Mostrando ítems 1359-1378 de 1587

S-curve and landscape maps for the analysis of trends on industrial textile wastewater treatment

Urbina-Suarez, Nestor Andres; Angel-Ospina, Astrid C.; Lopez-Barrera, German Luciano; Barajas Solano, andres F; Machuca-Martínez, Fiderman (Environmental Advances, 2024-01-18)

The textile industry is one of the most important and economically significant industries in the world. China is the largest textile producer, for countries such as India, Pakistan, Bangladesh and Malaysia this sector is ...
El saber administrativo: Entre teorías y modas

Arenas Pérez, Luz Stella; Ordoñez Santos, Mary Luz (Revista EspaciosVenezuela, 2016)

Este artículo es producto del proyecto de investigación denominado Enfoques Cognitivos y modelos teóricos de los procesos investigativos en el campo de las Ciencias Administrativas; hace un recorrido por el desarrollo ...
Saber, manipulación y poder. La universidad como institución social

MURCIA PEÑA, NAPOLEON; AMBOA SUAREZ, AUDIN ALOISO (El Ágora UsbMedellín, Colombia, 2015-01-26)

El texto es una reflexión sobre la universidad como institución social, realizada a partir de varios estudios desarrollados en cuyos hallazgos se evidencia, en primer lugar, el interés de algunas estancias por convertirla ...
Satisfacción laboral de los docentes: un análisis desde los factores extrínsecos e intrínsecos

Avendaño Castro, William Rodrigo; luna, henry; rueda vera, gerson (Revista Venezolana de GerenciaCaracas, Venezuela, 2021-08-07)

La satisfacción laboral se constituye en un elemento identificador del ambiente de trabajo, la productividad y de la motivación en cualquier tipo de organización o institución, al respecto, este artículo presenta un análisis ...
School success in mathematics and the impact on interpersonal relations

GALLARDO PÉREZ, HENRY DE JESÚS; Vergel Ortega, Mawency; Santiago Carrillo, M C (Journal of Physics: Conference Series, 2019-02-13)

Students who are excellent in their academic performance face challenges and difficulties associated with the social relationships they develop when living within the school environment. In similar studies, there are ...
School success in mathematics and the impact on interpersonal relations

SANTIAGO CARRILLO, MARTHA CECILIA; Vergel Ortega, Mawency; GALLARDO PÉREZ, HENRY DE JESÚS (Journal of Physics: Conference SeriesBogota , Colombia, 2019-02-13)

Students who are excellent in their academic performance face challenges and difficulties associated with the social relationships they develop when living within the school environment. In similar studies, there are ...
School success, attitude towards science and interpersonal relations

SANTIAGO CARRILLO, MARTHA CECILIA; Paz Montes, Luisa Stella; Vergel Ortega, Mawency (Logos Ciencia & TecnologíaBogota , Colombia, 2018-08-01)

Students who are excellent in their academic performance face challenges and difficulties associated with the social relationships they develop when living within the school environment. In similar studies, there ...
Scientific competencies around the study of physics in secondary school students. A review of knowledge

HERNANDEZ SUAREZ, CESAR AUGUSTO; luna, henry; Avendaño Castro, William Rodrigo (Journal of Physics: Conference Series, 2020-12-01)

This research seeks to analyze the degree of promotion and development of scientific competences based on the document Basic Standards of Competences in Natural Sciences proposed by the Ministerio de Educación Nacional, ...
Scientific skills in the physics learning process. A pilot study in secondary education

Avendaño Castro, William Rodrigo; HERNANDEZ SUAREZ, CESAR AUGUSTO; Aloiso, Audin (Journal of Physics: Conference Series, 2020-12-16)

The objective of this article is to identify the competencies of students studying the subject of natural sciences - physics at the high school level, in accordance with the curricular guidelines of the Ministerio de ...
Scientometric analysis of research on emissions control from 2007 to 2017

Acevedo Peñaloza, Carlos Humberto; Valencia, Guillermo; Cardenas Escorcia, Yulineth; Quiñones, Diego H.; Camargo Vanegas, Josué (International Journal of Applied Engineering ResearchColombia, 2018-01)

A scientometric analysis of the production of scientific publications on emissions control from 2007 to 2017 was carried out. HistCite was used to analyze information collected from Web of Science (WoS) on this topic during ...
Scientometric analysis of research on eSports from 2007 to 2017

