Table of Content

20 May 2005, Volume 41 Issue 3

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Robust Lagrange Stabilization of Uncertain Pendulum-Like Systems Based on Nonlocal Reduction Method

LI Xinbin,ZHONG Jiaqing

2005, 41(3):  358-365. 

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The robust Lagrange stabilization problem is considered as a class of uncertain nonlinear systems with infinite equilibria set,called pendulum-like systems. Firstly,sufficient conditions of Lagrange stability for nominal unperturbed pendulum-like systems are derived based on the nonlocal reduction method. Then the static state feedback controller design methods are presented for uncetain pendulum-like systems with time-varying norm-bounded parameter uncertainty to obtain robust Lagrange stability. It is shown that the above problem can be reduced to the existence of the solutions to a set of LMIs.

Geometric Approach to Robust D-Stability Analysis

LI Haibin,WANG Zhizhen,WANG Long,LI Zhaoping,CHENG Gong

2005, 41(3):  366-372. 

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The problem of robust D-stability analysis with respect to an LTI SISO feedback system is studied. First, the geometric properties of the sum of the segments in the complex plane are proved, Based on which, the robust problem is interpreted as a special point location problem of computing geometry. Therefore, some necessary and sufficient conditions for the stability of the perturbed systems subject to the robust performance are proposed. Then, several efficient algorithms are presented using computational geometric techniques.

Dynamic Behavior and Buckling Analysis of Thin Rectangular Plate Rotating around Its Symmetrical Axis

XIAO Shifu,CHEN Bin,LIU Caishan

2005, 41(3):  373-380. 

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A nonlinear dynamic model of thin rectangular plate rotating around its symmetrical axis with two opposite simply-supported edges and two opposite free edges is established using general Hamilton's Variational Principle. Three lower modes and the critical bifurcation values of the plate are analyzed approximately by employing assumed modes method. The results show that the overall motions can result in dynamic softening in the flexible multi-body system. Furthermore, the same method is also used to investigate the post-buckling behaviour of the plate. The symmetrical stable post-buckling solutions which are developed from the trivial solution through first bifurcation, the asymmetrical stable post-buckling solutions which are developed from the symmetrical post-buckling solutions through the second bifurcation and the antisymmetry unstable post-buckling solutions which are developed from the trivial solution through its second bifurcation are obtained.

The Existence of p-Blocks of Defect Zero

WANG Lizhong

2005, 41(3):  335-337. 

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The existence of blocks of defect 0 for some special classes of finite groups is determined. A proof of another form of G Robinson's theorem is given too.

Phenomenon of Reverse Transition on a Heated Flat Plane with Stable Temperature Stratification

LI Yiming,YAN Dachun

2005, 41(3):  381-387. 

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In the twodimensional wind tunnel, systematic experimental researches were carried out on the phenomenon of reverse transition on a heated plane with stable density stratification. The detailed experimental investigation of the distribution and evolution of the mean velocity profile were executed. The signal of instantaneous velocity, the energy spectra of velocity and wave characteristics in the boundary layer have been analyzed. All of these results described the process of the phenomenon and delineated the mechanism of it. The experiment was performed in two conditions: heated plane and unheated plane. When the plane was heated, observation showed that the shape factor increased from 1.5 to 2.6; the mean velocity profile departed from the law of the wall; the inertial subrange in the energy spectra curves disappeared; the intermittent phenomenon occurred. All of the results indicated the turbulent boundary layer had been turned into the laminar layer. The skin friction coefficient drops rapidly. This result not only proved the phenomenon of reverse transition had occurred, but also showed that this condition was drag-reducing condition.

Textured Image Segmentation Based on Multiresolution Wavelet and Gaussian Mixture Models

YU Peng,FENG Jufu

2005, 41(3):  338-343. 

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The author proposes a textured image segmentation algorithm which is based on multiresolution wavelet and Gaussian mixture models. At first a preceding process is taken in this algorithm. Then, the image is decomposed by wavelet pyramids. All of those lower resultant image and original image are integrated to a feature vector of a pixel. Those pixels are segmented by Gaussian mixture models. Experiment show the algorithm can give a good result.

