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Dynamic swarm multiobjective optimization PSO-based maximin function Feng, Lin (1); Mao, Zhi-Zhong (1); Yuan, Ping (1) 2010, 31 (7):  913-916.  DOI: - Abstract ( 306 )   HTML   PDF (1204KB) ( 750 )   Since the local convergence was often found in the process that the PSO algorithm is used to deal with multiobjective optimization problems, an new algorithm based on Maximin PSO algorithm is presented for multiobjective PSO, where the swarm size is adjusted dynamically to avoid converging at a false Pareto optimal solutions. Meanwhile, the relative fitness variance of particle is introduced into the formula of Maximin to get rid of the effect of reducing the diversity of particle swarm. Then, based on the idea about Pareto optimum, the variance Maximin strategy is used to evaluate the optimal solutions and the non-dominated solutions are stored in a size-variable elitism repository so as to provide a good diversity in its solutions. Experimental results showed the feasibility of the algorithm in solving complicated multi-objective optimization in industry. References | Related Articles | Metrics

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A weighted averaging method based on overall weight of discounted evidences Fu, Yan-Hua (1) 2010, 31 (7):  917-920.  DOI: - Abstract ( 375 )   HTML   PDF (2164KB) ( 1083 )   For a class of evidence fusion problems that integrate different importance with credibility, a new weighted average method based on overall weight of discounted evidence is proposed by combining the static weight with the dynamic weight embodying the similarity between evidences. According to the transcendental information, i.e., static weight and the similarity between evidences, the dynamic weight of evidence is acquired by calculating the distances between all evidences discounted via a static weight computation and their weighted average, then the static weight is integrated with dynamic weight to form an overall weight of evidence. An evidential reasoning model is thus developed with some discount, where the overall weight plays the role as a discounting factor. Finally, the modified evidences are combined together by the weighted average method proposed. A numerical example shows the effectiveness of the method in the integration of those evidences which are in sharp conflict with each other. References | Related Articles | Metrics

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Joint decisions model and algorithm for single product in multi-plants with capacity Zang, Jie (1); Tang, Jia-Fu (1); Li, Dan (1) 2010, 31 (7):  921-924.  DOI: - Abstract ( 263 )   HTML   PDF (854KB) ( 717 )   To deal with the production-distribution network for a manufacture with multiple plants with capacity constraints and multiple retailers, a joint decisions problem with production and transportation capacity constraints is studied. The decision variables include the production cycle length, delivery frequency in a cycle from the warehouse to the retailers and the economic production allocation. The optimization objective is to minimize of the average total cost per unit time. Since this problem is a noncocave-and-nonconvex nonlinear programming, its model is improved. A heuristics is developed to solve this joint decisions model. With a numerical example given to compute the problem of different sizes via either the proposed algorithm or the quasi-Newton method(QNM). The results showed the correctness of the model and the effectiveness of the proposed algorithm. References | Related Articles | Metrics

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A new protocol of hypercube-based cross-domain authentication Yao, Yao (1); Wang, Xing-Wei (1) 2010, 31 (7):  925-928+937.  DOI: - Abstract ( 235 )   HTML   PDF (1196KB) ( 637 )   A new cross-domain authentication protocol model is developed on hypercube basis, where the structural features of hypercube support the reversible entity authentication between different trust domains. Compared with the conventional cross-domain authentication model, the proposed model is able to not only reduce the registration workload but also simplify the distribution and management of shared cipher keys among authentication servers. In addition, the model can avoid the network bottleneck and single-point collapse due to the authentication by a single authority. Analytical results showed that the protocol model is highly secure and reliable, thus enabling the server in application to access and control so as to ensure the network security. References | Related Articles | Metrics

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Betweenness analysis of class nodes in large-scale software network Li, Bo (1); Zhao, Hai (1); Liu, Hong (1); Wang, Jia-Liang (1) 2010, 31 (7):  929-932.  DOI: - Abstract ( 334 )   HTML   PDF (1229KB) ( 820 )   Regarding the architecture of a large-scale software as a directional network graph, where the class in the network and the relation between classes are thus referred to as a node and an edge respectively, a software network graph is given as an example. Then, a concept named betweenness is defined and calculated correspondingly. The BTS algorithm is proposed for the betweenness of network nodes and used to solve the betweenness of ten softwares with the computing time given. The results show that the magnitude of betweenness reflects the importance of a node in network and provides a guidance for developing softwares. It is found there is an increasing correlation between the betweenness and the product of accessibilites(degin × degout), and the correlation is fitted with the least square method in four softwares, thus giving the slope of the fitted straight line. References | Related Articles | Metrics

