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Biosignals and Biorobotics Conference (BRC), ISSNIP

作者： Alexandre Geraldo Pomer-Escher Maria Dolores Pinheiro de Souza Teodiano Freire Bastos Filho Post-Graduate Program in Biotechnology Federal University of Espirito Santo Vitoria Brazil Post-Graduate Program in Electrical Engineering Federal University of Espirito Santo Vitoria Brazil Post-Graduate Program in Psychology Federal University of Espirito Santo Av Fernando Ferrari 514 Vitoria Brazil

Stress can affect all people, regardless of age, gender or ethnicity. The human body uses stress as an adaptive response against several situations, but it can cause physical, mental or emotional distress. In stress situation the nervous system evokes the same physiological responses, whatever the type of stress and these responses cause changes in the physical, cognitive, emotional and social performance. This paper proposes to develop a methodology for analyzing the stress level using electroencephalographic signals (EEG) based on asymmetry patterns of alpha waves. The subjects of this research are professionals from Vitoria's Fire Department. Activities of the Central Nervous System are capture using Emotiv Epoc Headset, placed on the volunteer's scalp. The signals are analyzed from the frontal cortex at positions Fp1 (AF3), Fp2 (AF4), F3 and F4, according to of the international 10-20 system. The results are analyzed together with some peripheral physiological signals, such as: heart beat rate (ECG), peripheral blood flow, skin conductance, breath rate, body temperature and change in level of salivary cortisone. In addition, a psychological assessment of voluntary's stress is performed through a questionnaire of LIPP-ISS (Inventory of Symptom Stress). A validation study is conducted through a comparison with data available in literature, as well as with evaluation conducted by a psychologist. The results are analyzed in order to get a correlation between EEG signals and physical, mental or emotional stress.

关键词： Electroencephalography Stress Psychology Physiology Temperature sensors Skin Temperature measurement

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Characterization of contacts degradation in circuit breakers through the dynamic contact resistance

Characterization of contacts degradation in circuit breakers...

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2014 IEEE PES Transmission and Distribution Conference and Exposition - Latin America, PES T and D-LA 2014

作者： De Souza, R.T. Da Costa, E.G. De Oliveira, A.C. De Sousa, W.V. De Morais, T.C.M. Post-Graduate Program in Electrical Engineering COPELE Campina Grande Federal University Brazil Industry Academic Unit Paraíba Federal Institute Brazil Department of Electrical Engineering Campina Grande Federal University Brazil Energisa Paraíba Brazil

ISBN: (纸本)9781479962501

Static resistance measurement of circuit breakers has been a crucial technique to assess the state of contacts, supporting maintenance procedures. However, in many cases, the obtained results do not provide accurate data for correct diagnosis, since the test examines only the main contact. This article discusses the application of the contact dynamic resistance measurement (DRM) in the evaluation of main and arcing contacts. The DRM is a contact resistance test, and the resistance is determined during the opening of contacts, analyzing the main and arcing contacts. The research objective is to get the DRM parameters that can assist in the contacts diagnosis. The obtained results indicate that DRM has presented more qualitative parameters than the static resistance test in the evaluation of contacts. The resistance tests were performed applying a direct current with 300 A of amplitude. © 2014 IEEE.

关键词： Electric circuit breakers

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Causes of blindness and vision impairment in 2020 and trends over 30 years, and prevalence of avoidable blindness in relation to VISION 2020: the Right to Sight: an analysis for the Global Burden of Disease Study (vol 2, pg 144, 2021)

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LANCET GLOBAL HEALTH 2021年第4期9卷 E408-E408页

作者： Steinmetz, Jaimie D. Vision and Eye Research Institute Anglia Ruskin University Cambridge United Kingdom Biomedical Informatics Seoul National University Hospital Seoul South Korea Institute for Health Metrics and Evaluation University of Washington Seattle WA United States Department of Health Metrics Sciences School of Medicine University of Washington Seattle WA United States Institute of Health Services Research Yonsei University Seoul South Korea Department of Ophthalmology University of Washington Seattle WA United States Department of Mathematics Imperial College London London United Kingdom WHO Collaborating Centre for Public Health Education and Training Imperial College London London United Kingdom Department of Primary Care and Public Health Imperial College London London United Kingdom School of Population and Global Health University of Melbourne Carlton VIC Australia School of Optometry and Vision Science UNSW Sydney NSW Australia Brien Holden Vision Institute Sydney Australia Department of Ophthalmology University of Adelaide Adelaide SA Australia Department of Parasitology and Mycology Jahrom University of Medical Sciences Jahrom Iran Department of Clinical Sciences University of Sharjah Sharjah United Arab Emirates Ophthalmic Research Center Shahid Beheshti University of Medical Sciences Tehran Iran Department of Ophthalmology Shahid Beheshti University of Medical Sciences Tehran Iran Research Institute for Endocrine Sciences Shahid Beheshti University of Medical Sciences Tehran Iran Ophthalmic Epidemiology Research Center Shahid Beheshti University of Medical Sciences Tehran Iran Health Services Management Department Qazvin University of Medical Sciences Qazvin Iran Department of Systems Populations and Leadership University of Michigan Ann Arbor MI United States Department of Medicine Sofia Ismail Memorial Medical Centre Bogura Bangladesh The Fred Hollows Foundation Sydney NSW Australia Berhan Public Health & Eye Care Consultancy Addis A

