PEN may refer to International PEN , the worldwide association of writers Penang International Airport in Penang, Malaysia IATA airport code Penarth railway station , Wales National Rail station code PEN Peruvian nuevo sol , ISO 4217 currency code for the currency of Peru Polyethylene naphthalate , a polymer Private enterprise number , an object identifier in computing Protective earth neutral, an earthing system conductor in electricity supply systems Olympus Pen is a series of half frame cameras made by Olympus from 1959 to the beginning of the 1980s See also Pen disambiguation disambig cs PEN de PEN es PEN eo PEN fr PEN ko Pen it PEN hu PEN egy rtelm s t lap nl PEN ja PEN pl Pen pt PEN sv PEN ... more details
Other uses pp move indef File 03 BICcristal2008 03 26.jpg thumb A ballpoint pen A pen Latin penna , feather ..., reed pens, quill pens, and dip pen s were used, with a Nib pen nib of some sort to be dipped in the ink. Ruling pen s allow precise adjustment of line width, and still find a few specialized uses, but technical pen s such as the Rapidograph are more commonly used. Modern types also include ballpoint pen ballpoint , rollerball pen rollerball , fountain pen fountain , and Marker pen felt or porous point pen ceramic tip pens. Modern pens The main modern types of pens can be categorized by the kind ... pen, and the tip of that pen A ballpoint pen dispenses viscosity viscous oil based ink ... . ref cite web title How does a ballpoint pen work? work Engineering publisher HowStuffWorks date ... almost immediately on contact with paper. The ballpoint pen is usually reliable and inexpensive. citation needed date November 2011 It has replaced the fountain pen as the most common tool for everyday writing. A crowquill pen is a favorite instrument of artists, sch s David Stone Martin and Jay ... with slight pressures while drawing. A fountain pen uses water based liquid ink delivered through a Nib pen nib . The ink flows from a reservoir through a feed to the nib, then through the nib, due to capillary ... surface. A fountain pen reservoir can be refillable or disposable, this disposable type being an ink cartridge . A pen with a refillable reservoir may have a mechanism, such as a piston, to draw ... cartridges. File Fountain Pen.jpg thumb A fountain pen A marker , or felt tip pen , has a porous tip ... shipping cases or other packages are usually permanent marker s. A rollerball pen dispenses a water based liquid or gel pen gel ink through a ball tip similar to that of a ballpoint pen. The less viscous ink is more easily absorbed by paper than oil based ink, and the pen moves more easily across a writing surface. The rollerball pen was initially designed to combine the convenience of a ballpoint ... more details
PenPen may refer to PenPen TriIcelon , a video game released for the Sega Dreamcast PenPen Neon Genesis Evangelion PenPen Neon Genesis Evangelion , a character in the Japanese anime Neon Genesis Evangelion and the movies Evangelion Death and Rebirth and The End of Evangelion disambig ... more details
Unreferenced date June 2009 Otheruses Pen disambiguation Infobox Television episode Title The Pen Series Seinfeld Image Caption Season 3 Episode 3 Airdate October 2, 1991 Production 305 Writer Larry David Director Tom Cherones Guests Episode list Seinfeld season 3 Seinfeld season 3 br List of Seinfeld episodes List of Seinfeld episodes Prev The Truth Seinfeld The Truth Next The Dog Seinfeld The Dog The Pen is the twentieth episode of Seinfeld . The episode was the third episode of the third season. It aired on October 2, 1991. This is the only episode in which both George Costanza George and Cosmo Kramer Kramer do not appear. Plot Jerry Seinfeld character Jerry and Elaine Benes Elaine go to Florida to visit List of Seinfeld minor characters morty Jerry s parents for the weekend and plan on going scuba diving . Morty Seinfeld , Jerry s father, is also being honored at a ceremony the next night. Jack Klompus comes over to write Morty a check for a previous night s dinner and Jerry notices Space Pen Jack s pen . When Jerry asks Jack about it, Jack tells him that it can write upside down and that astronauts use it in space. Jack offers an interested Jerry the pen. Jerry refuses his offer several times, but Jack persists and Jerry finally gives in. Helen Seinfeld , Jerry s mother, asks why he took the pen and says he should give it back because Doris Klompus will tell everyone in the condo that Jerry made Jack give it to him. Elaine sleeps on a sofa bed with a bar that sticks up through ... around the community that Jerry wanted Jack to give him the pen. Jerry goes scuba diving without Elaine ... and pressure was too tight on his mask. Jack comes over again and Jerry returns the pen. Morty yells at Jack for taking Jerry s pen . Elaine decides she wants to take the muscle relaxants, but takes ... cracks about Morty at the podium. Morty starts arguing with Jack again about taking back the pen ... DEFAULTSORT Pen Category Seinfeld season 3 episodes Category 1991 television episodes ... more details
