期刊：
INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS,2021年34(3):e4698.1-e4698.15 ISSN：1074-5351
通讯作者：
Tang, Shengda
作者机构：
[Tang, Shengda] Guangxi Normal Univ, Coll Math & Stat, Guilin, Guangxi, Peoples R China.;[Tan, Liansheng] Cent China Normal Univ, Dept Comp Sci, Wuhan, Peoples R China.;[Liu, Tao] Southwest Minzu Univ, Sch Comp Sci & Technol, Chengdu, Peoples R China.
通讯机构：
[Tang, Shengda] G;Guangxi Normal Univ, Coll Math & Stat, Guilin, Guangxi, Peoples R China.
关键词：
Blocking probability;Computational complexity;Energy utilization;Flow of fluids;Probability distributions;Quality of service;Renewable energy resources;Stochastic models;Stochastic systems;Performance analysis;Performance metrics;Primary energy source;Quality of service (QoS) guarantees;Reliable communication;Renewable energy source;Stationary distribution;Wireless communication system;Energy harvesting
摘要：
Energy harvesting wireless communication system (EH-WCS) has the capability of harvesting energy for system operations from the surrounding renewable energy sources. However, the randomness and instability of the harvested energy will result in the depletion of the energy consumption. To provide reliable communication services with the quality of service (QoS) guarantee, it is necessary for the EH-WCS to use a reliable energy backup (REB) for supplying energy to the system during the failure of its primary energy source. In this paper, a novel stochastic model, i.e., the extended Markov fluid flow model, is proposed to describe the EH-WCS with REB. The Kolmogorov forward equations of the system model are derived. By solving the corresponding equations, we obtain the stationary distributions of the key performance metrics for the EH-WCS with REB, including the average energy consumption rate of the EH-WCS, the residual energy distribution, the average energy supply rate by REB, the packet queue length in data buffer, the data queue delay, and the packet blocking probability. A numerical example is provided to investigate the theoretical results, and the effects of the system parameters on the performance are further studied numerically. Both the theoretical insights and the numerical analyses are believed to be important for the design of EH-WCSs.
关键词：
cyclic routing;Gauss-Newton method;incremental learning;nonlinear least squares;sequential fusion
摘要：
In multi-agent networked systems, parameter estimation problems arising in many practical applications are often required to solve Non-Linear Least Squares (NLLS) problems with the usual objective function (i.e., sum of squared residuals). The aim is to estimate a global parameter of interest across the network, such that the discrepancy between the estimation model and the real output of the system is minimized. There are challenges to face when applying the conventional Gauss-Newton method, such as non-cooperation and prosaic learning behavior. In this paper, we propose two Gauss-Newton type fusion estimation algorithms for solving overdetermined NLLS optimization problems arising frequently in multi-agent networked environment. One is the cycle-based Gauss-Newton (CGN) algorithm that is more attractive in performance due to its distributed nature than its peer: the known centralized Gauss-Newton algorithm. On the basis of CGN, we put emphasis on developing a simple but effective learning scheme leveraging an incremental technique, which is distributed on each computing agent over network. Such scheme results in the Incremental Gauss-Newton (IGN) algorithm that achieves a clear increase on convergence rate at the expense of higher computation cost than the CGN algorithm as well as the centralized one by deeper learning over the networking cycle. Both algorithms utilize Gauss-Newton iteration update in a cyclic cooperative manner, which offers the flexibility in exploiting the network topology. We provide the detailed analysis and the sufficient conditions for convergence of proposed IGN algorithm. By applying to target localization in wireless sensor networks, the numerical results confirm our convergence analysis and show that the proposed incremental scheme outperforms the centralized one in term of convergence performance.
