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Development of distributed time-variant gain model for nonlinear hydrological systems

Science China Earth sciences 2005年第6期48卷 713-723页

作者： XIA Jun1, 2, WANG Gangsheng1, TAN Ge1, YE Aizhong2 & G. H. Huang3.1. key laboratory of Water Cycle & Related Land Surface Processes, Institute of Geographic sciences and Natural Resources Research,{3., Beijing 100101, China 2. State key laboratory of Water Resources & Hydropower Engineering sciences, wuhan University, wuhan 43.072, China 3. Faculty of Engineering, University of Regina, 3.3. Wascana Parkway, Regina, Sask., S4S 0A2, Canada Correspondence should be addressed to Xia Jun key laboratory of Water Cycle & Related Land Surface Processes Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China State key laboratory of Water Resources & Hydropower Engineering sciences Wuhan University Wuhan China Faculty of Engineering University of Regina Sask Canada

In this paper, a rainfall-runoff modeling system is developed based on a nonlinear Volterra functional series and a hydrological conceptual modeling approach. Two models, i.e. the time-variant gain model (TVGM) and the distributed time-variant gain model (DTVGM) that are built on the platform of Digital Elevation Model (DEM), Remote Sensing (RS) and Unit Hydro-logical Process were proposed. The developed DTVGM model was applied to two cases in the Heihe River Basin that is located in the arid and semiarid region of northwestern China and the Chaobai River basin located in the semihumid region of northern China. The results indicate that, in addition to the classic dynamic differential approach to describe nonlinear processes in hy-drological systems, it is possible to study such complex processes through the proposed sys-tematic approach to identify prominent hydrological relations. The DTVGM, coupling the advan-tages of both nonlinear and distributed hydrological models, can simulate variant hydrological processes under different environment conditions. Satisfactory results were obtained in fore-casting the time-space variations of hydrological processes and the relationships between land use/cover change and surface runoff variation.

关键词： hydrological process, nonlinearity, time-variant gain model, distributed hydrological model.

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Ionospheric eclipse factor method (IEFM) for determining the ionospheric delay using GPS data

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Progress in Natural Science:Materials International 2004年第9期 56-60页

作者： YUAN Yunbin* and OU Jikun(key laboratory of dynamic {3., Institute of {3. and Geophysics, chinese academy of sciences, wuhan 43.077, China) key laboratory of dynamic {3. Institute of Geodesy and Geophysics Chinese Academy of Sciences Wuhan 430077 China

By establishing the ionospheric eclipse factor (IEF) λ of the ionospheric pierce point (IPP) and its ionospheric influence factor (IFF) , and combining λ, with t of IPP, a new method of modeling high precision ionospheric delay using GPS data—ionospheric eclipse factor method (IEFM)—is presented in this paper. The IEFM can effectively select the proper ionospheric models to model the total electron content (TEC) with different changes corresponding to annual, seasonal and diurnal variations. Initial experimental results show that the correction precision of ionospheric delay modeled by the IEFM seems to be close to that of using L3.GPS observations to directly correct the corresponding ionospheric delay.

关键词： global positioning system (GPS) ionospheric delay total electron content ionospheric eclipse factor method.

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A unified dynamic model for locomotion and manipulation of a snake-like robot based on differential geometry

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Science China(Information sciences) 2011年第2期54卷 318-333页

作者： WANG ZhiFeng1,3. MA ShuGen1,2, LI Bin1 & WANG YueChao1 1State key laboratory of Robotics, Shenyang Institute of Automation, chinese academy of sciences, Shenyang 110016, China 2Department of Robotics, Ritsumeikan University, Shiga-ken 525-8577, Japan 3.raduate University of chinese academy of sciences, Beijing 10003., China State key laboratory of Robotics Shenyang Institute of Automation Chinese Academy of Sciences Shenyang China Graduate University of chinese academy of sciences Beijing China Department of Robotics Ritsumeikan University Shiga-ken Japan

