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15 May 2009, Volume 30 Issue 5 Previous Issue    Next Issue
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Simulation platform for optimal operation and control of roasting process in shaft furnace Ding, Jin-Liang (1); Geng, Dan (1); Yue, Heng (1); Chai, Tian-You (1) 2009, 30 (5):  609-612.  DOI: - Abstract ( 258 )   HTML   PDF (505KB) ( 709 )   Determining the technological indices of the roasting process in shaft furnace is difficult in not only the online measurement but also the modeling of their nonlinear and strong-coupling dynamic behavior in relation to the outputs from control loops to describe exactly the complexity that the process in varying with boundary conditions. To solve the problems of optimal operation/control of the roasting process in shaft furnace, a hardware-in-loop simulation (HILS) platform is developed with openness and modularity. It adopts the optimal operation/control strategy which is a two layered structure, i.e. the optimal operation layer and conventional control layer. The modules of the platform include mainly the optimal operation system, process monitoring system, programmable logic controller (PLC), virtual instruments and actuators, virtual plant system. Seamless integration features all the modules and their communication signals consist with in-site actual ones. Experiment results show the effectiveness of the platform. References | Related Articles | Metrics

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Exponential stability of a class of static neural networks with time varying delay Zhang, Rui (1); Wang, Zhan-Shan (1); Jing, Yuan-Wei (1) 2009, 30 (5):  613-616.  DOI: - Abstract ( 206 )   HTML   PDF (1507KB) ( 621 )   Based on the linear matrix inequalities and considering the different effects of change rate of time varying delay on stability, two criteria for exponential stability are set up, i.e. the criterion that just depends on the upper bound of the delay and the criterion that depends wholly on the delay information. The two stability criteria obtained can be adaptable to either quickly changed or slowly changed time varying delay, thus providing wider applications, less conservativeness and verification easy to do, and with some remarks given and in comparison to the results in earlier works, simulations were done to exemplify the effectiveness of the proposed approaches. References | Related Articles | Metrics

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Dynamic output feedback stabilization for T-S fuzzy control systems via LMI Chen, Zhao-Na (1); Jing, Yuan-Wei (1); Zheng, Hai-Qing (1) 2009, 30 (5):  617-620.  DOI: - Abstract ( 286 )   HTML   PDF (1161KB) ( 583 )   Discusses the output feedback control of a class of nonlinear systems in terms of T-S fuzzy models. A new design method is proposed for the dynamic output feedback controllers to give the sufficient conditions for the existence of the quadratic stability of fuzzy systems, thus converting the control problem into the solutions to LMIs. Analyzing in depth the interaction between each and all fuzzy subsystems, the sufficient conditions become more relaxed. With an inverted pendulum on a cart as an example taken in numerical simulation, the result revealed the quickness and robustness of such nonlinear systems. References | Related Articles | Metrics

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Stage-based recursive MFDA strategy for fault diagnosis on hydrostatic tube tester Wang, Shu (1); Hu, Xue-Fa (1); He, Da-Kuo (1); Wang, Fu-Li (1) 2009, 30 (5):  621-624.  DOI: - Abstract ( 227 )   HTML   PDF (244KB) ( 613 )   Because of the complexity of process modeling on a hydraulic tube tester, it is difficult to diagnose the process fault in view of its mechanism. On the other hand, the fault diagnosis based on MFDA (multiway Fisher discriminant analysis) has high diagnostic capability because it takes advantage of both normal and fault data in modeling. To solve the problem of uneven-length batches, a stage-based header-even method is proposed according to the characteristics of data sampled from hydrostatic testing process, thus adjusting all the batches to become average length. Then, different MFDA models are developed for every sub-stage that was divided in testing process. Combining with the recursive method, the diagnosis results of three stages are intergrated together to improve the diagnostic precision. The effectiveness of the proposed method is tested and verified by applying it to the fault data of four shuttle valves. References | Related Articles | Metrics

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Set-partition based heuristic algorithm to solve the problem of pick-up and delivery of air-passengers Kong, Yuan (1); Tang, Jia-Fu (1); Pan, Zhen-Dong (1); Dong, Gang (1) 2009, 30 (5):  625-627+660.  DOI: - Abstract ( 271 )   HTML   PDF (945KB) ( 968 )   Considering the strict time requirements for air-passengers who have to get to airport punctually and the detour that brings inconvenience to them, the time they require is quantified to their satisfaction to a certain degree so as to develop a mathematical model involving the weights of both trip and detour time of shuttle buses with the single minimum objective. According to the characteristics of the problem to be solved and the model, a set-partition based heuristic algorithm is designed, in which a set of the sequences of efficient trips of shuttle buses are all routed, then a heuristic PNAC (per-node average-cost), algorithm is developed in combination with the scheduling optimization process to choose a group of route sections to visit all relevant passengers. Simulation results verified the effectiveness of the proposed model and algorithm. References | Related Articles | Metrics

