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Scaling Laws of Multicast Capacity for Power-Constrained Wireless Networks under Gaussian Channel Model

IEEE Transactions on computers 2012年第5期61卷 713-725页

作者： Cheng Wang Changjun Jiang Xiang-Yang Li Shaojie Tang Yuan He Xufei Mao Yunhao Liu Key Laboratory of Embedded System and Service Computing Ministry of Education Shanghai China Department of Computer Science and Engineering Building of Electronics and Information Engineering University of Tongji Shanghai China Department of Computer Science Illinois Institute of Technology Chicago IL USA Tsinghua National Laboratory for Information Science and Technology (TNLIST) Tsinghua University Beijing China Department of Computer Science and Engineering University of Tongji China Department of Computer Science Hong Kong University of Science and Technology Kowloon Hong Kong China Tsinghua National Laboratory for Information Science and Technology (TNLIST) School of Software Tsinghua University Beijing China Beijing Key Laboratory of Intelligent Telecommunications Software and Multimedia Beijing University of Posts and Telecommunications Beijing China

We study the asymptotic networking-theoretic multicast capacity bounds for random extended networks (REN) under Gaussian channel model, in which all wireless nodes are individually power-constrained. During the transmission, the power decays along path with attenuation exponent α >; 2. In REN, n nodes are randomly distributed in the square region of side length √n. There are n s randomly and independently chosen multicast sessions. Each multicast session has n d + 1 randomly chosen terminals, including one source and n d destinations. By effectively combining two types of routing and scheduling strategies, we analyze the asymptotic achievable throughput for all n s = ω(1) and nd. As a special case of our results, we show that for n s = Θ(n), the per-session multicast capacity for REN is of order Θ(1/√n d n) when nd = O(n/(log n) a+1 ) and is of order Θ(1/n d · (log n) -n/2 ) when n d = Ω(n/log n).

关键词： Lattices Throughput Upper bound Road transportation Receivers Interference Routing

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Exploiting constructive interference for scalable flooding in wireless networks

Exploiting constructive interference for scalable flooding i...

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IEEE Annual Joint Conference: INFOCOM, IEEE computer and Communications Societies

作者： Yin Wang Yuan He Xufei Mao Yunhao Liu Zhiyu Huang Xiangyang Li MOE Key Laboratory for Information System Security School of Software TNLIST Tsinghua University China Department of Computer Science and Engineering HKUST Hong Kong China Institute of Software Chinese Academy of Sciences China Department of Computer Science Illinois Institute of Technology USA

ISBN: (纸本)9781467307734;9781467307758

Exploiting constructive interference in wireless networks is an emerging trend for it allows multiple senders transmit an identical packet simultaneously. Constructive interference based flooding can realize millisecond network flooding latency and sub-microsecond time synchronization accuracy, require no network state information and adapt to topology changes. However, constructive interference has a precondition to function, namely, the maximum temporal displacement Δ of concurrent packet transmissions should be less than a given hardware constrained threshold. We disclose that constructive interference based flooding suffers the scalability problem. The packet reception performances of intermediate nodes degrade significantly as the density or the size of the network increases. We theoretically show that constructive interference based flooding has a packet reception ratio (PRR) lower bound (95:4%) in the grid topology. For a general topology, we propose the spine constructive interference based flooding (SCIF) protocol. With little overhead, SCIF floods the entire network much more reliably than Glossy [1] in high density or large-scale networks. Extensive simulations illustrate that the PRR of SCIF keeps stable above 96% as the network size grows from 400 to 4000 while the PRR of Glossy is only 26% when the size of the network is 4000. We also propose to use waveform analysis to explain the root cause of constructive interference, which is mainly examined in simulations and experiments. We further derive the closed-form PRR formula and define interference gain factor (IGF) to quantitatively measure constructive interference.

关键词： constructive interference Wireless networks Flood NECTIN1 gene ATP6AP2 gene PULSE REPETITION RATE stem cell inhibitory factor Glossy

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Logical difference analysis based on variable precision lower approximation operator and graded upper approximation operator

Logical difference analysis based on variable precision lowe...

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2012 International Conference on computer science and information Processing, CSIP 2012

作者： Zhang, Xianyong Miao, Duoqian Department of Computer Science and Technology Tongji University Shanghai 201804 China Key Laboratory of Embedded System and Service Computing Ministry of Education Tongji University Shanghai 201804 China College of Mathematics and Software Science Sichuan Normal University Chengdu Sichuan 610068 China

ISBN: (纸本)9781467314114

This paper aims to construct and analyze an original logical difference based on the quantitative approximation operators. According to the variable precision lower approximation operator and graded upper approximation operator, we first put forward the specific logical difference;the new concept makes the specific logical combination on precision and grade, and has the practical multiple quantitative meaning. Then, both the fundamental structure and properties are investigated and obtained for the logical difference. Furthermore, two algorithms, the regular and structural algorithms, are proposed and analyzed, and the structural algorithm has more advantages. Finally, an example is provided. The proposed concept partially extends the graded and classical approximation operators;thus, some properties are achieved correspondingly for these previous approximation operators. © 2012 IEEE.

