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15 February 2013, Volume 34 Issue 2 Previous Issue    Next Issue
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Information & Control

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MultiplePacket Transmissionbased Controller Design of Networked Control Systems WANG Tianbao， WU Chengdong， WANG Yulong， ZHANG Yunzhou 2013, 34 (2):  157-161.  DOI: - Abstract ( 537 )   HTML   PDF (337KB) ( 996 )   Considering the nonuniform distribution characteristic of networkinduced delay and packet dropout in a sensortocontroller channel， a new model is established for multiple packet transmissionbased continuoustime network control systems (NCSs). Then， by defining a new Lyapunov functional and using continuous Jensen inequality， the stabilizing controller design method is presented for the considered NCS. The result is also extended to NCSs with nonuniformly distributed controllertoactuator delay and packet dropout. Even for NCSs with multiplepacket transmission in both sensortocontroller and controllertoactuator channels， the proposed controller design method is still applicable. A numerical example is given to illustrate the effectiveness of the proposed method. References | Related Articles | Metrics

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WSNbased Optimal Path Planning for Escaping from Disaster Scene HUANG Yue， WU Chengdong， DONG Jingjing， JIA Zixi 2013, 34 (2):  162-165.  DOI: - Abstract ( 782 )   HTML   PDF (355KB) ( 1936 )   For many problems to be solved in the building disaster relief currently， a new approach was proposed to plan the escaping paths for people trapped in the building. In this method， a model of disaster threat was developed using the realtime information from the wireless sensor network laid in the building， including the global environmental information of disaster scenes and its changes. The conventional ant colony (AC) algorithm was improved by using the Dijkstra algorithm and the pheromone updating mechanism， thus optimal escaping paths were obtained using the improved AC algorithm. In the dynamic disaster environment， the proposed method can provide an optimal strategy for person evacuation， guiding the trapped people and firefighters， which can effectively reduce casualties and increase rescue efficiency. References | Related Articles | Metrics

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Geodesic Active Contour Model Combined with CV and GVF PAN Gai， GAO Liqun， ZHANG Ping 2013, 34 (2):  166-169.  DOI: - Abstract ( 599 )   HTML   PDF (774KB) ( 1105 )   An image with concave edges or weak edges cannot be segmented precisely using the conventional geodesic active contour (GAC) method. So， a novel image segmentation algorithm was proposed by combining the CV and GVF models with the GAC model. In this algorithm， the unit inward normal of the GAC model was joined to the gradient vector flow of the GVF model， moving the contour curve towards the boundary of the object. Also， it was joined to the region information of the CV model， getting the curve not only to move to but also to stay at the boundary of the object. Simulation results show that the algorithm proposed is effective and robust to the initial location of the contour curve. References | Related Articles | Metrics

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Crossing Obstacle Detection Based on Monocular Vision LIU Wei， ZHANG Conglei， YU Hongfei， YUAN Huai 2013, 34 (2):  170-173.  DOI: - Abstract ( 762 )   HTML   PDF (608KB) ( 1297 )   An algorithm for detecting obstacles crossing a vehicle’s path was proposed by using a monocular camera. According to the flat road assumption， some pairs of feature points on the ground were extracted based on the feature points’ position constraints and properties under IPM (inverse perspective mapping). Then， the egomotion parameters were estimated from the feature point pairs using iteratively reweighted least squares algorithm. The estimated parameters were used to compensate the rotational motion in the optical flow field of the image， and the candidate points of the obstacle were marked in the road Cvelocity space. Finally， an obstacle region was obtained by grouping and verifying these candidate points. The experimental results in various scenes illustrate that the method proposed is suitable for all kinds of egomotion and can detect a crossing obstacle effectively. References | Related Articles | Metrics