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An intrusion detection method based on principal component analysis and decision tree Liu, Yong (1); Sun, Dong-Hong (2); Chen, You (3); Wang, Wan-Shan (1) 2010, 31 (7):  933-937.  DOI: - Abstract ( 320 )   HTML   PDF (2595KB) ( 901 )   A feature selection algorithm can improve efficiently the detection speed and result, with irrelevant and redundant data eliminated and denoised in an intrusion detection system. Taking advantage of the algorithm, a new hybrid feature selection algorithm based on the principal component analysis (PCA) in combination with decision tree algorithm (C4.5) was proposed to develop a lightweight intrusion detection system. Verifying the proposed algorithm in detail via tests with the KDD 1999 dataset, the algorithm was proved that it is available to not only ensure the high detection rate and low false alarm rate but also improve obviously the training/testing time of the intrusion detection system. Furthermore, as a result of comparative tests, the algorithm is superior to GA-SVM algorithm in training/testing time, detection rate and false alarm rate. References | Related Articles | Metrics

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A detection method for motion-blurred iris image based on ellipse fitting Wang, Qi (1); Zhang, Xiang-De (1); Yin, Yu (1); Zhang, Tie (1) 2010, 31 (7):  938-941.  DOI: - Abstract ( 250 )   HTML   PDF (1621KB) ( 795 )   A detection method for motion-blurred iris images was developed based on ellipse fitting to make the iris recognition system more accurate. The positions of luminous spots were estimated preliminarily in iris image by Gabor filter, then the actual luminous spot was detected in iris image which has been magnified to 5 times. With the ellipse fitting done to the boundary of every luminous spots, the fitting error and the ratio of major axis to minor axis are both calculated. An image could be judged as a motion-blurred one if the ratio is greater than 1.55 with relatively small fitting error. Results of the experiments carried out on CASIA-IrisV3-Lamp database indicated that the accuracy of detection of motion-blurred images is up to 100%, thus improving the accuracy of the whole iris recognition system. References | Related Articles | Metrics

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Microstructure and mechanical properties of HB450 ultra-high strength low-alloy abrasion resistant steel Deng, Xiang-Tao (1); Wang, Zhao-Dong (1); Yuan, Guo (1); Wang, Guo-Dong (1) 2010, 31 (7):  942-946.  DOI: - Abstract ( 402 )   HTML   PDF (2296KB) ( 802 )   The new type of Ti-Cr-B HB450 low-alloy abrasion resistant steel was designed on lab conditions. The basic characteristics, microstructure, precipitates and effects of cooling rate on microstructure and mechanical properties of the steel were also investigated. The results showed that the steel has high hardenability, and lots of martensite structure can be found when the cooling rate is higher than 20°C/s. After controlled rolling, quenching at 950°Cand tempering in the range from 250 to 300°C, the fine martensite plus residual austenite can be got with hardness up to HB450 in combination with high toughness, thus meeting the requirements of HB450 ultra-high strength low-alloy abrasion resistant steel. The TEM analyses showed that Ε-carbide particles precipitate in the lath martensite when tempering at 250°C, and these carbide precipitates play a very important role in strengthening the steel. References | Related Articles | Metrics

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Commercial test of ultra-fast cooling for bearing steel bar Zhao, Xian-Ming (1); Sun, Yan-Kun (1); Wang, Yong-Hong (2) 2010, 31 (7):  947-952.  DOI: - Abstract ( 262 )   HTML   PDF (2061KB) ( 877 )   Commercial ultra-fast cooling industrialized tests were carried out after high temperature final rolling of the Cr15 bearing steel bar by installing three ultra-fast cooling systems in addition to the original continuous rolling line in a special steel plant. The cooling rate was controlled by readjusting water pressure, nozzle size and the number of turn-on taps of water tanks after high temperature deformation of steel bar. The results showed that the C and Cr contents at the grain boundaries of secondary carbides are reduced with the size of pearlite pellets and the pearlitic lamellar gaps both decreased but the micro-hardness increases along with the continuously increasing cooling rate. Moreover, the cooling rate at anyplace on the cross section of the steel bar is available to restrain the precipitation of network carbides and transform all the overcooled austensites into pearlites. As a result, the class of the network carbides is lower than the grade II that is the professional standard. References | Related Articles | Metrics

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Effect of modification parameters on microstructure and anticorrosivity of 0Cr17Ni4Cu4Nb steel Zhao, Yi (1); Wang, Fu (1) 2010, 31 (7):  953-956+961.  DOI: - Abstract ( 271 )   HTML   PDF (2718KB) ( 768 )   The anticorrosivity and microstructure of 0Cr17Ni4Cu4Nb steel in artificial seawater after different heat treatment processes were investigated by electrochemical methods, such as polarization and cyclic polarization curves. The results indicated that if a modification follows the solution treatment of 0Cr17Ni4Cu4Nb steel before aging treatment, the steel structure will become finer and more homogeneous with the breakdown potential, width of passivation zone and protection potential all enhanced obviously. Thus, the anticorrosivity of the steel in seawater will be entirely superior to the steel without the modification. The modification and changes in its parameters will result in the variation of the quantity and sorts of carbide precipitates during heating, thus affecting the microstructure and anticorrosivity of the steel. References | Related Articles | Metrics

