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A 3-D Polarization Quadrature Amplitude Modulation Method and Constellation Mapping

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China Communications 2015年第10期12卷 16-26页

作者： SUN Xuehong ZHANG Haiying zeng zhimin GUO Caili Beijing Key Laboratory of Network System Architecture and Convergence School of Information and Communication EngineeringBeijing University of Posts and Telecommunications Key Laboratory of Intelligent Sensing for Desert Information School of Physics Electrical EngineeringNingxia University

As a new three-dimensional(3-D)modulation,Polarization Quadrature Amplitude Modulation(PQAM) can be regarded as the combination of Pulse amplitude modulation(PAM) and Quadrature Amplitude Modulation(QAM) *** can better improve the digital communication efficiency and reduce the Symbol error rate(SER) of the system than one-dimensional or two-dimensional modulation *** to design a feasible constellation is the most concerned problem of PQAM *** paper first studies the relationship between the SER theoretical value of PQAM and the distribution of M and N,proposes a new M,N allocation ***,a new and straightforward design method of constructing higher-level 3-D signal constellations,which can be matched with the PQAM,and the constellation can divided into three different structures according to the ary for ***,the simulation results show that:in PQAM system,the modulation scheme and the constellation mapping scheme are proposed in this paper which can effectively reduce the system SER and improve the anti-noise performance of the system.

关键词： polarization quadrature amplitude modulation minimum euclidean distance symbol error probability 3-D constellation

Limited Feedback Bit Allocation for Cooperative Multi-cell Systems with Multi- user MIMO

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China Communications 2012年第1期9卷 34-39页

作者： Shi Junfeng Zhang Tiankui zeng zhimin Laboratory of Network System Architecture and Convergence Key Laboratory of Beijing CityBeijing University of Posts and TelecommunicationsBeijing 100876P.R.China

For the cooperative multi-cell systems with muki-user MIMO, a new limited feedback bit allocation scheme is proposed to minimize the rate loss caused by quantization error. In the proposed scheme, the Channel State Information （CSI） feedback of cell-edge user for the local service cell and the adjacent interference cell are separately quantized. Based on the upper bound of the rate loss of cell-edge user due to the limited feedback, the number of feedback bits for quantized CSI of the local service cell and the adjacent cell are optimized with the fixed total bits of the limited feedback. The simulation shows that our proposed scheme of feedback bits allocation efficiently decreases the interference and increases the rate of systems compared with that of equal bits allocation and those of other allocations.

关键词： limited feedback Block Diagonalization(BD) precoding multi-cell multi-user MIMO

Best Effort Spectrum Allocation Scheme for Femtocell Networks in Dense Deployment

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China Communications 2014年第8期11卷 109-116页

作者： XIA Hailun ZHAO Yan zeng zhimin Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Postsand Telecommunications Beijing100876 R R. China

In orthogonal frequency division multiple access(OFDMA) based femtocell networks,the co-tier interference among femto base stations(FBS) becomes important in multiuser and densely deployed *** order to mitigate the co-tier interference and enhance the system total throughput,this paper proposed a best effort spectrum allocation scheme based on the extension of graph *** the scheme,a controller was proposed to collect the channel state information(CSI)of all femtocell user equipments(FUEs) in a certain ***,the controller evaluated the signal-to-interference Ratio(SIR) of each FUE and determined the set of its interference *** calculating the received power matrix(RPM) among FUEs and building interference graph matrix(IGM),different spectrum resource blocks(RBs) were assigned to the users with interference relation,while users without interference relation shared the same RBs,which could increase the spectrum *** results show that the proposed algorithm can significantly improve the RB usage efficiency compared with the basic graph coloring theory,and more than 80% improvement can be acquired in dense deployment ***,the throughput of both cell edge macro user equipments(MUEs) and cell edge FUEs is guaranteed on the premise of low interference.

