• 대한수학회논문집
• /
• 제32권3호
• /
• pp.745-763
• /
• 2017

The Borel-Serre partial compactification gives cofinite models for the proper classifying space for arithmetic lattices. Non-arithmetic lattices arise only in semisimple Lie groups of ${\mathbb{R}}$-rank one. The author generalizes the Borel-Serre partial compactification to construct cofinite models for the proper classifying space for lattices in semisimple Lie groups of ${\mathbb{R}}$-rank one by using the reduction theory of Garland and Raghunathan.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
• /
• pp.105-108
• /
• 1997

This paper proposes a new approach of balanced model reduction using matrix pencil. The algorithm presented in this paper is to convert full-rank high-order system into rank-deficient system using perturbation made by matrix pencil method. Then the system can be truncated to a low-order system that we want via balanced realization. We discuss the comparison with other methods and the various observations by simulations.

• 한국음향학회:학술대회논문집
• /
• 한국음향학회 1992년도 학술논문발표회 논문집 제11권 1호
• /
• pp.123-126
• /
• 1992

A new class of data transformation matri is introduced for estimation of angles of arrivals by the rank reduction of multiple wideband sources. The proposed unitary focusing matri minimizes the average of the squared norm of focusing error over the angles of interest without a priori knowledge of source locations. The merit that result as a consequence is a lower resolution threshold. These matrices can be applied to the case of the multigroup sources. Simulations and the comparison of statistical performance are compared with the algorithms (especially, spatial resampling method) which does not require the pre-estimation.

• ETRI Journal
• /
• 제36권1호
• /
• pp.167-170
• /
• 2014

In this letter, we propose an unsupervised framework for speech noise reduction based on the recent development of low-rank and sparse matrix decomposition. The proposed framework directly separates the speech signal from noisy speech by decomposing the noisy speech spectrogram into three submatrices: the noise structure matrix, the clean speech structure matrix, and the residual noise matrix. Evaluations on the Noisex-92 dataset show that the proposed method achieves a signal-to-distortion ratio approximately 2.48 dB and 3.23 dB higher than that of the robust principal component analysis method and the non-negative matrix factorization method, respectively, when the input SNR is -5 dB.

• 한국멀티미디어학회논문지
• /
• 제12권1호
• /
• pp.26-30
• /
• 2009

본 논문에서는 로버스트 통계학의 순위 추정을 기반으로 하고 순서통계학의 L-추정자를 이용한 적응 순환 최소 순위(RLR) L-필터를 제안한다. 제안한 RLR-L 필터는 비선형 적응알고리즘을 가진 비선형 적응 필터로서 오차의 분산측정을 최소화하는 관점의 최적 필터로 가변적인 스텝 크기를 가지며 적응한다. 제안한 필터는 영상신호와 같은 비정체 신호나 가우시안 잡음 또는 임펄스 잡음과 같은 비선형 채널에 적합하다.

• 정보와 통신
• /
• 제31권11호
• /
• pp.35-45
• /
• 2014

주성분 분석 기법(PCA)는 가장 널리 사용되는 데이터 차원 감소 (dimensionality reduction) 기법으로 알려져 있다. 하지만 데이터에 이상점 (outlier)가 존재하는 환경에서는 성능이 크게 저하된다는 단점을 가지고 있다. Rank-Sparsity(Robust PCA) 기법은 주어진 행렬을 low-rank 행렬과 저밀도(sparse)행렬의 합으로 분해하는 방식으로, 이상점이 많은 환경에서 PCA기법을 효과적으로 대체할 수 있는 알고리즘으로 알려져 있다. 본 고에서는 RPCA 기법을 간략히 소개하고, 그의 적용분야, 및 알고리즘에 관한 연구들을 대해서 알아본다.

• 한국음향학회지
• /
• 제30권3호
• /
• pp.129-135
• /
• 2011

An algorithm is presented for estimating the 3-D location (i.e., azimuth angle, elevation angle, and range) of multiple sources with a uniform circular array (UCA) consisting of an even number of sensors. Recently the rank reduction (RARE) algorithm for partly-calibrated sensor arrays was developed. This algorithm is applicable to sensor arrays consisting of several identically oriented and calibrated linear subarrays. Assuming that a UCA consists of M sensors, it can be divided into M/2 identical linear subarrays composed of two facing sensors. Based on the structure of the subarrays, the steering vectors are decomposed into two parts: range-independent 2-D direction-of-arrival (DOA) parameters, and range-relevant 3-D location parameters. Using this property we can estimate range-independent 2-D DOAs by using the RARE algorithm. Once the 2-D DOAs are available, range estimation can be obtained for each source by defining the 1-D MUSIC spectrum. Despite its low computational complexity, the proposed algorithm can provide an estimation performance almost comparable to that of the 3-D MUSIC benchmark estimator.

