Iván Portnoy - Academia.edu (original) (raw)
Papers by Iván Portnoy
Procedia Computer Science, Dec 31, 2023
Tropical coastal lagoons are valuable ecosystems that provide vital ecological services. Understa... more Tropical coastal lagoons are valuable ecosystems that provide vital ecological services. Understanding vegetation health dynamics is essential to conserve and manage these environments effectively. Also, some landscape-related aspects suffer changes through time due to natural and human-driven factors. Analyzing a landscape's evolution allows getting to know the place's identity and underlying interactions with its population. This study employed satellite imagery from the Landsat 8 mission and advanced data analysis techniques to investigate vegetation health's temporal and spatial patterns in Ciénaga de Mallorquín, a coastal lagoon in Northern Colombia. The normalized difference vegetation index (NDVI) was calculated from the satellite data to quantify vegetation biomass and its health. The results show a significant decline in NDVI values between 2013 and 2018, followed by a recovery phase between 2018 and 2022. However, the NDVI levels in 2022 remain significantly lower than those in 2013, indicating the need for continued conservation efforts. This study demonstrates the power of remote sensing as a tool for monitoring vegetation dynamics and informing sustainable management practices in tropical coastal ecosystems.
Procedia Computer Science, Dec 31, 2023
Procedia Computer Science, Dec 31, 2023
Procedia Computer Science, Dec 31, 2023
Our goal is to understand process innovation activities, constraints, and challenges. Collaborati... more Our goal is to understand process innovation activities, constraints, and challenges. Collaboration and Research and Development (R&D) are vital for innovation, but many Small-and Medium-size Enterprises (SMEs) need to improve on these, necessitating focused efforts. Innovation is linked to growth, productivity, and capacity, demanding new offerings and process improvement. Surveying 56 Colombian exporting SMEs with a 19-question survey, we employed Artificial Neural Network (ANN) models and Spearman correlation for predicting Process Innovation. Scrutinizing requisite activities and their impact is essential for economic growth, allowing SMEs to enhance performance through market-driven innovation. Collaboration with research institutions and suppliers is pivotal, highlighting its importance for process innovation. Process-focused firms emphasize process innovation, while Colombian exporting SMEs prioritize it for competitiveness. Technological learning shapes strategies, and SMEs leverage market innovation. We identified links between R&D/innovation (R&D+I) and export behavior. Innovation aids internationalization despite Colombia's innovation gap. Enterprises invest in R&D+I and external collaboration, while SMEs focus on efficiency. Prospective research should explore interconnections in innovation facets, harnessing machine learning.
To explore sustainable alternatives to meet the growing energy demand worldwide, it is necessary ... more To explore sustainable alternatives to meet the growing energy demand worldwide, it is necessary to analyze strategies promoting the efficient use of energy, the mitigation of environmental impact, the diversification of power resources, and the orientation toward energy transition. Due to their location, Latin America and the Caribbean have a significant renewable energy potential. For instance, Colombia has an installed thermoelectric capacity accounting for over 40% of its total power generation resources. Nevertheless, its legislation promotes the fair transition toward alternative sources while leveraging the installed infrastructure. Additionally, worldwide projections show that hydrogen-based power generation will foster the hybridization of power generation systems. This research addresses the evaluation of four increasingly complex systems, starting with a Combined Cycle Gas Turbine (CCGT), successfully adding subsystems up to a hybrid system comprising a CCGT, a photovoltaic field, a methane reformer with carbon capture, a Proton Exchange Membrane (PEM) electrolyzer, and a hydrogen compression-storage stage. The appraisal is performed with the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS), using technical, economic, sociopolitical, and environmental indicators. We used the Colombian energy market as a case study. The evaluation found that the scenario incorporating all the subsystems achieves the best trade-off across all considered criteria. In nominal conditions, this scenario achieves an overall efficiency of 63.67%, a levelized cost of energy of 0.032 USD/kWh, a carbon footprint of 0.047 kgCO 2 /kWh, and a conventional-to-total power ratio of 70.77%. Integrating electrolysis, reforming with carbon capture for hydrogen generation, and using surplus gas and power reduce CO 2 emissions while increasing profits. Additionally, the combination of hydrogen storage and solar energy enhances overall power generation capabilities. The proposed assessment methodology can be extended to evaluate the viability of similar hybrid systems in other regions and energy markets.
