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1.
Introduction.     
This article introduces the current issue of Health Psychology. The call for early intervention to prevent adulthood health problems and the need to consider each period of children's lives within its developmental perspective are the main emphases in this special issue of the journal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
2.
The transport of video images is likely to be a major application of high-speed networks of the future. These applications are capable of utilizing the high bandwidths that will become available with the advent of B-ISDN. In this paper, we propose a new methodology (called TES) for modeling the frame bitrate stream generated by compressed video sources. The main characteristic of this method is that it can model an arbitrary marginal distribution and approximate the autocorrelation structure of the random bitrate process generated by compressed frames. We present a modeling example utilizing this method, based on data from a video coding algorithm employing a layering technique. Using the source model, we develop a simulation model of a multiplexer of video sources. We show that this model can be used to address a number of design issues that arise in this class of problem. In particular, we show that for a layered video coding algorithm, it is possible to have a gain in the number of sources multiplexed at the cost of some loss of low priority packets.  相似文献   
3.
Minimizing envy in distributed discrete resource or task allocation, is an unusual distributed optimization challenge, since the quality of the allocation for each of the agents is dependent, not only on its own allocation, but on the allocation of others as well. Thus, in order to perform distributed search for allocations with minimal envy there is a need to design innovative algorithms that can cope with the challenging constraint structure of an envy minimization problem. Distributed methods for minimizing envy among agents in indivisible resource allocation problems are presented. First, Distributed Envy Minimization Problems (DEMP) are formulated as Distributed Constraint Reasoning problems. When the DEMPs are large, and cannot be solved by a complete search an incomplete local search algorithm is presented. Each transfer of a good from one agent to another involves the change of state of more than one agent. Thus, a minimizing envy local search algorithm must build upon actions (transfers) that include multiple agents. Since DEMPs are particularly susceptible to local minima during local search, the paper proposes an algorithm that alternates between two different hill climbing search phases. The first phase uses one-transfer steps while the other exploits envy cycle elimination steps. An algorithm that minimizes envy while preserving efficiency, is proposed. The proposed algorithm finds a Pareto optimal allocation with low envy. In the context of resource allocation problems, a Pareto optimal solution is particularly desirable since it presents a stable solution. The proposed algorithm first finds a divisible Pareto optimal envy-free allocation using a Fisher market equilibrium. This allocation is transferred into an indivisible allocation of goods while maintaining the Pareto optimal characteristic of the allocation and a low envy level among agents.  相似文献   
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The authors investigated the direct and interactive effects of the job demand– control–support (JDC-S) model’s components on subsequent changes in high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides (TRI) separately for male and female employees. In contrast to all 14 past studies on these relationships, the authors used a longitudinal design. Study participants (N = 1,137, 66% men) were all apparently healthy employees who underwent a routine health check at 2 points in time (Time 1 and Time 2) about 22 months apart. In these analyses, the authors controlled for the Time 1 level of each criterion and for other confounders. Most of the direct and moderating effects found did not support the predictions of the JDC-S model; this finding is in agreement with the majority of past cross-sectional studies. The authors did not find any evidence supporting the existence of a reverse causation for either of the components of the JDC-S model. The authors suggest that serum lipids may not be a physiological mechanism mediating the effects of the JDC-S model on atherosclerotic diseases. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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S Melamed  J Luz  T Najenson  E Jucha  M Green 《Ergonomics》1989,32(9):1101-1110
This study was designed to evaluate the association of a single, integrated measure of simultaneous exposure to a number of adverse work and environmental conditions, termed the Ergonomic Stress Level (E-S-L), on workers' accident and sickness absence rates. The factors determining the E-S-L were body motion and posture, physical effort, active hazards and environmental stressors. E-S-L evaluation was based on 'walk-through' hazard inventories, direct observations, measurements and interviews. Workers were assigned to one of four stress levels ranging from low (A) to high (D). Subjects were 729 males, aged 20-67 years, employed in five factories in Israel. A linear relationship between E-S-L AND accident incidence was found, increasing from the lowest to the highest E-S-L. Moreover, workers more sensitive to environmental stressors, as indicated by their reported subjective annoyance, showed higher accident rates across all the ergonomic stress levels, a tendency which was statistically significant at levels C and D. On the other hand, sickness absence was significantly related to the overall subjective stress experienced, as manifested by reported job dissatisfaction and somatic complaints, and not directly to E-S-L. These findings highlight the role of aggregate work stress, coupled with individual sensitivity to environmental stressors, in increasing the risk of accidents.  相似文献   
9.
An analysis is made of the role and the place of Russian nuclear power stations on the federal (all-Russia) wholesale market for electrical energy and power, the structure of the costs of producing electricity at these stations, the competitiveness of nuclear energy sources with other producers of electricity. Possible ways are discussed for reducing the cost of producing electricity at nuclear power stations. Journal version of the plenary paper “From the first nuclear power station in the world to the power engineering of the twenty first century” (Annual Conference of Nuclear Society, Obninsk, June 28 to July 2, 1999). Rosénergoatm Concern. Translated from Atomnaya énergiya, Vol. 87, No. 2, pp. 92–101, August, 1999.  相似文献   
10.
This third-generation 1.1-GHz 64-bit UltraSPARC microprocessor provides 1-MB on-chip level-2 cache, 4-Gb/s off chip memory bandwidth, and a new 200 MHz JBus interface that supports one to four processors. The 87.5-million transistor chip is implemented in a seven-layer-metal copper 0.13-/spl mu/m CMOS process and dissipates 53 W at 1.3 V and 1.1 GHz.  相似文献   
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