Journal of Northeastern University(Natural Science)

ADP approach to solve unknown nonlinear zero-sum game

Zhang, Xin (1); Hui, Guo-Tao (1); Luo, Yan-Hong (1)

2012, 33 (12): 1673-1676+1689. DOI: -

Abstract ( 532 )

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An approximate dynamic programming (ADP) approach was proposed for a class of unknown nonlinear zero-sum game. A model based on a recurrent neural network (RNN) was used to approximate the unknown system dynamics. A novel adjustable term related to the modeling error was added to the RNN model, which guaranteed the modeling error convergent to zero. Then, an ADP approach was given to solve the optimal performance index and the optimal control pair under the saddle point of the zero-sum game existence or not. Simulation results demonstrated the effectiveness of the proposed control scheme.

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Non-fragile H∞ control for a class of uncertain time-delay switched systems

Li, Chun-Ji (1); Chen, Xia (1)

2012, 33 (12): 1677-1680. DOI: -

Abstract ( 449 )

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The problem of non-fragile state feedback H∞ control for a class of uncertain time-delay switched systems was discussed on the particularly switched condition. Based on the common Lyapunov function, convex combination technique and linear matrix inequality, the sufficient condition for the existence of non-fragile state feedback controller was given, and this condition also met the H∞ performance index. In the end, the simulation example was given to verify the effectiveness of the proposed method. The condition of the theorem in the form of linear matrix inquality was put forward, which is easy to realize in practice.

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H∞ control of multiple observers-based networked control systems with variable sampling period

Zhang, Yi (1); Sun, Fu-Xue (2); Zhang, Qing-Ling (1)

2012, 33 (12): 1681-1684. DOI: -

Abstract ( 451 )

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The joint design problem of the variable sampling interval and multiple state observers was studied. The network-induced delay was considered which could be larger than one sampling period, and the sampling period was assumed to be switched in a finite set. The Markovian jumping models of the networked control systems with multiple state observers and single state observer were constructed, based on which, the sufficient conditions for stochastic stability and optimal H∞ norm bound were derived for the closed-loop networked control systems by the application of Markovian theory. Furthermore, the controllers and observers were designed in terms of linear matrix inequalities (LMIs) technology. Simulations were compared to show the effectiveness of multiple state observers for networked control systems.

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Fault diagnosis based on CVA-ICA and CSM

Yang, Ying-Hua (1); Li, Zhao (1); Chen, Yong-Lu (1); Chen, Xiao-Bo (1)

2012, 33 (12): 1685-1689. DOI: -

Abstract ( 629 )

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In order to handle the problem of fault diagnosis for industrial processes, an improved fault detection method was proposed based on canonical variable analysis (CVA) and independent component analysis (ICA). At the same time, combined with continuous string matching (CSM), a new fault diagnosis method based on the library of complete faults was proposed. First, the CVA algorithm was used to calculate the canonical variable of the data, and then, the ICA algorithm was used to decompose the canonical variable. Finally, the CSM algorithm was used to diagnose the faults. A case study of Tennessee Eastman (TE) process showed that the proposed algorithm is feasible and efficient.

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A visual perception based fuzzy C-means clustering algorithm

Pan, Gai (1); Gao, Li-Qun (1); Yi, Yu-Feng (1)

2012, 33 (12): 1690-1693+1730. DOI: -

Abstract ( 554 )

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A visual perception based fuzzy C-means clustering algorithm was proposed to solve the problems that the results of complex structural image segmentation are not satisfactory. Firstly, on the basis of the receptive field properties analysis of neurons in the primary visual cortex, a visual nerve cell response function was proposed to calculate image structural feature. Secondly, a ramp function was used to simulate the visual perception of relative brightness change and calculate the difference between pixels in the image and the cluster centers. The relationship in direction, relative position and periodic between neighboring stimuli and the central neuron were fully considered, so the image structural information could be accurately described with the proposed model, and the noise and the complex texture interferences could be effectively suppressed. The experimental results demonstrated that the shortcoming of traditional fuzzy C-means clustering algorithm was overcome with the proposed algorithm, and accurate segmentation of complex background images was achieved.