• 한국항만경제학회지
• /
• 제28권1호
• /
• pp.105-122
• /
• 2012

항만에서 운용되는 선박, 트럭, 기차, 하역장비들이 배출하는 온실가스는 현장 근로자들뿐만 아니라 인근 지역민들의 건강 및 생활환경을 악화시키고 있다. 세계 주요항만 대기오염 문제 해결을 위해 다양한 노력을 하고 있다. 본 연구는 항만 중 온실가스 배출량 비중이 가장 높은 컨테이너터미널을 대상으로 온실가스 저감방안에 대한 연구를 하였다. 연구를 위해 먼저 저감대안들을 추출하였고 이에 대한 중요 우선순위를 결정하는 계층적 의사결정 모델 제시와 실증분석을 실시하였다. 컨테이너터미널 온실가스 저감대안을 선정 하는데 있어 5가지 요소 기준을 적용하였고, 실무자와 전문가의 의견을 수렴하여 대안들을 추출하였다. 또한 선정된 온실가스 저감방안에 대한 평가영역과 요소들을 평가하는데 있어 언어척도의 애매모호하고 불확실한 상황을 고려하여 퍼지모형과 계층적분석방법(Analytic Hierarchy Process)을 결합한 Fuzzy-AHP을 적용하였다. 연구결과 컨테이너터미널 온실가스 저감방안의 측정영역에 대한 중요도 평가는 장비영역이 가장 높았고, 다음으로 운영영역과 에너지영역 순으로 나타났다. 온실가스 저감대안들의 전체 우선순위를 보면 전기T/C 도입이 우선순위가 가장 높은 것으로 분석되었다. 다음으로 Y/T하이브리드 개조, AMP도입, MLS 도입 순으로 나타났다.

• 대한수학회논문집
• /
• 제30권2호
• /
• pp.65-72
• /
• 2015

The minimum rank mr(G) of a simple graph G is defined to be the smallest possible rank over all symmetric real matrices whose (i, j)-th entry (for $i{\neq}j$) is nonzero whenever {i, j} is an edge in G and is zero otherwise. The corona $C_n{\circ}K_t$ is obtained by joining all the vertices of the complete graph $K_t$ to each n vertex of the cycle $C_n$. For any t, we obtain an upper bound of zero forcing number of $L(C_n{\circ}K_t)$, the line graph of $C_n{\circ}K_t$, and get some bounds of $mr(L(C_n{\circ}K_t))$. Specially for t = 1, 2, we have calculated $mr(L(C_n{\circ}K_t))$ by the cut-vertex reduction method.

• 보건교육건강증진학회지
• /
• 제30권5호
• /
• pp.201-210
• /
• 2013

Objectives: The public relies on the news media to understand health risks. To examine the surveillance function of Korean health journalism, this study compared the rank-order of the 10 most frequently diagnosed cancers with that of the 10 cancers most frequently covered by three major Korean newspapers. Methods: News stories published between 1999 and 2010 by the Chosun-Ilbo, Joong-Ang-Ilbo, and Dong-A-Ilbo were examined. Data on cancer incidence were collected using the epidemiological data published by a governmental public health institution. To compare the level of the crude rates and the amount of news coverage, rank-order correlation tests and regression analyses were employed. Results: A reduction in the rank-ordered correlation coefficient was observed despite an increase in the overall number of cancer news stories released. The significance of the correlation disappeared after 2006. The big difference of the rank order between the crude rate and the amount of news coverage was observed in the cancer of breast, uteri, thyroid, and gallbladder/biliary. Finally, the three newspapers did not follow the amount change in stomach, lung, liver, and uterine cervix cancer. The four cancers' rank orders of crude rate were lowering, signifying a reduction of the comparative dangerousness of the four cancers. Conclusions: The news media's customization of news content and the negative bias in journalism are suggested as possible influences on the news media's inaccurate representation of cancer risk.