西南交通大学学报

Potential Damage Analysis of Near-Fault Ground Motion Based on Response Spectra

LI Ming, 2, XIE Lili, 3, YANG Yongqiang, HU Jinjun

2010, 23(3): 331-335. doi: 10. 3969/ j. issn. 0258-2724.

[Abstract](909)

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Abstract:
To provide a basis for seismic code revision, differences of the potential damage caused by near-fault and far-field ground motions were analyzed in terms of elastic and inelastic acceleration, velocity, and displacement response spectra, dynamic factor spectra, and inelastic to elastic acceleration ratio response spectra. And, a comparison was made between the calculated response spectra and the design spectra in Chinese Seismic Code. The results show that near-fault ground motion with two pulses has the highest response spectral value, which is almost seven times higher than those of ground motions of other types, and hence can cause the highest potential damage. The high response spectral value is mainly attributed to the peak value of near-fault ground motion in site A+B; and is not only attributed to the peak value, but also to the increase of dynamic factor during the medium-long period in site C +D. The characteristic period of Chinese Seismic Code tends to be unsafe when considering the effect of near-fault ground motion with two pulses.

Influence of Intersection Angle between Railway Route and Fault Strike on Roadbed of Qinghai-Tibet Railway

YUAN Bingxiang, 2, CHEN Wenwu, LIANG Shouyun, HAN Wenfeng, 3, LI Jincheng

2010, 23(3): 336-340. doi: 10. 3969/ j. issn. 0258-2724.

[Abstract](993)

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To investigate the influence of intersection angle between railway route and fault strike on roadbed of the Qinghai-Tibet railway, a statistic for 154 faults intersecting with the Qinghai-Tibet railway was carried out. With the inverse distance weighted interpolation method (IDW) and software ANSYS, the intersection of roadbed and active faults was simulated numerically. From the IDW simulation result, the influencing coefficient is mainly above 0. 5 when the intersection angle is between 0'and 40'; while the influencing coefficient distributs evenly and its average is small when the intersection angle is from 50'to 90'. From the ANSYS simulation result, the intersection angle has a great influence on the relative displacement of roadbed when it is between 0'and 40'; while the intersection angle has a small influence on the relative displacement when it is between 50'and 90'. The research results show that in the sections with many faults, the intersection angle should be over 40'to reduce the influence of faults on the roadbed of a railway

Approximate Analytical Solution of Aseismic Analysis of Shield Tunnel and Its Application

YAN Qixiang, MA Tingting, HE Chuan, GENG Ping

2010, 23(3): 341-345. doi: 10. 3969/ j. issn. 0258-2724.

[Abstract](1085)

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To simplify the aseismic analysis of deeply-buried underground structures, an approximate analytical method considering the common action of P and S waves on shield tunnels was presented based on the Fotieva method for successive medium strata, and a comparison was carried out between the calculational results of bending moment and axial force, obtained respectively by the approximate analytical method and FEM (finite element method) based on the Fotieva method, acting on a deeply- buried underground structure. The comparison result shows that the approximate analytical solutions for bending moment and axial force on deeply-buried underground structures are basically the same as those based on the Fotieva method, indicating that the proposed approximate analytical method can simplify the complexity and workload of aseismic analysis of shield tunnels.

Rigidity Characteristics of Multi-span Suspension Bridges under Train Loads

KANG Rui, ZHENG Kaifeng, LI Huaiguang, CHEN Libo

2010, 23(3): 346-350. doi: 10. 3969/ j. issn. 0258-2724.

