Wiktionarypar overlapOverlap may mean one of In music theory, overlap is a synonym for reinterpretation of a chord at the boundary of two musical phrases. In railway signalling, an Overlap railway signalling is the length of track beyond a stop signal that is proved to be clear of vehicles in the controls of the previous signal, as a safety margin. Overlap road , a place where multiple road numbers overlap. Overlap add , an efficient convolution method using FFT. Overlap , important concept in quantum mechanics describing a type of orbital interaction as described by the overlap integral . Overlap in molecules affects bond strength . disambig ja ... more details
The overlap coefficient is a similarity measure related to the Jaccard index that computes the overlap between two sets which is defined as follows math mathrm overlap X,Y frac X cap Y min X , Y math If set X is a subset of Y or the converse then the overlap coefficient is equal to one. References http www.dcs.shef.ac.uk sam stringmetrics.html Similarity Metrics , University of Sheffield, Department of Computer Science Category Information retrieval Category String similarity measures Category Measure theory ... more details
Context date April 2011 Orphan date February 2009 In memory research, concurrent overlap , or task appropriate processing, is a type of processing overlap between an activity engaged in before the prospective memory is to be remembered and a cue that directs attention towards the prospective memory ref Meier B., & Graf P. 2000 . Transfer appropriate processing for prospective memory tests. Applied Cognitive Psychology, 14, S11 S27 ref . It is prospective memory specific and is distinct from sequential overlap, or transfer appropriate processing, which occurs in both retrospective and prospective memory and is defined as the overlap in processing the to be remembered memory between planning or study in retrospective memory and test times. References references Category Memory processes ... more details
Infobox disease Name Overlap syndrome Image Alt Caption DiseasesDB ICD10 ICD10 M 35 1 m 30 ICD9 ICDO OMIM MedlinePlus eMedicineSubj eMedicineTopic MeshID GeneReviewsID GeneReviewsName An overlap syndrome is an autoimmune disease of connective tissue ref DorlandsDict eight 000104573 overlap syndrome ref in which the patient presents with symptoms of two or more diseases. As much as 25 of all patients with connective tissue disease show signs of an overlap syndrome. Examples of overlap syndromes include MCTD and scleromyositis , but the exact diagnosis depends from which diseases the patient shows symptoms. In overlap syndromes, features of systemic lupus erythematosus SLE , systemic sclerosis , polymyositis , dermatomyositis , rheumatoid arthritis RA and Sj gren s syndrome are found often. ref cite journal title Overlap syndromes and mixed connective tissue disease author Maddison PJ. journal Curr Opin Rheumatol. year 1991 volume 3 pages 995 1000 pmid 1772755 doi 10.1097 00002281 199112000 00016 issue 6 ref References reflist Category Autoimmune diseases Category Rheumatology Category Syndromes disease stub Systemic connective tissue disorders pl Zesp nak adania ... more details
Unreferenced date December 2009 Orphan date December 2009 An overlap zone , in radio frequency engineering , is a zone in which the signals from two or more radio station s, transmitting at the same frequency, can be received with comparable intensity. Co channel interference Interference occurs frequently in such a zone. In order to avoid this, a receiver with directional antenna is used, which can then be aligned in such a way that it will only receive the signal of one transmitter. Alternatively, the signals could be separated using a demodulator in single sideband single sideband mode . With digital radio Digital Radio Mondiale and Digital Audio Broadcasting being two common types , there is no interference in the overlap zone. See also Technoparade DEFAULTSORT Overlap Zone Category Telecommunications de Verwirrungsgebiet ... more details
The overlap matrix is a square matrix , used in quantum chemistry to describe the inter relationship of a set of basis vector s of a Quantum mechanics quantum system. In particular, if the vectors are orthogonal to one another, the overlap matrix will be diagonal. In addition, if the basis vectors form an orthonormal set, the overlap matrix will be the identity matrix . The overlap matrix is always n × n , where n is the number of basis functions used. It is a kind of Gramian matrix . In general, the overlap matrix is defined as math mathbf S jk left langle b j b k right rangle int Psi j Psi k d tau math where math left b j right rangle math is the j th basis Bra ket notation ket vector geometric vector , and math Psi j math is the j th wavefunction , defined as math Psi j x left langle x b j right rangle math . In particular, if the set is normalized though not necessarily orthogonal then the diagonal elements will be identically 1 and the magnitude of the off diagonal elements less than or equal to one with equality if and only if there is linear dependence in the basis set as per the Cauchy Schwarz inequality . See also Roothaan equations Hartree Fock References Quantum Chemistry Fifth Edition , Ira N. Levine, 2000 Category Quantum chemistry Category Matrices ar it Matrice di sovrapposizione sv verlappsmatris ... more details
