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991.
In an in-home digital network it may be expected that several data streams (audio, video) run simultaneously over a shared
communication device, e.g., a bus. The burstiness of a data stream can be reduced by buffering data at the sending and receiving
side, thereby allowing a lower bus share allocation for the stream. In this paper we present an algorithm that determines
how much of the bus capacity and buffer space should be allocated to each stream, in order to have a feasible transmission
schedule for each stream. Furthermore, the algorithm determines a transmission schedule for each stream, indicating how much
data is transmitted over time. We show how this multiple-stream problem can be solved by repeatedly solving single-stream
problems. We present efficient algorithms to solve these single-stream problems. Furthermore, we present some experimental
results.
This revised version was published online in September 2006 with corrections to the Cover Date. 相似文献
992.
In most individuals, food intake occurs as discrete bouts or meals, and little attention has been paid to the factors that normally determine when meals will occur when food is freely available. On the basis of experiments using rats, the authors suggest that when there are no constraints on obtaining food and few competing activities, 3 levels of interacting controls normally dictate when meals will start. The first is the genetically determined circadian activity pattern on which nocturnal animals tend to initiate most meals in the dark. The second is the regularly occurring changing of the light cycle: These changes provide temporal anchors. The third relates to the size of the preceding meal, such that larger meals cause a longer delay until the onset of the next meal. Superimposed on these 3 are factors related to learning, convenience, and opportunity. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
993.
Ren M.J. Benders Rixt Kok Henri C. Moll Gerwin Wiersma Klaas Jan Noorman 《Energy Policy》2006,34(18):3612-3622
Large-scale energy reduction campaigns focusing on households generally have two shortcomings. First, an energy reduction campaign is either personalized but time intensive or time extensive but generalized. Second, because only the direct energy requirements are addressed, only 50% of the total household energy requirement is subject to reduction. The other 50%, the indirect energy requirement, is much more difficult to calculate and address and therefore not subject to reduction.
In this paper, we describe a web-based tool that has the potential to overcome both of these shortcomings. The tool addresses direct as well as indirect energy requirements. By means of a simple expert system participants obtain personalized reduction options and feedback on the energy reduced. The tool was tested in Groningen (the Netherlands) with a sample of 300 households, resulting in a direct energy reduction of about 8.5% compared to a control group. The reduction in indirect energy was not statistically significant. 相似文献
994.
Nedyalka V. Yanishlieva Emma Marinova Jan Pokorný 《European Journal of Lipid Science and Technology》2006,108(9):776-793
There is a growing interest in natural antioxidants found in plants because of the world‐wide trend toward the use of natural additives in food and cosmetics. Herbs and spices are one of the most important targets to search for natural antioxidants from the point of view of safety. This review presents the results on stabilization of lipids and lipid‐containing foods with different herbs and spices (ground materials or extracts) and reports the structure of the main antioxidatively acting compounds isolated from them. The review presents information about the antioxidative effects of rosemary, sage, oregano, thyme, ginger, summer savory, black pepper, red pepper, clove, marjoram, basil, peppermint, spearmint, common balm, fennel, parsley, cinnamon, cumin, nutmeg, garlic, coriander, etc. Among the herbs of the Labiatae family, rosemary has been more extensively studied and its extracts are the first marketed natural antioxidants. Sage and oregano, which belong to the same family, have gained the interest of many research groups as potential antioxidants. 相似文献
995.
Jan M. Macak 《Electrochimica acta》2006,52(3):1258-1264
In this paper, we investigate the electrochemical formation of layers of self-organized high aspect ratio TiO2 nanotubes, grown by anodization of Ti in viscous electrolytes at different temperatures. In electrolytes consisting of glycerol or ethylene glycol with small additions of fluorides, the nanotube morphology can be strongly influenced by the viscosity, the electrolyte temperature and the applied potential. Compared with water-based electrolytes, in viscous electrolytes much longer and smoother tubes can be grown. Depending on experimental conditions, the nanotubes have an aspect ratio reaching up to about 150 for glycerol and 32 for ethylene glycol. The results further show that in glycerol electrolytes the current efficiency for nanotube formation is close to 100% (this is significantly higher than for comparable water-based electrolytes). 相似文献
996.
