Archive

15 May 2010, Volume 31 Issue 5 Previous Issue    Next Issue
---
OriginalPaper


For Selected:

Download Citations EndNote Ris BibTeX

Toggle Thumbnails

OriginalPaper

Select

Multi-source localization based on Tabu search in wireless sensor networks Wu, Cheng-Dong (1); Cheng, Long (1); Zhang, Yun-Zhou (1); Jia, Zi-Xi (1) 2010, 31 (5):  609-612.  DOI: - Abstract ( 309 )   HTML   PDF (700KB) ( 614 )   To solve the problem that the multi-source localization in wireless sensor networks is easy to fall into the local optimization as a trap, a new approach to multi-source localization based on Tabu search was proposed the way on acoustic energy model was developed by measuring the signal energy received by several individual sensors, then such parameters as acoustic energy and relevant source location were estimated. To avoid falling into local optimization, the search area including 8 neighbors at 3 levels in grids was introduced, with such parameters as the length of Tabu list and initial estimation selected reasonably. Those sensors with the maximum energy received were the initial estimation nodes. Simulation results showed that in comparison with the multi-resolution (MR) search, EM algorithm and AMR algorithm, the Tabu search algorithm can avoid well falling into local optimization with higher estimating accuracy and lower computation complexity. References | Related Articles | Metrics

Select

MLS-SVRs-based soft sensor modeling of granularity of pulverizing coal during ball milling Wang, Jie-Sheng (1); Gao, Xian-Wen (1); Zhang, Li (1) 2010, 31 (5):  613-616.  DOI: - Abstract ( 470 )   HTML   PDF (708KB) ( 462 )   Inspired by the idea that combining several models can improve the prediction accuracy and robustness on the whole, a multiple least squares-support vector machine regressor(MLS-SVRs) soft sensing modeling of the granularity of pulverized coal is proposed based on fuzzy C-means(FCM) clustering algorithm. Genetic algorithm based on sizable chromosome is introduced to optimize the number of fuzzy clustering and cluster centers. Then, the whole training data set is divided into several clusters with different centers by FCM algorithm and each subset is trained by LS-SVRs, and the degrees of membership resulting from fuzzy clustering are used to weight and summarize the outputs of all submodels, thus giving the finial soft sensing outcome. Simulation results showed that the proposed model is effective in the granularity prediction and meets the requirement of the on-line soft sensor for real-time optimization control in pulverized coal production process. References | Related Articles | Metrics

Select

Optimal control model of bilevel replenishment for distribution system in network marketing Liu, Bao-Zheng (1); Wang, Ding-Wei (1) 2010, 31 (5):  617-620.  DOI: - Abstract ( 300 )   HTML   PDF (274KB) ( 541 )   A regional distribution system including a distribution center and multiple retailers was studied, where the demand all replenishing intervals complied with the random variables of a certain probability distribution. Each retailer can decide its own optimal demand via replenishing in time independently with fixed replenishing intervals. So, the distribution center shall deliver goods to each retailer regularly, i.e., the same to the fixed replenishing intervals. In view of that the demand of a retailer is in uniform distribution in a replenishing interval, where the demand is assumed to be even, the control strategres to make the replenishment optimal for retailers and make the purchase of goods optimal for the distribution center were both proposed through optimization of costs. A numerical example was given to verify the control strategies proposed. References | Related Articles | Metrics

Select

Supply chain coordination based on consignment stock in multi-cycle stochastic demand Li, Dan (1); Tang, Jia-Fu (1); Zang, Jie (1) 2010, 31 (5):  621-624.  DOI: - Abstract ( 349 )   HTML   PDF (103KB) ( 918 )   For a two-echelon supply chain composed of just a single supplier and buyer with decentralized channels in multi-cycle stochastic demand, its coordination was investigated analytically, where the dominant party is the supplier who decided to sell goods on the basis of consignment stock. The results revealed that such a supply chain can be modeled as a Stackelberg leader-follower game to which there is a unique equilibrium solution, and that in the decentralized game the supplier can design his consignment contract parameter, i.e., the wholesale price, thus enabling the buyer to maximize his own profit and, meanwhile, it maximizes supplier's profit as well as the supply chain optimized. It means that the consignment stock can completely coordinate the two-echelon supply chain in multi-cycle stochastic demand. References | Related Articles | Metrics

Select

Handover decision scheme based on multi-PSO Wang, Xing-Wei (1); Zhao, Huan-Yan (1); Huang, Min (1) 2010, 31 (5):  625-629.  DOI: - Abstract ( 308 )   HTML   PDF (188KB) ( 588 )   A handover decision scheme was proposed to support ABC. It considered the following factors comprehensively: access network conditions, application requirements, users' preference for access network coding schemes and access network providers, terminals' current moving speed and residual battery capacities. Then, an optimal handover solution was found out to assign N terminals to M access networks, based on the multi-PSO (particle swarm optimization) with optimum mutation. By virtue of gaming analysis, the utility of both users and network providers achieved or approached the Pareto optimum under Nash equilibrium in the found solution. Simulation results showed that the handover decision scheme is feasible and effective. References | Related Articles | Metrics

