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15 September 2009, Volume 30 Issue 9 Previous Issue    Next Issue
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A new soft sensor modeling method based on improved AdaBoost algorithm for molten steel composition in LF Sun, Feng-Qi (1) 2009, 30 (9):  1217-1220.  DOI: - Abstract ( 213 )   HTML   PDF (957KB) ( 522 )   To make up for the shortages of existing updating methods of soft sensor modeling, a new improved AdaBoost algorithm available to increment learnability was proposed by combining the increment learning with AdaBoost algorithm for ensemble learning. Then, an ensemble BP network was formed by integrating the new improved AdaBoost with BP neural network so as to develop a soft sensor model which will not only improve the accuracy by using single BP network but also ensure the updating ability for increment learning. A soft sensor model of molten steel composition in a 60-ton LF (ladle furnace) in Fu-Steel was developed according to the new method proposed, and its prediction result showed that it can meet the requirements for production. References | Related Articles | Metrics

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Application of improved breeding algorithm to optimizing current letters' arrangement on cell phone key panel Wu, Cheng-Dong (1); Tang, Jun-Hui (1); Zhang, Yun-Zhou (1); Zou, Xue-Min (2) 2009, 30 (9):  1221-1224.  DOI: - Abstract ( 196 )   HTML   PDF (988KB) ( 603 )   Nowadays the arrangement of English letters on the key panel of cell phone is alphabetical, but it is unsuitable for the input of Chinese pinyin system because of long searching time and slow convergence rate. Introducing the abortion mechanism and evolutionary mutation coefficient into the unsuitability model for cell phone, the breeding algorithm is improved and available to solve the problem as above with the English letters arranged in optimized order on the key panel of cell phone, thus improving greatly the inputting efficiency of Chinese characters. Simulation results showed that the improved breeding algorithm has higher computation speed with better convergence results. References | Related Articles | Metrics

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An optimal control method of PWM converters for active power filters Li, Jun (1); Wang, Da-Zhi (1) 2009, 30 (9):  1225-1228.  DOI: - Abstract ( 241 )   HTML   PDF (1320KB) ( 603 )   The PWM converter of an active power filter has a time-delay link, thus making it difficult to be controlled optimally. Analyzes the PID control principle and the reason why the PWM converter is unable to implement the optimal control, and proposes the way and conditions to realize optimal control with a mathematical model developed correspondingly. A general expression of the state observers to a class of time-delay system is given as well as the ITAE optimal control law. The method combining the ITAE optimal control law with PID controller to realize the PWM converter's optimization control is therefore proposed according to the PWM converter's characteristics. The MATLAB simulation results indicated that the controller can trace signal quickly after ITAE optimization and has better dynamic performance than other optimal methods. References | Related Articles | Metrics

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Influence of oxide skin thickness on photoemissivity of polarizing angle from surface of continuous casting billets Chen, Liang (1); Xie, Zhi (1); Hu, Zhen-Wei (1); Zhang, Da (1) 2009, 30 (9):  1229-1231+1240.  DOI: - Abstract ( 249 )   HTML   PDF (539KB) ( 603 )   Photoemissivity is an important factor to the measurement accuracy by optical thermometry for the surface of continuous casting billets, while the oxide skin thickness affects greatly the photoemissivity in the measuring process. According to the theory of electromagnetic wave propagation, a multilayer model was developed for the surface radiation of the billets to investigate how the oxide skin thickness affects the photoemissivity. A recursion formula was deduced for the photoemissivity of polarizing angle from billet surface, where the physic parameters of different layers were given as shown in relevant literature. The calculated results revealed that the photoemissivity is significantly increased when the horizontal polarizing angle is in the range from 60° to 80°. However, the photoemissivity comes to be stabilized after the oxide skin thickness increases to a certain extent. The two conclusions will benefit theoretically the instrument layout for surface thermometry in site. References | Related Articles | Metrics

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Hand gesture recognition based on fourier descriptor-BP neural network Tan, Wen-Jun (1); Wu, Cheng-Dong (1); Zhao, Shu-Ying (1); Chen, Shuo (1) 2009, 30 (9):  1232-1235.  DOI: - Abstract ( 298 )   HTML   PDF (337KB) ( 717 )   Hand is a highly variable organ and hand features are easily affected by environmental factors. Considering the characteristics of hand gesture, a novel hand gesture recognition algorithm based on Fourier descriptor and BP neural network is presented. According to the complementarity of the YCbCr and Nrg color models and the background model that is available to exclude the similar skin colors from the complicated background, the hand gesture region is extracted by the segmentation of hand gestures through multi-feature integration. Then, the advantages of the Fourier descriptor which can describe well the profiles and of the BP neural network which is strong at self-learning are taken and combined together to recognize hand gestures. The experimental results showed that the method proposed has better robustness and higher recognition rate. References | Related Articles | Metrics

