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15 June 2004, Volume 25 Issue 6 Previous Issue    Next Issue
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Observer-based robust decentralized stabilization for a class of uncertain interconnected time-delay systems Liu, Xiao-Zhi (1); Li, Hua (1); Jing, Yuan-Wei (1); Zhang, Si-Ying (1) 2004, 25 (6):  511-514.  DOI: - Abstract ( 200 )   HTML   PDF (169KB) ( 475 )   The robust decentralized stabilization based on observer was discussed on a class of uncertain interconnected time-delay systems in which the time-varying parameter uncertainties are unknown and norm-bounded. The delayed terms are found in all the system state, control input and interconnection terms. Based on Lyapunov stability theory and linear matrix inequality (LMI) technique, a decentralized output feedback controller is designed so that the closed loop large-scale interconnected system is asymptotically stable with a sufficient condition for the stability derived in terms of LMIs. The simulation is given to illustrate the validity of the proposed methods. References | Related Articles | Metrics

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PD control comparison between two schemes of angular velocity estimation for robots Wang, Yong-Fu (1); Chai, Tian-You (1); Yue, Heng (1) 2004, 25 (6):  515-518.  DOI: - Abstract ( 267 )   HTML   PDF (270KB) ( 1301 )   Estimate of the joint angular velocity of robot is preferable with two methods, i.e. the most popular model-free high-gain observer and the simplest LPP numerical difference method. Two PD controllers based on high-gain observer and on LPP numerical difference are given differently. In robot simulation, the tracking error and estimated error of the scheme of high-gain observer-based PD control are shown and compared with those of the same PD controller using numerical difference method. The results show that if the encoder can give very accurate measurement for joint position, the performance of robot using LPP numerical difference method is better than that using high-gain observer and vice versa. References | Related Articles | Metrics

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Reduced-order H∞ controllers based on genetic algorithm Pan, Wei (1); Jing, Yuan-Wei (1) 2004, 25 (6):  519-522.  DOI: - Abstract ( 242 )   HTML   PDF (173KB) ( 604 )   An approach to designing reduced-order H∞ controller for a class of linear continuous dynamic systems is presented based on genetic algorithm. Necessary and sufficient conditions for existence of the controller are given by means of linear matrix inequality. Taking the rank restriction condition as an object function of genetic algorithm, the minimum order nk of the controller and the relevant paired parameter (X,V) of positive definite matrix are obtained by searching the object function globally. Then, the reduced-order H∞ controllers are designed. The genetic algorithm's code is float, the selection operator is rank-based fitness assignment and elitist model, the crossover operator is real valued recombination and the mutation operator is real mutation. The simulation results show that the proposed controller has the same control effect as all-order H∞ controllers based on MATLAB. References | Related Articles | Metrics

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Input-output energy decoupling of linear singular systems Dong, Xin-Zhuang (1); Zhang, Qing-Ling (1) 2004, 25 (6):  523-526.  DOI: - Abstract ( 178 )   HTML   PDF (301KB) ( 1068 )   The problem of input-output energy decoupling is considered for linear singular systems. It means an approximate decoupling process enabling the energy of every input controls mainly the energy of a corresponding output with minimized effect on the energy of other outputs. By means of linear matrix inequalities, sufficient conditions are presented to realize the input-output energy decoupling for a linear singular system so as to feature the closed-loop system with the performance above and admissibility (i.e. regular, stable and impulse-free), and the design methods for such controllers are provided in terms of the solution of linear matrix inequalities. Moreover, a computational method is presented with an example given to show how to solve the input-output energy decoupling problem for linear singular systems. References | Related Articles | Metrics

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Optimal multi-objective model and algorithm for order matching problems in iron and steel plants Hu, Kun-Yuan (1); Gao, Zheng-Wei (1); Wang, Ding-Wei (1) 2004, 25 (6):  527-530.  DOI: - Abstract ( 201 )   HTML   PDF (234KB) ( 798 )   Aiming at solving the problem to match orders with inventory surplus in an iron and steel plant, an optimal multi-objective 0-1 programming model is established to maximize the utilization of material surplus on inventory and minimize the matching cost orders. Two objective functions are incorporated by fuzzy decision-making approach and the model is solved by improved PBIL (Population-based increased learning). Natural number encoding is used to represent the result of orders matching based on the model's characteristic with the impractical chromosomes repaired in terms of learning probability. Then, the computation of a practical instance and a comparison of the computational result with the result by genetic algorithm further demonstrate that the model and the algorithm are the ideal way to solve the optimal problem of order matching. References | Related Articles | Metrics

