Handling Imbalanced Classification Problems With Support Vector Machines via Evolutionary Bilevel Optimization

Support vector machines (SVMs) are popular learning algorithms to deal with binary classification problems. They traditionally assume equal misclassification costs for each class; however, real-world problems may have an uneven class distribution. This article introduces EBCS-SVM: evolutionary bilevel cost-sensitive SVMs. EBCS-SVM handles imbalanced classification problems by simultaneously learning the support vectors and optimizing the SVM hyperparameters, which comprise the kernel parameter and misclassification costs. The resulting optimization problem is a bilevel problem, where the lower level determines the support vectors and the upper level the hyperparameters. This optimization problem is solved using an evolutionary algorithm (EA) at the upper level and sequential minimal optimization (SMO) at the lower level. These two methods work in a nested fashion, that is, the optimal support vectors help guide the search of the hyperparameters, and the lower level is initialized based on previous successful solutions. The proposed method is assessed using 70 datasets of imbalanced classification and compared with several state-of-the-art methods. The experimental results, supported by a Bayesian test, provided evidence of the effectiveness of EBCS-SVM when working with highly imbalanced datasets.Comment: Copyright 2022 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other work

Existencia de arcos ordenados en los hiperespacios C(X) y 2X

"El presente trabajo se encuentra inmerso dentro de la rama de la topología conocida como teoría de los continuos e hiperespacios. Particularmente, se centra en la existencia de arcos ordenados en los hiperespacios 2X y C(X) de un espacio métrico X, siguiendo los resultados expuestos en 1999 por Sam B. Nadler Jr. y Alejandro Illanes en los capítulos 14 y 15 de su obra Hyperspaces: Fundamental and Recent Advances. El propósito de esta tesis es desarrollar de manera profunda las demostraciones expuestas en estos capítulos, a fin de facilitar la consulta a futuros lectores, así como ser fuente de inspiración para posibles futuros trabajos relacionados a la teoría de los continuos y sus hiperespacios"

Empowering One-vs-One Decomposition with Ensemble Learning for Multi-Class Imbalanced Data

Zhongliang Zhang was supported by the National Science Foundation of China (NSFC Proj. 61273204) and CSC Scholarship Program (CSC NO. 201406080059). Bartosz Krawczyk was supported by the Polish National Science Center under the grant no. UMO-2015/19/B/ST6/01597. Salvador Garcia and Francisco Herrera were partially supported by the Spanish Ministry of Education and Science under Project TIN2014-57251-P and the Andalusian Research Plan P10-TIC-6858, P11-TIC-7765. Alejandro Rosales-Perez was supported by the CONACyT grant 329013.Multi-class imbalance classification problems occur in many real-world applications, which suffer from the quite different distribution of classes. Decomposition strategies are well-known techniques to address the classification problems involving multiple classes. Among them binary approaches using one-vs-one and one-vs-all has gained a significant attention from the research community. They allow to divide multi-class problems into several easier-to-solve two-class sub-problems. In this study we develop an exhaustive empirical analysis to explore the possibility of empowering the one-vs-one scheme for multi-class imbalance classification problems with applying binary ensemble learning approaches. We examine several state-of-the-art ensemble learning methods proposed for addressing the imbalance problems to solve the pairwise tasks derived from the multi-class data set. Then the aggregation strategy is employed to combine the binary ensemble outputs to reconstruct the original multi-class task. We present a detailed experimental study of the proposed approach, supported by the statistical analysis. The results indicate the high effectiveness of ensemble learning with one-vs-one scheme in dealing with the multi-class imbalance classification problems.National Natural Science Foundation of China (NSFC) 61273204CSC Scholarship Program (CSC) 201406080059Polish National Science Center UMO-2015/19/B/ST6/01597Spanish Government TIN2014-57251-PAndalusian Research Plan P10-TIC-6858 P11-TIC-7765Consejo Nacional de Ciencia y Tecnologia (CONACyT) 32901

Determining Strategies on Playing Badminton using the Knuth-Morris-Pratt Algorithm

