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A preliminary study on vegetation-erosion dynamics and its applications

Science china Earth Sciences 2005年第5期48卷 689-700页

作者： WANG Zhaoyin 1,2., WANG Guangqian 1 , LI Changzhi 1 & WANG Feixin 1 1. Department of Hydraulic engineering, Tsinghua University, beijing 100084,{2. 2. International research and Training center on Erosion and Sedimentation, beijing 100084,{2. 1. Department of Hydraulic engineering Tsinghua University 100084 Beijing China 2. International research and Training {2. on Erosion and Sedimentation 100084 Beijing China

Vegetation-erosion dynamics is a new interdisciplinary science, studying the laws of evolution of watershed vegetation under the action of various ecological stresses. Introducing a qualitative expression of ecological stresses in this paper, the present authors establish the cou- pled differential equations for the vegetation-erosion process and derive a theoretical solution. The model is applied to the Anjiagou watershed on the Loess Pateau and the Xiaojiang water- shed and its sub-watersheds on the Yunnan Plateau. The calculated results agree well with the vegetation development processes. Abstracted from the differential equations the so-called vegetation-erosion chart is worked out, with which we can predict the development trend of vegetation under no human stresses. It is demonstrated that the erosion control is important for vegetation development and reforestation must be a long-term strategy. On the Yunnan Plateau with relatively high precipitation and temperature, vegetation can be greatly improved if erosion is controlled. On the dry and cold Loess Pateau suffering from high rate of soil erosion, however, vegetation can effectively control erosion but erosion reduction exhibits low effectiveness on vegetation development. Vegetation in the area is not stable and management is always needed to maintain the vegetation.

关键词： vegetation-erosion dynamics, human activities, coupled differential equations, erosion control, vigor ofvegetation.

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A new navigation approach of terrain contour matching based on 3-D terrain reconstruction from onboard image sequence

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Science china(Technological Sciences) 2010年第5期53卷 1176-1183页

作者： LI LiChun1,2.YU QiFeng2.SHANG Yang2.YUAN Yun2.LU HongWei3 & LIU XiaoLin4 1 beijing Aerospace Control center,beijing 100094,china 2.College of Aerospace and Material engineering,national University of Defense technology,Changsha 410073,china 3 Equipment research Institute of PLA’s Second Artillery,beijing 100085,china 4 College of Mechatronic engineering and Automation,national University of Defense technology,Changsha 410073,china 1. beijing Aerospace Control center Beijing 100094 China2. College of Aerospace and Material Engineering National University of Defense Technology Changsha 410073 China3. Equipment Research Institute of PLA’s Second Artillery Beijing 100085 China4. College of Mechatronic Engineering and Automation National University of Defense Technology Changsha 410073 China

This article presents a passive navigation method of terrain contour matching by reconstructing the 3-D terrain from the image sequence(acquired by the onboard camera).To achieve automation and simultaneity of the image sequence processing for navigation,a correspondence registration method based on control points tracking is proposed which tracks the sparse control points through the whole image sequence and uses them as correspondence in the relation geometry ***,a key frame selection method based on the images overlapping ratio and intersecting angles is explored,thereafter the requirement for the camera system configuration is *** proposed method also includes an optimal local homography estimating algorithm according to the control points,which helps correctly predict points to be matched and their speed ***,the real-time 3-D terrain of the trajectory thus reconstructed is matched with the referenced terrain map,and the result of which provides navigating *** digital simulation experiment and the real image based experiment have verified the proposed method.

关键词： terrain contour matching vision-based navigation 3-D reconstruction control points key frame registration optimal local homography

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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 national Laboratory for information Science and technology(TNList) ,{2. 100084,china 1. Network research center Tsinghua University Beijing 100084 China 3. Tsinghua national Laboratory for information Science and {2. (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)

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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 Laboratory for information Science and {2.,Tsinghua University,beijing 100084,china 2.Department of Computer Science and {2.,Tsinghua University,beijing 100084,china 3 Network research center,Tsinghua University,beijing 100084,china 1. Tsinghua national Laboratory for information Science and {2. 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

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Calculation of maximum ground movement and deformation caused by mining

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中国有色金属学会会刊：英文版 2011年第S3期21卷 562-569页