关键词：
heterogeneous networks;social networks;friend recommendation;co-author recommendation;random walk with restart
摘要：
It is of great importance to recommend collaborators for scholars in academic social networks, which can benefit more scientific research results. Facing the problem of data sparsity of co-author recommendation in academic social networks, a novel recommendation algorithm named HeteroRWR (Heterogeneous Random Walk with Restart) is proposed. Different from the basic Random Walk with Restart (RWR) model which only walks in homogeneous networks, HeteroRWR implements multiple random walks in a heterogeneous network which integrates a citation network and a co-authorship network to mine the k mostly valuable co-authors for target users. By introducing the citation network, HeteroRWR algorithm can find more suitable candidate authors when the co-authorship network is extremely sparse. Candidate recommenders will not only have high topic similarities with target users, but also have good community centralities. Analyses on the convergence and time efficiency of the proposed approach are presented. Extensive experiments have been conducted on DBLP and CiteSeerX datasets. Experimental results demonstrate that HeteroRWR outperforms state-of-the-art baseline methods in terms of precision and recall rate even in the case of incorporating an incomplete citation dataset.
作者机构：
[Tan, Liansheng; Wu, Xiangcheng] Cent China Normal Univ, Dept Comp Sci, Wuhan 430079, Peoples R China.;[Tan, Liansheng] Univ Tasmania, Coll Sci & Engn, Hobart, Tas 7001, Australia.;[Tang, Shengda] Guangxi Normal Univ, Sch Math & Stat, Guilin 541004, Peoples R China.
通讯机构：
[Tan, Liansheng] C;[Tan, Liansheng] U;Cent China Normal Univ, Dept Comp Sci, Wuhan 430079, Peoples R China.;Univ Tasmania, Coll Sci & Engn, Hobart, Tas 7001, Australia.
关键词：
Transmitters;Energy consumption;Energy harvesting;Task analysis;Reliability;Data communication;Fading channels;Energy harvesting transmitter;reliable energy backup (REB);energy supplementary policy;Markov decision process (MDP)
摘要：
For the Energy harvesting (EH) transmitter equipped with a Reliable Energy Backup (REB), the following problem is challenging and important: how to minimize the amount of energy supplied by the REB, such that the harvested energy is efficiently utilized for transmitting a given amount of data within a fixed delay constraint. In this paper, we first develop a stochastic model for this problem. We then discuss the optimization issue of delay-constrained data transmission over a fading wireless channel. We transform the delay constraint into the penalty function, and then the energy constrained control problem is modeled as a Markov decision process (MDP) without constraint, by which we obtain the optimal energy supplementary policy and the minimum of the expected energy consumption from REB. In the special case that the energy of the transmitter is supplied by REB alone, we find that the optimal energy supplementary policy is non-decreasing in the elapsed transmission time and for the remaining task of data transmission. This substantially reduces the computational complexity required to implement the optimal energy supplementary policy for a general EH wireless device. Numerical studies validate the theoretical findings, and observations are outlined to demonstrate the characteristics of the optimal energy supplementary policy and the minimum expected energy expenditure from the REB.
作者机构：
[Tan, Liansheng; Li, Xuefeng; Li, Feifei] Cent China Normal Univ, Comp Sci Dept, Wuhan 430079, Hubei, Peoples R China;[Li, Xuefeng] South Cent Univ Nationalities, Fac Math & Stat, Wuhan 430074, Hubei, Peoples R China
通讯机构：
[Tan, Liansheng] C;Cent China Normal Univ, Comp Sci Dept, Wuhan 430079, Hubei, Peoples R China.
关键词：
Cloud computing;cost performance ratio;Internet of Things (IoT);utility function;wireless sensor networks (WSNs)
摘要：
Internet of Things (IoT) still faces many challenges, one of which is how to efficiently and effectively allocate the cloud resources in order to obtain the desired quality of service (QoS) for the IoT users and communication domains. To face the above challenges, this paper first identifies that there is an issue of cost performance tradeoff, which is stemmed from various limited resources in the IoT systems and the competing services requirements. We second propose a nonlinear optimization model that attacks the resource allocation problem. Within the constraints of resources and service demands, this model seeks to maximize the suggested IoT cost performance ratio. We then find that the problem can be treated as a quasiconcave maximization problem. We are able to reduce the original problem to a pseudoconcave maximization problem and thereby identify a local solution, which is proved to be exactly the desired global one. We therefore propose a feasible direction method and design its corresponding algorithm to yield the desired solution. Finally, we provide a numerical example to demonstrate the theoretical findings of resource allocation and the proposed algorithm for the cloud computing based on IoT systems. The mathematical results and method proposed in this paper can act as designing guidelines for resource allocation and managements, computing scheduling, and networking protocol designing in the cloud infrastructure of IoT.