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Expert system of fuzzy temperature control for continuous annealing simulator Cui, Xi-Yong (1); Hua, Fu-An (1); Li, Jian-Ping (1); Zhang, Dian-Hua (1) 2010, 31 (7):  957-961.  DOI: - Abstract ( 266 )   HTML   PDF (887KB) ( 809 )   According to the disadvantages of the continuous annealing simulator's temperature control system, such as nonlinearity, time-varying, variable structure, multi-level and long time delays, an expert system of fuzzy temperature control was developed via introducing the structure and theoretical basis of fuzzy expert system in combination with some expert control strategies generalized from actual debugging process, i.e., combining the sectional PID control with dynamic structure-varying control. Testing results showed that the control system is effective with low temperature overshoot, steady controllability for the specimens of different sizes and wide scopes of applications. Thus, the temperature control system comes up to its performance indices designed for the continuous annealing simulator to cold strips. References | Related Articles | Metrics

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Numerical simulation of ultrasound-induced cavitation bubbling behavior in magnesium alloy melt Shao, Zhi-Wen (1); Le, Qi-Chi (1); Cui, Jian-Zhong (1) 2010, 31 (7):  962-965.  DOI: - Abstract ( 300 )   HTML   PDF (1848KB) ( 666 )   Based on the theoretical studies on the ultrasound-induced cavitation, a numerical simulation to solve the Rayleigh-Plesset equation with Matlab was done to investigate the influence of different ultrasonic conditions including ultrasonic frequency, acoustic pressure and initial radius of cavitation bubble on the cavitation bubbling behavior in magnesium alloy melt. In addition, the effects of melt bulk temperature and acoustic pressure on the maximum temperature/pressure in collapsing bubble were also discussed. The results showed that what will benefit the ultrasound-induced caviatation are the lower ultrasonic frequency, melt bulk temperature and higher acoustic pressure, as well as the initial radius of cavitation bubble, which is equal to or less than the size that will cause resonance. References | Related Articles | Metrics

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Mathematical simulation of continuous casting process of round billet solidification of 37Mn5 steel Zhang, Zhi-Xiang (1); Min, Yi (1); Jiang, Mao-Fa (1) 2010, 31 (7):  966-969.  DOI: - Abstract ( 495 )   HTML   PDF (1646KB) ( 1061 )   To control the quality of continuous casting round billets used for oil well pipes, a mathematical model based on slice moving method was developed for the solidification and heat transfer process of the round billets. Then, a mathematical simulation was done using the ProCAST software for the solidification process of the φ150 mm round billets of 37Mn5 steel. As a result, the predicted billet surface temperature is in accordance with testing results of industrial experiments. The simulation results showed that, on the conditions that the superheat is (20 ± 5)°C, with a drawing velocity 2.5 m · min-1, the billet shell thickness at mold exit, the liquid core length, and the surface temperature of strand can all be controlled in appropriate range to prevent the billets from surface/internal cracks and ensure the casting safety with productivity improved. References | Related Articles | Metrics

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Study on temperature/stress distribution in porous plug for bottom-blowing ladle furnace Li, Bing-Qiang (1); Li, Zhi-Qiang (1); Liu, Tao (1); Yu, Jing-Kun (1) 2010, 31 (7):  970-972+989.  DOI: - Abstract ( 262 )   HTML   PDF (905KB) ( 796 )   The temperature/stress distribution in the porous plug for ladle furnace was investigated using ANSYS software. The results showed that the surface temperature of the plug is the same to the molten steel, while the temperature in the plug changes with working time, no matter where it is. Inside the plug the temperature comes up to its maximum and down to its minimum when the working time is 15 min and 60 min, respectively, then it starts to rerise gradually with increasing working time. The stress near the plug surface is highest with high axial stress gradient, i.e., higher than 80 MPa at plug surface but about 50 MPa at the depth of 0.005 m as calculated from the surface. The laminar spalling due to the thermal stress near plug surface is the basic cause of the damage to the plug. References | Related Articles | Metrics

