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MODELING AND IMPLEMENTATION OF SPEED GOVERNOR FOR THE HYBRID ELECTRIC VEHICLE ENGINE

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Chinese Journal of Mechanical Engineering 2005年第4期18卷 603-608页

作者： Feng qishan zhang Jianwu Yin Chengliang School of Mechanical Engineering Shanghai Jiaotong University Shanghai 200030 China

A speed control analysis for an in-line gasoline fueled internal combustion （IC） engine is presented for the purpose of alleviation of high frequency oscillations in engine revolutions. A dynamic cylinder-by-cylinder model is proposed, base on slider-crank mechanism, which is extended to develop a digital governor providing a high fidelity estimation of rotary speed oscillation for hybrid vehicle engines. A modified PID controller that P and I gain is placed in feedback path is also described for hybrid electric vehicle （HEV） engine speed regulation, By comparison between measured and estimated signals, it is demonstrated that a good agreement has been achieved and the governor behaves an excellent damping speed ripple.

关键词： Digital speed governor Engine dynamic model Slider-crank mechanism Hybrid electric vehicle (HEV)

A NEW KEY MANAGEMENT METHOD FOR AD HOC NETWORKS

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China Communications 2007年第1期4卷 8-13页

作者： Liu, Chun Liu, Jianwel zhang, qishan Beihang Univ Sch Elect & Informat Engn Beijing 100083 Peoples R China

Some security-sensitive fields like military scenarios are the main application areas of ad hoc *** those areas,security issues have to be considered seriously for the *** this paper, a key management method based on the combined public key is proposed for ad hoc networks. Through this method,private and public key pairs can be distributed to nodes of ad hoc networks *** certificate or other authentic channel is needed while two nodes perform authentication and key agreement *** key management method is especially suitable for ad hoc networks,which has no fixed infrastructure and has constrained resources.

关键词： key management combined public key ad hoc networks

The estimation method of GPS instrumental biases

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Chinese Science Bulletin 2001年第3期46卷 204-207页

作者： CHANG Qing zhang Donghe XIAO Zuo zhang qishan Department of Geophysics Peking UniversityBeijing 100071China Department of Electronic Engineering Beijing University of Aeronautics and AstronauticsBeijing 100083China

A model of estimating the global positioning system (GPS) instrumental biases and the methods to calculate the relative instrumental biases of satellite and receiver are presented. The calculated results of GPS instrumental biases, the relative instrumental biases of satellite and receiver, and total electron content (TEC) are also shown. Finally, the stability of GPS instrumental biases as well as that of satellite and receiver instrumental biases are evaluated, indicating that they are very stable during a period of two months and a half.

关键词： GPS instrumental biases TEC ionosphere.

H.264 MOTION ESTIMATION ALGORITHM BASED ON VIDEO SEQUENCES ACTIVITY

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Journal of Electronics(China) 2008年第1期25卷 125-128页

作者： Hu Weiwei zhang qishan School of Electronic and Information Engineering Beijing University of Aeronautics and Astronautics Beijing 100083 China

Motion estimation is an important part of H.264/AVC encoding progress, with high com- putational complexity. Therefore, it is quite necessary to find a fast motion estimation algorithm for real-time applications. The algorithm proposed in this letter adjudges the macroblocks activity degree first; then classifies different video sequences, and applies different search strategies according to the result. Experiments show that this method obtains almost the same video quality with the Full Search (FS) algorithm but with reduced more than 95% computation cost.

关键词： Motion estimation Block matching Diamond search H.264

A new approach for generating function sequences——Hybrid Bridge functions derived from Walsh functions

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Progress in Natural Science:Materials International 2009年第9期19卷 1153-1158页

作者： Yan Li, Qing Chang*, qishan zhang School of Electronic and Information Engineering, Beihang University, Beijing 100083, China School of Electronic and Information Engineering Beihang University Beijing 100083 China

This paper reviews the essence of the Walsh and Bridge functions from the point of view of the recursive relationship; it also unifies their expressions. A new kind of function-the hybrid Bridge function-is constructed from the definition of the hybrid matrix, in which the row vectors are taken from the Walsh and Bridge function matrices. We also propose a new approach for generating function sequences; one that uses the column vectors of the hybrid Bridge function matrix as the new function sequences. These sequences are able to adjust the number of zeroes flexibly; thus, resolving the constraint on the application of excessive zeroes in Bridge function sequences, while at the same time maximizing the research field for function sequences. Through strict mathematical analysis, it is proved that when the initial matrix order of the parent matrices and the similarity of the hybrid matrices meet certain conditions, the hybrid function sequences exhibit good orthogonal characteristics. This provides a theoretical basis for its further applications in communication systems.