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Heuristic method for solving PDP scheduling problem Lu, Rui (1); Wang, Cheng-En (1) 2009, 30 (5):  628-631.  DOI: - Abstract ( 264 )   HTML   PDF (338KB) ( 790 )   For the scheduling problem of PDP (product design project), the stochastic effect of task duration and the possibility of rework are both taken into account to extend the conventional computational method of priority rules. A heuristic scheduling approach is therefore presented introducing the extended priority rules and the stochastic serial schedule generation scheme so as to form a schedule with the objective of minimizating the project makespan. The near-optimum scheduling strategy is obtained by means of sampling the stochastic task duration vectors. The proposed method was tested with different duration variabilities, and the results verified its effectiveness and revealed that the stochastic method for PDP scheduling is able to provide much higher quality of solutions in the case of duration uncertainty and rework possibility are higher. References | Related Articles | Metrics

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Fuzzy extension of semantic web rule language Wang, Xing (1); Ma, Zong-Min (1); Meng, Xiang-Fu (1) 2009, 30 (5):  632-635.  DOI: - Abstract ( 274 )   HTML   PDF (185KB) ( 868 )   Although SWRL, i.e. semantic Web rule language, has highly expressive power, it is unable to express the imprecise and uncertain knowledge/information which is so much in semantic Web. In addition, a single membership degree in fuzzy sets is inaccurate to express the fuzzy information, and the weights in f-SWRL can only express the importance of fuzzy classes and fuzzy properties. A fuzzy SWRL extension named vague-SWRL is therefore proposed on the basis of vague sets, with the notion of second-degree weight introduced to modify and restrict the membership degrees of fuzzy classes and fuzzy properties. The syntax and semantics of vague-SWRL are investigated and specified, and a rule example is given to illustrate the features of vague-SWRL. Introducing the vague sets especially the second-degree weights into rule languages, the expressive power of vague rules is enhanced so as to conform to the developmental trend of semantic Web with significant superiority. References | Related Articles | Metrics

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F-HMIPv6 based handover scheme for QoS context transfer Ma, Xue-Bin (1); Wen, Tao (1); Guo, Quan (2); Wang, Gang (1) 2009, 30 (5):  636-639.  DOI: - Abstract ( 274 )   HTML   PDF (361KB) ( 659 )   In conventional mobile Ipv6 handover schemes, each and every handover operation requires a large number of interactive signalings, thus increasing the time delay. Based on the architecture for fast mobile hierarchical MIPv6, a new QoS context transfer solution is proposed to ensure the QoS of real-time applications when using mobile node to perform the handover. It shortens the delay caused by the time taken from QoS resignaling to QoS retransmission after handing over the mobile node, thus reducing the possibility of interruption of talk through mobile node. Theoretic analyses and simulations showed that the proposed scheme can obviously decrease the delay and jitter in real-time handover operation, especially in the frequent ping-pong handover operation. Smooth handover of mobile node is therefore available. References | Related Articles | Metrics

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Design and implementation of growth model of internet topology based on AS level Zhao, Hai (1); Yao, Dong (1); Zhang, Xin (1) 2009, 30 (5):  640-643.  DOI: - Abstract ( 252 )   HTML   PDF (678KB) ( 709 )   Based on the massive data authorized by CAIDA (cooperative association for Internet data analysis) Skitter project, of which the time span of collection data was from January 2002 to June 2006, the continuing tendencies of genetic and extinct modes in AS-level network and their degree distribution are discussed after analyzing and collating the data. According to the dynamic analysis of the continuing tendency and degree distribution, the PFP model is taken as a prototype where the degree distribution is chosen as the power law distribution, thus giving an AS-level-oriented Internet topology model. Experimental result revealed that the model can embody better the growth process of the AS-level Internet topology if the degree distribution of nodes is ensured to present the power law. References | Related Articles | Metrics