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CBR system with embedded adaptation model for scheduling system in steel-making process Chang, Chun-Guang (1); Wang, Ding-Wei (1); Hu, Kun-Yuan (1); Zheng, Bing-Lin (1) 2004, 25 (6):  531-534.  DOI: - Abstract ( 190 )   HTML   PDF (157KB) ( 486 )   With the purpose to optimize dynamic scheduling in steel-making, a CBR (case-based reasoning) system with embedded adaptation model or CBR/EAM is established, of which the function and establishing process of the model, especially how to solve it are presented. To solve it easily, the nonlinear adaptation model is converted into linear one. Then a two-stage algorithm is utilized to improve solving efficiency. First, the genetic algorithm (GA) that introduces heuristics to generate population is adopted to pretreat the problem so as to reduce relevant dimensions, the 3-dimensional natural number encoding is adopted to meet the requirement of practice. Then, the simplified model is solved with simplex method. The simulation result is verified that the validity of CBR/EAM is better than that of single model approach or conventional CBR approach to solve the dynamic scheduling problem in steel-making process. With the prototype system further perfected, it could be put into application with benefits expected. References | Related Articles | Metrics

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Comprehensive fuzzy evaluation for medical-care quality Wang, Shu (1); Wang, Ding-Wei (1) 2004, 25 (6):  535-538.  DOI: - Abstract ( 233 )   HTML   PDF (732KB) ( 658 )   Based on Parasuraman, Zeithaml, Berry (PZB) model for service quality, a comprehensive fuzzy evaluation model for medical-care quality is presented, of which the performance criteria and criterion weights are both determined by the questionnaire method and fuzzy multiple attribute decision making. It's found that satisfactory medical equipments and good medical-care results are the most important ones among the 19 performance criteria through a 4-factor investigation made to the study. The result proves the feasibility of evaluating medical-care quality with comprehensive fuzzy evaluation method and offers directions for future improvement of hospitals. References | Related Articles | Metrics

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Model and algorithm of reliability evaluation for complex device networks Liu, Yan-Qiu (1); Zhang, Ying (2); Wang, Ding-Wei (1); Ip., W.H. (3) 2004, 25 (6):  539-542.  DOI: - Abstract ( 201 )   HTML   PDF (251KB) ( 799 )   The problem of reliability evaluation for complex device networks was studies through model that is designed in terms of structure functions. Comparing with traditional algorithms, it can reduce the complexity to compute such problems and improve the accuracy and operability in the process of evaluation. An instance for computation is given showing the feasibility and effectiveness of the algorithm. It requires neither taking all the cut set and spanning trees as preconditions nor computing the disjoint sum once more, but requires just starting from a spanning tree to determine the network reliability. A algorithm for the reliability analysis of multi-state and all terminal complex device networks is therefore given on the basis of the characteristics of spanning tree and loop-sum theory of network diagram. References | Related Articles | Metrics

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ILS and TS hybrid algorithm based on random kick mechanism for FSFIS problem Li, Shao-Hua (1); Tang, Li-Xin (1) 2004, 25 (6):  543-546.  DOI: - Abstract ( 231 )   HTML   PDF (955KB) ( 502 )   An iterative local search algorithm (ILS) is presented and implemented which is based on random kick strategy to solve the flowshop scheduling problem with finite intermediate storage (FSFIS). The kick move of ILS is designed by using several pairs of non-across swap moves with a backtracking mechanism used to make the algorithm search in a promising area. This algorithm is proved quick and effective by a computer experiment in which the algorithm is implemented with 4 different neighborhood structures and 480 randomly generated problem instances. Because the ILS is a random algorithm and has a very good performance to escape from local optimal solutions and tabu search (TS) has a strong search ability, a hybrid algorithm is constructed to embed random mechanism into the static tabu search algorithm. This hybrid algorithm can synthesize the advantages of the two original algorithms. The computer experiment shows that the hybrid algorithm is better than the best known algorithm by 0.21% in the worst case. References | Related Articles | Metrics