[Abstract](1144)

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To probe into the feasibility of super-long multi-span suspension bridges, the rotational deformation of super-long multi-span suspension bridges under train loads was researched. The classical gravity stiffness method was employed to derive the influence line of rotational deformation. The stiffening girder was divided into three units in the light of the position of train: front-train unit, under-train unit and rear-train unit. The maximum clockwise and anticlockwise rotational angles were analyzed. Parametric studies were carried out for different sag-to-span ratios, span lengths and span numbers, and their influences on the rotational deformation were evaluated. The research result shows that the rotational deformations of the front-train unit and the rear-train unit increase as sag-to-span ratio raises and span length decreases, and the rotational deformation of the front-train unit decreases with the increase of span number, while the rotational deformation of the rear-train unit raises as span number increases.

Spatial Mechanical Behavior of Thin-Walled Members with Parallelogrammic Closed Cross Section

LI Cuijuan, WEI Xing, QIANG Shizhong

2010, 23(3): 351-356. doi: 10. 3969/ j. issn. 0258-2724.

[Abstract](1052)

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In order to investigate the static behavior of thin-walled members with a parallelogrammic closed cross section under a moment or an axial compression, a thin-walled member with a parallelogrammic closed cross section was tested. The theory of oblique bending was applied and a FEM model was presented to study the spatial behavior of the tested member. The results show that the distribution of stresses is uniform in the whole cross section under an axial compression, and the effect of web inclination on the stress distribution is slight. Under a moment, the distribution of stresses in the top and bottom plates of the cross section is uneven because of oblique bending and is influenced significantly by the web inclination.

Experimental Investigation of Dynamic Earth Pressure on Gravity Retaining Structures

LIU Changqing, LI Shiyuan, LIU Shaofei

2010, 23(3): 357-360. doi: 10. 3969/ j. issn. 0258-2724.

[Abstract](1122)

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In order to explore the distribution and magnitude of dynamic earth pressure on retaining structures, a full scale model test was carried out. Through the testing of gravity road shoulder wall, gravity road embankment wall and balance weight retaining wall, the dynamic earth pressure under different load amplitudes and loading distances were acquired. By combining with calculational results based on the present methods, a comparative analysis was carried out. The research results indicate that the dynamic earth pressure is approximately linear functions of the load amplitude and the loading distance. In addition, the calculated values of the dynamic earth pressure based on the Coulomb theory are much larger than the experimental ones.

Design Method of Rail Asymmetric Silhouette

LIU Changqing, LI Shiyuan, LIU Shaofei

2010, 23(3): 361-365. doi: 10. 3969/ j. issn. 0258-2724.

[Abstract](1165)

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In order to determine the asymmetric silhouette of rail scientifically to guide the asymmetric grinding of rail, a method of designing the asymmetric silhouette and evaluating the asymmetric grinding was proposed based on the classical wheel/ rail contact geometry. The judgment bases of this method are equivalent taper, contact stress level, grinding quantity, and so on. A case study shows that this comprehensive evaluation method considers the effects of different grinding schemes on curve performance, rolling contact fatigue and grinding cost to provide a theoretical basis for objective silhouette selection and design.

Classification Research on Object-Oriented High-Resolution Remote Sensing Images in Chengdu Plain

LIN Xiancheng, 2, LI Yongshu

2010, 23(3): 366-372. doi: 10. 3969/ j. issn. 0258-2724.

[Abstract](944)

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In order to quickly and accurately extract the information of land use and its changes in the Chengdu Plain, high-resolution remote sensing images were selected as a data source, and using the object-oriented image analysis method, the classification method of these high-resolution remote sensing images of the Chengdu Plain was discussed. Especially, a more in-depth experiment of the best segmentation scale was conducted, and a fast, accurate access to the information of land use and its changes in the Chengdu Plain was proposed. The results show that the object-oriented image analysis technology can rapidly extract the information of land use and its changes very well, and the key is the choice of image segmentation scale and the extraction of various characteristic information about the image objects.

Selection of Data Smoothing Methods in Wheel Wear Analysis

GUO Jun, LI Xia, DU Xing, JIN Xuesong

2010, 23(3): 373-377. doi: 10. 3969/ j. issn. 0258-2724.

