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Container stacking rules are an important factor in container terminal efficiency. In this paper, we investigate two concepts to increase efficiency and compare them to several benchmark algorithms, using a discrete-event simulation tool. The first concept is to use knowledge about container departure times, in order to limit the number of reshuffles. We stack containers leaving shortly before each other on top of each other. The second concept is the trade-off between stacking further away in the terminal versus stacking close to the exit points and accepting more reshuffles. It is concluded that even the use of imperfect or imprecise departure time information leads to significant improvements in efficiency. Minimizing the difference in departure times proved to be important. It was also found that the trade-off between stacking further away in the terminal versus stacking close by the exit points and accepting more reshuffles leads to improvements over the benchmark.  相似文献   
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Integrins play a central role in cellular adhesion and anchorage of the cytoskeleton and participate in the generation of intracellular signals, including tyrosine phosphorylation. We have recently isolated a cDNA encoding a unique, focal adhesion-associated protein tyrosine kinase (FAK) that is a component of an integrin-mediated signal transduction pathway. Here we report the isolation of cDNAs encoding the C-terminal, noncatalytic domain of the FAK kinase, termed FRNK (FAK-related nonkinase). Both the FAK- and FRNK-encoded polypeptides, pp125FAK and p41/p43FRNK, are expressed in normal chicken embryo cells. pp125FAK and p41/p43FRNK were localized to focal adhesions, suggesting that pp125FAK is directed to the focal adhesions by sequences within its C-terminal domain. We also show that the fibronectin-dependent increase in tyrosine phosphorylation of pp125FAK is accompanied by a concomitant posttranslational modification of p41FRNK.  相似文献   
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e-Research is intended to facilitate collaboration through distributed access to content, tools, and services. Lessons about collaboration are extracted from the findings of two large, long-term digital library research projects. Both the Alexandria Digital Earth Prototype Project (ADEPT) and the Center for Embedded Networked Sensing (CENS) project on data management leverage scientific research data for use in teaching. Two forms of collaboration were studied: (1) direct, in which faculty work together on research projects; and (2) indirect or serial, in which faculty use or contribute content to a common pool, such as teaching resources, concepts and relationships, or research data. Five aspects of collaboration in e-Research are discussed: (1) disciplinary factors, (2) incentives to adopt e-Learning and e-Research technologies, (3) user roles, (4) information sharing, and (5) technical requirements. Collaboration varied by research domain in both projects, and appears partly to be a function of the degree of instrumentation in data collection. Faculty members were more interested in tools to manage their own research data than in tools to facilitate teaching. They also were more reflective about their research than teaching activities. The availability of more content, tools, and services to incorporate primary data in teaching was only a minimal incentive to use these resources. Large investments in a knowledge base of scientific concepts and relationships for teaching did not result in re-use by other faculty during the course of the project. Metadata requirements for research and for teaching vary greatly, which further complicates the transfer of resources across applications. Personal digital libraries offer a middle ground between private control and public release of content, which is a promising direction for the design of digital libraries that will facilitate collaboration in e-Research.  相似文献   
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The influence of short-term heating or cooling and exposure to visible light on the bleaching of a gamma-irradiated glass stored at 20°C is investigated by photometry. The decay of radiation-induced color centers is retarded under the action of heating and gradually regains its initial rate after the heating ceases. The transient stage can be described as relaxation. It is revealed that isothermal photobleaching does not exhibit a similar aftereffect.  相似文献   
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Dietary alteration or intervention is an ideal method of preventing or treating hypertension. Medication may be eliminated or reduced in many cases. Correction of obesity and alcohol abuse are confirmed methods of treating hypertension. Reduction of sodium intake is effective in that portion of the population which is salt-sensitive. Probably, the ratio of sodium to potassium is of importance and increasing potassium intake while reducing sodium intake is effective in many situations. Evidence is being reported which indicates that adequate intake of calcium, and perhaps magnesium, is effective in preventing hypertension. Limited information indicates that a sufficiency of dietary essential fatty acids and fibre are effective in hypertension prevention. The role of dietary protein, carbohydrates, fat, cholesterol, vitamins, and essential elements (other than those mentioned above) in the pathogenesis has not been fully elucidated at this time, but there are indications that adequate intakes are beneficial in hypertension. Water hardness may have some effect in reducing hypertension incidence, and any effectiveness would probably result from calcium and magnesium in the drinking water. Animal studies and limited human studies indicate some detrimental effects of heavy metals, such as lead and cadmium, upon the pathogenesis of hypertension. Information regarding caffeine intake is inconclusive.  相似文献   
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Several programs based on the Fast Fourier Transform (FFT) Algorithm developed by Cooley and Tukey are available. The Cooley and Tukey algorithm for the FFT requires the number of data N be a power of 2. Along with a subroutine which implements the Cooley and Tukey algorithm, six other new subroutines which are extensions of the Cooley and Tukey algorithm are given in this paper. Some applications to geoscience, along with some examples where the FFT subroutine based on the Cooley and Tukey algorithm is undesirable also are given.  相似文献   
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