Select

A grid task scheduling with dynamic equilibrium based on ant colony algorithm Sun, Da-Wei (1); Chang, Gui-Ran (1); Chen, Dong (1); Wang, Xing-Wei (1) 2010, 31 (5):  630-633.  DOI: - Abstract ( 382 )   HTML   PDF (325KB) ( 450 )   Resource allocation in grid is an NP-hard problem. To optimize the grid system, a performance QoS optimization model is developed for grid task scheduling and objective function, with the number of resources and tasks analyzed in detail. Then, an improved ant colony algorithm named RACO(reputation-based ant colony algorithm) is presented to schedule tasks in grid, based on the dynamic reputation. Introducing a dynamic scheduling factor involving both space and time efficiencies, a local and global pheromone updating strategy is applied to RACO. Simulation results showed that RACO algorithm outperforms the conventional Min-min, Max-min and ACO in resource utilization rate and dynamic equilibrium. References | Related Articles | Metrics

Select

Selection of QoS-aware Web services Li, Ying-Qiu (1); Wen, Tao (1); Chen, Ming-Hua (2) 2010, 31 (5):  634-638.  DOI: - Abstract ( 298 )   HTML   PDF (956KB) ( 724 )   A composite web service can be constructed by combining together the component services which have different non-functional QoS (quality of service) attributes. A problem is thus caused, i.e., how to select the most suitable services in accordance to the different QoS attributes as criteria as to meet the global QoS requirements of the composite web services. To solve the problem, an approach is proposed to simply the complex process model of the composite service with the layered graph technique used to reduce the problem to be a routing problem in directed graph. Then, the selection algorithm for the composite service is performed taking no account of different flow operations, such as sequence, selection, concurrency and loop, thus reducing the complexity of selection algorithm and improving execution efficiency. According to the simplified model and based on adaptive genetic algorithm, a QoS-aware selection algorithm is given for composite web services. Simulation results showed that the proposed approach is feasible and effective. References | Related Articles | Metrics

Select

Research and application of hybrid fragmentation method for dynamic service process model Bi, Jing (1); Zhu, Zhi-Liang (1) 2010, 31 (5):  639-643.  DOI: - Abstract ( 328 )   HTML   PDF (1133KB) ( 561 )   To unify the inter-organization service processes, a hybrid fragmentation method was presented for the dynamic service process model based on high-level Petri nets, i.e., global web services-business process execution language (WS-BPEL or BPEL) model was divided into several self-contained execution sub-chips which are assigned to different BPEL execution engines according to the difference between organizations for collaborative execution. Then, the correctness of the proposed method was verified with an instance given to illustrate the feasibility of the hybrid fragmentation method. A prototype system was thus given to support the hybrid fragmentation of the model. Simulation results showed that the execution of decentralized BPEL engines supported by the hybrid fragmentation method for dynamic service process is obviously superior to that of centralized BPEL engines, thus increasing the throughput of those engines with the cost involved in service response time reduced. References | Related Articles | Metrics

Select

Feedback-mechanism-based virus spreading model in scale-free networks Zhao, Hai (1); Zheng, Yan-Qin (1); Dang, Qun (1); Fu, Yao (1) 2010, 31 (5):  644-646.  DOI: - Abstract ( 345 )   HTML   PDF (514KB) ( 700 )   Under the precondition that there is a highly virulent infector in network, no virus spreading threshold is found in conventional virus spreading models in infinitive scale-free networks. However, there is no highly virulent infector in many real scale-free networks. For this reason, a virus spreading/controlling model with finite maximum infectivity was developed in scale-free network, based on the feedback mechanism. In the model there is a virus spreading threshold that has been proved mathematically. The feedback mechanism and the effects of the maximum value of infectivity on the infection rate of network, control of virus diffusion and spreading threshold are all analyzed through numerical simulation. The results provide an important reference for controlling the virus spreading in real networks. References | Related Articles | Metrics

