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Stripper temperature control method based on variable universe fuzzy-PID Gao, Shu-Zhi (1); Gao, Xian-Wen (1); Zhu, Zhi-Cheng (1) 2010, 31 (10):  1369-1372.  DOI: - Abstract ( 516 )   HTML   PDF (930KB) ( 905 )   The stripping process in a stripper is characterized by high nonlinearity, large time delay, strong coupling and that the temperature is difficult to control accurately. A stripper temperature control system based on the variable universe fuzzy-PID was therefore designed. With the scale factor chosen according to fuzzy rules and the concept of variable universe combined with fuzzy-PID, a variable universe fuzzy-PID control system was formed. Then, the three simulation curves of conventional PID algorithm, fuzzy-PID algorithm and variable universe fuzzy-PID algorithm of the stripper temperature control system were compared with each other, and the results showed that the variable universe fuzzy-PID control algorithm has a shorter response time, smaller overshoot and better tracking performance. References | Related Articles | Metrics

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QR code recognition system based on Blackberry mobile phone Xu, Jiu-Qiang (1); Liu, Hui (1); Lang, Feng-Gao (1); Wang, Jing (1) 2010, 31 (10):  1373-1376+1380.  DOI: - Abstract ( 528 )   HTML   PDF (1542KB) ( 599 )   The QR code recognition technology was applied first to Blackberry mobile phone, i.e., an effective QR code image recognition algorithm was designed for the limited processing ability of mobile phone after the QR code image processing and decoding techniques were investigated in depth. As a result, QR code recognition system was developed on the development platform of Blackberry mobile phone(Blackberry JDE 4.6.1) and applied to the Blackberry mobile phone 8320. Test results showed that this system can recognize the QR code information through camera and meet the requirements for time-saving and high accuracy. References | Related Articles | Metrics

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Feature extraction of ECoG signals using band power Zhao, Hai-Bin (1); Liu, Chong (1); Li, Chun-Sheng (1); Wang, Hong (1) 2010, 31 (10):  1377-1380.  DOI: - Abstract ( 433 )   HTML   PDF (1018KB) ( 840 )   A feature extraction algorithm was proposed using band power (BP) for a typical ECoG-based brain-computer interface (BCI) system, when the subject imaged movements of either the left small finger or the tongue. In the method the BP features are taken to select the channels, and 11 channels with most distinctive features are selected from 64 channels for analysis. Then, the features of ECoG signals are extracted according to BP, and the dimensions of feature vector are reduced with principal components analysis (PCA). Consequently, two different mental tasks are classified via Fisher linear discriminant analysis (LDA). The results of off-line analysis showed that the algorithm proposed has high classification accuracy for test data set. References | Related Articles | Metrics

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P2P authentication based on durable P2P storage technique Wen, Tao (1); Zhang, Yong (1); Guo, Quan (1); Li, Ying-Qiu (1) 2010, 31 (10):  1381-1384.  DOI: - Abstract ( 256 )   HTML   PDF (522KB) ( 539 )   Analyzing the security, easy-to-use operation and cost of authentication, introducing the password-based authentication into a P2P system is regarded as necessary. With the durable P2P storage techniques and the ideas about reliable computation and virtual system taken into account to provide a decentralized database for storing users' information and reliable entity for authentication, the two key problems using durable techniques of password-based identity authentication can be solved, i.e., a user's individual information is unable to store and lack of objectively reliable entity for implementing the password-based authentication. The theoretical analysis and prototype both verify the feasibility of the way proposed for authentication, which is a try beneficial to the improvement of authentication. References | Related Articles | Metrics

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Routing algorithm based on load balance in wireless sensor network Zhang, Zhen-Chuan (1); Zhang, Xin-Xiu (1) 2010, 31 (10):  1385-1388.  DOI: - Abstract ( 443 )   HTML   PDF (1134KB) ( 618 )   To solve the problems of blind area monitoring and "hotspot" in conventional clustering routing protocols, an improvement is made on the basis of LEACH and PEGASIS to propose a load-balance routing algorithm in wireless sensor networks. In cluster formation, considering the composite distance including that from node to cluster head and from cluster head to base station, the unclustered nodes with minimum composite distance are chosen to be included in the cluster, thus balancing the network energy efficiently. Since inter-cluster communication is carried out in a multi-hop mode, the next hop routing is chosen according to the network communication cost and residual energy of cluster head so as to balance the network load further. The simulation results by NS2 showed that the improved algorithm proposed not only balances the energy consumption of the whole network efficiently but also results in the prolonged network lifetime. References | Related Articles | Metrics

