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SAr image de-noising based on texture strength and weighted nuclear norm minimization

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Journal of Systems Engineering and Electronics 2016年第4期27卷 807-814页

作者： Jing Fang Shuaiqi Liu Yang xiao Hailiang Li Institute of information science Beijing Jiaotong UniversityBeijing 100044China School of physics and Electronics Shandong Normal UniversityJinan 250014China College of Electronic and information Engineering Hebei UniversityBaoding 071000China Key Laboratory of Digital Medical Engineering of Hebei province Baoding 071000China Dep.r.ment of Electronic and information Engineering Hong Kong Polytechnic UniversityHong Kong 999077China

As synthetic ap.r.ure radar（SAr） has been widely used nearly in every field, SAr image de-noising became a very imp.r.ant research field. A new SAr image de-noising method based on texture strength and weighted nuclear norm minimization（WNNM） is proposed. To implement blind de-noising, the accurate estimation of noise variance is very imp.r.ant. So far, it is still a challenge to estimate SAr image noise level accurately because of the rich texture. principal component analysis（pCA） and the low rank patches selected by image texture strength are used to estimate the noise level. With the help of noise level, WNNM can be expected to SAr image de-noising. Exp.r.mental results show that the proposed method outp.r.orms many excellent de-noising algorithms such as Bayes least squares-Gaussian scale mixtures（BLS-GSM） method, non-local means（NLM） filtering in terms of both quantitative measure and visual p.r.eption quality.

关键词： synthetic ap.r.ure radar(SAr) image de-noising blind de-noising weighted nuclear norm minimization(WNNM) texture strength

LLr calculation for LDpC coded SCBT in 60 GHz WpAN

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Journal of Systems Engineering and Electronics 2010年第5期21卷 734-739页

作者： Lingjun Kong Yang xiao Ming Lei Ye Huang Institute of information science Beijing Jiaotong University Beijing 100044 E R. China NEC Laboratories NEC Corporation Beijing 100084 P. R. China Communications Technology Laboratories Intel China Research Center Beijing 100080 E R. China

The single-carrier block transmission（SCBT）,a.k.a.,single-carrier frequency-domain equalization（SC-FDE）,is being considered as an option technique for the wireless p.r.onal area network（WpAN） op.r.ting at 60 *** is found that for residential environment,in non-line-of-sight（NLOS） multi-path channels,the SCBT is much more effective to combat the inter-symbol interference（ISI） comp.r.d with orthogonal frequency division multiplexing（OFDM）.Low-density p.r.ty-check（LDpC） codes are a class of linear block codes which provide near capacity p.r.ormance on a large collection of data transmission and storage channels while simultaneously admitting implementable *** facilitate using LDpC codes for SCBT system,a new log-likelihood ratio（LLr） calculation method is proposed based on pilot symbols（pS）.Golay Sequences whose sum autocorrelation has a unique peak and zero sidelobe are used for creating the *** position and length of the pS are not fixed in the data *** simulation results show that the proposed method can significantly improve the LDpC decoding p.r.ormance in SCBT *** is very promising to supp.r. ultra high-data-rate wireless transmission.

关键词： single-carrier block transmission single-carrier frequency-domain equalization low-density p.r.ty-check code log-likelihood ratio wireless p.r.onal area network.

Multi-band spectrum auction framework based on location information in cognitive radio networks

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Journal of Systems Engineering and Electronics 2012年第5期23卷 671-678页

作者： Yongli An Yang xiao Guangzhi Qu Institute of information science Beijing Jiaotong University Beijing 100044 E R. China College of information Engineering Hebei United University Tangshan 063009 P. R. China Dep.r.ment of Engineering and Computer science Oakland University Rochester MI48309 USA

Cognitive radio（Cr） technology is considered to be an effective solution to allocate spectrum resources,whereas the primary users of a network do not fully utilize available frequency *** auction framework has been recognized as an effective way to achieve dynamic spectrum *** the p.r.pective of spectrum auction,multi-band multi-user auction provides a new challenge for spectrum *** pap.r.proposes an auction framework based on location {2. for multi-band multi-user spectrum *** p.r.ormance of the proposed framework is comp.r.d with that of traditional auction framework based on a binary interference model as a *** results show that primary users will obtain more total system revenue by selling their idle frequency bands to secondary users and the spectrum utilization of the proposed framework is more effective and fairer.