Select

RSSI-based anti-interference WSN positioning algorithm Xu, Jiu-Qiang (1); Liu, Wei (1); Zhang, Yuan-Yuan (1); Wang, Cheng-Long (1) 2010, 31 (5):  647-650.  DOI: - Abstract ( 351 )   HTML   PDF (680KB) ( 1157 )   In respect of positioning, the RSSI is affected greatly by external factors, so it is hard to ensure the accuracy in either ranging or positioning. Due to the interference that is at both variance and mean levels, RSSI should be amended at the two levels. In the data acquisition stage of RSSI, a Gaussian model based on deviation (D-Gaussian) is developed to filter the interference at variance level so as to improve the availability of RSSI signal. Then, in the ranging stage, a dynamic window mechanism EWMA is introduced, i.e., the R-EWMA, to deal with the interference at mean level. Experimental results showed that the contradiction between positioning accuracy and the hardware costs in conventional positioning algorithm is moderated efficiently, thus reducing basically the error of RSSI positioning algorithm via processing RSSI properly. References | Related Articles | Metrics

Select

Effects of inversed surface segregation of phosphorus in twin roll cast strips on mechanical properties of low carbon steel Zhou, Guo-Ping (1); Liu, Zhen-Yu (1); Qiu, Yi-Qing (1); Wang, Guo-Dong (1) 2010, 31 (5):  651-654.  DOI: - Abstract ( 320 )   HTML   PDF (1671KB) ( 557 )   How the inversed surface segregation of P forms in strip casting was discussed by structure observing and analyzing, and its effects on the mechanical properties of twin roll cast strips were investigated through tests. The results showed that a homogeneous P-rich surface layer forms on the strip after cold rolling and annealing. The percentage elongation of conventional strips will drastically decrease if P content is over 0.15%, but it will be kept to about 30% if P content is 0.26%. It means that the twin roll strip casting process can raise the P tolerance in strip by about 0.1%. In addition, the ductile-brittle transition temperature (DBTT) of the cast strips is lower than that of conventional strips though the P content is the same. References | Related Articles | Metrics

Select

Effects of hot deformation on microstructure and deformation resistance of ultra-high strength pipeline steel Zhang, Kai (1); Qiu, Chun-Lin (1); Du, Lin-Xiu (1); Wu, Di (1) 2010, 31 (5):  655-659.  DOI: - Abstract ( 338 )   HTML   PDF (2385KB) ( 773 )   The microstructure of X120 ultra-high strength pipeline steel and precipitates during its hot deformation were characterized by optical microscope and electronic microscope. The results showed that the Nb-Ti diphase precipitate forms at 1020°C in the austenite recrystallization region when the steel is rolled, thus affecting the grain refinement somewhat. With the accumulated reduction kept unchanged, the effects of heavy reduction and a few number of passes on hot-deformed austenite size are small, while the effects on the deformation bands, substructure, final structure morphology and grain size are comparatively greater to a certain extent. Moreover, the effects of rolling temperature in recrystallization region and rolling schedule for non-recrystallized region on deformation resistance were analyzed. References | Related Articles | Metrics

Select

Comparative investigation on wear behavior of iron matrix composites reinforced by different ceramic particles Li, Jie (1); Zong, Ya-Ping (1); Wang, Yao-Mian (1); Zhuang, Wei-Bin (1) 2010, 31 (5):  660-664.  DOI: - Abstract ( 384 )   HTML   PDF (2456KB) ( 630 )   A number of iron matrix composites reinforced by different types of ceramic particles were prepared by the process of two-step dynamic electric current heating and sectional hot pressing to investigate the effects of reinforcing particles on the wear behavior of the composites. The results showed that the wear loss of all those iron matrix composites is lower than 15% of that of the #45 carbon steel which is widely used in China. The Ti(C, N) particles function as the strongest influencing factor on improving the wearability in the four ceramic particles used, i.e., the reinforced ceramic particles which are endurable to a certain deformation on the interfaces between them and matrix are most beneficial to improving wearability. On the other hand, the wearability of all those composites come up to their maximum if the volume fraction of reinforcing particles is 10%, and the wearability becomes better if the friction coefficient of the composites is high. Such features make the composites superior in many application fields, such as brake making. References | Related Articles | Metrics

Select

TEM study on structure of oriented domains in La0.7Ca0.3MnO3 Wang, Ming-Guang (1); Ning, Ce (1); Yang, Hui (1); Qi, Yang (1) 2010, 31 (5):  665-668.  DOI: - Abstract ( 309 )   HTML   PDF (2184KB) ( 808 )   The structure of oriented domains in colossal magneto-resistance material La0.7Ca0.3MnO3 (LCMO) was investigated by transmission electron microscopy(TEM) and high resolution electron microscopy (HREM). Electron diffraction verified that LCMO presents just a single phase with an orthorhombic symmetry which meets the extinction conditions: 0kl, k+l=2n+1; hk0, h=2n+1; h00, h=2n+1; 0k0, k=2n+1; 00l, l=2n+1, with no other phases observed. The oriented domains in LCMO crystal have two kinds of typical morphologies, i.e., formless and wedge ones. HREM results showed that the domain boundaries are almost diffuse and consist of some interfaces with low energy and high index. References | Related Articles | Metrics