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An infrared target tracking algorithm based on optimal template matching Liu, Yu-Hui (1); Yan, Qian-Qian (1); Zhang, Guang-Yuan (2); Yuan, Huai (2) 2010, 31 (10):  1389-1392.  DOI: - Abstract ( 322 )   HTML   PDF (1267KB) ( 758 )   An effective infrared target tracking algorithm for video images is proposed to improve the accuracy of target tracking if the surroundings change or are being disturbed, based on a new similarity measurement algorithm in accordance to the normalized and cross-correlated distances with a matching confidence designed for tracking. Thus, the proposed algorithm is actually a weighted adaptive template updating algorithm based on tracking confidence. With respect to the template updating, an adaptive threshold adjustment strategy is proposed in the process of target tracking, by which the thresholds can be adjusted dynamically according to matching confidence, getting rid of the effect of fixed thresholds on tracking accuracy. Testing results showed that the proposed algorithm improves the adaptability to the change in surroundings and tracking stability greatly. References | Related Articles | Metrics

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Minimum spanning tree integrated with gradient information for medical image registration Zhang, Shao-Min (1); Zhi, Li-Jia (1); Zhao, Da-Zhe (1); Zhao, Hong (1) 2010, 31 (10):  1393-1396.  DOI: - Abstract ( 314 )   HTML   PDF (300KB) ( 523 )   The conventional MST (minimum spanning tree) image registration based on uniform sub-sampling is so sensitive to sampling rate that the registration robustness is thus reduced. To solve the problem, MST integrated with gradient information is proposed as a medical image registration algorithm. In the algorithm, the uniform sub-sampling point set is extracted to form MST, which is used to estimate the Re´nyi entropy directly. As a result, the edge gradient information between images is integrated into the registration framework. Comparison results of the images obtained from Vanderbilt retrospective registration project (RREP) showed that the algorithm proposed can provide smoother registration function and better robustness than both the MST registration algorithm based on conventional uniform sub-sampling and the registration algorithm based on normalized mutual information (NMI). References | Related Articles | Metrics

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Vein image feature extraction based on box counting dimension and multiple wavelets Cui, Jian-Jiang (1); Jia, Xu (1); Liu, Jing (1); Ding, Wan-Qiang (1) 2010, 31 (10):  1397-1400+1409.  DOI: - Abstract ( 252 )   HTML   PDF (387KB) ( 617 )   A global/local feature extraction algorithm is proposed on the bases of box counting dimension and multiple wavelets to improve the matching rate in vein recognition process. In this algorithm the vein texture roughness is extracted as global feature by the box counting dimension, with the local features of vein image extracted by multiple wavelets decomposition and described by the encoding with one-dimension coefficients and that with multi-scale coefficients. It is proved by the test results of existing vein images that the proposed feature extraction algorithm is effective, and the recognition accuracy of its relevant matching algorithm improved. References | Related Articles | Metrics

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Microstructure and toughness of welded 00Cr12Ni stainless steel in heat-affected zone Zheng, Huai-Bei (1); Ye, Xiao-Ning (2); Jiang, Lai-Zhu (1); Liu, Zhen-Yu (1) 2010, 31 (10):  1401-1404.  DOI: - Abstract ( 302 )   HTML   PDF (1792KB) ( 553 )   Welding thermal cycle of 00Cr12Ni stainless steel with different heat inputs were simulated on Gleeble 3800 thermo-mechanical simulator to investigate the microstructure and impact toughness of the heat-affected zone (HAZ). The results showed that the grain size and martensite volume fraction in the coarse-grain heat-affected zone (CGHAZ) both increase with the heat input, while the microstructure of the fine-grain heat-affected zone (FGHAZ) consists mainly of martensites with a small content of ferrites. The impact work done in CGHAZ at room temperature decreases with increasing heat input, but in FGHAZ all specimens are of high impact toughness no matter how the heat input varies. The specimens all present brittle fracture in CGHAZ and present ductile fracture in FGHAZ. A conclusion is therefore drawn that the welding heat input should be scheduled as low as possible so as to obtain an HAZ where the fine grains and high toughness are both available. References | Related Articles | Metrics

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Continuous cooling transformation behaviour of V-Bearing 0.2C-0.5Si-0.08P-Mn TRIP steel Hou, Xiao-Ying (1); Xu, Yun-Bo (1); Wu, Di (1) 2010, 31 (10):  1405-1409.  DOI: - Abstract ( 259 )   HTML   PDF (2374KB) ( 450 )   The continuous cooling transformation (CCT) behaviour was investigated for the 0.2C-0.5Si-0.08P-Mn TRIP steel with 0.19% vanadium on a thermo-simulator. The results revealed that the starting transformation temperature of ferrite (Ar3) is increased by 42~58°C during subsequently continuous cooling after the deformation rate has been up to 50% in the zone where the austenite has not been recrystallized. At the same cooling rate especially it is lower than 20°C/s, the deformation of austenite stimulates the formation of ferrite with the bainitic nucleation rate reduced. The vanadium nitrides and vanadium carbides both disperse and precipitate within ferritic grains or at grain boundaries, and most of the precipitated particle sizes are in the range from 2 to 5 nm at the cooling rate 0.5°C/s, regardless of whether the austenite is deformed or undeformed. It was found in specimens that only a few precipitate particle sizes are about 20 nm. References | Related Articles | Metrics

