Abstract: Considering a temporary bottleneck made by special accidents, we proposed a new two-lane traffic model based on the KKW (Kerner–Klenov-Wolf) model. According to the difference of driver behavior and vehicle type, we present a new asymmetry lane-changing rules and the model of grabbing the entrance of a bottleneck. In our simulation, as demonstrated by various examples, the asymmetry lane-changing and the heterogeneous distribution of vehicles easily result in complex fluctuations of traffic flow and jam.
Abstract: Electronic Product Code (EPC) system and Radio-frequency Identification (RFID) play an important role in the Internet of things. We analyze the security threats which exist in the communication channel among RFID components, for this reason, an encryption mechanism which is added into it. And, hundreds of sensor nodes can form one Wireless Sensor Network (WSN) successfully, which, to a large extent, owes to the special node architecture. This paper proposes a secure EPC system model to ensure the security of the whole EPC system by implanting the components of RFID into WSN nodes.
Abstract: Direct methanol fuel cell (DMFC) is one of the ideal powers of low-power portable electrical devices, witch is cheap, safe, easy to store and rich source of fuel, and is more and more attentive and researched in recent years. In this paper, graphite electrode samples were coated by chemical plating Co and then by vacuum ion plating Pt. The microstructure of samples were observed by scanning electron microscope SEM and X-ray fluorescence spectrometry to analyze XRF then determined the surface composition of graphite electrode. The electrocatalysis properties of graphite electrodes were studied by electrochemical impedance spectra (EIS), cyclic voltammeter (CV) and linear sweep voltammeter (LSV). The results show that electrocatalysis properties of methanol on the electrode was stronger as the chemical plating time extended and methanol concentration increase if the parameters of the plating Pt in a vacuum ion plating process was unchanged, and Co Chemical Plating time was shouter than 120s.
Abstract: Analysis of turbulence characteristics in the confined space has important influence on strengthen grinding, and it is a main point and difficult point in the research of fluid theory. For the purpose of studying the technological parameters of strengthen grinding, and obtaining its characteristic signal group, calculation and spatial distributing simulation of turbulence’s kinetic energy entropy in the confined space is investigated. Through the meshing of flow field the turbulence particle is gotten, then with the velocity and direction of particle motion, turbulence kinetic energy under model and the given boundary conditions is calculated. After determining the kinetic energy’s three-dimensional projecting components and the energy value’s occurrence probability, the integrating process in the flow field’s effective space is conducted then a computing formula of kinetic energy entropy is deduced. In experiment the turbulence caused by strengthen grinding is used as an example, the kinetic energy entropy is calculated and revised in the whole flow field; and the computer simulating of entropy’s spatial distribution is conducted in Fluent 6.2.23 environment. Thus the influence mechanism and relationship between turbulence kinetic energy entropy’s calculation and its spatial distributing simulation are established, and the technology reference and research idea for turbulence monitoring in strengthen grinding are also be provided.
Abstract: For the purpose of accurate inspecting IC chip by image, fuzzy gray theory is used for quantitative evaluating the IC micro-topography’s influence on its image characteristics. Through extracting topography’s feature-points by precise coordinate measuring apparatus, its spatial surface model is structured and the topography characteristic parameters array is established, thus a mathematical model of fuzzy gray evaluating system is obtained. After calculating the fuzzy gray relational degree between the topography characteristics and the image ones, the influence has been quantified. By experiment repeatedly the influence discipline is analyzed and the conclusions are reached. It provides theoretical foundation and technical preparation for IC image sampling condition’s selection and adjustment.
Abstract: Context-based Adaptive Variable Length Coding (CAVLC) as a new entropy coding algorithm has been introduced into H.264/AVC standard. Through analysing the CAVLC coding algorithm detailedly, the paper proposes an overlapping coverage storage method and a new stream merger method, and gives the specific implementation. This idea improves the structure and performance of the complex module and reduces the implementation complexity. The experimental results show that the proposed entropy encoder is correct, and the highest coding frequency of 81.70MHz can be achieved. Meanwhile all the hardware resource consumption is less than 2% of total hardware resources. The new entropy encoder achieves a better balance in system performance and resource consumption.
Abstract: Taking the polisher as the example，this paper described the process of precision ceramic polisher and built up the mathematical model for polishing process and simulation．First, it contrasted to single–single-grit grinding head in the grinder for the general motion and planetary motion .Second, it contrasted to multi-single-grit grinding head in the grinder for the general motion and planetary motion. The simulated model provides the convenience of adjusting process parameters with Matlab for comparison of polishing effects，thus it is of avail to the determination of polishing parameters and the control of polishing quality．
Abstract: The multi-step forward finite element method is presented for the numerical simulation of multi-step sheet metal forming. The traditional constitutive relationship is modified according to the multi-step forming processes, and double spreading plane based mapping method is used to obtain the initial solutions of the intermediate configurations. To verify the multi-step forward FEM, the two-step simulation of a stepped box deep-drawing part is carried out as it is in the experiment. The comparison with the results of the incremental FEM and test shows that the multi-step forward FEM is efficient for the numerical simulation of multi-step sheet metal forming processes.
Abstract: Numerical simulation can be used to predict die filling, and hence to optimize the die design. In the study, the flow characteristics of liquid filling comparing with those of semi-solid filling were analyzed. The results indicated that the liquid filling turned out to be turbulent, while the semi-sold filling had laminar flow characteristics which could reduce the foundry defects such as gas cavity and oxidation mixture. The distribution of pressure reduced gradually in the filling direction during semi-solid filling process which would generate back pressure that was favorable for filling process.
Abstract: Railway transportation hold a leading post in the long-distance passenger transport market. Passengers spend most of their time sitting, so seat affect passenger comfort most among interior facilities of coach. One of the major tasks of interior design is functionality and comfort of seat. Seat width, seat depth and seat height are basic functions factors of seat. The seat depth is major issue of functionality design of 25g car. The shape of cushion and backrest are main comfort factors of seat. The backrest angle is major issue of comfort design of 25g car now. The interior system design of railway passenger car can be developed if we stress and make rational use of these factors of seat design.