Select

Numerical simulation of LFEC process of magnesium billets with a metal bushing mold Le, Qi-Chi (1); Zhang, Zhi-Qiang (1); Guo, Shi-Jie (1); Cui, Jian-Zhong (1) 2010, 31 (5):  669-672.  DOI: - Abstract ( 363 )   HTML   PDF (1710KB) ( 845 )   It was found that the mold with hot top was unsuitable for magnesium ingots in the DC low-frequency electromagnetic casting (LFEC) process, because of the high reactivity between hot top and magnesium melt which will affect greatly the productivity and quality of the billets. The effects of the electromagnetic (EM) parameters on the EM distribution and how they affect the magnesium melt were investigated by numerical simulation with a metal bushing attached to the mold. The results indicated that EM frequency affects not only the magnitude of Lorentz force but also its direction. In the low-frequency EM field, the long penetration depth, low Joule heat, weak magnetic confinement, strong convection and shallow melt trap can all be achieved. When the excitation coil is held at high level, the EM penetration becomes deeper with the melt pushed outwards more rapidly, and the Joule heat in the high-resistivity bushing becomes lower. References | Related Articles | Metrics

Select

On the thixo-compression deformation behavior of aluminum alloys Zhi, Li-Qun (1); Lu, Gui-Min (2); Cui, Jian-Zhong (1) 2010, 31 (5):  673-676+684.  DOI: - Abstract ( 330 )   HTML   PDF (1736KB) ( 831 )   The thixo-compression deformation behavior of three aluminum alloys prepared by near-liquidus-casting were investigated on the Gleeble 3800 thermo-mechanical simulator. The true stress-strain curves were modified considering the influence of thermal expansion on flowing stress. The results showed that the true stress-strain curves are all of the type of dynamic recrystallization, and that the flowing stress decreases sharply with increasing strain mainly because of the rapid collapse of solid skeleton under the action of external force with the liquid squeezed out to the sample surface. The peak stress is affected obviously by deformation temperature, strain rate, strain and initial strength of materials, while the steady stress is just affected obviously by the initial strength of materials. The peak strain value is around 0.06, and the steady strain value is between 0.2 and 0.3. The reliable data resulting from the proper design and control of experimental setup lays a foundation on which the semi-solid constitutive relationship is available to establish. References | Related Articles | Metrics

Select

Physical modeling of inclusion removing behavior in continuous casting tundish Zheng, Shu-Guo (1); Zhu, Miao-Yong (1); Wang, Ying (1) 2010, 31 (5):  677-680.  DOI: - Abstract ( 370 )   HTML   PDF (1207KB) ( 451 )   The effects of the initial molten steel level in tundish, filling flowrate through long nozzle and flow control devices on removing inclusions from continuous casting tundish during ladle changing were investigated via physical model testing with emulsion drops used to simulate inclusions. The results showed that the inclusions removed quickly in the range from 1/4 to 3/4 of the full depth which is calculated from the initial molten steel level in tundish, and the level of 3/4 of full depth seems to be an ideal working level for ladle changing. The inclusion removal rate increases with the increasing of the filling flowrate through long nozzle, and the removal of inclusions is improved significantly if the filling flowrate is higher than 2.5 m3/h. The removal of inclusions is further improved in tundish with a flow control device containing dam/wall especially a turbulence inhibitor used. References | Related Articles | Metrics

Select

Method and implementation of 3D design for heating furnace steel construction Zhao, Yao (1); Yu, Qing-Bo (1); Li, Ling-Xin (1) 2010, 31 (5):  681-684.  DOI: - Abstract ( 353 )   HTML   PDF (1394KB) ( 937 )   It's hard to express the spatial structure in the 2-D design of steel structure of a heating furnace because of the complex projective relationships. A new way is proposed taking the 3-D technology as a core to redevelop the Solid Edge with Visual Basic, based on the ActiveX automation technology. Drawing a layout diagram as frame then filling the materials is used as design mode. The steel structure is divided into several sub-systems according to the concept of modularization. With the bottom-up pattern in design, every member is designed independently first then assembled together with each other to develop an interactive drawing software which has friendly user interface and is easy to use. In this way a 3-D parametric design system is implemented in Solid Edge environment, thus improving the design efficiency and quality. A design of engineering drawing is given as example to verify the feasibility and applicability of the method proposed. References | Related Articles | Metrics

