Titulo: Brief introduction to tropical geometry

Autor: Varios

Publicacion: 2014

Editorial: Autoedición

Num. Paginas: 75

Tamano: 990 Kbs (zip)

Idioma: Inglés

Categorias: Ciencia, Matemáticas, Textos Académicos

Etiquetas: Ciencia, Geometría, Matemáticas, Paper, Polinomios, Topología

The paper consists of lecture notes for a mini-course given by the authors at the Gökova Geometry & Topology conference in May 2014. We start the exposition with tropical curves in the plane and their applications to problems in classical enumerative geometry, and continue with a look at more general tropical varieties and their homology theories. The goal of these lectures is to give a basic introduction to tropical geometry focusing on some of its particularly simple and visual aspects. The first section is devoted to tropical arithmetic and its relations to classical arithmetic. The second section reviews tropical curves in R2. The content of these two sections is quite standard, and we refer to [Bru09, Bru12, BS14a] for their extended versions. Section 3 contains a tropical version of the combinatorial patchworking construction for plane curves, as well as a tropical reformulation of Haas’ theorem. Section 4 presents some enumerative applications of tropical geometry, as well as the floor diagram technique. Section 5 looks at general tropical subvarieties of Rn and their approximation by complex algebraic varieties. Section 6 is devoted to a basic study of tropical curves inside non-singular affine tropical surfaces. Finally, in Section 7 we define abstract tropical manifolds and review their homology theories.

]]>Titulo: Anand vs Topalov 2010: An Amateur’s View of the World Chess Championship Final

Autor: Umesh P. N.

Publicacion: 2010

Editorial: Autoedición

Num. Paginas: 70

Tamano: 356 Kbs (zip)

Idioma: Inglés

Categorias: Ajedrez, Ensayos

Etiquetas: Ajedrez, Anand, Juegos, Topalov

Every time a world chess championship concludes, we see a flurry of books and web pages with annotations, computer analysis and background information. Most of them are written by grandmasters and very strong players. Some contain detailed analysis and some have only superficial comments. While in-depth reports from grandmasters who attended the championship in person (like Raymond Keene’s book on Karpov–Korchnoi and Karpov–Kasparov matches) are valuable with anecdotes, psychological notes and insider information, I always felt that a grandmaster is an overkill to annotate world championship games. Even an amateur player, with sufficient theoretical knowledge and patience, can analyze and annotate a grandmaster game. That is the motivation behind this book. In 2008, I published a Malayalam blog post with a brief analysis of the Anand–Kramnik match. While the 2010 match was in progress, I had discussed the games with a few of my friends using Google buzz. Some people found my analysis good and suggested to compile that effort as book. This is the result of that work. Even though I was never better than a state-level player in India and class A level (USCF rating 1800-2000) in the United states, I believe my 18 years of over-the-board tournament experience and 7 years of correspondence chess experience make me qualified to understand the games between Anand and Topalov in the world championship match 2010. I hope this book will be useful to chess lovers. Please let me know your comments about this book.

]]>Titulo: GIMP Magazine #11

Autor: Varios

Publicacion: 2015

Editorial: Autoedición

Num. Paginas: 40

Tamano: 9.19 Mbs (zip)

Idioma: Inglés

Categorias: Diseño / 3D, GIMP Magazine, Revistas

Etiquetas: Creatividad, GIMP Magazine, Retoque fotográfico, Revistas, Software libre

This issue is a showcase of excellence in illustration and animation by multimedia artist and digital storyteller Turi Scandurra, who uses GIMP as part of his animation tool flow. Be sure to visit Turi's website for details, videos, and tutorials of his work. This issue also features a digital portrait gallery by Rafael Lagatic, who uses GIMP for his amazing illustrations.

]]>Titulo: Chess

Autor: Wikibooks

Publicacion: 2015

Editorial: Wikibooks

Num. Paginas: 84

Tamano: 1.55 Mbs (zip)

Idioma: Inglés

Categorias: Ajedrez, Ensayos

Etiquetas: Ajedrez, Aperturas, Estrategía, Juegos

Chess, unlike many other games, does not involve chance. It does not hinge on the roll of dice or which card is drawn. The outcome completely depends on the decisions of both the players. However, because of its vast complexity, the far-reaching consequences of some decisions are practically unforeseeable. One player ("White") has the white pieces while the other ("Black") has the black pieces. In friendly games the choice of colors can be made by any method, such as flipping a coin - if there is no coin at hand, another typical way of deciding would be to conceal a black piece in one hand and a white piece in the other and ask one's opponent to select a hand, the colored piece selected will be the opponent's color. In competitive games the players are assigned their colors. Cotent: Playing the Game Notating the Game Tactics Strategy Basic Openings The Endgame

