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排序方式: 共有253条查询结果,搜索用时 38 毫秒
61.
随着WIFI网络的大面积覆盖,移动终端用户有了更快捷的数据传输效率以及更好的用户体验.为了解决移动终端视频实时传输过程中电量消耗过大以及因编码方式不同所造成的视频传输实时性较差的问题,分别提出适合Android系统的H.263、H.264视频流的封装策略和传输框架,利用终端对所拍摄现场进行视频采集和编码,这样能够随时将场景在服务器端实时显示.同时,为了解决终端在传输过程中电量损耗过大的问题,在对影响终端电量的不同参数分析的基础上,找出了这些参数和电量之间的权重关系,即在视频清晰度正常的情况下,影响手机电量的3个主要参数编码方式、分辨率、帧率的能耗比值约为6∶5∶1,在视频清晰度高的情况下,三者的比值约为6∶7∶2,这对移动终端的节能有很好的参考价值. 相似文献
62.
本文设计实现了一个用于视频流分发的应用层组播系统,系统由视频采集、视频编解码、组播传输和服务器四个模块构成。视频捕获采用Video for Windows(VFW)技术实现,编解码基于H.263标准。网络结构上提出使用混合P2P树形结构,降低了中心服务器的压力。服务器负责会议成员信息的管理,为组播树的建立与维护提供支持。组播传输使用基于度约束的构造算法,考虑了节点带宽和计算能力。系统已投入运行,基本达到设计目标。 相似文献
63.
In this letter,a novel method based on Temporal and Spatial Prediction(TSP)to detect all-zero DCT coefficients based on temporal and spatial prediction between neighboring blocks is proposed.The presented algorithm uses the knowledge of all-zero block distribution in the previous frame combined with the Sum of Absolute Difference(SAD)of the corresponding macroblock as a criterion .The algorithm almost needs no additional computation ,and it shows an excellent overall detection performance in simulations. 相似文献
64.
P. Mastanaiah G. Madhusudhan Reddy K. Satya Prasad C.V.S. Murthy 《Journal of Materials Processing Technology》2014,214(11):2316-2324
Futuristic aerospace applications such as advanced turbojet and scramjet engines used in subsonic, supersonic, and trans-atmospheric flights require materials with ever-increasing temperature and load bearing capabilities for improved performance. The materials C103 niobium alloy and C263 nimonic alloy are widely employed in the manufacturing of scramjet engine components. Efforts to join these two materials by fusion welding process have revealed that they are metallurgically incompatible due to the extreme propensity to form brittle intermetallics. The possibility of interdicting interlayer is explored to overcome the formulation of intermetallics and the attempts have not yielded fruitful results. Explosive welding/cladding is one of the possible ways to join these materials, as it is a solid state joining process. 相似文献
65.
A comparative study of nickel-base, iron-base, and iron-nickel base superalloys showed Inconel MA754 (oxide dispersion strengthened)
to be particularly high in vibration damping capacity. 相似文献
66.
The current paper presents the simulated 3D Finite Element Model (FEM) and experimental validation while turning the Nimonic C-263 super alloy using a cemented carbide cutting tool. FEM machining simulations was carried out using a Lagrangian finite element based machining model to predict the tangential cutting force, temperature distribution at tool tip and the effective stress and strain. All simulations were performed according to the cutting conditions designed, using the orthogonal array. The work piece was considered as perfectly plastic and its shape was taken as a curved model. An experimental validation of the cutting process was conducted in order to verify the simulated results of tangential cutting force and temperature at tool tip and the comparison shows that the percentage error 6% was observed and the shear friction factor 0.6 indicates good agreement between the simulated results and the experiment results. As the cutting speed is increased from 22 m/min to 54 m/min at higher feed rate, a larger strain to an extent of up to 6.55 mm/mm, a maximum value of 810 MPa stress and higher temperature localization to an extent of 620 °C at tool tip were observed. 相似文献
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69.
用软件实现在低码率信道上的实时视频编解码是图象压缩领域的研究热点,本文就此提出了一种基于离散余弦变换(DCT)系数的频域块匹配法,通过引入阈值矩阵,降低了运动估值的运算量,提高了搜索效率。计算机仿真表明,该算法可在PC机上用软件实时实现,具有较好的实用价值。 相似文献
70.