Select

Dynamic simulation of gas system in iron and steel complex Song, Jun (1); Cai, Jiu-Ju (1); Zhang, Qi (1) 2010, 31 (5):  685-688.  DOI: - Abstract ( 364 )   HTML   PDF (652KB) ( 603 )   Based on the gas imbalance theory in an iron and steel complex, the fluctuation, distribution, emission and buffer of gas surplus are analyzed to develop a dynamic mathematical model statistically. Then, with the gas system in a certain steel trust taken as example, an easy-to-debug dynamic gas simulation platform is developed, on which the simulation results show that an optimal distribution algorithm can alleviate the fluctuation of gas surplus and the simulation model will facilitate the comparative analysis of the merits and demerits of several gas recycling schemes, thus making the gas system available to realize the ideal gas tank capacity through readjusting plant parameters and debugging. By hybrid scheduling, both the emission of gas and frequency of pipeline alarm can be reduced. The converter gas tank in joined pipeline system can improve the gas recovery rate by about 20%. #1 and #2 coke ovens reformed, the near-zero emission will be achieved only if the relevant gas tank capacity is double. References | Related Articles | Metrics

Select

Experimental study on cooling process of sinter Dong, Hui (1); Li, Jie (1); Luo, Yuan-Qiu (2); Cai, Jiu-Ju (1) 2010, 31 (5):  689-692.  DOI: - Abstract ( 324 )   HTML   PDF (1072KB) ( 984 )   An experimental setup was provided to investigate the cooling process of sinter and relevant influencing factors on the process. The results showed that the cooling air flowrate and thickness of sinter bed are both the main factors. With the thickness of sinter bed kept unchanged and increasing cooling air flowrate, the temperature of hot air passing through the sinter bed decreases gradually, while the sensible heat of hot air begins to increase and comes up to its peak value, then decreases gradually. It implies that there is an appropriate value at which the hot air carries maximum. Moreover, keeping up the opening of air-blower constant, the hot air temperature increases gradually with the increasing thickness of sinter bed, and there is an appropriate value of the thickness, too. The appropriate thickness and appropriate cooling air flowrate affect and constrain mutually. References | Related Articles | Metrics

Select

On the structure and electrochemical properties of LiCoO2 with nanograde ZrO2 coating Liu, Guo-Qiang (1); Liu, Yan-Min (1); Liu, Guang-Yin (1); Tian, Yan-Wen (1) 2010, 31 (5):  693-695+699.  DOI: - Abstract ( 340 )   HTML   PDF (735KB) ( 821 )   To improve the electrochemical properties of LiCoO2, a nanograde ZrO2 coating was deposited on it via impregnation. With the Zr(OH)x(CH3COO)y dissolved in deionized water, the LiCoO2 powder was immersed in the solution. Then, the LiCoO2 with ZrO2 coating was obtained after ultrasonic agitation, solvent evaporation and calcination at high temperature. X-ray absorption near edge spectrum(XANES) was used to investigate the structure of coated LiCoO2 and check the effect of the coating on the structure. The results of cyclic voltammogram testing showed that the ZrO2 coating can affect both the oxidation and reduction processes of LiCoO2. The results of charge/discharge tests revealed that the electro chemical properties of LiCoO2 change little at normal temperature after coating, but its charging/discharging efficiency can be improved at higher temperature, e.g., 55°C. References | Related Articles | Metrics

Select

Study on electrical conductivity of the molten salts of KNO3-NaNO2-NaNO3 ternary system Gao, Bing-Liang (1); Liu, Feng-Guo (1); Wang, Zhao-Wen (1); Shi, Zhong-Ning (1) 2010, 31 (5):  696-699.  DOI: - Abstract ( 487 )   HTML   PDF (1710KB) ( 781 )   The electrical conductivity of the molten salts of KNO3-NaNO2-NaNO3 ternary system with different compositions was measured at different temperatures by the continuously varying cell constant (CVCC) technique. The main influencing factor on electrical conductivity was analyzed. Experimental results showed that the electrical conductivity measured by CVCC technique is accurate and reliable, of which the relative error is just 0.78% in comparison with what was given by the reference [9]. There is an exponential relationship between the conductivity and reciprocal value of temperature in the system, and the conductivities of the melts are variable because they are affected by the different compositions of the system. With the increasing content of NaNO2, the electrical conductivity of this system increases, while it decreases with increasing content of KNO3. As to the content of NaNO3, it affects little the conductivity. References | Related Articles | Metrics

Select

Research on mechanical properties of impeller assembly in turbine compressor You, Xiao-Mei (1); Meng, Lei (2); Li, Ling-Xuan (1); Wen, Bang-Chun (1) 2010, 31 (5):  700-703.  DOI: - Abstract ( 425 )   HTML   PDF (1361KB) ( 578 )   The mechanical properties of the closed impeller assembly in a heavy-duty turbine compressor was investigated under actual operating conditions. Based on FEM and nonlinear contact theory, the size and distribution of stress of the assembly were analyzed structurally in assembling process and under variable operating conditions. The results showed that the assembly cannot fail structurally due to the internal stress caused during its assembling. There are stable and non-stable operating regions of a closed impeller assembly and most of those assemblies will malfunction structurally if they work at a speed over 12?000?r/min. The analysis method proposed is highly practical in applications as a reference for the study on mechanical properties of other rotor assemblies. References | Related Articles | Metrics