Wikify date January 2011 Orbital overlap was an idea first introduced by Linus Pauling to explain the molecular bond angles observed through experimentation and is the basis for the concept of orbital hybridisation . s orbitals are spherical and have no directionality while p orbitals are oriented 90 to one another. A theory was needed therefore to explain why molecules such as methane CH sub 4 sub had observed bond angles of 109.5 . ref Anslyn, Eric V. Dougherty, Dennis A. 2006 . Modern Physical Organic Chemistry . University Science Books. ref Pauling s theory was that bonds are created by the overlap of adjacent atomic orbitals of two atoms. The greater the overlap of the two orbitals, the stronger the bond. The resulting bond is known as an sp hybrid and it exhibits strength greater than that of an s or p orbital. ref Pauling, Linus. 1960 . The Nature Of The Chemical Bond . Cornell University Press. ref Sources references Category Chemical bonding Category Molecular geometry Category Quantum chemistry Chemistry stub ... more details
Incomplete date February 2009 An overlap in railway signalling is the length of track beyond a Railway signal stop signal that is proved to be clear of vehicles in the controls of the previous signal, as a safety margin. Overview Enough braking distance is provided to allow a train to comfortably stop at the stop signal, but should it fail to do so for any reason slippery rail s, brake failure, inattention by driver, etc. there is still some distance to allow the train to stop short of any obstruction, such as another train. Length The length of an overlap may be a nominal length, or else calculated on the full emergency braking distance for the gradients and speeds for that particular section of line. Two signal protection If the overlap is long enough to extend from one stop signal to the next, then the effect is to provide two signal protection or double blocking , with the first signal having a full overlap, and the second signal having a short overlap. With two signal protection, only one track circuit is needed between successive signals. However, overlaps may then be longer than is necessary with an adverse effect on headway, should headway be important on that section of line. With one signal protection, there may be two track circuits between successive signals, which has a cost, however headways can be optimised. Country practice Overlap design vary widely with signalling practice in different countries and types of Automatic Warning System AWS and Automatic Train Protection ATP . Many countries do not use overlaps at all. In Germany the following distances before entry to a station or another critical point are used ref Haldor Jochim, Frank Lademann Planung von Bahnanlagen. Grundlagen Planung Berechnung , Hanser Verlag, 2008, ISBN 9783446413450 ref class wikitable style text align right Maximum br Speed Required br Overlap 60 km h 200 m 60 km h 100 m 40 km h 50 m 30 km h 0 m References references Category Railway signalling rail stub de Durchrutschweg ... more details
In mathematics , computer science and logic , overlap , as a property of the reduction rules in term rewriting system , describes a situation where a number of different reduction rules specify potentially contradictory ways of reducing a reducible expression or redex within a term. More precisely, if a number of different reduction rules share function symbols on the left hand side, overlap can occur. Often we do not consider trivial overlap with a redex and itself. For example, consider the term rewriting system defined by the reduction rules math rho 1 f g x , y rightarrow y math math rho 2 g x rightarrow f x, x math The term f g x , y can be reduced via &rho sub 1 sub to yield y , but it can also be reduced via &rho sub 2 sub to yield f f x , x , y . Note how the redex g x is contained in the redex f g x , y . The result of reducing different redexes is described in a Critical pair logic critical pair the critical pair arising out of this term rewriting system is f f x , x , y , y . Overlap may occur with fewer than two reduction rules. Consider the term rewriting system defined by the reduction rule math rho 1 g g x rightarrow x math The term g g g x has overlapping redexes, which can be either applied to the innermost occurrence or to the outermost occurrence of the g g x term. References cite book title Term Rewriting Systems author Terese coauthors Marc Bezem, J. W. Klop, Roel de Vrijer series Cambridge Tracts in Theoretical Computer Science publisher Cambridge University Press year 2003 isbn 0 521 39115 6 page 48 math stub Category Rewriting systems ... more details