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AAPF algorithm and its application to the path planning problems of multiple mobile-robots Gao, Wei (1); Zhao, Hai (1); Luo, Gui-Lan (1); Song, Chun-He (1) 2009, 30 (5):  644-647.  DOI: - Abstract ( 256 )   HTML   PDF (171KB) ( 909 )   The path planning of a system composed of multiple mobile-robots is investigated, and an adaptive-artificial potential field (AAPF) algorithms is proposed, in which the adaptive sliding strategy is introducted to solve the problem that the basic APF is easy to come to lobal extremum. And the adaptive anticollision strategy is introduced into the algorithm to solve the problem of collinsion in the path planning of the system of multiple mobile-robots. The effectiveness of AAPF algorithm was verified by a simulation test where AAPF was applied to the path planning of the system of multiple mobile-robots. References | Related Articles | Metrics

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Error analysis of triangle location algorithm Zhu, Jian (1); Zhao, Hai (1); Xu, Jiu-Qiang (1); Wang, Jing (1) 2009, 30 (5):  648-651.  DOI: - Abstract ( 605 )   HTML   PDF (390KB) ( 1151 )   A triangle location model is developed to study the location error in triangle. The condition for the formation of minimal location error is found via an analysis of the location model. Then, based on the condition, how the error changes within the triangle is abstracted and its correctness is verified through some testings. The conclusion is entirely drawn by calculation and it gives theoretically a convincible gist and support for the study on location algorithms. References | Related Articles | Metrics

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ABC-supported QoS unicast routing scheme based on ant algorithm Wang, Xing-Wei (1); Zou, Rong-Zhu (1); Huang, Min (1) 2009, 30 (5):  652-655.  DOI: - Abstract ( 237 )   HTML   PDF (1446KB) ( 880 )   Introducing the knowledge relevant to fuzzy mathematics and microeconomics, an ABC-supported QoS unicast routing scheme is proposed. In the scheme the intervals are used to describe users' flexible QoS requirements with the edge-suited membership function introduced to adapt to the inaccurate information on the status of link. With the mechanisms introduced in for bandwidth pricing and edge/path evaluation and based on the ant algorithm, the QoS unicast path is sought to enable the utility of both users and network provider to achieve or approach the Pareto optimum in Nash equilibrium. The routing scheme was implemented through NS2 simulation, and its performance was evaluated on several actual and virtual network topologies. The results showed that the routing scheme is feasible and efficient. References | Related Articles | Metrics

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Localization technology based on the RSSI for wireless sensor networks Qu, Wei (1); Li, Zhe (1) 2009, 30 (5):  656-660.  DOI: - Abstract ( 242 )   HTML   PDF (213KB) ( 992 )   The node localization technology in wireless sensor networks was studied, and a flexible trilateration localization (FTL) based on RSSI was presented. In the FTL process three cooperant beacons are taken to generate sensors' effective error ranges where the unknown nodes exist in, thus completing the node localization with the assistance by one or two hops of neighboring nodes. Simulation results showed that FTL needs low request for the positions of sensors relative to beacons in comparison to the RSSI-based distributed node localization using three common beacons. When the mean ranging error is 10%, the mean localization error is about 20% of sensors' RF communication distance. References | Related Articles | Metrics

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Microstructure, texture and deep drawability of ultra-purified ferritic stainless steel Liu, Hai-Tao (1); Liu, Zhen-Yu (1); Wang, Guo-Dong (1); Jiang, Lai-Zhu (2) 2009, 30 (5):  661-664.  DOI: - Abstract ( 252 )   HTML   PDF (619KB) ( 930 )   The microstructure, texture and deep drawability of an ultra-low carbon/nitrogen ferritic stainless steel were investigated focusing on the influence of reduction on cold rolling and recrystallization texture. The results indicated that the hot-rolled strip after annealing is mainly characterized by {111} recrystallization texture when hot rolling is finished at 750°C. The orientation density of γ-fiber texture decreases but that of α-fiber texture increases with increasing cold rolling reduction. And, the orientation density of {111} recrystallization texture increases significantly as well. The volume fraction of {111} recrystallization component is up to 64.5% when the cold rolling reduction is 84%, and the cold-rolled sheet after annealing shows that its deep drawability is so favorable that the values of average strain ratio (R¯) and planar anisotropy (ΔR) are 1.69 and -0.17, respectively. References | Related Articles | Metrics