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Optimization of 7-strand tundish configuration in continuous casting of billet Zhong, Liang-Cai (1); Shi, Di (1); Chen, Bo-Yu (2); Wang, Can-Rong (2) 2010, 31 (7):  973-976.  DOI: - Abstract ( 275 )   HTML   PDF (864KB) ( 869 )   A physical model of fluid flow in a 7-strand tundish was developed in laboratory and the influence of tundish configuration with different flow controllers on flow characteristics was investigated. The results showed that the flow characteristics are poor with the previously designed baffles by which the minimum residence time and peak time are both short, especially for the third and fourth strands. For all the strands their average residence time is short with their dead volume fractions higher than 49%. With the optimized tundish configuration, the flow characteristics of molten steel are greatly improved. Residence time distribution curves change from sharp/narrow form to short/wide one, and the minimum residence time of all the strands are measured to be 44.75 to 73.75 s with a mean residence time over 400 s, but the dead volume fraction markedly decreases to 14.45%~21.10%. As to the multi-strand tundishes, they should have suitable impacting zone volume, and the flow control function at both ends of tundish should be taken into account in the design of flow controllers. References | Related Articles | Metrics

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A modified direct collocation spectral method for radiative heat transfer between parallel plane media Sun, Ya-Song (1); Li, Ben-Wen (1) 2010, 31 (7):  977-981.  DOI: - Abstract ( 287 )   HTML   PDF (2670KB) ( 657 )   A collocation spectral method based on modified Chebyshev polynomials expansions is presented to directly solve the one-dimensional radiative heat transfer problems with absorbing, emitting and anisotropically scattering media. Two cases of one-dimensional radiative heat transfer are examined to verify the performance of the modified Chebyshev collocation spectral method. The predicted radiative intensity and heat fluxes are compared with the results obtained by the least squares finite element method and analytic values. These results show that the present method can provide high accuracy to solve the radiative heat transfer between parallel plane media. References | Related Articles | Metrics

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Investigation on the method to generate medium-size standard sections for steel structure of heating furnace Zhao, Yao (1); Yu, Qing-Bo (1); Wang, Kun (1) 2010, 31 (7):  982-985.  DOI: - Abstract ( 218 )   HTML   PDF (1045KB) ( 974 )   Lots of standard sections are indispensable for the steel structure of heating furnace. Designers pay much attention to shortening time required for the generation of those standard sections. According to the structural characteristics of the sections and based on the Solid Edge software, the ″part family″ idea is introduced in the design of the standard sections. The parameter information table is used to sort through all of the standard sections. With the principal model shared, the sections of definite specifications can be generated quickly via the combination of different features and parameters changing. Such a method applies to other CAD platforms for setting up the database of standard sections as well, thus shortening the design period and improving the design efficiency greatly. References | Related Articles | Metrics

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A study on absorption of low-concentration SO2 by Bayer red mud Nan, Xiang-Li (1); Zhang, Ting-An (1); Wu, Yi-Quan (1); Dou, Zhi-He (1) 2010, 31 (7):  986-989.  DOI: - Abstract ( 275 )   HTML   PDF (687KB) ( 831 )   The effects of the liquid/solid ratio and reaction temperature of Bayer red mud and stirring speed on the absorption rate of sulfur dioxide and dealkalization rate of red mud were investigated, as well as the relationship between time and absorption rate of sulfur dioxide. The result showed that the optimal conditions on which the absorption rate of low-concentration SO2 is 93.14% are the liquid/solid ratio 5:1, stirring speed 150 r/min and reaction temperature 25°C, with the SO2 concentration in tail gas conforming to the National Discharge Standard. The absorption rate of SO2 decreases with prolonging time. Meanwhile, the dealkalization rate of red mud is 70.45%, i.e., the dealkalized red mud is available to be a raw material for cement production. References | Related Articles | Metrics

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Corrosion behavior of a new weldable aluminum alloy: 6005A Ji, Kai (1); Zu, Guo-Yin (1); Yao, Guang-Chun (1) 2010, 31 (7):  990-994.  DOI: - Abstract ( 485 )   HTML   PDF (2136KB) ( 1037 )   The effect of Cu content in the 6005A aluminum alloy used for high-speed trains on its electrochemical behavior was investigated by electrochemical impedance spectroscopy(EIS), immersion test and polarization curves. The results showed that a proper Cu content can improve efficiently the compactness of the alloy's surface oxide films. When the Cu content is 0.4%, the reactive resistance Rct due to corrosion as shown on the electrochemical impedance spectroscopy of 6005A increases and the double-layer capacitance Q2 decreases, and the polarization curve exhibits an anode passivation zone in a wide range of potential. However, the alloy's self-corrosion density increases slightly, which means that the corrosion resistance of the alloy decreases. Moreover, the immersion test for the alloy immersed in the 3.5% NaCl solution revealed that the pitting corrosion, intergranular corrosion and exfoliation corrosion occur sequentially on the alloy. The main influence factor on the corrosion resistance of the alloy is the compactness of its surface oxide film. References | Related Articles | Metrics

