Table of Content

30 November 2010, Volume 44 Issue 11 Previous Issue    Next Issue

Automation Technique, Computer Technology

Select

An Improved Algorithm for Real Root Isolation of Univariate Polynomials LIU Dong1，FENG Yong1，ZHANG Caihuan2，ZHAO Xianghui1 2010, 44 (11):  1477-1480.  Abstract ( 3445 )   Save An improved algorithm for real root isolation of univariate polynomials was proposed mainly based on bisection method and a kind of specially designed efficient interval Newton operator. Its structure is similar to Trealroot, a function in Maple package Discoverer, however, it is more efficient than Trealroot for sparse polynomials with large degrees and few terms. Generally speaking, performing Taylor shift is very costly, so Trealroot uses many techniques to decrease the number of Taylor shifts. Different from Trealroot, the proposed algorithm performs a specially designed efficient exact interval Newton operator to rule out intervals not containing real zeros quickly and avoids completely Taylor shifts. The algorithm is super efficient for sparse polynomials. The polynomial is sparser, and the algorithm is more efficient. A large number of polynomials generated randomly by Maple were tested, compared with Trealroot and realroot (a function in Maple), and the result was reported. Related Articles | Metrics

Select

On Continuity Conditions for Quartic Bézier Curves and Surfaces with Shape Parameters HU Gang,DAI Fang,QIN Xinqiang,ZHANG Suxia 2010, 44 (11):  1481-1485.  Abstract ( 3468 )   Save To tackle the problem that the engineering complex curves or surfaces can not be constructed by using a single curve or surface, the continuity condition of quartic quasiBézier(quartic qBézier) curves and surfaces with shape parameters was studied. Based on the analysis of the basis functions and terminal properties, the necessary and sufficient conditions of G1 and G2 continuity, and C1 and C2 continuity between two adjacent quartic qBézier curves were proposed. In order to overcome the shortcomings that the circular arc and ellipse can not be accurately represented by quartic qBézier curves, the continuity condition between quartic qBézier curves and CBézier curves was also presented. In addition, the geometric model of the quartic qBézier surfaces was constructed and the condition of G1 continuity between two adjacent quartic qBézier surfaces in u and v directions was derived and simplified by choosing the control parameters properly. The modeling examples illustrated that the continuity condition of the quartic qBézier curves and surfaces could be widely applied to the complex curves and surfaces modeling system. Related Articles | Metrics

Select

Twodimensional Boolean Operation ZHANG Yi1，YU Haiyan2，HE YuanJun1 2010, 44 (11):  1486-1490.  Abstract ( 3056 )   Save In this paper, a mechanismic analysis was made on singular condition of multipoints and multiedges in boolean operation. On the basis of intersection points eigenvalue, the problem of quadruplepoint and multiedges was addressed, and a complete solution for the singular problem on 2D boolean operation was given in a simple way. Related Articles | Metrics

Select

Facial Animation Based on CANDIDE Model GE Meiling,YAO Lixiu,LI Juan,YANG Jie 2010, 44 (11):  1491-1500.  Abstract ( 3368 )   Save Imagebased facial animation is useful in practical applications because of its realistic texture and easy implementation. Facial animation driven by complex mesh can improve the sense of reality but reduce the efficiency of animation. In this paper, modelphoto matching was made easy because of CANDIDE model. Local optimization of the mesh after the sketchy matching not only improves the representative of the model but also reserves the matching efficiency. Mesh deformation based on thinplate splines interpolation instead of the traditional nodemoving can effectively improve the reality. The experimental results demonstrate that this method can generate vivid facial animation and the replacement of character becomes easier and faster. Related Articles | Metrics

Select

Topic Evolution Based on LDA and Topic Association CHU KeMing，LI Fang 2010, 44 (11):  1501-1506.  Abstract ( 3418 )   Save Topic evolution will help people to learn information quickly. In this paper, a method was proposed to discover topic’s evolution over time by topic detection and relating topics in different time periods. The method applies LDA model on temporal documents to extract topics. The number of topics in different time periods is different. Relating topics in consecutive time periods is based on JensenShannon divergence and features similarity. Experiments show that the method can detect new topics and describe topic’s evolution over time effectively. It not only shows that the topics evolve with time, but also that the content of topics change with time. Related Articles | Metrics

