• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.37 no.6
• /
• pp.586-594
• /
• 2009

This paper is the study on random, sinusoidal and shock vibration responses for the STSAT-3(science and technology satellite-3) proto-model which is the first small size all-composite satellite in Korea. The structure system of the STSAT-3 forms box type structure by joining several hybrid sandwich panels comprised of honeycomb core and carbon fiber reinforced laminated composite skins on both side. Mode shape, stress, displacement and acceleration responses are obtained on both the frequency domain and time domain by means of a commercial FEA software MSC/NASTRAN. From these analysis results, failure, safety factor and design validity are assessed. These results can be successfully applicable as reference data when a new satellite is developed as well as giving out an excellent criteria in satellite vibration treatment design.

• Korean Journal of Culture and Arts Education Studies
• /
• v.6 no.3
• /
• pp.21-37
• /
• 2011

The purpose of this study was to discuss the cultural competency model which can be applied for all the fields in one's life and to develop the cultural competency of media part for school education, lifelong education, and corporate education. To achieve this purpose, the cultural competency model of media part was developed through literature review, panel workshop with high-performers of media part, and experts verification. In the result of this study, core performance of media part was identified. They were improvement of work efficiency, possibility of creative design, change of media context, increase of understanding and participation to social culture, improvement of relationship skill, increase of chance of self-examination, and self-satisfaction. It was 62 that The cultural competencies which were needed to achieve these core performance, then, finally the definition and standard of behaviors of each competencies were drawn and the cultural competency model was proposed.

• Journal of KIBIM
• /
• v.12 no.4
• /
• pp.19-31
• /
• 2022

With the development of 3D-based CAD (Computer Aided Design), attempts at freeform building design have expanded to small and medium-sized buildings in Korea. However, a standardized system for continuous utilization of shape data and BIM conversion process implemented with 3D-based NURBS is still immature. Without accurate review and management throughout the Freeform building project, interference between members occurs and the cost of the project increases. This is very detrimental to the project. To solve this problem, we proposed a continuous utilization process of 3D shape information based on BIM parameters. Our process includes algorithms such as Auto Split, Panel Optimization, Excel extraction based on shape information, BIM modeling through Adaptive Component, and BIM model utilization method using ID Code. The optimal cutting reference point was calculated and the optimal material specification was derived using the Panel Optimization algorithm. With the Adaptive Component design methodology, a BIM model conforming to the standard cross-section details and specifications was uniformly established. The automatic BIM conversion algorithm of shape data through Excel extraction created a BIM model without omission of data based on the optimized panel cutting reference point and cutting line. Finally, we analyzed how to use the BIM model built for automatic conversion. As a result of the analysis, in addition to the BIM utilization plan in the general construction stage such as visualization, interference review, quantity calculation, and construction simulation, an individual management plan for the unit panel was derived through ID data input. This study suggested an improvement process by linking the existing research on atypical panel optimization and the study of parameter-based BIM information management method. And it showed that it can solve the problems of existing Freeform building project.

• Korean Journal of Social Welfare Studies
• /
• v.42 no.3
• /
• pp.33-56
• /
• 2011

The purpose of this study is to investigate the effect of grandparenting on the grandparent's level of depression. In addition, it is to test the mediating effect of social support and the moderating effect of household type on the relationships between variables. The 555 grandparent sample in this study was from the Korean Longitudinal Study of Aging(KLoSA). The findings indicated that grandparenting(grandparenting time per day and total weeks of grandparenting per year) was significantly related to the grandparent's level of depression. In addition, the grandparent's age was also associated with grandparenting, grandparent's depression, and social support. Grandparent's health condition and marital status was associated with social support. Grandparent's gender had a significant relationship with grandparent's depression and grandparenting time per day. Social support had a direct effect to the grandparent's depression; however, it was not a statistically significant mediator between grandparenting and grandparent's depression. In addition, household type was not a significant moderator of measuring the relationships among grandparenting, grandparent's depression, and social support. Implications for social work practice were discussed based on the result of the study.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.20 no.4
• /
• pp.46-51
• /
• 2012

Injection pressure, an important factor in filling process, should be minimized to enhance injection molding quality. Injection pressure can be controlled by valve gate open timing. In this work, we decided the valve gate open timing to minimize the injection pressure. To solve this design problem, we integrated MAPS-3D (Mold Analysis and Plastic Solution-3Dimension), a commercial injection molding CAE tool, to PIAnO (Process Integration, Automation and Optimization), a commercial PIDO (Process Integration, and Design Optimization) tool using the file parsing method. In order to reduce computational cost, we performed an approximate optimization using meta-models that replaced expensive computer simulations. At first, we carried out DOE (Design of Experiments) using OLHD (Optimal Latin Hypercube Design) available in PIAnO. Then, we built Kriging models using the simulation results at the sampling points. Finally, we used micro GA (Genetic Algorithm) available in PIAnO. Using the proposed design approach, the injection pressure has been reduced by 13.7% compared to the initial one. This design result clearly shows the validity of the proposed design approach.

• Journal of the Korean Society of Child Welfare
• /
• no.59
• /
• pp.183-208
• /
• 2017

The purpose of this study was to identify groups depending on the change trajectory of child maltreatment in childhood and early adolescence. For this study, the data from waves two through six (2011-2015) of the Korean Children and Youth Panel Survey (KCYPS) were used. Participants included first-grade (n=2,300) and fourth-grade (n=2,325) elementary school students. A latent class growth model (LCGM) using Mplus 7.21 was adopted to classify the types of developmental trajectories of child maltreatment. The main results were as follows: First, in physical abuse, childhood from the second to the sixth grades was classified into four groups: decreased, low maintenance, increased, and no maltreatment type. In addition, early adolescence from the fifth grade of elementary school to the third grade of middle school was also classified into the same types. Second, in emotional abuse, childhood was classified into three groups: decreased, increased, and no maltreatment type. Early adolescence was classified into four groups: decreased, low maintenance, increased, and no maltreatment type. Third, in neglect, childhood was classified into four groups: maintenance, low decreasing, low increasing, and no maltreatment type. Early adolescence was classified into three groups: maintenance, low increasing, and no maltreatment type. According to the change of child maltreatment by developmental period, physical abuse continued from childhood to early adolescence, whereas emotional abuse and neglect increased in early adolescence compared to childhood. This study is meaningful in classifying latent classes depending on maltreatment types. Theoretical and practical implications were suggested based on the study results.

