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15 June 2006, Volume 27 Issue 6 Previous Issue    Next Issue
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Discrete-time variable structure control based on sliding mode for acrobot system Zheng, Yan (1); Jing, Yuan-Wei (1) 2006, 27 (6):  591-594.  DOI: - Abstract ( 210 )   HTML   PDF (1109KB) ( 539 )   Applies discrete-time variable structure control to the design of balance controller for Acrobot system. Develops a discrete-time mathematical model for Acrobot system at its upright equilibrium point to analyse the mechanism of chattering which occurs in compliance with the discrete-time exponential approximation law in a variable structure control systems. To improve the discrete-time exponential approximation law, a modified one is presented and applied to the design of discrete-time variable structure balance controller for Acrobot. Simulation results showed that the modified exponential approximation law will not only take the advantage of original one, but also reduce the chattering effectively, so as to keep the Acrobot system asymptotically stable, thus enabling the discrete-time variable structure control based on sliding mode for Acrobot system to come true. References | Related Articles | Metrics

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Robust stability of a class of uncertain nonlinear switched systems Zhao, Sheng-Zhi (1); Zhao, Jun (2); Zhang, Qing-Ling (1) 2006, 27 (6):  595-597.  DOI: - Abstract ( 241 )   HTML   PDF (279KB) ( 663 )   Making full use of the structural properties, the robust stability of a class of uncertain nonlinear switched systems is derived from the stability of every part of their nominal systems. When there are common Lyapunov functions found in both the linear parts and zero dynamics of the nominal systems, the robust stability of the systems available to arbitrary switching can be obtained by way of constructing a common Lyapunov function relying on uncertain parameters. Furthermore, when no subsystems of linear parts and zero dynamics are asymptotically stable in the nominal systems, the sufficient conditions ensuring the robust stability of such systems are given by designing a certain switching law through convex combination. References | Related Articles | Metrics

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Global asymptotic synchronization of a class of delayed chaotic neural networks Wang, Zhan-Shan (1); Zhang, Hua-Guang (1); Wang, Zhi-Liang (1) 2006, 27 (6):  598-601.  DOI: - Abstract ( 269 )   HTML   PDF (222KB) ( 622 )   The global asymptotic synchronization of a class of delayed chaotic neural networks is studied on the basis of drive-response synchronization. Constructing a suitable Lyapunov-Krasovskii functional and based on the scheme of decentralized control, the design of a control law is proposed to ensure the global asymptotic synchronization of state trajectories of two chaotic neural networks of which the structure are the same and the initial conditions are different. In this way the control law obtained is not only easy to be implemented but highly reliable in practice, thus making up for the inadequacy of conventional centralized control. Two illustrative examples are used to demonstrate the effectiveness of the proposed method. References | Related Articles | Metrics

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On-line estimate of biomass concentration in fermentation process Sang, Hai-Feng (1); Wang, Fu-Li (1); He, Da-Kuo (1); Zhang, Da-Peng (1) 2006, 27 (6):  602-605.  DOI: - Abstract ( 284 )   HTML   PDF (248KB) ( 888 )   In a fermentation process several variables, such as biomass concentration are conventionally determined by off-line laboratory analysis, i.e., the process control is unavailable to industrial production in time just because of time delay that often makes the analysis results inefficient. In this respect, however, soft sensing is a good solution. Based individually on neural network and LS-SVM (least square support vector machine), two on-line soft sensing models are designed to estimate the biomass concentration, i.e., the black-box model and hybrid model. The data for model training and verifying are both got from a real experiment process-the fermentation of Nosiheptide which is also used to evaluate the model performance. The results show that the way of soft sensing is good at estimating the biomass concentration, and what's more higher estimating accuracy of hybrid model can be obtained if adding prior knowledge to the model. References | Related Articles | Metrics

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Implementation of an improved hardware for DWT of lifting scheme Zhao, Nan-Nan (1); Sun, Hong-Xing (1); Xu, Xin-He (1) 2006, 27 (6):  606-609.  DOI: - Abstract ( 195 )   HTML   PDF (390KB) ( 523 )   Lifting scheme requires less computation than conventional Mallat's algorithm. A new method called flipping architecture has been proposed recently, which speeds up further the computation for lifting scheme. A recursive architecture is thus designed on the basis of flipping architecture to implement the 2-level 1-D DWT of 9/7 wavelet, which will insert the 2nd-level DWT into the gaps during 1st-level DWT. Furthermore, the coefficient quantization of flipping architecture is also discussed aiming at eliminating multiplication in the whole design process. The experimental results show that the proposed architecture has many merits, such as faster speed, lower power consumption and hardware saving. References | Related Articles | Metrics