Geometric integration can refer to Homological integration &ndash a method for extending the notion of integral to manifold s. Geometric integrator , a numerical method that preserves of geometric properties of the exact flow of a differential equation . disambig Category Mathematics ... more details
Geometric calculus may refer to Calculus on a geometric algebra , developed by David Hestenes and others. Elementary Calculus An Infinitesimal Approach , a book by Jerome Keisler. mathdab ... more details
Geometric analysis is a mathematics mathematical discipline at the interface of differential geometry and differential equations . It includes both the use of geometrical methods in the study of partial differential equation s when it is also known as geometric PDE , and the application of the theory of partial differential equations to geometry. It incorporates problems involving curves and surfaces, or domains with curved boundaries, but also the study of Riemannian manifold s in arbitrary dimension. The calculus of variations is sometimes regarded as part of geometric analysis, because differential equations arising from variational principle s have a strong geometric content. Geometric analysis also includes global analysis , which concerns the study of differential equations on manifolds, and the relationship between differential equations and topology . References cite book title Riemannian geometry and Geometric Analysis first J rgen last Jost edition 4th edition year 2005 publisher Springer isbn 978 3540259077 cite book title Groups and Geometric Analysis Integral Geometry, Invariant Differential Operators and Spherical Functions first Sigurdur last Helgason authorlink Sigurdur Helgason mathematician edition 2nd edition year 2000 publisher American Mathematical Society isbn 978 0821826737 cite book title Geometric Analysis on Symmetric Spaces first Sigurdur last Helgason edition 2nd edition year 2008 publisher American Mathematical Society isbn 978 0821845301 Category Mathematical analysis Category Differential geometry mathanalysis stub ... more details
notability Companies date August 2011 Infobox Company company name Geometric Limited company logo Image Geometric logo.svg 200px Geometric Logo br Company Type br Public traded as BSE 532312 br NSE GEOMETRIC foundation 1984 location city Mumbai location country India key people br Manu Parpia M D & CEO br industry Engineering Services, PLM Solutions, Technology revenue profit United States dollar 136.47 million small FY 11 small num employees 3900 2011 homepage http www.geometricglobal.com www.geometricglobal.com Geometric Ltd BSE 532312 , NSE GEOMETRIC is a software services and consulting company headquartered in Mumbai , India . Its portfolio includes Product Lifecycle Management Product lifecycle management PLM , ref cite web url http www.nasscom.in upload it innovators09 geometric.pdf title IT Innovators 2009 publisher www.nasscom.in date accessdate 2010 07 23 ref ref cite web url http ... and Offshore Product Development OPD solutions and technologies. Geometric was set up as a Division of Godrej Group Godrej and Boyce ref cite web url http www.dnaindia.com money report geometric to set up new centres in brazil china 1085086 title Geometric to set up new centres in Brazil, China ... in 1994 ref cite web url http www.expressindia.com fe daily 19980411 10155074.html title Geometric ... Stock Exchange of India . Its portfolio includes Engineering Services along with PLM. Geometric ... certified. The company has two main business subsidiaries. Geometric Engineering, Inc., formerly Modern ... engineering solutions to the automotive and industrial sectors. Geometric Technologies, Inc ... solutions for manufacturing operations. Geometric has a joint venture with Dassault Syst mes ... respectively. ref cite web url http www.thefreelibrary.com Geometric Software Solutions and Dassault Systemes Create Consulting... a088543440 title Geometric Software Solutions and Dassault Systemes ... The Official Site of Geometric Ltd Category Software companies of India Category ... more details
. Geometric models can be built for objects of any dimension in any space geometric space . Both 2D geometric model 2D and 3D modeling 3D geometric models are extensively used in computer graphics . 2D geometric model 2D model s are important in computer typography and technical drawing . 3D ... . Geometric models are usually distinguished from procedural modeling procedural and Object Oriented ... for instance, geometric shapes can be represented by obect oriented programming objects a digital image can be interpreted as a collection of color ed Square geometry square s and geometric shapes ... often requires a combination of geometric and procedural techniques. Geometric problems originating ... geometric design, and discrete differential geometry. ref H. Pottmann, S. Brell Cokcan and J. Wallner ... wps find journaldescription.cws home 505604 description description Computer Aided Geometric Design Category Geometric algorithms Category Computational science Category Computer aided design de Geometrische ... more details
