파레토최적해를 이용한 버스네트워크 설계 다목적 최적화

학위논문 (박사) -- 서울대학교 대학원 : 공과대학 건설환경공학부, 2020. 8. 고승영.Public transportation is a service that provides access to various opportunities and can reduce the mobility gap through efficient network design. However, services are concentrated in a specific area considering economic efficiency, resulting in spatial imbalances in services and inefficiency to users. In this study, bus network design algorithms were presented, including operators, users, and public aspects. An efficiency of operators and users and the competitiveness of public transportation between modes and areas were considered. Toy network was organized according to the urban network topology and demand pattern, and the analysis was performed by applying the algorithm of this study. The applicability of the algorithm was confirmed through the actual network. An improved network could be derived from both operators and the public compared to previous research focused on operational efficiency. Suggested a method to select and apply Pareto optimal according to the planner's judgment. The bus network design algorithm in this study can be used as a means of decision criteria and it can be applied to cities that require a balanced network supply with limited resources.Chapter 1. Introduction ···········································1 1.1 Background ·····································································1 1.2 Research Scope ·····························································4 Chapter 2. Literature Review ·······························7 2.1 Transit Network Design ···········································7 2.2 Unmet Demand ······························································12 2.3 Equity ················································································17 2.4 Algorithm ·········································································26 2.4.1 Multi-objective Optimization ········································26 2.4.2 Local Search ·····································································31 2.5 Summary and Research Direction ·································34 Chapter 3. Methodology ··········································37 3.1 NSGA-II ···········································································37 3.2 Algorithm ·········································································40 3.2.1 Procedure and Network Encoding ······························40 3.2.2 Cross-over and Mutation ··············································43 3.2.3 Local search ······································································44 Chapter 4. Model Formulation ·····························47 4.1 Summary ··········································································47 4.2 Assumption and Variables ·······································48 4.3 Model Formulation ·······················································52 4.3.1 Objective Function ··························································52 4.3.2 Logit Model ······································································54 4.3.3 Traffic Assignment ·························································56 4.3.4 Transit Assignment ······················································58 Chapter 5. Numerical Example ····························61 5.1 Toy Network ································································61 5.1.1 Network Explanation ····················································61 5.1.2 Result Analysis ································································65 5.1.3 Marginal Effect ································································75 5.1.4 Comparison with Previous Research ·························80 5.2 Large Network ······························································83 5.2.1 Network Explanation ······················································83 5.2.2 Result Analysis ································································86 5.2.3 Marginal Effect ································································91 5.2.4 Comparison with Previous Study ·······························92 5.3 Discussion ·······································································94 Chapter 6. Result and Future Research ·········· 97 Reference ·······································································100 Appendix ·······································································110Docto