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Multiple-feature recognition of microimages Wang, Ya-Jie (1); Li, Dian-Qi (1); Fu, Ping (1); Xu, Xin-He (1) 2006, 27 (6):  610-613.  DOI: - Abstract ( 301 )   HTML   PDF (864KB) ( 727 )   A new way to recognize the microimage of powdered Chinese medical herbs is put forward on multiple-feature basis according to their textural characteristics. It includes three analytic methods, i.e., fractal analysis, wavelet analysis and gray level-gradient joint occurrence matrix. As the foundation on which the images are efficiently recognized, the characteristic vector is formed by combining together the characteristic quantities that are picked out according to different methods as above and how important the rates they play in the classification of images. Using the k-nearest neighbour classification, the experimental results show that the way proposed is feasible and effective and provides a theoretical reference for the quantitative recognition of Chinese medical herbs. References | Related Articles | Metrics

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Space-location of cameras in multiple linear arrays via nonlinear correction Liu, Yan-Mei (1); Xue, Ding-Yu (1); Dong, Zai-Li (2); Xu, Xin-He (1) 2006, 27 (6):  614-617.  DOI: - Abstract ( 232 )   HTML   PDF (216KB) ( 433 )   A new space-location vision system of cameras in multiple linear arrays is developed making full use of their high speed resolution. The space location is determined on the basic principle that some projective planes intersect with each other in non-parallel space and their locations can be solved by geometric projection. Then, a nonlinear correction is proposed by means of neural network for those cameras to enable the PSD after correction to output high-linearity location signal in a broader range. Experimental results showed that the pose measurement system for those cameras can reduce effectively the computational complexity in the space location for stereovision, and that the cameras work well at location accuracy range and sampling speed. References | Related Articles | Metrics

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On the integrated automation in small/medium-scale cement business and its implementation Yu, Hong-Liang (1); Hao, Li-Na (1); Wang, Xiao-Hong (2); Xu, Xin-He (1) 2006, 27 (6):  618-622.  DOI: - Abstract ( 235 )   HTML   PDF (437KB) ( 782 )   Reviewing briefly the status of automation and process flow in China's cement businesses and combining them with the 3-level ERP/MES/PCS integrated automation architecture that is adaptable to normal industries, a 2-level integrated automation architecture is proposed to integrate management with control function for simplification, of which the two levels are named basic process control and operation optimization. Supported by the advantages of IndustrialIT, ERP and MES, the technologies owned by these businesses are integrated systematically with some existing commercial hardwares/softwares and, eventually, a concrete scheme of integrated automation system is proposed to adapt to the characteristics of those small/medium-scale cement businesses. Practical applications have verified its applicability and validity. References | Related Articles | Metrics

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Influence of joint injury on frequency characteristics of the spine Guo, Li-Xin (1); Lin, Tian-Liang (2); Li, Chun-Lei (3) 2006, 27 (6):  623-626.  DOI: - Abstract ( 233 )   HTML   PDF (242KB) ( 564 )   To investigate the biomechanic characteristics of human lumbar spine, a three-dimensional finite element model was developed for the spine segment T12-S1 to describe in details both of external configuration and internal components as well as all kinds of ligaments so as to show the real human spine as exact as possible. The analytical results indicated that the resonant frequency of the vertebra T12-S1 is 7.68 Hz in vertical direction. Both intervertebral denucleation and removal of facets and their capsular ligaments may decrease the resonant frequencies to different degrees, but the influence of the denucleation exerts on the frequencies much greater than that due to the removal. It was shown that the dynamic characteristics of the T12-S1 model comply with the actuality of human spine, so available to the relevant studies. References | Related Articles | Metrics

