Applied Mechanics and Materials Vols. 303-306

Abstract: Because of the DV-Hop algorithm has a big error in the estimation of the average hop distance, this paper proposed a weighted hop distance correction localization algorithm. The improved algorithm is carried out by introducing the average hop distance error correction value of the weighting processing, thereby reducing the hop distance error, and avoid the accumulation of errors in the subsequent computation process. The simulation results show that the improved DV-Hop algorithm reduces localization error effectively and has good stability without additional devices; therefore, it is a practical localization solution for WSN.

Abstract: This paper presents an electromechanical coupled analysis for a single proof-mass one-axis capacitive accelerometer to supply a reference of design specification for subsequent readout circuit. Considering electrostatic force effect, the displacement of proof mass based on dynamic principle is calculated. Then the output of differential capacitive interface is simulated. It indicates that this accelerometer has a sensitivity of 2.09mV/G and capacitance change of 0.31fF.

Abstract: Packaging thermal stress is harmful to the performance of the micromechanical silicon resonant accelerometer. In order to decrease the packaging thermal stress, correlations of packaging thermal stress with the material properties, curing temperature and geometrical size of adhesive layers of adhesive materials were discussed. A finite element model of package was developed to analyze the influence of surface mounting technology (SMT） on the micromechanical silicon resonant accelerometer. The simulation results show that the Young’s modulus, thermal expansion coefficient, curing temperature and geometrical sizes of adhesive layers are important influencing factors for packaging thermal stress and the warpage of the chip. The thermal stresses during the process of SMT will cause the resonant frequency shift.

Abstract: Mine fire occurrence, continues to be one of the most enduring problems faced by the mining industry. The purpose of this study is to assess strategies for detecting the most important ingredient in the coal mine gas explosion-proof monitoring-oxygen content, so as to make the best foresee and prediction to the mine fire. The oxygen concentration within atmosphere located in the area of the seal gas explosion hazard safety zone should be less than 8%. In accordance with the national standard, the mine requires oxygen detection accuracy of 1%. The performances of an oxygen content monitoring system is influenced by such four elements as gas line, sensor, signal conditioning and processing as well as terminal handling system, etc.. In this work, through the use of computer-controlled technology, the oxygen content monitoring system was first made a linear open-loop calibration based on hardware, then made a linear closed loop calibration based on software programming, and at last, the famous OriginPRO data analysis system was used to analyze and interpret the sampling data, a programmed planning and real-time information correction of linear closed-loop calibration based on software was achieved, so that an oxygen content monitoring sensitivity limit of less than 0.36% was obtained in the system.

Abstract: This paper studies the methodology for the evaluation of the gain of the airborne radar system. Three internal calibration pulses are used to compute the system gain according to the equation, which is derived from the difference of the three calibration paths. The computed absolute gain can be used for the reference for the radiometric calibration of airborne radar system and the experiment data is provided to support the performance analysis.

Abstract: Based on the unique electronic properties and high adsorption capacity of carbon nanotubes, as well as the specific recognition ability of molecularly imprinted polymers, a novel molecularly imprinted carbon nanotubes electrochemical sensor with high sensitivity and selectivity was developed for bisphenol A (BPA) determination in water. The sensor was fabricated by directly thermalpolymerising molecularly imprinted film on a multi-wall carbon nanotubes (MWNTs) modified glassy carbon electrode (GCE). The linear sweep voltammogram of BPA on this sensor exhibited a well defined anodic peak. Under optimum conditions, the oxidation peak currents were linear to the concentration of BPA in the range of 0.1 mg/L-10.0 mg/L with a correlation coefficient of 0.9987 and a detection limit of 24.2 μg/L (S/N = 3). The proposed electrode exhibited good sensitivity and selectivity, and provided operation and store stability for the determination of BPA. The experiment results indicated a good potential application of the modified sensor in the detection of BPA.

Abstract: According to the demand of practical operation of drills in the live working simulation training , sensor technology using in simulation training systems is put forward in this paper.On the bases of brief introduction of sensor technology and summarizing of sensing technology’s application in the simulation training, the sensing system of the live working simulation training system is established.With the sensor system, trainees can simulate a live working process of self participations, achieve real-time interaction with the virtual scene of live working, the objectives of practical operation of drills is achieved, the effect of the simulation training is effectively improved.

Abstract: Wireless visual sensor network (WVSN) is emerging with many potential applications. The lifetime of a WVSN is seriously dependent on the energy shored in the battery of its sensor nodes as well as the adopted compression and resource allocation scheme. In this paper, we use the energy harvesting to provide almost perpetual operation of the networks and compressed-sensing-based encoding to decrease the power consumption of acquiring visual information at the front-end sensors. We propose a dynamic algorithm to jointly allocate power for both compressive-sensing-based visual information acquisition and data transmission, as well as the available bandwidth under energy harvesting and stability constraints. A virtual energy queue is introduced to control the resource allocation and the measurement rate in each time slot. The algorithm can guarantee the stability of the visual data queues in all sensors and achieve near-optimal performance.

Abstract: Energy aware routing is a critical issue in WSN. Prior work in energy aware routing concerned about transmission energy consumption and residual energy, but often do not consider path hop length, which leads to unnecessary consumption of power at sensor nodes. Improved algorithm adds the control of routing hops. Simulation proof the improved algorithm is feasible, effectively reducing the network delay and the path of energy consumption. Taking into account the WSN is dynamic, in the end we put up dynamic hops control in order to adapt to WSN and select the optimal path.

Abstract: In this paper, a new triangle centroid localization algorithm for wireless sensor networks based on received signal strength indicator (RSSI) was demonstrated in great detail, and was simulated using MATLAB , and was compared with the original algorithm. Finally, wireless localization system based on CC2430/31 was set up in IAR development environment. Through hardware testing and comparison, The impact on the localization accuracy is illustrated about the signal transmission loss, beacon node density and outside interference. The superiority of this new algorithm is verified.