To explore sustainable alternatives to meet the growing energy demand worldwide, it is necessary ... more To explore sustainable alternatives to meet the growing energy demand worldwide, it is necessary to analyze strategies promoting the efficient use of energy, the mitigation of environmental impact, the diversification of power resources, and the orientation toward energy transition. Due to their location, Latin America and the Caribbean have a significant renewable energy potential. For instance, Colombia has an installed thermoelectric capacity accounting for over 40% of its total power generation resources. Nevertheless, its legislation promotes the fair transition toward alternative sources while leveraging the installed infrastructure. Additionally, worldwide projections show that hydrogen-based power generation will foster the hybridization of power generation systems. This research addresses the evaluation of four increasingly complex systems, starting with a Combined Cycle Gas Turbine (CCGT), successfully adding subsystems up to a hybrid system comprising a CCGT, a photovoltaic field, a methane reformer with carbon capture, a Proton Exchange Membrane (PEM) electrolyzer, and a hydrogen compression-storage stage. The appraisal is performed with the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS), using technical, economic, sociopolitical, and environmental indicators. We used the Colombian energy market as a case study. The evaluation found that the scenario incorporating all the subsystems achieves the best trade-off across all considered criteria. In nominal conditions, this scenario achieves an overall efficiency of 63.67%, a levelized cost of energy of 0.032 USD/kWh, a carbon footprint of 0.047 kgCO 2 /kWh, and a conventional-to-total power ratio of 70.77%. Integrating electrolysis, reforming with carbon capture for hydrogen generation, and using surplus gas and power reduce CO 2 emissions while increasing profits. Additionally, the combination of hydrogen storage and solar energy enhances overall power generation capabilities. The proposed assessment methodology can be extended to evaluate the viability of similar hybrid systems in other regions and energy markets.
Our goal is to understand process innovation activities, constraints, and challenges. Collaborati... more Our goal is to understand process innovation activities, constraints, and challenges. Collaboration and Research and Development (R&D) are vital for innovation, but many Small-and Medium-size Enterprises (SMEs) need to improve on these, necessitating focused efforts. Innovation is linked to growth, productivity, and capacity, demanding new offerings and process improvement. Surveying 56 Colombian exporting SMEs with a 19-question survey, we employed Artificial Neural Network (ANN) models and Spearman correlation for predicting Process Innovation. Scrutinizing requisite activities and their impact is essential for economic growth, allowing SMEs to enhance performance through market-driven innovation. Collaboration with research institutions and suppliers is pivotal, highlighting its importance for process innovation. Process-focused firms emphasize process innovation, while Colombian exporting SMEs prioritize it for competitiveness. Technological learning shapes strategies, and SMEs leverage market innovation. We identified links between R&D/innovation (R&D+I) and export behavior. Innovation aids internationalization despite Colombia's innovation gap. Enterprises invest in R&D+I and external collaboration, while SMEs focus on efficiency. Prospective research should explore interconnections in innovation facets, harnessing machine learning.
Cogent Education, Aug 13, 2023
Control Engineering Practice, 2017
The WARP algorithm (Weighted Adaptive Recursive PCA) is a novel recursive adaptation method (Port... more The WARP algorithm (Weighted Adaptive Recursive PCA) is a novel recursive adaptation method (Portnoy et al., 2016) for PCA-based fault detection techniques with a reduced computational complexity suitable for online adaptation required when there is an increase in the false alarm rate in monitoring schemes due to the natural, slow and normal process changes related to model aging and other similar dynamic trends on process behavior. This paper offers a broader discussion on WARP implementation as an adaptive fault detection technique triggered by the outcome of a diagnosis stage and a more comprehensive analysis on the computational complexity reduction it achieves. Furthermore, a comparison on this criterion is made with two state-of-the-art recursive algorithms based on an operation breakdown analysis resulting on WARP exhibiting the best performance, that is the least FLOPs consumption for a complete operating condition update. Finally, clarifies the use of some symbols and provides more implementation details based on feedback received.
Volume 14: Emerging Technologies; Materials: Genetics to Structures; Safety Engineering and Risk Analysis, 2017
Natural gas transmission infrastructure is a large-scale complex system often exhibiting a consid... more Natural gas transmission infrastructure is a large-scale complex system often exhibiting a considerable operating states not only due to natural, slow and normal process changes related to aging but also to a dynamic interaction with multiple agents overall having different functional parameters, an irregular demand trend adjusted by the hour, and sometimes affected by external conditions as severe climate periods. As traditional fault detection relies in alarm management system and operator’s expertise, it is paramount to deploy a strategy being able to update its underlying structure and effectively adapting to such process shifts. This feature would allow operators and engineers to have a better framework to address the online data being gathered in dynamic on transient conditions. This paper presents an extended analysis on WARP technique to address the abnormal condition management activities of multiple-state processes deployed in critical natural gas transmission infrastructu...
Tropical coastal lagoons are valuable ecosystems that provide vital ecological services. Understa... more Tropical coastal lagoons are valuable ecosystems that provide vital ecological services. Understanding vegetation health dynamics is essential to conserve and manage these environments effectively. Also, some landscape-related aspects suffer changes through time due to natural and human-driven factors. Analyzing a landscape's evolution allows getting to know the place's identity and underlying interactions with its population. This study employed satellite imagery from the Landsat 8 mission and advanced data analysis techniques to investigate vegetation health's temporal and spatial patterns in Ciénaga de Mallorquín, a coastal lagoon in Northern Colombia. The normalized difference vegetation index (NDVI) was calculated from the satellite data to quantify vegetation biomass and its health. The results show a significant decline in NDVI values between 2013 and 2018, followed by a recovery phase between 2018 and 2022. However, the NDVI levels in 2022 remain significantly lower than those in 2013, indicating the need for continued conservation efforts. This study demonstrates the power of remote sensing as a tool for monitoring vegetation dynamics and informing sustainable management practices in tropical coastal ecosystems.