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Transformation of V-bearing steel P510L for chassis frame girder during continuous cooling Zheng, Dong-Sheng (1); Zhu, Fu-Xian (1); Li, Yan-Mei (1); Liu, Yong (2) 2009, 30 (5):  665-668.  DOI: - Abstract ( 223 )   HTML   PDF (603KB) ( 773 )   The transformation behavior of V-bearing steel P510L for chassis frame girder under continuous cooling was investigated by means of MMS-200 thermomechanical simulator, with the CCT curves given statically and dynamically by thermal dilation in combination with metallography. The influences of deformation condition and cooling rate on the microstructure of the steel were analyzed. The results showed that the transformation of ferrite and pearlite is stimulated but that of bainite is inhibited through the deformation of austenite in low-temperature region, and the ferrite amount decreases and bainite amount increases with increasing cooling rate. References | Related Articles | Metrics

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High-precision rolling force prediction model for hot strip continuous rolling process Li, Hai-Jun (1); Xu, Jian-Zhong (1); Wang, Guo-Dong (1) 2009, 30 (5):  669-672.  DOI: - Abstract ( 324 )   HTML   PDF (337KB) ( 1307 )   The precision of gauge control of hot-rolled strip is directly affected by the calculating precision of rolling force model, where the rolling pressures in the models are mostly decomposed and become the product of the influence coefficient in stress state and resistance to deformation. A high-precision rolling force prediction model was developed choosing Misaka Yoshisuke formula as the model of influence coefficient in stress state, which conforms well with Simon's formula, with the effects of residual strain considered. The influences of residual strain on the rolling force action on carbon steel and alloy steel were analyzed to give a calculation model for the residual strain of tandem hot strip rolling mill. The application results showed that the rolling force model has high prediction precision to satisfy the on-line requirements. References | Related Articles | Metrics

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Safety control strategy for hydrogen utilization in continuous annealing simulator Cui, Xi-Yong (1); Hua, Fu-An (1); Li, Jian-Ping (1); Zhang, Dian-Hua (1) 2009, 30 (5):  673-676.  DOI: - Abstract ( 359 )   HTML   PDF (302KB) ( 925 )   Analyzing the working principle of continuous annealing simulator for cold rolled strip and physical characteristics of hydrogen, a safety control strategy of hydrogen utilization was proposed including the controls of hermetical performance of furnace, gas content in furnace, alarm of hydrogen detection in plant, safety interlocking and emergency measures. A continuous annealing simulator of cold rolled strip has therefore been developed successfully and used in good condition in a steel plant without faults though hydrogen was utilized so frequently. The fact showed that the safety control strategy proposed ensures the safe utilization of hydrogen. References | Related Articles | Metrics

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On the influencing factors of backup roll profile for a hot strip 4-high mill Zhao, Xu-Liang (1); Gong, Dian-Yao (1); Xu, Jian-Zhong (1); Zhang, Dian-Hua (1) 2009, 30 (5):  677-680.  DOI: - Abstract ( 251 )   HTML   PDF (958KB) ( 834 )   The impact of influencing factors of backup roll profile, a curve surface, on the distribution of rolling pressure and the strip crown at exit of a 1250 mm hot strip mill was investigated, based on the influence function method to analyze the elastic deformation of rolls on a 4-high hot strip mill. The aim is to lay an important foundation theoretically for the optimum design of backup roll profile. The results showed that the length, height and type of roll chamfers and roll crown have great influence on the distribution of rolling pressure and the strip crown at exit. It's important to select suitable rolls' curve surfaces and relevant parameters in accordance to the actuality in site during the optimum design of backup roll profile, with the crown controllability of the mill ensured to meet the productive requirements. References | Related Articles | Metrics

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Effect of plastic deformation rate on plate steel during roller leveling Xue, Jun-An (1); Cui, Li (1); Hu, Xian-Lei (1); Liu, Xiang-Hua (1) 2009, 30 (5):  681-684.  DOI: - Abstract ( 308 )   HTML   PDF (412KB) ( 867 )   To investigate the deformation behavior of plate steel during roller leveling in depth, the curvature integration by elastic-plastic differences was introduced to simulate and analyze the effect of plastic deformation rate on the leveling results. A method of dispersion calculation was proposed for plastic deformation rate, thus getting the relationships between the plastic deformation rate, residual curvature and average residual stress for different combinations of reduction schedule under conditions of single-valued initial curvature. The plastic deformation rate cannot be justified theoretically that it is the only criterion for leveling results. However, because the initial curvature is very hard to determine on line, the plastic deformation rate has to come up to about 80% after roller leveling. In addition, the optimized leveling conditions are pointed out for the single-valued initial curvature. References | Related Articles | Metrics

