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81.
82.
ABSTRACT

This article works to dispel the myth that Puerto Rican female urban high school students living in poverty are not capable of performing at high academic levels. This article attempts to counteract these beliefs by describing the four success factors that seven Puerto Rican female high school students attribute to their high academic achievement. These success factors are: (1) religiosity and extracurricular activities as sources of social capital, (2) affirming and maintaining a Puerto Rican identity, (3) maternal influences on students' academic achievement and, (4) the potential for caring teachers and other school staff to influence high academic achievement. Finally, our findings suggest that opportunities for Latinas and other youth of color are still inequitably structured in large, comprehensive high schools. Hence, we argue that schools must continue to bridge the large gap between themselves and the families/communities they serve and utilize the funds of knowledge and social capital that their students already bring to school.  相似文献   
83.
We develop a property‐rights model of the firm in which production entails a continuum of uniquely sequenced stages. In each stage, a final‐good producer contracts with a distinct supplier for the procurement of a customized stage‐specific component. Our model yields a sharp characterization for the optimal allocation of ownership rights along the value chain. We show that the incentive to integrate suppliers varies systematically with the relative position (upstream versus downstream) at which the supplier enters the production line. Furthermore, the nature of the relationship between integration and “downstreamness” depends crucially on the elasticity of demand faced by the final‐good producer. Our model readily accommodates various sources of asymmetry across final‐good producers and across suppliers within a production line, and we show how it can be taken to the data with international trade statistics. Combining data from the U.S. Census Bureau's Related Party Trade database and estimates of U.S. import demand elasticities from Broda and Weinstein (2006), we find empirical evidence broadly supportive of our key predictions. In the process, we develop two novel measures of the average position of an industry in the value chain, which we construct using U.S. Input–Output Tables.  相似文献   
84.
Abstract

The 24-h dietary intake, nutritional status parameters and psychosomatic factors of two-shift, three-shift and day workers were compared. Estimations of the dietary intake (across a work cycle) were made by use of a nutrient database. No significant differences were found between the groups for a large number of nutritional variables: intake of energy; intake and percentage of energy from protein, fat, total carbohydrates and sucrose; intake of coffee; and intake and density of vitamins and minerals. Only minor differences were found between the groups with regard to the quantitative intake of alcohol and calcium, and with regard to the quality of the diet (percentage of energy from alcohol, density of calcium). The groups differed significantly with respect to attitude towards work hours (three-shift workers being most negative in their attitude) and sleep disturbances (shift workers being most negative). The three-shift workers were more evening-oriented and they had higher concentrations of glucose in their blood. It was concluded that work hours not related to nutritional intake—at least not when total amounts across time are considered. It was also concluded that work hours were not related to Body Mass Index or blood lipids: triglycerides, total cholesterol, LDL (low-density lipoprotein) cholesterol and HDL (high-density lipoprotein) cholesterol.  相似文献   
85.