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Feature extraction and matching of vein based on geometrical shape and wavelet moment Cui, Jian-Jiang (1); Song, Xing-Yue (2); Chen, Guo-Kun (1); Chen, Da-Li (1) 2009, 30 (9):  1236-1240.  DOI: - Abstract ( 271 )   HTML   PDF (1193KB) ( 1213 )   For the feature extraction and matching algorithm to recognize the vein inside the back of human hand, a matching method combining generality with particularity is proposed. In the generality phase the characteristics of image feature descriptors are analyzed, involving the global information on vein images to determine the shape descriptors for boundary/region of which the translation, rotation, scaling and affinity are all invariable. And in the particularity phase based on wavelet moment the local features are considered to make better the shape descriptor for its higher resolution capability, with the advantages of wavelet moment taken because of its multi-scale analysis and invariant moment of wavelet. Testing results showed the highly improved recognition rate. References | Related Articles | Metrics

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Risk management of virtual enterprise based on stochastic programming and GA Lu, Fu-Qiang (1); Huang, Min (1); Wang, Xing-Wei (1) 2009, 30 (9):  1241-1244.  DOI: - Abstract ( 285 )   HTML   PDF (291KB) ( 1546 )   The main feature of risk factor in a virtual enterprise (VE) is stochastic, and a stochastic risk factor can be regarded as a stochastic variable with which a stochastic programming model is developed for risk management of VE. To solve the stochastic programming model, a Monte Carlo simulation is combined in genetic algorithm (MCS-GA) since the Monte Carlo simulation is a very effective method to deal with stochastic variables. The simulation analysis is given to illustrate the effectiveness of the MCS-GA, and the proposed model is verified to be an important role to play in the VE. References | Related Articles | Metrics

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A distributed trust model for P2P overlay networks based on correlativity of communication history Tan, Zhen-Hua (1); Wang, He (1); Cheng, Wei (1); Chang, Gui-Ran (2) 2009, 30 (9):  1245-1248.  DOI: - Abstract ( 284 )   HTML   PDF (347KB) ( 897 )   Develops a new distributed P2P trust model named NBRTrust (node behavior relation trust) for appraising the degree of confidence of nodes. The global trust model NBRTrust with the correlativities between nodes as factors was developed. A distributed network β-list was built in correlation with the communication histories of nodes to appraise locally the degree of confidence of nodes, then the behavioral correlativities between nodes were computed distributively. Defines the mathematical expression of the model and distributed computation, with the P2P communication model developed on the basis of NBRTrust model. Simulation results revealed that the NBRTrust model is more objective and effective than the simply local or global trust model, which is able to resist efficiently the fraudulent acts from a single or grouped malignant nodes. References | Related Articles | Metrics

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Recognition of 3-D lung nodules based on K-L transform and support vector machine Liu, Yang (1); Zhao, Da-Zhe (1); Liu, Ji-Ren (2) 2009, 30 (9):  1249-1252.  DOI: - Abstract ( 244 )   HTML   PDF (1070KB) ( 669 )   Based on the K-L transform and support vector machine, a new recognition algorithm for the 3-D lung nodule was presented to solve the problem that the details of lung nodule were often ignored in the 3-D space when extracting the characteristics of lung nodule in the interested area by the conventional 2-D method. The geometry and intensity features of lung nodule were analyzed and the 3-D features were calculated and extracted to form an original feature space. Then, the K-L transform method was used to exclude the correlativity between features, and the support vector machine (SVM) was introduced to categorize and recognize the potential lung nodules with the receiver operating characteristic (ROC) curve introduced to evaluated the performance of the algorithm proposed. A test involving 36 sets of clinical lung HRCT data was carried out, where the lung nodules were marked with 'golden standard'. The results indicated that the validity of the algorithm or the accuracy of recognition is up to 94.33% and the value of Az (area under the ROC curve) is 0.94. References | Related Articles | Metrics

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Delay and bandwidth constrained intelligent static traffic grooming scheme Wang, Xing-Wei (1); Tong, Cheng-Cheng (1); Huang, Min (1) 2009, 30 (9):  1253-1256.  DOI: - Abstract ( 250 )   HTML   PDF (1370KB) ( 778 )   Based on the layered graph, a delay and bandwidth constrained intelligent static traffic grooming scheme is proposed in IP over DWDM optical Internet. With the idea of orthogonal design evolution, ecological-niche population and the hybridization are introduced into the scheme to maximize the comprehensive user traffic request delay satisfaction degree and minimize the network cost simultaneously. The scheme proposed was simulated with VC++6.0 and compared with certain existing traffic grooming scheme. Several performance indices of the scheme were evaluated, such as the comprehensive measure and blockage rate of traffic grooming request, over some actual network topologies. Simulation results showed that the proposed scheme is both feasible and effective with better performance. References | Related Articles | Metrics

