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Performance analysis and optimization model based on dynamics equation for heterogeneous wireless networks

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The Journal of China Universities of Posts and Telecommunications 2015年第3期22卷 49-55页

作者： Zhu Xiaorong Zhao Ya'nan Wang Yong Wireless Communication Key Lab of jiangsu province Nanjing University of Posts and Telecommunications National Mobile Communications Research Laboratory Southeast University patent information service institution of jiangsu province

In this paper, we propose a model based on dynamics equation for performance analysis and optimization for heterogeneous wireless networks （HWNs）. First, the channel occupation state with time of HWNs is modelled by dynamics equation, in which users＇ mobility as an important factor affecting system performance is considered. Then the steady state probability distribution of channel occupation is derived. Based on the results, the expression of the throughput of HWNs is deduced, which includes a factor p which is the ratio of service arrival rate accessing one of the networks to the total service arrival rate in the overlapping area. And this paper proposes to maximize the throughput of the HWNs by optimizing the factor p to efficiently utilize the resources. Simulation results show that the proposed optimization method can effectively improve the throughput and in the meanwhile decrease the blocking probability of the whole system.

关键词： heterogeneous wireless networks dynamics equation handoff rate performance analysis

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An advanced discrete‐time RNN for handling discrete time‐varying matrix inversion:Form model design to disturbance‐suppression analysis

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CAAI Transactions on Intelligence Technology 2023年第3期8卷 607-621页

作者： Yang Shi Qiaowen Shi Xinwei Cao Bin Li Xiaobing Sun Dimitrios K.Gerontitis School of information Engineering Yangzhou UniversityYangzhouChina jiangsu province Engineering Research Center of Knowledge Management and Intelligent service Yangzhou UniversityYangzhouChina School of Business Jiangnan UniversityWuxiChina Department of information and Electronic Engineering International Hellenic UniversityThessalonikiGreece

Time‐varying matrix inversion is an important field of matrix research,and lots of research achievements have been *** the process of solving time‐varying matrix inversion,disturbances inevitably exist,thus,a model that can suppress disturbance while solving the problem is *** this paper,an advanced continuous‐time recurrent neural network(RNN)model based on a double integral RNN design formula is pro-posed for solving continuous time‐varying matrix inversion,which has incomparable disturbance‐suppression *** digital hardware applications,the corresponding advanced discrete‐time RNN model is proposed based on the discretisation *** a result of theoretical analysis,it is demonstrated that the advanced continuous‐time RNN model and the corresponding advanced discrete‐time RNN model have global and exponential convergence performance,and they are excellent for suppressing different ***,inspiring experiments,including two numerical experiments and a practical experiment,are presented to demonstrate the effectiveness and superiority of the advanced discrete‐time RNN model for solving discrete time‐varying matrix inversion with disturbance‐suppression.

关键词： neural control neural network real‐time systems

Knowledge Graph Enhanced Transformers for Diagnosis Generation of Chinese Medicine

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Chinese Journal of Integrative Medicine 2024年第3期30卷 267-276页

作者： WANG Xin-yu YANG Tao GAO Xiao-yuan HU Kong-fa School of Artificial Intelligence and information Technology Nanjing University of Chinese MedicineNanjing210023China School of information Management Nanjing UniversityNanjing210023China jiangsu Collaborative Innovation Center of Traditional Chinese Medicine in Prevention and Treatment of Tumor Nanjing210023China jiangsu province Engineering Research Center of TCM Intelligence Health service Nanjing210023China

Chinese medicine(CM)diagnosis intellectualization is one of the hotspots in the research of CM *** traditional CM intelligent diagnosis models transform the CM diagnosis issues into classification issues,however,it is difficult to solve the problems such as excessive or similar *** the development of natural language processing techniques,text generation technique has become increasingly *** this study,we aimed to establish the CM diagnosis generation model by transforming the CM diagnosis issues into text generation *** semantic context characteristic learning capacity was enhanced referring to Bidirectional Long Short-Term Memory(BILSTM)with Transformer as the backbone ***,the CM diagnosis generation model Knowledge Graph Enhanced Transformer(KGET)was established by introducing the knowledge in medical field to enhance the inferential *** KGET model was established based on 566 CM case texts,and was compared with the classic text generation models including Long Short-Term Memory sequence-to-sequence(LSTM-seq2seq),Bidirectional and Auto-Regression Transformer(BART),and Chinese Pre-trained Unbalanced Transformer(CPT),so as to analyze the model ***,the ablation experiments were performed to explore the influence of the optimized part on the KGET *** results of Bilingual Evaluation Understudy(BLEU),Recall-Oriented Understudy for Gisting Evaluation 1(ROUGE1),ROUGE2 and Edit distance of KGET model were 45.85,73.93,54.59 and 7.12,respectively in this *** with LSTM-seq2seq,BART and CPT models,the KGET model was higher in BLEU,ROUGE1 and ROUGE2 by 6.00–17.09,1.65–9.39 and 0.51–17.62,respectively,and lower in Edit distance by 0.47–*** ablation experiment results revealed that introduction of BILSTM model and prior knowledge could significantly increase the model ***,the manual assessment indicated that the CM diagnosis results of the KGET model used