Mastery techniques in badminton game are a main ability that must be possessed by players. One part of these techniques is the strategy in proper shuttlecock placement, so that the opposing player is difficult to restore it. Therefore, this study aims to build a computational model and its implementation that are able to provide predictions/recommendations for trainers and players on determining strategies of shuttlecock’s placements and strokes. The proposed model takes into account historical game patterns that have been done by world class athletes. Then, string matching using the Knuth-Morris-Pratt algorithm and a clustering method are utilized to provide solutions to be some strategies on shooting the shuttlecock. The model is then implemented in the R programming language. Several experiments, involving 20 series of world matches collected as historical data, have been conducted to validate the system. From the results obtained, it can be concluded that the system can be used as an alternative tool for players and coaches to determine the strategy in the placement and strokes of shuttlecock on badminton game

JUSECA: UN JUEGO SERIO PARA LA COMPRENSIÓN DE ALGORITMOS

The understanding of algorithms is one of the difficulties for students in university-level introductory programming courses. Although there are already strategies to stimulate the understanding of algorithms, a strategy that meets the needs of the subject “Programming 1” at the University of Los Andes was not found. Therefore, a serious game oriented towards this subject is proposed in this study for the understanding of algorithms, applying the ADDIE (Analysis, Design, Development, Implementation, and Evaluation) methodology. The Analysis, Design, and Development phases focused on the construction of JUSECA (Serious Game for the Comprehension of Algorithms); in the Implementation phase, the game was distributed to a group of students; and in the Evaluation phase, an ad hoc test was administered to evaluate the understanding of algorithms, and MEEGA+ (Model for the Evaluation of Educational Games) was applied to evaluate the students’ experiences and the usability of the game. On the one hand, the results of the ad hoc test showed that the game prompted students to correctly solve the easiest algorithm. On the other hand, the results of MEEGA+ indicated that the game moderately meets the requirements of an educational gameLa comprensión de algoritmos es una de las dificultades para estudiantes de cursos introductorios de programación a nivel universitario. Aunque ya existen estrategias para estimular la comprensión de algoritmos, no se encontró una estrategia que cubra las necesidades de la asignatura “Programación 1” de la Universidad de Los Andes, por lo tanto, en esta investigación se propone un juego serio, orientado a esta asignatura, para la comprensión de algoritmos, aplicando la metodología ADDIE (Análisis, Diseño, Desarrollo, Implementación y Evaluación). Las etapas de Análisis, Diseño y Desarrollo se destinaron a la construcción de JUSECA (Juego Serio para la Comprensión de Algoritmos); en la etapa de Implementación se proporcionó el juego a un grupo de estudiantes; y en la etapa de Evaluación se aplicó una evaluación ad hoc de rendimiento en la comprensión de algoritmos, y se aplicó MEEGA+ (Modelo para la Evaluación de Juegos Educacionales) para evaluar la experiencia de los estudiantes y la usabilidad del juego. Los resultados de la evaluación ad hoc indicaron que el juego fomentó en los estudiantes la resolución correcta del algoritmo más fácil. Por otro lado, los resultados de MEEGA+ permitieron conocer que el juego propuesto cumple moderadamente con los requerimientos de un juego educacional

Los filmes educativos. Una vía para el desarrollo de la expresión oral en los estudiantes (Original)

One of the main problems in the teaching of the Spanish and Literature subject is a component of the communicative abilities, comes to the development of the oral expression sphere. This work aims at contributing to the development of this component with the use of educative films in the lessons. The diagnose mode regarding the teaching of oral expression, is offered, to bring teachers activities able to be introduced in their lessons. This article is a summary of the former investigation of the main authoress.Uno de los mayores problemas que aparecen en la enseñanza del Español Literatura, como parte de la competencia comunicativa de los estudiantes, es el desarrollo de habilidades en el campo de la expresión oral. El trabajo tiene como fin contribuir al desarrollo de la misma mediante el empleo de los filmes educativos en las clases. Se constata el estado actual que presenta la enseñanza de la expresión oral, para  ofrecer al docente actividades que pueden ser incorporadas a sus clases. El artículo es una síntesis de la tesis de Maestría en Ciencias de la Educación de la autora principal