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Underground image tracking based on data fusion Gong, Yi-Shan (1); Zhao, Hai (1) 2004, 25 (6):  547-550.  DOI: - Abstract ( 224 )   HTML   PDF (194KB) ( 450 )   A underground image tracking algorithm is developed by way of a fusion done between a commonly-used mean square image correlator and Kalman filter, based on Bayes rule. With the fusion of both the information from the MSD correlator and Kalman filter, the improved algorithm can enhance the information feedback between them and its tracking performance and robustness so as to minimize the out-of-control possibility. Furthermore, the improved algorithm also incorporate the statistical characteristics of noise to improve noise suppression ability. The theoretical and practical results show that the images acquired from the algorithm are much more real and accurate than the correlative algorithms. References | Related Articles | Metrics

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New character-abstraction method based on generalization and reduction Zhang, De-Gan (1); Yin, Guo-Cheng (1); Hao, Xian-Chen (1); Zhao, Hai (1) 2004, 25 (6):  551-554.  DOI: - Abstract ( 217 )   HTML   PDF (324KB) ( 661 )   To meet the requirements of information fusion computing at character-level, a character-abstraction method based on generalization and reduction is presented based on the rough set theory. The method of generalizing the values of attribute is studied according to the concept of level tree. Then, based on the principles of minimum average relativity and maximum consistency factor, two kinds of reduction methods are designed owning to their special goals, i.e., reducing redundancy attributes and reducing relative mapping relationship. The designed method can overcome the existing shortcomings of narrow object range and bad effect of the methods within the rough set theory. The correctness and dependability of the method are verified by application example. References | Related Articles | Metrics

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Convergence time of BGP based on dispute digraph Wang, Hong-Jun (1); Wang, Duan-Jun (1); Wang, Da-Dong (1); Gao, Yuan (1) 2004, 25 (6):  555-558.  DOI: - Abstract ( 224 )   HTML   PDF (176KB) ( 521 )   BGP convergence time is studied on the basis of dispute digraph, which reveals the relationships between routing policies of different autonomous systems. Dispute arc and transmission arc of the dispute digraph indicate respectively the policy conflict and policy consistency. The results show that the routing convergence time correlates with the length of the longest path in dispute digraph for a network. The BGP convergence time based on dispute digraph is given. The convergence time is greater than or equals to the minimum. Time required for the local longest paths, which only consists of the transmission arcs followed with or without a dispute arc in the dispute digraph corresponding to the network, whereas it is less than or equals to the maximum time required for all the paths of the dispute digraph. The convergence time given is proved sound and exemplified through an SSFNET simulation. References | Related Articles | Metrics

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Effect of compositions of mold flux on crystalline phase Zhu, Chuan-Yun (1); Liu, Cheng-Jun (1); Shi, Pei-Yang (1); Jiang, Mao-Fa (1) 2004, 25 (6):  559-562.  DOI: - Abstract ( 524 )   HTML   PDF (221KB) ( 1808 )   Mold flux films were made molten slag was cooled to room temperature in graphite crucible at 2°C/min in MoSi2 high temperature resisting furnace, and the crystalline phase were analysed by petrographic microscope. The results showed that: (1) the crystalline phases are mainly the cuspidine, wollastonite and gehlenite with nepheline, fluorite and olivine in some samples under the experimental conditions; (2) with the bacisity and CaF2 content increasemeng, crystalline proportion of mold flux rises with the cuspidine growing, thus the fluorite comes into being with more CaF2; (3) Na2O accelerates the nepheline to come into being; (4) the crystalline portion of mold flux increases with the increasing mass fractions of Li2O, Na2O and K2O with the cuspidine growing; (5) with more MgO found, the form of cuspidine is restrained with wollastonite growing; (6) with more Al2O3 found, the form of cuspidine is restrained with nepheline growing, (7) the crystalline proportion lowers with the increasing mass fractions of BaO and MnO. References | Related Articles | Metrics