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Injection Speed Control Based on RBF Neural Network Inverse System CHANG Yuqing， ZHANG Hongyan， WANG Shu 2013, 34 (2):  174-177.  DOI: - Abstract ( 613 )   HTML   PDF (499KB) ( 840 )   Taking account of the nonlinear timevariant characteristics of injection speed， a control method based on a neural network inverse system was proposed to control injection speed precisely. The injection speed system was characterized by the M. Rafizadeh model， and its reversibility was confirmed through calculating the relative degree of the system. Considering the difficulty in obtaining the analytical form of reversible model for injection speed system， the RBF neural network (RBFNN) was used to build an inverse system of injection speed. The RBFNNbased inverse system， which has unsatisfied control effect due to openloop control， was combined with the conventional PID control， thus realizing the composite control of injection speed. The simulation results show that the control system proposed has good tracking and antidisturbance performance. References | Related Articles | Metrics

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An Arc Model for Arc Furnace System and Parameter Identification YU Feng， MAO Zhizhong 2013, 34 (2):  178-181.  DOI: - Abstract ( 768 )   HTML   PDF (432KB) ( 1456 )   Based on the principle of arc radiation， an arc model for arc furnace system was presented， with the influence of changes in furnace temperature on the arc performance considered. In this model， the arc changing with furnace temperature was equivalent to the timevariant arc， for it was difficult to measure furnace temperature. How the model parameters varied with the time during smelting was studied. The spline transformationbased partial leastsquares regression was used to determine the parameters according to production data， which could cope with the correlation between the parameters. The changes with time in these identified parameters conform to the results proposed in the literatures before and actual situation， and the model fully reflects the characteristic of the arc in the entire smelting process. References | Related Articles | Metrics

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TwoPhase Algorithm for Routing Optimization of FourthParty Logistics with Time Windows HUANG Min， BO Guihua， XIE Daye 2013, 34 (2):  182-185.  DOI: - Abstract ( 598 )   HTML   PDF (378KB) ( 1075 )   Based on the background of fourthparty logistics， a twophase algorithm was proposed for solving the fourthparty logistics routing problem with time windows. A simple graph was generated from a multigraph in the distribution network using harmony search mechanism， and then the top K shortest paths in the simple graph were obtained using deletion algorithm. The proposed algorithm can ensure all the solutions to be feasible paths and the information of solution to be reserved. Because no ineffective paths were needed to be repaired， a lot of computational time can be saved. Three cases of different sizes were solved by the proposed algorithm， and the results were compared with the harmony search and the enumeration algorithms， which shows that the proposed algorithm outperforms the other two ones. References | Related Articles | Metrics

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Algorithm Design for Fast Automatic Segmentation of Airway Tree QI Shouliang， YUE Yong， ZHU Chenkun， GUO Qiyong 2013, 34 (2):  186-190.  DOI: - Abstract ( 613 )   HTML   PDF (742KB) ( 1116 )   To extract the tracheobronchial tree from lung CT images， an automatic rapid algorithm was proposed， which consisted of three steps including 3D region growing， 3D wave propagation and morphological optimization. The final segmentation results were obtained through iterations of the three steps. The basic airway tree was segmented during region growing， and then the bronchial trees were obtained through 3D wave propagation and morphological optimization. A fuzzy logic criterion was adopted to end the wave propagation and the morphological features were used to prevent leakage. The proposed algorithm was applied to 28 cases and it was shown that the airway tree with the 5th or 6th bronchia could be extracted successfully while no leakage occurred. Besides， the proposed algorithm worked very fast， taking less than 2 seconds to extract one airway tree. References | Related Articles | Metrics

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A Singularity Eliminating Algorithm Based on Kalman Filter for High Altitude Airship’s SINS ZHAO Hai， PENG Haixia， LI Dazhou， DING Xuyang 2013, 34 (2):  191-194.  DOI: - Abstract ( 728 )   HTML   PDF (514KB) ( 1612 )   To eliminate singularities which disturb the solution to high altitude airship’s attitude， an algorithm based on the Kalman filter was proposed for excluding singularities. Based on the developed Kalman filtering model， the current state variables as priori estimates were substituted into the timeupdating equations of the filter in order to be mapped onto the measurementupdating equations in time and get the data required in the measurementupdating equations. And then， the priori estimates were corrected by the measurementupdating equations so as to obtain the posterior estimates. The obtained posterior estimates were further substituted for the singularities from accelerometer sensors so as to eliminate the singularities. The Matlab experiments verify the effectiveness of the proposed algorithm， and the experimental results show that the algorithm eliminates signal burrs from the system’s sensors effectively， with no delay introduced. References | Related Articles | Metrics

