Does Regular Nature Exposure Benefit Environmentally Engaged Students? Effects of Botanical Garden Walks on Psychological and Behavioral Outcomes

Seunguk Shin,조혜정,조장환 인간식물환경학회 2024 인간식물환경학회지 Vol.27 No.5

Background and objective: The psychological and behavioral benefits of nature have been widely documented; yet less isknown about whether these benefits are salient among environmentally engaged groups. This study examined the effectsof walking regularly in a natural environment on the biospheric values, nature relatedness, psychological well-being, andpro-environmental behavioral intentions of university students in an environmental major. Methods: A total of 39 students were randomly assigned into treatment (n = 21) and control (n = 18) groups for a 15-weektrial. The treatment group walked for 15 minutes in a campus botanical garden twice a week while the control group stayedindoor. Results: Pre- and post-test survey results indicated no significant effects of the treatment on the outcome variables,suggesting that those who engage with nature for disciplinary purposes did not benefit from prescribed exposure to nature. Conclusion: Programs that provide nature exposure to enhance mental well-being and pro-environmental behavior shouldtake into account participants’ background and baseline interactions with nature.

Part 23급 수소연료전지 항공기 개념설계

오승욱(Seunguk Oh),나바니타 브라마차리(Nabanita Brahmachari),박재현(Jaehyeon Park),이학진(Hakjin Lee),명노신(Rho shin Myong) 한국항공우주학회 2024 한국항공우주학회 학술발표회 논문집 Vol.2024 No.4

High Growth Yield of Single Multiwall Carbon Nanotube With Different Length Effect

Jaehan Im,Seunguk Kim,Jeong Hee Shin,Youngjin Choi,Seung Nam Cha,Jae Eun Jang IEEE 2014 IEEE TRANSACTIONS ON NANOTECHNOLOGY Vol.13 No.2

<P>Vertically aligned single multiwalled carbon nanotube (MWCNT) is quite an interesting nanostructure due to its high probability of nanodevice realization with an ultrahigh integration density. Although ~200 nm catalyst diameter size and plasma-enhanced chemical vapor deposition (PECVD) method have been known as key parameters to grow a single MWCNT, the details and the phenomenon of below 200 nm catalyst size have not been studied or published well. Here, we report the details of catalyst size effect below 200 nm. One-hundred-nanometer diameter Ni catalyst on SiO<SUB>2</SUB> layer shows 95% yield of single MWCNT growth. Surface roughness of substrate makes a large deviation in the yield and the critical catalyst size for single MWCNT. The various catalyst sizes result in the different growth rate of carbon nanotube (CNT) at the same growth condition. The change of diffusion surface area induces such a difference. From the results, single MWCNTs with various lengths are successfully grown on the same substrate by a one-step growth process.</P>

Evaluation of Angle Dependence on Positional Radioisotope Source Detector using Monte Carlo Simulation in NDT

Moojae Han,Seunguk Heo,Yohan Shin,Jaehoon Jung,Kyotae Kim,Yeji Heo,Deukhee Lee,Heunglae Cho,Sungkwang Park 한국방사선학회 2019 한국방사선학회 논문지 Vol.13 No.1

