Applied Mechanics and Materials Vol. 678

Abstract: Character type cipher is always used in web application system and can be deciphered by the illegal users through "run dictionary", so, a new random encryption algorithm for character type cipher is put forward in this paper. The encryption parameters are randomly generated in the algorithm, and random confusion is adopted in the cipher text structure, so the same plaintext can produce different ciphertexts.the experimentation shows that the algorithm is feasibility and validity.

Abstract: Speculative Multithreading (SpMT) technology is an effective mechanism for automatic parallelization of irregular programs. While speculative parallelization can potentially deliver significant speedup for irregular applications, several speculative parallelization overheads resulting from the factors, especially inter-thread load imbalance, limit these speedups in practice. Most existing thread partitioning methods are mainly based on heuristic rules strategies to generate speculative threads. However, these heuristic rules extracted from people’s experiences cannot estimate quantitatively but qualitatively the overhead. Based on the thorough analysis of the speculative parallelization overhead resulting from inter-thread load imbalance, we propose a novel method to balance the inter-thread load. In this method, we firstly determine a method by which to unroll the loops. Then, we introduce cluster method to search the solution space of speculative threads and finally get the optimal solution. The experimental results show that, the proposed method can effectively reduce the inter-thread load imbalance; and the load imbalance overhead can be effectively reduced by 43.7%. And we can gain 8.8% performance improvement on Olden benchmark suits.

Abstract: The clustering analysis of the cancer gene expression data can provide bases for the early diagnosis of cancer and accurate classification of the cancer subtypes. For the characteristics of cancer gene expression data, an algorithm named FNMF-ITWC (Fast Nonnegative Matrix Factorization Interrelated Two_Way Clustering) is proposed. FNMF-ITWC algorithm firstly selects genes from the original gene expression data, implements non-negative matrix factorization on the row (gene dimension), and then performs clustering on the column (sample dimension). Matlab experimental results show that FNMF-ITWC algorithm improves the computing speed of the algorithm and reduces the data storage space. At the same time, it is able to reveal correlation among genes under certain experimental conditions and the correlation among experiments for some genes.

Abstract: Web text exists non-certain and non-structure contents ,and it is difficult to cluster the text by normal classification methods. We propose a web text clustering algorithm based on fuzzy set to increase the computing accuracy with the web text. After abstracting the key words of the text, we can look it as attributes and design the fuzzy algorithm to decide the membership of the words. The algorithm can improve the algorithm complexity of time and space, increase the robustness comparing to the normal algorithm. To test the accuracy and efficiency of the algorithm, we take the comparative experiment between pattern clustering and our algorithm. The experiment shows that our method has a better result.

Abstract: High precision calibration of Micro inertial measurement unit (MIMU) for large installation misalignment can improve the instrument and the practical use of the system precision. It can use high precision turntable to get the coarse value of installation misalignment angle as the optimization initial value, and take the standard deviation of turntable angular rate and the acceleration of gravity as the optimum index to find MIMU misalignment parameters using artificial fish swarm algorithm. Simulation and analysis are carried out based on the position and rate experiment. In addition, static navigation test is taken by using self-developed MEMS heading and attitude measurement system. Both the simulation and experimental results show that this method can improve the calibration accuracy of MIMU effectively with reduced of heading and attitude error.

Abstract: the risk evaluation indicator system by enterprise resource planning (ERP) system is characterized by excessive subjectivity, lack of reasonable basis for establishing, and redundancy. The paper adopts the rough set theory, proposes attribute reduction algorithm based on information entropy, and makes attribute reduction on risk control indicators for implementation of ERP system by integrating cases from 10 enterprises that have already implemented ERP systems. The resultsshow that attribute reduction algorithm based on rough set is effective and available on reduction of risk control indicator for implementation of ERP system.

Abstract: Perception of environment in front of driving vehicle is a core investigation theme of intelligent vehicle technologies aiming to increase safety, convenience and efficiency of driving. Using stereo vision for environment perception is a hot technology. This paper developed an algorithm for stereo matching in intelligent vehicle application. The experimental results indicate that this algorithm is effective. Furthermore, this algorithm paves the way for the implementation of automotive driver assistance system.

Abstract: Arrange the ships reasonable as much as possible in the lock chamber, can help improving the traffic ability and the utilization rate of the lock. At present, it is not enough for the factors that considered in the automatic layout algorithm, such as: the safety distance between the ships, ship bottom sill depth. The algorithm can be further optimized. This paper will present a new automatic layout algorithm for single chamber which is able to enhance the efficiency of the chamber space and improve the traffic ability.

Abstract: Computer teaching should emphasize the engineering practicality, creativity, and pay more attention to the project and its application. It is important to evaluate the teaching effect. An evaluation system and corresponding algorithm are presented in this paper. There is a certain correlation between some evaluation factors, and the factors can be divided into key factors and secondary factors by rough set. The evaluation algorithm based on the key factors can reduce redundant factors and improve the efficiency. We designed a clustering algorithm based on fuzzy set on evaluation entities, which can reduce the dada size and improve the accuracy of the algorithm. Through the example analysis the algorithm of factors reduction based on rough set and clustering method based on fuzzy set are described in detail.