285 results
Search Results
102. Boosting Support Vector Machines.
- Author
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García Díaz, Elkin Eduardo and Martínez, Fernando Lozano
- Subjects
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ALGORITHMS , *MACHINE theory , *GENERALIZATION , *VECTOR analysis , *MATHEMATICAL models - Abstract
In this paper we present an algorithm of binary classification based on Support Vector Machines. It is combined with a modified Boosting algorithm. It run faster than the original SVM algorithm with a similar generalization error and equal complexity model but it has more compact representation. [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF
103. Aerodynamic Characteristics of Airfoils with Blunt Trailing Edge.
- Author
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Gómez, A. and Pinilla, Álvaro
- Subjects
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AERODYNAMICS , *LIFT (Aerodynamics) , *DRAG (Aerodynamics) , *ANGLE of attack (Aerodynamics) - Abstract
This paper is a computational study of the behaviour of aerodynamic characteristics of NACA (National Advisory Committee for Aeronautics, today known as NASA) profiles with tailored trailing edges. 39 different profiles 4-digit NACA family were studied during the research. A computational research was made, using simple theoretical models to explain and to understand the results. The results describe the changes in lift and drag characteristics and changes in stall angle of attack. [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF
104. Eficiencia técnica de los centros educativos distritales en Bogotá D.C.
- Author
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Mutis, Hernando and Díaz Torres, Gloria Maritza
- Subjects
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STOCHASTIC analysis , *SYMMETRY , *NOISE - Abstract
In the first part of this paper the basics of the estimation of the stochastic production function is discussed. In the second part an application of the former is presented aimed at the hierarquization of the educational institutions which depend of the District of Bogotá, according to a measure of the technical efficiency --using inputs to maximize the output. For the present, a Cobb-Douglas production function is assumed with a symmetric noise and a semi-normal efficiency perturbations. Using maximum likelihood the parameters are obtained and the efficiency for each institution is calculated. [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF
105. Estudio del Canal de Radio en las Bandas ISM, UNII I/II y de las Interferencias en el Hospital de la Samaritana.
- Author
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Sánchez G., Fernando Andrés, Bustamante M., Roberto, Téllez M., Juan Manuel, and Rojas, Miguel A.
- Subjects
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ELECTRIC interference , *ELECTROMAGNETIC noise , *COMPUTER architecture , *HOSPITALS , *MICROWAVE ovens , *STATISTICS - Abstract
The work that is presented in this paper is comprised of two studies, carried out on the ISM, UNII I and UNII II bands, in the Hospital Universitario de la Samaritana. In the first study, measurements of the level of interference and electromagnetic noise were carried out on the 3 mentioned bands. The objective of this study was to have indications on the electromagnetic environment in: the ISM band, in which operates the wireless network that is installed in the hospital and on the UNII I and UNII II bands, in which some wireless local area networks can operate. It was found that microwave ovens emit radiation on the ISM band, the greater power registered was -52.48dBm. Additionally sporadic and short term radiation was found on the ISM band, although the source could not be determined. It was found convenient that the Access Points that operate near microwave ovens were configured in the channel 1. In the UNII I and UNII II bands, it was not found levels of power greater that the noise floor of the employed system. In the second study narrow band statistical path loss models were developed. The objective of this study was to adjust path loss models to the particular characteristics of the hospital's facilities. Such models constitute a starting point in the design of a wireless network, however it is clarified explicitly that the design of the wireless network does not do part of this work. It was found that in the new renal unit the electromagnetic energy is confined due to its architecture and to the materials with which it was built, this fact probably can be employed to achieve a convenient reassignment of frequencies. [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF
106. Evolution of Network Access Points (NAPs) and agreements among Internet Service Providers (ISPs) in South America.
- Author
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Beltrán, Fernando
- Subjects
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INTERNET , *MARKETS , *INTEGRATED circuit interconnections , *INTERNET users , *COST recovery method - Abstract
This paper presents the main aspects of the historical development and the current issues at stake in the South American Internet access market: the interconnection schemes for the exchange of local and regional traffic in the South American region, the incentives Internet access providers have for keeping or modifying the nature of the agreements, and the cost recovery methods at the traffic exchange points. Some threats to the stability of the scheme for domestic traffic exchange adopted throughout the region are also identified and subsequently illustrated with country-cases. [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF
107. Estudio de la hidrólisis del crudo de aceite de palma africana empleando como catalizador la lipasa de la levadura C.rugosa.
- Author
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Molano, Miguel, Riveros, Diana, and Vargas, Edgar
- Subjects
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HYDROLYSIS , *PETROLEUM , *PALM oil , *LIPASES , *CANDIDA , *RUGOSA - Abstract
This paper shows the study of the hydrolysis reaction of crude palm oil giving by lipase from Candida rugosa. The studied factors were agitation level, bleaching effect and lipase concentration. Experimentally 79 - 93% hydrolysis were achieved in 2 and a half hour. The reaction rate was increased with the increment of the impeller rotational speed as well as increasing the lipase concentration. Although the literature cites bleaching as a beneficial advantages to enzymatic hydrolysis, this procedure do not have a significant beneficial effect on the reaction. [ABSTRACT FROM AUTHOR]
- Published
- 2005
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108. Optimización operacional de redes de distribución de agua potable con el fin de maximizar la uniformidad de presiones en los nodos de consumo.