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Co-Pt perpendicular magnetic recording film induced by Ti underlayer Xiao, Na (1); Pei, Wen-Li (1); Zhao, Xiang (1); Qin, Gao-Wu (1) 2010, 31 (10):  1410-1413.  DOI: - Abstract ( 271 )   HTML   PDF (1129KB) ( 561 )   The magnetic Co1-x-Ptx thin films with different Pt atom fractions (x:0,15%,26%,35%) were deposited on the Ti underlayer which was deposited first on the glass substrate heated at 300°C by DC magnetron sputtering. The crystal structure and magnetic properties of the films were investigated by XRD and VSM, respectively. The results showed that the Pt atom fraction affects greatly the lattice constants of Co-Pt. With the increasing Pt atom fraction, the lattice constants of Co (a,c) increase, thus reducing the lattice mismatching between Co-Pt and Ti underlayer on the (00.2) crystal plane and benefiting the c-axis orientation to be perpendicular to the film surface. In this way the better magnetic properties can be obtained. With the co-sputtering process of Ti and SiO2 introduced to prepare the underlayer, it was found that the perpendicular magnetic properties of Co-Pt film can be improved with increasing SiO2 volume fraction. References | Related Articles | Metrics

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Software development of strip flatness off-line display and pattern recognition Hao, Liang (1); Di, Hong-Shuang (1); Gong, Dian-Yao (1); Liu, Guang-Ming (1) 2010, 31 (10):  1414-1416+1420.  DOI: - Abstract ( 294 )   HTML   PDF (595KB) ( 626 )   Based on the data recorded on shapemeter in a cold rolling mill and the strip flatness measuring principle, an off-line dynamical analysis software was developed in the environment VB 6.0 by VBA technique for the cold strip flatness. Thus, the real-time flatness data recorded and the roll speed of finishing mill could both be dynamically displayed off-line. According to strip shape recognition principle, the strip shape was recognized statically, and the results conformed with the actuality in production. The software we developed is of significance to the evaluation of its effect on flatness control and the analysis and solution to the problem of cold-rolled strip. References | Related Articles | Metrics

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Classification and their formation mechanism of typical rolled-in scales on hot rolled plates Sun, Bin (1); Liu, Zhen-Yu (1); Wang, Guo-Dong (1) 2010, 31 (10):  1417-1420.  DOI: - Abstract ( 406 )   HTML   PDF (1631KB) ( 1344 )   Typically the scales on the plates during hot rolling can further divided into two kinds, i.e., being rolled into superficial layer and being embedded in plate, and the defects resulting from both kinds of scales were investigated. The results showed that the casting powder adhering to the slab surface is combined with the scales formed in reheating furnace. After the rough descaling, the residual combinations were wholly rolled into the plate and passing through the surface during rough rolling, thus forming the embedded scales. If the casting powder is adhering to a continuous casting billet, the residual casting powder after rough descaling is combined with the primary scales in reheating furnace, then the combinations are rolled into the superficial layer of plate during rough rolling, thus forming the scales in superficial layer. References | Related Articles | Metrics

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Research and design of flatness control system of single-stand reversing cold mill Liu, Jia-Wei (1); Zhang, Dian-Hua (1); Wang, Peng-Fei (1); Wang, Jun-Sheng (2) 2010, 31 (10):  1421-1423+1428.  DOI: - Abstract ( 281 )   HTML   PDF (521KB) ( 432 )   To upgrade the automatic control of flatness of strip, a relevant control system was designed and developed for the signal-stand reversing cold mill in Ansteel, with a domestic magnetic-pressure flatness meter used for cold-rolled strip. The structure, operating principle and implementation of the flatness control system were described in detail. In the design of the control system the efficiency factor of flatness was introduced to develop the control model, and efficiency factor of flatness can serve the function of improving the control accuracy of strip shape. With the online flatness control system applied to the detection of the strip as the products from a reversing cold mill, the flatness error is available to be controlled within ±50 μm/m. References | Related Articles | Metrics

