Browsing by Author "Vanegas Peralta, Pablo Fernando"

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A procedure for semi-automatic segmentation in OBIA based on the maximization of a comparison index
(SPRINGER VERLAG, 2014-06-30) Auquilla Sangolquí, Andrés Vinicio; Vanegas Peralta, Pablo Fernando
In an Object Based Image Analysis Classification (OBIA) process, the quality of the classification results are highly dependent on segmentation. However, a high number of the studies that make use of an OBIA process find the segmentation parameters by making use of trial-and-error methods. It is clear that a lack of a structured procedure to determine the segmentation parameters produces unquantified errors in the classification. This paper aims to quantify the effects of using a semi-automatic approach to determine optimal segmentation parameters. To this end, an OBIA process is performed to classify land cover types produced by both a manual and an automatic segmentation. Even though the classification using the manual segmentation outperforms the automatic segmentation, the difference is only 2%. Since the automatic segmentation is performed with optimal parameters, a procedure to accurately determine those parameters must be performed to minimize the error produced by a misjudgment in the segmentation step. © 2014 Springer International Publishing.
A subject syllabus similarity analysis to address students mobility issue
(International Institute of Informatics and Systemics, IIIS, 2018) Saquicela Galarza, Víctor Hugo; Baculima Cumbe, John Fernando; Orellana, Gerardo; Orellana, Marcos; Piedra, Nelson; Espinoza Mejía, Jorge Mauricio; Vanegas Peralta, Pablo Fernando; Saquicela Galarza, Víctor Hugo
Currently, students' mobility in Higher Education has become very common and frequent. Although the transitioning process could be thought to be smooth and quick, students moving from one institution to another must go through rigorous and unfortunately, non-standardized academic validation processes. Usually, most part of the process, including credits recognition and syllabi comparison are manually performed, consuming excessive time and massive human effort. Some of these academic processes however, could be optimized by means of computer technologies, which support data processing and help solving real-life problems usually found in the academic field. In the specific case of Ecuador, we have identified that each Higher Education Institution (HEI) manages customized curricular information management systems which include non-standard syllabi structured documents. The existence of custom made formats at every HEI has originate a large variety of data models. In this work, we propose to address these problems by identifying similarities between different current syllabi of Ecuadorian HEIs, aiming to the optimization, integration and improvement of the academic activities related to the students' mobility processes, such as credits recognition. This proposal relies on the definition of a standard data model, which is used to describe the academic syllabus and that allows the implementation of a computer-based system focused on similarities detection through the use of semantic web technologies and text mining tools. Copyright © 2018 by the International Institute of Informatics and Systemics.
Air jet spray of nylon 6 membrane structures for bone tissue engineering
(ELSEVIER, 2014-06-15) Abdal-Hay, A; Vanegas Peralta, Pablo Fernando
A novel porous nylon 6 (N6) scaffold with high and low porosity was designed using a facile, one-step approach. The scaffold samples were prepared using air jet spray (AJS) to obtain high production rates as an alternative low cost, effective technique with precise thickness control. The present results show that AJS adequately produced interconnected porous networks ranging from micron to submicron scales that were observed using a scanning electron microscope. The effect of AJS on the secondary structure of N6 was examined to identify and quantify conformational changes that occurred due to processing. The mechanical properties of the fabricated samples were tested. The results of tensile tests indicated higher tensile strength of AJS scaffold than that of electrospun scaffold. © 2014 Elsevier B.V. All rights reserved.
