937 resultados para weak instruments


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El presente proyecto es un estudio teórico-práctico de una plataforma: Multi-Standart Senortag (denominada “Sensortag” en este proyecto). En este contexto se evalúa la viabilidad de Sensortag como plataforma de desarrollo para redes de sensores, y su competitividad en diferentes aspectos respecto a las Cookies, otra plataforma desarrollada por el Centro de Electrónica Industrial (CEI). El objetivo de presente trabajo es estudiar las posibilidades de Sensortag, tanto para medir como procesar y transmitir la información, así como evaluar su simplicidad de uso. Para lograrlo se introducen los conceptos de Red Inalámbrica de Sensores y Internet de Cosas, se desarrolla una serie de aplicaciones prácticas de prueba, y para completar el estudio se propone posibles aplicaciones en la vida real así como vías de investigación futura. El estudio se puede dividir según la siguiente estructura: - Introducción y avances tecnológicos relacionados con el ámbito de estudio (Capítulos 1). - Desarrollo del proyecto (Capítulo 2): - Sensortag: sus características y sus prestaciones. - El estudio del dispositivo, su arquitectura, su diseño de Hardware. - El estudio de las herramientas y del Software que puede soportar: - El procesado – el Sistema Operativo - Transmisión de datos - Protocolos de comunicación - Las pruebas y las aplicaciones realizadas: - Resultados (Capítulo 3) - Experiencia, conclusiones y líneas futuras de investigación (Capítulo 4): - Trabajos previos y experiencia personal, - Resumen y conclusiones del estudio - Propuestas para seguir investigando

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Physical and social transformation processes that take place in urban contexts with strong spatial growth and hardly any economic development frequently have significant adverse impacts for the affected people, which tend to be made invisible. This paper presents an analytical framework to explore different ways to approach urban transformation processes (supply side), their impacts on the set of needs of the community (demand side) and their consequences on the urban environment as a whole (context). The proposed method has been used to assess three actions related to the physical and social transformation of the largest self-made settlement in the city of Dakar, Senegal, during the 2005–2012 period. Research findings show how exogenous interests are privileged over the common good when the affected citizens are not effectively involved in decision-making processes.

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As condições inadequadas vivenciadas nas organizações afligem não só os trabalhadores da iniciativa privada, pois são igualmente encontradas no segmento estatal, contrariando a expectativa de que o aparato governamental eliminaria as condições insalubres e criaria outras melhores nas quais prevalecesse à promoção de saúde. Diante desse panorama questionou-se porque, uma vez que, pelo menos do ponto de vista da sociedade leiga, esses servidores estão submetidos a condições privilegiadas de trabalho. O presente estudo objetivou identificar e descrever possíveis relações entre o clima organizacional e o burnout em servidores públicos de uma instituição federal de ensino. Objetivou-se ainda descrever o clima organizacional predominante. A pesquisa realizada teve cunho quantitativo, tipo estudo de caso e exploratória. A coleta de dados deu-se por meio das escalas ECO (escala de clima organizacional), ECB (escala de caracterização do burnout) e um questionário sociodemográfico, todos os instrumentos autoaplicáveis eletronicamente disponíveis à instituição. Participaram do estudo 201 servidores públicos federais, com idade média de 37 anos, majoritariamente de nível superior e casados. Os resultados revelaram que cerca de um quarto dos participantes raramente experimentaram burnout, no entanto outra quarta parte deles frequentemente experimentaram altos níveis de burnout, resultado bastante expressivo. Os servidores perceberam clima organizacional mediano, destacando-se a boa coesão entre os colegas de trabalho e a percepção de baixa recompensa. Merece destaque a grande dispersão entre as percepções de clima, o que permite inferir haver subclimas não identificados nesta investigação, possivelmente ocasionados por uma força de clima fraca e pela participação dos servidores de unidades de ensino geograficamente distintas, geridas por gestores locais com relativa autonomia. Os resultados dos cálculos de correlação revelaram que, quanto menos os participantes percebem apoio da chefia e da organização, coesão entre colegas, e mais controle/pressão, mais exaustos se sentem, mais desumanizam as pessoas com quem tratam e mais se decepcionam no trabalho e vice-versa. Conforto físico menor está associado a maior desumanização e a mais decepção no trabalho e vice-versa; e que controle/pressão, relaciona-se positiva e fracamente com desumanização e vice-versa. Desta forma, a hipótese de que existe associação entre burnout e clima organizacional foi confirmada. Os resultados também revelaram que os servidores com burnout, perceberam pior clima organizacional que os seus pares sem burnout, confirmando a segunda hipótese. Esses servidores também se mostraram neutros quanto à percepção de apoio da chefia e conforto físico; não percebem controle pressão, nem recompensa; todavia percebem coesão entre os colegas. Esses resultados sugerem que os participantes têm se apoiado nessas relações para suportar a indiferença e ausência de estímulos experimentados no trabalho. Os resultados obtidos nesse estudo permitiram concluir que o clima organizacional é fraco, provavelmente influenciado por uma cultura organizacional fraca, explicando a heterogeneidade da percepção do clima organizacional pelos servidores. Além disso, embora haja burnout entre poucos participantes, há que se atentar que cerca de um quarto deles, encontra-se acometido desta síndrome e isto poderá contagiar os demais.

