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QoS-guaranteed multi-relay selection and power allocation optimization in cooperative systems

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The Journal of China Universities of posts and Telecommunications 2010年第6期17卷 25-31页

作者： CHEN Dan,JI Hong,LI Xi,LI Yi College of Information and Communication Engineering,beijing university of posts and Telecommunications,beijing 100876,China [a] College of Information Communication Engineering Beijing University of Posts Telecommunications Beijing 100876 China

This paper investigates the relay selection and power allocation problem in multi-user based cooperative networks,where intermediate relay nodes help source forward information to destination using decode-and-forward （DF） relaying protocol. Specifically,we propose a novel multi-relay nodes selection strategy taking both instantaneous channel state information （I-CSI） and residual energy into consideration,by which ＇emergence＇ diversity gain can be achieved and the imbalance of resource utilization can be overcome. Besides,using Largangian dual-primal decomposition and subgradient projection approach,an optimal power allocation algorithm at source and cooperative relay nodes is presented with the constraints of each user＇s individual quality of service （QoS） requirements and system total transmit power. Theoretical analysis and simulation results demonstrate that the proposed scheme can significantly improve energy efficiency,while guaranteeing a good balance between achievable data rate and average network lifetime with relatively low implementation complexity.

关键词： cooperative diversity relay selection resource allocation Lagrangian dual-primal decomposition subgradient projection

Decoding algorithms for shortened-extended turbo product codes in WiMAX systems

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Science in China(Series F) 2009年第12期52卷 2415-2423页

作者： XU ChangLong1,3,4. YANG Wei1,2 & YE WeiChen4.1 State Key Laboratory of Networking and Switching Technology, beijing university of posts and Telecommunications, beijing 10004., China 2 State Key Laboratory of Rail Traffic Control and Safety, beijing Jiaotong university, beijing 10004., China 3 National Mobile Communications Research Laboratory, Southeast university, Nanjing 210096, China 4.Intel Corporation, beijing Kerry Center, Guanghua Road 1, beijing 100020, China State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 100044 China State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University Beijing 100044 China National Mobile Communications Research Laboratory Southeast University Nanjing 210096 China Intel Corporation Beijing Kerry Center Guanghua Road 1 Beijing 100020 China

The component codes of turbo product codes in WiMAX systems are extended Hamming codes and single parity check codes as well as their shortened forms, In this paper, three novel iterative decoding algorithms based on Chase, MAP algorithms and their combination are proposed for shortened-extended turbo product codes. The iterative decoding algorithm based on Chase algorithm is proposed to reduce the decoding complexity without any performance loss. An efficient MAP algorithm is then proposed to decode the component codes of shortened single parity check codes and shortened-extended Hamming codes. A comprehensive performance comparison of the proposed decoding schemes is conducted for three typical classes of turbo product codes in WiMAX OFDMA systems. The suitable decoding algorithms are recommended for different classes based on the simulation results.

关键词： block code product code iterative decoding

Digital Rights Management：Model,Technology and Application

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China Communications 2017年第6期14卷 156-167页

作者： Zhaofeng Ma School of Cyberspace Security Beijing University of Posts and Telecommunications Beijing 100876 China

with rapid achievement of current information technology and computing ability and applications,much more digital content such as films,cartoons,design drawings,office documents and software source codes are produced in daily work,however to protect the content being copying,shared or deliberately stolen by inside or outside,digital rights management(DRM) became more and more important for digital content *** this paper,we studied various DRM model,technology and application,and first proposed DRM Security Infrastructure(DSI),in which we defined encryption,hash,signature algorithm,watermarking algorithms,authentication,usage control,trusted counter,conditional trace,secure payment,and based on the DSI we then proposed a whole classification approach and architecture of all kinds of DRMs,in which we proposed 6 typical classes of copyrights and content protection DRMs architecture:(1) Software-oriented DRM,(2) e Book-oriented DRM,(3) Video-oriented DRM,(4. Image-Oriented DRM(5) Unstructured data oriented DRM,(6) Text-oriented *** on the above DSI,we then proposed a dynamic DRM model selection method for various DRM application,which can be adapted dynamically for different technology of different applications,which can provide awhole solution for variant DRM development in a rapid and customized *** proposed DRM method,technology and application in this paper provided a common,flexible and extendable solution for variant DRM scenes,and can support rapid and customized ***,we proposed an opinion that the future life will enter into a new era that the content usage and consumption will not again adopt DRM technology rather than with law,liberty and morality.

