• Title/Summary/Keyword: Regional Frequency Analysis

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A Study on Estimation of Quantile using Regional Scaling Model and Frequency Analysis (빈도해석과 지역 스케일 모델을 이용한 확률강우량 추정에 대한 연구)

  • Jung, Younghun;Kim, Sunghun;Kim, Hanbeen;Heo, Jun-Haeng
    • Proceedings of the Korea Water Resources Association Conference
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    • 2016.05a
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    • pp.301-301
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    • 2016
  • 국내의 경우 수공구조물을 설계하기 위해서는 빈도해석을 통해 설계수문량을 산정한다. 일반적으로 실무에서는 지점빈도해석을 수행하게 되는데 설계빈도보다 대부분 짧은 기간의 자료를 이용하여 산정한다. 지역빈도해석은 이러한 자료기간이 가지는 문제점을 극복하기 위하여 확률수문량의 정확도와 신뢰도를 향상시키는 기법이다. 스케일 모델은 지속기간별로 관측된 강우자료를 이용하여 재현기간에 대한 지속기간의 함수로 표현이 가능하며, 이를 통해 강우의 IDF곡선을 제시할 수 있는 수학적 모델이다. 대상지역의 강우관측소에서 관측된 강우자료가 일단위이면, 기준지속기간이 24시간이 되며, 기준지속기간에 대한 확률강우량으로부터 임의의 지속기간에 대한 확률강우량을 스케일 모델을 이용하여 추정할 수 있다. 따라서 짧은 자료를 보유한 지역이거나 미계측 지역에 대한 확률강우량을 추정을 위해 지역빈도해석과 지역 스케일 모델을 이용하여 확률강우량을 추정하여 지점빈도해석과 비교하고자 한다. 본 연구를 위해 한강유역의 강우 관측소를 이용하였으며, 군집분석 중 k-means방법을 적용하여 수문학적 동질성을 확보한 후 지역을 구분하였다. 구분된 지역은 지점 및 지역빈도해석을 수행한 후 상대평균제곱근오차(relative root mean square error, RRMSE)를 비교하여 정확도를 판단하였고, 정확도가 높은 빈도해석에 지역 스케일 모델을 적용하여 미계측 지점에 대한 임의의 시간에 대한 확률강우량을 추정하고자 한다.

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Empirical seismic fragility rapid prediction probability model of regional group reinforced concrete girder bridges

  • Li, Si-Qi;Chen, Yong-Sheng;Liu, Hong-Bo;Du, Ke
    • Earthquakes and Structures
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    • v.22 no.6
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    • pp.609-623
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    • 2022
  • To study the empirical seismic fragility of a reinforced concrete girder bridge, based on the theory of numerical analysis and probability modelling, a regression fragility method of a rapid fragility prediction model (Gaussian first-order regression probability model) considering empirical seismic damage is proposed. A total of 1,069 reinforced concrete girder bridges of 22 highways were used to verify the model, and the vulnerability function, plane, surface and curve model of reinforced concrete girder bridges (simple supported girder bridges and continuous girder bridges) considering the number of samples in multiple intensity regions were established. The new empirical seismic damage probability matrix and curve models of observation frequency and damage exceeding probability are developed in multiple intensity regions. A comparative vulnerability analysis between simple supported girder bridges and continuous girder bridges is provided. Depending on the theory of the regional mean seismic damage index matrix model, the empirical seismic damage prediction probability matrix is embedded in the multidimensional mean seismic damage index matrix model, and the regional rapid prediction matrix and curve of reinforced concrete girder bridges, simple supported girder bridges and continuous girder bridges in multiple intensity regions based on mean seismic damage index parameters are developed. The established multidimensional group bridge vulnerability model can be used to quantify and predict the fragility of bridges in multiple intensity regions and the fragility assessment of regional group reinforced concrete girder bridges in the future.