Geometric tomography is a mathematical field that focuses on problems of reconstructing homogeneous often convex objects from tomographic data this might be X rays, projections, sections, brightness functions, or covariograms . More precisely, according to R.J. Gardner who introduced the term , Geometric tomography deals with the retrieval of information about a geometric object from data concerning its projections shadows on planes or cross sections by planes. ref name ref1 Gardner, R.J., Geometric Tomography, Cambridge University Press, Cambridge, UK, 2nd ed., 2006 ref Theory A key theorem in this area states that any convex body in math E n math can be determined by parallel, coplanar X rays in a set of four directions whose slopes have a transcendental cross ratio . See also Tomography Discrete tomography References reflist External links http cgm.cs.mcgill.ca godfried research tomography.html Geometric tomography applet I http faculty.wwu.edu gardner GeometricTomography.html Geometric tomography applet II Category Tomography Category Projective geometry ... more details
Geometric modeling is a branch of applied mathematics and computational geometry that studies methods and algorithms for the mathematical description of shapes. The shapes studied in geometric modeling are mostly two or three dimension al, although many of its tools and principles can be applied to sets of any finite dimension. Today most geometric modeling is done with computers and for computer based applications. 2D geometric model Two dimensional model s are important in computer typography and technical drawing . 3D geometric model Three dimensional model s are central to computer aided design and computer aided manufacturing manufacturing CAD CAM , and widely used in many applied technical fields such as civil engineering civil and mechanical engineering , architecture , geologic modeling geology and medical image processing . ref Farin, G. A History of Curves and Surfaces in CAGD, http books.google.com books?id 0SV5G8fgxLoC&printsec frontcover&dq Computer Aided GEOMETRIC DESIGN&source gbs summary s&cad 0 Handbook of Computer Aided Geometric Design ref Geometric models are usually distinguished from procedural model procedural and object oriented model s, which define the shape implicitly by an opaque algorithm that generates its appearance. They are also contrasted with digital image s and volumetric model s which represent the shape as a subset of a fine regular partition of space and with fractal models that give an infinitely recursive definition of the shape. However, these distinctions are often blurred for instance, a digital image can be interpreted as a collection of color ed square geometry square s and geometric shapes such as circle s are defined by implicit ... Geometric Modeling and Industrial Geometry http demonstrations.wolfram.com topic.html?topic 3D Graphics&limit .... I. Wu & M. Abdulla, Landmobile Radiowave Multipaths DOA Distribution Assessing Geometric Models ... Geometric algorithms Category Computational science Category Computer aided design de Geometrische ... more details
History of Greek art Geometric art is a phase of Greek art , characterised largely by geometric motifs ... Aegean . ref cite journal last Snodgrass first Anthony M. title Greek Geometric Art by Bernhard Schweitzer ... 23 jstor 707869 ref Pottery in the Geometric periods Protogeometric period During the Protogeometric ... bands with a few written geometric shapes within, usually concentric cycles or semicircles engraved with a caliper. Early Geometric period In the Early geometric period 900 850 BC the height of the vessels ... design, the most characteristic element of geometric art. Middle geometric period At the Middle geometric ... the handles. Image Eleusis geometric amhora.JPG 200px thumb right Amphora of 8th c.BC from the Archaeological Museum of Eleusis with geometric motifs Late Geometric period While the technique from the Middle Geometric period was still continued at the beginning of 8th century BC some laboratories ... form. This was the first phase of the Late Geometric period 760 700 BC , in which the great ... at a height of 1.50 m and the perfection of their execution, the highest expression of the Greek geometric ... eased, the geometric shapes have become more freely, and areas with