关键词： Rough set theory

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Algorithms and analyses of logical difference of graded lower and upper approximation operators

Algorithms and analyses of logical difference of graded lowe...

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2012 International Conference on computer science and information Processing, CSIP 2012

ISBN: (纸本)9781467314114

Grade serves as a fundamental quantitative index, and the graded rough set model is a basic model. Thus, this paper aims to investigate an original logical difference in the graded rough set model. According to the specific logical requirement on the grade index, the logical difference is put forward based on the graded lower and upper approximation operators;the new concept has the practical logical quantitative meaning. Then, both the macroscopic essence and microscopic fundamental structure are obtained for the new concept. For calculation, two algorithms, the conventional and microscopic algorithms are proposed and analyzed emphatically, and we conclude that the microscopic algorithm has more advantages in time and space complexity. Finally, the logical difference and its algorithms are both illustrated by an example. © 2012 IEEE.

关键词： Rough set theory

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Process Calculus with Data Structure and its Model Checking Algorithm

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Physics Procedia 2012年 33卷 782-789页

作者： Qing Zheng Zi-Ning Cao Department of Computer Science and Technology Nanjing University of Aero. & Astro. Nanjing 210016 P.R. China Provincial Key Laboratory for Computer Information Processing Technology Soochow University Suzhou 215006 P.R. China National Key Laboratory of Science and Technology on Avionics System Integration Shanghai 200233 P.R. China

Model checking is one of the most important technology for automatically verification. So this paper generally proposed a method of combining CCS and Z language, to perform model checking. It combines the advantage of current CCS and Z systems, where CCS is good at describing concurrent systems, also Z is a good tool for data structure. As a result, form the new system CCS-Z. Then we give the syntax and semantics of it, at last give the model checking *** advantage of this paper is combined data stucture on the famous system CCS, and increase the capacity of system description.

关键词： Model Checking CTL Z Language CCS

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Providing fairness on shared-memory multiprocessors via process scheduling 12

Providing fairness on shared-memory multiprocessors via proc...

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12th Joint International Conference on Measurement and Modeling of computer systems, ACM SIGMETRICS/Performance 2012

作者： Xu, Di Wu, Chenggang Yew, Pen-Chung Li, Jianjun Wang, Zhenjiang State Key Laboratory of Computer Architecture Institute of Computing Technology Chinese Academy of Sciences Beijing China Graduate University Chinese Academy of Sciences Beijing China Department of Computer Science and Engineering University of Minnesota at Twin-Cities MN United States Institute of Information Science Academia Sinica Taiwan

ISBN: (纸本)9781450310970

Competition for shared memory resources on multiprocessors is the most dominant cause for slowing down applications and makes their performance varies unpredictably. It exacerbates the need for Quality of Service (QoS) on such systems. In this paper, we propose a fair-progress process scheduling (FPS) policy to improve system fairness. Its strategy is to force the equally-weighted applications to have the same amount of slowdown when they run concurrently. The basic approach is to monitor the progress of all applications at runtime. When we find an application suffered more slowdown and accumulated less effective work than others, we allocate more CPU time to give it a better parity. Our policy also allows different weights to different threads, and provides an effective and robust tuner that allows the OS to freely make tradeoffs between system fairness and higher throughput. Evaluation results show that FPS can significantly improve system fairness by an average of 53.5% and 65.0% on a 4-core processor with a private cache and a 4-core processor with a shared cache, respectively. The penalty is about 1.1% and 1.6% of the system throughput. For memory-intensive workloads, FPS also improves system fairness by an average of 45.2% and 21.1% on 4-core and 8-core system respectively at the expense of a throughput loss of about 2%. © 2012 ACM.

关键词： Throughput

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Trust Model Based on Structured Protection for High Level security system

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China Communications 2012年第11期9卷 70-77页

作者： Liao Jianhua Zhao Yong Zhan Jing School of Electronics Engineering and Computer Science Peking University Beijing 100871 P. R. China School of Computer Science and Technology Beijing University of Technology Beijing 100124 P. R. China Key Laboratory of Network Security and Cryptology Fujian Normal University Fuzhou 350007 P. R. China State Key Laboratory of Information Security Institute of So ware Chinese Academy of Sciences Beijing 100049 P. R. China

In order to ensure the security of information systems, it's essential to make sure that system behaviors are trusted. By analyzing threats that exist in executing procedures, a trust model based on structured protection is proposed. We consider that functional components, system actions and message flows between components are three key factors of information systems. Structured protection requirements on components, connections and action parameters are also provided. Four trusted properties of the model are deducted through formal analysis, and trusted system behavior is defined based on these properties. Furthermore, decision theorem of trusted system behavior is proved. The developed prototype system indicates the model is practical. It is a general theory model built on logic deduction and independent on specific environment and the behaviors of the system designed and implemented following the model are trusted.

