• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.4B
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• pp.319-328
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• 2009

This study quantified the data by applying the EDA techniques considering the data structure, and the results were then used for the frequency analysis. Although traditional methods based on the method of moments provide very sensitive statistics to the extreme values, the EDA techniques have an advantage of providing very stable statistics with their small variation. For the application of the EDA techniques to the frequency analysis, it is necessary to normalization transform and inverse-transform to conserve the skewness of the raw data. That is, it is necessary to transform the raw data to make the data follow the normal distribution, to estimate the statistics by applying the EDA techniques, and then finally to inverse-transform the statistics of transformed data. These statistics decided are then applied for the frequency analysis with a given probability density function. This study analyzed the annual maxima one hour rainfall data at Seoul and Pohang stations. As a result, it was found that more stable rainfall quantiles, which were also less sensitive to extreme values, could be estimated by applying the EDA techniques. This methodology may be effectively used for the frequency analysis of rainfall at stations with especially high annual variations of rainfall due to climate change, etc.

• Geophysics and Geophysical Exploration
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• v.12 no.4
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• pp.309-315
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• 2009

Integrated interpretation of multi-geophysical data has been continuously used in terms that it has provided more confident information than the result from single-geophysical data. Especially, geostatistical integration has its own superiority that it is possible to deal with spatial characteristics as well as physical properties of survey data and the process of integration is clear. This paper further extends the previous work of geostatistical inversion for integrated interpretation. In this paper, we propose a new way of dealing with the case that the multi-geophysical data do not share the measurement range. According to the geostatistical kriging, the closer between the measurement points, the smaller kriging variance we get, and vice versa. We used this spatial properties as a weighting value to the process of geostatistical inversion for the geophysical data integration. An objective way to integrate different kinds of geophysical data measured at different ranges is provided with this algorithm.

• The Korean Journal of Applied Statistics
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• v.28 no.6
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• pp.1275-1288
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• 2015

A microscale weather analysis module (about 1km or less) is a microscale numerical weather prediction model designed for operational forecasting and atmospheric research needs such as radiant energy, thermal energy, and humidity. The accuracy of the module is directly related to the usefulness and quality of real-time microscale weather information service in the metropolitan area. This paper suggests an object based verification method useful for spatio-temporal evaluation of the accuracy of the microscale weather analysis module. The method is a graphical method comprised of three steps that constructs a lattice field of evaluation statistics, merges and identifies objects, and evaluates the accuracy of the module. We develop lattice fields using various evaluation spatio-temporal statistics as well as an efficient object identification algorithm that conducts convolution, masking, and merging operations to the lattice fields. A real data application demonstrates the utility of the verification method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.2603-2609
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• 2014

Reliability analysis of mechanical systems requires statistical modeling of input random variables such as distribution function types and statistical parameters that affect the performance of the mechanical systems. Some random variables are correlated, but considered as independent variables or wrong assumptions on input random variables have been used. In this paper, joint distributions were modeled using copulas and Bayesian method from limited number of data. To verify the proposed method, statistical simulation tests were carried out for various number of samples and correlation coefficients. As a result, the Bayesian method selected the most probable copula types among candidate copulas even though the candidate copula shapes are similar for low correlations or the number of data is limited. The most probable copulas also yielded similar reliabilities with the true reliability obtained from a true copula, so that it can be concluded that the Bayesian method provides accurate statistical modeling for the reliability analysis.

• Journal of Educational Research in Mathematics
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• v.13 no.4
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• pp.463-483
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• 2003

In the learning of mathematics, students experience the semiotic activities of representing and interpreting mathematical signs. We called these activities as the representing and interpreting of mathematical signs. On the foundation of Peirce's three elements of the sign, we analysed that students constructed the representamen to interpret the concept of correlation as for the object, "as one is taller, one's size of foot is larger" 4 middle school students who participated the gifted center in Seoul, arranged the statistical data, constructed their own representamen, and then learned the conventional signs as a result of the whole class discussion. In the process, students performed the detailed representing and interpreting of signs, depended on the templates of the known signs, and interpreted the process voluntarily. As the semiotic activities were taken place in this way, it was needed that mathematics teacher guided the representing and interpreting of mathematical signs so that the representation and the meaning of the sign were constructed each other, and that students endeavored to get the negotiation of the interpretants and the representamens, and to reach the conventional representing.

