• Earthquakes and Structures
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• v.13 no.6
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• pp.573-588
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• 2017

The earthquake input is required when the soil-structure interaction (SSI) analysis is performed by the direct finite element method. In this paper, the earthquake is considered as the obliquely incident plane body wave arising from the truncated linearly elastic layered half space. An earthquake input method is developed for the time-domain three-dimensional SSI analysis. It consists of a new site response analysis method for free field and the viscous-spring artificial boundary condition for scattered field. The proposed earthquake input method can be implemented in the process of building finite element model of commercial software. It can result in the highly accurate solution by using a relatively small SSI model. The initial condition is considered for the nonlinear SSI analysis. The Daikai subway station is analyzed as an example. The effectiveness of the proposed earthquake input method is verified. The effect of the obliquely incident earthquake is studied.

• Steel and Composite Structures
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• v.29 no.5
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• pp.647-657
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• 2018

Geometric imperfections may be created during the production process or setting borders of single-layer graphene sheets (SLGSs). Vacancy defects are an instance of geometric imperfection, so investigating the effect of these vacancies on the mechanical properties of single-layer graphene is extremely important. Since very few studies have been conducted on the structure of imperfect graphene (with the vacancy defect) as an anisotropic structure, further study of this defective structure seems imperative. Due to the vacancy defects and for the proper assessment of mechanical properties, the graphene structure should be considered anisotropic in certain states. The present study investigates the effects of site and size of vacancy defects on the mechanical properties of graphene as an anisotropic structure using the lekhnitskii interaction coefficients and Molecular Dynamic approach. The effect of temperature on the severity of the SLGS becoming anisotropic is also investigated in this study. The results reveal that the amount of temperature has a big effect on the severity of the structure getting anisotropic even for a graphene without any defects. The effect of aspect ratio, temperature and also size and site of vacancy defects on the material properties of the graphene are studied in this research work. According to the present study, using material properties of flawless graphene for imperfect structure can lead to inaccurate results.

• Geomechanics and Engineering
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• v.30 no.1
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• pp.1-10
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• 2022

Seismic ground response evaluation is one of the main issues in geotechnical earthquake engineering. These analyses are subsequently divided into one-, two- and three-dimensional methods, and each of which can perform in time or frequency domain. In this study, a novel approach is proposed to assess the seismic site response using two-dimensional transfer functions in frequency domain analysis. Using the proposed formulation, a program is written in MATLAB environment and then promoted utilizing the equivalent linear approach. The accuracy of the written program is evaluated by comparing the obtained results with those of actual recorded data in the Gilroy region during Loma Prieta (1989) and Coyote Lake (1979) earthquakes. In order to precise comparison, acceleration time histories, Fourier amplitude spectra and acceleration response spectra diagrams of calculated and recorded data are presented. The proposed 2D transfer function diagrams are also obtained using mentioned earthquakes which show the amount of amplification or attenuation of the input motion at different frequencies while passing through the soil layer. The results of the proposed method confirm its accuracy and efficiency to evaluate ground motion during earthquakes using two-dimensional model. Then, studies on irregular topographies are carried out, and diagrams of amplification factors are shown.

• Nuclear Engineering and Technology
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• v.53 no.6
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• pp.2046-2055
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• 2021

This paper analyzed the primary concerns about radiation among the Korean public with a big data analysis of questions posted at the section of "Knowledge iN" on the portal site NAVER in Korea from January 2010 to August 2020. First, we extracted questions about radiation and categorized them into the three categories with TF-IDF analysis: "Medical," "Career Counseling," and "General Interest". The "Medical" category includes questions about radiation diagnosis or treatment. The "Career Counseling" category includes questions about entering college and the prospect of finding jobs in radiation-related fields. The "General Interest" category includes questions about terminology and the basic knowledge of radiation or radioisotopes. Second, we extracted common questions for each category. Finally, we analyzed the temporal change in the numbers of questions for each category to confirm whether there is any correlation between radiation-related events and the number of questions. The analysis results demonstrate that major radiation-related events have little relevance to the number of questions except during March 2011.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.1202-1208
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• 2022

Techniques based on computer vision are becoming increasingly important in construction safety monitoring. Using AI algorithms can automatically identify conceivable hazards and give feedback to stakeholders. However, the construction site remains various potential hazard situations during the project. Due to the site complexity, many visual devices simultaneously participate in the monitoring process. Therefore, it challenges developing and operating corresponding AI detection algorithms. Safety information resulting from computer vision needs to organize before delivering it to safety managers. This study proposes a framework for computer vision-aided construction safety monitoring using collaborative 4D BIM information to address this issue, called CSM4D. The suggested framework consists of two-module: (1) collaborative BIM information extraction module (CBIE) extracts the spatial-temporal information and potential hazard scenario of a specific activity; through that, Computer Vision-aid Safety Monitoring Module (CVSM) can apply accurate algorithms at the right workplace during the project. The proposed framework is expected to aid safety monitoring using computer vision and 4D BIM.