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Research on fixing inconsistencies in spatiotemporal XML document

Bai, Lu-Yi (1); Ma, Zong-Min (1)

2012, 33 (12): 1694-1697. DOI: -

Abstract ( 444 )

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As being the core and the base of spatiotemporal database, a considerable amount of spatiotemporal data models have been proposed to enable the increasing applications. However, less research has been done in modeling spatiotemporal data based on XML, especially in fixing inconsistencies of spatiotemporal data in XML document. A spatiotemporal data model based on XML was established. On the basis of the model, consistency conditions of spatiotemporal data in XML document were given. In succession, how to fix inconsistencies of the three primitive change operations, namely update, insert, and delete, were demonstrated. Subsequently, examples were given to illustrate approaches for fixing inconsistencies. Finally, types of inconsistencies of the three primitive change operations were discussed.

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Spray and wait routing based on relay-probability in DTN

Geng, Rong (1); Tang, Mei-Si (1); Jiang, Xiang-Hong (2)

2012, 33 (12): 1698-1701. DOI: -

Abstract ( 490 )

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Due to the blindness in choices of relay nodes, a DTN routing algorithm named R-SW (spray and wait routing based on relay-probability) was proposed. In the stage of relay node selection, the probability of packet forwarding and the number of packet copies were under control. If the forwarding probability of a relay node was greater than the current node, packet forwarding would be permitted. Therefore, nodes with larger forwarding probability could carry more packets to avoid causing poor performance in transmission delay and packet delivery ratio. Furthermore, with congestion control, NS2 network simulation software was used to analyze the validity and reliability of the proposed DTN routing algorithm. Simulation results showed that the proposed algorithm could decrease routing overhead and transmission delay, and it could also improve packet delivery ratio, which is suitable for DTN.

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Analysis and modeling for the PEV charging regularity impact to the distribution grid

Han, Peng (1); Wang, Jin-Kuan (1); Han, Ying-Hua (1)

2012, 33 (12): 1702-1705. DOI: -

Abstract ( 646 )

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Combined with the actual grid data and latest travel information in the U. S., the regularity curve of charging time was fitted, which was based on the PEV types, distribution grid power limits together with different seasons and time. The impact model of charging regularity for the plug-in electric vehicle was also proposed. The simulation examples indicated that the proposed model can well reflect the impact in different time, penetration and seasons practically and accurately, and will help to strategize the distribution grid construction, safety monitoring, and optimized scheduling of plug-in electric vehicles.

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An energy-hole avoidance algorithm for wireless sensor networks based on adjusting transmission power

Song, Xiao-Ying (1); Wen, Tao (1); Guo, Quan (1); Sheng, Guo-Jun (1)

2012, 33 (12): 1706-1709. DOI: -

Abstract ( 517 )

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Due to the many-to-one characteristic of the data collection in wireless sensor network(WSN), lack of original network coverage or failure to reach the sink node would often occur because of the early energy depletion, which would lead to the effect of energy holes. An ATPAEH algorithm was proposed which could solve the problem of energy holes. In the algorithm, the nodes were firstly classified into the threshold nodes and the sufficient nodes according to residual energy of each node. In succession, the threshold nodes were sent to the sink node using multi-hops through the shortest path tree, and the sufficient nodes were sent to the sink node directly after adjusting transmission power according to the distance of each corresponding node and the sink node. Finally, the experimental results demonstrated the performances advantage of the proposed algorithm through being compared with the MILD algorithm. With the proposed algorithm, the energy consumption of the network was effectively balanced and the energy-hole was avoided so that the lifetime of the entire network was prolonged.

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Quantum artificial fish school algorithm

Chen, Xiao-Feng (1); Song, Jie (1)

2012, 33 (12): 1710-1713. DOI: -

Abstract ( 462 )

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Many newly-proposed algorithms, which combine both quantum computing and intelligent optimization, are becoming mainstream of optimization algorithm studies. For introducing quantum computing to the fish school algorithm, a new evolution algorithm, named as quantum artificial fish school algorithm, was proposed. The actions of fish school were re-described through quantum computing. The artificial fishes were encoded by quantum bits. The update of artificial fishes was implemented by quantum rotated gate. Mutation of fishes was performed by quantum negation gate, and finally the optimized solution of target functions was retrieved. The algorithm was simulated by extremum problem and TSP problem and was proved to be effective and efficient.

