检索结果-南通市图书馆

Studies and advances on joint source-channel encoding/decoding techniques in flow media communications

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china.information Sciences) 2010年第1期53卷 1-17页

作者： TU GuoFang1, LIU JianJun1, ZHANG Can1,2, GAO ShaoShuai3 & LI ShiDong4 1School of information Science and Engineering, Graduate University of Chinese Academy of Sciences, beijing 100049, china.2state key lab.ratory of information security, Graduate University of Chinese Academy of Sciences, beijing 100049, china.3National Institute of Standards and Technology, Gaithersburg, MD 20899, USA, 4Department of Mathematics, San Francisco state University, San Francisco, CA 94132, USA 1. School of information Science and Engineering Graduate University of Chinese Academy of Sciences Beijing 100049 China2. State Key Laboratory of Information Security Graduate University of Chinese Academy of Sciences Beijing 100049 China3. National Institute of Standards and Technology Gaithersburg MD 20899 USA4. Department of Mathematics San Francisco State University San Francisco CA 94132 USA

Joint source-channel coding/decoding (JSCC/JSCD) techniques in flow media communications have become a state-of-the-art and one of the challenging research subjects in the spatial communication area. They have great application prospective and deep impact in various manned space flights, satellite missions, mobile radio communications and deep-space explorations. In the last few years, there have been influential achievements in JSCC/JSCD studies. This paper aims at an introduction to the basic principles of joint source-channel optimal design. A general summarization and classification for various existing JSCC/JSCD methods is addressed. Also presented is a JSCD scheme based on variable-length coding, capable of providing reliable resolutions for flow media data transmission in spatial communications.

关键词： joint source-channel coding/decoding rate allocation variable-length coding/decoding iterative decoding

Study on attribute characterization for reservoir dynamic monitoring by seismic

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china.Earth Sciences 2008年第S2期51卷 218-225页

作者： CHEN XiaoHong1,3,LI JingYe2,3 & ZHAO Wei4 1 key lab.of Geophysical Exploration of CNPC,china.Petroleum University,beijing 102249,china.2 Basin & Reservoir Research Center,china.Petroleum University,beijing 102249,china.3 state key lab.ratory of Petroleum Resource and Prospecting,china.University of Petroleum,beijing 102249,china.4 Research Center of CNOOC,beijing 100027,china 1. key lab.of Geophysical Exploration of CNPC China Petroleum University Beijing 102249 China 3. state key lab.ratory of Petroleum Resource and Prospecting China University of Petroleum Beijing 102249 China 2. Basin & Reservoir Research Center China Petroleum University Beijing 102249 China 4. Research Center of CNOOC Beijing 100027 China

Study on characterizing reservoir parameters dynamic variations by time-lapse seismic attributes is the theoretical basis for effectively distinguishing reservoir parameters variations and conducting time-lapse seismic interpretation,and it is also a key step for time-lapse seismic application in real oil fields. Based on the rock physical model of unconsolidated sandstone,the different effects of oil saturation and effective pressure variations on seismic P-wave and S-wave velocities are calculated and analyzed. Using numerical simulation on decoupled wave equations,the responses of seismic amplitude with different offsets to reservoir oil saturation variations are analyzed,pre-stack time-lapse seismic attributes differences for oil saturation and effective pressure variations of P-P wave and P-S converted wave are calculated,and time-lapse seismic AVO (Amplitude Versus Offset) response rules of P-P wave and P-S converted wave to effective pressure and oil saturation variations are compared. The theoretical modeling study shows that it is feasible to distinguish different reservoir parameters dynamic variations by pre-stack time-lapse seismic information,including pre-stack time-lapse seismic attributes and AVO information,which has great potential in improving time-lapse seismic interpreta-tion precision. It also shows that the time-lapse seismic response mechanism study on objective oil fields is especially important in establishing effective time-lapse seismic data process and interpreta-tion scheme.