orphan date June 2009 One source date December 2010 Morisita s overlap index , named after Masaaki Morisita, is a dispersion statistics statistical measure of dispersion of individuals in a population. It is used to compare overlap among Sample statistics samples Morisita 1959 . This formula is based on the assumption that increasing the size of the samples will increase the diversity because it will include different habitats i.e. different faunas . Formula math C D frac 2 sum i 1 S x i y i D x D y XY math x sub i sub is the number of times species i is represented in the total X from one sample. y sub i sub is the number of times species i is represented in the total Y from another sample. D sub x sub and D sub y sub are the Simpson s index values for the x and y samples respectively. Completely different samples If the species occur in the same proportions in both samples, then C sub D sub 1. Horn s modification of the index is Horn 1966 math C H frac 2 sum i 1 S x i y i left sum i 1 S x i 2 over X 2 sum i 1 S y i 2 over Y 2 right X Y ,. math External links http www.tnstate.edu ganter B412 20Ch 2015&16 20CommMetric.html Community Metrics References Morisita, M. 1959 . Measuring of the dispersion and analysis of distribution patterns . Memoires of the Faculty of Science , Kyushu University, Series E. Biology. 2 215 235. Morisita, M. 1962 . I sub &delta sub Index, A Measure of Dispersion of Individuals . Researches on Population Ecology , volume 4, number 1, pages 1 7. Horn, H. S. 1966 . Measurement of Overlap in comparative ecological studies. The American Naturalist 100 419 424. DEFAULTSORT Morisita s Overlap Index Category Population ecology statistics stub ... more details
The overlap add method OA, OLA is an efficient way to evaluate the discrete convolution of a very long signal math x n math with a finite impulse response FIR filter math h n math math begin align y n x n h n stackrel mathrm def sum m infty infty h m cdot x n m sum m 1 M h m cdot x n m , end align math where h m 0 for m outside the region 1, M . The concept is to divide the problem into multiple convolutions ..., evaluated over math N math discrete points. The algorithm Image Depiction of overlap add algorithm.png frame none Figure 1 the overlap add method Fig. 1 sketches the idea of the overlap add method .... The overlap arises from the fact that a linear convolution is always longer than the original ... i i L end Circular convolution with the overlap add method When sequence x n is periodic, and N ... convolution Evaluate Algorithm 1 y 1 M 1 y 1 M 1 y Nx 1 Nx M 1 y y 1 Nx end Linear convolution with overlap ... z b j 0 for k 1 d b j b j z k,j end end disp b source Cost of the overlap add method The cost of the convolution .... It turns out that the number of complex multiplications of the overlap add method are math C OA left ... in the circular version of the overlap add method is usually very small and can be neglected for the sake ... of the overlap add method are computed efficiently. Once evaluated the value of math N math it turns ... 2 N x 1 right , math Hence the cost of the overlap add method scales almost as math O left N x log 2 ... convolution using the overlap add method in the form of Alg 2, vs. the sequence and the filter ... of the region where the overlap add method is faster ratio 1 than the standard circular convolution. Note that the overlap add method in the tested cases can be three times faster than the standard ... Eq.1 and the time required by the overlap add Alg. 2 to evaluate a complex circular convolution, vs the sequence length math N x math and the filter length math M math . See also Overlap save method ... New York isbn 0 07 027389 8 pages External links DEFAULTSORT Overlap Add Method Category Signal processing ... more details
