• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.281-285
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• 2011

본 연구에서는 연최대치 독립 호우사상 계열과 연최대치 계열의 차이를 살펴보았다. 이를 위해 본 연구에서는 몇 가지 경우의 IETD 및 절단값을 적용하여 독립 호우사상을 결정하고, 그 특성을 살펴보았다. 이어 연최대치 계열과 연 최대치 독립 호우사상 계열을 비교하였다. 본 연구는 1961년부터 2010년까지 서울지점의 시강우 자료를 분석대상으로 사용하였다. 그 결과, IETD의 증가에 따라서 독립 호우사상의 발생빈도 및 평균 강우강도는 감소하고, 평균 지속기간은 증가하였다. 절단값의 증가에 따라 독립 호우사상의 발생빈도 및 평균 지속기간은 감소하고, 평균 강우강도는 증가하였다. 호우사상의 평균 강우강도는 강우 지속기간에 관계없이 거의 일정한 것으로 나타났다. 이러한 결과를 통해 지속기간이 짧은 호우사상의 최대 강우강도는 지속기간이 긴 호우사상의 최대 강우강도보다 매우 작을 것으로 파악되었다. 지속 기간이 짧은 경우, 연 최대치 계열과 연 최대치 독립 호우사상 계열의 차이는 매우 크며, 강우 지속기간이 길게 적용한 경우에는, 두 계열의 차이는 매우 줄어드는 것으로 나타났다.

• The Korean Journal of Applied Statistics
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• v.23 no.3
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• pp.521-531
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• 2010

Interval-censored observations are common in medical and epidemiologic studies; however, limited studies exist due to the complexity and special structure of interval-censoring. This paper introduces the imputation method and the self consistency method in the interval-censored data. We propose a new method of generating random numbers under an interval-censoring set-up. Through simulation studies we compare two methods under various simulation schemes in the sense of the mean squared error for estimating the median survival time and the mean integrated squared error for estimating the survival function. Under a moderate censoring percentage, the mean imputation method showed a better performance than the self-consistency method in estimating the median survival time and the survival function.

• 대한치과보철학회:학술대회논문집
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• 1996.11a
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• pp.106-107
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• 1996

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.1
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• pp.1-6
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• 2003

A novel Solid Freeform Fabrication System, which makes prototype by cutting tapes at the boundary of object and accumulating the tapes, has been developed. In order to overcome the staircase shape at the surface of prototype, the laser beam is irradiated tangent to the surface. Five axis cutting system and the tangent cutting trajectory generation algorithm have been developed.

• The Korean Journal of Rheology
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• v.2 no.1
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• pp.46-52
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• 1990

배추의 조직감 특성을 기계적으로 측정하는 방법을 수립하기 위하여 여러 가지 형 태의 탐침에 의한 침투 및 절단시험에서 나타난는 힘-거리 곡선을 비교분석하였으며 그 결 과를 배추잎의 미세구조와 관능적특성과 연관하여 해석하였다. 배추잎의 침투심험에서 탐침 의 선단각, 선단면적 및 둘레에 따라 힘-거리 곡선의 형태는 크게 달라지며 선단면적과 둘 레가 커질수록 파열력이 크게 증대되었다. 절단시험에서는 표피와 내부유관속 조직을 절단 하는 세 개의 특징적인 피크를-나타내었다. 배추잎의 염장에 의하여 침투시험의 최대 변형 력은 크게 감소된 반면 파열력은 크게 증대되어 최대 변형력에 대한 파열력의 비(a/c) 는 증가되었으며 이것은 탐침의 선단면적과 둘레가 큰경우에 더욱 두드러지게 나타났다. 염장 에 의하여 탄성한계까지의 변형거리가 커졌으며 최초 변형에서의 탄성치(a/l)는 감소하는 경 향을 나타내었다. 절단시험에서는 염장에의하여 외피의 절단력이 상대적으로 증가하였다. 배 추 및 절인배추의 아삭아삭한 정도는 침투시험의 최대변형력과 a/l의 변화와 밀접한 관계가 있으며 질긴 정도는 침투시험의 파열력과 a/c 절단시험의 절단력과 관계가 있으며 아작아작 한 정도는 침투시험의 a/c와 관계가 있는 것으로 판단되었다.

• The Journal of the Korean dental association
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• v.20 no.10 s.161
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• pp.824-824
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• 1982

• Proceedings of the KACD Conference
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• 2003.05a
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• pp.278-281
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• 2003

• Korean Journal of Applied Biomechanics
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• v.18 no.3
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• pp.51-59
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• 2008

The objective of this study is to kinematically analyze forehand & backhand strokes of abscission handicap wheelchair table tennis athletes. The participant of this study were picked out of national athletes who have abscission handicap. Forehand stroke movement was expected to show a throw like motion. However, external rotation and internal rotation of the right arm created a backswing and an impact. Backhand stroke was expected to show a push like motion, and as expected, proximal part of the body didn't participate in the stroke motion, but the distal part, the right arm, rotated internally to backswing and external rotated to impact to form a push like motion. Forehand swing was expected to show throw like motion according to the Link Segmental System principle. However, abscission handicap athlete didn't show clear linking structure connecting proximal and distal parts. Successful strokes were dependant only on the angle of arm rotation.

• Journal of Welding and Joining
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• v.5 no.1
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• pp.23-33
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• 1987

Plasma arc cutting is a fusion cutting process in which a gas constricted arc is employed to produce high temperature, high velocity jet at the workpiece. Even though the plasma arc cutting has been wid¬ely used in the industry, very little work has been done on the analysis of the process. In this paper, the kerf width was numerically analyzed by soving the temperature distribution in base metal under consideration of the latent heat effect. In modelling the heat flow problem, the heat intensity of the plasma arc was assumed to have a Gaussion distribution in the transverse direction and expone¬ntially decreasing in the thickness direction. The thermal efficiency and the heat input ratio of the top surface were experimentally deterimned for various thickness and cutting conditions, and used in numerical calculation of the kerf width. The experimental results were in eonsiderabely good agreement with the theoretically predicted kerf width.

• Radiation Oncology Journal
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• v.11 no.1
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• pp.43-50
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• 1993

We evaluated frequency and types of chromosomal aberrations by ionizing radiation in cancer patients treated with radiotherapy in our institution. Twenty-five patients with various types of carcinomas such as lung, uterine cervix, esophagus, rectum, head and neck and pancreatic cancers were studied immediately before and after external beam radiotherapy. The frequency of aberrant metaphase prior to treatment was $4.93{\%}$, which was higher than that of control group. Especially in lung cancer, the freuqency of aberrant metaphase was three times higher than control group. A comparison of chromosomal abnormalities observed before and after radiotherapy demonstrated that proportion of aberrant rnetaphases was significantly inreased to $22.13{\%}$. Major chromosomal aberrations like structural abnormalities showed remarkalbe increase from 65.45 to $88.45{\%}$ after the treatment. Also the numbers of chromosomal alterations per cell were increased by a factor of 6.5. Aberrations with two or more break points were more prominently increased, compared with aberrations with single break point. The number of chromosomal break points was noted to be higher than expected value in No.1, 3, 8 and 11 chromosomes and lower in No.13, 15, 17 and 21 chromosomes. Based on this study, we believe that the distribution of chromosomal breakage is related with gene and chromosomal rearrangement which could result in the development of cancers.