Characteristic large-scale circulation pattern of the persistent droughts of Northeast Asia from premonsoon season to monsoon season

학위논문 (박사)-- 서울대학교 대학원 : 지구환경과학부, 2014. 2. 임규호.Characteristic patterns of atmospheric circulation anomalies over the northeast Asian region in the dry and wet premonsoon seasons have been analyzed. The relationship between these patterns in the premonsoon season and the precipitation anomalies in the monsoon season has been also investigated. Since this study focuses on dry premonsoon season, features of anomalous large-scale atmospheric circulations during springtime droughts that occurred over the northeast Asia are revealed. The Palmer drought severity index is used in order to define drought years. In drought years, the anomalous circulation over the northeast Asia exhibits the weakened northward flow from the western North Pacific, and the position of the East Asian westerly Jet (EAWJ) maximum core at 300hPa is shifted southward. Thus, the rainfall band is moved southward, and the associated precipitation is suppressed over Korea, Japan, and southeastern China during spring droughts. The Sea Surface Temperature (SST) anomalies and outgoing longwave radiation anomalies, which show a north–south dipole pattern between the Philippines and the northeast Asian region, support these dry conditions through the Hadley circulation. The anomalously warm SSTs in the western North Pacific seem to play an important role in the atmospheric circulation associated with persistent northeast Asian droughts The persistent features of extreme precipitation over the northeast Asia frompremonsoon season to monsoon season are found. In order to understand some characteristics of the circulation anomalies associated with persistent features of extreme precipitation, six dry cases and six wet cases in the premonsoon season are selected. Both of the extreme conditions are nearly persistent in each case. As mentioned in spring drought analysis, the weakened western North Pacific subtropical high (WNPSH) and the southward-shifted EAWJ are predominant for dry cases. For wet cases, the strengthening of WNPSH, the northward-shifted EAWJ in spring, and southward-shifted EAWJ in summer are apparent. However, dry cases are associated with the warm SST anomalies of the western North pacific, whereas wet cases are related to the warm SST anomalies of the Indian Ocean and Bay of Bengal. The dependency of extreme precipitation on this SST anomaly pattern is supported through numerical experiments. Based on the observational analysis and model experiments, the main connection system between extreme precipitation such as drought and SST is the anomalous cyclonic circulation over the western North Pacific.Table of Contents Abstract ····················································································· i Table of Contents ········································································· v List of Figures ············································································ vii List of Tables ·············································································· xi 1. Introduction ············································································ 1 2. Data and methods ····································································· 5 2.1 Data ················································································ 5 2.2 Methods ··········································································· 8 2.2.1 Definition of premonsoon season ····································· 8 2.2.2 Analysis domain and selection of dry and wet years ··············· 17 3. Prominent features of large-scale circulation during drought ············ 21 3.1 Mean fields of atmospheric circulation during boreal spring ········ 21 3.2 Definition and selection of drought years ································· 25 3.3 Atmospheric circulation anomalies during drought years ············ 27 3.4 Teleconnection between drought and SSTs ······························· 36 3.4.1 SST and OLR anomalies ·············································· 36 3.4.2 Definition of the EAJ index ············································ 39 3.4.3 The relationship among the EAJ index, SST, and precipitation ··· 42 4. Characteristics of anomalous large-scale circulations in the spring and summer ···················································································· 47 4.1 Selection of dry and wet cases ··············································· 47 4.2 Precipitation anomalies ······················································· 48 4.3 Geopotential height anomalies at 850 hpa ································ 50 4.4 Zonal wind anomalies at 200 hpa ·········································· 57 4.5 Moisture flux anomalies at 850 hpa ········································ 60 4.6 Linkage of the anomalous circulation and SST anomalies ············ 64 5. Results of model experiments ······················································ 69 5.1 Model and experimental design············································· 69 5.2 Circulations at 850 hPa in dry/wet force run ···························· 71 5.3 EAWJ at 200 hPa in dry/wet force run ···································· 74 6. Summary and conclusions ·························································· 83 References ················································································· 91 국문초록 ··················································································· 98 감사의 글 ··············································································· 102Docto

한말 국가제사의 변화에 관한 사회학적 연구

학위논문(석사)--서울대학교 대학원 :사회학과,1998.Maste

Analysis of Semi-Rigid Connections on 3D Floating Structures Considering Wave Loads