Select

Vibration/comfortableness analysis of motor coach of a certain model of express train in China Li, Ling-Xuan (1); Ma, Yuan-Yuan (2); Feng, Fei (1); Wen, Bang-Chun (1) 2010, 31 (5):  704-707.  DOI: - Abstract ( 499 )   HTML   PDF (859KB) ( 857 )   How to predict the vibration/comfortableness characteristics of an express train(motor coach train) in China in its design was investigated. With the software ANSYS used to develop a finite element model for a motor coach, the frequency domain method is introduced to deal with the power spectrum density in MATLAB. Then, taking the horizontal irregularity of railroad as an example, a transient analysis is made to simulate the response from the running motor coach train with the acceleration responses collected at some nodes on a coach floor to calculate the degree of comfortableness and the coach's jolt-proof index. This method makes it possible to evaluate effectively the vibration characteristics and passengers' sitting comfortableness of a motor coach hence the whole train under different running conditions in the conceptual design. References | Related Articles | Metrics

Select

SPA evaluation model based on characteristic feature of aircraft combat resilience Zhang, Jun-Yong (1); Li, Wu-Qi (2); Zhou, Ping-Hui (2); Wen, Bang-Chun (1) 2010, 31 (5):  708-712.  DOI: - Abstract ( 358 )   HTML   PDF (507KB) ( 1619 )   An evaluation system was set up for aircraft combat resilience (ACR), and a SPA evaluation model was developed on the basis of characteristic feature with the divergencies of experts' views taken into account during the evaluation of combat resilience. In the evaluation model the singular values are decomposed in the evaluation matrix, and the singular values which make important contribution to the matrix characteristics are extracted for inverse decomposing operation of the evaluation matrix. Then, an SPA is made, based on IDC. An evaluation example of a certain battle damaged plane to be repaired was given to illustrate the proposed evaluation system/model practically. The results showed that the evaluation model is highly feasible and effective, and introducing properly the divergences of experts' views into SPA will enable the evaluation results to be more rational. References | Related Articles | Metrics

Select

On the anti-interference of electro-hydraulic control system for excavator's digging bucket arm Yang, Ke-Shi (1); Liu, Jie (1); Gu, Yu-Ming (1); Han, Ying (2) 2010, 31 (5):  713-716.  DOI: - Abstract ( 293 )   HTML   PDF (897KB) ( 486 )   Anti-interference is proposed as the key criterion for the lower-level electro-hydraulic control system in a two-level computer control system for the anthropomorphic operation of the digging bucket arm on the PC02 excavator, thus alleviating the effect of the sudden change of external load on the bucket's moving speed. With the state variables model and fuzzy/simulink-based model both developed for the electro-hydraulic system, the output scaling factor corresponding to the proportional coefficient of the conventional fuzzy-PID controller is adjusted online through the design of an auxiliary fuzzy inference controller (AFIC) so as to intensify the effect of proportionality. By simulation, the anti-interference characteristic of the electro-hydraulic control system was obtained when a sudden change of uncertain external load on the bucket happens, and the result also showed that the AFIC alleviates the effect of external load on the protruding velocity of piston rod and improves the time response. References | Related Articles | Metrics

Select

Removing impulse noise from surface defect images of steel strip based on threshold theory Yan, Yun-Hui (1); Peng, Yi-Shu (1); Song, Ke-Chen (1); Liu, Wei-Wei (2) 2010, 31 (5):  717-720.  DOI: - Abstract ( 330 )   HTML   PDF (1259KB) ( 626 )   To remove the impulse noise from surface defect images of strip steel, a threshold-based method of switching median filtering is presented according to the characteristics of impulse noise and surface defect images of strip steel. In the method, whether the central pixel point in the filter window is a noise point is determined by setting the threshold data, then the median filtering process is done for the noise point. Lots of simulation results showed that the method is simple and applicable, and it is evidently better than other conventional filtering methods for removing details kept up. The method has a wide applicability to low noise pollution and is available to engineering applications. It was also found that the inspection of images and relevant details are of importance to several technological processes. References | Related Articles | Metrics