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Optimization of work roll profile on finishing stands for 1422 hot-rolled strip in Meisteel Xia, Xiao-Ming (1); Di, Hong-Shuang (1); Bian, Hao (2); Zhang, Yong-Xue (2) 2010, 31 (10):  1424-1428.  DOI: - Abstract ( 240 )   HTML   PDF (2194KB) ( 552 )   In Meisteel the control of strip shape has been improved obviously after reforming the finishing mill for hot-rolled strip. However, the middle part and tail of the strip become instable if the rolling process is in accordance to the rolling schedule, thus making the strip crown and flatness unsatisfiable to market demand especially the high-crown requirement of workpiece for cold rolling, with the strip shape model unable to work normally. To solve the problem, the CVC work roll profiles on the finishing stands F1~F3 and the work roll profiles on the stands F4~F6 are both optimized on the basis of theoretical analysis. Then, the hit ratio of target crown is increased from 87% to about 98% with the work roll wear-off reduced. As a result, the wearability of work rolls of the same width is scheduled in terms of kilometers, and the strip for containers(1.6 mm×1185 mm) is therefore supplied by Meisteel in batches because of its improved rolling stability. References | Related Articles | Metrics

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Computation of hot tandem rolling rhythm based on confidence level and self-learning calibration Tian, Ye (1); Zhao, Zhao-Hong (2); Hu, Xian-Lei (1); Liu, Xiang-Hua (1) 2010, 31 (10):  1429-1431+1436.  DOI: - Abstract ( 239 )   HTML   PDF (546KB) ( 467 )   The control accuracy of conventional online rolling rhythm computation model is low in most hot tandem rolling plants in China at present. The problem was therefore investigated in the Baosteel Ningbo Hot Rolling Mill and, as a result, an improved algorithm of the rolling rhythm computation based on confidence level and self-learning calibration was proposed for hot tandem rolled strip. Verified by lots of in-situ testing data which were compared with that by the algorithm of conventional computation model, the prediction precision of the rolling rhythm computation model has greatly been improved, i.e., the error frequency is up to 97.94% within ±5 s and presents a normal distribution on the whole. In addition, the predicted time required for the whole rolling process of strip by the improved algorithm is superior to that by the conventional computation one. References | Related Articles | Metrics

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Effects of mold EMS parameters on distributions of magnetic induction and electromagnetic force during continuous casting Zhang, Jing (1); Wang, En-Gang (1); Deng, An-Yuan (1); He, Ji-Cheng (1) 2010, 31 (10):  1432-1436.  DOI: - Abstract ( 314 )   HTML   PDF (827KB) ( 737 )   A numerical simulation in combination with in-situ measurement was conducted according to the actual continuous casting process for the M-EMS(mold-electromagnetic stirring) behavior of Φ250 mm bloom. The effects of EMS current and frequency on the distributions of magnetic induction and electromagnetic force were then investigated. The results showed that the simulated results conform basically with the measured data. With the current kept constant and frequency increased, the magnetic induction decreases, and along the centerline in mold, the electromagnetic force increases with frequency though its increment decreases gradually. But, along the radius of electromagnetic stirrer the electromagnetic force decreases with increasing frequency and with the frequency kept constant and current intensity increased, the magnetic induction and electromagnetic force both increase in molten steel. Considering the results of numerical simulation as a whole, the optimal EMS parameters should be as follows: stirring current=480 A with a frequency=3 Hz. References | Related Articles | Metrics

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Analysis of heavy metal pollution in surface sediment in intertidal zone of Qinhuangdao coastal area of Bohai Bay Zhou, Xiu-Yan (1); Xue, Xiang-Xin (2); Leng, Wen-Fang (3); Liu, Zhi-Guo (3) 2010, 31 (10):  1437-1440.  DOI: - Abstract ( 332 )   HTML   PDF (1114KB) ( 569 )   Based on the investigation on the surface sediment in the intertidal zone of Qinhuangdao coastal area, the pollution characteristics of Cu, Pb, Zn and Cd in the surface sediment were analyzed with their distributions evaluated with the Hakanson's potential ecological risk index. The results showed that the average mass fractions of Cu, Pb and Zn come up to the grade-I of the national environmental quality standard for soil, while the average mass fraction of Cd exceeds 4.6 times as high as the grade-II of the standard. The potential ecological risks of the four kinds of heavy metals are different in comparison, i.e., Cd> Pb, Cu>Zn. On the whole, the ecological risks of Cu, Pb and Zn in surface sediment are all slight, whereas that of Cd is strong even very strong, which may hazard the littoral water quality and halobios. References | Related Articles | Metrics