The Formalization for UML Statechart Diagrams

SUN Meng,ZHANG Naixiao,Bernhard K Aichernig

2005, 41(3):  344-357. 

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It is presented that a formalization for UML statechart diagrams in the RAISE specification language RSL. By such a formalization, a general framework is proposed for integration of graphical UML statechart diagrams and formal RSL specifications, which forms the continuation of the previous work on formalization of UML class diagrams in RSL. This allows the definition of UML semantic interpretations that are precise and unambiguous, and also enhancing the readability, conciseness and abstraction of the resulting RSL specification. A case study illustrates how the framework can be used to create formal specification for UML models and analyze the properties of the models.

Orographic Influence on Precipitation of a Meso-Scale Convective System over Taiwan on 7-8 June, 1998

ZHU Xiaojin,ZHANG Qinghong

2005, 41(3):  388-398. 

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Mesoscale model MM5 is used to examine the orographic effect to the precipitation caused by a Mesoscale Convective System (MCS) over Taiwan. A series of sensitive simulations are carried out to investigate the sensitivity of model resolution and orographic accuracy to precipitation. The results show that model resolution is crucial to the precipitation forecast, and orographic accuracy is found to be essential to both the location and the amount of the precipitation for this case. In order to get reasonable prediction, 6km model grid resolution and 18km accuracy of orography are needed.
      Sensitivity simulations with and without orography of Central Mountain Range (CMR) in the model show there are two kinds of orographic effects to the precipitation in this case, which can be called as "induced" and "modified" effects. CMR in Taiwan blocks the movement of mesoα scale low that associated with the MCS in the lower troposphere, and help to generate local mesoβ scale lows interacting with the mesoα scale vortex at the north of CMR. Severe rainfall brought by these local stationary mesoscale circulation systems is "induced" in northern Taiwan. At the central CMR, where the MCS landed, both rainfall area and its intensity are increased. That means the central CMR only "modified" the rainfall.

Observational Study of Wind Fields, Temperature Fields over Beijing Area in Summer and Winter

HU Xiaoming,LIU Shuhua,LIANG Fuming,WANG Jianhua,LIU Heping,WANG Yingchun,LI Ju

2005, 41(3):  399-407. 

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The wind fields and temperature fields data provided by "D files" from 14 surface observation stations around Beijing area are used to produce the mean wind fields and the mean temperature fields over Beijing area in summer and winter. Such results are gotten: (1) Due to the unique topography the wind of Beijing area during the day time is southern anabatic wind and in the night is northern katabatic wind in summer. In winter, this phenomenon disappears due to the affect of the strong synoptic systems. (2) In summer, Haidian and Fengtai lie in an area with high temperature. These areas are the main are as of the Urban Heat Island over Beijing area. In winter Haidian and the area north to Haidian are high temperature areas during the night.

Estimating Land Surface Temperature of Huaihe River Basin from TRMM and GMS-5 Satellite

NIU Xiaolei,ZHOU Wei,LIU Huizhi,LI Wanbiao

2005, 41(3):  408-416. 

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The equation for estimating land surface temperature of Huaihe River Basin has been set up by using the data of split window channels of TRMM and GMS-5 satellite and the ground observation data of HUBEX. Comparison with the ground observation data of Huaihe River Basin from many aspects shows the result is in good agreement with observation. On the basis of the typical weather situation in Huaihe River Basin in 1998, the paper analyses the features of the land temperature of Huaihe River Basin in the four stages of the 1998's Meiyu of Yangtze.

Numerical Simulation of the Light Storage Based on Dynamic EIT and Analysis of Multi_Pulse Storage

ZHANG Yu,ZHANG Jianwei,CHEN Xuzong

2005, 41(3):  417-422. 

