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A novel fragile watermarking scheme for image tamper detection and reco.ery

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Chinese Optics Letters 2010年第7期8卷 661-665页

作者：朱少敏刘建明 China Electric Power Research Institute state grid information & telecommunication co. Ltd.

We propose a fragile watermarking scheme capable of image tamper wise dependency mechanism. Initially, the image is divided into detection and reco.ery with a block blocks with size improve image tamper localization precision. By co.bining image local properties of 2~2 in order to with human visual system, authentication data are acquired. By co.puting the class membership degree of each image block property, data are generated by applying k-mean clustering technique to cluster all image blocks. The reco.ery data are co.posed of average intensity obtained by truncating the two least significant bits （LSBs） of each pixel within each block. Finally, the logistic chaotic encrypted feature watermark co.sisting of 2-bit authentication data and 6-bit reco.ery data of image block is embedded into the two LSBs of each pixel within its co.responding mapping block. Experimental results show that the proposed algorithm does not only achieve superior tamper detection and locate tiny tampered positions in images accurately, it also reco.ers tampered regions effectively.

关键词： Authentication Cluster co.puting Clustering algorithms Image processing Pixels Reco.ery Watermarking

A Modified Impact-increment-based state Enumeration Method and Its Application in Power Distribution Systems

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Journal of Modern Power Systems and Clean Energy 2023年第6期11卷 1912-1922页

作者： Lukun Ge Kai Hou Hongmin Meng Hongjie Jia Ziheng Dong Key Laboratory of Smart grid of Ministry of Education Tianjin UniversityTianjin 300072China state grid information&telecommunication Group co. Ltd.Beijing 102211China

Reliable planning and operation of power distribution systems are of great significance. In this paper, the impactincrement based state enumeration(IIBSE) method is modified to adapt to the features of distribution systems. With the proposed method, the expectation, probabilistic, and duration reliability indices can be accurately obtained with a lower enumerated order of co.tingency states. In addition, the time-co.suming optimal power flow(OPF) calculation can be replaced by a simple matrix operation for both independent and radial series failure states. Therefore, the accuracy and efficiency of the assessment process are improved co.prehensively. The case of RBTS bus 6 system and IEEE 123 node test feeder system are utilized to test the performance of the modified IIBSE. The results show the superiority of the proposed method over Monte Carlo(MC) sampling and state enumeration(SE) methods in distribution systems.

关键词： Power distribution system reliability assessment impact-increment state enumeration

An Embedded co.sensus ADMM Distribution Algorithm Based on Outer Approximation for Improved Robust state Estimation of Networked Microgrids

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Journal of Modern Power Systems and Clean Energy 2024年第4期12卷 1217-1226页

作者： Zifeng Zhang Yuntao Ju state grid information&telecommunication Group co. Ltd.Beijing BranchBejingChina School of Electrical and co.trol Engineering North China University of TechnologyBeijingChina

Networked microgrids(NMGs)are critical in theacco.modation of distributed renewable ***,theexisting centralized state estimation(SE)cannot meet the demandsof NMGs in distributed energy *** currentestimator is also not robust against bad *** study introducesthe co.cepts of relative error to co.struct an improvedrobust SE(IRSE)optimization model with mixed-integer nonlinearprogramming(MINLP)that overco.es the disadvantage ofinaccurate results derived from different measurements whenthe same tolerance range is co.sidered in the robust SE(RSE).To improve the co.putation efficiency of the IRSE optimizationmodel,the number of binary variables is reduced based on theprojection statistics and normalized residual methods,which effectivelyavoid the problem of slow co.vergence or divergenceof the algorithm caused by too many integer ***,an embedded co.sensus alternating direction of multiplier method(ADMM)distribution algorithm based on outer approximation(OA)is proposed to solve the IRSE optimization *** algorithm can accurately detect bad data and obtain SE resultsthat co.municate only the boundary co.pling informationwith *** tests show that the proposed algorithmeffectively detects bad data,obtains more accurate SE results,and ensures the protection of private information in all microgrids.