animals, birds, scenes of shipwrecks, hunting scenes, themes from mythology or the Homeric epics led geometric pottery into more naturalistic expressions. ref http www.greek thesaurus.gr geometric period art.html Geometric ... geometric style, is an oldest surviving signed work of a Greek potter Aristonothos or Aristonophos 7th ... style of Corinth distinguished. Geometric motives File Dipylon vase.jpg thumb right Dipylon Vase Vases in the Geometric style are characterized by several horizontal bands about the circumference covering the entire vase. Between these lines the geometric artist used a number of other decorative motifs ... book last Coldstream first John N. title Geometric Greece 900 700 BCE publisher Routledge date 1979 ... period List of Greek vase painters Geometric period National Archaeological Museum of Greece ... more details
The geometric mean , in mathematics , is a type of mean or average , which indicates the central tendency ... product mathematics product is taken. For instance, the geometric mean of two numbers, say ... example, the geometric mean of the three numbers 4, 1, and 1 32 is the cube root of their product 1 ... x 1, ldots,x n math , the geometric mean math G math satisfies math G sqrt n x 1 x 2 cdots x n , math ... of the geometric mean is the arithmetic mean of the logs of the numbers. The geometric mean can also be understood in terms of geometry . The geometric mean of two numbers, a and b , is the length of one ... a and b . Similarly, the geometric mean of three numbers, a , b , and c , is the length of one ... given numbers. The geometric mean applies only to positive numbers. ref The geometric mean ... later in the article. Note that the definition is unambiguous if one allows 0 which yields a geometric mean of 0 , but may be excluded, as one frequently wishes to take the logarithm of geometric ... rates of a financial investment. The geometric mean is also one of the three classic Pythagorean means ... means, while the arithmetic mean is always the greatest of the three and the geometric mean is always in between see Inequality of arithmetic and geometric means . Calculation The geometric mean ... a 2 cdots a n . math The geometric mean of a data set inequality of arithmetic and geometric means ... the geometric and arithmetic means are equal. This allows the definition of the arithmetic geometric mean , a mixture of the two which always lies in between. The geometric mean is also the arithmetic ... then a sub n sub and h sub n sub will converge to the geometric mean of x and y . This can be seen ... Weierstrass theorem and the fact that geometric mean is preserved math sqrt a ih i sqrt frac a i h i ... f mean with f x log x . For example, the geometric mean of 2 and 8 can be calculated ... apart from each other while leaving the arithmetic mean unchanged then the geometric mean ... more details
Geometric combinatorics is a branch of mathematics in general and combinatorics in particular. It includes a number of subareas such as polyhedral combinatorics the study of Face geometry faces of convex polyhedron convex polyhedra , convex geometry the study of convex set s, in particular combinatorics of their intersections , and discrete geometry , which in turn has many applications to computational geometry . Other important areas include metric geometry of polyhedra , such as the Cauchy s theorem geometry Cauchy theorem on rigidity of convex polytopes. The study of regular polytope s, Archimedean solid s, and kissing number s is also a part of geometric combinatorics. Special polytopes are also considered, such as the permutohedron , associahedron and Birkhoff polytope . Also studied are Finite geometry finite geometries . Further reading http www.cis.upenn.edu cis610 topics.pdf Topics in Geometric Combinatorics http www.ams.org bookstore?fn 20&arg1 geotopo&item PCMS 13 Geometric Combinatorics , Edited by Ezra Miller and Victor Reiner http scholar.google.co.uk scholar?q 22Combinatorics of Finite Geometries 22 Combinatorics of Finite Geometries Category Combinatorics Category Discrete geometry combin stub bs Geometrijska kombinatorika ... more details
