Loading...

Archive

    For Selected: Toggle Thumbnails
    Information & Control
    A Class of Neural Networks for Solving Optimization Problems with Global Attractivity
    WANG Zhan-shan, KANG Yun-yun, NIU Hai-sha
    2017, 38 (2):  153-157.  DOI: 10.12068/j.issn.1005-3026.2017.02.001
    Abstract ( 796 )   HTML   PDF (425KB) ( 1319 )  
    A recurrent neural network in the form of differential inclusion was proposed for solving a class of nonlinear optimization problems, where the constraints were defined by a class of inequality and equality constraints. A higher-order compensation term was involved in the considered neural model, therefore, the convergence rate of the neural computation was significantly increased and the unstable problem of the optimal solution from infeasible domain to feasible domain was solved. In theory, it is proven that not only the solution of the proposed network exists globally and uniquely, but also the solution of the proposed network is bounded and is convergent to the optimal solution set of the optimization problem. Meanwhile, global attractivity of the neural network was analyzed. Three numerical examples were used to show the effectiveness and good performance of the proposed neural network.
    References | Related Articles | Metrics
    Design of Permanent Magnet Drive Based on Improved Support Vector Regression
    LI Zhao, WANG Da-zhi
    2017, 38 (2):  158-163.  DOI: 10.12068/j.issn.1005-3026.2017.02.002
    Abstract ( 626 )   HTML   PDF (712KB) ( 751 )  
    The multi-output support vector regression with composite kernel and the fuzzy theory were applied to design permanent magnet drive. In this method, the space particle swarm optimization (SPSO) algorithm was firstly introduced to obtain the most appropriate parameter of the multi-output support vector regression with composite kernel model. In addition, through the experiment the regression model between performances and structure parameters of permanent magnet drive was established. Secondly, by using fuzzy theory, multi-objective problem was converted into single one, and the mathematical model of optimization problem was set up, which was solved by SPSO. Finally, precision analysis of model, ANSYS simulation and prototyping test were carried out, and the results verified the effectiveness of the proposed method.
    References | Related Articles | Metrics
    A Multi-terminal Traveling Wave Fault Location Method for Distribution Network Based on Park’s Transformation
    NING Yi, WANG Da-zhi, JIANG Xue-chen, ZHANG Cui-ling
    2017, 38 (2):  163-167.  DOI: 10.12068/j.issn.1005-3026.2017.02.003
    Abstract ( 639 )   HTML   PDF (512KB) ( 952 )  
    It is difficult to accurately locate fault in a distribution network by one-terminal or two-terminal traveling wave method. So, a multi-terminal traveling wave fault location method was proposed. In this method, a self-adaptive strategy for traveling wave detection based on Parks transformation was made. The theory of multi-terminal traveling wave fault location method was established on the basis of analyzing the defects of the two-terminal traveling wave method. The detected arrival time of traveling wave on the terminal of distribution lines was used in fault location. The proposed method avoids the difficulty in recognizing reflect waves, and is independent of different fault types, fault inception angles and different fault resistances. Various fault cases in a distribution network were simulated by PSCAD/EMTDC and MATLAB. The results verify that the proposed method can locate fault point quickly and accurately, showing the method reliable and suitable.
    References | Related Articles | Metrics
    Ricochetal Brachiation Motion Planning and Control for Two-Link Bio-primate Robot
    CHENG Hong-tai, WAN Deng-ke, HAO Li-na
    2017, 38 (2):  168-173.  DOI: 10.12068/j.issn.1005-3026.2017.02.004
    Abstract ( 838 )   HTML   PDF (514KB) ( 954 )  
    The tight coupling of locomotion and underactuated characteristics are the main difficulties for realizing ricochetal brachiation of a bio-primate robot. For the locomotion coupling, the segmented dynamic/kinematic models were built and analyzed. Then, a flexible, comprehensive and adaptive ricochetal brachiation motion planning algorithm was proposed in consideration of the constraint condition and switching condition. Therefore, pre- and post-flying postures were obtained. As to the underactuated characteristics, virtual-constraint-based trajectory planning and tracking control methods were adopted to ensure that the system could arrive at the pre-flying posture accurately. Finally, a ricochetal brachiation simulation model was built and the results show the effectiveness of the proposed trajectory planning and control strategy.