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Security clustering algorithm based on reputation in mobile ad hoc networks Yu, Yao (1); Li, Zhe (1); Liu, Jun (1) 2009, 30 (9):  1257-1261.  DOI: - Abstract ( 248 )   HTML   PDF (328KB) ( 638 )   By analyzing the security problem of the hierarchical mobile Ad Hoc networks, a security clustering algorithm based on reputation (SCAR) is presented. In the algorithm, the nodes' reputation is acquired through monitoring the network behaviors by neighboring nodes so as to improve the security of the clustered architecture. The mechanism of reputation exchange between nodes increases the accuracy of reputation evaluation, and the stability of clusters is ensured by the two evaluation indices, i.e., correlation and relative mobility. The weight of each node is computed according to the demand for communication and running condition of networks, with the reputation correlation and relative mobility mentioned above considered comprehensively. Then, the clustered architectures are built, maintained and updated by modul weights to strengthen the security supervision of the cluster head and gateway. Simulation results showed that the proposed algorithm improves the system security and stability. References | Related Articles | Metrics

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An approach to fuzzy ontology framing based on fuzzy conceptual model Lü, Yan-Hui (1); Ma, Zong-Min (1); Zhang, Fu (1) 2009, 30 (9):  1262-1265.  DOI: - Abstract ( 224 )   HTML   PDF (216KB) ( 705 )   Classical ontology supported by formalized concepts is unable to represent the imprecision and uncertainty information. Ontology incorporated with fuzzy logic is a solution to the problem. Considering the difficulty to generate the fuzzy ontology in accordance to pre-defined concepts, framing the fuzzy ontology on the basis of fuzzy conceptual model is proposed. The UML conceptual model and OWL DL ontology are therefore fuzzily extended separately on the basis of fuzzy set theory, and the feasibility of framing the fuzzy OWL DL ontology by fuzzy UML class diagram is interpreted in the perspective of their logical foundation. Then, the formalized mapping transformation of fuzzy UML class diagram into fuzzy OWL DL ontology is studied to show the mapping rules and axiomatization process. Framing the fuzzy OWL DL ontology with existing fuzzy conceptual model can reduce efficiently the complexity of framing the fuzzy ontology and, meanwhile, enhance the expressibility of ontology. References | Related Articles | Metrics

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Personalized QoS model for composition service Zhu, Hong-Ning (1); Shi, Shao-Wei (1); Zhang, Bin (1) 2009, 30 (9):  1266-1269.  DOI: - Abstract ( 275 )   HTML   PDF (457KB) ( 546 )   A personalized QoS model is proposed for composition service to solve the problem that a single QoS model fails to consider fully such non-functional attributes in web service as subjectivity, relativity, dependency and uncertainty. The importance of criteria in view of the relativity of service is combined with the attention paid to service in view of subjectivity and uncertainty so as to form an initial weight vector. Then, the dependency is less considered to adjust the initial weight vector so as to get a personalized weight vector. As a result, the personalized QoS model is developed, on which the service functions are constrained and the dependency between criteria is less considered. The analysis of examples showed that the personalized QoS model thus developed is more reasonable and detailed than the single one through QoS evaluation. References | Related Articles | Metrics

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Microstructure and mechanical properties of high niobium X80 pipeline steel Deng, Wei (1); Gao, Xiu-Hua (1); Wen, Zhi-Hong (2); Zhao, De-Wen (1) 2009, 30 (9):  1270-1273.  DOI: - Abstract ( 542 )   HTML   PDF (734KB) ( 825 )   The low carbon-silicon-manganese alloyed billets with 0.10% niobium instead of molybdenum were rolled to be the X80 pipeline steel via HTP (high temperature processing) in lab, of which all the mechanical properties came up to the standard API Spec 5 L. The main parameters in rolling schedule were as follows: finishing temperature 830~850°C; end cooling temperature 500~550°C, cooling rate 25~28°C/sec; total percent reduction in finish rolling not less than 75%. It was found that the microstructure of the steel plate thus rolled is mainly composed of acicular ferrite with small parts of massive ferrite and granular bainite, and the island structure is found on grain boundary. Such a structure can provide high tensile strength and impact toughness. Metalloscopy, SEM and EDS were applied to observing the impact fracture and it was found that the brittle 2nd-phase particles and prior austenite grain boundaries are the main cracking sources. So, controlling the brittle 2nd-phase particles and avoiding the prior austenite grain boundaries will improve the toughness of the pipeline steel efficiently. References | Related Articles | Metrics

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Development of continuous annealing simulator for cold strip and its performance Wang, Wen-Le (1); Hua, Fu-An (1); Li, Jian-Ping (1); Liu, Xiang-Hua (1) 2009, 30 (9):  1274-1277.  DOI: - Abstract ( 306 )   HTML   PDF (418KB) ( 831 )   A new simulator was developed to investigate continuous annealing processes and develop cold-rolled steel grades, on which the close annealing process in N2/H2 protective anmosphere is available with sheet pieces as specimens. During simulation the specimen may be tensioned with a hydraulic cylinder resistance-heated at high current and cooled by narrow-mouth nozzles for high-speed jetting/spraying, and the heating, cooling, tensioning and composition of atmosphere were all controlled according to preset parameters. The whole annealing process was implemented with no specimen moved. Describes the principle of design, system configuration, characteristics and main technical specifications of the simulator. Simulating results showed the homogeneity of micro-structure and balanced mechanical properties of the annealed specimens especially the better reproducibility of testing data. References | Related Articles | Metrics

