Applied Mechanics and Materials Vols. 29-32

Abstract: Feature-based modeling is one of key technologies to implement intelligent STEP compliant CNC, which can associate not only geometric and topological information, but also form features, tolerances, material properties and other information which may be used during the process planning and STEP-NC machining. This paper presents a machining feature-based modeler to build parts and exports them as the format of STEP AP224 file. The modeling system provides three main steps to construct a part: (1) selection of raw stock form stock library, (2) selection of predefined machining features according to ISO14649 to be subtracted from the part being designed, and (3) providing information to define the machining feature attributes such as feature size, position, orientation etc. This feature-based modeling system is implemented by using Microsoft C# and NX Open technology in UG NX6.0 environment.

Abstract: State forecast of machine using support vector machines has good generalization ability in situation of rare samples. Appropriate parameter selection is very crucial to the learning results and generalization ability of support vector machines. In addition, embedding dimension influences the phase space reconstitution of nonlinear systems, as well as the precision of machine state forecasting. In this paper, an approach to optimize the parameters of SVM and the embedding dimension based on genetic algorithms was proposed. The proposed model is applied to the tendency forecasting of the vibration of shovel electric drive system. The results show that it can avoid blindness of manually selection of parameters and meanwhile improves the prediction performance greatly.

Abstract: In present, almost all of inline code dissemination algorithms focus on securing the propagation of code images and overlook the security vulnerabilities in the image management aspects of code dissemination, such as rebooting and erasing code images. In this paper, we first investigate the security issues in remote image management for code dissemination in wireless sensor networks and analyze the advantage and disadvantage of the algorithm proposed by Liu et al which employs three different key chains to design three different schemes. To reduce the computation load of authentication operation, a message cipher puzzle-based image management algorithm is proposed. In this approach, a one-way hash key chain is introduced to authenticate the Reboot and Erase command and a weak authentication mechanism is introduced to protect the version number. The message cipher puzzle-based authentication method is efficient, because it only introduces a few hash function operations and comparisons

Abstract: to study oil shale creep properties, we use rock SJ-1B three-axis creep instrument on oil shale to carry three axis creep test. Through test results, the creep of oil shale is nonlinear, and in accelerating creep stage oil shale injury increased dramatically. Using Burgers creep model introduced damage variable to analyse the oil shale surrounding stress and displacement field and Systematically analyse the creep properties under various support intensity. So it has important theoretical significance and value for the oil shale resource development and roadway stability control.

Abstract: This paper proposes a novel fuzzy similarity measure based on the relationships between terms and categories. A term-category matrix is presented to represent such relationships and each element in the matrix denotes a membership degree that a term belongs to a category, which is computed using term frequency inverse document frequency and fuzzy relationships between documents and categories. Fuzzy similarity takes into account the situation that one document belongs to multiple categories and is computed using fuzzy operators. The experimental results show that the proposed fuzzy similarity surpasses other common similarity measures not only in the reliable derivation of document clustering results, but also in document clustering accuracies.

Abstract: A new artificial boundary model is proposed based on conventional viscous-spring artificial boundary model. Firstly, the stress formula on artificial boundary are derived based on the wave propagation theory and the new artificial boundary model is constructed by adding the nodal force to conventional viscous-spring on the boundary of finite field, which could include the effect of lateral boundary displacement. And then the values of the stiffness, the damp and nodal force are deduced based on stress wave theory. Finally, a numerical example is given to verify the proposed model. Compared with viscous-spring artificial boundary, this proposed artificial boundary model possesses the merits of same efficiency and conciseness, but higher precision than conventional viscous-spring artificial model.

Abstract: Phase-based Stereo Matching (PSM) is an efficient matching method in binocular stereo vision. It bases on correspondence points which have the same phase-distribution. Sine raster generating algorithm is a basic and important step in PSM study. This paper advances that using defocusing rectify-binary patterns (DRBP) method substituted the focusing-sinusoidal-patterns (FSP) method. It has following advantages: (1) No gamma correction is required; (2) The object illuminance measurement is not desired; (3) The influence of noise is minified. There are same phases distribution in correspond points of the pair matching lines by experiment analysis. The feasibility of using DRBP to generate sine raster in PSM is demonstrated.

Abstract: Gibberella moniliformis is a common disease in C. oleifera, and always results in significant economic losses. Phosphoenolpyruvate carboxykinase is a critical gluconeogenic enzyme and catalyzes the first committed step in the diversion of tricarboxylic acid cycle intermediates toward gluconeogenesis. According to the relative conservation of homologous gene, a bioinformatics strategy was applied to clone phosphoenolpyruvate carboxykinase gene of Gibberella moniliformis by blasting search of EST database with homologous gene cDNA of Neurospora crassa and identified. Some characters of the PEPCK that can encode amino acid were analyzed and predicted by the tools of bioinformatics in the following aspects, including the composition of amino acid sequences, physical and chemical, O-glycosylation site and tertiary structure of protein and function. These results showed that the full-length of PEPCK was 1962 bp and it contained a complete ORF (1671bp), encoded 556 amino acids, which are much conserved in ascomycetes. The calculated molecular weight of PEPCK was 61893.1 Da, theoretical pI of 5.77, 20 a-helix, 37 sheets, 7 glycosylation sites; it was a stable protein with active site ATP -binding site, metal-binding site and substrate-binding site.

Abstract: Rhizopus oryzae is the most common causative agent of zygomycosis and has a world-wide distribution with a high prevalence in tropical and subtropical regions. Chitin deacetylase acting on carbon-nitrogen bonds other than peptide bonds, specifically in linear amides. In the present study, some characters of the amino acid sequence of Chitin deacetylase of R.oryzae were predicted and analyzed with the tools of bioinformatics. These results showed that the protein was composed of 20 kinds of amino acid; the theoretical pI of Chitin deacetylase was 5.03 and the theoretical molecular weight of Chitin deacetylase was 49177.9 Da; total number of atoms was 6786; the extinction coefficient was 108665(280 nm).The N-terminal of the sequence considered was M (Met) and the estimated half-life was 30 hours. The instability index (II) was computed to be 32.67. Aliphatic index was 67.91. There were 20 glycosylation sites,a signal peptide and conserved domains. It was a hydrolase.

Abstract: Traditional image clustering methods mainly depends on visual features only. Due to the well-known “semantic gap”, visual features can hardly describe the semantics of the images independently. In the case of Web images, apart from visual features, there are rich metadata which could enhance the performance of image clustering, such as time information, GPS coordinate and initial annotations. This paper proposes an efficient Flickr photo clustering algorithm by simultaneous integration information of multiple types which are related to Flickr photos using k-partite graph partitioning. For a personal collection of Flickr, we firstly determine the value of k which means the number of data types we used. Secondly, these heterogeneous metadata are mapped to vertices of a k-partite graph, and relationship between the heterogeneous metadata is represented as edge weight. Finally, Flickr photos could be clustered by partitioning the k-partite graph. Experiments conducted on the photos in Flickr demonstrate the effectiveness of the proposed algorithm.