16 results
Search Results
2. Una propuesta de reglas de sintonía robustas para controladores PI-2DoF.
- Author
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Sánchez Rivero, Maibeth and Llanes Santiago, Orestes
- Subjects
- *
PID controllers , *AUTOMATIC control systems , *FREQUENCY tuning , *ROBUST control , *DIFFERENTIAL evolution , *COMPUTER science - Abstract
A structure of two degrees of freedom permits uniting the controller's design so much for disturbances in the load same as for changes in the reference. In the design of a proportional integral derivative controller of two degrees of freedom (PI-2DoF) it is necessary to introduce conditions of robustness. The present paper proposes a rule of tuning that permits getting the level of robustness in a continuous interval with a smaller error than "± 0.06" of the desired value, surpassing the difficulty of the discreet margins of robustness. The rules was obtained using an adjustment of curves of the controller's optimal parameters, obtained as from the application of the differential evolution optimization's algorithm on a set of representative test's plants of industrial processes. The tuning rules for PI-2DoF control are used to establish the comparison with the rules in literature. [ABSTRACT FROM AUTHOR]
- Published
- 2017
3. Aplicación web basada en programación por restricciones para ingeniería de asignación de espectro.
- Author
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Guerrero, Fabio G., Díaz, Juan Francisco, and Delgado, Carlos Andrés
- Subjects
- *
CONSTRAINT programming , *COMPUTER programming , *SPECTRUM allocation , *COMPUTER engineering , *COMPUTER science , *COMBINATORIAL optimization - Abstract
The flexibility of spectrum usage required by emerging paradigms, radio spectrum demand driven by new wireless technologies, new applications and government policies oriented to massive use of Internet require spectrum management authorities to have smarter tools to do their work in an efficient way. This paper presents the design and implementation of a web application to support spectrum management activities using constraints programming. The design includes a mathematical model for allocation constraints, a mathematical model for interference constraints, a relational database of the National Allocation Table considering bands, channels and services associated with geopolitical division of Colombia, and an operator allocation database. These tools allow creating and to parameterize different levels of restrictions establishing different costs and weights. The interference analysis module takes into account the geographical location and technical characteristics of transmitting stations. The tool developed in this work can be used, among others, in allocation optimization studies, assessing policies of spectrum reallocation, allocation analysis to maximize specific criteria, reducing technology costs of implementing specific technologies and help identifying objective variables for spectrum price estimation. To facilitate the understanding and exploitation of the application several didactic examples are included. [ABSTRACT FROM AUTHOR]
- Published
- 2015
4. Aplicación del método de composición musical al problema de asignación de unidades de enseñanza y aprendizaje.
- Author
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Silva López, Rafaela Blanca, Cruz Miguel, Rosa Elena, Rincón García, Eric Alfredo, Mora Gutiérrez, Roman Anselmo, and Ponsich, Antonin
- Subjects
- *
MUSICAL composition , *HEURISTIC algorithms , *SCHEDULING , *ASSIGNMENT problems (Programming) , *LINEAR programming , *COMPUTER science - Abstract
Scheduling problems in educational institutions have a computational complexity that makes it difficult to obtain optimal solutions using exact methods. Thus, heuristic techniques have been used to generate feasible solutions in acceptable computation times. In this paper, we solve the problem of assigning teaching and learning units in the least number of quarters using a population heuristic, Method of Musical Composition. The generated solutions satisfy the requirements and show higher quality than manual-built schedules, so that they are currently being evaluated by the educational authorities. [ABSTRACT FROM AUTHOR]
- Published
- 2014
5. La especificación formal en contexto: actual y futuro.
- Author
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Serna M., Edgar and Serna A., Alexei
- Subjects
- *
SOFTWARE engineering , *COMPUTER science , *FORMAL organization , *COMPUTER engineering , *COMPUTER software - Abstract
Formal specification is an active research field in software engineering of this century, where different configurations and techniques are employed and although their industrial use is still limited, the scientific community currently has a different understanding about its usefulness and necessity. Until present time, researchers' work focuses on the specification written during the design of the preliminary functional model, for this reason it mainly focuses on evaluating the related tools. In this paper, a literature review is performed, covering the essence, function, use and disadvantages of formal specification techniques and some assessment and evaluation criteria are analyzed regarding their weaknesses. The results become the basis for future work formulation, aimed to the strengthening of formal specification as a core research activity. [ABSTRACT FROM AUTHOR]
- Published
- 2014
6. Validación de la caracterización estadística del tráfico de red de un servidor web de un campus universitario como mecanismo de un sistema de detección de intrusos.