Hospital El Salvador: a novel paradigm of intensive care in response to COVID-19 in central America. Lancet Glob Health 2021;9: e241?42?In this Comment, the conflict of interest statement should have included the following: ?By virtue of their roles within a public hospital or the Ministry of Health, MB, LC, WH, and XS are government employees. The findings and conclusions in the Comment are only those of the authors.? This correction has been made as of Feb 26, 2021.

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Computing stress-related emotional state via frontal cortex asymmetry to be applied in passive-ssBCI

Computing stress-related emotional state via frontal cortex ...

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Biosignals and Biorobotics Conference (BRC), ISSNIP

作者： Anibal C. Atencio Javier C. Garcia Alessandro B. Benevides Berthil B. Longo Andre Ferreira Alexandre Porner-Escher Maria Dolores P. de Souza Teodiano Bastos Post-Graduate Program of Electrical Engineering Federal University of Espirito Santo Vitoria ES Brazil Post-Graduate Program of Biotechnology Federal University of Espirito Santo Vitoria ES Brazil Universidade Federal do Espirito Santo Vitoria ES BR Post-Graduate Program of Psychology Federal University of Espirito Santo Vitoria ES Brazil

The identification of stress-related emotional states allows the use of a passive single-switch BCI (passive-ssBCI) together with a main multi-class BCI. Thus, the passive-ssBCI could work in the background of the main BCI, allowing it to recognize stress-related emotions and to switch to a “stress mode”, which allows a better adaptation to the user current mental state, leading the system to better success rates. Frontal cortex asymmetry gave evidence that greater right frontal activity seems to be more highly related to negative emotional states. In this work, index of asymmetry of alpha band was computed by comparing the power of contra-lateral frontal electrodes. Discrete Wavelet transformation was used to decompose the EEG signals in frequency bands. The power spectral density was then calculated using modified Hamming periodogram. Signals from a public database for the analysis of human affective states, which was labeled with volunteers self-assessment scores, were employed. In order to label negative stress-related emotional state, rules based on valence, arousal and dominance dimensional emotions were defined. The results were promissory, because computed index of asymmetry in the alpha band indicated activity into the right frontal hemisphere was higher than the left one for seven out of nine volunteers during negative emotional states. This index could be employed as switch to a “stress mode” in a passive-ssBCI.

关键词： Indexes Electroencephalography Electrodes Frequency estimation Emotion recognition Switches

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Four-wire Shunt Compensator Based on H-bridge Y-Connected Converters

Four-wire Shunt Compensator Based on H-bridge Y-Connected Co...

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Annual Conference of the IEEE Industrial Electronics Society

作者： E. L. L. Fabricio C. B. Jacobina V. F. Nobrega Post-Graduate Program in Electrical Engineering - PPgEE - COPELE Electrical Engineering Department (DEE) Federal University of Campina Grande (UFCG)

ISBN: (纸本)9781479940318

This paper investigates a power shunt filter composed by four standard h-bridge converters, acting in four-wire system. Compared with the usual four-wire shunt filters, the proposed converter permits reducing the dc-link voltages, the harmonic distortion or the switching frequency. Suitable control strategies to adjust the filter currents as well as the three dc-link voltages are presented. The PWM strategy is designed to command the converter according to the reference voltage provided by the controllers. Simulation and experimental results are presented.

关键词： Topology Voltage control Capacitors Harmonic distortion Pulse width modulation Shunts (electrical) Inverters

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Comparison between wire and wireless EEG acquisition systems based on SSVEP in an Independent-BCI

Comparison between wire and wireless EEG acquisition systems...

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Annual International Conference of the IEEE engineering in Medicine and Biology Society (EMBC)

作者： Richard M. G. Tello Sandra M. T. Müller Teodiano Bastos-Filho Andre Ferreira Post-Graduate Program of Electrical Engineering (PPGEE). UFES Vitoria Brazil Department of Computer and Electronics (CEUNES) Brazil

This paper presents a comparison between two different technologies of acquisition systems (BrainNet36 and Emotiv Epoc) for an Independent-BCI based on Steady-State Visual Evoked Potential (SSVEP). Two stimuli separat... 详细信息

关键词： Visualization Electrodes Indexes Accuracy Brain-computer interfaces Synchronization Feature extraction

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Six-phase open-end machine conversion system with reduced number of controlled components

Six-phase open-end machine conversion system with reduced nu...