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Control policy of stock replenishment level for randomly replenished perishable goods Liu, Bao-Zheng (1); Liu, De-Bao (1); Ren, Ping (1); Gao, Li-Qun (1) 2006, 27 (6):  627-630.  DOI: - Abstract ( 209 )   HTML   PDF (171KB) ( 513 )   Generally the problem of multiphase stock replenishment was studied with two assumptions, i.e., take inventory continuously to examine the whole quantity ordered at any time and take inventory cyclically to examine the quantity just ordered discretely. Differing from the two assumptions, the problem is studied further taking the replenishing interval as a continuous random variable in cyclical replenishment. This assumption reflects the real life that supplier usually visits a retailer randomly in a definite interval and the retailer shall replenish his stocks in accordance to the policy to control the replenishment up to a constant level. It is therefore deemed that only part of the unmet demand is backordered and the rest will lose the opportunity for selling. As a result, assuming that all the goods are perishable and their deteriorating rate is constant, a conditional equation of optimal stock level is given to maximize the mathematical expectation value of profit. It provides a reference for how to control actually the replenishment level. References | Related Articles | Metrics

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Robust beamforming algorithm based on minor component analysis technique Wang, Jin-Kuan (1); Tian, Dan (2); Liu, Zhi-Gang (1); Jia, Li-Qin (1) 2006, 27 (6):  631-634.  DOI: - Abstract ( 248 )   HTML   PDF (394KB) ( 709 )   Considering that prior knowledge has errors in practical application, a worst-case performance optimization beamforming algorithm with invariable weight vector length is presented instead of the conventional one that is linearly constrained. Analyzes the mathematical similarity between the neural minor component analysis (MCA) learning rule and beamforming optimization problem. Then, the neural MCA learning rule is used to implement robust adaptive beamforming. Computer simulations show that the proposed algorithm has stronger signal trackability and higher resistance to interference, and it is robuster in the presence of signal steering vector errors in comparison with the linearly constrained beamforming algorithm. References | Related Articles | Metrics

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Procession-competition evolutionary QoS multicast routing algorithm in NGI Wang, Xing-Wei (1); Ren, Wei (1); Yi, Xiu-Shuang (2); Huang, Min (1) 2006, 27 (6):  635-638.  DOI: - Abstract ( 256 )   HTML   PDF (154KB) ( 503 )   A non-NP QoS multicast routing algorithm in NGI (next generation Internet) is proposed. Aiming at the minimized cost, the algorithm is based on the procession-competition evolutionary algorithm to find a multicast routing tree involving the branches to constrain delay, delay jitter, bandwidth, error-rate in association with cost optimization, thus solving integrally the problem to assign routing and wavelength in a single process with network load balancing also taken into account. Simulation results showed that the proposed algorithm is feasible and effective and meets QoS requirements. In addition, it is evidently superior to the conventional QoS multicast routing algorithms based on classical genetic algorithm in cost of multicast routing tree and running time. References | Related Articles | Metrics

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Design and implementation of SNNEOS and its transfer protocol Su, Wei-Ji (1); Zhao, Hai (1); Xu, Ye (1); Zhang, Xin (1) 2006, 27 (6):  639-641.  DOI: - Abstract ( 207 )   HTML   PDF (251KB) ( 421 )   Discussing the particularity and diversity of the task of sensor network nodes, the commonly-used real-time operating system SNNEOS (sensor network node embedded operating system) is explored including its structure, management of kernel interruption and communications subsystems, as well as the implementation mechanism of its transfer protocol. As an event-driven, SNNEOS can avoid CPU round-robin and save power. By the real-time kernel and non-real-time kernel interruption, the real-time task is separated from non-real-time one so as to respond to key real-time tasks punctually. To implement SNNEOS easier and clearer, the communication subsystems are processed in layers and each layer provides an individual process. References | Related Articles | Metrics

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Decoding and monitoring a parallel data communication between computers Cui, Jian-Jiang (1); Deng, Tian-Min (2) 2006, 27 (6):  642-645.  DOI: - Abstract ( 243 )   HTML   PDF (157KB) ( 520 )   The design and implementation of a system to decode and monitor the data of parallel communication between Siemens R30 computers are discussed. By decoding the communication protocols and line orders, with the designing hardware electrocircuits and software designed, a system is implemented to monitor the parallel communication between Siemens R30 computers and send messages to Siemens R30 computers from PCs based on Windows. The hardware electrocircuits are mainly composed of four parts for receiving, photoelectric isolation, CPLD control and single chip control electrocircuit. The software is composed of three modules, i.e., CPLD, single chip and microcomputer module where the alarm message interface (AMI) mechanism is applied to data distribution. This monitoring system has been put into on-line operation in a cold-rolling mill and proved stable and reliable and available to meet R&D needs. References | Related Articles | Metrics