다중 라이다 관측을 통한 대기오염지역(서울)의 에어로졸 연직 분포 및 광학 특성 분석

학위논문(박사) -- 서울대학교대학원 : 자연과학대학 지구환경과학부, 2023. 8. 김상우.Accurate simulation of surface air quality and the assessment of the radiative and climate effects of aerosols heavily rely on obtaining information on the vertical distribution of aerosols and their specific optical properties. Due to the substantial variability of aerosol emission sources and the intricate pathways through which aerosols are transported, ground-based remote sensing measurements, such as lidar, have proven to be valuable in capturing continuous, vertically-resolved measurements of the atmosphere. This study investigated the vertical distribution and optical properties of aerosols from multiple ground-based lidar measurements in Seoul, Korea. The classification of aerosols based on lidar measurements has been a persistent challenge when it comes to accurately determining their properties. Consequently, it is crucial to achieve precise aerosol classification in order to obtain accurate aerosol retrievals using remote sensing measurements. The University of Wisconsin-Madisons High Spectral Resolution Lidar (HSRL) measurements during a 23-month deployment, in conjunction with a Mie-scattering lidar situated at Seoul National University (SNU) in Korea were used in this study to calculate the lidar ratio and mass extinction efficiency specific to different types of aerosols. Surface PM2.5 and PM10 in-situ measurements from the Sillim AirKorea site (located 3.6 km from the SNU site) were used to infer the aerosol type: pollution, dust, pollution and dust mixture, and clean. Using the surface PM size distribution information (e.g., PM10-2.5 and PM2.5/PM10) as references, lidar ratios measured by the HSRL were then classified into each respective aerosol type. The resulting mean lidar ratios of each aerosol type were reported to be 48 sr, 57 sr, 42 sr, and 49 sr for clean continental particles, pollution particles, dust particles, and mixed particles, respectively. Aerosol extinction coefficients from the Mie-scattering lidar were retrieved by applying the predefined type-specific lidar ratios. The lidar signals were initially classified into different aerosol types based on observations of the range-corrected signal and depolarization ratio. Subsequently, the corresponding lidar ratio values were applied in the calculation of aerosol extinction. A significant improvement in aerosol extinction coefficients was observed compared to the conventional method, which utilizes a single lidar ratio regardless of aerosol type. The new approach reduced errors in aerosol extinction coefficient retrievals by 7 Mm-1 when compared to collocated HSRL measurements. This decrease in mean bias of extinction coefficient from -0.026 km-1 to -0.019 km-1 led to a reduction of 0.042 error in aerosol optical depth (AOD; approximately 10% of the mean AOD in Seoul). Using the continuous aerosol extinction coefficient observations from 2-year HSRL measurements, the temporal variability of AOD was investigated and the contributions of boundary layer (BL) and free troposphere (FT) aerosols to AOD were estimated. HSRL AOD showed good agreement with co-located AERONET sun/sky radiometer AOD observations, with a mean bias of -0.00 and an R2 value of 0.87. Nighttime AOD displayed a larger mean and standard deviation (0.45 ± 0.47) than daytime (0.40 ± 0.29). Hygroscopic growth of aerosols under humid conditions was a key factor in the relative enhancement of nighttime AOD. AOD reached its peak at 04 local standard time (LST) and subsequently declined gradually to its minimum at 13 LST. The variation between daytime and nighttime AOD resulted in significant disparities in the daily mean AOD, as observed through 24-hour HSRL measurements and the AERONET sun/sky radiometers daytime measurements. Taking advantage of the HSRL's vertically resolved measurements, the contribution of aerosols within the boundary layer (BL) and free troposphere (FT) to AOD and its temporal variation were investigated. Unlike the diurnal AOD variation, AOD within the BL (AODBL) showed closer diurnal variations with the mixing layer height (MLH), displaying lower nighttime values and a peak around 14–15 local standard time. However, the low correlation between MLH and AODBL (R2 = 0.06) implied that MLH was not the sole deterministic factor of AODBL, and that the day-to-day aerosol concentration within the BL displayed significantly different temporal variability with the MLH. Although AODBL was largest around noon, the mean extinction coefficient within the BL (AODBL divided by MLH) displayed lows during the day, demonstrating the dilution of aerosols due to enhanced turbulent mixing within the mixing layer. The ratio between AODBL and AOD displayed larger ratios during daytime (42 ± 22%) than nighttime (27 ± 21%). AOD was largest during summer, followed by spring and fall. Although AOD was the smallest in winter, outlying large AOD values comparable to other seasons were characteristic, implying that although the overall AOD in winter was low, events with AOD values occurred frequently. AODBL and AODFT were also larger during summer, which can be attributed to hygroscopic growth of aerosols under high humidity conditions. Larger AODFT and AODFT-to-AOD ratios during spring coincided with large depolarization ratio values between 2 – 6 km, suggesting the presence of elevated dust layers. Using the BL mean extinction coefficient and surface PM10 concentrations, the mass extinction efficiency (MEE) of aerosols in Seoul was estimated. The PM10 MEE showed mean and median