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An efficient theoretically-exact algorithm for small field of view

Jiang, Yong-Sheng (1); Yu, Yan-Yan (1)

2012, 33 (12): 1714-1717. DOI: -

Abstract ( 419 )

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The problems of back projection filtered(BPF) reconstruction in small field of view were analyzed, and an efficient theoretically-exact reconstruction algorithm for small field of view was proposed. With the proposed algorithm, useless computation in reconstructing PI plane was avoided by redefining the sampling method of PI plane with multi-scale method, and interpolating the two different scale PI plane data. The algorithm depressed the computation of PI plane and got the same results as original BPF algorithm, which accelerated the BPF reconstruction for solving the inutility computation of BPF algorithm in small field of view reconstruction, and also provided a good chance for clinical use.

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3D liver segmentation algorithm based on probabilistic atlas and Random Walker

Jiang, Hui-Yan (1); Ma, Zhi-Yuan (1); Zong, Mao (1)

2012, 33 (12): 1718-1721. DOI: -

Abstract ( 705 )

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Due to the complicated structure of an abdominal CT image and the low segmentation precision leaded by the similarity of adjacent organs, a novel 3D liver segmentation algorithm based on probabilistic atlas and Random Walker methods was proposed. Firstly, a liver position probabilistic atlas was established by some liver region images segmented by doctors; then, an improved automated Random Walker algorithm was proposed and a gray probabilistic atlas improved by Random Walker algorithm was constructed; lastly, a three dimensional liver segmentation was conducted based on the proposed algorithm from abdominal CT image. Experimental results showed that the proposed algorithm could efficiently segment liver region and own good robustness. Comparing with the traditional algorithms, the segmentation precision is improved greatly.

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Changes of crystal structure in Ti thin films during N implantation

Wang, Jian-Jun (1); Kasukabe, Yoshitaka (2); Liu, Chun-Ming (1)

2012, 33 (12): 1722-1725. DOI: -

Abstract ( 431 )

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Ti thin films were deposited by electron beam deposition(EBD) method on the cleaned NaCl substrates, and were implanted with 62 keV N2⁺ by an accelerator. Changes of crystal structures in Ti thin films were analyzed for those samples before and after N implantation. TEM results showed that hcp-fcc transformation is induced due to the invasion of N atoms into Ti thin films, and hence parts of hcp-Ti in films are changed into fcc-TiNy. Implanted N atoms occupy the octahedral-sites in the crystal lattices and lead to lattice distortion, which supports inner stress as one of the possible driving force for hcp-fcc transformation. With the N/Ti ratio increasing, the amount of hcp-Ti decreases and that of fcc-TiNy increases. Changes in energy loss for Ti films were measured by EELS, and it is suggested that Ti atoms and implanted N atoms are combined into TiNy compounds for the bonding of the outer N 2p covalent electrons and Ti 3p-4s hybrid orbitals.

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Effects of DQ-T process on microstructure and mechanical properties of 12MnNiVR steel

Zhang, Peng-Yan (1); Zhu, Shu-Xun (1); Zhang, Hui-Yun (1); Zhu, Fu-Xian (1)

2012, 33 (12): 1726-1730. DOI: -

Abstract ( 470 )

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The effects of DQ-T(direct quenching-tempering) on the microstructure and mechanical properties of 12MnNiVR steel were investigated. The results showed that the main structure is bainite when quenched directly to 300°C, and is martensite when quenched to 30°C. After the offline tempering, the original ribbon lower bainite organization is replaced by tempered sorbite and lots of tiny FexC particles precipitated. With the increase of temperature in tempering process, the yield strength and hardness sharply decreases, and the toughness (-20°C) increases. With the increasing of tempering time, the strength reduces and the toughness increases. With the optimum DQ-T process, the yield strength, tensile strength, elongation rate and impact energy (-20°C) are 660 MPa, 700 MPa, 19.4% and 104 J, respectively.