[Abstract](1047)

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In order to efficiently remove the noise points from the calculation data of wheel wear, a comparative investigation on three existing data smoothing methods, namely, five-spot triple smoothing, cubic spline smoothing, and Supersmoother, was conducted by using these data smoothing methods to deal with the wear data obtained from a wheel wear predication model. The numerical results show that Supersmoother, which performs well in reducing noise error from the calculated wheel wear data and can preserve the detail information of the wear data better, is more suitable for smoothing the wheel wear data than the other two smoothing methods. Considering the stochastic fluctuation of wheel wear data, combination of the cubic spline smoothing and Supersmoother was used to smooth the noises in wear data, which proves able to ensure the smoothness of curves and prevent data distortion.

Fuzzy Self-Tuning of PID Parameters for Automobile Sensotronic Braking Control

SUN Ren-Yun, LI Zhi

2010, 23(3): 378-383. doi: 10. 3969/ j. issn. 0258-2724.

[Abstract](1555)

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In order to improve the performance of an automobile sensotronic braking control (SBC) system, the PID parameter fuzzy self-tuning method for the automobile SBC was studied. Using the least-square curve-fitting method in the approximate first-order lag plus delay model and the empirical formula for the optimum PID controller, the initial values of the three PID parameters were determined for the PID controller according to the SBC effect on single pavement, based on which a fuzzy PID regulator was then designed. Then, simulations for the SBC system with the self tuning PID fuzzy controller were made using Matlab/ Simulink software on single and variable pavement. The results show that the error between the estimated and expected adhesion coefficients in the longitudinal direction is small. When the initial braking speed was 160 km/ s, the error was -0. 71 to 0. 14, braking distance 114. 5 m, and braking time 5. 28 s on single pavement; while the error was -0. 71 to 0. 15, braking distance 128. 61 m, and braking time 7. 625 s on variable pavement.

Static and Dynamic Models for Reliability Calculation of Stress-Strength Interference

TANG Jia-Yin, ZHAO Yong-Xiang, SONG Dong-Li

2010, 23(3): 384-388. doi: 10. 3969/ j. issn. 0258-2724.

[Abstract](1194)

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To solve the problem of stress-strength correlation interference in the reliability calculation for mechanical parts, a static and a dynamic stress-strength correlation interference models were derived based on the Copula theory and the negative correlation structure between stress and strength. An algorithm for calculation of distributions of integrated stress and integrated strength and that for determination of correlation parameters were presented. The effect of the correlation parameter on Copula functions in the stress-strength correlation interference models was analyzed. The results reveal that the reliability of a mechanical part changes with a change in the correlation parameter, where the lower bound corresponds to the perfect negative correlation, and the upper one to the independent situation. An example showed that the reliability calculated with the traditional independent model was 2. 18% larger than that with the static stress-strength correlation interference model.

Fabrication and Corrosion Resistance of Ni-P Duplex Layer Coating

FANG Ximei, ZHANG Huiguang, HAO Jun, KUANG Liuwei, WANG Jie

2010, 23(3): 389-392. doi: 10. 3969/ j. issn. 0258-2724.

[Abstract](784)

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Three different coatings were prepared with different complexing agents and electroless plating procedures. The composition, microstructure and morphology of the coatings were characterized by X-ray diffractometer (XRD), X-ray energy dispersive spectrometer (EDS)and scanning electron microscope (SEM). The corrosion resistances and corrosion potentials of the coatings were measured chemically and chemicoelectrically, respectively. The results demonstrated that the composition and electroless plating procedure significantly affected phosphorus concetration and microstructure of the coating, but no obviouse trends were observed. As the increase in phosphorus concentration in the coatings, their microstructures changed from crystalline to crystalline and amorphous states, and finally to amorphous state,causing the self-corrosion potential and current of the coating to increase and decrease, respectively. The best corrosion resistance appeared when the outer layer had a low potential (-550 mV) and the inner layer a high potential (-295 mV), and the thickness of the inner layer was twice as that of the outer one.