values of 5.40 m2 g-1 and 4.28 m2 g-1, respectively. MEE displayed significant variability by PM2.5-to-PM10 ratio, season, ambient relative humidity, and aerosol type. MEE of dust and mixed aerosols displayed a weak correlation with RH, while pollution and clean aerosol MEEs displayed a strong correlation with increasing RH. The uncertainty of estimated surface PM10 concentrations was minimized when the aerosol type-specific, RH-dependent MEE values were used (the mean normalized bias decreased from 10.6% when using a single MEE value, to 3.5%). Using the presented look-up table of aerosol type and RH-specific MEE values, the monthly profiles of PM10 concentration were retrieved. Unlike the seasonality of the aerosol extinction coefficients, PM10 concentration was largest during spring, demonstrating the differences between aerosol optical properties and mass concentrations.에어로졸의 광학적 특성과 질량 농도의 연직 분포에 대한 정보는 정확한 대기질 모의 및 예보와 에어로졸의 복사 및 기후 영향 평가에 있어서 매우 중요하다. 다양한 에어로졸 배출원과 복잡한 에어로졸의 이동 및 수송 경로로 인해, 라이다(Lidar)와 같은 지상 원격 관측자료가 연속적인 에어로졸의 연직 분포에 대한 직접적인 관측 자료를 제공하는데 있어서 쓰임새가 널리 알려져 있다. 하지만, 라이다 측정을 기반으로 에어로졸의 특성을 정확하게 파악하는데 있어서 필수인 지역에 따른 에어로졸의 유형별 구분과 유형별 특성에 대한 상세한 연구는 부족한 실정이다. 따라서, 본 연구에서는 에어로졸에 의한 환경 및 기후 효과에 대한 논의가 활발하게 이루어지고 있는 동아시아 중, 특히, 서울에서의 다수의 지상 기반 라이다 관측자료를 통해 에어로졸의 연직 분포와 광학적 특성을 조사하였다. 본 연구에서는 2016년 3월부터 2018년 1월까지 서울대학교에서 동시 관측을 수행한 고분광해상라이다(High Spectral Resolution Lidar; HSRL)와 미산란 라이다(Mie-scattering lidar) 관측자료를 활용하여 에어로졸의 유형별 라이다 상수와 질량 소산 효율을 산출하였다. 라이다 관측 자료를 기반으로 한 에어로졸의 유형 구분에 앞서, 본 연구에서는 신림 지상 관측소에서 관측된 PM2.5와 PM10 질량 농도를 사용하여 본 연구 기간 동안의 에어로졸 유형 구분을 수행하였다. 지상 PM2.5와 PM10 자료를 바탕으로 에어로졸의 유형을 청정기원 에어로졸(이하 청정), 오염 입자(이하 오염), 황사, 황사와 오염 입자의 혼합된 에어로졸(이하 혼합)로 구분하였다. 이를 바탕으로 HSRL과 미산란 라이다 각각의 후방산란계수와 편광소멸도 관측자료와의 비교를 통하여 라이다 관측자료를 바탕으로 에어로졸의 유형 구분을 실시하였으며, 그 결과 HSRL에서 산출된 에어로졸 유형별 라이다 상수(532 nm)는 청정 에어로졸이 48 sr, 오염 에어로졸이 57 sr, 황사가 42 sr, 그리고 혼합 에어로졸이 49 sr으로 보고되었다. 이렇게 산출된 에어로졸 유형별 라이다 상수를 미산란 라이다 관측 자료에 적용하여 에어로졸 소산 계수를 산출하였다. 에어로졸의 유형구분이 필요 없는, 더 간단하고 보편적인 방법은 하나의 라이다 상수를 사용하여 에어로졸 소산계수를 산출하는 방법이다. 본 연구에서 적용한 에어로졸의 유형별 구분 및 유형별 라이다 상수를 적용한 결과, 일반적인 단일 라이다 상수를 이용했을 때보다 에어로졸 소산 계수의 현저한 개선을 확인할 수 있었다. 동시 관측을 수행한 HSRL의 소산 계수 측정값과 비교했을 때, 본 연구에서 사용한 방법이 에어로졸 소산 계수 오차를 -0.026 km-1에서 -0.019 km-1으로 줄였다. 이러한 7 Mm-1의 소산 계수 오차 감소는 에어로졸 광학 두께(AOD)의 오차를 0.042 줄이는 효과이며, 이는 서울의 평균 에어로졸 광학 두께의 약 10%에 해당한다. HSRL의 2016년 3월부터 2018년 1월까지의 에어로졸 소산 계수 관측 결과를 이용하여 에어로졸 광학 두께의 시간적 변동성을 조사하고, 대기경계층(BL) 및 자유대기(FT)에 분포한 에어로졸이 에어로졸 광학 두께에 기여하는 정도를 추정하였다. HSRL에서 관측한 에어로졸 광학 두께는 서울대학교에서 동시 관측을 이룬 AERONET의 스카이라디오미터 관측값과 잘 일치하는 결과를 보였다(평균편차= -0.00, R2 = 0.87). 야간 에어로졸 광학 두께는 주간에 비해 더 큰 평균과 표준 편차를 보여주었다(0.45 ± 0.47 대비 0.40 ± 0.29). 상대습도가 높은 습한 조건에서의 에어로졸의 흡습성 성장은 야간 에어로졸 광학 두께의 상대적 증가에 중요한 영향을 미치는 요인인 것으로 확인되었다. 에어로졸 광학 두께는 04시에 가장 높게 관측되었으며, 13시에 가장 낮게 관측되는 일변화를 보였다. 서울에서 관측되는 주간과 야간 에어로졸 광학 두께의 유의미한 차이로 인해 24시간 동안의 HSRL 측정과 AERONET 스카이라디오미터의 주간 측정에서 관측된 일일 평균 에어로졸 광학 두께에 상당한 격차가 발생하는 것으로 나타났다. HSRL의 연직 측정을 활용하여 대기경계층(BL)과 자유 대기층(FT) 내 에어로졸 광학 두께의 시간 변동성을 조사하였다. AOD의 일변동성과 달리, 대기경계층 내의 에어로졸 광학 두께(AODBL)는 야간 동안에 낮고 14-15시에 최고값을 보이는 혼합층 높이와 더 비슷한 일변동성을 보였다. 하지만 혼합층 높이와 AODBL 간의 낮은 상관관계(R2 = 0.06)는 혼합층의 높이가 AODBL의 유일한 결정 요인이 아니며, 대기경계층 내 에어로졸 농도가 혼합층의 높이와 매우 다른 시간적 변동성을 보인다는 것을 시사하였다. AODBL는 정오에 가장 크지만, BL 내 평균 에어로졸 소산 계수(AODBL을 혼합층 높이로 나눈 값)는 낮에 낮은 값을 보여 이를 통해 대기경계층 내 활발한 난류로 인한 에어로졸 농도의 희석을 확인할 수 있었다. AODBL과 에어로졸 광학 두께 사이의 비율은 주간(42 ± 22%)보다 야간(27 ± 21%)에 더 큰 값을 보였다. 에어로졸 광학 두께는 여름, 봄, 가을, 겨울 순으로 크게 나타났다. 겨울철 평균 에어로졸 광학 두께가 가장 작게 관측된데 반해, 겨울철의 일평균 에어로졸 광학 두께의 최댓값이 다른 계절의 최대 일평균 에어로졸 광학 두께 값과 비슷하게 관측되었다. 이는 겨울동안 전반적으로 에어로졸 광학 두께가 낮지만, 에어로졸 광학 두께 값이 크게 관측되는 고농도 에어로졸 사례들이 빈번하게 발생함을 시사하는 결과다. 여름에는 AODBL과 AODFT도 크게 나타났으며, 이는 상대습도가 높은 환경에서 활발한 에어로졸의 흡습 성장으로 설명된다. 봄에는 AODFT와 AODFT 대 에어로졸 광학 두께의 비가 크고, 2 km에서 6 km 사이의 편광 소멸도가 크게 나타나는 것으로 보아 빈번하게 서울 대기경계층 위로 지나가는 황사층의 영향으로 보인다. 서울 HSRL로 관측한 대기경계층 내 에어로졸의 평균 소산 계수와 지표면 PM10 농도를 사용하여 에어로졸의 질량 소산 효율 (Mass Extinction Efficiency, MEE)를 산출하였다. PM10 MEE의 평균값과 중앙값은 각각 5.40 m2 g-1과 4.28 m2 g-1으로 나타났다. PM2.5 대 PM10 비율, 계절, 상대 습도, 그리고 에어로졸 유형에 따라 MEE는 큰 변동성이 보였다. 황사와 혼합 에어로졸은 흡습성이 낮은 성분들로 이루어져 있어 MEE와 상대 습도 간에 약한 상관관계가 확인되었지만, 오염과 청정 에어로졸들은 상대 습도가 증가함에 따라 MEE가 급격하게 성장하는 것을 확인할 수 있었다. 이러한 에어로졸 유형별, 그리고 상대 습도에 따른 MEE 값을 사용하는 것이 라이다 관측 자료로부터의 지표면 PM10 농도 산출물의 불확실성이 가장 낮게 나타났다(단일 MEE 값을 사용할 때의 평균표준편차(Mean Normalized Bias; MNB)가 10.6%에서 3.5%로 감소). 본 연구에서 제시한 에어로졸의 유형 및 상대 습도에 따른 MEE 값의 조견표(Lookup Table)을 사용하여 월별 PM10 농도 프로파일을 추출하였다. 에어로졸 소산 계수의 계절 변동성과는 달리, PM10 농도는 봄에 가장 크게 나타났으며, 이는 에어로졸의 광학적 특성과 질량 농도 사이의 차이를 명확하게 보이는 결과다.Abstract i Table of Contents vii List of Tables ix List of Figures x Chapter 1 Introduction 1 1.1 Background and Motivation 1 1.2 Scientific Questions 5 1.3 Objectives of this study 8 Chapter 2 Instrumentation and Data 11 2.1 Mie-Scattering Lidar 11 2.2 High Spectral Resolution Lidar 12 2.3 AERONET sun/sky radiometer 14 2.4 Ground-based in-situ measurements 15 Chapter 3 Retrieval of aerosol extinction coefficient from Lidar measurements 17 3.1 Aerosol-type-specific lidar ratio for typical aerosol types in Seoul 19 3.2 Improvement of Mie-scattering lidar extinction coefficient retrievals using type-specific lidar ratios 30 Chapter 4 Diurnal variation of boundary layer and free troposphere aerosol optical depth 41 4.1 Diurnal variation of AOD 43 4.2 Boundary layer (BL) versus free troposphere (FT) AOD 52 Chapter 5 Aerosol mass concentration profiles from Lidar measurements 77 5.1 Mass extinction efficiency from lidar and in-situ measurements 79 5.2 Estimating surface PM mass concentration from lidar observations 85 Chapter 6 Summary and further directions 95 References 101 국문 초록 123박