关键词： digital rights management drm security infrastructure encryption watermark usage control drm-free

Location based spectrum sensing performance analysis over fading channels in cognitive radio networks

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The Journal of China Universities of posts and Telecommunications 2010年第5期17卷 26-31页

作者： YAO Hai-peng,ZHOU Zheng,SUN Xuan,LI Bin School of Information and Communication Engineering,beijing university of posts and Telecommunications,beijing 100876,China [a] School of Information Communication Engineering Beijing University of Posts Telecommunications Beijing 100876 China

This paper analyzes the spectrum sensing performance over fading channel,in which a licensee and multiple unlicensed users coexist and operate in the licensed channel in a local *** overall average probabilities of detection and false alarm by jointly taking the fading and the locations of all secondary users into account are derived,and a statistical model of cumulate interference is *** on the cumulate interference,a closed-form expression of outage probability at the primary user’s receiver according to a specific distribution of the fading is ***,the sensing parameters so as to minimize the total spectrum sensing error and maximize the average opportunistic throughput are *** is noted that the overall average performance analysis and results here enable to benchmark the design of specific spectrum sensing algorithms.

关键词： spectrum sensing cognitive radio cumulate interference outage probability

2023 Guideline for the management of hypertension in the elderly population in China

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Journal of Geriatric Cardiology 2024年第6期21卷 589-630页

作者： Hypertension Branch of Chinese Geriatrics Society,beijing Hypertension Association,National Clinical Research Center of the Geriatric Diseases Qi HUA Li FAN Zeng-Wu WANG Jing LI 不详 Xuanwu Hospital Capital Medical UniversityBeijingChina Chinese PLA General Hospital BeijingChina Fuwai Hospital Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina

Preamble Hypertension is one of the most common chronic diseases and the primary risk factor for stroke,myocardial infarction and even cardiovascular *** than half of the elderly population has high blood *** people are a unique group,and strategies for the prevention,diagnosis,evaluation,and treatment of hypertension in elderly individuals differ significantly from those in the general population.

关键词： hypertension prevention diagnosis

Some Properties of The Solutions of Higher Analogue of The Painlevé Equation

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Acta Mathematicae Applicatae Sinica 2006年第1期22卷 59-64页

作者： Ye-zhou Li School of Science,beijing university of posts and Elecommunications,beijing 100876,China School of Aeronautical Sciences and Engineering,beijing university of Aeronautics and Astronautics,beijing 100083 School of Science Beijing University of Posts Elecommunications Beijing 100876 China School of Aeronautical Sciences Engineering Beijing University of Aeronautics Astronautics Beijing 100083

In this paper, we investigate the value distribution properties for the solution w（z） of higher-order Painlevé equations. We prove that the Nevanlinna＇s second main inequality for w（z） is reduced to an asymptoti... 详细信息

关键词： Painlevé equation the second main inequality value distribution

Improved discriminative training for generative model

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The Journal of China Universities of posts and Telecommunications 2009年第3期16卷 126-130页

作者： WU Ya-hui,GUO Jun,LIU Gang Laboratory of Pattern Recognition and Intelligent System,beijing university of posts and Telecommunications,beijing 100876,China [a]Laboratory of Pattern Recognition and Intelligent System beijing university of posts and Telecommunications beijing 100876 China

This article proposes a model combination method to enhance the discriminability of the generative model. Generative and discriminative models have different optimization objectives and have their own advantages and drawbacks. The method proposed in this article intends to strike a balance between the two models mentioned above. It extracts the discriminative parameter from the generative model and generates a new model based on a multi-model combination. The weight for combining is determined by the ratio of the inter-variance to the intra-variance of the classes. The higher the ratio is, the greater the weight is, and the more discriminative the model will be. Experiments on speech recognition demonstrate that the performance of the new model outperforms the model trained with the traditional generative method.

