• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.2
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• pp.103-110
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• 2017

In this paper, it is covered in detail the process of generating structural alternatives with geometry change and its optimization by StrAuto. The main roof structure of the Exhibition Center is modelled parametrically and the optimal alt is derived by observing volume changes according to geometry change of main roof truss. Existing studies performed optimization process through sections and properties due to the limitations of shape change, but this study have meaning of performing the optimization with geometry changes which is the most critical skills of StrAuto. By the process of securing a sufficient margin by geometry changes and reducing volume with the optimization of sections, despite of a partial optimization of large space structure, it could be reduced by 11.7% of the total volume.

• Journal of the Korean Magnetics Society
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• v.11 no.1
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• pp.38-44
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• 2001

The magnetic field standard below 1 mT with the resolution of 0.26 nT has been established. Earth magnetic field (EMF) is compensated automatically down to 0.1 nT/10 min. by a closed feedback system with Cs optical pumping magnetometer and 3-axis Helmholtz coils in nonmagnetic facilities. A multi-layer precision solenoid with the optimized single-current method generates the uniform magnetic field better than 1.0$\times$10$\^$-7/ within $\pm$ 1 cm region at its center. The coil constant of solenoid determined from Helium optical pumping magnetometer is 1.231 058 9 mT/A, and temperature coefficient is 0.38 nT/$\^{C}$. This standard system is used for calibration of low field magnetometers and testing relates to low field.

• Land and Housing Review
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• v.2 no.1
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• pp.47-52
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• 2011

Recent advances of technology in materials science have made it easy to respond to user's needs on high performance steel in civil and building structures. The high-performance and high-strength steel are required for large scale structure and high-rise building to have high-strength, high fracture toughness and better weldability etc. Therefore development of 600MPa class steel for mega structure is necessary. high strength steels, however, may have mechanical properties that are significantly different from those of the conventional steels. The application of high-strength steels to building structures should be reviewed as to whether inelastic behavior equivalent to that of conventional steels can be attained or not. This study researched the structural behavior of high strength circular tubes compression and under flexure. Three column tests and three flexural tests were carried out. The suitability of existing design formulae(KBC 2009) and the structural behavior were investigated through these columns and beams with various types.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.694-697
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• 2008

A retaining wall system suitable for a construction project is selected on the basis of subsoil conditions. If the decision-maker selects an improper system, it has a negative effect on the cost and schedule of the construction project. There have been many studies related to the models and processes for selecting optimal retaining wall systems. However, engineers who are not familiar with formal analysis methods could not easily utilize the formal methods proposed by previous studies. In order to overcome this problem, we developed a web-based decision support system called Dr. Underground, which is both physically and technically easily accessible by engineers. Dr. Underground was developed based on a selection method developed from a precedent research project. It was developed using a server-side web language ASP.NET and MS Access as a database. Decision-makers can input data about the building's condition, construction site conditions and adjacent site conditions in this system. Based on the input data, Dr. Underground recommends an optimal retaining wall system for the inputted conditions and provides detail information on the system.

• The Journal of the Convergence on Culture Technology
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• v.6 no.2
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• pp.299-304
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• 2020

This paper considers the research content and its historical significance of the Study of Nature conducted by John Ruskin(1819-1900) who had a profound influence on art, architecture, social reformation, and preservation of natural environment in Great Britain. Because Ruskin's Study of Nature would be the key to understand totally the implicative meaning of his various academic trials for integrating a wider contexts among human, culture, and society, without being bound by the rules of conventional disciplines. For Ruskin, 'Nature' is defined as 'a system' governing every aspects of human and non-human beings, formulating certain laws of composition. This system has an ecological quality to form a state of harmony by internal interaction and process. Such organic quality of nature worked as 'a metaphor' in Ruskin's research practices. Therefore, Ruskin's Study of Nature would be the conceptual basis for organizing and connecting its various elements of Ruskin's spiritual world.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.5
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• pp.733-739
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• 2018

Various public construction projects have been performed for public welfare and appropriate evaluation of the effectiveness and efficiency has been required. In accordance with legislation of a post construction project evaluation in Construction Technology Promotion Act, all construction projects that exceed 30 billion won in budget are required to perform post evaluation. Korean Government provides post construction evaluation manual that includes both quantitative and qualitative criteria. However, it only provides general concepts and procedures not but detail guidelines for different construction project types and characteristics. Therefore, this paper developed a standard format for qualitative evaluation using survey through analyzing previous cases and research. As a result, the developed standard for survey can be applied for most civil and architectural facilities. However, it will need further research regarding establishment of detailed evaluation criteria for each type of facilities and data storage system for feedback.

