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지속가능한 농업을 위한 저탄소 인증 농산물 지불의사 분석: 20대를 중심으로
조용빈(Yong-Been Jo),김영균(Young-Gyun Kim),이은학(Eun-Hak Lee),이경한(Gyeong-Han Lee),이지용(Ji-Yong Lee),임세화(Se-Hwa Lim),장성원(Sung-Won Jang) 한국산학기술학회 2024 한국산학기술학회논문지 Vol.25 No.1
This study estimates the consumer value provided by low-carbon agrifood with a focus on people in their 20s, who are current and future consumers. Information was collected regarding the respondents experiences, environmental awareness, perceptions of climate change and low-carbon agrifood, and their willingness to pay for it. Consumer preference for low-carbon agrifood was analyzed using the Contingent Valuation Method, which is commonly employed to estimate consumers willingness to pay for non-market goods. To closely align with real market conditions and to facilitate respondents answers to questions, a double-bounded dichotomous choice format was utilized. The empirical results show that for people in their 20s, the willingness-to-pay ratio for low-carbon agrifood was approximately 27% relative to conventional food. Environmental interest shown by such consumers had a statistically significant impact on the willingness-to-pay decision for these products, while treatment information, climate change awareness, and prior purchasing experiences contributed to numerical differences in the willingness-to-pay ratio. The analysis indicates a noticeable shift in willingness to pay based on the level of environmental concern. Therefore, prioritizing enhancement of individuals awareness and interest in their environment should be considered a primary focus. However, while the awareness of climate change and the environment among individuals in their 20s appears to be high, their recognition of low-carbon agrifood seems comparatively low.
소동물 Iodine-125 SPECT 개발을 위한 컴퓨터 시뮬레이션
정진호 ( Jeong Jin Ho ),최용 ( Choe Yong ),송태용 ( Song Tae Yong ),정용현 ( Jeong Yong Hyeon ),정명환 ( Jeong Myeong Hwan ),홍기조 ( Hong Gi Jo ),민병준 ( Min Byeong Jun ),최연성 ( Choe Yeon Seong ),이경한 ( Lee Gyeong Han ) 대한핵의학회 2004 핵의학 분자영상 Vol.38 No.1
목적: I-125는 저에너지(27-35 keV) 방사선을 방출하기 때문에 두께가 얇은 섬광결정과 조준기를 사용할 수 있어 고분해능, 고민감도 영상획득에 유리한 물리적 특성을 가지고 있다. 이 연구의 목적은 새로운 시뮬레이션 도구인 GATE (Geant4 Application for Tomographic Emission)를 사용하여 최적의 I-125 SPECT 시스템 파라미터를 도출하는 것이다. 대상 및 방법: 시뮬레이션 방법의 신뢰성을 검증하기 위해, Weisenberger 등이 개발한 감사카메라 시스템을 모사하였다. 섬광채로 평판형 Mal(Tl)을 사용하였으며, 두께는 검출효율을 계산해서 결정하였다. 평행구멍조준기와 바늘구멍조준기의 여러 파라미터가 공간분해능과 민감도에 미치는 영향을 평가하였다. 그리고 최적화된 조준기를 결합한 I-125 SPECT의 성능을 평가하였다. 결과: 시뮬레이션에 대한 신뢰성 검증연구 결과, 측정과 시뮬레이션에서 공간분해능(4%)과 민감도(3%)가 유사함을 확인하였다. Nal(Tl) 두깨는 I-125 감마선을 98% 검출할 수 있도록 1 mm로 결정하였다. 시뮬레이션 결과 고분해능 평행구멍조준기로 구멍크기가 0.2 mm이고 길이가 5 mm인 사각구멍조준기를 선택하였고, 범용 평행구멍조준기로 구멍크기가 0.5 mm이고, 길이가 10 mm인 육각구멍조준기를 선택하였다. 바늘구멍주준기는 구멍지름이 0.25 mm이고 채널높이가 0.1 mm이며, 허용각도가 90도인 조준기를 선택하였다. 최적화된 고분해능 평행구멍조준기, 범용 평행구멍조준기, 바늘구멍조준기를 결합한 I-125 SPECT의 재구성 영상 공간분해능은 각각 1.2mm, 1.7 mm, 0.8 mm이였으며, 민감도는 39.7 cps/MBq, 71.9 cps/MBq, 5.5 cps/MBq이었다. 결론: GATE 시뮬레이션으로 I-125 영상에 적합한 섬광결정 파라미터 및 조준기 파라미터를 도출하였다. 이 연구결과는 I-125 SPECT로 탁월한 고분해능, 고민감도 영상을 얻을 수 있음을 보여준다. Purpose: Since 1-125 emits low energy (27-35 keV) radiation, thinner crystal and collimator could be employed and, hence, it is favorable to obtain high quality images. The purpose of this study was to derive the optimized parameters of 1-125 SPECT using a new simulation tool, GATE (Geant4 Application for Tomographic Emission). Materials and Methods: To validate the simulation methods, gamma camera developed by Weisenberger et al. was modeled. Nal(Tl) plate crystal was used and its thickness was determined by calculating detection efficiency. Spatial resolution and sensitivity curves were estimated by changing variable parameters for parallel-hold and pinhole collimator. Performances of 1-125 SPECT equipped with the optimal colimator were also estimated. Results: In the validation study, simulations were found to agree well with experimental measurements in spatial resolution (4%) and sensitivity (3%). In order to acquire 98% gamma ray detection efficiency, Nal(Tl) thickness was determined to be 1 mm. Hole diameter (mm), length (mm) and shape were chosen to be 0.2:5:square and 0.5:10:hexagonal for high resolution (HR) and general purpose (GP) parallel-hole collimator, respectively. Hole diameter, channel height and acceptance angle of pinhole (PH) collimator were determined to be 0.25 mm, 0.1 mm and 90 degree. The spatial resolutions of reconstructed image of the 1-125 SPECT employing HR:GP:PH were 1.2:1.7:0.8 mm. The sensitivities of HR:GP:PH were 39.7:71.9:5.5 첸/MBq. Conclusion: The optimal crystal and collimator parameters for 1-125 imaging were derived by simulation using GATE. The results indicate that excellent resolution and sensitivity imaging is feasible using 1-125 SPECT.