    References | Related Articles | Metrics
    Parking Spaces Allocation Model of Residential Areas Sharing Parking Based on Personalized Guidance
    DUAN Man-zhen, YANG Zhao-sheng, ZHANG Lin , TIAN Xiu-juan
    2017, 38 (2):  174-179.  DOI: 10.12068/j.issn.1005-3026.2017.02.005
    Abstract ( 692 )   HTML   PDF (610KB) ( 1170 )  
    In view of the local congestion caused by public parking guidance under the condition of limited parking resources, a personalized sharing parking guidance service model was proposed, with residential parking space joined. Personalized parking guidance strategy was discussed, several sharing parking indexes were defined, and then a bi-level design model of sharing parking guidance with residential joined was established. By controlling the mean value of unoccupied parking difference index in peak time and walking distance, the driver’s parking choice goal could be met and the balance and effective use of parking resources were achieved. The research shows that by the way of personalized parking guidance, the unoccupied time of residential parking lots can effectively alleviate the attraction of their adjacent buildings and the local parking congestion in peak time can be reduced. So the parking lots of residential areas will be the best sharing partner of the adjacent buildings in sharing parking.
    References | Related Articles | Metrics
    Iris Localization Method Based on SIFT and SDM
    WANG Qi, ZHANG Tie, ZHANG Xiao-meng, ZHANG Xiang-de
    2017, 38 (2):  180-184.  DOI: 10.12068/j.issn.1005-3026.2017.02.006
    Abstract ( 608 )   HTML   PDF (1198KB) ( 959 )  
    To improve the speed and stability of iris localization, an SDM(supervised descend method)-based iris localization algorithm was proposed. Firstly, radial symmetry transformation was adopted to localize pupil roughly, then, an integro-differential operator was used to segment pupil accurately. Secondly, SIFT(scale invariant feature transform)features were selected to describe the characteristic information of the outer boundary of the iris and eyelids. Thirdly, the SDM algorithm was employed to determine the key points on the outer boundary and eyelids.Finally,the least square algorithm was used to determine the parameters of the outer boundary, the upper and lower eyelids. Experimental results show that the proposed algorithm can greatly improve the efficiency and stability of iris localization.
    References | Related Articles | Metrics
    Gaussian Distribution Fitting Model Based on Local Intensity Clustering
    YU Xiao-sheng, HU Nan
    2017, 38 (2):  185-189.  DOI: 10.12068/j.issn.1005-3026.2017.02.007
    Abstract ( 719 )   HTML   PDF (1064KB) ( 774 )  
    A novel active contour model was developed for the problem that the Gaussian distribution fitting model is sensitive to a starting contour. According to the characteristics of the local intensity clustering, the bias field and a piecewise constant function were integrated to approximate the local image intensities, which made the objects be segmented with the starting contour being anywhere in the image. An efficient numerical schema was used for the implementation of the proposed model in order to converge rapidly and avoid re-initialization. Experimental results on a series of real and synthetic images demonstrate that the proposed model is robust to the starting contour and the images with intensity inhomogeneities can be effectively segmented.
    References | Related Articles | Metrics
    A Variable Workload Model and Algorithm for Real-Time Systems
    HUANG Ying-chun, DENG Qing-xu
    2017, 38 (2):  190-194.  DOI: 10.12068/j.issn.1005-3026.2017.02.008
    Abstract ( 679 )   HTML   PDF (741KB) ( 714 )  
    The traditional performance analysis of real-time systems relied on the input variable of worst-case execution time, which turned to be too pessimistic.Aiming at the problem of remarkably redundant design in real-time, a new model to characterize variable workload was created including workload curves, inverse workload curves and workload ratio curves. In the proposed model, event type, number and distribution were used as decision-variable, and relevant algorithm was proposed to solve the above model. In addition, the realistic applications were analyzed in mix scheduling based on VWM (variable workload model). The result indicates that the VWM can remarkably reduce execution workload of tasks, thus reducing the resource requirement of real-time systems.