Camargo Vanegas, Josué; Cárdenas-Gutiérrez, Javier Alfonso; Valencia Ochoa, Guillermo (Contemporary Engineering SciencesBulgaria, 2018-08-30)

A scientometric analysis about eSports publications from 2007 to 2017 was carried out. HistCite was used to analyze the data collected from Web of Science during the period mentioned. The results suggest that eSports ...
Sector del calzado en contextos de frontera: un análisis desde la tasa de cambio y el EBITDA en la rentabilidad del patrimonio

GUARDIOLA PLAZAS, LUIS FERNANDO; rueda vera, gerson; Avendaño Castro, William Rodrigo (Revista EspaciosVenezuela, 2020-06-18)

El presente artículo de investigación muestra un análisis sobre la relación entre la tasa de cambio, la rentabilidad del patrimonio y el Earnings Before Interest, Taxes, Depreciation, and Amortization, (EBITDA) del sector ...
SEED: A software tool and an active-learning strategy for data structures courses

Adarme Jaimes, Marco Antonio; Jabba Molinares, Daladier (Computer Applications in Engineering EducationEstados Unidos, 2018-03-13)

SEED is a software tool designed for Java consisting of a class library and a set of simulators to facilitate learning of the main data structures. The educational component is based on an active case-solving methodology ...
Seguridad vial y procesos psicológicos: acciones preventivas

Riaño-Garzón, Manuel; Raynaud Prado, Nathalie Claire; DIAZ-CAMARGO, EDGAR (Revista Logos Ciencia & TecnologíaColombia, 2017-01-01)

El artículo revisa la relación entre los procesos psicológicos y la seguridad vial desde una postura preventiva con el fin de proporcionar evidencias sobre alternativas utilizadas en terapia que puedan ser de utilidad para ...
SEMGROMI—a semantic grouping algorithm to identifying microservices using semantic similarity of user stories

Vera-Rivera, F. H.; Puerto Cuadros, Eduard Gilberto; PEREZ GUTIERREZ, BORIS RAINIERO; Astudillo, Hernán; Gaona, Carlos (PeerJ Computer Science, 2023-05-12)

Microservices is an architectural style for service-oriented distributed computing, and is being widely adopted in several domains, including autonomous vehicles, sensor networks, IoT systems, energy systems, telecommunications ...
A Semi-Physical Modeling of the Combustion Chamber and Inlet Manifold of a 2 MW Natural Gas Generation Engine

Valencia Ochoa, Guillermo; Duarte Forero, Jorge; Acevedo Peñaloza, Carlos Humberto (International Review on Modelling and SimulationsItalia, 2020-02)

This article presents a sensitivity analysis based on a validated model of average value in natural gas generation engines under the phenomenologically based semi-physical modeling methodology, which includes both the ...
Sensitivity analysis and multi-objective optimization of the energy, exergy and thermo-economic performance of a Brayton supercritical CO2-ORC configurations

VALENCIA OCHOA, GUILLERMO; Villada Castillo, Dora Clemencia; Mendoza-Casseres, Daniel (Energy Reports, 2023-03-25)

The following research compared some energy, exergetic and thermo-economic indicators of a supercritical CO2 simple Brayton cycle integrated with a simple organic Rankine cycle (SORC), and a regenerative organic Rankine ...
Sensitivity analysis applied to the thermodynamic diagnosis of combustion in a diesel engine with DIAGNO-DIESEL® software

Espinel Blanco, Edwin; Cárdenas-Gutiérrez, Javier Alfonso; Romero Garcia, Gonzalo (International Review of Mechanical EngineeringItalia, 2020-06)

At present, in order to mitigate the environmental impact of internal combustion machines and to increase their efficiency, it is necessary to carry out thermodynamic studies to predict their mechanical, thermal, and ...
Servidor web y punto de acceso basado en un sistema embebido para la supervisión de un proceso desde una aplicación móvil con sistema operativo Android

Celis Peñaranda, José Miguel; Sepúlveda Mora, Sergio B.; Escobar Amado, Christian David; Castro Casadiego, Sergio A. (IngeniumColombia, 2016-03-14)

Para monitorizar el proceso de control en una intersección semafórica, es decir, el encendido de cada una de las luces, el historial de los fallos presentados y la notificación en caso de un nuevo daño, se diseñó un sistema ...
Shaft pump power - effect of pipe network configuration

Obregon, Luis; Espinel Blanco, Edwin; Acevedo Peñaloza, Carlos Humberto (International Journal on Energy ConversionItalia, 2020-05)

Building design has often many engineering challenges to achieve the best possible energy and economic efficiencies. It is necessary to use technological tools capable of predicting with a high degree of accuracy the ...

