, then on the decoding side math x i y i oplus y i 1 . qquad 2 math can be reconstructed, where math oplus math indicates binary addition binary or modular arithmetic modulo 2 addition. Now math x i math depends only on a difference between math y i math and math ... differential coding Image Differential coding encoder.png right thumb A differential encoder Image Differential coding decoder.png right thumb A differential decoder A method illustrated above can ... synchronization frame synchronizer and sometimes it isn t. Generally speaking, a differential coding ... numbers are equivalent. Generalized differential coding Using the relation math y i 1 oplus x i ... for any math y 0 math and math u 0 math . Applications Differential coding is widely used in satellite ... keying PSK and QAM modulations. Drawbacks Differential coding has one significant drawback it leads .... Other techniques to resolve a phase ambiguity Differential coding is not the only way to deal ... coding and modulation for 11 12 GHz satellite services EN 300 421 Category Data transmission ... more details
No footnotes date October 2011 In computer science CDR coding is a data compression compressed data computing data representation for Lisp programming language Lisp linked list s. It was developed and patented by the MIT Artificial Intelligence Laboratory , and implemented in computer hardware in a number of Lisp machine s derived from the MIT CADR computing system CADR . CDR coding is in fact a fairly general idea whenever a data object A ends in a reference to another data structure B , we can instead place the structure B itself there, overlapping and running off the end of A . By doing this we free the space required by the reference, which can add up if done many times, and also improve locality of reference , enhancing performance on modern machines. The transformation is especially effective for the cons based lists it was created for we free about half of the space for each node we perform this transformation on. It is not always possible to perform this substitution, because there might not be a large enough chunk of free space beyond the end of A. Thus, some objects will end in a real reference, and some with the referenced object, and the machine must be able to tell by reading the final cell which one it is. This can be accomplished with some inefficiency in software by the use of tagged pointer s, which allow a pointer in a final position to be specifically tagged as such, but is best done in hardware. In the presence of mutable object s, CDR coding becomes more complex. If a reference is updated to point to another object, but currently has an object stored in that field ... of the store. This problem is typically avoided by using CDR coding only on immutable object immutable data structures. Unrolled linked list s are simpler and often higher performance than CDR coding ..., CDR coding uses the least amount of space. External links cite web editor1 Mark Kantrowitz editor2 ... Questions title 2 9 What is CDR coding? publisher Advameg, Inc. accessdate 2011 10 09 Category Lisp ... more details
The coding region of a gene , also known as the coding sequence or CDS , is that portion of a gene s DNA or RNA , composed of exon s, that codes for protein. The region is bounded nearer the Directionality molecular biology 5 end 5 end by a start codon and nearer the Directionality molecular biology 3 end 3 end with a stop codon . The coding region in mRNA is bounded by the five prime untranslated region and the three prime untranslated region , which are also parts of the exons. ref cite web last Twyman first Richard title Gene Structure publisher The Wellcome Trust date 1 August 2003 url http genome.wellcome.ac.uk doc WTD020755.html accessdate 6 April 2003 ref The coding region of an organism is sum total of the organism s genome that is composed of gene coding regions. ref Cite book last Goto et al. first Mami title Analysis of CpG Dinucleotide Frequency in Bacterial Genomes with Respect to Genomic Regions and Codon publisher The Fourth Annual International Conference on Computational Molecular Biology, Tokyo, Japan date April 8, 2000 url http recomb2000.ims.u tokyo.ac.jp Posters pdf 112.pdf accessdate 6 April 2009 ref Coding sequence annotation While identification of open reading frames within a DNA sequence is straightforward, identifying coding sequences is not, because the cell translates only a subset of all open reading frames to proteins. ref Cite journal last1 Furuno first1 Masaaki last2 Kasukawa first2 Takeya last3 Saito first3 Rintaro last4 Adachi first4 Jun last5 Suzuki first5 Harukazu last6 Baldarelli first6 Richard last7 Hayashizaki first7 Yoshihide last8 Okazaki first8 Yasushi title CDS Annotation in Full Length cDNA Sequence journal Genome Research volume 21 issue 9 pages 1478 1487 publisher Cold Spring Harbor Laboratory Press date September 2011 year 2011 url http genome.cshlp.org content 13 6b 1478.full.pdf html doi 10.1101 gr.1060303 accessdate 18 September 2011 postscript Bot inserted parameter. Either remove it or change its value to . for the cite ... more details