• Wind and Structures
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• v.39 no.1
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• pp.15-30
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• 2024

In this paper, detailed wind field data of the full path of typhoon "Bailu" were obtained based on site measurements. Typhoon "Bailu" made first landfall southeast of the Taiwan Strait with a wind speed of approximately 30 m/s near the center of the typhoon eye and a second landfall in Dongshang County in Fujian Province. The moving process is classified into 3 regions for analysis and comparison. Detailed analyses of wind characteristics including wind profile, turbulence intensity, gust factor, turbulence integral scale and wind power spectral density function at the full process of the typhoon are conducted, and the findings are presented in this paper. Wind speed shows significant dependence on both the direction of the moving path and the distance between the typhoon center and measurement site. Wind characteristics significantly vary with the moving path of the typhoon center. The relationship between turbulence intensity and gust factor at different regions is investigated. The integral turbulence scales and wind speed are fitted by a Gaussian model. Such analysis and conclusions may provide guidance for future bridge wind-resistant design in engineering applications.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.1280-1280
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• 2024

With the advancement of smart construction technologies, researches are being conducted on technologies to monitor construction site conditions in real-time. Particularly, with the advancement of communication technologies, it has become possible to transmit and receive information quickly and accurately even in environments with difficult communication such as construction sites. These communication technologies are utilized for real-time management of construction site information and safety management based on worker location etc. Therefore, in this study, a system is aimed to be constructed a system that can monitor concrete strength using the maturity method and transmit it wirelessly to a strength monitoring system, targeting Korean construction sites. As a result of the case application, the concrete maturity temperature was measured using sensor, and it was confirmed that the temperature data was properly transmitted to the concrete estimating system through Bluetooth Low Energy(BLE) transmission. It is anticipated that this study will contribute to the activation of smart construction technologies at construction sites, automation of safety and quality management, and improvement in construction accuracy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8394-8399
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• 2015

The paper studies on the site and space composition of Lee Ha-Bock's traditional thatched roof house. The house is located at a site with back to the mountain and facing the water and the rear and front mountains formulate a shape of Myungeonhyung(a sleeping dog figure) with HyungGug theory of Pungsu. The house has ㄱ shaped Anchae, ㅡ shaped Sarangchae and Gwangchae. Those are formulate ㅁ lay out followed the land form. Through the research I found the house shows a typical traditional farmhouse in the middle of Korea of Josen period. Nowadays there are many large Giwajip(tile roofed house) of Josen period is remained but only a few thatched-roof house is lived. In this situation, the house has considerable architectural values as a traditional thatched roof house.

• Journal of architectural history
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• v.14 no.3 s.43
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• pp.77-88
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• 2005

This study is to find out the characteristics of the changes of the site layout in Beopjusa which was built on Maitreya faith in the Shilla.. According to the analysis of it in this study, we make conclusions as follows; 1) The reconstruction of Beopjusa means a start in Dhamalsama(法相宗) and then it was supposed to be Buddhist temple which was formed by intersecting axis of centering around a wooden pagoda(捌相殿) with a main Buddhist hall and a lecture hall. 2) After the middle of Koryo dynasty, Beopjusa was changed to building layout of intersecting with Yongwabojeon(龍華寶殿) and Daeungbojeon(大雄寶殿) because of harmony with Avatamsaka(華嚴宗) and Dhamalsama centering around Avatamsaka. 3) The buildings of Zen Buddhism was built in the early Chosun dynasty owing to a prevalence of Zen Buddhism in the late Koryo dynasty. And since 17th century, Buddhist halls were each built in their a faith system according to interpenetrated Buddhism(通佛敎). 4) The courtyard type of mountainous district was made on interpenetrated Buddhism. On the other hand, the site layout of Beopjusa is being maintained by centripetal spatial organization through the wooden pagoda as object.

• Journal of Internet Computing and Services
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• v.4 no.3
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• pp.23-30
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• 2003

A component base technology can maintain effectively and save time and expenses of development. In this thesis we found many components including the setup/execution component to construct game sites and analyzed and designed the components by the use of UML. If programmers develop the game site by using the component that distributes, setups and executes the game program by one click and other components, they can manage the game site easily, distribute the game program effectively and offer a convenient user interface. Also, by the reuse of these components, programmers can construct the game site easily and economically.