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15 March 2004, Volume 25 Issue 3 Previous Issue    Next Issue
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Dynamic analysis of a class of generalized Hopfield neural networks with hysteresis Ji, Ce (1); Zhang, Hua-Guang (1) 2004, 25 (3):  205-208.  DOI: - Abstract ( 201 )   HTML   PDF (163KB) ( 629 )   The dynamic behaviour of a class of generalized Hopfield neural networks with hysteresis is investigated. Relaxing the restriction that an interconnecting structure must be symmetrical in Hopfield neural networks, the stability of a class of the generalized Hopfield neural network models with hysteresis and asymmetric interconnecting structure is considered. The sufficient condition of the asymptotic stability of equilibrium point is given by way of constructing suitable Lyapunov functional and sectorial conditions. In the process of design and implementation of Hopfield neural networks, the condition is very applicable. The simulation results have proved further the effectiveness of the conclusion. References | Related Articles | Metrics

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Robust fault-tolerant control for a class of uncertain switched nonlinear systems Zhao, Jun (1); Jin, Gang (1) 2004, 25 (3):  209-211.  DOI: - Abstract ( 268 )   HTML   PDF (218KB) ( 673 )   The problem of robust fault-tolerant control for a class of switched nonlinear systems with structural parameters uncertainty and unknown nonlinear disturbance is studied. The purpose is to design individual state feedback controller by means of common Lyapunov function to guarantee globally asymptotic stability under arbitrary switching. In the case of actuator failures, a pre-specified failure set of actuators is introduced and the closed-loop systems are shown to be globally asymptotically stable for all possible actuator failures. Finally, an illustrative example is used to demonstrate the feasibility of the proposed approach to design. References | Related Articles | Metrics

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Model reduction based on balanced realization for discrete-time singular systems Wang, Jing (1); Zhang, Qing-Ling (1); Liu, Wan-Quan (2) 2004, 25 (3):  212-215.  DOI: - Abstract ( 264 )   HTML   PDF (1131KB) ( 645 )   A model reduction for discrete-time singular systems especially the non-casual subsystems was investigated. A system transformation should be done first for the original system to enable the reduction problem to become merely as a simplification of the non-casual subsystems, thus getting a true model reduction of singular systems, i.e., retaining all the original non-casual attributes. Then, the controllability and observability were analyzed and they were weighed up in their corresponding states using the magnitude of Hankel singular values. The results showed that both the controllability and observability in the state corresponding to the smaller Hankel singular values were weakened. Based on it, a new reduction criteria was put forward with a new model reduction algorithm given. A numerical simulation illustrated the effectiveness of the proposed algorithm. References | Related Articles | Metrics

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Approach to extracting footprint edge using 2D threshold vectors Yang, Shu (1); Shi, Li-Min (2); Wang, Cai-Rong (3); Gao, Li-Qun (1) 2004, 25 (3):  216-219.  DOI: - Abstract ( 232 )   HTML   PDF (220KB) ( 734 )   The geometrical feature of the edge of human footprint contains lots of human body information, but it is of great significance to extract exactly the edge of footprint. According to the characteristics of footprint image, an approach for extracting footprint edge is presented on the basis of the segmentation of the image area of 2-dimensional gray level-gradient threshold vector. The 2-dimensional threshold vectors can be computed automatically, based on the gray level-gradient cooccurrent matrix model and maximum entropy theory. This method can segment the images by using auto-developed 2-dimensional gray level-gradient threshold vectors, and acquire high anti-noise capacity and high accuracy of segmentation of the fuzzy edge pixies as well. To extract and smooth the footprint edge, 2 structural operators are set up to adopt to the feature of footprint images, with the segmented images computed through a morphologic method. The satisfactory test results show that the footprint edges extracted in this way are of high similarity to original ones with noise suppressed. References | Related Articles | Metrics

