Revista Visión Electrónica: algo más que un estado sólido

152-158

Authors: Angel Regueiro Gómez, Carmen Brígida Busoch Morlán, Carmenchu Regueiro Busoch, René Joaquín Díaz Martínez

The work shows the didactic experiences reached in the research formation of biomedical engineers in the Technological University of Havana (Cujae), during the development of courses (Project of Research I and II) in the Biomedical Engineering program, that contribute to the scientific and methodological development of the Work of Diploma like act of culmination of the university studies, with the integrated employment of the resources of a Learning Management System: MOODLE (Forum, Dynamic Presentations, Videos, WIKI, Tasks, Surveys, Questionnaires, etc.) and the Teaching Based in Problems (EBP), to achieve the appropriate motivation and research formation in the students from the curriculum.

171-176

Authors: Sergio Alejandro Terán Rodríguez, Franklin Jonathan Rojas Caicedo, Esteban Mauricio Inga Ortega

In this document, the variation of temperature and radiation in a 100 kW photovoltaic assembly is connected to a 25 kV network through a DC-DC booster converter and a three-phase three-phase voltage source converter (VSC). Maximum power point tracking (MPPT) is implemented in the elevator converter using a Simulink® model that uses the technique of 'Incremental Conductance + Integral Regulator'. The switching duty cycle is optimized by an MPPT controller that uses the technique of 'Incremental Conductance + Integral Regulator'. This MPPT system automatically modifies the duty cycle to generate the voltage required to extract the maximum power.

185-195

Authors: Ricardo Alirio González Bustamante, Roberto Ferro Escobar, Harold Vacca González

The use of the Internet has Reached a point in the world in Which it has Become essential in everyday life, the need to Have information at hand in the shortest possible time has generated a technological revolution That incurs the constant connection to this tool, from our Personal life to the same objects That we use in daily life, creating a need to check what surrounds us to Improve our quality of life, reason for the birth of the Internet of Things (IoT, for acronym in English), as well as the convergence of our environment through the creation with Technology of smart cities (Smart City in English). In view of the above, this article addresses concepts about the future of smart cities in collaboration with the Internet of things, the advantages and Disadvantages of these, their comparison, reception, adaptability.

6-18

Authors: Juan Jairo Vaca González, Juan Felipe Escobar Huertas, Diego Alexander Garzón Alvarado

Electrical stimulation is a non-invasive therapy used to stimulate chondrocyte dynamics: proliferation, migration, morphology and molecular synthesis. Some studies have evidenced the role of frequency in the generation of electric fields; however, the electrical stimulation sensed by chondrocytes when the frequency varies is not well-documented. Accordingly, a computational model was implemented to assess the frequency dependence of electric fields that stimulate chondrocytes. Cells were modelled in three different scenarios: monolayer cultures, cartilage explants and scaffolds. Chondrocytes were stimulated with 100 Vp-p at frequencies of 0.001, 1, 10, 50, 100 and 1000 kHz. Results showed that frequency is a relevant factor when considering the stimulation of biological samples, since electric fields increased as frequencies were higher. Moreover, chondrocytes experienced different electric fields in both cytoplasm and extracellular environment. This model provides relevant information about the electrical parameters to stimulate cells; in fact, it could enhance experimental procedures, predicting the stimulation that improves chondrocyte dynamics. Electric fields are a promising tool to maintain either well-structured chondrocytes or biomimetic materials used in regenerative therapies such as autologous implantation to treat hyaline cartilage injuries.

26-34

Authors: Ernesto Cadena-Muñoz, Luis Fernando Pedraza-Martínez, Enrique Rodríguez-Colina

This paper presents the results of the characterization of the attack known as the "primary user emulation" in mobile cognitive radio networks performing the implementation and testing. The tools and their configuration to carry out the attack are presented and their effects on the network are analyzed. The results show how to generate the attack with a software-defined radio equipment (SDR) using GNU-Radio and OpenBTS. The effects of the possible configurations of the attack on the network are shown, the malicious type generates constant interference on the primary or cognitive network, the selfish type allows to imitate a licensed or primary user generating interference to the primary network and inability to access the Cognitive Network while active. If the emulator's power level is fixed, the services it provides are stable. If the power is variable the services suffer intermittency. Primary user emulation is the attack that most affects the cognitive radio network so its effects are analyzed in order to propose ways of detecting or applying countermeasures.