Free variation in linguistics is the phenomenon of two or more sounds or forms appearing in the same environment without a change in meaning and without being considered incorrect by native speaker s. ref name Clark cite book last1 Clark first1 John Ellery last2 Yallop first2 Colin last3 Fletcher first3 Janet year 2007 title Introduction to Phonetics and Phonology pages 110, 116 18 location Oxford publisher Blackwell isbn 1405130830 url http books.google.de books?id dX5P5mxtYYIC&pg PA116 v onepage&q&f false ref ref SIL International, 2004 01 05. http www.sil.org linguistics GlossaryOfLinguisticTerms WhatIsFreeVariation.htm What is free variation? . Retrieved 2011 01 26. ref Examples from English language English include glottalization of voiceless consonant voiceless stop consonant stops in word final position for example, the word stop may be pronounced with a plain unaspirated IPA p , IPA st p , or with a glottalized IPA p , IPA st p the word economics may be pronounced with IPA i or IPA in the first syllable although individual speakers may prefer one or the other, and although one may be more common in some dialect s than others, both forms are encountered within a single dialect and sometimes even within a single idiolect the comparative of many disyllabic adjective s can be formed either with the word more or with the Affix suffix er , for example more stupid or stupider . When phoneme s are in free variation, speakers are sometimes strongly aware of the fact especially where such variation is only visible across a dialectal or sociolectal divide , and will note, for example ... words show such variations. In the case of allophones , however, free variation is exceedingly common, and, along with differing intonation patterns, variation in allophony is the most important ... analysis References reflist Category Phonology als Freie Variation ar de Freie Variation Linguistik fr Variante libre ko it Variazione libera ru sv Fri variation ... more details
In musical composition music composition , developing variation is a musical form formal technique in which the concepts of musical development development and variation music variation are united in that variations are produced through the development of existing material. Though the term was coined by Arnold Schoenberg , inventor of the twelve tone technique , he felt it was one of the most important compositional principles since around 1750 ref name Haimo Haimo, Ethan. 1990. Schoenberg s Serial Odyssey The Evolution of his Twelve Tone Method, 1914 1928 , p.73n8. Oxford England Clarendon Press New York Oxford University Press ISBN 0 19 3152 60 6. ref quote Music of the homophony homophonic melody melodic style of composition, that is, music with a main theme music theme , accompaniment accompanied by and based on harmony , produces its material by, as I call it, developing variation . This means that variation of the features of a basic unit produces all the thematic formulations which provide for fluency, contrasts, variety, logic and unity, on the one hand, and character, mood, expression, and every needed differentiation, on the other hand thus elaborating the idea of the piece. Schoenberg distinguished this from the unravelling procedures of counterpoint contrapuntal tonality tonal music but developing variation may be related to other textures and to Schoenberg s own freely atonality atonal pieces which employ a method of atonal developing variation each chord music chord , line, and harmony results from the subtle alteration and recombination of musical idea musical ideas from earlier in the piece and Schoenberg describes its importance to his developmental of serialism. ref name Haimo quote Similarly, as in the case of Die Jakobsleiter , here also all main themes ... that Schoenberg reconciled serial organization and developing variation in the twelve tone technique. Further reading Frisch, Walter 1984 . Brahms and the Principle of Developing Variation , p.1 ... more details
See also Lunar theory Orbit of the Moon Variation is a generic word in astronomy as in other fields many observable astronomical quantities can show variations of some kind. But the term variation also has a specific meaning in astronomy, referring to the variation of the Moon . This is the name given to one of the principal perturbation astronomy perturbation s in the motion of the Moon. The variation was first discovered by Ab al Waf B zj n . ref Cajori, Florian, u A History of Mathematics u Macmillan, 1922 p105 ref Independently rediscovering the phenomenon, Tycho Brahe noticed that starting from a lunar eclipse in December 1590, that at the times of Syzygy astronomy syzygy new or full moon , the apparent velocity of motion of the Moon along its orbit as seen against the background of stars was faster than expected. On the other hand, at the times of first and last quarter, its velocity ..., vol.79 1967 , pp. 482 489, especially at p.485. The discovery of the variation was made accidentally ... pinned down the cause, a previously unrecognized inequality, since then called the variation. ref The main visible effect in longitude of the variation of the Moon is that during the course ... rather than its position. image Variation astronomy .gif frame right Variational orbit nearly an ellipse ... of Lunar theory Newton three mutually attracting bodies . This included a proof that the Variation ... by the Earth, and the major axis perpendicular to a line drawn between the Earth and Sun. The Variation ... motion of a body in an unperturbed orbit. The Variation effect would still occur if the undisturbed ... distortion of the Moon s orbit caused by the variation should not be confused with an undisturbed ... ellipse due to the variation, but an oval of another kind . ref D T Whiteside ed. 1973 , The Mathematical .... The Variation is the second largest solar perturbation of the Moon s orbit after the Evection ... republished by Dover, 1960 . Category Celestial mechanics de Variation Astronomie vi Nhi u qu o ... more details
