• 대한토목학회논문집
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• 제30권6B호
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• pp.561-569
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• 2010

본 연구에서는 현재 및 미래 기후에서의 가뭄심도-영향면적-지속기간 곡선의 비교를 통하여 극한 가뭄 사상에 대한 기후변화의 영향을 살펴보았다. 가뭄심도-영향면적-지속기간 곡선은 극한 호우사상을 특성화하기 위한 일반적으로 적용되는 우량깊이-영향면적-지속기간 곡선에서 우량깊이를 가뭄심도를 대표할 수 있는 적절한 지수로 대체함으로써 가뭄사상을 분석할 수 있는 도구를 제공한다. 미래 월 강수량 시계열은 $27km{\times}27km$의 공간적인 해상도를 가지는 기상청 지역기후모형으로부터 획득되었으며, 가뭄심도는 표준강수지수를 이용하여 산출하였다. 분석 결과, 농업가뭄에 대한 위험성은 특히 단기간의 지속기간의 경우에 현재보다 심화될 수 있는 것으로 분석되었으며, 수문학적 가뭄의 경우는 가뭄지속기간에 상관없이 모두 현재보다는 미래에 가뭄심도가 더 깊어질 가능성이 있는 것으로 예측되었다. 이에 따라 현재의 수자원 공급 시스템에 대한 기후변화 취약성 평가가 시급함을 제시하고 있다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.804-806
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• 2003

Probable Maximum Precipitation (PMP) is essential in the design of hydraulic structures such as dams, weirs and flood control structures. Up to the present, PMP has been derived from any proper single storm which can have a large error. PMP values should be evaluated from many historic heavy storm events from all over the country. Since this can be done at the spots of storm occurring and the calculated PMP from all spots in the country can be correlated. The objectives of this study are therefore to evaluate PMP from historic heavy storm data from 1972 to 2000 by using meteorological method, then to correlate and to present the results using GIS. The maximized rainfall depths can be calculate from depth of heavy rainfall and dew point temperature, and then can be analyzed for each rainfall duration to obtain spatial rainfall distribution by using GIS. The depth-area-duration relationship of maximized rainfall can be obtained and this helps to develop enveloped curves . The results from this study are a set of contour maps of PMP for each rainfall duration for all over the country and the depth-area-duration relationships for the area of 100 to 50,000 km.$^{2}$ at duration of 1, 2 and 3 days.

• 한국농공학회논문집
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• 제54권6호
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• pp.39-44
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• 2012

Water supply capacity and operational capability in agricultural reservoirs are expressed differently in the limited storage due to seasonal and local variation of precipitation. Since agricultural water supply and demand basically assumes the uncertainty of hydrological phenomena, it is necessary to improve probabilistic approach for potential risk assessment of water supply capacity in reservoir for enhanced operational storage management. Here, it was introduced the irrigation vulnerability characteristic curves to represent the water supply capacity corresponding to probability distribution of the water demand from the paddy field and water supply in agricultural reservoir. Irrigation vulnerability probability was formulated using reliability analysis method based on water supply and demand probability distribution. The lower duration of irrigation vulnerability probability defined as the time period requiring intensive water management, and it will be considered to assessment tools as a risk mitigated water supply planning in decision making with a limited reservoir storage.

• 약학회지
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• 제59권3호
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• pp.127-134
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• 2015

The aim of this study was to investigate the correlation among age, symptoms and initial medication (IM), and the tolerance duration of IM in Korean people with Parkinson's disease (PD). We studied 60 patients with untreated early PD who were initially diagnosed in our hospital between Jun 2006 and Sep 2014. We collected data on sex, age at diagnosis, symptom duration until diagnosis, main motor symptoms, frequency and duration of IM through electronic medical records. We divided patients into groups depending on the number of drugs (MONO/COMBI) and whether to contain dopaminergic property (DOPA/NDOPA). We analyzed the correlation between age and symptoms in each two groups and calculated the mean tolerance duration of IM in each of the groups. The mean symptom duration until diagnosis was 12.2 months. The most frequent drug was levodopa formulations (80%) compared to dopamine agonists (58.3%). The number of patients in the COMBI group (63.3%) was more than that in the MONO group (36.7%). Half of the patients in the COMBI group were taking LDF+DA (50%). Except for tremor, no other symptom showed a significant correlation between with IM. The mean tolerance duration of IM was within 200 days. The mean duration for COMBI group (342.7 days) was longer than that for MONO group (209.8 days). Among regimens, the mean tolerance duration of DOPA group (293.3 days) was longer than for NDOPA group (251.4 days). There was no difference in survival curves between any of the two groups. We found that patients experienced symptoms for over a year in Korea. This indicates that diagnosis time is faster than reported in other previous studies. The longest tolerance duration among IM was for dopaminergic combination therapy. More research is needed to design the most appropriate treatment for PD in Korean patients.

