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Achievement of Bluetooth adaptive packet selection strategies based on SNR estimation

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The Journal of China Universities of Posts and Telecommunications 2016年第1期23卷 8-13,48页

作者： Li Jing Chen Wanzhong Zhao Xiaohui School of Telecommunication Engineering Jilin University

It is necessary to estimate channel quality in order to put Bluetooth adaptive packet selection strategies into practice. However, the current Bluetooth channel quality estimation algorithms are either poor at timeliness or not applicable to systems which only support basic rate （BR） data packets （Gaussian frequency shift keying （GFSK） modulation scheme）. It is investigated to apply the channel quality estimation algorithm based on power spectrum to Bluetooth adaptive packet selection strategies in this paper. Simulation results and analysis show that the proposed channel quality estimation algorithm based on power spectrum can achieve the accuracy less than 0.2 dB in the estimation range required by Bluetooth adaptive packet selection strategies. It has simple calculation and strong timeliness. The algorithm can also be suitable for different modulation schemes of Bluetooth data packets. It provides a good precondition for the achievement of Bluetooth adaptive packet selection strategies.

关键词： computer application Bluetooth power spectrum signal-to-noise ratio estimation

Security Analysis and Improvement of TNC IF-T Protocol Binding to TLS

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China Communications 2013年第7期10卷 85-92页

作者：肖跃雷王育民庞辽军 State Key Laboratory of Integrated Service Networks School of Life Science and TechnologyXidian University

The TNC IF-T Protocol Binding to TLS(TIPBT) is specified by Trusted Computing Group(TCG) for TNC assessment ***,the TIPBT cannot be analysed by current Strand Space Model(SSM) because of the different requirements from the traditional security *** order to solve this problem,first,we give an extension of the SSM and point out the TIPBT cannot prevent Man-in-the-Middle(MITM) attacks in some cases based on the extended ***,we improve the TIPBT and show that the improved TIPBT can resist MITM attacks in the extended SSM.

关键词： computer application MITM attacks SSM TIPBT

Modeling and Simulation for Complex Repairable System with Built-in Test Equipment

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Defence Technology（防务技术） 2011年第2期7卷 119-125页

作者：吕学志于永利张柳任帆 Department of Equipment Command Ordnance Engineering College Shijiazhuang 050003 Hebei China Artillery Command Academy Xuanhua 075100 Hebei China

In order to research the effects of built-in test(BIT) on the system and select BITand test strategy,the complex repairable systems with BITequipment are modeled and simulated by using *** on the model,the influences of different built-in test equipments,maintenance time and error probabilities on the system usability are *** simulation results showthat they effect on the system *** simulation method of complex system based on Simulink provides a technique approach to research the effects of BITon the system and select BITand test strategy.

关键词： computer application complex system built-in test equipment Simulink

A Correlation Tracking Algorithm Based on Template Partition Motion Estimation

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Defence Technology（防务技术） 2009年第4期5卷 310-316页

作者：徐一鸣刘晓利刘怡昕 National Key Laboratory of Transient Physics Nanjing University of Science and Technology Nanjing Artillery Academy

A correlation tracking algorithm based on template partition motion estimation proposed for improving real time performance of the conventional correlation matching algorithms. The target trajectory fitted using the least square with equal space in whole interval and the target prediction point is found out. According to the requirements of block motion estimation(BME) algorithm,the template divided into some macro blocks. The searching process is conducted by using diamond search algorithm around the prediction point and the optimal motion vector of each block is calculated. A point corresponding to the motion vector with the best matching is taken as a rough matching point of the template. The relation of relative position between the block with matching point and the searching area determined to decide whether to conduct precise matching search or to construct a new search area in the gradient direction. The target tracking experiment results show that over 70% time cost can be reduced caompared with the conventional correlation matching algorithm based on full search method.