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A numerical simulation method is presented for studying the light storage based on the technique of dynamic EIT.Comparing with analytical method under certain limitations,this numerical method has advantages to study the change of the signal pulse with the effect of various factors, such as atomic decay and so on. Furthermore, both the feasibility and the prospect of the multi-pulse light storage in quantum information regime are also analyzed.

The Formation and the Motion of Copper Steps Induced by STM on the Surface of Cu(111) Covered with Glycine

GE Siping,ZHU Xing

2005, 41(3):  423-428. 

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Amino acid is the building block of protein and its adsorption on the surface of metal provides the model for the study of the interaction of protein with metal. Due to the adsorption of amino acid, the modification of morphology such as variation of reconstruction or faceting may happen on the entire metal surface. The induced formation and motion of copper steps on the surface of Cu (111) covered with glycine occur in the area where has been scanned by scanning tunneling microscope (STM) with higher negative bias voltage (|V_b|>2.5V). And the role of glycine in the modification of surface morphology is also discussed.

Adsorption of DDME on HOPG Investigated by Scanning Tunneling Microscopy

LIU Kai,DU Wenfeng,JI Hang,ZHAO Ruguang,

2005, 41(3):  429-433. 

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A thin film of 1, 1-dicyano-2, 2-(4-dimethylaminophenyl) ethylene (DDME) has been grown on HOPG by a modified vacuum deposition. The films were characterized by our homemade scanning tunneling microscopy (STM) under ambient conditions. The acquired STM images exhibit that DDME can form a uniform adsorption layer at room temperature. Highly ordered parallel molecular stacks were observed with STM.

Adsorption of Tryptophane on Graphite Investigated by Scanning Tunneling Microscopy

DU Wenfeng,LIU Kai,GE Siping,ZHAO Ruguang,

2005, 41(3):  434-439. 

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The adsorption behaviours of tryptophane on graphite (HOPG) have been investigated under low vacuum conditions at room temperature using scanning tunneling microscopy(STM). The acquired STM images exhibit that tryptophane can form a uniform adsorption layer at room temperature. Two kinds of structures were observed: two-dimensional stripe structure and two-dimensional monoclinic lattice. Possible models have been proposed for these two kinds of structures. The π stacking interactions between near tryptophane molecule's side chains are responsible for the formation of these two kinds of structures.

Matter Information Theory: Matter Information System of Various Layers and Their Philosophical Explorations

LUO Xianhan

2005, 41(3):  440-447. 

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According to the development of modern natural science, the relation exists between matter and information. In the early part of universe, the information carried by the elementary particles is the basic matter information, by which the solar system is formed. The biological molecules are the matter information systems with more layers through interaction of many factors between heavens and earth. The information of persons is closely relate to the stability and development of society. The author tries to establish a philosophical system of matter information theory, including the interpretation in ontology, the development outlook and the theory of knowledge.

A Novel Temporal Scenario Recognition Algorithm and Its Application in Intrusion Detection Alert Fusion

XU Hui,FENG Jinwen,PAN Aimin

2005, 41(3):  448-459. 

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A security alert fusion algorithm based on temporal scenario recognition is proposed. Known attack patterns are defined into temporal scenario models to process online or offline alert flow. Alert aggregation and alert correlation are performed simultaneously in the recognition procedure. Methods based on temporal reasoning are adopted to preprocess temporal scenario models, giving the recognition algorithm a high efficiency.

Theoretical Research on Reflection and Transmission Performances of 2-D Dielectric EBG Structures with Different Parameters

ZHAO Xiaoying,ZHOU Lezhu

2005, 41(3):  460-464. 

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The finite element method incorporated with Floquet theorem is used to solve the 2-Dimentsional scattering problem of dielectric Electromagnetic Band-Gap(EBG) upon which a plane wave is oblique or perpendicular incident. By exploiting the periodicity of EBG, the computation complexity and required memories are efficiently reduced. Comparisons of reflection and transmission properties for a kind of dielectric Electromagnetic Crystals with different structure parameters are presented, which will be helpful to the design of the similar structures.

