• The Korean Journal of Nuclear Medicine
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• v.30 no.1
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• pp.19-34
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• 1996

[ $[^{123}I]{\beta}$ ]-CIT [$2{\beta}$-carbomethoxy-$3{\beta}$-(4-iodophenyl)tropane]는 도파민 운반체 (dopamine transporter)에 특이결합하며 $[^{123}I]{\beta}$-CIT의 도파민 운반체 결합정도는 파킨슨병에서 도파민 뉴우런의 변성정도를 반영하는 것으로 제안되어 왔다. 이 연구의 주요 목적은 파킨슨병 환자에서 $[^{123}I]{\beta}$-CIT SPECT를 이용하여 측정된 $[^{123}I]{\beta}$-CIT의 선조체 결합지표들이 질병의 임상적 진행정도를 반영하는지를 검토하고, 간편화된 조직방사능비가 $[^{123}I]{\beta}$-CIT의 결합정도를 나타내는 정량적 지표로 이용될 수 있는지를 검증하는 것이었다. 파킨슨병 환자 30명($59{\pm}9$세, 평균${\pm}$표준편차: Hoehn-Yahr stage 1-3)과 정상인 6명 ($58{\pm}5$세)을 대상으로 $[^{123}I]{\beta}$-CIT SPECT 영상을 얻었다. $[^{123}I]{\beta}$-CIT 선조체 결합의 정량적 지표로서 (선조체 방사능-소뇌방사능)/소뇌방사능 비(specific binding ratio, SBR)와 추적자역학모델을 이용하여 측정한 선조체 결합능(binding potential)($k_3/k_4$)을 구하였다. 파킨슨병 환자에서 $[^{123}I]{\beta}$-CIT의 선조체 결합역학은 정상인에 비하여 현저하게 느렸으며 그 결합지표들은 정상인에 비하여 뚜렷하게 낮았다. 한편, 편측파킨슨병 환자에서 $[^{123}I]{\beta}$-CIT 결합은 증상 반대쪽 선조체 뿐만 아니라 같은 쪽 선조체에서도 정상인에 비해 유의하게 감소되어 있었다. 파킨슨병 환자에서 $[^{123}I]{\beta}$-CIT 투여 후 24시간의 선조체 SBR 및 최대 SBR, 선조체 결합능은 모두, 유병기간, Hoehn-Yahr stage, UPDRS(Unified Parkinson's Disease Rating Scale) 총점, UPDRS 운동점수, UPDRS 일상활동점수와 유의한 상관관계를 나타내었다. 24시간 선조체 SBR과 최대 SBR은 선조체 결합능과 우수한 상관관계를 보였다. 이상의 결과로부터 $[^{123}I]{\beta}$-CIT의 선조체 결합은 파킨슨병의 진행정도를 나타내는 지표로 이용될 수 있다. 또 $[^{123}I]{\beta}$-CIT 투여 후 24시간 영상으로부터 얻은 간편화된 조직방사능 비는 $[^{123}I]{\beta}$-CIT의 결합정도를 정량적으로 반영한다. $[^{123}I]{\beta}$-CIT SPECT는 파킨슨병의 조기진단 및 진행 추적에 임상적으로 유용할 것으로 판단된다.

• Journal of the Korean Solar Energy Society
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• v.31 no.5
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• pp.47-59
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• 2011

The purpose of this paper is to simulate the high ozone concentration in Shiwha Banwol indusrial complex. High pollution episodes (ozone alert) of this area are the results of geographical location and its air pollutants emission. This research has used meteorological model (RAMS) and photochemical air pollution Model (CIT model). As first step of the evaluate of this combined model system simulations are done in terms of meteorological characteristics like wind fields, PBL-height, etc.. Numerical simulations are carried out with real meteorological synoptic data on June. 24-25, 2010. In comparison with real measurement and another research the model reflects well local meteorological phenomena and shows the possibility to be utilized to analyse the pollutant dispersion over irregular terrain region. The high ozone concentration is deeply correlated to the ambient air temperature, wind speed and solar radiation. Local meteorological phenomena like sea-land breeze impact on horizontal dispersion of ozone. This analysis of meteorological characteristics can, in turn, help to predict their influences on air quality and to manage the high ozone episodes.