- Author
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Hernández Jaimes, Antonio and Prada Angarita, Lina
- Subjects
- *
INTERNET servers , *COMPUTER networks , *INTERNET traffic , *INTRUSION detection systems (Computer security) , *STATISTICS , *COMPUTER science - Abstract
This paper presents the results of statistical analysis of network traffic (in bits per second) from and to one university web server. Statistical analysis allows to know the hourly traffic trends and to establish a baseline for normal behavior. It documents, in addition, statistical goodness-fit tests results and analysis of variance, which provide elements that enhance the definition of the baseline. Finally, the outcomes are analyzed to determine its usefulness as intrusion detection mechanism or situations or behaviors that could suggest anomalies or atypical traffic. [ABSTRACT FROM AUTHOR]
- Published
- 2014
7. Modelos y configuraciones de cadenas de suministro en productos perecederos.
- Author
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Vianchá Sánchez, Zulma Hasbleidy
- Subjects
- *
CONFIGURATIONS (Geometry) , *SUPPLY chain disruptions , *PERISHABLE goods , *LOGISTIC regression analysis , *COMPUTER science - Abstract
The purpose of this article is to present a reference framework in the models and configurations of agricultural supply chains, specifically in perishables. The review was based on information research in the databases "ISI Web of Science", "Scopus" and "Science Direct", and the selection criterion of topics of interest. The paper presents some approaches to modeling and configuration of supply chains and the impact of the territory in their planning. The exploration established that the issue requires further study about configurations and their implications, for the design of models to improve logistic processes in agricultural supply chains of multiple producers, with diverse geographic locations in rural areas and needs to decrease operating costs. [ABSTRACT FROM AUTHOR]
- Published
- 2014
8. Bases para crear un modelo de madurez para Arquitecturas Orientadas a Servicios.
- Author
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Arias-Orizondo, Arturo César and Estrada-Senti, Vivian
- Subjects
- *
SERVICE-oriented architecture (Computer science) , *COMPUTER network architectures , *COMPUTER science , *COMPUTER networks in business enterprises , *BUSINESS enterprise digital resources - Abstract
The adoption of Service Oriented Architectures (SOA) by the companies shows high failure rates, mainly because of the way this paradigm is adopted. Thus, the complexity of this process should be addressed by using the evolutionary approach that maturity models offer. However, the diversity of maturity models makes difficult the selection and implementation of most of them. Taking this into account, the objective of this paper is to carry out a comparative analysis between the most representative maturity models and to determine whether they are sufficient in order to evaluating and planning the adoption of SOA with effectiveness. The inadequacies detected after a comprehensive assessment, restrict the evaluation and planning capacities that these models offer. In order to overcome them and using the international experience gained in this field, it were defined the constructs (principles, elements and structure) that support a more integral maturity model. [ABSTRACT FROM AUTHOR]
- Published
- 2013
9. Metodología para ubicar estudiantes en roles del proceso de desarrollo de software.
- Author
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Arza-Pérez, Lizandra, Verdecia-Martínez, Edistio Yoel, and Lavandero-García, José
- Subjects
- *
COMPUTER software development , *EMPLOYEE selection , *ARTIFICIAL intelligence , *PERSONNEL policies , *COMPUTER science , *COMPUTER scientists - Abstract
The University of Computer Sciences is responsible for the training of computer professionals as well as for the direct participation in the development of national computerization projects and export commitments as part of the industry. The integration model of formation-production- research processes expresses that students must perform a role in the software development process, linked to a real project. The objective of this paper is to establish a proposal of a methodology that systematizes the process of assigning students to a role. It has as a starting point the recruitment processes in the industry and a model for the comparison and prediction of student's behavior in each role. The methods used were document analysis, systemic method, among others. The analysis of the impact of the results of the methodology is analyzed and discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2013
10. Aprendizaje de y con robótica, algunas experiencias.
- Author
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López Ramírez, Pedro Antonio and Andrade Sosa, Hugo
- Subjects
- *
ROBOTICS in education , *STUDY & teaching of robotics , *EDUCATIONAL technology research , *COMPUTERS in education , *LEARNING strategies , *EDUCATIONAL resources , *COMPUTER science - Abstract
This paper analyzes some experiences, previously reviewed in literature, about the use of robotics in education in order to obtain relevant models for the design of a proposal about robotics learning at Basic Secondary and Middle education levels. Two scopes of application of robotics in education are considered: firstly, learning robotics by defining the context of each robot subsystems and then creating robots for different purposes. The objective in this case is the development of skills for the design and construction of robotic artifacts, a process that implies the acquisition of the necessary knowledge to accomplish this task. The second scope of application is the use of robotics to encourage knowledge construction in different areas, fostering students' development ok skills and competences. Learning robotics and learning with robotics can be supported by computer science since this area provides software technology and tools such as Math Modeling and language simulation, Multimedia Tutorials, Virtual and Remote laboratories, among others. The purpose of this article is to highlight the importance of robotics in the classroom to enrich learning strategies which contribute to student's comprehensive education. This field of study has a growing demand by teachers and researchers, and stimulus to encourage its research, development and spread. [ABSTRACT FROM AUTHOR]
- Published
- 2013
11. Análisis de los anglicismos informáticos crudos del léxico disponible de los estudiantes universitarios de traducción.