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Service Chain Recommending Method Based on Complex Network LIU Guoqi， WANG Zhuang， REN Jiefu， ZHU Zhiliang 2013, 34 (2):  195-198.  DOI: - Abstract ( 659 )   HTML   PDF (587KB) ( 846 )   A network model was developed and analyzed using invokable Web services. Based on the model above， a service chain recommending method was proposed. After a Web service was determined which could meet the user’s requirements， other Web services that could invoke the former one were found out through searching backward a drive service collection coming from network model so as to recommend the combination of services to users. The experimental results show that the method proposed for modeling a network model is feasible and the characteristics of the developed model conform to those of complex network. Service chains meeting user’s requirements can be combined by the service chain recommending method. References | Related Articles | Metrics

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CUDAbased Acceleration Algorithm of SIFT Feature Extraction WANG Beilei， ZHU Zhiliang， MENG Lu 2013, 34 (2):  200-204.  DOI: - Abstract ( 1582 )   HTML   PDF (1048KB) ( 2969 )   A novel algorithm for accelerating scaleinvariant feature transform (SIFT) was presented on the basis of compute unified device architecture (CUDA)， which could solve the timeconsuming problem in SIFT feature extracting. This algorithm took the advantages of graphic processing unit (GPU) in parallel computation， float point computation and memory management， and reasonably allocated the computational resources and the corresponding computational tasks to the host and device in the SIFT feature extracting. Experimental results show that， compared with the CPUbased acceleration algorithm， the proposed CUDAbased algorithm greatly speeds up the extracting of SIFT features. The acceleration ratio increases with the number of SIFT feature points. The maximum acceleration ratio in the experiments was 1954. References | Related Articles | Metrics

Materials & Metallurgy

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Synthesis of Fe2O3TiO2 Nanocomposite Particles by Pulsed Laser Control CHEN Suiyuan， ZHANG Yikun， Daniel WELLBURN， LIU Changsheng 2013, 34 (2):  205-208.  DOI: - Abstract ( 602 )   HTML   PDF (618KB) ( 745 )   Micron powders of 5wt% Fe2O3and 95wt% TiO2 were mixed to form a target for preparing Fe2O3TiO2 nanocomposite particles using the method of pulsed laser gas phase evaporatingliquid phase collecting. The morphology， microstructure， optical absorption properties and the synthetic mechanism of the prepared sample were characterized using the transmission electron microscopy， Xray diffraction， infrared spectroscopy， and UV spectrum detecting technology， respectively. The results showed that the prepared Fe2O3TiO2 particles were sphereshaped with average diameter of about 40nm and they linked up with one another like a chain. The Fe2O3dopant improved the magnetism of the TiO2 nanoparticles. The spectral analysis of the Fe2O3TiO2 particles in the range of 800-200nm exhibited redshift， indicating that the photocatalytic performance of TiO2 nanoparticles was improved. References | Related Articles | Metrics