    References | Related Articles | Metrics
    A Displacement Measurement Method of Micro/Nano Scale Based on Neighbor Principal Feature Matching
    LIU Yong-jun, WEI Yang-jie, WANG Yi
    2017, 38 (2):  195-199.  DOI: 10.12068/j.issn.1005-3026.2017.02.009
    Abstract ( 642 )   HTML   PDF (506KB) ( 762 )  
    A new sub-pixel displacement measurement method is proposed based on the neighbor principal feature matching. The improved main features extraction process enhances the accuracy and stability of the algorithm by reconstructing divergence correction matrix and maximizing the distance of adjacent image blocks. The overall micro/nano scale measurement method is designed based on the neighbor principal feature matching by off-line training process, and the simulation verifies the accuracy of the method which is used for the image blocks with different sizes and positions. The high-precision nano platform, the high power microscope and the standard grid are used together to validate the measurement. The accuracy of the algorithm is increased by nearly 10 times compared with the conventional blocks matching method. Further, the algorithm has higher robustness in selecting the position and size of the image blocks.
    References | Related Articles | Metrics
    Research on the Similarity of Fuzzy XML Documents and Fuzzy DTD
    ZHAO Zhen, MA Zong-min
    2017, 38 (2):  200-204.  DOI: 10.12068/j.issn.1005-3026.2017.02.010
    Abstract ( 665 )   HTML   PDF (492KB) ( 889 )  
    In fuzzy extensible markup language (XML) data management, the similarity between fuzzy XML document and fuzzy document type definition (DTD) is a key step of fuzzy XML data integration and fuzzy XML documents clustering. In order to study the similarity, the fuzzy DTD tree are transformed by rules, which mainly solves the disjunctive constraint and cardinality constraint problems of the elements and attributes, namely the transformation from disjunctive normal form into conjunctive normal form, thus the number of repetitions of elements or attributes being determined. And then, the tree edit distance algorithm is used to compare the similarity between the fuzzy XML document tree and the transformed fuzzy DTD tree. The advantages of the proposed method are verified by experiments.
    References | Related Articles | Metrics
    Comparison Analysis of Network Characteristics of OFC-based Simulated Earthquake Sequences
    XU Jiu-qiang, SONG Jia, HE Xuan , ZHAO Hai
    2017, 38 (2):  205-209.  DOI: 10.12068/j.issn.1005-3026.2017.02.011
    Abstract ( 639 )   HTML   PDF (383KB) ( 774 )  
    The Olami Feder Christensen (OFC) model shows the law of earthquake activities by simulating the earthquake energy transfer behavior. In order to truly describe the earthquake energy transfer, the underlying network of the OFC model of regular two-dimensional network is replaced by the real time-space domain network extracted from the California earthquake data in 1992. The simulated earthquake sequence is constructed by the improved OFC model to find the similarity between the simulated earthquake sequence and real earthquake data. Whether the improved simulated network is closer to the real network is determined through comparing the cumulative degree distribution trend of the two networks. The experimental results show that, in terms of macro network topology, the simulated earthquake sequences are consistent with the real earthquake data.
    References | Related Articles | Metrics
    Load Prediction Approach for Cloud Application Based on Deep Belief Networks
    MA An-xiang, ZHANG Chang-sheng, ZHANG Bin, ZHANG Xiao-hong
    2017, 38 (2):  209-213.  DOI: 10.12068/j.issn.1005-3026.2017.02.012
    Abstract ( 875 )   HTML   PDF (405KB) ( 1132 )  
    To implement the adaptive optimization to ensure the performance of cloud application, it is necessary to accurately predict the load for cloud application. According to the feature of load prediction in cloud application, an approach is proposed for load prediction based on deep belief networks. Explicit and implicit features for load data are given. Load prediction model is defined. Then, the algorithm of load prediction based on deep belief networks is designed and implemented. This approach is evaluated and compared with some related load prediction algorithms, which reveals very encouraging results in terms of the prediction quality.