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Analysis of breakage and restoration measures for cooling stave in Baosteel No.3 BF Liang, Li-Sheng (1); Wei, Guo (1); Zheng, Hai-Yan (1); Shen, Feng-Man (1) 2010, 31 (10):  1441-1444.  DOI: - Abstract ( 335 )   HTML   PDF (782KB) ( 1042 )   The occurrence of early breakage of the water pipe for cooling stave in the No.3 BF threatened seriously the operation of the BF and its service life. It was found that the main causes of the breakage are the unreasonable design of cooling system, low cooling intensity, defective stave and uncontrolled water quality. Several measures were taken to restore the function of stave, such as using miniature cooler, rebuilding the stave and external watering, and good results were thus achieved somewhat. To remove thoroughly the hidden perils of the breakage of water pipe for stave, the cooling staves in the sections S3 and S4 were quickly and successfully replaced integrally, thus improving the furnace conditions greatly. The BF then returned to its normal productivity very soon with a foundation laid down for its future production and prolonged service life. References | Related Articles | Metrics

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Effect of refining slag's basicity on inclusions in molten 304 stainless steel Zhuang, Ying (1); Jiang, Zhou-Hua (1); Li, Yang (1) 2010, 31 (10):  1445-1448.  DOI: - Abstract ( 310 )   HTML   PDF (1250KB) ( 795 )   The AOD process of the 304 stainless steel was simulated in lab, with the FeSi alloy taken as final deoxidant and the CaO-SiO2-Al2O3-MgO-CaF2 slag chosen as refining slag. Then, the effect of refining slag's basicity on the inclusions in the 304 stainless steel melts was investigated. The results showed that with the increasing basicity of refining slag the total mass fraction of oxygen decreases, as well as the total number, area and average size of inclusions. The fact means that the high basicity of slag benefits both the absorption of deoxidation products and the formation of fine inclusions. However, the effect of refining slag on the inclusions in molten steel revealed that a better result is available if the slag's basicity is 2 other than 1.5. So, it is recommended to taken the refining slag whose basicity should be greater than 2 in AOD process. References | Related Articles | Metrics

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Numerical analysis of heat loadings on oxygen lance tip in converter Li, Bao-Kuan (1); Zhang, Jian-Shi (1); Wang, Fang (1); Qi, Feng-Sheng (1) 2010, 31 (10):  1449-1452.  DOI: - Abstract ( 254 )   HTML   PDF (990KB) ( 639 )   A numerical fluid-solid coupling simulation was done with the commercial software FLUENT for the copper tip of conventional oxygen lance and the flow field in the cooling water passing through the lance tip. It was found that some dead zones are in the cooling water flow passage within the lance tip, thus affecting the effect of cooling. To prevent the lance tip from deformation or burn-out, several streamline rib deflectors are added to the original lance tip. Then, the effect of the new construction of lance tip cooling process was analyzed simulatively, and the vector distribution of swirling cooling water flow field was obtained with increasing turbulence intensity and enhanced cooling effect of oxygen lance tip. Comparing with the conventional oxygen lance tip, the temperature of end face of the new oxygen lance tip decreases by 10°C, i.e., the service life of lance tip will be prolonged considerably. References | Related Articles | Metrics

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Microstructural change of gibbsite particle in digestion process Bao, Li (1); Zhang, Ting-An (1); Lü, Guo-Zhi (1); Dou, Zhi-He (1) 2010, 31 (10):  1453-1456.  DOI: - Abstract ( 226 )   HTML   PDF (1329KB) ( 575 )   The change of microstructure of the gibbsite particle while digesting in sodium aluminate solution (liquid-solid reaction) was studied. The ASAP 2020 micrometric apparatus and SEM were employed to determine the specific surface area of particles, pore structure including average pore size and volume and apparent structure. The BET, Langmuir, t-plot and BJH methods were all used to calculate the specific surface area of gibbsite particles with the pore structure of particles calculated by the BJH method. The results showed that both the specific surface area of particles and pore volume increase then decrease slightly with prolonged digestion time, while the average pore size changes in a decrease-increase-decrease process. The SEM images showed that the surface structure of gibbsite particles becomes looser gradually in digestion process. A conclusion is therefore drawn that the surface area of gibbsite particles in contact with solution is not in direct proportional to the square of particle radius in the process of gibbsite dissolution in alkali solution. References | Related Articles | Metrics

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Welding parameters of 6005A aluminum alloy for new high-speed train Ji, Kai (1); Zu, Guo-Yin (1); Yao, Guang-Chun (1) 2010, 31 (10):  1457-1461.  DOI: - Abstract ( 511 )   HTML   PDF (1204KB) ( 1739 )   The 12 mm-thick 6005A-T6 aluminum alloy was welded with ER5356 wire by semi-automatic MIG welding, and the effects of main welding parameters on the tensile strength of weld joints and surface quality of welds were investigated by orthogonal tests. The result showed that the influencing factors on the tensile strength of weld joints can be ranked with the significance of difference considered, as follows: welding current, welding voltage, welding speed and preheating temperature, while the rankings of the influencing factors on the surface quality of welds are: welding speed, preheating temperature and welding current. The optimal MIG welding parameters for the 6005A-T6 plates are: welding current 180 A, welding voltage 18.0 V, welding speed 12 mm/s and preheating temperature 200°C. After welding, there is no overgrown grain founded in the heat affected zone (HAZ) of the alloy specimens, where the average grain size is less than 5 μm. Typically the welded plates show ductile fracture pattern if being pulled apart. References | Related Articles | Metrics