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Heterogeneity in web services composition Shen, De-Rong (1); Yu, Ge (1); Zhang, Rong (1) 2004, 25 (3):  220-222.  DOI: - Abstract ( 240 )   HTML   PDF (863KB) ( 729 )   Analyzing the process of publishing, discovering and invoking of Web services, the heterogeneities found in Web services composition are divided into 3 forms, i.e., semantic equivalent Web services profile description heterogeneity that limits the proper discovery of Web services, semantic equivalent Web services operation heterogeneity that limits the dynamic replacement of Web services and the data flow heterogeneity among sequential Web services in a composite Web service. Various heterogeneity conflicts in Web services composition are discussed briefly, and they fall into 6 conflicts, i.e., semantic conflict, data type conflict, structure type conflict, parameter number conflict, data unit conflict and data precision conflict. 6 transformation rules relevant to the 6 conflicts above mentioned are thus defined in details to settle various conflicts named Term2Term, Type2Type, Stru2Stru, Num2Num, Unit2Unit and Prec2Prec respectively. They are implemented on prototype-e-Scope4WS and verified that they are feasible. References | Related Articles | Metrics

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Intelligent network model based on information fusion theory for on-line fault diagnosis Wei, Shou-Zhi (1); Zhao, Hai (1); Wang, Gang (1); Zhang, Xiao-Dan (1) 2004, 25 (3):  223-226.  DOI: - Abstract ( 293 )   HTML   PDF (300KB) ( 832 )   In order to solve effectively the issues of on-line fault diagnosis for complex equipment, an intelligent network model is newly developed for on-line fault diagnosis based on the science of cognition and information fusion theories in Internet environment. It's such a diagnostic strategy that combines not only qualitative with quantitative diagnoses but local with integral diagnoses. In this way a qualitative diagnosis shall be made first. In case the equipment is abnormal, the integrated neural network group will start immediately the quantitative analysis and classification of multi-source characteristic information from sensors, and the ES module will explain qualitatively the reasoning process of ANNs. As a result, the D-S evidence reasoning module will diagnose synthetically the output of ANNs at integrated fusion center, thus improving evidently the precision and reliability of diagnosis conclusion. The model has been tested and run on Fengman Hydropower Station's digital simulation system we developed, and the result showed that the proposed model was not only effective, versatile and applicable in practical use but also beneficial to the development of local fault diagnosis system. References | Related Articles | Metrics

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Self-adapting mobile IPv6 model based on MAP Gao, Tian-Han (1); Guo, Nan (1); Zhao, Hong (1) 2004, 25 (3):  227-230.  DOI: - Abstract ( 259 )   HTML   PDF (176KB) ( 623 )   An optimal mobile IPv6 model based on hierarchical mechanism is proposed to optimize the performance of localized mobile node (MN) in remote region. The traditional hierarchical managing mechanism (HMIPv6) is improved through the proposed self-adapting binding update policy. In the policy, a map edge router (MER) is introduced with the passing binding match algorithm we designed and two new binding messages (binding update request, and binding update acknowledgement) provided. Thus, MER could directly intercept packets from or to MN to eliminate the triangle route within HMIPv6 and optimize the performance of MN. Moreover, the intra-CN processing policy is also proposed in terms of the location of correspondent node (CN) to reduce the communicating cost between intra-CN and MN. As a consequence, the model is capable of self-adapting to exterior network changes so as to improve the utilization of network resources. Finally, the prototype has verified the availability of the model. References | Related Articles | Metrics

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Parallel construction and inquiry algorithm of suffix trees Qiao, Bai-You (1); Ge, Jian (1); Wang, Guo-Ren (1); Han, Dong-Hong (1) 2004, 25 (3):  231-234.  DOI: - Abstract ( 287 )   HTML   PDF (155KB) ( 1004 )   A parallel suffix tree constructing algorithm is proposed to get rid of traditional space/time restriction while using suffix trees in bioinformatics. In this algorithm, the given string is divided into several continuous substrings. Then, the suffix trees for every substring are constructed in parallel, thus forming a suffix tree structure distributed separately on several processors. This algorithm can not only reduce the time needed to construct suffix trees but also avoid the restriction of main memory. The performance analysis shows that this algorithm outperforms any of existing parallel algorithms. Based on such a suffix tree structure, an efficient pattern matching algorithm is also proposed for the inquiries about traditional suffix trees. References | Related Articles | Metrics