作者： LI Pei-xian1, 2. TAN Zhi-xiang1, 2. DENG Ka-zhong1, 2.1. Key Laboratory for Land Environment and Disaster Monitoring of State Bureau of Surveying and Mapping, china University of Mining and technology, Xuzhou 2.1116, china 2. Jiangsu Key Laboratory of Resources and Environmental information engineering, china University of Mining and technology, Xuzhou 2.1116, china [a] Key Laboratory for Land Environment and Disaster Monitoring of State Bureau of Surveying and Mapping China University of Mining and Technology Xuzhou 221116 China [b] Jiangsu Key Laboratory of Resources and Environmental information engineering China University of Mining and Technology Xuzhou 221116 China

In order to know the maximum mining ground deformation of arbitrary surface point, directions of the maximum surface tilt, curvature,horizontal displacement and horizontal deformation caused by multi-working faces were deduced based on probability integral method. The distribution forms of surface deformations in all direction φ∈[0, 2.] were obtained and also equations of maximum deformations were given based on calculation of mining ground deformation in direction φ. A mining subsidence analysis system was developed with VB6.0. The system implements the probability integral mining subsidence prediction with direct integration method, and it can avoid errors of arbitrary shaped working face subdivision of traditional method, and accuracy of mining subsidence prediction can be improved with the direct integral method. The system implements the contour chart and profile chart and also data analysis automation by manipulation of the SURFER kernel function and it complements the defect of existing subsidence prediction software. Calculation of maximum deformations caused by multi-working faces mining in a coal mine of Xuzhou, china was shown as application example. engineering application indicates that maximum deformation of mining ground surface can be calculated and analyzed by the system. The {2. provides a theoretical basis and calculation tool for mining subsidence prediction and analysis.

关键词： mining subsidence probability integral method movement and deformation system development

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Theoretical analysis of polarization properties for tilted fiber Bragg gratings

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Science china(information Sciences) 2010年第2期53卷 390-397页

作者： XU Ou 1 , LU ShaoHua 2.& JIAN ShuiSheng 2.1 Faculty of information engineering, Guangdong University of {2., Guangzhou 510006, china 2.Institute of Lightwave {2., beijing Jiaotong University, beijing 100044, china 1. Faculty of information engineering Guangdong University of Technology Guangzhou 510006 China2. Institute of Lightwave Technology Beijing Jiaotong University Beijing 100044 China

The polarization properties for tilted fiber Bragg gratings (TFBGs) are investigated theoretically based on coupled-mode theory and Mueller matrix method. The expression of wavelength-related polarizationdependent loss (PDL) for TFBGs with different tilt angles is derived and calculated. Simulation results are compared, and the results indicate that the polarization capability of TFBGs with 45° angle is stronger than other TFBGs with smaller angles. The degree of polarization for unpolarized light passing TFBGs is also simulated to further evaluate the polarization properties for various tilt angles. In addition, the relationship between physical parameters of a TFBG and its polarization capability is discussed.

关键词： coupled-mode theory degree of polarization (DOP) Mueller matrix method polarization dependent loss (PDL) tilted fiber Bragg gratings

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AFM study on the adsorption and aggregation behavior of dissolved humic substances on mica

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Science china Chemistry 2006年第3期49卷 256-266页

作者： GE Xiaopeng1, ZHOU Yanmei2. Lü Chunhua1 & TANG Hongxiao1 1. State Key Laboratory of Environmental Aquatic Chemistry, research center for Eco-Environmental Sciences, Chinese Academy of Sciences, {2. 100085, china 2. School of Civil engineering & Architecture, {2. Jiaotong University, {2. 100044, china 1. State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China 2. School of Civil engineering & Architecture Beijing Jiaotong University Beijing 100044 China