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ECC-based secure routing algorithm for mobile Ad hoc networks Chen, Shu-Yi (1); Wang, Cui-Rong (1); Zhao, Hong (1) 2006, 27 (6):  646-649.  DOI: - Abstract ( 183 )   HTML   PDF (157KB) ( 475 )   The problem of secure routing for MANET (mobile ad hoc network) is studied. Analyzing the advantages and disadvantages of intrusion detection and secure routing policies, an ECC-based secure routing algorithm for MANET is presented and implemented according to the special secure routing requirements of the MANET. The algorithm has obviously the advantages of those of the on-demand and table driven routing policies such as low energy consumption, short delay and high delivery rate etc. The signature and authentication based on ECC are introduced in the process of routing to exclude the malicious nodes from joining the route, which can ensure the security of the route, the integrity of data and non-repudiation. The performance of the algorithm presented is analyzed with NS-2, and the simulative results show its high efficiency. References | Related Articles | Metrics

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On the martensite transformation kinetics of AISI 4340 steel Zhao, Hong-Zhuang (1); Lee, Young-Kook (2); Liu, Xiang-Hua (1); Wang, Guo-Dong (1) 2006, 27 (6):  650-653.  DOI: - Abstract ( 375 )   HTML   PDF (437KB) ( 1079 )   By means of thermal dilatation a AISI 4340 steel was austenitized at some different temperatures in a range from 900 to 1150°C to obtain different austenite grain sizes (AGS), then rapidly cooled to room temperature to obtain martensitic structures. The transmission electron microscopy (TEM) including electron diffraction and microanalysis was used to describe the microstructures. It was found that both AGS and A1N exert a great effect on the martensite transformation kinetics. The larger the AGS, the higher the starting temperature of martensite transformation (tms). Within different austenitizing temperature ranges, there are different kinds of compound precipitates found, affecting the nucleation of martensites. At and below 1000°C, since the particles of AlN play an important role during the martensite transformation, tms increased rapidly. However at and above 1050°C, tms still increases with AGS. This fact may be due to the precipitation of relatively higher dissolution temperature, such as TiC, on the boundary of austenite. References | Related Articles | Metrics

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Influence of submerged nozzle on temperature and flow fields in molten pool during twin-roll strip casting Zhang, Xiao-Ming (1); Zhao, Xiao-Hong (1); Liu, Xiang-Hua (1); Wang, Guo-Dong (1) 2006, 27 (6):  654-657.  DOI: - Abstract ( 280 )   HTML   PDF (520KB) ( 595 )   In a twin-roll strip casting process, the metal flow and temperature distribution in molten pool have a direct influence on the stability of this process and the quality of products. Using a 3D finite element coupling analysis of the temperature and flow fields, a numerical simulation of the twin-roll casting of stainless steel was conducted to investigate mainly the effects of the exit angle and depth of a submerged nozzle in molten pool on the two fields. Simulation result showed that when the exit angle of submerged nozzle is greater than 15°, a double-turbulence is found in the molten pool, which not only changes the metal flow and distribution of solutes, but also affects the temperature field in molten pool. Thus the temperature differences among different positions on the surface of molten pool decrease to improve the surface quality of cast strip. When the submerging depth of nozzle increases the surface temperature at molten pool lowers. While the nozzle is submerged shallowly, the temperature differences among different positions on the surface of molten pool increase to damage the surface quality of strip. The simulation result provides a theoretical reference to the reasonable design of the nozzle during twin-roll strip casting. References | Related Articles | Metrics

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Simulation and analysis of large cross-section bearing steel's TMCP process Li, Sheng-Li (1); Xu, Jian-Zhong (1); Wang, Guo-Dong (1); Liu, Xiang-Hua (1) 2006, 27 (6):  658-661.  DOI: - Abstract ( 281 )   HTML   PDF (543KB) ( 542 )   By using the Gleeble 1500 thermal simulator, the effects of various cooling rates on the microstructure of bearing steel after rolling at 850°C as finishing temperature has been investigated. Combined with large cross-section bearing steel rolling, the ANSYS finite element software was used to model the temperature field at varies cooling rates. It was found that the cooling rate plays an important role in carbide precipitation and the cooling rate after rolling is preferable to be about 3 °C/s to suppress the reticulated carbide precipitation. It also showed that for the large cross-section bearing steel, the bigger the temperature difference between the core and surface of the bar (up to about 450°C), the more difficult the cooling process of core. However, it's possible to control the cooling rate up to 3°C/s so as to suppress efficiently the reticulated carbide precipitation for the round bars (<60 mm) by way of matching properly the cooling intensity and cooling rate. References | Related Articles | Metrics

