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Efficient DPCA SAR imaging with fast iterative spectrum reconstruction method

science china(information sciences) 2012年第8期55卷 1838-1851页

作者： FANG Jian1,ZENG JinShan1,XU ZongBen1&ZHAO Yao2 1M inistry of Education key Lab for Intelligent Networks and Network security Xi'an Jiaotong University,Xi'an 710049,china 2N ational key laboratory of science and Technology on Microwave Imaging&institute of Electronics,chinese academy of sciences,beijing 100049,china 1. Ministry of Education key Lab for Intelligent Networks and Network security Xi’an Jiaotong University Xi’an 710049 China2. National Key Laboratory of Science and Technology on Microwave Imaging & Institute of Electronics Chinese Academy of Sciences Beijing 100049 China

The displaced phase center antenna(DPCA)technique is an effective strategy to achieve wide-swath synthetic aperture radar(SAR)imaging with high azimuth ***,traditionally,it requires strict limitation of the pulse repetition frequency(PRF)to avoid non-uniform ***,any deviation could bring serious ambiguity if the data are directly processed using a matched *** break this limitation,a recently proposed spectrum reconstruction method is capable of recovering the true spectrum from the nonuniform ***,the performance is sensitive to the selection of the *** regularization based imaging may provide a way to overcome this *** existing time-domain method,however,requires a large-scale observation matrix to be built,which brings a high computational *** this paper,we propose a frequency domain method,called the iterative spectrum reconstruction method,through integration of the sparse regularization technique with spectrum analysis of the DPCA *** approximately expressing the observation in the frequency domain,which is realized via a series of decoupled linear operations,the method performs SAR imaging which is then not directly based on the observation matrix,which reduces the computational cost from O(N2)to O(N log N)(where N is the number of range cells),and is therefore more efficient than the time domain *** sparse regularization scheme,realized via a fast thresholding iteration,has been adopted in this method,which brings the robustness of the imaging process to the PRF *** provide a series of simulations and ground based experiments to demonstrate the high efficiency and robustness of the *** simulations show that the new method is almost as fast as the traditional mono-channel algorithm,and works well almost independently of the PRF ***,the suggested method can be accepted as a practical and efficient wide-swath SAR imaging technique.

关键词： displaced phase center antenna sparse regularization iterative thresholding spectrum reconstruction

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A novel quantum information hiding protocol based on entanglement swapping of high-level Bell states

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chinese Physics B 2015年第5期24卷 231-238页

作者：徐淑奖陈秀波王连海钮心忻杨义先 Shandong Provincial key laboratory of Computer Networks Shandong Computer Science Center (National Supercomputer Center in Jinan) information security Center State Key Laboratory of Networking and Switching TechnologyBeijing University of Posts and Telecommunications state key laboratory of information security Institute of Information Engineering Chinese Academy of Sciences

Using entanglement swapping of high-level Bell states, we first derive a covert layer between the secret message and the possible output results of the entanglement swapping between any two generalized Bell states, and then propose a novel high-efficiency quantum information hiding protocol based on the covert layer. In the proposed scheme, a covert channel can be built up under the cover of a high-level quantum secure direct communication （QSDC） channel for securely transmitting secret messages without consuming any auxiliary quantum state or any extra communication resource. It is shown that this protocol not only has a high embedding efficiency but also achieves a good imperceptibility as well as a high security.

关键词： quantum information hiding quantum covert'channel entanglement swapping high-level Bell states

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Extended multivariate public key cryptosystems with secure encryption function

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science china(information sciences) 2011年第6期54卷 1161-1171页

作者： WANG HouZhen 1,2 , ZHANG HuanGuo 1,2 , WANG ZhangYi 1,2 & TANG Ming 1,2 1 The key laboratory of Aerospace information security and Trusted Computing, Ministry of Education, School of Computer, Wuhan University, Wuhan 430079, china 2 state key laboratory of software Engineering, Wuhan University, Wuhan 430072, china 1. The key laboratory of Aerospace information security and Trusted Computing Ministry of Education School of Computer Wuhan University Wuhan 430079 China2. State Key Laboratory of Software Engineering Wuhan University Wuhan 430072 China

Advances in quantum computers pose great threats on the currently used public key cryptographic algorithms such as RSA and ECC. As a promising candidate secure against attackers equipped with quantum computational power, multivariate public key cryptosystems (MPKCs) have attracted increasing attention in recently years. Unfortunately, the existing MPKCs can only be used as a multivariate signature scheme, and it remains unknown how to construct an efficient MPKC enabling secure encryption. Furthermore, some multivariate signature schemes have been shown insecure in recent years, and it is also not trivial to build MPKC which can serve as a secure signature scheme. By employing the basic MQ-trapdoors, this paper proposes a novel MPKC and shows how it can be used as a multivariate signature scheme and a multivariate encryption scheme, respectively. The goal is achieved by incorporating our new hash authentication techniques and some modification methods such as the Shamir's minus method. Thorough analysis shows that our schemes are secure and efficient. Our MPKC gives a positive response to the challenges in multivariate public key cryptography.