Fast Virtual Keyboard Typing Using Vowel Hand Gesture Recognition

학위논문(석사) -- 서울대학교대학원 : 공과대학 전기·정보공학부, 2023. 2. 이혁재.This paper proposes a fast virtual keyboard typing method that improves typing method that improves typing speed using hand gesture recognition. In the proposed method, five frequently used English vowels can be quickly input with five dedicated gestures. The proposed method reduces, not only the layer switching time of the multilayer keyboard layout, but also vowel typing time. To predict the performance of the proposed method, simulations are performed considering four scenarios according to the order of appearance of vowels and consonants. The result shows that the proposed method improves typing speed by 20.72%. Lastly user test with typing 4 sample sentences results that typing speed is improved by 12.45% based on WPM.최근 AR(Augmented Reality) 및 VR(Virtual Reality)기술이 발전 함에 따라 사용자 인터페이스 기술에 대한 연구가 활발히 진행되고 있다. 키보드, 마우스, 터치스크린 등 기존의 입력 장치를 대체할 수 있는 가상 입력 인터페이스로 손동작 인식이 주목받고 있으며, 이에 다양한 접근 방식으로 손동작 인식 모델이 제안되었다. 정교한 손 인식을 위해 센서가 내장된 장치형 인터페이스를 사용한 손동작 인식 연구가 이뤄지고 있다. 최근에는 딥러닝 기술의 발전에 따라 별도의 장치가 필요 없는 카메라 기반 비전 인식을 이용한 손동작 인식이 AR/VR의 핵심 어플리케이션인 가상 키보드, 가상 글쓰기, 수화 인식 등에 사용되기 위한 인터페이스로 활발한 연구가 이뤄지고 있으며, 특히 객체 인식 딥러닝 네트워크의 경우 실시간으로 손동작을 인식할 수 있다는 점에서 많이 사용되고 있다. 본 논문에서는 알파벳의 사용 빈도 및 연속적으로 나타나는 두 문자 간의 상관 빈도에 대해 통계적 분석을 진행 시, 모음의 사용 빈도수는 평균 39%이며 자음-모음 또는 모음-자음 순으로 배치되는 경우는 약 65% 정도로 모음의 입력의 속도를 향상시켜 가상 키보드 입력 속도를 개선하는 방법을 제안한다. 제안한 방식은 객체 인식 딥러닝 네트워크를 이용하여 가상 키보드 입력에 필요한 6개의 손동작에 5개의 알파벳 모음, a, e, i, o, u에 대해 특정된 손동작을 추가로 학습시켜, 자음의 경우 기존과 동일하게 가상 키보드 배열 내에서 선택되어 입력되도록 하며 모음의 경우 모음 손동작이 인식되면 입력되도록 한다. 인식이 필요한 손동작이 늘어남에 따라 자동 라벨링을 통해 다수의 학습 데이터를 확보하여 94.39%의 비교적 높은 평균 손동작 인식률을 확보했다. 제안한 방식 기반의 가상 키보드를 구현하여 사용자 테스트를 진행한 결과 기존에 제안된 가상 키보드 입력 방식보다 제안한 방식의 속도가 12.45% 개선되었다.제 1 장 서 론 1 제 1 절 연구 배경 및 내용 1 제 2 절 논문의 구성 3 제 2 장 관련 연구 4 제 1 절 손동작 인식 관련 연구 4 제 2 절 가상 키보드 관련 연구 7 제 3 장 가상 키보드 속도 향상 방안 제안 9 제 1 절 모음 손동작 추가 배경 9 제 2 절 제안한 가상 키보드 입력 시스템 10 제 4 장 실험 결과 및 분석 14 제 1 절 입력 시간 예측 시뮬레이션 결과 14 제 2 절 딥러닝 네트워크의 학습 16 제 3 절 가상 키보드의 사용자 실험 및 분석 19 제 5 장 결론 21 참고문헌 22 Abstract 25석

The Effect of Future Time Perspective on Children's Climate Change Behavioral Intention

