• 한국농공학회논문집
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• 제60권4호
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• pp.37-48
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• 2018

The extreme 2017 spring drought affected a large portion of central and western South Korea, and was one of the most climatologically driest spring seasons over the 1961-2016 period of record. This drought was characterized by exceptionally low precipitation, with total precipitation from January to June being 50% lower than the mean normal precipitation (1981-2010) over most of western South Korea. In this study, for the quantitative drought impact analysis, the widely-used Standardized Precipitation Index (SPI) and the statistical drought frequency are compared with observed meteorological characteristics and anomalies. According to the drought frequency analysis of monthly cumulative precipitation during January and May in 2017, Gyeonggi-do, Chungcheong-do, and Jeollanam-do areas showed more than drought frequency over 100 years. Gyeongsangnam-do area showed more than drought frequency over 200 years based on annual precipitation in 2017. The South Korean government (Ministry of Agriculture, Food and Rural Affairs (MAFRA) and Korea Rural Community Corporation (KRC)) have been operating a government-level drought monitoring system since 2016. Results from this study can be used to improve the drought monitoring applications of future drought events, as well as drought planning and preparedness in South Korea.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2007년도 정기총회 및 학술발표대회
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• pp.575-578
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• 2007

The objective of this study is to analyze the regionalization of point rainfall by statistical methods for regional frequency analysis of the rainfall. The rainfall data used in this study are annual maximum rainfall at 57 stations during the period of more than 30 years for 12 durations(10min, 1, 2, 3, 4, 5, 6, 8, 10, 12, 18, 24hr) in Korea. The Mann-Whitney U test, Kruskal-Wallis one-way analysis of variance of nonparametric test the principal component and the cluster analysis have been performed to analyze the regionalization of rainfall. The results of this study are as follows; (1) The region which hydrological homogeneous is accepted does not exist for whole duration in Korea. (2) The result of nonpametric test shows that hydrological homogeneous regions of point rainfall are divided by 5 regions. (3) In case of cluster analysis hydrological homogeneous regions of point rainfall are divided by 6 regions and 4 other areas.

• Communications for Statistical Applications and Methods
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• 제10권2호
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• pp.371-385
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• 2003

In this paper, contour plot is considered as a method to explore the structure of categorical data. For this purpose, the paper suggests a method to sort two-way contingency table with respect to the expected marginals. It is found that the suggested plot provides us with valuable information for the underlying data structure. Firstly, we can investigate independency between the categories by examining the differences of expected frequency contours and observed frequency contours. With the plot, we can also visually investigate the existence of outliers inherent in the data. These properties of the suggested contour plot will be demonstrated by several sets of real data.

• 천문학회보
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• 제41권2호
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• pp.59.1-59.1
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• 2016

Blue Straggler Stars(BSS) affect their host star cluster in various parameters like color, dynamics, etc. For this reason, it is important to know how to relate BSS frequency and evolution of their host stellar system. To statistical study about global properties of open clusters as the environments of BSS formation, we use three catalogues - (1) two galactic open clusters catalogues including BSS candidate, (2) Milky Way Star Cluster (MWSC) survey data. Then, we compare with the data of two BSS catalogues for test of the result of Marchi et al. 2006. We also investigate the radial mass distribution in open cluster, because it is possible that changing the gradient of radial mass distribution cause increasing the BSS frequency. When we group the open cluster into having BSS or not and other criteria, the groups show slight discrepancies, but we show some important results.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1725-1731
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• 2010

This paper aims to find out the statistical characteristics of the railroad accidents by weather phenomena. For this, It is investigated occurrence frequency of railroad accidents and operation obstacles from 1996 to 2008 in Korea using the KROIS data and Korea railroad accidents reports. The results are as follows; The occurrence frequency of railroad accidents and operation obstacles decrease gradually, and most of railroad accidents is a railroad traffic accidents. The amount of damages by a railroad weather-related accidents is higher than the one of the railroad accidents and operation obstacles. Weather events which is influenced the railroad weather-related accidents and incidents are rainfall, snowfall, lightning, strong winds. And they have occurred a railroad weather-related accidents and incidents, such as rail obstruction, signal failure, and power supply failure.