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S-curve and landscape maps for the analysis of trends on industrial textile wastewater treatment
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Urbina-Suarez, Nestor Andres | 2024-01-18

The textile industry is one of the most important and economically significant industries in the world. China is the largest textile producer, for countries such as India, Pakistan, Bangladesh and Malaysia this sector is of crucial importance and it is also a growing sector in Latin America. This industry is responsible for 10 % of annual global carbon emissions and 20 % of global wastewater. This figure is worrying as this wastewater is highly recalcitrant, which has led to research into different treatment methods that are efficient and can provide a sustainable solution to this problem. The aim of this literature review was to identify the existing methods for the treatment of dry scrubber wastewater (TWWT) and the effects of this wastewater and its composition, focusing on biological, chemical and physicochemical processes from the point of view of advantages and disadvantages. It was analyzed which are the most important scientific areas of TWWT and which countries are the most important in this field, as well as the primary pollutants and TWWT processes. Finally, this analysis provides a context for current trends in TWWT research. In general, coagulation methods have been found to be fast but present difficulties due to the use of toxic coagulants; advanced oxidation processes (AOPs) are positioned as very effective methods that can disinfect and decontaminate these effluents. Currently, biological systems coupled with AOPs are a growing trend. Microalgae and cyanobacteria processes coupled with AOPs have attracted great interest due to the possibility of obtaining high added value products through the biorefining of biomass.

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El saber administrativo: Entre teorías y modas
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Arenas Pérez, Luz Stella | 2016

Este artículo es producto del proyecto de investigación denominado Enfoques Cognitivos y modelos teóricos de los procesos investigativos en el campo de las Ciencias Administrativas; hace un recorrido por el desarrollo histórico en los aportes teóricos y la práctica administrativa, en un intento por mostrar la producción de saberes. Este análisis histórico documental aborda desde el enfoque hermenéutico, la respuesta sobre la forma cómo ha avanzado la disciplina y los determinantes que actúan simultáneamente o en varias direcciones y que privilegian la búsqueda y generación de un nuevo conocimiento en este campo, donde los resultados dan cuenta de un auge en las llamadas modas administrativas a partir de las década de los ochenta con una amplia diversidad conceptual respecto al ideal teórico de la práctica administrativa, en un inevitable “nudo gordiano cognitivo” para quienes defienden el carácter científico de la teoría que legitima la generación de nuevos conocimientos en las ciencias administrativas.

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Saber, manipulación y poder. La universidad como institución social
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MURCIA PEÑA, NAPOLEON | 2015-01-26

El texto es una reflexión sobre la universidad como institución social, realizada a partir de varios estudios desarrollados en cuyos hallazgos se evidencia, en primer lugar, el interés de algunas estancias por convertirla en un escenario de manipulación y control, reduciéndola a la racionalidad de los organismos funcionales, frente a la dinámica propia que la universidad instaura como institución social cuya base se moviliza desde las significaciones imaginarias sociales. En este proceso, sen muestra desde la lógica de la teoría de los imaginarios sociales, la forma como la universidad se configura e institucionaliza en una tensión constante, entre el saber y el control, entre la función y la institución y se dan las bases que la definen y posicionan como institución imaginaria social.

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Satisfacción laboral de los docentes: un análisis desde los factores extrínsecos e intrínsecos
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Avendaño Castro, William Rodrigo | 2021-08-07

La satisfacción laboral se constituye en un elemento identificador del ambiente de trabajo, la productividad y de la motivación en cualquier tipo de organización o institución, al respecto, este artículo presenta un análisis de la satisfacción laboral de docentes en una institución de educación de básica y media ubicada en la región del Catatumbo, en el departamento de Norte de Santander, en consideración de los factores intrínsecos y extrínsecos que impactan en el ejercicio docente. La orientación metodológica estuvo determinada por el paradigma cuantitativo – descriptivo. Se utilizó como técnica de recolección de datos la encuesta compuesta por un cuestionario con 33 ítems que abordan los factores extrínsecos e intrínsecos que afectan la satisfacción laboral en el ejercicio de su profesión a los docentes La muestra estuvo representada por 58 docentes y los resultados del estudio muestran que un porcentaje importante de los docentes encuestados tienen una postura de rechazo ante la baja remuneración económica y a las limitadas oportunidades de ascenso que ofrece el sistema educativo colombiano. Se concluye que los docentes han tenido algún tipo de afectación en su satisfacción laboral debido al cambio de la enseñanza presencial a la asistida por tecnologías digitales.