作者机构：
[Tan, Liansheng; Liu, Ming; Zhang, Wei; Ge, Fei] Huazhong Normal Univ, Wuhan, Hubei, Peoples R China.;[Gao, Xun] Wuhan Univ, Wuhan, Peoples R China.;[Luo, Juan] Hunan Univ, Changsha, Peoples R China.
会议名称：
25th Annual International Conference on Mobile Computing and Networking (MobiCom)
会议时间：
OCT 21-25, 2019
会议地点：
Los Cabos, MEXICO
会议主办单位：
[Ge, Fei;Tan, Liansheng;Zhang, Wei;Liu, Ming] Huazhong Normal Univ, Wuhan, Hubei, Peoples R China.^[Gao, Xun] Wuhan Univ, Wuhan, Peoples R China.^[Luo, Juan] Hunan Univ, Changsha, Peoples R China.
关键词：
wireless networks;capacity;multi-hop;joint node unit
摘要：
Achievable capacity in multi-hop wireless networks is seriously lower than single-hop communication. Two full-duplex nodes potentially have 2x capacity in wireless communications, compared to two half-duplex nodes. Organize the two nodes as one unit and reorganize nodes to be the units in multi-hop paths, the capacity can achieve 1x to 2x under space division simultaneous transmission mode, which is verified by analysis and simulation results.
摘要：
Flexi-grid networks with orthogonal frequency-division multiplexing has recently been proposed in optical networks, which can provide flexible capacity granularity. We investigate the network performance under dynamic subcarrier allocation methods. The performance measurements, including blocking probability and average link efficiency, are considered by simulations. The results demonstrate the performance profiles of three scenarios, and show that the performance of the network with first fit method is better than that with next fit one in a single fiber link; the traffic requests in one connection can influence the performance of related connections; the blocking probability of connection with multiple alternative paths is smaller than that of connection with just one path.
作者机构：
[Lu, Hongxu] Yulin Normal Univ, Sch Comp Sci & Engn, Yulin, Guangxi, Peoples R China.;[Tang, Shengda] Guangxi Normal Univ, Sch Math & Stat, Guilin, Guangxi, Peoples R China.;[Tan, Liansheng; Zhang, Wei] Cent China Normal Univ, Dept Comp Sci, Wuhan, Hubei, Peoples R China.
通讯机构：
[Tan, Liansheng] C;Cent China Normal Univ, Dept Comp Sci, Wuhan, Hubei, Peoples R China.
关键词：
Optical packet switching (OPS);Packet with delay constraint;Blocking probability;Mean delay
摘要：
Within the communication networks, a delayed constrained data packet is the one that will be dropped if not being served before a certain deadline time, which causes data packet loss affecting the quality of service (QoS). In this paper, we study the blocking probability and the mean delay of such delay constrained packets in an asynchronous single-wavelength optical buffer in optical packet switching networks, where the packet arrival process follows the Poisson process and the packet-length distribution is assumed to be general. We obtain the integral equations of the modeled system and the exact expressions of blocking probabilities and the mean delays. Numerical examples are provided to validate the results with interesting observations being highlighted.
摘要：
As an emerging novel technology, optical buffering via fiber delay lines (FDLs) is adopted in optical burst switching (OBS) networks for contention resolution. In this paper, we study the blocking probability and the mean delay of an asynchronous single-wavelength optical buffer, where the burst arrival process is Poisson and burst-length distribution is general. With the aid of Level Crossing (LC) method, we first derive the integral equations to model the dynamics of the buffer. We then propose a method to solve these equations. Finally we present the mathematical expressions of blocking probabilities and the mean delays for the optical buffer with general burst size distribution. Numerical examples are provided to validate our results, and some interesting observations from the numerical examples are highlighted.
