1,342 research outputs found

    Padronização de uma bateria para a avaliação de fatores de risco psicossociais trabalhistas em trabalhadores colombianos

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    A battery of questionnaires to assess psychosocial risk factors at work was developed in 2010 in response to Resolution 2646 created by the Colombian Ministry of Social Protection. However, this battery presents some theoretical and practical limitations. A new battery of instruments has been designed and validated that includes instruments and risk indicators of the demand-control-social support and the effort-reward imbalance models. Other factors, not included in these models, but that Resolution 2646 suggests should be assessed, have also been added, and with this additional information, the new battery allows us to also calculate a “global indicator” of demand, control, and social support; family and social risk conditions, coping and personality; and health and wellbeing. The new battery was administered to a sample of 16,095 workers from different occupations and representative Colombian regions. An analysis of the various domains indicates that internal consistency of the various scales is high. The new battery has the following properties: it is simple to use in paper format or when administered by computer, it enables comparison between occupations, it offers unified scores for each variable, and provides information to assess the risk factors suggested by Resolution 2646. In addition, it will make it possible to compare the results obtained when analyzing Colombian workers with those obtained from studies of workers from other countries.Em 2010, desenvolveu-se uma bateria de instrumentos para avaliar fatores psicossociais trabalhistas de risco para a saúde, em resposta à Resolução 2 646 do Ministério da Proteção Social da Colômbia. Contudo, esta conta com algumas limitações que, a partir da construção e da validação de uma nova bateria, neste estudo se pretendem superar. Além disso, a nova bateria oferece recursos adicionais para a avaliação desses fatores: a presente bateria incorpora os instrumentos e os indicadores centrais dos modelos demanda-controle-apoio social e desiquilíbrio esforço-recompensa e os fatores internos do trabalho não considerados nesses modelos, mas que a Resolução considera necessários, mediram-se com testes preexistentes ou desenvolvidos pelos autores. Com os dados coletados, é possível calcular indicadores globais de demanda, controle e apoio social; além de condições familiares e sociais de risco, enfrentamento, personalidade e indicadores de saúde e bem-estar. Para a validação, a bateria foi aplicada a uma amostra de 16 095 trabalhadores de diferentes cargos e municípios colombianos. As anál i ses de consistência interna e validade permitem afirmar que a bateria é simples de aplicar em papel ou digital, permitirá comparar cargos, obter pontuações unificadas por variável, oferecer um diagnóstico de um número importante das variáveis sugeridas na Resolução bem como permitirá comparar os resultados dos trabalhadores colombianos com os de outros países. Palavras-chave: fatores trabalhistas de risco psicossocial, Resolução 2 646 de 2008, modelo demanda-controle-apoio social, modelo desiquilíbrio esforço-recompensa, estresse profissional, avaliação.En 2010 se desarrolló una batería de instrumentos para evaluar factores psicosociales laborales de riesgo para la salud, en respuesta a la Resolución 2646 de 2008 del Ministerio de la Protección Social de Colombia. Sin embargo, esta cuenta con algunas limitaciones que, a partir de la construcción y validación de una nueva batería, en el presente estudio se buscan superar. La nueva batería ofrece recursos adicionales para la evaluación de estos factores: incorpora los instrumentos e indicadores centrales de los modelos demanda-control-apoyo social y desequilibrio esfuerzo-recompensa, y los factores intralaborales no contemplados en dichos modelos, pero que la Resolución considera necesarios, se midieron con pruebas preexistentes o desarrolladas por los autores. Con los datos recolectados es posible calcular indicadores globales de demanda, control y apoyo social; además de condiciones familiares y sociales de riesgo, afrontamiento, personalidad e indicadores de salud y bienestar. Para la validación, la batería se aplicó a una muestra de 16.095 trabajadores de diferentes ocupaciones y municipios colombianos. Los análisis de consistencia interna y validez permiten afirmar que la batería es sencilla de aplicar en papel o por computador, permitirá comparar ocupaciones, obtener puntuaciones unificadas por variable, ofrecer un diagnóstico de un número importante de las variables sugeridas en la Resolución y comparar los resultados de los trabajadores colombianos con los de otros países

    Dimensionality reduction for point feature SLAM problems with spherical covariance matrices

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    © 2014 Elsevier Ltd. All rights reserved. The main contribution of this paper is the dimensionality reduction for multiple-step 2D point feature based Simultaneous Localization and Mapping (SLAM), which is an extension of our previous work on one-step SLAM (Wang et al.; 2013). It has been proved that SLAM with multiple robot poses and a number of point feature positions as variables is equivalent to an optimization problem with only the robot orientations as variables, when the associated uncertainties can be described using spherical covariance matrices. This reduces the dimension of original problem from 3m+2n to m only (where m is the number of poses and n is the number of features). The optimization problem after dimensionality reduction can be solved numerically using the unconstrained optimization algorithms. While dimensionality reduction may not provide computational saving for all nonlinear optimization problems, for some SLAM problems we can achieve benefits such as improvement on time consumption and convergence. For the special case of two-step SLAM when the orientation information from odometry is not incorporated, an algorithm that can guarantee to obtain the globally optimal solution (in the maximum likelihood sense) is derived. Simulation and experimental datasets are used to verify the equivalence between the reduced nonlinear optimization problem and the original full optimization problem, as well as the proposed new algorithm for obtaining the globally optimal solution for two-step SLAM

    Die Biegefestigkeit von Keilzinkenverbindungen aus Brettern der Buche (Fagus silvatica L.)

