Applied Mechanics and Materials Vols. 457-458

Abstract: The movement of the Straddled Jaeger Salto with a 1/2 Turn performed by Kexin He, the UB princess, who was the only individual event grand slam winner of the Chinese Women's Gymnastics Team, was videotaped and 3-D analyzed. The kinematic characteristics of this perfectly performed high skilled movement provided useful information for the technical training of coaches and athletes and enriched gymnastic theories. Overall, Kexin He performed the Straddled Jaeger Salto with a 1/2 Turn well. Nevertheless, there was still some room for her to improve, such as she straddle was performed a little bit too early and the after the somersault had been completed, both legs were brought together a little bit later.

Abstract: As a recently proposed technique, sparse representation (SR) has been widely used for pattern recognition. Sparse representation emphasizes the coefficient sparsity and ignores the importance of the collaboration between classes. In this paper, collaborative representation is introduced for palmprint recognition, and the inter-class collaboration is employed to estimate the representation coefficient with regularized least square method. The algorithm based on collaborative representation was evaluated on the Hong Kong PolyU (v2) palmprint database and ideal recognition performance was achieved.

Abstract: From their own characteristics and actual situation of real estate enterprise, according to the connotation of core competitiveness, through different angles, the paper builds up the index system of the real estate enterprises core competitiveness. Then calculate the core competitiveness of 40 samples with factor analysis method and get the comprehensive score. Found that management ability and operation ability are important factors to decide the real estate enterprises core competitiveness .Based on this study use cluster analysis to classify 40 samples and make comments and suggestions accordingly.

Abstract: The surface roughness is a physical quantity of micro geometry error surface material used for assessment of processed composed of peak, valley and the spacing of the. Have a great influence on the parts usage. Generally speaking, the surface roughness is small, can improve the matching quality, reduce wear, extending the service life of parts, but the processing cost of parts will increase. Commonly used assessment parameters can be divided into height parameters, spacing and shape parameters (parameter) three series. Measurement methods are commonly used surface texture tester, optical surface profiler and atomic force microscope. This paper makes a comparative analysis on the different measurement methods.

Abstract: In brief introduction of the pneumatic shape measuring roller's construction and work principle, the static and dynamic state experiments of the roller then found distributing regulation and characteristics of the measuring differential pressure which following circumference direction. Then we put forward dynamic phase correction method to improve the testing accuracy of the roller. It passes by experimentation to prove the possibility of method in this text.

Abstract: The low probability of intercept (LPI) radar waveform is reflected in a lower pulse power and complex structure of the pulse series. The previous one ensures that it avoids being intercepted by the electronic measures system (ESM) carried by the goal; the latter makes it difficult for ESM to separate and identify. As for pulse position jitter pulse array, because of pulse position's random jitter in a specific pulse interval of the pulse repetition interval (PRI), the spectrum broadens and spectral density reduces, making it hard for the ESM to intercept. Meanwhile, because the waveform doesn't have a fixed PRI, it's also difficult to be sorted or identified Therefore pulse position jitter waveform is a rational LPI waveform. Combined with a design about the LPI radar signal waveform, this paper carries out a research on PRI jitter waveform, and provides a waveform generating and echo signal processing method; then the paper simulates the LPI characteristics and comes to a conclusion which has an important applying value .

Abstract: The pneumatic servo system has characteristics of nonlinear, time-variant, large parameter variations and external disturbances, which is difficult to control. The conventional PID control is not suitable for the variable parameters of the controlled object, external disturbances. In this paper, the neural network controller combined with PID control is used to control the pneumatic servo system, and the structure diagram, algorithm and learning rule of the single neuron adaptive PID controller are put forward. The results show that,compared with the traditional PID control, the controller has significantly improved the control performance of system, Namely, the system has faster computational speed (real-time), stronger robustness and better adaptive ability.

Abstract: After introducing the basic definition, technical principle and applied scope of elastic wave CT technology, the paper makes a detailed introduction of the development process of elastic wave CT technology domestic and overseas and main technical problems it faces and believes that the imagining precision of elastic wave CT is often influenced by various factors such as the observation system, test precision, imaging method and error control. Thereinto, the hot issue in the research is put onto the study about inversion algorithm and the paper also elaborates the research direction and development tendency of current inversion algorithm at home and abroad.

Abstract: Technology of spatial angle measurement is widely used in the aviation and national defence. Based on research of the spatial angle measurement, a system to measure the spatial angle is devised in this paper, which uses position sensitive detectors (PSD) as the detector and the laser beam emitted from a semiconductor laser as the straightness reference. The detecting system has some characteristics. A novel method is introduced to correct the spatial angle between the incident beam laser and the photoelectric surface of the PSD, which makes the incident beam laser vertical to the PSD. Besides, a back-propagation (BP) neural network is used in this system to compensate the nonlinearity errors of the 2-D PSD, which can improve the credibility of the detectors output data. It also has advantage of reliable data and high precision to measure the spatial angle of the large-scale gyroidal components. Meanwhile, the measuring principle, optical system and electric circuits of the experimental equipment are analyzed in the paper. The result shows that the experimental equipment is more precise and sensitive than old equipment. The relative error can achieve good accuracy. The detecting system has some theoretical research significance in realizing untouched measurement of large-scale gyroidal components in other similar situation.

Abstract: Six early-warnning subsystems are build, the control parameters of tension value and time for seat belt are determined, based on the analysis of function and components for intelligent seat belt pretension system. The hardware and software are designed, the software for seat belt retractor motor is integrated to set the ralative time distance, vehicle yaw rate, steering wheel angle, vehicle deceleration, this four signals which are used as input for simulation, the output show that the tension value and tension force are directly proportional to input signal, which can be early warn for intelligent seat belt successfully and provide passengers active safety effectively.