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Intelligent QoS multicast routing algorithms in next generation internet Wang, Xing-Wei (1); Cheng, Hui (1); Huang, Min (2); Yu, Rui-Yun (3) 2004, 25 (3):  235-238.  DOI: - Abstract ( 274 )   HTML   PDF (1088KB) ( 627 )   Three intelligent algorithms, GA (genetic algorithm), SAA (simulated annealing algorithm) and TSA (tabu search algorithm), were introduced in computing the QoS-based optimization multicast routing tree. A QoS-based high-speed network model was established to support QoS multicast. Then, the mathematical model for multicast algorithm problems was established based on the network model. The three intelligent algorithms and relevant key issues were analyzed with the solutions given to them when applying them to QpS-based multicast routing algorithms. Finally, the three algorithms were compared in terms of the request for network cost and runtime. The simulation shows that the three algorithms all have high performance and can meet the requirements for QoS multicast in NGI. References | Related Articles | Metrics

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Influence of electromagnetic stirring on the thermal parameters of steel solidification process Wang, En-Gang (1); Zhang, Hong-Li (2); Deng, An-Yuan (1); He, Ji-Cheng (1) 2004, 25 (3):  239-242.  DOI: - Abstract ( 297 )   HTML   PDF (201KB) ( 1148 )   An experiment of the solidification process of steel billets under linear electromagnetic stirring (EMS) was carried out on a special setup of which a unilateral water cooling copper plate was mounted to the mould. A computer dynamic data acquisition system was provided to perform real-time measurements of some heat exchange parameters during the solidification of steel. The results show that in the mould the heat flux increases obviously in initial solidification period under the action of EMS to expedite the overheat dissipation in molten steel. Thus, the internal temperature of the ingots tends to be distributed uniformly with the temperature gradient at the solidifying front reduced. As a result, the growth of columnar grain is suppressed, which will be helpful to the nucleation in molten steel and the formation of equiaxed grain solidification structure. Therefore, the rate of equiaxed grains in ingots with EMS can be improved to 76% from 47% without EMS. The fact indicates that the overheat dissipation in molten steel with EMS is one of key factors to increase the rate of equiaxed grains in the solidification structure. References | Related Articles | Metrics

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Preparation of metallic nanopowders Li, Zhi-Jie (1); Qu, Jia-Hui (1); Zuo, Liang (1); Wang, Fu (1) 2004, 25 (3):  243-246.  DOI: - Abstract ( 379 )   HTML   PDF (184KB) ( 644 )   Producing nanopowders of Al, Fe, Cu and Pb by hydrogen plasma D. C. arc process and determining their morphologies, compositions, crystalline structures and particle sizes were studied. The results showed that they were all of monocrystals, among which the particle sizes of Al nanopowder distributed in a range from 10 to 138 nm with 75 nm on average, and the average size of Fe, Cu and Pb nanopowders were 56 nm, 81 nm and 77 nm, respectively. All of them are of fcc structure except α-Fe that is of bcc. When the volume of oxygen feed is the same, the feeding speed affects greatly the oxygen content of nanopowders. For example, the mass fraction of oxygen in Al nanopowder is about 5.9% after a passivation for 6 h and about 11.3% for 2 h. However, the result of X-ray diffraction analysis of Al nanopowder is different from that of others, because the oxygen is dissolved into Al nanopowder to split the diffraction peak. Thus, the lattice constant of part of powder particles increase by 0.0036 nm, though their structures remain unchanged. Unlike the spherical shape of particles of other nanopowders, the tadpole-like morphology features the particles of Al nanopowder. References | Related Articles | Metrics

