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Non-ambiguity of blind watermarking:a revisit with analytical resolution

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Science in China(Series F) 2009年第2期52卷 276-285页

作者： KANG XianGui HUANG JiWu ZENG WenJun shi Yun q. School of Information Science & Technology Sun Yat-Sen University Guangzhou 510275 China Department of CS University of Missouri-Columbia MO65211 USA Department of ECE New Jersey Institute of Technology NJ 07102 USA

Resistance to ambiguity attack is an important req.irement for a secure digital rights management （DRM） system. In this paper, we revisit the non-ambiguity of a blind watermarking based on the computational indistinguishability between pseudo random seq.ence generator （PRSG） seq.ence ensemble and truly random seq.ence ensemble. Ambiguity attacker on a watermarking scheme, which uses a PRSG seq.ence as watermark, is viewed as an attacker who tries to attack a noisy PRSG seq.ence. We propose and prove the security theorem for binary noisy PRSG seq.ence and security theorem for general noisy PRSG seq.ence. It is shown that with the proper choice of the detection threshold Th = α n （a is a normalized detection threshold; n is the length of a PRSG seq.ence） and n i≥ 1.39 × m/α^2 （m is the key length）, the success probability of an ambiguity attack and the missed detection probability can both be made negligibly small thus non-ambiguity and robustness can be achieved simultaneously for both practical q.antization-based and blind spread spectrum （SS） watermarking schemes. These analytical resolutions may be used in designing practical non-invertible watermarking schemes and measuring the non-ambiguity of the schemes.

关键词： watermarking ambiguity attack PRSG seq.ence computational indistinguishability digital rights management (DRM)

Seismic and geological evidence of hidden faults in the Yinpan Reservoir area based on a dense seismic array

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Science China Earth Sciences 2024年第7期67卷 2401-2407页

作者： Guangyao YIN Huai ZHANG Liwen GONG q.ipeng BAI Yicun GUO Bing ZHANG Yaolin shi Key Laboratoryof Earth System Numerical Modeling and Application(Chinese Academyof Sciences) College of Earth and Planetary SciencesUniversity of Chinese Academy of SciencesBeijing 100049China Key Laboratory of Computational Geodynamics Chinese Academy of SciencesBeijing 100049China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519080China Beijing Yanshan Critical Zone National Field Scientific Observation and Research Station Beijing 101408China Chongq.ng Earthq.ake Agency Chongq.ng 401147 China Institute of Earthq.ake Forecasting China Earthquake AdministrationBeijing 100036China Hangzhou Applied Acoustics Research Institute Hangzhou 311100China State Key Laboratory of Geodesy and Earths Dynamics Innovation Academy for Precision Measurement Science and TechnologyCASWuhan 430077China

*** November 23,2017,an M_(S)5.0 earthq.ake occurred in Wulong,Chongq.ng,China,resulting in tens of casualties and considerable economic ***,the epicenter of this earthq.ake was located in the transition zone from the... 详细信息

关键词： earthq.ake southeast seismic

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固态电池中的物理问题专题编者按

物理学报 2020年第22期69卷 1-2页

作者： Li H. shi S.-q. Wu F.

新能源汽车是当前我国优先发展的支柱性产业,是国家科技和产业发展的重要方向,担负着保障国家能源安全、降低环境污染和汽车行业快速发展等多重责任.我国制定的《节能与新能源汽车产业规划(2011—2020)》中指出,纯电动汽车、混合动力汽... 详细信息

新能源汽车是当前我国优先发展的支柱性产业,是国家科技和产业发展的重要方向,担负着保障国家能源安全、降低环境污染和汽车行业快速发展等多重责任.我国制定的《节能与新能源汽车产业规划(2011—2020)》中指出,纯电动汽车、混合动力汽车是未来发展的重要方向,动力电池为其中的关键技术.