Select

Study on refined elements used for FEA of contact between rolls Zhao, Jian-Guo (1); Sun, Da-Le (1); Chen, Liang-Yu (1) 2010, 31 (5):  721-724.  DOI: - Abstract ( 291 )   HTML   PDF (422KB) ( 504 )   Locally refined elements in FEA enable the computational cost to be reduced with the accuracy ensured simultaneously. The multilevel refined method (MRM) is therefore proposed on the basis of the h method and existing element transition method, with its implementation procedure given. To alleviate the effect of local over-rigidity on the refined element boundary, an improving scheme is given. A new concept, refined scale, is described and how the computational accuracy varies with the scale is studied to establish the functional relationship between them. Thus, the computational accuracy of finite element model can be forecast and, what's more, a reference is provided for determining the element refining extent so as to balance the computational accuracy and cost. The method proposed is highly applicable to technological processes. References | Related Articles | Metrics

Select

On the service-oriented web digital mine system Wang, Yan-Bin (1); Wu, Li-Xin (1) 2010, 31 (5):  725-727+732.  DOI: - Abstract ( 525 )   HTML   PDF (717KB) ( 790 )   Digital mine is a complex system engineering. To solve the problems of data sharing and interoperability and to break down the information silos, a service-oriented web digital mine system is put forward. The service-oriented architecture of the system and the web service as the basic way to implement the system architecture are discussed. With the 3D geological body modeling in combination with visualization and attribute inquiring for the architecture a practise was advanced, the results showed that it is feasible to build a distributed web digital mine system based on SOA, and that the service-oriented web digital mine system can integrate all of the sub-systems of different departments in an enterprise. SOA is also proved of high expansibility and maintainability, thus making it applicable to be used widely in the future. References | Related Articles | Metrics

Select

Influence of apex diameter and cone angle on the flow field inside hydrocyclone Gao, Shu-Ling (1); Wei, De-Zhou (1); Han, Cong (1); Hu, Rui-Biao (1) 2010, 31 (5):  728-732.  DOI: - Abstract ( 313 )   HTML   PDF (1558KB) ( 816 )   A CFD-based numerical simulation of the flow field inside a hydrocyclone was carried out at different levels to reveal the influence of apex diameter and cone angle on the flow field. The results showed that the flow velocity of the field decreases, with increasing apex diameter, then the enveloping surface at zero axial velocity shrinks. When the cone angle increases the size of the enveloping surface changes, and the smaller the cone angle, the less the influnce of apex diameter on the velocity field within the enveloping surface and the more unobvious the effect of improving separation. With the apex diameter increased, the pressure of the flow field decreases but the pressure gradient within the apex region increases differently in accordance to the change in cone angle. The phenomenon reveals the interactive influence between the cone angle and apex diameter in the flow field inside a hydrocyclone to a certain extent. References | Related Articles | Metrics

Select

Influence of reaction media on morphology of Mg(OH)2 crystals under hydrothermal condition Niu, Yong-Xiao (1); Wang, En-De (1); Fu, Jian-Fei (1); Zeng, Jing (1) 2010, 31 (5):  733-736.  DOI: - Abstract ( 284 )   HTML   PDF (1169KB) ( 719 )   Mg(OH)2 colloid was precipitated at room temperature using MgCl2 and NH3·H2O as precursors. Then, the superfine high-purity Mg(OH)2 particles were obtained by hydrothermal treatment of Mg(OH)2 precipitate in different reaction media. The crystal phase, morphology and particles size of the Mg(OH)2 particles obtained were characterized with XRD and SEM. The results indicated that different reaction media play an important role in the formation of Mg(OH)2 crystals, and the NaOH solution, ethylenediamine or ethanol solution can significantly improve the crystal morphology and dispersion of Mg(OH)2 crystals. The influence of reaction media on the morphology of Mg(OH)2 crystals under hydrothermal conditions was discussed preliminarily. References | Related Articles | Metrics

Select

Effects of subsurface depths on pollutant removal with SWIS Li, Ying-Hua (1); Sun, Tie-Heng (1); Li, Hai-Bo (2); Xu, Xin-Yang (1) 2010, 31 (5):  737-740.  DOI: - Abstract ( 268 )   HTML   PDF (1459KB) ( 557 )   SWIS as a simulation system was set up with brown meadow soil as filtering medium to monitor the changes in the concentrations of organic pollutants, nitrogen and phosphorus and investigate how the pollutants are removed at different depths of the matrix and the removal efficiency. The results revealed that the SWIS can get rid of organic matter, nitrogen and phosphorus well when the daily wastewater intake is 0.04 m3/m2 and wastewater dispersion depth 55?cm, and the removal rate tends to stable with time prolonged. The sequence of pollutant removal efficiencies in accordance to the depth of matrix is Q(100)>Q(80)>Q(20)>Q(40)>Q(60), where the basic range of removing organic matter is at the depth 20~40 cm via physical-chemical adsorption and biodegradation. It was found that the nitrification mainly takes place at the depth 0~60 cm, while the denitrification plays the leading role in the region below the depth 80 cm. Based on the Langmuir adsorption model, the maximum adsorption capacity of phosphorus in brown meadow soil is 545.3 mg/kg. References | Related Articles | Metrics

