기술 교육에 있어서 학습 장소에 따른 교수 방법의 효율성에 관한 이론적 고찰

권현진,류창열 충남대학교 공업교육연구소 2000 論文集 Vol.23 No.1

This study is to find the effective ways of achieving learning goals by applying appropriate teaching methods in various learning conditions. The study areas are as follows: 1. surveying various characteristics in accordance to the learning places which affect teaching methods, 2. investigating teaching methods suitable to the industrial education and workplaces, 3. researching the teaching method of the school in detail. This study is adopted literature review and analytic research in order to obtain the object. The major findings of this study are as follows: 1. The learning place can be divided into the workplace and school because of the characteristic of technology education. We should try to use these places effectively. 2. In the workplace, several teaching methods like as work observation, general work experience program, work-study, cooperative education system, internship are applied to general education and vocational education 3. Teaching methods of school are classified with the specific property of learning contents, the learning purpose, the ability of student and so on.

Stacking Ensemble Technique for Classifying Breast Cancer

권현진,박진혁,이영호 대한의료정보학회 2019 Healthcare Informatics Research Vol.25 No.4

Objectives: Breast cancer is the second most common cancer among Korean women. Because breast cancer is strongly associated with negative emotional and physical changes, early detection and treatment of breast cancer are very important. As a supporting tool for classifying breast cancer, we tried to identify the best meta-learner model in a stacking ensemble when the same machine learning models for the base learner and meta-learner are used. Methods: We used machine learning models, such as the gradient boosted model, distributed random forest, generalized linear model, and deep neural network in a stacking ensemble. These models were used to construct a base learner, and each of them was used as a meta-learner again. Then, we compared the performance of machine learning models in the meta-learner to determine the best meta-learner model in the stacking ensemble. Results: Experimental results showed that using the GBM as a meta-learner led to higher accuracy than that achieved with any other model for breast cancer data and using the GLM as a meta learner led to low root-meansquared error for both sets of breast cancer data. Conclusions: We compared the performance of every meta-learner model in a stacking ensemble as a supporting tool for classifying breast cancer. The study showed that using specific models as a metalearner resulted in better performance than single classifiers, and using GBM and GLM as a meta-learner is appropriate as a supporting tool for classifying breast cancer data.

Encapsulation of Peroxide Initiator in a Polyurea Shell: Its Characteristics and Effect on MMA Polymerization Kinetics

권현진,이은주,김미래,천강호,박희정,이기윤 한국고분자학회 2019 Macromolecular Research Vol.27 No.2

Microcapsule with polyurea shell was prepared from oil-in-water (O/W) emulsion under various agitation speeds (230, 500, and 700 rpm) to encapsulate cumene hydroperoxide (CHP) and tert-butyl peroxy-2-ethyl hexanoate (TBPEH). Thus prepared microcapsule size and shell contents were observed to be decreased as the agitation speed increased. Differential scanning calorimetry (DSC) was used to measure and compare the effect on the reaction kinetics of the methyl methacrylate (MMA) radical polymerization in the presence of various initiators. When encapsulated initiator was used instead of unencapsulated initiator the maximum conversion and maximum reaction rate were decreased and the reaction temperature was delayed. The delay in reaction temperature was lager as the agitation speed decreased. In the case of encapsulated CHP at 230, 500, 700 rpm, the temperature at the maximum reaction rate was delayed by 5.8, 3.0, and 0.4 °C, respectively, compared to unencapsulated CHP.

국제금융위기 전·후 가계부채와 수도권 주택매매시장의 구조적 변화

권현진,유정석 국토연구원 2014 국토연구 Vol.81 No.-

There has been an ongoing debate on easing LTV and DTI in order to activate the metropolitan housing markets. Is deregulation a proper remedy to boost the housing market, or does it destabilize the household’s financial structure? In this study, we measure the systematic size of household debt with the ratio of household debt to GDP and use the panel GMM model to analyze how our household debt size proxy and other debt financing variables affect the housing market. Our findings indicate that an increase in household debt has a negative relationship with housing price after the Global Financial Crisis. However, the increase in the systematic size of household debt has a positive impact on market liquidity. Meanwhile, M1 and other interest rates have an insignificant relation with the housing market. Our findings suggest that the Korean government should have a comprehensive and thorough review over its credit risk management plan and mortgage loan regulations. 최근 수도권 주택매매시장 활성화 대책의 일환으로 대출 규제완화를 통한 매매수요의 확충이 꾸준히 논의 중이다. 이에 본 논문에서는 가계대출액 대비 국내총생산의 비율을 ‘가계부채의 구조적 크기’로 규정하고, 관련 시계열변수를 포함하여 수도권 주택시장과의 영향을 패널 GMM 모형으로 분석하였다. 분석 결과 국제금융위기 이전에는 가계부채에 대한 시장의 부담이 주택가격의 상승으로 상쇄되었다면, 위기 이후에는 차입금융의 증가에도 가격하락세가 지속되었다. 그러나 주택매매시장의 유동성 측면에서는 다소 도움이 되었다. 이와 달리 유동자금의 증대와 대출금리 인하로 인한 효과는 미미하였다. 그러므로 정부는 대출규제와 가계 부문의 신용 위험 증대에 대한 위험관리방안을 종합적으로 고려하여 시장활성화방안을 제시해야 할 것이다.