Algoritmo para gestión de horarios de la Facultad de Ingeniería de la Universidad de Cuenca
(2013) Barrero Barros, Sonia Edith; López Villavicencio, Luis Alberto; Vanegas Peralta, Pablo Fernando
Allocating reforestation areas for sediment flow minimization: an integer programming formulation and a heuristic solution method
(2012) Vanegas Peralta, Pablo Fernando
Policy and decision makers dealing with environmental conservation and land use planning often require identifying potential sites for contributing to minimize sediment flow reaching riverbeds. This is the case of reforestation initiatives, which can have sediment flow minimization among their objectives. This paper proposes an Integer Programming (IP) formulation and a Heuristic solution method for selecting a predefined number of locations to be reforested in order to minimize sediment load at a given outlet in a watershed. Although the core structure of both methods can be applied for different sorts of flow, the formulations are targeted to minimization of sediment delivery. The proposed approaches make use of a Single Flow Direction (SFD) raster map covering the watershed in order to construct a tree structure so that the outlet cell corresponds to the root node in the tree. The results obtained with both approaches are in agreement with expert assessments of erosion levels, slopes and distances to the riverbeds, which in turn allows concluding that this approach is suitable for minimizing sediment flow. Since the results obtained with the IP formulation are the same as the ones obtained with the Heuristic approach, an optimality proof is included in the present work. Taking into consideration that the heuristic requires much less computation time, this solution method is more suitable to be applied in large sized problems.
An educative environment based on ontologies and e-learning for training on design of speech-language therapy plans for children with disabilities and communication disorders
(INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS INC., 2016-11-30) Chuchuca-Mendez, F; Vanegas Peralta, Pablo Fernando
Nowadays several developing countries must to face several problems related with the lack of personnel, resources or adequate health-care structures to attend children with disabilities and communication disorders. Some studies of the World Health Organization (WHO) and other organizations point that in some countries of Africa exists one Speech-Language Pathologist (SLP) per each 2 to 4 million people, whereas in developed countries like United States or Australia the ratio is much higher: One SLP per each 2500 to 4700 people. For these reasons, in this paper we propose an intelligent educative environment aimed to support the training and development of practice skills of the future SLPs. Our proposal relies on ontologies and several e-learning modules and at the moment is able to support the learning process of designing therapy plans. Currently, the ontology that we have designed contains more than 1,005 instances and two tests to evaluate the articulation, and hearing skills on children.
Aplicación de servicios web estándares para el monitoreo hidrometeorológico automático, integrando información de sensores diversos mediante ontologías
(2018) Veintimilla Reyes, Jaime Eduardo; Vanegas Peralta, Pablo Fernando; Estrella Maldonado, René Gustavo
The last developments in worldwide technology and the continuous growth in telecommunications have resulted in the requirement to make available the information generated by a number of devices, especially for those that incorporate sensors, with the goal of reacting to any relevant events that could occur. The latest advances in this area have resulted in the development of several devices with heterogeneous types and from different vendors. This paper presents a proposal for an architecture that integrates several standard web services for the compilation, organization and storage of the information generated by a network of hydrometeorology sensors. Likewise, the paper proposes the application of standard services for controlling remotely these sensors and for managing events and generating early warnings. The aforementioned web services are some examples of the set of services that form the Sensor Web Enablement standard. Considering the diversity, both in type and vendor, that is typically found among the stations and sensors in a hydrometeorology monitoring network, this paper additionally proposes the application of ontologies with the goal of homogenizing and integrating the information coming from this diverse infrastructure.
Artificial neural networks applied to flow prediction: A use case for the Tomebamba river
(Elsevier Ltd, 2016) Veintimilla Reyes, Jaime Eduardo; Cisneros Espinoza, Felipe Eduardo ; Vanegas Peralta, Pablo Fernando; Veintimilla Reyes, Jaime Eduardo
The main aim of this research is to create a model based on Artificial Neural Networks (ANN) that allows predicting the flow in Tomebamba river, at real time and in a specific day of a year. As inputs, this research is using information of rainfall and flow of the stations along of the river. This information is organized in scenarios and each scenario is prepared to a specific area. For this article, we have selected two scenarios. The information is acquired from the hydrological stations placed in the watershed using an electronic system developed at real time and it supports any kind or brands of this type of sensors. The prediction works very good three days in advance. This research includes two ANN models: Backpropagation and a hybrid model between back propagation and OWO-HWO (output weight optimization–hidden weight optimization) to select the initial weights of the connection. These last two models have been tested in a preliminary research. To validate the results we are using some error indicators such as MSE, RMSE, EF, CD and BIAS. The results of this research reached high levels of reliability and the level of error is minimal. These predictions are useful to avoid floods in the city of Cuenca in Ecuador.
