• Journal of the Korean earth science society
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• v.23 no.7
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• pp.587-596
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• 2002

A super ensemble model was developed for the seasonal prediction of regional precipitation in Korea using the lag correlated large scale predictors, based on the empirical orthogonal function (EOF) analysis and multiple linear regression model. The predictability of this model was also evaluated by cross-validation. Correlation between the predicted and the observed value obtained from the super ensemble model showed 0.73 in spring, 0.61 in summer, 0.69 in autumn and 0.75 in winter. The predictability of categorical forecasting was also evaluated based on the three classes such as above normal, near normal and below normal that are clearly defined in terms of a priori specified by threshold values. Categorical forecasting by the super ensemble model has a hit rate with a range from 0.42 to 0.74 in seasonal precipitation.

• Proceedings of the Acoustical Society of Korea Conference
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• 1987.11a
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• pp.39-39
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• 1987

자동차에서 발생되는 소음은 여러 가지 발생원으로부터의 복합적인 것으로서 차량의 속도가 고속화하면서 타이어 소음의 기여도가 매우 커지는 것으로 알려져 있다. 타이어 소음은 근본적으로 노면과 타이어의 상호작용에 의하여 발생되는 데 타이어/노면의 상호작용에 영향을 미치는 인자로는 마모상태, 차량속도, 하중, 공기압, carcass 구조, 타이어 온도등 여러 가지가 있으나 tread 모양과 노면의 상태에 가장 크게 영향을 받는다. 본 연구에서는 승용차용 155SR13 radial 타이어를 대상으로 하여 실내에 설치된 dynamometer를 이용하여 groove 의 개수, groove 길이, groove 폭, groove 깊이, groove 방향 등 트레드 패턴 인자가 발생소음에 미치는 기여도를 실험적으로 측정하고 트레드 패턴형상에 따른 소음도를 예측할 수 있는 실험식을 구했다. 또한 단일 groove 내에서 발생되는 소음의 시간신호를 측정하여 모델화하고 차량속도와 groove 사이의 간격에 따른 시간신호를 합성하고 이 신호로부터 FFT 알고리듬을 통해 소음 spectrum을 구하는 소음 예측 프로그램을 개발하였다. 비교적 단순한 tread 패턴에 대해 이를 적용한 결과 실험적으로 구한 spectrum과 상당히 유사함을 볼 수 있었다.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.67-68
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• 2010

The bond stress and crack spacing are effected the calculated crackwidth. EC2 and MC90 suggest crackwidth function that maximum crack spacing and difference average strain. This study is predict crackwidth, according to each design standard than comprison and analyis test data. The result, each design standard ways are predict well to test data.

• Proceedings of the KIPE Conference
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• 2020.08a
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• pp.359-360
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• 2020

리튬 이온 배터리가 전기 자동차의 주 동력원으로 사용됨에 따라 배터리의 잔존 수명 예측기술의 중요성이 부각되고 있다. 사용 환경에 적합한 잔존 수명 예측을 위해 전기 자동차의 주행 환경을 모사하여 충전 및 방전이 빈번하게 나타나는 UDDS 프로파일에서 범용적으로 사용할 수 있는 수명 인자를 선정하는 것이 필수적이다. 배터리의 잔존 용량과 가장 상관도가 높은 수명 인자를 선정함으로써, 인공지능 기반 예측 알고리즘의 정확도 향상을 기대 할 수 있으며, 태양광 ESS와 같은 상이한 특성의 어플리케이션에도 범용적인 적용이 가능하다.

• Investigative Magnetic Resonance Imaging
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• v.1 no.1
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• pp.125-129
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• 1997

Purpose: The aim of this study was to find correlation between the expression of epidermal growth factor receptor (EGFR) and MR findings in the brain glioma. Materials and Methods: MR features including edema, margin, necrosis, heterogeneity, hemorrhage and contrast enhancement were retrospectively analyzed with preoperative MR images in 41 patients with proven brain gliomas (8 low grade astrocytomas, 12 anaplastic astrocytomas, 21 glioblastoma multiformes). Immunohistochemical study of EGFR was done and their expressions were graded by both stained distribution and intensity. Correlation analysis between the MR features and EGFR expressions was done. Results: Peritumoral edema was correlated with both distribution (r=0.71, p=0.00) and stain intensity (r=0.69, p=0.00) of EGFR expression. Other MR features showed no statistical correlation with EGFR expression. Conclusion: MRI is useful in evaluation of brain glioma, and peritumoral edema is useful finding that suggests EGFR expression as well as malignant histopathologic grade of the tumor.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.5
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• pp.378-385
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• 2014

The chlorophyll-a concentration in algae bloom warning system of Hangang basin did not predict the cyanobacteria dominance. In this study, suggest the predicting indicator of cyanobacteria dominance through analyzing the environmental factors affecting on the cell count of cyanobacteria. Firstly, the dominance of algae was analyzed with seasonal variation during Jan. 2012~Sep. 2013. The diatom dominated phytoplankton communities during the period of January~April. In the May~June, the green algae dominated. And, the dominance of algae was changed to cyanobacteria in the July~August. Also, the environmental factors affecting to cyanobacteria blooms ; nutrients (TN, TP), temperature, precipitation, dam-discharge were evaluated during the study period. Rather than temperature factor, relatively low dam discharge causes cyanobacteria to grow rapidly and create a blooms. The low dam-discharge may increase the water retention time. Finally, it is proved that a low ratio of TN to TP (<29:1) can favour the development of cyanobacteria blooms. Thus, the predicting indicator (TN:TP) have need to apply to the alarm bloom warning system of Hangang basin.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4D
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• pp.635-647
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• 2006