플로팅 상부구조물은 일반 건축물과 형태는 같지만 기초가 땅이 아닌 하부 부체에 지지되는 구조물로 파랑하중에 의한 영향을 크게 받으며, 파랑하중에 의한 하부구조물의 변형이 접합부에 영향을 미쳐 상부구조물의 이용자에게 사용성 및 안전성의 문제를 발생시키게 된다. 이에 따라 본 논문에서는 3차원 플로팅 구조물의 상부구조물과 하부구조물을 일체화한 전해석을 통하여 강접과 반강접(TSD)접합에 대해 탄성 해석을 실시하고, 하부구조물을 제외한 상부구조물해석을 통하여 소성해석을 분석하였다. 구조물의 전해석과 하부구조물을 제외한 상부구조물해석을 비교 분석 하였으며 탄성 해석을 통해 파랑하중의 CASE를 나누어 파랑하중의 변화에 따른 구조물의 모멘트 및 변위를 접합부에 따라 분류하고 소성하석을 통해 3차원 플로팅 구조물의 거동을 비교한 결과 다음과 같은 결론을 도출하였다. 1. 구조물의 전해석과 하부구조물을 제외한 상부구조물해석의 모멘트 비교한 결과 전체적인 모멘트 값은 비슷하지만 전해석의 경우 상부구조물해석 보다 하부구조물의 영향으로 저층 보 부재에서 모멘트 값이 대체적으로 작은 것을 알 수 있었다. 이에 따라 상부구조물과 하부구조물의 일체화하여 전해석을 할 경우 상부구조물만 해석한 기존의 자료에 비해 좀 더 정확한 해석이 가능하리라 사료된다. 2. 파랑하중에 대해 파향을 0o와 90o로 나누어 모멘트를 비교한 결과 파향 0o에서는 파향 90o일때에 비하여 보부재의 모멘트가 거의 발생하지 않아 파향 90o일때 상부구조물에 미치는 영향이 더 큰 것을 알 수 있었다. 3. 파향 90o에서는 파랑하중을 적용시켰을 때와 조합하중을 적용시켰을 때 모두 CASE2에서 최대 모멘트가 발생하였고 조합하중의 결과 반강접을 적용하였을 경우 최대 모멘트는 단부에서 감소하였다. 반강접을 적용한 보 중앙부에서는 모멘트가 증가하였지만 결과적으로는 보부재의 최대 모멘트는 감소하였다. 이에 따라 플로팅 상부구조물의 반강접 접합부 사용 시 최대 모멘트를 줄일 수 있어 부재의 단면을 줄일 수 있을 거라 사료된다. 4. 플로팅 구조물의 최대 변위는 파랑하중에 의해 지배적으로 발생하며 파랑하중에 의한 강접과 반강접의 변위차이는 거의 발생하지 않고 정적하중에 의한 변위 차는 반강접 일때 강접에 비해 증가하였다. 파랑하중의 위치 변화에 따라 상부구조물의 -변형을 하게 될 경우 반강접 접합부는 최대 변위가 감소하게 되며 +거동을 하게 될 경우 증가하게 된다. 파랑하중의 진폭이 커질수록 파랑하중에 의한 응답이 지배적이게 되어 강접과 반강접의 최대 변위 차이는 줄어들게 된다. 5. 파랑하중의 진폭이 커지게 됨에 따라 플로팅 상부구조물의 최대 하중계수는 감소하고 최대 변위는 증가하게 되어 구조물이 최대 받을 수 있는 하중은 감소하게 된다. 접합부에 반강접을 적용하게 되면 접합부의 연성이 증가하여 강접일 때에 비해 최대 하중계수는 감소하게 되며 변위는 증가 하는 거동을 보였다.목 차 목 차 표목차 그림목차 ABSTRACT 1. 서 론 1.1 연구의 배경 및 목적 1.2 연구동향 1.3 연구범위 및 방법 2. 반강접 접합부 분류 및 해석 모델 2.1 개요 2.2 규준에 따른 반강접 접합부의 분류 2.3 반강접 접합부의 종류 2.4 반강접 접합부의 모델링 3. 플로팅 구조물의 구조해석 3.1 플로팅 구조물의 계획 및 해석 3.2 플로팅 구조물의 파랑하중 산정 3.3 하부구조물의 변형 및 응력 변화 4. 반강접 접합부를 적용한 적용예제 구조물 4.1 적용 예제 구조물 4.2 TSD 반강접 접합부 특성 4.3 부력 산정 4.4 하중 산정 4.5 전해석과 상부구조물해석의 비교 4.6 상부구조물의 응력 검토 5. 파랑하중 변화에 따른 구조물의 응답 해석 5.1 파랑하중별 최대 모멘트 비교 5.2 파랑하중별 최대 변위 비교 5.3 소성해석에 의한 거동분석 6. 결 론 참고 문