Renewable Energy and Power Quality Journal, 2012
It is known that the performance of Diesel engine at partial load is different from the performan... more It is known that the performance of Diesel engine at partial load is different from the performance at full load, but engines manufacturers usually provide only the operation characteristics in the highest efficiency condition. In order to determine the Diesel engine performance at all operation condition an investigation has been conducted. The purpose is to develop a theoretical model based on the iso-consumption curve of the IVECO 8360.46.417 Diesel engine that allows predicting the refuse trucks engine consumption used in this work. With the curve and the information provided by the manufacturer the prediction of the specific consumption and performance of a refuse truck turbocharged engine fueled by Diesel was made using a two-variables regression with a third grade polynomial approximation. The result is a third grade polynomial that allows the specific consumption calculation depending on the torque and the engine speed.
Información tecnológica, 2019
A partir de un modelo paramétrico para procesos de primer orden más tiempo muerto, se desarrollan... more A partir de un modelo paramétrico para procesos de primer orden más tiempo muerto, se desarrollan ecuaciones de sintonía para controladores PID. Se usa como criterio de optimización la minimización de una función objetivo, compuesta por una combinación de la integral del valor absoluto del error (IAE) y la varianza de la señal del controlador. Se obtienen dos conjuntos de ecuaciones de sintonía, uno para 0.1<t0/τ<1.5 y otro para 1.5<t0/τ<5.0. Ambos conjuntos de ecuaciones de sintonía se evalúan con procesos de referencia, y sus resultados se comparan con las sintonías de mínimo IAE, integral cuadrada del error (ISE), integral cuadrada del error por el tiempo (ISTE), por control de modelo interno (IMC) y Lambda (λ). A diferencia de las ecuaciones tradicionales, las propuestas en este trabajo consideran la respuesta de la variable controlada y la variabilidad en la señal que se envía a los actuadores.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Procedia Computer Science
Eco-innovation refers to developing goods, processes, and services that seek companies' s... more Eco-innovation refers to developing goods, processes, and services that seek companies' sustainable positioning and permanence in an ever-evolving and demanding market. On the other hand, the cluster approach has proven a successful strategy for companies to accomplish eco-innovation. This paper aims to pinpoint the factors that generate economic effects on the companies of a cluster when they engage in eco-innovation activities. The study was applied to a 40-company cluster in the Colombian metalworking sector, implementing the Fuzzy-set Qualitative Comparative Analysis (FsQCA) methodology, which identifies the inherent causal relationships between factors having economic impacts on the cluster's companies. Through the FsQCA analysis, we identified those factors that have significant economic effects, to which companies must give special attention to achieve benefits and reduce operative costs while complying with environmental regulations. Moreover, the necessary and sufficient conditions analysis showed different pathways to achieving such benefits. The factors found to have economic effects are the companies' capacity, market demand, and regulatory policies. Finally, the paper shows that by focusing on the correct factors and actions, the cluster approach fosters the companies' competitiveness and leads them to successfully engage in eco-innovation. Thus, this work provides companies with a roadmap to achieve eco-innovation-related results.
Eco-innovation refers to developing goods, processes, and services that seek companies' sustainab... more Eco-innovation refers to developing goods, processes, and services that seek companies' sustainable positioning and permanence in an ever-evolving and demanding market. On the other hand, the cluster approach has proven a successful strategy for companies to accomplish eco-innovation. This paper aims to pinpoint the factors that generate economic effects on the companies of a cluster when they engage in eco-innovation activities. The study was applied to a 40-company cluster in the Colombian metalworking sector, implementing the Fuzzy-set Qualitative Comparative Analysis (FsQCA) methodology, which identifies the inherent causal relationships between factors having economic impacts on the cluster's companies. Through the FsQCA analysis, we identified those factors that have significant economic effects, to which companies must give special attention to achieve benefits and reduce operative costs while complying with environmental regulations. Moreover, the necessary and sufficient conditions analysis showed different pathways to achieving such benefits. The factors found to have economic effects are the companies' capacity, market demand, and regulatory policies. Finally, the paper shows that by focusing on the correct factors and actions, the cluster approach fosters the companies' competitiveness and leads them to successfully engage in eco-innovation. Thus, this work provides companies with a roadmap to achieve eco-innovation-related results.