    References | Related Articles | Metrics
    A Multiple-Object Tracking Algorithm Using TLD-based Adaptive Adjustment of Detection Areas
    MENG Yu, ZHANG Bin
    2017, 38 (2):  214-218.  DOI: 10.12068/j.issn.1005-3026.2017.02.013
    Abstract ( 682 )   HTML   PDF (1329KB) ( 1143 )  
    Traditional tracking-learning-detection (TLD) object tracking algorithm takes long time for detection because the area to be detected is too large, and the algorithm is not satisfactory for tracking similar objects, and it is only suitable for single object tracking tasks. Therefore, an efficient TLD-detector optimization for multiple objects (TLD-DOMO) approach is proposed for tracking multiple objects, which is built on a novel algorithm named DKF (double Kalman filter). Detection areas are adjusted adaptively by the prediction method accelerated by double Kalman filtering operation. The multiple-object detectors of TLD-DOMO algorithm can predict potential motion range of each object to optimize the scale and position of detection areas adaptively. Thus, the accuracy and efficiency of multiple-object tracking will be improved. Moreover, the proposed method also reduces the interference among tracked objects effectively for supporting similar objects tracking. Experimental results show that the detection efficiency is improved in all test videos, and the speedup ratios are between 155% and 294%. The effect of detection and recognition of multiple objects surpasses the original TLD approach in tracking multiple similar objects.
    References | Related Articles | Metrics
    A Source Localization Method for Information Diffusion on Dynamic Social Networks
    ZHANG Xi-zhe, MENG Qing-hu, ZHANG Bin
    2017, 38 (2):  219-223.  DOI: 10.12068/j.issn.1005-3026.2017.02.014
    Abstract ( 759 )   HTML   PDF (694KB) ( 1062 )  
    The topology of social networks changes over time, which makes it very difficult to determine unknown spreading source. A localization method about diffusion source on dynamic networks is presented. The hidden source can be localized by means of modeling the network and deducing the spreading topology. First, the topological change of networks in the diffusion process is deduced based on the link analysis method given by hyperbolic geometry, and then the source based on the propagation topology is located. The large-scale experiments based on the actual networks and the synthetic networks show the feasibility of the proposed algorithm.
    References | Related Articles | Metrics
    Materials & Metallurgy
    Mechanical Properties and Strain Hardening Behavior of Fe-8/11Mn-4Al-0.2C Steels
    CAI Zhi-hui, LI Zhi-chao, CAI Bo, DING Hua
    2017, 38 (2):  224-228.  DOI: 10.12068/j.issn.1005-3026.2017.02.015
    Abstract ( 757 )   HTML   PDF (1274KB) ( 854 )  
    In order to optimize austenite volume fraction and stability, Fe-8Mn-4Al-0.2C (8Mn)and Fe-11Mn-4Al-0.2C (11Mn)steels were quenched at different temperatures. The variation of austenite fraction during tensile testing was measured by XRD. The results showed that 8Mn steel and 11Mn steel quenched at 750℃ obtain the best tensile property combinations, i.e., the product of strength and elongation is up to 46.4GPa% and 66.9GPa%, respectively. 8Mn-750 sample and 11Mn-750 sample exhibit a similar three-stage strain hardening behavior. TRIP effect mainly occurs in stage 2 and 3. The 11Mn-750 sample, which has higher austenite fraction, transformation ratio and stability, has a much better ductility than 8Mn-750 sample.
    References | Related Articles | Metrics
    Pilot Mill Development for Difficult-to-Deform Materials and Experimental Research
    JIAO Zhi-jie, SUN Tao, LI Jian-ping
    2017, 38 (2):  229-233.  DOI: 10.12068/j.issn.1005-3026.2017.02.016
    Abstract ( 654 )   HTML   PDF (450KB) ( 848 )  
    A new pilot mill was developed for the experimental rolling of difficult-to-deform materials. Hydraulic tension cylinders and clamps were used for direct pulling tension rolling on short material specimen. In order to realize the differential speed rolling with continuously variable speed ratio, two main motors were used and the motors’ speeds were adjusted respectively for upper and lower work rolls. Warm rolling process was implemented through strip resistance heating. The clamps at the two sides of the mill were used as the positive and negative electrodes, while low voltage and high current DC power was acted on the strip specimen. These functions were realized on the new pilot mill for experimental validation. The 3% Si silicon steel was rolled with direct pulling tension and differential speed rolling mode. With speed ratio of 1.12, the total thickness reduction was increased by 28.4%. The AZ31 magnesium alloy was rolled with direct pulling tension and warm rolling mode, and the thickness was reduced from 4mm to 0.633mm with good surface quality. This new pilot mill can be used as an effective tool for the difficult-to-deform material experimental research.
