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A formal model of fair exchange protocols

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Science in China(Series F) 2005年第4期48卷 499-512页

作者： QING Sihan1,2.3.& LI Gaicheng1,2.3.1. Engineering Research Center for Information Security Technology, Institute of Software, Chinese Aca- demy of Sciences, {2. 100080, China 2. {2. Zhongke Ansheng {2. of Information Technology, {2. 100080, China 3. Graduate School of the Chinese Academy of Sciences, {2. 10003., China 1. Engineering Research Center for Information Security Technology Institute of Software Chinese Academy of Sciences 100080 Beijing China 2. beijing Zhongke Ansheng corporation of Information Technology 100080 Beijing China 3. Graduate School of the Chinese Academy of Sciences 100039 Beijing China

Based on the study of existing fair exchange protocols, this paper sets up an accurate formal model by stepwise refinement. In the process of refinement an unreliable channel is employed to simulate an attack behavior. The model provides a novel formal definition of exchanged items, and presents the formal goals for fairness, accountability, etc., reflecting the inherent requirements for fair exchange protocols across-the-board. In order to check, prove, and design fair exchange protocols effectively and efficiently, the model puts forward a novel property of abuse-freeness which applies to all fair exchange protocols, gives a formal definition for trust strand of the third party, and presents general criteria of designing a secure and effective fair exchange protocol. Taking a typical fair exchange protocol as an example, this paper presents the analysis steps of fair exchange protocols appealing to our model. An unknown attack is uncovered. The analysis reveals the process of a complete attack, discovering deeper reasons for causing an attack. Finally, we modify the flawed protocol and the revised protocol ensures the desirable properties.

关键词： events local causal relation local temporal relation global relation exchanged item security goals.

The regular representation and regular covariant representation of crossed products of Woronowicz C^(*)-algebras

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Science China Mathematics 2005年第9期48卷 1245-1259页

作者： ZHANG Xiaoxia~(1,2. & GUO Maozheng~(1,3. 1. School of Mathematical Sciences,Peking University,beijing 100871,China 2. Department of Mathematics,Yantai University,Yantai 2.4005,China 3. LMAM,Peking University,beijing 100871,China 1. School of Mathematical Sciences Peking University 100871 Beijing China 2. Department of Mathematics Yantai University 264005 Yantai China 3. LMAM Peking University 100871 Beijing China

In this paper,it is shown that the regular representation and regular covariant representation of the crossed products A×α G correspond to the twisted multiplicative unitary operators,where A is a Woronowicz C~*-algebra acted upon by a discrete group ***,it is also shown that the regular covariant C~*-algebra is the Woronowicz C~*-algebra which corresponds to a multiplicative ***,an explicit description of the multiplicative unitary operator for C(SU_q(2. )×α (?) is given in terms of those of the Woronowicz C~*-algebra C(SU_q(2. ) and the discrete group G.

关键词： multiplicative unitary operator, Woronowicz C*-algebra, crossed product.

Formal analysis and design of multi-party fair exchange protocols

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Science in China(Series F) 2006年第2期49卷 155-174页

作者： QING Sihan1,2.3.& LI Gaicheng1,3.1. Engineering Research Center for Information Security Technology, Institute of Software, Chinese Academy of Sciences, {2. 100080, China 2. {2. Zhongke Ansheng {2. of Information Technology, {2. 100080, China 3. Graduate School of the Chinese Academy of Sciences, {2. 10003., China 1. Engineering Research Center for Information Security Technology Institute of Software Chinese Academy of Sciences Beijing 100080 China 2. beijing Zhongke Ansheng corporation of Information Technology Beijing 100080 China 3. Graduate School of the Chinese Academy of Sciences Beijing 100039 China

Based on the origin of message items and channel combination between transacting parties, and events and relations among events, this paper presents a concise, precise, and hierarchical model for general fair exchange protocols, formally specifies various security requirements which are able to reflect inherent requirements for fair exchange protocols more rigorously, and partition these security requirements with fine granularity. This work helps analyze, debug, and design multi-party fair exchange protocols more effectively and elaborately,

关键词： fair exchange logical protocol formal model security requirement.

Influence of valence electron structures of phase and biphase interfaces of sulfides on hot brittleness in steel

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Science China(Technological Sciences) 2004年第4期47卷 488-504页

作者： LIU Yan1,3. LIU Zhilin1, ZHANG Chengwei1,2.& ZHOU Yingchun1 1. Liaoning Institute of Technology, Jinzhou 12.001, China 2. China National Oil and Gas Exploration and Development corporation, {2. 100011, China 3. College of Science, {2.eastern University, Shengyang 110006, China 1. Liaoning Institute of Technology 121001 Jinzhou China 2. College of Science Northeastern University 110006 Shengyang China 3. China National Oil and Gas Exploration and Development corporation 100011 Beijing China

This paper calculates the electron structures of phase of FeS, MnS and their biphase interface electron structures with austenite in steel. The precipitation and the transformation of FeS and MnS are investigated through studying the valence electron pair numbers on the strongest bond n A with the structure formation factor S. The continuity of electron density and its relation with stress are explored in the biphase interfaces with the electron density difference απ Using n A, S, απ we explain the reason why FeS can bring about hot brittleness in steel and the physical mechanism why MnS may eliminate or inhibit hot brittleness, based on which satisfying results are obtained by calculating several rare-earth sulfides.