Procedia Computer Science, 2022
The throughput of a finite-capacity queueing system is the mean number of clients served during a... more The throughput of a finite-capacity queueing system is the mean number of clients served during a time interval. The COVID-19 outbreak has posed a serious challenge for many commercial establishments, including the retails, which have struggled to adapt to new working dynamics. Retails have been forced to adjust their service guidelines to comply with biosecurity protocols, ensuring to observe governmental and public health policies. A significant change for the retail market has been the capacity restrictions to ensure social distancing, i.e., a limitation on the number of customers simultaneously shopping in the store. Such a constraint has an impact on the throughput that can be achieved by a retail. This article assesses the impact of the capacity restriction measures on an Amazon Go-like retail performance through a throughput analysis under COVID-19-related capacity restrictions. For the assessment, we first retrieved real data from a retail located in Cartagena, Colombia. Two scenarios were considered: i) low demand and ii) high demand. Further, we built an Amazon Go-like, two-queue, M/M/c/K retail model with a CONWIP (Constant Work-In-Process) approach, considering biosecurity-based capacity restrictions due to the COVID-19 pandemic. The R package ‘queueing’ was used to set up the model, and an algorithm was created to go over each sampling period and find the hourly optimum capacity and throughput under the dynamic conditions of both scenarios (low and high demand). Results from the performance analysis show that, for some operational conditions, the optimum maximum throughput is achieved with capacities below the biosecurity-based capacity, while for some other operational conditions the maximum throughput cannot be achieved with the restrictions, as the optimum capacity lies beyond the biosecurity-based capacity. These results suggest that the maximum capacity definition should not be static. Instead, it should be done considering the retail’s dimensions, the biosecurity policies, and the dynamic retail’s operational conditions such as the demand and service capacity.
Procedia Computer Science
The education sector was considerably affected by the COVID-19 pandemic, risking the learning pro... more The education sector was considerably affected by the COVID-19 pandemic, risking the learning process and forcing governments to pull out contingency actions to ensure the students' development of generic and specific skills and guarantee education quality. These actions include the shift to online and hybrid (i.e., online and in-person) classes. This work assesses the pandemic effect on the generic skills of undergraduate students in a Colombian university. The study aims to determine the effect of COVID-19 on the development of generic skills quantitatively. Two datasets were retrieved: i) A dataset with the scores obtained by the students in an institutional Generic Skills test and in the midterm tests; ii) A dataset with the students' scores in the Colombian standardized test for undergraduate students, called the Saber Pro test. Three analysis stages were performed: i) Univariate exploratory analysis; ii) Differential analysis to compare the No COVID vs. COVID scenarios; iii) A correlation analysis. Results showed that the scores of the Generic Skills and the Midterm tests increased significantly when comparing the two scenarios, except for the Written Communication. As for the Saber Pro test, only the scores for Written Comprehension, Quantitative Reasoning, and the global scores increased significantly. On the other hand, the correlation analysis showed a strong correlation only between the scores obtained at the Generic Skills and the Saber Pro tests for the English Proficiency skill. In addition, the analysis elucidated a weak correlation between the Generic Skills test's average and the Saber Pro's global score. Finally, the results prove that online education is a feasible alternative that offers students more flexibility to ensure the development of generic and specific skills.
The education sector was considerably affected by the COVID-19 pandemic, risking the learning pro... more The education sector was considerably affected by the COVID-19 pandemic, risking the learning process and forcing governments to pull out contingency actions to ensure the students' development of generic and specific skills and guarantee education quality. These actions include the shift to online and hybrid (i.e., online and in-person) classes. This work assesses the pandemic effect on the generic skills of undergraduate students in a Colombian university. The study aims to determine the effect of COVID-19 on the development of generic skills quantitatively. Two datasets were retrieved: i) A dataset with the scores obtained by the students in an institutional Generic Skills test and in the midterm tests; ii) A dataset with the students' scores in the Colombian standardized test for undergraduate students, called the Saber Pro test. Three analysis stages were performed: i) Univariate exploratory analysis; ii) Differential analysis to compare the No COVID vs. COVID scenarios; iii) A correlation analysis. Results showed that the scores of the Generic Skills and the Midterm tests increased significantly when comparing the two scenarios, except for the Written Communication. As for the Saber Pro test, only the scores for Written Comprehension, Quantitative Reasoning, and the global scores increased significantly. On the other hand, the correlation analysis showed a strong correlation only between the scores obtained at the Generic Skills and the Saber Pro tests for the English Proficiency skill. In addition, the analysis elucidated a weak correlation between the Generic Skills test's average and the Saber Pro's global score. Finally, the results prove that online education is a feasible alternative that offers students more flexibility to ensure the development of generic and specific skills.
Eco-innovation is the development of products and processes that contribute to searching for solu... more Eco-innovation is the development of products and processes that contribute to searching for solutions to differentiate and position companies or businesses in the market sustainably. The cluster is considered a cooperative strategy for businesses to achieve competitive efficiency. Nowadays, companies have the intrinsic responsibility of reducing their environmental impact significantly, creating novel, enhanced products and services. This work aims to identify the drivers or determinant factors fostering the ecoinnovation within industrial clusters for a Case Study in Colombia, South America. The study was applied to 40 companies in the Colombian metalworking sector. The Fuzzy-set Qualitative Comparative Analysis (fsQCA) methodology was implemented, allowing the identification of underlying causal relationships ruling the levels of eco-innovation in industrial clusters. Results show that the capacity, the regulatory policies, and the competitive pressure are the main drivers for the clusters to reach high innovation levels, achieving the desired economic and environmental outcomes. Furthermore, even with low-demand conditions and unclear policies, companies in the cluster can successfully generate profits and stay competitive depending strongly on the three identified factors. Future research will focus on extrapolating the study to industrial clusters in different countries, regions, and business sectors.
