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random walk Routing in WSNs with Regular Topologies

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Journal of Computer Science & Technology 2006年第4期21卷 496-502页

作者：田慧沈鸿松泽照男 Department of Computer Science and Technology University of Science and Technology of China Hefei 230027P.R. China Department of Computing and Mathematics Manchester Metropolitan University U.K. School of Information Science Japan Advanced Institute of Science and Technology Ishikawa Japan

Topology is one of the most important characteristics for any type of networks because it represents the network＇s inherent properties and has great impact on the performance of the network. For wireless sensor networks （WSN）, a well-deployed regular topology can help save more energy than what a random topology can do. WSNs with regular topologies can prolong network lifetime as studied in many previous work. However, little work has been done in developing effective routing algorithms for WSNs with regular topologies, except routing along a shortest path with the knowledge of global location information of sensor nodes. In this paper, a new routing protocol based on random walk is proposed. It does not require global location information. It also achieves load balancing property inherently for WSNs which is difficult to achieve by other routing protocols. In the scenarios where the message required to be sent to the base station is in comparatively small size with the inquiry message among neighboring nodes, it is proved that the random walk routing protocol can guarantee high probability of successful transmission from the source to the base station with the same amount of energy consumption as the shortest path routing. Since in many applications of WSNs, sensor nodes often send only beep-like small messages to the base station to report their status, our proposed random walk routing is thus a viable scheme and can work very efficiently especially in these application scenarios. The random wall〈 routing provides load balancing in the WSN as mentioned, however, the nodes near to the base station are inevitably under heavier burden than those far away from the base station. Therefore, a density-aware deployment scheme is further proposed to guarantee that the heavy-load nodes do not affect the network lifetime even if their energy is exhausted. The main idea is deploying sensors with different densities according to their distance to the base station. It will be s

关键词： wireless sensor networks routing random walk shortest path

random walk Based Method for Automatic Segmentation of Intravascular Ultrasound Images

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Journal of Donghua University(English Edition) 2015年第5期32卷 770-776页

作者：严加勇崔崤峣黄永锋 School of Electronics & Information Shanghai Dian Ji University School of Medical Instrumentation Shanghai University of Medicine & Health Sciences Suzhou Institute of Biomedical Engineering and Technology Chinese Academy of Sciences School of Computer Science & Technology Donghua University

Intravascular ultrasound( IVUS) is an important imaging technique that is used to study vascular wall architecture for diagnosis and assessment of the vascular diseases. Segmentation of lumen and media-adventitia boundaries from IVUS images is a basic and necessary step for quantitative assessment of the vascular *** to ultrasound speckles, artifacts and individual differences,automated segmentation of IVUS images represents a challenging task. In this paper,a random walk based method is proposed for fully automated segmentation of IVUS images. Robust and accurate determination of the seed points for different regions is the key to successful use of the random walk algorithm in segmentation of IVUS images and is the focus of the present work. Performance of the proposed algorithm was evaluated over an image database with 900 IVUS image frames of nine patient cases. The preliminary experimental results show the potential of the proposed IVUS image segmentation approach.

关键词： intravascular ultrasound(IVUS) random walk media-adventitia segmentation lumen segmentation

random walk immunization strategy on scale-free networks

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控制理论与应用（英文版） 2009年第2期7卷 151-156页

作者： Weidong PEI Zengqiang CHEN Zhuzhi YUAN Department of Automation Nankai University Tianjin 300071 China College of Computer and Information Engineering Tianjin Normal University Tianjin 300387 China

A novel immunization strategy called the random walk immunization strategy on scale-free networks is proposed. Different from other known immunization strategies, this strategy works as follows： a node is randomly chosen from the network. Starting from this node, randomly walk to one of its neighbor node; if the present node is not immunized, then immunize it and continue the random walk; otherwise go back to the previous node and randomly walk again. This process is repeated until a certain fraction of nodes is immunized. By theoretical analysis and numerical simulations, we found that this strategy is very effective in comparison with the other known immunization strategies.

关键词： Scale-free networks Immunization strategy random walk SIS model Epidemic spreading control

A random walk evolution model of wireless sensor networks and virus spreading

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Chinese Physics B 2013年第1期22卷 154-160页

作者：王亚奇杨晓元 Network and Information Security Key Laboratory of the Armed Police Force Department of Electronics Technology Engineering University of the Chinese People's Armed Police Force

In this paper, considering both cluster heads and sensor nodes, we propose a novel evolving a network model based on a random walk to study the fault tolerance decrease of wireless sensor networks （WSNs） due to node failure, and discuss the spreading dynamic behavior of viruses in the evolution model. A theoretical analysis shows that the WSN generated by such an evolution model not only has a strong fault tolerance, but also can dynamically balance the energy loss of the entire network. It is also found that although the increase of the density of cluster heads in the network reduces the network efficiency, it can effectively inhibit the spread of viruses. In addition, the heterogeneity of the network improves the network efficiency and enhances the virus prevalence. We confirm all the theoretical results with sufficient numerical simulations.