    References | Related Articles | Metrics
    Development of Thermoforming Equipment with Inner High Atmospheric Pressure for Ultra-strength Steel Pipe
    WANG Gui-qiao, LI Jian-ping, SUN Tao, ZHAO An-shi
    2017, 38 (2):  234-239.  DOI: 10.12068/j.issn.1005-3026.2017.02.017
    Abstract ( 562 )   HTML   PDF (1158KB) ( 864 )  
    A set of thermoforming equipment was developed by State Key Laboratory of Rolling and Automation, based on thermoforming with high inner atmospheric pressure theory, to study thermoforming process of ultra-strength steel pipes. The resistive heating was used to accurately control the temperature of the pipes. The high-pressure sealing structure of pipe ends, rapid inflation system and hydraulic servo system were designed. The heated pipes were shaped under the action of both high inner atmospheric pressure and axial feed. By means of the mold inner loop cooling circuit designed, the pipes touched the cold mold and were quenched directly. Therefore, pipe heating, forming and quenching were finished in single-position. The experiment results show that maximum gas pressure reaches 40MPa with the sealing effect reliable. Temperature control accuracy is ±1℃ and the inflation velocity can be adjusted continuously. The equipment provides reliable support for the research of ultra-strength steel pipe thermoforming process with inner high atmospheric pressure.
    References | Related Articles | Metrics
    Building and Application of Synchronized Data in Tandem Cold Rolling Process
    CHEN Shu-zong, ZHANG Xin, SUN Jie, ZHANG Dian-hua
    2017, 38 (2):  239-243.  DOI: 10.12068/j.issn.1005-3026.2017.02.018
    Abstract ( 569 )   HTML   PDF (1578KB) ( 816 )  
    In view of the shortcomings of existing data collection and analysis system in the production process of tandem cold mill, a synchronization method of strip segment data for tandem cold mill was proposed based on the mill equipment and instrument configuration of a 1450mm five-stand tandem cold mill, which consists of two parts: photo data building and synchronized data building. With this method, the various measurement parameters of rolling process can be synchronized to the rolled length at the last stand, and the rolling parameters of any coil length can be monitored through synchronized segment data. The method of synchronizing the strip segment data has been applied successfully in a five-stand tandem cold mill, and the control system runs steadily after putting into operation. The method of synchronizing segment data offers a convenient way for the technicians, who can diagnose production fault and analyze products quality rapidly.
    References | Related Articles | Metrics
    Mechanical Engineering
    Simulation and Experiment of Micro-surface in Pre-stressed Hardening Grinding Process
    DENG Yan-sheng, SONG Jian-wei, XIU Shi-chao, WANG Yu-shi
    2017, 38 (2):  244-248.  DOI: 10.12068/j.issn.1005-3026.2017.02.019
    Abstract ( 733 )   HTML   PDF (1784KB) ( 1026 )  
    To reveal the effect of pre-stressing on grinding hardening process and micro-surface, single grain cutting simulations on test specimens made of 45 steel under action of different pre-stresses were carried out by using DEFORM-3D based on the thermal-elastic-plastic finite element theory. The equivalent strain, groove depth, surface layer microstructure as well as the micro-surface were analyzed by simulation and experiment of pre-stressed hardening grinding process. The results indicate that pre-stressing has little effect on thermal-mechanical equivalent strain, but has obvious effect on microstructure transformation which has indirect effect on surface roughness by affecting the dislocation density and grain size. As the pre-stress increases within a low range, the groove depth decreases and the surface roughness value reduces. However, once the pre-stress exceeds a certain value, surface fold appears and surface roughness value increases instead.
