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71.
72.
某型飞机航空军械仿真训练系统设计 总被引:1,自引:1,他引:1
针对航空军械保障训练成本高、风险大、实施难等问题,设计了一种基于工控机与PLC控制的某型飞机航空军械仿真训练系统,该系统能设置航空军械保障的训练任务,仿真外挂物管理系统对武器的操作控制,对军械保障训练的结果进行分析评估,实现了航空军械保障训练的全流程的仿真,实际仿真训练结果表明,采用该系统实施军械保障训练能量化训练过程,降低训练风险,节约训练成本。 相似文献
73.
This paper presents a new parallel computing model, called H-BSP, which adds a hierarchical concept to the BSP(Bulk Synchronous Parallel) computing model. An H-BSP program consists of a number of BSP groups which are dynamically created at run time and executed in a hierarchical fashion. H-BSP allows algorithm designers to develop more efficient algorithms by utilizing processor locality in the program. Based on the distributed memory model, H-BSP provides a group-based programming paradigm and supports Divide & Conquer algorithms efficiently. This paper describes the structure of the H-BSP model, complexity analysis and some examples of H-BSP algorithm. Also presented is the performance characteristics of H-BSP algorithms based on the simulation analysis. Simulation results show that H-BSP takes advantages of processor locality and performs well in low bandwidth networks or in a constant-valence architecture such as 2-dimensional mesh. It is also proved that H-BSP can predict algorithm performance better than BSP, due to its locality-preserving nature. 相似文献
74.
Low temperature wafer direct bonding 总被引:11,自引:0,他引:11
Qin-Yi Tong Cha G. Gafiteanu R. Gosele U. 《Journal of microelectromechanical systems》1994,3(1):29-35
A pronounced increase of interface energy of room temperature bonded hydrophilic Si/Si, Si/SiO2, and SiO2/SiO 2 wafers after storage in air at room temperature, 150°C for 10-400 h has been observed. The increased number of OH groups due to a reaction between water and the strained oxide and/or silicon at the interface at temperatures below 110°C and the formation of stronger siloxane bonds above 110°C appear to be the main mechanisms responsible for the increase in the interface energy. After prolonged storage, interface bubbles are detectable by an infrared camera at the Si/Si bonding seam. Desorbed hydrocarbons as well as hydrogen generated by a reaction of water with silicon appear to be the major contents in the bubbles. Design guidelines for low temperature wafer direct bonding technology are proposed 相似文献
75.
A heterogeneous system or distributed system typically contains different types of processors. Some jobs can execute on certain types of processors but not other types. Processors of different types may have different speeds. We present several worst-case upper bounds and efficient algorithms for determining the completion times of independent jobs that have arbitrary timing constraints and variable execution times and are scheduled on available processors dynamically in a priority-driven manner. Bounds and algorithms take into account the effects of nonmigratability, nonpreemptability and different levels of migratability. 相似文献
76.
Lee Cha DiVerdi Stephen H llerer Tobias 《IEEE transactions on visualization and computer graphics》2009,15(1):20-33
We present an immaterial display that uses a generalized form of depth-fused 3D (DFD) rendering to create unencumbered 3D visuals. To accomplish this result, we demonstrate a DFD display simulator that extends the established depth-fused 3D principle by using screens in arbitrary configurations and from arbitrary viewpoints. The feasibility of the generalized DFD effect is established with a user study using the simulator. Based on these results, we developed a prototype display using one or two immaterial screens to create an unencumbered 3D visual that users can penetrate, examining the potential for direct walk-through and reach-through manipulation of the 3D scene. We evaluate the prototype system in formative and summative user studies and report the tolerance thresholds discovered for both tracking and projector errors. 相似文献
77.
