Applied Mechanics and Materials Vols. 644-650

Abstract: In order to conduct signal detection in linear frequency modulation model, using Bayes Criterion, Neyman-Pearson criterion, Minimum error probability criterion and Maximum likelihood criterion. The experimental results show that: Neyman-Pearson criterion is a special case of the alternative Bayes detection; maximum posteriori probability criterion and minimum error probability criterion are equivalent; if equal prior probability, then the maximum a posteriori probability criterion and the maximum likelihood detection have the same probability. So in the actual operation, select appropriate criterion based on the specific conditions.

Abstract: With the rapid development of today's society, air pollution is becoming one of the hottest topics of humans’ concern. Looking at the daily life, some peoples’ awareness in the dangers of indoor air pollution and household gas safety is not enough, so it may lead to a number of respiratory diseases, or "sub-health" conditions. (Such as influenza, pharyngitis and other diseases) On the other hand, some families, because of a gas leak, has not been timely warning of fires and caused the tragedy. To solve these problems, this work is designed based on low-power microcontroller as the master chip HT32F1765 100LQFP between the various smart sensors and did data exchange with the home environment monitoring system. The HT chip use as the master chip and combined with using Sharp PM2.5 gas sensors, temperature and humidity sensors, gas concentration sensor as gas sensing devices. We use all these sensors as information collection module, to collect the data information of air quality, temperature, humidity and combustible gas concentration in different rooms and different locations. The real-time data acquisition and sensor would be displayed on the touch screen. In addition, the creation of data monitoring hardware devices, as well as match the mobile phone in APP. Our users can log on the APP remotely to view home monitoring information, or to receive alarm information.. Thus, adults can safely work outside, avoiding unnecessary worry.

Abstract: The calibration process of a digital Multi-meter (DMM) is complicated and tedious. The whole procedure needs to calibrate dozens of test points of several measuring ranges. Usually, the automatic calibration system is used to replace the manual operation. In metrology, the MAT/CAL which is a software produced by Fluke company has been widely used, but it can’t meet our special needs. This article is mainly on the introduction of design method of an automatic calibration system for DMM basing on Fluke MAT/CAL. It describes the setup of hardware, the improvement of ACC file in MAT/CAL and the basic principle of our software.

Abstract: To study the data consistency of Three-pin/T-shaped probe and thread scanning measurement. Through the analysis and summary of the measurement methods and experimental data obtained in two methods of measurement uncertainty can meet the thread gauge diameter measurement requirements. Experiment to obtain the maximum difference of the actual size of the corresponding point of 1.1μm, verify the correctness of the two thread measurement method and propose the appropriate application program.

Abstract: The detection of landmines has become a hard task to deal with because of the diversity of landmines and the complexity of minefield. The development of terahertz technologies has provided a feasible way to detect the buried landmines. Landmines’ shell is usually made of ceramics, plastics, even wood and so on, which terahertz wave could penetrate them easily. The explosives are the major part of landmines. Many types of explosives have the characteristic spectrum in terahertz range, so it would be an effective method to detect landmines by measuring the spectrum of explosives with terahertz time-domain spectroscopy.

Abstract: For large-scale structural damage in various forms, a single regional monitoring is difficult to finish. The paper introduces a design method of a large-scale structural health monitoring system based on wireless sensor networks. ZigBee wireless communication technology is used for the system. The ZigBee-based double wireless sensor network architecture is designed. The wireless sensor node, sink node, a gateway node of this system is designed by using the CC2530 chip as core of data processing and wireless transceiver. In the IAR development platform, the lower position machine software is designed by using C language and the LabVIEW is used to finish the remote display in the host computer. The results show that the monitoring system meets the design requirements, has the advantage of good on-line and real-time monitoring etc.

Abstract: This Paper proposes a quick matching method for vehicle plate data based on NoSQL database technology considering the huge amounts of traffic information, the method uses the basic traffic network information database which built based on vehicle license plate auto recognition system and it improves the effectiveness and applicability of huge data-matching. Besides, the paper fits the travel time by the time priority principle, and estimates the average travel time by the mean estimation and median estimation according to sample capacity. The practical application shows that this method can effectively improve the efficiency of the mass data processing, and obtain travel time information quickly.

Abstract: Thanks to recent technological advances in the field of eye tracking, eye typing provides means of communication for people with severe disabilities. Typing with gaze using dwell time has been made possible by the development of eye tracking technologies. Recent research indicates that pupil size is viewed as a subtle cue of people is making a decision. Therefore, it may help to infer users’ willing of typing. The present study describes the design process for improving eye typing by adding pupil size index into dwell time triggering. Experimental evaluations showed that the approach was effective; design considerations for such optimization of the gaze typing interfaces are discussed.

Abstract: Mobile carrier satellite communications are becoming increasingly attention. Civil, with satellite television, satellite Internet access, as well as development of civilian systems such as video phones, on growing demand for mobile communications carrier; the military, rapid response to equipment and mobility as well as steady aim, track and combat capabilities of mobile high demand, also depend on the mobile carrier satellite communications. Mobile carrier satellite communications system is the key equipment of satellite antenna auto-tracking system. Develop performance-price ratio reasonable automatic satellite antenna tracking system to fill the gaps in this area, is of great significance.

Abstract: As the geological hazards in mountainous areas in Southwest of China has the characteristic of different varieties, wide distribution and great harm. So, it is important to conduct the roads in scientific and rational method under the changing environment, especially to choose the traffic corridor with lower risk. In this paper, including the contents of analyzing the factors which influence the disaster risk and using the analytic hierarchy process with GIS spatial analysis to evaluate the disaster risk level of the mountainous areas of the traffic corridor under the given example-Sichuan-Tibet Railway from Changdu to Kangding.