A snake-like robot, whose body is a seried-wound articulated mechanism, can move in various environments. In addition, when one end is fixed on a base, the robot can manipulate objects. A method of dynamic modeling for locomotion and manipulation of the snake-like robot is developed in order to unify the dynamic equations of two states. The transformation from locomotion to manipulation is a mechanism reconfiguration, that is, the robot in locomotion has not a fixed base, but it in manipulation has one. First, a virtual structure method unifies the two states in mechanism (e.g., an embedding in the configuration space); second, the product-of-exponentials formula describes the kinematics; third, the dynamics of locomotion and manipulation are established in a Riemannian manifold; finally, based on the analysis of the dynamic model, the dynamics of manipulation can be directly degenerated from those of locomotion, and this degeneration relation is proved through using the Gauss equations. In the differential geometry formulation, this method realizes the unification of the dynamics of locomotion and manipulation. According to a geometrical point of view, the unified dynamic model for locomotion and manipulation is considered as a submanifold problem endowed with geometric meaning. In addition, the unified model offers an insight into the dynamics of the snake-like robot beyond the dynamic model separately established for locomotion or manipulation.

关键词： snake-like robot dynamics unified model differential geometry locomotion manipulation

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Effects of fundamental structure parameters on dynamic responses of submerged floating tunnel under hydrodynamic loads

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Acta Mechanica Sinica 2009年第3期25卷 335-344页

作者： Xu Long Fei Ge Lei Wang Youshi Hong State key laboratory of Nonlinear Mechanics, Institute of Mechanics, chinese academy of sciences, Beijing 100190, China State key laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences Beijing China

This paper investigates the effects of structure parameters on dynamic responses of submerged floating tunnel （SFT） under hydrodynamic loads. The structure parameters includes buoyancy-weight ratio （BWR）, stiffness coefficients of the cable systems, tunnel net buoyancy and tunnel length. First, the importance of structural damp in relation to the dynamic responses of SPT is demonstrated and the mechanism of structural damp effect is discussed. Thereafter, the fundamental structure parameters are investigated through the analysis of SFT dynamic responses under hydrodynamic loads. The results indicate that the BWR of SFT is a key structure parameter. When BWR is 1.2, there is a remarkable trend change in the vertical dynamic response of SFT under hydrodynamic loads. The results also indicate that the ratio of the tunnel net buoyancy to the cable stiffness coefficient is not a characteristic factor affecting the dynamic responses of SFT under hydrodynamic loads.

关键词： Submerged floating tunnel Structural dampBuoyancy-weight ratio Cable stiffness coefficient ,Tunnel net buoyancy - Hydrodynamic load

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Black-box testing based on colorful taint analysis

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Science China(Information sciences) 2012年第1期55卷 171-183页

作者： CHEN Kai1,2,3.FENG DengGuo1,SU PuRui1&ZHANG YingJun1,2,3.1State key laboratory of Information Security,Institute of Software,chinese {3. of Science,Beijing 100190,China 2State key laboratory of Information Security,Graduate University of chinese academy of sciences,Beijing 100049,China 3.ational Engineering Research Center of Information Security,Beijing 100190,China State key laboratory of Information Security Institute of Software Chinese Academy of Science Beijing China State key laboratory of Information Security Graduate University of Chinese Academy of Sciences Beijing China National Engineering Research Center of Information Security Beijing China

Software vulnerability detection is one of the most important methods for guaranteeing software *** main classes of methods can detect vulnerabilities in binary files:white-box testing and black-box *** former needs to construct and solve path constraints to detect *** has two main drawbacks:path exploding and complexity of *** latter often aimlessly exhausts various inputs to test binary *** paper combines both testing methods to detect vulnerabilities in binary *** analyzing the input elements that aect check condition corresponding to a certain check point,we can generate one class of inputs that get to the check point to increase fuzzing *** analyzing the relationship between guard conditions and check condition,the redundant check points are *** taint analysis method(CTAM)is proposed to compute guard conditions,which is more ecient than traditional taint analysis method(TTAM).We implemented a prototype and made several experiments on *** results showed that our method could increase the eciency of black-box testing.

