• 대기
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• 제18권4호
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• pp.441-458
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• 2008

A TP/WVP-3000A, ground-based microwave radiometer, that was first introduced to South Korea has been operated since August 22, 2007 at the National Center for Intensive Observation of Severe Weathers (NCIO). Using the dual-band, the radiometer provides temperature and humidity soundings from the surface up to 10 km height with the high-temporal resolution of a few minutes. In this study, the performance of the radiometer on the predictability of the high impact weathers was evaluated and various practical applications were investigated. To verify the retrieved profile data from the radiometer, temperature and relative humidity soundings are compared with those from the rawinsonde launched at the NCIO and Gwangju station. The root mean squared errors for temperature and relative humidity soundings were smaller under rainy weather conditions. The correlation coefficient between PWVs (Precipitable Water Vapors) obtained from the radiometer and Global Positioning System satellite at Mokpo station is 0.92 on average. In order to investigate the structure and characteristics of precipitation, stability indexes related to rainfall such as the Convective Available Potential Energy (CAPE), K-index, and Storm RElative Helicity (SREH) were calculated using windprofiler at the NCIO from 14 to 16 September, 2007. CAPE and K-index tended to be large when the thermodynamic unstability was strong. On the other hand, SREH index was dominantly large when the dynamic unstability was strong due to the passage of the typhoon 'Nari'.

• 대기
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• 제28권2호
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• pp.187-200
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• 2018

The heavy snowfall phenomenon with thunder and lightning occurred in Yeongdong coastal region on 20 January 2017. Amount of snow on that day was a maximum of 47 cm and was concentrated in a short time (2 hours) at the Yeongdong coastal area. The mechanism of thundersnow was investigated to describe in detail using observational data and numerical simulation (Weather Research and Forecast, WRF) applied lightning option. The results show that a convective cloud occurred at the Yeongdong coastal area. The east wind flow was generated and the pressure gradient force was maximized by the rapidly developed cyclone. The cold and dry air in the upper atmosphere has descended (so called tropopause folding) atmospheric lower layer at precipitation peak time (1200 LST). In addition, latent heat in the lower atmosphere layer and warm sea surface temperature caused thermal instability. The convective cloud caused by the strong thermal instability was developed up to 6 km at that time. And the backdoor cold front was determined by the change characteristics of meteorological elements and shear line in the east sea. Instability indexes such as Total totals Index (TT) and Lightning Potential Index (LPI) are also confirmed as one of good predictability indicates for the explosive precipitation of convective rainfall.

• 대기
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• 제26권1호
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• pp.35-45
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• 2016

Initialization of the global seasonal forecast system is as much important as the quality of the embedded climate model for the climate prediction in sub-seasonal time scale. Recent studies have emphasized the important role of soil moisture initialization, suggesting a significant increase in the prediction skill particularly in the mid-latitude land area where the influence of sea surface temperature in the tropics is less crucial and the potential predictability is supplemented by land-atmosphere interaction. This study developed a new soil moisture initialization method applicable to the KMA operational seasonal forecasting system. The method includes first the long-term integration of the offline land surface model driven by observed atmospheric forcing and precipitation. This soil moisture reanalysis is given for the initial state in the ensemble seasonal forecasts through a simple anomaly initialization technique to avoid the simulation drift caused by the systematic model bias. To evaluate the impact of the soil moisture initialization, two sets of long-term, 10-member ensemble experiment runs have been conducted for 1996~2009. As a result, the soil moisture initialization improves the prediction skill of surface air temperature significantly at the zero to one month forecast lead (up to ~60 days forecast lead), although the skill increase in precipitation is less significant. This study suggests that improvements of the prediction in the sub-seasonal timescale require the improvement in the quality of initial data as well as the adequate treatment of the model systematic bias.

• Journal of Periodontal and Implant Science
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• 제51권2호
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• pp.100-113
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• 2021

Purpose: Previous studies have solely focused on fresh extraction sockets, whereas in clinical settings, alveolar sockets are commonly associated with chronic inflammation. Because the extent of tissue destruction varies depending on the origin and the severity of inflammation, infected alveolar sockets may display various configurations of their remaining soft and hard tissues following tooth extraction. The aim of this study was to classify infected alveolar sockets and to provide the appropriate treatment approaches. Methods: A proposed classification of extraction sockets with chronic inflammation was developed based upon the morphology of the bone defect and soft tissue at the time of tooth extraction. The prevalence of each type of the suggested classification was determined retrospectively in a cohort of patients who underwent, between 2011 and 2015, immediate bone grafting procedures (ridge preservation/augmentation) after tooth extractions at Seoul National University Dental Hospital. Results: The extraction sockets were classified into 5 types: type I, type II, type III, type IV (A & B), and type V. In this system, the severity of bone and soft tissue breakdown increases from type I to type V, while the reconstruction potential and treatment predictability decrease according to the same sequence of socket types. The retrospective screening of the included extraction sites revealed that most of the sockets assigned to ridge preservation displayed features of type IV (86.87%). Conclusions: The present article classified different types of commonly observed infected sockets based on diverse levels of ridge destruction. Type IV sockets, featuring an advanced breakdown of alveolar bone, appear to be more frequent than the other socket types.