关键词： femtocell OFDMA interferencemitigation spectrum allocation throughputenhancement

Exploring the intellectual structure based on co-citation network analysis: A case study of diabetes

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Data Science and Informetrics 2023年第3期3卷 98-124页

作者： Zhibo Zhuang Penghui Lyu zhimin zeng School of Public Administration Sichuan UniversityChengduChina Shenzhen Institute for Advanced Study University of Electronic Science and Technology of ChinaShenzhenChina

As the number of diabetics increases worldwide,the amount of research so as to bibliometric re-search on diabetes is also *** order to review the existing research on diabetes from a macro perspective and to remedy the lack of attention given to conference papers,this paper collected a total of 67,104 diabetes-related conference papers on the theme of"diabetes"up to 23 October 2020 in the core collection of Web of *** for bibliometric analysis include Citespace and vosviewer and other tools such as Excel and Origin are applied for statistical analysis and visualization of the ***,publication trend,document co-citation,journal co-citation and author co-citation are analyzed based on these papers,and core docu-ments,journals and authors are *** study not only shows the current situation of a-cademic conferences related to diabetes research but also,to a certain extent,reveals the devel-opment of the diabetes research situation in the whole ***,this study quantitatively analyzed the intellectual base on diabetes,which can be an illustration of the benefits of biblio-metric analysis as a tool in scientific research.

关键词： Co-citation analysis Bibliometrics Diabetes Conference papers Visualization

国有企业经济行为的法律规制:以中国铁路总公司为例

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维普期刊数据库

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中国行政管理 2014年第2期 87-90页

作者：曾志敏清华大学公共管理学院博士研究生北京100084

本文以中国铁路总公司为例,探讨了国有企业的性质及其经济行为的法律规制问题,认为国有企业天然地具有国家性质和市场性质的双重性质,其经济行为也必然呈现出不同性质,应受到不同性质的法律规制。本文主张必须要对国有企业的国家性质和... 详细信息

本文以中国铁路总公司为例,探讨了国有企业的性质及其经济行为的法律规制问题,认为国有企业天然地具有国家性质和市场性质的双重性质,其经济行为也必然呈现出不同性质,应受到不同性质的法律规制。本文主张必须要对国有企业的国家性质和市场性质及其相应的业务范畴进行较为清晰地划分:对于国家性质的业务范畴必须创建一套精密周到的公法尤其是行政法的规制系统,以保障社会公平和正义的资源分配;而对于市场性质的业务范畴则要纳入经济公法的规制系统并接受民商法律体系的规范,从而保障市场的公平竞争。从根本上说,这种法制安排是为了防止国有资产的流失以及政治利益集团绑架国家利益等至为恶劣情形的出现。

关键词：国有企业法律规制中国铁路总公司公法

Enhanced autophagic clearance of amyloid-βvia histone deacetylase 6-mediated V-ATPase assembly and lysosomal acidification protects against Alzheimer's disease in vitro and in vivo

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Neural Regeneration Research 2025年第9期20卷 2633-2644页

作者： zhimin Long Chuanhua Ge Yueyang Zhao Yuanjie Liu Qinghua zeng Qing Tang Zhifang Dong Guiqiong He Institute of Neuroscience School of Basic Medical SciencesChongqing Medical UniversityChongqingChina Department of Anatomy Chongqing Medical UniversityChongqingChina Department of Physiology Chongqing Medical UniversityChongqingChina Pediatric Research Institute Children’s Hospital of Chongqing Medical UniversityChongqingChina Ministry of Education Key Laboratory of Child Development and Disorders Children’s Hospital of Chongqing Medical UniversityChongqingChina National Clinical Research Center for Child Health and Disorders Children’s Hospital of Chongqing Medical UniversityChongqingChina Chongqing Key Laboratory of Child Neurodevelopment and Cognitive Disorders Children’s Hospital of Chongqing Medical UniversityChongqingChina

Recent studies have suggested that abnormal acidification of lysosomes induces autophagic accumulation of amyloid-βin neurons,which is a key step in senile plaque ***,resto ring normal lysosomal function and rebalancing lysosomal acidification in neurons in the brain may be a new treatment strategy for Alzheimer's *** acetylation/deacetylation plays a central role in lysosomal ***,we show that inhibiting the classic microtubule deacetylase histone deacetylase 6 with an histone deacetylase 6 shRNA or thehistone deacetylase 6 inhibitor valproic acid promoted lysosomal reacidification by modulating V-ATPase assembly in Alzheimer's *** rthermore,we found that treatment with valproic acid markedly enhanced *** clearance of amyloid-βaggregates,and ameliorated cognitive deficits in a mouse model of Alzheimer's *** findings demonstrate a previously unknown neuroprotective mechanism in Alzheimer's disease,in which histone deacetylase 6 inhibition by valproic acid increases V-ATPase assembly and lysosomal acidification.