关键词： software testing vulnerability detection dynamic testing black-box testing colorful taint analysis

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Characterization and Tribological Behavior of Octadecene,Dodecene and Undecenoic Acid Films on Si Substrate

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Journal of Materials Science & Technology 2005年第5期21卷 671-674页

作者： Jinfang ZHOU+ and Shengrong YANGState key laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, chinese academy of sciences, Lanzhou73.000, China State key laboratory of Solid Lubrication Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou 730000 China

The films of octadecene, dodecene, and undecenoic acid were prepared on H-terminated Si surface in the presence of ultraviolet irradiation. The resulted films were characterized with water-contact angle measurement and infrared spectroscopy. The friction-reducing behavior of the prepared films was examined on a static-dynamic friction coefficient measurement apparatus and on an atomic force microscope. It was found that all the reacted films on the Si substrate showed good friction-reducing ability; especially, the film of the octadecene exhibited the best friction-reducing ability. This was attributed to the transfer of the reacted films onto the counter face with formation of a transfer film on the counterpart surface, which led to the transformation of the sliding between the reacted films and the hard ceramic to fiat between the reacted films and its transfer film on the counterpart surface. The macroscopic and microscopic friction behaviors of the prepared films were dependent on their molecular chain lengths. Thus the octadecene reacted film with the highest degree of ordering arrangement showed the best friction-reducing and antiwear abilities in sliding against Si3.4.

关键词： Alkese Reaction film Hydrogen-terminated silicon Tribological behavior

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The universal fuzzy logical framework of neural circuits and its application in modeling primary visual cortex

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Science China(Life sciences) 2008年第10期51卷 902-912页

作者： HU Hong1, LI Su2, WANG YunJiu2, QI XiangLin2 & SHI ZhongZhi1 1 key laboratory of Intelligent Information Processing, Institute of Computing Technology, chinese academy of sciences, Beijing 100080, China 2 laboratory of Visual Information Processing, Institute of Biophysics, chinese academy of sciences, Beijing 100101, China key laboratory of Intelligent Information Processing Institute of Computing Technology Chinese Academy of Sciences Beijing China laboratory of Visual Information Processing Institute of Biophysics Chinese Academy of Sciences Beijing China

Analytical study of large-scale nonlinear neural circuits is a difficult task. Here we analyze the function of neural systems by probing the fuzzy logical framework of the neural cells' dynamical equations. Al- though there is a close relation between the theories of fuzzy logical systems and neural systems and many papers investigate this subject, most investigations focus on finding new functions of neural systems by hybridizing fuzzy logical and neural system. In this paper, the fuzzy logical framework of neural cells is used to understand the nonlinear dynamic attributes of a common neural system by abstracting the fuzzy logical framework of a neural cell. Our analysis enables the educated design of network models for classes of computation. As an example, a recurrent network model of the primary visual cortex has been built and tested using this approach.

关键词： nonlinear dynamical system fuzzy logic visual cortex

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An iterative wavefront sensing algorithm for high-contrast imaging systems

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Research in Astronomy and Astrophysics 2011年第2期11卷 198-204页

作者： Jiang-Pei Dou 1,2,De-Qing Ren 1,2,3.and Yong-Tian Zhu 1,2 1 National Astronomical Observatories/Nanjing Institute of Astronomical Optics & Technology,chinese academy of sciences,Nanjing 210042,China 2 {3. {3. of Astronomical Optics & Technology,Nanjing Institute of Astronomical Optics & Technology,chinese academy of sciences,Nanjing 210042,China 3.Physics & Astronomy Department,California State University Northridge,18111 Nordhoff Street,Northridge,California 913.0-8268,USA National Astronomical Observatories / Nanjing Institute of Astronomical Optics & Technology Chinese Academy of Sciences Nanjing 210042 China key laboratory of Astronomical Optics & Technology Nanjing Institute of Astronomical Optics & Technology Chinese Academy of Sciences Nanjing 210042 China Physics & Astronomy Department California State University Northridge 18111 Nordhoff Street Northridge California 91330-8268 USA

Wavefront sensing from multiple focal plane images is a promising technique for high-contrast imaging ***,the wavefront error of an optics system can be properly reconstructed only when it is very *** paper presents an iterative optimization algorithm for the direct measurement of large static wavefront errors from only one focal plane *** first measure the intensity of the pupil image to get the pupil function of the system and acquire the aberrated image on the focal plane with a phase error that will be *** we induce a dynamic phase on the tested pupil function and calculate the associated intensity of the reconstructed image on the focal *** algorithm will then try to minimize the intensity difference between the reconstructed image and the aberrated test image in the focal plane,where the induced phase is a variable of the optimization *** simulation shows that the wavefront of an optical system can theoretically be reconstructed with high precision,which indicates that such an iterative algorithm may be an effective way to perform wavefront sensing for high-contrast imaging systems.