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Experimental study on gas flow distribution affected by constructional parameters of pelletizing shaft furnaces Dong, Hui (1); Cai, Jiu-Ju (1); Wang, Guo-Shen (2); Fu, Wei (1) 2004, 25 (6):  563-566.  DOI: - Abstract ( 198 )   HTML   PDF (224KB) ( 633 )   Pelletizing shaft furnace (PSF) is usually used to produce acidic pellet in China. A cold-state experimental set-up was built according to the principle of similitude, and then the flow-net diagrams with different constructional parameters were plotted to make sure of the gas flow distribution in PSF and how the gas flow distribution is affected by the constructional parameters. The results showed that among such constructional parameters the widths of vertical air internal channels, roasting zone and cooling zone and the heights of roasting zone, soaking zone and cooling zone are the main influencing factors on gas flow distribution in PSF. In case the width of internal channels or the height of roasting zone is increased or the width of roasting zone decreased, the upward cooling gas tends to decrease while the downward roasting gas tends to increase with the critical ratio of inflow k* decreased gradually, and vice versa. It is important that the width of roasting zone is the key influencing factor on the uniformity of gas flow distribution in PSF. The results can be applied to the initial design of PSF especially in CAD. References | Related Articles | Metrics

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Study on the oxide as anode material for lithium ion batteries Lu, Cheng-Xue (1); Chu, Jia-Yi (1); Zhai, Yu-Chun (1); Tian, Yan-Wen (1) 2004, 25 (6):  567-569.  DOI: - Abstract ( 270 )   HTML   PDF (192KB) ( 1014 )   Three powder materials, SnO, Sb2O3 and GeO2, were prepared by aminolysis, and each of them was used as an active material for the anode of lithium-ion cells. Using a constant-current cell tester to measure their electrochemical properties, the results show that their initial discharge capacities are 1520, 820 and 1040 mA·h/g and initial charge capacities are 800, 520 and 800 mA·h/g for GeO2, Sb2O3 and SnO, respectively, both are high. On the other hand, their irreversible capacities were high by experiments. References | Related Articles | Metrics

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Measurement of rheologic characteristics of melts Liu, Run-Zao (1); Wu, Keng (2); Zhao, Yong (2); Jian, Mao-Fa (1) 2004, 25 (6):  570-573.  DOI: - Abstract ( 280 )   HTML   PDF (1513KB) ( 828 )   A conventional rotary viscometer was restructured available to variable speeds to measure the rheological characteristics of melts, e.g., the oil viscosities with different standard grades. The reproducibility error of this viscometer and the total error of measurements, i.e., the maximal permissible measuring error of Newtonian fluid in measurement process are given. The maximal permissible error caused by neglecting the effect of yield stress on viscous factor was determined through the analysis of measured data. An approach to determine whether a melt is non-Newtonian fluid and whether there is a yield stress in the non-Newtonian fluid was further given. The results provide a necessary basis for further research on the rheologic characteristics of melts. References | Related Articles | Metrics

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General expression of grinding temperature field and its visual simulation analysis Gao, Hang (1); Li, Jian (1) 2004, 25 (6):  574-577.  DOI: - Abstract ( 200 )   HTML   PDF (215KB) ( 714 )   A visual simulation of grinding temperature field is realized on the basis of the general expression derived for grinding temperature. In the simulation process of simulation the relevant graphs or distribution of temperature on different grinding conditions and the effect of some parameters on grinding temperature can be displayed automatically by and just input grinding parameters. It is helpful for the quantitative analysis of grinding parameters and selection of grooving parameters of grinding wheel in practice. Some examples are given to analyze the effect of grinding parameters on grinding temperature. References | Related Articles | Metrics

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Rub-impact analysis of rotor system with slow-varying mass Wang, Zong-Yong (1); Wu, Jing-Dong (1); Yao, Hong-Liang (1); Wen, Bang-Chun (1) 2004, 25 (6):  578-581.  DOI: - Abstract ( 222 )   HTML   PDF (283KB) ( 912 )   A differential equation is developed for expressing the motion of a rotor system with slow-varying mass, based on a theoretical study on the rub-impact dynamic characteristics of a rotor system with slow-varying mass in a centrifuge with large eccentricity under the action of linear collisional/frictional forces. The effects of changes in rotor speed and unbalance on the vibration of a rubbed/impacted rotor system are analyzed through numerical method. The periodical and quasi-periodical motions of rotor system with slow-varying mass are revealed and described at different aspects, and how their forms evolved and transformed are discussed. The results indicate that the rotor system with slow-varying mass is equivalent to a rotor system with time-dependent damping and stiffness, which has obvious quasi-periodical motion features in its rubbed/impacted process without a chaotic motion arising from the constant mass of rotor system. References | Related Articles | Metrics