Procedia Computer Science, Dec 31, 2023
Tropical coastal lagoons are valuable ecosystems that provide vital ecological services. Understa... more Tropical coastal lagoons are valuable ecosystems that provide vital ecological services. Understanding vegetation health dynamics is essential to conserve and manage these environments effectively. Also, some landscape-related aspects suffer changes through time due to natural and human-driven factors. Analyzing a landscape's evolution allows getting to know the place's identity and underlying interactions with its population. This study employed satellite imagery from the Landsat 8 mission and advanced data analysis techniques to investigate vegetation health's temporal and spatial patterns in Ciénaga de Mallorquín, a coastal lagoon in Northern Colombia. The normalized difference vegetation index (NDVI) was calculated from the satellite data to quantify vegetation biomass and its health. The results show a significant decline in NDVI values between 2013 and 2018, followed by a recovery phase between 2018 and 2022. However, the NDVI levels in 2022 remain significantly lower than those in 2013, indicating the need for continued conservation efforts. This study demonstrates the power of remote sensing as a tool for monitoring vegetation dynamics and informing sustainable management practices in tropical coastal ecosystems.
Procedia Computer Science, Dec 31, 2023
Procedia Computer Science, Dec 31, 2023
Procedia Computer Science, Dec 31, 2023
Our goal is to understand process innovation activities, constraints, and challenges. Collaborati... more Our goal is to understand process innovation activities, constraints, and challenges. Collaboration and Research and Development (R&D) are vital for innovation, but many Small-and Medium-size Enterprises (SMEs) need to improve on these, necessitating focused efforts. Innovation is linked to growth, productivity, and capacity, demanding new offerings and process improvement. Surveying 56 Colombian exporting SMEs with a 19-question survey, we employed Artificial Neural Network (ANN) models and Spearman correlation for predicting Process Innovation. Scrutinizing requisite activities and their impact is essential for economic growth, allowing SMEs to enhance performance through market-driven innovation. Collaboration with research institutions and suppliers is pivotal, highlighting its importance for process innovation. Process-focused firms emphasize process innovation, while Colombian exporting SMEs prioritize it for competitiveness. Technological learning shapes strategies, and SMEs leverage market innovation. We identified links between R&D/innovation (R&D+I) and export behavior. Innovation aids internationalization despite Colombia's innovation gap. Enterprises invest in R&D+I and external collaboration, while SMEs focus on efficiency. Prospective research should explore interconnections in innovation facets, harnessing machine learning.
To explore sustainable alternatives to meet the growing energy demand worldwide, it is necessary ... more To explore sustainable alternatives to meet the growing energy demand worldwide, it is necessary to analyze strategies promoting the efficient use of energy, the mitigation of environmental impact, the diversification of power resources, and the orientation toward energy transition. Due to their location, Latin America and the Caribbean have a significant renewable energy potential. For instance, Colombia has an installed thermoelectric capacity accounting for over 40% of its total power generation resources. Nevertheless, its legislation promotes the fair transition toward alternative sources while leveraging the installed infrastructure. Additionally, worldwide projections show that hydrogen-based power generation will foster the hybridization of power generation systems. This research addresses the evaluation of four increasingly complex systems, starting with a Combined Cycle Gas Turbine (CCGT), successfully adding subsystems up to a hybrid system comprising a CCGT, a photovoltaic field, a methane reformer with carbon capture, a Proton Exchange Membrane (PEM) electrolyzer, and a hydrogen compression-storage stage. The appraisal is performed with the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS), using technical, economic, sociopolitical, and environmental indicators. We used the Colombian energy market as a case study. The evaluation found that the scenario incorporating all the subsystems achieves the best trade-off across all considered criteria. In nominal conditions, this scenario achieves an overall efficiency of 63.67%, a levelized cost of energy of 0.032 USD/kWh, a carbon footprint of 0.047 kgCO 2 /kWh, and a conventional-to-total power ratio of 70.77%. Integrating electrolysis, reforming with carbon capture for hydrogen generation, and using surplus gas and power reduce CO 2 emissions while increasing profits. Additionally, the combination of hydrogen storage and solar energy enhances overall power generation capabilities. The proposed assessment methodology can be extended to evaluate the viability of similar hybrid systems in other regions and energy markets.
