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排序方式: 共有380条查询结果,搜索用时 15 毫秒
1.
Distributed fair scheduling in a wireless LAN 总被引:1,自引:0,他引:1
Fairness is an important issue when accessing a shared wireless channel. With fair scheduling, it is possible to allocate bandwidth in proportion to weights of the packet flows sharing the channel. This paper presents a fully distributed algorithm for fair scheduling in a wireless LAN. The algorithm can be implemented without using a centralized coordinator to arbitrate medium access. The proposed protocol is derived from the Distributed Coordination Function in the IEEE 802.11 standard. Simulation results show that the proposed algorithm is able to schedule transmissions such that the bandwidth allocated to different flows is proportional to their weights. An attractive feature of the proposed approach is that it can be implemented with simple modifications to the IEEE 802.11 standard. 相似文献
2.
Samarthya Bhagia Nidia C. Gallego Nitilaksha Hiremath David P. Harper Richard A. Lowden Richard R. Lowden Yunqiao Pu Uday Vaidya Soydan Ozcan Arthur J. Ragauskas 《应用聚合物科学杂志》2021,138(32):50797
High speed friction grinding has been used to grind plant and food substances in water but never been explored for grinding of thermoplastics like polylactic acid (PLA), low and high density polyethylene and polypropylene. Such grinding was investigated in this work and was made possible by using 0.5% guar gum solution instead of just water because increasing the viscosity of water reduced their settling and the speed of passing through the grinder. Tensile, flexural, and impact strengths of the plastics were studied and higher grinding efficiency of PLA could be explained by its low elongation-at-break compared to low density polyethylene, high density polyethylene, and polypropylene. The microplastics (2000–45 μm) were studied for mass and particle size distributions and by scanning electron microscopy, 13C CP/MAS NMR, Fourier transform infrared spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. In addition, viscosity of guar gum and contact angles was measured. This new technology can produce finely ground microplastics (710–45 μm) for a variety of applications. 相似文献
3.
Utilising the methodology of content analysis, this study uses a multidisciplinary approach to define public e-procurement. Various aspects of e-procurement have been discussed from information systems, supply chain management, electronic commerce/electronic government, and public procurement to come up with an integrated definition of public e-procurement. Following this, e-procurement assimilation has been defined and its impact on procurement efficiency has been evaluated. Following the confirmatory factor analysis in structural equation modelling, dimensional level analysis in ANOVA has been undertaken for the three forms of e-procurement technologies namely e-tendering, e-catalogue management systems, and e-marketplace. The results show the positive and significant impact of the assimilation process on procurement efficiency. 相似文献
4.
Kaushik Patel Jagdish Prajapati Rajiv Vaidya S. G. Patel 《Bulletin of Materials Science》2005,28(5):405-410
Single crystals of the lamellar compound, ZrSe3, were grown by chemical vapour transport technique using iodine as a transporting agent. The grown crystals were characterized
with the help of energy dispersive analysis by X-ray (EDAX), which gave confirmation about the stoichiometry. The optical
band gap measurement of as grown crystals was carried out with the help of optical absorption spectra in the range 700–1450
nm. The indirect as well as direct band gap of ZrSe3 were found to be 1.1 eV and 1.47 eV, respectively. The resistivity of the as grown crystals was measured using van der Pauw
method. The Hall parameters of the grown crystals were determined at room temperature from Hall effect measurements. Electrical
resistivity measurements were performed on this crystal in the temperature range 303–423 K. The crystals were found to exhibit
semiconducting nature in this range. The activation energy and anisotropy measurements were carried out for this crystal.
Pressure dependence of electrical resistance was studied using Bridgman opposed anvils set up up to 8 GPa. The semiconducting
nature of ZrSe3 single crystal was inferred from the graph of resistance vs pressure. The results obtained are discussed in detail. 相似文献
5.
Discontinuity-Preserving Surface Reconstruction Using Stochastic Differential Equations 总被引:1,自引:0,他引:1
We address the problem of reconstructing a surface from irregularly spaced sparse and noisy range data while concurrently identifying and preserving the significant discontinuities in depth. It is well known that, starting from either the probabilistic Markov random field model or the mechanical membrane or thin plate model for the surface, the solution of the reconstruction problem can be eventually reduced to the global minimization of a certain “energy” function. Requiring the preservation of depth discontinuities makes the energy function nonconvex and replete with multiple local minima. We present a new method for obtaining discontinuity-preserving reconstruction based on the numerical solution of an appropriate Ito vector stochastic differential equation (SDE). The reconstructed surface is found by following the sample path of the (stochastic) diffusion process that solves the SDE in question. Our central contribution is the demonstration of the efficacy of the stochastic differential equation technique for solving a vision problem. Through comparisions of the results of our method to those of the two well-known existingglobalminimization based reconstruction techniques, we show a significant improvement in the final reconstructions obtained. 相似文献
6.
7.
Careful selection of steaming and attrition conditions during thermo‐mechanical pretreatment can increase enzymatic conversion of softwood 下载免费PDF全文
8.
S. Prasanth Vaidya P. V. S. S. R. Chandra Mouli 《Multimedia Tools and Applications》2018,77(5):5609-5635
Multimedia Tools and Applications - Ownership identification and copyright protection are two major concerns for digital data. Digital watermarking provides the best solution for these issues. In... 相似文献
9.
10.
The bactericidal characteristics of nano-copper oxide or functionalized zeolite coated concrete pipes against Acidithiobacillus thiooxidans were studied by measuring the temporal variation of bacterial dry cell weight measurement, cellular Adenosine Triphosphate production, as well as oxygen uptake rate of the aforementioned bacterium. Uncorroded (UC), severely corroded (SC), and moderately corroded (MC) concrete pipes were electrochemically coated with a nano-copper oxide, while another uncorroded concrete pipe was used to apply functionalized zeolite coating (Z2). Specimens were characterized by field emission-scanning electron microscopy, and optical microscopy. Oxygen uptake rate of the bacterium was the highest in UC followed by the MC. Oxygen uptake rate and cellular Adenosine Triphosphate decreased progressively in Z2 and SC throughout the duration of the experiment due to decline in live bacterial cell. The maximum bacterial specific growth rate was 1.1 × 10−2 day−1 for both UC and MC, with a decay rates varying from 1.4 × 10−2 to 2.6 × 10−2 day−1. The minimum concentration limits for the inhibition of the bacterium in the nano-copper oxide coated concrete pipes ranged from 2.3 mg to 2.6 mg Cu per mg dry cell weight. 相似文献