학위논문(석사) -- 서울대학교대학원 : 사범대학 협동과정 환경교육전공, 2022.2. 류재명.기후위기에 대응하기 위한 교육이 시급해지며 기후변화 교육 내용과 행동 변인에 대한 논의가 활발해지고 있다. 환경교육에서는 미래세대와 타 생물종까지 아울러 생각하는 생태시민성을 기르는 것을 목표로 먼 미래까지 내다보는 역량을 기르기 위한 노력이 계속되고 있다. 그러나 미래 시간에 대한 주관적 인식을 행동의 주요 변인으로 다루는 연구나 교육적 시도는 부족하다. 이에 본 연구는 아동이 가진 미래에 대한 인식이 기후변화에 대응하고자하는 행동 의도에 영향을 미치는지 확인하고자 했다. 미래에 대한 주관적인 인식을 첫째, 앞으로 남은 시간에 대해 심리적으로 지각하는 정도인 미래시간조망과 둘째, 인지-동기적 구인으로서 미래에 대한 총체적 관점을 의미하는 미래지향시간관으로 나누어 각각의 변인이 기후변화 대응 행동의도에 영향을 미치는지 두 가지 실험연구로 확인하였다. 먼저, 아동의 미래시간조망과 기후변화 대응 행동의도의 관계를 확인하기 위하여 서울 소재 초등학교 6학년 188명을 대상으로 환경 위기 시계로 미래 환경에 대해 유한성을 인식한 실험집단과 통제집단의 미래 환경에 대한 시간적 거리감과 기후변화 대응 행동의도를 설문하였다. 이후 집단 간 행동의도의 차이를 독립표본 t-검정으로, 두 변인간의 상관관계를 회귀분석을 통해 알아보았다. 다음으로 아동의 미래지향시간관과 기후변화 대응 행동의도의 관계를 확인하기 위하여 서울 소재 초등학교 5,6학년 89명을 대상으로 Husman&Shell의 미래지향성 척도와 기후변화 대응 행동의도를 측정하고 회귀분석을 통해 두 변인의 상관관계를 알아보았다. 연구결과 30년 후의 미래 환경에 대한 시간적 거리감이 짧을수록 기후변화 대응 행동의도가 더 높은 것으로 나타났다. 실험 자극물의 검증 과정에서 시간의 유한성을 인식한 아동이 통제집단의 아동보다 동일한 거리의 미래 환경을 더 가깝게 느끼는 것이 확인되었다. 또한 미래지향성이 높을수록 아동의 기후변화 대응 행동의도가 더 높은 것으로 나타나 기후변화에 대응하는 환경행동의도에 아동의 미래에 대한 주관적인 인식이 영향을 미친다는 것이 확인되었다. 본 연구의 시사점은 다음과 같다. 첫째, 아동이 확장된 미래시간조망을 가질 수 있도록 환경교육에서 환경위기시계와 같은 제한된 미래에 대한 인식을 갖게 할 수 있는 교육 및 교육자료가 필요하다. 둘째, 환경행동의 변인 중 하나로 주관적 시간인식을 다루었으며 아동의 미래지향성의 향상이 환경행동에 주요 변인이 될 수 있음을 시사한다.As education to cope with the climate crisis becomes urgent, discussions on the content and behavioral variables of climate change education are becoming more active. In environmental education, efforts are continuing to develop the ability to look far into the future with the aim of fostering ecological citizenship that also think about future generations and other species. However, research or educational attempts to deal with subjective perception of future time as a major variable of behavior are insufficient. Therefore, this study attempted to confirm whether children's Future Time Perspective(FTP) affects their climate change behavioral intention. Therefore, Future Time Perspective was firstly divided into FTP meaning a future time view, which is the degree of psychological perception of the remaining time, and secondly, FTP meaning a future-oriented perspective, which means a total perspective on the future as a cognitive-motivated factor. Two experimental studies confirmed whether each variable affects the climate change behavioral intention. First, in order to confirm the relationship between children's future time view and climate change behavioral intention, 188 6th grade students in Seoul surveyed psychological perspection of the remaining time and behavioral intention deal with climate change. In this survey, students were divided into an experimental group that recognizes finiteness in the future environment with an environmental crisis clock and a control group. Next, in order to confirm the relationship between children's future-oriented perspective and behavior intention, 89 5,6th grade students in Seoul surveyed and the relationship between the two variables was investigated through regression analysis. As a result of the study, it was found that the shorter the psychological distance to the future environment 30 years later, the higher the willingness to respond to climate change. In the process of verifying the experimental stimulus, it was confirmed that children who recognized the finiteness of time felt closer to the future environment of the same distance than children in the control group. In addition, it was confirmed that the higher the future-oriented perspective, the higher the children's climate change behavioral intention and therefore the subjective perception of the child's future affects the climate change behavioral intention. The implications of this study are as follows. First, education and educational materials that can make children aware of a limited future, such as an environmental crisis clock, are needed in environmental education so that they can have an expanded future view. Second, subjective time perception was dealt with as one of the variables of environmental behavioral intention, suggesting that the improvement of children's future orientation can be a major variable in climate change behavioral intention.제 1 장 서 론 1 제 1 절 연구의 필요성 1 제 2 절 연구 목적 및 연구 문제 4 제 2 장 이론적 배경 7 제 1 절 미래시간인식 7 1. 미래시간조망 10 2. 미래지향시간관 14 제 2 절 기후변화 대응 행동의도 18 제 3 절 미래시간인식과 기후변화 대응 행동의도 21 1. 미래시간조망과 기후변화 대응 행동의도 21 2. 미래지향시간관과 기후변화 대응 행동의도 25 제 3 장 연구 방법 27 제 1 절 가설 설정 및 연구 모형 27 제 2 절 연구 계획 29 1. 연구의 흐름 29 2. 연구 대상 선정 31 3. 실험물 제작 32 제 3 절 연구 1 : 미래시간조망이 기후변화 대응 행동의도에 미치는 영향 35 1. 연구 대상 및 절차 35 2. 측정 도구 및 분석 방법 36 제 4 절 연구 2 : 미래지향시간관이 기후변화 대응 행동의도에 미치는 영향 41 1. 연구 대상 및 절차 41 2. 측정 도구 및 분석 방법 41 제 4 장 연구 결과 및 논의 44 제 1 절 연구 1 : 미래시간조망과 기후변화 대응 행동의도의 상관관계 회귀분석 결과 44 제 2 절 연구 2 : 미래지향시간관과 기후변화 대응 행동의도의 상관관계 회귀분석 결과 49 제 3 절 연구 결과 분석 53 1. 연구 가설 검증 53 2. 결과에 대한 논의 54 제 5 장 결론 및 제언 60 제 1 절 요약 및 결론 60 제 2 절 한계 및 제언 63 참고문헌 65 부록 74 Abstract 83석

