Applied Mechanics and Materials Vol. 441

Abstract: Stabilization of the operating speed is a vital factor that affects a combine harvester's productivity. In this paper, the pretreatment of CAD models is set for precise simulation. Using CAE tools, the research concentrates on the static and kinematic characters of the gear assembly in the power train. Ultimately, the comparisons of the simulation results with the theoretical ones are conducted. The results indicate that the designed gear assembly can remain the operating speed stable and reliable under the assumed condition.

Abstract: A 7-DOF half-car dynamic model which includes the cab mounting system and seat suspension system was established to study the performance of active seat suspension. The optimal control method was applied to design the active control system. Two dynamic simulation models of the passive seat suspension and the active seat suspension were set up by Matlab/Simulink, and the performance of the passive and active seat system was simulated in the time and frequency domain. The simulation results show that the active seat suspension can greatly improve the vehicle seat performance and the study has supplied the academic reference in the applications of the active seat suspension.

Abstract: The aim of the system is to achieve query expansion. The method works combining clustering of hierarchical methods. Through the information proffered by a background document, doc_ID, concerning the initial query, a cluster containing doc_ID can be produced by hierarchical clustering. And the word co-occurrence information can be extracted from the candidate documents in this cluster. Compared with the content in doc_ID, the result of the experiment using the system shows an expected performance to develop expanded terms which are qualified to add to original query.

Abstract: A rapid template matching algorithm is used to locate l-emitting d (LED) die array on wafer planes in vision-based LED sorting or die-bonding system, the image of LED die array is first converted to binary image and is pre-processed through morphological operations such as dilation and erosion, and the cross correlation operation between LED die templatae and wafer image in frequency domain is implemented by using fast Fourier transform (FFT), and the pixel coordinates of all LED dies on the wafer plane can be determined at one time using the cross correlation in frequency domain (CCFD) instead of in spacial domain. Experimental results of LED die array measurement to a large-diameter LED wafer show that detection efficiency is far higher than conventional normalized cross-correlation (NCC) algorithm, and is only half of consumed time to compare with the sequential similarity detection algorithm (SSDA), the proposed CCFD algorithm can be used for rapid LED die array location in vision-baesd LED sorting or die-bonding machines.

Abstract: Extraction of License plate region is an important stage in the intelligent vehicle license plate recognition system. A practical license plate extraction algorithm based on edge detection and mathematical morphology is presented, the algorithm mainly consists of six modules: pre-processing, edge detection, binaryzation and denoising, morphology operation, filtration of connected regions, finding license plate region. From the experiments, the algorithm can detect the region of license plate quickly with 98% average accuracy of locating vehicle license plate region.

Abstract: The display speed of image and large real-time data processing is a huge challenge for realtime system. This paper completed a thorough research on existing drawing technology on the platform of windows; analyzed adaptive characteristics of using the general high-speed drawing techniques for high speed drawing and its merits and demerits. Finally, through a lot of experiments and simulations of high speed drawing process after optimization and combination, tested their drawing performance and efficiency in order to select an appropriate drawing method to develop a high-speed graphics engine for large real-time data.

Abstract: In order to solve the problem that the small and middle converters unable to introduce the sublance detection technology to improve the control precision of endpoint because of the constraints of economy and technology, a method which combine the pedigree cluster and neural network is studied, the pedigree cluster divide the large data sets into several categories, the degree of similarity will be relatively high in each category after division, then train neural model for every category. Finally make predictions. Simulation results show that the multi-neural network model has better prediction results.

Abstract: An interference image edge detection method for laser interferometer hydrophone based on wavelet packet is investigated. Considering the effect of ocean background noise on the interference image, we propose the use of a class of wavelet packet functions to make decomposition on noisy interference image, and then make reconstruction on approximate parts of the decomposed image. The approximate parts with the wavelet packet decomposition is of more clear image layers comparison to the original image, and the wavelet packet decomposition method can reduce the influence of background noise on the interference image. Taking the wavelet packet decomposition method and other edge detection algorithms for contrast, it is proved that the wavelet packet decomposition method for edge detection algorithm is more effective than the other algorithms.

Abstract: In this paper, a novel method for one-dimension-signal coding based on non-uniform regional partition is proposed. A given 1D signal can automatically be partitioned into different regions with different lengths and the one-variable polynomial is used to do the Least Square Approximation for signal values in each sub-region. When the approximation error and initial partition are specified, a specific signal partition result is obtained. Based on this algorithm, an effective denoising scheme of 1D signal is implemented and some of the experimental examples are illustrated to prove that the quality of the re-constructed signal, the denoising effect are all satisfactory and can be referenced by other researchers.

Abstract: We analyzed a typical cryptosystem and an easy extended knapsack subset sum problem is proposed. The solution is not chosen from any longer but from. Based on the problem, we construct a public key cryptosystem in which the plaintext is divided into some groups and each group has bits, so that the encryption and decryption can be very fast. The possible attacks are analyzed. Our cryptosystem not only can resist Shamir's attack but also can resist the low density attack, because of its high density. The number of the sequence is also much shorter than before with the same density.