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Effects of Alloy Elements and Solution Temperature on Microstructure of High Mn TRIP/TWIP Steel LI Huaying， DING Hua， DING Hao， QIU Chunlin 2013, 34 (2):  209-213.  DOI: - Abstract ( 758 )   HTML   PDF (1461KB) ( 1168 )   High manganese steels with and without Nb were solutiontreated at different temperatures. Their mechanical properties were investigated through tensile tests and their microstructures were characterized by means of optical microscope， Xray diffraction and transmission electron microscope， as well as the morphologies and distribution of the Nb precipitates. The tensile strength of the two experimental steels decreased with increasing the solution temperature. After solution treatment at 900℃ for 1hr， unlike the steel without Nb， there was still a small quantity of banded structures formed in hotrolling of the steel with Nb. When the steels were solutiontreated at 1000℃， the grains in the steel with Nb were finer than those without. During the tensile tests， the deformation mechanisms of the two experimental steels are attributable to the TRIP and TWIP effects， and the TRIP effect becomes dominant for the steel without Nb. References | Related Articles | Metrics

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Cutting Performance of Al2O3/Ti(C， N)NiTi Ceramic Cutting Tool LI Qian， CAO Xiujuan， XIU Zhimeng， SUN Xudong 2013, 34 (2):  214-217.  DOI: - Abstract ( 877 )   HTML   PDF (693KB) ( 1525 )   The influence of cutting parameters on cutting force was investigated during continuous drycutting of the quench hardened 35CrMo alloy steel using the Al2O3/Ti(C， N)NiTi composite cutting tool. The results indicate that the cutting depth has the most significant influence， while the cutting speed has the smallest. The abrasion performance and cutting lifetime of the Al2O3/Ti(C， N) and the Al2O3/Ti(C， N)NiTi cutting tools were studied. The cutting lifetime of the latter one is significantly longer， and that of the Al2O3/Ti(C， N)5vol%(Ni， Ti) composite is the longest. The Al2O3/Ti(C， N)NiTi cutting tools are mainly characterized with abrasive abrasion and fatigue wear. Due to their higher bending strength and fracture toughness， they are less susceptible to chipping and breakage， which enable them more suitable for highspeed cutting. Under the highspeed cutting conditions (ap=006mm， vc=2549m/min and vf=009mm/r)， the cutting lifetime of the Al2O3Ti(C， N)5vol%(Ni， Ti) composite cutting tool is 150min. References | Related Articles | Metrics

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Determination of Exchange Coupling and Switching Field Distribution for Perpendicular Magnetic Recording Media XIAO Na， LI Song， REN Yuping， QIN Gaowu 2013, 34 (2):  218-222.  DOI: - Abstract ( 751 )   HTML   PDF (1413KB) ( 1491 )   The magnetic properties of the CoPt perpendicular magnetic recording films were characterized with a vibrating sample magnetometer. The measurement techniques of the isothermal remanent magnetization (IRM) and direct current demagnetization remanence(DCD) and demagnetization factor calculation were presented in detail for the perpendicular recording media. In addition， the calculation methods of ΔM and switching field distribution(SFD) from the corrected demagnetization IRM as well as DCD curve were introduced. Finally， the relationship was discussed in detail among the intergranular exchange coupling， SFD， demagnetization， microstructure， and the easy magnetization axis orientation distribution of the CoPt thin films. The results show that the intrinsic constant of intergranular exchange coupling that mainly depends on the microstructure and easy magnetization axis orientation distribution of recording media is decreased with the demagnetization， while the SFD will be broaden， and the easy magnetization axis orientation distribution is an influencing factor for SFD. References | Related Articles | Metrics

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Effect of FeDoping on Structure and Magnetic Behavior of Zn1xCoxO Nanocrystal Powders GAO Qian， QI Yang， FAN Ming 2013, 34 (2):  223-225.  DOI: - Abstract ( 548 )   HTML   PDF (801KB) ( 973 )   The Fedoping Zn1xCoxO nanocrystal powders were prepared by the solgel method. The crystal structures， lattice parameters， and magnetic properties were characterized and analyzed using the Xray diffraction， transmission electron microscopy， and vibrating sample magnetometer. Amorphous materials and secondary phase such as Fe or Co groups are not detected in all the synthesized samples， which indicate that the Fedoping does not change the hexagonal structure of the wurtzite ZnO， the sizes of the particles and the ferromagnetic behavior of Zn1xCoxO at room temperature. However， the magnetic parameters such as the saturation magnetization intensity， remnant magnetization intensity， coercive force and the exchange bias are improved with increasing the Fedopant. Furthermore， the contribution of single Fe atom to spontaneity magnetization is lower than that of the single Co atom. It indicates that the Fe and Co codoped ZnO is different from the Co doped ZnO in the magnetic mechanism. References | Related Articles | Metrics

