Tecnura

30-48

Authors: Lely Adriana Luengas; Luis Felipe Wanumen Silva

Objective: To perform the classification and mapping of body sway parameters from static posturography data to differentiate unilateral transtibial amputees from non-amputees using machine learning and data mining techniques. Methodology: Body sway was measured in 74 individuals, 37 landmine amputees and 37 healthy controls. Stability was classified by group using five machine learning algorithms. A continuous two-dimensional map of posture alterations was developed using Shannon's information theory, the U Mann-Whitney test (p <0,05) was used to identify differences between groups. Results: Five machine learning algorithms (decision tree, decision rules, neural network, vector support machine and clustering) were trained. Validation and comparison were carried out with the metrics obtained from the confusion matrix, using cross-validation to obtain two subsets. The most discriminatory posture condition was classified as displacement of the center of pressure (CoP) on the non-amputated side, anteroposterior direction. The algorithm with the highest performance was the vector support machine and the one with the lowest performance was the cluster; however, all the models performed group classification with an F1 score greater than 0,4. Conclusions: Mapping of sway displacement characteristics into 2D space revealed clear clusters between amputees and controls, confirming that machine learning can aid in the classification of clinical sway patterns measured with static posturography. Computational models allow to objectively evaluate the stability, as well as to recognize the contribution of the contralateral limb in the control of the static bipedal posture, since it compensates for the non-existence of the ipsilateral afferents and efferents. Financing: Scientific research article derived from the research "Characterization of Stability in Unilateral Transtibial Amputees", funded by "Francisco José de Caldas District University".

67-85

Authors: Brandon Steven Ardila Murillo, Edison Andrés Soto Ríos

Objective: This paper presents a methodology to determine the zones and elevated structures with the highest number of lightning strikes (Hotspots) in Barrancabermeja and Yondó. Methodology: It starts from the division of the surface of these two municipalities into polygons of 600 meters. In this way, using the information of lightning activity (cloud-ground impacts) provided by the Colombian Network for Total Lightning Detection LINET between January 2016 and February 2020, the number of impacts per polygon was determined, which made it possible to identify the hotspots in the study areas. Likewise, elevated structures such as transmission towers, telecommunications antennas and buildings were identified and located and a radius of influence of 300 meters was established for each one of them taking into account the mean error of location of the LINET network. In this way it was possible to determine the twenty structures with the highest number of lightning strikes. Results: The polygones with the highest lightning activity were found, of which 34 are located in Barrancabermeja and 235 in Yondó, which is consistent with maps of Density of Discharges to land made in the area where there is an increase in the number of flashes per square kilometer per year in Yondó compared to Barrancabermeja. 616 elevated structures were located in the municipalities of Barrancabermeja and Yondó, of which the twenty with the highest number of lightning strikes were chosen, which correspond 50% to transmission towers, the structure with the highest number of impacts being a transmission tower of 70 meters high located on the border of the two study municipalities with a total of 68 impacts. Conclusions: Of the 27 elevated structures found in Yondó, only 6 are located in a hotspot, which shows that in this municipality the presence of an elevated structure does not guarantee a hotspot and that the sites with the highest lightning activity are not influenced by the presence of elevated structures. Now, in the case of Barrancabermeja, 10 elevated structures were found in one of the hotspots, of which 7 are located in the urban area where 9 hotspots were found, from which it is inferred that in this municipality the urban planning and the presence of elevated structures, indeed increases the lightning activity. Financing: Universidad Industrial de Santander.

98-114

Authors: Jorge Enrique Herrera-Rubio, Angelo Joseph Soto-Vergel, Darwin Orlando Cardozo-Sarmiento

Context: Transmission lines are structures constructed of uniform material arranged as an array of conductor or semiconductor pairs to guide electromagnetic waves carrying radio frequency energy between a transmitting device and a receiving device. Its importance in communications lies in the knowledge of its fundamental parameters, which requires specialised measurement equipment and laboratory instruments to make important decisions on the coupling of technologies in data transmission systems. Methodology: To do so, a hardware and software architecture is created and implemented using analogue inputs to measure attenuation and digital and timed interruptions to measure the delay between the incident and transmitted waves, whose data are used to calculate characteristic impedance, attenuation constant, phase constant, propagation speed, resistance, conductance, capacitance and inductance, by means of experimental equations. Four experiments are carried out using 305 meters of coaxial cable, checking the data obtained with the manufacturer's theoretical data and validating with measurements of specialised specialized electronic instrumentation equipment, such as the function generator and the digital oscilloscope, with the aim of finding out the error of the proposed tool designed compared to advanced instruments. Results: As a result, a device is built that calculates the basic parameters of a transmission line with an error between 3 % and 9 % in the measurements. Conclusions: The developed tool delivers results close to the theoretical values and when compared with electronic measurement instruments (digital oscilloscope and function generator), it measures the characteristic impedance accurately; it presents a percentage error of 3.7 % when measuring the phase constant; and finally, it presents a percentage error of less than 9 % when measuring the attenuation constant, delay, propagation speed, resistance, conductance, capacitance and inductance. This determines that the maximum error of the measurements is 8.98 %, demonstrating that the proposed device developed is suitable for measuring the parameters of transmission lines.

130-141

Authors: Yeyson Becerra, Mario Ricardo Arbulu Saavedra

Context: The COVID-19 has accelerated robotics and automated systems integration to the different economic sectors, it has mainly gotten presented by the necessity to keep estranged people in order to reduce contagious risk. All around the World, robotic systems have been emerging and adapting to fight against pandemic and reactivate economy again. Method: This paper initially presents the measures has gotten taken to combat COVID-19, as well as the impact the virus has gotten in the world economy. Subsequently, three categories of robots have been selected and its main duties during the pandemic. Discussion: While robotics turn to a tool to combat COVID-19 and an engine to reactivate economy again, it should be considered the following challenges: humans replaced by robots in some labours, rise of inequity, lack of privacity at public spaces, and rise of resources to research in robotics. Conclusions: Raise in robot demand is foreseen for the next years, as well as human interaction decrement is waited. The end of the pandemic will not go back the robot integration to the diverse economy sectors. Robotics is a disruptive technology that will change the World in the next years.