• Smart Structures and Systems
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• 제30권6호
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• pp.557-569
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• 2022

Vibration-based structural health monitoring (SHM) is crucial for the dynamic maintenance of civil building structures to protect property security and the lives of the public. Analyzing these vibrations with modern artificial intelligence and deep learning (DL) methods is a new trend. This paper proposed an unsupervised deep learning method based on a convolutional autoencoder (CAE), which can overcome the limitations of conventional supervised deep learning. With the convolutional core applied to the DL network, the method can extract features self-adaptively and efficiently. The effectiveness of the method in detecting damage is then tested using a benchmark model. Thereafter, this method is used to detect damage and instant disaster events in a rubber bearing-isolated gymnasium structure. The results indicate that the method enables the CAE network to learn the intact vibrations, so as to distinguish between different damage states of the benchmark model, and the outcome meets the high-dimensional data distribution characteristics visualized by the t-SNE method. Besides, the CAE-based network trained with daily vibrations of the isolating layer in the gymnasium can precisely recover newly collected vibration and detect the occurrence of the ground motion. The proposed method is effective at identifying nonlinear variations in the dynamic responses and has the potential to be used for structural condition assessment and safety warning.

• 한국태양에너지학회 논문집
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• 제32권1호
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• pp.8-14
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• 2012

Concerning about global warming due to emission of greenhouse effect gas like C02 and depletion of fossil fuels have been spreading. So the need for solar energy utilization is increased. It is essentially important to make efforts to reduce usage of fossil energy resources. In this study, we analyzed the correlation between climatic elements and the photovoltaic power generation. Cloud cover of the correlation coefficient was 0.93. The order of the correlation coefficient was average temperatures, hours of sunshine duration of sunshine and the humidity. To accurately analyze of the degree of correlation for the photovoltaic power generation, additional research about climatic elements that show a high correlation is needed.

• Structural Monitoring and Maintenance
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• 제10권3호
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• pp.261-281
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• 2023

Magnetic flux sensors are commonly used in monitoring the cable force, but the application of the sensors in large diameter non-closed Galfan cables, as those adopted in Yueqing Gymnasium which is located in Yueqing City, Zhejiang Province, China and is the largest span hybrid space structure in the world, is seldom done in engineering. Based on the construction of Yueqing Gymnasium, this paper studies the cable tension monitoring using the magnetic flux method across two stages, namely, the pre-calibration stage before the cable leaves the rigging factory and the field tension formation stage of the cable system. In the pre-calibration stage in the cable factory, a series of 1:1 full-scale comparative tests were carried out to study the feasibility and relability of this kind of monitoring method, and the influence on the monitoring results of charging and discharging voltage, sensor location, cable diameter and fitting method were also studied. Some meaningful conclusions were obtained. On this basis, the real-time cable tension monitoring system of the structure based on the magnetic flux method is established. During the construction process, the monitoring results of the cables are in good agreement with the data of the on-site pressure gauge.The work of this paper will provide a useful reference for cable force monitoring in the construction process of long-span spatial structures.

• 한국과학교육학회지
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• 제39권2호
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• pp.233-248
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• 2019

본 연구는 칸톤학교 아라우가 19세기 전체에 걸쳐 독일의 김나지움 교육 이념 논쟁과 밀접한 관련이 있음을 보였다. 이 논쟁 속에서 아인슈타인이 바이에른에서 정규 과학교육의 혜택을 거의 받지 못했다는 점을 원전 자료 분석을 통해 입증했다. 아인슈타인은 정규교육의 결핍에도 불구하고 일찍부터 독학에 의해 자기 학습을 하는 습관을 가졌고, 이 방식은 평생 유지되었다. 그는 권위주의적이었던 뮌헨의 학교에서는 매우 힘들게 지냈지만, 자유정신과 자율성이 보장되었던 아라우의 민주적 학교에서는 정서적 안정감을 얻을 수 있었다. 아라우는 오랫동안 외지와 자유로운 교류와 프랑스 계몽주의 영향으로 종교적, 지역적, 민족적 차별이 없이 적대적 사상들에 대해 관대한 다문화적 사상을 갖고 있었다. 이로 인해 소규모 공립학교인 칸톤학교는 스위스를 넘어 교사와 학생의 막강한 인적 자원을 확보할 수 있었고, 교육이념 논쟁을 통해 시대정신에 맞는 실용주의와 계몽주의 사상을 선택했다. 이는 김나지움에서 인간교육-인문주의-엘리트 양성을 실시하고, 상공업학교에서는 시민교육-사실주의-시민 양성을 동시에 독립적으로 운영하는 체제로 정착된다. 특히 김나지움은 1835년부터 순수한 신인문주의를 벗어나 자연사와 같은 실물교과를 도입함으로써 양형주의를 선택하게 되었다. 이로써 칸톤학교는 참다운 인간성 교육, 철저한 학문적 교육, 생활 속에서 시민적 삶의 능력을 추구하는 학교가 되었으며, 아인슈타인은 여기서 진정한 민주주의가 실현되고 자신에게 잊을 수 없는 인상은 남긴 교육기관의 모범을 찾게 된다.