When referring to Transcription genetics DNA transcription , the coding strand is the DNA strand which has the same Nucleobase base sequence as the RNA transcript produced although with thymine replaced by uracil . It is this strand which contains codons , while the non coding strand contains anti codons. Alternative terms for strands Wherever a gene exists on a DNA molecule , one strand is the coding strand or sense strand or non template strand , and the other is the noncoding strand also called the antisense strand antisense is a general term for a sequence of DNA or RNA that is complementary to mRNA http books.google.com books?id BrNpbPkzoxAC&pg PA129&lpg PA129&dq coding strand antisense&source web&ots t6yUAob0Km&sig O3UVL8ZYlFi0ljVYax8hp695sRo PPA75,M1 , anticoding strand, template strand, or transcribed strand . Strands in transcription bubble During Transcription genetics transcription , RNA polymerase unwinds a short section of the DNA double helix near the start of the gene. This unwound section is known as the transcription bubble . The RNA polymerase, and therefore the transcription bubble, travels along the noncoding strand in the opposite, 3 to 5 , direction, as well as polymerizing a newly synthesized strand in 5 to 3 or Upstream and downstream DNA downstream direction. The DNA double helix is rewound by RNA polymerase at the rear of the transcription bubble Lewin, pp 235 http books.google.com books?id BrNpbPkzoxAC&pg PA129&lpg PA129&dq coding strand antisense&source web&ots t6yUAob0Km&sig O3UVL8ZYlFi0ljVYax8hp695sRo PPA75,M1 . Like how a zipper works, only it unzips it and rezips it without going back and forth. RNA DNA hybrid Where the helix is unwound, the coding strand consists of unpaired bases, whilst the template strand consists of an RNA DNA composite, followed by a number of unpaired bases at the rear. This hybrid consists of the most recently added ... York, USA. http books.google.com books?id BrNpbPkzoxAC&pg PA129&lpg PA129&dq coding strand antisense&source ... more details
Levenstein coding , or Levenshtein coding , is a universal code data compression universal code encoding the non negative integers developed by Vladimir Levenshtein . ref cite web url http www.compression.ru download articles int levenstein 1968 on the redundancy and delay.pdf title 1968 paper by V. I. Levenshtein in Russian ref ref cite book title Variable length codes for data compression author David Salomon publisher Springer year 2007 isbn 9781846289583 page 80 url http books.google.com books?id 81AfzW6vux4C&pg PA80&dq 22Levenstein coding 22&hl en&ei tYKZTIfzKJScsQP 1eWpAw&sa X&oi book result&ct result&resnum 3&ved 0CDgQ6AEwAg v onepage&q&f false ref The code of 0 number zero is 0 to code a positive number Initialize the step count variable C to 1. Write the binary numeral system binary representation of the number without the leading 1 to the beginning of the code. Let M be the number of bits written in step 2. If M is not 0, increment C , repeat from step 2 with M as the new number. Write C 1 bits and a 0 to the beginning of the code. The code begins 0 0 1 10 2 110 0 3 110 1 4 1110 0 00 5 1110 0 01 6 1110 0 10 7 1110 0 11 8 1110 1 000 9 1110 1 001 10 1110 1 010 11 1110 1 011 12 1110 1 100 13 1110 1 101 14 1110 1 110 15 1110 1 111 16 11110 0 00 0000 17 11110 0 00 0001 To decode a Levenstein coded integer Count the number of 1 bits until a 0 is encountered. If the count is zero, the value is zero, otherwise Start with a variable N , set it to a value of 1 and repeat count minus 1 times Read N bits, prepend 1 , assign the resulting value to N The Levenstein code of a positive integer is always one bit longer than the Elias omega coding Elias omega code of that integer. However, there is a Levenstein code for zero, whereas Elias omega coding would require the numbers to be shifted so that a zero is represented by the code for one instead. See also Elias omega coding Iterated logarithm References reflist Compression Methods DEFAULTSORT Levenshtein Coding Category Numeral ... more details