An index of qualitative variation IQV is a measure of statistical dispersion in nominal distribution s. There are a variety of these, but they have been relatively little studied in the statistics literature. The simplest is the variation ratio , while the most sophisticated is the information entropy . Properties There are various indices of qualitative variation a number are summarized and devised by Wilcox Harv Wilcox 1967 , Harv Wilcox 1973 , who requires the following standardization properties to be satisfied Variation varies between 0 and 1. Variation is 0 if and only if all cases belong to a single category. Variation is 1 if and only if cases are evenly divided across all category. ref This can only happen if the number of cases is a multiple of the number of categories. ref In particular, the value of these standardized indices does not depend on the number of categories or number of samples. For any index, the closer to uniform the distribution, the larger the variance, and the larger the differences in frequencies across categories, the smaller the variance. Indices of qualitative variation are in this sense complementary to information entropy , which is maximized when ... be used as an index of qualitative variation. One characterization of a particular index of qualitative variation IQV is as a ratio of observed differences to maximum differences. Formulae Wilcox gives ... DM for Deviation from the Mode , is a standardized form of the variation ratio , and is analogous to variance ... Different indices give different values of variation, and may be used for different purposes ... Diversity index Variation ratio Information entropy Notes reflist References Citation last1 ... and Significance Test for Differences in Qualitative Variation journal Social Forces volume 55 issue ... first Allen R. title Indices of qualitative variation year 1967 url http www.ornl.gov info reports 1967 3445605133753.pdf Citation last Wilcox first Allen R. title Indices of Qualitative Variation and Political ... more details
Focus variation is a method to calculate a sharp image and to measure the depth with an optics with limited depth of field . Algorithm The algorithm work as follows at first images with difference focus are captured. This is done by moving the sample or the optics in relation to each other. then for each position the focus over each plane is calculated the plane with the best focus is used to get a sharp image. the corresponding depth gives the depth at this position Optics Focus variation requires an optics with very little depth of field . This can be realized if a microscopy like optics and a microscope objective is used. These objectives have a high numerical aperture which gives a small depth of field. Usage The use of this method is for optical surface metrology and coordinate measuring machine . This means measuring form, waviness and surface roughness roughness on samples. With optimized hardware and software components a lateral resolution of 500 nm limitation of wavelength of light and a vertical resolution of several nm can be reached. Advantages and Disadvantages Advantages can be used on samples with steep flankes. This is because a ring light can be used to extend the illumination aperture can deliver color information can measure on rough surfaces Disadvantages can not be used if the surface of the sample does not give structure in the image. This means it can not be used for wafers and glass Standardisation ISO committee is working on a new series of ISO standards that is called the ISO 25178 series. The part 6 document describes the available methods for surface roughness roughness measurement. Focus variation is one of the described methods. External links surface roughness Roughness Surface metrology Alicona http www.alicona.com . Manufacturer implementing focus variation into a product. http www.alicona.com cms upload pdf magazine PaperAlicona NonDestructiveTestingLaibach.pdf FOCUS VARIATION A NEW TECHNOLOGY FOR HIGH RESOLUTION OPTICAL 3D SURFACE ... more details
About the musical form other uses Variation disambiguation align right Listen filename Schubert Impromptu ... , variation is a musical form formal technique where material is musical repetition repeated ... or any combination of these. Variation form Variation forms include ground bass , passacaglia ... typically continuous evolving structures. Theme and variation forms are however based specifically on melodic variation, in which the fundamental musical idea, or Theme music theme , is repeated in altered form or accompanied in a different manner. Theme and variation structure igenerally begins ... two bars in length each variation, particularly in music of the eighteenth century and earlier ... led the player to indulge in extempore variation and ornament ref Raymar 1931, 5. ref however, the format .... Variation forms can be written as free standing pieces for solo instruments or ensembles, or can ... used as variation movements. ref name White History of variations Although the first isolated example emerged in the 14th century, works in theme and variation form first emerge in the history of classical ... of the variation form, since it provides a way of giving an overall shape to a variation set, rather letting it just form an arbitrary sequence. Keyboard works in variation form were written ... . Two famous variation sets from the Baroque music Baroque era, both originally written for harpsichord ... . Joseph Haydn specialized in sets of double variation s, in which two related themes, usually minor ..., H XVII 6. ref name Sisman 2001 Ludwig van Beethoven wrote many variation sets in his career. Some ... No. 3 Beethoven Third Symphony Eroica . Variation sets also occur in several of his late works ... movement of the Symphony No. 9 Beethoven Ninth Symphony . Franz Schubert wrote five variation ... as a whole takes its popular name from the lied. In the Romantic music Romantic era, the variation .... Variation sets have also been composed by notable twentieth century composers, including Sergei Rachmaninoff ... more details
