Now showing items 764-783 of 798

    • Variable control tool in MATLAB for energy transformation processes 

      Cardenas, Y; Carrillo, G E; Alviz, A; Carrillo, G (Cartagena de Indias, 2020-10)
      During the stages of transformation of energy in a process, exercise control over the variables that intervene in it, improve its performance, and identify undesirable conditions in these. Thus, this study is developed as ...
    • Variation in experimentation styles and domain-specific knowledge 

      Córdoba M.; Larreamendy-Joerns J. (2007)
      This study explored the relationship between experimental strategies and domain-specific knowledge within a task of scientific discovery. Groups of expert biologists, experimental psychologists, and lag people in both ...
    • Variational thermodynamics of relativistic thin disks 

      Gutiérrez-Piñeres A.C.; Lopez-Monsalvo C.S.; Quevedo H. (Springer New York LLC, 2015)
      We present a relativistic model describing a thin disk system composed of two fluids. The system is surrounded by a halo in the presence of a non-trivial electromagnetic field. We show that the model is compatible with the ...
    • Vehicle speed estimation using audio features and neural networks 

      Giraldo-Guzman J.; Marrugo A.G.; Contreras-Ortiz S.H. (Institute of Electrical and Electronics Engineers Inc., 2017)
      Many car accidents that result in pedestrian deaths or serious injuries are due to their inattention when crossing the street. Pedestrians often get distracted using mobile phones or music players, what prevents them to ...
    • Vehicular road influence areas 

      Huertas M.E.; Huertas J.I.; Valencia A. (Elsevier Ltd, 2017)
      Vehicle operation over paved and unpaved roads is an emission source that significantly contributes to air pollution. Emissions are derived from vehicle exhaust pipes and re-suspension of particulate matter generated by ...
    • Viable business models for M-commerce: The key components 

      Gan J.; Gutiérrez J.A. (IGI Global, 2011)
      As mobile applications increase in popularity, the issue of how to build viable business models for the m-commerce industry is becoming a clear priority for both organizations and researchers. In order to address this ...
    • Vibration analysis of shear deformable shallow shells using the Boundary Element Method 

      Useche J. (2014)
      In this work, the modal and harmonic analysis of elastic shallow shells, using a Dual Reciprocity Boundary Element formulation, is presented. A boundary element formulation based on a direct time-domain formulation using ...
    • Vibrational response of elastic membranes coupled to acoustic fluids using a BEM–BEM formulation 

      Useche J.; Narvaez A. (Springer New York LLC, 2014)
      In the last two decades, few works have been reported in the literature related to analysis of fluid–structure interaction problems using Boundary Element Method for modeling both structure and fluid. To the author’s ...
    • Virtual lab in Modelica of a cement clinker cooler for operator training 

      Acuña O.; Martin-Villalba C.; Urquia A. (2014)
      Plant operator training plays a fundamental role in improving the energy efficiency of the cement manufacturing process and in reducing the CO2 emission. A virtual lab of a clinker grate cooler, intended for the training ...
    • Viscosity analysis in lubricants through factorial design with three factors 

      Rojas, L.; Hurtado, J.; Rodríguez-Arias, H.A. (Latin American and Caribbean Consortium of Engineering Institutions, 2018)
      In the field of statistics, the experimental design becomes an analysis tool to establish the ideal conditions of a very important process and / or product, analysis of variance it is very useful in cases where there are ...
    • Visual servoing of a five-bar linkage mechanism 

      Mora S.N.; Martinez-Santos J.C. (Institute of Electrical and Electronics Engineers Inc., 2015)
      This paper presents a position-based visual servoing system with fixed camera to control the position of a five-bar linkage mechanism. The document records the goals set, the used methods, the obstacles encountered, the ...
    • Voice compression using discrete cosine transform and wavelet transform 

