• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.11a
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• pp.137-140
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• 2009

Nowadays, the high performance composite materials are famous for the new construction materials as the construction buildings are bigger and higher. Out of them of all, the fiber reinforced concrete and mortar have been studied to develop and strengthen the performances of concrete, such as tensile strength, durability and the resistibility of crack. Also, it is considered that precast concrete is important alternatives of dry process for saving time, upgrading the material's quality and the productivity. Thus, PC panel is being produced for the use of dry wall as well as exterior finishing materials and it requires lots of tests and studies to be conducted to meet the various functional conditions. According to this study, it is considered that PVA fiber might be more effective than nylon fiber for developing the exterior PC panels.

• KCI Concrete Journal
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• v.12 no.1
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• pp.47-56
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• 2000

Once a structure fabricated with mass concrete is in a form of wall such as retaining wall, side walls of a concrete caisson and so on, cracks induced by hydration heat have been known to be governed by exterior restraints which are mainly related to the boundary conditions of the structure. However, it is thought that the degree of restraints can be alleviated considerably only if a lift height of concrete placement or a panel size of the wall is selected properly before construction. As a way of minimizing thermal cracking commonly observed in massive wall-typed structure, this study aimed at evaluating effects of geometrical configuration on the temperature rise and thermal stress through parametric study. Evaluation of the effect was also performed for cement types using anti-sulphate cement, blast furnace slag cement and cement blended with two mineral admixture and one ordinary Portland Cement. so called ternary blended cement. As a result of analytical study, it was found that a lift height of concrete placement is the most important factor in controlling thermal cracking in massive wall, and the increase of a lift height is not always positive to the crack occurrence as not expected.

• Steel and Composite Structures
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• v.26 no.3
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• pp.329-345
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• 2018

This paper systematically investigated the mechanical performance of the weak-axis cover-plate connection, including a beam end monotonic loading test and a column top cyclic loading test, and a series of parametric studies for exterior and interior joints under cyclic loading using a nonlinear finite element analysis program ABAQUS, focusing on the influences of the shape of top cover-plate, the length and thickness of the cover-plate, the thickness of the skin plate, and the steel material grade. Results showed that the strains at both edges of the beam flange were greater than the middle's, thus it is necessary to take some technical methods to ensure the construction quality of the beam flange groove weld. The plastic rotation of the exterior joint can satisfy the requirement of FEMA-267 (1995) of 0.03 rad, while only one side connection of interior joint satisfied ANSI/AISC 341-10 under the column top cyclic loading. Changing the shape or the thickness or the length of the cover-plate did not significantly affect the mechanical behaviors of frame joints no matter in exterior joints or interior joints. The length and thickness of the cover-plate recommended by FEMA 267 (1995) is also suitable to the weak-axis cover-plate joint. The minimum skin plate thickness and a design procedure for the weak-axis cover-plate connections were proposed finally.

• Journal of Korean Society of Steel Construction
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• v.21 no.3
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• pp.221-232
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• 2009

The load distribution factor (LDF) values of simplified composite H beam panel bridges (SCHPBs) that were subjected to one lane and two lane loads were investigated using three dimensional finite element analyses with the computer program ABAQUS (2007). This study considered some design parameters such as the slab thickness, the steel plate thickness, the span length, and the continuity of the SCHPBs in the development of new LDFs. The distribution values that were obtained from these analyses were compared with those from the AASHTO Standard, LRFD, and the equations presented by Tarhini and Frederick, Huo et al., Back and Shin, and Cai. The AASHTO Standard distribution factors for SCHPBs were found to be very conservative. Sometimes, the distribution values from the finite element analyses for interior girders were similar to the results of the AASHTO LRFD, whereas the values for exterior girders were conservative in most cases. The new distribution values that were presented in this study produced LDFs that are more conservative than those from the finite element method. For the simple application of the design to SCHPBs, bridge engineers can use 0.42 for the interior girder and 0.32 for the exterior girder. The proposed values improve the current design procedure for the LDF problem and increase SCHPB design efficiency.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.295-296
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• 2021

With the recent diversification and complication of buildings, the functions of building are also developing. As much as the development of buildings, the machine or equipment used for them is also developing. Thus, all sorts of domestic/foreign industrial facilities and fire stations in the whole nation are using the electric shutter that could meet the insulation just like the exterior wall of general buildings, for bringing-in/storage and crime prevention/fire prevention. Currently, various types of electric shutters are used. Such wrong operation and poor management are causing many panel-falling accidents. This study researched the reduction of electric shutter panel-falling risk by reviewing the domestic/foreign laws and standards, and researching the new safety equipment. First, the causes for falling and accident types were drawn by analyzing the cases of electric shutter accidents. After that, a checklist as the measures for reducing the falling of electric shutter in building was suggested by analyzing the items for the inspection of electric shutter.

