Applied Mechanics and Materials Vols. 241-244

Abstract: Quartz crystal oscillators are often used as the reference frequency sources, but they are very sensitive to accelerations. This paper discussed how accelerations affect oscillators’ frequency stability. The frequency shifts caused by gravity was shown through 2g-tipover experiment. Then a vibration experiment system was built up, which consist of the vibrating platform, the controlling part, the measuring part and the oscillator. We studied the relationship between accelerations and oscillator’s frequency shifts by imposing sinusoidal and random vibrations onto the oscillator and observing the phase noise degradation via signal source analyzer. The paper also brought up the measuring method of the acceleration sensitivity vector.

Abstract: The quality of overall national surface water has been slightly polluted, large number of cheap and convenient wireless sensor were used by environmental protection departments to 24 hours water quality monitor, in order to layout convenient the wireless sensor node generally used battery for power supply, the node require working up to several months or even years but battery replacement was difficult or impossible. In this paper, research does not affect the function of WSN how to save the node energy consumption, which can work more time in large-scale collection, processing and communication of complex environmental data. Results show that the node energy-saving technologies and network integrated energy-saving technologies can be to reduce the energy consumption of nodes 31.8% and 55.6%, which can greatly extend the working life of the wireless sensor node battery.

Abstract: A multi-walled carbon nanotube (MWNT) film-based sensor was fabricated using layer-by-layer self-assembly method, and its ethanol gas-sensing properties with varying gas concentration are characterized at room temperature. The experiment results shown that the layer-by-layer self-assembled MWNT film sensor exhibit a fast response and linear resistance change when exposed to ethanol gas, indicated a prospective application for ethanol gas detection with high performance and low-cost.

Abstract: The shunt coefficient of a model of constructions was measured by a pulse current generator, an induction coil, a digital oscilloscope. The experimental results demonstrate that the method is effective, the distribution of pulse current in a buildings can be directly measured without damage.

Abstract: This paper presents an investigation of the geometric quality of three-dimensional data obtained by a thermal-sensing system. On the basis of the presented mathematical model, it is possible to detect not only the three-dimensional shape but also the temperature distribution of an object. Here, the whole 3D shape of the object is reconstructed using the ICP (Iterative Closest Point) algorithm. The measurement system is established using a three-dimensional measurement sensor (Kinect) and thermographic device. Since the three-dimensional surface shape of the object can be measured using the 3D sensor, and the corresponding temperature data obtained by thermography can be allocated to the reconstructed surface of the object on a computer, the data can be used for a quantitative analysis of heat radiation by considering the area and the roughness of the heat source object. Experimental results show the feasibility of the measurement system.

Abstract: Wireless Sensor Networks (WSN) has been increasingly used in various fields of modern production and life, such as industrial control and environmental monitoring. However, there is no effective and universal algorithm at present for optimizing the deployment of WSN nodes in buildings. The main reason is the complex environment of the monitoring region which brings about the difficulty in determining the attenuation of wireless signal. The relationship between the Received Signal Strength Indicator (RSSI) and Packet Error Rate (PER) are discovered by the experimental method, then the corresponding mathematical model is also established by the experimental data. Based on different PER value, one method for optimizing the deployment of nodes in buildings is proposed by the RSSI value of the sensor node. This method can use fewer sensor nodes to cover the required monitoring region, which has the advantage of low-cost network construction, easy maneuverability and good versatility and et al. Finally, the deployment method of sensor nodes and the deployment example of temperature and humidity monitoring system are given in the paper.

Abstract: Wireless sensor networks (WSNs) are gradually adopted in the industrial world due to their less cost and easy deployment. The contributions of this paper are modeling transmission reliability in typical industrial environment and implementing the model as extended simulation framework for optimizing the hopping scheme. The statics model is realized as Extended Industrial Framework (EIF) based on OMNet++ to support the description of diverse wireless link characteristics in diverse industrial utility. The simulation results show accuracy of EIF with consistent trend as actual measurement and validity to simulate the operation of industrial WSN protocols.

Abstract: A novel WSNS (wireless sensor network sniffer) is used to analyze and evaluate the Wireless Sensor Networks (WSN) effectively, which is designed to monitor IEEE 802.15.4 protocol frame of the Ethernet. Unlike the existed monitoring system, this design has higher efficiency and needs less resource. It is analyzed in this paper that the monitor network framework, time synchronization, and analysis program design. The results show that WSNS can real time display the monitored frame and dynamic changes of WSN topology.

Abstract: A difficulty of multisensor data fusion lies in the switching of the state of sensor clusters. That is, which direction should the sensor data been fused into at a given moment In this paper, firstly, the rough set was used for access of knowledge. The typical clustering distributions of 54 sensors within one day were regarded as sample space for the decision-making table of the "data - fusion distribution". Next, based on the method of knowledge reduction using rough set, the redundant properties and samples of data in one month were removed. Then, the ART2 network was applied for clustering and analyzing, and the distribution rules of multisensor data fusion are formed. The experiment results show that the model is efficient in classification and rapid in sensor clustering distribution decide.

Abstract: The purpose of the paper is to design a sensor to satisfy the need of the strain transmission measurement for the underwater gun. In this paper, after a statement of the working principle of the sensor system, the entirely standards sensor making process involving the performance and intensity limitation of the strain tube are conducted. Then this will be followed by an analysis of the working bridge road. Finally, by the existing standard sensor, the designed sensor is calibrated and contrasted. The test results show that the designed strain cylinder sensor offers advantages over linearity, and hence can be used in engineering practice.