Select

A New Fusion Method for Lostfocus Images Based on Vision Structural Similarity CAO Yin,CAI Yunze,HAN Yu 2010, 44 (11):  1507-1512.  Abstract ( 3625 )   Save When an image is captured by optical sensor, some parts of the scene will be blur due to lost focus. Image fusion is a method for integrating multifocus images into a composite image which is more suitable for work. In order to fuse multifocus images, a new blind image quality assessment metric, Vision Structural Similarity (VSS), was first proposed in this paper. Based on this metric, multifocus image fusion problem could be described as an optimization process. Through optimizing source images by evolutionary computation, the image with best VSS value would be chosen as fusion result. The experimental results of the proposed method show high performance in both consistency and reliability comparing with other fusion schemes. Related Articles | Metrics

Select

An AttributeBased Encryption Scheme Suitable for Distributed Network ZHANG Lei,CAO Zhenfu 2010, 44 (11):  1507-1512.  Abstract ( 2275 )   Save In this paper, the necessity of protecting the data exchanged between nodes was elaborated and a distributed attributedbased encryption scheme was proposed based on Ganglia Network. The advantages of this scheme was also discussed and compared with other existing schemes. Finally, the value of use in practice of this scheme, such as constant ciphertext length, high effiencies in encryption and decryption, and good flexibility was summarized. Related Articles | Metrics

Select

Synchronization Control Strategy between Heterogeneous Structures Hyperchaotic Systems LIU Yuliang1,2,3,ZHU Jie1,ZHANG Hua2 2010, 44 (11):  1513-1518.  Abstract ( 3268 )   Save Based on nonlinear dynamics theory and Lyapunov stability theorem, the synchronization between chaotic systems and between hyperchaotic systems were studied, respectively. Focusing on deriving and proving the synchronization controller’s expressions, the synchronization control strategy studied in this paper improved the flexibility in both chaos signal’s generation and hardware’s realization, and the result was verified by numerical simulations. Related Articles | Metrics

Select

Design and Manufacture of An Integrated Micro Flow Sensor with SU-8 Channel LU Qi，CHEN Xiang，XIAO Lijun，CHEN Di 2010, 44 (11):  1519-1523.  Abstract ( 3492 )   Save A micro flow sensor integrated inside the flow channel was manufactured by using SU8 as the flow channel which integrated electrodes inside and packaged through the bonding between SU8 and PDMS（polydimethylsiloxane）. According to the calorimetric theory, comsol, a multiphysics simulation and analysis software, was implemented to build the model of thermal micro flow sensor to analyze the key factors’ influences on its sensitivity. Then a micro flow sensor was designed and manufactured with MEMS technology. Finally, the flowvoltage testing of the micro flow sensor was executed. Related Articles | Metrics

Select

Path Planning and Navigation for Intelligent Wheelchair in Dynamic Environments WANG Lijun,WANG Jingchuan,CHEN Weidong 2010, 44 (11):  1524-1528.  Abstract ( 3570 )   Save A planning and navigation algorithm was proposed for intelligent wheelchair in dynamic environments. Having a hierarchical structure, this algorithm adopted a selflocaliztion method based on mapmatching, combined preplanning with online replanning for getting a semioptimal path in dynamic environments, and designed a behaviorbased control and behaviorselection method based on the local scan map. The experimental results of the intelligent wheelchair prototype show that the proposed algorithm can get an optimized path and improve safety in dynamic environments. Related Articles | Metrics

Select

Design of a Humanoid Robot Simulation Platform Based on MRDS YIN Hang,YAN Yonghua 2010, 44 (11):  1529-1533.  Abstract ( 4252 )   Save To facilitate the research on gait of biped walking in humanoid robotics, design and implementation of a simulation platform based on Microsoft Robotics Developer Studio(MRDS) were discussed in this paper. Simulated robot modelling was conducted and the design patterns of robotics application under ServiceOriented Architecture were studied. Concurrent and coordinate control of robot behaviour were achieved and realized. Successful experiments, both on biped walking and basic vision, demonstrate that the platform can be expected to provide basic support for further control algorithm research. Related Articles | Metrics