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Application of soft-sensing to prediction of ingot cracking trend Huang, Song-Lin (1); Cui, Jian-Zhong (1) 2009, 30 (5):  685-688.  DOI: - Abstract ( 218 )   HTML   PDF (285KB) ( 597 )   At present no measure is available to predict the trend of crack propagation online during ingot forming. To solve the problem, the soft sensing technique was applied to the semi-continuous electromagnetic casting process of Al-alloys, where the auxiliary parameters available to direct online sensing were chosen to develop a soft sensing model of cracks on the basis of multilayer feed forward neural network. The outputs from the model are the quantized values of crack, which means that the quantized values of ingot cracks are indirectly censored online and the trend of crack propagation is predicted. Experiment/simulation results revealed that the predicted values of crack from the model conform well the values actually measured, thus reflecting well the actual trend of cracks so as to make online prediction/control of cracks available. References | Related Articles | Metrics

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Preparation and performance of titanate-zirconate phosphonate hybrid films on aluminum alloys Wang, Shuang-Hong (1); Liu, Chang-Sheng (1); Shan, Feng-Jun (1); Liu, Chuan-Hai (1) 2009, 30 (5):  689-691+695.  DOI: - Abstract ( 454 )   HTML   PDF (392KB) ( 1097 )   The titanate-zirconate phosphonate hybrid films were prepared by two-step method on AA6061 aluminum alloy for corrosion resistance. The morphology of those films was investigated by SEM with the chemical structure analyzed by Fourier transform infrared spectroscopy. Furthermore, the phase composition was examined by X-ray photoelectron spectroscopy with the corrosion resistance performance tested by salt spay test. The results showed that the titanate-zirconate aminotrimethylene phosphonate films are of hybrid/composite structure that is composed of the titanate-zirconate film and aminotrimethylene phosphonate layer. The corrosion area of the hybrid film is less than 10% after continual salt spay for 72 hr. References | Related Articles | Metrics

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Three-dimensional numerical model of blast furnace hearth in tapping process Li, Yu (1); Chen, Liang-Yu (1); Shen, Feng-Man (2); Zhang, Ke-Wen (1) 2009, 30 (5):  692-695.  DOI: - Abstract ( 304 )   HTML   PDF (545KB) ( 670 )   According to the thermofluid dynamics and enthalpy-porosity method of computational fluid dynamics, a 3-D steady-state tapping model of blast furnace hearth was developed, including solidification and phase transition of hot metal and slag. The cooling conditions for hearth and bottom were transformed reasonably by equivalent coefficient of convective heat transfer. The velocity field, temperature field and skull figure in a blast furnace hearth were computed and analyzed. The skull data and flow character of hot metal were given under conditions of different utilization factors of blast furnace and cooling intensities, thus providing the reference for blast furnace operation. References | Related Articles | Metrics

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Experimental study on cold strength of carbon composite iron ore hot briquette Chu, Man-Sheng (1); Wang, Zhao-Cai (1); Ai, Ming-Xing (1); Liu, Zheng-Gen (1) 2009, 30 (5):  696-700.  DOI: - Abstract ( 277 )   HTML   PDF (492KB) ( 1143 )   The effects of coal from different mines and hot briquetting process parameters on the cold strength of CCB were investigated, as well as the mechanism of acquiring high strength of CCB. The experimental results showed that the process parameters including the coal used, coal proportioning, hot-briquetting temperature/pressure and coal size all have significant effects on the cold strength of CCB, among which the hot-briquetting temperature is the most important factor. With the thermal plasticity of coal, the hot-briquetting process could ensure that the coal particles are in full contact with iron ore and enlarge the bonding area, thus providing the higher cold strength for CCB in comparison to cold-bonded briquette. To keep up the cold strength with the soft coal from Hegang Mine used for CCB, the appropriate hot-briquetting process parameters of CCB are recommended as follow: coal proportioning 25%-35%, coal fine size less than 90 μm and hot-briquetting pressure higher than 35 MPa. References | Related Articles | Metrics

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On the silica-coated surface of magnesium carbonate particles Ji, Hai-Bin (1); Zu, Guo-Yin (1); Yao, Guang-Chun (1); Liu, Le-Tian (1) 2009, 30 (5):  701-703+707.  DOI: - Abstract ( 275 )   HTML   PDF (295KB) ( 1304 )   With the tetraethylorthosilicate (TEOS) used as starting material which was hydrolyzed on the surfaces of MgCO3 particles by sol-gol method, and the surfaces of MgCO3 particles were coated by the silicic acid thus formed. Then, silica films were formed on the surfaces of MgCO3 particles after heating-drying. Orthogonal tests were performed to investigate the influence of different conditions for TEOS hydrolysis on such a coating, and XRD was done to analyze the coated surfaces of MgCO3 particles. The results showed that the silica is really contained in the surface of MgCO3 particles, and the decomposition rate of coated MgCO3 particles lowers. As a result, the coated MgCO3 particles can be taken as a foaming agent to prepare foam metals. References | Related Articles | Metrics