The geometric albedo of an astronomical body is the ratio of its actual brightness at zero Phase angle astronomy phase angle i.e., as seen from the light source to that of an idealized flat, fully reflecting, diffuse reflection diffusively scattering Lambertian disk with the same cross section. Diffuse reflection Diffuse scattering implies that radiation is reflected isotropically with no memory of the location of the incident light source. Zero phase angle corresponds to looking along the direction of illumination. For Earth bound observers this occurs when the body in question is at opposition astronomy opposition and on the ecliptic . The visual geometric albedo refers to the geometric albedo quantity when accounting for only electromagnetic radiation in the visible spectrum . Airless bodies The surface materials regolith s of airless bodies in fact, the majority of bodies in the Solar system are strongly non Lambertian and exhibit the opposition effect , which is a strong tendency to reflect light straight back to its source, rather than scattering light diffusely. The geometric albedo of these bodies can be difficult to determine because of this, as their Bidirectional reflectance distribution function reflectance is strongly peaked for a small range of phase angles near zero ... to zero phase angle to obtain an estimate of the geometric albedo. For very bright, solid, airless ... them a geometric albedo above unity 1.4 in the case of Enceladus . Light is preferentially reflected ..., whereas a Lambertian surface would scatter the radiation much more broadly. The geometric albedo above ... of a plane surface, the geometric albedo is the albedo of the surface when the illumination is provided by a beam of radiation that comes in perpendicular to the surface. Examples The geometric albedo ..., California. references DEFAULTSORT Geometric Albedo Category Observational astronomy Category Radiometry ... geom trico fr Alb do g om trique pt Albedo geom trico simple Geometric albedo sl Geometri ni albedo ... more details
In mathematics , specifically differential geometry , a geometric flow is the gradient flow associated to a functional on a manifold which has a geometric interpretation, usually associated with some curvature extrinsic or intrinsic curvature . They can be interpreted as flows on a moduli space for intrinsic flows or a parameter space for extrinsic flows . These are of fundamental interest in the calculus of variations , and include several famous problems and theories. Particularly interesting are their critical point mathematics critical point s. A geometric flow is also called a geometric evolution equation . Examples Extrinsic Extrinsic geometric flows are flows on embedded submanifold s, or more generally immersed submanifold s. In general they change both the Riemannian metric and the immersion. Mean curvature flow , as in soap film s critical points are minimal surface s Willmore flow , as in minimax eversion s of spheres Inverse mean curvature flow Intrinsic Intrinsic geometric flows are flows on the Riemannian metric , independent of any embedding or immersion. Ricci flow , as in the Solution of the Poincar conjecture , and Richard Hamilton professor Richard Hamilton s proof of the Uniformization theorem Calabi flow Yamabe flow Classes of flows Important classes of flows are curvature flows , variational flows which extremelize some functional , and flows arising as solutions to parabolic partial differential equation s. A given flow frequently admits all of these interpretations, as follows. Given an elliptic operator L , the parabolic PDE math u t Lu math yields ... of the flow correspond to critical points of the functional. In the context of geometric flows, the functional ... Bakas, I. title The algebraic structure of geometric flows in two dimensions year 2005 arxiv hep th 0507284 cite journal author Bakas, I. title Renormalization group equations and geometric flows year 2007 arxiv hep th 0702034 DEFAULTSORT Geometric Flow Category Geometric flow Category Riemannian ... more details
Argento s mind and hand attempting something different within the geometric genre . The SoHo Weekly ... No. 10. , 1939 42 However, geometric abstraction cannot only be seen as an invention of 20th century ... figures, is a prime example of this geometric pattern based art, which existed centuries before ... in the architecture of Islamic civilations spanning the 7th century 20th century, geometric patterns ... of geometric abstraction. Selected artists Artists who have worked extensively in geometric ... Abstract Artists References references External links commons cat Geometric abstraction http geoform.net ... Geometric Abstraction. DEFAULTSORT Geometric Abstraction Category Modernism Category Modern art Category ... Geometric abstraction sk Geometrick abstrakcia ... more details