A method for evaluating the robustness of medium term multisite distributed schedule is presented. The method of robustness evaluation is based on steps and tools associated with the conceptual model of a MultiSite Reactive Production Activity Control (MSR-PAC). The MSR-PAC makes it possible to study the sensitivity of the scheduled plans in presence of perturbations. These must be evaluated before being dispatched to the shop-floors. At present, to the best of the authors' knowledge, there is no means to make this evaluation in the distributed systems such as extended enterprise. The monitoring of errors is based on the discrepancy between the two flow-shape functions that model respectively the dynamics of the scheduled manufacturing orders and the state of the perturbed production. The MSR-PAC is based on a multisite agent system and on the monitoring of the perturbed virtual jobshops. The method can also be used for controlling short term distributed production activities.  相似文献   
86.
This article deals with a stochastic optimal control problem for a class of buffered multi-parts flow-shops manufacturing system. The involved machines are subject to random breakdowns and repairs. The flow-shop under consideration is not completely flexible and hence requires setup time and cost in order to switch the production from a part type to another, this changeover is carried on the whole line. Our objective is to find the production plan and the sequence of setups that minimise the cost function, which penalises inventories/backlogs and setups. A continuous dynamic programming formulation of the problem is presented. Then, a numerical scheme is adopted to solve the obtained optimality conditions equations for a two buffered serial machines two parts case. A complete heuristic policy, based on the numerical observations which describe the optimal policies in system states, is developed. It will be shown that the obtained policy is a combination of a KANBAN/CONWIP and a modified hedging corridor policy. Moreover, based on our observations and existent research studies extension to cover more complex flow-shops is henceforth possible. The robustness of such a policy is illustrated through sensitivity analysis.  相似文献   
87.
The purpose of this study was to examine the viability of hybrid competitive strategies, which combine differentiation and cost elements, and their impact on organizational performance in comparison to pure strategies and ‘stuck‐in‐the‐middle’ combinations. Previous studies have focused above all on US data. The analysis carried out in this paper has centred on a multisectorial sample of 164 Spanish firms. The findings show that a large number of the organizations use different types of hybrid strategies and also that such strategies tend to be associated with higher levels of firm performance, particularly those strategies which place emphasis on a greater number of strategic dimensions, and specifically on innovation differentiation.  相似文献   
88.
This study aimed to deepen our understanding of the motivational mechanisms involved in the relationship between transformational leadership (TFL) and employee functioning. Drawing on the TFL literature, the job demands–resources model and self-determination theory, we propose an integrative model that relates TFL to employee psychological health (burnout and psychological distress), attitudes (occupational commitment and turnover intention) and performance (professional efficacy, self-reported individual and objective organizational performance) through two explanatory mechanisms: perceived job characteristics (job demands and resources) and employee motivation (autonomous and controlled). This research was conducted in two occupational settings (nurses and school principals), using a distinct variable operationalization for each. Results of both studies provide support for the hypothesized model, suggesting that TFL relates to optimal job functioning (psychological health, job attitudes and performance) by contributing to favourable perceptions of job characteristics (more resources and less demands) and high-quality work motivation (more autonomous motivation and less controlled motivation) in employees. Theoretical contributions and managerial implications as well as directions for future research are presented.  相似文献   
89.
The aim of this study was to provide insight into the differential relationships between job characteristics (job demands and resources) and employee functioning by examining the psychological and motivational processes involved. Drawing on self-determination theory, we tested a model in which job demands are positively related to negative manifestations of employee functioning (psychological distress and psychosomatic complaints) through psychological need frustration and low-quality work motivation (controlled motivation), whereas job resources are positively related to positive manifestations of employee functioning (work engagement and job performance) through need satisfaction and high-quality work motivation (autonomous motivation). Data were collected from 699 Canadian nurses. Structural equation modelling (SEM) results support the proposed model: psychological needs and work motivation partially mediated the relationship between job characteristics and employee functioning. Specifically, job demands negatively predicted employee functioning (high distress and psychosomatic complaints, low engagement and performance) through need frustration and controlled motivation. In contrast, while positively predicting need satisfaction and negatively predicting need frustration, job resources fostered optimal work motivation (more autonomous and less controlled motivation) and employee functioning. The implications for self-determination theory (SDT) and research on occupational health and stress are discussed.  相似文献   
90.
Zusammenfassung:  Der Beitrag beschreibt die Einbettung des 360-Grad-Feedbacks in ein Programm der Führungskr?fteentwicklung. 360-Grad-Feedback ist eine Voraussetzung für die systematische Kompetenzentwicklung der Führungskr?fte eines Unternehmens. Darüber hinaus k?nnen die Entwicklungs- und Lernm?glichkeiten, die ein individuelles Coaching bietet, durch ein vorheriges 360-Grad-Feedback optimiert werden. Die bei ThyssenKrupp Services mit dem F?rderprogramm „best-for-best“ gesammelten Erfahrungen zeigen deutlich, dass die Kombination von einem 360-Grad-Feedback mit gezielten Coaching-Angeboten ein echtes Erfolgsmodell darstellt.
Danièle SchwarzEmail:
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