Application of Fuzzy Comprehensive Analysis to Information Security Evaluation

FU Mao-Ming

2010, 23(3): 389-392. doi: 10. 3969/ j. issn. 0258-2724.

[Abstract](875)

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In order to improve the accuracy and validity of information system security evaluation and reduce the effects of diversities of experts'subjectivity on evaluation results, a clustering method based on the fuzzy comprehensive analysis was proposed. With this method, scores given by experts are pre- processed and transformed to relative weight ratios based on the weights of evaluation indexes, and after the transformation, difference scores with a large discrete degree are removed. Examples show that this clustering method makes the concentration range of valuation interval and the convergence of assessed scores be respectively increased by 30% and 15% to enhance the effect of the important evaluation indexes on evaluation results.

Effect of Intermittent Operation on Thermal Performance of Heat Exchanger with U Shape Buried Pipe

YUAN Yanping, LEI Bo, CAO Xiaoling, YANG Conghui

2010, 23(3): 393-399. doi: 10. 3969/ j. issn. 0258-2724.

[Abstract](911)

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A heat transfer model for heat exchanger was derived to investigate the effects of intermittent operations on the thermal performance of a heat exchanger with U shape buried pipes. In the model, the calculation area was divided into two parts, one in the borehole and the other outside the borehole, with the borehole wall as the boundary, a steady heat transfer model and a numerical unsteady heat transfer model were applied respectively. Three intermittent operation modes were defined as those of office building, shopping mall and residential building. The calculation results indicated that after one month operation, the heat fluxes under the three modes increased by 45. 57%, 58. 43% and 88. 05%, respectively, compared with a continuous operation mode, and the largest restoration of heat flux and average temperature were under the residential building mode.

Time-Frequency Presentation Using Empirical Mode Decomposition Combined with Cohen Class to Suppress Crossterms

NING Jing, ZHU Zhaokun

2010, 23(3): 400-404. doi: 10. 3969/ j. issn. 0258-2724.

[Abstract](808)

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To suppress the crossterm interference in the Cohen class quadratic time-frequency distribution, a method based on empirical mode decomposition (EMD) and Cohen class distribution was proposed. In this method, the time-domain signal is first decomposed into a sum of multiple intrinsic mode functions (IMFs) in frequency domain using EMD. Then, the Cohen class distributions of the IMFs are calculated to obtain the sum of all the Cohen class distributions. The time-frequency distributions of three typical simulation signals were calculated by the proposed method, and compared with their Wigner-Ville distribution and Cohen class distribution using generalized exponential kernel. The results show that the proposed method can effectively suppress the crossterms in the quadratic time- frequency distributions, and can produce a more desired time-frequency distribution.

Parameter Optimization of Maglev PID Controller Based on Improved PSO Algorithm

LIU Dong, 2, FENG Quanyuan, JIANG Qilong, 3

2010, 23(3): 405-410. doi: 10. 3969/ j. issn. 0258-2724.

[Abstract](1241)

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To reduce the effect of nonlinearization on maglev gap control, the PSO (particle swarm optimization) algorithm was used to optimize the parameters of a maglev controller, and an improved algorithm was proposed based on the linear decreasing weight particle swarm optimization (LDW- PSO). In order to improve the optimization speed and convergence performance, neighborhood topologies, stagnation detection and global best perturbation were adopted to build the improved algorithm. The simulation and experiment results show that the output overshoot of an optimized PID (proportional-integral-derivative) controller based on the improved algorithm is 45% smaller than that of a traditional PID maglev controller.

Progressive LOD Terrain Rendering Algorithm Based on Nine Palaces

YIN Guisheng, CHEN Huaiyou, 2, ZHANG Jing, LI Jianjun

2010, 23(3): 411-417. doi: 10. 3969/ j. issn. 0258-2724.