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作者： Melo, Victor F. M. B. Jacobina, Cursino B. Rocha, Nady Marinus, Nustenil S. Post-Graduate Program in Electrical Engineering COPELE UFCG Campina Grande Paraíba Brazil Electrical Engineering Department Federal University of Campina Grande UFCG Campina Grande Paraíba Brazil Federal University of Paraíba UFPB João Pessoa Paraíba Brazil

ISBN: (纸本)9781479940325

This paper presents two six-phase open-end machine conversion systems. They are composed of three three-leg converters connected in series to a six-phase machine with open terminals, in an open-end winding connection. The converters use diodes to replace controlled switches, making the conversion system non-reversible and with a reduced number of controlled components. In this case, the machine must work always as a generator. A study concerning harmonic distortion and semiconductor losses is carried out. PWM and control strategies are developed. Simulation and experimental results in order to test these strategies are presented. © 2014 IEEE.

关键词： Energy conversion

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Single-phase AC-AC double-star chopper-cells (DSCC) converter without common DC-link capacitor

Single-phase AC-AC double-star chopper-cells (DSCC) converte...

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IEEE Energy Conversion Congress and Exposition, ECCE

作者： Italo Roger F. M. P. da Silva Alexandre C. Oliveira Cursino B. Jacobina Post-graduate Program in Electrical Engineering - PPgEE/COPELE Department of Electrical Engineering (DEE) Federal University of Campina Grande (UFCG) Brazil

This paper presents a single-phase AC-AC converter based on Modular Multilevel Cascade Converter (MMCC) with Double-Star Chopper-Cells (DSCC). This structure is composed by three DSCC-legs, the middle leg is shared, and also it does not present a common DC-link capacitor. It is suitable for regenerative low-power AC-AC conversion. The voltage-balancing control is presented to regulate the floating DC capacitor voltages. Furthermore, a grid current and terminal load voltage control is presented to correct the Power Factor (PF) and to ensure sinusoidal waveforms. Details about a designed 16-SM prototype are also presented. The experimental results allow validating the control strategies and the effectiveness of the proposed structure.

关键词： Voltage control Pulse width modulation Capacitors Topology Digital signal processing Inductance Inductors

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Hybrid open-end and NPC AC six-phase machine drive systems

Hybrid open-end and NPC AC six-phase machine drive systems

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作者： Melo, Victor F.M.B. Jacobina, Cursino B. Rocha, Nady Post-Graduate Program in Electrical Engineering - PPgEE COPELE UFCG Campina Grande Paraíba Brazil Electrical Engineering Department Federal University of Campina Grande - UFCG Campina Grande Paraíba Brazil Federal University of Paraíba - UFPB João Pessoa Paraíba Brazil

ISBN: (纸本)9781479956982

This paper presents two machine drive system based on a six-phase machine (SPM) and three-leg converters. The machine is composed of two three-phase groups. For the first configuration, one of the groups is connected to a three-leg converter and the other is connected to other two three-leg converters in an open-end winding configuration (see Fig. 4). For the second configuration, one of the groups is connected to a three-leg converter (similar to first one) and the other group is connected to a three-level NPC converter (see Fig. 5). Since the machine two groups are fed differently, the system topology is considered to be hybrid. The purpose of these topologies is to be an alternative configuration, being midway between the conventional six-leg inverter system (see Fig. 1) and the NPC six-leg inverter system (see Fig. 2) and Conventional twelve-leg Open-end inverter system (see Fig. 3). Compared with the conventional six-leg system, the proposed systems permits reducing the power processed by the semiconductor switches and their ratings, the dc-link voltage and the harmonic distortion. On the other hand, the proposed systems constitute less complex alternatives, compared with the open-end and NPC counterparts (see Fig. 3). PWM and control strategies are discussed. Simulation and experimental results are also presented. © 2014 IEEE.

关键词： Topology

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Brushless DC motor torque improvement with mgnetic material stator core

Brushless DC motor torque improvement with mgnetic material ...

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International Conference on Electrical engineering and Computer Science (ICEECS)

作者： Muhammad Nizam Hery Tri Waloyo Agus Mujianto Inayati Agus Purwanto Mechanical Engineering Post Graduate Program Sebelas Maret University Surakarta Indonesia Chemical Engineering Department Sebelas Maret University Surakarta Indonesia

In transportation, BLDC motors are required to have high torque. This BLDC electric motor is designed to drive an electric car. Increased torque can be done in many ways one of which is the selection of the stator material. Effect on the generated torque can be studied by replacing its stator materials. Design was begun with determining the electrical circuit and the coil for the excitation power. Electric motors which was simulated in this paper was a 3-phase BLDC motor. Voltage and current data were analyzed to study the motor performance when different core materials used. It can be concluded that applying ferrite materials stator core reduced core loss, while using ferrite core on the stator slots produces higher voltages and lower currents. Based on the magnitude of the torque produced by the electric motors, ferrite materials was more suitable to be used as slots of the stator core for better motor.

关键词： Permanent magnet motors Torque Stator cores Materials Brushless DC motors

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