TS Yeh YY Jan LB Jeng TC Chen TL Hwang MF Chen 《Canadian Metallurgical Quarterly》1998,26(5):1224-1226
We performed a 17-year retrospective analysis of 10 cases of hepatocellular carcinoma presenting as pyogenic liver abscess. Spontaneous tumor necrosis and biliary obstruction caused by tumor thrombi, superimposed with bacterial infection, were the two major pathogeneses. Exact diagnosis of the underlying hepatocellular carcinoma was made for five of the 10 patients before management was attempted. Main clinical manifestations included fever, chills, right-upper-quadrant pain, malaise, anorexia, jaundice, and hepatomegaly. Characteristics such as middle age and male sex, seropositivity for hepatitis B and/or hepatitis C, chronic liver disease, unexplained anemia, marked weight loss, and a severely inversed albumin/globulin ratio raise suspicions about the underlying hepatocellular carcinoma. Management strategies included percutaneous drainage (n = 3), surgical drainage (n = 4), and hepatectomy (n = 3) in addition to administration of parenteral antibiotics in all cases. The prognosis was dismal, with a mean survival of 3.5 months (range, 8 days to 6 months). 相似文献
997.
[Correction Notice: An erratum for this article was reported in Vol 92(1) of Journal of Applied Psychology (see record 2006-23339-016). The issue number at the upper left corner of the title page (p. 1359) is wrongly stated as 5 rather than 6. Furthermore, in Table 1 (p. 1362), the value in Column 12, Row 4 (Emo resources) should be -.07 rather than -0.7.] Two longitudinal studies investigated the issue of match between job stressors and job resources in the prediction of job-related strain. On the basis of the triple-match principle (TMP), it was hypothesized that resources are most likely to moderate the relation between stressors and strains if resources, stressors, and strains all match. Resources are less likely to moderate the relation between stressors and strains if (a) only resources and stressors match, (b) only resources and strains match, or (c) only stressors and strains match. Resources are least likely to moderate the relation between stressors and strains if there is no match among stressors, resources, and strains. The TMP was tested among 280 and 267 health care workers in 2 longitudinal surveys. The likelihood of finding moderating effects was linearly related to the degree of match, with 33.3% of all tested interactions becoming significant when there was a triple match, 16.7% when there was a double match, and 0.0% when there was no match. Findings were most consistent if there was an emotional match or a physical match. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
998.
Jan Willem Polderman 《Systems & Control Letters》1997,32(5):7742-269
We consider behaviors in which we distinguish two types of variables, manifest variables, the variables that are of interest to the user and latent variables, the variables that are introduced to obtain a first representation. The problem is to find a representation of the manifest behavior, that is, we want to eliminate the latent variables. If the original behavior can be represented by linear differential equations with constant coefficients, then under certain conditions the same is true for the manifest behavior. In this note we formulate and study these conditions. The results are illustrated by means of some examples. As an application we study behaviors in image representation. 相似文献
999.
1000.
On the Role of Oxygen Storage in Three-Way Catalysis 总被引:1,自引:0,他引:1
The role of the so-called oxygen storage and release capacity (OSC) in promoting the activity of noble metals in the three-way catalysts (TWCs) is critically discussed. It is shown that the promoting effects of CeO2 in the TWCs cannot be attributed to a simple redox type of effect according to the reaction CeO2 ? CeO2 ? x + x/2O2, since multiple and sometimes intriguing effects of CeO2 promoter have been observed, particularly in the latest generation of TWCs containing modified CeO2–ZrO2 mixed oxides. 相似文献