Regional Variations and Related Factors of Mastication Difficulty Rate among the Korean Elderly (우리나라 노인의 저작불편 호소율의 지역 간 변이와 관련 특성)

  • Kim, Ranhee;Kim, Ji Man;Park, Chong Yon;Park, Keun-Young;Lee, Changwoo;Shin, Euichul
    • The Journal of Health Technology Assessment
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    • v.6 no.2
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    • pp.100-105
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    • 2018
  • Objectives: The purpose of this research is to investigate regional variations of mastication difficulty rates in the elderly over 65 in 229 primary autonomous districts in Korea and explore relevant characteristics. For the research data, local community health survey conducted in 2015 and data from Ministry of the Interior and Safety, Ministry of Health & Welfare, National Health Insurance Service and Statistics Korea were used. Methods: Frequency analysis was conducted for general characteristics and mastication difficulty rates of each region, and distribution of mastication difficulty rates was displayed for each town, city and province by mapping them. Extremal quotient (EQ), coefficient of variation (CV) values were calculated for regional variations, and logistic regression analysis was performed to reveal the relationship between each independent variable and mastication difficulty rates. Results: The average of standardized mastication difficulty rate was 46.78%, and regional variations were significant with EQ 3.46, CV 0.18. Characteristic factors that have significant effects on mastication difficulty rate included sex ratio, elderly population and the number of dentists per 10000 people. Conclusion: As a result, there were variations among mastication difficulty rates in 229 primary local governments across the country, and the distribution of health care resources by the characteristics of the local environment by region affected mastication difficulty rates. Accordingly, it is required to provide political supports to overcome regional inequality of oral health levels and develop cooperative system between local governments and local dentists.

A Determination of Magnitude and Frequency of River Floods (하천 홍수량의 크기 및 빈도 결정)

  • Noh, Jae Sik;Lee, Kil Choon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.12 no.2
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    • pp.141-150
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    • 1992
  • In this study, six gaging stations(T/M bureau) in the Han River basin were selected for flood frequency analysis and was carried out frequency analysis by POT(peaks Over a Threshold) model where existing flood data of short record length are available. Frequency and magnitudes of each station floods in the river basins were estimated by POT model based on statistical method, and also were compared with standard errors to verify applicability of the estimates by POT model. Furthermore, in order to evaluate for the adequate design flood which is needed for the design of the hydrologic structures in the ungaged watersheds, it is considered to be possible to develop the statistical regionalized model by regional frequency analysis.

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The Distribution and Characteristics of Geographical Names on 1:50,000 Topographic Map of the Korean Peninsula in the Early 20th Century ("오만분일지형도(五萬分一地形圖)"에 나타난 20세기 초 한반도의 지명 분포와 특성)

  • Kim, Sun-Hee
    • Journal of the Korean Geographical Society
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    • v.43 no.1
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    • pp.87-103
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    • 2008
  • The geographical name is an expression of human knowledge about living conditions and a basic tool for understanding about regional cultures and history as a result of spatiotemporal changes. This study aims to understand the historical and regional characteristics by analyzing the frequency and distribution of geographical names of 1:50,000 topographic map in the early 20th century and materializing on electronic cultural atlas. The result of this analysis is as follows. First, the aspect of distributed geographical names on the Korean Peninsula reflects a general trait of the country's natural and human environment included geographical features, population, arable land, the number of counties and villages, and functions of administration and military, etc. Second, through the frequency and weight of their names, the analysis shows not only the change of native names, but also the country's phase of the time by Japanese colonial policies such as exploitation of resources, the construction of railroads, and a desire to control of the border area with Manchuria. In addition, the study identified regional characteristics and differences in environmental perception and preferences, and naming basis and forms by the comparative analysis of each type of geographical names associated with village and ridge such as 'Chi' 'Ryung' 'Duk' 'Hang' 'Pyeong' 'Gok'. In particular, those characteristics were largely affected from environmental difference of each area.

Song Variations of Great Tits Inhabiting Chirisan and Ullungdo (지리산과 울릉도에서 서식하는 박새 Song의 변이)

  • Hahm, Kye-Hwang;Woon-Kee paek
    • The Korean Journal of Ecology
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    • v.17 no.2
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    • pp.213-222
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    • 1994
  • Songs recorded in Chirisam(1990~1993) and $Ull\v{u}ngdo$(1992~1993) areas were analyzed to investigate the features and variances in songs of Great tit, Parus major. Songs of Great tits were identified, most of which were repetitions of phrases composed of high-frequency note and low-frequency note. The CV range of the Chirisan Great tit group was wider than that of the $Ull\v{u}ngdo$ area. ANOVA analysis level was highly significant (p<0.0001) for Chirisan area and $Ull\v{u}ngdo$ area. Inter-regional variance level was significant (p<0.05) in the maximum of low-frequency.