Auditoría Informática a la Superintendencia de Telecomunicaciones
(2012) Quintuña Rodríguez, Verónica Karina; Vanegas Peralta, Pablo Fernando
Buscador semántico universitario: caso de estudio Universidad de Cuenca
(2018) Aucapiña Pineda, Yolanda del Carmen; Plaza Villa, Carlos Orlando; Vanegas Peralta, Pablo Fernando; Saquicela Galarza, Víctor Hugo
Semantic technology provides characteristics such as: semantic notation, generation of new knowledge and interoperable data model to resources on web. Through common ontological models that allow linking data and not web pages as in traditional web, by allowing computer to be able to understand the data and return accurate information to users. In University of Cuenca large volumes of data are generated and they have been preserved over time; therefore, the information has been stored in different technologies at the moment, which has led to disintegrated university information both at the level of data models and storage technologies (heterogeneous data sources). In this context, the process to retrieve information from these sources requires considerable time due to the need to perform complex processes to integrate and extract only information useful to the user. As solution to the recovery of information, semantic technology has been used with the purpose of taking advantage of its main features. In this way, an ontological model is developed that represents the university domain, by allowing to integrate data from heterogeneous sources, for later, through the prototype of a single search engine that works on the integration model, extract and visualize information through simple queries write by the user. In addition, several stages carried out for the achievement of the semantic search engine prototype follow proven methodologies, and in some cases are supported by automated processes.
Cardiac Motion Estimation in Magnetic Resonance Images Using Optical Flow
(IEEE COMPUTER SOCIETY, 2016-06-01) Medina Molina, Ruben; Morocho Zurita, Carlos Villie; Vanegas Peralta, Pablo Fernando
This paper reports an optical based method for quantification of cardiac motion in MRI images. The cardiac motion is quantified in a Short-Axis (SAX) slice located at the mid-cavity of the left ventricle. In this slice, the left ventricle wall is segmented for extracting the endocardium, the epicardium and the midwall. The velocity field for these contours is available after performing the optical flow estimation for the given slice. Post-processing of this motion field enables estimation of the radial displacement. The core of this cardiac motion quantification method is a sparse based algorithm for optical flow estimation. This algorithm is presented and compared with several classical optical flow estimation algorithms. The comparison is performed using several video sequences available from the Middlebury benchmark where the ground truth optical flow is known. The algorithms with better performance are also tested using a 4 D cardiac Magnetic Resonance Image (MRI) sequence. Results show that he sparse algorithm estimates an optical flow field that represents the motion of contraction during the systole interval. Moreover, results about radial displacement estimation on real MRI sequences for a normal subject and a patient with hypertrophy show that the proposed quantification method could be useful for quantification of left ventricle motion.
Compactness and flow minimization requirements in reforestation initiatives: A heuristic solution method
(KLUWER ACADEMIC PUBLISHERS, 2014-01-01) Vanegas Peralta, Pablo Fernando; Wijffels Anja, Louisa María
A heuristic solution method to identify a predefined number of cells in raster maps optimizing both multiple intrinsic cell characteristics and cell patch compactness (Vanegas et al. in Lect. Notes Comput. Sci. 5072:389-404, 2008), is extended so that also spatial interaction is taken into account. Spatial interaction is e.g., present in the flow of sediment between cells in a rasterised watershed as modified by the presence or absence of tree cover in a given cell. The resulting HLC-method is elaborated and tested in the context of a site location problem for reforestation in which the following criteria are considered: (1) the sediment flow reaching the outlet of the watershed is minimized, (2) two intrinsic environmental performances of the cells are maximized/minimized, and (3) the selected cells form a compact patch. To evaluate the performance of the HLC, its results are compared to the ones obtained with an Integer Programming (IP) formulation. This comparison suggests that the HLC identifies high quality, near-to-optimal patches of cells and that its computational efficiency makes it applicable to regional sized cases. © 2011 Springer Science+Business Media, LLC.
