Le point sur la virtualisation en 2010 : Introduction La virtualisation n’est pas une idée nouvelle. En fait, elle remonte aux débuts de l’informatique. On peut ainsi citer les travaux de Popek et Goldberg en 1974, qui ont analysé les différents types de solutions de virtualisation possible, leurs inconvénients respectifs et ont jeté les bases des développements futurs. Pour rappel, la virtualisation consiste à exécuter un système d'exploitation dans une machine virtuelle, ce qui permet d'utiliser plusieurs systèmes sur la même machine, soit pour utiliser un système d'exploitation différent de l'hôte soit pour compartimenter de façon efficace les différents services d'une machine. Historiquement, la virtualisation est devenue à la mode en 2006, quand des logiciels permettant de lancer Windows dans Mac OS X sont apparus.
Project Euler Online Conversion - Convert just about anything to anything else VirtualBox American Mathematical Society :: Feature Column Voronoi diagrams have been used by anthropologists to describe regions of influence of different cultures; by crystallographers to explain the structure of certain crystals and metals; by ecologists to study competition between plants; and by economists to model markets in the U.S. economy... Introduction Suppose that you live in a desert where the only sources of water are a few springs scattered here and there. Maps like this appear frequently in various applications and under many names. Voronoi diagrams are rather natural constructions, and it seems that they, or something like them, have been in use for a long time. Since that time, Voronoi diagrams have been used by anthropologists to describe regions of influence of different cultures; by crystallographers to explain the structure of certain crystals and metals; by ecologists to study competition between plants; and by economists to model markets in the U.S. economy. Constructing Voronoi diagrams and as from .We will use . is given by
Circle A circle can be defined as the curve traced out by a point that moves so that its distance from a given point is constant. Terminology[edit] History[edit] Circular piece of silk with Mongol images The circle has been known since before the beginning of recorded history. Early science, particularly geometry and astrology and astronomy, was connected to the divine for most medieval scholars, and many believed that there was something intrinsically "divine" or "perfect" that could be found in circles.[2][3] Some highlights in the history of the circle are: 1700 BCE – The Rhind papyrus gives a method to find the area of a circular field. 300 BCE – Book 3 of Euclid's Elements deals with the properties of circles.In Plato's Seventh Letter there is a detailed definition and explanation of the circle. Analytic results[edit] Length of circumference[edit] The ratio of a circle's circumference to its diameter is π (pi), an irrational constant approximately equal to 3.141592654. Area enclosed[edit] . or
Comparison of platform virtual machines Platform virtualization software, specifically emulators and hypervisors, are software packages that emulate the whole physical computer machine, often providing multiple virtual machines on one physical platform. The table below compares basic information about platform virtualization hypervisors. General[edit] Features[edit] ^ Providing any virtual environment usually requires some overhead of some type or another. Image type compatibility[edit] Other features[edit] ^ Windows Server 2008 R2 SP1 and Windows 7 SP1 have limited support for redirecting the USB protocol over RDP using RemoteFX.[29]^ Windows Server 2008 R2 SP1 adds accelerated graphics support for certain editions of Windows Server 2008 R2 SP1 and Windows 7 SP1 using RemoteFX.[30][31] Restrictions[edit] This table is meant to outline restrictions in the software dictated by licensing or capabilities. Note: No limit means no enforced limit. See also[edit] Notes[edit] References[edit] External links[edit]
The trouble with five December 2007 We are all familiar with the simple ways of tiling the plane by equilateral triangles, squares, or hexagons. These are the three regular tilings: each is made up of identical copies of a regular polygon — a shape whose sides all have the same length and angles between them — and adjacent tiles share whole edges, that is, we never have part of a tile's edge overlapping part of another tile's edge. Figure 1: The three regular tilings. In this collection of tilings by regular polygons the number five is conspicuously absent. Figure 2: Three pentagons arranged around a point leave a gap, and four overlap. But there is no reason to give up yet: we can try to find other interesting tilings of the plane involving the number five by relaxing some of the constraints on regular tilings. Is it now possible to find a set of shapes with five-fold symmetry that together will tile the plane? Going for simple shapes Figure 3: Constructing a tiling piece by piece. Dividing monsters forever