[Abstract](1081)

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In order to decrease the times of dividing terrain and viewpoint center squared in terrain rendering and improve rendering efficiency, a fast nine palaces terrain rendering algorithm was put forward. In this algorithm, a multiresolution ground block structure is set up based on the characteristic of nine palaces, and level switching of resolution occurs in 8 surrounding squares in the nine palaces. As a result, the operations of dividing terrain and viewpoint center squared are combined to one, and the number of triangles to be processed and rendered declines at the rate of 17/81 to improve the process rate greatly. An algorithm of avoiding cranny was put forward in order to revise the cranny bought by the multiresolution model. The performance analysis and error estimation for the algorithm were carried out. The experimental results indicate that under the condition of holding the visual effect, the rendering efficiency of this algorithm is about 14. 7 times that of the quadtree algorithm when level number is 3.

Reactive Power Optimization Based on Oriented Search Algorithm

ZHANG Xuexia, CHEN Weirong

2010, 23(3): 418-423. doi: 10. 3969/ j. issn. 0258-2724.

[Abstract](1263)

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The oriented search algorithm (OSA) was used to optimize reactive power flow in a power system. In the OSA, the search-individual simulates human behavior, and the search-object (the optimal solution of the objective function) works like an intelligent agent that can transmit oriented information to search-individuals, so that search-individuals and the search-object can communicate with each other. The OSA was tested on IEEE 57-bus and IEEE 118-bus power systems in order to verify its efficiency, and the numerical results were compared with the ones obtained by the comprehensive learning particle swarm optimizer ( CLPSO) and the adaptive genetic algorithm (AGA). The research results show that compared with the CLPSO and the AGA, the OSA can find high-quality optimal solutions, and the active power losses for optimized IEEE 57-bus and IEEE 118- bus power systems are decreased by 13. 871% and 13. 223%, respectively.

Improvement of Multipath Routing Algorithm Based on OLSR and Source Routing

GAO Yu, ZENG Huashen, ZHANG Hong

2010, 23(3): 424-429. doi: 10. 3969/ j. issn. 0258-2724.

[Abstract](754)

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The OLSR (optimized link state routing) and source routing-based multipath algorithm (SR-MPOLSR) was simulated. The simulation results indicate that the SR-MPOLSR has disadvantages in finding a source routing path and can not improve the success rate of end-to-end packet transmission because of uncompleted topology information and multipath coupling problem. In order to get the complete structure of network topology, redundant diffusion, agent announcement and agent selection were extended on OLSR. A multipath selection algorithm with a coupling factor 0 was proposed to avoid interferences among multipath flows from a same source. The research results show that the end-to-end packet success rate of the improved algorithm is approximately 10% higher than that of the SR- MPOLSR in heavy network load conditions.

Polycrystalline Silicon Video Inspection System Based on Small Area Tracking

ZHOU Xiu-Yun, HUANG Jian-Guo, FENG Zhong-Zheng

2010, 23(3): 430-434. doi: 10. 3969/ j. issn. 0258-2724.

[Abstract](949)

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A polycrystalline silicon video inspecting system was designed for the real-time measuring the diameter of polycrystalline silicon stick. In this system, the machine vision method founded on the imaging information from two fixed cameras are adopted to track the edge of goal silicon stick and measure its diameter. The image partitioning method based on left-middle-right difference is used to pick up targets, and the mass centroid tracking algorithm based on small area tracking is utilized to track the targets. The system can measure real-time the diameter of polycrystalline silicon after it is calibrated. The experimental result shows that the system can find and track feeble edges, and its precision can meet the industry demand in the range of 8 to 150-mm-diameter.

Dynamic Power Management Based on Subtask and Executing Time

JIANG Lian-Xiang, YANG Gen-Qiang, LI Hua-Wang

2010, 23(3): 435-439. doi: 10. 3969/ j. issn. 0258-2724.

