Now showing items 1-20 of 1328

    • Development of a first 3D crustal velocity model for the region of Bogotá, Colombia 

      Riaño, Andrea C.; Reyes, Juan C.; Yamin, Luis E.; Montejo, Julian S.; Bustamante, Jose L.; Bielak, Jacobo; Pulido, Nelson; Molano, Carlos E.; Huguett, Alcides
      Knowledge regarding the characteristics of soils in Bogotá basin has been possible to get through previous microzonation studies. However, there is still insufficient knowledge of the crustal velocity structure of the ...
      Universidad Nacional de Colombia Revistas electrónicas UN Ingeniería e Investigación. 
    • A Linear Criterion to sort Color Components in Images 

      Rodriguez, Leonardo Barriga; Hernandez, Hugo Jimenez; Cajiga, Jorge Alberto Soto; Balanzar, Luciano Nava; Barbosa, Jose Joel Gonzalez; Espinosa, Alfonso Gomez; Ortega, Jesus Carlos Pedraza
      The color and its representation play a basic role in Image Analysis process. Several methods can be beneficial whenever they have a correct representation of wave-length variations used to represent scenes with a camera. ...
      Universidad Nacional de Colombia Revistas electrónicas UN Ingeniería e Investigación. 
    • Determination of pedestrian displacement velocity for ground exploration programs 

      Ochoa Gutierrez, Luis Hernán; Hernandez Pardo, Orlando; Martinez Martinez, Luis Joel
      In Engineering and Geophysics field exploration, uncertainty for determination of the velocity of ground data acquisition due to extreme topographic conditions has been underestimated in the calculation of the displacement ...
      Universidad Nacional de Colombia Revistas electrónicas UN Ingeniería e Investigación. 
    • Mechanical characterization of porous asphalt mixes modified with fatty acid amides -FAA- 

      Senior Arrieta, Vanessa; Córdoba Maquilon, Jorge Eliecer
      Porous asphalt mixes (PAM), form a special road surface for asphalt pavement structures, have a special particle size distribution that lets infiltrate to the runoff storm water through of it because of its voids content ...
      Universidad Nacional de Colombia Revistas electrónicas UN Ingeniería e Investigación. 
    • A CMOS Micro-power, Class-AB “Flipped” Voltage Follower using the quasi floating-gate technique 

      Ocampo-Hidalgo, Juan Jesus; Vázquez-Álvarez, Iván; Sandoval-Perez, Sergio; Garcia-Lozano, Rodolfo; Gurrola-Navarro, Marco; Molinar-Solis, Jesus Ezequiel
      This paper presents the design and characterization of a new analog voltage follower for low-voltage applications. The main idea is based on the “Flipped” Voltage Follower and the use of the quasi-floating gate technique ...
      Universidad Nacional de Colombia Revistas electrónicas UN Ingeniería e Investigación. 
    • Model-based implementation of self-configurable intellectual property modules for image histogram calculation in FPGAs 

      Garcés Socarrás, Luis Manuel; Romero Ares, Daniel Alejandro; Cabrera Sarmiento, Alejandro José; Sánchez Solano, Santiago; Brox Jiménez, Piedad
      This work presents the development of self-modifiable Intellectual Property (IP) modules for histogram calculation using the modelbased design technique provided by Xilinx System Generator. In this work, an analysis and a ...
      Universidad Nacional de Colombia Revistas electrónicas UN Ingeniería e Investigación. 
    • Pre-conceptual-schema-based patterns for deriving key performance indicators from strategic objectives 

      Zapata Jaramillo, Carlos Mario; Castro Rojas, Luis Fernando
      Performance measurement is crucial for achieving business success. Moreover, such success is also related to the fulfillment of the organizational strategic objectives. Hence, an adequate determination of relevant performance ...
      Universidad Nacional de Colombia Revistas electrónicas UN Ingeniería e Investigación. 
    • Determination of leachate toxicity through acute toxicity using Daphnia pulex and anaerobic toxicity assays 

      Torres Lozada, Patricia; Carabalí Rivera, Yazmín Stefhany; Barba Ho, Luz Edith
      The municipal solid waste (MSW) of large cities, in particular in developing countries, is mainly disposed of in landfills (LFs), whose inadequate management generates the emission of greenhouse gases and the production ...
      Universidad Nacional de Colombia Revistas electrónicas UN Ingeniería e Investigación. 
    • Weed recognition by SVM texture feature classification in outdoor vegetable crops images 

      Pulido Rojas, Camilo; Solaque Guzmán, Leonardo; Velasco Toledo, Nelson
      This paper presents a classification system for weeds and vegetables from outdoor crop images. The classifier is based on support vector machine (SVM) with its extension to nonlinear case using radial basis function (RBF) ...
      Universidad Nacional de Colombia Revistas electrónicas UN Ingeniería e Investigación. 
    • A new monitoring and characterization system of partial discharges based on the analysis of the spectral power 

      Ardila Rey, Jorge Alfredo; Albarracín Sánchez, Ricardo; Robles, Guillermo
      Partial Discharges (PD) are one of the possible causes for unexpected faults in power systems equipment, so that its measure is an essential tool for high-voltage electrical equipment maintenance. In order to characterize ...
      Universidad Nacional de Colombia Revistas electrónicas UN Ingeniería e Investigación. 
    • Comparison of maintenance scheme effects on power transformer reliability performance 

