Applied Mechanics and Materials Vols. 130-134

Abstract: There're two issues should be concerned about during the optimization design of structural concept. The one is The using performance of structure, the another is the cost of foundation should be contained in the cost of whole structure. And it is suggested that The cost performance in value engineering should be used during the optimization design of structural concept. In this paper, the method and the process of the optimum structural design is expounded by optimizing a structural concept of project.

Abstract: In this research, a new Memetic Algorithm (MA) for Multi-Objective (MO) optimization is proposed, which combines ability of chaos optimization algorithm is proposed based on the ergodic and stochastic properties of the chaos variables. A new MA updating strategy is proposed based upon the concept to deal with the problem of premature convergence and diversity maintenance within the chromosome. The proposed features are examined to show effects in MO optimization. The comparative study shows the effectiveness of the proposed MA, which produces solution sets that are highly competitive in terms of convergence Measurement and Spread Measurement.

Abstract: This research proposed a comparison of accuracy based on data imputation between unconstrained structural equation modeling (Uncon-SEM) and weighted least squares (WLS) regression. This model is developed by University of California, Irvine (UCI) and measured using the mean magnitude of relative error (MMRE). Experimental data set is created using the waveform generator that contained 21 indicators (1,200 samples) and divided into two groups (1,000 for training and 200 for testing groups). In fact, training group was analyzed by three main factors (F1, F2, and F3) for creating the models. The result of the experiment show MMRE of Uncon-SEM method based on the testing group is 34.29% (accuracy is 65.71%). In contrast, WLS method produces MMRE for testing group is 55.54% (accuracy is 44.46%). So, Uncon-SEM is high accuracy and MMRE than WLS method that is 21.25%.

Abstract: The heat metering system is one of the key facilities to reform the heating systems of city and to charge according to heat quantity consumption. The design of heat metering system based on mcs-51 includes two sections--hardware and software. The hardware section is composed of flow sensor, temperature sensor and single-chip microcontroller (SCM for short). The system can calculate heat quantity intelligently, so the users pay the actual heat quantity consumption.

Abstract: IEEE1588 Precision Clock Protocol is applied to Can Bus distributed system platform constructed of STM 32 chips to accomplish the clock synchronous system between primary and subsidiary base stations, thus ensuring the clock synchronization with the precision of millisecond.

Abstract: The paper illustrates the optical access network which includes AON (active optical network), PON (Passive optical network) and EOC (Ethernet over COAX) systems, implementing DVB business and IP business. The optimal optical access technology is selected according to different access situations in the project. The optical access network accomplishes the wire access and wireless access. In order to reduce the cost, the coax is efficiently used.

Abstract: This paper analyses the process of obtaining real color image based on a single CCD/CMOS sensor. Bayer CFA Interpolation algorithm and White Balance algorithm are presented. The proposed interpolation algorithm which can obtain better color image and is easier to implement by hardware is provided. In order to cancel chromatic aberration, one White Balance algorithm which aims at sequential image is presented and process of FPGA design is given. Experimental results show that the design works normally. The color of corrected picture is vivid compared to the real world.

Abstract: It is very important for a distributed generating system to have an islanding detection part. Focused on the problem of islanding, this paper proposes a new and effective islanding detection scheme: a thyristor is placed between any two phases just by the port of the distributed generator (DG). An artificial short time phase to-phase short circuit is formed by triggering the thyristor periodically when the voltage between this thyristor is almost equal to zero, so the short-circuit current and voltage pulse can be extracted out. Because that short-circuit current and voltage pulse contain plentiful frequency components, the frequency response of system can be acquired according to the theory of harmonic impedance, so that the impedance measured from DG port can be obtained. Whether the DG is islanding can be determined quickly by monitoring the changes of impedance. This method is proved to be correct and effective by theoretical analysis and simulation.

Abstract: A method for orthogonal grid generation is presented. The generating system is based on solution of a system of partial differential equations with finite difference discretization. The influence of the number of grid points, type of boundary, and intensity of the grid quality control function and grid properties are investigated. Specification of both boundary point distribution on all sides is used. The proposed method is applied to various test problems£¬which shows this method provides a good balance between controlling grid orthogonality and cell aspect ratio.

Abstract: The stability and nonlinear dynamics are studied for a slender flexible cylinder subjected to axial flow. A nonlinear model is presented, based on the corresponding linear equation of motion, for dynamics of the cylinder supported at both ends. The nonlinear terms considered here are the quadratic viscous force and the additional axial force induced by the lateral motions of the cylinder. Using two-mode discretized equation, numerical simulations are carried out for the dynamical behavior of the cylinder to explain, with this relatively simple nonlinear model, the flutter instability found in experiment. The results of numerical analysis show that at certain value of flow velocity the system loses stability by divergence, and the buckled configuration becomes unstable at higher flow leading to post-divergence flutter. As the flow velocity increases further, the system is restabilized in the buckled configuration prior to another dynamic instability at higher flow.