친환경 건축물의 가치 및 향후 과제 : 원가법을 중심으로

권현진 한국부동산연구원 2023 부동산연구 Vol.33 No.3

As environmental pollution and climate change intensify, many buildings are increasingly adopting equipment and materials that affect their energy efficiency. However, there are insufficient tools, guidance materials, and studies for determining the value of green buildings. When comparing the cost of green buildings and eco-friendly certification systems, we must consider whether the certification system is viewed from a regulatory or a benefit perspective. This study is a foundational study for the appraisal of eco-friendly buildings. It focused on building energy efficiency certification among eco-friendly certification systems and the construction cost factors that affect the cost method from a regulatory standpoint. Accordingly, we conducted a theoretical review focusing on research data pertaining to the domestic and international construction costs of eco-friendly buildings, as well as appraisal standards and guidelines. Additionally, examples of construction costs were applied and compared to reflect the value of eco-friendly buildings from the perspective of cost method. It is necessary to differentiate between use value and capital premium when calculating reconstruction costs and facility prices. In addition, an expert council must discuss cases in which the certification validity period has expired.

Differential Scanning Calorimetry (DSC)를 이용한 유리섬유 Bisphenol-A(BPA)계 에폭시 프리프레그의 경화 반응 속도 연구

권현진,박희정,이은주,구상민,김선홍,이기윤 한국복합재료학회 2018 Composites research Vol.31 No.1

본 연구에서는 시차주사열량계(differential scanning calorimetry, DSC)를 이용하여 유리섬유로 보강된 BPA계 에폭시 프리프레그의 경화 거동을 확인하였다. 기지재로 사용된 에폭시 수지의 전체 발열량(ΔHtotal = 280.3 J/g)을 측정하기 위해 승온 실험을 하였다. 110~130oC 등온 조건에서 측정된 발열량을 통해 높은 온도 조건일수록 최대 전환율과 최대 반응 속도가 증가하는 것을 확인하였다. 또한, 에폭시 프리프레그의 자기 촉매 반응을 해석하기 위해 Kamal 방정식을 적용하였으며 높은 온도 조건에서 반응 속도 상수(k1, k2)가 큰 값으로 나타났다. 이때 얻어진 반응 속도 상수를 이용해 계산한 이론 추정치와 실험치를 비교한 결과 잘 부합하는 것을 확인하였다. 반응 초기에는 두 값이 유사하나 반응이 최종 단계에서는 반응 속도가 확산에 의해 결정되는 현상으로 인해 반응 속도의 실험치가 이론 추정치보다 더 작은 반응 속도 값을 가짐을 확인하였다. The curing behavior of glass fiber reinforced epoxy prepregs based on Bisphenol-A (BPA) was studied by differential scanning calorimetry (DSC). The total heat of reaction(ΔHtotal = 280.3 J/g) was determined based on the results of the dynamic heating scanning experiments. Isothermal experiments were carried out at 110~130°C, and it was observed that the maximum conversion and the maximum reaction rate were increased as temperature increased. Also Kamal equation was applied to analyze autocatalytic reaction of epoxy prepregs. The higher temperatures, the greater reaction rate constants (k1, k2). Theoretical values were calculated by these reaction rate constants and compared with experimental values. And it was confirmed that they were in reasonable agreement. At the beginning of the reaction, the experimental data and theoretical prediction were shown the same tendency, but at the end of reaction, the experimental data were smaller than theoretical predicted values due to reaction rates controlled by diffusion.

Morphological difference of symphysis according to various skeletal types using cone-beam computed tomography

권현진,전윤식,김민지 대한턱관절교합학회 2014 구강회복응용과학지 Vol.30 No.3

Purpose: The aim of this study was to investigate differences between the morphology of the mandibular symphysis and four facial skeletal types. Materials and Methods: 40 cone-beam computed tomographies were selected and classified in to 4 groupsaccording to their vertical and anterior-posterior skeletal patterns. The bone volume (mm3) of the symphysis, the cross sectional area corresponding to the 4 mandibular incisors’ axis: the cross sectional area of total bone (mm2), the area of the cancellous bone (mm2) and the thickness (mm) of labial and lingual alveolar bone at 2 mm, 3 mm under the cemento-enamel junction (CEJ) were measured. General linear model (GLM), Kruskal-Wallis test and Tukey honestly significant difference (HSD) test were subsequently used for statistical analysis. Results: The lingual cortical bone thickness of the lateral incisors at 2, 3 mm under CEJ was greater in the Class I low angle group than the other 3 groups (P < 0.05). There were no statistically significant differences in the volume of the mandibular incisor bony support, cross-sectional area of total bone and cancellous bone at the mandibular incisor’ axis. Conclusion: Patients in Class I, low angle group have a thicker lingual mandibular symphysis than Class I, high angle patients.

[장려상] 마을안의 학교 ; 학교안에 마을

권현진,고동희 한국교육시설학회 2015 교육시설디자인 공모전 Vol.2015 No.4

[장려상] 마을안의 학교;학교안의 마을

권현진,고동희 한국교육시설학회 2015 교육시설디자인 공모전 Vol.2015 No.1

SBR에서 폐수 주입 방법에 따른 질소제거 효율과 이때의 질산화/탈질 미생물 분포에 대한 연구

권현진,김동진 한국물환경학회 2006 공동 추계학술발표회 Vol.2006 No.-