摘要：
Least mean squares (LMS) adaptive algorithms are attractive for distributed environment parameter estimation problems in a smart city due to the benefits of cooperation, adaptation, and rapid convergence. To obtain a reliable estimate of the network-wide parameter vector, local results can be further fused by intermediate agents in a distributed incremental way. In this paper, we propose an intelligent variable step size incremental LMS (VSS-ILMS) algorithm to solve the dilemma between fast convergence rate and low mean-square deviation (MSD) in conventional incremental LMS (ILMS) algorithms. The main idea behind our proposal is that the local step-size is adaptively updated by minimizing the MSD in every iteration, where Tikhonov regularization and time-averaging estimation methods are adopted. A theoretical analysis of proposed algorithm is presented in terms of mean square performance and mean step size in a closed form. Simulation results show that VSS-ILMS algorithm outperforms the constant step size ILMS algorithm and several classical variable step-size LMS algorithms. The derived theoretical results shows good agreement with those based on simulated data. For a practical consideration, the proposed algorithm is also verified by the model of target localization in sensor networks.
作者机构：
[Tan, Liansheng; Tang, Shengda] Cent China Normal Univ, Dept Comp Sci, Wuhan 430079, Peoples R China.;[Tang, Shengda] Guangxi Normal Univ, Sch Math & Stat, Guilin 541004, Peoples R China.
通讯机构：
[Tan, Liansheng] C;Cent China Normal Univ, Dept Comp Sci, Wuhan 430079, Peoples R China.
摘要：
Energy harvesting wireless sensor network (EH-WSN) is promising in applications, however the frequent occurrence of temporal death of nodes, due to the limited harvesting capability, presents a difficulty in meeting the quality-of-service requirements of the network. For a node with temporal death in an EH-WSN, this paper presents a new model, which consists of, a Markov model to trace the energy harvesting process, a queuing analytical model to model the working mechanism of the sensor node and a continuous fluid process to capture the evolution of the residual energy in the EH-WSN node. Using the Markov fluid queue (MFQ) theory, we discuss various performance aspects of the EH-WSN node with temporal death, including the temporal death occurrence probability, the probability density of the residual energy, the stationary energy consumption, the queue length distribution in the data buffer, the packet blocking probability, and so on. In order to obtain the dropping probability of a given packet, based on the structure of the MFQ, we develop an auxiliary MFQ and derive the formulations of two types of the packet dropping probabilities, i.e., the packet dropping probability due to energy depletion and that due to channel error. Numerical examples are provided to illustrate the theoretical findings, and new insights into understanding the impacts of the parameters on the performance metrics are presented.
摘要：
首届IEEE计算机通信和互联网国际学术会议（The First IEEE International Conference on Computer Communication and the Intemet，ICCCI2016）于2016年10月13～15日在武汉举行。该学术会议是由华中师范大学计算机学院谭连生教授发起、旨在促进国际互联网与通信领域学术交流的纯学术性研讨会。本届会议由华中师范大学主办、华中师范大学计算机学院承办。本届大会主席是谭连生教授，程序委员会主席为澳大利亚国立大学RodKennedy教授（IEEE Fellow）。华中师范大学副校长王恩科教授出席本届会议开幕式并致辞。
作者机构：
[Tan, Liansheng; Tang, Shengda] Cent China Normal Univ, Dept Comp Sci, Wuhan 430079, Peoples R China.;[Tang, Shengda] Guangxi Normal Univ, Sch Math & Stat, Guilin 541000, Peoples R China.
通讯机构：
[Tan, Liansheng] C;Cent China Normal Univ, Dept Comp Sci, Wuhan 430079, Peoples R China.
作者机构：
[Tan, Liansheng; Tang, Shengda] Cent China Normal Univ, Dept Comp Sci, Wuhan, Hubei, Peoples R China.;[Tang, Shengda] Guangxi Normal Univ, Sch Math & Stat, Guilin, Guangxi, Peoples R China.;[Chan, Sammy] City Univ Hong Kong, Dept Elect Engn, 83 Tat Chee Ave, Kowloon, Hong Kong, Peoples R China.
通讯机构：
[Tan, Liansheng] C;Cent China Normal Univ, Dept Comp Sci, Wuhan, Hubei, Peoples R China.
摘要：
Optical burst switching (OBS) provides a future-proof alternative to the current electronic switching in the backbone. In this letter, we study a horizon-based single-channel multi-class OBS node, for which the multiple traffic classes are differentiated using a different offset time of each class. By assuming Poisson burst arrivals and general burst size distribution, using the well-known level crossing method, we obtain the expressions of per-class blocking probabilities. We validate our results using a numerical example.
