Applied Mechanics and Materials Vols. 556-562

Abstract: Chinese word segmentation is a fundamental problem in natural language processing. CRFs (Conditional Random Fields, CRFs) is an undirected graph model. It can work well with a variety of features, full use of the text information. Thus, this article adopts CRFs based Chinese word segmentation. This paper first gives the definition of CRFs model, the model parameter learning methods and reasoning algorithms. Then, it introduces the word tagging system which is widely used in Chinese word segmentation. The Bakeoff 2005 corpora are used in Chinese word segmentation experiments, and we achieve an excellent result on both MSRA and PKU corpora. The F-Measures on both corpora are 0.964 and 0.943, while the ROOV Values are 0.705 and 0.765.

Abstract: Robust estimation method in generalized Gaussian distribution of observations under obedience can effectively eliminate or reduce the influence of gross errors, however, peculiarity of different estimation methods are not the same. In this paper, it’s used simulation method, the commonly used 13 kinds of robust features robust estimation methods were compared. The results showed that: L1 method, Danish method, German-McClure method and IGGIII program is more efficient robust estimation methods in Observations to obey generalized gaussian distribution, which method is more effective than other commonly used to eliminate the impact of robust estimation of gross errors or weaken .

Abstract: This paper is concerned with the stabilization problem for fuzzy Markovian jumping systems with distributed time delay. First, fuzzy Markovian jumping systems with distributed time delay are peoposed. Second, a novel criterion of delay-dependent robust stabilization for fuzzy Markovian jumping systems is established in terms of linear matrix inequalities (LMIs) by using Lyapunov stability theory and free-weighting matrix method. When these LMIS are feasible, an explicit expression of a desired adjustable state feedback controller is given. Based on the obtained criterion, the introduced controller ensures the overall closed-loop system asymptotically stable in mean square sense for all admissible uncertainties and time delay.

Abstract: Belt and airbag are the most important protection devices in vehicle frontal crash, which can have the best protective performance when only they were well matched with vehicle body structure. In this paper the theoretical guidance for optimizing belt and airbag parameters is researched, in order to improve the effect and efficiency of parameters optimization of restraint system. Firstly, a simulation model for occupant restraint system is developed based on the finite element theory combined with multi rigid body theory, and its effectiveness for simulating the occupant dynamic response in frontal impact is validated. Then, the energy dissipation characteristics of occupant head and chest in typical frontal crash are analyzed based on the developed model. Lastly, the adaptive level of restraint system parameters are evaluated according to the dissipation characteristics of occupant energy, and theoretical guidance for parameters optimization are summarized based on the evaluation. The analysis results indicate that: (1) airbag with low stiffness cannot fully utilize the deformation of vehicle body to dissipate the energy of occupant head, but may increase the risk of head injury; (2) belt with high stiffness would apply a big force to occupant, which could increase the compression amount of chest and may increase the risk of chest injury.

Abstract: According to the similarity between ontology and complex network, the article analyzes the network characteristics of ontology and brings forward a series of theories based on structural and semantic characteristics as well as quantization criteria for nodes and edges. These theories and quantization criteria are applied to the selection of core nodes and measurement of edge weight. In this article, the problem of ontology matching is transformed into the matching of weighed label graphics, which are based on individual characteristics and organizational structure. The matching of approximately optimization is acquired through quadratic programming. Results of experiments have showed that the structural characteristics of ontology have great influence on ontology matching and the close coupled with the matching of core nodes will significantly improve the accuracy of matching.

Abstract: In this paper, a compounding pressure sensing structure of Fiber Bragg Grating (FBG) based on circular plate diaphragm and equal strength cantilever is proposed. Based on mechanics of materials principle and mode coupling theory, a linear expression between uniform pressure and central wavelength shift of fiber grating fixed on the surface of the cantilever has been achieved. The pressure shift of fundamental modes resonance wavelength is investigated by means of simulation method. The results show that the resonance wavelengths are linearity increased with ambient pressure. The conclusion is of great aid to the application of the fiber Bragg grating.

Abstract: The numerical simulation of multipahse flow characteristics during the launch process from the tube of the submarine vehicle are investigated, obtains the variation rules of the movement characteristic of the gas inside the tube, the cavity shape of around the vehicle body, the surface pressure coefficient during the movement process. The resluts show that the launch depth and velocity have significiant impact on the shouder cavitation of the submarine vehicle, the smaller values of the depth and the velocity are, the more obvious shouber cavitation, and which led to the distribution difference of the surface pressure coefficient

Abstract: An improved clock synchronization algorithm for time triggered architecture has been proposed in this paper. A single reference real time is added in the system, so periodically calibration to real time can be achieved. This algorithm is based on the classical Welch-Lynch^[1] fault tolerant clock synchronization process. Systematic clock drift problem has been solved by using the algorithm. Formal analysis is presented, and verification is taken on Matlab/Simulink platform. Simulation result has verified the performance of the algorithm, and the clock difference is bounded as expected.

Abstract: In this paper, a comparative study on the performance of scheduling rules in job shop. Four new dispatching rules are proposed. mean, maximum ,variance of tardiness and proportion of tardy jobs have been used to evaluate the performance of various scheduling rules. Breakdown level, shop load level was considered in the comparative study. The simulation result indicate the performance of dispatching rules is being influenced by Breakdown level, shop load level.

Abstract: The drawbacks of active object orienting system which is difficult to guarantee the concealment and security are obvious. Hence, the passive object orienting system becomes the research focus. Based on line array of microphone, the passive acoustic orienting system collects and records acoustic signals. The acoustic signals are processed by Conventional Beamforming (CBF) algorithm. The hardware of system is proved to be effective in the sound acquisition experiments. The results of acoustic orienting experiments are given, which shows that the error of acoustic orienting is less than 1%. The system which implements acoustic orienting and has a high accuracy is the base of the latter research in the laboratory.