关键词：支柱性产业国家能源安全新能源汽车动力电池纯电动汽车节能与新能源汽车产业混合动力汽车汽车行业

Understanding the mechanism of environmental, social, and governance impact on enterprise performance in the context of sustainable development

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Mechanical Behavior of Bamboo,and Its Biomimetic Composites and Structural Members:A Systematic Review

Corporate Social Responsibility and Environmental Management 2024年第2期31卷 784-800页

作者： shi X.K. Zhang q.M. School of Finance Zhejiang Gongshang University Zhejiang Hangzhou China

In transitional economies characterized by digital finance and uncertainty, the environmental, social, and governance (ESG) impact on enterprise performance has become a core issue in the sustainable development of enterprises. The existing literature does not pay attention to the simultaneous existence of digital finance and economic policy uncertainty in transition countries such as China. This paper introduces ESG as intangible capital into the Cobb–Douglas production function, considers the impact of digital finance and economic policy uncertainty, establishes a theoretical analysis framework, and empirically tests the impact of ESG on enterprise performance using panel data of 1688 listed companies in China from 2011 to 2020. The results reveal that ESG promotes enterprise performance; digital finance strengthens the positive impact of ESG on enterprise performance, and increased economic policy uncertainty strengthens the positive moderating effect of digital finance. Heterogeneity analysis reveals that the impact of ESG on enterprise performance and the moderating effect of digital finance are significant in both the eastern region and the central and western regions, but the former performs better when economic policy uncertainty increases. The research conclusion provides a policy reference for selecting appropriate digital finance policies to promote the sustainable development of enterprises with ESG as the core. © 2023 ERP Environment and John Wiley & Sons Ltd.

关键词： digital finance economic policy uncertainty enterprise performance ESG

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Journal of Bionic Engineering 2024年第1期21卷 56-73页

作者： Shanyu Han Yuyuan He Hanzhou Ye Xueyong Ren Fuming Chen Kewei Liu Sheldon q.shi Ge Wang Institute of Biomaterials for Bamboo and Rattan Resources International Centre for Bamboo and RattanBeijing 100102China Key Laboratory of National Forestry and Grassland Administration/Beijing for Bamboo&Rattan Science and Technology Beijing 100102China National Forestry and Grassland Engineering Technology Center for Wood Resources Recycling College of Materials Science and TechnologyBeijing Forestry UniversityBeijing 100083China International Bamboo and Rattan Organization Beijing 100102China School of Civil Engineering Tsinghua UniversityBeijing 100084China Mechanical Engineering Department University of North TexasDentonTX 762077102USA

Bamboo is a typical biological material widely growing in nature with excellent physical and mechanical *** is lightweight with high strength and *** naturally optimized bamboo structure,which has inspired global material scientists and engineers for decades,is significantly important for the bionic design of novel structural materials with ultra-light,ultra-strong,or ultra-tough and comprehensive *** literature on innovative composite materials and structural members inspired by bamboo are reviewed in this paper,and the research progress and prospects in this field are expounded in three ***,the structural characteristics of the bamboo wall layer along the thickness and height directions are described in terms of chemical composition,gradient structure,pore structure,and hollow structure with variable ***,this paper summarizes the research progress on new composite materials and structural components by applying bamboo’s structural features from the perspective of sustainability,designability,and ***,given the limitations of current research,the biomimetic scientific research on bamboo’s structural characteristics is prospected from the interpretation of bamboo structure,new bamboo-like materials,and structural design optimization perspectives,providing a reference for future research on biomimetic aspects of biomass.

关键词： Bamboo Structural characteristics-Bamboo-like material Physical and mechanical properties

Implication of Water-Rock Interaction for Enhancing Shale Gas Production

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Fluid Dynamics and Materials Processing 2024年第7期20卷 1441-1462页

作者： Cheng q. You L. Chang C. Xie W. Hu H. Wang X. Shale Gas Research Institute PetroChina Southwest Oil and Gas Field Company Chengdu 610056 China Sichuan Province Key Laboratory of Shale Gas Evaluation and Exploitation PetroChina Southwest Oil and Gas Field Company Chengdu 610056 China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum University Chengdu 610500 China

Horizontal well drilling and multi-stage hydraulic fracturing technologies are at the root of commercial shale gas development and exploitation. During these processes, typically, a large amount of working fluid enters the formation, resulting in widespread water-rock interaction. Deeply understanding such effects is req.ired to optimize the production system. In this study, the mechanisms of water-rock interaction and the associated responses of shale fabric are systematically reviewed for working fluids such as neutral fluids, acid fluids, alkali fluids and oxidative fluids. It is shown that shale is generally rich in water-sensitive components such as clay minerals, acidsensitive components (like carbonate minerals), alkali-sensitive components (like q.artz), oxidative-sensitive components (like organic matter and pyrite), which easily lead to change of rock fabric and mechanical properties owing to water-rock interaction. According to the results, oxidizing acid fluids and oxidizing fracturing fluids should be used to enhance shale gas recovery. This study also indicates that an aspect playing an important role in increasing cumulative gas production is the optimization of the maximum shut-in time based on the change point of the wellhead pressure drop rate. Another important influential factor to be considered is the control of the wellhead pressure considering the stress sensitivity and creep characteristics of the fracture network. © This work is licensed under a Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

