Applied Mechanics and Materials Vols. 602-605

Abstract: Because the reentry telemetry wireless channel multipath propagation effects and the effect, channel will introduce transmission time delay dispersion, caused between the PCM/FM telemetry signal crosstalk and signal to noise ratio is too low, significantly increase BER. While traditional demodulation method because the demodulator threshold higher no longer apply. Study the problem, a multiple Symbol Detection method based on sliding strategy (Multi - Symbol Detection, MSD), can effectively overcome the low SNR and inter symbol interference. The simulation and test results verify the effectiveness of the method.

Abstract: This paper briefly summarized the logical structure of the model’s attribute characteristics in the wireless sensor network management system of coal enterprise. Due to all kinds of mapping relations between different datum, while extracting some device status information, we can detect it by the method of hierarchical search, and according to the determined geographical location, then obtain the attribute and graphic information, finally get all the relative information of the device, so that the information management system is fast and convenient to be used.

Abstract: A water environmental monitoring system based on a wireless sensor network is proposed. It consists of three parts: data monitoring nodes, data base station and remote monitoring center. This system is suitable for the complex and large-scale water environment monitoring, such as for reservoirs, lakes, rivers, swamps, and shallow or deep ground waters. This paper is devoted to the explanation and illustration for our new water environment monitoring system design. The system had successfully accomplished the online auto-monitoring of the water temperature and pH value environment of an artificial lake. The monitoring system thus promises broad applicability prospects. The system's measurement capacity ranges from 0 to 90 °C for water temperature, with an accuracy of ±0.5 °C; from 0 to 16 on pH value, with an accuracy of ±0.05 pH units. Sensors applicable to different water quality scenarios should be installed at the nodes to meet the monitoring demands for a variety of water environments and to obtain different parameters.

Abstract: The acquisition of information about channel coding sequences is the research emphasis and difficulties at present, and recognizing the channel coding parameters is the prerequisite for information acquisition. RS Codes are a class of linear block codes as well as a special class of BCH Codes and cyclic codes. It regards a group of symbols with a length of n as a unit to process with, and the n symbols are generated by k transmitting information symbols under some proper associated rules. RS Codes are widely used in various communication systems. In this paper, an algorithm of RS Codes blind recognition is researched. And a blind recognition model is established on MATLAB. At last, the paper presents the recognition rates of situations with different error rates.

Abstract: The chlorophyll content in crop leaf is an indicator of health situation and the crop yield. Hence, it is very important to retrieval of accurate chlorophyll content in paddy rice. This research selected Zhengyi town of Suzhou city as the study area, measurements were acquired during the summer of 2009, in a field campaign in which for 288 rice leaf samples, rice hyperspectral data was measured by ASD FieldSpec3 spectrometer, chlorophyll content was measured by using a SPAD-502 chlorophyll meter. And the parameters of support vector machine were optimized by genetic algorithm, then support vector machine and PROSPECT radiative transfer model were adopted to build estimation model, which used to retrieve the chlorophyll content of rice. The results indicate that: the coefficient of determination for the rice chlorophyll estimation model is 0.8825, and RMSE is 8.7491. Research of this paper provides some reference for quickly and accurately estimating the chlorophyll content in rice.

Abstract: With the continuous improvement of security awareness, home security has become the focus of attention. The actual demand for home video surveillance system, designed a cheap, practical, small size and low power consumption of video surveillance systems, this paper uses microprocessor S3C2440 ARM9 core as the core hardware control, embedded Linux operating system with software the control core, and cheap, generic USB camera video capture device as a front end to complete the design of a home video surveillance system.

Abstract: Due to the highly developed modern technology,Smart phones and other mobile devices are become more and more universal. Most of those devices are used to process or store sensitive and confidential data.Consequently,it may cause many problems,such as privacy disclosure,mobile phone virus,spyware,etc. In order to solve those issues,We need to monitor applications`s behaviour to tell those malicious ones. Here we use MobileSubstrate to hook every sensitive system API the application invokes in iOS planform,and send this invocation to our matching algorithm,the matching algorithm will evaluate if the API are being invoked in a safe way according to Application API Review Model.If a application trying to call some APIs which is totally unnecessary,we can reject this invoke and give user a warning.

Abstract: In this paper a reliable secured handover with less time delay is suggested. To enhance the reliability of data transfer during handover, the exact location of the Mobile Node (MN) is to be known. Hence a GPS based Mobile Node location and direction prediction is suggested, which helps to handover to the appropriate Base Station. The security in transfer of data is ensured by a novel Mobile Information Centre (MIC) based dual authentication algorithm.

Abstract: It is the precondition of vibration fault diagnosis technology that appropriate signal analysis method is applied to separate mechanical fault character message from vibration monitoring signal. Based on the characteristics of multi-exciting, multi-model, non-stationary, nonlinear of the complex mechanical vibration signal, the EMD (Empirical Mode Decomposition) method is firstly applied to decompose the most refined IMF (Intrinsic Mode Function) components of vibration monitoring signal, and then the time series analysis method is applied to estimate power spectrums of IMF components and separate the fault character messages. The feasibility and advantage of the associated method are proved by analyzing the diesel engine crankshaft vibration monitoring signal in the paper.

Abstract: This paper introduced the principle of three pulse method and the method’s advantages and disadvantages on cable fault detection, modeled three pulse detection method of cable fault in the Simulink environment, analyzed the Wavelet threshold denoising effect on cable fault detection accuracy under different threshold selection rules, and proposed a three pulse detection method based on the wavelet threshold de-noising.