Select

Parallel Algorithms for Transport Vehicles and Construction Tunnel Dynamic Coupling System CAO Lufen1,2,JIN Xianlong1,2,WU Huiming3,DU Xinguang1,2 2010, 44 (11):  1534-1538.  Abstract ( 3482 )   Save Tail transport vehicles were used to transport concrete lining in the process of construction tunnel in largescale water diversion project of QingCaoSha. A three dimension finite element was built up for the tunnels and transport vehicles, to accurately simulate the impact of transport vehicles on the surrounding tunnel. The threedimensional dynamic contact method was used to simulate the dynamic interaction between structures, such as wheelrail, railtunnel, and tunnelsoil. The explicit nonlinear finite element method was used to numerically simulatle and analyze the dynamic response of the tunnel when each section of the transport vehicles passes through the work shaft. Since the calculation of wheelrail contact was very timeconsuming, considering the highperformance computer structure of Shanghai Dawning 5000A supercomputer, the wheelRail Contact Balance Bisection (WRCBB) Algorithm, based on Recursive Coordinate Bisection (RCB) Algorithm, was designed. The accelerating effects of two kinds of parallel algorithms were analyzed and compared. The result indicates that, compared with the RCB method, the WRCBB method has improved the acceleration ratio and parallel efficiency in solving contact problem of largescale structural dynamic analysis. Related Articles | Metrics

Select

The Half Open Multidepot Vehicle Routing Problem LIU Ran，JIANG Zhibin，GENG Na，LIU Tiantang 2010, 44 (11):  1539-1544.  Abstract ( 3505 )   Save The half open multidepot vehicle routing problem (HOMDVRP) was proposed to meet the requirement of modern logistic industry in China. In terms of similarity and difference among HOMDVRP, multidepot vehicle routing problem and open vehicle routing problem, a mathematical model was built. In order to solve this new NPhard problem, the saving algorithm, the sequence insertion algorithm and parallel regretted insertion algorithm were proposed base on the classical heuristics for the vehicle routing problem. Meanwhile, three kinds of local search methods were adopted when the heuristics were designed. The results were analyzed by studying the impact of parameters and local search methods on the performance of the heuristics. Simultaneously, the performances of different heuristics were assessed by comparing them with benchmark instances. Related Articles | Metrics

Environmental Science

Select

Degradation Behavior of Ceftazidime in Aquatic Environment GU Jiaping,WANG Penghua,YUAN Tao,LI Jinhua,ZHOU Baoxue 2010, 44 (11):  1546-1549.  Abstract ( 3113 )   Save The degradation behavior of ceftazidime in water was studied using highperformance liquid chromatography. Experiments were conducted under conditions with different temperature, pH, water samples, sterile & nonsterile and light. The results show that the standard degradation kinetic process can be described by the firstorder reaction (halflife = 1.83 d). Increasing temperature (from 5 to 45 ℃) or pH (5 to 9) can accelerate degradation of ceftazidime (38.27 times for temperature and 13.03 times for pH, respectively). The degradation rate of ceftazidime in wastewater is relatively high among the tested samples. This study provides some fundamental data for assessing the behavior and ecological risk of ceftazidime in aquatic environment. Related Articles | Metrics

