당뇨망막병증 검진에 있어 무산동 디지털 안저사진기의 효용성

이대웅,배정훈,송수정.Dae Woong Lee. MD. Jeong Hoon Bae. MD. Su Jeong Song. MD 대한안과학회 2011 대한안과학회지 Vol.52 No.5

Purpose: To evaluate the efficacy of a single field, non-mydriatic, 45° digital photography as a diagnostic tool for diabetic retinopathy. Methods: A total of 303 consecutive diabetic patients (606 eyes) who underwent digital fundus photography and indirect ophthalmoscopy were included in the present study. The optical discs and macular area of all patients were subjected to single fundus photography using a non-mydriatic 45-degree digital fundus camera. All patients also underwent fundus examinations after pupil dilation via indirect ophthalmoscopy. Results: The sensitivity and specificity for determining diabetic retinopathy were 47.6% and 97.6%, respectively. The false positive rate, false negative rate, positive predictive value, and negative predictive values were 2.3%, 2.1%, 45.5%, and 97.8%, respectively. Among the digital fundus images, 12.9% (78 eyes) were non-gradable. The patients with non-gradable digital fundus images were older (p < 0.001), had a longer duration of diabetes, (p < 0.001) and more often suffered from systemic hypertension (p = 0.003) compared to patients with gradable photographs. Conclusions: The present study showed that single-field, non-mydriatic, 45 degree digital photography for detecting diabetic retinopathy had relatively low sensitivity and high technical failure rates. The failure rates could be improved with higher resolution non-mydriatic wide-field photography cameras and with additional peripheral images for diabetic retinopathy screening. J Korean Ophthalmol Soc 2011;52(5):531-536

제2형 당뇨병 환자에서 당뇨망막병증에 대한 지식 및 인지도조사: 서울시 당뇨병예방사업 설문 조사결과

이대웅,박철영,송수정,Dae Woong Lee,Chul Young Park,Su Jeong Song 대한안과학회 2011 대한안과학회지 Vol.52 No.11

Purpose: To investigate the knowledge and awareness level of diabetic retinopathy (DR) in type 2 diabetes patients. Methods: A total of 437 participants with diabetes were recruited in the Seoul Metro-City Diabetes Prevention Program (SMC-DPP). Participants underwent clinical and laboratory examinations and questionnaire survey to evaluate diabetes complications. The DR was diagnosed by grading fundus photographs 5 standard fields taken per eye. Results: The overall prevalence of any DR was 20.4% and only 6.6% of patients were aware of their DR. The DR patients who underwent an eye examination within the previous year were 42.3%, and 50.3% out of 437 patients enrolled were educated on diabetes. Of the survey participants, 83.8% answered positive to ‘Evaluation of diabetes mellitus complication must be performed every year’, 61.1% answered positive to ‘Must control blood pressure and lipid level for diabetes management’ and 28.4% believed ‘It takes a long time for complications of diabetes to develop’. The DR self awareness was 14.6% and an eye examination within the previous year was 50.6% among the 89 DR participants. Conclusions: Results of the survey with SMC-DPP type 2 diabetes participants showed a low knowledge and awareness level of chronic complications such as DR. J Korean Ophthalmol Soc 2011;52(11):1296-1301

자동차 냉각수 폐열회수 열전발전 시스템의 성능에 관한 연구

이대웅(Dae-Woong Lee) 대한설비공학회 2014 설비공학 논문집 Vol.26 No.7

This study indicated the possibility of energy regeneration from waste coolant heat, by using thermoelectric generation integrated with heat pipe. The internal combustion engine rejects more than 60% wasteful energy to the atmosphere by heat. The thermoelectric generator has recently been studied, to convert the energy from engine waste heat into electricity. For coolant waste heat recovery, a thermoelectric generator was investigated, to find out the possibility of vehicular application. Performance characteristics were conducted with various test conditions of coolant temperature, coolant mass flow rate, air temperature, and air velocity, with the thermoelectric generator installed either horizontally or vertically. Experimental results show that the electric power and conversion efficiency increases according to the temperature difference between the hot and cold side of the thermoelectric generator, and the coolant flow rate of the hot side heat exchanger. Performance improvement can be expected by optimizing the heat pipe design.