关键词： cryptography post-quantum cryptography MQ problem hash function

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Capability description and discovery of Internetware entity

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science china(information sciences) 2010年第4期53卷 685-703页

作者： WANG PuWei1*, JIN Zhi2,3* & LIU HongYan4 1key laboratory of Data Engineering and Knowledge Engineering of the Ministry of Education, Renmin University of china, beijing 100872, china 2key laboratory of High Confidence software Technologies of the Ministry of Education, Peking University, beijing 100871, china 3academy of Mathematics and System sciences, chinese academy of sciences, beijing 100190, china 4Department of Management science and Engineering, Tsinghua University, beijing 100084, china 1. key laboratory of Data Engineering and Knowledge Engineering of the Ministry of Education Renmin University of China Beijing 100872 China2. Key Laboratory of High Confidence Software Technologies of the Ministry of Education Peking University Beijing 100871 China3. Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing 100190 China4. Department of Management Science and Engineering Tsinghua University Beijing 100084 China

Internetware can be formed through aggregation of Internetware entities bottom-up to satisfy the user's requirements. In the process, capability description of Internetware entity plays an important role. This paper proposes a capability description of Internetware entity based on environment ontology. The environment ontology includes environment entities and possible interactions with the environment entities in a particular domain. Tree-like hierarchical state machines are also included in the ontology to describe domain life-cycle of the environment entities. On the basis of the ideas, the capability of Internetware entity is embodied by interacting with environment entities and the changes of the environment entities during the interactions. Finally, this paper describes the matchmaking between capability descriptions of Internetware entities to support the discovery of Internetware entity. An example of online education course is given to illustrate the ideas.

关键词： Internetware capability description domain environment ontology tree-like hierarchical state machine

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Instantiate Random Oracles in OAEP with Pseudorandom Functions

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Wuhan University Journal of Natural sciences 2008年第6期13卷 651-656页

作者： JIA Xiaoying LI Hongda LI Bao state key laboratory of information security/Graduate University of chinese academy of sciences Beijing 100049 China

This paper focuses on the instantiation of random oracles in public key encryption schemes. A misunderstanding in the former instantiations is pointed out and analyzed. A method of using this primitive as a substitution of random oracles is also proposed. The partial and full instantiations of random oracles in optimal asymmetric encryption padding （OAEP） implemented by pseudorandom functions are described and the resulted schemes are proven to be indistinguishable secure against adaptive chosen ciphertext attack （IND-CCA2） secure. Using this method, one can transform a practical public key encryption scheme secure in the random oracle model into a standard-model secure scheme. The security of the scheme is based on computational assumptions, which is weaker than decisional assumptions used in Cramer- Shoup like schemes.

关键词： random oracle(RO) model instantiation optimal asymmetric encryption padding(OAEP) indistinguishable securitity against adaptive chosen ciphertext attack (IND-CCA2)

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A heuristic path-estimating algorithm for large-scale real-time traffic information calculating

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science china(Technological sciences) 2008年第S1期51卷 165-174页

作者： L WeiFeng1,ZHU TongYu1,WU DongDong2,DAI Hong3 & HUANG Jian1 1 state key laboratory for software Development Environment,Beihang University,beijing 100083,china 2 beijing Transportation information Center,beijing 100055,china 3 College of Arts & science,beijing Union University,beijing 100083,china 1. state key laboratory for software Development Environment Beihang University Beijing 100083 China 2. beijing Transportation information Center Beijing 100055 China 3. College of Arts & science Beijing Union University Beijing 100083 China

As the original Global Position System (GPS) data in Floating Car Data have the accuracy problem,this paper proposes a heuristic path-estimating algorithm for large-scale real-time traffic information calculating. It uses the heuristic search method,imports the restriction with geometric operation,and makes comparison between the vectors composed of the vehicular GPS points and the special road network model to search the set of vehicular traveling route candidates. Finally,it chooses the most optimal one according to weight. Experimental results indicate that the algorithm has considerable efficiency in accuracy (over 92.7%) and com-putational speed (max 8000 GPS records per second) when handling the GPS tracking data whose sampling rate is larger than 1 min even under complex road network conditions.