Overlap save is the traditional name for an efficient way to evaluate the Convolution Discrete convolution discrete convolution between a very long signal math x n math and a finite impulse response FIR filter math h n math NumBlk math y n x n h n stackrel mathrm def sum m infty infty h m cdot x n m sum m 1 M h m cdot x n m , , math EquationRef Eq.1 where h m 0 for m outside the region 1, M . The concept is to compute short segments of y n of an arbitrary length L , and concatenate the segments together. Consider a segment that begins at n kL M , for any integer k , and define math x k n stackrel mathrm def begin cases x n kL & 1 le n le L M 1 0 & textrm otherwise . end cases math math y k n stackrel mathrm def x k n h n , math Then, for kL M n kL L M 1, and equivalently M n kL L M 1, we can write math begin align y n sum m 1 M h m cdot x k n kL m & x k n kL h n & stackrel mathrm def y k n kL . end align math The task is thereby reduced to computing y sub k sub n , for M n L M 1. Now note that if we ... over N discrete points. Pseudocode font color green Overlap save algorithm for linear convolution ... has a minimum with respect to N . It diverges for both small and large block sizes. Overlap discard Overlap discard and Overlap scrap are less commonly used labels for the same method described here. However, these labels are actually better than overlap save to distinguish from Overlap add method overlap add , because u both u methods save , but only one discards. Save merely refers to the fact ... overlap save The overlap save algorithm may be extended to include other common operations of a system ... last Borgerding first Mark title Turning Overlap Save into a Multiband Mixing, Downsampling Filter ... Category Numerical analysis de Overlap Save Verfahren zh ... more details
Zero differential overlap is an approximation that is used to ignore certain integrals, usually two electron repulsion integrals, in semi empirical quantum chemistry methods quantum chemistry molecular orbital methods. If the molecular orbitals math mathbf Phi i math are expanded in terms of N basis functions, math mathbf chi mu A math as math mathbf Phi i sum mu 1 N mathbf C i mu mathbf chi mu A , math where A is the atom the basis function is centred on, and math mathbf C i mu math are coefficients, the two electron repulsion integrals are then defined as math langle mu nu lambda sigma rangle iint mathbf chi mu A 1 mathbf chi nu B 1 frac 1 r 12 mathbf chi lambda C 2 mathbf chi sigma D 2 d tau 1 ,d tau 2 math The zero differential overlap approximation ignores integrals that contain the product math mathbf chi mu A 1 mathbf chi nu B 1 math where &mu is not equal to &nu . This leads to math langle mu nu lambda sigma rangle delta mu nu delta lambda sigma langle mu mu lambda lambda rangle math where math delta mu nu begin cases 0 & mu ne nu 1 & mu nu end cases math The total number of such integrals is reduced to N N 1 2 approximately N sup 2 sup 2 from N N 1 2 N N 1 2 1 2 approximately N sup 4 sup 8 , all of which are included in Ab initio quantum chemistry methods ab initio Hartree&ndash Fock and post Hartree&ndash Fock calculations. Methods such as the Pariser&ndash Parr&ndash Pople method PPP and CNDO 2 use the zero differential overlap approximation completely. Methods based on the intermediate neglect of differential overlap, such as INDO , MINDO , ZINDO and SINDO do not apply it when A B C D , i.e. when all four basis functions are on the same atom. Methods that use the neglect of diatomic differential overlap, such as MNDO , PM3 chemistry PM3 and Austin Model 1 AM1 , also do not apply it when A B ... more details
cgi pmidlookup?view long&pmid 10077584 pmc 15842 ref Target site overlap limits the modularity ... site overlap may also affect the Zinc finger chimera Zinc finger protein selection by phage display ... target site overlap occurs is largely unknown, with a variety of amino acids having shown involvement ... more details
Lupus erythematosus lichen planus overlap syndrome also known as Lichen planus lupus erythematosus overlap syndrome ref name Fitz2 Freedberg, et al. 2003 . Fitzpatrick s Dermatology in General Medicine . 6th ed. . McGraw Hill. ISBN 0071380760. ref rp 466 is a true overlap syndrome with features of both lupus erythematosus and lichen planus, with skin lesions usually large, atropic, hypopigmented, red or pink patches and plaques. ref name Andrews James, William Berger, Timothy Elston, Dirk 2005 . Andrews Diseases of the Skin Clinical Dermatology . 10th ed. . Saunders. Page 159. ISBN 0721629210. ref Lichen planus lupus erythematosus overlap syndrome is a rare variant of lichen planus characterized by lesions that share features with lupus erythematosus . ref name Fitz2 rp 470 Atrophic plaques and patches with hypopigmentation and a livid red to blue violet color with telangiectasia and minimal scaling are characteristic. ref name Fitz2 rp 470 1 See also Lichen planus Lupus erythematosus List of cutaneous conditions References reflist Category Cutaneous lupus erythematosus Category Lichenoid eruptions Cutaneous condition stub ... more details