关键词： wireless sensor network random walk network efficiency virus spreading

A trust-aware random walk model for return propensity estimation and consumer anomaly scoring in online shopping

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Science China(Information Sciences) 2019年第5期62卷 75-91页

作者： Xiaolin LI Yuan ZHUANG Yanjie FU Xiangdong HE School of Business Nanjing University Department of Computer Science Missouri University of Science and Technology Network and Information Center Nanjing University

In online shopping, most of consumers will not clear their return reasons when submitting return requests(e.g., select the option "other reasons"). Prior literature mostly investigates into the return event at the transaction level, and the underlying force of returns remains untracked. To deal with this problem, we propose a machine learning algorithm named as trust-aware random walk model(TARW). In the proposed model, four patterns of consumers can be identified in terms of return forces:(i) selfish consumers,(ii) honest consumers,(iii) fraud consumers, and(iv) irrelevant consumers. To profile consumers’ return patterns, we capture consumers’ similarities in order preferences and return tendencies separately. Based on consumers’ similarities, we obtain a return pattern trust network by introducing the trust network and collaborative filtering algorithms. Subsequently, we develop two important applications based on the trust network:(i)estimating consumers’ return propensities for product types;(ii) scoring the anomaly for consumers’ returns for one product. Finally, we conduct extensive experiments with the real-world data to validate the model’s effectiveness in predicting and tracing consumers’ returns. With the proposed model, we can help retailers improve the conversion rates of selfish consumers, retain honest consumers, and block fraud consumers.

关键词： machine learning return abuse random walk collaborative filtering return pattern

Ergodicity recovery of random walk in heterogeneous disordered media

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Chinese Physics B 2020年第5期29卷 165-173页

作者： Liang Luo Ming Yi Department of Physics Huazhong Agricultural UniversityWuhan 430070China Institute of Applied Physics Huazhong Agricultural UniversityWuhan 430070China School of Mathematics and Physics China University of GeosciencesWuhan 430074China

Significant and persistent trajectory-to-trajectory variance are commonly observed in particle tracking experiments,which have become a major challenge for the experimental data *** this theoretical paper we investigate the ergodicity recovery behavior,which helps clarify the origin and the convergence of trajectory-to-trajectory fluctuation in various heterogeneous disordered *** concepts of self-averaging and ergodicity are revisited in the context of trajectory *** slow ergodicity recovery and the non-Gaussian diffusion in the annealed disordered media are shown as the consequences of the central limit theorem in different *** strange ergodicity recovery behavior is reported in the quenched disordered case,which arises from a localization *** first-passage approach is introduced to the ergodicity analysis for this case,of which the central limit theorem can be employed and the ergodicity is recovered in the length scale of diffusivity correlation.

关键词： anomalous diffusion random walk disordered systems non-Gaussian diffusion

A random walk simulation of scalar mixing in flows through submerged vegetations

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Journal of Hydrodynamics 2014年第3期26卷 343-350页

作者：梁东方 WU Xuefei MOE Key Laboratory of Hydrodynamics School of Naval Architecture Ocean and Civil Engineering Shanghai Jiao Tong University Department of Engineering University of Cambridge

The scalar transport phenomena in vertical two-dimensional flows are studied using the random walk method. The established Lagrangian model is first applied to study the idealized longitudinal dispersion in open channels, before being used to investigate the scalar mixing characteristics of the flows through submerged vegetations. The longitudinal dispersion coefficients of the fully-developed boundary layer flows, with and without vegetations, are calculated based on the positions of the particles. A convenient way of incorporating the effects of vegetations is proposed, where all the flow parameters are regarded to be continually distributed over the depth. The simulation results show high accuracy of the developed random walk method, and indicate that the new method of accounting for the vegetation effects is appropriate for all the test cases considered. The predicted longitudinal dispersion coefficients agree well with the measurements. The merit of the new method is highlighted by its simplicity and efficiency in comparison with the conventional method that assumes the discontinuous distribution of the flow parameters over the depth.

关键词： random walk longitudinal dispersion submerged vegetations scalar mixing

Estimates for the Tail Probability of the Supremum of a random walk with Independent Increments

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Chinese Annals of Mathematics,Series B 2011年第6期32卷 847-856页

作者： Yang YANG Kaiyong WANG School of Mathematics and Statistics Nanjing Audit University Nanjing 210029 China Department of Information and Computational Science School of Mathematics and Physics Suzhou University of Science and Technology Suzhou 215009 Jiangsu China

The authors investigate the tail probability of the supremum of a random walk with independent increments and obtain some equivalent assertions in the case that the increments are independent and identically distributed random variables with Osubexponential integrated distributions.A uniform upper bound is derived for the distribution of the supremum of a random walk with independent but non-identically distributed increments,whose tail distributions are dominated by a common tail distribution with an O-subexponential integrated distribution.

关键词： random walk O-Subexponential distribution Integrated distribution Supremum

Mean and variance of first passage time of non-homogeneous random walk

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Frontiers of Mathematics in China 2012年第3期7卷 551-559页

作者： Huaming WANG Business College Beijing Union UniversityBeijing 100025China

The prime concern of this paper is the first passage time of a nonhomogeneous random walk, which is nearest neighbor but able to stay at its position. It is revealed that the branching structure of the walk corresponds to a 2-type non-homogeneous branching process and the first passage time of the walk can be expressed by that branching process. Therefore, one can calculate the mean and variance of the first passage time, though its exact distribution is unknown.

关键词： random walk 2-type branching process first passage time,variance