关键词： valence electron structure, sulfide, hot brittleness, and rare earth.

Human hepatopoietin augmenter of liver regeneration──A hepatotrophic factor for liver regeneration, and its potential antihepatitis effect in vivo

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Chinese Science Bulletin 1998年第12期43卷 1026-1031页

作者： YANG Xiaoming 1, WANG Aimin 2. ZHOU Ping 3. XIE Ling 1, WANG Qingming 1, WU Zuze 1 and HE Fuchu 1 1. Institute of Radiation Medicine, beijing 100850, China 2. No. 2.2.Hospital of PLA, Baoding 071000, China 3. General Hospital of the Air Institute of Radiation Medicine Beijing China No. 2.2.Hospital of PLA Baoding China General Hospital of the Air Force of PLA Beijing China

The effect of human hapatopoietin i.e. augmenter of liver regeneration (hALR) was determined on hepatocyte DNA synthesis, and on CCl 4-induced hepatitis in animal in vitro and in vivo. It is found that ALR could directly stimulate DNA synthesis of hepatocytes in primary culture in a dose-dependent manner. In 3.% hepatectomied rats, significant DNA synthesis occurred in control rats ; even so, exogenous hALR gene encoding protein increased DNA synthesis of regeneration liver by 2.3.fold compared with control rats. A lower dose of CCl 4 was administrated in rats and the effect of ALR on DNA synthesis of regenerating liver 48 h after CCl 4 administration was analyzed. Few Budr-labeled hepatocytes were visible in control rats. However, exogenous hALR markedly increased the number of labeled cells in a dose-dependent manner. Statistical analysis showed that 10 or 40 μg·kg -1 ALR protein stimulated DNA synthesis by 1.7 and 4.8 fold respectively. In addition to enhancing cell growth, adiministration of hALR achieved a significant improvement in reversing the lethality of rat hepatic failure when compared with that of control {2.; the elevation of cytosolic enzymes was dramatically suppressed by exogenous hALR in CCl 4-treated mice in vivo and in vitro; histologically, hepatocytes around the central vein were necrotic, and the degree of hepatocyte necrosis in control mice was more prominent than that in the mice given 40 μg·kg-1 hALR 48 h after CCl 4 administration. We also noted that hALR had a strong antihepatitis effect in vitro which was determined with primary cultured rat hepatocytes. These findings suggest that hALR protects the integrity of hepatocytes against severe hepatitis, and indicate that ALR may be an important regulator of liver regeneration and play a major role in liver injury repair. It proves ALR adminstration to be a useful treatment to accelerate liver regeneration and to prevent the onset of hepatitis or intrahepatic cholestasis induced by toxin.

关键词： liver regeneration hepatopoietin DNA synthesis hepatitis.

A tentative study for the prediction of the CME related geomagnetic storm intensity and its transit time

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Science China(Technological Sciences) 2005年第6期48卷 648-668页

作者： ZHAO Xinhua1,2.& FENG Xueshang1,3.1. SIGMA Weather group, Key Laboratory of Space Weather, Center for Space Science and Applied Re-search, Chinese Academy of Sciences, {2. 100080, China 2. Graduate School of the Chinese Academy of Sciences, {2. 10003., China 3. School of Geophysics and Geoinformation Systems, China University of Geosciences, {2. 100083. China 1. SIGMA Weather group Key Laboratory of Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences 100080 Beijing China 2. Graduate School of the Chinese Academy of Sciences 100039 Beijing China 3. School of Geophysics and Geoinformation Systems China University of Geosciences 100083 Beijing China

Using 80 CME-ICME events during 1997.1―2.02.9, based on the eruptive source locations of CMEs and solar magnetic field observation at the photosphere, a current sheet magnetic coordinate (CMC) system is established in order to study the propagation of CME and its geoeffectiveness. In context of this coordinate system, the effect of the eruptive source location and the form of heliospheric current sheet (HCS) at the eruptive time of CME on the geomagnetic storm intensity caused by CME and the CME’s transit time at the Earth is investigated in detail. Our preliminary conclusions are: 1) The geomagnetic disturbances caused by CMEs tend to have the so-called “same side-opposite side effect”, i.e. CMEs erupt from the same side of the HCS as the earth would be more likely to arrive at the earth and the geomagnetic disturbances associated with them tend to be of larger magnitude, while CMEs erupting from the opposite side would arrive at the earth with less probability and the corresponding geomagnetic disturbance magnitudes would be relatively weaker. 2. The angular separation between the earth and the HCS affect the corresponding disturbance intensity. That is, when our earth is located near the HCS, adverse space weather events occur most probably. 3. The erupting location of the CME and its nearby form of HCS will also affect its arrival time at the earth. According to these conclusions, in this context of CMC coordinate we arrive at new prediction method for estimating the geomagnetic storm intensity (Dstmin) caused by CMEs and their transit times. The application of the empirical model for 80 CME-ICME events shows that the relative error of Dst is within 3.% for 59% events with Dstmin≤?50 nT, while the averaged absolute error of transit time is lower than 10 h for all events.