Select

Removal of Cephalosporin Antibiotics in Wastewater Treatment Plant and Preliminary Risk Assessment WANG Penghua,YUAN Tao 2010, 44 (11):  1550-1555.  Abstract ( 3551 )   Save The occurrences and removals of five cephalosporin antibiotics in two local Wastewater Treatment Plants (MHWWTP and XZWWTP) at different seasons were investigated by applying the analytical method of Solid Phase ExtractionHigh Performance Liquid ChromatographyUltraviolet Detector (SPEHPLCUVD). The preliminary risk assessment of discharge wastewater to the receiving water was performed. The results showed that all the five cephalosporin antibiotics were identified in the influent and effluent of WWTPs with the range (average values) of 1.122.75 μg/L and 0.011.32 μg/L, respectively. The comparison of seasonal data in MHWWTP showed the analyte concentrations in samples collected in July were relatively lower than those in samples collected in other seasons. This might be due to the usage fluctuation of cephalosporin antibiotics and the enhanced degradation by high temperature. In addition, it was indicated that higher removal efficiencies of cephalosporin antibiotics were obtained in the treatment process of oxidation ditch rather than that of A2/O. According to the daily mass flow of five cephalosporin antibiotics in effluent samples, it was noted that different cephalosporin antibiotics had different discharge load in varied seasons and might potentially pose dissimilar ecological and environmental risks to the receiving water. Related Articles | Metrics

Select

Joint Toxicity of Nitrobenzene and Intermediate Products to Photobacterium Phosphoreum ZHU Jun,HUANG Yang,ZHAO Hao,DING Zhuhong,XU Yanhua 2010, 44 (11):  1556-1560.  Abstract ( 3448 )   Save There were many intermediate products in the process of nitrobenzene wastewater pretreatment. Some of the intermediate products were more toxic than nitrobenzene, which had bad effect on the microbe in biological treatment. So the toxicity assessment was necessary. The single toxicity and joint toxicity of nitrobenzene and its primary intermediate products (onitrophenol, mnitrophenol and pnitrophenol) in wastewater were studied by using the method of photobacterum phosphoreum in this paper. The joint toxicity of multiple mixtures was evaluated by three evaluation methodology: Toxic Unit (TU), Additive Index(AI) and Mixture Toxicity Index(MTI). The results suggest that the -log EC50 value of the single toxicity for nitrobenzene, onitrophenol, mnitrophenol and pnitrophenol is 3.21, 3.40, 3.30 and 4.15, respectively. The joint toxicity of multiple mixtures is primary additive action or synergistic action. Related Articles | Metrics

Select

Numerical Simulation for Friction Factor of Laminar Flow of Water in Microchannels with MicroPinFin Arrays DONG Lining,QUAN Xiaojun,CHENG Ping 2010, 44 (11):  1561-1565.  Abstract ( 3815 )   Save Numerical simulations were conducted for the laminar flow of water through 22 microchannels with staggered square short micropinfin arrays with various geometry parameters in the Reynolds number range of 5 to 400. The effects of height and pitch of pinfin arrays on laminar flow friction factor were investigated. An empirical correlation was developed as a function of porosity and tortuosity, Reynolds number, and aspect ratio. It is found that this correlation can predict the friction factor in microchannels with micropinfin accurately. It is expected that this novel form of correlation equations can be extended for micro pinfin arrays with complex and irregular geometries and porous media with complex microstructures. Related Articles | Metrics

Select

Experimental and CFD Study on Combustion Noise and Pollutant Emissions of Diesel Engine with Split Injections of Common Rail System SHI Xiuyong1,2,QIAO Xinqi2,NI Jimin1,ZHENG Yuanyuan3 2010, 44 (11):  1566-1572.  Abstract ( 3543 )   Save In order to explore the impact laws of split injection strategies on combustion noise and emission characteristics, experimental studies and CFD simulations were conducted on a heavy duty diesel engine with common rail sytem, by varying different pilot and post injection parameters. The results showed that the combustion noise was mitigated by introducing fuel pilotinjection; the NOx emission could be reduced by pilotinjection combination of 1.0 mg fuel quantity and/or 45°CA injection interval, without penalty of PM emission too much. Besides, PM emission could be decreased under all postinjection conditions with no NOx increased. More important, through CFD simulation with HARR soot model revised showed that the turbulent flow motion caused by postinjection spray was one of the key factors enhancing soot oxidization. Related Articles | Metrics