    References | Related Articles | Metrics
    Simulation and Experimental Research on Grinding Temperature of Micro-grinding Quartz Glass
    WEN Xue-long, GONG Ya-dong, BA De-chun
    2017, 38 (2):  249-253.  DOI: 10.12068/j.issn.1005-3026.2017.02.020
    Abstract ( 635 )   HTML   PDF (838KB) ( 846 )  
    To investigate the effect of different grinding conditions on micro-grinding temperature, the heat transfer model in micro-grinding process was established and the finite element simulation analysis was conducted to study the temperature distribution in micro-grinding quartz glass. The single factor experiments with quartz glass were conducted by micro-grinding tools with size 500#. The influence of different grinding factors on micro-grinding temperature was analyzed. The simulation and experimental results show that the highest surface temperature of the grinding zone increases with the increase of cutting depth and grinding speed, and the measured highest temperature in the grinding zone is 94.2℃ without grinding burning.
    References | Related Articles | Metrics
    Finite Element Simulation of Surface Residual Stress in Micro-milling Inconel 718
    LU Xiao-hong, WANG Fu-rui, LU Yan-jun, GAO Lu-si
    2017, 38 (2):  254-259.  DOI: 10.12068/j.issn.1005-3026.2017.02.021
    Abstract ( 727 )   HTML   PDF (1261KB) ( 1282 )  
    Rounded cutting edge radius and feed per tooth have significant influence on the residual stress in micro-milling nickel-based superalloy Inconel 718. A 3D finite element model of micro-milling Inconel 718 based on ABAQUS was built. The Johnson-Cook model was adopted to simulate the plastic behavior of workpiece material. Residual stress of the same element in the direction of S11 and S22 was obtained to study the effects of feed per tooth on surface residual stress. Micro-milling experiments of Inconel 718 by changing feed per tooth were conducted, and residual stress was measured by X-ray diffraction in both the feed direction and the vertical direction of feed. In the direction of feed, the maximum relative error between the experimental and simulation results is 21.1% and the average relative error is 8.9%. While in the vertical direction of feed, the maximum relative error between the experimental and simulation results is 31.0% and the average relative error is 12.3%. The results show the validity of the as-built 3D FEM model.
    References | Related Articles | Metrics
    Numerical Simulation of Two-Stage Slurry Pump Based on Structural Mesh
    YANG Fang-qiong, ZHOU Zhuo, XU Hai-liang ,WU Bo
    2017, 38 (2):  260-264.  DOI: 10.12068/j.issn.1005-3026.2017.02.022
    Abstract ( 672 )   HTML   PDF (1081KB) ( 1127 )  
    In order to investigate the solid-liquid fluid flowing law and work performance of two-stage slurry pump for deep-sea mining,numerical simulation and performance prediction to the two-stage slurry pump were conducted by using the computational fluid dynamics software. The methods of topological blocking and structural meshing in the domain of the slurry pump were described. A three-dimensional turbulent flow simulation was performed with a RNG κ-ε turbulence model and multiple reference frame to obtain pressure, velocity and kinetic energy distribution. Furthermore, the performance curve of the slurry pump with different particle properties was determined based on the simulation results. The research shows that the particle properties have an important influence on the working performance of slurry pump. With the same particle concentration, the head and efficiency of the pump are increased with the decrease of particle size. It is appropriate to control the particle concentration of 5%-10%.
    References | Related Articles | Metrics
    Resources & Civil Engineering
    Blocks Searching and Program Development Based on Overlapping Technology
    WANG Shu-hong, WANG Fei-li, ZHANG Zi-shan
    2017, 38 (2):  265-270.  DOI: 10.12068/j.issn.1005-3026.2017.02.023
    Abstract ( 559 )   HTML   PDF (2154KB) ( 803 )  
    Based on the principle of constructing independent blocks by overlapping, the paper discusses the problem of blocks searching. And the overlapping principle and method of the surfaces with the same and opposite directions are studied. At the same time, the cutting and searching process of blocks is given, which includes the meshing of three-dimensional structural surface, the analysis of intersection about structural plane and boundary, and the searching of key blocks. Based on the principle of overlapping technology, a new searching technique is proposed for identifying the key blocks. With the searching technique introduced into the 3D digital analysis system—the three-dimensional geotechnical structural modeling and analysis system (GeoSMA-3D) developed by ourselves, the searching technique is available to identify the key blocks. Meanwhile, an engineering application is performed to validate the effectiveness of overlapping technology and the superiority of GeoSMA-3D software.