In computer science and information theory , Huffman coding is an entropy encoding algorithm used for lossless ... of Minimum Redundancy Codes . Huffman coding uses a specific method for choosing the representation ... probability distribution and a number of members which is a power of two , Huffman coding is equivalent to simple binary Block code block encoding , e.g., ASCII coding. Huffman coding is such a widespread ... algorithm is optimal for a symbol by symbol coding i.e. a stream of unrelated symbols with a known input ... is more common than cta . Other methods such as arithmetic coding and LZW coding often have better compression ... coding, and generally adapt to the actual input statistics, the latter of which is useful when ... of Huffman coding should not be overstated it can be used adaptively, accommodating unknown ... avoided the major flaw of the suboptimal Shannon Fano coding by building the tree from the bottom ... can be left out of the formula above. As a consequence of Shannon s source coding theorem , the entropy ... coding example.svg thumb A source generates 4 different symbols math a 1 , a 2 , a 3 , a 4 math ... optimality of the Huffman coding while both minimizing variance and minimizing the length ... text implementations employ various tricks to store tables efficiently. Huffman coding is optimal ... before Huffman coding helps both to reduce that inefficiency and to take advantage of statistical ... case for Huffman coding can happen when the probability of a symbol exceeds 2 sup 1 sup 0.5, making ... called run length encoding for the simple case of Bernoulli process es, Golomb coding is a provably optimal run length code. Arithmetic coding produces some gains over Huffman coding, although arithmetic coding has higher computational complexity. Also, arithmetic coding was historically a subject ... for arithmetic coding have passed into the public domain as the early patents have expired. Variations Many variations of Huffman coding exist, some of which use a Huffman like algorithm, and others ... more details
Lead missing date September 2009 Unreferenced date May 2008 Computer security History has proven that software defects, bugs and logic flaws are consistently the primary cause of commonly exploited software vulnerabilities. Through the analysis of thousands of reported vulnerabilities, security professionals have discovered that most vulnerabilities stem from a relatively small number of common software programming errors. By identifying the insecure coding practices that lead to these errors and educating developers on secure alternatives, organizations can take proactive steps to help significantly reduce or eliminate vulnerabilities in software before deployment. See also Defensive programming Secure input and output handling Security bug References Reflist No footnotes date September 2010 Cite book last Taylor first Art coauthors Brian Buege, Randy Layman title Hacking Exposed J2EE & Java year 2006 publisher McGraw Hill Primis pages 426 isbn 0390599751 page External links http www.safercode.com blog Safer Code Secure Coding In C and C , Making Your Code Faster, Stronger, Safer DEFAULTSORT Secure Coding Category Computer security Software stub mk ... more details
Conjugate coding is a cryptographic tool, introduced by Stephen Wiesner ref http portal.acm.org citation.cfm?id 1008908.1008920 ref in the sixties . Because its publication has been surprisingly rejected, it was developed to the world of public key cryptography in the eighties as Oblivious Transfer , first by Michael O. Rabin Rabin and then by Shimon Even Even . It is used in the field of Quantum Computing . References references Category Cryptography Category Information theory crypto stub ... more details
Coding conventions are a set of guidelines for a specific programming language that recommend programming ... science white space , Identifier naming convention naming conventions , Best Coding Practices programming ... easier. Coding conventions are only applicable to the human maintainers and peer review ers ... team or company follows, or may be as informal as the habitual coding practices of an individual. Coding ... the cost of software maintenance is the most often cited reason for following coding conventions. In their introduction ... long after the code was originally written. Coding conventions can help. Consistent use of Whitespace ... with a team s stated coding standards after its initial release. Any change that does not alter ... 08 url http www.xprogramming.com xpmag whatisxp.htm design ref Task automation Coding conventions allow ... project estimates . Consistent coding standards can, in turn, make the measurements more consistent ..., but their use within a project is determined by convention. Coding conventions simplify writing new ... web last Hoff first Todd title C Coding Standard Naming Class Files date 2007 01 09 url http www.possibility.com Cpp CppCodingStandard.html cflayout ref ref http wiki.fifengine.de index.php?title Coding standards FIFE coding standards ref Java has gone one step further the Java compiler returns an error ... the end of a command . Common conventions As mentioned above, common coding conventions may cover ... convention programming Naming conventions Best Coding Practices Programming practices Category ... Some programmers suggest that coding where the result of a decision is merely the computation ... convention programming Programming style References reflist External links Coding conventions for languages wikibooks Ada Style Guide ActionScript http opensource.adobe.com wiki display flexsdk Coding Conventions Flex SDK coding conventions and best practices Ada http www.adaic.com docs 95style ... Flight Software Branch &mdash Ada Coding Standard Ada ftp ftp.estec.esa.nl pub wm wme bssc bssc983.pdf ... more details