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The Effect of Tourists' Participative Motivation of a Festival on Satisfaction and Behavior Intention : Case of Baekjae Cultural Festival (관광객의 축제 참여동기가 만족도 및 행동의도에 미치는 영향 - 백제문화제를 대상으로 -)

  • Kim, Si-Joong
    • Journal of the Korean association of regional geographers
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    • v.18 no.4
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    • pp.433-444
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    • 2012
  • This study aims to examine the effect of tourists' participative motivation of a festival on satisfaction and behavior intention in terms of satisfaction, revisit intention, and recommendation based on Baekjae Cultural Festival. For this study, frequency analysis, reliability analysis, factor analysis, and multiple regression analysis were made. The survey was conducted among 287 samples for the study. The results are as follows: According to the factor analysis, five factors were drawn such as new experience, deviation from daily life, family harmony, amusement & novelty, cultural tour of Baekjae, and sociability. Festival satisfaction was affected by amusement & novelty, new experience & deviation from daily life, and cultural tour of Baekjae, while revisit intention was influenced by cultural tour of Baekjae, amusement & novelty, family harmony, and new experience & deviation from daily life respectively. On the other hand, recommendation was affected by cultural tour of Baekjae, sociability, amusement & novelty, and family harmony respectively.

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A Study on Estimation of Target Precipitation in Seoul using AWS minutely Rainfall Data (AWS 분(分) 단위 강우자료를 이용한 서울지역 특성에 따른 행정자치 구(區)별 목표강우량 산정에 관한 연구)

  • Kim, Min-seoka;Son, Hong-mina;Moon, Young-il
    • Journal of Korea Water Resources Association
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    • v.49 no.1
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    • pp.11-18
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    • 2016
  • It is very important to decide probability precipitation that is used as hydraulic structure design and target rainfall for urban disaster prevention. Especially, National Emergency Management Agency (NAMA) announced target rainfall from probability precipitation in korea on city and district level. It make use to performance evaluation of disaster prevention and planning of development for disasters prevention capacity target. In this study was calculated target rainfall that is duration 1~3 hour based unit of gu (borough) by point and regional frequency analysis using rainfall data of Surface Synoptic Stations (SSS) and Automatic Weather Stations (AWS). The result of this study can utilized as a reference to related business such as disaster capability assessment and achievement of prevention capacity target against disasters. And it also will be contribute to establishment of prevention capacity target against disasters.

Evaluating the Spatio-temporal Drought Patterns over Bangladesh using Effective Drought Index (EDI)

  • Kamruzzaman, Md.;Hwang, Syewoon;Cho, Jaepil;Park, Chanwoo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2018.05a
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    • pp.158-158
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    • 2018
  • Drought is a recurrent natural hazard in Bangladesh. It has significant impacts on agriculture, environment, and society. Well-timed information on the onset, extent, intensity, duration, and impacts of drought can mitigate the potential drought-related losses. Thus, drought characteristics need to be explained in terms of frequency, severity, and duration. This paper aims to characterize the spatial and temporal pattern of meteorological drought using EDI and illustrated drought severity over Bangladesh. Twenty-seven (27) station-based daily rainfall data for the study period of 1981-2015 were used to calculate the EDI values over Bangladesh. The evaluation of EDI is conducted for 4 sub-regions over the country to confirm the historical drought record-developed at the regional scale. The finding shows that on average, the frequency of severe to extreme drought is approximately 0.7 events per year. As a result of the regional analysis, most of the recorded historical drought events were successfully detected during the study period. Additionally, the seasonal analysis showed that the extreme droughts were frequently hit in northwestern, middle portion of the eastern and small portion of central parts of Bangladesh during the Kharif(wet) and Rabi(dry) seasons. The severe drought was affected recurrently in the central and northern regions of the country during all cropping seasons. The study also points out that the northern, south-western and central regions in Bangladesh are comparatively vulnerable to both extreme and severe drought event. The study showed that EDI would be a useful tool to identify the drought-prone area and time and potentially applicable to the climate change-induced drought evolution monitoring at regional to the national level in Bangladesh. The outcome of the present study can be used in taking anticipatory strategies to mitigate the drought damages on agricultural production as well as human sufferings in drought-prone areas of Bangladesh.

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