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Application of Queue Storage Technology in ADCOSPM CHEN Xiaolin， YUAN Guo， WANG Zhaodong， WANG Guodong 2013, 34 (2):  227-230.  DOI: - Abstract ( 516 )   HTML   PDF (1022KB) ( 1067 )   To upgrade a cooling system after rolling， ultrafast cooling (UFC) and original acceleration cooling (ACC) systems were combined to form a newgeneration plate cooling system after rolling (ADCOSPM). Since the first level of the ACC system was shielded as a “black box”， the mathematical model of the second level was analyzed in depth. Considering the independence and integrity of the original ACC system， the “firstin firstout” queue storage technology was proposed on the basis of the cooling mode switching principle. Using the proposed method， the seamless combination of the newadded UFC system and the primitive ACC control system was achieved. Furthermore， this new system was applied to the plate industry production successfully. References | Related Articles | Metrics

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Development and Application of Full Automatic Rolling and Cooling Function of Experimental Mill for Hot Flat Rolling GAO Yang， NIU Wenyong， LI Jianping， ZHANG Zerui 2013, 34 (2):  231-234.  DOI: - Abstract ( 579 )   HTML   PDF (717KB) ( 818 )   The full automatic rolling and cooling functions were developed on the basis of basic fullautomation system， which can automatically make realtime judgment about the experimental process and then generate operation instructions. It is mainly composed of instrument signal acquiring and processing， plate tracking， and logical judgment and operating instruction generation modules. The fullautomatic control was realized in the processes of plate transporting， descaling， rolling， centering， temperature waiting， and cooling. The operation of turning steel and some other few necessary intervention are manual control. The functions were successfully applied to a 550 mm hotrolling experimental mill of the Technical Center of Steel Union Co. Ltd. of Baotou Steel(Group) Corp. The maximum deviation of head position is 29 mm with length deviation of 241%. References | Related Articles | Metrics

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Ferrous Oxide Activity of BF Slag Containing Alkali LI Jianchao， KONG Yanchang， LI Fumin， L Qing 2013, 34 (2):  240-243.  DOI: - Abstract ( 1056 )   HTML   PDF (799KB) ( 956 )   The FetO activity (aFetO) of BF slag containing alkali was determined by the zirconia solid electrolyte battery using gasslagmetal balance technique so as to understand the relationship between aFetO， potassium capacity(CK)， sulfide capacity(CS) and the composition. The results show that the aFetO and CS increase with the binary basicity， while CK decreases. As the MgO content and Al2O3 content increase， the aFetO decreases and CK increases， and the CS increases first and then decreases. When the alkali load of BF is high， the aFetO of slag should be maintained in the range of 0074-0078 by controlling composition， thus the slag has suitable desulphurization capacity and large capacity of removing alkali， which is helpful to reduce the alkali metal hazards to BF. References | Related Articles | Metrics

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Simulation for Bloom Heatingup Process in Reheating Furnace XU Dong， JI Cheng， ZHU Miaoyong， TANG Zhengyou 2013, 34 (2):  244-247.  DOI: - Abstract ( 703 )   HTML   PDF (1006KB) ( 1398 )   The bloom heatingup process of a reheating furnace was calculated and analyzed using the FEM based commercial software ABAQUS. A thermalmechanical coupling model was established and the distribution of stress and strain was calculated under different hot charging conditions. The results show that the stress increases from the bloom surface to center with increasing the heating time and temperature. As the hot charging temperature rises， the maximum strain gradually decreases with a turning point of stress appearing， evolving double peak stress curve. The analysis indicates that the proper hot charging temperature is about 600℃ in the existing heating system. References | Related Articles | Metrics