Humic substances constitute the major organic fractions of soils, sediments and natural waters, and play a dominant role in the binding, mobilization, transport and ultimate fate of organic contaminants in subsurface systems. In this paper, two humic acid samples, Guanting and Tianjin, with different origin and chemical compositions have been investigated with AFM imaging for their adsorption and aggregation behaviors on mica. While the Tianjin humic sample is found to form small spheres with 2.0 to 330 nm in diameter at lower concentrations, irregular loop-chain assemblies of hundreds of nanometer in diameter with the chain width of about 40 nm are dominant for the Guanting humic sample, which may attribute to the more polar aliphatic fractions in the chemical composition in the latter. The heterogeneous and polydisperse nature of humic substances with multiple structural features, such as sponge-like structures, perforated sheets, aggregate of spheres, branches and chain-like assemblies etc., is apparent at higher concentrations for both humic samples, showing morphologically new evidence for the dominant view of the humic dual-mode sorption model. With naphthalene introduced, the assemblies of Guanting humic substances clearly become more compact with significantly narrowed branches and less porous the perforated sheet-like structures. It is indica- tive of that smaller nanometer scale rings present along the perforated assemblies could potentially represent hydrophobic domains, which may facilitate the adsorption and aggregation of naphthalene onto the natural particle surfaces and therefore lead to an important role of dissolved humic sub- stances in the sorption of environmental pollutants.

关键词： atomic force microscopy (AFM) dissolved humic substances morphology aggregation adsorption

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Scheduling of Development Projects with Uncertain Iterations

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Journal of Systems engineering and Electronics 2001年第2期12卷 82-86页

作者： Yan Jihong & Wu Cheng national CIMS engineering {2. center, Tsinghua University, beijing 100084, P R. china national CIMS engineering {2. center Tsinghua University Beijing 100084 P. R. China

This paper studies the scheduling of design projects in concurrent development process with uncertain number of feedback revisions. An optimization based methodology that combines heuristic algorithm, artificial intelligence (fuzzy, genetic algorithm) and scheduling theory is developed. In the algorithm, weighting values of some key factors are defined by genetic algorithm. In addition, fuzzy logic is used to decide the ability coefficients of different roles taken by designers. Moreover, the process of pre-release and feedback revision is realized. Simulation example is a fraction of practical development project, and satisfied results are obtained.

关键词： Concurrent engineering Product development process Optimization scheduling.

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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,beijing 100084,china 2.Network {2. center,Tsinghua University,beijing 100084,china 3 Tsinghua national Laboratory for information Science and technology(TNList) ,beijing 100084,china 1. Department of Computer Science Tsinghua University Beijing 100084 China 2. Network research center Tsinghua University Beijing 100084 China 3. Tsinghua national Laboratory for information Science and {2. (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 {2. plans; analyzes its basic characteristics and the principal contradictions during the development; detsiledly introduces the {2. carried out by 973 Project ＂{2. of Future Internet Architecture＂ on the key scientific issues of new-generation Internet architecture and its latest {2. results; and looks to the future of the {2.-focus faced with the new situations of the basic {2. 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

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Bioinformatics analyses for signal transduction networks

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Science china(Life Sciences) 2008年第11期51卷 994-1002页

作者： LIU Wei1,2. LI Dong2. ZHU YunPing2.& HE FuChu1,2.1 College of Mechanical & Electronic engineering and Automatization, national University of Defense {2., Changsha 410073, china 2.State Key Laboratory of Proteomics, beijing Proteome research center, beijing Institute of Radiation Medicine, beijing 102.06, china 1. College of Mechanical & Electronic engineering and Automatization National University of Defense Technology Changsha 410073 China 2. State Key Laboratory of Proteomics Beijing Proteome Research Center Beijing Institute of Radiation Medicine Beijing 102206 China

research in signaling networks contributes to a deeper understanding of organism living activities. With the development of experimental methods in the signal transduction field, more and more mechanisms of signaling pathways have been discovered. This paper introduces such popular bioin-formatics analysis methods for signaling networks as the common mechanism of signaling pathways and database resource on the Internet, summerizes the methods of analyzing the structural properties of networks, including structural Motif finding and automated pathways generation, and discusses the modeling and simulation of signaling networks in detail, as well as the research situation and tendency in this area. Now the investigation of signal transduction is developing from small-scale experiments to large-scale network analysis, and dynamic simulation of networks is closer to the real system. With the investigation going deeper than ever, the bioinformatics analysis of signal transduction would have immense space for development and application.

关键词： signal transduction structural motif automated pathways regeneration dynamics simulation

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