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NiFe2O4 spinel based inert anode for aluminum electrolysis Ma, Jia (1); Yao, Guang-Chun (1); Zhang, Xiao (1); Zhang, Zhi-Gang (1) 2010, 31 (10):  1462-1465.  DOI: - Abstract ( 208 )   HTML   PDF (665KB) ( 390 )   NiFe2O4 spinel based inert anode was prepared for aluminum electrolysis via solid-state reaction sintering, and the variation of porosity in sintering process was investigated by spherical model to explore the effects of sintering temperature on the micromorphology, porosity and bending strength of the anode. The results showed that sintering temperature can significantly improve the performance of the inert anode, and the reaction between Fe2O3 and NiO belongs to the spontaneous reaction which may be carried out at room temperature in view of thermodynamics and the temperature elevating is just to meet the kinetic conditions for reactions. The porosity of the specimens decreases from 30.41% to 1.72% and the bending strength increases from 14.62 to 71.94 MPa when the temperature increases from 1150 to 1400°C. References | Related Articles | Metrics

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Controlling the biodegradation rate of magnesium by biomimetic coatings Zhang, Ya-Jing (1); Wu, Zhi-Lin (2); Liu, Yue (1); Zhang, Dan (1) 2010, 31 (10):  1466-1469.  DOI: - Abstract ( 229 )   HTML   PDF (1498KB) ( 538 )   Silica and silica calcium sol-gels were coated on the surface of magnesium, and then the hydroxyapatite (HA) coating was formed on the surfaces of pure magnesium samples by biomimetic process, regardless of the sol-gel coating. The coating layers were characterized by XRD, EDX and SEM, and the morphology of sample surfaces was observed by an emission scanning electron microscope (FESEM). The samples were subsequently immersed in the simulated body fluid (SBF) for the degradation test. The results showed that HA coating is formed on the surface of pure magnesium 24 h after biomimetic process no matter whether the sol-gels have already been coated before. It was found that the HA coating can decrease the corrosion rate of the substrate in SBF, i.e., the degradation rate of samples is controllable if controlling the chemical composition and morphology of coating layers. References | Related Articles | Metrics

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Characteristic analysis on nonlinear faults of two-span rotor system due to the combination vibration of bending, torsion and swinging Yuan, Hui-Qun (1); Kou, Hai-Jiang (1); Li, Dong (1) 2010, 31 (10):  1470-1474.  DOI: - Abstract ( 251 )   HTML   PDF (2622KB) ( 568 )   With respect to an asymmetrically elastically supported two-span rotor system under the fault coupling loosened pedestal with tub-impact, a nonlinear dynamic model was developed to study numerically the dynamic characteristics of the system during a combination vibration of bending, torsion and swinging. Analyzing the effect of swinging on the system via the bifurcation diagram, phase diagram and amplitude-frequency spectrum, the typical nonlinear characteristics of such rotor systems with different structural parameters were revealed, thus providing a reference to the fault diagnosis of such rotor systems. The results showed that the effect of the vibration due to swinging on a running two-span rotor system is of significance, and that the nonlinear amplitude-frequency characteristic curve of a rotor system with looseness fault presents several unsmoothed peaks. References | Related Articles | Metrics

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RBF parameter identification of valve-controlled cylinder system for excavator robot Wang, Fu-Bin (1); Liu, Jie (1); Chen, Zhi-Kun (2); Zeng, Xiu-Li (2) 2010, 31 (10):  1475-1478.  DOI: - Abstract ( 461 )   HTML   PDF (905KB) ( 879 )   To improve the planned control accuracy of trajectory of the working parts of a hydraulic excavator robot, i.e., to develop an applicable control model for the valve-controlled cylinder system instead of the ideal one so as to make the control of the robot more actual with control error decreased. By way of RBF neural network, a set of nonlinear equations was deduced involving the parameters to be identified for the valve-controlled cylinder system and relevant Jacobian information. With the bucket arm/cylinder system of the excavator robot investigated via tests, such parameters of cylinder's oil inlet/outlet pressure and rake angle of bucket arm were given to identify the valve's gain coefficient kq, oil volumetric coefficient Eoil and inner leak coefficient Cliin the valve-controlled cylinder model. It is verified that the model involving identification parameters has high control accuracy and robustness as the result of a comparative force control test for the valve-controlled cylinder system. References | Related Articles | Metrics