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Research on regularity of the effect of incoming wedge on lateral curvature of plate

Xu, Jian-Zhong (1); Gong, Dian-Yao (1); Wang, Jun (1); Wang, Guo-Dong (1)

2012, 33 (12): 1731-1733. DOI: -

Abstract ( 419 )

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The calculation module of influence coefficient method under asymmetrical condition was developed based on the dual cantilever theory to research the regularity of the effect of incoming wedge on lateral curvature of plate, as well as enhance the control efficiency and accuracy of lateral curvature for a domestic plate rolling 4-high mill. The roll and work piece discretizing method, the decision of key mathematic model, vectors and arrays were described. Using the calculation module, the calculation was carried out based on actual data in-site. The regularity of effect on radius of curvature was obtained, the rigid titling of rolls is indicated to be effective method to control lateral curvature. The mathematic models of target wedge and curvature control when the incoming plate is wedge-shaped were also built.

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Dynamic recovery behavior in hot deformation of ultra-purified Cr17 ferritic stainless steel

Liu, Hai-Tao (1); Wang, Meng (1); Gao, Fei (1); Liu, Zhen-Yu (1)

2012, 33 (12): 1734-1736+1753. DOI: -

Abstract ( 555 )

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Using a thermomechanical simulator, single-pass compression tests were carried out to clarify the dynamic recovery behavior in the hot deformation process of ultra-purified Cr17 ferritic stainless steel. The microstructure evolution during hot deformation was investigated at 900~1150°C with the maximum true strain of 0.8 and strain rate of 1 s^-1. The results show that the stress-strain curves of single-pass compression are all characterized by dynamic recovery. As deformation temperature increases, the dynamic recovery occurs much faster. When the compression is performed at low temperature, deformed grains are formed and bulging of initial grain boundary occurs. While, at high temperature, the microstructure evolution will be characterized with the formation of a large quantity of sub-grain boundaries and sub-grains.

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Study on the desulfurization of hot metal with composite reagent of calcium oxide and aluminum

Wei, Guo (1); Sun, Yu (1); He, Yi-Bo (1); Shen, Feng-Man (1)

2012, 33 (12): 1737-1740. DOI: -

Abstract ( 596 )

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Al addition can not only promote the desulfurization by deoxidation in the hot metal, but also improve the kinetic conditions of desulfurization with lime. To reduce the cost of desulfurization treatment, theoretical and experimental studies have been conducted for hot metal desulfurization with composite reagent of calcium oxide and aluminum. The experiment results show that, with the addition of a certain amount Al in CaO-based desulfurizer, the desulfurization rate can be improved. With 5 g/kgFe Al addition, the desulfurization ratio can be increased by 31.4%. With 0.6 g/kgFe Al addition, the sulfur content in hot metal can be reduced to below 0.02% within 20 min. The rate constant of desulfurization reaction was also calculated for different amounts of Al addition.

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Preparation of solar grade silicon by electrorefining

Zou, Xiang-Yu (1); Xie, Hong-Wei (1); Zhai, Yu-Chun (1); Dai, Yong-Nian (2)

2012, 33 (12): 1741-1744. DOI: -

Abstract ( 539 )

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Purification of metallurgical grade silicon (MG-Si) for solar grade silicon (SOG-Si) preparation with electrorefining in molten NaF-KF eutectic was studied. SEM and ICP-MS were used to examine and characterize the refining products. The effects of voltage, temperature and time on refining efficiency were analyzed and discussed. The results show that, under the refining conditions in 1073 K NaF-KF molten salt at 2.0 V for 400 min, the electrolyzed products are Si wires with length of several tens of micrometers and diameter of 50 nm to 150 nm. The removal efficiency of metal impurities from MG-Si can reach above 92%, with B and P removal efficiencies of 92.1% and 97.6% respectively. The purity of refined silicon product can reach up to 99.999%.

