2016 volumne 37卷 Issue 01
Mao Xiaobo, Hao Xiangdong, Liang Jing
Abstract: In view of the problem of object deviation when occlusions occur during the target tracking, a new algorithm using Mean Shift with ELM is proposed. According to the formal information of the object’ s loca-tion, current possible location was predicted by ELM, the iteration was started from the possible location in-stead of formal location, and the object’ s real center is calculated by mean shift algorithm. The simulation re-sults show that proposed algorithm can track precisely target occluded, operation time and number of iteration are reduced so that efficiency and robustness are improved.
Liao Xiaohui1,Zhou Bing1,Yang Dongqiang1,Wu Jie2
Abstract: Short-term electricity price forecasting guarantees the maximum benefit of the parties involved in the power market. In view of the fact that the market clearing price has strong randomness and volatility, the paper proposes a combination forecasting model based on Hilbert-Huang transform. The price sequence is decom-posed into a number of intrinsic mode function components and the remainder by using the empirical mode de-composition theory. Different models were built for each intrinsic mode function according to the size of each component’ s average instantaneous frequency. Then the prediction results of each component are added up to obtain the final prediction value. And the model uses the actual data of PJM power market in the United States to test. Compared to the prediction results of any one sole model, this method accuracy were higher than single forecasting model, the maximum absolute error is 1. 53 S|/MWh and the mean absolute percentage error is 1. 61.
Xu Min1;Shen Jinglei1;Yan Zhenshan2
Abstract:
In this paper, Entropy Weights Method and TOPSIS method are used to study and analyze the eval-uation of multi-section coordination level of the generation side, the transmission side, the distribution side in power system planning. We establish the corresponding evaluation model and evaluate the coordination level of planning examples to verify the feasibility and reliability of the evaluation model. We can learn from the analy-sis of the evaluation result that the plan need improve the grid structures, new energy investments and reasona-ble utilization, as well as topological structure. Then coordination will be improved to some extent.

Han Jianpeng, Lu Gaifeng, Cao Wensi
Abstract: The transient disturbance signals of power system have characteristics of nonlinear, irregular and mutation. Thus the local mean decomposition ( LMD) algorithm is used for detecting disturbance signals to get higher measurement accuracy. And the typical power quality transient disturbance signals including voltage swell signal, voltage sag signal, voltage interruption signal, transient oscillation signal, transient pulses sig-nal, frequency fluctuation signal, harmonics and voltage swell signals as well as actual disturbance signals oc-curred in smart substation are analyzed with the LMD algorithm. The simulation results show that LMD algo-rithm is rather effective in measuring transient disturbance signals of power system and has higher precision and faster computing speed than Hilbert-Huang transform ( HHT) algorithm.
Hu Qiguo, Xie Guobin, Luo Tianhong, Tuokui
Abstract: In view of the problem of the gear transmission optimization design, based on the integration of fuzz-y mathematics and reliability optimization design theory, a mathematic model of reliability optimization design of the mud-pump gear transmission mechanism was built with its stress and intensity obeyed certain probability distributions, when the film thickness ratio and critical speeds ratio ware put into constraint. The global opti-mization result was found by using GA toolbox in Matlab. The optimal results show that the comprehensive per-formance of the gear transmission is improved efficiently, and the correctness and applicability of that optimiza-tion method is proved, hence it provides a new reference for the gear transmission optimization design.
He Yilin, Xu Shiwei, Liu Rui, Xie Xuefei
Abstract: The key to the improvement of the performance of electric racing vehicle is to promote its dynamic performance, while the main factor of restraining dynamic performance is energy resource. In view of this, the research method and experiment scheme of synergic power for electric racing vehicle is put forward. The com-ponents of synergic power are obtained and the synergic power mathematical model is established. The control strategy is worked out according to different working models in different conditions. Finally, the performance of synergic is testified with experiment. The research is of great significance to improve the dynamic performance of electric racing vehicle. At the same time, it can also prolong the life span of battery.
Zeng Falin,Xu Kai
Abstract: Identification method of least squares complex exponential LSCE ( least squares complex method) is applied to both the weak and strong damping damping to identify the intensive modal. For a car dual exhaust pipes, exhaust pipe experimental modal has been to be analyzed by using LSCE method and the conclusion is drawn that modal distribution of the exhaust pipe is more intensive. The tests showed LSCE method has strong adaptability for modal parameter identification.
Wang Hainian1,Zhang Ran2,Zhou Jun2,Liu Yu2,You Zhanping3
Abstract: The base material of geocell reinforced gravel has strong ability to adapt to the deformation of the subgrade, but its bearing capacity and deformation mechanism not clear. The discrete-continuous coupling cal-culation was used to calculate the mechanical properties of different geocell reinforced gravel composite struc-ture and the composite structure in which the geocell was not set up in the process of loading. The geocells in-clude 9 kinds whose height is 100mm, 150mm and 200mm,whose welding torch is 400 mm, 600 mm and 800 mm. Then the elasticity modulus of the bearing layer is analyzed. The results indicated that the bearing capac-ity of the subgrade got an obvious improvement after gravel was enforced by the geocell. Elasticity modulus of structure layer increased by 38. 61%. When the height of the geocell is fixed, with the decreasing of the geo-cell welding torch, the loading capacity of geocell structural layer is increasing. When the geocell welding torch is fixed, with the increasing of the geocell height, the loading capacity of geocell structural layer is accordingly increasing. The geocell model of 400 -200 mm, which big vertical displacement accounted for 17. 36% of whole bearing layer area, evenly distributed, and the best reinforced.
