Applied Mechanics and Materials Vol. 197

Abstract: The utilization of Al/SiCp metal matrix composites in different engineering fields has undergone a tremendous increase due to its tailor-made properties that can be achieved by varying the size and volume fraction of reinforcement. However, the difficulty in machining of metal matrix composites (MMCs) arises not only from the excessive wear of the cutting tools but also from fracturing of the reinforcement particles on machined surfaces that leaves behind adhered particle fragments, pits and cavities. These characteristics in machining of MMCs tend to adversely affect the machined surface quality/integrity. Hence, some attempts are made to improve the machinability of MMCs and surface quality by hot machining using wiper inserts. Experimental results indicate that the moderate heating of Al/SiCp composite material prior to machining (60-90°C) reduces the machining forces and improves the surface quality by minimizing, debonding, fracture and pull-out of reinforcement particles from the matrix material.

Abstract: Each casting produced in a foundry is a research experiment, since no two castings have the exactly same values of their geometric, material and process parameters. By the time, castings are inspected the link to the originating (influencing) parameters is lost, since they are never systematically recorded and correlated with quality characteristics. Thus, a valuable opportunity to improve casting quality is lost. In this work, we present a systematic approach for classifying casting defects by correlating them with the originating parameters; the proposed classification approach is hierarchical and more comprehensive. The defects are classified under geometry, integrity and property related defects. The defects analysis system includes an expandable library of images to facilitate correct identification of a given defect, and presents the various causes and remedies based on the user inputs. The entire system is being implemented in a web-based environment for wide access to practicing foundry engineers.

Abstract: The traditional cable television broadcasting, digital mobile television broadcasting and the direct satellite video broadcasting ensure the television services of people’s daily life. Owing to digital broadcast satellite, also known as the digital video broadcasting (DVB) protocol applying terminal, direct-to-home television services with an outdoor dish of one meter come true. In order to accommodate the requirements of various broadcasting services, the DVB-S.2 protocol provides more efficient technology details. The LDPC codes concatenated with BCH codes achieve high performance near the Shannon limit and have low encoding and decoding complexity. Some high efficiency modulation methods are introduced into theDVB-S.2, such as QPSK, 8PSK, 16APSK and 32APSK. The adaptive coding and modulation (ACM) according the channel performance (E s /N 0 ) is applied in the DVB-S.2 technology. In order to preventing the burst disturbance, satellite broadcasting via variable frequency band is presented in this paper to ensure the quality of services. The DVB-S.2 via variable frequency is simulated based on Matlab/Simulink in this paper, and the simulation implements the video streams coding and modulation, ACM and frequency change with the channel performance.

Abstract: According to the benefit sharing problem among the market competitive vehicledealers, vehicle manufacturers and auto parts suppliers consisting of three-echelon automotive supply chain, by using decentralized and centralized decision-making ways, we set up a mathematical model, which meet the coordinated conditions and achieve a win-win model for enterpricses within the supply chain.After analyzing the pricing of three-echelon vehiclesupply chain with the applicationof game theory, get the balanced result and profit at all levels in the condition of complete information. According to the interests of the entire supply chain based on the principle of contribution distribution, designed the parameters to make the entier supply chain achieving the maximize profit. We also proposed the way of determining revenue sharing system of three-echelon vehiclesupply chain. Finally, the reasonableness of the sharing factor determining method is proved by numerical examples.

Abstract: This study primarily focuses on solving a practical OVRP by applying a novel hybrid adaptive Genetic Algorithm and Tabu Search (GA-TS). The GA-TS combines the GA's parallel computing and global optimization with TS's Tabu search skill and fast local search. In the GA-TS Algorithm, individuals of population do TS local search with a certain degree of probability using natural number coding. It not only ensures global optimization, but also improves the speed of computing. The Algorithm is applied to optimize the mines material transport vehicle routing of China Zhengzhou Coal Mine and power Supply Co., Ltd. Through the applications, the optimal economical transport routing has been set up and economic costs have been greatly reduced.

Abstract: The focal length, zoom, irradiating power and cylinder speed of laser head influence the exposure quality directly in computer-to-plate (CTP) process. This paper determined the most optimal parameters which used screen thermal sensitive device PT-R4100 by changing the focal length, zoom, irradiating power and cylinder speed of laser head. The most optimal parameters of focal length, zoom, irradiating power and cylinder speed in CTP process were 1500puls, 6700puls, 90%, 600r/min respectively。Compared with computer-to-film (CTF), we found that the image quality of CTP process was better. The average density, register accuracy and ink trapping of CTP process were higher than that of CTF. Ink formation was also better.

Abstract: The security usage and management of removable storage devices has become a vital problem for enterprises and individuals. However, the required strict security policies for preventing unauthorized access to sensitive data raise the decrease of usability and flexibility. The main problem rests on the binding between security and application domains which stifles the initiative of the devices on themselves. This paper presents TRS, an efficient active architecture that binds a feather-weight virtual machine (FVM) to the removable storage device. It is designed based on an inside-bound smart card as well as the chip operation system (COS) which builds a trust channel between the FVM and the device. The FVM is set up by a trust chain and provides isolated usage environment for process accessing the device which prevents the obtained data from leakage. Finally, we implement a USB flash disk we call as UTrustDisk based on the hardware structure of Amordisk which is a security product of Nationz Technologies Inc. The results show the average overhead of read and write is 7.5% and 11.5%.

Abstract: Contourlet transform has better performance in directional information representation than wavelet transform and has been studied by many researchers in retrieval systems and has been shown that it is superior to wavelet ones at retrieval rate. In order to improve the retrieval rate further, a contourlet-S transform based texture image retrieval system was proposed in this paper. In the system, the contourlet transform was constructed by non-subsampled Laplacian pyramid cascaded by critical subsampled directional filter banks, sub-bands absolute mean energy and kurtosis in contourlet-S domain are cascaded to form feature vectors, and the similarity metric is Canberra distance. Experimental results on 109 brodatz texture images show that using the features cascaded by absolute mean and kurtosis can lead to a higher retrieval rate than the combination of standard deviation and absolute mean which is most commonly used today under same dimension of feature vectors. contourlet-S transform based image retrieval system is superior to those of the original contourlet transform, non-subsampled contourlet system under the same system structure with same length of feature vectors, retrieval time and memory needed, contourlet-S decomposition structure parameters can make significant effects on retrieval rates, especially scale number.

Abstract: Zigbee technology which targets low data rate, low power consumption and low cost application is suitable for Wireless Sensor Network (WSN) as its wireless communication technology. In the construction of WSN using Zigbee, the factors which could affect the stability of communication links should be considered. In this work, we discuss the construction environment of WSN. Then, in order to access the performance of Cluster-Tree network, we develop an NS2 simulator for Cluster-Tree WSN, and analysis the influence to stability of communication links caused by sending packet ratio and communication range. The simulation results show that it is not useful to improve the stability of communication links by increasing sending packet ratio and communication range simply. Both of them should be in a relatively balanced state.

Abstract: Computer Controller has found their place in many different applications. A Controller can be a good choice whenever controlled movement is required. This paper presents the usage of the applications of stepper motors in different areas including printers, plotters, high-end office equipment, hard disk drives, medical equipment, fax machines, robotic, washing machine, power generator automation, satellite automation, sensing automation, bio-sensing systems, earthquake measurement any automotive and many more. Practical experiment shows that when Controller is connected with parallel port, it can be controlled by the computer.