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Development of ferritic stainless steel with 15% chromium for automobile exhaust system Li, Hua-Bing (1); Jiang, Zhou-Hua (1); Li, Zhen (1); Zhang, Zu-Rui (1) 2009, 30 (9):  1278-1281+1297.  DOI: - Abstract ( 276 )   HTML   PDF (1333KB) ( 558 )   The ferritic stainless steel with 15% chromium (FSSNEW) for automobile exhaust system was developed. Its mechanical properties at room and high temperature and resistance to high-temperature oxidization and corrosion were investigated. The results showed that the developed steel exhibits higher strength than T409L and SUS430J1L with high plasticity and formability provided to meet the deep drawing requirements. Its high-temperature tensile yield strength is superior or equivalent to that of some other ferritic stainless steel now used. Moreover, its resistance to high-temperature oxidization, pitting corrosion and intergranular corrosion is more excellent than T409L. References | Related Articles | Metrics

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Analysis of meniscus fluctuation in mold for round billets by IF soft-contact electromagnetic continuous casting Wang, Zhao-Yang (1); Wang, En-Gang (1); Zhang, Xing-Wu (1); He, Ji-Cheng (1) 2009, 30 (9):  1282-1285+1290.  DOI: - Abstract ( 260 )   HTML   PDF (1195KB) ( 484 )   The fluctuation of the meniscus of molten steel in the mold for round billets produced by the intermediate frequency soft-contact electromagnetic continuous casting process was measured in different positions during tests with different electrical parameters and process parameters. The results showed that the meniscus fluctuates greatly under the action of IF electromagnetic field, while the center of meniscus fluctuates relatively smaller to the margin of meniscus. The whole area of meniscus fluctuates further with increasing electric power, while the fluctuation at the center of meniscus is smaller than that of the margin. It was found that the closer the level of molten steel to the center height of induction coil, the greater the fluctuation of the level, and the level is more stable in a position below the central height in comparison with the level in the similar position above the height. The fluctuation of meniscus in mold tends to be stable with increasing frequency, but its attenuation amplitude of the variance of fluctuation decreases. In an overall view, the frequency 2.5 kHz is chosen as an appropriate one. References | Related Articles | Metrics

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Experiment of titanium-bearing blast furnace slag adsorbing phosphorus in water Ma, Xing-Guan (1); Liu, Jian-Mei (1); Han, Chong (1); Xue, Xiang-Xin (1) 2009, 30 (9):  1286-1290.  DOI: - Abstract ( 505 )   HTML   PDF (594KB) ( 743 )   With the titanium-bearing blast furnace slag as the main object, the effects of particle size and dose of adsorbent, pH value and initial concentration of solution and adsorbing time on the adsorbing-dephosphorization were investigated experimentally. The results showed that the adsorbility of ultrafine titaniumous blast furnace slag to remove phosphates increases with decreasing particle size and increasing slag's dosage, pH value and reaction time, but decreases with increasing initial concentration of phosphates if slag particle size is greater than 10 μm. The adsorbtion process of phosphates by the slag is so rapid that the saturated adsorbtion is basically available within 20~30 min. The XRD patterns and SEM images before and after the absorbtion of phosphates by the slag were compared with each other, and the results showed that massive crystals form on the slag surface after absorbtion and adhere to powdered surface with the multi-layer adhesion found partially. References | Related Articles | Metrics

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Effect of Ld2O3 doping on wave absorbability of Ni-Zn ferrite/Al-alloy foams composite Xue, Xiang-Xin (1); Zhang, Yu (1) 2009, 30 (9):  1291-1294.  DOI: - Abstract ( 219 )   HTML   PDF (308KB) ( 542 )   To investigate the effect of Ld2O3 doping on the microwave absorbability of Ni-Zn ferrite/Al-alloy foam composite, the surface of Al-alloy foam was separately coated with Ni-Zn ferrite and Ld2O3-doped Ni-Zn ferrite powdered composite (with different contents of doping). The coated Al-alloy foams were tested according to the Standard GJB2038-94 "method to test the reflectivity of radar absorbing materials", i.e., the RCS (radar cross-section) method. The topography of wave absorbent was analyzed through scanning electron microscopy (SEM). The results indicated that in the 12~18 GHz band the wave absorbability of the Al-alloy foam sample coated with Ld2O3-doped Ni-Zn ferrite is better than the sample coated with simple Ni-Zn ferrite. However, in the 26.5~40 GHz band, the best wave absorbability belongs to the Al-alloy foam coated with the powdered composite absorbent in which the Ld2O3 content is 1wt%, and the absorbability goes down if the content is higher than 1wt%. So, the absorbability of the Al-alloy foam coated with the powdered composite of Ni-Zn ferrite to which the content of Ld2O3 doping is appropriate can be improved further. References | Related Articles | Metrics