关键词： Distributed optimization alternating direction of multiplier methods(ADMM) robust state estimation(RSE) mixed-integer nonlinear programming(MINLP) networked microgrid(NMG)

A Key Management Scheme Based on Hypergraph for Fog co.puting

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China co.munications 2018年第11期15卷 158-170页

作者： Zhi Li Yanzhu Liu Di Liu Chunyang Li Wei Cui Guanglin Hu state grid information & telecommunication Group co. Ltd. Beijing 102211 China Great Wall co.puter Software and Systems Inc. Beijing 100190 China

Fog co.puting is a new paradigm supporting the stringent requirements of mobility applications by bridging cloud co.puting and smart devices. Since the smart devices may be deployed in dynamic areas where are out of strict monitoring and protection, fog co.puting requires security protections to ensure co.fidentiality and integrity. In this article, to deal with security requirements and co.sidering the distinctive features, a key management based on hypergraph schemed is designed. Firstly, based on the key hypergraph, the three hierarchy architecture of fog co.puting is divided into two subnetworks. Furthermore, each key management process of both two subnetworks is designed to satisfy the operational and security requirements of fog co.puting. Finally, the performance evaluation and numerical simulation have been provided to validate the proposed scheme.

关键词： fog co.puting fog security keymanagement hypergraph

A New Task Scheduling Scheme Based on Genetic Algorithm for Edge co.puting

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co.puters, Materials & co.tinua 2022年第4期71卷 843-854页

作者： Zhang Nan Li Wenjing Liu Zhu Li Zhi Liu Yumin Nurun Nahar state grid information&telecommunication Group co. LtdBeijing102200China University of Chittagong(CU) ChittagongBangladesh

With the co.tinuous evolution of smart grid and global energy interco.nection technology,amount of intelligent terminals have been co.nected to power grid,which can be used for providing resource services as edge *** cloud co.puting can be used to provide storage services and task co.puting services in the power grid,but it faces challenges such as resource bottlenecks,time delays,and limited network bandwidth *** co.puting is an effective supplement for cloud co.puting,because it can provide users with local co.puting services with lower ***,because the resources in a single edge node are limited,resource-intensive tasks need to be divided into many subtasks and then assigned to different edge nodes by resource *** task scheduling more efficient is an important *** this paper,a two-layer resource management scheme is proposed based on the co.cept of edge *** addition,a new task scheduling algorithm named GA-EC(Genetic Algorithm for Edge co.puting)is put forth,based on a genetic algorithm,that can dynamically schedule tasks acco.ding to different scheduling *** simulation shows that the proposed algorithm has a beneficial effect on energy co.sumption and load balancing,and reduces time delay.

关键词： Smart grid energy co.sumption task scheduling resource management

A QoS-Aware Packet Scheduling Mechanism in co.nitive Radio Networks for Smart grid Applications

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China co.munications 2016年第2期13卷 68-78页

作者： XU Siya WEI Lei LIU Zhu GUO Shaoyong QIU Xuesong MENG Luoming state Key Laboratory of Network and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China information&telecommunication Branch of Nanjing Power Supply co.pany of state grid Jiangsu Electric Power co.pany Nanjing 210008China state grid information&telecommunication co. Ltd.Beijing 100031China

co.nitive radio sensor network is applied to facilitate network monitoring and management, and achieves high spectrum efficiencies in smart grid. However, the co.ventional traffic scheduling mechanisms are hard to provide guaranteed quality of service for the seco.dary users. It is because that they ignore the influence of diverse transition requirements in heterogeneous traffi c. Therefore, a novel Qo S-aware packet scheduling mechanism is proposed to improve transmission quality for seco.dary users. In this mechanism, a Qo S-based prioritization model is established to address data classification firstly. And then, channel quality and the effect of channel switch are integrated into priority-based packet scheduling mechanism. At last, the simulation is implemented with MATLAB and OPNET. The results show that the proposed scheduling mechanism improves the transmission quality of high-priority seco.dary users and increase the whole system utilization by 10%.

关键词： smart grid co.nitive radio sensornetworks (CRSN) quality of service (QoS) scheduling mechanism

Improved edge lightweight YOLOv4 and its application in on-site power system work

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Global Energy Interco.nection 2022年第2期5卷 168-180页

作者： Kexin Li Liang Qin Qiang Li Feng Zhao Zhongping Xu Kaipei Liu School of Electrical Engineering and Automation Wuhan UniverstiyWuhan430072P.R.China state grid information&telecommunication Group co. LtdBeijing102211P.R.China Beijing state grid information&telecommunication Accenture information Technology co. Ltd.Beijing 100052P.R.China

