Applied Mechanics and Materials Vols. 44-47

Abstract: The extended nonholonomic double integrator (ENDI) cannot be asymptotically stabilized by a continuous and time-invariant feedback controller since it violates the Brockett’s condition. In this paper, a new continuous control scheme is proposed to stabilize the ENDI system without drift. The dynamics of an ENDI system is enlarged to a higher dimensional space where a continuous but time-varying control law is designed for its stabilization. Besides the theoretical proofs, simulations conducted on the dynamics of a mobile robot are also presented to demonstrate the validity and performance of the proposed method.

Abstract: A common approach to motion planning of robots and vehicles involves finding suitable trajectories for the positions of each configuration variable, and then using feedback to regulate the system to these trajectories. However, when the system has less actuator than dynamical degrees of freedom, it is not always possible to do this arbitrarily. In this paper a tracking control Lyapunov function (TCLF) is proposed to guarantee that the trajectory generation is convergent and executable under nonholonomic constraint, and the simulation result conducted on surface vehicle shows its effectiveness.

Abstract: Supply chain management concept (SCM) was begun to be accepted by the industry, but there were several barriers identified during the application of this concept. The purpose of this research was to identify the barriers faced by manufacturing industry especially among SMEs in implementing SCM. This study was carried out using questionnaire distribution method to research sample consisting of SME manufacturing company. The results shows the list of obstacles existed in SCM implementation in industry with involvement of; lack of skill; lack of knowledge; lack of power; lack of infrastructure; and lack of trust. Extensive discussion based on previous studies/research related to SCM was done in this research. Improvement in SCM which can be made as reference by researcher in the future was proposed. It hopes the research can support the body of knowledge.

Abstract: According to problems of flatness error measurement of revolving body end-face, sampling method and evaluation method are studied in this paper. First, spiral sampling method is presented, in order to meet the needs of flatness error measurement sampling of revolving body end-face. Second, combined with least squares method, mathematical model applied to flatness error measurement evaluation of revolving body end-face is proposed. Finally, through the simulation, the mathematical model is proved to be correct.

Abstract: With the development of computer’s hardware, main memory becomes bigger and bigger and can hold more data, so some operation before need disk I/O, now can be completed in main memory. In OLAP what-if or hypothetical analysis may need modify data or alter structure of cube, it should recalculate cube and is a long process. This paper presents how to do What-if analysis in main memory database environments and the experience shows that main memory OLAP is obvious superior to disk OLAP.

Abstract: The important properties of permutation ration function are surveyed. Subsequently investigate a new permutation rational functions including the aspect of important algebraic, arithmetic and properties. Finally, application of permutation rational function to public-key cryptosystem and key exchange scheme will also be considered.

Abstract: A novel kernel hardness tester was introduced in the paper, and the detection and control system was studied in detail. The stylus of the tester is forced into grain which placed in a container. The force which was acquired by a load cell and the displacement of the stylus which was measured by an optical encoder were used as a new hardness index. The core microcontroller unit (MCU) applied in the paper is STC89C52 to accomplish the data acquisition and the position control of a DC servo motor.

Abstract: Inverse problem of scattering coefficients in one-dimensional non-uniform medium has been investigated. A stochastic particle swarm optimization algorithm (SPSO) with a stochastic selection is adopted to estimate the absorption coefficients in a one-dimensional absorbing, emitting and scattering medium. The directional radiative intensities simulated by discrete ordinate method are served as input for the inverse problems. The performances of this algorithm on the accuracy of estimation are examined. Numerical results show that the proposed algorithm can guarantee the convergence of the global optimization solution, and is proved to be fast. The distribution of scattering coefficients could be estimated accurately.

Abstract: Rang-free distributed localization algorithm has advantages of low power consumption, low cost etc, but it is weak in the localization accuracy, energy consumption of localization and the algorithm extend ability.That can not meet to the needs of practical application. To overcome the disadvantage of DV-Hop algorithm, in this paper, Two aspects improved algorithm are proposed based on the characteristics research of the original DV-Hop localization algorithm, which are the coverage area of beacon nodes and average size for one hop received by unknown nodes. Simulation results prove their validity and show the performance of the improvement algorithms is superior to the original DV-Hop algorithm.

Abstract: In this paper, Prim algorithm is used to solve the problem of optimizing inter-city highway paving in highway construction project. In the paper circles are used to indicate the cities, the inter-city highway with the line between circles, and the line weights on the behalf of the relative costs of highway construction. Prim minimum spanning tree algorithm is constructed on the inter-city highway, and finally make the project cost cut down from 53 to 20 in highway construction project and obtain a better eco-efficiency and social benefits under cutting down of the project cost.