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School success in mathematics and the impact on interpersonal relations
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GALLARDO PÉREZ, HENRY DE JESÚS | 2019-02-13

Students who are excellent in their academic performance face challenges and difficulties associated with the social relationships they develop when living within the school environment. In similar studies, there are limitations such as the identification of the variables involved without reaching the level of correlation in the educational experience. The main objective of this research is to evaluate the impact of high academic performance on the interpersonal relationships of young adolescents in the I.E. College of the Sacred Heart of Jesus. The methodology used responds to the mixed approach, in the quantitative field follows a correlational method, from the qualitative field follows an ethnographic method, is designed for three phases and applies the instruments of the Davis empathy test (IRI), interview and non-participant observation. The results obtained show that there is a significant relationship between the academic success of the students and the quality of the relationships they have with their classmates, in general they tend to be less emotional and interested in cultivating significant bonds.

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School success in mathematics and the impact on interpersonal relations
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SANTIAGO CARRILLO, MARTHA CECILIA | 2019-02-13

Students who are excellent in their academic performance face challenges and difficulties associated with the social relationships they develop when living within the school environment. In similar studies, there are limitations such as the identification of the variables involved without reaching the level of correlation in the educational experience. The main objective of this research is to evaluate the impact of high academic performance on the interpersonal relationships of young adolescents in the I.E. College of the Sacred Heart of Jesus. The methodology used responds to the mixed approach, in the quantitative field follows a correlational method, from the qualitative field follows an ethnographic method, is designed for three phases and applies the instruments of the Davis empathy test (IRI), interview and non-participant observation. The results obtained show that there is a significant relationship between the academic success of the students and the quality of the relationships they have with their classmates, in general they tend to be less emotional and interested in cultivating significant bonds.

LEER
School success, attitude towards science and interpersonal relations
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SANTIAGO CARRILLO, MARTHA CECILIA | 2018-08-01

Students who are excellent in their academic performance face challenges and difficulties associated with the social relationships they develop when living within the school environment. In similar studies, there are limitations such as the identification of the variables involved without reaching the level of correlation in the educational experience. The main objective of this research is to evaluate the impact of high academic performance on the interpersonal relationships of young adolescents in the I.E. College of the Sacred Heart of Jesus. The methodology used responds to the mixed approach, in the quantitative field follows a correlational method, from the qualitative field follows an ethnographic method, is designed for three phases and applies the instruments of the Davis empathy test (IRI), interview and nonparticipant observation. The results obtained show that there is a significant relationship between the academic success of the students and the quality of the relationships they have with their classmates, in general they tend to be less emotional and interested in cultivating significant bonds. Nowadays it is essential to consider in a holistic way the educational experience of the new generations, especially before the possibility of forming integral and well-being human beings that can be assertive in front of the obstacles of the future

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Scientific competencies around the study of physics in secondary school students. A review of knowledge
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HERNANDEZ SUAREZ, CESAR AUGUSTO | 2020-12-01

This research seeks to analyze the degree of promotion and development of scientific competences based on the document Basic Standards of Competences in Natural Sciences proposed by the Ministerio de Educación Nacional, Colombia, specifically the competences associated with Physics. To this end, a twenty-item questionnaire is designed with a dichotomous response scale. The reliability analysis showed that the proposed scale had a good internal consistency regarding the measurement of scientific competences. The research adopts a quantitative descriptive approach based on the processing of data provided by 87 students from a private educational institution with emphasis on natural sciences in the city of San José de Cúcuta and enrolled between the ninth and eleventh grades. The results identify as a weakness in the teaching process, that teachers do not promote the use and articulation of diverse registers of semiotic representation of a set of data, a situation that limits the process of reasoning and resolution of problematic situations in everyday scenarios where the concepts of physics are present. Likewise, it was observed as a strength that teachers promote attitudinal skills in their students based on mutual respect, cooperative work and good communication. This type of research expands the knowledge that is available on the process of developing scientific competencies in the courses prior to entering higher education, so it is suggested to replicate this research process in students from different social contexts in order to improve the robustness of the questionnaire and provide valuable information to educational institutions on the design of improvement plans.