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Research on the Al-Ca-based conditioning flux for ladle slag Dou, Li-Wei (1); Yu, Fu-Zhi (2); Li, Xiao-Wei (2); Shen, Feng-Man (1) 2009, 30 (9):  1295-1297.  DOI: - Abstract ( 484 )   HTML   PDF (711KB) ( 600 )   An Al-Ca-based conditioning flux was newly developed and the comparative experiments were carried out between the conventional Al-CaO-based and the Al-Ca-based conditioning fluxes to control the tapping slag in ladle for the 180 t BOF at a certain steel plant. Then, the effects of the two conditioning fluxes on the slag and both the Al-killed and unkilled molten steel were investigated. The results indicated that 200 kg of the Al-Ca-based conditioning flux is equivalent to 400 kg of the Al-CaO-based conditioning flux for each melt in the BOF, and no obvious increase in carbon content is found in molten steel no matter which conditioning flux is used. In addition, if the conditioning effect remains the same, the Al-Ca-based conditioning flux is more convenient for ladle refining with the cost reduced significantly. References | Related Articles | Metrics

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Hydrothermal synthesis and electrochemical properties of lithium iron phosphate Kang, Xiao-Xue (1); Tian, Yan-Wen (1); Yuan, Wan-Song (1) 2009, 30 (9):  1298-1301.  DOI: - Abstract ( 215 )   HTML   PDF (474KB) ( 1448 )   High-purity and well-crystallized LiFePO4 powders with uniformly distributed fine particles were synthesized in a direct hydrothermal reaction. The microstructure and morphology of the samples were characterized via XRD, SEM and constant current charge-discharge cycle test so as to investigate the influences of hydrothermal temperature/time on the electrochemical properties of as-prepared LiFePO4 powder. The results showed that increasing hydrothermal temperature/time benefits the improvement of crystallinity but coarsens the particles. The best electrochemical properties of the LiFePO4 hydrothermally synthesized are found at 200°C/5 hr with a specific capacity 138.0 mA·h·g-1 at 0.1C rate during initial discharging. It means that the hydrothermal synthesis is commercially practical. Moreover, adding the ascorbic acid and glucose in the hydrothermal synthesis can avoid efficiently the oxidation of Fe2+, thus enhancing the electric conductivity of LiFePO4 powder. References | Related Articles | Metrics

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Characteristics of synchronization for self-synchronous vibration machine with center of mass deviated vibrator Zhang, Nan (1); Hou, Xiao-Lin (2); Wen, Bang-Chun (1) 2009, 30 (9):  1302-1304+1309.  DOI: - Abstract ( 263 )   HTML   PDF (1368KB) ( 475 )   A dynamic electromechanical coupling model was developed, then a numerical simulation was done reasonably for the self-synchronous machine's whole running process including all parameters from system starting to entering into stable state. The results verified fully the self-synchronous characteristics of the machine as shown by the topic. Based on the testing data in combination with simulating data, the synchronization characteristics of such vibrational systems were discussed. It was found that the stably synchronous running state is impossible until the self-synchronous vibration machine satisfies the theoretical conditions of synchronization. References | Related Articles | Metrics

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LS-SVM-FLANN-based nonlinear dynamic compensation for virtual instrument system Li, Li-Na (1); Liu, Hong-Yi (1); Luo, Zhong (1); Wang, Fei (1) 2009, 30 (9):  1305-1309.  DOI: - Abstract ( 328 )   HTML   PDF (1820KB) ( 485 )   A new compensating method is presented to eliminate nonlinear dynamic measurement error of virtual instrument system. In this method, according to the static and dynamic calibrated data of virtual instrument system, the parameters of static and dynamic compensation link models are identified on the basis of the functional link artificial neural networks (FLANN) that is constructed by the least square-support vector machine (LS-SVM), then both the compensation link models are connected in series to the original virtual instrument system so as to correct its nonlinear characteristics and improve its dynamic performance, thus obtaining the desired input/output characteristics of the system. Test results revealed that this method is effective and superior to compensating nonlinear dynamic error for virtual instrument system. References | Related Articles | Metrics

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Reliability analysis and parametric design of piston rod of a reciprocating compressor Chen, Peng-Fei (1); Sun, Zhi-Li (1); Teng, Yun-Nan (1) 2009, 30 (9):  1310-1313.  DOI: - Abstract ( 282 )   HTML   PDF (522KB) ( 724 )   To improve the design level of reciprocating compressor, the VC++ and Pro/E were used to develop a system software for the fatigue reliability analysis and parametric design of piston rod. The loading state of piston rod was analyzed to find out the weak link in the design in accordance to the deformation compatibility principle of elastic mechanics and then the results were verified by FEM. A limit-state equation for the weak link was given according to the randomness of design parameters, such as geometric dimensions, machining process and material strength, so as to analyze both the reliability of fatigue strength and relevant economical level, thus determining all the design parameters of the piston rod, including dimensions, process technology and material to carry out parametric design. The results showed that the combination of reliability theory with parametric design is very promising in engineering practice. References | Related Articles | Metrics