Structural variation also genomic structural variation is the variation in structure of an organism s chromosome . It consists of many kinds of variation in the genome of one species , and usually includes ..., inversions and translocations. Typically a structure variation affects a sequence length about ... have some overlapping . ref cite journal pages 85 97 doi 10.1038 nrg1767 title Structural variation ... of structural variation does not imply anything about frequency or phenotypical effects. Many of structural ... variation Microscopic means that it can be detected with optical microscope s, such as aneuploidies , marker chromosome , gross rearrangements and variation in chromosome size. ref cite journal pages 135 42 doi 10.1038 ng947 title Human genome sequence variation and the influence of gene history ... BF00319995 title Size variation and orientation of the human Y chromosome year 1964 last1 Gripenberg ... date April 2011 ref Copy number variation main Copy number variation Copy number variation CNV is a large category of structural variation, which includes Insertion genetics insertions , Deletion genetics ... ref ref cite journal pages 949 51 doi 10.1038 ng1416 title Detection of large scale variation in the human ... and Structural Variation in the Human Genome year 2010 last1 Lupski first1 James R. journal Cell ... structural variation of the human genome year 2005 last1 Tuzun first1 Eray last2 Sharp first2 Andrew ... them. Citation needed date April 2011 Structural variation and phenotypes Some genetic diseases are suspected ... title Structural Variation of Chromosomes in Autism Spectrum Disorder year 2008 last1 Marshall first1 .... Different frequency of a same variation can be used as a genetic mark to infer relationship between populations in different areas. A complete comparison between human and chimpanzee structural variation ... journal pages 444 54 doi 10.1038 nature05329 title Global variation in copy number in the human genome ... Zhou first9 Y pmc 1569689 ref Database of structural variation Some of genome browsers and bioinformatic ... more details
Mergeto Functional derivative discuss Talk Functional derivative Merge proposal date July 2009 Mergeto Gateaux derivative discuss Talk Functional derivative Merge proposal Gateaux derivative date October 2009 In applied mathematics and the calculus of variations , the first variation of a Functional mathematics functional J y is defined as the linear functional math delta J y math mapping the function h to math delta J y h lim varepsilon to 0 frac J y varepsilon h J y varepsilon left. frac d d varepsilon J y varepsilon h right varepsilon 0 , math where y and h are functions, and is a scalar. Example Compute the first variation of math J y int a b yy dx. math From the definition above, math begin align delta J y h & left. frac d d varepsilon J y varepsilon h right varepsilon 0 & left. frac d d varepsilon int a b y varepsilon h y prime varepsilon h prime dx right varepsilon 0 & left. frac d d varepsilon int a b yy prime y varepsilon h prime y prime varepsilon h varepsilon 2 hh prime dx right varepsilon 0 & left. int a b frac d d varepsilon yy prime y varepsilon h prime y prime varepsilon h varepsilon 2 hh prime dx right varepsilon 0 & left. int a b yh prime y prime h 2 varepsilon hh prime dx right varepsilon 0 & int a b yh prime y prime h dx end align math External links http www.exampleproblems.com Exampleproblems.com has more examples of computing the first variation of functionals. Category Calculus of variations mathanalysis stub zh de Erste Variation ... more details
In probability theory and information theory , the variation of information or shared information distance is a measure of the distance between two clusterings Partition of a set partitions of elements . It is closely related to mutual information indeed, it is a simple linear expression involving the mutual information. Unlike the mutual information, however, the variation of information is a true metric mathematics metric , in that it obeys the triangle inequality . Even more, it is a universal metric , in that if any other distance measure two items close by, then the the variation of information will also judge them close. ref Alexander Kraskov, Harald St gbauer, Ralph G. Andrzejak, and Peter Grassberger , Hierarchical Clustering Based on Mutual Information , 2003 http arxiv.org abs q bio 0311039 ArXiv q bio 0311039 ref Background Empty section date July 2010 Definition Suppose we have two clusterings a division of a Set mathematics set into several subset s math X math and math Y math where math X X 1 , X 2 , ..,, X k math , math p i X i n math , math n Sigma k X i math . Then the variation of information between two clusterings is math VI X Y H X H Y 2I X, Y math where math H X math is entropy information theory entropy of math X math and math I X, Y math is mutual information between math X math and math Y math . This is completely equivalent to the Mutual information Metric shared information distance . References references Further reading Cite journal last Meila first Marina title Comparing Clusterings by the Variation of Information journal Learning Theory and Kernel Machines year 2003 pages 173 187 cite doi 10.1016 j.jmva.2006.11.013 Cite web last Kingsford first Carl title Information Theory Notes year 2009 url http www.cs.umd.edu class spring2009 cmsc858l InfoTheoryHints.pdf format PDF accessdate 22 September 2009 Use dmy dates date September 2010 External ... Variation Of Information Category Entropy and information ... more details
