• Geomechanics and Engineering
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• 제18권5호
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• pp.535-543
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• 2019

Building on/with expansive soils with no treatment brings complications. Compacted expansive soils specifically fall short in satisfying the minimum requirements for transport embankment infrastructures, requiring the adoption of hauled virgin mineral aggregates or a sustainable alternative. Use of hauled aggregates comes at a high carbon and economical cost. On average, every 9m high embankment built with quarried/hauled soils cost $12600MJ.m^{-2}$ Embodied Energy (EE). A prospect of using mixed cutting-arising expansive soils with industrial/domestic wastes can reduce the carbon cost and ease the pressure on landfills. The widespread use of recycled materials has been extensively limited due to concerns over their long-term performance, generally low shear strength and stiffness. In this contribution, hydromechanical properties of a waste tyre sand-sized rubber (a mixture of polybutadiene, polyisoprene, elastomers, and styrene-butadiene) and expansive silt is studied, allowing the short- and long-term behaviour of optimum compacted composites to be better established. The inclusion of tyre shred substantially decreased the swelling potential/pressure and modestly lowered the compression index. Silt-Tyre powder replacement lowered the bulk density, allowing construction of lighter reinforced earth structures. The shear strength and stiffness decreased on addition of tyre powder, yet the contribution of matric suction to the shear strength remained constant for tyre shred contents up to 20%. Reinforced soils adopted a ductile post-peak plastic behaviour with enhanced failure strain, offering the opportunity to build more flexible subgrades as recommended for expansive soils. Residual water content and tyre shred content are directly correlated; tyre-reinforced silt showed a greater capacity of water storage (than natural silts) and hence a sustainable solution to waterlogging and surficial flooding particularly in urban settings. Crushed fine tyre shred mixed with expansive silts/sands at 15 to 20 wt% appear to offer the maximum reduction in swelling-shrinking properties at minimum cracking, strength loss and enhanced compressibility expenses.

• 한국지리정보학회지
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• 제22권3호
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• pp.133-145
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• 2019

우리나라 미래 핵심과제 중 하나인 자율주행자동차를 지원하는 정밀도로지도에 대한 구축과 연구가 민간, 국가 차원에서 빠른 실용화를 목표로 적극적으로 추진되고 있다. 이러한 상황에서 정밀도로지도의 변화정보의 최신성 확보 및 갱신에 대한 방법이 핵심과제로 부각되고 있다. 따라서 이 연구에서는 정밀도로지도의 효율적인 갱신체계 정립 방안을 마련하기 위하여 도로의 종류, 도로변화의 원인과 연간 변화율 등의 현황과 정밀도로지도 관련 시스템과 정밀도로지도 갱신체계 구축을 위한 고려사항을 분석하였다. 이러한 현황분석을 토대로 정밀도로지도의 전각문자, 내용, 지역 등을 고려하여 도로변화 정보의 수집 탐지 방법과 정밀도로지도의 갱신체계를 단기적 방안과 중장기적 방안으로 제시하였다. 현재는 기술적, 시스템적 제한으로 인해 단기적 갱신체계를 적용해야 할 것으로 판단되었으며 향후에는 기술개발과 업무협조 체계 구축 등 시스템적 개선을 통해 중장기 갱신체계 방안을 조속히 도입해 효율적이고 실시간적인 정밀도로지도 갱신체계를 구축해야 할 것으로 판단된다.

• 건축역사연구
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• 제28권2호
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• pp.53-64
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• 2019

This study examines the restoration project of Sokkuram, and introduces its preliminary plans by the architect Pai Ki Hyung. The restoration project started in 1958 with an inquiry committee of the restoration project, and was completed in 1964. Despite having undergone extensive repair work under Japanese supervision from 1913 and 1923, the repair work caused water leakages inside Sokkuram, and regular cleaning work that began in 1933 caused a lot of damage to the sculpture. In result of the surveys, the top priority of this project was to protect the sculptures inside Sokkuram by improving the environment of the cave. At that time, the architect Mr. Pai participated as a head of the fourth field surveyors to plan the restoration project and to design the preliminary plans. He proposed the installation of a double dome structure to prevent further water leakages on the concrete addition that was built up around the grotto by the Japanese. However, in 1961, the Cultural Heritage Committee of Korea examined the plans of Mr. Pai and immediately rejected them. The factors of the rejection were the omitting of entrance design, system of new double dome structure that presses the existing structure, and these changes that had to be made outside of the drainage plans. The repair work of Sokkuram began in 1961, and the main construction was building double dome structure and entrance installation. In this we realize that Mr. Pai's double dome structure plans were very important key concept of this project. This study attempts to demonstrate the double dome installations that Mr. Pai initially proposed, which ultimately remains as emblematic factors of Sokkuram's legacy.