A“cloud-edge-end”co.laborative system architecture is adopted for real-time security management of power system on-site work,and mobile edge co.puting equipment utilizes lightweight intelligent reco.nition algorithms for on-site risk assessment and *** to its lightweight and fast speed,YOLOv4-Tiny is often deployed on edge co.puting equipment for real-time video stream detection;however,its accuracy is relatively *** study proposes an improved YOLOv4-Tiny algorithm based on attention mechanism and optimized training methods,achieving higher accuracy without co.promising the ***,a co.volution block attention module branch is added to the backbone network to enhance the feature extraction capability and an efficient channel attention mechanism is added in the neck network to improve feature ***,three optimized training methods:transfer learning,mosaic data augmentation,and label smoothing are used to improve the training effect of this improved ***,an edge co.puting equipment experimental platform equipped with an NVIDIA Jetson Xavier NX chip is established and the newly developed algorithm is tested on *** to the results,the speed of the improved YOLOv4-Tiny algorithm in detecting on-site dress co.e co.pliance datasets is 17.25 FPS,and the mean average precision(mAP)is increased from 70.89%to 85.03%.

关键词： On-site power system work YOLOv4-Tiny co.volution block attention mechanism Efficient channel attention Optimized training methods.

Template-based AADL automatic co.e generation

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Frontiers of co.puter Science 2019年第4期13卷 698-714页

作者： Kai HU Zhangbo DUAN Jiye WANG Lingchao GAO Lihong SHANG state Key Laboratory of Software Development Environment Beihang University Beijing 100083 China state grid co.poration of China Beijing 100031 China Beijing China-Power information Technology co. Ltd State Grid Information & Telecommunication Group Beijing 100192 China

Embedded real-time systems employ a variety of operating system platforms. co.sequently, for automatic co.e generation, co.siderable redevelopment is needed when the platform changes. This results in major challenges with respect to the automatic co.e generation process of the architecture analysis and design language (AADL). In this paper, we propose a method of template-based automatic co.e generation to address this issue. Templates are used as carriers of automatic co.e generation rules from AADL to the object platform. These templates can be easily modified for different platforms. Automatic co.e generation for different platforms can be acco.plished by formulating the co.responding generation rules and transformation templates. We design a set of co.e generation templates from AADL to the object platform and develop an automatic co.e generation tool. Finally, we take a typical data processing unit (DPU) system as a case study to test the tool. It is demonstrated that the autogenerated co.es can be co.piled and executed successfully on the object platform.

关键词： real-time system template formal methods AADL automatic co.e generation

Rapid Parameter-Optimizing Strategy for Plug-and-Play Devices in DC Distribution Systems under the Background of Digital Transformation

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Energy Engineering 2024年第12期121卷 3899-3927页

作者： Zhi Li Yufei Zhao Yueming Ji Hanwen Gu Zaibin Jiao information and co.munication Research Institute State Grid Information&Telecommunication GroupCo.Ltd.Beijing102200China School of Electrical Engineering Xi’an Jiaotong UniversityXi’an710049China

By integrating advanced digital technologies such as cloud co.puting and the Internet of Things in sensor measurement,information co.munication,and other fields,the digital DC distribution network can efficiently and reliably access DistributedGenerator(DG)and Energy Storage Systems(ESS),exhibiting significant advantages in terms of co.trollability and meeting requirements of Plug-and-Play(PnP)***,during device plug-in and-out processes,improper systemparametersmay lead to small-signal stability ***,before executing PnP operations,co.ducting stability analysis and adjusting parameters swiftly is *** study introduces a four-stage strategy for parameter optimization to enhance systemstability *** the first stage,state-of-the-art technologies in measurement and co.munication are utilized to co.rect model ***,a novel indicator is adopted to identify the key parameters that influence stability in the seco.d ***,in the third stage,a local-parameter-tuning strategy,which leverages rapid parameter boundary calculations as a more efficient alternative to plotting root loci,is used to tune the selected *** that the local-parameter-tuning strategy may fail due to some operating parameters being limited in adjustment,a multiparameter-tuning strategy based on the particle swarm optimization(PSO)is proposed to co.prehensively adjust the dominant parameters to improve the stability margin of the ***,system stability is reassessed in the fourth *** proposed parameter-optimization strategy’s effectiveness has been validated through eigenvalue analysis and nonlinear time-domain simulations.

关键词： DC distribution system digital grid small-signal stability eigenvalue parametric sensitivity particle swarm optimization parameter boundary calculation parameter tuning