Remote sensing in the analysis between forest cover and COVID-19 cases in Colombia

This article explores the relationship between forest cover and coronavirus disease 2019 (COVID-19) cases in Colombia using remote sensing techniques and data analysis. The study focuses on the CORINE land cover methodology's five main land cover categories: artificial territory, agricultural territories, forests and semi-natural areas, humid areas, and water surfaces. The research methodology involves several phases of the unified method of analytical solutions for data mining (ASUM-DM). Data on COVID-19 cases and forest cover are collected from the Colombian National Institute of Health and Advanced Land Observation Satellite (ALOS PALSAR), respectively. Land cover data is processed using QGIS software. The results indicate an inverse relationship between forest cover and COVID-19 cases, as evidenced by Pearson's index ρ of -0.439 (p-value <0.012). In addition, a negative correlation is observed between case density and forests and semi-natural areas, one of the land cover categories. The findings of this study suggest that higher forest cover is associated with lower numbers of COVID-19 cases in Colombia. The results could potentially inform government organizations and policymakers in implementing strategies and policies for forest conservation and the inclusion of green areas in densely populated urban areas

International Journal of Electrical and Computer Engineering: a bibliometric analysis

This study is focused on analyzing seven years of bibliometric data of the International Journal of Electrical and Computer Engineering (IJECE) from 2014 to 2020. The analysis of 2,928 papers exhibits multi-folded growth of 34.25%, rising from 109 articles in 2014 to 638 articles by 2020. In addition, the analysis of the structure of publications as well as the mapping of bibliographic data based on co-citation, bibliographic coupling, and co-occurrence showed the intellectual structure and connection between universities, countries, and contributing authors. As the journal’s first retrospective, this study not only educates and enriches IJECE’s global readership and aspiring contributors, but may also be useful to its editorial board, as it provides several inputs for navigating future research

Analysis of electromagnetic pollution by means of geographic information system

Currently, telecommunications systems have become more widespread and there is still a discrepancy between whether or not non-ionizing radiation produces health problems in living beings at cellular level. From an experimental point of view, it is interesting to raise the correlation of high levels of electromagnetic pollution with health problems in urban populations which would make it possible to clearly determine the effects of this type of radiation on human health and the environment. By means of remote sensing, a geographic information system (GIS) has been developed for the analysis of electromagnetic pollution levels generated by emissions from non-ionizing radiation (NIR) sources in a city. A method for measuring electromagnetic pollution was applied, which allows the generation of a table of attributes of the GIS that is the input to generate by inverse distance weighting (IDW), the layer of electromagnetic pollution. The method, as a case study, was applied in the city of Manizales, located in Colombia, obtaining as a result a layer that allows evidence that the highest levels of electromagnetic pollution are concentrated in the most central area of the city. In this way, the effects of NIR on public health can be analyzed by means of correlations

Unit vector template generator applied to a new control algorithm for an UPQC with instantaneous power tensor formulation, a simulation case study

In this paper we present a new algorithm to generate the reference signals to control the series and parallel power inverters in an unified power quality conditioner “UPQC” to enhance power quality. The algorithm is based in the instantaneous power tensor formulation which it is obtained by the dyadic product between the instantaneous vectors of voltage and current in n-phase systems. The perfect harmonic cancelation algorithm “PHC” to estimate the current reference in a shunt active power filter was modified to make it hardy to voltage sags through unit vector template generation “UVGT” while from the same algorithm it extracts the voltage reference for series active power filter. The model was validated by mean of simulations in Matlab-Simulink®

Parameter estimation of three-phase linear induction motor by a DSP-based electric-drives system

This work describes a method to characterize a three-phase linear induction motor in order to determine the various parameters used in its per-phase equivalent circuit by a DSP-based electric-drives system. In LIM (Linear Induction Motor), the air gap is very large compared with the RIMs (Rotary Induction Motors). Further, the secondary part normally does not have slotted structure. It is just made of aluminum and steel plates. Therefore, the effective air gap is larger than the physical air gap. High air gap makes a larger leakage inductance. It leads to lower efficiency and lower power factor. DC resistance test will be done to determine the value of Rs. The primary Inductance Ls will be calculated by running the LIM at synchronous speed. The secondary parameters i.e. Llr and Rr′ will be calculated by blocked-mover test. The experiment for no load test is shown and include a DC motor coupled to the LIM under test. Two methods to calculate the secondary parameters are described

Comparación numérica y experimental de técnicas de control quasi-sliding, sliding y PID en un convertidor buck