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Study on magnetic properties and structure of Co66Fe4Mo2 Si16B12 alloy Zhang, Ya-Jing (1); Wang, Zhi (2); Wang, Shu (1); He, Kai-Yuan (1) 2006, 27 (6):  662-664.  DOI: - Abstract ( 231 )   HTML   PDF (142KB) ( 422 )   At different annealing temperatures, the magnetic properties, saturation magnetostriction and Curie temperature of amorphous phase of the Co66Fe4Mo2 Si16B12 alloy were investigated by a ballistic galvanometer, small-angle magnetization tester and core tester. The experimental results showed that the Curie temperature of the residual amorphous phase of the alloy increase with annealing temperature, and the magnetic properties of the alloy become worse after annealed at a temperature higher than 500°, because of the increasing coefficient of saturation magnetostriction. References | Related Articles | Metrics

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Numerical simulation of fluid flow in continuous casting mould for compound roll Feng, Ming-Jie (1); Wang, En-Gang (1); Deng, An-Yuan (1); He, Ji-Cheng (1) 2006, 27 (6):  665-668.  DOI: - Abstract ( 256 )   HTML   PDF (206KB) ( 448 )   The fluid flow of molten steel in the continuous casting mould for compound roll has been simulated numerically using the κ-Ε double equation model of turbulence to discuss the effects of casting speed and pouring angle on the fluid flow. The results showed that the molten steel enters into the mould assembly in three flows of which the two move upward peripherally at the same time to form symmetrically two eddies at the upper part of the mould, while the other one moves downward peripherally and, eventually, goes out of the mould at the speed about the same. And the eddy center moves downward with increasing casting speed. At the same casting speed, the eddy center is the lowest if the pouring angle is about 60° and the penetrating depth of molten steel flow increases with the increasing pouring angle. The scouring velocity of the molten steel against roll core is the highest and lower when the pouring angle is 15° and 90°, respectively. References | Related Articles | Metrics

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Microstructural evolution of semi-solid ZL201 alloy during reheating Lu, Gui-Min (1); Shi, Li-Feng (1); Wang, Ping (1); Cui, Jian-Zhong (1) 2006, 27 (6):  669-672.  DOI: - Abstract ( 264 )   HTML   PDF (818KB) ( 462 )   The semi-solid ZL201 alloys cast with near-liquidus casting technology were reheated, and its microstructural evolution and α-grain growth mechanism were studied by means of theoretical calculation and actual observation. The results indicated that the microstructural evolution of the α-grain formation consists of three stages, i.e., eutectic structure melting, grain spheroidizing and theoretical liquid-solid equilibrium. The α-grains grow in form of coalescence in the first two stages in accordance to Ostwald model in the third stage. In addition, the microstructure evolves faster with increasing reheating temperature,and the spheroidization of α-grain depends on the isothermal holding time. It implies that the homogeneous, fine and near-spherical microstructure can be obtained via thixoforming at relatively higher reheating temperature within shorter holding time. References | Related Articles | Metrics

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Effects of different ions on morphology of ZnO crystals Zhang, Yan-Hui (1); Tian, Yan-Wen (1); Shao, Zhong-Cai (2); Li, Hui-Li (1) 2006, 27 (6):  673-676.  DOI: - Abstract ( 456 )   HTML   PDF (1124KB) ( 1079 )   Different Zn salts including Zn(CH3COO)2·2H2O, ZnCl2, Zn(NO3)2·6H2O and ZnSO4·7H2O and different alkalies including NaOH and KOH were used as raw materials to produce the precursory solution Zn(OH)42-, and ZnO crystals were synthesized when Zn(OH)42- decomposed in hydrothermal environment. The phase identification, morphology and size of the products were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The anions of CH3COO-, SO42-, NO3- and Cl- in the solution formed individually interfering ion pairs with Na+ at 170°C. The morphologies of ZnO crystals obtained along with their growth for 12 h are flake/ball-like aggregates, bloomy with obvious of unobvious polarity growth and small-size bloomy. In addition, the ion pairs formed individually by Na+, K+ and CH3COO- at 140°C interfered the crystal growing and, after reacting for 12 h, they were prepared into flaky and needle-like ZnO nanocrystals. It could be known from the analysis of SEM images that different interfering ions in the solution have great effects on the morphologies of ZnO crystals. And the interference mechanism of the interfering ions was analyzed simply. References | Related Articles | Metrics