• 한국지구과학회지
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• 제42권6호
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• pp.605-622
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• 2021

Seasonal forecasting has numerous socioeconomic benefits because it can be used for disaster mitigation. Therefore, it is necessary to diagnose and improve the seasonal forecast model. Moreover, the model performance is partly related to the ocean model. This study evaluated the hindcast performance in the upper ocean of the Global Seasonal Forecasting System version 5-Global Couple Configuration 2 (GloSea5-GC2) using a multivariable integrated evaluation method. The normalized potential temperature, salinity, zonal and meridional currents, and sea surface height anomalies were evaluated. Model performance was affected by the target month and was found to be better in the Pacific than in the Atlantic. An increase in lead time led to a decrease in overall model performance, along with decreases in interannual variability, pattern similarity, and root mean square vector deviation. Improving the performance for ocean currents is a more critical than enhancing the performance for other evaluated variables. The tropical Pacific showed the best accuracy in the surface layer, but a spring predictability barrier was present. At the depth of 301 m, the north Pacific and tropical Atlantic exhibited the best and worst accuracies, respectively. These findings provide fundamental evidence for the ocean forecasting performance of GloSea5.

• 한국수자원학회논문집
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• 제57권4호
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• pp.249-261
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• 2024

최근 기후변화로 인해 극한홍수가 증가하여 댐 운영에 큰 어려움으로 작용하고 있다. 그간 댐 설계 시 제시되는 홍수조절방식은 하류 상황에 대한 고려 없이 계획홍수량이라는 특정 홍수상황을 가정하여 수립된 것으로, 실제 상황에는 기상예보를 기반으로 저수지 모의운영을 통해 홍수조절을 실시한다. 하지만 기상예보의 불확실성과 댐 관리자마다 달라지는 의사결정 등 한계가 존재한다. 따라서 본 연구에서는 섬진강댐에 대해 댐 유입량을 기준으로 댐 운영 제약사항을 고려한 단계적 방류량 증량을 실시하는 홍수조절방식을 제시하고, 계획홍수량 및 역대 최대홍수사상을 적용한 저수지 모의운영을 통해 효과를 평가하였다. 본 연구에서 제시한 홍수조절방식은 다양한 댐 운영자가 현실적 댐 운영 여건을 반영하여 일관성 있는 홍수조절 의사결정에 활용 가능할 것으로 판단된다.

• 환경생물
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• 제21권2호
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• pp.87-100
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• 2003

환경오염이 심각해짐에 따라 국내외적으로 환경에 대한 관심이 고조되고 인체에 해를 끼치는 환경요인으로부터 방어하기 위한 많은 노력들이 기울여지고 있다. 특히 내분비계장애물질이 생식기능과 면역기능을 약화시키고, 행동 이상을 일으키며, 암 발생률을 높인다는 점이 밝혀지기 시작하면서 많은 연구들이 발표되고 여러 가지 방법들이 내분비계장애물질과 더불어 환경분야연구에 응용되어왔지만 단백질을 대상으로 연구하여 유전자기능을 연구하는 프로테오믹스(proteomics) 연구를 접목시키려는 시도가 아직까지는 빈약하다. 프로테오믹스는 기능을 갖는 단백질들의 발현을 종합적이고 정량적으로 측정하는 가장 직접적인 수단이고, 질병, 약물투여, shock 등 생물학적인 동요(perturbation)에 의하여 변하는 단백질들의 발현양상의 변화를 정확하게 관찰할 수 있으며, 생체내 유전자발현의 궁극적인 양상을 규명할 수 있고, 또한 유전자, 단백질 및 질병간의 연결고리를 제공한다. 기존의 biomarker는 다른 질병 표지자와 연관성이 높아 직접적인 유해물질 노출 위험도를 정확히 판정하기 어렵다. 따라서 대량발굴탐색(high-throughput screen-ing)이 가능한 2차원 전기영동 분석과 MALDI-TOF 또는 protein chip array와 SELDI-TOF에 의한 단백질 분자구조 분석기술 및 이들을 지원하는 생물정보학(bio-informatics)의 발전을 이용하여 환경독성 연구에 이용 할 수 있는 표적단백질(biomarker)발굴에 적절한 이용이 가능할 것이다.