File beetle.svg thumb 340px Vector graphics consists of geometrical primitives The term geometric primitive in computer graphics and CAD systems is used in various senses, with the common meaning of the simplest i.e. atomic or irreducible geometric objects that the system can handle draw, store . Sometimes the subroutine s that draw the corresponding objects are called geometric primitives as well. The most primitive primitives are point and straight line segment, which were all that early vector graphics systems had. In constructive solid geometry , primitives are simple geometry geometric shapes such as a Cube geometry cube , cylinder geometry cylinder , sphere , cone geometry cone , Pyramid geometry pyramid , torus . Modern 2D computer graphics systems may operate with primitives which are lines segments of straight lines, circles and more complicated curves , as well as shapes boxes, arbitrary polygons, circles . A common set of two dimensional primitives includes lines, points, and polygon s, although some people prefer to consider triangles primitives, because every polygon can be constructed from triangles. All other graphic elements are built up from these primitives. In three dimensions, triangles or polygons positioned in three dimensional space can be used as primitives to model more complex 3D forms. In some cases, curves such as B zier curve s, circle s, etc. may be considered primitives in other cases, curves are complex forms created from many straight, primitive shapes. Commonly used geometric primitives include Point geometry point s line mathematics lines and line segment s Plane mathematics plane s circle s and ellipse s triangle s and other polygon s spline mathematics spline curves Note that in 3D applications basic geometric shapes and forms are considered to be primitives rather than the above list. Such shapes and forms include sphere s cube s or box ...&seqNum 5 Peachpit.com Info On 3D Primitives Category Computer graphics Category Geometric algorithms ... more details
Image Geometric progression convergence diagram.svg thumb 350px Diagram showing the geometric series 1 1 2 1 4 1 8 ... which converges to 2. In mathematics , a geometric progression , also known as a geometric ... b 2 ac math For example, the sequence 2, 6, 18, 54, ... is a geometric progression with common ratio 3. Similarly 10, 5, 2.5, 1.25, ... is a geometric sequence with common ratio 1 2. The sum of the terms of a geometric progression is known as a geometric series . Thus, the general form of a geometric sequence is math a, ar, ar 2, ar 3, ar 4, ldots math and that of a geometric series is math a ar ... s start value. Elementary properties The n th term of a geometric sequence with initial value a and common ratio r is given by math a n a ,r n 1 . math Such a geometric sequence also follows the recursive ... a given sequence is geometric, one simply checks whether successive entries in the sequence all have the same ratio The common ratio of a geometric series may be negative, resulting in an alternating ..., 81, 243, ... is a geometric sequence with common ratio 3. The behaviour of a geometric sequence depends ... there is exponential growth towards positive and negative infinity due to the alternating sign . Geometric ... exponentiating each term of an arithmetic progression yields a geometric progression, while taking the logarithm of each term in a geometric progression with a positive common ratio yields an arithmetic progression. Geometric series This section is linked from Time value of money main Geometric series A geometric series is the sum of the numbers in a geometric progression math sum k 0 n ar k ... ar n ar n 1 & a ar n 1 end align math since all the other terms cancel. Because r 1 for geometric ... formula for a geometric series math sum k 0 n ar k frac a 1 r n 1 1 r . math If one were ... k 1 n kr k 1 frac 1 r n 1 1 r 2 frac n 1 r n 1 r . math For a geometric series containing only even ... ar 2k 1 ar ar 2n 3 math and math sum k 0 n ar 2k 1 frac ar 1 r 2n 2 1 r 2 . math Infinite geometric ... more details
In mathematical physics , geometric quantization is a mathematical approach to defining a Quantum mechanics quantum theory corresponding to a given classical theory . It attempts to carry out Quantization physics quantization , for which there is in general no exact recipe, in such a way that certain analogies between the classical theory and the quantum theory remain manifest. For example, the similarity between the Heisenberg equation in the Heisenberg picture of quantum mechanics and the Hamilton equation in classical physics should be built in. One of the earliest attempts at a natural quantization was Weyl quantization , proposed by Hermann Weyl in 1927. Here, an attempt is made to associate a quantum mechanical observable a self adjoint operator on a Hilbert space with a real valued function on classical phase space . Here, the position and momentum are reinterpreted as the generators ... for the nonvanishing angular momentum of the ground state Bohr orbit in the hydrogen atom. The geometric ... field X . Geometric quantization of Poisson manifolds and symplectic foliations also is developed ... Geometric Quantization and Quantum Mechanics publisher Springer isbn 0 387 90496 7 url cite book author N.M.J. Woodhouse year 1991 title Geometric Quantization publisher Clarendon Press isbn 0 19 853673 ... Sardanashvily G. Sardanashvily year 2005 title Geometric and Algebraic Topological Methods in Quantum ... math ph 0208008 William Ritter s review of Geometric Quantization presents a general framework for all problems in physics and fits geometric quantization into this framework http math.ucr.edu home baez quantization.html John Baez s review of Geometric Quantization , by John Baez is short and pedagogical http www.blau.itp.unibe.ch lecturesGQ.ps.gz Matthias Blau s primer on Geometric Quantization ... Roy, Mathematical foundations of geometric quantization, http arxiv.org abs math ph 9904008 arXiv math ph 9904008. Gennadi Sardanashvily G. Sardanashvily , Geometric quantization of symplectic foliations ... more details