关键词： time-lapse seismic dynamic monitoring rock physical model pre-stack attribute Amplitude Versus Offset (AVO)

维普期刊数据库

Multiparty quantum secret sharing of classical and quantum messages

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2007年第1期17卷 26-31页

作者： CHEN Pan, DENG Fuguo and LONG Guilu ( key lab.ratory for Quantum information and Measurements, and Department of Physics, Tsinghua University, beijing 100084, china.key lab.ratory of Beam Technology and Material Modification, MOE, Institute of Low Energy Nuclear Physics, and Department of Material Science and Engineering, beijing Normal University, beijing 100875, china.beijing Radiation Center, beijing 100875, china.key lab.ratory for Atomic and Molecular Nano-Sciences, Tsinghua University, beijing 100084, china. [a]key lab.ratory for Quantum information and Measurements and Department of Physics Tsinghua University Beijing China [b]key lab.ratory of Beam Technology and Material Modification MOE Institute of Low Energy Nuclear Physics and Department of Material Science and Engineering Beijing Normal University Beijing China [c]beijing Radiation Center Beijing China [d]key lab.ratory for Atomic and Molecular Nano-Sciences Tsinghua University Beijing China

A scheme for multiparty quantum secret sharing of classical and quantum messages is proposed by using entanglement swapping. This scheme can distribute not only the classical information but also the quantum informati... 详细信息

关键词： quantum secret sharing classical message quantum message EPR pair.

Accountable authority key policy attribute-based encryption

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china.information Sciences) 2012年第7期55卷 1631-1638页

作者： WANG YongTao 1,2 ,CHEN KeFei 1,3 ,LONG Yu 1,4 & LIU ZhaoHui 2 1 Department of Computer Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240,china.2 china.information Technology security Evaluation Center,beijing 100085,china.3 Shanghai key lab.ratory of Scalab.e Computing and Systems,Shanghai Jiao Tong University,Shanghai,200240,china.4 state key lab.ratory of information security,Graduate School of Chinese Academy of Sciences,100039,china 1. Department of Computer Science and Engineering Shanghai Jiao Tong University Shanghai 200240 China2. China Information Technology Security Evaluation Center Beijing 100085 China3. Shanghai Key Laboratory of Scalable Computing and Systems Shanghai Jiao Tong University Shanghai 200240 China4. State Key Laboratory of Information Security Graduate School of Chinese Academy of Sciences Beijing 100039 China

We present an accountable authority key policy attribute-based encryption (A-KPABE) *** this paper,we extend Goyal's work to key policy attribute-based encryption *** first generalize the notion of accountable authority in key policy attribute-based encryption scenario,and then give a *** addition,our scheme is shown to be secure in the standard model under the modified Bilinear Decisional Diffie-Hellman (mBDDH) assumption.

关键词： accountable authority key policy attribute-based encryption standard model access structure

A Group-Oriented (t,n) Threshold Signature Scheme with Traceable Signers

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural Sciences 2008年第6期13卷 680-684页

作者： TAN Zuowen1,2 1. School of information Technology, Jiangxi University of Finance and Economics, Nanchang 330013, Jiangxi, china.2. state key lab.ratory of information security/Institute of Software, Chinese Academy of Sciences, beijing 100190, china School of information Technology Jiangxi University of Finance and Economics Nanchang 330013 Jiangxi China state key lab.ratory of information security/Institute of Software Chinese Academy of Sciences Beijing 100190 China

A group-oriented （t, n） threshold signature scheme employs the cryptographic techniques of secret share, allows any subset of t players out of n players to sign message on behalf of the group and disallows the creation of a valid signature if fewer than t players take part in the signature protocol. In this paper, we proposed a new group-oriented （t, n） threshold signature schemes with traceable signers based on Schnorr signature. The proposed scheme is proved traceable, robust and unforgeable against the ＂static＂ adversary with the discrete logarithm assumption in the random oracle model and existence of broadcast channel. The proofs of the strongest security （existential unforgeability against adaptively chosen message attacks under the discrete logarithm assumption） are provided in the random oracle model.

关键词： threshold signature random oracle model robustness

维普期刊数据库

A novel adaptive spectrum forming filter:Application in cognitive ultra-wideband

在线全文

学校读者我要写书评

暂无评论

Science china.information Sciences) 2010年第12期53卷 2584-2599页

作者： LI Bin ,ZHOU Zheng & ZOU WeiXia key lab.of Universal Wireless Communications,MOE.Wireless Network lab.beijing University of Posts and Telecommunications,beijing 100876,china 1. key lab.of Universal Wireless Communications MOE. Wireless Network Lab Beijing University of Posts and Telecommunications Beijing 100876 China

