• Water for future
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• v.14 no.3
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• pp.37-46
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• 1981

The purpose of this paper is to provide a method of estimating the magnitude and frequency of floods on five major streams in Korea such as the Han, the naktong, the Geum, the Seomjin and the Yeongsan. Derivation of the flood frequency formulae is based on the multiple correlation method. For each gaging station in the region, flood frequency curves are drawn by GumbelChow and Weibull plot. where 24 gaging stations are selected for this study. After the station flood-frequency cruves have been prepared, discharges are read at selected recurrence intervals. Each set of discharges is then correlated with basin parameters, using regression equation. The basin parameters that are considered include drainage area, length of main stream, shape facotr, mean basin slope and main channel slope.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1768-1772
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• 2007

본 연구에서는 국내 도시지역의 특성을 고려한 설계강우의 시간분포형에 따른 첨두유량의 변화를 규명하고자 Huff 및 Yen과 Chow의 시간분포방법을 이용하여 단시간 강우특성을 분석하였으며, 또한, 기왕의 연구인 건설교통부의 전기간 강우에 의한 시간분포와의 비교를 실시하고, 실제 도시지역에 적용하여 첨두유량의 변화를 분석하였다. 한다. 본 연구에서 선정한 대상지역은 서울, 부산과 대구지점이며, 강우자료는 1961년부터 2004년까지 44년간의 연속된 자료로서 기상청의 자기우량지 및 AWS자료를 이용하여 수집하였다. 첨두유량분석을 위한 대상유역으로는 서울특별시 일원의 성내와 반포배수구역과 부산광역시 일원의 동의대 시험유역, 경북 구미시 일원의 광평배수구역을 선정하였다. 본 연구의 수행으로 인해 얻어진 결과를 요약하면 다음과 같다. 첫째, Huff의 시간분포방법의 경우에는 단시간 강우자료의 지속기간에 따른 최대강우강도는 제1구간에서 발생할 확률이 가장 높게 나타났고, 제3구간에서 가장 낮게 발생하였으며, 기왕의 연구들과 차이가 발생하였다. 둘째, Yen과 Chow의 시간분포방법에서는 기왕의 연구와 본 연구의 결과에서 전반적으로 큰 차이가 발생하지 않았으며, 셋째, 첨두유량의 비교에서는 시간분포방법에 따라 변화가 발생함을 알 수 있었다.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.10
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• pp.523-530
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• 2020

The efficient market hypothesis explains the random walk hypothesis suggesting that stock prices are independent of each other, hence, it is impossible to earn abnormal profits. The positive effect of a well-functioning and highly efficient stock market on the performance of an economy motivated the Philippine Stock Exchange to pursue massive modernization initiatives. This research provides evidence of the existence of random walk in the Philippine stock market employing the Augmented Dickey-Fuller (1981) and Phillips-Perron (1988) unit root tests, the Lo-MacKinlay's (1988) conventional variance ratio test, and Chow-Denning's (1993) simple multiple variance ratio test. Results of the ADF and PP unit root tests confirm the necessary condition for a random walk. The Chow-Denning (1993) maximum /z/ statistic and the Wald test statistic as in Richardson and Smith (1991) for the joint hypotheses and the Lo and MacKinlay (1988) individual statistics variance ratio test generally accepted the null hypothesis of a random walk. That is, the unit root and variance ratio tests consistently indicate that the null hypothesis of random walk cannot be rejected. The existence of a random walk in weak-form efficiency can be attributed to market liquidity as a result of continuous development and modernization of the Philippine equity market.

• Journal of Korea Water Resources Association
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• v.46 no.10
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• pp.1029-1040
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• 2013

This study aims to develop a multivariate daily rainfall simulation model considering spatial coherence across watershed. The existing Hidden Markov Model (HMM) has been mainly applied to single site case so that the spatial coherences are not properly addressed. In this regard, HMM coupled with Chow-Liu Tree (CLT) that is designed to consider inter-dependences across rainfall networks was proposed. The proposed approach is applied to Han-River watershed where long-term and reliable hydrologic data is available, and a rigorous validation is finally conducted to verify the model's capability. It was found that the proposed model showed better performance in terms of reproducing daily rainfall statistics as well as seasonal rainfall statistics. Also, correlation matrix across stations for observation and simulation was compared and examined. It was confirmed that the spatial coherence was well reproduced via CLT-HMM model.

• Journal of Nutrition and Health
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• v.31 no.7
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• pp.1100-1111
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• 1998

The incorporation of docosahexaenoic acid(DHA) and arachidonic acid(AA) into brain and liver lipid has been compared in male pups from binth to 10 weeks old by feeding DHA-rich experimental diets or chow diets to dams from pregnancy in rats. The experimental DHA-rich diets contained 7g fish oil and 3g corn oil per 100g diet. There were three experimental groups, FO-I : Dams were fed DHA-rich diet during pregnancy and lactation, and their it pups fed the same diet until 10 weeks old. FO-II Dams fed chow diet during pregnancy and DHA-diet during lactation, and their pups fed the same DHA-diet until 10 weeks. FO-III : Dams fed chow diet during gestation and lactation, and then the pups fed DHA-diet after weaning. The relative % of DHA in hepatic lipid was about 12% with chow diets, but increased rapidly to 20-25% level when DHA-rich diets were supplied after weaning. The AA(%) of FO-III group was relatively high when a chow diet containing higher amount of linoleic acid was given, but there was no significant difference between the groups after feeding on a DHA-rich diet. When the DHA-rich diet was supplied from pregnancy(FO-I), the relative % of DHA in brain lipid was 13.7% at birth and continuously increased to a maximum level(17.2%) at 3-weeks and then was sustained until 5 weeks old. Similar levels of DHA incorporation were observed when DHA-rich diet was supplied from lactation(FO-II). However, the pups of FO-III group showed significantly lower levels of DHA incorporation(72%) at birth. These livels slowly increased and reached an 87% level of FO-I at 10 weeks when the pups ate DHA-rich diets after weaning. The relative % of AA in brain lipid was 10.4% in the FO-I group at birth, which was significantly lower than those of other groups, but there was no significant difference between groups after feeding DHA-rich diets in all groups. The Ah(%) level increased to maximum(11-12%) at 3-weeks and then was slightly reduced and was sustained at about 10% after S-weeks. Total amounts of DNA in the whole brain rapidly reached maximum level at 3-weeks and then was sustained at a constant level after S-weeks. DNA content was not significantly different between groups at birth, but it was significantly higher in FO-I and FO-II groups than in FO-III group at 3-weeks. However, DNA content in FO-III group was continuously increased to 80% level of FO-I at 10-weeks after feeding DHA-rich diet since weaning. In conclusion, the DHA(%) in whole brain was most effectively deposited when DHA-rich diet had been supplied during pregnancy and lactation in rats. However, DHA supplementation after weaning also improved the incorporaton of DHA into brain and content of DNA even though brain development was almost completed, which suggests that DHA supplementation might be necessary to improve brain development in humans during infancy as well as pregnancy and lactation. (Korean J Nutrition 31(7) 1100-1111, 1998)

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09b
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• pp.1440-1442
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• 2005

• The Korean Journal of Nuclear Medicine
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• v.19 no.2
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• pp.17-23
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• 1985

• Water for future
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• v.40 no.5 s.166
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• pp.96-103
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• 2007

• 대한치과보철학회:학술대회논문집
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• 1999.04a
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• pp.43-43
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• 1999

• 대한치과보철학회:학술대회논문집
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• 1999.04a
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• pp.91.1-91.1
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• 1999