关键词： techniques: image processing -- methods: numerical -- planetarysystems

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Kinematics and dynamics of the Mesozoic orogeny and late-orogenic extensional collapse in the Sino-Mongolian border areas

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Science China Earth sciences 2005年第7期48卷 849-862页

作者： ZHENG Yadong 1 & WANG Tao2 1. key laboratory of Orogenic Belts and Crustal Evolution (Peking University), Ministry of Education, Beijing 100871, China 2. Institute of Geology, chinese {3. of Geological {3., Beijing 10003., China key laboratory of Orogenic Belts and Crustal Evolution (Peking University) Ministry of Education Beijing 100871 China Institute of Geology Chinese Academy of Geological Sciences Beijinq 100037 China

The Sino-Mongolian border areas underwent two important tectonic events during Mesozoic time after late Paleozoic orogeny: a late Triassic to earlier Jurassic contractional event that resulted in a large-scale south-vergent thrust during the orogeny and a late Jurassic-earlier Cretaceous extensional event in a north-south direction that formed a metamorphic core complex. The kinematic and dynamic analyses show that the thrust sheet moved southwards with a kinematic vorticity number of ca. -0.10 and sub-horizontal maximum compressive stress axis that belongs to a contraction-thickening shear. The upper plate of the late-orogenic detachment relatively moved in a 165°direction. The average kinematic vorticity in its earlier stage was 0.74 that belongs to simple shear dominated shearing and related to the maximum compressive stress axes dipping at ～66°, while the later average kinematic vorticity was ～0.55°that belongs to pure shear dominated shearing with sub-vertical maximum compressive stress axes. This suggests that the thrusting led to the crust thickened and the lower plate rocks that were originally located in the upper crust depressed through a brittle-ductile transition zone into the lower crust and became warmer. The heated rocks trended to uplift since their increasing volume and decreasing density while the loading of the upper-plate rocks increased due to the structural thickening. Under the combined effect of the loading and the thermal-uplifting, the ductile shear zone in between increased in its component of vertical pure shear. Once its pure-shear component exceeded its simple-shear one the ductile shear zone became an extension-thinned shear zone. This progressive transitional process reflects internal and essential temporal and spatial relationships: the extensional factor nucleated during the crust thickening by thrusting and increase of the extensional factor finally led to late-orogenic collapse.

关键词： Mesozoic thrusting,late-orogenic collapse,kinematic vorticity number,stress state.

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dynamic calculation model and seismic response for frame supporting structure with prestressed anchors

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Science China(Technological sciences) 2010年第7期53卷 1957-1966页

作者： DONG JianHua1’2, ZHU YanPeng1, ZHOU Yong1 & MA Wei2 1 College of Civil Engineering, Lanzhou University of Technology, Lanzhou 73.050, China 2 State key laboratory of Frozen Soil Engineering, Cold and Arid Regions Environmental and Engineering Research Institute, chinese academy of sciences, Lanzhou 73.000, China College of Civil Engineering Lanzhou University of Technology Lanzhou China State key laboratory of Frozen Soil Engineering Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou China

A dynamic calculation model of frame supporting structures with prestressed anchors for the slope stability is proposed. The frame and soil are closely contacted in the role of prestressed anchors and they cannot be separated along the whole slope. The lateral displacement of frame and soil is nearly in phase. The movement characteristic satisfies the theory of elastic foundation beam. The frame is treated with elastic foundation beam in this model. The influence of prestressed anchors is simplified as linear spring and damped system related with velocity. Under the condition of horizontal earthquake excitation, the equation of vibration response is established by using the model of dynamic Winkler beam and the analytical solutions are obtained for simple harmonic vibration. This method is applied to a case record for illustration of its capability, in order to verify the method, 3. nonlinear FEM (ADINA) is used to analyze the seismic performance of this case, the comparative results show that the design and the analysis are safe and credible by using the proposed method. The calculation model provides a new way for earthquake analysis and seismic design of slope stability supported by frame structure with prestressed anchors.

关键词： frame supporting structure with prestressed anchor slope dynamic calculation model seismic performance seismic design

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