Aeronautics & Astronautics

Select

Tether Dynamic Research of Electrodynamic Tether Deorbiting System KONG Xianren,XU Dafu,LIAO Jun,WANG Benli 2010, 44 (11):  1573-1578.  Abstract ( 3118 )   Save Considering inflecting effect, this paper presents a flexible cable model, which can be used for analyzing the dynamic behavior of the electrodynamic tether (EDT) deorbiting system. The model can describe tether inflecting and bowing under action of electrodynamic drag and gravity gradient induced force, and the influences on electro motive force and electrodynamic drag. Two mathematical simulations are employed to show the differences between the flexible cable model and the drumbell model. Vibration of the EDT system during deorbiting course is discussed. The simulation result shows that vertical response is the main vibration of EDT. Related Articles | Metrics

Select

Experimental Study of Hot Air Antiicing System of Inlet Guide Vane DONG Wei，HOU Yuzhu，MIN Xianhua 2010, 44 (11):  1579-1582.  Abstract ( 3267 )   Save The experiment method for studying the hot air antiicing system of inlet guide vane was introduced. Some antiicing tests were performed in different external icing flow conditions. In experiments, the blade surface temperature change was measured by thermalcouples thermal couple and the experiment process was recorded by an image recording system. The experiment results show that the ice accretion is located at the leading edge and suction side, and the guide vane internal hot air channel should be designed efficiently in the hot air antiicing system to improve antiicing performance. Related Articles | Metrics

Select

Structural Analysis of Flexible Airship on Stratospheric Platform Based on Engineering Elastic Theory GAO Haijian,CHEN Wujun,FU Gongyi,HE Yanli 2010, 44 (11):  1583-1587.  Abstract ( 3146 )   Save On the basis of engineering elastic theory, structural analysis of flexible airship on stratospheric platform was conducted. Using nonmoment shell theory and virtual work principle respectively, the envelope stress and overall deflection were formulated for flexible airship. The deflection formula of inflatable fabric beam was extended to calculate the deflection of flexible airship with superposition principle, and the results of these two methods were validated. The critical loadcarrying moment and minimum pressure were presented for the airship in normal operation serviceability limit state. Eventually, buoyant center, gravity center, and other parameters of a 25meterslong demonstration airship were obtained, the minimum pressure of this airship was calculated, and the moment of flexible airship and corresponding deflection were investigated sequentially, providing valuable information for flexible airship designing. Related Articles | Metrics

Biomedical Engineering

Select

Threedimensional Finite Element Analysis of Three Removable Partial Dentures under Different Loading Conditions CUI Wen1,WANG Dongmei1,WANG Chengtao2,HUANG Qingfeng2,ZHANG Fuqiang2 2010, 44 (11):  1588-1594.  Abstract ( 3369 )   Save To investigate the biomechanical effects of three removable partial dentures，the 3D finite element analysis(FEA) models of the mandible with molar missing, rehabilitated using traditional, RPI and implantsupported removable partial denture, were built based on models from the Mechanical Virtual Human of China database. The FEA was conducted in ABAQUS6.51. Two types of forces, vertical and oblique force, were loaded on these models. The FEA results suggest that the RPI removable partial denture is more helpful than the traditional RPD against the vertical and oblique loads, and the implantsupported RPD is more helpful than the other two, especially under oblique loading. Related Articles | Metrics

Select

Overdetermined ICA and Its Application on the Analysis of Human Colonic Pressure Signals PAN Cheng，TIAN Sheping，YAN Guozheng 2010, 44 (11):  1595-1599.  Abstract ( 3173 )   Save Independent component analysis (ICA) is a broadly used method for blind source separation (BSS). The mature ICA model has a restriction that the number of sources must equal that of sensors used to collect data, which is hard to meet in practice. An overdetermined ICA method was proposed and successfully used in the analysis of human colonic pressure signals. Using principal component analysis (PCA), the method estimated the number of sources and reduced the dimension of observed signals so that it is the same with that of the sources; and then, FastICA was used to estimate all the sources. From 26 groups of colonic pressure recordings, colonic motility patterns were extracted, which not only proved the effectiveness of this method, but also would greatly facilitate further medical researches. Related Articles | Metrics

