• Communications for Statistical Applications and Methods
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• 제16권4호
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• pp.647-658
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• 2009

It is already known from the previous study that flood seems to have heavier tail. Therefore, to make prediction of future extreme label, some agreement of tail behavior of extreme data is highly required. The LH-moments estimation method, the generalized form of L-moments is an useful method of characterizing the upper part of the distribution. LH-moments are based on linear combination of higher order statistics. In this study, we have formulated LH-moments of five distributions useful in hydrology such as, two types of three parameter kappa distributions, beta-${\kappa}$ distribution, beta-p distribution and a generalized Gumbel distribution. Using LH-moments reduces the undue influences that small sample may have on the estimation of large return period events.

• 여성건강간호학회지
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• 제27권1호
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• pp.40-48
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• 2021

Purpose: This study compared maternal age at childbirth, the number of live births, and the weight of live births between Korean women and immigrant women using statistical data from the Republic of Korea for the period of 2008-2018. Methods: The analysis was conducted using data from the Microdata Integrated Service of Statistics Korea (https://mdis.kostat.go.kr/index.do). Results: Korean women and immigrant women showed a higher age at childbirth in 2018 than in 2008. The percentage of newborns of Korean women with a birth weight of less than 2.5 kg increased slightly for 3 consecutive years from 2016 to 2018, whereas for immigrant women, this percentage increased in 2017 compared to 2016 and then decreased again in 2018. Very low birth weight (less than 1.5 kg) became more common among immigrant women from 2016 to 2018. Birth at a gestational age of fewer than 37 weeks increased both among Korean and immigrant women from 2016 to 2018. In both groups, the percentage of women who had their first child within their first 2 years of marriage decreased from 2008 to 2018. Conclusion: Immigrant women had higher birth rates than Korean women, while both groups showed an increasing trend in preterm birth. Greater attention should be paid to the pregnancy and birth needs of immigrant women, and steps are needed to ensure health equity and access in order to prevent preterm births. It is also necessary to identify factors that affect preterm birth and birth of very low birth weight infants among immigrant women in the future.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2002년도 추계학술발표논문집 (상)
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• pp.723-726
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• 2002

기존의 화상처리 방법으로는 불필요한 정보까지 포함하여 특징을 추출하여 많은 시간이 소용된다는 문제점이 있었다. 본 논문에서 적합한 HLAF 알고리즘를 이용하여 홍채 병변 인식의 수렴속도를 빠르게 하는 신경망을 사용하였으며, HLAF 알고리즘이 일반 BP 알고리즘보다 수렴속도면과 병변 추출 인식면에서 훨씬 우수함을 보였다.

• 대한수학회논문집
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• 제21권2호
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• pp.375-384
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• 2006

We consider a class of bilinear models with periodic regime switching and find easy-to-check sufficient conditions that ensures the existence of a stationary process obtained from given difference equation. Existence of a higher order moments is examined.

• 대한전자공학회논문지SP
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• 제43권2호
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• pp.87-92
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• 2006

Array 신호처리에서 복소 지수함수의 합으로 구성된 신호의 파라미터를 추정하는데 고차 통계를 이용할 수 있다. 본 논문에서는 4차 cumulant를 이용한 고차 Matrix Pencil method(MPM)를 제안하였다. 4차 cumulant는 Gaussian 잡음를 억제할 수 있기 때문에, MPM의 응답은 기존의 방법에 비하여 더 좋은 잡음 면역을 가지고 있다. 본 논문에서는 높은 정확성을 가지는 MPM의 모든 장점을 유지하면서 성공적으로 고차 MPM을 공식화하였다. 그리고 Numerical simulation을 통해서 본 논문에서 제안된 4차 cumulant를 이용한 방법이 Gaussian 잡음환경에서 더 우수한 DOA 분해능을 가지고 있음을 증명하였다.

• Communications for Statistical Applications and Methods
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• 제6권1호
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• pp.305-318
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• 1999

In this paper we derive the higher order expansions of the first four cumulants of multi-dimensional Maximum Likelihood Estimator (MLE) under the general parametric model up to and including terms of order O({{{{ {n }^{-1 } }}}}) Also we obtain the explicit form of the expansion of the normalizing trans formation of multi-dimensional MLE and show that the suggested normalizing process is much better than the normal approximation based on central limit theorem through example.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2002년도 봄 학술발표논문집 Vol.29 No.1 (B)
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• pp.289-291
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• 2002

Host of source separation methods focus on stationary sources so higher-order statistics is necessary In this paler we consider a problem of source separation when sources are second-order nonstationary stochastic processes . We employ the natural gradient method and develop learning algorithms for both 1inear feedback and feedforward neural networks. Thus our algorithms possess equivariant property Local stabi1iffy analysis shows that separating solutions are always locally stable stationary points of the proposed algorithms, regardless of probability distributions of

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.1127-1132
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• 2000

Impulsive acoustic and vibration signals within rotating machinery are often induced by irregular impacting. The detection of these impulses can be useful for fault diagnosis purposes. Recently there has been an increasing trend towards the use of higher order statistics for fault detection within mechanical systems based on the observation that impulsive signals tend to increase the kurtosis values. This paper considers the use of the third and fourth order Wigner moment spectra, called the Wigner bi- and tri- spectra receptively, for analysing such signals. Expressions for the auto-and cross-terms in these distributions are presented and discussed. It is shown that the Wigner trispectrum is a more suitable analysis tool and it performance is compared to its second order counterpart for detecting impulsive signals. These methods are also applied to measured data sets from an industrial gearbox.

• 응용통계연구
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• 제12권2호
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• pp.347-362
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• 1999

강수 형태 및 강수량을 동시에 고려하는 1차의 마코브 연쇄-의존 모델을 고차의 모델로 확장하였다. 남한의 53개 지역의 강수량 자료에 대해 계절별로 마코브 연쇄의 차수를 결정하였고, 고차의 마코브 연쇄-의존 모델을 적용하여 강수량의 분포특성을 살펴 보았다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -1
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• pp.241-244
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• 2000

This paper addresses a new method of blind source separation (BSS) when sources are nonstationary signals. Our method requires only multiple correlation matrices of the observed data at several time-windowed data frames to estimate the mixing matrix. In contrast to most existing BSS methods where higher-order statistics is necessary, our method is based on only second-order statistics. In the framework of correlation matching, we develop a new BSS algorithm. The useful behavior of the proposed method is verified by numerical experiments.