No footnotes date October 2011 A geometric program GP is an optimization mathematics optimization problem of the form Minimize math f 0 x math subject to math f i x leq 1, quad i 1, dots,m math math h i x 1, quad i 1, dots,p math where math f 0, dots,f m math are posynomials and math h 1, dots,h p math are monomials. In the context of geometric programming unlike all other disciplines , a monomial is defined as a function math f mathbb R n to mathbb R math with math mathrm dom f mathbb R n math defined as math f x c x 1 a 1 x 2 a 2 cdots x n a n math where math c 0 math and math a i in mathbb R math . GPs have numerous application, such as components sizing in Integrated circuit IC design ref http www.stanford.edu boyd papers opamp.html ref and parameter estimation via logistic regression in statistics. The maximum likelihood estimator in logistic regression is a GP. Convex form Geometric programs are not in general convex optimization problems, but they can be transformed to convex problems by a change of variables and a transformation of the objective and constraint functions. In particular, defining math y i log x i math , the monomial math f x c x 1 a 1 cdots x n a n mapsto e a T y b math , where math b log c math . Similarly, if math f math is the posynomial math f x sum k 1 K c k x 1 a 1k cdots x n a nk math then math f x sum k 1 K e a k T y b k math , where math a k a 1k , dots,a nk math and math b k log c k math . After the change of variables, a posynomial becomes a sum of exponentials of affine functions. References cite book author Richard J. Duffin coauthors Elmor L. Peterson, Clarence Zener title Geometric Programming publisher John Wiley and Sons date 1967 pages 278 isbn 0471223700 External links S. Boyd, S. J. Kim, L. Vandenberghe, and A. Hassibi, http www.stanford.edu boyd gp tutorial.html A Tutorial on Geometric Programming S. Boyd, S. J. Kim, D. Patil, and M. Horowitz http www.stanford.edu boyd gp digital ckt.html Digital Circuit Optimization via Geometric ... more details
Taxobox name Geometric moray image Gymnothorax griseus by Marek Jakubowski.jpg regnum Animalia phylum Chordata classis Actinopterygii ordo Anguilliformes familia Muraenidae genus Gymnothorax species G. griseus binomial Gymnothorax griseus binomial authority Bernard Germain de Lac p de Lac p de , 1803 The geometric moray , Gymnothorax griseus , is a moray eel of the family biology family Muraenidae , found throughout the western Indian Ocean at depths down to 40 m. Its length is up to 65 cm. References FishBase species genus Gymnothorax species griseus month June year 2006 Category Gymnothorax griseus Category Animals described in 1803 af Geometriese bontpaling ca Gymnothorax griseus de Graue Mur ne es Gymnothorax griseus fr Gymnothorax griseus nl Gymnothorax griseus ... more details
dablink For another use of the term median in geometry, see Median geometry . The geometric median of a discrete ... nearest center. ref The geometric median is an important estimator of location parameter location ... x 1, x 2, dots, x m , math with each math x i in mathbb R n math , the geometric median is defined as Geometric Median math underset y in mathbb R n operatorname arg ,min sum i 1 m left x i y right 2 ... s is minimum. Properties For the 1 dimensional case, the geometric median coincides with the median . This is because the univariate median also minimizes the sum of distances from the points. The geometric median is unique whenever the points are not Line geometry collinear . The geometric median ... either by transforming the geometric median, or by applying the same transformation to the sample data and finding the geometric median of the transformed data. This property follows from the fact that the geometric median is defined only from pairwise distances, and doesn t depend on the system ... of the choice of coordinates. The geometric median has a breakdown point of 0.5. ref Lopuha and Rousseeuw .... Special cases For 3 points, if any angle of the triangle is more than 120 then the geometric median is the point making that angle. If all the angles are less than 120 , the geometric median is the point ... of the four points is inside the triangle formed by the other three points, then the geometric median is that point. Otherwise, the points form a convex quadrilateral and the geometric median is the crossing point of the diagonals of the quadrilateral. The geometric median of four coplanar points is the same ... concept, computing the geometric median poses a challenge. The centroid or center of mass , defined similarly to the geometric median as minimizing the sum of the squares of the distances to each ... but no such formula is known for the geometric median, and it has been shown that no explicit ... ref However, it is straightforward to calculate an approximation to the geometric median using ... more details
