• Proceedings of the Korea Society for Industrial Systems Conference
• /
• 1998.03a
• /
• pp.305-311
• /
• 1998

본 논문에서는 회전과 크리에 무관한 상관결과를 얻기 위하여 WCHF-fSDF(wavelet circular harmonic function-filter modulation synthetic discriminant function)필터를 제안하였다. WCHF-fSDF 필터는 기준영상에 대하여 크기변화된 영상들을 웨이브릿 변환한 후, 이들로부터 추출한 단일 원형고조함수를 학습영상으로 사용하여 합성한다. 웨이브릿 변환은 입력영상과 웨이브릿 함수와의 상관으로 정의되므로 웨이브릿 변환을 이용한 패턴인식을 하기 위해서는 두 개의 4f 광 상관 시스템이 필요하다. 여기서 입력영상에 필요한 웨이브릿 함수를 제안된 필터의 설계과정에 포함시켜 전체 광 상관 시스템을 하나의 4f 광상관시스템을 대체시켰다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.34 no.1
• /
• pp.91-98
• /
• 2016

In order to apply Kriging methods for geostatistics of spatial data, an estimation of spatial coherency functions is required priorly based on the spatial distance between measurement points. In the study, the typical coherency functions, such as semi-variogram, homeogram, and covariance function, were estimated using the national geoid model. The test area consisting of 2°×2° and the Unified Control Points (UCPs) within the area were chosen as sampling measurements of the geoid. Based on the distance between the control points, a total of 100 sampling points were grouped into distinct pairs and assigned into a bin. Empirical values, which were calculated with each of the spatial coherency functions, resulted out as a wave model of a semi-variogram for the best quality of fit. Both of homeogram and covariance functions were better fitted into the exponential model. In the future, the methods of various Kriging and the functions of estimated spatial coherency need to be studied to verify the prediction accuracy and to calculate the Mean Squared Prediction Error (MSPE).

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.38A no.5
• /
• pp.409-415
• /
• 2013

In this paper, we propose a correlation function using newly designed local signals for cosine-phased binary offset carrier (BOC) signal tracking. First, we divide a sub-carrier pulse over one pseudo random noise code period into multiple rectangular pulses, and subsequently, design novel local signals. Then, we obtain a correlation function with no side-peak based on a combination of correlations between the newly generated local signals and received cosine-phased BOC signal. From numerical results, it is confirmed that the proposed correlation function provides a tracking performance improvement over the conventional correlation functions in terms of the tracking error standard deviation.

• Proceedings of the IEEK Conference
• /
• 2000.09a
• /
• pp.799-802
• /
• 2000

음성신호처리 분야에서 음성신호의 기본 주파수를 정확히 검출 할 수 있다면 음성인식을 할 때 화자에 따른 영향을 줄일 수 있으므로 인식의 정확도를 높일 수 있고, 음성합성을 할 때 자연성과 개성을 쉽게 변경하거나 유지할 수 있다. 또한 분석을 할 때 피치에 동기시켜 분석하면 성문의 영향이 제거된 정확한 성도 파라미터를 얻을 수 있다. 위와 같은 피치검출의 중요성 때문에 피치검출에 대하여 다양한 방법 이 제안되었다〔1〕. 본 논문에서는 음성신호의 분석 시 불안정한 구간에 대해 피치 시점을 검출하는 방법을 연구하였다. 음성신호의 분석에 있어서 기존의 자기상관함수법(Autocorrelation Function)은 주기성을 강조할 수 있다는 장점을 가지고 있다. 그러나 자기상관함수는 위상성분을 보존하지 못한다는 단점을 가지고 있다. 따라서, 자기상관함수를 사용하면서 위상성분을 보존할 수 있는 알고리즘을 제안하고자 한다. 실험결과 피치시점을 수동으로 찾은 경우와 비교하였을 때 약 98% 정도의 정확도를 얻을 수 있었다. 위의 결과와 같이 위상 성분이 보존된 자기상관함수를 사용할 경우 음성합성, 코딩, 인식에서 유용하게 쓰일 수 있다.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.4 no.1
• /
• pp.50-56
• /
• 1999