• 한국태양에너지학회 논문집
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• 제35권6호
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• pp.51-60
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• 2015

In statutes on the promotion of distribution of new and renewable energy, which were revised in 2014, daylight system and fuel cell were added in addition to existing new and renewable energy sources. This study, therefore, aimed at setting up targets for the introduction of daylight system and analyzing the installation rate of new and renewable energy which can be provided by daylight system for the aggressive use of daylight system, thereby deducting the optimal combination ratio with other new and renewable energy sources. The results of the study are as follows. First, when a prism-shaped daylight system was installed to a round indoor gymnasium among domestic indoor gymnasiums, out of a supply obligations allotment rate of 15% of new and renewable energy, the rate of daylight system was basically set at 2.5%. Second, therefore, with daylight system coming first, the lacked supply obligations rate was taken up by solar photovoltaic, solar heat and geothermal heat. In addition, using the KRESS Program, economic, technical, environmental and complexity evaluations for the upper 5% was made, deducting the optimal ratio of the system. The results produced the following optimal combination ratios: solar photovoltaic (83.3%) in economic evaluation, solar heat (8.3%) and geothermal heat (75%) in technical evaluation, solar photovoltaic (83.3%) in environmental evaluation, and solar photovoltaic (83.3%, the same as in economic evaluation) in complexity evaluation.

• 한국공간구조학회논문집
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• 제9권4호
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• pp.49-59
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• 2009

학교체육관과 같은 소규모 공간구조물의 지진응답은 본래 지진동에 대한 동적응답을 시각이력해석에 의해 검증해야 하지만 통상은 정적해석에 의해 평가하고 있다. 본 연구에서는 학교 체육관의 내진성능평가를 가능하게 하는 정적해석의 진행수순을 나타내기로 한다. 지진하중은 2개의 성능 레벨 즉, 일본의 건축기준법에 정의되어 있는 레벨 1과 2에 대응하는 등가인 정적하중으로 근사한다. 또한, 재하 패턴으로서 고유모드형을 사용하는 것에 대한 중요성을 논의하고, 정적해석의 간단한 순서에 의해 최대연직방향가속도를 평가할수 있는 것을 나타낸다. 아울러, 레벨 2의 입력에 의한 정적해석은 동적해석으로 얻어진 응답치를 과소평가하지만, 일본의 중층구조에 사용되는 "극한내력계산법"에 근사한 등가선형차 기법에 의해 레벨 2의 입력에 대한 탄소성응답이 가능하다는 것을 나타내고자 한다.

• 교육시설
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• 제14권4호
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• pp.14-24
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• 2007

Recently, there are three major trends in building school facilities by government. First trend is to reconstruct facilities that have been built for 30 years. Second is the creation of a new town, new construction demanded from the redeveloping area. Finally, third is to build educational convenience facilities such as gymnasium, auditorium and cafeteria etc. When building or reconstructing school facilities, it is important to consider the 7th Education curriculum. The purpose of this study is to propose the guide line of the planning the dimension of Science Laboratory in in elementary school, corresponding to teaming contents and method.

• 한국학교ㆍ지역보건교육학회지
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• 제12권1호
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• pp.71-89
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• 2011

Objectives: The purpose of this study is to identify risk behavior related to the school accident between male and female elementary school students. Methods: 838 School accident data provided by Seoul School Safety Council were analyzed by gender. Based on the results above, survey questionnaires on characteristics of school accident were developed. Self-reported data were collected from a sample population of 433 students in grade 5 to 6 students attending 4 elementary schools in Seoul. Results: The students who answered they experienced the accident in school for the past 1 year, accounts 60.5% of male and 39.5% of females students, which has statistically significant difference. The male's cases happened most around corridor/door, while female's cases happened most in the playground/gymnasium. As for the accident risk behavior, male students had the risk behavior by using the personal belongings/toys, while the female students had much risk behavior related to physical facility/playground. When classifying the characteristics of risk behaviors according to the accident causes, male students showed higher score in the accident risk behaviors related to play/fight than in those of the female students(p<0.05). Conclusions: Health care providers should develop school safety programs by characteristics of risk behavior between male and female elementary school students.

• 교육시설 논문지
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• 제22권1호
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• pp.47-57
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• 2015

This study aimed to identify secondary school students' perceptions of school spaces by researching their place preferences and the reasons for them. For the purpose, we analyzed students' written statements regarding places they like and dislike at school, which were collected from 836 middle and 1,100 high school students enrolled at 4 middle and 4 high schools, respectively. Data were transcribed, encoded, and analyzed so as to be clustered to themes revealing the students' senses of places at school. The results are as follows: (1) for middle school students, the most preferred places had to do with physical activities, including playground, auditorium, gymnasium etc., whereas high school students preferred indoor places such as classrooms; (2) the reasons for like-places were categorized into three themes: functions (physical, social, learning, and everyday activities), emotions (belonging, healing, and aesthetics), and physical characteristics; (3) both middle and high school students regarded restroom as the place that they disliked most; (4) the reasons for dislike-places included physical conditions, atmosphere, person-related, subject-related, and circumstances such as the happening of violence or punishment. These may provide educators, parents, school architects and administrators with practical considerations needed for making school a better place for students at secondary schools.

• 교육시설
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• 제5권3호
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• pp.98-106
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• 1998

This paper is to find out a possibility that, adapting article 81 of regional finacing law, the community develops community facilities such as gymnagiums, swimming pools, and parking facilities in school site. The study requires an agreement about managements between the mayor and the superintendent of education. This paper also surveys community's needs with respect to use of school facilities before and after class, willingness to pay for the school use, and use of school facilities by private institutions. This paper adopts two experimental case studies to find a feasibility of community building construction in school sites. It also adopts dscriptive analysis of the statistics to find out the degree of willingness to use by community people. It is found, first, that regional finacing law permits community facilities' development in school sites and an agreement between the mayor and the superintendent of education about usage and profits should be made by the rate of construction fee and land cost. The second is that 65.8% of community people want to use school facilities such as gymnasium and school ground. And favorite series of physical exercise is swimming, baminton, tennis in order. The third is that 66.4% of community people have willingness to pay for the use of school facilities. The fourth is that school facilities such as class room, special class room, and computer room can be used by private institutions. 75% of community people agree to use school facilities by the private institutions. Favorite series on these are classes for reviewing the lessons, language classes, classes for playing musical instruments in order.