Distinguish Algebraic geometry Geometric algebra GA , together with the associated Geometric calculus ... algebra Grassmann algebra plays a part. Spacetime algebra and Conformal Geometric Algebra .28CGA.29 Conformal Geometric Algebra are specific examples of GA. A feature of GA is its geometric interpretation due to the natural correspondence between geometric entities and the elements of the algebra ... easy to understand properties of the geometric algebra in a concrete way. Given a finite dimensional real quadratic space nowrap 1 V R sup n sup with quadratic form nowrap 1 Q V R , the geometric ... the geometric product , and it is just the Clifford product . It is standard to denote the geometric ... G 4,1 math a 3D Conformal Geometric algebra. Standard bases and grading The geometric product creates ... in increasing order, including 1 as the empty product, forms a basis for the geometric algebra. As an illustration, the following is a basis for the geometric algebra math mathcal G 3,0 math math 1,e ... for the geometric algebra, and any other orthogonal basis for V fitting the above description will produce another standard basis. Each standard basis consists of 2 sup n sup elements. The geometric product ... scalars commute math , AB C A BC ABC math associative property associativity of the geometric product math , A B C AC BC math and math ,C A B CA CB math distributive property distributivity of the geometric product over addition . These first four rules give the geometric product of any two elements ... 2 e 1e 4. math The geometric product of any two elements in the algebra can be computed with these rules ... grading over the geometric product of some elements in the geometric algebra. Normal vectors in the span ... of differing grade. Such elements are said to be of mixed grade . Generic elements of the geometric ... the grade r portion of A . As a result math A sum r 0 n langle A rangle r math As an example, the geometric ... other important operations on nowrap 1 V V in the geometric algebra besides the geometric product ... more details
about infinite geometric series finite sums geometric progression File GeometricSquares.svg thumb right ... , a geometric series is a series mathematics series with a constant ratio between successive term ... , , cdots math is geometric, because each successive term can be obtained by multiplying the previous term by 1 2. Geometric series are one of the simplest examples of infinite series with finite sums, although not all of them have this property. Historically, geometric series played an important role ... series convergence of series. Geometric series are used throughout mathematics, and they have important ... , and finance . Common ratio The terms of a geometric series form a geometric progression , meaning that the ratio of successive terms in the series is constant. The following table shows several geometric ... the series has no sum. See for example Grandi s series 1 &minus 1 1 &minus 1 . Sum The sum of a geometric ... of 2 3 the original size. Consider the sum of the following geometric series math s 1 , , frac 2 ... 1 math , the Geometric progression Geometric series sum of the first n terms of a geometric series ... r , math the left hand side being a geometric series with common ratio r . We can derive this formula ... restrictions, for the complex number complex case. Proof of convergence We can prove that the geometric series convergent series converges using the sum formula for a geometric progression math begin ... A repeating decimal can be thought of as a geometric series whose common ratio is a power of 1 10 .... math The formula for the sum of a geometric series can be used to convert the decimal to a fraction ... of a geometric series to compute the area enclosed by a parabola and a straight line. His method was to dissect ... 64 , , cdots. math This is a geometric series with common ratio nowrap 1 4 and the fractional part ... s, geometric series often arise as the perimeter , area , or volume of a self similarity self similar ... area of the twelve yellow triangles, and so forth. Excluding the initial 1, this series is geometric ... more details
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