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Experimental study on fire smoke movement in a multi-floor and multi-room building

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science china(Technological sciences) 2005年第3期48卷 292-304页

作者： ZHONG Maohua 1, 2., LI Peide 2., LIU Tiemin 1 , WEI Xing 1, 2.& LIAO Guangxuan 2.1. national center of Safety {2. and technology, State Administration of Work Safety, beijing 10002., china 2. State Key laboratory of Fire {2., University of {2. and technology of china, Hefei 2.002., china 1. national center of Safety {2. and technology State Administration of Work Safety 100029 Beijing China 2. State Key laboratory of Fire science University of Science and Technology of China 230026 Hefei China

Fire smoke movement of multi-floor and multi-room (MFMR) fire was studied at the model test building in State Key laboratory of Fire science (SKLFS). The ingredient, temperature, air pressure difference and air velocity of smoke were measured and analyzed. Meanwhile, the hazard of smoke ingredient to exposed occupants was analyzed based on the {2. standard, Occupational Exposure Limit for Hazardous Agents in the Workplace (GBZ2.2.02.. The experimental results showed that the maximum temperature difference in MFMR fire was located along the vertical height from the fire source. With the spreading and diffusion of smoke, the temperature of smoke layer would tend to be no difference. In the fire of woodpile and kerosene, the main smoke ingredients such as SO 2., CO and CO 2.would first exceed human’s average physiological limit, while smoke ingredients such as NO and NO 2.would come behind. Because of the higher fluctuation range and frequency of air pressure difference of smoke in multi-layer building fire, the fire smoke would spread around everywhere of the passageway and made the human evacuation more difficult.

关键词： multi-floor and multi-room,fire experiment,smoke spread,smoke toxicity.

RRM:An incentive reputation model for promoting good behaviors in distributed systems

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science in china(Series F) 2008年第11期51卷 1871-1882页

作者： ZHANG Hong1,2.DUAN HaiXin1,3 & LIU Wu1,3 1 tsinghua national {2. for Information science and technology,tsinghua University,beijing 100084,china 2.Department of Computer science and technology,tsinghua University,beijing 100084,china 3 Network Research center,tsinghua University,beijing 100084,china 1. tsinghua national {2. for Information science and technology Tsinghua University Beijing 100084 China 2. Department of Computer science and technology Tsinghua University Beijing 100084 China 3. Network Research center Tsinghua University Beijing 100084 China

Reputation systems represent soft security mechanisms that complement traditional information security mechanisms. They are now widely used in online e-commerce markets and communities in order to stimulate good behaviors as well as to restrain adverse behaviors. This paper analyzes the limitations of the conversational reputation models and proposes an incentive reputation model called the resilient reputation model （RRM） for the distributed reputation systems. The objective of this reputation model is not only to encourage the users to provide good services and, therefore, to maximize the probability of good transaction outcomes, but also to punish those adverse users who are trying to manipulate the application systems. The simulation results indicate that the proposed reputation model （RRM） could effectively resist against the common adverse behaviors, while protecting the profits of sincere users from being blemished by those adversaries.

关键词： reputation model distributed system trust soft security

A formal method to real-time protocol interoperability testing

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science in china(Series F) 2008年第11期51卷 1723-1744页

作者： WANG ZhiLiang1,3,YIN Xia2.3 & JING ChuanMing2.3 1 Network Research center,tsinghua University,{2. 100084,china 2.Department of Computer science and technology,tsinghua University,{2. 100084,china 3 tsinghua {12. laboratory for Information science and technology(TNList) ,{2. 100084,china 1. Network Research center Tsinghua University Beijing 100084 China 3. tsinghua national {2. for Information science and technology (TNList) Beijing 100084 China 2. Department of Computer science and technology Tsinghua University Beijing 100084 China

Interoperability testing is an important technique to ensure the quality of implementations of network communication protocol. In the next generation Internet protocol, real-time applications should be supported effectively. However, time constraints were not considered in the related studies of protocol interoperability testing, so existing interoperability testing methods are difficult to be applied in real-time protocol interoperability testing. In this paper, a formal method to real-time protocol interoperability testing is proposed. Firstly, a formal model CMpTIOA （communicating multi-port timed input output automata） is defined to specify the system under test （SUT） in real-time protocol interoperability testing; based on this model, timed interoperability relation is then defined. In order to check this relation, a test generation method is presented to generate a parameterized test behavior tree from SUT model; a mechanism of executability pre-determination is also integrated in the test generation method to alleviate state space explosion problem to some extent. The proposed theory and method are then applied in interoperability testing of IPv6 neighbor discovery protocol to show the feasibility of this method.