In probability theory and statistics , the coefficient of variation CV is a normalization statistics ... as unitized risk or the variation coefficient. The absolute value of the CV is sometimes known ... with RSD i.e. one term should be used consistently . Definition The coefficient of variation CV is defined ... in relation to mean of the population. The coefficient of variation should be computed only for data ... of variation may not have any meaning for data on an interval scale . ref cite web url http ... of variation for the normal and log normal distributions year 1964 last1 Koopmans first1 ... the same. This estimate is sometimes referred to as the geometric coefficient of variation ref http ... in order to distinguish it from the simple estimate above. However, geometric coefficient of variation ... This term was intended to be analogous to the coefficient of variation, for describing multiplicative variation in log normal data, but this definition of GCV has no theoretical basis as an estimate ... the corresponding formula. Comparison to standard deviation Advantages The coefficient of variation ... units or widely different means, one should use the coefficient of variation instead of the standard deviation. Disadvantages When the mean value is close to zero, the coefficient of variation ... directly to construct confidence interval s for the mean. Applications The coefficient of variation ... coefficient of variation is equal to 1. Distributions with CV 1 such as an Erlang distribution are considered ... high variance. Some formulas in these fields are expressed using the squared coefficient of variation , often abbreviated SCV. In modeling, a variation of the CV is the CV RMSD . Essentially the CV ..., the probability distribution of the coefficient of variation for a sample of size n has been shown ... Distribution of the Coefficient of Variation year 1936 last1 Hendricks first1 Walter A. last2 ... External links http www.thinkingapplied.com cov folder geo cov.htm Geometric Coefficient of Variation ... more details
In mathematical analysis , a function of bounded variation , also known as a BV function , is a real number real valued function mathematics function whose total variation is bounded finite the graph of a function ... Variable mathematics variable , being of bounded variation means that the distance along the Direction .... Functions of bounded variation are precisely those with respect to which one may find Riemann&ndash ... of bounded variation on a closed interval are exactly those f which can be written as a difference ... bounded variation if its distribution mathematics distributional derivative is a finite Vector valued function vector Radon measure . One of the most important aspects of functions of bounded variation ... on generalized function s, function of bounded variation are the smallest Algebra over a field ... Tonelli plane variation for an analysis of this concept and its relations to other generalizations, see the entry Total variation . ref who introduced a class of continuous function continuous BV functions ... for the first time the class of functions of bounded variation of several variables in its ... variation of a first order partial differential equation in the paper Harv Oleinik 1959 few ... problem for such equations is a function of bounded variation, provided the Cauchy boundary condition ... for BV functions in the paper Harv Vol pert 1967 he proved the Bounded variation Chain rule for BV ... Definition 1.1. The total variation ref name Tvar See the entry Total variation for further details ... and its derivative is Riemann integrable, its total variation is the vertical component ... variation BV function on a chosen interval mathematics interval a , b if its total variation ... is of bounded variation in an interval if and only if it can be written as the difference sub ... of bounded variation on a closed interval a , b defines a bounded linear functional on C a , b . In this special ... of several variables Functions of bounded variation, BV function mathematics functions , are functions ... more details
Antigenic variation refers to the mechanism by which an Pathogen infectious organism such as a protozoan ..., repeatedly infect a single host and are easily transmittable. Antigenic variation not only enables ... system generates new antibodies to target the newly identified antigen. Antigenic variation can ... molecular mechanisms behind antigenic variation, including gene conversion , ref name Cell cite journal title Gene conversion as a mechanism for antigenic variation in Trypanosomes journal Cell year ... of an Active Promoter to vsp Genes via Site Specific DNA Inversions Generates Antigenic Variation ... hypermutation , ref name Infection and Immunity cite journal title Bacterial Antigenic Variation, Host ... journal title Antigenic Variation in Lyme Disease Borreliae by Promiscuous Recombination of VMP like ... first4 Steven J issue 2 pmid 9108482 ref In all cases, antigenic variation and phase variation , a type of antigenic variation, result in a heterogenic phenotype of a clonal population. ref name ... journal title Phase and Antigenic Variation in Bacteria journal American Society for Microbiology year ... last2 Baumler first2 A. J. issue 3 pmid 15258095 pmc 452554 ref Antigenic Variation in Bacteria To generate intra population diversity, some bacteria can produce variation by various methods such as antigenic or phase variation . Antigenic variation is the expression of various alternative forms of antigen on the cell surface. Whereas phase variation is the phenotypic switch that is usually reversible and is referred to as an ON OFF switch. The outcome of either method of variation has a beneficial .... Antigenic variation in bacteria is best demonstrated by species of the genus Neisseria most notably ... Wisniewski Dy F, Vial L title Phase and antigenic variation mediated by genome modifications journal ... 008 9267 6 pmc url ref Antigenic Variation in Protozoa Antigenic variation is employed by a number ... variation and Plasmodium Plasmodium falciparum are some of the most well studied examples of protozoan ... more details