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Vibration suppression based on negative impulse input shaping for a 3-DOF parallel manipulator Li, Bing (1); Xie, Li-Yang (1); Wei, Yu-Lan (1); Wu, Ying (1) 2010, 31 (10):  1479-1482.  DOI: - Abstract ( 323 )   HTML   PDF (755KB) ( 934 )   The negative impulse input shaper was designed to implement the accurate and rapid responses to the system motion. A 3-DOF parallel manipulator system was thus introduced, as well as the system model and its dynamic equations. With the architectures of the ZV, ZVD and EI input shapers involving negative impulses given and applied to the 3-DOF manipulator system, the negative impulse input shaper was investigated in view of decreasing the time delay of the system response and its robustness and in comparison with the positive impulse input shapers. The simulation results showed that the negative impulse input shaper can suppress the residual vibration and, at the same time, decrease the time delay of the system response. References | Related Articles | Metrics

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A multi-shape and multi-scale edge detection algorithm based on mathematical morphology Huang, Hai-Long (1); Wang, Hong (1); Guo, Fan (1); Zhang, Jin-Feng (1) 2010, 31 (10):  1483-1486.  DOI: - Abstract ( 347 )   HTML   PDF (906KB) ( 821 )   In the process of edge detection based on mathematical morphology, the structural elements of different shapes/scales play different roles in noise filtering and keeping edge details intact. An adaptive edge detection algorithm based on multi-shape/scale structural elements was therefore proposed, where the image edge was extracted using different directions/sizes structural elements. Then, the weight factors were determined adaptively by computing the information entropy so as to integrate the edges detected by multi-shape and multi-scale structural elements. Experimental results showed that the proposed algorithm can suppress the interference of noise more effectively in comparison with several classical edge detection algorithm, thus improving the detection accuracy and robustness of different images. References | Related Articles | Metrics

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Study on multilevel refinement of 3-D elements Zhao, Jian-Guo (1); Sun, Da-Le (1); Chen, Liang-Yu (1) 2010, 31 (10):  1487-1490.  DOI: - Abstract ( 221 )   HTML   PDF (460KB) ( 527 )   Conventionally the local refinement of mesh division is done via the hexahedral elements, which takes a long time to develop relevant mathematical model and distorts the elements at complex boundaries even requires the tetrahedral transition, thus lowering the solution accuracy. For this reason, the multilevel refinement method (MRM) of elements is proposed with the way given to implement it, based on the h-method and existing element transition. The effectiveness of MRM is verified by comparing it with Hertz method and other conventional refinement method. As to the problem of local excessive stiffness at boundaries as a result of multilevel refinement, the solution is to expand the refinement area, which has been verified by an exemplification of the rolls in contact on a mill. References | Related Articles | Metrics

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Numerical simulation and discussion on strength of layered rockmass Guo, Mu-Dan (1); Wang, Shu-Hong (1); Zhang, Hang (1); Xu, Yuan (1) 2010, 31 (10):  1491-1494.  DOI: - Abstract ( 386 )   HTML   PDF (638KB) ( 601 )   Based on the date as a result of the in-situ geological survey for the Dahuofang Reservoir, a source for water supply, a numerical model of layered rockmass was developed introducing the methods of bedding plane weakening and Interface command. Then, a numerical simulate of the layered rockmass was done using the software FLAC3D with the results analyzed emphasizing the discussion on the accuracy of simulated results by both methods. It was found that although the vertical displacement of rockmass computed by the method of Interface command is discontinuous, the ultimate axial compressive strength is basically the same to that computed by theoretical analysis at different obliquities of bedding plane, with the error both within 10%. So the method of interface command is regarded as the better one to describe the failure conditions of layered rockmass, and it will provide a reference for the construction of subsequent and similar projects of layered rockmass. References | Related Articles | Metrics

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Experimental research on anti-bending performance of composite RC-filled GFRP tube members Chen, Bai-Ling (1); Wang, Lian-Guang (1); Qin, Guo-Peng (1) 2010, 31 (10):  1495-1498.  DOI: - Abstract ( 237 )   HTML   PDF (1029KB) ( 778 )   The anti-bending performance of the composite RC-filled GFRP tube member was researched experimentally. The results showed that the hooping effect of GFRP tube on concrete is found obviously only in the compressive zone, but it is unobvious in the tensile zone. There are three stages shown clearly on the load-deformation curves of the composite members, i.e., the linearly elastic, nonlinearly elastic-plastic and linearly ascending sections. The section steel provided within the GFRP tube can improve the rigidity and bearing capacity of the composite member efficiently. The computed results with the program based on fiber model are well in agreement with the experimental ones, and show that the bearing capacity of the composite member increases with area fraction of steel, concrete strength and wall thickness of GFRP tube. References | Related Articles | Metrics