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Research on a high-precision algorithm of RBF neural network and its applications Zheng, Xi-Jian (1); Zhang, Guo-Zhong (1); Xie, Zheng-Yi (2) 2009, 30 (9):  1314-1317+1345.  DOI: - Abstract ( 251 )   HTML   PDF (173KB) ( 608 )   Analyzes the principle of the basic algorithm of RBF neural network and the problem that the excitation function parameters and the number of hidden layer elements are both selected empirically. A new high-precision algorithm of RBF neural network is proposed according to RBF neural network structure where the threshold and weight values are taken as design variables with network error as objective function, and all of the dynamic variables are ranked reasonably with a computation program given. Compared with the basic algorithm of RBF neural network, the algorithm proposed is really an optimization process taking the threshold and weight values as unknown variables so as to implement the high-precision computation of the RBF neural network. According to the equation theory, a reasonable way is given to determine the hidden layer structure in network. The program analysis by examples indicated that the optimization algorithm has a high goodness of fit with samples and high-precision interpolation results, thus providing the foundation for further theoretic study and engineering applications. References | Related Articles | Metrics

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On the UG-based modeling design system of cold-punching dies Sheng, Zhong-Qi (1); Xie, Hua-Long (1); Lin, Dong-Ling (1); Liu, Yong-Xian (1) 2009, 30 (9):  1318-1321.  DOI: - Abstract ( 287 )   HTML   PDF (347KB) ( 780 )   Current CAD system of cold-punching dies has some problems such as low degree of standardization, weak specificity, behindhand development tool and so on. The basic theory and methods of parametric design and feature-based modeling were thus investigated to develop a UG-based modeling design system for cold-punching dies. With the secondary development tools of UG used, the libraries of both standard parts and common dies were framed, by which the assembly design of any cold-punching dies is available to be completed according to the bottom-up design method. The UG WAVE technology is applied in the modeling process of die parts. Exemplifying the design of a blanking die for car parts in a certain car manufacturer, the modeling design system for cold-punching dies is of significance to improve the efficiency of die design and standardize it. References | Related Articles | Metrics

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On the counterweight law of 3-PRS parallel machine tool Meng, Xiang-Zhi (1); Liu, Chun-Shi (2); Li, Ming (1); Yang, Liu (3) 2009, 30 (9):  1322-1325.  DOI: - Abstract ( 248 )   HTML   PDF (429KB) ( 577 )   Because of the big mass of moving parts, three motors are needed on parallel machine tool to drive those parts, and the dynamic balance of the machine tool is needed during moving. Three counterweight pulleys are therefore provided for relevant branch chains to implement the spatial dynamic balance via the parallel mechanisms positioned between the moving and resting platforms for every branch chain. By means of theoretical derivation and practical calculation, the counterweights needed for two branch chains are 31.09 kg and 57.69 kg, and that for the moving platform is 157.36 kg. Simulation results showed that the maximum force output of drive rod is about 10N after dynamic balance-it is less by far than before dynamic balance: 1100 N. A satisfactory balancing result is thus obtained. References | Related Articles | Metrics

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Study on the mechanism of ground stress in coal-gas outburst Duan, Dong (1); Tang, Chun-An (1); Li, Lian-Chong (2); Feng, Xiao-Jing (3) 2009, 30 (9):  1326-1329.  DOI: - Abstract ( 357 )   HTML   PDF (534KB) ( 975 )   According to the rock failure damage theories and gas-solid coupling method, the RFPA2D-GasFlow soft code in combination with the stress distribution in coal body and process and the result of gas outburst was applied to the analysis of the effect of ground stress on gas outburst process. The results showed that the ground stress will obstruct the gas outburst if it is lower than 1 MPa. However, when it is higher than 1 MPa, the horizontal compression stress will enhance the resistance to the failure of coal body and, additionally, the shear stress will stimulate the failure of coal body. Then, the results were used to analyze the gas outburst in shallowly buried coal bed. It was found that the ground stress acted on the shallowly buried coal bed is relatively small, and the horizontal and vertical tensile stresses in coal bed are both of great extension-these are just the reasons why the gas outburst occurs in such coal bed and why the gas outbursts thus evoked are mainly of extra-serious type. References | Related Articles | Metrics

