• Journal of Korean Association for Spatial Structures
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• v.20 no.4
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• pp.131-139
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• 2020

In this paper, the hybrid prefabricated retrofit method is suggested and examined. Six specimens were manufactured in order to evaluate their flexural performance of RC beams. Test parameters include the added beam depth, the thickness of bottom plate, the number of the steel plate with openings. The effects of these parameters on the flexural performance of reinforced concrete beams were examined. The load-deflection behavior and modes of cracks are presented from the test results. At the test result, the flexural capacity and the ductility of the hybrid prefabricated retrofit method was increased satbly. Also, comparing the flexural performance of RC beam and retrofitted RC beams, it was increased that the flexural strength is about 3.3 times, the ductility is about 2.55 times, and energy dissipation capacity is about 7.34 times.

• Journal of the Korea Concrete Institute
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• v.24 no.4
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• pp.407-414
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• 2012

The purpose of this study is to experimentally investigate the shear behavior of reinforced concrete beams embedded with GFRP (glass fiber reinforced polymer) plate with openings. In this study, the parameters include the shape of reinforcement, reinforcement area, and thickness and width of reinforcements. The test was performed on 9 specimens with shear spanto-depth ratio of 2.8. When the reinforcement area was varied, the GFRP plate showed 3.6 times greater shear strength than steel stirrup. The test result showed that shear strength increased as reinforcement area increased. Also, when the shape of a parallelogram GFRP plate was used, it showed higher shear strength than that with rectangular shape. Effect of thickness and width of reinforcement showed that shear capacity increased as width increased. For a comparison study, a calculation of the shear strength of reinforced beams with GFRP plate based on the ACI 318M-08 was compared with the test results. The test results were compared with the maximum shear reinforcement areas required by ACI 318M-08, CSA-04, and EC2-02 provision.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.1089-1095
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• 2023

Windows are essential and important architectural elements for the organization of architectural spaces, and they give character to the space and have a great impact on the reaction of users. Virtual windows are installed to activate architectural spaces such as underground spaces where windows cannot be installed, and to provide a sense of psychological security to users in hospital clinics, etc. In this study, we reviewed the literature and collected and analyzed the precedents of virtual windows to discuss the factors necessary to improve the realism of virtual windows. The factors that affect the realism of virtual windows are further grouped into five categories: 1. Use of reproduced images or videos for views, 2. Representation of temporality, 3. Responsiveness to changes in the observer's perspective, 4. Realistic reproduction of sunlight, and 5. Provision of non-visual sensory elements. Virtual windows are not just a replacement for traditional windows, but a way to realize a virtual environment using digital media, and it is necessary to expand the discussion to the realization of the virtual environment and the relationship with architectural elements.

• Journal of the Korea Concrete Institute
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• v.20 no.1
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• pp.3-11
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• 2008

An experimental investigation was conducted with half-scale representations of the reinforced concrete shear walls with the opening subjected to cyclic loads. Specimens were half scale representations of a one-story wall in the apartment built in 1980. The area ratio of the opening section, as well as the size and critical section of coupling slabs, were decided based on results from a previous researches. The test result of WS-0.23 specimen, which has artificial damages to install the opening, the strength of the wall decreased due to the opening. It is apparent that influence of cutting reinforcing bars and decrease of effective section area lead to early first yield of the reinforcing bars before the allowable limit of drift ratio of the shear walls was reached. Therefore, proper reinforcing method is needed to prevent this. The decrease of strength of the shear walls by installation of openings shows a great deal of difference compared to previous researches. This is because flexural capacity of the slabs is working as coupling elements for the shear walls. The critical section of coupling slabs that works as coupling elements for shear walls was a little different from the results of previous researches.

• Journal of the Korea Concrete Institute
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• v.21 no.2
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• pp.129-138
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• 2009

Recently, for more demands of the economical benefits and environmental conservation, many engineers prefer to choose remodeling. Artificial openings are often unavoidable to make house wider, which will degrade wall strength and stiffness by losing effective wall section that may cause the weakening of system capacity. In these cases the damaged shear walls need to be retrofitted by additional materials or members. In this research, four specimens were tested to investigate the capacity of the damaged wall and the retrofitted wall. The artificially damaged wall was prestressed by tendons to improve the shear capacity of the wall, and the other walls were retrofitted by adding steel plate at the surface for the same purpose. Consequently, these retrofitted walls had improved capacity and stiffness in both shear and flexure. Especially, the wall with steel plate showed ductile behavior after ultimate load and the prestressed wall had greater stiffness than the unstrengthened prototype wall.