• 한국전자파학회논문지
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• 제8권2호
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• pp.207-213
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• 1997

주파수 30 MHz-18 GHz에서의 무선 주파수 도시잡음 측정이 1994년과 1995년에 걸쳐, 전국 21개 도시에서 실시되었다. 각각의 지역에 대해 계절별, 또한 주.야로 실시된 측정 데이터를 분석하였으며, 그 분석 방법으로 APD,NAD, ACR 둥과 같은 통계적 분석 방법을 선택하였다. GUI (Graphical User Interface) 프로그램을 이용한 컴퓨터 분석 결과, 봄, 여름, 겨울의 도시 잡음은 약간의 차이를 보이는 반면, 가을에는 다른 계절에 비해 다소 높게 나타났으며, 또한 야간의 잡음레벨이 주간보다 높게 나타나는 것을 확인할 수 있었다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.371.1-371
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• 2002

At lift-off, the jet noise of launch vehicle produces a severe acoustic environment and the loads induced by the acoustic pressure may be damaging to paylaod and equipments. Prediction of the acoustic environment is needed to support the design and test-qualification of components. Currently, such a high frequency problem is usually dealt with by using the SEA, of which the assumptions match reasonably well with the vibro-acoustic condition of system. (omitted)

• 가정과삶의질연구
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• 제16권2호
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• pp.83-96
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• 1998

The purpose of this study was to investigate the level of assets and liabilities of farm households and to evaluate the financial status of rural middle-aged and old-aged household using financial ratios. For these purposes an empirical survey data was gathered from rural middle-aged and old-aged households in 8 provinces using structured questionnaires. 877 households data were used in final analysis. The statistical methods used for data analysis are frequency percentile mean The statistical methods used for data analysis are frequency percentile mean median standard deviation $\chi$2 and t-test using SPSS/PC WIN program. Among financial ratios 64.7% of total households could meet the guideline of consumption to income ratio 5.9% of total households could meet the appropriate level of short-term and long-term liquidity. In the case of debt burden ration 82% of total households could meet the guideline. And 28.5% of total households could meet the guideline of capital stock ratio .

• Communications for Statistical Applications and Methods
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• 제31권1호
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• pp.37-53
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• 2024

In this study, flood records from 79 sites across Thailand were analyzed to estimate flood indices using the regional frequency analysis based on the L-moments method. Observation sites were grouped into homogeneous regions using k-means and Ward's clustering techniques. Among various distributions evaluated, the generalized extreme value distribution emerged as the most appropriate for certain regions. Regional growth curves were subsequently established for each delineated region. Furthermore, 20- and 100-year return values were derived to illustrate the recurrence intervals of maximum rainfall across Thailand. The predicted return values tend to increase at each site, which is associated with growth curves that could describe an increasing long-term predictive pattern. The findings of this study hold significant implications for water management strategies and the design of flood mitigation structures in the country.

• 한국안전학회지
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• 제13권1호
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• pp.104-111
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• 1998

Statistical analyses of occupational accidents associated with construction work were carried out to explore the basic statistical characteristics of their damage consequences. Emphasis was placed upon the probabilistic and statistical analyses to clarify, in particular, the relationship between frequency of labour accidents and their damage consequences. Damage consequences were classified into two categories such as the number of workdays lost due to accidents and the number of injured workers involved in one accident. Two types of accident data were collected for the analyses. From the analyses, it was found that the relation between damage due to accidents and their frequencies can be represented by a simple power function which indicates a log-log linear relation. By making use of this relationship, various probabilistic evaluations such as the estimation of the mean time periods between accidents, expected damage consequences, and expected damage ratio between different mean time period of accidents were conducted.