Applied Mechanics and Materials Vols. 128-129

Abstract: A wireless temperature monitoring system based on fluorescence lifetime is researched in this paper, which mainly consists of the temperature acquisition unit and the master control monitoring unit. The wireless module with the core of low-power microcontroller (SX1212) and the sensor based on optical-fiber fluorescence are designed. And the unit of fluorescence temperature measurement is introduced in detail. Testing result indicates that the communication distance of the wireless module can be up to 300 meters, which meets the requirements very well. There are many advantages in this system, such as no wiring, better scalability, real-time monitoring.

Abstract: This paper gives a new definition, the Miss Distance Sensitivity to Target Maneuvers (MDSTM), which evaluates the robustness of the Terminal Guidance System (TGS) and gives the degree of exact miss distance caused by the inaccurate estimates of target maneuver. In this paper, the criterion of sensitivity analysis is the ratio of miss distance to target maneuver. The form of the TPN is investigated and then the GTPN guidance law is also proposed. Then, considering cases that the flight control system without dynamics and the dynamics characteristic can not be ignored, the MDSTM performance of TGS governed with TPN and GTPN for step acceleration target maneuvers are analyzed. Finally, the sensitivity analysis results of the system are listed in the paper, and the conclusions of how the effect the MDSTM were given in the end of the paper.

Abstract: The traditional algorithm of searching a new radio signal is not from the nature of the signal, but from the simple statistics and four arithmetic operation. So, there must be a big gap to decide which signal is a abnormal signal. This paper draws the innate character of the signal and then uses the ordered weighted averaging aggregation operators (OWA) and k-means to deal with the datum. The signal type is decided by multiple attribute decision making (MADM). The result of experiment show the method is effective.

Abstract: Soil test is the key-point for formulated fertilization. The traditional chemical analysis methods for estimating soil nutritional parameters were time-consuming. The present aims to use portable acousto-optic tunable filter (AOTF) near-infrared (NIR) spectrometer to measure soil parameters, thus provide basis for field analysis of soil quality. A total of 231 soil samples were collected, Partial least squares (PLS) was used to construct the calibration model between the NIR spectra and the reference values measure by standard chemical methods, including organic matter, pH, ammonium nitrogen, nitric nitrogen, and total kalium content. Results showed that the prediction of organic matter and pH had high correlation (R=0.8745, R=0.8594, respectively), the prediction of ammonium nitrogen and total kalium content were acceptable (SEP%=23.2595%, 10.1516%), and the calibration model for nitric nitrogen had the worst performance. The present study indicated that portable AOTF-NIR spectrometer could be used to measure the nutrient parameters of soil.

Abstract: The post-disaster road monitoring system provides an interesting application area for wireless sensor networks. After the earthquake, roads are subject to be blocked by landslides. The people require a scalable and low-cost technology for getting real-time dynamic data about road available because aftershocks occur continuously. Wireless sensor networks are a promising candidate to fulfill these requirements. Then the post-disaster road monitoring system solution is put forward. In this system, the ordered arrangement of node number greatly reduces the complexity of node location and provides the premise and guarantee for designing efficient route algorithm for the system. The algorithms of route established and route forwarding are designed for the arrangement and transmission characteristics of nodes, then are more efficient than general-purpose route protocol.

Abstract: Data mining is the process of abstracting unaware, potential and useful information and knowledge from plentiful, incomplete, noisy, fuzzy and stochastic data. The reliability of colliery equipments takes an essential role in the safety of production. Not only since their continuance of operation, had the accumulation of historical error data of colliery equipments resulted in a mass of surplus data, but also because their lacks of helpful information, which as a result makes colliery managers as well as equipment operators hard to make decisions. Seeing that, we introduced ways here that makes use of data mining technology by processing and analyzing historical monitoring data, recognizing and extracting meaningful patterns so as to provide scientific information for decision-making on the safety of colliery operations, which would help for the forecasting of potential threatens of colliery equipments’ operation, thus, make great contributions to prevent disasters from happening.

Abstract: A low-power consumption heat meter with long-distance communication was designed based on MSP430F413 and TDC-GP2. The new flow measurement circuit and correction method were introduced in detail, which improved the accuracy of the heat meter effectively. In order to reduce the power consumption, the running time of the CPU was minimized, the floating-point operation was avoided, and the communication circuit was designed specially. The experiments showed the design is valid.

Abstract: A new dual-wavelength optic-fiber temperature sensor is introduced in this paper. Transmitted probe of this sensor system is designed. LED IR880 and LED IR940 which peak wavelength is 880nm and 950nm are used as the survey light source and the reference light source of the sensor system. So the infection from the changes of the optical fiber transmission loss, the temperature effect of the temperature probe and the optical detector excursion of the sensor can be eliminated. The accuracy and stability of the temperature sensor can be improved and the cost of temperature sensor can be reduced.

Abstract: This paper proposes a hardware and software design proposal of video collection and processing used in digital multimedia microteaching system. The system core is H.264 hardware encoder. 4-channel video data in the case of D1 (720*576) @25fps can be encoded in real-time and uploaded to the PC in distance control room. On the premise of stability, the system adopts friendly operating interface, the user operation is very convenience.

Abstract: An improved project based on double thresholds method in noisy environments is proposed for robust endpoints detection. Firstly, in this method, the distribution of zero crossing rate (ZCR) on the preprocessed signal is taken into account, and then the speech signal is divided into different parts to obtain appropriate thresholds with decision trees on the basis of the ZCR distribution. Finally, the double thresholds method, focusing on different importance of the energy and ZCR, is taken in the corresponding situation to determine the input segment is speech or non-speech. Simulation results indicate that the proposed method with decision trees obtains more accurate data than the traditional double thresholds method.