467 research outputs found

    Retrasos en la medición del tiempo con el uso de computadoras en la investigación del Tiempo de Reacción : una revisión sistemática

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    El tiempo de reacción (TR) es una medida sensible y se ha aplicado en la Psicología moderna y la Psicología del Deporte y del Ejercicio. Este estudio tuvo como objetivo identificar los posibles retrasos en la medición del tiempo con el uso de computadoras en la investigación con TR mediante el análisis de la producción científica de los artículos publicados en la base de datos electrónica Web of Science® de la Thomson Reuters Web of KnowledgeSM . Los items investigados fueron: tema central del estudio, sistema operacional, lenguaje de programación, accesorios utilizados para registrar la respuesta a los estímulos y el retraso medido en milisegundos. Las publicaciones analizaron los retrasos generados en el uso del monitor CRT/LCD, teclado o ratón, encontrando diferencias significativas. Los sistemas operacionales investigados fueron DOS, Mac, Linux y Windows. Los resultados de los estudios muestran retrasos que varían de 0.0006 a 80ms en los teclados evaluados; de 8 a 52ms en los "mouses"; y de 0.0005 a 68ms en los monitores. A pesar de que el ordenador es bastante utilizado para las mediciones de TR, la fiabilidad de la medida de tiempo está directamente relacionada con las características técnicas de los accesorios utilizados y de la configuración de los sistemas operacionales, concluyéndose que la realización de los estudios en las tareas de TR en el ordenador deben de ser cuidadosamente analizados, una vez que la eficacia de los tiempos de medida está directamente relacionada a los tipos de cualidad de los equipamientos utilizados. Además, los sistemas operacionales y software desarrollados, requieren que la investigación con TR considere la demora causada por el recurso utilizado. Puede ser útil para la Psicología del Deporte y del Ejercicio una discusión en torno a la producción de tareas que envuelven la medición del tiempo, los posibles errores que envuelven el uso de software y hardware, así como las soluciones ya encontradas para disminuir su impacto en la medición del tiempo, lo que nos permite sugerir los cuidados necesarios para obtener una medida confiable.Reaction time (RT) is a sensitive measure and has been applied in modern Psychology and in Psychology of Sport and Exercise. This study aimed to identify potential delays in time measurement with the use of computers in RT research through the analysis of scientific production from articles published in the electronic database Web of Science® powered by Thomson Reuters Web of KnowledgeSM. The publications analyzed delays generated in the use of a CRT/LCD monitor, keyboard or mouse, finding significant differences. DOS, Mac, Linux and Windows Operating systems were investigated. The results of the studies reported delays ranging from 0.0006 to 80ms in the keyboards evaluated; 8 to 52ms in 'mice'; and 0.0005 to 68ms in the monitors. Although computers are widely used for RT measurements, the reliability of time measurement is directly related to the technical characteristics of the accessories used and the configuration of the operating system. We conclude that studies with computer-measured RT tests must be carefully analyzed, since the effectiveness of the time measurements is directly related to the type and quality of the equipment used, as well as the operating systems and software developed. A discussion regarding the scientific literature on the problem of using computers to perform tests involving time measurement, possible errors involving the use of software and hardware, as well as the solutions that have already been found to decrease their impact on time measurement is important for Psychology of Sport and Exercise, because it will enable us to suggest the care needed to obtain a reliable measurement.O tempo de reacção (TR) é uma medida sensível e tem sido aplicada na Psicologia moderna e na Psicologia do Desporto e do Exercício. Este estudo teve como objectivo identificar os possíveis atrasos na mediação do tempo com o recurso a computadores na investigação com TR mediante a análise da produção científica dos artigos publicadas na base de dados electrónica Web of Science® da Thomson Reuters Web of KnowledgeSM. Os itens investigados foram: tema central do estudo, sistema operacional, linguagem de programação, acessórios utilizados para regista a resposta aos estímulos e o atraso medido em milissegundos. As publicações analisaram os atrasos gerados no uso do monitor CRT/LCD, teclado ou rato, encontrando diferenças significativas. Os sistemas operativos investigados foram DOS, Mac, Linux y Windows. Os resultados dos estudos revelam atrasos que variam de 0.0006 a 80ms nos teclados avaliados; de 8 a 52 ms nos ratos; e de 0.0005 a 68ms nos monitores. Apesar do computador ser bastante utilizado para as medições de TR, a fidelidade da medida de tempo está directamente relacionada com as características técnicas dos acessórios utilizados e da configuração dos sistemas operativos, concluindo-se que a realização dos estudos em tarefas de Tr no computador devem ser cuidadosamente analisados, uma vez que a eficácia dos tempos de medida está directamente relacionada com os tipos de qualidade dos equipamentos utilizados. Adicionalmente, os sistemas operativos e o software desenvolvidos, requerem que a investigação com TR considere a demora causada pelo recurso utilizado. Pode ser útil para a Psicologia do Desporto e do Exercício uma discussão em torno do delineamento de tarefas que envolvam a medição do tempo,os possíveis erros que envolvem o uso de software e hardware, assim como as soluções já encontradas para diminuir o seu impacto na medição do tempo, o que nos permite sugerir os cuidados necessários para obter uma medida fiável