Hu Xuefang
Abstract: The finite element model which takes a SUV as the object is established based on finite element a-nalysis,and this paper simulates the center and angle collision process of the rear bumper. It evaluates the per-formance of the rear bumper collision by analyzing the energy absorption characteristics. According to the laws and regulations, this paper simulates the 100% and 40% overlap of the rear part low-speed collision and ana-lyzes the collision deformation of every part, stress distribution and energy change, In the end,it verifies the rationality of the design. The results provide a basis for the further optimization of the structure and offer a new idea for the vehicle collision,and they are of great reference value for further study of the rear bumper, the ve-hicle collision simulation and real vehicle crash test.
Song Danqing1,Wang Feng2,plum star3,Liu Pengfei4
Abstract: The landslide stability is affected by the reservoir impoundment in a large degree, taking an exam-ple of Yanziping(28#)Landslide of Jiudianxia reservoir in Gansu province. The landslide displacement was monitored by using GPS regularly for analyzing the law of the landslide stability affected by the the impound-ment, and the law is validated by using the method of slope entropy. The results show that:(1) the process of impoundment can be divided into three stages including the 0~1/2 , 1/2 to 3/4 and 3/4 above the stage of the storage level,which is affected to different influence degrees;(2) the landslide stability is affected at dif-ferent levels between the range of water levelⅠ(100 m~115 m) andⅡ(115 m~130 m) in different degree;(3) it is suitable that the relationship between impoundment and the stability of reservoir bank landslide is val-idated by using the method of slope entropy with being provided by other similar studies.
Wei Yanbing
Abstract: In order to seek more economic and environmental protection treatment methods. Three different vacuum preloading methods were adopted in this paper to study the treatment of building mud pool, and moni-toring data of settlement and pore water pressure were analyzed. After unloading, the field vane test and plate loading test were conducted to detect the bearing capacity of foundation. Moreover, the physical and mechani-cal parameters of soil were compared. The results show that the foundation bearing capacity of different sites has been improved significantly, and the combination of air pipe and chimney filter can get a better treatment effect.
[70-74]
Ma Qiang, Zhu Jian, Xing Wenwen, Hu Xing
Abstract: According to the characteristics of the load of the lateral embankment filling on the culvert, based on the limit equilibrium theory and the ultimate bearing capacity formula of Meyehof and Hanna, the formula for calculating ultimate bearing capacity of the culvert foundation with crust layer was deduced. A series of comparisons were carried out among the calculation results obtained from Hansen’s weighted average method, the stress diffusion angle method, the improved formula proposed in this paper and the finite element method. And the influences of the height of embankment filling, the thickness of crust layer, the ratio of cohesive and the internal friction angle of the crust layer to the subjacent soil layer on the ultimate bearing capacity were in-vestigated, in addition, a comparison of the results was made from engineering practical examples and the cal-culation results from the four theoretical calculation methods. The results show that with the increase of height of embankment filling and the thickness of crust layer, the results of the foundation bearing capacity calculated by the proposed improved formula method and finite element method are the closest. The influence of the variations of co-hesive ratio and internal friction angle ratio on the calculated results of the proposed formula method is more con-sistent with that of the finite element method. The results of the proposed formula method are more approximate to the engineering practical examples than Hansen’s weighted method and the stress diffusion angle method.
Zhang Yinxia, ​​Jiang Zhiqiang , Duan Liuyang, Wang Dong , Liu Zhihua
Abstract: In this paper, the dynamic simulation and analysis of TBM ( Tunnel Boring Machine) hob cutting rock process is simulated by using ANSYS/LS-DYNA. The load of TBM hob in the cutting process and the effect of cutting parameters such as disc rotation speed and cutting depth of hob effects on the hob cutting load are studied. The results show, when the epitaxial compressive strength of rock is 45 MPa, the average value of the lateral force, rolling force and normal force under the hob is about 0 kN, 0. 45 kN, 4. 5 kN, and the best penetration and rational cutting speed is 10 mm and 3. 6 r/min, which provides a reasonable basis for the de-signing staff parameters under the condition of the second hard rock.
Liu Zhuli1,Zhou Hao1,Hou Donghong2
Abstract: The basic structure and operating principle of the trailer-tractor are introduced. The loads on entry capstan are calculated. Then, the static analysis is obtained by large finite element analysis software ANSYS. Finally, in combination with with the actual working status, the improvement project is proposed. Compared with the former entry capstan, the maximum stress of new structure reduces 28. 9% and the maximum dis-placement reduces 23. 8%. The aim of optimization design is achieved.
Jin Zunlong,Guo Yueming,Li Zhao,Wang Dingbiao,Wang Yongqing
Abstract: Tensile test on PTFE composites filled with graphite was carried out to investigate the effect of the graphite content on the tensile strength of modified composite materials. The tensile performance curve and tensile strength were obtained. The results showed that the mechanical properties of modified PTFE composites were influenced significantly by the graphite content. When the volume fraction of graphite is 24%, the tensile strength of the modified PTFE composites decreased by 48%, which was only 12. 2 MPa. With the increase of the graphite content, the mechanical properties of the modified PTFE composites continued to decrease obvi-ously.
Chen Enqing, Xiao Suzhen
Abstract: Based on the characteristics of the system struture of MIMO-OFDM, a novel MIMO-OFDM channel estimation algorithm based on factor graph is proposed. The algorithm uses a small amount of pilot carrier, es-tablishes first-order AR channel model, and uses the message passing algorithm to estimate the MIMO-OFDM channel. Compared with other traditional algorithms, the MATLAB simulation shows that this algorithm can accurately estimate the MIMO-OFDM channel, with lower complexity than MMSE algorithm. Especially under the condition of low SNR,the estimation performance of MIMO-OFDM is better than other algorithms.
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