Arithmetic coding is a form of variable length code variable length entropy encoding used in lossless ... in fewer bits used in total. Arithmetic coding differs from other forms of entropy encoding such as Huffman coding in that rather than separating the input into component symbols and replacing each with a code, arithmetic coding encodes the entire message into a single number, a fraction n where ... P , see source coding theorem . Compression algorithms that use arithmetic coding start ... even be adaptive coding adaptive , so that they continuously change their prediction of the data based ... coding methods like arithmetic encoding can produce an output message that is larger than the input message, especially if the probability model is off. Adaptive arithmetic coding One advantage of arithmetic coding over other similar methods of data compression is the convenience of adaptation. Adaptation ... occurring during the encoding and decoding process. Adaptive arithmetic coding significantly ... in the result. Precision and renormalization The above explanations of arithmetic coding contain ... 1 0101011 0 1111111 1 Arithmetic coding as a generalized change of radix Recall that in the case where the symbols had equal probabilities, arithmetic coding could be implemented by a simple change of base, or radix. In general, arithmetic and range coding may be interpreted as a generalized change ... Connections with other compression methods Huffman coding Main Huffman coding There is great similarity between arithmetic coding and Huffman coding in fact, it has been shown that Huffman is just a specialized case of arithmetic coding but because arithmetic coding translates the entire message into one ... of 1 3, Huffman coding may produce the following code a tt 0 tt 50 b tt 10 tt 25 c tt 11 tt 25 This code has an expected 2 2 1 3 1.667 bits per symbol for Huffman coding, an inefficiency of 5 percent compared to log sub 2 sub 3 1.585 bits per symbol for arithmetic coding. For an alphabet 0, 1 ... more details
unreferenced date June 2009 bot yes Adaptive coding refers to variants of entropy encoding methods of lossless data compression . They are particularly suited to streaming data, as they adapt to localized changes in the characteristics of the data, and don t require a first pass over the data to calculate a probability model. The cost paid for these advantages is that the encoder and decoder must be more complex to keep their states synchronized, and more computational power is needed to keep adapting the encoder decoder state. Almost all data compression methods involve the use of a model , a prediction of the composition of the data. When the data matches the prediction made by the model, the encoder can usually transmit the content of the data at a lower information cost, by making reference to the model. This general statement is a bit misleading as general data compression algorithm would include the popular LZW and LZ77 algorithms, which are hardly comparable to compression techniques typically called adaptive . Run length encoding and the typical JPEG compression with run length encoding and predefined Huffman codes do not transmit a model. A lot other methods adapt their model to the current file and need to transmit it in addition to the encoded data, because both the encoder and the decoder need to use the model. In adaptive coding, the encoder and decoder are instead equipped with a predefined meta model about how they will alter their models in response to the actual content of the data, and otherwise start with a blank slate, meaning that no initial model needs ... handling and compresses it more efficiently approaching the efficiency of the static coding. Adaptive ... adaptive coding method has a corresponding static model method, in which the data model is precalculated ... to receive Decode the next symbol using the data model and output it. Examples Adaptive image coding ... size, there is a slight modification to the image coding scheme so that each compressed line is effectively ... more details