열전모듈을 이용한 자동차용 1 kW급 보조 냉난방 시스템의 성능에 관한 실험적 연구

이대웅(Dae-Woong Lee) 대한설비공학회 2014 설비공학 논문집 Vol.26 No.5

The purpose of this paper is to investigate the performance of supplemental cooling and heating system equipped with the 1 kW thermoelectric module. The system consist of 96 thermoelectric modules, heat sink with louver fin and water cooling jacket which is attached on the hot side of the thermoelectric module. The cooling and heating performance test of the thermoelectric system is conducted with various conditions, such as intake voltage, air inlet temperature, air flow volume, water inlet temperature and water flow rate at calorimeter chamber in consideration of environmental conditions in realistic vehicle drive. The experimental results of a thermoelectric system shows that the cooling capacity and COP is 1.03 kW, and 1.0, and heating capacity and COP is 1.53 kW, and 1.5 respectively.

한국 지방정부의 정책확산에 관한 연구 - 반부패 신고포상금제도를 중심으로 -

이대웅 ( Dae Woong Lee ),권기헌 ( Gi Heon Kwon ) 한국정책학회 2015 韓國政策學會報 Vol.24 No.3

본 논문의 목적은 분권적 정책체제 하에서, 사회적 문제에 대한 대응을 위한 한국 지방정부들의 정책혁신과 이의 확산 기제(mechanism)가 무엇인가에 대해 분석하는 것이다. 따라서 지방정부간 정책혁신과 정책확산의 발현이 지방정부의 합리적·주체적 의사결정에 의한 채택인지, 아니면 정치적 동기 또는 지방정부들 간의 단순 모방·경쟁 등에 의한 것인지에 대하여 분석·검토하였다. 더불어 선행연구를 보완하고자 네트워크 효과에 대한 논의와 채택되어지는 정책의 혁신 수준에 따른 각각의 확산 영향요인에 대한 비교분석을 추가적으로 실시하였다. 본 연구를 통해, 첫째, 정책확산 연구의 외부적 확산모형과 내부적 결정모형에서 나아가 네트워크 모형을 설정하여 정책확산 모형에 대한 논의의 폭을 확장시켰다. 특히 네트워크 변수들은 한국 지방정부의 정책혁신의 확산에 유의미한 영향을 미치는 것으로 나타났다. 둘째, 혁신성이 높은 정책일수록 네트워크 요인에 강하게 영향을 받는 것으로 나타났으며, 혁신성이 낮은 정책일수록 상위정부에 의한 강압적 영향을 받는 것으로 나타났다. 이를 통해 지방정부에게 정부 간 네트워크는 새롭고 혁신적인 정책에 대한 확장된 정보와 지식을 제공하고 이를 통한 정책학습 효과를 촉진시키는 것을 알 수 있다. 또한 정책의 형식적 채택이 나타나는 지방정부의 경우 상위정부의 정책 채택에 의한 강압적 영향력이 강한 것으로 나타났다. 이에 따라 지방분권체제의 본래의 취지에 적합한 정책혁신 수준의 상향을 위해서는 지방정부 자율권을 기반으로 한 네트워크를 통해 정책결정 및 채택이 지향되어야 함이 도출되었다. The research question of this study is 'what are influencing factors of diffusion at innovation policy that is newly adopted to solve social problems in local governments'. The specific research purposes of this study are the following. First, this study will find diffusion influence factors of policies. Specially, this study mainly deals with the influence of network that is a new channel of policy learning and policy emulation among local governments within the policy diffusion process. Thereby the study could construct the new model of policy diffusion network-based on trust among local governments. Second, the purpose of this study based on the hypothesis that diffusion mechanism is a different according to the policy type (on the basis of policy innovation level). So, this study will implement comparison analysis about influence factors of diffusion, depending on the degree of innovation. Third, this study will suggest policy implications for effective accomplishments of anti-corruption policy on local governments. This study's theoretical implications are as follows, first, previous studies of policy diffusion mainly consider to external effect and inter effect, but this study suggests a new model of policy diffusion that is consider to network effect. This is meaningful because of suggesting needs of consider about network as new mechanism and channel of communication and informationㆍknowledge among local governments. Second, this study will find the difference of the diffusion mechanism in accordance to policy type. Specifically, this study will find the difference of influence factors of policy diffusion in accordance to policy innovation level through empirical analysis and has implication that suggests new direction and need of policy diffusion study. This study's policy implications as follows. First, in order to achieve actual purpose of policy, local government tries to construct networks and specific cooperation on the basis of trust among local governments. That will improve the opportunities to learn and exchange knowledgeㆍinformation is an important process to adopt high-level innovation policy. Second, phenomenon of policy emulation is necessary on the local government age. But formal adoption as simply an emulation of policy will be discouraged to achieve the purposes of the policy. Therefore creative emulation through analytic learning that is considered to administrationㆍpolitic environment on local government about innovation policy must appear.