• 대한건축학회논문집:계획계
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• 제34권2호
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• pp.23-31
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• 2018

In recent years, as the development of construction technology and population increase, buildings are becoming more complex and high-rise. These large scale buildings are difficult to secure fire and evacuation safety when fire occurs. So it is necessary to prepare specific measures. According to this situation, in 2011, Republic of Korea officially launched Performance-based Design in "Fire-fighting system Installation business Act". But even 6 years passed since the enforcement, there are still faces manifold problems in the course of implementation. In order to examine the necessary improvements, in this study, I conducted interviews and questionnaires with experts, investigated the improvement items under current laws. And draw up a measures for that items. The subjects of the survey were fire-fighting officer, professional engineer fire fighting, fire protection planner and professor in Daegu. As a result of twice surveys, a total of 19 items are derived. And then compared and analyzed the criteria of overseas countries, and suggested improvement directions for final items. In addition, conducted a third questionnaire survey on the proposed improvement direction to verify the appropriateness of the alternative. The results of this study will be used as basic data to deal with the general problems of performance-based design in future, and further study on each item will be needed.

• 정보보호학회논문지
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• 제20권6호
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• pp.83-96
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• 2010

우리사회는 급격한 스마트폰 확산은 개인생활 뿐만 아니라 조직의 업무 환경을 바꾸고 있다. 특히 스마트폰은 애플리케이션을 누구나 개발하고 사용할 수 있는 특성으로 인해 타산업과의 융합이 촉진되는 등 사회의 디지털 패러다임을 변화시키고 있다. 정부도 스마트폰 환경에 맞는 대국민서비스 향상과 국민과의 소통을 위해 '모바일 전자정부' 구축을 추진하고 있다. 하지만 스마트폰에 대한 보안위협이 급증하고 있어 이에 대한 대책을 마련하지 않으면 모바일 전자정부 활성화에 장애가 될 수 있다. 본 논문에서는 국가기관의 안전하고 효율적인 모바일 환경 구축을 위해 필요한 정보보호 방안과 이를 체계적으로 관리하기 위한 모바일 전자정부 정보보호관리체계(ISMS)를 제시하고자 한다.

• 한국산업융합학회 논문집
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• 제26권1호
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• pp.59-68
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• 2023

A new type of private education institute appeared starting from the 16^th century, called Seowon consist of educational spaces and Jesa(a form of memorial ritual for the family's ancestors) space. Seowon Architecture is representative Confucian Architecture. Seowon is a kind of private school and it is a higher educational institute. the time of establishment was from the middle of 16^th century to the end of 19^th century, but the famous Seowon which remains up to now had been mainly built from the end of 16^th century to the beginning of 17^th century. Seowon was built on a quiet place far from the town for Students and Scholars to concentrate on their study. and it has beautiful surrounding scenery. Seowon has a place for study in the front and a place for sacrifice at the back regardless of configuration of ground. Gangdang is a building in the place for study in which teacher and students study. It is smilar place to Myongryundang of Hyanggyo. As a plan composition, there is a wide Daechong and two rooms at the both sides. Infront of Cangdang, there are Dongjae and Seojae on the right and the left side which are student' dormitory. This study argues that the Confucianist ideas and topography are the factors that determine the hierarchy Seowon. In light of this, A Study on Spatial Configuration of Education Area in Do-dong Sewon attempted to conduct an analysis by applying such backgrounds, and therefore studied the arrangement rules and construction methods for Seowons.

• Advances in concrete construction
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• 제14권5호
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• pp.317-330
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• 2022

This paper investigated computationally and experimentally the interaction here between a notch as well as a micropore under uniaxial compression. Brazilian tensile strength, uniaxial tensile strength, as well as biaxial tensile strength are used to calibrate PFC2d at first. Then, uniaxial compression test was conducted which they included internal notch and micro pore. Experimental and numerical building of 9 models including notch and micro pore were conducted. Model dimensions of models are 10 cm × 10 cm × 5 cm. Joint length was 2 cm. Joints angles were 30°, 45° and 60°. The position of micro pore for all joint angles was 2cm upper than top of the joint, 2 cm upper than middle of joint and 2 cm upper than the joint lower tip, discreetly. The numerical model's dimensions were 5.4 cm × 10.8 cm. The fractures were 2 cm in length and had angularities of 30, 45, and 60 degrees. The pore had a diameter of 1 cm and was located at the top of the notch, 2 cm above the top, 2 cm above the middle, and 2 cm above the bottom tip of the joint. The uniaxial compression strength of the model material was 10 MPa. The local damping ratio was 0.7. At 0.016 mm per second, it loaded. The results show that failure pattern affects uniaxial compressive strength whereas notch orientation and pore condition impact failure pattern. From the notch tips, a two-wing fracture spreads almost parallel to the usual load until it unites with the sample edge. Additionally, two wing fractures start at the hole. Both of these cracks join the sample edge and one of them joins the notch. The number of wing cracks increased as the joint angle rose. There aren't many AE effects in the early phases of loading, but they quickly build up until the applied stress reaches its maximum. Each stress decrease was also followed by several AE effects. By raising the joint angularities from 30° to 60°, uniaxial strength was reduced. The failure strengths in both the numerical simulation and the actual test are quite similar.