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Temperature Distribution of SiO2 Trench Wafer in Rapid Thermal Process WANG Aihua， LI Liya 2013, 34 (2):  248-250.  DOI: - Abstract ( 724 )   HTML   PDF (866KB) ( 1130 )   The heat transfer of a wafer in rapid thermal process was simulated using a model combining heat conduction with heat radiation to investigate the effects of the width of SiO2 trenches and their arrangement density on the temperature distribution of the wafer. The results show that， in the case of the same SiO2 trench width， the temperature level of the wafer rises with the increase of the pattern arrangement density， but the temperature uniformity on the wafer surface changes little. Increasing the pattern density can enlarge the proportion of SiO2 on the wafer surface and， as a result， the surface absorptance and the incident radiation absorption increase， which elevates the temperature level. When the arrangement density of the SiO2 trenches is constant， the SiO2 trench width has little influence on the temperature level and uniformity. References | Related Articles | Metrics

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Evolution of Flame Inclination of Filtration Combustion in Porous Media SHI Junrui， LI Benwen， YU Chunmei， YAN Zhongyuan 2013, 34 (2):  252-256.  DOI: - Abstract ( 726 )   HTML   PDF (1058KB) ( 1052 )   In order to study the evolution of inclinational flame during propagation of a filtration combustion wave in porous media and the causes of the evolution， a twotemperature and twodimensional numerical model was established. A 500mmlong quartz tube with 40mm in diameter was used as the burner model which was filled with grained carborundum (SiC). The software Fluent was used to simulate the combustion， fluid flow and heat transfer of filtration combustion. The evolution of inclinational flame and the reasons causing this evolution were analyzed from three aspects of temperature field， gas velocity field and pressure field， respectively. Temperature field， gas velocity field and pressure field can affect the chemical reaction rate， the direction of gas flow and heat loss at the walls， etc.， and further can affect the evolution of inclinational flame. These factors can advance the continuous development of the inclination. The results show that， if an initial inclination is set， the inclination of flame will progress and become more serious. References | Related Articles | Metrics

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Quantifying Social Stock of Metal Substance and Its Relationship with Economic Output YUE Qiang， HOU Limin， WANG Heming， LU Zhongwu 2013, 34 (2):  257-260.  DOI: - Abstract ( 504 )   HTML   PDF (581KB) ( 798 )   A formula for calculating social stock of metal substance was given. It was also combined with GDP index in order to attain the relationship formula between social stock of metal substance and GDP. As an example， the Chinese aluminum industry was analyzed based on the proposed idea. Assuming that the average service life of aluminum products is 16 years， the analysis results were as follows:the social stock of Alcontent increased from 5420×104 t to 8890×104 t and GDP generated per unit social stock of Alcontent decreased from 3969×104 dollars/t to 3307×104 dollars/t over the period 2006-2009. According to the present situation of Chinese aluminum industry， it was believed that raising the annual decline rate of aluminum consumption per unit GDP could gradually slow the growth rate of aluminum consumption， and two scenarios were analyzed for the future development of Chinese aluminum industry. References | Related Articles | Metrics

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Corrosion Resistance of Rare EarthBorided Titanium Alloy LI Fenghua， YI Xiaohong， FAN Zhanguo， ZHANG Jinglei 2013, 34 (2):  261-264.  DOI: - Abstract ( 698 )   HTML   PDF (710KB) ( 1114 )   Rare earth and B atoms were penetrated into Ti6Al4V (TC4) alloy surface using the solid powder technique without protective atmosphere. The rare earthborided， borided and TC4 alloys were corroded in the 35wt% NaCl and 5wt% H2SO4 solutions， respectively. The Xray diffraction analysis shows that the borided layer on the TC4 surface is composed of TiB2 and TiB. Scanning electron microscopy study shows that the outer TiB2 layer has a flat growth front， while the inner TiB layer appears serration. Some pinholes present in the outer layer， which may be due to the Kirkendall effects caused by the codiffuse of Ce and B atoms synchronically. The Tafel polarization curve shows that， in the 35wt% NaCl and 5wt% H2SO4 solution， the corrosion resistance of the samples follows the order of borided， rare earthborided and TC4 alloy. References | Related Articles | Metrics