Korean construction companies first advanced to the international markets in 1960's and so far have brought more than 4,900 projects which account for 193 billion dollars approximately. With the large increase of national employment and income being followed by the achievement, Korea's construction industry has made an enormous contribution to the improvement of domestic economy for the last 40 years. However, recently the increased risk in international markets as well as the sharpening competition with foreign companies promising in terms of advanced technologies and low labor cost have been driving Korean construction away from the market shares. According to ENR (Engineering News Record, 1994~2003), it is revealed that 15.1% of top 225 global contractors are suffering from loss in international construction markets. This phenomenon is largely due to the highly uncertain characteristics of international projects, which are inherently exposed to various and complicated risky situations. Furthermore, especially for Korean construction companies, it is often the case that the failure in an international construction project cannot be offset by even a sufficient number of successful domestic achievements. Therefore, not only the selective screening among the nominated projects which have strong possibility of collapse but the systematic strategies for controlling potential risk factors are also considered indispensable in international construction portfolio management. The purpose of this study is to first analyze the causal relationships of the profit-influencing variables and the project success, and develop the profitability forecasting model in international construction projects.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2016.05a
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• pp.332-335
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• 2016

2000년대 들어 정보기술의 발달로 정보공유와 수집을 쉽게 할 수 있게 되면서 많은 정보를 활용하여 미래의 사람들의 행동과 생각을 예측하기에 이른다. 특히, 정부는 보안과 위험관리 분야에 빅데이터 개념을 도입하여 미래에 대한 위험을 예측하고 효과적으로 관리할 수 있게 되었다. 선박도 사람과 마찬가지로 선박운항과 관련된 수많은 정보들을 만들어낸다. 이렇게 생성된 정보는 각 기관에 흩어져 관리되고 있으며, VTS센터에서 수집되는 정보들은 아직까지 체계적인 관리조차 이루어지지 않고 있다. 본 제언은 국내 VTS센터, 나아가 인근 국가의 VTS센터에서 생성되는 각종 정보들과 관련 기관에서 활용되는 정보들을 한 곳에서 통합하여 관리하는 시스템을 구축하고 이곳에서 공유 분석되는 정보를 통해 조금이나마 선박사고의 위험성을 감소시킬 수 있는 관제 방법에 대해서 생각해보았다. 이에 대한 방안 중 하나로 정보공유를 통한 선박 사고 개연성 예측 모델을 제시하고자 한다. 이후 연구를 통해, 본 제언에서 제시된 사고 개연성 예측 모델을 위한 위험유발 인자와 사고의 발생과의 상관을 통계적으로 해명할 수 있게 된다면 본 모델을 활용하여 보다 선제적이고, 효율적인 선박관제를 수행할 수 있을 것으로 생각된다.

• Aerospace Engineering and Technology
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• v.2 no.1
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• pp.1-10
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• 2003

Methodology of predicting steady performance of gas turbine engine from transient test data was explored to develop an economic performance test technique. Discrepancy of transient performance from steady performance was categorized as dynamic, thermal and aerodynamic transient effects. Each effect was mathematically modeled and quantified to provide correction factors for calculating steady performance. The influence of engine inlet/outlet condition change on engine performance was corrected firstly, and then steady performance was predicted from the correction factors. The result was compared with steady performance test data. This correction method showed an acceptable level of precision, 3.68% difference of fuel flow.

• Clinical and Experimental Pediatrics
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• v.52 no.10
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• pp.1161-1166
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• 2009

Purpose : Kawasaki disease—the most common cause of acquired heart disease in children—incidence is increasing yearly. Therefore, we evaluated the predictive indicators of coronary complications of Kawasaki disease based on clinical and laboratory data. Methods : Between January 2005 and March 2008, of the 201 children with Kawasaki disease treated at the Gil Hospital of Gachon University of Medicine and Science, 51 had coronary artery lesions (Group II) and 150 had no lesions (Group I). The reasons for coronary artery lesions were deduced from the clinical and laboratory data. Results : Analysis of the 2 groups revealed that fever duration and days of fever after and before initial intravenous gammaglobulin (IVIG) treatment were significantly longer in Group 2 than in Group I. IVIG infusions were statistically higher in Group II than in Group I. As per the laboratory data, C-reactive protein (CRP) value was significantly higher in Group II. Collectively, >10 days of fever duration, >48 h of fever duration after, and >10 days of fever before IVIG treatment increased the risk of coronary artery lesions 6-, 5-, and 3.5-fold, respectively. Furthermore, additional IVIG courses and higher CRP level increased the risk of coronary artery lesions 4-fold and 2-3-fold, respectively. Conclusion : The following 3 factors were responsible for increased risk of coronary artery lesions in children with Kawasaki disease: fever duration and days of fever after and before IVIG treatment. To identifythe predictive indicators of coronary complications, it is necessary to further elucidate the relationship between well-known forecasting factors.