    References | Related Articles | Metrics
    Defining Stress Thresholds of Rock Failure Process Based on Acoustic Emission Activity Parameters
    ZHAO Xing-dong, XU Ji-tao, JI Xiang, LIU Jian-po
    2017, 38 (2):  270-274.  DOI: 10.12068/j.issn.1005-3026.2017.02.024
    Abstract ( 727 )   HTML   PDF (887KB) ( 1034 )  
    The uniaxial compression experiments were carried out on 25 granite samples by application of acoustic emission testing system in the laboratory. Through continuous real-time monitoring these characteristics of the acoustic emission sources such as event rate, cumulative energy, energy rate, time duration and amplitude in the failure process of granite rock samples, the stress thresholds at each loading stage were obtained in the whole failure process. Furthermore, by comparing the stress threshold at each stage with peak strength during the process of rock fracturing and with previous experimental results, we find that rock deformation characteristics are consistent with the evolution of the crack in rock.
    References | Related Articles | Metrics
    Research on Transient Unloading-Induced Plastic Zone in Surrounding Rock Based on Modified Mohr-Coulomb Criterion
    ZHOU Jing-ren, WEI Jiong, WANG Qing-yuan, LI Ru-fei
    2017, 38 (2):  275-279.  DOI: 10.12068/j.issn.1005-3026.2017.02.025
    Abstract ( 751 )   HTML   PDF (723KB) ( 933 )  
    Taking the unloading as a dynamic process, the plastic zone generated from different excavation sections and in-situ stress conditions due to transient unloading was analyzed using modified Mohr-Coulomb criterion including tension cut-off and elliptic cap models in surrounding rock. The numerical results indicate that transient unloading will cause plastic deformation in the vicinity of excavation perimeter. The plastic deformation increases with the increase of depth and in-situ stress. Tensile stress is a key factor in accounting for the surrounding rock plastic deformation during transient unloading. The plastic deformation direction coincides with the maximum compressive principal stress. But it can induce serious compressive deformation in the minimum principal stress if the in-situ stress satisfies certain condition. The bigger the section curvature is, the smaller the plastic deformation becomes, so it is better to avoid linear boundary.
    References | Related Articles | Metrics
    Strength Determination of Crude Tailings Backfill in Deep Mine Based on Non-linear Constitutive Model
    KE Yu-xian, WANG Xin-min, ZHANG Qin-li, LIU En-yan
    2017, 38 (2):  280-283.  DOI: 10.12068/j.issn.1005-3026.2017.02.026
    Abstract ( 596 )   HTML   PDF (442KB) ( 832 )  
    Backfill strength in deep mining is commonly determined by analogy with shallow mining experience at present. In order to change this unreasonable situation, non-linear constitutive models of crude tailing backfills (CTBs) before peak strength were constructed based on uniaxial compression experimental results of CTBs in a deep mine, and the equation of necessary compressive strength was consequently derived based on the principle that there is approximate energy loss within a backfill and surrounding rock compound system. It is proved by a case study that the non-linear constitutive model of CTB before peak strength is identical to the experimental result and that the CTB strength in deep mining is related not only to the mechanical performance of the CTB itself, but also to the in-situ stress and elastic modulus of surrounding rock. The case study also suggests that the calculated necessary backfill strength by the non-linear constitutive model is more accurate than that by the linear constitutive model.