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Comprehensive evaluation based on stochastic simulation Guo, Ya-Jun (1); Yi, Ping-Tao (1); Li, Ling-Yu (1) 2010, 31 (10):  1499-1503.  DOI: - Abstract ( 245 )   HTML   PDF (179KB) ( 956 )   In sequential relation analysis, the ratios of weightnesses between indices as given by experts are always an interval of ratios. A comprehensive evaluation method based on Monte Carlo simulation as a stochastic one is therefore presented, where the dot assignment can be extended to the interval assignment. Based on the stochastic simulation and according to the classical comprehensive evaluation process, the superiority matrix reflecting the relation between the superiority and inferiority of the objects being evaluated is simulated. Then, the optimal ranking of all the objects to be evaluated is given. This method is the extension and generalization of the classic sequential relation analysis. A numerical example is given to verify its validity. References | Related Articles | Metrics

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Agent evaluation of managerial competency based on individuality advantage identification in manufacturing industry Jia, Jian-Feng (1); Zhao, Xi-Nan (1); Zhu, Zhu (2); Wang, Yan-Mei (1) 2010, 31 (10):  1504-1507.  DOI: - Abstract ( 217 )   HTML   PDF (320KB) ( 454 )   Based on the ideas of goal programming and 2-norm distance, an identification model of individuality advantage was developed, where the weight coefficient was determined from the perspective to make the evaluation most beneficial to evaluate. Then, the solution to the model was given in terms of Lagrange multiplicator. Based on the identification result of individuality advantage, two evaluation methods were proposed, i.e., individual agent and democratic agent. With 20 managers chosen from manufactory as samples for empirical analysis, the result showed that the proposed evaluation method was objective, scientific and reasonable, and the relevant conclusion would provide the reference for management decision-making in an enterprise. References | Related Articles | Metrics

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A new way for comprehensive evaluation of a grassroots government's execution of public policy Yu, Zhao-Ji (1); Wang, Wen-Juan (2); Su, Chang-Hai (2) 2010, 31 (10):  1508-1511.  DOI: - Abstract ( 279 )   HTML   PDF (338KB) ( 583 )   A comprehensive evaluation index system was developed for a grassroots government's execution of public policy, in view of the principle of people the first, with harmony and sustainability both taken into account. The optimal weights to indices were determined combining the objective weighting (by grading method) with subjective weighting (by G1 method), thus avoiding the dual defects that the objective weighting can not reflect the expertise and the subjective weighting can not reflect the change of objective conditions and enabling the fuzzy comprehensive evaluation system to evaluate a grassroots government's execution of public policy. In this way the evaluations of the execution of public policies of the grassroots governments at different levels are available, and the empirical results prove that the method is easy to operate accurately and effectively. References | Related Articles | Metrics

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Influence of government bailout on financial company's income Lu, Yang (1); Zhuang, Xin-Tian (1) 2010, 31 (10):  1512-1515.  DOI: - Abstract ( 218 )   HTML   PDF (2141KB) ( 450 )   The influence of government bailout on a financial company was studied microscopically by developing an incentive model. The results showed that cutting fixed salaries and MBO (management buy-out) can increase a company's income, while cutting performance rewards will reduce its income. Shifting the original high-risk assets to low-risk assets of a financial company also affects its income. Sharpe ratio is an appropriate indicator that could be used to value and choose low-risk assets, a financial company's income can be increased only when the Sharpe ratio of a target low-risk asset is higher than certain times of the Sharpe ratio of its original high-risk assets, and treasury bill is one of low-risk assets that boost company's income. References | Related Articles | Metrics

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A network dynamic model based on SSE composite index and trading volume fluctuation Huang, Wei-Qiang (1); Yao, Shuang (2); Zhuang, Xin-Tian (1) 2010, 31 (10):  1516-1520.  DOI: - Abstract ( 311 )   HTML   PDF (630KB) ( 521 )   Based on SSE(Shanghai Stock Exchange) composite index and its trade volume, the index-volume networks of security market was built for different periods via grain coarsening method and symbolization. Then, the topological characteristics of those networks were analyzed. The results showed that the index-volume fluctuation patterns in SSE are stable statistically. The out-degree distribution of network nodes obeys the power law, i.e., a few index-volume fluctuation patterns showed relatively great influence on the market and the majority of the patterns showed small influence. The basic fluctuation exhibited different patterns during different periods. In summary, the index-volume behavior is complex and unpredictable on the security market. References | Related Articles | Metrics