• Journal of Fashion Business
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• v.27 no.3
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• pp.96-114
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• 2023

In modern society, there is a tendency to prioritize both fashion and comfort, with a preference for loose-fit clothing that enhances mobility. While darts may not be visibly present on the garment's exterior, their effects should be dispersed and incorporated into the design. However, there is a significant lack of systematic research on dartless patterns in the current state. Therefore, this study focuses on investigating dartless patterns used in loose-fit clothing tailored to the body measurements of women in their 20s. The objective of this research is to develop foundational dartless patterns that serve as a basis for diverse design possibilities in loose-fit clothing. To achieve this purpose, seven dartless patterns introduced in clothing construction references were selected for the production of experimental prototypes, which were then subjected to visual evaluations by a panel of experts. Based on the evaluation results, superior patterns were selected and they underwent modification and improvement to develop the research patterns. The developed research patterns were derived through the formulation of calculation formulas, and based on these formulas, garments were produced. Subsequently, a second round of visual evaluations was conducted by a panel of experts, and notable improvements were observed in most of the aspects assessed. However, it should be noted that this study was limited to women in their 20s it did not explore a wide range of fabrics. Therefore, further research is needed in the future.

• Fire Science and Engineering
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• v.33 no.3
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• pp.105-111
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• 2019

In Korea, the results of a field survey on the construction of flammable exterior materials implemented in 2018 revealed that 147,559 buildings belong to this category. It was found that the fire spreading cases in upper and adjacent constructions are about 3,500 per year, the fires of starting in flammable exterior material are about 1,500 per year. In this study, we investigated the repair method of buildings constructed by flammable exterior material and conducted performance verification of each repair materials for prevention of similar fire. In the case of the repair method, a method of reinforcing with a repair material after removing the existing building finishing material and a method of attaching the repair material after performing the face finishing are proposed. In addition, we conducted cone calorimeter tests of 6 materials such as fireproof gypsum board, mineral wool, hard urethane foam, ceramic board and ALC panel as dryvit and repairing materials, and investigated basic combustion performance of that materials.

• Fire Science and Engineering
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• v.26 no.6
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• pp.85-91
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• 2012

To reduce human life and property damage at the fire in a building, it is most critical to control flame spread in the early stage. Fire spread prevention measure generally includes fire resistance performance securing of structure member in the arson zone and use limitation based on combustion performance of finishing material. The latter is most fundamental fire safety design to determine flame spread, but domestic combustion test determines combustion performance by specimen sized fire test method. Thus, there are many restrictions in the determination of combustion performance by composite material such as sandwich panel. Especially, outer finishing material uses a variety of composite material such as dry bit, aluminum composite panel, and metal panel compared to inner finishing material. Therefore, this study would determine vertical fire spread features by a full scaled fire experiment through the test method of ISO 13785-2, an international test standard.

• Korean Journal of Construction Engineering and Management
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• v.12 no.3
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• pp.11-21
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• 2011

The most critical issue in free-form buildings is how to construct the free-formed exterior facade panels. Their geometric complexity delivers many cons and problems in fabricating and constructing their shapes. To construct a free-form building, first of all, its skin has to be chopped into small pieces, which is called panelization. After panelization, the panels go through an optimization process to construct them economically. The panel's geometries are modified or regenerated through this optimization process. In this study, the panel optimization process of free-form buildings are performed through a case study. The panel shapes of the case study are modeled with Digital Project. To test the constructability of the various panels, 8 mock-up panels are made and laser scanning technology is applied to measure the preciseness of the panels manufactured in comparison with their original design.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.141-142
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• 2015

This literature study is focused on the improvement of lightweight concrete in perspective of foaming agent. Lightweight concrete is the cured concrete as putting required amount of foaming agent to slurry which is a mixture of a certain amount of cement, sand, and water. It has lower density than general concrete, because foaming agent disintegrates numerous bubbles evenly and independently. Thus, it is capable of lightening the weight and great for sound absorption and insulation, In foreign countries, studies for structural lightweight concrete mainly of tunnel grouting and weight lightening of heavy structures are going along actively. Domestically, exterior panel and ALC blocks are alternatively used for flooring. Therefore, this research consider improvement of lightweight concrete in perspective of foaming agent with foundation study.