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Effects of pickling on purification of titanium prepared by metallothermic reduction with an indirect contact method

Zheng, Hai-Yan (1); Gu, Jian (1); Wang, Zhi-Qing (1); Shen, Feng-Man (1)

2012, 33 (12): 1745-1749. DOI: -

Abstract ( 455 )

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The influences of pickling conditions on the purification effect of the titanium product from indirect-contact metallothermic reduction were investigated. The experiment results show that it is feasible to remove oxides and impurity elements from metallothermic reduction product by acid pickling for producing high-purity titanium. Titanium doesn't react with acetic acid, but dissolves in hydrochloric acid slowly, and thus the pickling time should not be too long. Otherwise the titanium loss due to dissolution will lead to decrease of its yield. With the increase of acid concentration and pickling time, the purity of metallic titanium increases. Considering the purity and the yield of titanium, the optimum pickling conditions are determined as the combination of 50% volume concentration acetic acid for 6 h and 20% volume concentration hydrochloric acid for 0.5 h.

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Effect of pyrite in roasting-ammonium leaching of nickel oxide ore

Du, Xing-Hong (1); Liu, Hui (1); Jing, Han (1); Lou, Tai-Ping (1)

2012, 33 (12): 1750-1753. DOI: -

Abstract ( 425 )

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The objective of this study is to confirm the effect and action mechanism of pyrite in the process of roasting-ammonium leaching of nickel oxide ore. XRD and chemical analysis are used to analyze the phase change and the leaching effect. The results show that, after adding a little pyrite in nickel oxide ore, nickel exists as pentlandite in the calcined product. Pentlandite is then oxidized and leached in the form of ammonium nickel sulfate complex in the system of NH3-(NH4)2CO3, and the enrichment and separation of nickel is thereby realized.

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Self-synchronization of two identical exciters in a resonant vibrating system

Zhao, Chun-Yu (1); Wang, Li (1); Ren, Jie (1); Wen, Bang-Chun (1)

2012, 33 (12): 1754-1757. DOI: -

Abstract ( 501 )

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A new structure of resonant vibrating machinery with dual-motor drives is proposed. The vibrating body consists of a supporting rigid frame and a material box. The material box exhibits four degrees of freedom and the rigid frame exhibits only one degree of freedom in the resonant direction. The material box is installed on a plane perpendicular to the resonant direction by soft springs. The material box not only moves together with the rigid frame, but also exhibits two translational degrees and one rotational degree of freedom and operates at the super-resonant state. The vibration amplitude increases with increasing amount of material. Motion equations for the vibrating system are established by using the Lagrange's equation. The conditions of synchronization and stability are deduced. The relation between the coefficient of synchronization ability and the structural parameters of the system is also studied by numerical computation. The results demonstrate that the smaller the distance between the two unbalanced rotors and the smaller the resonant exciting angle, the greater the coefficient of synchronization ability is. The ratio of the mass of the material box to that of the vibrating system affects little on the coefficient of synchronization.

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Research on dynamic characteristics of blade-casing with impulse loading

Tai, Xing-Yu (1); Ma, Hui (1); Tan, Zhen (1); Wen, Bang-Chun (1)

2012, 33 (12): 1758-1761+1799. DOI: -

Abstract ( 515 )

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The dynamical equation of blade with impulse loading was established based on the Timoshenko beam element with considering the effect of Coriolis and centrifugal forces. The dynamic characteristics of the blade at different rotating speeds were analyzed. The results show that synchronization is produced between blade displacement and impulse loading under low speed, and the blade is in high-frequency vibration when the force is removed. Non-synchronization is observed under high engine speed because of inertia and the blade is in low-frequency due to the shorter vibration. Moreover, the displacement of blade in high speed is less than that in low speed for the effect of centrifugal rigidization.

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Dynamic characteristics of crankshaft-connecting rod of diesel engine

Sun, Li-Na (1); Li, Shen (1); Hua, Chun-Li (1); Liu, Ying (1)

2012, 33 (12): 1762-1765. DOI: -

Abstract ( 729 )

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The dynamic characteristics of crankshaft-connecting rod of the Cummins 6BT5.9 diesel engine were studied using a combined method of experimental modal and finite element analysis to optimize the dynamic performance, intensity of vibration and structure design. In the finite element analysis, the boundary conditions of combined structure were simulated by methods of coupled degrees of freedom, spring-damper unit connection and virtual material, respectively. Frequency criteria was then used to investigate the correlation analysis of the modal parameters obtained. It shows that the correlation between the calculated and experimental parameters by spring-damper unit connection and virtual material method is higher, which are more reasonable in dealing with the joint surface contact. It provides a theoretical basis for dynamic analysis and optimization design of diesel engine.

