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Content subscribing mechanism in P2P streaming based on gamma distribution prediction

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第12期8卷 1983-1989页

作者： GUO Tong-qiang weng jian-guang ZHUANG Yue-ting School of Computer Science Zhejiang University Hangzhou 310027 China

P2P systems are categorized into tree-based and mesh-based systems according to their topologies. Mesh-based systems are considered more suitable for large-scale lnternet applications, but require optimization on latency issue. This paper proposes a content subscribing mechanism （CSM） to eliminate unnecessary time delays during data relaying. A node can send content data to its neighbors as soon as it receives the data segment. No additional time is taken during the interactive stages prior to data segment transmission of streaming content. CSM consists of three steps. First, every node records its historical segments latency, and adopts gamma distribution, which possesses powerful expression ability, to express latency statistics. Second, a node predicts subscribing success ratio of every neighbor by comparing the gamma distribution parameters of the node and its neighbors before selecting a neighbor node to subscribe a data segment. The above steps would not increase latency as they are executed before the data segments are ready at the neighbor nodes. Finally, the node, which was subscribed to, sends the subscribed data segment to the subscriber immediately when it has the data segment. Experiments show that CSM significantly reduces the content data transmission latency.

关键词： P2P streaming Gamma distribution Content subscribing mechanism (CSM)

Pirate decoder for the broadcast encryption schemes from Crypto 2005

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Science in China(Series F) 2007年第3期50卷 318-323页

作者： weng jian LIU ShengLi CHEN KeFei Department of Computer Science and Engineering Shanghai Jiao Tong University Shanghai 200240China

In Crypto＇05, Boneh et al. presented two broadcast encryption schemes. Their work has exciting achievements： the header （also called ciphertexts） and the private keys are of constant size. In their paper, they give an open question to construct a traitor tracing algorithm for their broadcast encryption schemes, and combine the two systems to obtain an efficient trace-and-revoke system. In this paper, we give a negative answer to their open question. More precisely, we show that three or more insider users are able to collude to forge a valid private key for pirate decoding against their schemes. Moreover, we prove that there exists no traitor tracing algorithm to identify the colluders. Our pirate decoding can also similarly be applied to Lee et al.＇s broadcast encryption schemes in ISPEC＇06.

关键词： broadcast encryption pirate decoder traitor tracing

Fully distributed certificateless threshold signature without random oracles

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Science China(Information Sciences) 2018年第9期61卷 259-269页

作者： Wenjie YANG Weiqi LUO Xizhao LUO jian weng Anjia YANG College of Cyber Security/College of Information Science and Technology Jinan University Guangdong Key Laboratory of Data Security and Privacy Preserving Guangzhou Key Laboratory of Data Security and Privacy Preserving School of Computer and Technology Soochow University

A certificateless(t,n)threshold signature(CLTS)scheme allows at least t members to cooperatively sign a message on behalf of an n-member group,which is a good way to share the responsibility and *** researchers have f... 详细信息

关键词： Fully distributed certificateless threshold signature without random oracles PKR Si DKG CLS

Provably secure attribute-based authenticated encryption with keyword search from ideal lattices

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Science China(Information Sciences) 2024年第1期67卷 308-309页

作者： Lisha YAO Lin HOU jian weng Feixiang ZHAO College of Cyber Security Jinan University

A public-key authenticated encryption with keyword search(PAEKS)[1, 2] system overcomes the problem of an inside adversary forging searchable ciphertexts and guessing the keyword information from the given token. This system allows the sender to encrypt and authenticate a ***, traditional PAEKS schemes require the sender to specify the intended receiver in advance, losing much flexibility.

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Reduced Ti-MOFs encapsulated black phosphorus with high stability and enhanced photocatalytic activity

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Journal of Energy Chemistry 2021年第2期30卷 185-191,I0007页

作者： Xiao Liu Peijie Fan Liangping Xiao jian weng Qingchi Xu Jun Xu Department of Biomaterials College of Materials.Xiamen UniversityXiamen 361005Fujian.China Department of Physics Research Institute for Biomimetics and Soft MatterFujian Provincial Key Laboratory for Soft Functional MaterialsXiamen UniversityXiamen 361005FujianChina Shenzhen Research Institute of Xiamen University.Shenzhen 518057 GuangdongChina China State Key Lab of Physical Chemistry of Solid Surfaces Collaborative Innovation Center of Chemistry for Energy MaterialsCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005FujianChina

The generation of green hydrogen(H_2) energy is of great significance to solve worldwide energy and environmental issues. Reduced Ti based photocatalyst has recently attracted intensive attention due to its excellent photocatalytic activity, while the synthesis of reduced Ti based photocatalysts with high stability is still a great challenge. Here, we report a facile method for synthesis of reduced Ti metal organic frameworks(small amounts of Pt incorporated) encapsulated BP(BP/R-Ti-MOFs/Pt) hybrid nanomaterial with enhanced photocatalytic activity. The strong interaction between Ti and P reduces the valence state of the binding Ti^(4+)on the BP surface, forming abundant reduced Ti^(4+)within R-Ti-MOFs/BP. Such reduced Ti^(4+)render R-Ti-MOFs/BP efficient charge transfer and excellent light absorption capability, thus promote the photocatalytic H_2 production efficiency. Furthermore, the Ti-P interaction stabilizes both reduced Ti^(4+)and BP during the photocatalytic reaction, which greatly enhanced the stability of the obtained BP/R-TiMOFs/Pt photocatalyst.

