• Proceedings of the Korean Society of Computer Information Conference
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• 2011.06a
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• pp.59-61
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• 2011

스마트폰 사용자 1천만 시대가 도래하였다. 올해 안에 스마트폰 가입자가 2천만 시대를 열 것으로 기대되면서 소위 대박을 꿈꾸는 스마트 폰 앱 개발의 열풍에 불을 지피고 있다[1]. 이에 따라 네비게이션 관련 앱도 속속들이 출시되고 있는 상황이다[2]. 하지만 최근 출시된 네비게이션 앱이라 할지라도 기능상으로는 기존 네비게이션의 틀에서 크게 벗어나지 못하고 있는 형편이다. 또한, 스마트폰 가입자의 30% 가량이 20대 이하의 연령임을 고려해 볼 때 비운전자를 타켓으로 한 네비게이션의 필요성도 대두되고 있다[3]. 본 논문에서는 기존 네비게이션에서 원하는 목적지의 정보만을 제공하는 단순한 시스템을 벗어나 비운전자라도 유용하게 쓸 수 있는 사용자 의도에 기반한 네비게이션 시스템을 제안한다. 본 논문에서 제안한 시스템은 모바일 환경이라는 가정 하에 온톨로지를 기반으로 설계되었고, 온톨로지는 사용자 의도를 추론하기 위한 수단으로 사용된다.

• Journal of Energy Engineering
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• v.6 no.1
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• pp.52-57
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• 1997

Dynamic characteristics of compressible flow fields in super-circled constricted tube have been studied numerically. By applying MacCormack's explicit scheme, time marching method with predictor/corrector step, Euler equation is solved to find characteristics of fluid flow in a constricted tube where a two-dimensional inviscid compressible flow is assumed. The effects of tube diameter and aspect ratios on the pressure variations are discussed extensively. The results of the developed numerical schemes are compared with those of commercial FLUENT code, and show a good agreement.

• Tuberculosis and Respiratory Diseases
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• v.39 no.2
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• pp.141-149
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• 1992

In order to establish predicted normal values of volume of isoflow($V_{iso}\dot{V}$), $V_{iso}\dot{V}$ were measured in a total 234 healthy adults, consisting of 78 male nonsmokers, 108 male smokers and 48 female nonsmokers. The volumes of isoflow were determined through analysis of maximal expiratory flow volume curves recorded with a mixture of 80% helium and 20% oxygen(He-$O_2$ gas) following one(1VC) and three vital capacity(3VC) maneuver and with room air. Based upon the correlation of the observed values of the parameters to age and physical characteristics, the following regression formulars for the prediction of the parameters, using age in year(A) as a variable, were obtained. 1VC method ($V_{iso}\dot{V}_1$) Male smoker : 0.614A+2.347 Male nonsmoker : 0.370A-2.792 Female nonsmoker : 0.588A-2.459 3VC method ($V_{iso}\dot{V}_3$) Male smoker : 0.467A+1.696 Male nonsmoker : 0.288A-1.538 Female nonsmoker : 0.367A-0.114.

• Journal of the Korean Institute of Intelligent Systems
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• v.10 no.6
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• pp.575-583
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• 2000

본 논문에서 임의의 데이터가 입력되면 기준 영상 중에서 가장 유사도가 큰 영상을 찾아 국부 승리자로 선택하고, 그 국부 승리자 중에서 전체 승리자를 선택하여 최종 출력값을 얻는 계층적 FGNN(Fuzzy Genetic Neural Network)을 제안하고, 이에 하이브리드 퍼지 소속함수와 유전자 알고리즘을 적용하였다. 하이브리드 퍼지 소속함수는 입력 값을 0~1 사이의 값으로 함으로써 시스템의 속도를 빠르게 하고 유전자 알고리즘을 입력값을 일정한 오차 이내로 하여 최적의 영상을 얻도록 하였다. 위의 계층적 FGNN 알고리즘을 회로 설계 및 검증하였다. 또한 제안한 FGNN을 이용하여 영상에 포함된 잡음을 제거하고, 이와 유사한 구조를 가진 FDNN(Fuzzy Decision Neural Network) 성능보다 FGNN의 성능이 우수함을 여러 가지 영상을 통하여 확인하였다. 또한 모의 실험 결과 영상에 대한 평균자승오차(MSE : Mean Square Error)를 비교하였으며, 그 결과 하이브리드 퍼지 함수와 유전자 알고리즘을 적용한 FGNN이 메디안 필터, OC, CO, FDNN 등에 비해 우수함을 확인하였다. FGNN 알고리즘을 Top-Down 방식으로 VHDL(VHSIC Hardware description Language)을 이용하여 코딩(Coding)하고, Synopsys 툴을 이용하여 하드웨어를 설계하였다. 이 알고리즘의 하드웨어는 총 5개의 블록으로 가지고 있고 각각의 블록은 파이프라인 형태로 구성하고, 이는 Synopsys 툴을 이용하여 동작 및 성능을 검증하였다.