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Study on microstructure of high whiteness-aluminum hydroxide fillers Yu, Hai-Yan (1); Li, Wen-Cheng (2); Bi, Shi-Wen (1); Wang, Tao (1) 2010, 31 (7):  995-998.  DOI: - Abstract ( 457 )   HTML   PDF (1213KB) ( 1188 )   High-whiteness aluminum hydroxide fillers obtained from different precipitation techniques are all possessed of their own morphology of crystal growth. The microstructures of the fillers obtained from both carbonization precipitation and seed precipitation were investigated by scanning electron microscope (SEM), X-ray diffraction and Raman spectra. The results showed that the aluminum hydroxide crystals of high-whiteness fillers belong to monoclinic system with the space group P21/n, and the preferred growth crystal faces in both precipitations are (002), while the value of preferred orientation factor of seed precipitation crystals is smaller than that of carbonization precipitation crystals, and the former is of polycrystal face growth. Comparing the seed precipitation crystals with carbonization precipitation ones, the former's lattice parameter and Raman full width at half-maximum(FWHM) are both lower than the latter's, as well as the crystalline inclusions and lattice defects. However, the former's crystallinity is remarkably superior to the latter's. References | Related Articles | Metrics

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Conditions for biosorption measuring on chalcopyrite surface Pan, Hao-Dan (1); Yang, Hong-Ying (1); Chen, Shi-Dong (1) 2010, 31 (7):  999-1002.  DOI: - Abstract ( 261 )   HTML   PDF (1284KB) ( 732 )   The ninhydrin colorimetry was used to measure the absorbance of the bacterial cell lysis solution adsorbed on the surface of chalcopyrite during bacterial leaching. The influencing factors on the absorbance, such as measuring wavelength, lysing time, pH value of the solution, heating time and cooling time were investigated experimentally to get the optimal measuring conditions for the absorbance of the lysis solution, i.e., wavelength 560 nm, lysing time 25 min, pH value 7.0, heating time 15 min and cooling time 6 min. A standard curve showing the relationship between the absorbance and bacteria adsorption under optimal conditions was therefore given. It was found that the bacterial concentration is directly proportional to the absorbance of the lysis solution. References | Related Articles | Metrics

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Effect of CaCO3 nanowhiskers on behavior of hybridized PBT/PE/LCI blends Qu, Wen-Zhong (1); Xu, Xin-Yu (1); Li, Ming-Chao (1); Zhang, Bao-Yan (1) 2010, 31 (7):  1003-1006.  DOI: - Abstract ( 264 )   HTML   PDF (654KB) ( 762 )   CaCO3 nanowhiskers and a liquid crystalline ionomer (LCI) were synthesized separated in lab, then the CaCO3 nanowhiskers and LCI were blended with PBT and PE to prepare the hybridized PBT/PE/LCI/CaCO3 nanowhiskers blends. The thermal behavior, morphology structure and mechanical properties of the blends were investigated by differential scanning calorimetry (DSC), FT-IR spectra, and tensile tester. The results showed that the crystallizing temperature and crystallinity of PBT are both increased by adding 3% LCI in the blends, and the LCI disperses homogeneously in the PBT matrix, thus verifying that LCI serves the function of compatibilizer. The mechanical properties of the hybridized blend come up to the maximum values if the contents of LCI and CaCO3 are 3% and 5%, respectively, thus verifying that LCI serves the functions of compatibilization and reinforcement simultaneously. References | Related Articles | Metrics

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Synthesis and properties of liquid crystalline polymers containing β-cyclodextrin groups Yao, Dan-Shu (1); Lü, Shuang (1); Qian, Pu (1); Zhang, Bao-Yan (1) 2010, 31 (7):  1007-1010.  DOI: - Abstract ( 249 )   HTML   PDF (675KB) ( 689 )   With the chiral monomer mono-(6-acryl ethylenediamino-6-deoxy)-β-cyclodextrin twenty acetate(M1) and liquid crystal monomer 4-[(p-undecylen-1-yloxy) benzoyloxy]-4'-(p-ethoxy) benzoyloxy biphenyl ester(M2) both grafted onto the backbone of polymethylhydrosiloxane, a new kind of liquid crystalline polymers P1~P7 containing β-cyclodextrin was prepared. Their structures and properties were characterized with FT-IR, 1HNMR, DSC, POM, TG, X-ray and SROT. The results showed that M1 is a chiral non-mesogenic monomer whose optical rotation is +95.30 and M2 presents a threaded texture of the nematic phase, while P1~P7 are thermotropic liquid crystalline polymers with high thermal stability and 5% heat loss about 300°C. With increasing M1 content in the polymers, the liquid crystal phase is shortened and specific opticity is increased. References | Related Articles | Metrics