한국의 녹지이용 건강증진 프로그램 근거기반 구축 연구

학위논문(박사) -- 서울대학교대학원 : 보건대학원 환경보건학과, 2021.8. 박수진.In accordance with entering aged society, modernization and growing interest in health, attempts are increasing to restore health conditions and improve quality of life by utilizing nature and forests. The natural environment offers a variety of benefits in terms of psychological, social, educational and physiological aspects. Green spaces such as forests, parks, trees, and gardens are known to have a direct and indirect impact on people's health and well-being in various ways. There are three main mechanisms by which green space exposure affects health: providing opportunities for physical activity, promoting and developing social activities, and improving health conditions through green space exposure itself. Researches into the link between health and green spaces are ongoing, and evidence is accumulating from diverse perspectives. This study was conducted to provide scientific evidences for the effects of the use of green space, which is expanding beyond public service functions to prevent diseases and promote health, on the human body psychologically and physiologically. The current status of prior researches on health levels according to forest exposure was analyzed, and psychological and physiological effects of participation in forest-based health promotion programs were reviewed through systematic literature review. The current status of forest healing programs conducted in Korea was investigated, and the composition of the programs and the level of health-related evidence were evaluated. In addition, various interventions of forest exposure levels were carried out and the results of change in health indicators were identified. Based on previous studies, 33 literature were analyzed and the activities performed in forest-based interventions were typified as staying, walking, exercising, and indirect exposure. In fact, walking in forests has consistently shown health improvement in the overall psychological and physiological domains. Forest-based activity programs have been shown to be effective such as depression, anxiety, cognitive function, stress hormones, and inflammatory relief, but lack evidence to assess differences in health effects according to activity types. According to an analysis of 75 representative forest healing programs developed and operated in Korea, more than 90% of the programs were designed for the normal with the aim of promoting health. The participants in the program were teenagers and adults at a high rate. For detailed factors of forest healing programs, dynamic activities using plants or stimulating touch were the most common. In addition, the forest healing program consisted mainly of walking activities, and it was revealed that the program mostly consisted of one-day or accommodation-type forest healing programs, including more than 60 minutes of outdoor programs in spring and summer. As a result of classifying the level of effectiveness of forest healing programs according to the results of Chapter 2, on the psychological side, less than an hour of walking was found to have the greatest effect while less than an hour of staying and exercising was found to have the most considerable levels of effectiveness on the physiological aspect. However, current forest healing programs were mainly concentrated on walking and exercising for more than an hour. Therefore, it is necessary to consider activities in areas with high levels of evidence when developing forest healing programs in the future. To verify the health effects of forests, various health-related indicators were observed to analyze how the experience of participating in forest healing programs for two nights and three days causes changes in health conditions before, right after and after a certain period of time from the program participation. Short exposure times and activities alone had positive health effects such as immunity and cardiovascular conditions, and showed significant changes after the program. This study examined the possibility of forest-based health promotion programs as a way to promote public health by objectively and quantitatively evaluating the health effects on forest exposure. The significance of this study is to establish basis necessary for designing forest healing programs in the future, and to arrange a foundation for big data base related to the effectiveness verification of green-space use.고령사회로의 진입과, 현대화, 건강에 관한 관심증가에 따라 자연과 산림을 활용하여 건강을 회복하고, 삶의 질을 향상시키려는 시도가 증가하고 있다. 자연환경은 심리적, 사회적, 교육적, 생리적인 측면에서 다양한 혜택을 준다. 숲, 공원, 나무, 정원과 같은 녹지공간은 사람들의 건강과 웰빙에 다양한 경로로 직, 간접적인 영향을 준다고 알려져 있다. 녹지 노출이 건강에 영향을 미칠 수 잇는 주요한 메커니즘으로 녹지가 신체활동의 기회를 제공하는 것, 사회적 활동을 촉진시키고 발전시키는 것, 녹지 노출 자체가 건강에 도움된다는 세가지가 제시되고 있다. 건강과 녹지 간의 연관성에 대해 지속적으로 연구되고 있으며 다양한 관점에서 근거가 축적되고 있다. 본 연구는 공익기능을 넘어 질병의 예방, 건강증진의 활동으로 확장되고 있는 녹지가 심리, 생리적으로 인체에 미치는 영향에 대한 과학적인 근거 마련을 위하여 수행되었다. 녹지노출에 따른 건강 수준의 연구 현황을 분석하고 체계적인 문헌고찰을 통해 녹지기반 프로그램 참여에 따른 심리, 생리학적 효과를 검토하였다. 국내에서 운영되고 있는 녹지 이용 프로그램의 현황을 조사하고, 프로그램의 구성현황과 보건학적인 근거 수준을 평가하였다. 또한 실제로 다양한 녹지 노출 중재를 수행하고 이에 따른 건강지표의 변화 수준을 확인하였다. 기존에 수행된 연구를 바탕으로 33개의 문헌을 분석한 결과, 산림 기반 중재에서 수행되는 활동을 머물러 있기, 걷기, 운동, 간접노출로 유형화하였다. 실제 녹지에서 행해지는 걷기는 심리적, 생리적으로 전반적인 영역에서 일관되게 건강증진 효과를 보였다. 녹지를 기반한 활동은 우울 및 불안, 인지기능, 스트레스 호르몬, 염증완화 등에서 녹지에서의 프로그램이 효과를 보이는 것으로 나타났으나 활동 유형에 따른 건강영향의 차이를 평가할 수 있는 근거는 부족하였다. 국내에서 개발, 운영되고 있는 대표적인 산림치유 프로그램 75개를 분석한 결과, 90%이상의 프로그램이 건강증진을 목적으로 하는 정상인을 대상으로 계획한 프로그램이었다. 프로그램 참여자는 청소년과 일반성인이 가장 높은 비율을 차지 하고 있었다. 세부 인자는 식물을 활용하고, 촉각을 자극하는 동적인 활동이 가장 많았고, 주로 걷기를 하였으며, 봄과 여름철에 시행되는 60분 이상의 실외 프로그램으로 당일형과 숙박형으로 이루어지는 것으로 조사되었다. 프로그램의 효과 수준을 chapter 2의 연구결과에 따라 구분한결과, 정신적인 측면에는 걷기를 1시간 미만으로 시행하였을 때, 신체적 측면에는 머무르기와 운동을 1시간 미만으로 시행하였을 때 효과의 크기가 가장 큰 것으로 나타났으나, 현재 운영되고 있는 프로그램들은 1시간 이상 걷기와 운동에 대부분의 프로그램들이 집중되어 있는 것을 알 수 있었다. 따라서 향후 프로그램 개발 시 근거의 수준이 높은 영역의 활동을 고려하는 것이 필요하다. 녹지가 건강에 미치는 영향에 대해 검증하기 위하여 2박 3일간의 산림에서의 프로그램 참여 경험이 사전, 사후, 그리고 일정한 시간이 지난 다음에는 어떻게 변화하는지 다양한 건강영향 지표들을 활용하여 그 양상을 분석하였다. 짧은 노출시간과 활동만으로도 면역과 심혈관계 등 건강상의 효과가 있었고, 통계적으로 유의미한 변화를 보였다 본 연구는 녹지노출에 대한 건강 영향을 객관적이 정량적으로 평가함으로써 국민건강증진을 위한 방안으로 녹지기반 프로그램의 가능성을 검토하였다. 향후 산림치유 프로그램 기획 시 필요한 기초자료를 구축하고, 녹지 이용에 대한 효과 검증 빅데이터 구축을 위한 기초체계를 마련하였다.Chapter 1. Introduction 1 1.1 The Significance of Nature and Green Space 1 1.2 Definition of spatial extent 1 1.3 Theory of Preference for The Natural Environment 3 1.4 Green Space and Health Impact Mechanisms 4 1.5 Various Health Promotion Effects of Green Space 4 1.6 Current Status of Forest Utilization for Health Promotion 5 1.6 Definition of Concepts 6 1.7 Extent of Nature-based Programs 7 1.8 Objective of This Study 9 1.6 References 12 Chapter 2. Health Benefits of Activities in the Forest: A systematic Review 16 2.1 Introduction 16 2.2 Materials and Methods 19 2.3 Results 24 2.4 Discussion 56 2.5 Conclusions 61 2.6 References 63 Chapter 3. Analysis of the Management status of Forest Healing Program 69 3.1 Introduction 69 3.2 Materials and Methods 73 3.3 Results 79 3.4 Discussion 90 3.5 Conclusions 92 3.6 References 94 Chapter 4. Psychological assessments for the Establishment of Evidence-Based Forest Healing Program 97 4.1 Introduction 97 4.2 Materials and Methods 101 4.3 Results 109 4.4 Discussion 118 4.5 Conclusions 126 4.6 References 127 Chapter 5. Summary and Overall Discussion 132 5.1 Summary and Conclusions 132 5.2 Recommendations for future studies 133 Abstract in Korean 134박