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Microstructure and properties of high-boron steel Liu, Chang-Sheng (1); Cui, Hong-Wen (1); Chen, Sui-Yuan (1); Ren, Xiao-Yu (1) 2004, 25 (3):  247-249.  DOI: - Abstract ( 164 )   HTML   The as-cast and hot rolling microstructures of high-boron steel prepared from vacuum induction furnace were investigated, in which the element B was uniformly distributed. Titanium added into it had a significant effect on decreasing the amount of Fe2B and FeB precipitated at grain boundaries and increasing the distribution of boron within the grain and grain boundaries, with precipitations of TiB2 distributing dispersively and uniformly on ferritic matrix. The hot rolling conditions were determined reasonably by simulation, i.e., the soaking temperature was 1080-1120°C, slab rolling temperature was 1070-1110°C, finish rolling temperature was 810-850°C and pass reduction ratio was 10%-20%. After multi-pass rolling and subsequent air-cooling, the mechanical properties of the high-boron steels were enhanced significantly. References | Related Articles | Metrics

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Roll wear prediction for plate mill Qiu, Hong-Lei (1); Tian, Yong (1); Wang, Zhao-Dong (1); Wang, Guo-Dong (1) 2004, 25 (3):  250-253.  DOI: - Abstract ( 330 )   HTML   PDF (111KB) ( 805 )   Discussing the existing empirical formulae of roll wear due to plate rolling, an on-line roll wear model based on regression analysis was studied utilizing the wear-out data acquired in situ. Based on the statistical wear-out distribution along roll barrel, the wearing value of a roll is considered as a function of roll length to predict the roll wear in next rolling period. Predictions by relevant model based on statistical regression analysis and measurement were both carried out for roll wear, with a roll taken from the 3500 mm plate mill in Shougang Steel Plant as specimen. The comparison shows that the predicted values fit with measured values well. The roll wear prediction model can improve significantly the precision of calculated values of roll wear obtained from empirical formula, this providing favorable controls of thickness precision, shape and crowning of plates. References | Related Articles | Metrics

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Effect of reduction partition in two-pass cold rolling on drawability of IF sheet Liu, Zhan-Ying (1); Li, Jin-Xia (1); Liu, Xiang-Hua (1); Wang, Guo-Dong (1) 2004, 25 (3):  254-257.  DOI: - Abstract ( 227 )   HTML   PDF (217KB) ( 959 )   A 2-pass cold rolling process was conducted in lab with lubricant used for hot rolled IF strips, with the purpose of improving the drawability of IF steel after cold rolling. The results show that the partition of the fixed overall reduction is of key importance to the drawability of the IF sheet. If the overall reduction remains unchanged, the measured plastic strain ratio, r, after 2-pass rolling is higher than that after single pass rolling. The r increases if the first pass reduction is smaller than the second one, and the r also increases if the overall reduction increases properly. The r can be up to over 3. 2 if both the reduction ratios are 75%. The ODF texture analysis made to the rolled specimen shows its identity with the r measured, and the micrographic results show that the equiaxed grain benefits the drawability. References | Related Articles | Metrics

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Structure and Li-embedding behavior of lithium cells reusing carbon nanopowder as cathode material Zhang, Ai-Li (1); Fu, Yan (1); Zhai, Xiu-Jing (1); Zhai, Yu-Chun (1) 2004, 25 (3):  258-260.  DOI: - Abstract ( 224 )   HTML   PDF (172KB) ( 820 )   An industrially by-product carbon nanopowder was reused as the raw material to make cathodes of lithium cell for the purpose of reducing cost and improving performance. After the purification of the carbon nanopowder, its purify was measured with an electrochemical investigation done for the lithium embedding behavior. The results of charge/discharge test showed that for the nanopowder the discharging specific capacity was 358.3mA·h/g, the first rechargeable capacity was 336.4 mA ·h/g and 76.1% of rechargeable capacity could be held on after the 9th recharging actions done. The TEM result showed that the morphology of the nanopowder particles were spherical with a diameter about 30 nm, and the XRD result showed structurally that its interlayer distance, d002 was 0.3481 nm, i.e., between that of graphite and of soft carbon. References | Related Articles | Metrics