- Author
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Araque Fuentes, Diego Alejandro and Saldarriaga, Juan Guillermo
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ALGORITHMS , *WATER distribution , *WATER utilities , *WATER-pipes , *PRESSURE - Abstract
The present paper will show that throughout the development of a deterministic algorithm the uniformity of the pressure service level in the Water Distribution Network (WDN) can be maximized. To obtain this in an optimal way, one must maximize an Index that relates the power by unit of weight dissipated by the network and the power by unit of weight available to dissipate by the same one (Resilience Index [2]), it improves the ability of the WDN to cope with possible failures in the system, slows down the pipes renovation processes and diminishes the level of leaks in the network. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
109. Agua y saneamiento en la interfaz periurbana: Un vistazo a cinco estudios de caso.
- Author
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Allen, Adriana, Dávila, Julio D., and Hofmann, Pascale
- Subjects
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SANITATION , *WATER utilities , *PUBLIC utilities -- Management , *RESEARCH , *METROPOLITAN areas - Abstract
This paper presents preliminary results from an on-going research project on the governance of water and sanitation services in the PUI of five metropolitan areas in three continents. It explores differences and similarities in the formal and informal practices in the delivery and consumption of these services. It deals with issues of access to decision-making, exploring the role that different actors, including state institutions, play in the political process. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
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110. Aplicación de un modelo numérico para la priorización de la inversión en tratamiento de aguas residuales en Colombia.
- Author
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Barrera, Sergio, Díaz-Granados, Mario, Ramos-Bonilla, Juan Pablo, Camacho, Luís A., Rosales, Ramón, Escalante, Nicolás, and Torres, Mario
- Subjects
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SEWAGE disposal plants , *PLANNING , *CITIES & towns , *GOVERNMENT agencies - Abstract
Colombia has lacked an adequate planning process for the design, construction, and operation of wastewater treatment facilities in most of the municipalities. National, regional and local agencies have conflicting criteria for managing this sector. Furthermore, there is a lack of adequate tools to support decisions with appropriate environmental, financial, social, and technical information. In this paper, a computer model is presented as a tool to support at a national level the decision making process for planning municipal wastewater treatment facilities in Colombia. A geographical information system was used to obtain a structured river network from a digital elevation model. Modeling flows, dissolved oxygen, biochemical oxygen demand, and coliform bacteria throughout the entire national drainage network allowed the analysis of several wastewater treatment scenarios, using bacteriological contamination (i.e.: coliform bacteria) as the main indicator of public health risks resulting from wastewater pollution. Total length of oxygen deprived river reaches in the hydrological network was much less than the length of the bacteriological degraded reaches. Using multivariate analysis, different wastewater treatment scenarios were analyzed to determine their effectiveness to mitigate wastewater pollution, based on environmental, socioeconomic and infrastructure criteria. As a result, prioritizations for investment in wastewater treatment plants were obtained at municipal and basin levels. The decision making tool integrates the objectives of the national agencies involved in wastewater management policies, solving the conflicts between agencies and optimizing the use of financial resources for the sector. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
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111. Páramos: Hidrosistemas Sensibles.
- Author
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Díaz-Granados Ortiz, Mario A., Navarrete González, Juan D., and Suárez López, Tatiana
- Subjects
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PARAMOS , *BIOTIC communities , *SEA level , *BOTANY - Abstract
Páramos are vulnerable zonal ecosystems located in the tropical mountains of Central and South America, approximately between 3000 and 4500 meters above the sea level. Their special characteristics generate particular floral, ecological, edaphological, geomorphological and climatic typologies. Páramos have great ecologic, genetic and scientific importance due to their endemic flora and landscapes, as well as their socio-economical functions, represented by their fundamental roll in water regulation for water supply in some cities downstream. Some efforts have been done to quantify the water balance in these special hydrosystems. This paper presents an approximation to the hydrologic modeling of these hydrosystems, based on the integration of the AvSWAT model, a horizontal precipitation model, and a geographic information system. As a case study, the upper Blanco river basin was analyzed. This basin is one of the principal areas of the Chingaza páramo, the main Bogotá City water supply source. Protection of these ecosystems is stressed in order to preserve flow regimes, mainly those associated with dry conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
112. La implantación del Sistema Penal acusatorio en Colombia: un estudio multidisciplinario.
- Author
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Reyes, Alfonso
- Subjects
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CONSTITUTIONS , *JUSTICE administration , *CRIMINAL justice system , *GOVERNMENT agencies , *CRIMINAL investigation - Abstract
On December 19th 2002 the accusatory system was formally introduced in the Colombian Constitution. This is, perhaps, the most complex change that our judicial system has undergone in the last decade. The implementation of the new criminal system implied a profound change in several institutions: a) the criminal courts, b) the general prosecution office; c) the national defense office; and d) all other state agencies that support criminal investigations. In order to design this transition the Comisión Interinstitucional para la Implantación del Sistema Penal Acusatorio (a governmental Commission responsible for the implementation of the accusatory system) open up a bidding. Uniandes in a temporal Union with the Instituto SER de Investigación, won this call for tenders. This paper briefly describes the way this multidisciplinary effort was done under the direction of the industrial engineering department. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
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113. Efectividad sistémica, integración y desarrollo empresarial en Colombia a través del Sistema Nacional de Innovación.
- Author
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Vargas Guerrero, Germán Eduardo
- Subjects
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SYSTEM analysis , *EMPIRICAL research , *SOCIAL networks , *POLICY sciences , *ANALYTIC mappings - Abstract
This paper proposes an approaching focus from systems point of view, and empirical observation from the social networks design for the National Innovation System (NIS), through a typological and situational mapping that illustrate the articulation degree in the system, which from build a system dynamics model for the policy exploration, pointed to stimulate systemic efficiency of NIS. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
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114. Generación de modelos reducidos para micro-actuadores electrostáticos.
- Author
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Ávila, Alba G. and Villarraga, Carlos E.