The Comparison between the Echocardiographic Data to the Cardiac Catheterization Data on the Diagnosis, Treatment, and Follow-Up in Patients Diagnosed as Pulmonary Valve Stenosis

BACKGROUND: Isolated pulmonary valve stenosis (PS) makes up 6-9% of all congenital heart defects among children. The initial gold standard for diagnosis, follow-up of PS is by echocardiography. However, the most accurate diagnosis still remains to be measurement of the pressure gradient through transcatheterization. The purpose of this study is to compare the difference between the echocardiographic data to the cardiac catheterization data on the diagnosis, treatment, and follow-up in patients diagnosed as PS, and to see what parameters should be closely monitored. METHODS: A total of 112 patients (Male : Female = 46 : 66) who underwent balloon pulmonary valvuloplasty (BPV) at Severance Cardiovascular Hospital, between December, 2002 to August, 2012 were retrospectively analyzed. The patients were all under 16 years of age and critical PS patients who underwent BPV were excluded from this study. RESULTS: The pre-BPV right ventricle (RV)-pulmonary artery (PA) systolic pressure gradient and post-BPV systolic pressure gradient showed statistically significant decrease. The pre-BPV RV-PA systolic pressure gradient and 3 month post-BPV systolic pressure gradient showed statistically significant decrease. The consistency between the echocardiographic data and cardiac catheterization data shows statistically significant consistency. The mean pressure gradient and systolic pressure gradient on the echocardiography shows high consistency when comparing with the cardiac catheterization data. CONCLUSION: Our study shows that BPV in PS is a safe and effective procedure in children and adolescent. The standard echocardiographic evaluation of PS, during diagnosis and follow-up, should include mean transpulmonic pressure gradient, as well as the peak systolic pressure gradient. The success of the procedure should be held off until at least 3 months, only if the patients do not show any symptoms.ope

Bronchial compression in an infant with isolated secundum atrial septal defect associated with severe pulmonary arterial hypertension.

