Advanced Materials Research Vols. 694-697

Abstract: The need for economic and reliable operation of power equipment has lead to the search for effective methods for evaluating the condition of equipments. In this paper, fuzzy synthetic evaluation based on optimized weights is proposed to enhance the precision and flexibility. This method makes dual optimization on the weights of the factors which have vital influence on the accuracy of condition evaluation. At first, the initial weights are adjusted by entropy method effectively. Then variable weight model is introduced to make correction according to the deviation of actual data and normal state. At last, the fuzzy evaluation thought is utilized to value the ultimate operation condition of power equipment. A numerical example of a condenser in generator set is provided to illustrate the feasibility and effectiveness of the proposed method.

Abstract: This paper for product obeys exponential distribution, in the case of data with only one failure, one-sided Bayesian upper credible limit, two-sided Bayesian lower and upper credible limits of failure rate are proposed, moreover, the one-sided Bayesian lower credible limit, two-sided Bayesian lower and upper credible limits of the reliability are also provided. Finally, calculation performed on practical problems, show that the provided method is feasible and easy to perform in engineering.

Abstract: This paper presents a simple and accurate coordinate transformation method for extending the tracking space of the Intersense IS-900 spatial and motion tracking system using multiple pre-configured emitter towers to form the emitter constellation, but without resorting to the use of a surveyor machine. The proposed approach uses the differences of positional coordinate readings from each emitter tower among a set of commonly viewed spatial points to calculate the parameters needed to define the coordinate transformation. By applying this method, the tracking accuracy using the entire emitter constellation can be achieved by less than 0.5 inches error in most of the working space, and as low as 0.2 inches error in the frontal part of the working space.

Abstract: This paper proposes a microstrip wide-ring sensor for percentage of broken rice determination based on transmission power measurement. The microstrip wide-ring sensor with low insertion loss was designed to operate at frequency range from 1 GHz to 3 GHz. Calibration equations for measurement of percentage of broken rice at 1.93 GHz and 2.50 GHz were obtained and validated with white rice for percentage of broken rice ranging from 0% to 100%. The lowest error in percentage of broken rice prediction was 11.03% at 1.93 GHz.

Abstract: A new localization method has been proposed to overcome the limitations of systems relying on GPS or other terrestrial infrastructure. This method fuses both pseudorange measurements from GNSS satellites and RSSI-based ranging measurements between peers of a wireless network, and uses improved collaborative subtree algorithm to partition the network. In each collaborative subtree, the nodes’ positions can be computed by using the least square algorithm based on Taylor series expansion-based. Simulation results showed that this method improves both availability and positioning accuracy.

Abstract: Optimizing the curing temperature to reducing the process costs may influence the properties of the material and bring quality assurance aspects. To solving the problem, real-time strain monitoring of the curing process has become more and more important and urgent. Fiber Bragg grating sensors were successfully used in this work to monitoring the residual strain building-up and the gelling phenomena of an RTM epoxy resin. The results shows chemical shrinkage strain during isothermal curing is bigger for higher curing temperature, but the average linear shrinkage ratio during cooling is smaller.

Abstract: A fast and high-precision ‘thermoelectric potential - temperature (E-T)’ sensor conversion method for the transient aerodynamic heating control systems of high-speed aircraft is proposed. The developed method has the advantages of easy calculation, rapid conversion speed and high calibration precision, and can thus be employed for fast non-linear dynamic control of rapidly-changing temperature fields in the aerodynamic heating process of high-speed aircraft.

Abstract: According to the grim situation of current global forest and wildland fires, the article presents a real-time fire detection system based ZigBee wireless sensor network and GPRS network. The system gives the hardware design of wireless sensor node and software implementations. The ZigBee nodes are mainly responsible for collecting and transporting the special environment parameters of the forest including temperature, humidity and smoke concentrate and so on, and send the data through the GPRS module to the remote monitoring center. It has a simple structure, low power consumption, flexibility of the node and other advantages that accomplish data acquisition and long distance transmission.

Abstract: A kind of gene detection biochip model based on biological micro electro mechanical systems (BioMEMS) technology and micro optical electro mechanical systems (MOEMS) technology is designed and simulated. In order to detect whether there are nucleic acid components in the testing samples, the biochip in this study issues horizontal light by laser, then receives and reads the deformation signals of MEMS cantilever by optical detector. The MEMS optical reflecting system can amplify MEMS cantilever deformation signal 22 times by micro reflectors which are set on the side wall of the cantilever free end. In order to improve optical detection sensitivity, gold nanoparticles (GNPs) which are combined with hybridization information is taken to aggravate MEMS cantilever, and employ Au - S chemical bond of GNPs and dithiol HS(CH₂)₆SH to combine and fix DNA probe, and then employ target DNA which is marked with biotin to combine GNPs by Biotin - Streptavidin combining. The simulation results show that this biochip can detect biological samples fast, high throughput, low cost, high sensitivity and reliably.

Abstract: This paper presents the system design of a high order single loop electromechanical ΣΔ accelerometer. The noise-coupled is employed in the fourth-order feed-forward micro-accelerometer ΣΔ modulator to provide fifth-order noise shaping performance. It is implemented without degrading the loop stability and without changing original loop coefficients of the fourth-order accelerometer.