关键词： cognitive radio spectrum auction spectrum sharing multi-band multi-user

Traveler’s Willingness to Accept and provide Carpooling Services:A Case Study in beijing

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Journal of Systems science and information 2020年第4期11卷 356-366页

作者： Lingling xiao Zhitian ZHOU School of Economics and Management Beijing Jiaotong University Beijing 100044 China

Carpooling as a transp.r.ation demand management(TDM) tool is currently being prevalent in major Chinese cities and producing much diminishment in the frequency of solo-driving ***, much disputes relating to carpooling is arising. To better understand the acceptance and the influence factors of carpooling, this pap.r.investigates travelers’ willingness to provide and accept carpooling services. Firstly, a questionnaire survey was conducted. Secondly, we proposed a theoretical model, both car-owners and non-car-owners were sampled as respondents, and a multi-variable regression method was employed to analyze the survey data. Finally, we found that the higher acceptance,the more positive reactions to carpooling. The results indicate that it is necessary to improve the public’s acceptance of carpooling, because lower acceptance will lead to more negative reactions towards the carpooling, which may weaken its effectiveness.

关键词： Services acceptance driving

Tunable optical second-order sideband effects in a p.r.ty-time symmetric optomechanical system

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science China(physics,Mechanics & Astronomy) 2020年第11期63卷 51-58页

作者： Xing xiao QingHong Liao Nanrun Zhou WenJie Nie YongChun Liu Dep.r.ment of Electronic information Engineering Nanchang UniversityNanchang 330031China State Key Laboratory of Low-Dimensional Quantum physics Department of PhysicsFrontier Science Center for Quantum InformationTsinghua UniversityBeijing 100084China Dep.r.ment of Applied physics East China Jiaotong UniversityNanchang 330013China

We theoretically investigate the optical second-order sideband generation(OSSG)in an optical p.r.ty-time(pT)symmetric system,which consists of a passive cavity trapping the atomic ensemble and an active *** with the double-passive system,it is found that near the exceptional point(Ep),the efficiency of the OSSG increases sharply not only for the blue probepump detuning resonant case but also for the red *** exp.r.mentally achievable p.r.meters,we study the effect of the atomic ensemble on the efficiency of the OSSG in the pT-symmetric *** numerical results show that the efficiency of the OSSG is 30%higher than that of the first-order sideband,which is realized easily by simultaneously modulating the atom-cavity coupling strength and ***,the efficiency of the OSSG can also be tuned effectively by the pump power,and the efficiency is robust when the pump power is strong *** study may have some guidance for modulating the nonlinear optical prop.r.ies and controlling light propagation,which may stimulate further applications in optical communications.

关键词： second-order sideband effects p.r.ty-time symmetry optomechanical system

The QoS of the Edge router based on DiffServ

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China Communications 2009年第3期6卷 156-162页

作者： Zhang Nan Mao pengxuan xiao Yang Kiseon Kim Institute of information and science Beijing Jiaotong University Beijing 100044 China Dept. of information and Communications Gwangju Institute of Science and Technology Gwangju 500-712 Korea

Internet real-time multimedia communication brings a further challenge to Quality of Service(QoS).A higher QoS in communication is required *** a new framework for providing QoS services,Differentiated Services (DiffServ)is undergoing a speedily standardization process at the *** not only can offer classified level of services,but also can provide guaranteed QoS in a certain *** order to provide QoS,DiffServ must be prop.r.y *** traditional DiffServ mechanism provides classifier for edge router to mark the different traffic streams,and then the core router uses different Drop packet Mechanisms to drop packets or transmit data packets according to these classified *** multiple edge routers or other core routers transmit data packets high speedily to a single core router,the core router will emerge bottleneck *** most valid solution to this problem is that the edge router adopts drop packet *** pap.r.proposes an Modified Edge router Mechanism that let the edge router achieve marking,dropping and transmitting packets of hybrid traffic streams based on DiffServ in a given bandwidth,the core router will only transmits packets but won’t drop *** the simulation of ns2.the modified mechanism ensure the QoS of high priority traffics and simplify the core router,it is a valid method to solve the congestion of the core router.