- Subjects
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SIMULATION methods & models , *METHODOLOGY , *MODELS & modelmaking , *ELECTROSTATICS , *SYSTEMS engineering - Abstract
The computational cost and complexity level of multiphysics analysis used in microsystems have demanded the creation of methodologies to create simplified models that provide accurate results in a fast and efficient way. These simplifications are known as the reduced order model (ROM) extraction. The ROM model captures lineal and nolineal behaviors accurately, in addition such a model is generated in a form that can be integrated into system level simulators. This paper introduces perhaps the most famous method to generate ROM models at the present. The method is applied to the analysis of a micro clamped-clamped beam electrostatically actuated, for this structure different simulations are performed; these analyses characterize the deflection of the structure for different kinds of voltage excitations. The outcomes demonstrate that sophisticated analysis can be carried out almost immediately once the ROM model is created. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
115. Implementación y análisis de un modelo estocástico de despacho de vehículos de transporte masivo.
- Author
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Riaño, Germán and Acero, Juan Camilo
- Subjects
- *
TRAVEL time (Traffic engineering) , *TRAFFIC surveys , *SIMULATION methods & models , *STOCHASTIC processes , *TRAFFIC engineering - Abstract
In this paper we describe the implementation of a single-route city-bus timetabling LP model proposed by Riaño [15]. The aforementioned model considers stochastic issues like travel time and demand. A simulation model is also described, which was used to compare results from this model with others proposed in the literature. Preliminar results are promising. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
116. REVISIÓN DE LAS EMISIONES DE MATERIAL PARTICULADO POR LA CUMBUSTIÓN DE DIESEL Y BIODIESEL.
- Author
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Rojas, Néstor Y.
- Subjects
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AIR pollution , *EMISSIONS (Air pollution) , *DIESEL automobile emissions , *DIESEL automobiles , *BIODIESEL fuels - Abstract
This paper shows a review of studies comparing particulate emissions from diesel engines running on diesel, biodiesel and their blends, based not only on particle mass concentrations, but also on particle number concentrations and particulate chemical composition. Finally, it summarizes the need for thoroughly characterizing particulate matter emissions in studies comparing Colombian diesel and biodiesel from palm oil (or other oil-producing Colombian species). [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
117. DETECCIÓN SEMIATOMÁTICA DE CONTORNOS EN IMÁGENES DE ECOCARDIOGRAFÍA MODO M.
- Author
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Lamus G-H., Camilo, Nieto P., Elsa M., and Hernández Hoyos, Marcela
- Subjects
- *
SEPTUM (Brain) , *ENDOCARDIUM , *ALGORITHMS , *DETECTORS , *ECHOCARDIOGRAPHY - Abstract
This paper is focused on the extraction of myocardial borders (septum, endocardium and epicardium) on M-mode echocardiograms. The proposed method combines two algorithms, each developed specially to extract certain borders. The extraction of the epicardium is done by means of a basic maximum tracking algorithm [8]. For the extraction of the endocardium and the left wall of the interventricular septum, a 2 stages discontinuity detector [6] is used. In the first stage the local mean of the image is calculated, and for the second stage the local variance is used. The output of this detector represents the discontinuities in the M-mode echocardographic image. Additionally, the method allows for manually correction of errors in the detection. Experimental examples are presented to test the performance of the methodology. [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
118. MODELING THE EVOLUTION OF INTERCONNECTION AGREEMENTS BETWEEN INTERNET SERVICE PROVIDERS.
- Author
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Beltrán, Fernando
- Subjects
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INTERNET service providers , *INTERNET industry , *INTERNET , *INTERNET users - Abstract
This paper presents and analyzes some critical issues aspects at stake in the South American Internet access market. We present the prevalent interconnection schemes for the exchange of local and regional traffic in the South American region, trying to identify the main incentives large Internet Service Providers or ISPs have for improving the financial conditions under which interconnection agreements occur, usually at the expense of smaller ISPs. In fact, the model of cooperative agreement for the exchange of domestic (national) traffic has been adopted all through the region and the Internet access market has benefited from the cost reduction and the improvement in the quality of service that the operation of a traffic exchange point has brought in each country. Our work has focused on the impact of new forms of interconnection agreements such as secondary peering arrangements and multi-homing on the stability of Internet growth in the region. We use a model of bargaining to identify the threats which the current agreements are currently facing. [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
119. MODELAMIENTO Y CONTROL DE SISTEMAS HÍBRIDOS.
- Author
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Villa, J. L., Duque, M., Gauthier, A., and Rakoto-Ravalontsalama, N.
- Subjects
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MATHEMATICAL models , *SIMULATION methods & models , *PREDICTIVE control systems , *AUTOMATIC control systems , *INFORMATION theory - Abstract
Hybrid systems arise by the interaction between continuous dynamical systems and Discrete-event systems. This paper presents two modeling frameworks for this type of systems, in particular Mixed and Logical Dynamical (MLD) systems is explained. Then, model predictive control using MLD models is presented. The results are applied to a three-tank benchmark system as example. [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
120. ¿INFERENCIA Y RAZONAMIENTO PROBABILÍSTICO O DIFUSO?
- Author
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Torres M., Alvaro and Tranchita R., Carolina
- Subjects
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UNCERTAINTY (Information theory) , *PROBABILITY theory , *FUZZY sets , *INFERENCE (Logic) , *REASONING - Abstract
Data and information analysis, together with the representation and modeling of the uncertainties associated with real world phenomena and reality perception are fundamental tasks in any engineering work. Traditionally, uncertainty has been represented by the probability theory. However, there are uncertainty types which could be better represented by other theories like fuzzy sets, possibility theory and Depster-Shafer theory, among others. This paper describes uncertainty types and the use of fuzzy sets, fuzzy inference and fuzzy reasoning as alternative to well known techniques of probabilistic inference and reasoning when vagueness is present and expert knowledge and experience is to be included in the reasoning system. [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
121. EVALUACIÓN DE VEHÍCULOS EN CARRETERA.
- Author
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Forero Martínez, Juan, Valencia Cruz, Alexander, and Ángela Bedoya, Chris
- Subjects
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STANDARDS , *TESTING , *NATURAL gas , *NATURAL gas vehicles ,MOTOR vehicle testing - Abstract
Vehicle performance road testing is based on international standards, particularly those developed by SAE. The Centro de Investigación en Control Ambiental, Vehículos y Combustibles -- CICOM designed a system capable of testing vehicles according to those standards. The system has already been used on different vehicles. This paper describes the procedure followed in order to perform vehicles tests, the equipment used to perform it, and results from a study done on a vehicle converted to natural gas. [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