Unwarranted variation or geographic variation in healthcare service delivery, first so termed by Dr. John Wennberg , ref http www.businessweek.com magazine content 06 22 b3986001.htm Medical Guesswork Bot generated title ref refers to differences that cannot be explained by illness, medical need, or the dictates ... UnwarrantedVariation.htm Health Dialog Unwarranted Variation Bot generated title ref History Working ... mhe article articleDetail.jsp?id 46508 Clamping down on variation Managed Healthcare Executive Bot ... disease management company that is hired to address unwarranted variation blockquote If you live ... from, is called practice pattern variation. And it isn t limited to treating back pain, or even surgical decisions. There is also variation in treatment for chronic conditions, such as use of beta blockers ... healthcare is practiced around the country. They have also asserted that most of this variation is, in fact, unwarranted. Health Dialog was built to directly address unwarranted variation in healthcare ... that if unwarranted variation in the healthcare system could be reduced, the quality of care would go up and healthcare costs would go down. Studies have shown that if unwarranted variation could be reduced ... variation in medical practice, as noted by Martin Sipkoff in 9 Ways To Reduce Unwarranted Variation , is costly and deadly. Analysis of Medicare data reveals that per capita spending per enrollee ... Variation Bot generated title ref We re literally dying, waiting for the practice of medicine ... Variation Bot generated title ref blockquote Practice variation is one of the greatest problems ... 0311 0311.variation.html 2003 11 9 Ways To Reduce Unwarranted Variation Bot generated title ref blockquote ... Variation from Dr. John Wennberg Further reading Newspaper publications http www.nytimes.com 2007 ... mhe article articleDetail.jsp?id 46508 Clamping down on variation, Michael T. McCue ... variation in the amount of care provided to patients with three common chronic conditions , Health ... more details
Phase variation is a method for dealing with rapidly varying environments without requiring random mutation employed by various types of bacteria, including Salmonella species. It involves the variation of protein expression, frequently in an on off fashion, within different parts of a bacterial population ... in many other areas as well. Phase variation is defined as the random switching of phenotype at frequencies that are much higher sometimes 1 than classical mutation rates. Phase variation contributes ... Molecular switches the ON and OFF of bacterial phase variation journal Mol Microbiol year 1999 volume ... of phase variation rate and the fitness implications of differing rates for bacterial pathogens ... Phase variation site specific recombination inversion.jpg right 450px Phase variation site specific ... variation mediated by genome modifications journal Antonie Van Leeuwenhoek year 2008 volume 94 issue ... title Environmental regulation of the fim switch controlling type 1 fimbrial phase variation in Escherichia ... sequence of DNA is restored, reversible phase variation can be mediated by Transposable element transposition . Phase variation mediated by transposition targets specific DNA sequences. ref name pmid15258095 cite journal author van der Woude MW, B umler AJ title Phase and antigenic variation ... of a type of phase variation. Type IV pili of Neisseria gonorrhea are controlled in this way. There are several ... Unlike other mechanisms of phase variation, epigenetic modifications do not alter DNA sequence ... variation mediated by two proteins, DNA methylating enzyme deoxyadenosine methyltransferase Dam and the oxidative ... ref Nested DNA Inversion In this form of phase variation. The promoter region of the genome can move ... DNA sequences. ref name pmid18663597 File PV SSM.JPG right 450px Phase variation slipped strand ... MW title Slipped strand mispairing can function as a phase variation mechanism in Escherichia coli ... Alphen L, Mooi FR, van Putten JP title Phase variation of H. influenzae fimbriae transcriptional control ... more details
refimprove date November 2011 Ecophenotypic variation ecophenotype refers to Phenotype phenotypical variation as a function of life station. In wide ranging species, the contributions of heredity and environment are not always certain, but their interplay can sometimes be determined by experiment. Plants Plants display the most obvious examples of ecophenotypic variation. One example are trees growing in the woods developing long straight trunks, with branching crowns high in the canopy, while the same species growing alone in the open develops a spreading form, branching much lower to the ground. Genotype s often have much flexibility in the modification and expression of phenotype s in many organisms these phenotypes are very different under varying environmental conditions. The plant Hieracium umbellatum is found growing in two different habitats in Sweden. One habitat is rocky sea side cliffs, where the plants are bushy with broad leaves and expanded inflorescence s the other is among sand dunes where the plants grow prostrate with narrow leaves and compact inflorescences. These habitats alternate along the coast of Sweden and the habitat that the seeds of H. umbellatum land in determines the phenotype that grows. ref name Botanyonline cite web url http www.biologie.uni hamburg.de b online e37 37b.htm title Botany online Evolution The Modern Synthesis Phenotypic and Genetic Variation Ecotypes work accessdate 2009 12 29 ref Invasive species Invasive plants such as the honeysuckle can thrive by altering their morphology biology morphology in response to changes in the environment, ref http www.jstor.org pss 2997251 ref which gives them a competitive advantage. The more immediate responses shown by vascular plants to their environment, for instance a vine s ability to conform to the wall or tree upon which it grows, are not usually considered ecophenotypic, even though ... plastic than plants, ecophenotypic variation is noteworthy. When encountered, it can cause confusion ... more details