Two Algorithms That Simulate RMESH by PRAM

CHEN Peng,ZHANG Li'ang

2005, 41(3):  465-475. 

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Both PRAM and RMESH are important parallel computing models. This paper gives two algorithms that simulate RMESH by PRAM. The first algorithm is to use PRAM-CRCW with n processors to simulate RMESH with sqrt(n)×sqrt(n) processors, whose time complexity is O(nlogn). The algorithm has three steps respectively used to simulate the following three basic sub-steps of a unit computing time step of RMESH: bus reconfiguration, bus write and bus read. The most core part is to simulate bus reconfiguration on PRAM, which is implemented by an algorithm based on bus combination technique. The second one improves the efficiency, which is O(logn), but with the number of processors increased to n². Simulations on PRAM-EREW and PRAM-CREW are also discussed.

An Orthogonal Frequency Divided Group Code for CP-CDMA System: Comb Spectrum Code

CHENG Hongbing,MA Meng,JIAO Bingli

2005, 41(3):  476-483. 

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The motivation is to develop better CDMA codes for reducing the hardware complexity of the conventional CP-CDMA. This technology combines the frequency orthogonality of OFDM to CDMA code design for grouping the codes and allows a significant reduction for the calculations in channel equalization. The proposed method is referred to as OFDG code, which divides the codes of M chips in length into N groups, which are orthogonal one another in frequency domain. Each of the groups contains K codes which are mutually orthogonal in time domain. The design principle is introduced and a solution, called CS code, is obtained by the use of two operations to the conventional orthogonal code set; (1) an operation of cyclic repetition and (2) an operation of angle rotation. In comparison with the CP-CDMA, the points taken to channel equalization of CP-CS CDMA can be reduced by a factor of 1/N. The simulation results confirm the effectiveness of this approach.

Analysis on Combined Security Efficiency and Vulnerability for Information System Security Evaluation

DUAN Yunsuo,LIU Xin,CHEN Zhong

2005, 41(3):  484-490. 

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To meet the requirements of information system security evaluation, some key technologies are discussed in terms of international and domestic standards. Especially, the combined efficiency of different security functional components and anti-attack strength classification are described in detail.

Research on the Technology of Multi-Granularity Optical Switching

YIN Hongxi,ZHANG Yu,GUO Zhongmei,QUAN Haifeng,XU Anshi

2005, 41(3):  491-494. 

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Automatic Switched Optical Network (ASON) represents the development trend of optical networks. Multi-granularity optical switching is the importantly physically supporting techniques for ASON to realize traffic engineering and quality of service(QoS). The type of node structure realizing multi-granularity optical swithing in ASON is put forward and a multi-granularity optical switch using this structure is developed. The software for controlling the node in ASON is compiled. The experimental research is carried out with campus network as signalling network and the data network is of mesh architecture, which is a typical architecture in ASON. The main functions of ASON are verified.

RSA Cryptoprocessor Based on a Redesigned Systolic Array

LIU Qiang,MA Fangzhen,TONG Dong,CHENG Xu

2005, 41(3):  495-500. 

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A novel and generic approach is presented to the hardware implementation of the RSA cryptoprocessor in deep submicro (DSM) technology with a redesigned systolic array. With deep submicro technology scaling, integrated circuit performance bottleneck has shifted from logic gates to global interconnection. Besides using the systolic architecture which is popular in hardwarebased RSA systems, a blockbased scheme is proposed to eliminate global signals, with a pipelined bus to convey data globally. The control signals and intermediate results used for sequential multiplications are transmitted by shift registers. All signals, except for the clock signal, are limited in one block or between two adjacent blocks. The Chinese Remainder Theorem (CRT) technique increases the decryption data rate by a factor of four. Two redundant blocks are added to adapt to the online partition of the multiplier and the variation of the length of P and Q in CRT mode. The blockbased global signal transportation scheme and the redundancy scheme are quite different from those of previous works.