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    Die Biegefestigkeit von Brettschichtholz aus Buche hängt ebenso wie beim Nadelholz von der Festigkeit der Bretter und der Keilzinkenverbindungen ab. Über den Einfluss einer visuellen oder maschinellen Sortierung von Buchenbrettern auf deren Zugfestigkeit und damit auf die Biegefestigkeit von Brettschichtholz wurde in einer kürzlich abgeschlossenen Forschungsarbeit berichtet. Darin wurde gezeigt, dass in Abhängigkeit von einer zunächst variablen Keilzinkenbiegefestigkeit eine visuelle Sortierung eine charakteristische Biegefestigkeit des Brettschichtholzes von 36 N/mm2 und eine maschinelle Sortierung von 48 N/mm2 ermöglicht. Der Nachweis, ob die Sortierungen auch die dafür erforderliche Keilzinkenbiegefestigkeit gewährleisten, stand noch aus. In der vorliegenden Arbeit wird nun über die unterschiedliche Wirkung von visuellen oder maschinellen Sortierungen auf die Biegefestigkeit von Keilzinkenverbindungen berichtet. Anhand von 367 Biegeversuchen an Keilzinkenverbindungen aus Buche wird gezeigt, dass eine Sortierung von Buchenbrettern in die Sortierklassen LS10 oder LS13 nach DIN 4074-5 bezüglich der Keilzinkenbiegefestigkeit die notwendigen Vorraussetzungen für die Herstellung von GL36 aus Buche schafft. Eine geeignete maschinelle Sortierung nach dem dynamischen Elastizitätsmodul ermöglicht GL48

    Can becoming a leader change your personality? An investigation with two longitudinal studies from a role-based perspective

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    Organizational research has predominantly adopted the classic dispositional perspective to understand the importance of personality traits in shaping work outcomes. However, the burgeoning literature in personality psychology has documented that personality traits, although relatively stable, are able to develop throughout one’s whole adulthood. A crucial force driving adult personality development is transition into novel work roles. In this article, we introduce a dynamic, role-based perspective on the adaptive nature of personality during the transition from the role of employee to that of leader (i.e., leadership emergence). We argue that during such role transitions, individuals will experience increases in job role demands, a crucial manifestation of role expectations, which in turn may foster growth in conscientiousness and emotional stability. We tested these hypotheses in two 3-wave longitudinal studies using a quasi-experimental design. We compared the personality development of 2 groups of individuals (1 group promoted from employees into leadership roles and the other remaining as employees over time), matched via the propensity score matching approach. The convergent results of latent growth curve modeling from the 2 studies support our hypotheses regarding the relationship between becoming a leader and subsequent small, but substantial increases in conscientiousness over time and the mediating role of job role demands. The relationship between becoming a leader and change of emotional stability was not significant. This research showcases the prominence of examining and cultivating personality development for organizational research and practice

    JUMPING MODE ATOMIC FORCE MICROSCOPY ON GRANA MEMBRANES FROM SPINACH

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    Новые языковые реальности употребления претерита в немецком гипотаксисе

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    Целью статьи являются обобщение и теоретическое обоснование нового употребления претерита в относительном значении в конкретных видах придаточных предложений с презенсом в главном предложении. В статье анализируются коннотативные нюансы относительного значения претерита, регулярность замены префекта-пассива и перфекта именного составного сказуемого с глаголом "sein" на претеритальные формы в гипотаксисе, а также особое место претерита в системе немецких временных форм.Метою статті є узагальнення та теоретичне обґрунтування нового вживання претериту у релятивному значенні у конкретних видах сурядно-підрядних речень з презентом у сурядному реченні. У статті подано аналіз конототивні нюанси претериту і регулярність зміни перфекту пасиву та іменного присудка з дієсловом "sein" на претеритальні форми у гіпотаксису, а також особливе місце претериту у системі німецьких часових форм.The article aims at generalization and theoretical Explanation of modern preterit usage in relative meaning in certain types of clauses, with the Present tense in the main clause. The article deals with the analysis of connotative component meanings of the relative preterit and the regularity of substitution of preterit forms in hypotaxes for the passive perfect tense and the perfect form of the nominal compound predicate with the verb 'sein' as well as the specificity of preterit in the system of German tenses

    Increasing human motor skill acquisition by driving theta-gamma coupling

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    Skill learning is a fundamental adaptive process, but the mechanisms remain poorly understood. Some learning paradigms, particularly in the memory domain, are closely associated with gamma activity that is amplitude-modulated by the phase of underlying theta activity, but whether such nested activity patterns also underpin skill learning is unknown. Here we addressed this question by using transcranial alternating current stimulation (tACS) over sensorimotor cortex to modulate theta-gamma activity during motor skill acquisition, as an exemplar of a non-hippocampal-dependent task. We demonstrated, and then replicated, a significant improvement in skill acquisition with theta-gamma tACS, which outlasted the stimulation by an hour. Our results suggest that theta-gamma activity may be a common mechanism for learning across the brain and provides a putative novel intervention for optimising functional improvements in response to training or therapy
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