To explore sustainable alternatives to meet the growing energy demand worldwide, it is necessary ... more To explore sustainable alternatives to meet the growing energy demand worldwide, it is necessary to analyze strategies promoting the efficient use of energy, the mitigation of environmental impact, the diversification of power resources, and the orientation toward energy transition. Due to their location, Latin America and the Caribbean have a significant renewable energy potential. For instance, Colombia has an installed thermoelectric capacity accounting for over 40% of its total power generation resources. Nevertheless, its legislation promotes the fair transition toward alternative sources while leveraging the installed infrastructure. Additionally, worldwide projections show that hydrogen-based power generation will foster the hybridization of power generation systems. This research addresses the evaluation of four increasingly complex systems, starting with a Combined Cycle Gas Turbine (CCGT), successfully adding subsystems up to a hybrid system comprising a CCGT, a photovoltaic field, a methane reformer with carbon capture, a Proton Exchange Membrane (PEM) electrolyzer, and a hydrogen compression-storage stage. The appraisal is performed with the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS), using technical, economic, sociopolitical, and environmental indicators. We used the Colombian energy market as a case study. The evaluation found that the scenario incorporating all the subsystems achieves the best trade-off across all considered criteria. In nominal conditions, this scenario achieves an overall efficiency of 63.67%, a levelized cost of energy of 0.032 USD/kWh, a carbon footprint of 0.047 kgCO 2 /kWh, and a conventional-to-total power ratio of 70.77%. Integrating electrolysis, reforming with carbon capture for hydrogen generation, and using surplus gas and power reduce CO 2 emissions while increasing profits. Additionally, the combination of hydrogen storage and solar energy enhances overall power generation capabilities. The proposed assessment methodology can be extended to evaluate the viability of similar hybrid systems in other regions and energy markets.
Our goal is to understand process innovation activities, constraints, and challenges. Collaborati... more Our goal is to understand process innovation activities, constraints, and challenges. Collaboration and Research and Development (R&D) are vital for innovation, but many Small-and Medium-size Enterprises (SMEs) need to improve on these, necessitating focused efforts. Innovation is linked to growth, productivity, and capacity, demanding new offerings and process improvement. Surveying 56 Colombian exporting SMEs with a 19-question survey, we employed Artificial Neural Network (ANN) models and Spearman correlation for predicting Process Innovation. Scrutinizing requisite activities and their impact is essential for economic growth, allowing SMEs to enhance performance through market-driven innovation. Collaboration with research institutions and suppliers is pivotal, highlighting its importance for process innovation. Process-focused firms emphasize process innovation, while Colombian exporting SMEs prioritize it for competitiveness. Technological learning shapes strategies, and SMEs leverage market innovation. We identified links between R&D/innovation (R&D+I) and export behavior. Innovation aids internationalization despite Colombia's innovation gap. Enterprises invest in R&D+I and external collaboration, while SMEs focus on efficiency. Prospective research should explore interconnections in innovation facets, harnessing machine learning.
Cogent Education, Aug 13, 2023
Control Engineering Practice, 2017
The WARP algorithm (Weighted Adaptive Recursive PCA) is a novel recursive adaptation method (Port... more The WARP algorithm (Weighted Adaptive Recursive PCA) is a novel recursive adaptation method (Portnoy et al., 2016) for PCA-based fault detection techniques with a reduced computational complexity suitable for online adaptation required when there is an increase in the false alarm rate in monitoring schemes due to the natural, slow and normal process changes related to model aging and other similar dynamic trends on process behavior. This paper offers a broader discussion on WARP implementation as an adaptive fault detection technique triggered by the outcome of a diagnosis stage and a more comprehensive analysis on the computational complexity reduction it achieves. Furthermore, a comparison on this criterion is made with two state-of-the-art recursive algorithms based on an operation breakdown analysis resulting on WARP exhibiting the best performance, that is the least FLOPs consumption for a complete operating condition update. Finally, clarifies the use of some symbols and provides more implementation details based on feedback received.
Volume 14: Emerging Technologies; Materials: Genetics to Structures; Safety Engineering and Risk Analysis, 2017
Natural gas transmission infrastructure is a large-scale complex system often exhibiting a consid... more Natural gas transmission infrastructure is a large-scale complex system often exhibiting a considerable operating states not only due to natural, slow and normal process changes related to aging but also to a dynamic interaction with multiple agents overall having different functional parameters, an irregular demand trend adjusted by the hour, and sometimes affected by external conditions as severe climate periods. As traditional fault detection relies in alarm management system and operator’s expertise, it is paramount to deploy a strategy being able to update its underlying structure and effectively adapting to such process shifts. This feature would allow operators and engineers to have a better framework to address the online data being gathered in dynamic on transient conditions. This paper presents an extended analysis on WARP technique to address the abnormal condition management activities of multiple-state processes deployed in critical natural gas transmission infrastructu...
Tropical coastal lagoons are valuable ecosystems that provide vital ecological services. Understa... more Tropical coastal lagoons are valuable ecosystems that provide vital ecological services. Understanding vegetation health dynamics is essential to conserve and manage these environments effectively. Also, some landscape-related aspects suffer changes through time due to natural and human-driven factors. Analyzing a landscape's evolution allows getting to know the place's identity and underlying interactions with its population. This study employed satellite imagery from the Landsat 8 mission and advanced data analysis techniques to investigate vegetation health's temporal and spatial patterns in Ciénaga de Mallorquín, a coastal lagoon in Northern Colombia. The normalized difference vegetation index (NDVI) was calculated from the satellite data to quantify vegetation biomass and its health. The results show a significant decline in NDVI values between 2013 and 2018, followed by a recovery phase between 2018 and 2022. However, the NDVI levels in 2022 remain significantly lower than those in 2013, indicating the need for continued conservation efforts. This study demonstrates the power of remote sensing as a tool for monitoring vegetation dynamics and informing sustainable management practices in tropical coastal ecosystems.