关键词： hydraulic fracturing oxidation production system Shale gas reservoir shut-in water-rock interaction working fluid

Adaptive Space Expansion for Fast Motion Planning

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IEEE/CAA Journal of Automatica Sinica 2024年第6期11卷 1499-1514页

作者： Shenglei shi Jiankui Chen State Key Laboratory of Digital Manufacturing Eq.ipment and Technology School of Mechanical Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

The sampling process is very inefficient for sam-pling-based motion planning algorithms that excess random sam-ples are generated in the planning *** this paper,we pro-pose an adaptive space expansion(ASE)approach which belongs to the informed sampling category to improve the sampling effi-ciency for q.ickly finding a feasible *** ASE method enlarges the search space gradually and restrains the sampling process in a seq.ence of small hyper-ellipsoid ring subsets to avoid exploring the unnecessary ***,for a con-structed small hyper-ellipsoid ring subset,if the algorithm cannot find a feasible path in it,then the subset is ***,the ASE method successively does space exploring and space expan-sion until the final path has been ***,we present a particular construction method of the hyper-ellipsoid ring that uniform random samples can be directly generated in *** last,we present a feasible motion planner BiASE and an asymptoti-cally optimal motion planner BiASE*using the bidirectional exploring method and the ASE *** demon-strate that the computation speed is much faster than that of the state-of-the-art *** source codes are available at https://***/shshlei/ompl.

关键词： Adaptive space expansion(ASE) hyper-ellipsoid ring informed sampling motion planning.

q.antization and Event-Triggered Policy Design for Encrypted Networked Control

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IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 946-955页

作者： Yongxia shi Ehsan Nekouei the Department of Electrical Engineering City University of Hong KongHong KongChina

This paper proposes a novel event-driven encrypted control framework for linear networked control systems(NCSs),which relies on two modified uniform q.antization policies,the Paillier cryptosystem,and an event-triggered *** to the fact that only integers can work in the Pailler cryptosystem,both the real-valued control gain and system state need to be first q.antized before *** is dramatically different from the existing q.antized control methods,where only the q.antization of a single value,e.g.,the control input or the system state,is *** handle this issue,static and dynamic q.antization policies are presented,which achieve the desired integer conversions and guarantee asymptotic convergence of the q.antized system state to the ***,the q.antized system state is encrypted and sent to the controller when the triggering condition,specified by a state-based event-triggered strategy,is *** doing so,not only the security and confidentiality of data transmitted over the communication network are protected,but also the ciphertext expansion phenomenon can be ***,by tactfully designing the q.antization sensitivities and triggering error,the proposed event-driven encrypted control framework ensures the asymptotic stability of the overall closedloop ***,a simulation example of the secure motion control for an inverted pendulum cart system is presented to evaluate the effectiveness of the theoretical results.

关键词： Cyber-security encrypted control event-triggered control(ETC) networked control systems(NCSs) semi-homomorphic encryption

No Reference Image Sharpness Assessment Based on Global Color Difference Variation

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Chinese Journal of Electronics 2024年第1期33卷 293-302页

作者： Chenyang shi Yandan LIN School of Artificial Intelligence Anhui Polytechnic University School of Mechanical Engineering Anhui Polytechnic University Department of Light Sources and Illuminating Engineering Fudan University Academy for Engineering & Technology Fudan University

Image q.ality assessment(Iq.) model is designed to measure the image q.ality in consistent with subjective ratings by computational models. In this research, a valid no reference Iq.(NR-Iq.) model for color image sharpness assessment is proposed based on local color difference map in a color space. In the proposed model, the absolute color difference variation and relative color difference variation are combined to evaluate sharpness in YIq.color space(a color coordinate system for the development of the United States color television system). The difference between sharpest and blurriest spot of an image is represented by the absolute color difference variation, and relative color difference variation expresses the variation in the image content. Extensive experiments are performed on five publicly available benchmark synthetic blur databases and two real blur databases, and the results prove that the proposed model work better than the other state-of-the-art and latest NR-Iq. models for the prediction accuracy on blurry images. Besides, the model maintains the lowest computational complexity.

关键词： Image q.ality TV Image color analysis Databases Computational modeling Color Predictive models