유전율에 따른 입자의 유전영동에 의한 거동에 대한 연구

이대웅(Dae Woong Lee),이상엽(Sang Youp Lee) 대한기계학회 2017 대한기계학회 춘추학술대회 Vol.2017 No.11

열전소자를 이용한 차량용 독립 냉난방시스템에 대한 실험적 연구

이대웅(Dae-Woong Lee) 대한설비공학회 2014 설비공학 논문집 Vol.26 No.8

The purpose of this paper is to investigate the cooling and heating performance of a standalone-type thermoelectric system equipped with a thermoelectric module. The system consists of a blower and two thermoelectric modules with a fin, which is soldered onto both sides of the thermoelectric module and a courtesy light. The thermoelectric system experiment is conducted with the intake voltage to find the optimum cooling and heating performance of each. The results showed that the cooling capacity and coefficient of performance (COP) were 22 W and 0.31, and the heating capacity and COP were 147 W and 1.1, respectively. In the vehicle cooling and heating performance test in a climate wind tunnel, the results showed that the standalone thermoelectric system"s cooling performance was slightly better than the base system; and the heating performance of the standalone thermoelectric system was 54.1°C and the COP was 1.3, compared to the base system.

자동차 배기폐열 회수용 열전발전 시스템의 성능에 관한 연구

이대웅(Dae-Woong Lee) 대한설비공학회 2014 설비공학 논문집 Vol.26 No.6

Internal combustion engines release 30~40% of the energy from fossil fuels into the atmosphere in the form of exhaust gases. By utilizing this waste heat, plenty of energy can be conserved in the auto industry. Thermoelectric generation is one way of transforming the energy from engine’s exhaust gases into electricity in a vehicle. The thermoelectric generators located on the exhaust pipe have been developed for vehicle applications. Different experiments with thermoelectric generators have been conducted under various test conditions as following examples: hot gas temperature, hot gas mass flow rate, coolant temperature, and coolant mass flow rate. The experimental results have shown that the generated electrical power increases significantly with the temperature difference between the hot and the cold side of the thermoelectric generator and the gas flow rate of the hot-side heat exchanger. In addition, the gas temperature of the hot-side heat exchanger decreases with the length of the thermoelectric generator, especially at a low gas flow rate.

근로장려세제(EITC)의 정책효과에 관한 연구 -성향점수 매칭(PSM) 이중,삼중차이 분석을 중심으로-

이대웅 ( Dae Woong Lee ),권기헌 ( Gi Heon Kwon ),문상호 ( Sang Ho Moon ) 한국정책학회 2015 韓國政策學會報 Vol.24 No.2