Mechanical Engineering

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Influence of Root Connecting Stiffness on Vibration Responses of Rotating Blades MA Hui， TAI Xingyu， ZHANG Zhi， WEN Bangchun 2013, 34 (2):  265-269.  DOI: - Abstract ( 640 )   HTML   PDF (786KB) ( 1216 )   Taking a rotating twisted blade with variable crosssection as a research object， a finite element model of the blade was established using shell elements with variable thickness in the ANSYS software. The model was verified by comparing the natural frequencies and their modal shapes of the shell elements with those of the solid elements. The influence of the radial blade root connecting stiffness on the blade dynamic frequency characteristics was analyzed under the joint action of centrifugal force， spin softening and the Coriolis force， as well as on its amplitudefrequency response under the joint action of centrifugal force and aerodynamic force. The results show that， when the radial connecting stiffness is low， the rigid body vibration modes appear within low frequencies， the modest radial connecting stiffness contributes the coupling vibration modes which occur mainly at high frequencies， and the vibration mode under the large radial connecting stiffness condition is similar to that of fixed support and the response amplitude is smaller than that of the first two. References | Related Articles | Metrics

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ReachingLawbased Controlled Synchronization Strategy in Harmonic Vibration of SingleMass Nonlinear Systems LI Xiaohao， ZHAO Qunchao， LIU Jie 2013, 34 (2):  271-274.  DOI: - Abstract ( 691 )   HTML   PDF (615KB) ( 1014 )   Based on the electromechanical coupling dynamic model of the singlemass nonlinear vibration machinery， statespace equations of the speed difference and phase difference were constructed for the double driven motors. A controlled synchronization strategy based on the sliding mode reaching law was designed for harmonic vibration of the double driven motors. The Kalman filter was introduced into the strategy to cope with the sensibility of the harmonic vibration synchronization of the nonlinear vibration machines. The simulation analysis results verified the validity of the strategy， which shows that the double driven motors can synchronize the machinery in harmonic vibration satisfactorily. References | Related Articles | Metrics

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Fabrication and Characterization of DSSC by Combining TiO2 Nanoparticle Bilayer with Silver Reflection Film CONG Wei， BA Dechun， WANG Hequan， HAN Enxiang 2013, 34 (2):  275-279.  DOI: - Abstract ( 505 )   HTML   PDF (1259KB) ( 807 )   A novel structure of dyesensitized solar cell (DSSC)， with TiO2 nanoparticle bilayer on the photoanode and silver reflection film on the counter electrode， was proposed. The structure and morphology of the TiO2 bilayer were characterized using the transmission electron microscopy， scanning electron microscopy， and Xray diffraction. The optimized thickness of the nanoparticle film was obtained and the light reflection was analyzed. The results show that the photoelectric efficiency of 438% with a shortcircuit photocurrent density of 1117mA/cm2， an opencircuit photovoltage of 075V， and a fill factor of 0523 were obtained for the DSSC. It is about 241% higher than that of the traditional sandwichstructure DSSC under the same testing conditions of AM 15 and 100mW/cm2. References | Related Articles | Metrics

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Camouflage Design Method Combining MeanShift and Minimal Spanning Tree Algorithms WANG Zhan， YAN Yunhui， CHEN Xiangan 2013, 34 (2):  280-283.  DOI: - Abstract ( 567 )   HTML   PDF (1115KB) ( 761 )   To solve the design problem of camouflage technology and realize high fusion of the camouflage image and the background environment， a method of image segmentation by combining mean shift and minimal spanning tree algorithm is presented. The method can accurately exact the camouflage spot pattern of background， and its operation speed was greatly improved in comparison with that of the others. It ensures the accuracy of the whole camouflage design and enhances the instantaneity of camouflage effect. Moreover， through the quantification of color histogram， the dominant background color is extracted as the display color of the camouflage pattern. The combination of plaque and color generates the final camouflage image. The experimental results confirm the validity of the method. References | Related Articles | Metrics