• 한국지구과학회지
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• 제44권6호
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• pp.540-556
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• 2023

본 연구는 여름 및 초가을(6-9월)에 한반도에서 관측된 레윈존데 사운딩을 분석하여 대류가용잠재에너지와 대류억제도가 깊은 습윤 대류 및 강수 발생 예측에 유용성이 있는지를 확인해보았다. 레원존데 사운딩은 열역학적으로 깊은 습윤 대류가 발생할 가능성이 높은 고 대류가용잠재에너지 저 대류억제도 그룹과 대류 발생을 억제시킬 수 있는 저 대류가용잠재에너지 고 대류억제도 그룹으로 분류하였다. 이후, 두 그룹의 12시간 누적 강수량, 12시간 평균 최저운고, 12시간 평균 중하층운량의 분포 차이가 유의미한지 여부를 통계적 가설검정을 통해 확인하였다. 그 결과, 무강수인 경우 21:01-09:00 KST 시간대의 12시간 평균 최저운고를 제외하고 두 그룹은 통계적으로 유의미한 차이가 있음이 검증되었다. 이 결과는 고 대류가용잠재에너지 저 대류억제도 그룹이 저 대류가용잠재에너지 고 대류억제도 그룹보다 깊은 습윤 대류 및 강수 발생에 더 유리함을 시사한다.

• 유통과학연구
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• 제14권1호
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• pp.93-102
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• 2016

Purpose - The purpose of paper is studying the static and dynamic side for long-term memory storage properties, and increase the explanatory power regarding the long-term memory process by looking at the long-term storage attributes, Korea Composite Stock Price Index. The reason for the use of GPH statistic is to derive the modified statistic Korea's stock market, and to research a process of long-term memory. Research design, data, and methodology - Level shifts were subjected to be an empirical analysis by applying the GPH method. It has been modified by taking into account the daily log return of the Korea Composite Stock Price Index a. The Data, used for the stock market to analyze whether deciding the action by the long-term memory process, yield daily stock price index of the Korea Composite Stock Price Index and the rate of return a log. The studies were proceeded with long-term memory and long-term semiparametric method in deriving the long-term memory estimators. Chapter 2 examines the leading research, and Chapter 3 describes the long-term memory processes and estimation methods. GPH statistics induced modifications of statistics and discussed Whittle statistic. Chapter 4 used Korea Composite Stock Price Index to estimate the long-term memory process parameters. Chapter 6 presents the conclusions and implications. Results - If the price of the time series is generated by the abnormal process, it may be located in long-term memory by a time series. However, test results by price fixed GPH method is not followed by long-term memory process or fractional differential process. In the case of the time-series level shift, the present test method for a long-term memory processes has a considerable amount of bias, and there exists a structural change in the stock distribution market. This structural change has implications in level shift. Stratum level shift assays are not considered as shifted strata. They exist distinctly in the stock secondary market as bias, and are presented in the test statistic of non-long-term memory process. It also generates an error as a long-term memory that could lead to false results. Conclusions - Changes in long-term memory characteristics associated with level shift present the following two suggestions. One, if any impact outside is flowed for a long period of time, we can know that the long-term memory processes have characteristic of the average return gradually. When the investor makes an investment, the same reasoning applies to him in the light of the characteristics of the long-term memory. It is suggested that when investors make decisions on investment, it is necessary to consider the characters of the long-term storage in reference with causing investors to increase the uncertainty and potential. The other one is the thing which must be considered variously according to time-series. The research for price-earnings ratio and investment risk should be composed of the long-term memory characters, and it would have more predictability.

• 한국작물학회지
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• 제36권6호
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• pp.560-567
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• 1991

콩잎의 광합성능력이 잎의 내부형태 변이와 관련되어 있는지 검토하기 위해 대두품종 ‘Hodg-son 78’을 공시하여 포장실험을 수행하였다. 잎의 내부 형태면이를 촉진시키기 위해 착협시(R3 stage)에 유아주기 (1m이랑당 26주에서 6.5주)와 곁가지 치기를 통해 source활성 증대를, 계속적인 꼬투리 제거 (절위당 한개의 꼬투리만 남김)를 통해 sink활성 감소를 시도하였다. 협신장기(R4 stage)로부터 3-4일 간격으로 5회에 걸쳐 제 10절위 복엽의 중앙소엽을 대상으로 기체교환특성, 잎의 두께, 엽육세포의 체적 및 표면적, 그리고 주변 미기상변수를 측정하였다. 가설검증을 위해 기존의 광합성모형을 엽육세포의 표면적이 기체확산과, 엽육세포의 체적이 생화학적 활성과 관련되도록 수정하였다. 실측 광합성속도의 변이가운데 79%는 이 수정된 모형에 의해 설명 가능하였으며, 엽내부형태의 영향을 무시한 기존의 광합성모형에 비해 평균 14.5%의 추정능력 향상을 확인할 수 있었다.