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15 July 2003, Volume 24 Issue 7 Previous Issue    Next Issue
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Decentralized variable structure control for uncertain interconnected systems Li, Hua (1); Liu, Xiao-Zhi (1); Jing, Yuan-Wei (1); Zhang, Si-Ying (1) 2003, 24 (7):  613-615.  DOI: - Abstract ( 198 )   HTML   PDF (136KB) ( 552 )   The design of a decentralized variable structure controller for interconnected systems was investigated. Based on variable structure-control (VSC) theory and by exploiting the structure of interconnected systems, a concise approach of decentralized VSC was presented. The design of decentralized variable structure controller required the uncertainties of the systems were bounded, but the interconnected item and the uncertain interconnected item was not required to be matched. The designed controllers guaranteeing the closed-loop systems are global asymptotically stable. The design approach is simple. References | Related Articles | Metrics

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Guaranteed cost reliable control with actuator failures Wang, Fu-Zhong (1); Yao, Bo (2); Zhang, Si-Ying (1) 2003, 24 (7):  616-619.  DOI: - Abstract ( 243 )   HTML   PDF (244KB) ( 667 )   The reliable design of guaranteed cost for linear systems with actuator failures was concerned. A practical and general model of actuator failures was given. On the basis of considered influence of actuator failures, a sufficient condition of asymptotic stability with guaranteed cost control was presented. A dynamic feedback controller was designed by applying algebra Ricatti equation. Furthermore, when the actuators failures do not occur, the system is asymptotic stability and the performance index is good, when the actuator failures occur, the system is still asymptotic stability. A simulation example is given to illustrate the effectiveness of the result. References | Related Articles | Metrics

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Robust multiple actuators fault diagnosis for stochastic linear systems Jia, Ming-Xing (1); Wang, Fu-Li (1) 2003, 24 (7):  620-623.  DOI: - Abstract ( 232 )   HTML   PDF (189KB) ( 502 )   A new fault diagnosis method for stochastic linear control system was presented. When actuator fault occurs, the faults are translated into unknown inputs of the system through mathematic transforms. The actuator fault diagnosis can be realized through using unknown input kalman filter technique. Diagnosis algorithm gives the estimated values of the faults. In order to obtain the accurate values of the faults, the wavelet transform method was adopted. Multi-actuator faults that occur simultaneously or successively can be diagnosed effectively through the organic combination of the two methods. The fault diagnosis system can detect faults in good time and evaluate fault values accurately. References | Related Articles | Metrics

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Output-based benchmarking method for performance improvement in supply chain distribution Yin, Mei-Ying (1); Wang, Meng-Guang (1); Liu, Shi-Xin (1) 2003, 24 (7):  624-626.  DOI: - Abstract ( 221 )   HTML   PDF (101KB) ( 716 )   The method of selecting target enterprises and the learning route in benchmarking method was summarized. The output-based benchmarking means of performance measurement and improvement was studied, and some concepts such as output-specific increase were proposed. The data envelopment analysis (DEA) C2GS2 model was extended to confirm the specific output increase. In the model, all the evaluated enterprises were regarded as the decision making units (DMUs) with the same inputs and outputs. The smallest output-specific increase is the shortest approach to improve performance for inefficient enterprises. The corresponding goal is the best benchmark for the learning enterprises. The approach is easy to operate in supply chain management practice. In supply chain distribution phase, some enterprises could improve their operational performance by increasing outputs and remaining the inputs level. References | Related Articles | Metrics

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Genetic algorithm approach to optimal adaptive noise cancellation for multi-sensory signals Lun, Shu-Xian (1); Feng, Jian (1); Zhang, Hua-Guang (1); Wang, Zhan-Shan (1) 2003, 24 (7):  627-630.  DOI: - Abstract ( 202 )   HTML   PDF (127KB) ( 791 )   A fast adaptive algorithm for noise cancellation using multi-sensory signal recordings of the same noise source was described. In order to avoid the trap of local minima, a design method based on the genetic algorithm was introduced to treat the nonlinear optimization of the fixed-order optimal adaptive noise cancellation. The designed method utilized genetic algorithm to adjust the weights of linear combiner(LC) of multi-sensor signals adaptively and reduced the large estimated error of the averaging method of all sensor signals. The design method can obtain simplicity of implementation, conservation of operation time and better reconstruction performance by fully utilizing multi-sensor signals. References | Related Articles | Metrics