• Asia Marketing Journal
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• v.6 no.1
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• pp.1-16
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• 2004

서비스품질의 차원과 위계에 대한 논의가 최근 들어 늘어나고 있다. 그 이유는 서비스품질, 고객만족, 고객의 긍정적 행동의향, 수익성 간의 선순환 때문이다. 차원모델은 SERVQUAL과 SERVPERF 모델이 있고 위계모델은 Grönroos(1984)모델과 미국학자들이 개발한 모델이 대표적이다. 최근들어 이들을 결합한 하이브리드모델이 제안되고 있다. 하지만 기존의 하이브리드모델은 차원과 위계를 결합하여 일반성은 높지만 위계를 정하는 이론적 근거가 분명하지 않다. 본 연구는 욕구위계이론 중 Herzberg(1968)의 두 요인이론에 근거하여 서비스품질의 위계모델을 제시하려 한다. 이를 위해 CIT로 판매접점에서 고객이 느끼는 결정적 사건(critical incidents)을 조사하였다. 먼저 중복요인과 단독요인으로 나누고 각각을 다시 불만족중심과 만족중심으로 나눌 때 이들 결정적 사건이 잘 분류되었다. 분류결과 신뢰성은 불만족중심 중복요인, 응답성은 만족중심 중복요인, 공감성은 단독만족요인으로 나타났다. 본 연구에서 제시하는 서비스품질의 욕구위계모델에 따르면 신뢰성, 응답성, 공감성의 순으로 서비스품질이 중요하다. 확신성과 유형성은 따로 분류되는 결정적 사건이 없어 만족, 불만족 요인을 도와주는 조절요인으로 볼 수 있다.

• Knowledge Management Research
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• v.25 no.2
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• pp.135-153
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• 2024

With the recent emergence of smart tourist cities, premium mobility is being considered an important means of transportation in the tourism. However, there has been insufficient research conducted on the experience of premium mobility among its users. Accordingly, this study used CIT to analyze the components of the user experience of customers who used premium mobility. In order to specifically identify the factors that make up the premium mobility experience, 366 cases of satisfaction and 13 cases of dissatisfaction were collected through a total of 273 online surveys. As a result of the study, based on the customer's experience using premium mobility, CIT was applied to derive 6 categories and 9 sub-factors that constitute the perception of premium mobility. In particular, this study is different from existing studies in that convenience was added as a new category out of the 6 categories, and wide ride comfort and high price were derived as new sub-factors among the 9 sub-factors. Because of this, it has academic significance. Therefore, if scales suitable for quantitative research are developed based on the derived constructs, they could be widely applied to various topics related to premium mobility in the tourism field.

• Atmosphere
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• v.33 no.5
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• pp.531-548
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• 2023

We developed the Aviation Convective Index (ACI) for predicting deep convective area using the operational global Numerical Weather Prediction model of the Korea Meteorological Administration. Seasonally optimized ACI (ACI_SnOpt) was developed to consider seasonal variabilities on deep convections in Korea. Yearly optimized ACI (ACI_YrOpt) in Part 1 showed that seasonally averaged values of Area Under the ROC Curve (AUC) and True Skill Statistics (TSS) were decreased by 0.420% and 5.797%, respectively, due to the significant degradation in winter season. In Part 2, we developed new membership function (MF) and weight combination of input variables in the ACI algorithm, which were optimized in each season. Finally, the seasonally optimized ACI (ACI_SnOpt) showed better performance skills with the significant improvements in AUC and TSS by 0.983% and 25.641% respectively, compared with those from the ACI_YrOpt. To confirm the improvements in new algorithm, we also conducted two case studies in winter and spring with observed Convectively-Induced Turbulence (CIT) events from the aircraft data. In these cases, the ACI_SnOpt predicted a better spatial distribution and intensity of deep convection. Enhancements in the forecast fields from the ACI_YrOpt to ACI_SnOpt in the selected cases explained well the changes in overall performance skills of the probability of detection for both "yes" and "no" occurrences of deep convection during 1-yr period of the data. These results imply that the ACI forecast should be optimized seasonally to take into account the variabilities in the background conditions for deep convections in Korea.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.4
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• pp.100-108
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• 2016

