Analysis and improvement of authenticatable ring signcryption scheme

We show that the Zhang-Yang-Zhu-Zhang identity-based authenticatable ring signcryption scheme is not secure against chosen plaintext attacks.Furthermore, we propose an improved scheme that remedies the weakness of the Zhang-Yang-Zhu-Zhang scheme.The improved scheme has shorter ciphertext size than the Zhang-Yang-Zhu-Zhang scheme.We then prove that the improved scheme satisfies confidentiality, unforgeability, anonymity and authenticatability.     

Power network parameter estimation method based on data mining technology

The parameter values which actually change with the circumstances, weather and load level etc.produce great effect to the result of state estimation. A new parameter estimation method based on data mining technology was proposed. The clustering method was used to classify the historical data in supervisory control and data acquisition (SCADA) database as several types. The data processing technology was impliedto treat the isolated point, missing data and yawp data in samples for classified groups. The measurement data which belong to each classification were introduced to the linear regression equation in order to gain the regression coefficient and actual parameters by the least square method. A practical system demonstrates the high correctness, reliability and strong practicability of the proposed method.     

浅议新能源汽车驱动电机维护保养与故障维修

随着对环境保护的重视,国家大力扶持新能源汽车产业的建设和发展,相关政策不断推出,各大车企也纷纷投入到新能源汽车的生产和研发中来.驱动电机作为新能源汽车的三大核心部件之一,在新能源汽车销量不断攀升的情况下,其维护、保养以及维修的需求也在增加.本文从驱动电机的原理和构造出发,简要论述新能源汽车驱动电机维护保养的主要方法以及...     

摄影测量与激光扫描融合技术研究

基于提高激光扫描和摄影测量在三维建模和信息提取上优势互补效果的目的,采用了一种激光扫描技术在摄影建模基础上进行平差融合的方法,通过对建筑物进行摄影测量和地面摆站激光扫描相结合的数据处理试验,得出了通过两者技术融合在统一坐标系点云构建具备可行性的结论,并在试验结论中提出了进一步研究的意见.     

Virtual prototype simulation on underwater hydraulic impingement shovel

The virtual prototype technology is applied to the design of the hydraulic impingement shovel, which is to increase the reliability of the design. The work principle of hydraulic impingement shovel is expatiated, and its dynamic equations are established. The 3D model of virtual prototype is built by PRO/E. Then the couple between the mechanical body of prototype and the hydraulic system is completed by virtue of ADAMS. Finally, the simulation is made on the virtual prototype. The simulation results show that the design of underwater hydraulic impingement shovel is rational. The virtual prototype technology could lay sound foundation of successful manufacturing of physical prototype for the first time and offer highly effective and feasible means for the design and production of underwater equipments.     

Experimental study on the width of the turbulent area around bridge pier

At present, the method of calculating the turbulent flow width around the bridge pier is not given in the "Standard for Inland River Navigation" (GB50139-2004) in China, and the bridge designer usually increases the bridge span in order to ensure the navigation safety, which increases both of the structural design difficulty and the project investments. Therefore, it is extremely essential to give a research on the turbulent flow width around the bridge pier. Through the experiments of the fixed bed and the mobile bed, the factors influencing the turbulent flow width around the bridge pier have been analyzed, such as the approaching flow speed, the water depth, the angles between the bridge pier and the flow direction, the sizes of bridge pier, the shapes of the bridge pier, and the scouring around the bridge pier, etc. Through applying the dimension analytic method to the measured data, the formula of calculating the turbulent flow width around the bridge pier is then inferred.     

A second order volume of fluid （VOF） scheme for numerical simulation of 2-D breaking waves

Among all environmental forces acting on ocean structures and marine vessels, those resulting from wave impacts are likely to yield the highest loads. Being highly nonlinear, transient and complex, a theoretical analysis of their impact would be impossible without numerical simulations. In this paper, a pressure-split two-stage numerical algorithm is proposed based on Volume Of Fluid (VOF) methodology. The algorithm is characterized by introduction of two pressures at each half and full cycle time step, and thus it is a second-order accurate algorithm in time. A simplified second-order Godunov-type solver is used for the continuity equations. The method is applied to simulation of breaking waves in a 2-D water tank, and a qualitative comparison with experimental photo observations is made. Quite consistent results are observed between simulations and experiments. Commercially available software and Boundary Integral Method (BIM) have also been used to simulate the same problem. The results from present code and BIM are in good agreement with respect to breaking location and timing, while the results obtained from the commercial software which is only first-order accurate in time has clearly showed a temporal and spatial lag, verifying the need to use a higher order numerical scheme.     

Using a SVM to evaluate damage to vibration isolators in an elastic raft system

Predicting damage to vibration isolators in a raft experiencing heavy shock loadings from explosions is an important task when designing a raft system. It is also vital to be able to research the vulnerability of heavily shocked floating rafts unreliable, especially when the allowable values The conventional approach to prediction has been or ultimate values of vibration isolators of supposedly uniform standard in a raft actually have differing and uncertain values due to defective workmanship. A new model for predicting damage to vibration isolators in a shocked floating raft system is presented in this paper. It is based on a support vector machine（SVM）, which uses Artificial Intelligence to characterize complicated nonlinear mapping between the impacting environment and damage to the vibration isolators. The effectiveness of the new method for predicting damage was illustrated by numerical simulations, and shown to be effective when relevant parameters of the model were chosen reasonably. The effect determining parameters, including kernel function and penalty factors, has on prediction results is also discussed. It can be concluded that the SVM will probably become a valid tool to study damage or vulnerability in a shocked raft system.     

新能源汽车充电用户行为大数据分析及应用

随着新能源汽车行业快速发展,电动汽车充电功能及安全问题受到广泛关注。结合新能源汽车充电大数据可视化系统,从用户类型、车辆类型、充电方式、地域分布维度进行交叉分析,洞察用户充电行为统计分布规律;通过数据分析驱动充电安全设计,并结合数据资源和大数据分析技术,挖掘数据背后蕴藏的丰富价值,以改善当前新能源汽车充电问题和促进新能源汽车产业发展。