Diseño e implementación de un sistema de información para la gestión de seguimiento a ex alumnos de la Facultad de Ingeniería
(2015) Alvarado Cárdenas, Andrés Felipe; Vanegas Peralta, Pablo Fernando
ABSTRACT This thesis focuses on the design and implementation of a methodology for establishing a system to monitor graduates. With this, the Faculty of Engineering is expected to begin a process of continuous improvement. This work was based on surveys developed at the University of Pennsylvania, which were translated and modified to suit the needs of the Faculty of Engineering. Additional documentation of different universities that developed and implemented a similar methodology for tracking graduates was revised. With the aim of designing the monitoring methodology, the first step was defining the following focus groups: Alumni, Graduates, Professionals from other universities, Faculty of Engineering Staff, Final year students and Employers. These groups were surveyed through Limesurvey software tool to assess the current curriculum. Next, the methodology for tracking graduates was designed following the Deming cycle. The methodology was applied in a pilot project to collect information using Limesurvey. Alumni, Graduates, Teachers and Students of Last Year were considered for the survey. Using this software helped to reduce the information analysis time and provides results in real time. Finally, the analyzed information gave the level of satisfaction of graduates with undergraduate curriculum and employment of graduates of the Faculty of Engineering. It also allowed evaluating the current curriculum of the Faculty of Engineering.
ECG Multilead QT interval estimation using support vector machines
(2019) Dugarte, Nelson; Medina, Ruben; Cuadrado, Jhosmary; Morocho Zurita, Carlos Villie; Vanegas Peralta, Pablo Fernando
This work reports a multilead QT interval measurement algorithm for a high-resolution digital electrocardiograph. The software enables off-line ECG processing including QRS detection as well as an accurate multilead QT interval detection algorithm using support vector machines (SVMs). Two fiducial points ( and ) are estimated using the SVM algorithm on each incoming beat. This enables segmentation of the current beat for obtaining the P, QRS, and T waves. The QT interval is estimated by updating the QT interval on each lead, considering shifting techniques with respect to a valid beat template. The validation of the QT interval measurement algorithm is attained using the Physionet PTB diagnostic ECG database showing a percent error of with respect to the database annotations. The usefulness of this software tool is also tested by considering the analysis of the ECG signals for a group of 60 patients acquired using our digital electrocardiograph. In this case, the validation is performed by comparing the estimated QT interval with respect to the estimation obtained using the Cardiosoft software providing a percent error of .
Electrical energy conversion system design with single-phase inverter and H5 transformerless topology
(UNIVERSIDAD DE ANTIOQUIA, 2014-01-01) Colina Morles, Eliezer; Sempertegui Alvarez, Rodrigo Efrain; Vanegas Peralta, Pablo Fernando; Gonzalez Morales, Luis Gerardo
This paper presents the design of an electrical energy conversion system (EECS) for the use of solar energy and its conditioning for injection of energy to the commercial power grid. A single-phase full-bridge inverter with transformerless H5 topology coupled to an LCL filter is used. The system is identified using an averaged small-signal state space model; while the used cascade control scheme is tuned by pole placement and includes a maximum power disturb-observe tracking type algorithm of that increases efficiency by operating the system at the optimum operating point of the solar panel. This design describes essential technical aspects in the components sizing and selection for experimental development, as well as the control structure design for a good performance to face systems perturbations.
Energy self-supply estimation in intermediate cities
(2020) Barragán Escandón, Edgar Antonio; Zalamea León, Esteban Felipe; Vanegas Peralta, Pablo Fernando
© 2020 Elsevier Ltd Cities are responsible for more than three quarters of greenhouse gas emissions due to their intensive use of fossil resources. Hence, proposals to modify the current urban energy model have been established. The comprehensive inclusion of renewable energies in the urban area of the intermediate city of Cuenca will be analysed. In previous studies, it was established that five renewable technologies have the greatest opportunities for implementation in the city. Therefore, this research proposes a methodological approach to establish the impact of the inclusion of each of these technologies, and the Long-range Energy Alternative Planning (LEAP) model is used to establish the urban energy balance. Through the construction of scenarios and the evaluation of energy balances, it is concluded that it is possible to reduce the energy flows that enter the city by applying these five energy sources. The results indicate a self-supply potential of up to 33.9% of the total urban consumption; however, due to the type of local energy matrix, only 13% of this energy could be consumed under current conditions, and the remained would be surplus power. Photovoltaic (PV) technology has a significantly higher potential than the other technologies as it exceeds the electricity demand 3.19-fold. The conclusion is that the conversion of currently fuel-powered services to electrical power is necessary to maximize clean self-generation.