• 한국지구과학회지
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• 제44권4호
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• pp.331-341
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• 2023

The goal of this study was to examine the PCK required for science teachers and PCK required for university teacher educators in terms of school science knowledge, science teaching and learning, and the role of science educators, which are the main axes of science education in future schools, and to explore the relationship between them. This study is a follow-up to a previous stage of research that explored the prospects for changes in schools in the future (2040-2050) in terms of school knowledge, educational methods, and teacher roles. Based on in-depth interviews, qualitative and semantic network analyses were conducted to derive and compare the characteristics of PCK and PCK. As for the main research results, science teacher PCK in future schools should include expertise in organizing science classes centered on convergence topics, expertise in digital platforms and ICT use, and expertise in building a network of learning communities and resources, as part of the expertise of human teachers differentiated from AI. Teacher educators' PCK includes expertise in the research and development of T-L methods using AI, expertise in the knowledge construction process and practice, and expertise in developing preservice teachers' research competencies. Discussed in the conclusion is the change in teacher PCK and teacher educator PCK with changes in science knowledge, such as convergence-type knowledge and cognition-value integrated knowledge; and the need to emphasize values, attitudes, and ethical judgments for the coexistence of humans and non-humans as school science knowledge in the post-humanism future society.

• Steel and Composite Structures
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• 제51권3호
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• pp.271-288
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• 2024

The primary objective of this study is to investigate the production and performance characteristics of structural concrete incorporating varying proportions (0%, 25%, and 50% by volume) of pumice stone, as well as aluminum lathe as an additive at 0%, 1%, 2%, and 3%, under fire conditions. The experiment will be conducted over a period of up to 1 hour, at temperatures ranging from 24℃, 200℃, 400℃ and 600℃. For the purpose of this, a total of twelve test samples were manufactured, and then tests of compressive strength (CS), splitting tensile strength (STS), and flexural strength (FS) were performed on these samples.Next, a comparison was made between the obtained values and the influence of temperature. To achieve this objective, the manufactured samples were placed at temperatures of 200℃, 400℃, and 600℃ for a duration of 1 hour, and were subjected to the influence of temperature.These values at 24 ℃ were then contrasted with the CS results obtained from test samples that were subjected to the temperature effect for an hour at 200 ℃, 400 ℃, and 600 ℃. A comprehensive analysis of the test outcomes reveals that the incorporation of aluminum lathe wastes into a mixture results in a significant reduction in the compressive strength of the concrete. As a result of this adjustment, the CS values dropped by 32.93%, 45.70%, and 52.07%, respectively. Furthermore, It was shown that testing the ratios of pumice stone alone resulted in a decrease in CS outcomes. Additionally, it was found that the presence of higher temperatures is clearly the primary factor contributing to the decrease in the strength of concrete. Due to elevated temperatures, the CS values decreased by 19.88%, 28.27%, and 38.61% respectively.After this investigation, an equation that explains the connection between CS and STS was provided through the utilization of the data of the experiments that were carried out.

• 대한교통학회지
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• 제25권6호
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• pp.197-208
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• 2007

건축기술의 발달로 세계적으로 초대형 건축물들이 나타나고 있다. 건축물들의 대형화, 복잡화는 안전상의 큰 문제점을 가지고 있으며, 이에 걸맞는 안전대책이 요구된다. 본 연구에서는 건물에 적용되는 최신기술 및 시스템을 외국사례를 기준으로 소개하고 더 나아가 이를 바탕으로 건물에서 화재시 직접적으로 피난자들을 유도할 수 있는 방안을 제시하였다. 구체적으로 빌딩에서 화재를 실시간으로 감지하여 영향을 파악할 수 있는 무선센서 네트워크가 현실화됨에 따라 이러한 정보를 이용할 수 있게 되었고, 이점에 착안하여 방향성유도등을 전제로 한 직접적인 유도방안을 마련하였다. 화재 정보를 이용함에 있어서 기본적으로 Quickest Path Algorithm에서 비지배경로의 개념을 사용하여 시간과 용량을 고려한 경로를 선택하게 하였고, 화재의 영향을 시간과 용량의 제한조건으로 설정하여 경로의 선택에 영향을 주도록 하였다. 마지막으로 사례연구를 통해 네트워크에 적용해본 결과 Quickest Path Algorithm은 링크의 용량에 따라 효율적인 분산유도가 가능하였으며, 화재상황을 부여하여 경로상 화재에 의한 온도, 연기에 의해 링크 이용이 제한되는 경우에 있어서 해당링크를 피하거나, 수요를 제한하여, 실제적용시 안전과 피난시간의 최소화 등 피난유도의 목적을 얻을 수 있었다.