Papers by Keyword: Correlation Function

Abstract: We considered the Ising 1D chain in an external magnetic field taking into account the nearest and next-nearest interactions. By the method of Kramers–Wannier transfer-matrix, the rigorous analytical expression for Fourier-transform of pair spin-spin correlation function was obtained, and the temperature evolution of the scattering was analyzed for various relations of exchange parameters.

Abstract: At present, the safety of explosion-proof protective device can't meet the need of the development of coal industry.The problems mainly display that the flameproof machine is easy to lead to the electric spark explosion which large current cause and is easily affected by underground distractions. The article puts forward a kind of intrinsically safe explosion-proof device which use related functions to eliminate interference. the device regard T I company production of ultra low power 16-bit MSP430F149 MCU as the core device which can automatically in real time detection of the leakage, overload, short circuit, over/under voltage, phase and other power grid fault and trip alarm.

Abstract: According to the operation status of the transportation enterprise in our country, choose financial benefit, asset operational condition, debt paying ability and development ability as a benefit evaluation system. In order to achieve the goal of comprehensive evaluation, the Extension Matter-element Model is applied to the benefit evaluation field. And correlation function is used to represent the benefit of transportation enterprise.Through the comprehensive level evaluation of transportation enterprise benefit, we analyze the reasons for the poor financial results of enterprise and corresponding improving measures are put forward according to the results of the evaluation.

Abstract: The principle of imaging method based on matched filtering and chaos theory are introduced. On this basis, a new method of range imaging using the correlation function of the chaotic signal is provided. At the same time, simulation models and simulation results are given. The experiment results show this method has the advantages of good range resolution and excellent anti-interference performance, the quality of the reconstruction image is fine.

Abstract: Nowadays, urbanization becomes a hot spot and the evaluation of urbanization becomes an important part of urban management. Based on the urbanization development status of central region of China, considering the indicators impact on the urbanization level and using the matter-element theory, an extension evaluation model of urbanization is set up in this paper, which is used in the comparison of urbanization level in central China. The practicality of model is verified through the case and the management measures to improve the urbanization level is proposed through analysis the correlation function, while some reference for urban development of various regions in China is offered.

Abstract: Main problem in operation of diagnostic systems of power transmission systems is analysis of the energy of these harmonic components of the signal, which could be considered as diagnostic symptoms. Measured values can be affected i.a. by energy of random effects or other, less important components of the signal. Coherence and correlation functions are ones of classical methods of signal analysis being applied to analyze deterministic signals affected by random noise. In time domain autocorrelation function allows to determine time cohesion between adjacent fragments of analyzed process, shifted by different time values. In the paper author describes the method of minimization the impact of disturbances on signals being analyzed using basic properties of autocorrelation function. For the analysis of deterministic phenomena (including nonlinear) ordinary coherence function was applied. Showed examples were implemented and solved in MATLAB environment. The method was verified by analysis of model signals and signals (vibration accelerations) recorded on real object.

Abstract: To solve acquired the membership degree in fuzzy evaluation. we use correlation function in extension theory to calculate the degree of association between evaluation indicators and fuzzy scales, and then the degree of association is done standers conversion and normalized processing,, getting the membership value of evaluation matrix in fuzzy comprehensive evaluation. Comprising traditional statistical methods and expert evaluation method, the membership value of evaluation matrix which is gat through correlation function method of extension theory is more simple and reasonable. Comprehensive evaluation value is got from Calculating linear weighted between evaluation matrix and the index weight coming from analytic hierarchy process. Finally, using two type of home made NC machine tools as example to do the practical application study of the proposed method, the results show that this method can give the reasonable evaluation.

Abstract: This paper introduced Extension optimization theory into the parameters optimization of lapping process, the five process parameters of the lapping load pressure, the platen speed, the abrasive particle size, slurry flow, lapping fluid concentration are considered, the target extension decision models and integrated decision-making correlation function are established. According to the selection criteria, the optimum solution is obtained. The results showed that: as the lapping speed of 35rpm, the pressure of 11 MPa, the abrasive particle size of W7.95, the slurry flow rate of 228.75ml/min, the slurry concentration of 25%, the surface removal rate increased, the surface roughness decreases, flatness decreases.

Abstract: The correlation distance is one of the important parameters for the application of random field theory to reliability analyses. Soil spatial variability is related to soil point variability with the reduction factor of variance in random field theory, and the reduction factor of variance depends on both soil auto-correlation distance and spatial area. The sampling space effect on auto-correlation distance is studied. The vertical and horizontal correlation distances of typical stratum are analyzed in statistics based on a large amount of investigation data and the representative values of correlation distance of local area are obtained. It is concluded that that the correlation distances estimated by different soil parameters are similar, and the horizontal correlation distance is much larger than the vertical one for the same soil parameter. The sampling space should be paid attention to when calculating correlation distance of soil parameter.

Abstract: In order to evaluate the quality of hardware products comprehensively and objectively, an evaluation model of extension multilevel optimization about hardware products has been established. The model was based on analyzing the quality management of hardware enterprises and took the hardware valve as an example. The solving process firstly used scale index and the first evaluation in restricting and reducing the scope of evaluation so as to improve solving efficiency. Then the values of correlation function, correlation degree, standard correlation degree and the optimization were calculated. Finally the comprehensive evaluation results could be got objectively through comparative analyzing these values. The results indicated that higher degree of satisfaction program would be obtained by applying the multilevel optimization evaluation method of product. And the products quality largely depended on its production stage. Thereby it aided the production managers to do the right choice.