• Structural Engineering and Mechanics
• /
• 제51권6호
• /
• pp.989-1003
• /
• 2014

In the preliminary design stage of an RC 3D-frame, repeated sequential analyses to determine optimal members' sizes and the investigation of the parameters required to minimize the differential column shortening are computational effort consuming, especially when considering various types of loads such as dead load, temperature action, time dependent effects, construction and live loads. Because the desired accuracy at this stage does not justify such luxury, two backpropagation feedforward artificial neural networks have been proposed in order to approximate this information. Instead of using a commercial software package, many references providing advanced principles have been considered to code a program and generate these neural networks. The first one predicts the typical amount of time between two phases, needed to achieve the minimum maximorum differential column shortening. The other network aims to prognosticate sequential analysis results from those of the simultaneous analysis. After the training stages, testing procedures have been carried out in order to ensure the generalization ability of these respective systems. Numerical cases are studied in order to find out how good these ANN match with the sequential finite element analysis. Comparison reveals an acceptable fit, enabling these systems to be safely used in the preliminary design stage.

• 항공우주기술
• /
• 제10권2호
• /
• pp.94-100
• /
• 2011

본 논문에서는 고성능 저궤도 지구관측위성의 예비연성하중 해석결과에 대하여 평가한다. 연성하중해석을 수행하기 위하여 위성체 모델을 Craig-Bampton 모델로 축약한 후 발사체 개발업체로 제공하였다. 제공된 Craig-Bampton 모델은 인공위성의 질량행렬, 강성행렬, 가속도변환행렬 및 변위변환행렬이다. 발사체 개발업체에서는 위성체 Craig-Bampton 모델과 발사체 모델을 결합하여 연성하중해석을 수행한 후 그 결과를 제공하였다. 제공받은 연성하중해석 결과를 바탕으로 발사시 위성체가 구조적으로 이상이 없는지를 평가하였다. 평가결과 위성체는 발사하중하에서 안전함을 확인할 수 있었다.

• International journal of advanced smart convergence
• /
• 제11권4호
• /
• pp.104-119
• /
• 2022

Life safety awareness level diagnosis is necessary for customized safety education and continuous safety awareness. As the starting stage of safety education for each life cycle, a scale that has verified the reliability and validity of high school students' life safety awareness has not yet been developed. In this context, the purpose of this study is to develop and validate the life safety awareness scale of high school students and to analyze interindividual differences. Questionnaire data was collected from April to June 2022 from 834 students in the first, second, and third grades of high schools in △△ city in Jeollabuk-do. A final 25-item scale was developed using the preliminary survey, preliminary test, the main test, descriptive statistical analysis, and exploratory and confirmatory factor analysis. This scale consists of four sub-factors: 'safety prevention', 'safety knowledge', 'safety preparation', and 'safety protection'. Good reliability and validity were verified by analysis of content validity and construct validity. The generalizability of the scale was verified by crossover validation between the search group and the crossover group. Based on the interindividual differences analysis, although there was a difference between genders in life safety awareness, there was no difference by grade level and academic achievement. This study is significant in developing the first valid scale that can measure high school students' life safety awareness and providing the necessity and rationale for life safety education by life cycle considering individual gender differences.

• 한국산학기술학회논문지
• /
• 제18권11호
• /
• pp.445-453
• /
• 2017

최근 정부 R&D 방향을 보면 정부출연연의 역할은 중장기, 대규모 신규사업발굴에 초점을 두고 있으며 출연연 자체적으로 연구기획에 많은 투자와 노력을 하고 있다. 하지만, 출연연 주요사업 연구기획에 철저한 준비가 되어야 함에도 기획 전문지식이 체계적으로 축적되지 않았으며 좋은 연구기획 본보기에 대한 요구가 지속적으로 이어져왔다. 이에 본 연구에서는 심도 있는 사전 검토 절차를 거치는 국가연구개발 예비타당성조사 사업 보고서를 본보기로 제안하고자 한다. 이를 위해 예비타당성조사의 계층구조와 세부평가항목을 고찰하고 주요사업 기획에 도움이 되는 세부평가항목들과 내용을 선별하고자 한다. 우선 현재 공개된 예비타당성조사 보고서 중에서 연구에 해당하는 대상을 선별하고, 보고서의 평가항목들 중에서 메타분석을 통해 출연연 주요사업 기획에 반영될 수 있는 12개 평가항목들을 선별하였다. 아울러, 전문가 회의를 거쳐 분석된 내용들에서 각 세부평가항목별 주요사업 기획관련 시사점을 도출하였다. 본 연구를 통해 주요사업 기획 연구자들에게 실무적으로 R&D 연구기획과 평가 향상에 기여할 것이라 기대한다.