    References | Related Articles | Metrics
    Application of Set Pair Analysis Method Based on Entropy Weight to the Stability Evaluation of Salt Rock Gas Storage
    JIANG De-yi, PENG Hui-hua, ZHAO Li-jun, LIU Chun
    2017, 38 (2):  284-289.  DOI: 10.12068/j.issn.1005-3026.2017.02.027
    Abstract ( 631 )   HTML   PDF (472KB) ( 727 )  
    To establish a stability evaluation system, the mechanical parameters of salt rocks, cavity parameters of gas caverns, and operation parameters of gas caverns were considered. Combining each evaluation index’s weight with its connection degree based on the entropy and set pair analysis, respectively, the stability levels of gas caverns were determined. The results were consistent with those of the grey correlation analysis, proving that the set pair analysis method applied in the stability evaluation of gas storage is scientific and feasible. The evaluation by the set pair analysis method, which reflects the stability situation more objectively, can not only avoid the outcome disparity due to the uncertainty of distinguishing coefficients, but also obtain the stability level of gas storage, which provides more detailed information for project practices.
    References | Related Articles | Metrics
    Identification of Bridges Damage by Dynamic Fingerprints and Bayes Data Fusion
    SUN Shuang, LIANG Li, LI Ming, LI Xin
    2017, 38 (2):  290-294.  DOI: 10.12068/j.issn.1005-3026.2017.02.028
    Abstract ( 671 )   HTML   PDF (502KB) ( 852 )  
    Using a single index to evaluate bridge safety is likely to draw a false conclusion due to the effect of measurement noise. Thus, an identification method of bridge damage based on the Bayes theory was proposed, which includes location identification and degree identification. First, the Bayes formula was used to fuse the normalized dynamic fingerprints and identify the damage locations. Then, only the fingerprints of damaged locations were extracted to construct the Bayesian network and the conditional probability of every node was calculated in order to identify the damage degrees. By simulating a simple beam, the result shows that the proposed method has a good anti-noise performance, especially can accurately locate tiny damages and distinguish the damages with slight differences.
    References | Related Articles | Metrics
    Management Science
    Kansei Quality Evaluation of Bottled Water Appearance Based on Customer Preferences
    JIN Hai-zhe, CHEN Han, ZHOU Yu-lin, LIU Wei-lin
    2017, 38 (2):  295-299.  DOI: 10.12068/j.issn.1005-3026.2017.02.029
    Abstract ( 594 )   HTML   PDF (443KB) ( 930 )  
    Thirteen word pairs for kansei quality evaluation were extracted to evaluate customer preferences for bottled water comprehensively and pertinently. The comprehensive emotional element, ‘want to buy’, served as the kansei quality evaluation element of bottled water.Seven representative samples were determined by the evaluation elements combined with the cluster analysis, and etc. The evaluation scale of the kansei quality of bottled water was suggested on the basis of the semantic differential methods, and the relational model of customer preferences and kansei evaluation word pairs was established by using the multiple regression model analysis. The relational model has effectively solved the problem, i.e., how to identify customer preferences and kansei quality requirements, and how to integrate these preferences and requirements into the process of product design.
    References | Related Articles | Metrics
    Influencing Factors of Carbon Emissions in Hebei Province Based on the STIRPAT and Decoupling Models
    YANG Mo, CHEN Kai
    2017, 38 (2):  300-304.  DOI: 10.12068/j.issn.1005-3026.2017.02.030
    Abstract ( 773 )   HTML   PDF (373KB) ( 840 )  
    The decoupling state of Hebei Province from 2007 to 2014 was analyzed by using the decoupling model, and the results showed that the decoupling state has changed from the growing coupling to the weak decoupling, which finally realizes the strong decoupling in volatility. The influencing factors of carbon emission in Hebei Province were analyzed by using the STIRPAT model, and the carbon emission of 2015-2022 in Hebei Province was predicted by using the grey model GM (1, 1). The results showed: industrial structure has the biggest influence on carbon emission; coal consumption, per capita GDP, urban population proportion and overall population have promoting effect on carbon emission, while energy price and expenditure on R&D have a small influence coefficient on carbon emission; and energy structure and energy intensity have a certain inhibitory effect on carbon emission. The prediction results from the GM (1, 1) model showed that Hebei Province should pay greater attention to the development trend of carbon emission, face the pressure of low carbon development, and achieve low carbon economy in Hebei Province by adjusting all the influencing factors.
    References | Related Articles | Metrics