Select

Analyzing Method for Clinical Pathway Variations Based on Fuzzy Neural Network with Knowledge DU Gang1，JIANG Zhibin1，DIAO Xiaodi2，YAO Yang3 2010, 44 (11):  1600-1604.  Abstract ( 3843 )   Save The application of the Mamdani, TakagiSugeno fuzzy neural network, and BP neural network in clinical pathway control was investigated. The analyzing method for clinical pathway variations based on fuzzy neural network with knowledge was given. Finally, a case study on liver poisoning of osteosarcoma preoperative chemotherapy was used to validate the proposed method, and their effectiveness, and respective advantages and disadvantages were analyzed. The result shows that knowledge fuzzy neural networks have obvious advantages over standard neural networks for analyzing and reasoning of clinical pathway variations. Related Articles | Metrics

Chemical Engineering

Select

Dynamic Mechanical Properties of Biodegradable Stents WANG Yihan1,DOU Hongjing1,SUN Kang1,SUN Kun2,FENG Qimao2 2010, 44 (11):  1605-1609.  Abstract ( 3422 )   Save Permanent metallic stents are associated with limitations such as continued biological interaction with the surrounding tissue, thrombosis and mismatch to the vessel size. Thus, biodegradable stents woven by polydioxanone (PDO) fiber were studied. The dynamic mechanical properties of the fiber and the stents were tested with DMTA. The results show that different weaving methods impact the mechanical properties of the stents. Related Articles | Metrics

Select

Cyclic Compression of Rigid PU/ER Interpenetrating Polymer Networks Foams HUA Xingyan1,ZHAO Peizhong2,ZHU Jinhua3,WANG Yuansheng3 2010, 44 (11):  1610-1614.  Abstract ( 3297 )   Save A series of rigid polyurethane (PU)/epoxy resin (ER) IPN foams were prepared. Changes of the chemical structure and morphology of IPN foams were investigated by FTIR spectroscopy and SEM. The FTIR show that there exist some chemical bonds between PU and ER component. The cell shapes of all the IPN foams are almost uniform. The cyclic compression behaviors of the IPN foams were tested. The results indicate that the stress at any given strain and the dissipated energy both decrease with the number of cycles. The stress and dissipated energy both increase with the ER content. The loading and unloading response can be fully described by modified Ogden’s model. The accumulated dissipated energy can be expressed by Weibull equation. Related Articles | Metrics

Select

Synthesis and Characterization of Symmetrical Trisubstituted Functionalized αCyclodextrin LIANG Tao1,2,AI Tingting1,ZHENG Chao1,TU Chunlai1,SHU Mouhai1,2 2010, 44 (11):  1615-1618.  Abstract ( 3044 )   Save A new symmetrical trisubstituted derivative of αcyclodextrin(α-CD), 6A,6C,6Etri-S-2-pyridyl-2A,2B,2C,2D,2E, 2F,3A,3B,3C,3D,3E,3F,6B,6D,6Fpentadeca-O-methyl-α-cyclodextrin, was synthesized by the reaction of trimesylated derivatives of α-cyclodextrin with 2-mercaptopyridine at the presence of K2CO3 in N,Ndimethylformamide(DMF). The compound was characterized by 1H, 2D COSY, 2D HSQC, dept135° and dept90° 13C NMR spectroscopy and electrospray ionization mass spectroscopy. - Related Articles | Metrics

Communication and Transportation

Select

Model Predictive Controller Design for Electromagnetic Active Suspension HUANG Kun，YU Fan，ZHANG Yongchao 2010, 44 (11):  1619-1624.  Abstract ( 3651 )   Save For the developed electromagnetic actuator prototype, the range of control current during the stroke of actuator was derived through analysis of simplified circuit control model. Based on model predictive control methodology, an active suspension controller was designed, which could take into account the constraints of actuator and quarter vehicle. The simulation results indicate that, under the condition of vertical shock and random uneven road, the model predictive controller can obtain better ride comfort than linear optimal control. Related Articles | Metrics