]]>Titulo: Light and Matter

Autor: Benjamin Crowell

Publicacion: 2015

Editorial: Autoedición

Num. Paginas: 1026

Tamano: 80.95 Mbs (zip)

Idioma: Inglés

Categorias: Ciencia, Física

Etiquetas: Ciencia, Cinemática, Electromagnetismo, Física, Ondas, óptica, Relatividad, Termodinámica, Vectores

If you drop your sho e and a coin side by side, they hit the ground at the same time. Why do esn’t the sho e get there first, since gravity is pulling harder on it? How do es the lens of your eye work, and why do your eye’s muscles need to squash its lens into different shap es in order to fo cus on ob jects nearby or far away? These are the kinds of questions that physics trie s to answer ab out the b ehavior of light and matter, the two things that the universe is made of. This is an introductory text intended for a one-year introductory course of the type typically taken by biology majors, or for AP Physics 1 and 2. Algebra and trig are used, and there are optional calculus-based sections. Brief Contents: Motion in one dimension Motion in three dimensions Conservation laws Vibrations and waves Relativity and electromagnetism Optics The modern revolution in physics

]]>Titulo: Open Government

Autor: Daniel Lathrop & Laurel Ruma

Publicacion: 2010

Editorial: O'Reilly

Num. Paginas: 431

Tamano: 8.92 Mbs (zip)

Idioma: Inglés

Categorias: Ensayos / Novelas, Información

Etiquetas: Ciudadanía, Democracia, Gobierno Abierto, Inteligencia cívica, Sociedad

What is open government? In the most basic sense, it’s the notion that the people have the right to access the documents and proceedings of government. The idea that the public has a right to scrutinize and participate in government dates at least to the Enlightenment, and is enshrined in both the U.S. Declaration of Independence and U.S. Constitution. Its principles are recognized in virtually every democratic country on the planet. But the very meaning of the term continues to evolve. The concept of open government has been influenced—for the better—by the open source software movement, and taken on a greater focus for allowing participation in the procedures of government. Just as open source software allows users to change and contribute to the source code of their software, open government now means government where citizens not only have access to information, documents, and proceedings, but can also become participants in a meaningful way. Open government also means improved communication and operations within the various branches and levels of government. More sharing internally can lead to greater efficiency and accountability. The subtitle of this book is “Transparency, Participation, and Collaboration in Practice.” The terms were borrowed from President Barack Obama’s memorandum on transparency and open government, issued his first day in office. In it, he committed the U.S. government to “establish a system of transparency, public participation, and collaboration.” In this book we have found leading visionaries, thinkers, and practitioners from inside and outside of government who share their views on what this new balance looks like, how to achieve it, and the reforms that are needed along the way.

]]>Titulo: Da Vinci and the 40 Answers: a playbook for creativity and fresh ideas

Autor: Mark L. Fox

Publicacion: 2008

Editorial: Wizard Academy Press

Num. Paginas: 311

Tamano: 8.53 Mbs (zip)

Idioma: Inglés

Categorias: Diseño / 3D

Etiquetas: Creatividad, Diseño

We’ve all heard the expression, “think outside the box.” The problem with this concept is that many people do not understand what the box is, much less how to escape this cage. When we are facing a problem, we use what we already know to determine the solution. The box is the frame of reference, the starting point for deductive reasoning. When we deduce something, we start with a known point. Deductive reasoning applies logic that moves us from the general to the specific by using known facts, definitions, principles, and properties to reach a conclusion. The problem with “the box” is quite simple. If you’re starting with what is known and you’re only willing to look at what can be extrapolated from the known, then how do you discover a thing that is not directly relative to the known? The answer to this quandary lies in duality. Duality is the concept of equal but opposite. When we identify a thing – an idea, a concept, a principle, or a problem for example, we must be able to then step back and look at the thing we haven’t been looking at. What is the opposite of this thing or this problem?