산업 비파괴 분야에서 사용되는 방사선원은 장비의 노후화 및 작업자의 부주의로 인해 선원이 노출되는 사고가 발생되어 왔다. 이에 선원의 위치를 실시간으로 추적할 수 있는 안전관리 시스템의 필요성이 부곽 되고 있다. 이에 본 연구에서는 방사선원의 위치 추적을 위한 line-array 선량계를 구성하는 unit-cell 선량계 단위의 각도의존성을 분석하기 위해 Monte Carlo Simulation을 수행하였다. 그 결과 각 기울기에서 상위 1 0% 수치에 대한 오차율은 0°에서 5.90%, 30°에서 8.08%, 60°에서 20.90%의 오차율을 보였다. 총 흡수선량의 비율은 0°(100%)를 기준으로 30°에서 83.77%, 60°에서 53.36%로 나타났으며 기울기가 증가함에 따라 낮아지는 경향성을 보였다. 모든 기울기에서 최대 수치는 30°의 No. 9에서 나타났으며, No. 10에서는 7.24% 낮아지는 경향성을 보였다. 본 연구 결과 각도의존성은 크게 발생되는 것으로 나타났으며, 이를 낮추기 위해서는 선원과 line-array 선량계의 적정거리는 1 cm 이상의 거리에서 유지해야 하는 것으로 사료된다. Radiation sources used in the field of industrial non-destructive pose a risk of exposure due to ageing equipment and operator carelessness. Thus, the need for a safety management system to trace the location of the source is being added. In this study, Monte Carlo Simulation was performed to analyse the angle dependence of the unit-cell comprising the line-array dosimeter for tracking the location of radiation sources. As a result, the margin of error for the top 10% of each slope was 5.90% at 0°, 8.08% at 30°, and 20.90% at 60°. The ratio of the total absorbed dose was 83.77% at 30 ° and 53.36% at 60 ° based on 0 °(100%) and showed a tendency to decrease with increasing slope. For all gradients, the maximum number was shown at 30° No. 9 pixels, and for No. 10, there was a tendency to drop 7.24 percent. This study has shown a large amount of angle dependence, and it is estimated that the proper distance between the source and line-array dosimeters should be maintained at a distance of not less than 1 cm to reduce them.

A Case of Multivessel Spontaneous Coronary Artery Dissection

( Seung Ki Moon ),( Seunguk Lee ),( Dong Hoon Yang ),( Cheol Min Park ),( Shin Hyoung Cho ),( Soo Kim ),( Dong Goo Kang ),( Sang Ki Cho ) 대한내과학회 2015 대한내과학회 추계학술발표논문집 Vol.2015 No.1

Spontaneous coronary artery dissection (SCAD) is a rare cause of acute myocardial infarction (AMI) which may be related with sudden cardiac death. The incidence, causes, pathogenesis, and treatment have not been defined clearly. Among them, multivessel SCAD is extremely rare and only a few cases have been reported. we experienced a rare case of an elderly man with multivessel SCAD presenting as AMI, which was treated with percutaneous coronary intervention. A 63-year-old man was transferred with squeezing chest pain that had increased over the past four days. He had no risk factors for coronary artery disease and no history of trauma, infection, or systemic vasculitis. Electrocardiogram showed premature ventricular beats but cardiac enzymes were elevated. Echocardiography demonstrated akinesia in the inferior wall and septal wall with a decreased ejection fraction (EF=40%). He underwent emergent coronary angiography, which revealed diffuse long lesion from the proximal to midright coronary artery (RCA) and proximal to mid left anterior descending artery(LAD) with suspicious radiolucent intimal flap. Intravascular ultrasound (IVUS) showed the dissection flap with intramural hematoma compressing the true lumen. We treated with everolimus-eluting stents in the p-m RCA and p-m LAD. Subsequent IVUS demonstrated a fully covered dissection lesion and showed good distal flow without residual stenosis. He was discharged with dual antiplatelet therapy and has been followed up at the outpatient clinic. At 12-month follow-up, the patient was well and aymptomatic.

저고도 전리권 관측을 위한 사운딩 로켓 실험용 IAMMAP(Ionospheric Anomaly Monitoring by Magnetometer And Plasma-Probe)의 과학적 목표와 임무 설계

Jimin Hong,Yoon Shin,Sebum Chun,Sangwoo Youk,Jinkyu Kim,Wonho Cha,Seongog Park,Seunguk Lee1,Suhwan Park,Jeong-Heon Kim,KWANG-SUN RYU 한국우주과학회 2024 우주기술과 응용 Vol.4 No.2