The climatic index for tourism(CIT) has recently been advanced, which includes complete human energy balance models such as physiological equivalent temperature(PET) and universal thermal climate index(UTCI). This study investigated human thermal sensation and comfort at Woljung-ri Beach, Jeju, Republic of Korea, in spring and summer 2015 for landscape planning and design in beach areas. Microclimatic data measurements and human thermal sensation/comfort surveys from ISO 10551 were conducted together. There were 869 adults that participated. As a result, perceptual and thermal preference that consider only physiological aspects had high coefficients of determination($r^2$) with PET in linear regression analyses: 92.8% and 87.6%, respectively. However, affective evaluation, personal acceptability and personal tolerance, which consider both physiological and psychological aspects, had low $r^2s$: 60.0%, 21.1% and 46.4%, respectively. However, the correlations between them and PET were all significant at the 0.01 level. The neutral PET range in perceptual for human thermal sensation was $25{\sim}27^{\circ}C$, but a PET range less or equal to 20% dissatisfaction, which was recommended by ASHRAE Standard 55, could not be achieved in perceptual. Only PET ranges in affective evaluation and personal tolerance affected by both aspects were qualified for the recommendation as $21{\sim}32^{\circ}C$ and $17{\sim}37^{\circ}C$, respectively. Therefore, the PET range of $21{\sim}32^{\circ}C$ is recommended to be used for the human thermal comfort zone of beach areas in landscape planning and design as well as tourism and recreational planning. PET heat stress level ranges on the beach were $2{\sim}5^{\circ}C$ higher than those in inland urban areas of the Republic of Korea. Also, they were similar to high results of tropical areas such as Taiwan and Nigeria, and higher than those of western and middle Europe and Tel Aviv, Israel.

• The Korean Journal of Nuclear Medicine
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• v.31 no.1
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• pp.73-82
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• 1997

Regional myocardial blood flow (rMBF) can be noninvasively quantified using N-13 ammonia and dynamic positron emission tomography (PET). The quantitative accuracy of the rMBF values, however, is affected by the distortion of myocardial PET images caused by finite PET image resolution and cardiac motion. Although different methods have been developed to correct the distortion typically classified as partial volume effect and spillover, the methods are too complex to employ in a routine clinical environment. We have developed a refined method incorporating a geometric model of the volume representation of a region-of-interest (ROI) into the two-compartment N-13 ammonia model. In the refined model, partial volume effect and spillover are conveniently corrected by an additional parameter in the mathematical model. To examine the accuracy of this approach, studies were performed in 9 coronary artery disease patients. Dynamic transaxial images (16 frames) were acquired with a GE $Advance^{TM}$ PET scanner simultaneous with intravenous injection of 20 mCi N-13 ammonia. rMBF was examined at rest and during pharmacologically (dipyridamole) induced coronary hyperemia. Three sectorial myocardium (septum, anterior wall and lateral wall) and blood pool time-activity curves were generated using dynamic images from manually drawn ROIs. The accuracy of rMBF values estimated by the refined method was examined by comparing to the values estimated using the conventional two-compartment model without partial volume effect correction rMBF values obtained by the refined method linearly correlated with rMBF values obtained by the conventional method (108 myocardial segments, correlation coefficient (r)=0.88). Additionally, underestimated rMBF values by the conventional method due to partial volume effect were corrected by theoretically predicted amount in the refined method (slope(m)=1.57). Spillover fraction estimated by the two methods agreed well (r=1.00, m=0.98). In conclusion, accurate rMBF values can be efficiently quantified by the refined method incorporating myocardium geometric information into the two-compartment model using N-13 ammonia and PET.