• Journal of Astronomy and Space Sciences
• /
• 제29권3호
• /
• pp.275-285
• /
• 2012

In this study, we present preliminary results of precise orbit determination (POD) using satellite laser ranging (SLR) observations for International Laser Ranging Service (ILRS) Associate Analysis Center (AAC). Using SLR normal point observations of LAGEOS-1, LAGEOS-2, ETALON-1, and ETALON-2, the NASA/GSFC GEODYN II software are utilized for POD. Weekly-based orbit determination strategy is applied to process SLR observations and the post-fit residuals check, and external orbit comparison are performed for orbit accuracy assessment. The root mean square (RMS) value of differences between observations and computations after final iteration of estimation process is used for post-fit residuals check. The result of ILRS consolidated prediction format (CPF) is used for external orbit comparison. Additionally, we performed the precision analysis of each ILRS station by post-fit residuals. The post-fit residuals results show that the precisions of the orbits of LAGEOS-1 and LAGEOS-2 are 0.9 and 1.3 cm, and those of ETALON-1 and ETALON-2 are 2.5 and 1.9 cm, respectively. The orbit assessment results by ILRS CPF show that the radial accuracies of LAGEOS-1 and LAGEOS-2 are 4.0 cm and 5.3 cm, and the radial accuracies of ETALON-1 and ETALON-2 are 30.7 cm and 7.2 cm. These results of station precision analysis confirm that the result of this study is reasonable to have implications as preliminary results for administrating ILRS AAC.

• 한국철도학회논문집
• /
• 제10권6호
• /
• pp.766-771
• /
• 2007

본 연구에서는 도시내 보조간선도로의 역할을 하고 있는 도시철도의 운영비용을 추정할 수 있는 함수를 개발하고자 하였다. 이를 위하여 서울 지하철 1호선$\sim$8호선의 운행실적을 바탕으로 운영비용에 영향을 줄 수 있는 23개의 변수들을 추출하여 최종변수간의 인과관계 분석을 위한 회귀분석(Regression)을 활용하였다. 분석결과 총 6개의 최종변수가 선정되었으며 그 중 도시철도 운영비용함수를 설명하는 변수는 전동차보유량, 차량소유_첨두 및 역수인 것으로 나타났다. 연구 결과 도시철도의 투자우선순위나 정책 격정과정에 큰 기여를 할 수 있을 것으로 기대된다.

• 한국학교ㆍ지역보건교육학회지
• /
• 제7권
• /
• pp.1-17
• /
• 2006

Background: School is a primary health education setting for adolescents and the continuous support should be provided to renew school health education curriculum correspondent to cultural changes in Korean society. Objectives: This study was conducted to identify the principals and teachers' health education needs for their students and to analyze their conceptual map for health education curriculum at school. Methods: The sample size of the preliminary study was 321 of the teachers in elementary, middle, and high school, and that of the main study was 355 middle school principals and teachers over the country. The self-administered mailing survey was conducted to collect the available health education topics in the preliminary study, to identify the factor structure of the health education topics and to analyze the conceptual properties on health education with exploratory factor analysis and multidimensional scaling analysis in SPSS 12.0. Results: A total of 21 health education topics were collected from the preliminary survey and 31 topics were, comprehensively, generated for the main survey. In exploratory factor analysis, seven factors were generated in 1.0 or greater Eigen value standard. The seven factors were 'life health promotion,' 'disease prevention and drug control,' 'bulling and aggression prevention,' 'injury and sexual harassment prevention,' human-efficacy and regulation,' 'health protection for adolescence,' and 'alcohol and tobacco control.' The educational need scores were the highest in 'human-efficacy and regulation' and 'injury and sexual harassment prevention.' The two-dimensional cooperates were generated for the 31 health education topics and the two dimensional properties which divided the conceptual space were 'health-safety' for one and 'public/environmental-individual/personal' for the other. That is, middle school principals and teachers primarily, understand the health education curriculum in the sense of 'health vs. safety' and 'public/environmental vs individual/personal.' Conclusions: Health education curriculum and textbook should be developed based on teachers' needs and conditions for health education in school fields. The field-based health education programs or textbook would make more possible problem-solving health education for youth in real school fields.