122. TRABAJO INTERDISCIPLINARIO EN EL DESARROLLO DE TECNOLOGÍAS DE APOYO A LA DISCAPACIDAD.
- Author
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Bohórquez Reyes, Juan Carlos, De Salazar, Nahir, Garcia Rozo, Antonio, Pinilla, Mario Alberto, and Gonzalez, Mónica Paola
- Subjects
- *
TECHNOLOGY , *LANGUAGE & languages , *LEARNING , *INTERPERSONAL communication , *PEOPLE with disabilities - Abstract
Language capacity, acquiring and learning of other symbolic systems and the development of more elaborate thinking behaviors seem to be improving due to technology that constitutes a platform which allows research and problem resolution for disabled people with communication problems. This paper outlines the results of a interdisciplinary project experience between the Electric Engineering and Industrial Design department of the Los Andes University, and the Pedagogy department of the Pedagogic National University, which focuses on generating functional tool prototypes for people with disabilities. [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
123. COMPORTAMIENTO SÍSMICO Y ALTERNATIVAS DE REHABILITACIÓN DE EDIFICACIONES EN ADOBE Y TAPIA PISADA CON BASE EN MODELOS A ESCALA REDUCIDA ENSAYADOS EN MESA VIBRATORIA.
- Author
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Yamin, Luis E., Rodríguez, Ángel E., Fonseca, Luis R., Reyes, Juan C., and Phillips, Camilo A.
- Subjects
- *
EARTH (Planet) , *SEISMOLOGY , *WIRE netting , *CONSTRUCTION - Abstract
This paper summarizes the main results of a research project carried out to determine the main characteristics and mechanical properties of the structural elements that conform the earth made constructions, and to propose seismic rehabilitation alternatives according to the seismic hazard and characteristics of this kind of structures in Colombia. The proposed seismic rehabilitation alternatives consist of reinforcement with wire mesh covered with lime based mortar, and confining reinforcement with wooden elements. These alternatives were subjected to a series of tests on small specimens, full scale walls loaded on both directions, shaking table tests on 1:5 scale models and cyclic horizontal loading on 1:1.5 house models. The results of the research allow to establish advantages and disadvantages for the rehabilitation alternatives studied. Considering the high seismic vulnerability of earth made constructions, the confining reinforcement with wooden elements was found to be a promising alternative to reduce the seismic risk of this type of constructions. [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
124. METODOLOGÍA PARA LA CONSTRUCCIÓN DE AMBIENTES VIRTUALES COMO SOPORTE PARA LA EDUCACIÓN PRESENCIAL DE LA UNIVERSIDAD DE LOS ANDES.
- Author
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Aldana Vargas, María Fernanda, Arango Muñoz, Martha Luz, Leal Fonseca, Diego Ernesto, López Reyes, Esperanza, Osorio Gómez, Luz Adriana, and Salazar Villegas, Ana María
- Subjects
- *
TEACHING methods , *CURRICULUM - Abstract
The use of virtual media as a support to formal higher education requires a methodology able to support the teacher's specific educative needs and the pedagogical requirements of diverse subjects and knowledge areas. This paper presents the methodology used on the construction of Learning Virtual Environments as a complement to the face to face activities of ten different disciplines courses on the Universidad de los Andes, at Bogotá (Colombia). The procedure and balance of this methodology are part of the reflection contained in this document. [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
125. ¿QUÉ TIENEN DE COMÚN CIERTAS TÉCNICAS ESTADÍSTICAS MULTIVARIADAS CONOCIDAS?
- Author
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Mutis G., Hernando E.
- Subjects
- *
MULTIPLE regression analysis , *MULTIVARIATE analysis , *ANALYSIS of variance , *CANONICAL correlation (Statistics) , *DISCRIMINANT analysis - Abstract
This paper presents the common elements of the multivariate multiple regression, multivariate analysis of variance (manova), canonical correlation analysis and discriminant analysis of canonical variates focusing on the statistical tests and, in some extent, on the mathematics behind the techniques [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
126. CAPACIDAD ÓPTIMA DE PLANTAS INDUSTRIALES.
- Author
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Poveda Ramos, Gabriel
- Subjects
- *
MATHEMATICAL models , *FACTORIES , *INDUSTRIAL capacity , *INDUSTRIAL engineering , *PROJECT management - Abstract
This paper presents a rigorous mathematical method -created by the author- to calculate accurately the optimal size (or capacity) of an industrial plant while it is beeing planned and evaluated. Text-books on Proyect Evaluation, Financial Mathematics and connected subjects do not mention this method neither any othe for solving this important problem in Industrial Engineering. [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
127. ASIGNACIÓN ÓPTIMA DEL ANCHO DE BANDA PARA REDES ATM CONSIDERANDO LA CALIDAD DE SERVICIO.
- Author
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Duque, Catalina Herrera, Rodríguez Guzmán, Johanna Carolina, and Peña, Néstor Misael
- Subjects
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DIGITAL video standards , *ASYNCHRONOUS transfer mode , *VIDEO compression standards , *MPEG (Video coding standard) , *DIGITAL communications , *BROADBAND communication systems - Abstract
In this paper we present a method, which has been denominated off/on-line, its objective is to calculate the reserve of resources (optimal bandwidth) in an ATM network, based on the characteristics of the traffic (MPEG-I video traces with category VBR), the characteristics of the network and certain parameters of quality of service: maximum delay between emitter and receiver and the cell loss rate in the transmission. [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
128. UNA CLASIFICACIÓN DE LAS ZONAS RURALES DE MUNICIPIOS SIN PREDIALIZACIÓN CATASTRAL.
- Author
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Mutis G., Hernando E.