근로장려세제(EITC)는 ‘빈곤’과 ‘사회양극화’라는 현대사회의 주요한 문제를 해결하고자 등장한 근로연계복지정책(workfare policy)이다. 이는 근로빈곤층 지원과 근로의욕 촉진을 통해 경제활동참여와 근로소득 증가로 탈 빈곤을 유도하는 것을 정책목적으로 하고 있다. 이에 본 연구에서는 근로장려세제의 정책효과를 준실험적 모델인 이중차이모델을 이용하여 분석하였다. 이때 선택편의(selection bias)를 줄이기 위해 성향점수 매칭(propensity score matching) 방법을 활용하여 실험집단과 비교집단을 구성하고, 이를 매칭 이중차이(DID)분석과 삼중차이(DDD)분석을 실시하여 각 집단의 두 시점 간 성과변수 차이를 비교하였다. 주요한 분석결과는 다음과 같다. 첫째, 근로장려세제의 1차 목적인 근로의욕을 촉진시켜 경제활동참가를 증가시키는데 기여하고 있음이 분석되었다. 다만, 여성 가구주에게는 정책적 효과가 남성에 비해 상대적으로 낮게 분석되어, 향후 근로연계 복지정책으로써 세액 공제 수단과 더불어 일과 양육의 양립을 가능케 하는 제도적 장치 및 추가적인 유인수단에 대한 확보 논의가 필요함을 도출하였다. 둘째, 노동공급과 노동성과 측면에서 근로장려세제 수급집단에 비해 정책효과가 나타났으나, 통계적으로 유의미하지 않는 것으로 분석되었다. 따라서 근로장려세제의 구간별 소득 한계선를 매년 자동적으로 갱신하는 제도적 장치를 체계화하여 소득경계선 고정에 따른 제도의 실효성 저하를 방지해야 함을 확인하였다. 더불어 저소득층에 대한 적극적 유인 수단으로 점증구간의 확대, 최대급여액의 상향조정 등의 수단에 대한 논의가 필요함을 도출하였다. EITC(Earned Income Tax Credit) is workfare policy that was adopted to solve a problem of modern society, such as 'poverty' and 'social polarization'. The policy purpose is that induces anti-poverty of the poor strata through participating to economic activity and increasing of a earned income. This research analyzed policy effects of EITC by using a DID(Difference in Difference) which is quasi-experimental model. Furthermore, to reduce a selection bias, PSM(Propensity Score Matching) method is used. The findings of the study indicate that: First, EITC is contributed to increasing a participation of economy activity through promoting labour morale. Specifically, it is less effective in female householders than male householders. Thus, EITC needs systematic complement and to provide strong incentive for female householders to balance between work and child rearing. Second, in aspect of labor supply and labor performance, policy effect appears in treat group. But the difference between the two groups was not statistically significant. Thus, through establishing an added institutional strategy, declining effectiveness of institution must be prevented. Also, in terms of quantity, it needs to discuss means that will expand a incremental section and raise the maximum wage.

데이터마이닝 분석방법을 활용한 대졸 청년층의 노동시장 성과 결정요인 분석 - 근사 의사결정나무모형과 로짓모형을 중심으로 -

이대웅 ( Dae Woong Lee ),권기헌 ( Gi Heon Kwon ),문상호 ( Moon Sang Ho ) 한국정책학회 2016 韓國政策學會報 Vol.25 No.3

본 연구는 오늘날 한국사회가 직면한 다양한 사회적 문제(social problem) 가운데 대졸청년층의 노동시장으로의 이행 실패에 대한 문제의식에 기반하고 있다. 따라서 ‘무엇이 노동시장으로의 이행의 성공과 실패를 결정짓는가’ 라는 연구질문을 중심으로 ‘보다 좋은일자리(decent job)’로의 이행에 대해 분석하였다. 특히, 인문사회계열과 자연과학계열로 분석대상의 세분화를 시도하여 차후의 정책적 대안 마련에 적실성을 확보하고자 하였다. 이를 위한 분석방법으로는 데이터마이닝(data mining) 근사 의사결정나무모형과 로짓모형을 활용하였다. 특히, 유의미한 다양한 독립변수 간의 상호작용(interaction) 패턴에 대한분석을 시도하여 개개인 가지고 있는 다양한 상황과 특성들에 적합한 개별적 개입 방안을 마련하는 근거를 제시하고자 하였다. 분석결과, 인문사회계열 대졸 청년층의 노동시장으로의 이행에는 ‘성별’.‘공인영어성적’.‘전공만족도’.‘자격증’.‘교내취업교과목’.‘GPA’ 등이 주요한 요인으로 도출되었다. 다음으로 자연과학계열 대졸 청년층의 경우에는 ‘전공만족도’.‘성별’.‘직접고용정책’.‘GPA’ 등이 도출되었다. 결과적으로 본 연구에서는 전술한 분석결과를 토대로 대졸 청년층의 노동시장으로 이행에 대한 정책적 함의를 제시하며 향후 관련 정책설계 및 대응방안 구축에 기여하고자 하였다. This research focus on the fundamental social problem: the failure of youth graduates`` transition to the labor market. Especially, to improve the previous literatures, the analysis by methods of data mining was conducted in this research. The research tried to discover the predictive factors and the interaction pattern among the factors by Decision Three Analysis, Logit Analysis Model. Furthermore, the research aimed to suggest the reason for developing customized solutions to respond properly to the various situation and features of each individuals. Based on the research results, this research aims to contribute to the policy design and solution building in the future by suggesting policy implications. In other words, the research propose the methods to improve the youth graduates`` labor market result.