Symptomatic pulmonary arterial hypertension (PAH) in patients with isolated atrial septal defect (ASD) is rare during infancy. We report a case of isolated ASD with severe PAH in an infant who developed airway obstruction as cardiomegaly progressed. The patient presented with recurrent severe respiratory insufficiency and failure to thrive before the repair of the ASD. Echocardiography confirmed volume overload on the right side of heart and severe PAH (tricuspid regurgitation [TR] with a peak pressure gradient of 55 to 60 mmHg). The chest radiographs demonstrated severe collapse of both lung fields, and a computed tomography scan showed narrowing of the main bronchus because of an intrinsic cause, as well as a dilated pulmonary artery compressing the main bronchus on the left and the intermediate bronchus on the right. ASD patch closure was performed when the infant was 8 months old. After the repair of the ASD, echocardiography showed improvement of PAH (TR with a peak pressure gradient of 22 to 26 mmHg), and the patient has not developed recurrent respiratory infections while showing successful catch-up growth. In infants with symptomatic isolated ASD, especially in those with respiratory insufficiency associated with severe PAH, extrinsic airway compression should be considered. Correcting any congenital heart diseases in these patients may improve their symptoms.ope

Transcatheter Treatment of Patent Foramen Ovale Combined with Abnormal Drainage of Left Superior Vena Cava to Left Upper Pulmonary Vein

Patent foramen ovale (PFO) has been known to be the cause of transient ischemic attacks or stroke, and transcatheter device closure has been the treatment of choice for these defects. Combined defect of abnormal drainage of left superior vena cava (LSVC) to left superior pulmonary vein (LSPV) in PFO patients is an uncommon combination, and both can act as a pathway for paradoxical embolism. We report a successful closure of PFO, using Amplatzer® PFO occluder (St. Jude Medical, St. Paul, MN, USA) and persistent LSVC connected to LSPV using an Amplatzer® Vascular Plug II (St. Jude Medical, St. Paul, MN, USA). Because this combined anomaly of PFO and persistent LSVC can be treated by a single transcatheter intervention, if clinically suspected, a complete evaluation for this anomaly should be considered.ope

Various Applications of Purse-String Suture and Its Cosmetic Outcome in Cutaneous Surgical Defects

Background: Purse-string suture is a simple technique to reduce wound size and to achieve complete or partial closure of skin defects. Objective: To classify situations in which purse-string sutures can be utilized and to assess the long-term size reduction and cosmetic outcome of the final scar. Methods: Patients (93 from Severance hospital and 12 from Gangnam Severance hospital) in whom purse-string sutures were used between January 2015 and December 2019 were retrospectively reviewed. Wound site, final reconstruction method, repair duration, final wound size, and Vancouver scar scale were assessed. Results: A total of 105 patients were reviewed. Lesions were located on the trunk (48 [45.7%]), limbs (32 [30.5%]), and face (25 [23.8%]). Mean ratio of wound length/primary defect length was 0.79±0.30. Multilayered purse-string suture showed the shortest duration from excision to final repair (p<0.001) and most effectively minimized the scar size (scar to defect size ratio 0.67±0.23, p=0.002). The average Vancouver scar scale measured at the latest followup visit at least 6 months postoperatively was 1.62, and the risk of hypertrophic scarring was 8.6%. There was no significant difference in the Vancouver scar scale and the risk of hypertrophic scarring between the different surgical method groups. Conclusion: Purse-string sutures can be utilized in many stages of reconstruction to effectively reduce scar size without compromising the final cosmetic outcome. Copyright © The Korean Dermatological Association and The Korean Society for Investigative Dermatology.ope

Morphologic Characteristics and Relating Factors to the Need of Technical Modification in Transcatheter Closure of Large Atrial Septal Defect (>/25 mm)

BACKGROUND AND OBJECTIVES: The rigid coupling between the delivery wire and the right atrial disk has been occasionally encountered during transcatheter closure of atrial septal defect (ASD). Therefore the device frequently makes a perpendicular angle, and the leading edge of left atrial disk slips through the defect and prolapses into right atrium (RA) before it is properly placed in the septum. The purpose of this study is to investigate relating factors to the need of technical modification in transcatheter closure of large ASD and to evaluate relevant morphologic characteristics of atrial septal rim in this situation. SUBJECTS AND METHODS: From July, 2003 to May, 2007, 312 patients underwent transcatheter occlusion of ASD with Amplatzer Septal Occluder(R) (ASO, AGA medical corporation, Golden Valley, MN, USA) at Yonsei Cardiovascular Center and among them 109 patients had large ASD (>/=25 mm) and these patients were enrolled in our study. Patients were divided into two groups according to the deploying methods of the device (Group I: standard method, Group II: modified methods). Assessments of the defects and its surrounding rims were made by echocardiography. RESULTS: There were no differences between 2 groups in age, body weight and height except for balloon-stretched diameter (stop-flow technique) and device size. Group II patients with modified methods showed larger balloon-stretched diameter and device size than group I patients with standard method. The mean length of anterosuperior (AS) rim in group II was significantly shorter than group I (p<0.05). As the size of the device used in procedure increased, there was a trend towards increase in the need of modified methods. CONCLUSION: This study shows that AS rim deficiency and the size of ASD may be the relating factors to the need of technical modification in transcatheter closure of ASD. Therefore, when the initial try with standard method is not successful in large ASD with deficient AS rim, we suggest that changing strategy of implantation may save time and efforts and possibly reduce the risk of complications associated with prolonged procedureope