- Subjects
- *
STATISTICAL correlation , *MULTIVARIATE analysis , *CLUSTER analysis (Statistics) , *RANDOM variables , *SPATIAL analysis (Statistics) , *DISCRIMINANT analysis - Abstract
The main purpose of this paper is developing and applying a methodology based on multivariate statistical procedures to endorse a classification of certain rural regions in Colombia. In order to achieve the aims, cluster analyses were the basic procedures made. The techniques of principal components, canonical variates, discriminant analysis and Andrews' plots were used to validate the cluster analyses results. [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
129. COMPORTAMIENTO DE PERFILES DE LÁMINA DELGADA ANTE CARGAS DE COMPRESIÓN AXIAL.
- Author
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Peña Flórez, Elsa Cristina and Yamin L., Luis Eduardo
- Subjects
- *
STEEL , *STRAINS & stresses (Mechanics) , *RESIDUAL stresses , *STRENGTH of materials , *DEFORMATIONS (Mechanics) , *CONSTRUCTION , *METAL fatigue , *HEAT treatment of metals - Abstract
This paper presents results of experimental tests of thin walled steel columns under pure axial loading. Twelve different elements in terms of slender factors were tested. Typical failure modes correspond to expected ones such as global or local buckling. Ultimate axial compression stresses were compared with analytical expressions given by the national building code, Norma Colombiana de Diseño y Construccion Sismo Resistente, NSR-98, presenting a relatively good agreement of results. Fabrication details as well as residual stresses play an important role when estimating axial strength of thin walled steel columns. [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
130. EL TEOREMA DE INGRESO EQUIVALENTE PARA SUBASTAS DE UN OBJETO: APROXIMACIÓN EXPERIMENTAL.
- Author
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Beltrán, Fernando, Santamaría, Natalia, Restrepo, Camilo, and Cardoso, Pamela
- Subjects
- *
AUCTIONS , *PRICES , *COST , *TRANSACTION costs , *COMMERCE , *BIDDERS , *BREAK-even analysis ,REVENUE - Abstract
Auctions are price setting mechanisms that reduce transaction costs. In addition, auctions are efficient mechanisms because the winner will have the object to its best use. This paper presents the results of extensive simulated experimentation to observe and test the results given by the Revenue Equivalence Theorem. The Theorem says that all members of a certain family of auctions with some defined properties yield the same expected revenue to the seller. The auctions studied are Sad Losers, Santa Claus, All Pay, and Last Pay; these auctions satisfy the assumptions needed for the results of the Theorem to be valid. [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
131. GENERACIÓN DE ENERGÍA ELÉCTRICA CON TURBINAS WELLS.
- Author
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Santa, Alfredo, Lozano, Marco, and Pinilla, Alvaro E.
- Subjects
- *
WELLS , *TURBINES , *WATER waves , *HYDRAULIC machinery , *TELECOMMUNICATION systems - Abstract
The present article, briefly, describes the theoretical design procedure of Wells turbines, typically utilized in Pneumatic Wave Energy Conversion Systems (PWECS). The principle behind the PWECS consists of extracting the pneumatic energy caused by an oscillating water column by the entrance of water waves in enclosed spaces. The paper establishes the design and experimental testing of a small permanent magnet generator suited for the wells turbine under development. The adequate matching between the Wells turbine and the generator has been conceived as a portable 50w d.c. electricity generation device; to be used, either, to powering telecommunications systems in military operations or to power navigation aids in rivers or at sea [ABSTRACT FROM AUTHOR]
- Published
- 2002
- Full Text
- View/download PDF
132. GENERACIÓN DE FUENTES SINTÉTICAS DE TRÁFICO DE VIDEO VBR MPEG.
- Author
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Ramírez Fajardo, José Luis and Peña Traslaviña, Néstor Misael
- Subjects
- *
MPEG (Video coding standard) , *DIGITAL video standards , *VIDEO compression standards , *MARGINAL distributions , *DISTRIBUTION (Probability theory) - Abstract
This paper presents a methodology for implementation of synthetic of VBR MPEG video traffic, that also of model the marginal distribution capture in a high grade the pres ent correlations in the empirical video traffic traces. It realizes an statistical and simulation comparison with empirical and synthetic traces. In the simulation its compare the parameters of performance of a system conformed for a buffer finite and an ATM link of output with empirical and synthetic traffic input. Its evidence that temporal dependence is the characteristic limitative of the models of generation of synthetic traffic. [ABSTRACT FROM AUTHOR]
- Published
- 2002
- Full Text
- View/download PDF
133. LA ACUMULACIÓN DE BASURAS COMO MATERIAL GEOTÉCNICO II: COMPORTAMIENTO DE LAS BASURAS.
- Author
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Espinosa Silva, Augusto and González García, Alvaro
- Subjects
- *
HAZARDOUS wastes , *LANDSLIDES , *SANITARY landfills , *ENGINEERS , *MECHANICS (Physics) - Abstract
Human wastes constitute an evergrowing by-product of civilization. Several catastrophic landslides have taken place in these so-called sanitary land fills. It is apparent that geotechnical and environmental engineers follow divergent paths to solve the related technical problems. Part I of this paper addresses the development of mechanical sciences leading to Soil Mechanics (1925) and Rock Mechanics (1960). Part II is dedicated to show how these sciences and arts are applied to huge accumulations of garbage of what could be referred to as anthropic wastes. [ABSTRACT FROM AUTHOR]
- Published
- 2001
- Full Text
- View/download PDF
134. EXPLORACIÓN GEOFÍSICA Y MEDIO AMBIENTE.
- Author
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Sarria, Alberto
- Subjects
- *
SEISMIC reflection method , *SEISMOMETRY , *HYDROCARBONS , *GEOPHONE , *GEOPHYSICISTS - Abstract
Seismic surveying for hydrocarbon detection is done in several ways; perhaps the most extended procedure is the reflection method where small charges of seimigel are detonated and reflections are gathered in geophones. The analysis of the records allow the geophysicist to estimate the spatial position of geologic formations that may accumulate hydrocarbons. There is the concern if detonations have some environmental impact. This paper explores it and concludes that if some minimum distances from the explosion to constructions and the like are maintained, there is no possibility to affect the environment. [ABSTRACT FROM AUTHOR]
- Published
- 2001
- Full Text
- View/download PDF
135. LA ACUMULACIÓN DE BASURAS COMO MATERIAL GEOTÉCNICO I: FUNDAMENTOS TÉCNICOS.
- Author
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Espinosa Silva, Augusto and González García, Alvaro J.