Sociolinguistics In sociolinguistics , variation in language use among speakers or groups of speakers is a principal concern. Such variation may occur in pronunciation Accent linguistics accent , word choice lexicon , or even preferences for particular Grammar grammatical patterns. ref name Meecham Cite book last1 Meecham first1 Marjory last2 Rees Miller first2 Janie chapter Language in social contexts editor1 last O Grady editor1 first William editor2 last Archibald editor2 first John editor3 last Aronoff editor3 first Mark editor4 last Rees Miller editor4 first Janie title Contemporary Linguistics edition Fourth year 2001 publisher Bedford St. Martin s isbn 0 312 24738 9 ref Studies of language variation and its correlation with Sociology sociological categories, such as William Labov William ... first J.K. title Sociolinguistic Theory Linguistic Variation and its Social Significance publisher ..., language variation and change remains an important issue at the heart of the field. Sociolinguistic ... variable is the frequency of negative concord known colloquially as a double negative . Variation associated with age There are several different types of age based variation one may see within ... age range, age graded variation, and indications of linguistic change in progress. One example ..., since it does not apply to all individuals of that age bracket within the community. Age graded variation is a stable variation which varies within a population based on age. That is, speakers of a particular ... change in progress, one would expect to see variation over a broader range of ages. William Bright ... age based variation is taken as an indication of linguistic change in progress. Variation associated with geography Main Dialectology A commonly studied source of variation is regional dialects. Dialectology ... to regional areas are often called dialectologists. Variation associated with gender Main Language and gender ... Category Language varieties and styles Category Linguistics ar de Variation Linguistik ... more details
The double variation also known as alternating variations is a musical form used in European classical music classical music . It is a type of variation music theme and variations that employs two themes. In a double variation set, a first theme to be called A here is followed by a second theme B , followed by a variation on A, then a variation on B, and so on with alternating A and B variations. Often there is a coda music coda at the end. The double variation is strongly associated with the composer Joseph Haydn , who wrote many such movements during his career. The double variation in Haydn The double variation first appears Haydn s work of the 1770s. Haydn may have been inspired by an earlier ..., though not so close as to be an actual variation of it. The total number of variations ..., almost amiable. Rosen s remark could be applied to several of the other major double variation themes. List of works by Haydn written in double variation form According to Sisman, ref name Sisman Haydn wrote 21 double variation movements. Sisman s list is restated below in chronological order .... XVI 34. 3 Vivace molto td td ABA sub 1 sub B sub 1 sub A sub 2 sub . First variation in A is lengthened ... followed by a second quasi variation on B in Presto tempo, expanded to full sonata form. For discussion ... Croatian folk tunes . td td c td td C td tr table The double variation in Beethoven Although the double variation is associated strongly with Haydn, Elaine Sisman has pointed out that, provided we ... structural formulae given below. Thus flexibly construed, the double variation emerges as the musical ... argues that a double variation structure is present. table class wikitable tr td Year td td Work .... Later double variations After Beethoven, the double variation appears to have been only ... http www.oup.co.uk music repprom harper prognotes program notes . Other senses of the term double variation ... variation in a quite different sense. This definition presupposes that the theme consists of two parts ... more details
In statistics , explained variation or explained randomness measures the proportion to which a mathematical model accounts for the variation apparent randomness of a given data set. Often, variation is quantified as variance then, the more specific term explained variance can be used. The complementary part of the total variation randomness variance is called unexplained or residual . The simplified assumption of explained variance as equal to the square algebra square of the Pearson product moment correlation coefficient correlation coefficient has been criticized. for most social scientists, is of doubtful meaning but great rhetorical value . ref Achen 1990, p. 183 ref ref C H Achen 1982 ref Definition Explained variation is a relatively recent concept. The most authoritative source seems to be Kent 1983 who founded his definition on information theory . Information gain by better modelling Following Kent 1983 , we use the Fraser information Fraser 1965 math F theta int textrm d r ,g r , ln f r theta math where math textrm d r ,g r math is the probability density of a random variable math R , math , and math f r theta , math with math theta in Theta i math math i 0,1 , math are two families of parametric models. Model family 0 is the simpler one, with a restricted parameter space math Theta 0 subset Theta 1 math . Parameters are determined by maximum likelihood estimation , math theta i mbox arg max theta in Theta i F theta math . The information gain of model 1 over model 0 is written as math Gamma theta 1 theta 0 2 F theta 1 F theta 0 , math where a factor of 2 is included for convenience. is always nonnegative it measures the extent to which the best model of family 1 is better than the best model of family 0 in explaining g r . Information gain by a conditional model Assume a two dimensional random variable math R X,Y math where X shall be considered as an explanatory variable, and Y as a dependent variable. Models of family 1 explain Y in terms of X , math f ... more details