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Preparation of Ni-Mo alloy coating by pulse plating and its HER activity Han, Qing (1); Sun, Ke-Ning (1); Dong, Xiao-Hui (2); Chen, Jian-She (1) 2009, 30 (5):  704-707.  DOI: - Abstract ( 444 )   HTML   PDF (308KB) ( 1095 )   The effects of different electrodeposition conditions in the pulse plating process to prepare Ni-Mo coating on its composition, apparent morphology and HER (hydrogen evolution reaction) activity were investigated. If the quantitative ratio of nickel to molybdenum is lower than 1 (mol%), the Mo content in the coating decreases gradually with the molybdenum salt adding to the coating, while the corresponding HER overpotential increases. The Ni-Mo coating thus prepared presents amorphous structure (w(Mo)=30%) in combination with homogeneous, smooth and characteristics, especially it provides a higher catalytic activity (80°C, η200=62 mV) with high corrosion resistance. After the galvanostatic electrolysis in 33% NaOH solution for 100 hr, the amorphous structure is destroyed due to Mo dissolution, then the bubbling comes to pass with increasing porosity. References | Related Articles | Metrics

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Study on extraction of SiO2 from nickel laterite ore through leaching by high concentration NaOH solution Mu, Wen-Ning (1); Zhai, Yu-Chun (1); Liu, Yan (1); Liu, Jiao (1) 2009, 30 (5):  708-711.  DOI: - Abstract ( 304 )   HTML   PDF (487KB) ( 717 )   A new leaching process for nickel laterite ore with high concentration NaOH solution was investigated, to which the effects of stirring speed, leaching temperature, initial NaOH concentration, leaching time and mass ratio of alkali to ore on the leaching rate of SiO2 were discussed. The results showed that when the stirring speed is 600 r/min at 225°C for 90 min with initial NaOH concentration 85%, and the mass ratio of alkali to ore is 5:1 in leaching process, the leaching rate of SiO2 can be up to 82.77%. In the residues the iron, magnesium and nickel are enriched, among which the NiO content increases from 1.29wt% to 2.85wt%. References | Related Articles | Metrics

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AHP-based assignment of weight in product design quality Jing, Hong-Ying (1); Zhang, Li (2); Wen, Bang-Chun (1) 2009, 30 (5):  712-715.  DOI: - Abstract ( 338 )   HTML   PDF (430KB) ( 1526 )   The product design quality is the integration of product major, auxiliary functions and product constructional, operating, technological performances. The assignment of weight of those functions and performances is studied. An AHP model is developed for product design quality to form a pairwise comparison matrix. Based on the pairwise comparison, the assignment of weight of each and all functions/performances as above is determined in product design quality through hierarchical ranking and consistency test. Taking a vibrating screen as example, the weight of each and all functions/performances in product design quality are calculated, thus verifying the feasibility/effectiveness of the AHP-based assignment of weight in product design quality. References | Related Articles | Metrics

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FEM-based study on dynamic behavior of nonlinear rotor system Li, Chao-Feng (1); Sun, Wei (1); Ma, Hui (1); Wen, Bang-Chun (1) 2009, 30 (5):  716-719+732.  DOI: - Abstract ( 276 )   HTML   PDF (1465KB) ( 811 )   Based on the analysis of the discrete model, an FEM-based model of rotor-bearing system was developed considering some important influencing factors other than the nonlinear factors of the bearing, such as the inertia distribution, shear, transverse torsion, structural geometric parameters of the system. The dynamic behavior of the system and discrete system was discussed separately and comparatively on the same unbalance conditions, and the results showed that the dynamic behavior as expressed in the two models is different to a certain extent because of the increased influencing factors taken into account. The FEM model regarded as superior in design parameters, and it can provide more convincible data for the nonlinear characteristics of a rotor system, thus giving more accurate reference and verification to the nonlinearly dynamic design of the complex rotor system. References | Related Articles | Metrics