Morphea lichen sclerosus et atrophicus overlap is characterized by both lesions of morphea and lichen sclerosus et atrophicus, most commonly seen in women. ref name Andrews James, William Berger, Timothy Elston, Dirk 2005 . Andrews Diseases of the Skin Clinical Dermatology . 10th ed. . Saunders. Page 171. ISBN 0 7216 2921 0. ref See also Scleroderma List of cutaneous conditions References reflist Cutaneous condition stub Category Connective tissue diseases ... more details
Lichen planus lichen sclerosus overlap syndrome is a rare skin condition characterized by skin lesion s of lichen planus and lichen sclerosus . ref name Andrews cite book author James, William D. Berger, Timothy G. et al. title Andrews Diseases of the Skin clinical Dermatology publisher Saunders Elsevier location year 2006 pages isbn 0 7216 2921 0 oclc doi accessdate ref rp 220 See also Lichen planus List of cutaneous conditions References reflist Cutaneous condition stub Category Lichenoid eruptions ... more details
will allow, it is necessary to employ overlap extension PCR. In OE PCR the sequence being modified ... combinations as detailed in the diagram. Only the duplex without overlap at the 5 end will allow ... more details
seealso Transborder agglomeration Refimprove date December 2010 Here is a list of metroplexes that overlap multiple countries Excluded from list is City state s being part of the overlap. One example of that would be Rome since Vatican City is isolated within Italy. Africa Brazzaville , the capital of the Republic of the Congo , lies directly across the Congo River from Kinshasa , the capital of the Democratic Republic of the Congo Livingstone, Zambia , and Victoria Falls, Zimbabwe City of Lom , the capital of Togo , extends over the border to Ghana Asia Aqaba , Jordan Eilat , Israel and Taba Egypt Taba , Egypt Al Ain , UAE and Al Buraimi Governorate Al Buraimi , Oman The capital of Laos , Vientiane , spills over the Thai Lao Friendship Bridge Saphan Mittaphap to Nong Khai province, Thailand Singapore together with Johor Bahru in Malaysia and Riau Islands in Indonesia, also called the Sijori Growth Triangle . Hong Kong s metropolitan area spills over its border with Mainland China into Shenzhen and Dongguan . Europe Within the European Union Vienna Bratislava metropolitan area overlaps Austria and Slovakia Strasbourg Ortenau metropolitan area, France and Germany San Sebastian metropolitan area , Spain and France Meuse Rhine Euroregion extends over Maastricht , Netherlands, Li ge , Belgium and Aachen , Germany Oresund Region extends over northeast Zealand Copenhagen , Denmark and western part of Scania , Sweden Silesian metropolitan area extends from Katowice with Metropolitan Association of Upper Silesia Upper Silesian Metropolis , Poland to Ostrava , Czech Republic . This metropolitan area lies within Upper Silesian Coal Basin . Lille metropolitan area, France and Mouscron and Kortrijk , Belgium Luxembourg City Luxembourg metropolitan area, extends into Belgium , France , and Germany Frankfurt Oder , Germany and Slubice , Poland are one city divided by the river Oder G rlitz , Germany and Zgorzelec , Poland are one city divided by the river Nysa, Poland Nysa Cieszyn ... more details
Summary This is a screenshot I took on the Back to the Future trilogy article. It illustrates a bug in User Lupin Lupin s Wikipedia Tools Navigation popups Popups tool. Licensing wikipedia screenshot Copy to Wikimedia Commons bot Fbot Orphan image ... more details
Summary Overlap region of two ellipses. Vector version available Overlap region.svg Licensing PD self date December 2007 Copy to Wikimedia Commons Orphan image ... more details
Summary Screenshot of the overlap on the Succession crisis page for illustrating a point on a talk page. Licensing wikipedia screenshot Copy to Wikimedia Commons bot Fbot ... more details
Summary screenshot for diagnostic purposes text overlap problem not to be used in articles Licensing wikipedia screenshot Copy to Wikimedia Commons bot Fbot Orphan image ... more details
MECS is the Multi Element Code System, a markup system developed by the Wittgenstein Archives at the University of Bergen. It is very similar to SGML and XML except that it allows elements to overlap. MECS supports limited overlap, in that a given type of element for example a quotation , may overlap other types, but no element may overlap another of the same type. MECS has been influential in the theory of non hierarchical markup systems, and is discussed in many articles by Michael Sperberg McQueen and Claus Huitfeldt , among others. Other systems for representing overlapping markup include the Layered Markup and Annotation Language , CLIX , JITTS , and features of the Text Encoding Initiative and the Open Scripture Information Standard . Category Markup languages ... more details
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