[Abstract](1026)

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In order to reduce the energy consumption of embedded systems, a subtask and executing time-based device scheduling policy (SEBDSP) was proposed by analyzing the drawbacks of EODSA (the energy-optimal device-scheduling algorithm) and IEODSA1 ( the improved EODSA1). The SEBDSP divides tasks into several sub-tasks and manages I/ O (input/ output) devices in light of the executing time of the subtasks and the break-even points of the devices to extend the application area of the EODSA and the IEODSA1. The experimental results show that the average power consumption is respectively 31. 94% and 4. 95% lower with the proposed policy than with the EODSA and the IEODSA1.

Recognition Technology of Dynamic Magnetic Interference Based on Differential Magnetic Compasses

HAO Zhen-Hai, YANG Xin-Yong, HUANG Ku-Guo

2010, 23(3): 445-450. doi: 10. 3969/ j. issn. 0258-2724.

[Abstract](878)

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In order to solve the magnetic compass interference problem caused by the low-frequency dynamic magnetic interference in urban traffic, an integrated heading system based on the differential magnetic compasses (DMC) and the rate gyroscope was designed. When the low-frequency dynamic magnetic interference is recognized by DMC, the integrated heading system converts to the rate gyroscope working mode. The error of magnetic field intensity, the relative heading difference of DMC and their change rates were analyzed and taken as system characteristic parameters. A two-step dynamic magnetic deviation recognition technology of DMC based on the judgment of threshold value and fuzzy c-means classification was investigated. An experiment shows that the heading error of the system is less than 6'and the dynamic interference recognition rate exceeds 70%.

Test on Effectiveness of Sound as Countermeasure Against Driving Fatigue Based on Physiological Signals

DIAO Xiao-Hua, FANG Rui-Xue, MAO Ke-Dun, RONG Jian

2010, 23(3): 457-463. doi: 10. 3969/ j. issn. 0258-2724.

[Abstract](962)

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In order to mitigate driving fatigue and reduce traffic accidents, a study on the variation law of electroencephalograph (EEG) and electrocardiograph (ECG) with driving time was made in a driving simulator. The correlation between the original data of EEG and ECG and each indicator for assessing driving fatigue was analyzed, and the overall index of driving fatigue was determined by principal component analysis. An orthogonal experiment was carried out in the driving simulator cab to validate the effectiveness of sound stimulus as a countermeasure against driving fatigue. The results show that drivers in fatigue have an alerting reaction to the single sound stimulus; stimulation interval and sound intensity have a significant influence on driving fatigue, but stimulation time and sound frequency have a weak influence on driving fatigue. The best effect in alleviating driving fatigue was achieved when the sound intensity was 70 dB, the sound frequency 5 800 HZ, the stimulation time 7 s, and the stimulation interval 30 s.

Multi-airport Ground Holding Problem Based on Airline Schedule Optimization: Models and Algorithm

XIE Bo-Jia, HU Meng-Hua, TIAN Yong

2010, 23(3): 464-469. doi: 10. 3969/ j. issn. 0258-2724.

[Abstract](1289)

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To solve the multi-airport ground holding problem, a multi-objective and multi-airport optimization model was built based on airline schedule. This model consists of objective functions of the minimum total delay time, the minimum total delay cost, the minimum total number of adjusted flights, and the minimum total number of delayed flights, subjected to the constraints of airspace capacity, aircrafts turnover, etc. Then, the multi-objective optimization solution set of the model was obtained using the non-dominated sorting genetic algorithm II(NSGA-II). Finally, the proposed method was applied to schedule optimization for three main hub airports in Beijing, Shanghai, and Guangzhou, China, in autumn 2008. Compared with the results by the first-come-first-service (FCFS) policy, the average delay cost and the number of adjusted flights, after optimized by the proposed method, was reduced by 24% and 62%, respectively.