关键词： path-estimating floating car data (FCD) road network vector GPS

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A formal semantics for program debugging

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science china(information sciences) 2012年第1期55卷 133-148页

作者： LI Wei1&LI Ning1,2 1state key laboratory of software Development Environment,School of Computer science and Engineering,Beihang University,beijing 100191,china 2china Ship Research and Development academy,beijing 100192,china 1. state key laboratory of software Development Environment School of Computer Science and Engineering Beihang University Beijing 100191 China2. China Ship Research and Development Academy Beijing 100192 China

This work aims to build a semantic framework for automated debugging.A debugging process consists of tracing,locating,and fixing processes *** first two processes are accomplished by a tracing procedure and a locating procedure,*** tracing procedure reproduces the execution of the failed test case with well-designed data structures and saves necessary information for locating *** locating procedure will use the information obtained from the tracing procedure to locate ill-designed statements and to generate a system of fix-equations,whose solution will be used to fix the bugs.A structural operational semantics is given to define the functions of the tracing and locating *** of them are proved to *** main task of fixing process is to solve the *** turns out that for a given failed test case,there exist four types of fix-equations and three dierent solutions:1)The bug is solvable,i.e.,there exists a solution of the system of fix-equations,and the program can be repaired.2)There exists a structural design error in the program,i.e.,the system of fix-equations generated at each round of the locating procedure is solvable,but a new bug will arise when the old bug is being fixed.3)There exists a logical design error,and the system of fix-equations is not solvable.

关键词： debugging operational semantics failed test case fix-equations

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R-calculus without the cut rule

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science china(information sciences) 2011年第12期54卷 2550-2563页

作者： LUO Jie & LI Wei state key laboratory of software Development Environment, School of Computer science and Engineering, Beihang University, beijing 100191, china 1. state key laboratory of software Development Environment School of Computer Science and Engineering Beihang University Beijing 100191 China

R-calculus is an inference system for deducing all possible changes when a theory is refuted by the facts. In this paper, we try to eliminate the cut rule in R-calculus by modifying the existing rules and by introducing new rules. The result is the R-calculus without the cut rule, which still preserves the reachability, soundness and completeness as R-calculus does. R-calculus without the cut rule is a formal inference system of logical connective symbols and quantifier symbols solely. It can serve as the theoretical foundation of the automation of revision calculus.

关键词： revision R-calculus cut rule

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Reliability-aware automatic composition approach for web services

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science china(information sciences) 2012年第4期55卷 921-937页

作者： LI Mu 1,2,LI Bo 1,2 & HUAI JinPeng 1,2 1 state key laboratory of software Development Environment,Beihang University,beijing 100191,china 2 School of Computer science and Engineering,Beihang University,beijing 100191,china 1. state key laboratory of software Development Environment Beihang University Beijing 100191 China2. School of Computer Science and Engineering Beihang University Beijing 100191 China

In this paper,we study the reliability-aware synthesis problem for composing available services automatically and guaranteeing that the composed result satisfies the specification,such as temporal constraints of functionality and reliability,centered on a synthesis model for mediator of web services composition (CSM).This approach focuses on handling attributes and state relations,and permitting users and services to operate over them,i.e.,read /write their data values and compare them according to a dense state *** show that the reliability-aware synthesis problem for the specification is EXPTIME-complete and we give an exponential-time algorithm (CSM-NSA) which for a given formula ψ and a synthesis model,synthesizes available services in the library satisfying ψ over the synthesis model (if they exist) or responds with "not satisfiable" (otherwise).The specification ψ is a fragment of PCTL (probabilistic computation tree logic),obtained from "ordinary" CTL (computation tree logic) by replacing the EX,AX,EU and AU operation with their quantitative counterparts X >p,X =1,U >p,and U =1,*** opposed to NSA,we provide a more effective algorithm to replace the NSA algorithm called CSM-HSA (heuristic synthesis algorithm).Though HSA is an incomplete algorithm,the answer is *** experiments show that the HSA algorithm solves the problem of reliability-aware service synthesis effectively and efficiently.

关键词： reliability web services synthesis problem synthesis model heuristic algorithm

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Multiparty quantum secret sharing of classical and quantum messages

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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 laboratory for Quantum information and Measurements, and Department of Physics, Tsinghua University, beijing 100084, china key laboratory 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 laboratory for Atomic and Molecular Nano-sciences, Tsinghua University, beijing 100084, china) [a]key laboratory for Quantum information and Measurements and Department of Physics Tsinghua University Beijing China [b]key laboratory 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 laboratory 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.

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