Refimprove date November 2007 globalize UK date December 2010 A regional variation generally refers to times when a radio station or television station simultaneously broadcasts different Television program programmes , continuity broadcasting continuity or adverts to different parts of its coverage area. This may be so as to provide programming specific to a particular region , such as local news or may be so as to allow advertisements to be target ted to a particular area. Some regional variations are the consequence of a Federation federal style television network or radio network where a local station is part of a larger broadcast network and broadcasts the network s programmes some of the time and its own programming the rest of the time. The latter is therefore sometimes considered a regional variation. Examples of this include the UK s ITV network throughout much of its history, and American network affiliate stations. Regional variation is also a common term used in British television listings publications, such as magazines and newspapers, to show the different programmes broadcast in different areas of the country. Regional Variations in the UK The BBC has traditionally offered regional variations across many of its services. The BBC Home Service Home Service and its successor BBC Radio 4 Radio 4 provided regional variations until the late 1970s when BBC Local Radio Local Radio took over most of these responsibilities. BBC One and the BBC Television Service have provided ... no regional variations for programming or continuity, but offer variation during advertising breaks ..., both simultaneously and slightly behind though this is technically not a regional variation, rather ... national broadcast distribution feed, creating a local variation in output. Being a non commercial ... mainland, although the programme content comes from both Plymouth and Jersey. Considerable variation ... dates date December 2010 DEFAULTSORT Regional Variation Category Television in the United Kingdom ... more details
In mathematics , variation of parameters , also known as variation of constants , is a general method to solve inhomogeneous differential equation inhomogeneous linear differential equation linear ordinary differential equation s. It was developed by Joseph Louis Lagrange Citation needed date April 2011 . For first order inhomogeneous linear differential equations it is usually possible to find solutions via integrating factor s or method of undetermined coefficients undetermined coefficients with considerably less effort, although those methods leverage heuristics that involve guessing and don t work for all inhomogenous linear differential equations. Variation of parameters extends to linear partial differential equations as well, specifically to inhomogeneous problems for linear evolution equations like the heat equation , wave equation , and vibrating plate equation. In this setting, the method is more often known as Duhamel s principle , named after Jean Marie Duhamel who first applied the method to solve the inhomogeneous heat equation. Sometimes variation of parameters itself is called Duhamel s principle and vice versa. Description of method Given an ordinary non homogeneous linear differential equation of order n math y n x sum i 0 n 1 a i x y i x b x . math i let math y 1 x , ldots, y n x math be a Fundamental system Homogeneous equations fundamental system of the corresponding homogeneous equation math y n x sum i 0 n 1 a i x y i x 0. math ii Then a ordinary differential equation particular solution to the non homogeneous equation is given by math y p x sum i 1 n c i x y i x math iii where the math c i x math are continuous functions which satisfy the equations ... them u sub 1 sub and u sub 2 sub we can proceed with variation of parameters. Now, we seek the general ... differential equations ca M tode de variaci dels par metres de Variation der Konstanten fr M thode de variation des constantes ko it Metodo delle variazioni delle costanti nl Variatie van de ... more details
Infobox chess opening openingname Sicilian Defence, Chekhover Variation image Chess diagram rd nd bd qd kd bd nd rd pd pd pd pd pd pd pd ql pl nl pl pl pl pl pl pl rl nl bl kl bl rl moves 1.e4 c5 2. Nf3 d6 3. d4 cxd4 4. Qxd4 ECO B53 nameorigin Vitaly Chekhover parentopening Open Sicilian AKA Szily Variation, Hungarian Variation chessgid 2146947&move 4.5&moves e4.c5.Nf3.d6.d4.cxd4.Qxd4&nodes 21720.32033.32034.32069.32070.32071.2146947 The Sicilian Chekhover Variation is a chess opening named after Vitaly Chekhover , from Chekhover Lisitsin, Leningrad 1938. ref name Oxford citation last1 Hooper first1 David author1 link David Vincent Hooper last2 Whyld first2 Kenneth author2 link Kenneth Whyld year 1992 title The Oxford Companion to Chess edition 2 publisher Oxford University Press isbn 0 19 280049 3 page 75 ref It is also sometimes called the Szily or Hungarian Variation. ref name Oxford Although the Chekhover Variation is rarely played in grandmaster chess grandmaster games, it is actually not uncommon among amateurs. ref http www.chessgames.com perl explorer?node 32071&move 4&moves e4.c5.Nf3.d6.d4.cxd4&nodes 21720.32033.32034.32069.32070.32071 The Chekhover Variation chessgames.com Chess Opening Explorer ref On move four White ignores the standard chess opening opening advice to not move the queen chess queen out early in the game as it may become a target in the center . The Encyclopaedia of Chess Openings assigns code B53 to this variation. ref http www.chessgames.com perl chess.pl?eco B53&node 2146947 Sicilian ECO B53 ref Responses for Black Black s main response to the Chekhover Variation is the obvious looking 4...Nc6 attacking White s queen, however, there are many more to choose from. 4...Nc6 The most popular response 5. Bb5 Pinning the knight 5...Bd7 6. Bxc6 Bxc6 5. Qa4? Avoiding an exchange and keeping the light squared bishop 4...a6 Preventing a future pin 5. c4 Nc6 6. Qd1 4...Bd7 Preparing for 5...Nc6 4...Nf6 Avoiding exchanges and continuing development ... more details