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Domestic animals have played a key role in human history. Despite their importance, however, the origins of most domestic species remain poorly understood. We assessed the phylogenetic history and population structure of domestic goats by sequencing a hypervariable segment (481 bp) of the mtDNA control region from 406 goats representing 88 breeds distributed across the Old World. Phylogeographic analysis revealed three highly divergent goat lineages (estimated divergence >200,000 years ago), with one lineage occurring only in eastern and southern Asia. A remarkably similar pattern exists in cattle, sheep, and pigs. These results, combined with recent archaeological findings, suggest that goats and other farm animals have multiple maternal origins with a possible center of origin in Asia, as well as in the Fertile Crescent. The pattern of goat mtDNA diversity suggests that all three lineages have undergone population expansions, but that the expansion was relatively recent for two of the lineages (including the Asian lineage). Goat populations are surprisingly less genetically structured than cattle populations. In goats only ≈10% of the mtDNA variation is partitioned among continents. In cattle the amount is ≥50%. This weak structuring suggests extensive intercontinental transportation of goats and has intriguing implications about the importance of goats in historical human migrations and commerce.

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Oscillating electric fields can be rectified by proteins in cell membranes to give rise to a dc transport of a substance across the membrane or a net conversion of a substrate to a product. This provides a basis for signal averaging and may be important for understanding the effects of weak extremely low frequency (ELF) electric fields on cellular systems. We consider the limits imposed by thermal and "excess" biological noise on the magnitude and exposure duration of such electric field-induced membrane activity. Under certain circumstances, the excess noise leads to an increase in the signal-to-noise ratio in a manner similar to processes labeled "stochastic resonance." Numerical results indicate that it is difficult to reconcile biological effects with low field strengths.

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Esse trabalho teve como objetivo contribuir para o debate sobre a importância das políticas de incentivo à inovação no Brasil. Os resultados esperados do uso que as empresas fizeram dos diferentes tipos de instrumentos sobre os gastos em pesquisa e desenvolvimento (P&D) foram avaliados pelo método de diferenças em diferenças. O método permitiu obter as diferenças de gastos entre empresas beneficiárias de instrumentos e as não-beneficiárias em três períodos consecutivos: 2005 em relação à 2003; 2008 em relação à 2005 e de 2011 em relação à 2008. Ao fazer isso, foi possível identificar se tais diferenças foram positivas e significativas, podendo ser atribuídas às influências dos instrumentos. Os instrumentos utilizados foram: incentivos fiscais, Lei de Informática, financiamentos em parcerias, financiamentos sem parcerias e subvenção. E a utilização dos mesmos pelas empresas teve maior relevância no âmbito de diversos programas de apoio à inovação vigentes no país a partir da retomada das políticas industriais e tecnológicas, nos anos 2000. O estudo concluiu que os efeitos positivos e significativos são limitados à determinados grupos tecnológicos e à poucos instrumentos, em geral, de caráter fiscal. Além disso, esses efeitos positivos surgem em apenas um período, sendo que para cada grupo tecnológico foram efetuadas estimativas para três períodos. Também não houve evidências de que os instrumentos financeiros exerçam efeitos significativos sobre as decisões de gastos em pesquisa e desenvolvimento, apesar da maior ênfase dada aos mesmos no período estudado. Os resultados sugerem fraca influência dos mecanismos de apoio à P&D no Brasil sobre o aumento dos gastos privados, apesar dos avanços recentes.

