• 제어로봇시스템학회:학술대회논문집
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• 1993.10b
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• pp.150-154
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• 1993

A new method is proposed for obtaining Volterra kernals of a nonlinear system by use of a nonlinear systems by use of pseudorandom M-sequences and correlation technique. M-sequence is applied to a nonlinear technique. M-sequence is applied to a nonlinear system and the crosscorrelation function between the input and the output displays not only the linear impulse response of the linear part of the system, but also crosssections of the Volterra kernals of nonlinear system. Simulations are carried out for up to 3rd order Volterra kernal, and the results show a good agreement with the theoretical considerations.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.9C
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• pp.876-881
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• 2006

In this paper, we propose a complex-valued IIR filter for digital VSB signals based on CMA in order to efficiently mitigate multipath distortions, especially the leakage from the quadrature component. The proposed equalizer overcomes the drawback of the conventional real-valued IIR equalizers that it attempts to equalize Hilbert transform of quadrature component. We demonstrate via simulation that the proposed complex IIR filter successfully mitigates the leakages from the quadrature component, while the conventional real IIR filter requires a longer IIR filter to achieve the same performance. We present cost function analysis for a simple two-tap case showing that the proposed IIR equalizer with CMA for VSB signals has a global minimum at the desired location.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2007.11a
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• pp.477-481
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• 2007

The purpose of this study is to provide the ideal forecasting model of cadastral survey work load through the Economeatric Analysis of Time Series, Granger Causality and VAR Model Analysis, it suggested the forecasting reference materials for the total amount of cadastral survey general work load. The main result is that the derive of the environment variables which affect cadastral survey general work load and the outcome of VAR(vector auto regression) analysis materials(impulse response function and forecast error variance decomposition analysis materials), which explain the change of general work load depending on altering the environment variables. And also, For confirming the stability of time series data, we took a unit root test, ADF(Augmented Dickey-Fuller) analysis and the time series model analysis derives the best cadastral forecasting model regarding on general cadastral survey work load. And also, it showed up the various standards that are applied the statistical method of econometric analysis so it enhanced the prior aggregate system of cadastral survey work load forecasting.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.86.2-86
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• 2001

The method of pinpointing the place of the abnormalities of a power transmission system analyzes the voltage and the current information from the both ends of a power [1-2]. Now, there are only current and a voltage measuring instrument every about 20km, and the present condition is specifying the breaking down point by viewing of a worker in it. In this research, a power line circuit is assumed to be a line type system, and M-sequence is impressed to the end, it receives at other ends, the crosscorrelation function of input and output is taken, an impulse response is calculated, and the method in comparison with the time of normal is proposed. By this technique ...

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.1
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• pp.1-9
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• 1994

In general, when IIR digital filter are designed from analog filters, the bilinera transformation and the impluse invariant tramsformation are commonly used. It is known, however, that high frequency response of digital filters designed by these transformations can not be well approximated to the sampled analog signals. In this paper, the symbol pulse invariant transformation is analyzed theoretically so that the symbol pulse invariant transformation which was originally application to a rectangular pulse is newly applied to double rate pulse signals and generic shape pulse signals. Also, the relation of spectra between a transfer function of digital filter and one of analog filter is considered. Further, we apply to design the digital high pass filters using the symbol pulse invariant transformation method.

• Communications for Statistical Applications and Methods
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• v.9 no.1
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• pp.141-154
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• 2002

Foreign investors'shares and their influences on the Korean stock market have never been larger and greater before since the market was completely open to foreign investors in 1992 Quantitatively and qualitatively as well, as a result, changes in the patterns of foreign investments have caused enormous effects on the interactions of major macroeconomic indices of the Korean economy. This paper is intended to investigate the causal relations of the four variables, foreigners'buy-sell ratios, stock returns, ￦/＄ exchange rates and $\yen$/＄ exchange rates, over the two time periods of the pre-IMF (1996.1.1-1997.8.15) and the post-IMF (1997.8.16-2000.6.15) based on the daily data of the variables. Granger Causality Test, Forecast Error Variance Decomposition(FEVD) using VAR model and Impulse Response Function were implemented for the empirical analysis.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.1
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• pp.133-140
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• 2018

In this paper we discover the generation principle of a sequence when the characteristic polynomial of the sequence is a power of a primitive polynomial. With the generation principle, we can rearrange a sequence. Also we get the linear complexity and the required term of the sequence efficiently.

• Journal of Ocean Engineering and Technology
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• v.14 no.4
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• pp.1-8
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• 2000

The time simulation of motion responses of dolphin-moored BMP in waves is presented. The equation of motion based on Cummin's theory of impulse responses are employed, and solved in time domain by using the Newmark $\beta$ method. The hydrodynamic coefficient and first order wave exciting forces involved in the equations are obtained from a three-dimensional panel method in the frequency domain. The second order wave drift forces and mooring for dolphin system are taken into account. As for numerical example, time domain analysis are carried out for a BMP in irregular wave condition.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.4 no.3
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• pp.283-287
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• 2004

In this paper, a method of designing the efficient batch blind equalization with low complexity using a micro genetic algorithm (GA), is presented. In general, the blind equalization techniques that are focused on the complexity reduction might be carried out with minor effect on the performance. Among the advanced various subjects in the field of GAs, a micro genetic algorithm is employed to identity the unknown channel impulse response in order to reduce the search space effectively. A new cost function with respect to the constant modulus criterion is suggested considering its relation to the Wiener criterion. We provide simulation results to show the superiority of the proposed techniques compared to other existing techniques.

• Journal of the Optical Society of Korea
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• v.18 no.1
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• pp.15-22
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• 2014

We present a novel bandwidth measurement scheme for multimode optical fibers. Amplified spontaneous emission (ASE) radiation was utilized for a source of intrinsically modulated light with a wide modulation bandwidth. In our measurement scheme, the continuous-wave (CW) ASE light that passed through a multimode fiber (MMF) under test was analyzed by the fourth-order power with a high-speed photodetector and an electric spectrum analyzer. The modulation transfer function of the multimode fiber could be directly measured with the photoelectric spectra in the modulation frequency domain. The measurement result of our method was experimentally compared to that of the conventional measurement scheme based on the impulse response measurement. It has been found that our scheme provides a stable measurement means of MMF characterization that is suitable for the field testing due to the simplicity of the system.