    Unmet need for assistance with activities of daily life among older adults in Brazil

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    OBJECTIVE: To estimate the proportion of unmet need for personal assistance for basic and instrumental activities of daily life and to evaluate socioeconomic inequalities related to the unmet need among community-dwelling Brazilian older adults. METHODS: This was a cross-sectional study with data from the last National Health Survey in Brazil. Unmet need was considered as the presence of at least one unmet need for basic or instrumental activities of daily life among individuals reporting the need for assistance. Logistic regression models were used to assess the correlates and probabilities of unmet need. RESULTS: The proportion of unmet need was 18% and 7.1% for basic and instrumental activities of daily life, respectively. Unmet need was significantly related to living arrangements and socioeconomic status. Individuals in the first quintile of wealth status had about 50% higher probability of having an unmet need. A family member was the most prevalent type of caregiver. CONCLUSIONS: Long-term care policy is needed to reduce the proportion of unmet need, especially among socioeconomically disadvantaged groups. Future studies should address the availability, training, and remuneration of caregivers, as those are an indispensable labor force in an aging societ

    Dynamic Phenomenological Modeling of Pec Cells for Water Splitting Under Outdoor Conditions

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    AbstractA dynamic phenomenological model is proposed for better understanding the underlying mechanisms of photoelectrochemical (PEC) cells for water splitting. The main assumptions of the one-dimensional transient model are (1) that bulk recombination occurs between conduction band electrons and holes in the valence band; (2) that mobile charge transport takes place via diffusion and migration; and (3) that the effects of microscopic electric fields and screening in the cell are negligible. For modeling purposes, the photoanode was assumed to be a homogeneous nanocrystalline hematite structure, with thickness L, porosity ep and tortuosity x. The TCO/semiconductor interface was modeled as an ideal ohmic contact, while the electrolyte/platinised TCO interface was described by the Butler-Volmer equation. The continuity and transport governing equations were defined for the mobile species involved: electrons, holes and hydroxyl ions. The effect of outdoor conditions on the performance of the PEC cells, such as temperature and solar radiation variations during the day and for different seasons of the year, was simulated

    Análisis del protocolo IEC-61850 para la operación de sistemas de distribución inteligente