关键词： Alzheimer's disease amyloid-β APP/PS1 mice autophagy cognitive impairment histone deacetylase 6 lysosomal acidification microtubule acetylation valproic acid V-ATPase

Neighbour Peer Selection Scheme Based on Effective Capacity for Mobile Peer-to-Peer Streaming

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China Communications 2013年第5期10卷 89-98页

作者：夏海轮王宁曾志民 Beijing Key Laboratory of Network System Architecture and Convergence School of Information and Communication Engineering Beijing University of Posts and Telecommunications

For Peer-to-Peer (P2P) streaming services in mobile networks, the selection of appropriate neighbour peers from candidate peers with demanding data is an important approach to improve Quality-of-Service (QoS). This paper proposes a novel Effective Capacity Peer Selection (ECPS) scheme based on effective capacity. In the ECPS scheme, the neighbour peer selection problem was modeled using the Multiple Attribute Decision Making (MADM) theory, which considered multiple factors of candidate peers, including Signal to Interference and Noise Ratio (SINR), residency time, power level, security, moving speed, and effective capacity. This model could increase the suitability of ECPS for wireless mobile environments. Then, the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) was used to solve the MADM problem and identify the preferred neighbour peers. Simulation results show that the ECPS scheme can improve the network throughput, reduce packet delay by about 82%, and almost double the packet delivery ratio of the mobile P2P streaming service.

关键词： P2P mobile P2P streaming peer selection effective capacity MADM QoS

Key MAC Layer Technologies of Cognitive Radio Network

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ZTE Communications 2009年第2期7卷 21-26页

作者： zeng zhimin, Guo Caili (School of Information and Communication Engineering , Beijing University of Posts and Telecommunications , Beijing 100876 , P . R . China )

As a smart spectrum sharing technology, Cognitive Radio (CR) is becoming a hot topic in the field of wireless telecommunications. Besides providing traditional services, the cognitive radio network Media Access Control (MAC) layer is required to perform an entirely new set of functions for effective reusing spectrum opportunity, without causing any harmful interference to incumbents. Spectrum sensing management selects and optimizes sensing strategies and parameters by the selection of sensing mode, sensing period, sensing time, sensing channel, and sensing quiet period. Access control avoids collision with primary users mainly by cooperation access and transparent access. Dynamic spectrum allocation optimizes the allocation of uncertain spectrum for binary interference model and accumulative interference model. Security mechanism adds authentication and encryption mechanisms to MAC frame to defense MAC layer security attacks. Cross-layer design combines MAC layer information with physical layer or higher layers information, such as network layer, transmission layer, to achieve global optimization.

关键词： MAC Key MAC Layer Technologies of Cognitive Radio Network Radio

经济效率与政治价值:对公私伙伴关系(PPP)的反思

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河北经贸大学学报 2017年第5期38卷 16-21页

作者：裴俊巍曾志敏清华大学公共管理学院北京100084 华南理工大学公共政策研究院广东广州510640

公私伙伴关系(PPP)在最近十来年中备受世界各国青睐,其理论优势使其成为世界各国解决基础设施建设和公共服务供给资金问题的主要方式之一。然而,PPP在广受赞誉的同时,在能否实现经济效率以及是否违背传统政治价值的问题上,正在经受一股... 详细信息

公私伙伴关系(PPP)在最近十来年中备受世界各国青睐,其理论优势使其成为世界各国解决基础设施建设和公共服务供给资金问题的主要方式之一。然而,PPP在广受赞誉的同时,在能否实现经济效率以及是否违背传统政治价值的问题上,正在经受一股强烈的理论批判与反思的挑战。PPP到底是各国推动经济社会发展的"救命稻草"还是"美丽的谎言"?基于国外的最新理论进展进行全面反思,指出PPP并非"灵丹妙药",中国在发展PPP的过程中,需要以正确的态度和谨慎的方法对待PPP,也需要通过开展网络治理建立新的合作过程,尤其需要提高保障公私合作可持续性的政府治理能力。

关键词：公私伙伴关系经济效率政治价值基础设施公共服务政府治理