essay like date July 2011 unreferenced date April 2007 Hard coding also, hard coding or hardcoding refers to the software development practice of embedding what may, perhaps only in retrospect, be regarded as input or configuration data directly into the source code of a computer program program or other executable object, or fixed formatting of the data, instead of obtaining that data from external sources or generating data or formatting in the program itself with the given input. Overview Considered an anti pattern , hard coding requires the program s source code to be changed any time the input data or desired format changes, when it might be more convenient to the end user to change the detail by some means outside the program. Hard coding is sometimes required. Programmers may not have a dynamic user interface solution for the end user worked out but must still deliver the feature or release the program. This is usually temporary but does resolve in, a short term sense, the pressure to deliver the code. Later, softcoding is done to allow a user to pass on parameters that give the end user a way to modify the results or outcome. The term hard coded was coined in 1990 by R. Galichon then a Programmer Analyst at Mobil . Citation needed date January 2010 The term was used as an analogy to hardwiring circuits and was meant to convey the inflexibility which results from its usage within software design and implementation. In the context of run time extensible collaborative development environment s such as MUD s, hardcoding also refers to developing the core engine of the system ... t be run, since the floppy disk can t be inserted. This last example shows why hard coding may turn ... code would not have to be changed if the file moved. Hard coding is especially problematic ... the names of the constants for each appearance within the code. One important case of hard coding is when ... the strings. Hard coding in competitions In computing competitions such as the International Olympiad ... more details
In Set theory Ackermann coding or Ackermann interpretation is the encoding of Finite set finite sets as Natural number natural numbers as devised by Wilhelm Ackermann in his 1937 paper ref name ackermann cite journal last Ackermann first Wilhelm title Die Widerspruchsfreiheit der allgemeinen Mengenlehre journal Mathematische Annalen year 1937 volume 114 pages 305 315 url http www.digizeitschriften.de dms img ?PPN PPN235181684 0114&DMDID dmdlog23 accessdate 2012 01 09 ref ref cite journal last Kirby first Laurence title Finitary Set Theory journal Notre Dame Journal of Formal Logic year 2009 volume 50 issue 3 pages 227 244 url http projecteuclid.org DPubS?verb Display 26version 1.0 26service UI 26handle euclid.ndjfl 1257862036 26page record accessdate 31 May 2011 ref The Consistency of General Set Theory . Each natural number encodes a finite set and each finite set is represented by a natural number. This mapping uses the binary numeral system . If the number n encodes a finite set A and the i th binary digit of n is 1 then the set encoded by i is Element mathematics element of A . The Ackermann coding is a primitive recursive function . ref cite book page 261 last Rautenberg first Wolfgang doi 10.1007 978 1 4419 1221 3 title A Concise Introduction to Mathematical Logic url http www.springerlink.com content 978 1 4419 1220 6 publisher Springer Science Business Media location New York City New York edition 3rd isbn 978 1 4419 1220 6 year 2010 ref References Reflist Category Set theory settheory stub ... more details
Unreferenced date June 2009 Coding by exception is an anti pattern where software quickly degrades in performance and maintainability because it evolves by having special case functionality added piecemeal. This typically happens because an existing piece of software is extended to cover requirements that were not previously considered at the project s inception. This anti pattern is unrelated to software exception handling . As a general rule, well designed software projects contain very few corner case s. There are a variety of Software development process software development methodologies that purport to help engineers develop software that avoid these corner cases. They typically address Dependency computer science dependency management issues. Design pattern computer science Design patterns are another tool for arriving at less of a one off solution. See also Accidental complexity Creeping featurism Test driven development Category Anti patterns comp sci stub ... more details