关键词： protocol testing interoperability testing real-time testing test generation timed input output automata(TIOA)

Theoretical research progress in new-generation Internet architecture

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science in china(Series F) 2008年第11期51卷 1634-1660页

作者： WU JianPing1,2.3,LIU Ying2.3 & WU Qian2.3 1 Department of Computer science,tsinghua University,{2. 100084,china 2.Network Research center,tsinghua University,{2. 100084,china 3 tsinghua national {12. for Information science and technology(TNList) ,{2. 100084,china 1. Department of Computer science Tsinghua University Beijing 100084 China 2. Network Research center Tsinghua University Beijing 100084 China 3. tsinghua national {2. for Information science and technology (TNList) Beijing 100084 China

Internet has become the most important information infrastructure supporting modern socio-economic development, social progress and technological Innovation. Invented 30 years ago, today Internet is facing increasingly severe technical challenges. This paper introduces the progress of the major international newgeneration Internet research plans; analyzes its basic characteristics and the principal contradictions during the development; detsiledly introduces the research carried out by 973 Project ＂Research of Future Internet Architecture＂ on the key scientific issues of new-generation Internet architecture and its latest research results; and looks to the future of the research-focus faced with the new situations of the basic research of new-generation Internet architecture as well as the new demands of innovative applications on Internet architecture.

关键词： new-generation Internet network architecture multi-dimension scalability

Experimental realization of quantum cryptography communication in free space

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science china(Physics,Mechanics & Astronomy) 2005年第2期48卷 237-246页

作者： WANG Chuan1, ZHANG Jingfu1, WANG Pingxiao1, DENG Fuguo1, AI Qing1 & LONG Guilu1,2.1. Department of Physics, Key laboratory for quantum Information and Measurements, {2. Univer- sity, beijing 100084, china 2. center for Atomic and Molecular Nanosciences, {2. University, beijing 100084, china Department of Physics Key Laboratory for Quantum Information and Measurements Tsinghua University Beijing 100084 China Atomic and Molecular Nanosciences Tsinghua University Beijing 100084 China

Utilizing linear optical devices, the principle of B92.quantum key distribution (QKD) protocol is demonstrated in free space with a distance of transmission of 2.2.meters. The faint laser pulses with 650 nm wavelength are used as the single photon sources. The experimental results show that the eavesdropping behavior in the signal transmission can be detected. We also discuss the problems and solutions in using the quantum cryptography communication practically. It is pointed out that one of the approaches to increasing the distance of the quantum communication is to overcome the attenuation of the single photon in transmission. This could not be solved by the use of single photon source, and new quantum communication protocols are needed to solve these problems.

关键词： quantum key distribution, free space, linear optics, faint pulses.

Photogeneration of the free radicals and singlet oxygen by chrysophanol from rheum

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science china Chemistry 2004年第5期47卷 381-387页

作者： RAO Jing1,2. XIE Jie1, ZHAO Jingquan1 & ZHU Teng2.1. Key laboratory of Photochemistry, center for Molecular {2., Institute of Chemistry, The Chinese Academy of {2.s, beijing 100080, china 2. University of {2. and technology beijing, beijing 10083, china 1. Key laboratory of Photochemistry Center for Molecular Science Institute of Chemistry The Chinese Academy of Sciences 100080 Beijing China 2. University of science and technology {2. 10083 Beijing China

In the current work, chryosphanol (MHAQ) was isolated and purified from rheum, and the photosensitization activities were studied. In nitrogen-saturated DMSO solution, irradia- tion of chryosphanol (MHAQ) with visible light (>430 nm) produced the semiquinone radical anions (MHAQ??), which was intensified significantly by an electron donor NADH, suggesting electron transfer between the excited and ground state photosensitizer molecules. In an air-saturated DMSO solution, superoxide radical anions (O2.), trapped by DMPO, were detected. ?? It was proved that O2.was not originated from the singlet oxygen (1O2. but dependent on DMPO, ?? chrysophanol, oxygen and the irradiation time. The singlet oxygen and OH could also be pro- ? duced by the photosensitization of the photosensitizer. These suggest that chrysophanol pos- sesses the photosensitization activity via Type I mechanism and Type II mechanism. To evaluate the photosensitization activities of MHAQ, emodin and mixed anthraquinone derivatives ex- tracted from rheum, the relative productivities of O2.were estimated to be 1.8, 1.1 and 1.0 re- ?? spectively and the quantum yields for singlet oxygen to be 0.36, 0.53 and 0.14 respectively. Therefore, these low-cost pigments may be potentially used as phototherapeutic medicine for some kind of vascular diseases or photo-activated pesticides.