• 한국벤처창업학회:학술대회논문집
• /
• 2018.11a
• /
• pp.57-61
• /
• 2018

4차 산업혁명 시대에 접어 들어 불확실성이 높아지고 변동성의 상시화로 세계 경제가 급변하면서, 기업가정신 교육의 중요성은 점점 더 높아지고 있다. 이러한 시대의 흐름에 따라 최근 청소년 기업가정신 교육이 확산되었다. 지속가능한 청소년 기업가정신 교육이 이루어지기 위해서는 시대의 변화와 함께 부모들의 인식과 태도도 함께 변화해야 한다. 부모는 새로운 지식과 그 시대가 요구하는 바람직한 자녀관을 형성해야 하며, 사회 전반적인 변화에 따른 학교에서의 기업가정신 교육이 가정에서도 일관성 있게 유지되어야 한다. 이에 본 연구는 부모교육의 중요성을 확인하고, 교육을 통해 부모의 인식을 변화시키기 위해 필요한 역량 도출하기 위해 델파이 조사를 실시하였다. 기업가정신 교육 전문가와 청소년 교육 전문가로 구성된 전문가 패널들을 대상으로 3회에 걸쳐 델파이 조사를 실시하였다. 델파이 조사 분석 결과, 부모 인식 전환을 위해 필요한 최종 8가지 역량(환경의 변화, 도전정신, 주체성/자울성, 창업에 대한 이해, 직업의 다양성, 기업가정신에 대한 이해, 개인의 다양성, 팀/협업에 대한 가치)을 도출하였다. 향후 후속 연구를 통해 도출된 역량을 함양할 수 있는 부모 기업가정신 교육 모델 및 프로그램을 설계하고자 한다.

• The Journal of the Korea Contents Association
• /
• v.22 no.3
• /
• pp.354-360
• /
• 2022

Metabolic disease is a disease with a prevalence of 26% in Korean, and has three of the five states of abdominal obesity, hypertension, hunger glycemic disorder, high neutral fat, and low HDL cholesterol at the same time. This paper links the consumer panel data of the Rural Development Agency(RDA) and the medical care data of the National Health Insurance Service(NHIS) to generate a classification model that can be divided into a metabolic disease group and a control group through food consumption characteristics, and attempts to compare the differences. Many existing domestic and foreign studies related to metabolic diseases and food consumption characteristics are disease correlation studies of specific food groups and specific ingredients, and this paper is logistic considering all food groups included in the general diet. We created a classification model using regression, a decision tree-based classification model, and a classification model using XGBoost. Of the three models, the high-precision model is the XGBoost classification model, but the accuracy was not high at less than 0.7. As a future study, it is necessary to extend the observation period for food consumption in the patient group to more than 5 years and to study the metabolic disease classification model after converting the food consumed into nutritional characteristics.

• Korean Journal of Remote Sensing
• /
• v.39 no.6_3
• /
• pp.1693-1705
• /
• 2023

Rural areas, which account for about 90% of the country's land area, are increasing in importance and value as a space that performs various public functions. However, facilities that adversely affect residents' lives, such as livestock facilities, factories, and solar panels, are being built indiscriminately near residential areas, damaging the rural environment and landscape and lowering the quality of residents' lives. In order to prevent disorderly development in rural areas and manage rural space in a planned manner, detection and monitoring of hazardous facilities in rural areas is necessary. Data can be acquired through satellite imagery, which can be acquired periodically and provide information on the entire region. Effective detection is possible by utilizing image-based deep learning techniques using convolutional neural networks. Therefore, U-Net model, which shows high performance in semantic segmentation, was used to classify potentially hazardous facilities in rural areas. In this study, KOMPSAT ortho-mosaic optical imagery provided by the Korea Aerospace Research Institute in 2020 with a spatial resolution of 0.7 meters was used, and AI training data for livestock facilities, factories, and solar panels were produced by hand for training and inference. After training with U-Net, pixel accuracy of 0.9739 and mean Intersection over Union (mIoU) of 0.7025 were achieved. The results of this study can be used for monitoring hazardous facilities in rural areas and are expected to be used as basis for rural planning.

• Journal of the Society of Naval Architects of Korea
• /
• v.28 no.1
• /
• pp.12-18
• /
• 1991

Three-dimensional nonlinear sloshing effects due to tank motions are simulated by solving boundary value problem using the panel method based on boundary integral technique. While Shinkai used boundary elements on which source strengths vary linearly between nodes, the source of constant strength is distributed on each triangular panel in the present study. The source strength at each time step is determined by solving the Fredholm integral equation of the second kind obtained from Green's theorem. To avoid cumulative numerical errors as time elapses, Adam-Bashforth-Moulton method is employed. Numerical examples for the case of partially filled spherical tank on board oscillating in harmonic sway mode or pitch mode are solved. The elevation of the free surface is compared with the result by Shinkai and confirmed in good agreement during early time. The input and the output energy are comparatively evaluated to check the overall accuracy of the present numerical scheme. Although some leakage of energy are found as time marches, it is plausible when we take into account nonlinearities of the problem and the number of panels of the model.