numeral systems In mathematics , Fibonacci coding is a universal code data compression universal code which encodes positive integers into binary code word s. Each code word ends with 11 and contains no other instances of 11 before the end. Definition For a number math N math , if math d 0 ,d 1 , ldots,d k math represent the digits of the code word representing math N math then we have math N sum i 0 k 1 d i F i 2 , text and d k d k 1 1. math where F i is the i th Fibonacci number . It can be shown that such a coding is unique, and the only occurrence of 11 in any code word is at the end i.e. d k &minus 1 and d k . The first few Fibonacci codes are shown below, and also the so called Universal code data compression Relationship to practical compression implied distribution , the distribution of values for which Fibonacci coding gives a minimum size code. class wikitable Symbol Fibonacci representation Fibonacci code word implied distribution 1 math F 2 math 11 1 4 2 math F 3 math 011 1 8 3 math F 4 math 0011 1 16 4 math F 2 F 4 math 1011 1 16 5 math F 5 math 00011 1 32 6 math F 2 F 5 math 10011 1 32 7 math F 3 F 5 math 01011 1 32 8 math F 6 math 000011 1 64 9 math F 2 F 6 math 100011 1 64 10 math F 3 F 6 math 010011 1 64 11 math F 4 F 6 math 001011 1 64 12 math F 2 F 4 F 6 math 101011 1 64 13 math F 7 math 0000011 1 128 14 math F 2 F 7 math 1000011 1 128 The Fibonacci code is closely related to the Zeckendorf representation , a positional numeral system that uses Zeckendorf s theorem and has the property that no number has a representation with consecutive 1s. The Fibonacci ... with other universal codes Fibonacci coding has a useful property that sometimes makes it attractive ... is altered, none of the data that comes after it will be correctly read. With Fibonacci coding, on the other ... in Fibonacci coding as 0100100011, since nowrap 1 65 2 8 55 . The first two Fibonacci numbers ... isbn Compression Methods DEFAULTSORT Fibonacci Coding Category Non standard positional numeral ... more details
be solved in polynomial time . The theory and analysis of the color coding method was proposed in 1994 ... the method of color coding For every fixed constant math k math , if a graph math G V, E math ... graph where math V H O log V math , the method of color coding begins by randomly coloring ... of color coding involves enumerating possible colorings of a graph math G math , such that the randomness ... will be math k O k log V math . The derandomization of color coding method can be easily parallelized, yielding efficient NC complexity NC algorithms. Applications Recently, color coding has attracted ... consuming. However, by exploiting the color coding method, the motifs or signaling pathways with math ..., S. C. 2008. Biomolecular network motif counting and discovery by color coding. Bioinformatics ..., F., Wernicke, S., and Zichner, T. 2008. Algorithm Engineering for Color Coding with Applications ... s00453 007 9008 7 ref . References reflist DEFAULTSORT Color Coding Category Graph algorithms ... more details
Superdense coding is a technique used in quantum information theory to send two bits of classical information using only one qubit, with the aid of Quantum entanglement entanglement . Overview Suppose Alice would like to send classical information to Bob using qubit s, instead of classical bit s. Alice would encode the classical information in a qubit and send it to Bob. After receiving the qubit, Bob recovers the classical information via Measurement in quantum mechanics measurement . The question is how much classical information can be transmitted per qubit? Since non orthogonal quantum state s cannot be distinguished reliably, one would guess that Alice can do no better than one classical bit per qubit. Indeed Holevo s theorem this bound on efficiency has been proven formally. Thus there is no advantage gained in using qubits instead of classical bits. However, with the additional assumption that Alice and Bob share an entangled state , two classical bits per qubit can be achieved. The term superdense refers to this doubling of efficiency. Details Crucial to this procedure is the shared entangled state between Alice and Bob, and the property of entangled states that a Maximally entangled state maximally entangled state can be transformed into another state via local manipulation. Suppose parts of a Bell state , say math Psi rangle frac 1 sqrt 2 0 rangle A otimes 1 rangle B 1 rangle A otimes 0 rangle B math are distributed to Alice and Bob. The first subsystem, denoted by subscript A , belongs to Alice and the second, B , system to Bob. By only manipulating her particle locally, Alice can transform the composite system into any one of the Bell states this is not entirely surprising, for entanglement cannot be broken using local operations Obviously, if Alice does nothing ... whatsoever is gained by Eve unless she can interact with Bob s qubit. General dense coding scheme General dense coding schemes can be formulated in the language used to describe quantum channel ... more details
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