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Based on observer H∞ reliable controller design for descriptor systems Chen, Yue-Peng (1); Zhang, Qing-Ling (1); Zhai, Ding (1); Xu, Tian-Qun (2) 2003, 24 (7):  631-634.  DOI: - Abstract ( 229 )   HTML   PDF (165KB) ( 766 )   Using sensor failure models, the design problem of H∞ reliable controller for descriptor systems were studied. Firstly, common models of sensor failure of descriptor systems were constructed. In terms of these models, controllers based on observer were designed. Secondly, the definition of H∞ reliable controllers for descriptor systems was given. Thirdly, a sufficient condition that there exist H∞ reliable controllers was obtained when all sensors were operational in order as well as when some sensors failures happen. The sufficient condition is expressed by two generalized algebraic Riccati inequalities (GARI) with generalized constraints. These H∞ reliable controllers can make that closed-loop descriptor systems were admissible and H∞ performance. Meanwhile, these generalized constrains can be canceled by restricted system equivalent transformation for the descriptor systems such that these GAR1 with generalized constrains can be reduced. Therefore. these controllers can be designed by solving reduced two GARI. Finally, a numerical example is given to illustrate the design procedures and their effectiveness. References | Related Articles | Metrics

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Hybrid electric vehicle based on intelligent hierarchical structure control strategy Wang, Da-Zhi (1); Wang, Jian-Hui (1); Gu, Shu-Sheng (1) 2003, 24 (7):  635-638.  DOI: - Abstract ( 211 )   HTML   PDF (178KB) ( 551 )   A plan of a class of multiple models system was put forward, in which there is a kind of intelligent hierarchical supervisory control system(IHSC) that is a supervisor to control the engine subsystems of the multiple energy source assembly control system of the hybrid electric vehicle(HEV). A probability neural network(PNN) made the organizing level of IHSC, which equals to the identification system of HEV processes and indicates the working procedure of HEV, the hidden level function was made of Parzen window kernel function, the identification result depended on the biggest probability value of the output level of PNN. A fuzzy decision-maker, which belongs to the multiple attributes decision and optimizes the working rate between the motor system and engine system according to the results of the organizing level of IHSC, made the coordination level of IHSC. A simulation study of the multiple energy source assembly control system of HEV was given to verify its feasibility. References | Related Articles | Metrics

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Simulation supporting system of cold rolling process control system based on modelbase Liu, Xing-Gang (1); Yuan, Feng-Hua (1); Xu, Xin-He (1) 2003, 24 (7):  639-642.  DOI: - Abstract ( 264 )   HTML   PDF (220KB) ( 729 )   To meet the requirement of simplifying and improving simulation process of special industrial fields, a simulation supporting system was designed based on special modelbase. The design idea of supporting system framework was proposed by adopted reusing model technology. With the background of cold rolling process control system, the extract principle of standard simulation flow, the construction method of special field modelbase, and the mechanism of simulation support system were discussed. An application example was provided to prove the feasibility and practicability of the framework of supporting system presented in this paper. References | Related Articles | Metrics

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Web-based management model of embedded system Wang, Jin-Dong (1); Han, Guang-Jie (1); Wang, Ji-Yong (1); Zhao, Hai (1) 2003, 24 (7):  643-646.  DOI: - Abstract ( 266 )   HTML   PDF (200KB) ( 646 )   A Web-based device management model was presented based on embedded Internet technology and Web management technology for embedded system with limited computing resource. It resolved the proprietary, complexity, user-friendly and networked issues of traditional management models. It was integrated with three technologies: well-known Web Browser-Server technology as its framework, SNMP Manager-Agent technology as its management mode, and Java technology for its cross-platform. It provided a user-friendly, cross platform, open and ubiquitous method to monitor embedded system for administrators anywhere and anytime. The components of managing system and managed system were designed respectively. References | Related Articles | Metrics