关键词： trusted computing security assurance structured protection

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Analysis on the weighting factor of wavelet-based watermarking scheme

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Journal of Computational information systems 2012年第10期8卷 4285-4292页

作者： Liu, Lili Cao, Tianjie Lu, Yulong Zhang, Hongtai School of Computer Science and Technology China University of Mining and Technology Xuzhou 221116 China State Key Laboratory of Information Security Graduate School of the Chinese Academy of Sciences Beijing 100049 China

This paper studies an invisible and robust digital watermarking algorithm in the wavelet transform domain. The chose of Discrete Wavelet Transform is motivated by a good match with Human Visual system directives. However in the wavelet-based image watermarking, the most important issue is how to choose the coefficients to be embedded. Our purpose is to analyze the influence of the weighting factor on the watermarking algorithm satisfying the invisibility and robustness. In order to improve the security and concealment of the watermark information, the watermark image is scrambled by Arnold transform before embedded. Simulation experiments on a large set of different images have been done. The experimental results show that weighting factor has a great effect on the balance of invisibility and robustness. © 2011 by Binary information Press.

关键词： Discrete wavelet transforms

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Inertial estimator learning automata

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IEICE Transactions on Fundamentals of Electronics, Communications and computer sciences 2012年第6期E95-A卷 1041-1048页

作者： Zhang, Junqi Ni, Lina Xie, Chen Gao, Shangce Tang, Zheng Department of Computer Science and Technology Key Laboratory of Embedded System and Service Computing Tongji University Shanghai 200092 China College of Information Science and Engineering Shandong University of Science and Technology Qingdao China Department of Intellectual Information Systems Engineering University of Toyama Toyama-shi 930-8555 Japan

This paper presents an inertial estimator learning automata scheme by which both the short-term and long-term perspectives of the environment can be incorporated in the stochastic estimator-the long term information crystallized in terms of the running reward-probability estimates, and the short term information used by considering whether the most recent response was a reward or a penalty. Thus, when the shortterm perspective is considered, the stochastic estimator becomes pertinent in the context of the estimator algorithms. The proposed automata employ an inertial weight estimator as the short-term perspective to achieve a rapid and accurate convergence when operating in stationary random environments. According to the proposed inertial estimator scheme, the estimates of the reward probabilities of actions are affected by the last response from environment. In this way, actions that have gotten the positive response from environment in the short time, have the opportunity to be estimated as "optimal", to increase their choice probability and consequently, to be selected. The estimates become more reliable and consequently, the automaton rapidly and accurately converges to the optimal action. The asymptotic behavior of the proposed scheme is analyzed and it is proved to be Ε-optimal in every stationary random environment. Extensive simulation results indicate that the proposed algorithm converges faster than the traditional stochastic-estimator-based SERI scheme, and the deterministicestimator- based DGPA and DPRI schemes when operating in stationary random environments. Copyright © 2012 The Institute of Electronics, information and Communication Engineers.

关键词： Probability

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Asymptotic throughput for large-scale wireless networks with general node density

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Wireless Networks 2012年第5期19卷 559-575页

作者： Cheng Wang Changjun Jiang Xiang-Yang Li Yunhao Liu Department of Computer Science Tongji University Shanghai China Key Laboratory of Embedded System and Service Computing Ministry of Education Shanghai China The Tsinghua National Laboratory for Information Science and Technology (TNLIST) Department of Computer Science and Engineering Tongji University Shanghai China The Department of Computer Science Illinois Institute of Technology Chicago USA The TNLIST and School of Software Tsinghua University Beijing China CSE The Hong Kong University of Science and Technology Kowloon Hong Kong

We study the asymptotic throughput for a large-scale wireless ad hoc network consisting of n nodes under the generalized physical model. We directly compute the throughput of multicast sessions to unify the unicast and broadcast throughputs. We design two multicast schemes based on the so-called ordinary arterial road system and parallel arterial road system, respectively. Correspondingly, we derive the achievable multicast throughput by taking account of all possible cases of n s = ω(1) and 1 ≤ n d ≤ n − 1, rather than only the cases of $$n_s=\Uptheta(n)$$ as in most related works, where n s and n d denote the number of sessions and the number of destinations of each session, respectively. Furthermore, we consider the network with a general node density $$\lambda \in [1,n]$$ , while the models in most related works are either random dense network (RDN) or random extended network (REN) where the density is λ = n and λ = 1, respectively, which further enhances the generality of this work. Particularly, for the special case of our results by letting λ = 1 and $$n_s=\Uptheta(n)$$ , we show that for some regimes of n d , the multicast throughputs achieved by our schemes are better than those derived by the well-known percolation-based schemes.

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