关键词： 2D materials Reduced Ti-MOFs Black phosphorus Photocatalysis Solar-to-hydrogen conversion Metal-organic frameworks

Three-dimensional temperature prediction in cylindrical turning with large-chamfer insert based on a modified slip-line field approach

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Chinese Journal of Aeronautics 2021年第10期34卷 265-281页

作者： Cheng HU Kejia ZHUANG Yuanwei TANG jian weng Xiaoming ZHANG Han DING Hubei Digital Manufacturing Key Laboratory School of Mechanical and Electronic EngineeringWuhan University of TechnologyWuhan 430070China Institute of Advanced Materials and Manufacturing Technology Wuhan University of TechnologyWuhan 430070China AECC Guizhou Liyang Aviation Power CO.LTD Guiyang 550000China State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China

Chamfered inserts have found broader applications in metal cutting process especially in high-performance machining of hard-to-cut materials for their excellent edge resistance and cutting ***,excessive heat generation and resulting high cutting temperature eventually cause severe tool wear and poor surface integrity,which simultaneously limits the optimal selection of machining *** the present study,an analytical thermal–mechanical model is proposed for the prediction of the three-dimensional(3-D)temperature field in cylindrical turning with chamfered round insert based on a modified slip-line field ***,an innovative discretization method is introduced in a general 3-D coordinate system to provide a comprehensive demonstration of the irregular cutting geometry and heat generation ***,a plasticity-theory-based slip-line field model is developed and employed to determine the intensities and geometries of every elementary heat sources in Primary Deformation Zones(PDZ),Secondary Deformation Zones(SDZ)and Dead Metal Zones(DMZ).At last,a 3-D analytical model is suggested to calculate the temperature increases caused by the entire heat sources and associated *** maximum cutting temperature region predicted is found existing upon the chip-tool contact area rather than the tool ***,the rationalities of cutting parameters employed are analyzed along with theoretical material removal rates and ensuing maximum cutting *** results indicate that the cutting conditions with large depth of cut and high cutting speed are more desirable than those with high feed *** proposed models are respectively verified through a series of 3-D Finite Element(FE)simulations and dry cutting experiments of Inconel 718 with chamfered round *** agreement has been reached between the predictions and simulations as well as the measurements,which confirms the correctness and effectiveness of the presented analy

关键词： Analytical model Chamfered round insert Dead metal zone Prediction of temperature Slip-line field

DPPS: A novel dual privacy-preserving scheme for enhancing query privacy in continuous location-based services

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Frontiers of Computer Science 2023年第5期17卷 197-205页

作者： Long LI jianbo HUANG Liang CHANG jian weng Jia CHEN Jingjing LI College of Cyber Security Jinan UniversityGuangzhou 510632China Guangxi Key Laboratory of Trusted Software Guilin University of Electronic TechnologyGuilin 541004China Department of Computer Applications Guilin University of Technology at NanningNanning 530000China

Since smartphones embedded with positioning systems and digital maps are widely used,location-based services(LBSs)are rapidly growing in popularity and providing unprecedented convenience in people’s daily lives;however,they also cause great concern about privacy *** particular,location queries can be used to infer users’sensitive private information,such as home addresses,places of work and appointment ***,many schemes providing query anonymity have been proposed,but they typically ignore the fact that an adversary can infer real locations from the correlations between consecutive locations in a continuous *** address this challenge,a novel dual privacy-preserving scheme(DPPS)is proposed that includes two privacy protection ***,to prevent privacy disclosure caused by correlations between locations,a correlation model is proposed based on a hidden Markov model(HMM)to simulate users’mobility and the adversary’s prediction ***,to provide query probability anonymity of each single location,an advanced k-anonymity algorithm is proposed to construct cloaking regions,in which realistic and indistinguishable dummy locations are *** validate the effectiveness and efficiency of DPPS,theoretical analysis and experimental verification are further performed on a real-life dataset published by Microsoft,i.e.,GeoLife dataset.

关键词： location-based services privacy-preserving hidden Markov model k-anonymity query probability

An approach to synthesis of(Z)-2-chloro-1,3-diarylpropen-1-ones by Vilsmeier reagent(bis-(trichloromethyl)carbonate/DMF)

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Chinese Chemical Letters 2011年第12期22卷 1395-1398页

作者： Yi Yi weng jian Jun Li Wei Ke Su Key Laboratory of Pharmaceutical Engineering of Ministry of Education College of Pharmaceutical Sciences Zhejiang University of Technology Hangzhou 310014 China

A series of（Z）-2-chloro-1,3-diarylpropen-1-ones were unexpectedly synthesized in moderate yields by treatment of easily available 2,3-epoxy-1,3-diarylpropan-1-ones with Vilsmeier reagent,which was derived from bis（trichloromethyl） carbonate（BTC, triphosgene） and DMF.A possible mechanism was also proposed,where sequential ring-opening,halogenation and elimination reactions were involved.

关键词： Ring-opening Halogenation Vilsmeier reagent Bis-(trichloromethyl)carbonate (Z)-2-Chloro-1 3-diaryl-2-enones

Authentication Codes from-ASU Hash Functions with Partially Secret Keys

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Chinese Journal of Electronics 2014年第4期23卷 790-793页

作者： LIU Shengli TILBORG Henk van weng jian CHEN Kefei Deptartment of Computer Science and Engineering Shanghai Jiao Tong University Deptartment of Mathematics and Computer Science Eindhoven University of Technology Department of Computer Science Jinan University School of Science Hangzhou Normal University

An authentication code can be constructed with a family of-Almost strong universal(-ASU) hash functions, with the index of hash functions as the authentication key. This paper considers the performance of authentication codes from-ASU, when the authentication key is only partially secret. We show how to apply the result to privacy amplification against active attacks in the scenario of two independent partially secret strings shared between a sender and a receiver.

关键词： Information theory Authentication code Privacy amplification Unconditional security