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Preparation of silica-ruthenium dioxide as composite material for film electrode of supercapacitor Huo, Yu-Qiu (1); Yan, Yu-Tao (2); Zhai, Yu-Chun (1); Li, Ming-Dong (1) 2004, 25 (3):  261-264.  DOI: - Abstract ( 221 )   HTML   PDF (175KB) ( 1033 )   The composite material silica-ruthenium dioxide was prepared through thermolytic oxidation for the film electrodes of supercapacitor, taking RuCl3·xH2O mixed with TEOS as raw material and Ti slide as substrate. The surface morphology of film electrode was observed by SEM, and the capacitive property of that was studied through cyclic voltammetry to analyze how the mixing ratio of TEOS to RuCl3·xH2O and the sintering temperature/time affect the capacitive property. The results show that the film electrode made from the composite material has excellent capacitive property, e.g., the specific capacitance can be up to 137 mF/cm2 if the mixing ratio is 5:2 with sintering temperature/time at 350°C and for 1 h, which means near three orders of magnitude are available to increase greatly the specific capacitance in comparison with the results as shown in reference. References | Related Articles | Metrics

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CO/CO2 gas sensor: LaF3-based solid electrolyte Han, Yuan-Shan (1); Wang, Chang-Zhen (1); Tian, Yan-Wen (1); Zhai, Yu-Chun (1) 2004, 25 (3):  265-268.  DOI: - Abstract ( 235 )   HTML   PDF (164KB) ( 582 )   A CO/CO2 gas sensor was developed at low temperature, which was composed of Sn, SnF2|LaF3(mixed)|Pt (Ni), i.e., taking LaF3 (mixed) monocrystal or polycrystal as base material, Sn and SnF2 as reference electrode and Pt wire mesh as working electrode. It was used to measure separately the two gases CO and CO2 at 295.15-343.15 K for the relationships of EMF to volumetric fraction and to temperature under conditions that volumetric fractions were in the range from 5% to 30% (with Ar taken as gaseous diluent), as well as the response time needed for equilibrium EMF the cell just reach. The experimental results show a similarity between both gases that the EMF of cell increases with the increase of volumetric fraction at a fixed temperature and vise versa. In addition, the EMF value of monocrystal is higher than that of polycrystal for the same gas under the same conditions including volumetric fraction and temperature. The response time of both gases are about 2-5 min. References | Related Articles | Metrics

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Synthesis of TiO2-SiO2 complex material and its photocatalytic property Zhang, Xia (1); Zhao, Yan (2); Zhang, Cai-Bei (1) 2004, 25 (3):  269-272.  DOI: - Abstract ( 199 )   HTML   PDF (204KB) ( 1036 )   The dark-yellow clear block TiO2-SiO2 complex material was prepared with two-step sol-gel technique. Controlling the hydrolysis speed, the tetrabutyl titanate (TBOT) and n-Ethyl silicate (TEOS) were hydrolyzed simultaneously and the sol produced was dried to form gel at 60°C. Then, the gel was dried by supercritical drying method using alcohol as solvent and annealed at different temperatures. The morphology and structure of TiO2-SiO2 complex material were confirmed by means of TEM, XRD and FT-IR. The results showed that after annealing the nano-TiO2 powder grains of anatase structure were uniformly dispersed in amorphous-SiO2 matrix and there was a Ti-O-Si bond between TiO2 grains and SiO2 matrix. In the photocatalytic degradation the TiO2-SiO2 complex material presents better catalytic property and nearly 86% Rhodamine B is degraded within 1 hour. This TiO2-SiO2 complex material is easier to separate from solution by filtration or sedimentation and it is expected to be used widely in waste-water treatment. References | Related Articles | Metrics