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Calculation of stress intensity factor of MSD plate with multiple holes as an infinite continuum Zhao, Jin-Fang (1); Xie, Li-Yang (1); Liu, Jian-Zhong (2); Zhao, Qun (3) 2010, 31 (7):  1011-1014+1018.  DOI: - Abstract ( 306 )   HTML   PDF (791KB) ( 582 )   The complex variable stress function and its approximate superposition principle were clarified to solve the stress intensity factors (SIF) of MSD plate with multiple holes, which was regarded as an infinite continuum. This method was used to calculate some numerical examples of MSD plates on which the symmetrical cracks occurred arising from 2, 3 and 4 collinearly circular holes. Comparing with the FEA, the calculated results by this method are more accurate and reliable with easy calculating operation. Taking advantages of analytic function to solve the complex variable stress function and then calculate the stress intensity factor via the relevant approximate superposition, this method can be well applied to the MSD plate structure with multiple holes distributed randomly. So, it is worthy to popularize for the fracture problems in practical projects. References | Related Articles | Metrics

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Dynamic analysis of vibration-friction system on a vibrating pile driver Teng, Yun-Nan (1); Li, Xiao-Peng (1); Yang, Duo (2); Wen, Bang-Chun (1) 2010, 31 (7):  1015-1018.  DOI: - Abstract ( 356 )   HTML   PDF (1828KB) ( 806 )   Taking the vibrating pile driver as a typical example, the applications of vibration-friction to a class of similar machines were investigated. With the nonlinear dynamic model developed, the Runge-Kutta method was introduced into the numerical simulation of a vibrating pile driver to obtain the nonlinear dynamic characteristics of the system. The results revealed that the amplitude of pile increases to a certain extent with the amplitude and frequency of exciting force, and it decreases to a certain extent with the decreasing amplitude of exciting force. But the decreasing frequency of exciting force has no obvious influence on the amplitude of pile. The change in stiffness of the system will affect greatly the amplitude of pile. References | Related Articles | Metrics

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Numerical simulation and lubrication effect of oil mist temperature field in bearing cavities Song, Jin-Chun (1); Chen, Jian-Wen (1); Zhang, Zhi-Wei (1); Wang, Chang-Zhou (1) 2010, 31 (7):  1019-1022.  DOI: - Abstract ( 296 )   HTML   PDF (1267KB) ( 772 )   Combining the oil mist lubrication with CFD has become an effective way to investigate the mechanism of oil mist lubrication. A CFD-based numerical simulation of oil mist flow field was therefore done to investigate the oil mist temperature field and lubrication effect in the bearing cavities of supporting rollers for continuous annealing/leveling system. The results revealed the heat transfer process of oil mist in bearing cavities under condition that the calorigenic rates of rollers are different. The fitted equations of roller's calorigenic rates and bearing temperature rising were thus given with two different supplies of lubricant, thus showing the influence of roller's calorigenic rate on lubrication effect and the ways to enhance the heat dissipation potential and decrease the temperature of the supporting rollers. References | Related Articles | Metrics

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Effects of fluid viscosity and surface tension on the size of atomized droplets Chen, Jian-Wen (1); Zhang, Zhi-Wei (1); Wang, Chang-Zhou (1); Song, Jin-Chun (1) 2010, 31 (7):  1023-1025.  DOI: - Abstract ( 479 )   HTML   PDF (439KB) ( 2200 )   Aim at the industrial atomization process, the influence of surface tension, viscous drag and other physical properties of liquid on the atomizing effect were discussed. The two-flow outside-mixing atomizer was used to test the N46 lube and #150 gear oil, for which the viscosity and surface tension are different, and the size of atomized droplets and their distributions were measured by the laser particle size analyzer CLY-2003. The results showed that both viscosity and surface tension are the restricting factors to the increase in surface wave amplitude. Under the same atomizing pressure, the size of the droplets whose viscosity and surface tension are comparatively higher is relatively bigger, i.e., the atomizing effect is relatively poor. References | Related Articles | Metrics

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Quickly spatial identification process of blocks during rock excavation and its system modeling Wang, Shu-Hong (1); Zhang, Jing-Jie (1); Li, Yun-Long (1); Liu, Yu (1) 2010, 31 (7):  1026-1029+1057.  DOI: - Abstract ( 263 )   HTML   PDF (1031KB) ( 820 )   Based on the digital photogrammetry, the spatial searching for all blocks in a disturbed zone of rock mass was discussed, and a new searching technique was proposed for the identification of blocks. With the searching technique introduced into the 3D digital analysis system-the three-dimensional geotechnique structural modeling and analysis system (GeoSMA-3D) developed by ourselves, the spatial searching for all blocks is available to rock excavation. A numerical example showed that the system has the advantages of adding structural planes dynamically and modeling the geometrically complex excavation process. Moreover, the system is easy to implement the operation of software via data input through man-machine interface or documental representation, graphical representation of computed results and interfacing with general-purpose graphical software, such as AutoCAD. Therefore this method shows its strong commonality and reliability, and it can also be used for rock tunnel excavation process advanced prediction and reinforcing scheme optimization. References | Related Articles | Metrics