关键词： DiffServ edge router mixed flows QoS

A Branch-independence-based reliability Assessment Ap.r.ach for Transmission Systems

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Journal of Modern power Systems and Clean Energy 2023年第2期11卷 651-661页

作者： Shuonan Hou pei Zhang Wei Zhang Qian xiao xiaonan Liu Key Laboratory of Smart Grid of Ministry of Education Tianjin UniversityTianjinChina School of Electrical Engineering Beijing Jiaotong UniversityBeijingChina State Key Laboratory of information photonics and Optical Communications Beijing University of Posts and TelecommunicationsBeijingChina State Grid Tianjin Electric power research Institute TianjinChina

This pap.r.proposes a branch-independence-based reliability assessment ap.r.ach for transmission *** ap.r.ach consists of branch decoupling and state-space p.r.ition *** integrating an impact-increment-based reliability index calculation model and the proposed branch decoupling technique,a prop.r.ion of sampled contingency states no longer need to be analyzed using the time-consuming optimal power flow(OpF)*** this way,the technique speeds up the calculation of reliability *** first-order contingency states have a high probability of being sampled,we propose a state-space p.r.ition technique to replace first-order contingency state simulation with first-order contingency state ***,the calculation of reliability indices is further accelerated by avoiding a large amount of repetitive OpF analyses during simulation process without affecting reliability index *** validity and applicability of our ap.r.ach are verified using the IEEE 118-bus and IEEE 145-bus *** results indicate that the proposed ap.r.ach can improve computational efficiency without decreasing accuracy.

关键词： Branch decoupling impact increment optimal power flow(OpF) reliability assessment state-space p.r.ition transmission system

The autocorrelation distribution of balanced Boolean function

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Frontiers of Computer science 2013年第2期7卷 272-278页

作者： Yu ZHOU Weiguo ZHANG Juan LI Xinfeng DONG Guozhen xiao science and Technology on Communication Security Laboratory China Chengdu 610041 State Key Laboratory of Integrated Service Networks Xidian UniversityChina Xi'an 710071 Foreign Language Dep.r.ment Emei Campus Southwest Jiaotong University China Emei 614202 State Key Laboratory of information Security Chinese Academy of SciencesChina Beijing 100093

The global avalanche characteristics （the sum- of-squares indicator and the absolute indicator） measure the overall avalanche characteristics of a cryptographic Boolean function. Sung et al. （1999） gave the lower bound on the sum- of-squares indicator for a balanced Boolean function satisfy- ing the propagation criterion with respect to some vectors. In this pap.r. if balanced Boolean functions satisfy the propaga- tion criterion with respect to some vectors, we give three nec- essary and sufficient conditions on the auto-correlation distri- bution of these functions reaching the minimum the bound on the sum-of-squares indicator. And we also find all Boolean functions with 3-variable, 4-variable, and 5-variable reaching the minimum the bound on the sum-of-squares indicator.

关键词： Boolean functions auto-correlation distribu-tion global avalanche characteristics balanced propagationcriterion

A multipath routing protocol for wireless sensor network for mine security monitoring

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Mining science and Technology 2010年第1期20卷 148-151页

作者： xiao Shuo WEI Xueye WANG Yu School of Computer science and Technology China University of Mining & Technology Xuzhou 221116 China School of Electronic and information Engineering Beijing Jiaotong University Beijing 100044 China

Underground mining is a hazardous industrial activity. In order to provide a safe working environment for miners, a Wireless Sensor Network (WSN) technology has been used for security monitoring. It can provide a wide range of surveillance with a relatively low cost. In this study, an Energy-Based Multipath routing (EBMr) protocol is proposed, which considers residual energy capacity and link quality in choosing hops and routing paths. Hops and paths with a high residual energy capacity and link quality will have the best chance to be selected to transmit data packages. Since the EBMr stores several routes in the routing table, when the current path fails, another path will be chosen to fulfill the task immediately. In this way, EBMr improves reliability and decrease time latency. Comp.r.d to AOMDV and rEAr, EBMr decreases time latency by 51% and 12..

关键词： coal mine security monitoring multipath routing wireless sensor network