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A method to predict cutterhead specific energy for TBM based on CSM model

Li, Gang (1); Yu, Tian-Biao (1); Fei, Xue-Ting (2); Wang, Wan-Shan (1)

2012, 33 (12): 1766-1769. DOI: -

Abstract ( 849 )

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To overcome the difficulty in prediction of cutterhead specific energy for tunnel boring machines (TBM), the rock fragmentation mechanism and forces of TBM cutters are analyzed based on the fracture mechanics theory of rock. A new method to predict cutterhead specific energy for TBM is developed based on CSM model. The specific energy prediction model for TBM cutterhead is developed using the dynamic models of TBM cutters interaction with the rock. The data from the actual tunnel construction is analyzed by a tunnel example and the comparison is made with the field data. The results indicate that the model not only can predict real-time specific energy for cutterhead, but also provide a theoretical basis for the performance prediction and optimal design of cutterhead for TBM.

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Construction of embedded compound artificial boundary pillar from open-pit to underground mining

Zhang, Feng-Peng (1); Liu, Jian-Po (1); An, Long (1); Wang, Li-Jun (1)

2012, 33 (12): 1770-1773. DOI: -

Abstract ( 543 )

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Considering the disadvantages of traditional methods, such as great mine loss of open-pit bottom and bad isolation effect, an embedded compound artificial pillar that is used during the transition from open-pit to underground mining is designed. This method is to employ the underground mining method to extract the open-pit bottom, to lay out bottom structure and then to fill the mine-out area with concrete. It tends to connect the obturator with the embedded compound structure, to accomplish the man-made bottom layout access road, to backfill the access road and to anchor the rockmass between access road and rocks, between access and grooves and among access roads. Therefore, the 10 m thick complete artificial boundary pillar, covering the whole ore body, may be finished. Numerical calculation shows that the implementation procedure of the embedded compound artificial pillar may not exert great influence on the stress field of slopes and plastic zone, which means no harm to the slope stability. Engineering practice demonstrates that laying out embedded compound artificial pillar while exploring the ore body may lead to a recovery rate of 95%. The accomplished boundary pillars enjoy sound impermeability, waterproofness, flood control and load-bearing capability. This may perfectly isolate the interactive influence between open-pit and underground mining.

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Generation and determination of hydroxyl radicals from electrolytic process with periodically reversing

Hu, Xiao-Min (1); Sun, Zhao-Nan (1); Dong, Chang-E (1); Xiong, Ying-Yu (2)

2012, 33 (12): 1774-1777. DOI: -

Abstract ( 492 )

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The oxidation of free hydroxyl radicals (·OH) is one of the most important mechanisms for the electrolysis oxidation technology. The generation mechanism of producing ·OH in periodically reversing electrolysis process was investigated in the 0.015 mol/L Na2SO4 solution and the detective methods of ·OH were selected. Furthermore, the influence factors of the generation volume of ·OH were studied. The results showed that colorimetric analysis using dimethyl sulfoxide (DMSO) as the trapping agent was superior to that using salicylic acid as the trapping agent. The maximum amount of free hydroxyl radicals was detected when the volume of DMSO (200 mmol/L) was 50 mL, with the reaction voltage of 8?V, exchange period of 10 s and reaction time of 90 min. The cumulated amount of the free hydroxyl radicals by adding H2O2 increased more than that by adding H2SO4, indicating that the periodic reversing electrolysis method combined with adding H2O2 could be widely used in field of wastewater treatment.

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Characteristics of aerobic activated sludge in MBR treating butyl xanthogenate wastewater during startup period

Jiang, Bin-Hui (1); Fu, Li-Li (1); Huang, Ya-Qiong (3); Hu, Xiao-Min (1)

2012, 33 (12): 1778-1781. DOI: -

Abstract ( 452 )

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Operating characteristics of acclimation processes of the aerobic activated sludge and the start-up period of the treatment of the butyl xanthogenate wastewater using membrane bioreactor (MBR) were discussed. The formation, morphology, character and mechanism for the pollutant removal of the aerobic active sludge using MBR were analyzed. Floccule sludge was acclimated using beer wastewater treatment aeration tank sludge as the inoculum sludge and with the sodium acetate and butyl xanthogenate as the carbon sources. The results showed that after 35 days start-up period and acclimated, the MBR system reached normal operating state with the SVI of the floc sludge of 100 mL/g and MLVSS/MLSS of 0.75, the removal rates of COD and xanthogenate of 80% and 90% respectively. The formation of floc sludge and membrane efficient rejection enhanced the stability of the MBR and provided a guarantee for the efficient degradation of the xanthogenate wastewater.