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Effect of NO2 on mechanical properties of polyphenylene sulfide filter for smoke dust removal Liu, Jing-Xian (1); Zhang, Hai-Yan (1); Chang, De-Qiang (1); Sun, Xi (1) 2010, 31 (7):  1030-1034.  DOI: - Abstract ( 296 )   HTML   PDF (1409KB) ( 828 )   It was found that the composition of flue gas from coal-fired boiler affects adversely the mechanical properties of PPS(polyphenylene sulfide) filter during smoke dust removal. Simulating the flue gas conditions, the change in PPS filterability with the three factors, i.e., NO2 concentration, functioning time and temperature in NO2 atmosphere. The results showed that the mechanical strengths of the filter decrease obviously if the values of the three factors increases, and the retention rates of both the warp and weft filter strengths are just 55.8% and 48.7% at 3 mL/L, 120 h and 190°C. Some fibers of the filter are found broken from SEM images because of the oxidation of NO2, and the filter becomes darker in color with brittlement enhanced greatly after adding the oxygen atoms in the PPS molecule chain. NO2 is one of the reasons why the service life of the filter is shortened. So, the concentration of NO2 should be decreased on site via the technology measures available to take. References | Related Articles | Metrics

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Study on bearing capacity of axially-loaded GFRP tube filled with steel-reinforced concrete short columns Chen, Bai-Ling (1); Qin, Guo-Peng (1); Wang, Lian-Guang (1) 2010, 31 (7):  1035-1038.  DOI: - Abstract ( 313 )   HTML   PDF (1581KB) ( 694 )   GFRP tube filled with steel-reinforced concrete short column as a newly developed composite member named GSC column is proposed, which consists of an outer tube made from glass fiber reinforced polymer (GFRP), steel reinforcement as corn and concrete inside the tube. The axial loading tests including five GSC columns were done to investigate the mechanical properties of them. With the calculation of bearing capacity of GSC column programmed taking the percentage of steel reinforcement, GFRP tube thickness and strength of concrete as the main parameters, nine GSC members were computed to obtain the relationships between axial load and strain. The results showed that the bearing capacity of GSC columns enhances obviously with the increase of the three main parameters. The calculating formulae were thus given to the bearing capacity of GSC column, including two different methods, i.e., the simple superposition and unified theory. Both the calculation results conform well with test results. References | Related Articles | Metrics

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Periodic fluctuation analysis of real estate in China Qi, Xi-Jing (1); Song, Ming-Liang (1); Wang, Hong-Wei (2); Li, Bin (3) 2010, 31 (7):  1039-1042.  DOI: - Abstract ( 340 )   HTML   PDF (1037KB) ( 1179 )   A real estate market has its own periodic fluctuation. Based on the qualitative analysis of the periodic fluctuation of real estate markets at home and abroad and taking the investment in real estate development and the area of the commercial housing being constructed as the input index and the total floor space of commercial housing and sales amount of commercial housing as the output index, the longitudinal analysis (in the same city but different time) and transverse analysis (in the same time but different cities) were both made quantitatively via the data envelopment analysis method (C2R model of DEA) and Lingo mathematical software, where the data were acquired from the periodic fluctuation of real estate market in several cities in China. In this way some policies were envisaged to make advantages of the periodic fluctuation on the basis of existing macro/microscopic policies, thus improving the operational efficiency, i.e., to optimize the invalidity at present. References | Related Articles | Metrics

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Optimal design of team incentive mechanism based on principal-agent theory Wang, Yan-Mei (1); Zhao, Xi-Nan (1); Wang, Gao-Nan (2) 2010, 31 (7):  1043-1045.  DOI: - Abstract ( 334 )   HTML   PDF (1540KB) ( 728 )   Based on the principal-agent theory, a relevant model was developed for a team to study the optimization of team incentive mechanism, where the team included a principal and n agents. Solving the model to acquire the influencing factor on incentive to the members of the team, how the competence, attitude toward risks and team spirits of a team member, as the influencing factors, affect the incentive to him/her was discussed. The results showed that the relative incentive intensity or motive force among those members is decided jointly by the three factors as above. The higher the competence of a member, the lower the risk he/she will run and the stronger the motive force to push him/her. Moreover, the manager shall minimize the incentive gap between different members if the team spirit is high as a whole. References | Related Articles | Metrics