Evaluación de métodos heurísticos y matemáticos para la determinación del potencial de generación distribuida con energía fotovoltaica
(2013) Parra González, Diego Alejandro; Vanegas Peralta, Pablo Fernando
The purpose of this study is to evaluate heuristics and mathematical models that can be used for Determining the Potential of Distributed Energy with Photovoltaics, for this purpose used the information available in public, private , freely available on the net, being homogenized in format and length. The chosen study area corresponds to the territory of the Canton Cuenca, for analysis of solar radiation in the month of September 2001 , sources of information such as: InstitutoGeográficoMilitar, CONELEC , satellite data repositories of the area available on the web, meteorological yearbooks INAMHI, ConsejoNacional de Electricidad ( CONELEC ) - Atlas Ecuador Solar Electricity Generation purposes were used. The data were subjected to statistical analysis and geo -statistics to determine their performance and reliability in use established variables of central tendency and semivariogram analysis, methods : Inverse Distance Weighting , Universal Kriging and Natural Neighbor were used. The mathematical model used is that proposed by Suri , M., and J. Hofierka to implement in Geographic Information Systems including statistical analysis, while the heuristic corresponds to the proposal developed by P. Vanegas , Cattrysse D., Van Orshoven J. for analysis for analysis of similar areas in raster maps, and methods as Celular Automata. The results were compared with similar Solar Atlas, one of the limitations of this study is similar projects with existing information analysis in the area, concluding that existing information and methods used are reliable for determining potential areas for generation distributed approach remains as future research involving multiple criteria analysis variables and development stages for generating search areas, buildings or areas are siting.
Evaluación de métodos para la gestión óptima de los embalses Molino y Mazar
(2013) Pineda Alvarez, Daniel Fernando; Vanegas Peralta, Pablo Fernando
Fabrication of 3D bioactive ceramic scaffolds by robocasting
(SPRINGER VERLAG, 2014-10-29) Andrade Cabrera, Santiago Patrico; Abdalla, A; Vanegas Peralta, Pablo Fernando
Tricalcium phosphate ceramics are bioactive and osteoconductive biomaterials that support cellular functions and can develop appropriate mechanical characteristics for bone tissue engineering. Fast prototyping techniques permit to obtain accurate control over scaffolding architecture with high reproducibility. Flexible composites are considered to promote mechano-biological stimulation during cell culture. The aim of this study is to fabricate flexible bioceramic scaffolds by robocasting and to determine biological improvements related to their added flexible properties. Characterized 3D ? - TCP/gelatin scaffolds with interconnected porous structure were fabricated using robocasting. SEM micrographs showed fabricated porous scaffolds with desired pore size (~200 ?m), rods diameter (~840 ?m), porosity and mechanical strength. Alamar Blue assay was performed for static and dynamic cultures along 21 days. Oscillatory flow conditions allowed considerable higher cell proliferation compared with static conditions.
Factores que influyen en la selección de energías renovables en la ciudad
(2019) Barragán Escandón, Edgar Antonio; Zalamea León, Esteban Felipe; Terrados, Julio; Vanegas Peralta, Pablo Fernando
Urban energy models assume that energy is imported from outside the urban area. Forecast increases in urban population and energy use intensity will increase energy requirements. One alternative is to integrate sources of renewable energy within cities boundaries. To do so, differences in urban form, resources availability, energy requirements, condition of buildings, infrastructure, and population and building density make city-specific analysis necessary. This study identifies 14 factors that urban planners should consider to make the most appropriate technology choices for a given city. Through consultation with 78 experts, the presence of renewable energy sources was selected as the most important factor, followed by economic conditions in the city. The least important factors were environmental consequences of global warming, eutrophication and acidification