triangles A plane triangle is an object having 3 straight sides in 2-dimensional space. (Triangles in other spaces, for example spherical triangles, are not treated here.) Triangles have 3 sides, 3 vertices (the points where the sides meet), and 3 angles. <p class="scriptwarn">The calculator below uses JavaScript, and so it will not work for you. Triangle calculators If the sizes of three of the six parts (3 angles and 3 sides) of a triangle are known, and at least one of the known parts is a side, the sizes of the other sides and angles can be calculated. In what follows, the sides are named with lowercase letters, and the angle opposite a side is named by the same letter, but in uppercase. Equations about triangles For the equations below, the angles are named with the Greek letters alpha (α), beta (β) and gamma (γ). The Law of Sines The Cosine Law The Law of Tangents Area The area can also be calculated from the lengths of the three sides alone (Heron's formula). The inscribed circle c2 = a2 + b2
60 Tools in 60 Minutes Page 1 / 61 1. brian c. housand, phd 2. Jog the Web 3. EtherPad 4. Powered by JOGTHEWEB Index Share It : 60 Tools in 60 Minutes The page must be refreshed to take effect. What's special about this number? (1) is the only prime 1 less than a perfect square. - Robin Regan is the number of spatial dimensions needed to mathematically describe a solid. are the primary colors. are the geometric constructions you cannot build using just a ruler and compasses: 1. You cannot trisect - divide into three equal parts - a given angle; 2. Double a cube; and 3. Square a circle. A number is divisible by 3 when the sum of its digits can be divided by 3. If the denominator of a rational number is not divisible by 3, then the repeating part of its decimal expansion is an integer divisible by 9. 3 + 2 = log2 32 5 (sum of two square roots)= 4! 4) = XV/V = CL/L = MD/D = 4 + 4 – 5 = 43 + 43 – 53= 17,469 / 5,823 (this division contains all digits 1 through 9 once) 3 x 51249876 = 153749628 (the multiplication uses all 9 digits once - and so does its product!) 3 x 37 = 111 33 x 3367 = 111,111 333 x 333667 = 111,111,111 3333 x 33336667 = 111,111,111,111 33333 x 3333366667 = 111,111,111,111,111 3 x 1.5 = 3 + 1.5
Evil Mad Scientist Laboratories - Iterative Algorithmic Plastic One of our favorite shapes is the Sierpinski triangle. In one sense, a mere mathematical abstraction, on the other, a pattern that naturally emerges in real life from several different simple algorithms. On paper, one can play the Chaos Game to generate the shape (or cheat and just use the java applet). You can also generate a Sierpinski triangle in what is perhaps a more obvious way: by exploiting its fractal self-similarity. Beginning with a single triangle, replace that triangle with three half-size copies arranged so that their outer border form a new triangle of the same size as the original. Then, replace each of those three triangles with three triangles half that size, and so forth. We begin with a few packages of polymer clay– two colors of Fimo Soft, in this case. Form the two clay colors into long triangular shapes. Press the stack of triangles together to make sure that the edges fuse well. Cut the stretched “first iteration” piece into four pieces of equal length.
Geometry in Action This page collects various areas in which ideas from discrete and computational geometry (meaning mainly low-dimensional Euclidean geometry) meet some real world applications. It contains brief descriptions of those applications and the geometric questions arising from them, as well as pointers to web pages on the applications themselves and on their geometric connections. This is largely organized by application but some major general techniques are also listed as topics. Suggestions for other applications and pointers are welcome. Geometric references and techniques Design and manufacturing Graphics and visualization Information systems Medicine and biology Physical sciences Robotics Other applications Recent additions