• 농촌계획
• /
• 제24권3호
• /
• pp.117-125
• /
• 2018

After it was reorganized as the rural center revitalization project recently, there is an opinion that the nature of the project was changed to solve long-time aspired projects of some districts unlike various projects according to the previous project purposes. Therefore, this study analyzes the current status of revitalization project plans and operation monitoring to make rural center villages, establishes plans that can be applied to the rural center village revitalization project and suggests the improvement plans for monitoring. With the necessity of connectivity with centrality analysis for long-term and sustainable growth of the rural center revitalization project, the analysis on the 8 districts' centrality analysis and the function of the master plan were compared and analyzed, but there is not enough interrelation. Regarding the consulting methods for weak districts to activate facility operation after the project is implemented, the field consulting performed by the collaboration of Gyeongsangnam-do government, Gyeongnam Rural Revitalization Support Center and Gyeongnam branch of Korea Rural Community Corporation shows 87.6% of satisfaction level, which indicates it is the most effective. Based on the above results, it is necessary to reinforce the methods on resident demand survey, dimension and the reflection process of the project when preliminary plans are established for effective implementation of the rural center village revitalization project. It is also necessary to revise relevant standards not to change preliminary plans excessively during the master plan establishment process, and to oblige preliminary investigation of experts. The joint monitoring and consulting systems of experts and local governments should be applied from the establishment stage of the master plan, so that it can be sustainable rural center village revitalization project.

• 자원리싸이클링
• /
• 제29권2호
• /
• pp.48-54
• /
• 2020

우리나라는 제조업 중심 국가로서 다양한 분야에 많은 양의 금속이 사용되나, 이들 금속이 대부분 수입에 의존하고 있다. 상당수의 금속은 전세계적으로 제한된 부존량 및 생산량에 비해 소비량이 증가하는 실정이다. 어떤 금속들은 부존 및 생산국가가 편재되어 있는 경우가 종종 있어 향후 공급의 불안정성이 우려된다. 또한 이러한 금속이 유해성을 띄고 있을 경우 환경적 측면에서도 문제가 된다. 이를 해결하기 위해 사업장 폐기물내 유해성 유가금속 회수 및 재활용을 통해 공급을 안정화시키고 환경오염을 예방할 수 있으나, 유가 금속의 종류 및 국내 배출업체와 배출폐기물 종류가 매우 많아 초기에 관련 현황파악이 번거롭다. 따라서, 본 연구에서는 공공기관 공개자료를 통해 향후 국내산업에 중요한 유해성 유가금속 선정결과를 소개하고, 국내 화학물질 배출·이동량 정보 등을 이용하여 이러한 금속(니켈, 코발트, 망간 등)를 함유 폐기물을 배출하는 업체들을 보다 용이하게 초기 현황파악 하는 방안을 순서도 형식으로 제시하였다.

• 한국지진공학회논문집
• /
• 제6권4호
• /
• pp.1-6
• /
• 2002

일반설계에서 요구하는 구조물의 안전성은 탄성영역에서 일정수준의 안전계수를 확보하여 만족된다. 그러나 내진설계에서의 안전성은 소성영역에서 구조물의 형상에 따라 특정한 연성파괴메카니즘을 유도하여 확보하도록 요구하고 있다. 그러므로 이러한 안전성은 구조물의 기본설계단계에서 여러 개의 대안을 가지고 비교, 검토를 수행하여 확보되어야 하며 실시설계단계에서 이를 확인하는 작업이 이루어져야 한다. 이 연구에서는 일반도로교량을 대상으로 하여 기본설계와 실시설계에 사용하는 모델을 설정하였으며 양 모델의 동적거동특성인 주기와 모드형상을 비교하고 다중모드스펙트럼해석을 적용하여 파괴메카니즘을 규명하였다. 기본설계와 실시설계에 사용하는 모델로 각각 확인한 파괴메카니즘을 비교하여 기본설계모델의 타당성을 입증하고 실무에 적용할 수 있는 내진해석모델로 제시하였다.