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    Una correcta transmisión de energía eléctrica no es solamente llevar la energía de un punto a otro punto físico remoto; es también contar con las condiciones necesarias para garantizar que la cantidad de energía en Watios [W] llegue adecuadamente con la mínima perdida de energía. Para lograr lo anterior tendremos que implementar protocolos que nos permitan conocer en tiempo real lo que está pasando con las transmisiones eléctricas, pero los protocolos que conocemos para este tipo de proceso son protocolos compuestos por varios principios y además de un largo proceso de investigación. Por ende, en este trabajo de grado, estudiaremos el protocolo IEC 61850. El cual requiere que las líneas de transmisión, torres y demás elementos aisladores se encuentren en excelentes condiciones para así lograr automatizar las subestaciones y tener una lectura y análisis correcto en el momento que se necesite. El protocolo IEC 61850 cuenta con un tipo de paquetes que son llamados frames, que pueden transmitirse por medio de ethernet la cual es la conexión más común de los computadores u ordenadores que son usados en las centrales de vigilancia e inclusive nuestras casas, permitiendo visualizar en tiempo real lo que está pasando. La visualización puedes lograrse gracias a gráficos o texto dependiendo de la forma como este diseñado el programa que se comunica con el protocolo detectando así problemas como: fallas de transmisión, caídas de potencia eléctrica, fallas a tierra, fallas entre fase y neutros y fallas entre fases y en los casos más importantes que son: descargas eléctricas debido a las tormentas o caídas o voladura de torres cuando se presentan eventos naturales o problemas sociales.A correct transmission of electrical energy is not only carrying the energy from one point to another remote physical point; it is also to have the necessary conditions to guarantee that the amount of energy in Watts [W] arrives adequately with the minimum loss of energy. To achieve the above we will have to implement protocols that allow us to know in real time what is happening with electrical transmissions, but the protocols that we know for this type of process are protocols composed of several principles and in addition to a long research process. Therefore, in this degree work, we will study the IEC 61850 protocol. Which requires that transmission lines, towers and other insulating elements are in excellent condition in order to automate substations and have a correct reading and analysis at the time that is needed. The IEC 61850 protocol has a type of packets that are called frames, which can be transmitted through ethernet, which is the most common connection of computers or computers that are used in surveillance centers and even our homes, allowing visualization in real time what is happening. The visualization can be achieved thanks to graphics or text depending on the way the program that communicates with the protocol is designed, thus detecting problems such as: transmission faults, electrical power drops, ground faults, faults between phase and neutral and faults between phases and in the most important cases that are: electrical discharges due to storms or falls or blowing up of towers when natural events or social problems occur.PregradoIngeniero(a) ElectricistaTabla de contenido Introducción..................................................................................................................................................................... 5 CAPÍTULO 1....................................................................................................................................................................... 7 1.1 Definición del problema................................................................................................................................ 7 1.2 Justificación.......................................................................................................................................................... 8 1.3 Objetivos ..............................................................................................................................................................10 1.3.1 Objetivo general .........................................................................................................................................10 1.3.2 Objetivos específicos ................................................................................................................................10 1.4 Estado del arte..................................................................................................................................................10 CAPÍTULO 2.....................................................................................................................................................................14 Servicios y usos que presta el protocolo IEC 61850............................................................................16 CAPÍTULO 3.....................................................................................................................................................................22 Ventajas y limitaciones del protocolo IEC 61850..................................................................................22 CAPÍTULO 4.....................................................................................................................................................................27 Comparación del protocolo IEC 61850 con otros existentes en la literatura. ......................27 Diferencias entre ediciones ...................................................................................................................................29 CAPÍTULO 5.....................................................................................................................................................................31 Conclusiones..............................................................................................................................................................31 5.1 Principales conclusiones del trabajo...................................................................................................31 Bibliografía......................................................................................................................................................................33 Glosario .............................................................................................................................................................................3

    Arqueologia Histórica no Brasil: balanço bibliográfico (1960-1991)

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    A (in)visibilidade de crianças no registro arqueológico

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    Prevalência de absenteísmo entre trabalhadores do serviço público = Prevalence of absenteeism among public service workers

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    Objetivos: determinar a prevalência e as principais causas de absenteísmo entre os servidores públicos municipais de Vitória, Espírito Santo. Métodos: foi realizado um estudo transversal com uma amostra composta por 400 indivíduos os quais foram aleatoriamente selecionados entre os funcionários cadastrados no Departamento de Medicina do Trabalho da Prefeitura Municipal. A coleta de dados foi feita por meio de fichas padronizadas a partir das informações contidas nos prontuários dos participantes. Foram coletados dados sociodemográficos, informações referentes ao número de atestados médicos, número de dias afastados e motivos dos afastamentos de acordo com a Classificação Internacional de Doenças. O estudo foi aprovado pelo Comitê de Ética da Escola Superior de Ciências da Santa Casa de Misericórdia. Resultados: a maioria dos servidores (76,75%) apresentava vínculo efetivo com a instituição e possuía até cinco anos de trabalho (40,25%). Observou-se uma alta prevalência de absenteísmo (75,25%), principalmente por doenças respiratórias (35,79%) sendo que as neoplasias e a diabetes foram as doenças que apresentaram maiores medianas de dias afastados (19 e 19, respectivamente). As mulheres apresentaram mais atestados, sendo a relação entre a presença de atestados e sexo estatisticamente significativa (p=0,043). Foi verificada associação estatisticamente significativa (p=0,015 entre o número de dias ausentes e os anos de trabalho, sendo os indivíduos entre 16 e 20 anos de idade os que apresentaram maior mediana de número de dias afastados. Conclusões: houve uma alta prevalência de absenteísmo, ressaltando a importância de investimentos para a promoção e proteção da saúde do trabalhado