Vías de ingreso y nivel de preparación de estudiantes que optan por carreras de ciencias médicas / Ways of enrolment and level of training of the students opting for majors in medical sciences

En la actualidad son múltiples las vías de ingreso a la Educación Superior. La Universidad de Ciencias Médicas no escapa a esta realidad. Esto presupone técnicamente diversos problemas en la preparación de los estudiantes que optan por carreras de Ciencias Médicas. Con el objetivo de precisar las vías de ingreso de los estudiantes en las carreras de Medicina y Tecnología de la Salud, así como su nivel de preparación, se realizaron encuestas, visitas a clases, tests de contenido y análisis de instrumentos evaluativos, utilizados con este fin en varias dependencias educacionales de la provincia. Los resultados indican que existen dificultades en la pertinencia de la preparación que tienen los estudiantes que optan por carreras de Ciencias Médicas. Palabras clave: ESTUDIANTES DE MEDICINA, EVALUACIÓN EDUCACINAL/métodos, ESCUELAS MÉDICAS, PRUEBA DE ADMISIÓN ACADÉMICA, APTITUD. ABSTRACT Nowadays there are multiple ways of enrolment in high education .The medical school is not out of this reality. Technically, it presupposes certain problems in the training of the students who are opting for medical science and health technology majors, as well as the level of the training, visits to the classes, examinations and analysis of the evaluative tools used in various educational entities in the province. The outcome indicate the existence of difficulties in the training of the students opting for medical science majors. Key words: Medical students, Educational evaluation /method, Medical schools, Test for academic admission, Aptitude

Vías de ingreso y nivel de preparación de estudiantes que optan por carreras de ciencias médicas / Ways of enrolment and level of training of the students opting for majors in medical sciences

En la actualidad son múltiples las vías de ingreso a la Educación Superior. La Universidad de Ciencias Médicas no escapa a esta realidad. Esto presupone técnicamente diversos problemas en la preparación de los estudiantes que optan por carreras de Ciencias Médicas. Con el objetivo de precisar las vías de ingreso de los estudiantes en las carreras de Medicina y Tecnología de la Salud, así como su nivel de preparación, se realizaron encuestas, visitas a clases, tests de contenido y análisis de instrumentos evaluativos, utilizados con este fin en varias dependencias educacionales de la provincia. Los resultados indican que existen dificultades en la pertinencia de la preparación que tienen los estudiantes que optan por carreras de Ciencias Médicas. Palabras clave: ESTUDIANTES DE MEDICINA, EVALUACIÓN EDUCACINAL/métodos, ESCUELAS MÉDICAS, PRUEBA DE ADMISIÓN ACADÉMICA, APTITUD. ABSTRACT Nowadays there are multiple ways of enrolment in high education .The medical school is not out of this reality. Technically, it presupposes certain problems in the training of the students who are opting for medical science and health technology majors, as well as the level of the training, visits to the classes, examinations and analysis of the evaluative tools used in various educational entities in the province. The outcome indicate the existence of difficulties in the training of the students opting for medical science majors. Key words: Medical students, Educational evaluation /method, Medical schools, Test for academic admission, Aptitude

Implementation of intensity modulated radiotherapy for prostate cancer in a private radiotherapy service in Mexico

Intensity modulated radiation therapy (IMRT) allows physicians to deliver higher conformal doses to the tumour, while avoiding adjacent structures. As a result the probability of tumour control is higher and toxicity may be reduced. However, implementation of IMRT is highly complex and requires a rigorous quality assurance (QA) program both before and during treatment. The present article describes the process of implementing IMRT for localized prostate cancer in a radiation therapy department. In our experience, IMRT implementation requires careful planning due to the need to simultaneously implement specialized software, multifaceted QA programs, and training of the multidisciplinary team. Establishing standardized protocols and ensuring close collaboration between a multidisciplinary team is challenging but essential