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Study on microseismic activity in potential rockburst zone during deep excavation in Hongtoushan mine Zhao, Xing-Dong (1); Li, Yuan-Hui (1); Liu, Jian-Po (1); Tian, Jun (1) 2009, 30 (9):  1330-1333.  DOI: - Abstract ( 274 )   HTML   PDF (448KB) ( 869 )   The value of ground stress was measured by the method of surface strain during deep excavation in Hongtoushan Copper Mine to investigate the impact acting on the rockmass in the depths of the mine. A 3-D geological model was developed for the No.13 stope at the elevation of -767 m, where the sensors were arranged properly to form a microseismic monitoring system so as to obtain continuously the rule of the activity of deep ground pressure and seize the information microseismic activities due to ground pressure, thus locating the microseismic source. Then, the interfering signals were rejected in the seized information by the pattern recognition based on neural network, such as the signals of bursting, rock drilling and power supply. The efficient locating result by microseismic monitoring is thus shown, and the cause of different microseismic events can be distinguished with the magnitudes of released microseismic energies. Furthermore, it is probable to predict the rockburst in accordance to the number of microseismic events within a unit time that has been set via the time-dependent nonlinear analysis of the data of microseismic events monitored continuously, which is of actual importance to the prediction of dynamic hazard/disaster in the mine. References | Related Articles | Metrics

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Test method of measuring s-wave velocity of rock by V-shaped groove on specimen Ding, Wu-Xiu (1); Wang, Hong-Yi (2); Zhao, Wen (1) 2009, 30 (9):  1334-1336+1349.  DOI: - Abstract ( 619 )   HTML   PDF (823KB) ( 818 )   S-wave velocity is significant to the determination of dynamic parameters and evaluation of rockmass stability. A new measurement method of S-wave velocity for small-size rock samples is put forward according to the propagating law of elastic wave. The S-wave velocity can be measured with the probes for P-wave by the V-shaped groove on the bottom of specimen to eliminate the interference from P-wave. The S-wave velocities of rock samples with layered structure are thus obtained with the anisotropic coefficient of S-wave velocity calculated. The results showed that the change of S-wave velocity in rock is similar to that of P-wave velocity, i.e., observing the law of elliptic equation. It was proved that the new measurement method is applicable via the analysis of the ratio of P-wave velocity to S-wave velocity. References | Related Articles | Metrics

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Two-phase evaluation and selection to match employees with their positions in an organization Chen, Xi (1); Fan, Zhi-Ping (1) 2009, 30 (9):  1337-1340.  DOI: - Abstract ( 291 )   HTML   PDF (388KB) ( 829 )   A two-phase decision making method is proposed to match the employees with their positions in an organization, including evaluation and selection. An evaluation index system is framed for the match between the satisfaction degree of both employees and their positions. Then, a two-phase evaluation and selection method are proposed. In the first phase, the evaluation information on the linguistic satisfaction degree given by positions and employees separately is transformed into the two-tuple linguistic aggregation, thus giving a way to evaluate the match between employees and their positions via the two-tuple linguistic information processing. In the second phase, a matrix model is developed to select the match between employees and their positions, by which the matching results and the decision considering different areas are analyzed. A numerical example of KC consulting company is given to illustrate the practicality and validity of the proposed method. References | Related Articles | Metrics

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A method for selecting technologies considering compatibility in new product design Xu, Hao (1); Fan, Zhi-Ping (1); Yi, Wei (1) 2009, 30 (9):  1341-1345.  DOI: - Abstract ( 373 )   HTML   PDF (1269KB) ( 480 )   Generally, considering the compatibility of technologies is indispensable for selecting desirable technologies in new product design. A new method for decision analysis is therefore proposed to solve the technology selection problem with the compatibility considered, where an optimization model is developed on the basis of technology evaluation matrix and technology compatibility relationships matrix. Then, a technology alternative can be determined by solving the model. The analysis of a practical example shows the feasibility and validity of the proposed method. References | Related Articles | Metrics

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Evaluation and empirical study on incentive mechanism about general managers of large state-owned branch companies - Based on provincial branch companies' questionnaire investigation Feng, Duo (1); Wang, Shi-Quan (1); Yuan, Qing-Hong (2) 2009, 30 (9):  1346-1349.  DOI: - Abstract ( 338 )   HTML   PDF (824KB) ( 526 )   The evaluation index of incentive mechanism is constructed for general managers of large state-owned branch companies from 3 perspectives: competitive motivation, controlling right motivation and salary motivation, then an evaluation is done in combination with an empirical analysis based on survey data. The results showed that the incentive mechanism of large state-owned branch companies runs well as a whole. But, for the secondary indices, the salary motivation and competition motivation are better than that of controlling right and, they are better in financial industry than in non-financial industries on the whole. However, among the three motivations, the controlling right contributes more to the branch performance than the other two motivations. Based on this, some specific measures are put forward to enhance the incentive mechanism according to the problems found by the empirical analysis. Besides, because of strong "legal person characteristics" manifested by a state-owned branch company and the existence of the agent problem between headquarter and its branches, the manners of headquarter treating its branches should transfer from traditional management to governance, but, which then arouse some theoretical issues, such as "does a branch necessitate the governance", etc. References | Related Articles | Metrics

