Applied Mechanics and Materials Vols. 313-314

Abstract: This paper uses modern spectrum setimation to process stepped-frequency signals which have extracted to obtain high resolution range profile. This paper use FPE criteria and AIC criteria to estimate the order of AR model, and linear prediction is used to test the performance of AR model. Compared with conventional IFFT processing, the results of spectrum estimation is satisfactory, and the exact location of high resolution range profile is determined.

Abstract: the best reception technologyis an important part of communication technology ,this article starting fromthe perspective of improving receivers,mainly analyzes how to make the maximumprobability of correct signals,and minimize the probability of error signalunder the same channel noise conditions,which means the best reception.And give thebinary knowing signal in the white noise of the channel under the condition ofthe best receive structure and principle,filter to accept, analysis ofcommunication technology theoretical research and practical application is verysignificant.

Abstract: £oIn this paper, based on analysis of existing signal generator according to the system of indicators to a reasonable use of single-chip high-frequency precision function generator MAX038 control to produce the periodic waveform of the triangle wave, sine wave and square wave three. MAX038 chip as the core, the use of converters, digitally controlled potentiometers, electronic switches, proportional amplifier waveform type, amplitude, frequency programmable to adjust. The design frequency of mediation a wide range of high stability, and display are intuitive and easy to control. The high precision affordable price can be widely used in a variety of electronic measurement and control applications. Confirmed by the measurement of the effectiveness and feasibility of this program.

Abstract: In this paper we pay attention to the preprocessing of time series and its application. We apply Empirical Mode Decomposition (EMD) to decompose three kinds of series into their components in order to study the data and forecast more efficiently. We try to unite EMD analysis and autoregressive integrated moving average processes (ARIMA) into a new forecasting technique which we call EMD-ARIMA. We find that our method is extraordinarily close to the original data.

Abstract: In real life , arc fault circuit interrupter plays a very important role to prevent the arc fault from fire about protecting the circuit.This article mainly introduces the types of arc,and the main purpose of designing this new type interrupter.The paper tells that it knows about the basic principle of wavelet transformation and use the wavelet tested data to be analyzed.The paper uses the window moving method to summarizes how to judge the basis of arc fault.Some kinds of loads are suitable and some are not.The paper also designs arc detection flow chart.It applies for effective basis for further.

Abstract: A system that can control theunstable running process of automobile transmission repeatedly and sample thesignal consistently is designed, the unstable signal of automobile transmissionwith changing rotate speed is sampled by this system, and analyzed by themethod of order to ascertain the best test position corresponding to the speed,then the system’s repeatability of test is identified. The results ofexperiment and analysis show that the system can control the repeatableexecution of unstable running process of automobile transmission stably, so theproblem of repeatable test of unstable running process is well solved, and thatthe unstable signal of automobile transmission is analyzed by order and theinformation of mesh order is extracted effectively, and the analytical effectis clear and stable.

Abstract: This paper is focused on the application of acoustic emission (AE) based monitoring systems to grinding processes. To develop the AE signal model for the process monitoring, a comparison between the AE and power signals is presented. The AE model is developed according to a traditional grinding force model. Based on the developed model, experiment indicates the AE signal is similar to the power of spindle and verifies the proposed AE model can be used to predict the AE root meam square (RMS) signal for monitoring the grinding process.

Abstract: Digital Phase Locked Loop (PLL) is an algorithm that is used to detect the phase, frequency, and amplitude of a signal. The output of digital PLL algorithm can be used as synchronization reference for grid connected inverter. A digital PLL algorithm is very popular to be used since its structure is very simple and it has high accuracy. However, the output of digital PLL is not stable if the input reference frequency is shifted from the pre-defined fundamental frequency and that condition will result an oscillation in digital PLL output. In this paper, an algorithm modification is employed using low pass filter and all pass filter to improve the digital PLL output response under various condition. All simulation results will be shown and compared to the conventional algorithm.

Abstract: For Direct Sequence Spread Spectrum (DSSS) receiver, a parallel acquisition algorithm based on FFT-IFFT is proposed to improve speed of the DSSS signal acquisition. In order to ensure the FFT data points is equal to a power of 2(2N), Interpolation Algorithm is always used. In this paper, three interpolation algorithms are introduced in detail, and they are analyzed theoretically and compared by quantitative simulation, the resources occupied and test performance verification. We draw the conclusion that the linear interpolation is the optimal algorithm which offers the effective technique for the implementation of DSSS signal receiver.

Abstract: A method based on infrared thermal wave to distinguish coal and waste rock is introduced. Infrared thermal wave detection technology, a fast and effective detection method, can detect different characteristics of coal and gangue on the surface or subsurface. Test showed that coal and waste rock can be distinguished effectively by processing their infrared thermal wave image.