Sounding rockets are cost-effective and rapidly deployable tools for directly exploring the ionosphere and microgravity environments. These rockets achieve their target altitudes quickly and are equipped with various scientific instruments to collect real-time data. Perigee Aerospace plans its inaugural test launch in the first half of 2024, followed by a second performance test launch in January 2025. The second launch, scheduled off the coast of Jeju Island, aims to reach an altitude of approximately 150 km with a payload of 30 kg, conducting various experiments in the suborbital region. Particularly in mid-latitude regions, the ionosphere sporadically exhibits increased electron densities in the sporadic E layers and magnetic fluctuations caused by the equatorial electrojet. To measure these phenomena, the sounding rocket version of ionospheric anomaly monitoring by magnetometer and plasma-probe (IAMMAP), currently under development at the KAIST Satellite Research Center, will be onboard. This study focuses on enhancing our understanding of the mid-latitude ionosphere and designing observable missions for the forthcoming performance tests. 사운딩 로켓은 저렴한 비용과 빠른 개발 기간을 통해 전리권이나 무중력 환경을 직접 탐사하는 유용한 도구이다. 이러한 로켓은 목표 고도에 신속하게 도달하며, 다양한 과학적 장비를 탑재하여 데이터를 실시간으로 수집할 수 있다. 페리지에어로스페이스㈜는 2024년 상반기에 첫 시험 발사를 진행한 뒤, 2025년 1월경에는 2차 성능시험 사운딩 로켓을 발사할 예정이다. 이 로켓은 제주 해상에서 발사될 예정이며, 약 150 km의 목표 고도에 총 30 kg의 탑재체를 싣고, 준궤도 영역에서 다양한 실험을 수행할 것이다. 특히, 중위도 지역의 전리권에서는 간헐적으로 전자 밀도가 증가하는 스포라딕 E층과 적도 전기제트에 의한 자기장의 미세변화를 관측할 수 있을 것으로 예상된다. 이러한 관측을 위해 KAIST 인공위성연구소에서 개발 중인 탑재체 IAMMAP(ionospheric anomaly monitoring by magnetometer and plasma-probe)의 사운딩로켓 버전이 발사체에 실릴 예정이다. 본 연구는 중위도 지역의 전리권에 대해서 이해하고, 2차 성능시험에서의 관측 가능한 임무 설계에 중점을 두고자 한다.

실내 식물재배기 내 유로 설계를 통한 LED 의 열관리 연구

신봉규(Bong Kyu Shin),김보라(Bo Ra Kim),이승훈(Seung Hun Lee),남영효(Young Hyo Nam),정민흥(Min Heung Jeong),이승욱(Seunguk Lee),이정현(Jeonghyeon Lee),이재원(Jae Won Lee) 대한기계학회 2024 대한기계학회 춘추학술대회 Vol.2024 No.4

몬테카를로 시뮬레이션을 이용한 방사선원 위치 검출기의 각도의존성 연구

한무재 ( Moojae Han ),허승욱 ( Seunguk Heo ),신요한 ( Yohan Shin ),정재훈 ( Jaehoon Jung ),김교태 ( Kyotae Kim ),허예지 ( Yeji Heo ),이득희 ( Deukhee Lee ),조흥래 ( Heunglae Cho ),박성광 ( Sungkwang Park ) 한국방사선학회 2019 한국방사선학회 논문지 Vol.13 No.1

Radiation sources used in the field of industrial non-destructive pose a risk of exposure due to ageing equipment and operator carelessness. Thus, the need for a safety management system to trace the location of the source is being added. In this study, Monte Carlo Simulation was performed to analyse the angle dependence of the unit-cell comprising the line-array dosimeter for tracking the location of radiation sources. As a result, the margin of error for the top 10% of each slope was 5.90% at 0°, 8.08% at 30°, and 20.90% at 60°. The ratio of the total absorbed dose was 83.77% at 30 ° and 53.36% at 60 ° based on 0 °(100%) and showed a tendency to decrease with increasing slope. For all gradients, the maximum number was shown at 30° No. 9 pixels, and for No. 10, there was a tendency to drop 7.24 percent. This study has shown a large amount of angle dependence, and it is estimated that the proper distance between the source and line-array dosimeters should be maintained at a distance of not less than 1 cm to reduce them.