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Agent-based democratic evaluation for performances of urban water supply enterprises Chen, Xian-Li (1); Zhu, Chun-Hong (1); Zhao, Xi-Nan (1) 2009, 30 (9):  1350-1353+1361.  DOI: - Abstract ( 232 )   HTML   PDF (944KB) ( 568 )   According to the characteristics of urban water supply, the indices of performances evaluation were proposed for relevant enterprises. Then, an agent-based democratic evaluation system was suggested for different water supply enterprises, which has been applied to such enterprises in 13 cities of China. This evaluation takes full account of the natural value orientation of each and very enterprise, while the public value orientation is not neglected. So, it is able to not only reflect the individuality of an enterprise in evaluation but also avoid the divergences which were often found in the weights for evaluation. The results of applications with examples given showed that the simple evaluation system proposed can reflect quantitatively the performances of urban water supply enterprises actually. References | Related Articles | Metrics

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Performance evaluation system and method for governmental public management Hou, Hong-Bo (1); Guo, Ya-Jun (1); Liu, Ying-Bo (2) 2009, 30 (9):  1354-1357.  DOI: - Abstract ( 231 )   HTML   PDF (180KB) ( 770 )   Analyzing the basic theories of the performance evaluation (PE) for governmental public management (GPM) in two different ways, i.e., the management by objectives (MBO) and new public management (NPM), a series of integral links in the performance evaluation system are designed including the analysis of evaluation index system, objective orientation, index system framing and scoring. Discusses emphatically the different ways to deal with the weights and multiindex aggregation on the basis of different objective orientiation. Describes the numerical methods separately to deal with the economic and noneconomic single index with the way to integrate the absolute quantity with the relative one studied. Points out the dimensionless method for index values. Then, the integrated multiple-attribute evaluation comes to pass by determining the Grade I and Gade II weights for evaluation indices via rank correlation analysis and improved method of scatter degree. The demonstrating application results verified the validity of the evaluation system proposed. References | Related Articles | Metrics

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Game analysis of leader-follower alliance on international iron ore market Hou, Hui (1); Yang, Xi-Huai (1); Han, Chao-Ya (2); Zhao, Yan-Li (2) 2009, 30 (9):  1358-1361.  DOI: - Abstract ( 288 )   HTML   PDF (360KB) ( 722 )   The leader-follower alliance on international iron ore market was studied from the revenue-sharing angle. The profit models of the leader, follower and alliance itself were developed, and the profit sharing between the leader and follower was analyzed through Stackelberg game. Discussing the revenue-sharing proportion, order quantity and wholesale price, the game coordination strategies between leader and follower were presented respectively in decentralized and centralized patterns. Numerical simulation showed the result of the game in alliance mode on the iron ore market and indicated that the profit of alliance in centralized pattern was higher than that in decentralized pattern, i.e., shared by the leader and follower respectively. References | Related Articles | Metrics

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An improved interval estimate for the maximum eigenvalues of saddle point matrices Li, Zheng (1); Zhang, Tie (1); Li, Chang-Jun (1) 2009, 30 (9):  1362-1364+1368.  DOI: - Abstract ( 267 )   HTML   PDF (175KB) ( 470 )   The eigenvalue estimate theory of saddle point matrices is studied. Estimate for the lower bound of the maximum eigenvalues of saddle point matrices is improved, based on the analysis of the symmetry of saddle point matrices and the relation between maximum eigenvalues of saddle point matrices and the eigenvalues of their sub-matrices. Then, an improved interval estimate for the maximum eigenvalues of saddle point matrices is obtained. The maximum eigenvalues of saddle point matrices, which are derived from the stationary Stokes equation discretized by the P1-P0 mixed finite element method, are observed in the numerical experiment. The numerical results demonstrate that the involved interval estimate for the maximum eigenvalues of saddle point matrices is valid. References | Related Articles | Metrics

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Reciprocal theorem of work done for the solution of natural frequency of triangular plate Yu, Zheng-Wen (1); Lü, Peng-Yu (1) 2009, 30 (9):  1365-1368.  DOI: - Abstract ( 286 )   HTML   PDF (193KB) ( 566 )   Based on the principle of virtual work and the differential equation similarity of the free vibration to the elastic curved surface of sheet in both expression and mechanics, the inertia force due to sheet vibration is regarded as the transverse load to bend the sheet, and the reciprocal theorem of work done is used to solve the dynamic problem, thus obtaining the formula of natural frequency of sheet. Setting an appropriate vibration mode shape function, the natural frequency of simply-supported sheet in shape of isosceles right triangle or equilateral triangle is solved via the reciprocal theorem of work done, mapping and superposition. The method combining statics with the reciprocal theorem of work done to solve dynamic problems is easy to extend, and it is simple with high accuracy in solving the natural frequancy of a structure. References | Related Articles | Metrics