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Sub-path protection algorithms in WDM grooming networks He, Rong-Xi (1); Wang, Guang-Xing (1) 2003, 24 (7):  647-650.  DOI: - Abstract ( 252 )   HTML   PDF (170KB) ( 712 )   The problem of dynamically establishing dependable connections in wavelength division multiplexing (WPM) mesh networks with traffic grooming capabilities was investigated. A disjoint routing scheme under shared risk link groups (SRLG) constraints was proposed. It was called multi-granularity shared sub-path protection (MSSP) scheme. The scheme searches a primary path for each connection request firstly, and then segments the path into several equal length sub-paths, and calculates their SRLG-disjoint backup paths. In order to obtain the optimal spare capacity, MSSP makes use of the backup multiplexing technology to share backup bandwidth among different backup paths if their corresponding primary sub-paths are SRLG-disjoint. Based on dynamic traffic with different load, the performance of MSSP was investigated via simulations. MSSP can improve the performance of the network significantly and make the tradeoffs between the resource utilization and recovery times. References | Related Articles | Metrics

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Management architecture of integrated satellite information network and algorithm of cluster generation Wen, Ying-You (1); Jiang, Yue-Qiu (1); Zhao, Jian-Li (1); Wang, Guang-Xing (1) 2003, 24 (7):  651-654.  DOI: - Abstract ( 257 )   HTML   PDF (933KB) ( 683 )   Due to the peculiar composition and dynamic structure of integrated satellite information network, a new dynamic-layered management architecture was proposed. The architecture includes both management of single star and that of satellite cluster. By adopting this kind of architecture, the influence of high-delay on satellite network management was deduced at the most. The expansibility and robust of whole system was strengthened. An efficient network management was achieved. As to the cluster of satellite, a clustering algorithm based on ability, running actor and delay-jade was proposed. The delay of network management and the overload of network management were decreased by this algorithm. References | Related Articles | Metrics

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Nonlinear algorithm for fractal image compression coding Zhao, De-Ping (1); Wang, Guang-Xing (1) 2003, 24 (7):  655-657.  DOI: - Abstract ( 226 )   HTML   PDF (152KB) ( 877 )   A classical fractal compression dictionary is relatively small. A simple and nonlinear disk algorithm was designed to overcome this defect. It simplifies the disk algorithm by Popeseu etc. A computation formula of the gray value of integral pixel point was given according to the nonlinear disk algorithm. It can quickly compute gray value of integral pixel point in the image. The new fractal disk algorithm is simple, has better compression results, and generates high-quality rebuilding image. It also has better PSNR than the conventional fractal image compression coding. References | Related Articles | Metrics

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Voxel-based surface shading of three-dimensional medical objects Zou, Hao (1); Chen, Li-Hua (2); Liu, Ji-Ren (1) 2003, 24 (7):  658-661.  DOI: - Abstract ( 388 )   HTML   PDF (202KB) ( 2002 )   In many medical imaging modalities, such as CT, MRI or PET, a 3D anatomy is usually represented by a set of planar images. For its 3D visualization, a voxel model with a ray casting algorithm was introduced. Unlike the triangle method, this algorithm does not require a detection of the boundary of the 3D object beforehand, but derives the surface image directly from the object. The algorithm includes the capability of performing ray castings for different screen pixels concurrently. The concurrent capability facilitates hardware implementation to speed up the surface rendering. The function was given to rotate and to zoom the 3D object in object coordinates and show the result in screen coordinates. Some examples of the depth shading, Gouraud shading, the combination of the depth shading and Gouraud shading, 2D image map to 3D image were shown by using simple threshold segmentation. References | Related Articles | Metrics

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Proxy-based IP traceback system Wang, Cui-Rong (1); Gao, Yuan (1) 2003, 24 (7):  662-665.  DOI: - Abstract ( 278 )   HTML   PDF (235KB) ( 1140 )   A new technique was presented to trace spoofed packets back to their actual source host without relying on the cooperation of intervening ISPs. An agent-based distributed architecture for tracing suspicious IP packets was outlined. An agent server was designed to record packet digests, and a security control server was designed to traceback the originator of a spoofing IP packet. The arithmetic forwarding IP packet in Unix OS was expanded. The packet digest arithmetic and the agent-based automatic tracing system were realized. The methods for identifying suspicious packets and recording packet digest were tested through the simulation experiments. The agent-based method of tracing IP packet is feasible. References | Related Articles | Metrics