- Subjects
- *
SOIL mechanics , *ROCK mechanics , *LANDSLIDES , *ORGANIC wastes , *WASTE management - Abstract
Human wastes constitute an evergrowing by-product of civilization. Several catastrophic landslides have taken place in these so-called sanitary land fills. It is apparent that geotechnical and environmental engineers follow divergent paths to solve the related technical problems. Part I of this paper addresses the development of mechanical sciences leading to Soil Mechanics (1925) and Rock Mechanics (1960). Part II is dedicated to show how these sciences and arts or geomechanics are applied to huge accumulations of garbage of what could be referred to as anthropic waste deposits. [ABSTRACT FROM AUTHOR]
- Published
- 2001
- Full Text
- View/download PDF
136. ASIGNACIÓN DE RUTAS DE VEHÍCULOS PARA UN SISTEMA DE RECOLECCIÓN DE RESIDUOS SÓLIDOS EN LA ACERA.
- Author
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Ayala Rodríguez, Alexander and Gonzáles Butrón, Edgar
- Subjects
- *
REFUSE collection , *WASTE management , *INDUSTRIAL wastes , *REFUSE collection vehicles , *TRANSPORTATION - Abstract
Solid waste collection problems are of increasing concern to expanding cities and sectors with high volumes of waste generation. This paper deals with the optimization of a collection system in the sidewalk for urban sectors. This is a combinatorial problem in which all arcs of a mixed network are traversed, subject to vehicle capacity and time restrictions. A flexible formulation is proposed which works with separate collection and transportation networks. A sequencing scheme to assign routes is also proposed. The performance of the model is analyzed under different scenarios and applied to a collection zone of Bogotá with satisfactory results. [ABSTRACT FROM AUTHOR]
- Published
- 2001
- Full Text
- View/download PDF
137. REPORTE DE LA EXPERIENCIA EN LA REALIZACIÓN DE ENSAYOS DE COMPATIBILIDAD ELECTROMAGNÉTICA SOBRE VENTILADORES MECÁNICOS EN COLOMBIA /Report on electromagnetic compatibility tests on mechanical ventilators in Colombia
- Author
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Manosalva, Omar Ariel Nova and Traslaviña, Néstor Misael Peña
- Published
- 2020
138. CAZADORES DE LA MOLÉCULA PERDIDA: LA APREMIANTE NECESIDAD DE DESCUBRIR NUEVOS FÁRMACOS ANTIVIRALES CONTRA SARS-COV-2 /Hunting an unknown molecule: The compelling need to discover novel antiviral drugs against SARS-CoV-2
- Author
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Vásquez, Andrés Felipe, Orduz, Yasser Hayek, Hurtado, Felipe Sierra, Achenie, Luke E., and Barrios, Andrés González
- Published
- 2020
139. ESTUDIO SOBRE LOS EFECTOS DE VIRTUALIZAR EL CAMPUS COMO ESTRATEGIA PARA MINIMIZAR LOS CONTAGIOS POR SARS-COV-2 PRODUCIDOS EN LOS ESPACIOS ACADÉMICOS /A mathematical modeling approach to study on campus transmission dynamics of SARS-CoV-2
- Author
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Cordovez, Juan Manuel
- Published
- 2020
140. La vivienda en America Latina: revisando estrategias
- Author
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Gilbert, Alan
- Published
- 2011
141. ENERGIA Y PAZ: RETOS PARA LA CONSTRUCCION DE UN NUEVO PAIS RURAL/Energy and peace: challenges for the construction of a new rural country
- Author
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Torres, José Eddy
- Published
- 2019
142. Desafíos en la reducción de riesgos Natech
- Author
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Cruz, Ana Maria
- Subjects
industry ,risk governance ,lcsh:TA1-2040 ,gobernanza de riegos ,chemical accidents ,Natech ,lcsh:Engineering (General). Civil engineering (General) ,industria ,accidentes químicos ,risk management ,gestión de riesgos - Abstract
Natech refers to a conjoint natural and technological hazard or accident. This paper is concerned with Natechs involving hazards arising from the handling, processing and/or storage of hazardous materials, as well as the transportation of oil and gas by pipeline. Risk management of chemical accident hazards has generally been carried out using industrial risk management regulations and practices, engineering safety codes and standards, environmental regulations, and land use planning. However, there is evidence that existing regulations and practices may not be suffcient if the particular conditions associated with Natechs have not been factored in. Awareness of the need to better address Natech risk has been on the rise; nevertheless, this is not refected suffciently in the laws and re-gulations of individual countries, and a general framework for the governance of Natech risk is lacking. This paper provides an overview of Natechs, their characteristics, and the problems associated with Natech risk management. Natech se refere a una asociación entre los peligros naturales y los peligros o accidentes industriales. Este documento se ocupa de Natechs que involucran peligros derivados de la manipulación, procesamiento y/o almacenamiento de materiales peligrosos, así como del transporte del petróleo y el gas por oleoductos o gasoductos, respectivamente. En general la gestión de riesgos de accidentes químicos se ha hecho a través de normas y prácticas de gestión de riesgos industriales, códigos de ingeniería y estándares de seguridad, regulaciones ambientales y planifcación del uso de la tierra. Sin embargo, hay evidencia que la existencia de regulaciones y prácticas seguras no son sufcientes si las condiciones específcas asociadas a Natechs, no se tienen en cuenta. La conciencia de abordar mejor el riesgo Natech ha ido en aumento; no obstante, esto no se ha refejado lo sufciente en las normas y regulaciones de cada país y en general hay una ausencia de un marco general para la gobernanza del riesgo Natech. Este artículo propone una visión general de los riegos Natech, sus características y los problemas asociados con su manejo.