• KIEAE Journal
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• v.6 no.2
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• pp.67-74
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• 2006

As sustainable design technologies, advanced daylighting systems with lightshelves have been developed and are currently under monitoring the daylighting performance. This study aims to evaluate the comparative daylighting performance of sloped lightshelf and conventional glazing window with mock-up model, reconstructed as a prototype of Korean office building, sized $12.0m{\times}7.3m{\times}3.7m$ ($w{\times}d{\times}h$) and $1.8m{\times}4.8m$($w{\times}h$) for the south facing side-window was installed on the rooftop of engineering building, Kyung Hee University in Korea. It has an identical configuration of reference room and the test room. For the test room, the sloped type lightshelf system was designed as 10mm transparency sheet glass, tilt angle degree $29^{\circ}$, and total sized 1.28m (interior length 0.88m, exterior length 0.49m). It consisted of daylighting collector, entrance glazing and reflector. To assess daylighting performance, the totally 37 measuring points for illuminance and 2 view points of luminance were monitored in every 30 minutes from 12:00 to 15:00. For the detailed analysis, photometric sensors of each room were installed at work-plane (8 points), wall (7 points), ceiling (3points), and exterior horizontal illuminance (1 point). Luminance of window, rare of the room was measured under clear sky. It is to be monitored by Agilent data logger, photometric sensor Li-cor and the Radiant Imaging ProMetric 1400. Comparisons with a light factor, increase-decrease ratio, uniformity, and luminance are discussed.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.6
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• pp.559-566
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• 2017

This paper proposes a new composite deckplate system reinforced with inverted triangular truss girders(called 'D Deck'), which does not require the use of temporary supports at construction stage. The proposed system retains increased stiffness and strength while keeping the absolute floor height change to a minimum level and can be utilized as floor systems of various types beam members such as the conventional wide-flange and U-shaped composite beams. In order to evaluate the performance of the proposed system, five specimens with a span of 5.5 m were fabricated and tested under field loading conditions consisting of several intermediate steps. The load-deflection curves of each specimen were plotted and compared with the nonlinear three-dimensional finite element analysis results. The comparison showed that the effective load sharing between the truss girders and floor deck occurs and the maximum deflection under construction stage loading is well below the limit estimated by the provisions in Korea Building Code.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.33 no.2
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• pp.137-144
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• 2020

In this study, we propose a new truss deckplate system, which does not require temporary floor supports during construction, with ultra-high-performance concrete (UHPC) infilled top bars. The increased stiffness and strength of the proposed system were well retained as compared to those of the existing truss deckplate systems, thereby resulting in the reduction of maximum deflection at the span center. Four-point bending tests were performed on five specimens with a net span of 4.6 m to evaluate the structural performance of proposed system in the construction stage. In addition, the load-deflection curve was plotted for each specimen, and the effects of test parameters were analyzed. Further, a rigorous nonlinear three-dimensional finite element analysis was performed, and its results were compared with the test results. From the results, it was observed that the test specimens of the proposed system exhibited superior performance as compared to those of the existing one and also satisfied the serviceability requirement during construction provided by the Korea Building Code 2016.

• Progress in Medical Physics
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• v.15 no.4
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• pp.247-254
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• 2004

According to developing high energy linear accelerators and treatment methods, like (3 dimensional conformal radiotherapy (3D-CRT), intensity modulated radiotherapy (IMRT), many radiotherapy centers are replacing older linear accelerators with new higher technical machines. This often presents a shielding problem as the designed shield for the existing rooms is not adequate for the higher technical machines. Additional shielding in limited existing space becomes necessary. We are replacing older brachytherapy room with new higher technical linear accelerator for IMRT. This room is not adequate for the IMRT machine without additional shielding design. The logical development of optimum structural shielding designs with concrete and high density shielding blocks are presented. We obtained following results by comparison between the pre-calculating values and actual survey of completed LINAC installation. High density shielding blocks have more powerful radiation protection about 2 times.