• Journal of Labour Economics
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• v.42 no.3
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• pp.75-98
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• 2019

This paper examines the impact of on-the-job training (OJT) programs on turnover rates and employment status in the labor market. Exploiting the administrative data (the Employment Insurance Database), we apply the propensity score matching method to investigate 1) whether OJT participation increases the probability of remaining in the labor market after the job training, and 2) whether trainees are more likely to transition to a new employer. Our findings reveal positive effects of OJT on the continuous employment (2.4~5.3%p). We also observe that trainees show lower rates of turnover for some part of the study period, from 2008 to 2015.

• 한국사회정책
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• v.25 no.1
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• pp.99-123
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• 2018

Purpose: This study empirically investigates the utilization and expenditure of health care and long-term care at the last year of life for long-term care beneficiaries in Korea. Methods: This study used National Health Insurance and Long-term Care Insurance claims data of 271,474 LTCI beneficiaries, who died from July 2008 to December 2012. Their cause of death, place of death, health care costs, and the provision of aggressive care were analyzed. Results: Cardio-vascular disease(29.8%) and cancer(15.3%) were reported as their major cause of death, and hospital(64.4%), home(22.0%), social care facility(9.2%) were analyzed as the place of death. 99.3% of subjects used both health care and long-term care during the last 1 year of life. The average survival period were 516.2 days after they were LTCI beneficiaries. The health care expenditure gradually increased near the death, and the last month were three times more rather than the first month. Furthermore, 31.8% experienced some aggressive cares(CPR, blood transfusion, hemo-dialysis, etc.) at the last month of life. Conclusion: The results of this study suggest that it is important to develop the end of life care policies(for example, hospice, advanced care directives) for the LTCI beneficiaries. They might contribute to the improvement of quality of life and the reduction of health care expenditure of the elderly at the end-of-life.

• Information Systems Review
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• v.9 no.1
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• pp.67-84
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• 2007

In diffusing an information systems(IS), the provider of the IS can be more effective if they can identify user groups who can adopt the system early. By focusing on the user groups, system providers can encourage them to adopt the IS. After the early adopters adopt an IS, the diffusion of the system to other groups can be easier by early adopters' voluntary advertisement and help in adopting the IS. Instead of discrete choice methods which are usually used for this purpose, we suggest a decision tree method. Compared to discrete choice methods, this method is more accurate for prediction and can easily identify non-linear segments of groups. By testing the data of adopters of an IS in agricultural business, we show the excellence of this method in identifying target groups to focus on. This method would help system providers to diffuse their systems by starting from early adopters.

• Journal of the Korean Society of Radiology
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• v.12 no.5
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• pp.623-630
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• 2018

Non-alcoholic fatty liver disease is the most common cause of chronic liver diseases. This study was to characterize early hepatic lipid changes in fatty liver rat model by in vivo short-echo time(TE) $^1H$-MRS(Proton - Magnetic Resonance Spectroscopy). Each the examinations were measured from liver parenchyma in rats at 0, 2, 4, 6, 8 weeks followed by high fat diet, respectively. Significant increase in lipid signals. 0.9, 1.3, 2.3, 2.8, and 5.3 ppm was found in animals with 2 weeks(p<0.01). Therefore, $^1H$-MRS is useful in detecting and characterizing various hepatic lipid alterations as early as 2 weeks for the start high fat diet.

• The Journal of Korean Institute for Practical Engineering Education
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• v.3 no.1
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• pp.200-205
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• 2011

This research is first to analyze an electomygram reaction of the lower limbs among the muscles used during a back-round kicking of Taekwondo, second to analyze the relationship between the muscles of the kicking limb and those of the supporting limb, third to compare EMG activity of expert with novice. Measured muscles are as follows; rectus fermoris which control flexion and stretching of femora and knee joints, vastus medialis and vastus lateralis, which control flexion and stretching of legs, and biceps fermoris, which control stretching of femora, bending of knee joints and abduction of the crus. The electomygram reaction of all these selected muscles were analyzed. Three kicks were performed, and electomygram of each of kicks were measured. Then, electomygram reaction of the best kick was used for electomygram analysis.

• Proceedings of the KAIS Fall Conference
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• 2004.06a
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• pp.315-318
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• 2004

This study was designed to investigate the cytotoxic effect of Cephaxus koreana on human breast cancer cell lines (SCC-1395 and SK-BR-3) us ins MTT(3- [4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay. RPMII -1640 medium with $10\%$ FBS and $1\%$ of penicillin-streptomycin was used. The ethanol extrart of Cephaxus koreana after adsoption resin treatment showed higher anticancer activity against SCC- 1395 than the ethanol extract of Cephaxus koreana without adsoption resin treatment. SK-BR-3 showed higher sensitivity activity than SCC-1395 at the same concentration of 20000 ppm.