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Design of marketing management system for discrete manufacturers Liu, Yong-Xian (1); Sheng, Zhong-Qi (1); Jin, Yong-Ren (1) 2004, 25 (6):  582-585.  DOI: - Abstract ( 239 )   HTML   PDF (202KB) ( 847 )   Combining with the actual CIMS performance in a motor corporation, a marketing management system was introduced, which was set up in CIMS environment for discrete manufacturers. Based on a analysis of the characteristics of typical discrete manufacturers and the four main features of the production and marketing procedures in the corporation, the functional architecture of the marketing management system was determined by taking the contractual order as core. According to the process flowchart for implementation of the contractual order, the system was designed by introducing the system architecture consisted of both C/S and B/S. Describing the function contents of its web site for marketing, the functions of main modules and some key technologies of the system were analyzed. The information integration method of the system with other management systems was discussed in CIMS environment. References | Related Articles | Metrics

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- - 2004, 25 (6):  586-589.  DOI: - Abstract ( 288 )   HTML   PDF (157KB) ( 1257 )   - References | Related Articles | Metrics

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- - 2004, 25 (6):  590-593.  DOI: - Abstract ( 219 )   HTML   PDF (1033KB) ( 717 )   - References | Related Articles | Metrics

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- - 2004, 25 (6):  594-597.  DOI: - Abstract ( 257 )   HTML   PDF (1346KB) ( 472 )   - References | Related Articles | Metrics

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- - 2004, 25 (6):  598-601.  DOI: - Abstract ( 254 )   HTML   PDF (186KB) ( 937 )   - References | Related Articles | Metrics

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- - 2004, 25 (6):  602-605.  DOI: - Abstract ( 522 )   HTML   PDF (240KB) ( 3359 )   - References | Related Articles | Metrics

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Effect of anionics-oily additive on seed precipitation from sodium aluminate solution Chen, Feng (1); Zhang, Bao-Yan (1); Bi, Shi-Wen (2); Xie, Yan-Li (2) 2004, 25 (6):  606-609.  DOI: - Abstract ( 271 )   HTML   PDF (192KB) ( 861 )   The effect of anionics-oily additive on the seed precipitation from sodium aluminate solution was studied. How the particles strength and size and the rate of precipitation of Al(OH)3 are affected by adding fatty acid and heneicosane with different proportion and quantities. The results showed that when the mass fraction of fatty acid of the oily additive is in the range of 15% to 49% with the additive concentration in sodium aluminate solution in the range of 50×10-6g·L-1 to 150×10-6g·L-1, the particles size of A1(OH)3 increases with the quantity of fine particles reduce so as to improve the particle strength, but the rate of precipitation is reduced slightly. However when the mass fraction of fatty acid in the additive is 32% and its concentration in sodium aluminate solution is 150×10-6g·L-1, the comprehensive property of the additive proposed is better than that of similar foreign products. References | Related Articles | Metrics

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Synthetic process of a series of nitrones Cheng, Chun-Sheng (1); Li, Peng (2); Gai, Yong-Ming (2); Zhang, Bao-Yan (1) 2004, 25 (6):  610-612.  DOI: - Abstract ( 535 )   HTML   PDF (154KB) ( 1803 )   Six nitrones were prepared by using N-methylhydroxylamine sulfate and aromatic carbonyl substances by a synthetic process. Their purity were above 95% by using a suitable recrystallizing method with a yield over 90%. The melting points and 1H-NMR data of these products were measured with suitable instruments to characterize the chemical structure of these products together with the analysis of H-NMR wave spectrum. The influences of pH values and solvents used on the reaction systems and the purity of products were discussed. The synthetic process is ideal for the synthesis of a series of nitrones because of simple operation, high purity and high yield. References | Related Articles | Metrics