In this paper the Sliding Mode Control (SMC), PID and ZAD (Zero Average Dynamic) strategies are applied to an electronic DC-DC power converter. Time behavior for each controller is shown for numerical solution and experimental realization. The results in SMC and PID are contrasted with a ZAD-FPIC controller combined with a recently developed strategy named FPIC (Fixed Point Induction Control). Stability in SMC is guaranteed by the Lyapunov theorem. The PID controller is designed in an analytical way using pole placement. The main problem with the physical realization was the sample and hold in the variable acquisition system, in addition to time delay introduced by the computing process. From a practical point of view, the ZAD-FPIC technique has advantages no shown by PID and SMC working with sample and hold, these advantages have been corroborated experimentally. The designs have been tested in an RCP (Rapid Control Prototyping) system based on DSP from the dSPACE platform. Both numerical performance and experimental performance agree.En este artículo son aplicadas varias técnicas de control para un convertidor reductor DC-DC estas son: control por modos deslizantes (SMC), PID y promediado de dinámica cero (ZAD). El comportamiento en el tiempo para cada controlador es mostrado tanto numéricamente como experimentalmente. Los resultados de SMC y PID son contrastados con la estrategia de control ZAD-FPIC esta última es combinada con una reciente técnica de control llama FPIC (control por inducción al punto fijo). La estabilidad de SMC es garantizada mediante teorema de Lyapunov. El control PID es diseñado de forma analítica usando desplazamiento de polos. El principal problema en la realización experimental fue la velocidad de muestreo y retención de las variables adquiridas del sistema, adicionalmente el tiempo de retardo presente en los procesos de procesamiento. Desde el punto de vista práctico la técnica de control ZAD-FPIC tiene ventajas en comparación con PID y SMC cuando se trabaja con muestreo y retención, esas ventajas han sido corroboradas experimentalmente. Los experimentos han sido probados en sistema RCP (prototipo rápido de control) específicamente en una DSP de la compañía dSPACE, al final tanto los resultados de la simulación numérica y la experimental son muy similares

Comparación numérica y experimental de técnicas de control quasi-sliding, sliding y PID en un convertidor buck

In this paper the Sliding Mode Control (SMC), PID and ZAD (Zero Average Dynamic) strategies are applied to an electronic DC-DC power converter. Time behavior for each controller is shown for numerical solution and experimental realization. The results in SMC and PID are contrasted with a ZAD-FPIC controller combined with a recently developed strategy named FPIC (Fixed Point Induction Control). Stability in SMC is guaranteed by the Lyapunov theorem. The PID controller is designed in an analytical way using pole placement. The main problem with the physical realization was the sample and hold in the variable acquisition system, in addition to time delay introduced by the computing process. From a practical point of view, the ZAD-FPIC technique has advantages no shown by PID and SMC working with sample and hold, these advantages have been corroborated experimentally. The designs have been tested in an RCP (Rapid Control Prototyping) system based on DSP from the dSPACE platform. Both numerical performance and experimental performance agree.En este artículo son aplicadas varias técnicas de control para un convertidor reductor DC-DC estas son: control por modos deslizantes (SMC), PID y promediado de dinámica cero (ZAD). El comportamiento en el tiempo para cada controlador es mostrado tanto numéricamente como experimentalmente. Los resultados de SMC y PID son contrastados con la estrategia de control ZAD-FPIC esta última es combinada con una reciente técnica de control llama FPIC (control por inducción al punto fijo). La estabilidad de SMC es garantizada mediante teorema de Lyapunov. El control PID es diseñado de forma analítica usando desplazamiento de polos. El principal problema en la realización experimental fue la velocidad de muestreo y retención de las variables adquiridas del sistema, adicionalmente el tiempo de retardo presente en los procesos de procesamiento. Desde el punto de vista práctico la técnica de control ZAD-FPIC tiene ventajas en comparación con PID y SMC cuando se trabaja con muestreo y retención, esas ventajas han sido corroboradas experimentalmente. Los experimentos han sido probados en sistema RCP (prototipo rápido de control) específicamente en una DSP de la compañía dSPACE, al final tanto los resultados de la simulación numérica y la experimental son muy similares

Evaluation of leachate turbidity reduction in sanitary landfills following a coagulation/flocculation process enhanced by vegetable starch and thermal water

This study evaluates the reduction of leachate turbidity in landfills after applying a mixture of banana starch and thermal water. Principal component analysis was applied to study the combined effect with four variables: pH, concentration of starch and thermal water mixture, rapid mixing speed and slow mixing speed. The experimental design involved 16 experiments with repetition in the jar test to obtain the optimum dose while measuring turbidity as a response variable. The results showed that after the oxidation process of organic matter, under optimal conditions determined in the experiment, the mixture of starch and thermal water contributed to the reduction of leachate turbidity by 29.1%

Buck converter controlled with ZAD and FPIC for DC-DC signal regulation

This paper presents the performance of a fixed-point induction control (FPIC) technique working in conjunction with the non-linear control technique called zero average dynamics (ZAD) to control chaos in a buck converter. The control technique consists of a sliding surface in which the error tends to zero at each sampling period. A switch is controlled by using centered pulse width modulation (CPWM) control signal. The converter controlled with ZAD-FPIC has been simulated in Matlab and implemented using rapid control prototyping (RCP) in a DSP to make comparisons between simulation and experimental tests. To perform this comparison, some variations in the control parameter and the voltage reference are made in order to evaluate the performance of the system. Results are obtained with errors lower than 1 % which demonstrates the good performance of the control techniques