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Scientific skills in the physics learning process. A pilot study in secondary education
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Avendaño Castro, William Rodrigo | 2020-12-16

The objective of this article is to identify the competencies of students studying the subject of natural sciences - physics at the high school level, in accordance with the curricular guidelines of the Ministerio de Educación Nacional de Colombia. Methodologically, it was based on a quantitative design, using a student perception survey. The results show, from the students' point of view, that the teachers have knowledge of their discipline, but the follow-up and improvement of their pedagogical practice at the curricular, didactic and evaluation levels is questioned. It is questioned that the processes related to research and the scientific method are not linked to their classes, so that the students' level of competences is not the ideal one according to what is established from the curricular orientations at a national level.

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Scientometric analysis of research on emissions control from 2007 to 2017
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Acevedo Peñaloza, Carlos Humberto | 2018-01

A scientometric analysis of the production of scientific publications on emissions control from 2007 to 2017 was carried out. HistCite was used to analyze information collected from Web of Science (WoS) on this topic during this period. The results suggest that scientific publications in this field have steadily increased over the years during the last decade. China is the country with the highest number of publications, and the Chinese Academy of Sciences represents the institution with the highest number of publications. Most of the papers and citations came from developed countries. The top three journals with highest number of papers in this field are Applied Physics Letter, Atmospheric Environment, and Environmental Science & Technology.

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Scientometric analysis of research on eSports from 2007 to 2017
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Camargo Vanegas, Josué | 2018-08-30

A scientometric analysis about eSports publications from 2007 to 2017 was carried out. HistCite was used to analyze the data collected from Web of Science during the period mentioned. The results suggest that eSports research has increased during the 11 years of study; the country with the highest number of publications was the United States of America, with eight institutions predominant in the number of publications. Most of the articles and the highest local score of total citations come from countries where eSports are considered sport; the top three journals with the most publications were International Journal of Gaming and Computer-Mediated Simulations, Games and Culture and Psychology of Sport and Exercise, where the top three journals with the highest TLCS are Games and Culture, New Media & Society and Computers in Human Behavior.

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Sector del calzado en contextos de frontera: un análisis desde la tasa de cambio y el EBITDA en la rentabilidad del patrimonio
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GUARDIOLA PLAZAS, LUIS FERNANDO | 2020-06-18

El presente artículo de investigación muestra un análisis sobre la relación entre la tasa de cambio, la rentabilidad del patrimonio y el Earnings Before Interest, Taxes, Depreciation, and Amortization, (EBITDA) del sector calzado en Cúcuta – Colombia en el periodo 2008 – 2014. Asimismo, se presenta las percepciones de empresarios sobre el estado de esta actividad comercial en la ciudad fronteriza. La investigación es descriptiva - correlacional, con un diseño no experimental y de campo, realizado en una muestra de 13 empresas. Los resultados evidencian que el EBITDA confirmó las variaciones del Return on Equity (ROE) en mayor porcentaje que la tasa de cambio COP/Bs, mientras que la tasa de cambio COP/US$ no mostró incidencia alguna en el ROE.

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SEED: A software tool and an active-learning strategy for data structures courses
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Adarme Jaimes, Marco Antonio | 2018-03-13

SEED is a software tool designed for Java consisting of a class library and a set of simulators to facilitate learning of the main data structures. The educational component is based on an active case-solving methodology accompanied by a pedagogical strategy. This strategy allows for the development of a multilayer-model-programming work for the construction of basic and advanced applications in real domains and for integration of its use, development and operation assessment with data structures. The evaluation results of SEED as a pedagogical mediator in the issue of binary trees is presented. The evaluation indicates that students prefer to use SEED due to its simplicity and attractive GUIs which facilitate data structures learning.