Renewable Energy and Power Quality Journal, 2012
It is known that the performance of Diesel engine at partial load is different from the performan... more It is known that the performance of Diesel engine at partial load is different from the performance at full load, but engines manufacturers usually provide only the operation characteristics in the highest efficiency condition. In order to determine the Diesel engine performance at all operation condition an investigation has been conducted. The purpose is to develop a theoretical model based on the iso-consumption curve of the IVECO 8360.46.417 Diesel engine that allows predicting the refuse trucks engine consumption used in this work. With the curve and the information provided by the manufacturer the prediction of the specific consumption and performance of a refuse truck turbocharged engine fueled by Diesel was made using a two-variables regression with a third grade polynomial approximation. The result is a third grade polynomial that allows the specific consumption calculation depending on the torque and the engine speed.
Información tecnológica, 2019
A partir de un modelo paramétrico para procesos de primer orden más tiempo muerto, se desarrollan... more A partir de un modelo paramétrico para procesos de primer orden más tiempo muerto, se desarrollan ecuaciones de sintonía para controladores PID. Se usa como criterio de optimización la minimización de una función objetivo, compuesta por una combinación de la integral del valor absoluto del error (IAE) y la varianza de la señal del controlador. Se obtienen dos conjuntos de ecuaciones de sintonía, uno para 0.1<t0/τ<1.5 y otro para 1.5<t0/τ<5.0. Ambos conjuntos de ecuaciones de sintonía se evalúan con procesos de referencia, y sus resultados se comparan con las sintonías de mínimo IAE, integral cuadrada del error (ISE), integral cuadrada del error por el tiempo (ISTE), por control de modelo interno (IMC) y Lambda (λ). A diferencia de las ecuaciones tradicionales, las propuestas en este trabajo consideran la respuesta de la variable controlada y la variabilidad en la señal que se envía a los actuadores.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Procedia Computer Science
Eco-innovation refers to developing goods, processes, and services that seek companies' s... more Eco-innovation refers to developing goods, processes, and services that seek companies' sustainable positioning and permanence in an ever-evolving and demanding market. On the other hand, the cluster approach has proven a successful strategy for companies to accomplish eco-innovation. This paper aims to pinpoint the factors that generate economic effects on the companies of a cluster when they engage in eco-innovation activities. The study was applied to a 40-company cluster in the Colombian metalworking sector, implementing the Fuzzy-set Qualitative Comparative Analysis (FsQCA) methodology, which identifies the inherent causal relationships between factors having economic impacts on the cluster's companies. Through the FsQCA analysis, we identified those factors that have significant economic effects, to which companies must give special attention to achieve benefits and reduce operative costs while complying with environmental regulations. Moreover, the necessary and sufficient conditions analysis showed different pathways to achieving such benefits. The factors found to have economic effects are the companies' capacity, market demand, and regulatory policies. Finally, the paper shows that by focusing on the correct factors and actions, the cluster approach fosters the companies' competitiveness and leads them to successfully engage in eco-innovation. Thus, this work provides companies with a roadmap to achieve eco-innovation-related results.
Eco-innovation refers to developing goods, processes, and services that seek companies' sustainab... more Eco-innovation refers to developing goods, processes, and services that seek companies' sustainable positioning and permanence in an ever-evolving and demanding market. On the other hand, the cluster approach has proven a successful strategy for companies to accomplish eco-innovation. This paper aims to pinpoint the factors that generate economic effects on the companies of a cluster when they engage in eco-innovation activities. The study was applied to a 40-company cluster in the Colombian metalworking sector, implementing the Fuzzy-set Qualitative Comparative Analysis (FsQCA) methodology, which identifies the inherent causal relationships between factors having economic impacts on the cluster's companies. Through the FsQCA analysis, we identified those factors that have significant economic effects, to which companies must give special attention to achieve benefits and reduce operative costs while complying with environmental regulations. Moreover, the necessary and sufficient conditions analysis showed different pathways to achieving such benefits. The factors found to have economic effects are the companies' capacity, market demand, and regulatory policies. Finally, the paper shows that by focusing on the correct factors and actions, the cluster approach fosters the companies' competitiveness and leads them to successfully engage in eco-innovation. Thus, this work provides companies with a roadmap to achieve eco-innovation-related results.