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Robust model for multi-product supply chain considering supply disruption

Zhang, Cui-Hua (1); Wu, Wen-Xia (1); Wang, Hai-Ying (1)

2012, 33 (12): 1782-1785. DOI: -

Abstract ( 419 )

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A multi-product supply chain consisting of manufacturers, main suppliers and backup suppliers was analyzed with consideration of supply disruption. And Bertsimas' robust optimization method based on interval analysis was used to describe selling price uncertainty. Under the condition of the manufacturer's profit, the main supplier's profit and the backup supplier's profit maximization, the designed robust model could resist certain uncertainty. Numerical results showed that the proposed model is "robust" when the selling price changes within a certain range.

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Empirical research on the efficiency of city commercial banks based on modified DEA model

Wang, Jia (1); Gao, Ying (1)

2012, 33 (12): 1786-1789. DOI: -

Abstract ( 421 )

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A modified three-stage DEA model that can eliminate the influence of environmental variables and random errors is used to empirically analyze the operating efficiency of the city commercial banks in China from three aspects, namely technique, pure technique and scale efficiencies. Meanwhile, by comparing the efficiency of the state-owned and nationwide listed joint stock banks with that of the city commercial banks, the efficiency variation feature of the last one between the year of 2006~2010 is highlighted. The results show that the efficiency of city commercial banks is much lower than that of the other two kinds and the difference mainly comes from scale efficiency, which may provide a reference to the decision makers for deciding the business policy and improving the management strategy.

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Investigating moderators between perceived online reviews and initial trust under C2C contexts

Zhao, Jia (1); Ma, Qin-Hai (1); Zhang, Yue-Xian (2)

2012, 33 (12): 1790-1794. DOI: -

Abstract ( 495 )

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The lack of initial trust has become a barrier of using online shopping for customers. A conceptual model was built to investigate how the customer expertise and product involvement influence the relationship of customer reviews and initial trust. Based on a customer survey of online service, empirical research shows that customer expertise moderated the relationship between review quality and initial trust, as well as between reviewer expertise and initial trust. Additionally, product involvement moderated the relationship among review quality, review quantity, reviewer expertise and initial trust.

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Research on customer interpersonal skills, social norms behaviors and service satisfaction

Gao, Yuan (1); Ma, Qin-Hai (1)

2012, 33 (12): 1795-1799. DOI: -

Abstract ( 353 )

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The effect of customer's interpersonal skills on customer social norms behaviors and service satisfaction was investigated by the method of demonstration, and the complicated relationships between these variables based on structural equation model were discussed. The results show that the customer's interpersonal skills have significantly positive effect on the customer social norms behaviors and service satisfaction, and reveal the influence of the social psychological features on behavior decision and the finally service evaluation during the process of customer consuming the service products. The results also provide a comprehensive understanding of the pre-variables impacting on the consumer social norms behaviors.

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Lightlike helices in 3D Minkowski space

Qian, Jin-Hua (1); Liu, Hui-Li (1); Jin, Gang (2)

2012, 33 (12): 1800-1802. DOI: -

Abstract ( 618 )

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Lightlike helices in 3D Minkowski space are studied. First, the Frenet frame of lightlike curves in 3D Minkowski space is given and the method of describing lightlike curves with lightlike curvature functions is proposed. Then, the lightlike helix definitions are given, which are classified as general lightlike helix, first slant lightlike helix and second slant lightlike helix according to that the inner product is a constant between the tangent vector, principal normal vector, binormal vector of a lightlike curve and a fixed direction vector, respectively. Finally, the characterizations of lightlike curvature functions of lightlike helices are studied and their specific expression forms in different conditions are obtained.

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