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Although it may sound reasonable that American education continues to be more effective at sending high school students to college, in a study conducted in 2009, The Council of the Great City Schools states that "slightly more than half of entering ninth grade students arrive performing below grade level in reading and math, while one in five entering ninth grade students is more than two years behind grade level...[and] 25% received support in the form of remedial literacy instruction or interventions" (Council of the Great City Schools, 2009). Students are distracted with technology (Lei & Zhao, 2005), family (Xu & Corno, 2003), medical illnesses (Nielson, 2009), learning disabilities and perhaps the most detrimental to academic success, the very lack of interest in school (Ruch, 1963). In a Johns Hopkins research study, Building a Graduation Nation - Colorado (Balfanz, 2008), warning signs were apparent years before the student dropped out of high school. The ninth grade was often referenced as a critical point that indicated success or failure to graduate high school. The research conducted by Johns Hopkins illustrates the problem: students who become disengaged from school have a much greater chance of dropping out of high school and not graduating. The first purpose of this study was to compare different measurement models of the Student School Engagement (SSE) using Factor Analysis to verify model fit with student engagement. The second purpose was to determine the extent to which the SSE instrument measures student school engagement by investigating convergent validity (via the SSE and Appleton, Christenson, Kim and Reschly's instrument and Fredricks, Blumenfeld, Friedel and Paris's instrument), discriminant validity (via Huebner's Student Life Satisfaction Survey) and criterion-related validity (via the sub-latent variables of Aspirations, Belonging and Productivity and student outcome measures such as achievement, attendance and discipline). Discriminant validity was established between the SSE and the Appleton, Christenson, Kim and Reschly's model and Fredricks, Blumenfeld, Friedel and Paris's (2005) Student Engagement Instruments (SEI). When confirming discriminant validity, the SSE's correlations were weak and statistically not significant, thus establishing discriminant validity with the SLSS. Criterion-related validity was established through structural equation modeling when the SSE was found to be a significant predictor of student outcome measures when both risk score and CSAP scores were used. The third purpose of this study was to assess the factorial invariance of the SSE instrument across gender to ensure the instrument is measuring the intended construct across different groups. Conclusively, configural, weak and metric invariances were established for the SSE as a non-significant change in chi-square indicating that all parameters including the error variances were invariant across groups of gender. Engagement is not a clearly defined psychological construct; it requires more research in order to fully comprehend its complexity. Hopefully, with parental and teacher involvement and a sense of community, student engagement can be nurtured to result in a meaningful attachment to school and academic success.

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The UCM Instrumentation Group (GUAIX) is developing currently Data Reduction Pipelines (DRP) for four instruments of the GTC: EMIR, FRIDA, MEGARA and MIRADAS. The purpose of the DRPs is to provide astronomers scientific quality data, removing instrumental biases, calibrating the images in physical units and providing a estimation of the associated uncertainties.

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This study investigates a new way of assessing change in psychotherapy, with the goal of decreasing the schism in the field of psychology between research and clinical practice. Change in psychotherapy was assessed in clients presenting with depressive symptoms who were seeking therapy at the Professional Psychology Center (PPC) at the University of Denver. Prior to beginning treatment, the subjects completed the Beck Depression Inventory- II (BDI-II) and the Symptom Checklist-90-R (SCL-90), and were also assessed by independent clinicians using the Shedler-Westen Assessment Procedure II (SWAP-II). Six to nine months later, after completing at least 12 psychotherapy sessions (range 12-21 sessions), the assessment procedure was repeated.There were no significant differences pre- to post-treatment on any measure. However, two subjects in the sample appeared to benefit from treatment, as assessed by both the self-report measures and the SWAP-II. The findings for these two subjects suggest that the SWAP-II can provide a greater depth of understanding about what can change in therapy than self-report measures alone. Possible reasons for the lack of treatment effects in the larger sample are discussed.

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Several important collections of scientific instruments are preserved in secondary schools but just a small group have been properly catalogued and studied. Unfortunately, they are not commonly regarded as a relevant part of the cultural heritage. However, recent trends in history of science offer new perspectives to study these objects from new points of view. We review some recent studies about collections of scientific instruments in secondary schools and we offer preliminary conclusions of our current work on this topic.

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This paper proposes a new feature representation method based on the construction of a Confidence Matrix (CM). This representation consists of posterior probability values provided by several weak classifiers, each one trained and used in different sets of features from the original sample. The CM allows the final classifier to abstract itself from discovering underlying groups of features. In this work the CM is applied to isolated character image recognition, for which several set of features can be extracted from each sample. Experimentation has shown that the use of CM permits a significant improvement in accuracy in most cases, while the others remain the same. The results were obtained after experimenting with four well-known corpora, using evolved meta-classifiers with the k-Nearest Neighbor rule as a weak classifier and by applying statistical significance tests.