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Experimental Research and Analysis on Micro Milling Forces in Process of HighSpeed MicroScale Milling ZHANG Jinfeng， GONG Yadong， ZHANG Yongzhen， LIU Yueming 2013, 34 (2):  284-287.  DOI: - Abstract ( 530 )   HTML   PDF (771KB) ( 1599 )   The milling force on micro cutter blade was investigated in order to understand the characteristics and law of highspeed milling. The forced mechanism of end milling cutter was further analyzed theoretically. The experiment was carried out in a testplatform using typical materials and methods. The results show that the laws are closely linked to the physical and mechanical properties of the materials along with the changes of micro milling parameters. Moreover， the tool edge radius， feed per tooth， axial depth of cut， and grain size of the material are the main factors causing the dimensional effect. References | Related Articles | Metrics

Resources & Civil Engineering

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Slope Stability Analysis Based on SoftRock Rheological Characteristics LI Haizhou， YANG Tianhong， XIA Dong， ZHENG Chao 2013, 34 (2):  293-296.  DOI: - Abstract ( 630 )   HTML   PDF (1094KB) ( 1127 )   According to the results of creep testing on the sandy mudstone at Beishan open pit coal mine in Xinjiang， the creep curves were described by the viscoelastoplastic creep model and the timevarying parameters were revealed via HoekBrown strength criterion. The dynamic stability of the slope was analyzed using FLAC3D numerical software. The result shows that the slope safety factor is reduced to 115 from 159 after 18 years， which is lower than the specification requirements. This work provides a theoretical basis for the assessment of the dynamic safety of this slope during its service life. References | Related Articles | Metrics

Management Science

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Calculation Method of Evaluators’ Authority in Group Evaluation MAO Qiang， GUO Yajun， QI Yu 2013, 34 (2):  297-300.  DOI: - Abstract ( 708 )   HTML   PDF (237KB) ( 1024 )   Aimed at the inconsistent evaluation findings caused by multiple evaluators or multiple evaluation methods in group bargaining evaluation， a method for calculating evaluators’ authority is proposed in order to provide reference for the credibility of evaluation findings and the choice of evaluators in practical applications. First， the evaluation context is set and the research hypotheses are made. Then， several related concepts and definitions of evaluators’ authority are given after which a calculation model of evaluators’ authority is formulated and its validity is described. Theoretically， this method could solve the inconsistent evaluation findings and avoid peer evaluators’ subjectivity and uncertainty in the process of group bargaining evaluation. Finally， a numerical example is given to verify the effectiveness of the method. References | Related Articles | Metrics

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Empirical Study on the Measurement of China’s Economic Structure and Its Influencing Factors ZHANG Wei， FAN Decheng， WANG Shaohua 2013, 34 (2):  301-304.  DOI: - Abstract ( 528 )   HTML   PDF (228KB) ( 811 )   Based on an analysis of the components of economic structure， several representative indicators for measuring economic structure were determined， and by using the principal component analysis， China’s regional economic structures in 2005， 2007 and 2009 were measured. Taking the measured values of China’s regional economic structures as the dependent variables and the factors influencing economic structure as the independent variables， a path analysis was given in order to calculate the direct effect， indirect effect and total effect of various factors on economic structure. The results show that employment structure and technological advance play a positive role in the process of economic structure optimization， but the low level of urbanization and the rapid pace of economic development hinder the optimization of economic structure. At present， the favorable opportunity created by economic slowdown for the sake of structural adjustment should be seized so as to optimize economic structure by means of technological advance and urbanization. References | Related Articles | Metrics