Zhe Liang Wanpracha Art Chaovalitwongse Meeyoung Cha Sue B. Moon 《Computers & Operations Research》2010,37(10):1731-1739
This paper presents a redundant multicast routing problem in multilayer networks that arises from large-scale distribution of realtime multicast data (e.g., Internet TV, videocasting, online games, stock quotes). Since these multicast services commonly operate in multilayer networks, the communications paths need to be robust against a single router or link failure as well as multiple such failures due to shared risk link groups (SRLGs). The main challenge of this multicast is to ensure the service availability and reliability using a path protection scheme, which is to find a redundant path that is SRLG-disjoint (diverse) from each working path. The objective of this problem is, therefore, to find two redundant multicast trees, each from one of the two redundant sources to every destination, at a minimum total communication cost whereas two paths from the two sources to every destination are guaranteed to be SRLG-diverse (i.e., links in the same risk group are disjoint). In this paper, we present two new mathematical programming models, edge-based and path-based, for the redundant multicast routing problem with SRLG-diverse constraints. Because the number of paths in path-based model grows exponentially with the network size, it is impossible to enumerate all possible paths in real life networks. We develop three approaches (probabilistic, non-dominated and nearly non-dominated) to generate potentially good paths that may be included in the path-based model. This study is motivated by emerging applications of internet-protocol TV service, and we evaluate the proposed approaches using real life network topologies. Our empirical results suggest that both models perform very well, and the nearly non-dominated path approach outperforms all other path generation approaches. 相似文献
78.
VoIP (Voice over Internet Protocol), which provides voice calls as well as additional services at cheaper prices than PSTN (Public Switched Telephone Network), is gaining ground over the latter, which had been the dominant telephone network in the past. This kind of a VoIP service is evolving into a dedicated mVoIP service for the smartphone which allows calls to be made at cheap prices using a WiFi network, as the number of smartphone users is skyrocketing as of late. While an increase in the user base is expected for mVoIP, a packet network is an open network which means anyone can easily gain access and so there can be various problems. To mitigate this, in this paper an authentication system is designed which has an AA (Attribute Authority) server added to VoIP in order to increase security and discriminate user access. In this paper a system for addressing security vulnerabilities from the increase in the use of VoIP services and providing differentiated services according to user access privileges is designed. This paper is organized as follows: Chapter 1 gives the introduction; Chapter 2 is on related research; Chapter 3 describes the proposed technique and system; Chapter 4 implements the system and analyzes its the performance; and Chapter 5 gives the conclusions. 相似文献
79.
Automatic Real-Time Video Matting Using Time-of-Flight Camera and Multichannel Poisson Equations 总被引:1,自引:0,他引:1
Liang Wang Minglun Gong Chenxi Zhang Ruigang Yang Cha Zhang Yee-Hong Yang 《International Journal of Computer Vision》2012,97(1):104-121
This paper presents an automatic real-time video matting system. The proposed system consists of two novel components. In
order to automatically generate trimaps for live videos, we advocate a Time-of-Flight (TOF) camera-based approach to video
bilayer segmentation. Our algorithm combines color and depth cues in a probabilistic fusion framework. The scene depth information
returned by the TOF camera is less sensitive to environment changes, which makes our method robust to illumination variation,
dynamic background and camera motion. For the second step, we perform alpha matting based on the segmentation result. Our
matting algorithm uses a set of novel Poisson equations that are derived for handling multichannel color vectors, as well
as the depth information captured. Real-time processing speed is achieved through optimizing the algorithm for parallel processing
on graphics hardware. We demonstrate the effectiveness of our matting system on an extensive set of experimental results. 相似文献
80.
Maximum Likelihood Sound Source Localization and Beamforming for Directional Microphone Arrays in Distributed Meetings 总被引:1,自引:0,他引:1
In distributed meeting applications, microphone arrays have been widely used to capture superior speech sound and perform speaker localization through sound source localization (SSL) and beamforming. This paper presents a unified maximum likelihood framework of these two techniques, and demonstrates how such a framework can be adapted to create efficient SSL and beamforming algorithms for reverberant rooms and unknown directional patterns of microphones. The proposed method is closely related to steered response power-based algorithms, which are known to work extremely well in real-world environments. We demonstrate the effectiveness of the proposed method on challenging synthetic and real-world datasets, including over six hours of recorded meetings. 相似文献