• Journal of the Earthquake Engineering Society of Korea
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• v.19 no.2
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• pp.55-62
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• 2015

Shear wall systems behave as individual wall because of openings like window and elevator cage. When coupling beams are installed in shear walls, they will have high strength and stiffness so that be less damaged by lateral loads like earthquake. However, coupling beam is difficult construction method. And arranging reinforcement of slender coupling beams are especially hard. It is because the details of coupling beam provided by ACI 318 are complex. In this paper, experiments were conducted using coupling beams with 3.5 aspect ratio to improve the details of slender coupling beams provided by ACI 318. Two specimens were proposed for this study. One specimen applied with bundled diagonally reinforcement only. Another specimen applied both bundled diagonally reinforcement and High-Performance Fiber Reinforced Cementitious Composite (HPFRCC) so that coupling beams have half of transverse reinforcement. All specimen were compared with a coupling beam designed according to ACI 318 and were evaluated with hysteretic behaviors. Test results showed that the performance of two specimen suggested in this study were similar to that of coupling beam designed according to current criteria. And it was considered that simplification of the details of reinforcement would be available if transverse reinforcement was reduced by using bundled diagonally reinforcement and HPFRCC.

• Journal of architectural history
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• v.23 no.4
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• pp.7-17
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• 2014

This paper aims at researching the cave concept of the Japanese architect Terunobu Fujimori and the result could be summarised as follows. First, a cave is Fujimori's only theme related to the interior space. He set some design guidelines for practice concerning openings of the wall and finishing materials of the interior, following the two major characteristics of a cave: 'comfortability' and 'homogeneity in material'. And 'fire' was also the premise in the cave as a 'spirit' of the space. Second, Fujimori applied the concrete guidelines to Tanpopo House (1994~95), which had in fact borne the ideas. Yakisugi House (2005~07) that took the cave as its design theme showed the transition of his cave concept, from closedness to openness. Third, though his cave concept might deserve the criticism that it is inclined to 'image' rather than 'essence', it illustrates that he seeks after an archetype of human dwelling before the purity of the original space was tarnished with rationality and abstraction. And the cave idea allows the seemingly contradictory 'sachlich' and 'surrealistic' features to coexist. Summing up, Fujimori's cave concept proves that his architecture is a rejection of the Cartesian modernist ideal and the contemporary architects' desire for dematerialisation. In a fundamental level, however, it is a result of his strategic choice induced by his own primary principle that his building must not be similar to any styles in history or any other architects' works in the world.

• Journal of the Korean Institute of Rural Architecture
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• v.17 no.1
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• pp.19-26
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• 2015

The old Samcheok construction company housing in Donghae City was built for employees of Nitrogenous lime factory with railway construction in 1939. The 31 company houses are arranged in a rows including a House A, two No. 2 and 3 Houses, a dormitory, 12 row houses of two households, and 15 row houses of four households. At present, they are preserved with prototype at that time of building as a private company. Researching the architectural characteristics from A and No. $2{\cdot}3$ detached houses of them, the results are as follows. The tea room, living room, and kitchen are centralized and connected with toilet, bathroom, and maid's room by corridor. The exterior wall was finished with paintwork on cement mortar on stud wall framing plastered. The key exterior elements such as diamond shaped asbestos slate, large openings, corner bay window, lintel cornice are in accordance with drawings that they were first designed. The wooden roof structure is based on the structure that supports transverse load with a beam and beam plate instead of thrust. The kitchen and toilet are remodelled and only seem to be a mere shadow of their former self, but the position of sink and toilet bowl is the same as before.

• KIEAE Journal
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• v.9 no.5
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• pp.105-113
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• 2009

Daylighting provides the opportunity for both energy savings and improved visual comfort. An accurate estimation of the amount of daylight entering a building is the key step for daylight designing. This research aims to assess comparative daylighting performance of four different configurations of fenestration in case of unilateral windows and their variation under clear and overcast sky conditions. The selected window openings in this study were single punched, double punched, multiple punched and clerestory, and the area was same for each type of window. The experiment was designed for an office space using 1/10 scale model. Daylighting performance was evaluated by measuring the illuminance on work-plane height using Agilent data logger and photometric sensor Li-Cor. Thecomputer program ECOTECT was also used to simulate the pattern of interior illuminance distribution. Clerestory window showed the best performance in term of both illuminance level and distribution in the experiment. Multiple punched window provided more uniform illuminance distribution than single punched window. Lowest daylighting performance in the experiment was shown by double punched window.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.9
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• pp.207-214
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• 2019

Natural ventilation through openings such as windows in school buildings is an efficient resource for natural cooling during the intermediate season of the year. Because the natural ventilation uses the wind outside the building, the amount of ventilation will depend not only on the wind speed and wind direction but also on the window layout and open window ratio. Therefore, in this study, the natural ventilation plans of school classroom windows are divided into 4 types and 8 cases as shown in Table 1. The characteristics of cooling effect by natural ventilation are simulated by applying Energyplus's Airflow Network Model and the comfort of the occupants is evaluated by the number of hours included in the 80% acceptability range of the ASHRAE Standard 55-2010 adaptive comfort model for the weekdays (Monday-Friday) and the class hours (08: 00-19: 00). Based on the analysis results of the above, this study presents basic data related to classroom cooling plan using intermediate season natural ventilation.