关键词： model combination discriminability generative model training speech recognition

Network parameters awareness for routing discovery in autonomic optical Internet

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The Journal of China Universities of posts and Telecommunications 2009年第2期16卷 84-88,128页

作者： JIN Jin WANG Hong-xiang JI Yue-feng Key Laboratory of Optical Communication and Lightwave Technologies,beijing university of posts and Telecommunications,beijing 100876,China [a]Key Laboratory of Optical Communication and Lightwave Technologies beijing university of posts and Telecommunications beijing 100876 China

The article proposes a network parameter-awareness （NPA） method and applies it to routing discovery algorithms in autonomic optical Internet. This NPA method can perceive the main parameters of the network, such as delay, jitter and traffic, which can represent the current situation of the network. And these parameters enable network to determine the appropriate nodes for routing discovery. The simulation results of evaluating performance of a network with NPA method and its routing applications show that the method and its applications in routing improve the performance of the network significantly with quality of service （QoS） guaranteed.

关键词： NPA autonomic optical Internet self-aware muting QoS

Progress and review of the studies on the end-Triassic mass extinction event

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Science China Earth Sciences 2005年第12期48卷 2049-2060页

作者： DENG Shenghui1,2, LU Yuanzheng1,2,3 & XU Daoyi4.1. Research Institute of Petroleum Exploration and Development, beijing 100083, China 2. Key Laboratory of Oil and Gas Reservoir of PetroChina, beijing 100083, China 3. China university of Geosciences, beijing 100083, China 4. Institute of Geology, China Earthquake Administration, beijing 100029, China 1. Research Institute of Petroleum Exploration and Development 100083 Beijing China 2. Key Laboratory of Oil and Gas Reservoir of PetroChina 100083 Beijing China 3. China university of Geosciences 100083 Beijing China 4. Institute of Geology China Earthquake Administration 100029 Beijing China

The mass extinction at the end-Triassic is one of the five biggest in the Phanerozoic. However,it is the least well understood among these five events, and only till last decade it became a great academic interesting subject to geologists. The evidences for this event come obviously from bivalves, brachiopods, ammonites, corals, radiolaria, ostracods and foraminifera of marine habitats, and plants and tetrapods of terrestrial realm. By contrast, for some of other groups, such as marine gastropods and marine vertebrates, no mass extinction has been recog-nized yet. The extinction event is strongly marked at specific level but shown a complicated situa-tion at generic and family levels. Dramatic changing of the environment, such as the temperature raise due to the greenhouse effect, the marine anoxic habitats caused by a sudden transgression after the regression at the end of Triassic, has been claimed to be the main cause of the extinction. Many hypotheses have been suggested to demonstrate the mechanisms of the environment changing, among which two popular ones are the bolide impact and volcanic eruption. The Triassic-Jurassic (Tr-J) boundary mass extinction event is still poorly understood because no enough data have been obtained from the Tr-J boundary successional sections of both marine and terrestrial sediments, and most of these studies were regionally restricted. The basic aspects of the event and its associated environmental conditions remain poorly characterized and the causal mechanism or mechanisms are equivocal. Some authors even doubt its occurrence. China has many successionally developed terrestrial and marine Tr-J sections. Detailed studies of these sections may be important and significant for well understanding of the event.

关键词： progress, review, end-Triassic, mass extinction, mechanism, Tr-J boundary.