- Published
- 2013
143. Challenges in Natech Risk Reduction
- Author
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Ana Maria Cruz
- Subjects
History ,Engineering ,Polymers and Plastics ,business.industry ,Corporate governance ,Land-use planning ,Chemical accident ,Hazard ,Industrial and Manufacturing Engineering ,Industrial risk ,Risk analysis (engineering) ,Hazardous waste ,Operations management ,Business and International Management ,business ,Risk management - Abstract
Natech refers to a conjoint natural and technological hazard or accident. This paper is concerned with Natechs involving hazards arising from the handling, processing and/or storage of hazardous materials, as well as the transportation of oil and gas by pipeline. Risk management of chemical accident hazards has generally been carried out using industrial risk management regulations and practices, engineering safety codes and standards, environmental regulations, and land use planning. However, there is evidence that existing regulations and practices may not be suffcient if the particular conditions associated with Natechs have not been factored in. Awareness of the need to better address Natech risk has been on the rise; nevertheless, this is not refected suffciently in the laws and re-gulations of individual countries, and a general framework for the governance of Natech risk is lacking. This paper provides an overview of Natechs, their characteristics, and the problems associated with Natech risk management.
- Published
- 2012
144. Diez mitos que debilitan la política de vivienda en Latinoamerica/Ten Myths Undermining Latin American Housing Policy
- Author
-
Alan Gilbert
- Subjects
arriendo./Housing ,Vivienda ,subsidy ,pobreza ,poverty ,lcsh:TA1-2040 ,política gubernamental ,renting ,lcsh:Engineering (General). Civil engineering (General) ,subsidio ,government policy - Abstract
La política de vivienda de Latinoamérica no puede considerarse como un gran éxito. Las cifras oficiales muestran que el déficit de vivienda está incrementando en la mayoría de países. Por su puesto, resolver el problema de la vivienda es un asunto difícil, y el rápido crecimiento urbano junto con los altos niveles de pobreza hacen que sea aún más complicado. Sin embargo, hay muchas fallas en la política de vivienda actual, y este artículo identifica diez mitos que han infiltrado el léxico de la política de vivienda. Este artículo es una invitación a los gobiernos de la región para que consideren si alguno de los mitos identificados, o todos, aún persisten dentro de sus propias políticas, y si estos mitos son tan nocivos como se sugiere en este artículo. Housing policy in Latin America cannot be regarded as having been a huge success. Official figures show that the housing deficit is rising in most countries. Of course, solving the housing problem is difficult and complicated further by rapid urban growth and too much poverty. Nonetheless, there are many failings in current housing policy and the current paper identifies ten myths that have infiltrated the housing policy lexicon. This paper is an invitation to the region's governments to consider whether any or all of the identified myths persist within their own policies and whether those myths are as damaging as will be suggested here.
- Published
- 2011
145. Modelo de cálculo de demanda de potencia eléctrica en sistemas de tracción tipo metro, tren y tranvía
- Author
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Gabriel García and Mario A. Rios
- Subjects
rectifier substation ,traction effort ,Physics ,History ,Polymers and Plastics ,Electric power demand ,Demanda de potencia eléctrica ,esfuerzo de tracción ,Industrial and Manufacturing Engineering ,subestación rectificadora. / Diverse demand ,electric power demand ,lcsh:TA1-2040 ,demanda diversificada ,Business and International Management ,lcsh:Engineering (General). Civil engineering (General) ,Humanities - Abstract
Los sistemas eléctricos de transporte masivo (SETM) se han convertido en una de las alternativas para solucionar los problemas de movilidad en zonas urbanas o interurbanas. En este artículo, se presenta la teoría que permite modelar y determinar la demanda de potencia eléctrica de los SETM, la cual sirvió de base para el desarrollo de un modelo computacional. El artículo presenta dos ejemplos de aplicación, una línea de tranvía y una línea de metro, de donde se pueden observar requerimientos del suministro de energía de estos SETM a los sistemas de distribución eléctrica. / The Electrified Mass Rapid Transit Systems (EMRTS) are one of the possible alternatives in solving mobility problems in urban and interurban areas. In this paper, we present the theory which allows modeling and determination of the EMRTS electric load, which serves as a base for the development of a computing model. The paper presents two examples of application: a tramway line and a subway line, from which we can observe the energy supply requirements of these EMRTS to the electric distribution system.
- Published
- 2010
146. Aproximación a una ontología para lenguajes de modelado gráfico
- Author
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Patricia Carmona, Byron Portilla, Carlos Mario Zapata, Duvan Gómez, Marcela Naranjo, and Gloria Lucía Giraldo
- Subjects
History ,Diagrama ,model ,Polymers and Plastics ,Philosophy ,lenguaje de modelado gráfico ,lenguajes de modelado ,modelo ,WebML ,Industrial and Manufacturing Engineering ,UML ,graphical modeling languages ,lcsh:TA1-2040 ,ontología ,ontology ,Business and International Management ,SysML ,lcsh:Engineering (General). Civil engineering (General) ,Humanities ,modeling languages ,WebML. Diagram - Abstract
UML, SysML y WebML son lenguajes de modelado gráfico (LMG) similares que no se pueden interpretar conjuntamente, pues tienen diferencias en tipos de modelos y diagramas. En la literatura se encuentran técnicas que estudian las características de algunos LMG, pero se aplican sobre lenguajes particulares, sin considerar sus características comunes. En este artículo se propone el diseño e implementación de una ontología que resuma los principales conceptos y relaciones de los LMG, utilizando una metodología creada en la Universidad de Stanford. La ontología desarrollada responde 35 preguntas de competencia, de las cuales algunas se ejemplifican en el artículo./ UML, SysML, and WebML are graphical modeling languages (GML). Despite their similarities, these languages can not be jointly interpreted, since they exhibit different kinds of models and diagrams. Some studies for examining the features of some GML are proposed in the state of the art, but applied to individual languages, avoiding the common features among such languages. In this paper, we propose an ontology design and implementation for summarizing GML concepts and relations. We use a methodology created in the Stanford University. The developed ontology can successfully answer 35 competence questions, some of them exemplified in this paper.