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Sensitivity analysis of influencing parameters on fatigue life of aeroengine compressor disk Qian, Wen-Xue (1); Yin, Xiao-Wei (1); He, Xue-Hong (1); Xie, Li-Yang (1) 2006, 27 (6):  677-680.  DOI: - Abstract ( 294 )   HTML   PDF (1220KB) ( 528 )   The material parameters and stress level have important influence on the fatigue life of aeroengine compressor disk. A detailed calculation was done to determine the sensitivities of fatigue life to related parameters with relevant fatigue life-sensitivity curves given. It was found that the sensitivities to fatigue strength parameters and stress are greater than that to plastic fatigue parameters, among which the sensitivity to fatigue strength exponent is up to 10 as the greatest one. The sensitivity to fatigue ductility coefficient is less than 1, and therefore can be taken as a constant approximately in practical design during which the material, structure and process technology of the disk can all be determined reasonably according to different parameter sensitivities. A reference is thus provided further for the design of reliability and optimization. References | Related Articles | Metrics

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On the SolidWorks-based virtual design integrated hydraulic manifold blocks Li, Wei-Min (1); Xie, Li-Yang (1) 2006, 27 (6):  681-684.  DOI: - Abstract ( 255 )   HTML   PDF (267KB) ( 792 )   Taking the virtual technology as core, the software SolidWorks is redeveloped via Visual BASIC to implement the virtual design of integrated hydraulic manifold blocks, thus solving the laborious, time-consuming and error-prone problem to design the orifice network. The system architecture given, the ways to digitize the hydraulic function diagram and design/check the integrated blocks are proposed. By setting up a characteristic library, a SolidWorks-based 3D parameterized modeling is implemented using ActiveX Automation technique. Then, the virtual design approach is applied to forming a mode for such a design and a scheme to provide relevant environment so as to adapt to the characteristics of integrated hydraulic manifold blocks and CAD requirements. Moreover, the ways to solve the problems in virtual design are presented including interferometric check during assembling the blocks to make the design more successful. References | Related Articles | Metrics

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Computation of lubricant temperature at outlet of accessory gearbox Sun, Zhi-Li (1); Yan, Ming (1); Yang, Qiang (1); Li, Guo-Quan (2) 2006, 27 (6):  685-688.  DOI: - Abstract ( 419 )   HTML   PDF (875KB) ( 606 )   The lubricant temperature at the outlet of acceasory gearbox is an important parameter required in designing many kinds of aeroengine components. The temperature and its field distribution and the heat dissipation through gearbox case are conditional on each other in computation, thus making the computation much more difficult. A theoretical computation model is deduced, and the process to compute the heat dissipation by a finite element software is studied. In addition, an iterative method is introduced to solve the problem of the temperature field that is unknown. Then, the temperature field distribution of the accessory gearbox and the temperature at its outlet are both given. It is proved that the computed results comply with the safety-oriented empirical valves. The software we developed on the basis of the result database of ANSYS to compute the heat dissipation is available to the heat dissipation of complicated shapes and boundary conditions as well as that of anisotropic thermal conductors. The error computed by the program is less than 1 % in comparison with theoretical calculation. References | Related Articles | Metrics

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Self-adapting chaos-genetic hybrid algorithm and sensitivity analysis of its parameters Chen, Bing-Rui (1); Yang, Cheng-Xiang (1); Feng, Xia-Ting (1); Wang, Wen-Jie (1) 2006, 27 (6):  689-693.  DOI: - Abstract ( 270 )   HTML   PDF (127KB) ( 1253 )   Chaos optimization is good at searching local solutions and sensitive to initial value. A self-adapting chaos-genetic hybrid algorithm (SA-CGA) is thus proposed to combine the chaos optimization with TGA (typical genetic algorithm) together. Differing from other conventional chaos-genetic hybrid algorithms, in the algorithm proposed a chaos operator is introduced in the evolution process according to the measure of species diversity and an excellent solvability domain is given in global search space by means of random probability. Then, as a whole, two domains are chaotically disturbed, i.e., searching in the excellent solvability domain in detail together with disturbing greatly the global solvability domain. Numerical simulation shows that the algorithm not only accelerates the convergence rate but improves its accuracy, thus solving the premature problem frequently found in TGA. References | Related Articles | Metrics