关键词： Chinese medicine diagnosis knowledge graph enhanced transformer text generation

维普期刊数据库

Power Optimization in Cell-Free Massive MIMO with Non-ideal Hardware Transceiver

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Chinese Journal of Electronics 2020年第1期29卷 190-198页

作者： ZHANG Yao CAO Haotong ZHOU Meng LI Long YANG Longxiang Wireless Communications Key Laboratory of jiangsu province Nanjing University of Posts and Telecommunications Department of information Technology Party School of the Communist Party of China Shandong Provincial Committee

A downlink cell-free massive Multipleinput multiple-output(mMIMO) system is explored. To investigate the impact of hardware distortion on downlink cell-free mMIMO, this paper recalls a well-established model of hardware impairment and derives a new closedform downlink per-user Spectral efficiency(SE) expression for distributed conjugate beamforming precoding. Based on this trackable expression, two power control algorithms,namely max-total-SE and mixed Quality-of-service(QoS)algorithms, are proposed. Numerical results indicate that the downlink per-user SE is primarily limited by the hardware quality of the receiver, especially when the user corresponds to the receiver. In addition, the proposed max-total-SE algorithm has a fast convergence rate and can significantly improve the total SE compared to the Equal power control(EPC) scheme. What’s more, our mixed QoS algorithm also performs well in many respects.

关键词： Cell-free massive MIMO Conjugate beamforming Non-ideal hardware transceiver Spectral efficiency QoS constraint

Cooperative resource allocation in cognitive wireless powered communication networks with energy accumulation and deadline requirements

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Science China(information Sciences) 2019年第8期62卷 145-158页

作者： Ding XU Qun LI Wireless Communication Key Lab of jiangsu province Nanjing University of Posts and Telecommunications Engineering Research Center of Health service System Based on Ubiquitous Wireless Networks Nanjing University of Posts and Telecommunications

This study investigates a multi-carrier cognitive wireless powered communication network(CWPCN) with a wirelessly powered primary user(PU). A two-stage cooperative protocol between the PU and the secondary user(SU) is adopted so that the PU can harvest energy from the SU while the SU gains transmission opportunities. It is assumed that the energy harvested by the PU can be accumulated for future usage, and the quality of service of the PU is guaranteed by satisfying the required minimum number of data bits for a given deadline. Herein, we maximize the SU rate by considering the time allocation,subcarrier allocation, and power allocation in both an offline setting(in which the future channel gains are known a priori) and an online setting(in which only the current channel gains are known). In the offline and online schemes, the maximization problem is solved using the block-coordinate descent method and the Lagrange duality method. The effectiveness of the proposed schemes is evaluated and verified via simulation experiments against benchmark schemes.

关键词： wireless powered communication networks energy harvesting cognitive radio deadline constraint energy accumulation

Time-Efficient Power Allocation Scheme for Two-Way Multi-relay Cognitive Radio Networks

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Chinese Journal of Electronics 2016年第2期25卷 357-363页

作者： ZHOU Zhikang ZHU Qi The Key Wireless Lab of jiangsu province School of Telecommunication and Information EngineeringNanjing University of Posts and Telecommunications Key Lab on Wideband Wireless Communications and Sensor Network Technology of Ministry of Education

Cooperative relaying has been emerging as a key technology in Cognitive radio(CR) networks. A two-way Amplify-and-forward(AF) based multi-relay CR network is considered, where a primary user coexists with a pair of secondary users and multiple relays. A Timeefficient sub-optimal power allocation scheme(TESOPA)based on Cauchy-Schwarz inequality is provided to maximize the total end-to-end transmission rate of the secondary system. TESOPA is proposed under maximal transmission power constraints, while ensuring the quality of service of the primary user during the whole communication process. The computational complexity is sharply decreased by using the Cauchy-Schwarz inequality. Simulation results show that the proposed TESOPA scheme performs very close to the near-optimal Interior point method based power allocation(IPMPA), especially in interference dominant networks where interference constraints play a key role in determining power allocation results instead of maximal transmission power constraints.