      Rolon-Heredia J.A.; Garrido-Arevalo V.M.; Marulanda J. (Institute of Physics Publishing, 2019)
      Compressing information, such as voice, allows freeing up memory space, better utilizing bandwidth, in other words taking advantage of resources more efficiently in a time where technologies such as Voice over Internet ...
    • Volatile organic compounds in the atmosphere of Mexico City 

      Garzón, J.P.; Huertas, J.I.; Magaña, M.; Huertas, M.E.; Cárdenas, B.; Watanabe, T.; Maeda, T.; Wakamatsu, S.; Blanco, S. (Elsevier Ltd, 2015)
      The Mexico City Metropolitan Area (MCMA) is one of the most polluted megacities in North America. Therefore, it is an excellent benchmark city to understand atmospheric chemistry and to implement pilot countermeasures. Air ...
    • Voltage and Frequency Regulation on Isolated AC Three-phase Microgrids via s-DERs 

      Amin W.T.; Montoya O.D.; Garrido V.M.; Gil-González W.; Garces A. (IEEE Computer Society, 2019)
      This paper addresses the voltage regulation problem on isolated three-phase microgrids via passivity-based control (PBC) with a proportional regulator under the abc reference frame. This reference frame is employed to ...
    • Voltage regulation of an isolated DC microgrid with a constant power load: a passivity-based control design 

      Magaldi, Guillermo Luciano; Serra, Federico Martin; De Angelo, Cristian Hernán; Montoya, Oscar Danilo; Giral-Ramírez, Diego Armando (Cartagena de Indias, 2021-08-28)
      Passivity-based nonlinear control for an isolated microgrid system is proposed in this paper. The microgrid consists of a photovoltaic array and a battery energy storage connected to a point of common converters, supplying ...
    • Voltage Stability Analysis in Medium-Voltage Distribution Networks Using a Second-Order Cone Approximation 

      Montoya, Oscar Danilo; Gil-González, Walter; Arias-Londoño, Andrés; Rajagopalan, Arul; Hernández, Jesus C. (Cartagena de Indias, 2020-11-02)
      This paper addresses the voltage stability margin calculation in medium-voltage distribution networks in the context of exact mathematical modeling. This margin calculation is performed with a second-order cone (SOCP) ...
    • Voltage stability margin in DC grids with CPLs: A recursive Newton-raphson approximation 

      Montoya, Oscar Danilo; Gil-González, Walter; Garrido, V. M. (Cartagena de Indias, 2019-03-11)
      This express brief addresses the voltage collapse problem in direct-current (dc) networks by using a recursive heuristic search algorithm based on the Newton-Raphson method. The determinant of the Jacobian matrix in the ...
    • Vortex Search Algorithm for Optimal Power Flow Analysis in DC Resistive Networks With CPLs 

      Montoya, Oscar Danilo; Gil-González, Walter; Grisales-Noreña, L.F. (Cartagena de Indias, 2019-08-30)
      This express brief addresses the optimal power flow (OPF) analysis in direct-current (DC) resistive networks with constant power loads (CPLs). The OPF employs the vortex search algorithm (VSA) in conjunction with a power ...
    • Vortex Search Algorithm for Optimal Sizing of Distributed Generators in AC Distribution Networks with Radial Topology 

      Montoya O.D.; Grisales-Noreña L.F.; Amin W.T.; Rojas L.A.; Campillo J. (Springer, 2019)
      This paper proposes a vortex search algorithm (VSA) optimization for optimal dimensioning of distributed generators (DGs), in radial alternating current (AC) distribution networks. The VSA corresponds to a metaheuristic ...
    • Vortex search and Chu-Beasley genetic algorithms for optimal location and sizing of distributed generators in distribution networks: A novel hybrid approach 

      Montoya, Oscar Danilo; Gil-González, Walter; Orozco-Henao, César (Cartagena de Indias, 2020-08-03)
      In this study, we analyzed the optimal location and sizing of distributed generators (DGs) in radial distributed networks using a hybrid master-slave metaheuristic technique. The master stage corresponds to the selection ...