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Seguridad vial y procesos psicológicos: acciones preventivas
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Riaño-Garzón, Manuel | 2017-01-01

El artículo revisa la relación entre los procesos psicológicos y la seguridad vial desde una postura preventiva con el fin de proporcionar evidencias sobre alternativas utilizadas en terapia que puedan ser de utilidad para el adecuado funcionamiento psico-fisiológico y que determinen una mayor Seguridad Vial. Dicha revisión resulta pertinente en el marco de la Policía Nacional y de la Seguridad Vial en tanto ilustra metodologías empíricamente validadas que pueden ser utilizadas por las personas que desarrollen labores de alto esfuerzo cognitivo como la conducción. Con el fin de desarrollar la temática propuesta, se revisarán las nociones iniciales de la accidentalidad en tránsito dando paso a la revisión de los procesos cognoscitivos implicados en la seguridad vial citando algunos estudios empíricos que dan cuenta de métodos de utilidad en el incremento de las capacidades del conductor. Se concluye la efectividad de métodos basados en estimulación cognoscitiva y bioretroalimentación para el fortalecimiento de procesos cognoscitivos especialmente atencionales, advirtiendo la relación directamente proporcional entre la capacidad atencional y la seguridad al conducir.

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SEMGROMI—a semantic grouping algorithm to identifying microservices using semantic similarity of user stories
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Vera-Rivera, F. H. | 2023-05-12

Microservices is an architectural style for service-oriented distributed computing, and is being widely adopted in several domains, including autonomous vehicles, sensor networks, IoT systems, energy systems, telecommunications networks and telemedicine systems. When migrating a monolithic system to a microservices architecture, one of the key design problems is the “microservice granularity definition”, i.e., deciding how many microservices are needed and allocating computations among them. This article describes a semantic grouping algorithm (SEMGROMI), a technique that takes user stories, a well-known functional requirements specification technique, and identifies number and scope of candidate microservices using semantic similarity of the user stories’ textual description, while optimizing for low coupling, high cohesion, and high semantic similarity. Using the technique in four validation projects (two state-of-the-art projects and two industry projects), the proposed technique was compared with domain-driven design (DDD), the most frequent method used to identify microservices, and with a genetic algorithm previously proposed as part of the Microservices Backlog model. We found that SEMGROMI yields decompositions of user stories to microservices with high cohesion (from the semantic point of view) and low coupling, the complexity was reduced, also the communication between microservices and the estimated development time was decreased. Therefore, SEMGROMI is a viable option for the design and evaluation of microservices-based applications. The proposed semantic similarity-based technique (SEMGROMI) is part of the Microservices Backlog model, which allows to evaluate candidate microservices graphically and based on metrics to make design-time decisions about the architecture of the microservicesbased application.

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A Semi-Physical Modeling of the Combustion Chamber and Inlet Manifold of a 2 MW Natural Gas Generation Engine
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Valencia Ochoa, Guillermo | 2020-02

This article presents a sensitivity analysis based on a validated model of average value in natural gas generation engines under the phenomenologically based semi-physical modeling methodology, which includes both the cylinder, exhaust, and intake manifold and it can define the average operational variables and thermochemical properties of exhaust gases as a function of the variables instrumented in this type of engine at the industrial level. The results for a month of operation showed errors no greater than 5% in the temperature at the entrance of the cylinders (Temperature 6), while the power, load temperature and load pressure of the model presented deviations of less than 2% from the measured data. Additionally, the results of the sensitivity analysis evidenced that the main variable affecting most of the parameters under study is the flow of gas entering the engine, which causes a variation of 12.3% in Temperature 6, and 22.4% in electrical power. Next, the second most influential variable is Lambda, significantly affecting the efficiency by 8%. Finally, there is the RPM of the engine in its work cycle, which affects the temperature of the cylinder outlet by 34.5%. This means that when the flow of fuel in the engine decreases, there will be significant operational changes in the engine, and therefore in the thermal availability of exhaust gases.

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Sensitivity analysis and multi-objective optimization of the energy, exergy and thermo-economic performance of a Brayton supercritical CO2-ORC configurations
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VALENCIA OCHOA, GUILLERMO | 2023-03-25