关键词： coronal mass ejections, current sheet magnetic coordinate system, geomagnetic storm intensity, transit time, prediction method.

Modeling and characteristic analysis of underwater acoustic signal of the accelerating propeller

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Science China(Information Sciences) 2012年第2期55卷 270-280页

作者： FENG Yuan1,2.TAO Ran1 & WANG Yue11Department of Electronic Engineering,beijing Institute of Technology,beijing 100081,China 2.cience Research Institute of China{2. {3. group corporation,beijing 100081,China 1. Department of Electronic Engineering Beijing Institute of Technology Beijing 100081 China2. Science Research Institute of China North Industries Group Corporation Beijing 100081 China

The signal feature of propeller cavitation noise during acceleration or deceleration procedure can be used to passively detect and classify moving vessels and underwater vehicles in the port *** analyzing the chirp periodicity of the variation of propeller wake velocity under acceleration situation,this paper presents a time domain expression of the modulation envelope signal of the accelerating propeller noise,treating the signal as a Gaussian-shaped chirp periodic pulse train with increasing trend and fluctuating pulse *** paper investigates the characteristics of simplified fractional Fourier transform(SFRFT)spectrum of the chirp periodic signal,and thus obtains the relation between the chirp periodic signal and its chirp harmonics under the conditions of underwater passive ***,the experimental data of the cavitation tunnel satisfy the results obtained by simulation,which verifies the correctness of the proposed signal model.

关键词： accelerating propeller modeling of underwater acoustic signal chirp periodic signal simplified fractional Fourier transform

Integrated precise orbit determination of Shenzhou IV unmanned spacecraft

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Science China(Technological Sciences) 2004年第5期47卷 518-525页

作者： L Congmin1,2. GU Yidong3. LIN Baojun3.& GUO Jiong3.1. Center for Space Science and Applied Research, Chinese Academy of Sciences, beijing 100080, China 2. Graduate School of the Chinese Academy of Sciences, beijing 10003., China 3. General Establishment of Space Science and Application, Chinese Academy of Sciences, beijing 100080, China Correspondence should be addressed to L Congmin 1. Center for Space Science and Applied Research Chinese Academy of Sciences 100080 Beijing China 2. Graduate School of the Chinese Academy of Sciences 100039 Beijing China 3. General Establishment of Space Science and Application Chinese Academy of Sciences 100080 Beijing China

Considering the characteristic orbit of Shenzhou IV spacecraft and the advantages and disadvantages of several types of domestic orbit measurements, a scheme of IPOD is determined, which uses GPS, SLR and USB observation data jointly plus precise ionosphere corrections to GPS observation data. IPOD system and mathematic models of OD are introduced. The results of different joint OD are analyzed using true observation data, and show that radial accuracy is better than 2.m.

关键词： Shenzhou IV unmanned spacecraft integrated precise orbit determination GPS SLR USB.

On the Symmetry Classes of Functions

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Wuhan University Journal of Natural Sciences 2005年第5期10卷 813-816页

作者： ZHU Ping~1,2. FAN Yun~3.1. School of Mathematics and Statistics, Wuhan University, Wuhan 43.072. Hubei, China 2. School of Science, {2. University of Posts and Telecommunications, {2. 100876, China 3. School of Mathematics and Statistics, Huazhong Normal University, Wuhan 43.079, Hubei, China Wuhan University School of Mathematics and Statistics Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***) beijing University of Posts and Telecommunications School of Science Beijing China (GRID:grid.31880.32) Huazhong Normal University School of Mathematics and Statistics Wuhan Hubei China (GRID:grid.411407.7) (ISNI:***)

Let R be an integral domain of characteristic zero such that the corresponding group rings have block decompositions. We first prove that the submodule consisting of all the R-valued ξi-symmetric functions of several variables is a symmetry class, where ξi is any block character. Then we present a relationship among certain operators introduced for block character. Then we present a relationship among certain operators introduced for block characters. As a consequence, we obtain a decomposition of an arbitrary R-valued function of several variables. Finally, we describe the symmetry property of such summands and determine all the symmetry classes.

关键词： symmetry class strict symmetry class blockcharacter ξi-symmetric function block idempotent