(A)study on the commercial land use change in subway station area influenced by railroad station complex development

학위논문(석사) --서울대학교 대학원 :협동과정 도시설계학전공,2007.Maste

Computer simulation for the control of distillation columns using model predictive control algorithms

Maste

CNN-based ship resistance prediction using voxelization

The resistance of a ship can be analyzed using computational fluid dynamics (CFD) or model tests. To explore a number of design candidates, for instance in the early design stages, it is too expensive to use the CFD and model tests because of their relatively long analysis time. Ship designers tend to often use statistical methods that are simple and need a short analysis time. The statistical methods provide such advantages, but are often relatively inaccurate due to their simplicity. To deal with the problem, we present a method for predicting ship resistance that is based on convolutional neural networks (CNNs). This converts input hulls into 3D voxels, which are the suitable data structure to use the CNNs. The CNNs extract only important features from the input hulls and this often allows for better convergence in the training of artificial neural networks (ANNs). In a case study, the proposed method was applied to developing ANNs for ship resistance prediction. It was compared with a parametric method which is also an ANNs, but the input of the ANNs used hull parameters such as the length overall, block coefficient, etc. The results of the case study show that the voxelized input improves the resistance prediction accuracy compared with the parametric input in developing ANNs for ship resistance prediction.The resistance of a ship can be analyzed using computational fluid dynamics (CFD) or model tests. To explore a number of design candidates, for instance in the early design stages, it is too expensive to use the CFD and model tests because of their relatively long analysis time. Ship designers tend to often use statistical methods that are simple and need a short analysis time. The statistical methods provide such advantages, but are often relatively inaccurate due to their simplicity. To deal with the problem, we present a method for predicting ship resistance that is based on convolutional neural networks (CNNs). This converts input hulls into 3D voxels, which are the suitable data structure to use the CNNs. The CNNs extract only important features from the input hulls and this often allows for better convergence in the training of artificial neural networks (ANNs). In a case study, the proposed method was applied to developing ANNs for ship resistance prediction. It was compared with a parametric method which is also an ANNs, but the input of the ANNs used hull parameters such as the length overall, block coefficient, etc. The results of the case study show that the voxelized input improves the resistance prediction accuracy compared with the parametric input in developing ANNs for ship resistance prediction.1. 서론 1 1.1 연구 배경 1 1.2 선행 연구 1 1.3 연구 목표 및 개요 3 2. 딥러닝 모델 5 2.1 딥러닝 개요 5 2.2 합성곱 신경망 8 2.2 임베딩 10 2.3 완전연결층 12 3. 데이터 구성 13 3.1 데이터 개요 13 3.2 선형 데이터의 복셀화 13 3.3 부가 정보 데이터 16 3.4 저항 데이터 17 4. 비교 시험 20 4.1 입·출력 데이터 수집 및 결정 21 4.1.1 데이터 수집 21 4.1.2 딥러닝 모델을 위한 데이터 결정 25 4.2 딥러닝 모델 결정 30 4.3 방법론 비교 34 5. 결론 38 5.1 요약 38 5.2 향후 과제 39Maste

저출산 개선방안 워크숍(CNI세미나2017-028) (박종서, 김용현)

○목적 : 저출산이 심각한 사회문제로 떠오름에 따라 국책연구기관과 더불어 충남연구원이 중앙정부와 지방정부의 대응방안을 논의하기 위한 워크숍 개최 ○개요 - 주제 : 저출산 개선방안에 대한 논의 - 일시 : 2017년 4월 17일(월) 15:00 - 장소 : 충남연구원 대회의실 ○내용 - 주제발표 1 : 출산의 원인과 출산율 회복을 위한 정책방향성(한국보건사회연구원, 박종서 박사) - 주제발표 2 : 충남도 및 시군 저출산 정책 사례연구(충남연구원, 김용현 박사) - 지정토론   ·좌장 : 강현수(충남연구원장)   ·토론 : 최상진 과장(충청남도 저출산고령화대책과)            권경주 이사(세계도덕재무장 한국본부)            최은희 박사(충남여성정책개발원)- 주제발표 1 : 출산의 원인과 출산율 회복을 위한 정책방향성(한국보건사회연구원, 박종서 박사) - 주제발표 2 : 충남도 및 시군 저출산 정책 사례연구(충남연구원, 김용현 박사) - 지정토