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Acoustic properties of giant magnetostrictive transducer Yuan, Hui-Qun (1); Li, He (2); Sun, Hua-Gang (1); Wen, Bang-Chun (2) 2004, 25 (3):  273-276.  DOI: - Abstract ( 241 )   HTML   PDF (1042KB) ( 589 )   Terfenol-D bar is used in actuator and simplified as one-to-one linear input/output system for the equivalent dynamic magnetic-mechanical model. Based on test data of magnetostrictive material under compression, an exponent type horn of the magnetostrictive transducer is designed, the geometric size based on actual resonance, magnifying coefficient of amplitude, distributing functions of vibration speed and stress and position of nodal section are calculated and a natural frequency equation of the exponent type horn of magnetostrictive transducer is derived designing the magnetostrictive transducer. With the alloy TeDyFe as giant magnetostrictive material tested including its static mechanical properties, a new kind of giant magnetostrictive transducer was made with its dynamic properties tested as well. In such tests the transducer was proved that it had a wide frequency range with wave shape prominent apex and higher launching power and that a proper attached weight ratio could increase the conversion efficiency between electric and acoustic energies. References | Related Articles | Metrics

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Optimal control of vibration in restrained cantilever piping for fluid delivery Zou, Guang-Sheng (1); Jin, Ji-Duo (2); Wen, Bang-Chun (1) 2004, 25 (3):  277-279.  DOI: - Abstract ( 274 )   HTML   PDF (276KB) ( 793 )   The optimal vibration control in cantilever piping for fluid delivery, which is supported by a linear spring with nonlinear motion restrained was investigated theoretically taking a piezoelectric vibrator as actuator. The considering the extra moment formed due to the extension/contraction of powered piezoelectric actuator, the differential equations of motion of the controlled piping system were derived and then discretized by Galerkin's method. A controller was designed on the basis of optimal regulator theory, i.e., the deflection of pipe and the input energy of control could both be minimized simultaneously, the motional responses to both controlled and non-controlled systems were examined by numerical simulations to verify the validity of the control scheme. The comparison between the results of both systems revealed that the optimal control scheme presented here could control effectively both periodic and chaotic vibrations in the piping system. References | Related Articles | Metrics

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Determination of cars' moment of inertia Yu, Yan (1); Xie, Li-Yang (1); He, Hui (2); Zhang, Li-Jun (2) 2004, 25 (3):  280-282.  DOI: - Abstract ( 998 )   HTML   PDF (148KB) ( 3378 )   A new method was proposed to determine the moment of inertia of the sprung mass of a car around its mass center. An on-the-road brakeage test should be done first. Analyzing the characteristics of the frequency spectrum of those vertical vibration acceleration signals which were acquired from the test, the inherent angular frequency was obtained. A vibration model was thus developed for car body to calculate the moment of inertia. A SY622B minibus was taken to exemplify the model and the calculated value with measured value of the moment of inertia. The error is shown only 1 % that will meet completely the precision requirement in engineering. The method is accurate and applicable to the measurements of moment of inertia of various types of car. References | Related Articles | Metrics

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Buildings' fire risk assessment based on fuzzy gravity center Zheng, Shuang-Zhong (1); Liu, Yan-Jun (2); Ding, Ming-Zhen (1); Chen, Bao-Zhi (1) 2004, 25 (3):  283-286.  DOI: - Abstract ( 252 )   HTML   PDF (161KB) ( 499 )   A new fire risk assessment in terms of fuzzy gravity center is put forward to make the assessment result in connection with fuzzy intervals so as to improve the traditional marking procedure by experts. At the same time, the accuracy of assessment can be guaranteed. According to the actual survey of a marketplace, a system of fire risk assessment indices is established and used to assess its fire risk. A high mark is given to it and conforms with the actuality, showing a serious fire hazard. Compared with other assessment methods, more information and higher reliability can be got by the method in terms of fuzzy gravity center. In addition, the result of index gravity centers ranking will be beneficial to fire safety management. References | Related Articles | Metrics