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FEA of spindle assembly of NC lathe and its verification Zhang, Yao-Man (1); Wang, Wei (1); Liu, Yong-Xian (1) 2009, 30 (5):  720-723.  DOI: - Abstract ( 304 )   HTML   PDF (348KB) ( 1366 )   How to develop an FEA-based dynamic model of spindle assembly was investigated. The change in the central angles of equally and circularly arranged bearing supports of spring-damper elements around the spindle assembly has so small influence on FEA that the FEA-based dynamic model can be developed via developing a rational spindle-support model with those spring-damper elements. Exemplified with the CKS6125 NC lathe manufactured by Shenyang No.1 Plant of Machine Tools, a simulation was done to analyze dynamically the spindle assembly. And the dynamic performance tests of the spindle assembly verified the feasibility of the FEA-based model by experiments, after analysis and evaluation on its dynamic and the convincibility of FEA results. References | Related Articles | Metrics

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Virtual experiment/analysis based on stochastic FEM on bearing reliability Li, Chang (1); Sun, Zhi-Li (1); Han, Xing (2) 2009, 30 (5):  724-727.  DOI: - Abstract ( 345 )   HTML   PDF (541KB) ( 774 )   The inner contact stress and strain of a bearing change was found via developing a 3-D parameterized FEM model of bearings and a numerical simulation of the model with the software ANSYS. Then, the stochastic finite element method extended by Neumann (NSFEM) with Monte-Carlo method is introduced to consider comprehensively the effects of the original errors arising from manufacture and different working conditions including rotating speed and loads on the dynamic capability of bearing. With a stochastic virtual experiment done several times, the sensibilities to the reliabilities of all variable parameters of a bearing were given in form of probability, thus providing theoretically a reference for the fatigue strength calculation and optimum dynamic design of a bearing. References | Related Articles | Metrics

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Image fusion based on wavelet transformation for strip steel surface defects Wang, Yong-Hui (1); Yan, Yun-Hui (1); Wu, Yan-Ping (1); Liang, Hui-Sheng (1) 2009, 30 (5):  728-732.  DOI: - Abstract ( 305 )   HTML   PDF (523KB) ( 632 )   Two CCD camera sensors were applied to the same object to acquire different defect images on strip steel surface in several ways, then the images were implemented to those defects through wavelet transformation. The fusion algorithm and rules based on the abstract features from the real surface defects are discussed with the quality of defect images after fusion evaluated. Experimental results showed obviously the superiority of the approach mentioned above because it can acquire more accurate defect image data as much as possible, thus solving the problem of missing the defects due to the acquisition by single CCD camera and providing more useful and reliable data for further process of image recognition and classification. References | Related Articles | Metrics

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Study on Delaunay triangulation algorithm for polygon with inside islets Ma, Hong-Bin (1); Guo, Jia-Teng (1); He, Qun (1); Liu, Xin-Rui (1) 2009, 30 (5):  733-736.  DOI: - Abstract ( 425 )   HTML   PDF (753KB) ( 1339 )   A universal algorithm for Delaunay triangulation of any polygon with or without islets is presented. In this algorithm, the constrained Delaunay triangular irregular network (CD-TIN) including all the vertices of a polygon, i.e., the vertices of the polygon itself and vertices of all inside islets, is constructed, of which all the edges of the polygon are constrained, then the criterion for seeking triangles outside or inside the polygon is presented to identify or eliminate unwanted triangles from the CD-TIN so as to triangulate the polygon with inside islets. A testing triangulation experiment for a polygon with 100 inside islets was done with this algorithm, and the result showed that this algorithm is efficient and robust for triangulating complex polygons with large numbers of inside islets. This algorithm has been successfully applied to the three-dimensional ore-body modeling and visualization system, in which it is used to triangulate the sectional polygons with inside islets, e.g., the inside stones or holes in ore-body, and its high efficiency has been proved. References | Related Articles | Metrics

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Experimental study on compacting/curing of Marshall specimen for cold recycled plant-mixed asphalt pavements Wu, Ze-Feng (1); Zhang, Jun (1); Zhu, Fu-Sheng (1) 2009, 30 (5):  737-740.  DOI: - Abstract ( 264 )   HTML   PDF (166KB) ( 816 )   Combining lab experiment with sampling test by corebit in-situ, the compacting and curing of Marshall specimen for cold recycled plant-mixed asphalt pavements were studied. The results showed that if the time interval between two compacting operation was 4 hr, the stability of Marshall specimen is close to the results of the sampling testing especially the lab experimental of curing for long. If the specimen was cured for 24hr in lab, the stability changes slightly and is closer to the result of sampling test by corebit in-situ. The proposed compacting/curing method of Marshall specimen conforms comparatively to the actual formation process of cold recycled asphalt pavements and the Marshall specimen thus prepared can reflect the pavement performance more accurately in near future. References | Related Articles | Metrics