关键词： computer application correlation matching target trajectory prediction block motion estimation diamond search

A Method of Digitally Reconstructed Radiographs Based on Medical CT Images

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computer Aided Drafting,Design and Manufacturing 2009年第2期19卷 49-55页

作者： YU Wei-wei HE Fei XI Ping School of Mechanical Engineering and Automation Beijing University of Aeronautics and Astronautics Beijing 100191 China Department of Orthopaedic Surgery 1 st Affiliated Hospital of Kunming Medical College Kunming 650032 China

A complete and detail method is described to get digitally reconstructed radiographs （DRRs）. Casting rays to traverse CT images, computing CT values of resample points by interpolation, then converting CT value to its attenuation coefficient by using simplified segment function. Finally, DRRs enhancement is made to get the better display of region of interest （ROI）, and a new way is adopted to adjust the customization coefficient. The experimental results show that the proposed method is effective in generating the satisfied DRRs.

关键词： computer application digitally reconstructed radiographs DRR ray casting

An HLA/RTI Architecture Based on Multi-thread Processing

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Defence Technology（防务技术） 2010年第3期6卷 182-188页

作者：管莉邹汝平朱斌郝重阳 Institute of Electronics and Information Engineering Northwestern Polytechnical University No.203 Research Institute of China Ordnance Industries

In order to improve the real-time performance of the real-time HLA(high level architecture) in the application of massive data communication volume,multi-thread processing was adopted,thread pool structure was introduced into the system,different threads to handle corresponding message queues was utilized to respond different message ***,an allocation strategy of semi-complete deprivation of priority was adopted,which reduces thread switching cost and processing burden in the system,provided that the message requests with high priority can be responded in time,thus improves the system's overall *** design and experiment results indicate that the method proposed in this paper can improve the real-time performance of HLA in distributed system applications greatly.

关键词： computer application HLA/RTI multi-thread distributed interactive simulation system

Integrated Digital Design for Radar Typical Structure Using Knowledge Based Engineering

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computer Aided Drafting,Design and Manufacturing 2007年第2期17卷 8-14页

作者： DUAN Wen-rui LIU Chui XI Ping School of Mechanical Engineering and Automation Beijing University of Aeronautics and Astronautics Beijing 100083 China

With the deep research of knowledge engineering and the widespread applications of CAD technology, the joining of knowledge engineering with CAD is the focus of advanced manufacturing. An intelligent approach is presented for configurating the typical structural components of radar. Case based reasoning, rule based reasoning, geometric, constraint solving and domain ontology are merged into a compound knowledge model. The main frame and workflow of radar typical structural component design system are illustrated. Experiments show this approach is efficient and effective.

关键词： computer application radar knowledge based engineering (KBE) artificial intelligence

Research on the Component-Centered Version Model in the PDM System

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computer Aided Drafting,Design and Manufacturing 2006年第1期16卷 50-56页

作者： FANG Yong-ze ZHONG Yi-fang Jimei University Xiamen 361021 China Huazhong University of Science and Technology Wulaan 430074 China

A version of a product consists of the product structure tree and the versions of all its components. The model includes two sets of data： attributes and documents describing each component. The paper discusses the version change relations between a sub-node component and a up-node component in a product structure tree, analyzes the version control system for a static reference and that for a dynamic reference and proposes a product structure model in support of dynamic reference, which is easy to use and contains a complete set of information providing an essential way of data organization for the PDM system.

关键词： computer application version model product data management versioncontrol static reference dynamic reference

Simulation of Somatotype of Hydraulic Turbine Draft-Tube

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computer Aided Drafting,Design and Manufacturing 2011年第1期21卷 33-38页

作者： DU Ting-na HUI Yuan Chongqing Jiaotong University Chongqing 400074 China

Elbow draft-tubes are widely used in large- and medium-sized hydropower stations in many countries. During the application, handling the somatotype of elbow tubes has been found challenging： in order to maintain the designed shape of draft tube and to meet the requirement of construction lofting, the configuration of reinforcing bars and the fabrication of templates, the geometry of elbow tubes has to be accurately calculated to draw engineering graphics. Based on the derived equations in this paper, the motion of elbow tube curve envelope is simulated by using computers, which shows directly the smoothness of the curve and provides dynamic simulation for the study and optimization of the design and construction of elbow draft tubes, along with the front view and bottom view.

关键词： computer application draft-tube elbow tube curve envelope motion simulation hidden line elimination process computer graphic processing