Now showing items 1-20 of 1614

    • 3D Modeling and functional analysis of a Spanish historical invention of the nineteenth century for mineral extraction: The Emilina Machine 

      Rojas Sola, José Ignacio; Martínez Escobar, Juan Pedro
      In this paper, we analyze in detail a Spanish historical nineteenth-century invention used for mineral extraction: the Emilina machine. In particular, three-dimensional modeling is performed using software parametric (CATIA ...
      Universidad Nacional de Colombia Revistas electrónicas UN Dyna. 
    • 3D Parametric design and static analysis of the first Spanish winch used to drain water from mines 

      Rojas Sola, José Ignacio; Molino Delgado, Jesús
      En el presente artículo se analiza en detalle la primera máquina malacate desarrollada en España utilizada para la extracción del mineral. Se trata de un privilegio de invención diseñado por Bernave Dombon en 1850. En ...
      Universidad Nacional de Colombia Revistas electrónicas UN Dyna. 
    • A 2-tuple linguistic multi-period decision making approach for dynamic green supplier selection 

      Jiménez Moya, Gerdys Ernesto; Zulueta Véliz, Yeleny
      Green supplier selection aims to choose the best supplier, among several alternatives, taking into account not only traditional criteria such as cost and quality of service or product, but also considering the ability to ...
      Universidad Nacional de Colombia Revistas electrónicas UN Dyna. 
    • A branch and bound hybrid algorithm with four deterministic heuristics for the resource constrained project scheduling problem (RCPSP) 

      Morillo Torres, Daniel; Moreno Velasquez, Luis Fernando; Díaz Serna, Francisco Javier
      This paper addresses the Resource Constrained Project Scheduling Problem (RCPSP). For its solution, a hybrid methodology, which uses a Branch and Bound basic algorithm with dominance rules, is developed and implemented, ...
      Universidad Nacional de Colombia Revistas electrónicas UN Dyna. 
    • A college degree recommendation model 

      Maridueña, Milton; Febles-Estrada, Ailyn
      Selecting a profession suitable to students` expectations implies taking into account multiple factors. Despite its usefulness and high impact, there are shortcomings in current university major recommendation models. Among ...
      Universidad Nacional de Colombia Revistas electrónicas UN Dyna. 
    • A comparative study for the design of rectangular and circular isolated footings using new models 

      Luévanos Rojas, Arnulfo
      This paper presents a comparative study for design of reinforced concrete isolated footings of rectangular and circular form subjected to axial load and bending moments in two directions using new modelsto obtain the most ...
      Universidad Nacional de Colombia Revistas electrónicas UN Dyna. 
    • A comparative study of multiobjective computational intelligence algorithms to find the solution to the RWA problem in WDM networks 

      Montes Castañeda, Bryan; Patiño Garzón, Jorge; Puerto Leguizamón, Gustavo
      This paper presents a comparative study of multiobjective algorithms to solve the routing and wavelength assignment problem in optical networks. The study evaluates five computational intelligence algorithms, namely: the ...
      Universidad Nacional de Colombia Revistas electrónicas UN Dyna. 
    • A comparative study of multiscale representations for spatialspectral classification of hyperspectral imagery 

      Torres-Madronero, Maria Constanza
      Hyperspectral remote sensors acquire data coming from hundreds of narrow bands through the electromagnetic spectrum; this allows the terrestrial and maritime surfaces to be characterized for Earth observation. Hyperspectral ...
      Universidad Nacional de Colombia Revistas electrónicas UN Dyna. 
    • A comparative study of two aging and fusion methods in the synthesis of zeolitic materials from natural clinker 

      Lizcano Cabeza, Jeimer Alexander; Ávila Ascanio, Luis Fernando; Ríos-Reyes, Carlos Alberto; Vargas Fiallo, Luz Yolanda
      A sample of Colombian natural clinker was evaluated as a raw material in a laboratory-scale synthesis of zeolitic materials using two methods of alkaline fusion, followed by two aging methods, and finally hydrothermal ...
      Universidad Nacional de Colombia Revistas electrónicas UN Dyna. 
    • A comparative study on conversion of industrial coal by-products in low sio2 zeolite of faujasite type 

      Ríos Reyes, Carlos Alberto; Oviedo Villamizar, Jenny Andrea; Henao Martínez, José Antonio
      Colombian industrial coal by-products were evaluated as raw materials in the synthesis at laboratory scale of low SiO2 zeolite of faujasite type using an alkaline fusion step followed by the hydrothermal treatment under ...
      Universidad Nacional de Colombia Revistas electrónicas UN Dyna. 
    • A comparative study on slurry erosion behavior of HVOF sprayed coatings 