]]>Titulo: Resolución rápida del cubo de Rubik

Autor: Miguel Abreu García

Publicacion: 2011

Editorial: Autoedición

Num. Paginas: 121

Tamano: 5.98 Mbs (zip)

Idioma: Español

Categorias: Ciencia, Juegos

Etiquetas: Ciencia, Juegos, Matemáticas, Permutaciones, Puzzles, Rubik

El cubo de Rubik es uno de los puzzles más extendidos del mundo, creado por Ernö Rubik en 1974. Dicho cubo alcanzó gran fama como juguete, y salieron al mercado distintas versiones del mismo, e incluso algunas que no tienen forma de cubo. El cubo de Rubik tradicional supone un desafío, puesto que tiene muchos estados y sólo uno se considera “estado final” o “solución”. También es un desafío crear una aplicación capaz de resolver el cubo. Debido a la amplitud del problema, crear una aplicación que resuelva el cubo es una tarea complicada. Las aplicaciones actuales buscan resolver el cubo de manera óptima, eso implica una exploración de un espacio de estados enorme, lo que consumiría mucho tiempo. Hoy día se usan distintos métodos para encontrar la solución óptima en el menor tiempo posible. Pero hay un hecho curioso, en las competiciones oficiales del cubo de Rubik, donde se trata de resolver en el menor tiempo posible, los participantes no resuelven el cubo de manera óptima, es decir, hacen más movimientos de los necesarios. Entonces, ¿se puede resolver el cubo de Rubik de manera sub-óptima, pero ganando mucho tiempo? Siguiendo una de las metodologías que existen para resolverlo nos ahorramos la exploración de un árbol de estados muy grande dividiendo el desarrollo del cubo en etapas. Cada etapa tiene un objetivo concreto y definible, y es fácil verificar si se ha llegado al final de una etapa. El resultado será una cadena de movimientos que resuelve un cubo dado, y dicha solución la obtendremos casi al instante.

]]>Titulo: A First Course in Linear Algebra

Autor: Robert A. Beezer

Publicacion: 2014

Editorial: Congruent Press

Num. Paginas: 498

Tamano: 2.06 Mbs (zip)

Idioma: Inglés

Categorias: Ciencia, Matemáticas

Etiquetas: Álgebra lineal, Ciencia, Ecuaciones, Matemáticas, Matrices, Vectores

This text is designed to teach the concepts and techniques of basic linear algebra as a rigorous mathematical subject. Besides computational proficiency, there is an emphasis on understanding definitions and theorems, as well as reading, understanding and creating proofs. A strictly logical organization, complete and exceedingly detailed proofs of every theorem, advice on techniques for reading and writing proofs, and a selection of challenging theoretical exercises will slowly provide the novice with the tools and confidence to be able to study other mathematical topics in a rigorous fashion. Most students taking a course in linear algebra will have completed courses in differential and integral calculus, and maybe also multivariate calculus, and will typically be second-year students in university. This level of mathematical maturity is expected, however there is little or no requirement to know calculus itself to use this book successfully. With complete details for every proof, for nearly every example, and for solutions to a majority of the exercises, the book is ideal for self-study, for those of any age. While there is an abundance of guidance in the use of the software system, Sage, there is no attempt to address the problems of numerical linear algebra, which are arguably continuous in nature. Similarly, there is little emphasis on a geometric approach to problems of linear algebra. While this may contradict the experience of many experienced mathematicians, the approach here is consciously algebraic. As a result, the student should be well-prepared to encounter groups, rings and fields in future courses in algebra, or other areas of discrete mathematics.

]]>Titulo: GIMP Magazine #10A

Autor: Varios

Publicacion: 2015

Editorial: Autoedición

Num. Paginas: 17

Tamano: 26.48 Mbs (zip)

Idioma: Inglés

Categorias: GIMP Magazine, Revistas

Etiquetas: Gimp, GIMP Magazine, Retoque fotográfico, Revistas, Software libre

“Pie, pie, everywhere a pie Blockin' out the scenery, breakin' my mind Eat this, don't eat that, can't you eat the pie?” With all due respect to Ottawa’s own “Five Man Electrical Band” - I think they would have rather sung about pie than signs. Which brings me to my first point, who doesn’t love PIE? Pie has been in my life ever since I can remember—I have never been a cake fan, but who doesn’t love a good pie? In an effort to understand the correlation between the GIMP, Pie and Pi - We interviewed two lucky GIMP Magazine readers about using GIMP, eating pie, and loving life. Lisa Golladay’s pie-inspired artwork, “The Derivation of Pi(e)” is our first GIMP find this month!

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