Seniors' Participation in Gardening Improves Nature Relatedness, Psychological Well-being, and Pro-environmental Behavioral Intentions

조장환(Jang-Hwan Jo),Seunguk Shin,손영균(Young-Gyun Son),안병철(Byung-Chul An) 인간식물환경학회 2022 인간식물환경학회지 Vol.25 No.3

Background and objective: Mounting evidence suggests that nature-based recreation such as gardening can generatevarious mental and behavioral benefits. However, the benefits of gardening for older populations are largely unknown. Thisstudy aimed to assess how a seniors' gardening program affects older people's nature relatedness, psychologicalwell-being, and intent to engage in pro-environmental behavior. Methods: We designed a one-group pretest-posttest study. Twelve seniors in their 60s and 70s participated in a gardeningprogram occurring in a university botanical garden for 5 months. We used a 5-point Likert scale to measure the participants'nature relatedness, psychological well-being, and pro-environmental behavioral intentions at the beginning as well as theend of the program. We compared the pretest and posttest scores on each measure using a Wilcoxon signed-rank test fornature relatedness and paired t-tests for psychological well-being and behavioral intentions. Results: Our results indicated statistically significant increases in all three outcome variables after participation in thegardening program. The median score for nature relatedness was 4.167 after program participation compared to 3.500before participation (p < .05). Also, participants' psychological well-being mean score increased from 3.505 to 4.009 (p <.01) while their intent to engage in pro-environmental behavior mean score increased from 4.115 to 4.427 (p < .05). Conclusion: A seniors' gardening program can be an effective way for older people to connect with nature and improve theirmental health. Also, gardening can foster the capacity of the elderly to help reduce human impacts on the environment.

A study of Curved Dosimeter for Flattening Filter Free Beam Quality Assurance Evaluation using Curved Dosimeter in Radiotherapy

Moojae Han,Yohan Shin,Jaehoon Jung,Seunguk Heo,Kyotae Kim,Yeji Heo,Heunglae Cho,Sungkwang Park 한국방사선학회 2019 한국방사선학회 논문지 Vol.13 No.1

최근 도입된 FFF 빔을 활용하는 방사선치료는 flattening filter에서 비롯되는 빔의 감쇠를 막을 수 있어 치료효율을 높일 수 있지만, 불균일한 단면적 선량분포에 대하여 정확한 정도관리가 구축되어 있지 않은 실정이다. 이에 본 연구에서는 광도전체 물질 HgI2 기반의 곡면 선량계를 제작하였으며, 성능을 검증하기 위하여 6 MV 광자에너지에서 재현성 및 선형성을 평가하였다. 또한 곡면 계측의 유용성을 나타내기 위하여 아크릴 필터를 적용한 FFF beam에서 평면 기판과 곡면 기판 상에서 계측되는 신호를 비교하였다. 그 결과 Unit cell 선량계의 재현성은 SE 0.613%, 선형성은 R-sq 0.9999로 나타났으며, line array 곡면 선량계의 유용성 평가는 평면 기판에서 23.337%, 곡면 기판에서 12.264%로 11.073%p 감소된 신호 차이를 보였 다. Radiation therapy using flattening filter free beam can prevent beam attenuation caused by flattening filter and can improve treatment efficiency. However, accurate dose control is not established for nonuniform iso dose distributions. In this study, curved dosimeter based on photoconductive material HgI2 was fabricated and its reproducibility and linearity were evaluated at 6 MV photon energy to verify its performance. In order to show the usefulness of the curved measurement, the signals measured on the flat substrate and the curved substrate were compared in the flattening filter free beam using the acrylic filter. As a result, the reproducibility of the unit cell dosimeter was evaluated as SE 0.613%, and the linearity was evaluated as R-sq 0.9999. The usability evaluation of the array curve dosimeter demonstrated its usefulness by indicating a curvature error rate of 11.073%p and a reduced error rate.