Anti-glare Effect of Median Green Belt on High-Grade Highway

XIAO Dai-Quan, MA Rong-Guo, LI Tie-Qiang

2010, 23(3): 470-475. doi: 10. 3969/ j. issn. 0258-2724.

[Abstract](1081)

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In order to study the anti-glare effect of the median green belt on horizontal and vertical curve sections of highway, the methods for calculating the spacing and height of the plants along the median strip on straight sections were presented. The plant spacings for different plant canopy diameters and anti-glare angles, and the plant heights for different road cross-sections and traffic compositions were calculated. Then, an improved formula for calculating the plant spacing on horizontal curve sections was derived, and the corrected anti-glare angles were obtained. An improved method for calculating the plant height on concave vertical curve sections was proposed, by which the anti-glare plant height increments on the concave vertical curve sections were calculated. Meanwhile, some improvement measures were proposed to prevent the glare at the lower edge of the median plants on convex vertical curve sections. The results show that compared to that on straight road sections, plant spacing should be reduced by 0. 3 to 3. 8 m on horizontal curve sections; and the plant height on concave curve sections should be increased by 0. 03 to 0. 43 m.

Optimization of Logistics Buffer Zone Layout in Manufacturing Industry

WANG Zhanzhong, ZHENG Jiabin, XU Hongguo, WU Zhengmei

2010, 23(3): 476-481. doi: 10. 3969/ j. issn. 0258-2724.

[Abstract](1545)

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To reduce the increasing handling cost and speed the slow materiel movement caused by poor layout of logistics buffer zones in manufacture industry, an optimization model for the layout of logistics buffer zones was presented with the minimum product of total transportation volume and distance as the objective, and the maximum adjacency among operation units as the restraints. The optimization solution to the model was obtained using an improved genetic algorithm. The results of an example were that the average efficiency of forklifts was about 82. 75%, and that of unloading bays was 84. 74%.

Pallet Recovery Model Based on Modified Pallet Pool System

LIN Jian-Wei, ZHANG Xue-Yan

2010, 23(3): 482-485. doi: 10. 3969/ j. issn. 0258-2724.

[Abstract](817)

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To improve the utilization rate of pallets, a modification was made to the traditional pallet pool system. In the modified pallet pool system, a consignee could use received pallets to dispatch cargos as a consigner, reducing at least twice times of transportation of empty pallets. Two pallet recovery models, an integer programming model and a stochastic programming model with uncertain pallet supplies, were presented. The objective of the models is the minimum pallet recovery cost, and their constraints include the cost and capacity of inventory and transportation, and demand and supply. The validity of the models was demonstrated by case study.

Local Neighborhood Search Algorithm for Generalized Dynamic Wagon-Flow Allocation of Railway Technical Stations

ZHAO Jun, PENG Qiyuan, WEN Chao, XU Jin

2010, 23(3): 486-492. doi: 10. 3969/ j. issn. 0258-2724.

[Abstract](1444)

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To realize computer-aided stage plan making for railway technical stations, the collaborative optimization problem of static wagon-flow allocation for train break-up and make-up sequence adjustment was studied. A local neighborhood search algorithm was designed, which meets the comprehensive requirements for train making-up, such as giving make-up priority to loaded wagon- flows for the nearest destination and the empty wagons, withdrawal of under-loaded trains, and the time and wagon-flow relationship between arrival and departure trains. In the algorithm, the main loop is to solve the static wagon-flow allocation problem, and the neighborhood is constructed by adjusting the make-up sequence of under-loaded trains and the break-up sequence of the arrival trains related to them. In each search loop, the algorithm only searches the earliest under-loaded departure train, its local neighborhood is so constructed that no new under-loaded train is produced, and that a train is withdrew if it is still under-loaded after the neighborhood search. A computational example demonstrated that the proposed algorithm could find a better solution in terms of the numbers of make- up trains and wagons, and average detention time of wagons in transit than the existing algorithms.

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2010 Vol. 23, No. 3