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Correlation between actuarial approach and option pricing based on supply-demand equilibrium Zheng, Hong (1); Guo, Ya-Jun (1); Zeng, Hua (1) 2010, 31 (7):  1046-1049.  DOI: - Abstract ( 272 )   HTML   PDF (746KB) ( 1046 )   Based on a review of the studies on the correlation between option pricing and actuarial approach, the law of supply-demand equilibrium is applied to the deduction of actuarial pricing equation of pure premium instead of the no-arbitrage equilibrium theory about financial market. Then, assuming that the loss complies with the logarithmic normal distribution, the classic Black-Scholes option pricing model in the continuous-time state is deduced in actuarial way. As a result, the actuarial approach and option pricing are unified into the general economic research framework which proves economically that the actuarial pricing of pure premium we gave is just Pareto optimal pure premium, i.e., the price of call option. In this way we can get rid of the hindrance to the applications of option pricing model to the insurance field, thus laying theoretical foundation on which the integration and unification of actuarial approach with option pricing are available. References | Related Articles | Metrics

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A control-right-based model of venture companies' optimal financing contracts Zhong, Tian-Li (1); Liu, Qi-Gui (1); Meng, Xi (1) 2010, 31 (7):  1050-1053.  DOI: - Abstract ( 248 )   HTML   PDF (1086KB) ( 715 )   An analytic model of optimal financing contract was developed for venture companies, which takes the non-currency earnings, entrepreneurial spirit, realizability of investor's control right and its realizing cost as the main influencing factors on the optimal financing contract of a venture company. The influence of the disposition of control right on the financing structure of a venture company was discussed so as to propose the possible measures to take for improving its financing efficiency. The results showed that an effective financial market, bankrupt mechanism and guarantee system to ensure the control right of investors are crucial to the financing efficiency. To play the role of the control right on financial contracting, the following measures are advised to take, i.e., reduce the non-currency earnings of entrepreneur and the control right realizing cost of investors, and enhance the realizability of investors' control right and the guaranteed value of company assets. References | Related Articles | Metrics

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Empirical study on momentum effect on China's A share market Zhu, Jun (1); Zhuang, Xin-Tian (1) 2010, 31 (7):  1054-1057.  DOI: - Abstract ( 435 )   HTML   PDF (650KB) ( 1447 )   Based on the whole data of China's A share market in the period 1998~2005 and the discussion on the earlier works about the momentum effect at home and abroad, a check was carried out empirically for the momentum effect. The results revealed that the momentum effect on short-run investment is unobvious statistically in the A share market, while the excess returns on shart/medium-run investment are available for those investors who make use of the strategy of momentum effect. Most of both the winner and loser portfolios gain excess returns or suffer losses in the same direction, i.e., the simultaneous rise or fall of various stock prices characterizes China's stock market. It implies that the investors react to the market information in a positive feedback mode. For this reason, some suggestions are recommended for the development of China's stock market and investors' operational strategies. References | Related Articles | Metrics

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Analysis of the influence of network effect on patent pools Mei, Kai (1); Du, Xiao-Jun (1); Geng, Yuan-Xin (1) 2010, 31 (7):  1058-1060.  DOI: - Abstract ( 235 )   HTML   PDF (726KB) ( 604 )   The motive for the decision on organizing patent pools based on vertical structure under the action of network effect was studied, and two-staged dynamic game model was developed. In the first stage, the patent pool shall set up unit pool royalty rate in the upstream market of patent; in the second stage, the competition of output shall be done among the vertically integrated firms of the same patent pool in the downstream market of final goods. The unit pool royalty rate, the consumer demand and the profit of pool member were all computed on the condition of the network effect. A conclusion is therefore drawn that the network effect could reduce the unit pool royalty rate, and the consumer's demand is increasing with the enhancing network effect. So, gaining the benefits from the network effect is the important motive of the firms who organized patent pool. References | Related Articles | Metrics

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A combinatorial summation method for a class of multiple series Zhang, Xiang-De (1); Tang, Qing-Song (1); Zhu, He-Gui (1); Yang, Lian-Ping (1) 2010, 31 (7):  1061-1064.  DOI: - Abstract ( 224 )   HTML   PDF (1633KB) ( 626 )   Rao and Subbarao gave a transformation formula of triple series by complicated elementary operation. Based on the combinatorial method, the Bell polynomials are combined with Stirling number to give a brief proof to the transformation formula for a class of multiple series based on Riemann-Zeta function. The formula is available to not only get the classical conclusions offered by Rao and Subarao as particular cases, but also give some near findings. References | Related Articles | Metrics