• 한국가스학회:학술대회논문집
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• 1997.09a
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• pp.284-291
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• 1997

배관망의 해석은 유체역학을 필요로 하며 관내의 유체의 거동과 운전 상태에 따른 유동해석을 위해 여러 식들이 사용되어왔다. 본 연구에서는 정상상태의 유량방정식을 사용해 경인지역가스 배관망에 대한 수학적 모델을 만들고 모사 및 분석을 수행하였다. 개발된 수학적 모델에서 얻어진 데이터에 통계학적인 방법을 도입해 통계학적 모델을 만듦으로써 통계학적 모델을 이용한 배관망 해석의 가능성에 대해 검토하였다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.12 no.2
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• pp.147-154
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• 1994

Landslides in the close residential area occur loss of life and properties. Usually soil mechanical methods and multi-statistical methods used to analysis the landslide. The factors of landslide analysis by multi-statistical methods are composite operations of geology, topography, vegetation, and climate etc. In this study, existing landslide areas are cheesed to extract the characteristics of their geographical data for adaption of Multi-statical methods. Authors give a weight to their values and analyze the some area using technique of overlap on GSIS.

• Journal of the Korean Statistical Society
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• v.20
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• pp.10-18
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• 1991

한국통계학회 창립 20주년을 맞아 80년대의 한국통계의 현황과 장래의 나아갈 방향에 대해 의견을 교환하는 것은 뜻깊은 일이라 할 것이다. 그러나 통계이론에 관해 깊이 있는 의견을 제시하는 것은 쉬운 일은 아닌 것 같다. 10주년 기념호 통계학연구에서 백운붕 박사께서 통계이론의 범위를 광의의 수리통계학으로 해석하였듯이 필자도 통계이론을 이론통계학과 같은 차원의 넓은 의미로 사용하기로 한다. 한국통계에서의 통계이론의 현황을 살펴보기 위해서는 국제적인 현황을 먼저 살펴보아야 한다고 생각된다. 여기에는 여러가지 이유가 있겠지만 자연과학이라는 학문이 그러하듯이 통계학이란 학문 자체가 외국에서 발생되어 우리나라에 도입된 학문으로 우리나라에서 독자적으로 연구 교육되어온 학문이 아니기 때문에 당연히 국제적인 현황가 깊은 관계가 있으리라고 짐작되기 때문이다. 그러한 이유에서 먼저 1980년대에 Annals of Statistics와 JASA에 게재된 논문의 내용을 분류하여, 1970년대 후반기의 경향과 비교하여 1980년대의 흐름을 간략히 살펴보고자 한다. 물론 한국 통계의 현황을 알아보기 위해서는 한국통계학회지인 통계학연구를 분석해 보는 것이 무엇보다 필요하리라 생각된다. 그리고 한국통계학자들의 연구 동향을 고찰하기 위해서는 학술발표회의 논문을 분류하는 것이 타당하다고 생각된다. 따라서 본고에서는 1981년부터 1990년까지의 통계학연구지 논문과 1985년부터 1990년까지의 춘계 및 추계 학술논문발표회의 발표 논문을 분류하여 비교해 보고자 한다.

• 한국지구물리탐사학회:학술대회논문집
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• 2004.06a
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• pp.284-288
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• 2004

• Proceedings of the Korea Water Resources Association Conference
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• 1980.08a
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• pp.31-37
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• 1980

본 연구는 도시화에 따른 강우량의 변화를 통계학적 처리에 의하여 비교 검토하는 것으로서 도시화 지역과 비도시화 지역을 구분 설정하여 각 지역에 있어서 월별 강우량을 시대별(1931~1950, 1960~1978)로 조사하여 통계처리를 하였다. 자료를 분석한 결과 다음과 같은 추이를 알 수 있다. 1. 도시화 지역에서의 시대별 강우량은 증가 추세이다. 2. 도시화 지역의 강우량 증가치가 비도시화 지역의 증가치보다 많음을 알 수 있다.