    Elaboración de macerados con frutas orientales ecuatorianas para mixiología

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    Investigación de tipo exploratorio, en la elaboración de macerados con frutas orientales ecuatorianas para mixiología. Se evaluaron las características físico-químicas, organolépticas y grado de aceptabilidad de los macerados y derivados mixiológicos para conocer la calidad del producto. En donde se analizó el pH utilizando el papel medidor y la respectiva escala colorimétrica que está en el frasco contenedor, la densidad por el método de picnometría y para el grado alcohólico se utilizó el alcoholímetro. Características organolépticas determinan: gusto, sabor, olor y textura, además del nivel de aceptabilidad para conocer el grado de acogida que tengan los cocteles elaborados con macerados con frutas orientales ecuatorianas. Mediante el test de aceptabilidad se demuestra que los cocteles Mojito de Naranjilla, Cuba Libre de Pitahaya, Oriente Tropical y Cuba libre de Uva, fueron los que tuvieron mayor aceptabilidad en el test hedónico, demostrándose que presentan mayor potencialidad. Se concluye que los macerados con frutas orientales ecuatorianas, pueden incluirse dentro de la elaboración de cocteles, constituyendo de esta forma, nuevos productos agradables y aceptados por el consumidor.This investigation is based on an exploratory research whose study poses on the preparation of macerated with Ecuadorian Amazon fruits as mixology ingredients. In order to determine the product quality there were put under analysis physico-chemical, and organoleptic properties as well as other factors like marketing acceptability degree and mixology derivatives. Other quality factors to be analysed were first, the beverage pH by using test paper and the respective colour scale in the container, then the density which was tested by the pycnometry method and finally, the alcoholic degree established by the alcohol meter. Taking into account the organoleptic characteristics; they determine taste, flavor, odor and texture furthermore, the acceptance level to identify the success degree that the cocktails prepared with macerated Ecuadorian Amazon fruits have. Through the acceptability test it was showed that the cocktails: Naranjilla´s Mojito, Pitahaya´s Cuba libre, Oriente Tropical and Grape´s Cuba libre were the most successful drinks in the hedonic test, so they reveal more potentiality. It is concluded that the macerated with Ecuadorian Amazon fruits are able to be included into cocktails´preparation, for this reason, they represent new enjoyable products accepted by the consumer

    Educación matemática y formación ciudadana: un estudio que confronta la matemática escolar, el currículo y las prácticas docentes

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    El estudio examina la contribución de la matemática educativa a la formación ciudadana, a partir del análisis discursivo de docentes de entre dos y treinta años de ejercicio laboral, en torno a tres dimensiones: rol de la educación matemática en la formación ciudadana, currículo y práctica docente. La primera dimensión, buscó identificar las percepciones docentes respecto de la colaboración de la educación matemática en la formación ciudadana; la segunda, indagó la relación docente–currículo y la tercera dimensión exploró las prácticas docentes y la manera en que éstas tributan o no a la formación en ciudadanía. El estudio, de tipo cualitativo, revela la relación mercantilista y de alfabetización hacia el consumo que los docentes promueven en los procesos de enseñanza aprendizaje de esta asignatura, las contradicciones entre el currículo y la concepción matemática que subyace en torno a la formación ciudadana y la distancia entre el currículo escrito y las prácticas docentes

    Sediment toxicity assessment using zebrafish (Danio rerio) as a model system: Historical review, research gaps and trends

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    Embargo until June 22, 2023Sediment is an important compartment in aquatic environments and acts as a sink for environmental pollutants. Sediment toxicity tests have been suggested as critical components in environmental risk assessment. Since the zebrafish (Danio rerio) has been indicated as an emerging model system in ecotoxicological tests, a scientometric and systematic review was performed to evaluate the use of zebrafish as an experimental model system in sediment toxicity assessment. A total of 97 papers were systematically analyzed and summarized. The historical and geographical distributions were evaluated and the data concerning the experimental design, type of sediment toxicity tests and approach (predictive or retrospective), pollutants and stressors, zebrafish developmental stages and biomarkers responses were summarized and discussed. The use of zebrafish to assess the sediment toxicity started in 1996, using mainly a retrospective approach. After this, research showed an increasing trend, especially after 2014–2015. Zebrafish exposed to pollutant-bound sediments showed bioaccumulation and several toxic effects, such as molecular, biochemical, morphological, physiological and behavioral changes. Zebrafish is a suitable model system to assess the toxicity of freshwater, estuarine and marine sediments, and sediment spiked in the laboratory. The pollutant-bound sediment toxicity in zebrafish seems to be overall dependent on physical and chemical properties of pollutants, experimental design, environmental factor, developmental stages and presence of organic natural matter. Overall, results showed that the zebrafish embryos and larvae are suitable model systems to assess the sediment-associated pollutant toxicity.acceptedVersio
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