关键词： chrysophanol, ESR, semiquinone radical anions, superoxide radical anions, hydroxyl radical, singlet oxygen.

Polynomial analysis of canopy spectra and biochemical component content inversion

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science china Earth sciences 2005年第10期48卷 1780-1791页

作者： YAN Chunyan1, LIU Qiang1, NIU Zheng1, WANG Jihua2. HUANG Wenjiang2.& LIU Liangyun 2.1. State Key laboratory of Remote Sensing science, Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of sciences and beijing Normal University, beijing 100101, china 2. national Engineering Research center for Information technology in Agriculture, beijing 100089, china State Key laboratory of Remote Sensing science Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of sciences and beijing Normal University beijing china national Engineering Research center for Information {2. in Agriculture beijing china

A polynomial expression model was developed in this paper to describe directional canopy spectra, and the decomposition of the polynomial expression was used as a tool for re-trieving biochemical component content from canopy multi-angle spectra. First, the basic formula of the polynomial expression was introduced and the physical meaning of its terms and coeffi-cients was discussed. Based on this analysis, a complete polynomial expression model and its decomposition method were given. By decomposing the canopy spectra simulated with SAILH model, it shows that the polynomial expression can not only fit well the canopy spectra, but also show the contribution of every order scattering to the whole reflectance. Taking the first scattering coefficients a10 and a01 for example, the test results show that the polynomial coefficients reflect very well the hot spot phenomenon and the effects of viewing angles, LAI and leaf inclination angle on canopy spectra. By coupling the polynomial expression with leaf model PROSPECT, a canopy biochemical component content inversion model was given. In the simulated test, the canopy multi-angle spectra were simulated by two different models, SAILH and 4-SCALE re-spectively, then the biochemical component content was retrieved by inverting the coupled polynomial expression + PROSPECT model. Results of the simulated test are promising, and when applying the algorithm to measured corn canopy multi-angle spectra, we also get relatively accurate chlorophyll content. It shows that the polynomial analysis provides a new method to get biochemical component content independent of any specific canopy model.

关键词： polynomial expression, canopy spectra, decomposition, biochemical component content, inversion.

Arbitrarily long distance quantum communication using inspection and power insertion

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Chinese science Bulletin 2009年第1期54卷 158-162页

作者： WANG WanYing1,2.WANG Chuan1,2.ZHANG GuangYu1,3 & LONG GuiLu1,2.1 Department of Physics,tsinghua University,beijing {2.,china 2.tsinghua national laboratory for Information science and technology,tsinghua University,beijing {2.,china 3 College of Applied science,Harbin University of science and technology,Harbin 150080,china Department of Physics Tsinghua University Beijing 100084 China tsinghua national {2. for Information science and technology Tsinghua University Beijing 100084 China College of Applied science Harbin University of Science and Technology Beijing 100084 China

The biggest obstacle for long distance quantum communication is the channel loss and the channel noise on photons. In this paper,a method to solve this problem was analyzed using inspection and power insertion (IPI). It is proved that quantum communication may be established over arbitrarily long distance using this {2.. The amount of resources required is a polynomial function of the dis-tance. IPI is proposed as a general technique to prolong quantum secure direct communication where secret messages are transmitted directly over a quantum channel.

关键词：长距离量子通信量子安全通信量子密匙分布噪声

A TTCN-3-based protocol testing system and its extension

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science in china(Series F) 2008年第11期51卷 1703-1722页

作者： YIN Xia1,3,WANG ZhiLiang2.3,JING ChuanMing1,3 & SHI XinGang2.3 1 Department of Computer science and technology,{2. University,beijing 100084,china 2.Network Research center,{2. University,beijing 100084,china 3 {2. {12. laboratory for Information science and technology(TNList) ,beijing 100084,china 1. Department of Computer science and technology Tsinghua University Beijing 100084 China 3. ]tsinghua national {2. for Information science and technology (TNList) Beijing 100084 China 2. Network Research center Tsinghua University Beijing 100084 China

The protocol testing technology used in the next generation Internet should satisfy some new challenges and requirements. This paper focuses on the test suite description and test implementation techniques. TTCN-3 is chosen as the test suite description language and extended in both syntax and semantics to satisfy the requirements of protocol robustness testing. PITSv3, a protocol integrated testing system based on TTCN-3, is developed, and the extensions for robustness testing are implemented. Finally, two practical test applications are presented.

关键词： protocol testing TTCN-3 PITSv3 robustness testing