• 기술혁신연구
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• 제14권2호
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• pp.93-116
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• 2006

The purpose of this study is to contribute reference material that provides insight into innovative process management that increases R&D output in commercializing new products. A model of a process from research to commercialization with the cumulative profit and loss curve is put forward and hypotheses related to success and failure are developed at the stages up to product launch. Seventeen large projects that have resulted in successful product launches have been examined from the initial research stage to commercialization. Prefect duration, standardized cumulative R&D expenditures and research resource concentration are analyzed in terms of statistical method and patterns in cumulative profit and loss curves after product sales, as well as the reasons for and other aspects of success/failure are investigated and analyzed. Consequently, valuable information on future management tasks has been obtained such as: (1) project duration differs depending on market sectors, product types and presence/absence of materials research (2) cumulative profit and loss curves can be categorized into four patterns (3) reasons for failure can be divided into technological and market problem categories and (4) these factors have an impact on product sales.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2010년도 학술발표회
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• pp.1400-1404
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• 2010

본 연구에서는 현재 시행되고 있는 오염총량관리제 모니터링 시스템에 적용가능한 부하량 추정기법에 대하여 제시하였다. 수정 TANK 모형을 통하여 8일 간격 유량자료의 1일 간격 유량자료로 의 확장을 시행하였다. 그리고 최소분산 비편향 추정기법을 통한 7변수 대수 선형 모형으로 오염 부하량을 추정하였다. 그 결과 TOC 및 BOD 부하량 추정에서 만족스러운 결과를 확인할 수 있었다. 연구의 적용의 일환으로, 낙동강유역의 TOC 및 BOD 항목의 부하량 유황 곡선을 작성하여 전체적인 분포를 살펴보았다.

• 한국물환경학회지
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• 제23권3호
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• pp.332-338
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• 2007

In this study the flow duration curves for Nakdong river basin are analyzed. The TANK model is used as a hydrologic simulation model whose parameters are estimated from 8-day intervals flow data measured by NIER Nakdong River Water Environment Laboratory. As a comparison result between generated natural and present river flow, the present river flow is higher than the natural river flow in the up- and mid-stream of Nakdong river, while the present river flow is lower than the natural river flow in the down stream of Nakdong river.

• Management Science and Financial Engineering
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• 제16권3호
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• pp.49-70
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• 2010

Customer population management models can be classified into three categories: the first category includes the models that analyze the customer population at cohort level; the second one deals with the customer population at aggregate level; the third one has interest in the interactions among the customer populations in the competitive market. Our study proposes a model that can analyze the dynamics of customer population in consumer-durables market at aggregate level. The dynamics of customer population includes the retention curves from the purchase or at a specific duration time, the duration time expectancy at a specific duration time, and customer population growth or decline including net replacement rate, intrinsic rate of increase, and the generation time of customer population. For this study, we adopt mathematical ecology models, redefine them, and restructure interdisciplinary models to analyze the dynamics of customer population at aggregate level. We use the data of previous research on dynamic customer population management at cohort level to compare its results with those of ours and to demonstrate the useful analytical effects which the precious research cannot provide for marketers.

• 한국환경과학회지
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• 제11권7호
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• pp.621-626
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• 2002

Depth-area-duration(DAD) relations are important to hydrological plans and designs for the water resources as well as the flood defence. And these relations have been still in analysis and use today because they can be applied to readily available data. In this paper, rational and consistent DAD models were developed using the multiple regression analysis and basic relationships of area ratio-runoff volume about heavy rainfall occurring in the Im-Jin river basin, 1999. In addition, revised DAD models and curves that can convert a maximum point rainfall to mean area rainfall were developed and evaluated. As results, these models seem to have predictive value in order to plan and design hydrological structures of flood defence in the Im-Jin river basin.

• Journal of Astronomy and Space Sciences
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• 제14권2호
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• pp.233-241
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• 1997

충북대학교 천문대에서 1991년 10월부터 1993년 3월까지 총 42일간 근접쌍성 RZ Cas의 광전 측광 관측을 수행하여 UBV 광도곡선을 완성하였다. 제 1식심 의 광도곡선으로부터 8개의 제 1식심 시각 및 새로운 광도요소를 결정하였다. 우리의 광도곡선에서 제 1식심이 개기 식임을 확인하였고, 개기 식 지속시간이 평균 18.1분으로서 이 값은 약 $0.^{p}01$에 해당하는 값임을 알았다. Wilson Devinney 분석법을 사용하여 우리의 광도곡선과 Duerbeck & Hanel(1979)의 시선속도 곡선을 동시에 만족하는 RZ Cas 의 측광 및 분광학적 해를 구하고 이 값으로부터 이 쌍성 계의 절대량을 산출하였다.