- Published
- 2009
147. Aplicativo computacional para la planeación de la producción en una empresa fabricante de autopartes
- Author
-
Gonzalo Mejía and Andrea Hernández
- Subjects
plan maestro de la producción ,History ,Engineering ,Polymers and Plastics ,Operations research ,business.industry ,MRP ,scheduling ,Scheduling (production processes) ,sistemas de apoyo a la decisión. Decision support systems ,master plan scheduling ,Industrial and Manufacturing Engineering ,Production planning ,Master production schedule ,lcsh:TA1-2040 ,Service level ,Customer satisfaction ,Business and International Management ,lcsh:Engineering (General). Civil engineering (General) ,business ,programación de producción - Abstract
Este trabajo describe el desarrollo de un aplicativo computacional para la planeación y secuenciación de la producción en una empresa colombiana fabricante de autopartes. El aplicativo integra pronósticos de ventas y órdenes en firme para calcular el plan maestro de producción, que se secuencia en la planta de producción. Un caso de estudio muestra la funcionalidad de la aplicación propuesta y compara los resultados de las secuencias propuestas con las que resultaron de las prácticas actuales. Los resultados muestran que la implementación del aplicativo puede mejorar los niveles de servicio y la satisfacción del cliente si se cumplen ciertos prerrequisitos descritos en el artículo. / This paper describes the development of a computer application for production planning and scheduling in a Colombian auto part company. Such an application integrates sales forecasts and firm orders, to calculate a Master Production Schedule which is validated with a detailed shop floor scheduling plan. A case study illustrates the functionality of the proposed application and compares the computer-calculated production plans with the current practices. The results show that the implementation of the application can improve service levels and customer satisfaction, given some prerequisites described in the paper are met.
- Published
- 2008
148. Clasificación y detección de fallas en Sistemas Dinámicos
- Author
-
Javier Hernando Pardo Mayorga and Alain Gauthier Sellier
- Subjects
método LAMDA de clasificación ,Adaptive Observers ,History ,LAMDA classification Method ,Polymers and Plastics ,Principal Components Analysis ,Linear Matrix inequalities ,Industrial and Manufacturing Engineering ,LAMDA Classification Method ,Observadores adaptivos ,lcsh:TA1-2040 ,Observadores adaptivos./ Principal Components Analysis ,Desigualdades Lineales Matriciales ,Business and International Management ,lcsh:Engineering (General). Civil engineering (General) ,Analisis de Componentes Principales ,Análisis de Componentes Principales - Abstract
En los sistemas dinámicos se pueden presentar fallas en cualquier instante de tiempo, estas fallas pueden ser generadas en gran cantidad de casos por la variación de uno o más parámetros de la planta o del sistema dinámico. En este trabajo se propone la detección de fallas en una planta no lineal de dos tanques acoplados uno con área constante y otro variable con la altura esto basado en observadores adaptivos, sustentado con clasificación LAMDA y análisis de componentes principales. Se presenta la aplicación del algoritmo en un sistema no lineal, control del nivel en un sistema de tanques acoplados, así como el análisis de resultados conclusiones y perspectivas futuras./ In the dynamic systems a fail can occur in any moment, the fail can be present for variations in one or more parameter of the dynamic system. This paper present a fail detection in a non linear system compose by two tanks in parallel one with constant transversal area and the other one with variable area, the work is develop with adaptive observers and LAMDA classification. The application on this paper is in a non linear system, the level control in the two tank system.
- Published
- 2006
149. Análisis del comportamiento dinámico-acústico y comprobación computacional para el diseño de flautas traversas
- Author
-
Eduardo Perilla Castillo and Álvaro Enrique Pinilla Sepúlveda
- Subjects
Aeroacústica ,History ,Polymers and Plastics ,lcsh:TA1-2040 ,Flauta ,Business and International Management ,CFD Computational Fluid Dynamics ,lcsh:Engineering (General). Civil engineering (General) ,Industrial and Manufacturing Engineering - Abstract
El presente artículo muestra la evaluación y diseño de una flauta traversa tradicional a través de análisis experimentales y computacionales de ingeniería. Este trabajo requirió del estudio de los parámetros dinámicos y acústicos que gobiernan el comportamiento de este tipo de instrumento. Una flauta, como instrumento musical, debe tener ciertas cualidades sonoras y anatómicas para una ejecución placentera por parte del ejecutante así como por el oyente. El estudio de la generación de vórtices causada por la entrada de aire en el tubo se encontró ser de gran importancia, como se muestra en este articulo. Criterios básicos de diseño son presentados para la mejora y construcción de instrumentos musicales de viento, tales como órganos de tubo, quenas y ocarinas, solo por nombrar algunos. / This paper shows the evaluation and design of traditional traverse flute through experimental and computational engineering analysis. This work required the study of the dynamic and acoustic parameters that govern the behavior of this type of instrument. A flute, as a musical instrument, must have certain sonorous and anatomical qualities for a pleasant performance by the player, as well as to the listener. The study of vortex generation caused by air entrainment in the tube is found to be of great importance, as it is shown in this paper. Basic engineering design criteria are presented for the improvement and construction of wind musical instruments, such as pipe-organs, quenas, ocarinas, to quote just a few.
- Published
- 2004
150. Estrategias estatales para el mejoramiento de la red terciaria
- Author
-
Fernando Andrade, Luis
- Published
- 2017
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