This paper presents consideration on validity of instantaneous correlation power theory. The proposed power theory is defined and analyzed by time domain approach, thus it is easy to understand and instrument. The power is decomposed into active, fundamental reactive and harmonics components based on the autocorrelation and crosscorrelation signal techniques between voltage and current waveforms. On the compensation property, active power filter deal with three components only. Also, for real time control of active power filter, the power models with difficult concept are not cost effective. To verify the validity of the instantaneous correlation power theory, experimental work for voltage type DSP based active power filter is achieved. The power of thyristor controlled motor drives is decomposed into three orthogonal components by proposed power theory. From compensation results, validity of proposed theory is confirmed. feedback controller needs the information on some motor parameters. New recursive adaptation algorithms for rotor resistance and mutual inductance which can be applied to our nonlinear feedback controller are also presented in this paper. The recursive adaptation algorithms make the estimated values of rotor resistance and mutual inductance track their real values. Some simulation and experimental results show that the adaptation algorithms are robust against the variation of stator resistance and stator inductance.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.9C
• /
• pp.581-588
• /
• 2011

In this paper, we propose a novel unambiguous code tracking scheme for cosine phased binary offset carrier (BOC) signals. We first obtain the sub-correlation functions composing the BOC autocorrelation function, and then, re-combine the sub-correlation functions generating a correlation function with no side-peak. Finally, by using the correlation function with no side-peak in the delay lock loop, the proposed scheme performs unambiguous signal tracking. Numerical results demonstrate that the proposed scheme provides a performance improvement over the conventional unambiguous scheme in terms of the tracking error standard deviation (TESD).

• Proceedings of the Optical Society of Korea Conference
• /
• 2009.02a
• /
• pp.449-450
• /
• 2009

The spatial coherence and propagation property of laser beam propagating through several optical components were studied experimentally by using the measurement of Wigner distribution function. It is shown experimentally that the Wigner function measurement yields total degree of coherence, beam quality parameter, and the near and the far field information of the propagating beam. More complete characterization of the laser beam was achieved by applying the Schmidt mode decomposition to the Wigner distribution function, spatial coherence function and directional coherence function. Fine details of coherence property are understood by the characteristics of the contributing eigenmodes.

• Review of KIISC
• /
• v.6 no.1
• /
• pp.33-44
• /
• 1996

본 고에서는 참고문헌 [9]을 바탕으로 선형복잡도 특성이 우수하고 이상적인 자기상관함수 특성을 갖는 GMW 계열의 특성을 분석한다. 이를 위하여 먼저 LFSR 계열의 특성방정식을 제시한 후, 트레이스함수를 이용하여 GMW 계열을 정의한다. 그리고 GMW 계열의 자기상관함수를 구하며, 차수가 6인 GMW 계열의 생성기의 구조를 제시한다. 마지막으로 GMW 계열의 선형복잡도와 갯수를 구하는 수식을 유도한다.

• The Journal of the Acoustical Society of Korea
• /
• v.35 no.2
• /
• pp.118-124
• /
• 2016

In this paper, contribution analysis method using a partial coherence function is dealt with in the case of underwater radiation noise. When performing the contribution analysis using a partial coherence function, it is important to select the order of system input. But in the case of frequency correlated systems, it is very difficult to properly select the order of system input. In order to solve this problem, the contribution analysis is performed by subdividing the area of contribution using multiple coherence function. And the new contribution analysis method is presented by using the relationship between the contribution characteristic matrix and multiple coherence function. In order to validate the new method, calculation is performed about multi-input / single-output model which is composed of sine waves. The result of calculation shows that it is possible to derive the exact contribution values.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.34 no.1C
• /
• pp.131-137
• /
• 2009

Binary offset carrier (BOC) signal synchronization is one of the most important steps to recover the transmitted information in global navigation satellite systems (GNSS) including Galileo and global positioning system (GPS). Generally, BOC signal synchronization is based on the correlation between the received and locally generated BOC signals. Thus, the multiple side-peaks in BOC autocorrelation are one of the main error sources in synchronizing BOC signals. Recently, a novel correlation function with reduced side-peaks was proposed for BOC signal synchronization by Julien [8]; however, Julien's correlation function not only still has the side-peaks, but also is only applicable to sine phased BOC(n, n), where n is the ratio of the pseudo random noise (PRN) code rate to 1.023 MHz. In this paper, we propose a new correlation function for BOC signal synchronization, which does not have any side-peaks and is applicable to general types of BOC signals, sine/cosine phased BOC(kn, n), where k is the ratio of a PRN chip duration to the period of a square wave sub-carrier used in BOC modulation. In addition, an efficient correlator structure is presented for generating the proposed correlation function.