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Cushion design of composite foundation Wang, Feng-Chi (1); Zhu, Fu-Sheng (1); Wang, Shu-Hong (1); Dong, Tian-Wen (1) 2004, 25 (3):  287-290.  DOI: - Abstract ( 342 )   HTML   PDF (1113KB) ( 987 )   In order to determine the cushion parameters in design, the relationship between reinforcements and cushion can be considered as that the ground is under the action of inverted piles. The upward penetration of piles into cushion is likely to lead the cushion to such failures as monolithic shear, partial shear failure and piercing failures. Among them the rational model that can adjust the pile-soil stress ratio is monolithic shear failure. Based on the model, an iterative formula of upper limit value in terms of the internal friction angle of a cushion has been derived. According to Terzaghi's theory of slipping spirals, it is proved that the cushion thickness shall be the minimum one to set if the logarithmic slipping spirals intersect tangentially the bottom board of foundation. As a result, the adjustability of pile-soil stress ratio will be decreased if the cushion thickness is less than the minimum one to set, and the cushion width to set should be given on stress diffusion basis so as to prevent the cushion from failure. References | Related Articles | Metrics

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Inducement mechanism for leaders to make followers cooperative Tian, Hou-Ping (1); Guo, Ya-Jun (1) 2004, 25 (3):  291-294.  DOI: - Abstract ( 274 )   HTML   PDF (237KB) ( 631 )   The traditional non-cooperation Stackelberg Problem was extended to be in cooperative conditions where followers cooperated with leaders. Based on the original Stackelberg model, the problem how a leader designs an inducement mechanism to make his followers cooperative is discussed with the designing method proposed. In particular the inducement mechanism can serve the function that followers will cooperate voluntarily with the leader, thus leading to an automatic cooperation. A Stackelberg problem in purchasing system consisting of a seller as leader and a buyer as follower is given as example by which how the seller induces the buyer to cooperate with each other is analyzed by way of the mechanism. The result indicates that the leader succeeds in inducing the buyer to cooperate with himself, and their costs are both reduced. References | Related Articles | Metrics

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Partner selection based on fuzzy group decision-making for virtual enterprise formation Li, Shuai (1); Guo, Ya-Jun (1); Yi, Ping-Tao (1); Tian, Hou-Ping (1) 2004, 25 (3):  295-298.  DOI: - Abstract ( 261 )   HTML   PDF (190KB) ( 756 )   An index system is designed for the partner selection of a virtual enterprise in view of economic factors, with the aim to lower the total co-operative cost during the whole operational lifecycle of the virtual enterprise. Then 8 indices are given to pick out the partners after breaking down the total cost and influencing factors on it, such as the level of service to provide for customers. Because of the difficulties in determining the weight of index and measuring the index data, the experts' subjective judgments are utilized and transformed correspondingly into fuzzy numbers via linguistic variables. To make decisions more reasonable under the conditions that data are asymmetrical, an appropriate mathematic model is given through the decision-making process on fuzzy group basis, i.e. integrating all experts' information obtained from different fields. The overall evaluation value for a candidate is thus computed with fuzzy numbers, of which a simple and practical method is introduced to rank fuzzy numbers. A calculation is given to exemplify its applications. References | Related Articles | Metrics

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- - 2004, 25 (3):  299-302.  DOI: - Abstract ( 293 )   HTML   PDF (188KB) ( 897 )   - References | Related Articles | Metrics

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- - 2004, 25 (3):  303-306.  DOI: - Abstract ( 268 )   HTML   PDF (222KB) ( 1021 )   - References | Related Articles | Metrics