Ultra wideband impulse radio(UWB-IR) has important applications in high data rate communications,high precision positioning and penetrating target *** with cognitive radio(CR),UWB can also greatly alleviate the current spectrum ***,the existing UWB waveforms are faced with two *** spectrum utilization of UWB signal is rather low,which reduces the communication ***,it appears difficult for UWB-IR to avoid spectrum collision with other incumbent *** UWB will inevitably interfere other legal wireless *** by these considerations,we model the UWB waveform design into an interpolation *** on radial basis function neural network,a novel UWB pulse is presented in this *** UWB pulse is then realized though reasonable simplification on the already proposed theoretical *** designed UWB pulses can adaptively track the external spectral environment where UWB devices work and reconfigure its emission spectrum according to the state of primer users without any modification on *** frequency utilization is maximized when there is no active primary *** adequate spectrum avoidance has also been achieved without much spectrum utilization degradation within the non-primary *** and analysis show that our UWB-IR pulse is much superior to the other existing UWB signals in the frequency utilization,spectrum avoidance and in the transmission performance.

关键词： UWB-IR cognitive radio pulse design RBF network spectrum efficiency spectrum avoidance

Secure network coding in the presence of eavesdroppers

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china.information Sciences) 2010年第3期53卷 648-658页

作者： LUO MingXing1,2,3, YANG YiXian1,2,3, WANG LiCheng1,2,3 & NIU XinXin1,2,3 1information security Center, state key lab.ratory of Networking and Switching Technology, beijing University of Posts and Telecommunications, beijing 100876, china.2key lab.ratory of Network and information Attack and Defence Technology of MOE, beijing University of Posts and Telecommunications, beijing 100876, china.3National Engineering lab.ratory for Disaster Backup and Recovery, beijing University of Posts and Telecommunications, beijing 100876, china 1. information security Center State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 100876 China2. Key Laboratory of Network and Information Attack and Defence Technology of MOE Beijing University of Posts and Telecommunications Beijing 100876 China3. National Engineering Laboratory for Disaster Backup and Recovery Beijing University of Posts and Telecommunications Beijing 100876 China

Our concern, in the paper, is to construct information-theoretic secure network coding in the presence of eavesdroppers. Based on the generalized attack model and all-or-nothing transformation, the security of network coding in the generalized combination network can be characterized by the network capacity and the min-cut bound of wiretapping set from the source. Furthermore, it can be extended to any directed acyclic networks with single source. Compared with the traditional results, we construct information-theoretic secure network coding without additional encryptions and giving up any capacity.

关键词： all-or-nothing transformation secure network coding eavesdropping

Secure multi-party computation protocol for sequencing problem

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china.information Sciences) 2011年第8期54卷 1654-1662页

作者： TANG ChunMing 1,2,SHI GuiHua 1 & YAO ZhengAn 3 1 School of Mathematics and information Science,Guangzhou University,Guangzhou 510006, china.2state key lab.ratory of information security, Institute of Software Science,Chinese Academy of Sciences,beijing 100080,china.3 School of Mathematics and Computational Science,Sun Yat-Sen University,Guangzhou 510275,china 1. School of Mathematics and information Science Guangzhou University Guangzhou 510006 China2. State Key Laboratory of Information Security Institute of Software Science Chinese Academy of Sciences Beijing 100080 China3. School of Mathematics and Computational Science Sun Yat-Sen University Guangzhou 510275 China

In the field of multi-party computation,an important problem is how to construct an efficient and secure multi-party computation protocol for certain specific *** the present study,we make use of a secret sharing scheme to construct an efficient and secure multi-party computation protocol for sequencing *** protocols are perfectly secure against both a passive adversary that can corrupt at most t (n-1)/2 participants, and an active adversary that can corrupt at most t < n/3 *** simplest sequencing problem is the Millionaires' problem.

关键词： secure multi-party computation sequencing problem secret sharing

Weight hierarchies of linear codes satisfying the Near-Chain condition

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2005年第9期15卷 784-792页

作者： LIU Zihui1** and CHEN Wende2(1. School of Mathematical Sciences, Peking University, beijing 100871, china.2. lab.ratory of Systems and Control and key state lab.ratory of information security, Institute of Systems Science, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, beijing 100080, china. School of Mathematical Sciences Peking University Beijing 100871 China. lab.ratory of Systems and Control and key state lab.ratory of information security Institute of Systems Science Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China

The weight hierarchies of a linear [n,k;q] code C satisfying the Near-Chain condition are studied, almost all the weight hierarchies of such code are determined.

关键词： weight hierarchy Near-Chain condition difference sequence linear code.