The following research compared some energy, exergetic and thermo-economic indicators of a supercritical CO2 simple Brayton cycle integrated with a simple organic Rankine cycle (SORC), and a regenerative organic Rankine cycle (RORC). A thermodynamic model was developed to determine the net power, thermal efficiency, the fuel consumption, and the exergy destruction of all the components of the system. Also, a thermo-economic model was developed to determine some economic indicators such as the levelized cost of energy (LCOE), the payback period (PBP) and specific investment cost (SIC). A sensitivity analysis was carried out to study the influence of the primary turbine inlet temperature (TIT), the high-pressure in the compressor (PHigh), the evaporator pinch point temperature difference (PPT), and the pressure ratio (Pr) on the indicators performance. Three different working fluids were selected in this study: acetone, toluene and cyclohexane. The results showed that cyclohexane had the best energy performance giving an efficiency of 48.02% for the RORC system. Besides, it presented the best thermo-economic results for the LCOE (0.26 USD/kWh), SIC (2626.75 USD/kWh), and a PBP (11.2 years). Finally, a multi-objective optimization was developed based on energy, exergy and thermoeconomic performance parameters as objective functions to obtain a technical and economic feasible solution able to implement them in industrial applications

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Sensitivity analysis applied to the thermodynamic diagnosis of combustion in a diesel engine with DIAGNO-DIESEL® software
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Espinel Blanco, Edwin | 2020-06

At present, in order to mitigate the environmental impact of internal combustion machines and to increase their efficiency, it is necessary to carry out thermodynamic studies to predict their mechanical, thermal, and environmental behavior under different operational conditions. Within the thermodynamic modeling of thermal machines, it is necessary to carry out a process of characterization of the device under study. This article proposes a methodology for the characterization of 4JJ1 Isuzu Diesel engines applying combustion diagnosis, where the pressure signal in the combustion chamber is input, which is measured experimentally based on the angle of the crankshaft and how Exit the heat release curve. A motored procedure, in which the heat transfer process has been adjusted to the combustion chamber walls of the engine under study, has been performed. With this characterization, it has been verified that the change in 10% of the heat transfer adjustment coefficient in the chamber leads to a maximum change of 0.8% in the heat release rate through a sensitivity analysis of the developed model. The mass retained at the closing of the admission has a more pronounced effect, where a 10% change in this variable causes a 4.2% change in the heat release rate. A 10% change in the compression ratio has been observed, causing a maximum change of 6.1% in the heat release rate. Changes in the constants for piezoelectric transducer measurement, pressure level reference and crank angle measurement result in less than 5% change in maximum heat release rate values estimated by the diagnostic model.

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Servidor web y punto de acceso basado en un sistema embebido para la supervisión de un proceso desde una aplicación móvil con sistema operativo Android
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Celis Peñaranda, José Miguel | 2016-03-14

Para monitorizar el proceso de control en una intersección semafórica, es decir, el encendido de cada una de las luces, el historial de los fallos presentados y la notificación en caso de un nuevo daño, se diseñó un sistema de supervisión integrado por un servidor web y una aplicación móvil que ha sido desarrollada siguiendo la metodología propuesta por la comunidad de desarrolladores Android. Se utilizó el sistema embebido Raspberry Pi B+, configurándose como punto de acceso, y creando una red de área local mediante el estándar de comunicación inalámbrica IEEE 802.11n. Los resultados obtenidos evidencian la capacidad del sistema embebido usado para procesar múltiples tareas orientadas a las telecomunicaciones; la importancia y las ventajas que brinda utilizar tareas asíncronas al momento de desarrollar una aplicación móvil que ejecute varios procesos; y la escalabilidad que ofrece para un proyecto integrar un servidor web, servidor de base de datos, acondicionador de señales y punto de acceso en un mismo dispositivo.

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Shaft pump power - effect of pipe network configuration
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Obregon, Luis | 2020-05

Building design has often many engineering challenges to achieve the best possible energy and economic efficiencies. It is necessary to use technological tools capable of predicting with a high degree of accuracy the behavior of a pipe network system in order to obtain good designs that avoid problems in the future. This study is focused on the analysis of three pipe networks with different floors and the same configuration on each level. Four case studies have been developed in order to analyze the energy requirements and the outlet pressure of a pump for multiple pipe diameters, various floors, and fluid flow rates. The effects of the pipe diameter and the flow rate on the energy cost have been also analyzed. It has been observed that an increase in the flow rate in a pipeline of one inch of diameter causes a huge increase in the pump power when working on the net with a single floor. In addition, it has been found out that the higher the number of the floors is, the higher the pump powder is. However, this effect has not been significant when using pipelines with high diameters. Besides, it has been found out that the higher the number of the floors is, the higher the pressure drop in the system is. This effect is highly significant when using pipelines with small diameters. The total pump power cost had an exponential decay with the increase in pipe diameter.

LEER