      Duran Tovar, Ivan Camilo; Rosero Zuñiga, Laura Sofia; Pavas Martínez, Andrés; Duarte Velasco, Oscar Germán
      Power transformer failures have a significant impact on electrical systems reliability, as they compromise the electricity delivery. Failures impact the operational cost of electric utilities as they endanger the accomplishment ...
      Universidad Nacional de Colombia Revistas electrónicas UN Ingeniería e Investigación. 
    • Steady state signatures in the time domain for nonintrusive appliance identification 

      Jimenez, Yulieth; Duarte, Cesar; Petit, Johann; Meyer, Jan; Schegner, Peter; Carrillo, Gilberto
      Smart Grid paradigm promotes advanced load monitoring applications to support demand side management and energy savings. Recently, considerable attention has been paid to Non-Intrusive Load Monitoring to estimate the ...
      Universidad Nacional de Colombia Revistas electrónicas UN Ingeniería e Investigación. 
    • Validation of a non-uniform meshing algorithm for the 3D-FDTD method by means of a two-wire crosstalk experimental set-up 

      Jiménez-Mejía, Raúl Esteban; Herrera Murcia, Javier Gustavo
      This paper presents an algorithm used to automatically mesh a 3D computational domain in order to solve electromagnetic interaction scenarios by means of the Finite-Difference Time-Domain -FDTD-  Method. The proposed ...
      Universidad Nacional de Colombia Revistas electrónicas UN Ingeniería e Investigación. 
    • Analytical and experimental discussion of a circuit-based model for compact fluorescent lamps in a 60Hz power grid 

      Malagon, Gabriel Alexis; Bello Peña, Jeisson; Ordóñez Plata, Gabriel; Duarte Gualdrón, Cesar
      This article presents an analysis and discussion on the performance of a circuit-based model for Compact Fluorescent Lamps (CFL) in a 120V 60Hz power grid. This model is proposed and validated in previous scientific ...
      Universidad Nacional de Colombia Revistas electrónicas UN Ingeniería e Investigación. 
    • Electrical Performance of Distribution Insulators with Chlorella vulgaris Growth on its Surface 

      Rojas-Cubides, Herbert Enrique; Pérez, Carlos Daniel; León, Andrés Felipe; Cantor, Luis Felipe
      This paper presents a study about electrical performance of ceramic and polymeric insulators bio-contaminated with alga Chlorella vulgaris. The performed tests involve ANSI 55-2 and ANSI 52-1 ceramic insulators and ANSI ...
      Universidad Nacional de Colombia Revistas electrónicas UN Ingeniería e Investigación. 
    • Proposal for an automatic system correlation between failures on electrical distribution lines and atmospheric lightning discharges 

      Henao Céspedes, Vladimir; Cano Plata, Eduardo Antonio; Díaz Cadavid, Luis Fernando
      This paper presents a proposal for the development of an automatic system correlation between two variables, one represented by the failures on the electrical distribution lines during a storm process and another one ...
      Universidad Nacional de Colombia Revistas electrónicas UN Ingeniería e Investigación. 
    • Auto-tuning of PV controllers to improve the speed response and stability of the P and O algorithm 

      Ortiz Valencia, Paula Andrea; Ramos Paja, Carlos Andrés
      This paper proposes an auto-tuning control system to ensure a fast response of the photovoltaic (PV) voltage by reducing the perturbation time of a P and O algorithm. This solution accelerates the tracking of the maximum ...
      Universidad Nacional de Colombia Revistas electrónicas UN Ingeniería e Investigación. 
    • Harmonic distortion in public low-voltage grids Comparison of the situation in Colombia and Germany 

      Blanco Castañeda, Ana María; Meyer, Jan; Pavas, Fabio Andrés; Garzón, Camilo Andrés; Romero, Miguel Fernando; Schegner, Peter
      Current and voltage harmonic levels in LV grids depend not only on the harmonic emission of non-linear loads, but also on the characteristics of the grid and the voltage distortion of the upstream grid. Based on several ...
      Universidad Nacional de Colombia Revistas electrónicas UN Ingeniería e Investigación. 
    • Evaluation of the methodologies used to generate random pavement profiles based on the power spectral density: An approach based on the International Roughness Index 

      Goenaga, Boris Jesús; Fuentes Pumarejo, Luis Guillermo; Mora Lerma, Otto Andrés
      The pavement roughness is the main variable that produces the vertical excitation in vehicles. Pavement profiles are the main determinant of (i) discomfort perception on users and (ii) dynamic loads generated at the ...
      Universidad Nacional de Colombia Revistas electrónicas UN Ingeniería e Investigación. 
    • Growth and Production of rice (Oryza Sativa l.) under different fertilization plans with Silicon 

      Alvarez Herrera, Javier Giovanni; Pinzón Gómez, Linda Paola; Vélez, Javier Enrique
      The application of fertilizers to rice crops constitutes a large percentage of productions costs, which in recent years have increased; therefore, it is necessary to implement alternatives that optimize the application and ...
      Universidad Nacional de Colombia Revistas electrónicas UN Ingeniería e Investigación.