Volume III. Number 2. October 2013

We present the second number of the third volume of the Mathematical Thinking Journal. It includes some papers framed in the different sections of the Journal. The articles cover a wide range of the Mathematics topics and its applications.

Title: Créditos editoriales, Índice de artículos y Editorial del Número 2 (Vol. III)
Author: Equipo Editorial
Teaching Experiences

This paper presents the exhibition “Laugh with Maths: Mathematical Cartoons´´ that the Educational Innovation Group (GIE) “Mathematical Thinking´´ (“Pensamiento Matemático”) of the Polytechnic University of Madrid (UPM) has done with the collaboration of students of the Escuela Técnica Superior de Ingenieros de Caminos, Canales y Puertos of the UPM. The work wants to show the utility of the exhibitions as a teaching resource in the teaching of mathematics.

Title: Exposición: “Ríete con las Mates´´
Author: Mariló López González

Science should not stay out of public debate, but an open confrontation between scientists and non-scientists is not easy. All the more reason to try. Social Cafés are a suitable format to discuss about topics where science, technology and society mix. The resulting flavour may be attractive.

Title: Manifesto for a “Social Café´´
Author: Paolo Politi
History of Mathematics

In this paper we address the question of the place of ethics of scientific research in the thought of the great mathematician Alexandre Grothendieck, studied with particular attentionhis great work Récoltes et semailles, a workin which he analyzes his life as researcher and as professor. In this matter, we will refer to the ethicsof scientific research, both in terms of the research itself, as it has to do with the communal dimension of science and its social implications

Title:La ética de la investigación científica en Alexandre Grothendieck
Author: Domingo Fernández Agis
Mathematical Stories

This fictional short story, based on historical events, won the 2nd Stories Contest “San Isidoro´´ in the year 2001 and was published in the magazine “Topografía y Cartografía” in the same year, and in Mapping in 2010.In 2005, subsidised by the Community of Madrid and the town halls of Tenerife and El Hierro, it was shot in this island the short film of the same title based on this story which, performed for the first time in Santa Cruz in 2006, had a wide circulation in international festivals.

Title: El Cero
Author: José Miguel Bel Martínez

Data mining, and in particular decision trees have been used in different fields: engineering, medicine, banking and finance, etc., to analyze a target variable through decision variables. The following article examines the use of the decision trees algorithm as a tool in territorial logistic planning. The decision tree built has estimated population density indexes for territorial units with similar logistics characteristics in a concise and practical way.

Title: Use of decision trees algorithm for the territorial logistic planning
Authors: Jorge Quijada-Alarcón, Nicoletta González, Francisco Soler y Alberto Camarero

The steganography with private key, is a similar system to cryptographic systems of symmetric ciphers. In this paper a new steganographic algorithm is presented, which uses a private key, that it permits generating a binary pseudo-random sequence, indicating thus the pixels of the image where the elements of the binary sequence of the secret message will be inserted. The proposed algorithm, improves as to the level of imperceptibility in relation to the method of least significant bits.

Title: Algoritmo esteganográfico de clave privada
Authors: Anier Soria Lorente, Rayner Manuel Sánchez Reyes y Andys Marcos Ramírez Aberasturis

Obtaining the solution of specific engineering problems involves solving partial differential equations that have to be evaluated numerically. The finite element method is certainly the numerical resolution method most widely, which has outperformed the finite difference method mainly for its conceptual simplicity and by the limitations of the latter method to adapt to irregular meshes, however, several authors have continued to develop and implement the method of differences to all kinds of problems. This article presents a numerical application of the structural problem to calculate plates, which is solved by the finite difference method and allows optimal solutions even for localized load problems, demonstrating the suitability of application of generalized difference methods and presenting its formulation. In particular, three applications are resolved: plate with all four sides simply supported under uniform load, plate with all four sides simply supported under concentrated load at the center and plate with all four sides embedded under uniform load.

Title: Posibilidades de resolución de problemas de ingeniería por el método de diferencias finitas
Author: Rubén Galindo Aires
Games and Mathematical Odditiess

In this paper we show how we can use the Rubik cube to present some basic concepts of group theory and how we can use this to solve the Rubik cube.

Title: Las matemáticas del cubo de Rubik
Author: Ramón Esteban Romero
Cri­tics and Reviews

This article presents a review of this book, that reveals 150 universal secrets hidden behind the infinity. The author tries to show historically our knowledge about this concept through quite different disciplines as the link between the infinity and the space, the religion, the energy, the spirals, the thought, the probability, the geometry or the calculus.

Title: “Los Secretos del Infinito. 150 Respuestas al Enigma´´, Antonio Lamúa Olivar
Author: Mariano Soler Dorda

This time we chat with Juan Medina, mathematics lecturer at Cartagena University (Spain), and creator of lasmatematicas.es, a website that presents more than 3.000 self-help videos for students of every level. His web has become in this way a reference one for those interested in “improving´´ their mathematics.

Title: Juan Medina: creador de lasmatematicas.es
Author: Equipo Editorial

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