关键词： Copy theory Walsh functions Bridge functions Hybrid Bridge functions

Calcium-fortified fresh milk ameliorates postmenopausal osteoporosis via regulation of bone metabolism and gut microbiota in ovariectomized rats

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Food Science and Human Wellness 2024年第3期13卷 1258-1270页

作者： qishan Wang Bin Liu Xianping Li Junying Zhao Zongshen zhang Weicang Qiao Xinyue Wei Lijun Chen School of Bioengineering Dalian Polytechnic UniversityDalian 116034China National Engineering Research Center of Dairy Health for Maternal and Child Beijing Sanyuan Foods Co.Ltd.Beijing 100163China Beijing Engineering Research Center of Dairy Beijing Sanyuan Foods Co.Ltd.Beijing 100163China

The aging of the global population has made postmenopausal osteoporosis prevention essential;however,pharmacological treatments are ***,we evaluate the effect of calcium-fortified fresh milk(FM)in ameliorating postmenopausal osteoporosis in a rat model established using bilateral *** 3 months of FM(containing vitamin D,and casein phosphopeptides,1000 mg Ca/100 g)or control milk(110 mg Ca/100 g milk)supplementation,bone changes were assessed using dual-energy X-ray absorptiometry,microcomputed tomography,and bone biomechanical *** results revealed that FM can regulate bone metabolism and gut microbiota composition,which act on bone metabolism through pathways associated with steroid hormone biosynthesis,relaxin signaling,serotonergic synapse,and unsaturated fatty acid ***,FM administration significantly increased bone mineral content and density in the lumbar spine and femur,as well as femoral compressive strength,while improving femoral trabecular bone parameters and ***,we found that the effects may be due to increased levels of estrogen,bone formation marker osteocalcin,and procollagen typeⅠN-propeptide,and decreased expression of the bone resorption marker C-telopiptide and tartrate-resistant acid phosphatase ***,the findings suggest that FM is a potential alternative therapeutic option for ameliorating postmenopausal osteoporosis.

关键词： Dairy products Calcium Vitamin D Bone turnover markers Gut microbiota Postmenopausal osteoporosis

GLONASS接收机频率合成器的设计与实现

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北京航空航天大学学报 1999年第4期25卷 384-387页

作者：刘晖张其善北京航空航天大学电子工程系

根据ＧＬＯＮＡＳＳ系统的频率计划和ＧＬＯＮＡＳＳ接收机的特定结构，提出用变化钟频法实现ＧＬＯＮＡＳＳ接收机的前端．对相应的前端频率合成器部分提出了具体要求，并给出了基于集成频率锁相环的频率合成器的设计与实现．讨论了固... 详细信息

根据ＧＬＯＮＡＳＳ系统的频率计划和ＧＬＯＮＡＳＳ接收机的特定结构，提出用变化钟频法实现ＧＬＯＮＡＳＳ接收机的前端．对相应的前端频率合成器部分提出了具体要求，并给出了基于集成频率锁相环的频率合成器的设计与实现．讨论了固有合成频率偏差的来源和消除办法．分析了频率合成器的性能指标．实验表明，该合成器稳定性好，精度高。

关键词：卫星导航导航接收机频率合成器 GLONASS FDMA

A HIGH QUALITY TV MODULATOR FOR FULL CHANNEL

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Journal of Electronics(China) 1997年第3期14卷 247-252页

作者： zhang Xiaolin zhang qishan(Beijing University of Aeronautics and Astronautics, Beijing 100083)

This paper describes a full channel TV modulator for all TV systems, which has been developed successfully. It employs advanced technique such as PLL frequency synthesizer with microwave integrated circuit, and wideband microstrip VCO and digital-analog combined integrated circuits. The key technique of the modulator is settled successfully. All the specifications of the modulator agree with Technical Standard of China, which are tested by the authority of China.

关键词： TV modulator PLL frequency synthesizer Full channel

THE GIBBS DERIVATIVES OF GENERALIZED BRIDGE FUNCTIONS

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Analysis in Theory and Applications 1997年第2期13卷 57-62页

作者： Rao Xuefang zhang qishan(Beijing University of Aeronautics and Astronatvics) Department of Electrical Enineering Beijing University of Aernautics and Astronatuics Beijing China

The logical derivatives of p-adic copy-shift and shift-copy generalized Bridge functions are given in this paper. When p equals 2, they are exactly the logical derivatives of natural ordering copy-shift and copy-shift... 详细信息

关键词： oscillatory integral operator multiplier singularity