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Customer-oriented study on design support technology based on perception of car style Guo, Fu (1); Liu, Gai-Yun (1); Chen, Chao (1); Li, Sen (1) 2009, 30 (5):  741-744.  DOI: - Abstract ( 243 )   HTML   PDF (178KB) ( 716 )   To solve the urgent problem that the product design shall be done according to customer's perception of its features, the framework of design support technology is proposed guiding the designers to seek and recognize customer's preference. Exemplified with the cars as products, an appraisal scheme was framed for customer's perception of the features of car style. Then, by multivariate regression analysis, a model is developed for the relationship between customer's perception of preference and the perceivability of a car. The feasibility of the model is verified with the appraisal by 8 pictures chosen from image library. And the appearance design of a car is decomposed into several variables to develop the model for the relationship between customer's perception of the features of car style and car's design variables under the guidance of quantitative theory I. References | Related Articles | Metrics

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Selection of ordering policies based on H∞ norm computation in supply chain Ge, Ru-Gang (1); Huang, Xiao-Yuan (1) 2009, 30 (5):  745-748.  DOI: - Abstract ( 268 )   HTML   PDF (1181KB) ( 742 )   A new approach was proposed for the selection of ordering policies to solve the problem of lack of control theory analysis in studying the supply chain operation by use of transfer function, based on the H∞ norm computation. It is implemented the way the transfer function H∞ norm is computed to select the ordering policies in supply chain according to its magnitude computed. Then, two classes of supply are simulated, i.e., the replenishment system and the planning and inventory control (PIC) system in production so as to select the optimal ordering policy for supply chain system. References | Related Articles | Metrics

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On the dynamic pricing during group-buying auction Yan, Yan (1); Liu, Xiao (1); Meng, De-Kai (1) 2009, 30 (5):  749-752.  DOI: - Abstract ( 297 )   HTML   PDF (183KB) ( 797 )   Behavioral characteristics of the customers during group-buying auction are discussed to find out the influencing factors on customers' participation in group-buying, where seller's appropriate pricing policy can attract more customers. A pricing model is developed on the basis of an independent private evaluation model and some assumptions to maximize seller's profits, with a CPSO (chaos particle swarm optimization) solution given to it to seek optimal prices. Simulation results revealed that the markdown gradient in group-buying activities may affect the final gross sales, and the adjustment of markdown gradient will improve the values of customers' effectiveness. More customers will therefore participate in group-buying activities to increase sales so as to increase the profit of companies. References | Related Articles | Metrics

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Generalized prefix relations on free monoids and maximal independent languages Liu, Qun (1); Li, Hong (1) 2009, 30 (5):  753-756.  DOI: - Abstract ( 215 )   HTML   PDF (151KB) ( 566 )   Studies the languages that are independent of the L-prefix relation. The construction of the completion of codes are generalized as that of L-independent languages and on the other hand, the latter can be used to examine the former. In the completing process of codes the relation involved is bound up with the result of completion. It is therefore necessary to introduce various techniques into the process, and how they function can be expounded by the general construction of completion of L-independent languages. In this way a clear understanding is available to various methods of completion of codes. References | Related Articles | Metrics

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Proton conductivities of phosphoric acid based hydrous and anhydrous systems Che, Quan-Tong (1); Wang, Dong (1); Lü, Xiao-Mei (1); He, Rong-Huan (1) 2009, 30 (5):  757-760.  DOI: - Abstract ( 504 )   HTML   PDF (566KB) ( 1398 )   Imidazole and pyridine were mixed with pure phosphoric acid to form anhydrous proton conducting electrolyte. Conductivities of phosphoric acid based anhydrous solutions and proton transfer mechanism were investigated for the feasibility that the nitrogenous heterocyclic compounds become the carrier for proton transfer under anhydrous conditions. The results indicated that the viscosity of the anhydrous system has a significant influence on the proton migration. The nitrogenous heterocyclic compounds could not act as water molecules to decrease but increase the viscosity of phosphoric acid. The results of conductivity showed that the proton transferability due to self-ionization and self-dehydration of phosphoric acid is superior to that of both phosphoric acid and nitrogenous heterocyclic compounds. As to the imidazole-phosphoric acid aqueous solutions, its conductivity relates to the number of migrating ions and migration rate in addition to the viscosity of the system. References | Related Articles | Metrics