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Preparation of magnesium hydroxide from magnesite Jiang, Yu-Zhi (1); Han, Yue-Xin (1); Yin, Wan-Zhong (1); Bai, Li-Mei (1) 2006, 27 (6):  694-697.  DOI: - Abstract ( 598 )   HTML   PDF (591KB) ( 1477 )   Taking the magnesite as raw material, a process was developed to prepare magnesium hydroxide under atmospheric pressure. Optimum calcining conditions were determined through calcination tests at 600°C for 9hr, under which the magnesite can be fully decomposed with high chemical activity of the product magnesium oxide. When calcining at 700-750°C for 2-4 hr, the decomposition rate of magnesite can be maximized but the activity of magnesium oxide decreases somewhat. Then, taking the powdered magnesium oxide as raw material, the suitable synthesizing process was investigated for the preparation of magnesium hydroxide at normal temperature. The results showed that the powdered magnesium hydroxide with high filterability and purity and regular flaky hexagion crystal can be prepared via a hydro-thermal aging treatment at 80°C for 30 min done to the floccular magnesium hydroxide precipitate quickly synthesized. A conclusion is thus drawn that the hydro-thermal aging reaction is of importance to the preparation of magnesium hydroxide with regular crystal morphology. References | Related Articles | Metrics

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New approach to clustering multi-index linguistic assessment information Yu, Chun-Hai (1); Fan, Zhi-Ping (1); Sun, Xin-Bo (1) 2006, 27 (6):  698-701.  DOI: - Abstract ( 307 )   HTML   PDF (159KB) ( 788 )   With respect to a kind of clustering problem of which both the value of characteristic index and weight of index are of linguistic assessment information, a new approach is presented for cluster analysis. Defining such problems and by virtue of the conventional fuzzy cluster analysis via digital information networking. All the abbreviations are converted then expressed into triangular fuzzy numbers to give the computational steps so as to solve the clustering problems of multi-index linguistic assessment information. A numerical example is given to illustrate the new approach to cluster analysis, which is available to widen the applications of networking cluster analysis to multi-index linguistic assessment information. References | Related Articles | Metrics

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Wavelet neural network estimation model for mine safety Guo, Ya-Jun (1); Zhang, Shi-Chang (1) 2006, 27 (6):  702-705.  DOI: - Abstract ( 203 )   HTML   PDF (932KB) ( 511 )   Multiple procedures/sections, complex operation process, abrupt time/space change and severe working conditions feature are in the production of a coal mine. So, its safety system is typically a nonlinear one, and the safety estimation of a coal mine is inevitably of more and more importance nowadays in China. A safety estimation model is therefore developed via wavelet neural network, where the primary function of wavelet, which is based on retract and translation factors, is introduced instead of sigmoid transfer function, etc., with 23 indices picked out as input nodes. The model is able to make certain of network parameters automatically, thus avoiding the trouble in which the artificial intervention is needed to modify the structural parameters of network if using conventional neural network. It is exemplified that the mean absolute error of the estimation results via WNN network as proposed is 0.425%, while that via BP network is up to 3.1%. It means that the generalizability of WNN is much better than that of BP. So, the model is highly applicable. References | Related Articles | Metrics

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Performance evaluation of supply chain collaboration and its applications Zhang, Cui-Hua (1); Zhou, Hong (1); Zhao, Miao (1); Chang, Guang-Shu (2) 2006, 27 (6):  706-708.  DOI: - Abstract ( 325 )   HTML   PDF (154KB) ( 1317 )   Referring to some earlier works on supply chain collaboration and performance evaluation, an evaluation index system is set up including 23 indices for collaboration performance with the information flow, business flow and fund flow in supply chain taken into account in combination with the service to clients and system adaptability. Then, a food corporation is exemplified to evaluate its collaboration performance of supply chain by use of fuzzily integrated analysis, thus quantifying the system. Analyzing the evaluation results, it is found that the collaborative operation covering information flow, business flow, fund flow, service to clients and system adaptability will improve the performance of the whole supply chain. The analysis proves the feasibility of the evaluation index system and the operability of fuzzily integrated evaluation. Discusses how to improve further the performance evaluation of supply chain collaboration. References | Related Articles | Metrics