Infobox chess opening openingname Poisoned Pawn Variation image Chess diagram rd nd bd kd bd rd pd pd pd pd pd pd pd nd bl nl pl pl nl pl qd pl ql pl pl rl kl bl rl Black has accepted the poisoned b2 pawn with 8...Qxb2 moves 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Bg5 e6 7.f4 Qb6 8.Qd2 Qxb2 ECO B97 birth nameorigin parentopening Sicilian Defence AKA chessgid 1859759&move 8.5&moves e4.c5.Nf3.d6.d4.cxd4.Nxd4.Nf6.Nc3.a6.Bg5.e6.f4.Qb6.Qd2&nodes 32033.32034.32069.32070.32071.32072.32073.32074.65251.162533.162523.162524.1859747.1859759 The Poisoned Pawn Variation is any of several chess opening variations where a pawn chess pawn is said to be List of chess terms Poisoned Pawn poisoned because its capture can result in positional problems or material chess material loss for the captor. The best known of these, called the Poisoned Pawn Variation, is a line of the Sicilian Defense, Najdorf Variation that begins with the moves 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4 Nxd4 Nf6 5.Nc3 a6 6.Bg5 e6 7. Wikibooks Opening theory in chess 1. e4 1...c5 2. Nf3 2...d6 3. d4 3...cxd4 4. Nxd4 4...Nf6 5. Nc3 5...a6 6. Bg5 6...e6 7. f4 f4 Wikibooks Chess Opening Theory 1. e4 1...c5 2. Nf3 2...d6 3. d4 3...cxd4 4. Nxd4 4...Nf6 5. Nc3 5...a6 6. Bg5 6...e6 7. f4 7...Qb6 Qb6 after which 8.Qd2 Qxb2 usually follows ... later became an exponent, playing it with great success. The line was most famously played in game ... James Fischer 1972 Game 7 accessdate 2008 01 19 last first coauthors date work publisher ref and game ... Robert James Fischer 1972 Game 11 accessdate 2008 01 19 last first coauthors date work publisher ref ..., Spassky surprised Fischer with a List of chess terms Novelty theoretical novelty and won the game ... Pawn variation also exists in the French Defence Winawer Variation 3...Bb4 French Defence Winawer 1.e4 ... Nd7 . Like the Poisoned Pawn variation in the Sicilian Najdorf , this line gives significant ... a Poisoned Pawn variation in the Latvian Gambit 1.e4 e5 2.Nf3 f5 3.Bc4 fxe4 4.Nxe5 Qg5? This variation ... more details
Infobox chess opening openingname Sicilian Defence, Scheveningen Variation image Chess diagram rd nd ... In the opening chess opening of a game of chess , the Scheveningen Variation ref name chessgames b80 cite web url http www.chessgames.com perl chessopening?eco B80 title Sicilian, Scheveningen Variation B80 publisher Chessgames.com work Chess openings accessdate .... The Scheveningen Variation is a classically motivated defence which appreciates the advantages ... pos tocleft Origin of the Scheveningen Variation The variation first came under international .... During the tournament the variation was played several times by several players, including ... 10.Nb3 a6 11.0 0 0 Bd7 12.h4 gives White an equal game at best. 7... Nc6 8. Rg1 diagram and here Black ... nl pl pl nl bl bl pl pl pl pl rl ql rl kl Classical variation after 11.Bf3 Another very popular variation ... 2008 01 19 ref also known as Maroczy Variation which is initiated by 6. Be2 . Used to great ... 2010 bot H3llBot ref modeled after the Yugoslav Vsevolod Rauzer Rauzer Attack in the Dragon Variation ... castles long and a very sharp game is often the result. Black, however, does not have to acquiesce ... into this critical variation. Other variations Fischer Attack 6. Bc4 . ref name chessgames b86 cite ... ready to counter White s g2 g4 g5 with a7 a6 and b7 b5 b4 on the other flank. Tal Variation 6. f4 ... Variation ref In one of the main lines, 6... Nc6 7. Be3 Be7 8. Qf3 , White seeks to castle queenside ... to Black. Question of move orders and the Najdorf Variation The Keres Attack puts Black into a rather ... tend to play the Sicilian Defence, Najdorf Variation Najdorf Variation move order and then play 6...e6 ... move order was seen in World Chess Championship 1984 , where after game one when Kasparov had difficulties ... is under the rubric of the Sicilian Defence, Najdorf Variation Najdorf . In fact, many books exploring ... section above, is technically the Najdorf Variation of the Sicilian defense with the very popular ... more details
Defence, Scheveningen Variation Scheveningen Variation by playing 6...e6 or keeping the game ... Flank Game Najdorf Variation year 1969 publisher Batsford id ISBN 9780713403510 authorlink Alb ric ...Infobox chess opening openingname Sicilian Defence, Najdorf Variation image Chess diagram rd nd bd qd ... The Najdorf Variation ref name chessgames b90 cite web url ... Variation Scheveningen . It begins thus 1. b Chess Opening Theory 1. e4 e4 b Chess Opening Theory 1 ... however, ideas have been found by some Dutch players who call this variation De Verbeterde List The Improved .... This variation is covered by Ufuk Tuncer and Twan Burg in New In Chess , Yearbook 102 . The idea ... fianchetting the bishop to g7. The variation is covered by Ufuk Tuncer in New In Chess , Yearbook ... has not yet been given. The whole variation with 6...Nbd7 is covered in the book by ubom r Ft nik ... body of opening theory. 8...h6 9 Bh4 g5 . This is known as the Argentine Goteborg Variation ..., in a critical last round game. According to modern opening theory this position is a draw ... Poisoned Pawn Variation 8...Qxb2 9 Rb1 9 Nb3 is the other less common option 9...Qa3 and here ... for a win against the poisoned pawn variation since all other variations and that includes the other pawn move 10 f5 have been analysed to a draw with best play. An example is the game Francisco Vallejo ... draw by Kasparov himself in Revolution in the 70s page 164 . 8 Nb3 White opts for a quiet game, but Black ... it very hard to organise an attack. 7...b5 the ultra sharp Polugaevsky Variation. ref name chessgames ... Variation ref Black ignores White s threat and expands in Queenside. 8 e5 dxe5 9 fxe5 Qc7 here White ... Pawn Deferred. This variation is very popular at the moment. English Attack 6 Be3 This has become ... to transpose to the Sicilian Defence, Scheveningen Variation Scheveningen by playing 6...e6 . White ... option with 7 0 0 , but this cuts the aggressive possibility to castle long. Classical Variation ... more details
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