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Effect of filtration on mechanical properties of cobalt-base superalloy K640S Wang, Tie-Li (1); Yang, Hong-Cai (1); Ge, Wen (2); Guo, Jian-Ting (3) 2003, 24 (7):  670-672.  DOI: - Abstract ( 275 )   HTML   PDF (570KB) ( 553 )   Effect of filtration on composition, microstructure and mechanical properties of cobalt-base superalloy K640S was investigated. The results show that the filtration treatment can effectively decrease the content of O and N elements and increase creep life of the recycled superalloy K640S remarkably at the condition of 815°C , 205 MPa. But, the filtration treatment has no influence on the tensile property of the superalloy. The microstructure of the virgin superalloy K640S and the filtration treated recycle alloy consist of the same skeleton-like carbides in form of M23C6 and the flake-like carbides in form of M7C3 distributed among the dendrites and at grain boundary in r matrix. From the present data, it is suggested that superalloy K640S can still offer payoffs as a structural material in gas turbine application after filtration recycle. References | Related Articles | Metrics

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Aluminum titanate-mullite matrix composite reinforced by electroless Ni and Cu plated carbon fiber Mu, Bai-Chun (1); Sun, Xu-Dong (1); Chen, Yang (1) 2003, 24 (7):  673-676.  DOI: - Abstract ( 370 )   HTML   PDF (861KB) ( 641 )   The aluminum titanate-mullite matrix composites reinforced by surface modified carbon fibers were processed. The carbon fiber was coated with Ni, Cu and Cu + Ni by electroless plating process. The effects of content of various carbon fibers on bending strength, fracture toughness, dimensional shrinkage and porosity of the composite were studied. The results indicate that the surface modified carbon fibers particularly plated by the Cu + Ni can improve the properties of the composites remarkably. The bending strength and fracture toughness of the composites are 2.8 and 2.74 times as high as those of the matrix ceramic respectively and the dimensional shrinkage and porosity of the composites keep nearly the same as the matrix ceramic. References | Related Articles | Metrics

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Influence of complex electromagnetic stirring on the inner quality of continuous casting steel bloom Li, Chun-Long (1); Jiang, Mao-Fa (1); Wang, Bao-Feng (2) 2003, 24 (7):  677-680.  DOI: - Abstract ( 241 )   HTML   PDF (232KB) ( 1314 )   Based on the site experiments of complex electromagnetic stirring in Baogang steel bloom caster, the processing was designed and the subsequent element segregation were examined. The results showed that problems of inner porosity and composition segregation can be solved with the complex electromagnetic stirring technique. The ratio and index of central segregation and porosity can be reduced significantly. Therefore, casting processing, optimum mold and electromagnetic technique are very important to improve the inner quality of continuous casting bloom. References | Related Articles | Metrics

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Synthesis of calcium hydroaluminate of hexagonal structure and its desilication Liu, Lian-Li (1); Zhai, Yu-Chun (1); Tian, Yan-Wen (1); Liu, Yu-Jing (2) 2003, 24 (7):  681-684.  DOI: - Abstract ( 546 )   HTML   PDF (1077KB) ( 1065 )   Synthesis of calcium hydroaluminate of hexagonal structure was reported. The property of calcium hydroaluminate was examined by analysis of chemistry, XRD and TG-DTA. The experimental results showed that the synthetical sample comprise a little calcium hydroaluminate of cubic structure and calcium hydroxide besides calcium hydroaluminate of hexagonal structure. The content of SiO2 decreased to 0.009 g/L and the silicon capacity index reached 11111 by adding calcium hydroaluminate of hexagonal structure at 90°C after two hours. The desilication mechanism of calcium hydroaluminate of hexagonal structure was discussed. It was regarded that calcium hydroaluminate of hexagonal structure was a high-hydration, high-decentralization and loosen calcic compound. Its interval of layers was wide. Since the desilication reaction processed in the interval, the efficiency of desilication was high. References | Related Articles | Metrics

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DC submerged-arc furnace with twin electrodes for the fused magnesia production Qin, Qin (1); Yue, Qiang (1); Gu, Gen-Hua (1); Guo, Mao-Xian (1) 2003, 24 (7):  685-688.  DOI: - Abstract ( 636 )   HTML   PDF (298KB) ( 1748 )   A new type DC submerged-arc furnace with twin electrodes and oblate stack is introduced. The running characteristics are examined and the energy index of this furnace as well as the quality of MgO are investigated by comparing with AC submerged arc furnace performance. The results show that the main advantages of this furnace which use DC power and twin electrodes on current line are lower flicker effect, lower noise and steady operation state. The electric energy consumption of the DC furnace decreases and the electrode consumption is reduced by 50%. In addition, the oblate stack of the DC furnace is favorable MgO crystallization and the MgO yield with purity over 98% increase by 15%. References | Related Articles | Metrics