Select

Evaluation model based on information entropy and DEA for technological innovation capability of enterprises Wang, Dan (1) 2010, 31 (5):  741-745.  DOI: - Abstract ( 309 )   HTML   PDF (208KB) ( 786 )   In view of the limitations on the conventional evaluation of the technological innovation capability of an enterprise, an evaluation model based on DEA and information entropy was developed for the capability. In the model the evaluation result given by entropy method was combined with the computational result by DEA model to modify the conventional evaluation results reasonably, thus making the modified results available to analyze the output performance from different sizes of input unit comparatively. Computational results showed that the ranking of enterprises, which are obtained from such an evaluation, reflects not only the technological innovation performance of those enterprises but also their input-output efficiency and the validity of their output scale. The ranking of enterprises' technology innovation capability is therefore proved reasonable. References | Related Articles | Metrics

Select

An evaluation method for customer satisfaction of knowledge service Yu, Hong-Guo (1); Fan, Zhi-Ping (1); Zhang, Chong-Yang (1); Li, Xia (1) 2010, 31 (5):  746-749.  DOI: - Abstract ( 374 )   HTML   PDF (295KB) ( 646 )   A method is proposed to evaluate customer satisfaction of knowledge service. The connotation and characteristics of knowledge service are analyzed and the earlier works on the evaluation of service quality are reviewed. Then, an evaluation index system is set up for the customer satisfaction of knowledge service. Further, a fuzzy evaluation method is proposed considering the subjectivity and fuzziness of those indexes. A comprehensive evaluation results of customer satisfaction of knowledge service can be obtained by processing and aggregating linguistic assessment information provided by customers. An example is given to illustrate the applicability and potential of the proposed method. References | Related Articles | Metrics

Select

Study on correlation between A share market and B share market in China based on wavelet analysis Jin, Xiu (1); Wang, Jia-Xing (1); Liu, Ye (1) 2010, 31 (5):  750-752+756.  DOI: - Abstract ( 292 )   HTML   PDF (303KB) ( 660 )   With the time-varying characteristic of market fluctuations taken into account, the correlation between the A share market and B share market in both Shanghai and Shenzhen Stock Exchanges was discussed by wavelet analysis, i.e., the multi-scale change in wavelet function was introduced to correspond with the holding period of the shares purchased, then the correlation coefficient between the A and B shares is decomposed on multi-scale. The empirical result showed that price fluctuations of B shares is obviously higher than that of A shares, and the wavelet variance and share price fluctuations gradually decrease with the increasing time scale. Besides, the correlative uniformity between the Shanghai and Shenzhen Stock Exchanges, both are for buying/selling A and B shares, is higher than that between A share market and B share market. The wavelet analysis was thus proved able to investigate effectively the correlative time-varying characteristics of two share markets in China and their segmentability from the perspective of correlation. References | Related Articles | Metrics

Select

Many-body effect on spinning electron transport in a parallel double quantum dot structure Gong, Wei-Jiang (1); Xie, Xue-Feng (1); Wei, Guo-Zhu (1) 2010, 31 (5):  753-756.  DOI: - Abstract ( 309 )   HTML   PDF (779KB) ( 492 )   The spinning electron transport for the spin polarization induced by local Rashba spin-orbit coupling in a three-terminal parallel double-quantum-dot structure is theoretically studied by the nonequilibrium Green function method. It was found that when the electrons come from the source terminal to two drain terminals through quantum dot region, they can select a specific terminal in accordance to the spin state, i.e., the spin polarization and spin separation can both be simultaneously performed in such a structure. Meanwhile, the intra-dot Coulomb interaction affects greatly the spinning electron transport of the system where the intensity of Coulomb interaction in the quantum dot, which is coupled with the additional terminal, plays an important adjusting role in spinning electron transport. References | Related Articles | Metrics

Select

Study on the affinity between IAM and non-membrane proteins Jiang, Jing (1); Wang, Shan-Shan (2); Deng, Yu-Lin (3) 2010, 31 (5):  757-760.  DOI: - Abstract ( 311 )   HTML   PDF (831KB) ( 778 )   Owing to the low content of membrane protein in cell and its complicated extraction/purification process with high cost, the membrane-related study on screening the non-membrane proteins which have strong affinity for biomembrane is of significance. With the IAM taken as a biomembrane model, it was filled into a capillary as the stationary phase in micro-column liquid chromatography. Then, ten kinds of common proteins were selected for investigating the interactions between IAM and then under acidic, neutral and alkali conditions. The results showed that the neutral phosphate buffer solution provides the environment where the proteins will combine best with IAM, thus enabling five kinds of proteins to provide strong affinity for IAM. References | Related Articles | Metrics