Procedia Computer Science, 2022
The throughput of a finite-capacity queueing system is the mean number of clients served during a... more The throughput of a finite-capacity queueing system is the mean number of clients served during a time interval. The COVID-19 outbreak has posed a serious challenge for many commercial establishments, including the retails, which have struggled to adapt to new working dynamics. Retails have been forced to adjust their service guidelines to comply with biosecurity protocols, ensuring to observe governmental and public health policies. A significant change for the retail market has been the capacity restrictions to ensure social distancing, i.e., a limitation on the number of customers simultaneously shopping in the store. Such a constraint has an impact on the throughput that can be achieved by a retail. This article assesses the impact of the capacity restriction measures on an Amazon Go-like retail performance through a throughput analysis under COVID-19-related capacity restrictions. For the assessment, we first retrieved real data from a retail located in Cartagena, Colombia. Two scenarios were considered: i) low demand and ii) high demand. Further, we built an Amazon Go-like, two-queue, M/M/c/K retail model with a CONWIP (Constant Work-In-Process) approach, considering biosecurity-based capacity restrictions due to the COVID-19 pandemic. The R package ‘queueing’ was used to set up the model, and an algorithm was created to go over each sampling period and find the hourly optimum capacity and throughput under the dynamic conditions of both scenarios (low and high demand). Results from the performance analysis show that, for some operational conditions, the optimum maximum throughput is achieved with capacities below the biosecurity-based capacity, while for some other operational conditions the maximum throughput cannot be achieved with the restrictions, as the optimum capacity lies beyond the biosecurity-based capacity. These results suggest that the maximum capacity definition should not be static. Instead, it should be done considering the retail’s dimensions, the biosecurity policies, and the dynamic retail’s operational conditions such as the demand and service capacity.
Procedia Computer Science
The education sector was considerably affected by the COVID-19 pandemic, risking the learning pro... more The education sector was considerably affected by the COVID-19 pandemic, risking the learning process and forcing governments to pull out contingency actions to ensure the students' development of generic and specific skills and guarantee education quality. These actions include the shift to online and hybrid (i.e., online and in-person) classes. This work assesses the pandemic effect on the generic skills of undergraduate students in a Colombian university. The study aims to determine the effect of COVID-19 on the development of generic skills quantitatively. Two datasets were retrieved: i) A dataset with the scores obtained by the students in an institutional Generic Skills test and in the midterm tests; ii) A dataset with the students' scores in the Colombian standardized test for undergraduate students, called the Saber Pro test. Three analysis stages were performed: i) Univariate exploratory analysis; ii) Differential analysis to compare the No COVID vs. COVID scenarios; iii) A correlation analysis. Results showed that the scores of the Generic Skills and the Midterm tests increased significantly when comparing the two scenarios, except for the Written Communication. As for the Saber Pro test, only the scores for Written Comprehension, Quantitative Reasoning, and the global scores increased significantly. On the other hand, the correlation analysis showed a strong correlation only between the scores obtained at the Generic Skills and the Saber Pro tests for the English Proficiency skill. In addition, the analysis elucidated a weak correlation between the Generic Skills test's average and the Saber Pro's global score. Finally, the results prove that online education is a feasible alternative that offers students more flexibility to ensure the development of generic and specific skills.
The education sector was considerably affected by the COVID-19 pandemic, risking the learning pro... more The education sector was considerably affected by the COVID-19 pandemic, risking the learning process and forcing governments to pull out contingency actions to ensure the students' development of generic and specific skills and guarantee education quality. These actions include the shift to online and hybrid (i.e., online and in-person) classes. This work assesses the pandemic effect on the generic skills of undergraduate students in a Colombian university. The study aims to determine the effect of COVID-19 on the development of generic skills quantitatively. Two datasets were retrieved: i) A dataset with the scores obtained by the students in an institutional Generic Skills test and in the midterm tests; ii) A dataset with the students' scores in the Colombian standardized test for undergraduate students, called the Saber Pro test. Three analysis stages were performed: i) Univariate exploratory analysis; ii) Differential analysis to compare the No COVID vs. COVID scenarios; iii) A correlation analysis. Results showed that the scores of the Generic Skills and the Midterm tests increased significantly when comparing the two scenarios, except for the Written Communication. As for the Saber Pro test, only the scores for Written Comprehension, Quantitative Reasoning, and the global scores increased significantly. On the other hand, the correlation analysis showed a strong correlation only between the scores obtained at the Generic Skills and the Saber Pro tests for the English Proficiency skill. In addition, the analysis elucidated a weak correlation between the Generic Skills test's average and the Saber Pro's global score. Finally, the results prove that online education is a feasible alternative that offers students more flexibility to ensure the development of generic and specific skills.
Eco-innovation is the development of products and processes that contribute to searching for solu... more Eco-innovation is the development of products and processes that contribute to searching for solutions to differentiate and position companies or businesses in the market sustainably. The cluster is considered a cooperative strategy for businesses to achieve competitive efficiency. Nowadays, companies have the intrinsic responsibility of reducing their environmental impact significantly, creating novel, enhanced products and services. This work aims to identify the drivers or determinant factors fostering the ecoinnovation within industrial clusters for a Case Study in Colombia, South America. The study was applied to 40 companies in the Colombian metalworking sector. The Fuzzy-set Qualitative Comparative Analysis (fsQCA) methodology was implemented, allowing the identification of underlying causal relationships ruling the levels of eco-innovation in industrial clusters. Results show that the capacity, the regulatory policies, and the competitive pressure are the main drivers for the clusters to reach high innovation levels, achieving the desired economic and environmental outcomes. Furthermore, even with low-demand conditions and unclear policies, companies in the cluster can successfully generate profits and stay competitive depending strongly on the three identified factors. Future research will focus on extrapolating the study to industrial clusters in different countries, regions, and business sectors.