      Reyes-Mojena, Miguel Ángel; Sánchez-Orozco, Mario; Carvajal-Fals, Hipólito; Sagaro Zamora, Roberto; Camello-Lima, Carlos Roberto
      In actual work, slurry erosion behavior of three different HVOF sprayed cermet coatings has been studied. The coatings were developed using the powders feedstock having WC fine structured sizes, Cr3C2-NiCr 75-25 and ...
      Universidad Nacional de Colombia Revistas electrónicas UN Dyna. 
    • A comparative study tic/tin and tin/cn multilayers 

      Espitia-Rico, Miguel J.; Casiano-Jiménez, Gladys; Ortega-López, César; De la Espriella-Vélez, Nicolás; Sánchez-Pacheco, Luis
      We carried out a comparative study of TiC/TiN and TiN/CN multilayers using the linearized augmented plane wave (LAPW) scheme and density functional theory as implemented in the Wien2k code. Initially, we optimized the ...
      Universidad Nacional de Colombia Revistas electrónicas UN Dyna. 
    • A comparison between expert systems and autonomic computing plus mobile agent approaches for fault management. 

      Gutiérrez Betancur, Sergio Armando; Branch Bedoya, John Willian
      In this article, a revision of literature on application of expert systems to fault management is presented. Then, a new approach, based on the autonomic computing paradigm and mobile agents technology is introduced. The ...
      Universidad Nacional de Colombia Revistas electrónicas UN Dyna. 
    • A comparison of exponential smoothing and neural networks in time series prediction 

      Velásquez Henao, Juan David; Zambrano Pérez, Cristian Olmedo; Franco Cardona, Carlos Jaime
      In this article, we compare the accuracy of the forecasts for the exponential smoothing (ES) approach and the radial basis function neural networks (RBFNN) when three nonlinear time series with trend and seasonal cycle are ...
      Universidad Nacional de Colombia Revistas electrónicas UN Dyna. 
    • A comparison of trajectory granular based algorithms for the location-routing problem with heterogeneous fleet (LRPH) 

      Bernal-Moyano, José Alfonso; Escobar Velasquez, John Willmer; Marín-Moreno, Cesar; Linfati, Rodrigo; Gatica, Gustavo
      We consider the Location-Routing Problem with Heterogeneous Fleet (LRPH) in which the goal is to determine the depots to be opened, the customers to be assigned to each open depot, and the corresponding routes fulfilling ...
      Universidad Nacional de Colombia Revistas electrónicas UN Dyna. 
    • A conceptual trajectory multidimensional model: an application to public transportation 

      Moreno Arboleda, Francisco Javier; Arango Isaza, Fernando
      Currently, thanks to global positioning systems technologies and mobile devices equipped with sensors, a lot of data about moving objects can be collected, e.g., data related with the trajectories which are followed by ...
      Universidad Nacional de Colombia Revistas electrónicas UN Dyna. 
    • A design process for balanced educational video games with collaborative activities 

      Padilla-Zea, Natalia; Medina-Medina, Nuria; Gutiérrez-Vela, Francisco L.; López-Arcos, José R.; Paderewski, Patricia; González-González, Carina S.
      The efficiency of educational video games could be improved through the use of a specific development method that allows them to keep both their educational and recreational goals and maintains their playability. Accordingly, ...
      Universidad Nacional de Colombia Revistas electrónicas UN Dyna. 
    • A displacement-based design method for medium-rise reinforced concrete walls 

      Urrego, Hector; Bonett, Ricardo L.
      In displacement-based design methods some demand considerations, starting from the first mode of vibration, are usually made. However, some authors have called the attention on the importance of taking the higher modes ...
      Universidad Nacional de Colombia Revistas electrónicas UN Dyna. 
    • A first course in software engineering methods and theory 

      Zapata Jaramillo, Carlos Mario; Jacobson, Ivar
      Even though the software engineering curriculum has been designed many times, some problems still remain: the gap between academy and industry, the failure to continuously update the courses, the difficulties for combining ...
      Universidad Nacional de Colombia Revistas electrónicas UN Dyna. 
    • A framework for consistences in association relations between classes in uml 

      Fernández-Ledesma, Javier Dario
      The following article shows the process of building and validating a framework for the management of consistencies in class diagrams in UML, operating specifically on class diagrams, through the application of transformation ...
      Universidad Nacional de Colombia Revistas electrónicas UN Dyna.