- Author
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Bolaños-Medina, Alicia and Luján-García, Carmen
- Subjects
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LOANWORDS , *SPANISH language -- Terms & phrases , *COMPUTER terminology , *COLLEGE students - Abstract
Most technical terms in the field of Computer Science are English loanwords. English words are frequently preferred to Spanish terms because of different reasons, for instance, because of linguistic economy. In this paper, we reveal the results of an empirical study about the frequency of use of pure anglicisms. It has been carried out among students of Translating and Interpreting at the University of Las Palmas de Gran Canaria (Spain). The scope of use of lexical anglicisms by individuals in the analysed sample seems to be relatively high, but slightly lower than that of Computer Science students who participated in another preliminary partial study. Those students who provided more words for definitions also suggested more synonyms for the terms, and also used more English terms. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
12. DISEÑO E IMPLEMENTACIÓN DE UNA BASE DE DATOS DE IMÁGENES DE RANGO CON DECIMACIÓN PARA LA VISUALIZACIÓN EN WEB.
- Author
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Rodríguez, Isabel, Ceballos, Alexánder, Hernández, Jorge, and Prieto, Flavio
- Subjects
- *
DATABASES , *ELECTRONIC information resources , *ONLINE databases , *COMPUTER science , *ALGORITHMS - Abstract
Databases are tools to store and manage information, the better they are distributed, the easier and more efficient will its access be. At present, thanks to technological development of fields such as computer science and electronics, most of them have an electronic format, since they offer a wide rank of solutions to the store data problem. In this paper, we present the design and development of a database for range images, based on the relational model and a design methodology consisting of three steps: conceptual design, logical design, and physical design. The data base has a WEB access. A multi-resolution algorithm was developed to improve the time cost in visualization and renderization, by using decimation parameters based on the curvature. A WEB interface was developed in order to provide an easy access, consequently, it is possible to enter, update, and eliminate models on a reliable and simple way. At present, the database counts on 40 models divided in 3 categories: Faces (22), Museum (4) and objects of free form (14). The use of the multi-resolution algorithm allows saving up to 96% of computational cost. [ABSTRACT FROM AUTHOR]
- Published
- 2007
13. MODELADO DEL ÍNDICE DE TIPO DE CAMBIO REAL COLOMBIANO USANDO REDES NEURONALES ARTIFICIALES.
- Author
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Henao, Juan David Velásquez and Rivera, Lina María González
- Subjects
- *
FOREIGN exchange rates , *ARTIFICIAL neural networks , *STOCK price indexes , *FORECASTING , *COMPUTER science - Abstract
Modeling and forecasting exchange rates is a big economic headache. This paper uses an artificial neuronal network model to represent the Colombian real exchange index dynamics because it describes the series dynamics better than a self-regressive linear model does, as may be appreciated in the result of the verosimilitud radius contrast. The model was accepted after applying a series of standard tests and contrasting the results against those obtained using a self-regressive linear model. The results indicated that the current value of a series solely depends on its previous value. [ABSTRACT FROM AUTHOR]
- Published
- 2006
14. El perfeccionamiento de la educación superior y su repercusión en la enseñanza de las matemáticas en las carreras técnicas.
- Author
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Rodríguez, G. de los A. Torres and Vega, J. M. Anta
- Subjects
- *
EDUCATIONAL change , *MATHEMATICS education , *COMPUTER science , *COMMUNICATION & technology , *EFFECT of technological innovations on education , *HIGH technology & education - Abstract
The main objective of the present paper is to expose the achievement of Superior Education in Cuba, particularly at Mathematics' Discipline in Technical careers, and discuss the influence of computer science technology and communication in the education changes that promote the third educational revolution in Cuba. [ABSTRACT FROM AUTHOR]
- Published
- 2006
15. PERFIL PARA REPRESENTAR UNA ARQUITECTURA DE COMPONENTES EN UML.
- Author
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Pérez Lovelle, Sonia and Orejas Valdés, Fernando
- Subjects
- *
UNIFIED modeling language , *COMPUTER architecture , *COMPUTER software development , *COMPUTER systems , *COMPUTER science - Abstract
Unified Modeling Language, (UML) is a standard modeling language for general purposes, however it may be extended in order to represent specific domain such component-based architectures. This paper presents an extension using a profile for generic components and connectors-based architecture. [ABSTRACT FROM AUTHOR]
- Published
- 2006
16. AUTOMATIZACIÓN DE LA ARQUITECTURA DE COMPONENTES GENÉRICOS USANDO UML.
- Author
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Pérez Lovelle, Sonia, Orejas Valdés, Fernando, Fuentes Ramírez, Noel, and Leyva Pérez, Exiquio C.
- Subjects
- *
COMPUTER architecture , *UNIFIED modeling language , *COMPUTER science , *AUTOMATION , *COMPUTER software development - Abstract
The basis of consistency check of architectural elements (components and connectors) in the generic component-based architecture is the definition of embedding and refinement relations for their internal relationships and interconnections. The ideas which are presented here constitute a guide for the automation of this architecture description using UML beginning with classes and sequence diagrams formal definition as well as consistency checking of components and connectors. This paper presents a plugin extension to Visual Paradigm which instruments this proposal. [ABSTRACT FROM AUTHOR]
- Published
- 2006
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