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61.
Video transmission over IEEE 802.11e wireless networks still shows poor performance for large bandwidth demand and frequently changed environments. Thus, several enhancements of IEEE 802.11e were proposed. On the other hand, big frames and simultaneous sending of adjacent frames always cause packet dropping for buffer overflow. In the past, we proposed an IEEE 802.11e enhancement named DFAA and a content aware mechanism to solve the above problems. The motivation of this paper is to find a proper way to integrate these two mechanisms. A DFAA enhancement (DFAA-E) is proposed to make up the insufficiency of content aware mechanism. Experiments results show that the combination of DFAA-E and content aware mechanism improves the video decoded quality greatly. And its performance can be further enhanced by selecting the suitable settings of certain parameters. 相似文献
62.
Minghuan Wang Xia Chen Wenjun Tong Jiajie Wang Xindi Wang 《The International Journal of Advanced Manufacturing Technology》2020,107(1):157-166
Microdimples as a typical surface texture has been widely used for improving the properties in tribology and heat transfer fields. Ultrasonically assisted 相似文献
63.
User Modeling and User-Adapted Interaction - Personality plays a pivotal role at work. Many scholars have investigated the association between personality and language usage habits in the English... 相似文献
64.
Xi Shen Li-Peng Cao Jian-Fa Zhao Wei-Peng Wang Qing-Qing Liu Yuan Yao Jun-Jie Li Chang-Zhi Gu Ming-Wei Chen Chang-Qing Jin Ri-Cheng Yu 《Journal of the American Ceramic Society》2019,102(11):6469-6474
We propose the question of the modulated structures of copper oxide is caused by the [CuO2] in-plane oxygen vacancy or apical oxygen vacancy. Sr2CuO3+δ single-crystal samples were prepared using high-temperature and high-pressure methods. The major phase of Sr2CuO3+δ (δ = 0.4) single-crystal system is found to be constituted by the 5 a modulated structure with the Fmmm space group, which originates from the [CuO2] in-plane oxygen vacancy appearing in octahedral Cu-O. Besides, the presence of the [CuO2] in-plane oxygen vacancy may obliterate the superconductivity of the system. Experimental results deduce that the oxygen vacancy may appear in the apical oxygen sites in high-temperature copper oxide superconductors. 相似文献
65.
Li Zhang Huiqun Yuan Sheng-Hung Chang Anthony Lam 《The International Journal of Advanced Manufacturing Technology》2020,107(3):1081-1089
With the continuous development of the Internet of Things technology and the proposal of “Made in China 2025”, the construction of IoT applicat 相似文献
66.
赵源 《智能计算机与应用》2021,11(6):26-30
本文通过利用WIFI探针设备,将其布设在上海轨道交通列车车厢内探测客流,同时收集同日同车次的车厢称重数据、断面客流数据进行数据分析与融合,得到列车车厢满载率的估计值,从而建立起更为精确的地铁车厢满载率数据. 相似文献
67.
The flame front deformation instability of low-velocity filtration combustion within an inert packed bed is studied based on the initial preheating non-uniformity. Based on the experimental phenomena, an initial thermal perturbation model is numerically proposed so as to predict the deformation behaviors of the flame front instabilities. The numerical prediction indicates that the assumption of an initial thermal perturbation is a feasible explanation as the cause of the flame front inclination instability. As the initial thermal perturbation increases, the phenomena of the flame front break and shrinking instabilities could easily occur at high filtration velocity or low equivalence ratio. Moreover, the evolutions of the flame front break rate and the shrinking rate are quantitatively analyzed. 相似文献
68.
介绍了铁塔加工中角钢零件优化下料管理系统,阐明了系统的模块化结构及工作原理。建立的面向角钢加工工艺的优化下料管理系统可以将生产管理与下料优化两大功能整合为一体,使用极为方便。该系统在铁塔生产中,可节省大量材料,有效地提高了企业的经济效益。 相似文献
69.
PDC钻头水力结构优化设计研究 总被引:9,自引:0,他引:9
在PDC钻头工作过程中,钻井液对钻头体表面的冲洗、冷却和润滑是保证钻头正常工作的一个非常重要的条件。对PDC钻头而言,水力结构(主要是中心水眼和冠部水道)设计的重要性尤其突出。以前,对钻头水力系统研究只能通过实验的方法进行,研究周期长、成本高、结构调整不方便,而数值模拟的方法在几年前还不成熟,甚至静态的复杂结构流场问题基本无法解决。为此,在提出PDC钻头水力结构优化设计原则的基础上,对PDC钻头的三维流场进行了数值模拟。模拟中考虑了钻头的喷嘴布置位置、直径、数量以及切削齿对流场的影响。计算结果表明,原设计在喷嘴布置位置和喷射角度上存在不足,以此为基础进行了水力结构的优化设计。文中的研究成果成功地应用在新型钻头水力结构的设计中,研究方法为PDC钻头水力结构优化分析奠定了理论基础。 相似文献
70.
X.W. Lou C. Yuan E. Rhoades Q. Zhang L.A. Archer 《Advanced functional materials》2006,16(13):1679-1684
We report a general template strategy for rational fabrication of a new class of nanostructured materials consisting of multicore shell particles. Our approach is demonstrated by encapsulating Au or Pt nanoparticles in silica shells. Other superstructures of these hollow shells, like dimers, trimers, and tetramers can also be formed by nanoparticle‐mediated self‐assembly. We have also used the as‐prepared multicore Au–silica hollow particles to perform the first studies of Ostwald ripening in confined microspace, in which chloride was found to be an efficient mediating ligand. After treatment with aqua regia, Au–Cl complex is formed inside the shell, and is found to be very active under in situ transmission electron microscopy observations while confined in a microcell. This aspect of the work is expected to motivate further in situ studies of confined crystal growth. 相似文献