关键词： Power allocation Relay network Cognitive radio Amplify-and-forward Two-way communication

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Chinese Journal of Electronics 2021年第1期30卷 55-63页

作者： BO Lili ZHU Xuanrui SUN Xiaobing NI Zhen LI Bin School of information Engineering Yangzhou University jiangsu Engineering Research Center of Knowledge Management and Intelligent service State Key Laboratory for Novel Software Technology Nanjing University

Fine-grained change operations can help software developers fix software bugs more accurately and efficiently. However, the current fine-grained change operations are only used in specific fixing process, such as fixing of If statement. In this paper, we conducted an empirical study to explore the fine-grained change operations for bug fixing. Based on the Mozilla bug data,we examined whether similar bugs are fixed with similar change operations. The results show that: First, for bug reports with similar descriptions or bug-fix commits with similar descriptions, their corresponding fine-grained change operations are not related; Second, in the case where the descriptions of both bug reports and bug-fix commits are similar, the fine-grained change operations in patch code are not related; Third, by classifying bug reports, we find that the change operations in the same bug report category are similar; Finally, by analyzing the fine-grained change operations for each bug, we present some combined patterns that are often used together.

关键词： bug reports bug fixing If statement Mozilla bug data bug-fix commits similar descriptions program debugging fine-grained change operations

MIMO Scheduling Effectiveness Analysis for Bursty Data service from View of QoE

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Chinese Journal of Electronics 2017年第5期26卷 1079-1085页

作者： CHEN Lei JIANG Dingde BAO Rong XIONG Jiping LIU Fuqiang BEI Lulu jiangsu province Key Laboratory of Intelligent Industry Control Technology Xuzhou University of Technology School of Computer Science and Engineering Northeastern University College of Mathematics Physics and Information EngineeringZhejiang Normal University College of Electronics and information Engineering Tongji University

In the user selection phrase of the conventional Multiple-input-multiple-output(MIMO) scheduling schemes,the frequent user exchange deteriorates the Quality of user experience(Qo E) of the bursty data *** the channel vector orthogonalization computation results in a high time *** address these problems,we propose an inertial scheduling policy to reduce the number of noneffective user exchange,and substitute self-organization policy for channel vector orthogonalization computation to reduce computational *** relationship between the scheduling effectiveness and the inertia of objective function is observed in the *** simulation results show that the inertial scheduling policy effectively reduce the number of potential noneffective scheduling which is inversely proportional to the Mean opinion score(MOS)that quantifies the Qo *** proposed scheduling scheme provides significant improvement in Qo E performance in the *** the proposed scheduling scheme does not consider the channel vector orthogonalization in the user selection phrase,its throughput approaches the level of the throughput-oriented scheme because of its selforganization scheduling policy.

关键词： Bursty data service Multiple-inputmultiple-output(MIMO) Quality of user experience(QoE) Time perception

Measuring accessibility of bus system based on multi-source traffic data

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Geo-Spatial information Science 2020年第3期23卷 248-257,I0005页

作者： Yufan Zuo Zhiyuan Liu Xiao Fu School of Transportation Southeast UniversityNanjingChina jiangsu Key Laboratory of Urban ITS Jiangsu Province Collaborative Innovation Center of Modern Urban Traffic TechnologiesSoutheast UniversityNanjingChina

Accessibility is a representative indicator for evaluating the supply of bus *** studies have evaluated the accessibility from different *** the interaction among land use,bus timetable arrangement and individual factors,a more holistic accessibility measurement is proposed to combine static and dynamic characteristics from multisource traffic *** rationale of the proposed model is verified by a case study of bus system in Shenzhen,China,which is carried out to find the spatial and temporal discrepancy of service of bus *** is found that the adjustment of bus schedule to time-varying travel demand can affect accessibility of bus system and that Land-use development,average bus speed and bus facilities all have positive effects on accessibility of bus *** findings provide sig-nificant reference for transport planning and *** proposed model is not limited to accessibility measuring of bus system,but also applicable to other travel modes.

关键词： Accessibility bus system multi-source traffic data spatial-temporal distribution