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Elimination of nocuous elements in waste Zn-Mn dry battery Wei, Guo (1); Zhang, Li-Hua (1); Zhao, Deng-Bao (1); Shen, Feng-Man (1) 2003, 24 (7):  689-691.  DOI: - Abstract ( 256 )   HTML   PDF (150KB) ( 615 )   The pyrogenic process and wet process were used to eliminate the nocuous elements such as Cl, Zn which have negative effect on blast furnace operation in battery recycle. Results show that in the range of experiment, pyrogenic process can eliminate most of Cl but take no effect on Zn. Higher removal efficiency can be got at higher temperature and Cl was removed by 37% at 615 K. The removal effect of wet process is better than the pyrogenic process. The wet process can remove Cl by 85% and Zn by 30% in 15 min at 318 K. In the wet process, temperature and time have little effect on the results so it is convenient for industry application. Dry batteries treated by the wet process can meet the request standard of blast furnace operation so that they can be used as additives for pulverized coal injection. References | Related Articles | Metrics

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Simulation and calculation method of the length of transition segment of pipe belt conveyor Song, Wei-Gang (1); Zhang, Guo-Wei (1); Deng, Yong-Sheng (1) 2003, 24 (7):  692-695.  DOI: - Abstract ( 310 )   HTML   PDF (776KB) ( 724 )   A curve equation and a logical calculation method of the pipe-belt conveyor transition segment and the simulation figure were given according to the existent shaping theory in that the sections of the pipe-belt conveyor transition segment must be a circle. A non-linear numerical arithmetic was adopted. The calculation result of the transition segment can meet the conditions of the belt tension and metamorphose harmony equation. This arithmetic can get more accurate design length than other methods. The calculation result table was given, and the table may help to design the length of the head and the tail of the transition segment. References | Related Articles | Metrics

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Effects of rock mechanical characteristics on the rock blasting Dai, Chang-Bing (1); Chen, Li-Qun (2); Song, Shou-Zhi (1) 2003, 24 (7):  696-698.  DOI: - Abstract ( 309 )   HTML   PDF (126KB) ( 1105 )   Through analyzing mechanism of rock blasting, the rock blasting reason can be concluded that the action force of rock blasting generated is bigger than rock strength. The relationship of rock physical mechanical characteristics and rock blasting were examined. The influence of rock strength, density and porosity of rock blasting were demonstrated. It is found that the tensile strength of rock plays a key role in rock blasting and that the smaller rock porosity and the bigger rock density are favorable to rock blasting. The influence of water on rock blasting was investigated and it is shown that water medium is favorable to rock blasting. References | Related Articles | Metrics

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Experimental physical simulation of mineral moving Wang, Shu-Hong (1); Ren, Feng-Yu (1); Wei, Yong-Jun (2); Li, Wen-Zeng (1) 2003, 24 (7):  699-702.  DOI: - Abstract ( 303 )   HTML   PDF (191KB) ( 1079 )   According to the mechanical characters of mineral, stochastic theory was used to set up a physical model about mineral moving. The mineral moving parameters without any boundary condition restrict and with the side port moving were measured. The shape of blasted ore-rock moving(drawn body) was researched. The results show that it is better to optimize the shape of ore-rock mass according to the structure parameter of the stope. The physical simulation can effectively reduce the ore dissipation and the ore dilution. The structure parameters of the stope disagreeing with the rule of broken ore-rock movement are the main factors of ore lose. Based on the simulation result in-spot, a new caving method without bottom pillar was used. It is shown that the ore lose was reduced effectively, the mineral resource was recovered and economic overall return was encouraging and satisfactory. References | Related Articles | Metrics

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- - 2003, 24 (7):  703-706.  DOI: - Abstract ( 797 )   HTML   PDF (294KB) ( 1731 )   - References | Related Articles | Metrics

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- - 2003, 24 (7):  707-709.  DOI: - Abstract ( 204 )   HTML   PDF (221KB) ( 801 )   - References | Related Articles | Metrics

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- - 2003, 24 (7):  710-713.  DOI: - Abstract ( 189 )   HTML   PDF (162KB) ( 708 )   - References | Related Articles | Metrics