• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.5
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• pp.182-189
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• 2021

VPS(Void Plywood Slab System, VPS) has optimized the shape of the hollow material. In addition, it has a function to prevent the floating of the hollow material and the separation due to the working load. In this study, the punching shear capacity of flat plate was performed using Void Plywood Slab System with form work panel proposed in the previous study. As a result of the test, the strength of the VSPS specimen in which the hollow material was placed beyond 2.0 times the column width from the loading point was reduced by 9.4% compared to the reference specimen. However, the strength value was about 1.57 times higher than the design value suggested by KBC 2016. It was found that there was no change in stiffness compared to the reference specimen until shear failure occurred in the VSPS specimen in which the hollow material was placed. It can be seen that this experiment is being destroyed by shear as the flexural reinforcing bars are sufficiently reinforced.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.2
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• pp.200-207
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• 2021

The purpose of this study is to investigate experimentally the effects of type of superplasticizer on tensile behavior and cracking pattern of alkali-activated slag-based cementless composite. Three mixtures were prepared according to type of superplasticizer, and the compressive strength and tension tests were performed. Test results showed that differences of tensile strength, tensile strain capacity, and toughness of composites were up to 28.1%, 39.1%, and 66.2%, respectively, according to type of superplasticizer, although fiber balling or poor dispersion of fibers in fresh composites was not observed. It was also observed that the type of superplasticizer influenced number of cracks and maximum fiber bridging stress.

• Journal of the Korean Solar Energy Society
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• v.39 no.2
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• pp.23-32
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• 2019

PVT (Photovoltaic/thermal) system is technology that combines PV and solar thermal collector to produce and use both solar heat and electricity. PVT has the advantage that the energy production per unit area is higher than any single use of PV or solar thermal energy systems because it can produce and use heat and electricity simultaneously. Air-type PVT collectors use air as the heat transfer medium, and the air flow rate and flow pattern are important factors affecting the performance of the PVT collector. In this study, a new air-type PVT collector with improved thermal performance was designed and manufactured. And then thermal and electrical performance and characteristics of air-type PVT collector were analyzed through experiments. For the thermal performance analysis of the PVT collector, the experiment was conducted under the test conditions of ISO 9806:2017 and the electrical performance was analyzed under the same conditions. As a result, the thermal efficiency increased to 26~45% as the inlet flow rate of PVT collector increased from $60{\sim}200m^3/h$. Also, it was confirmed that the air-type PVT collector prevents the PV surface temperature rise according to the operating conditions.

• Journal of the Earthquake Engineering Society of Korea
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• v.23 no.5
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• pp.239-248
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• 2019

In this study, the out-of-plane seismic resistance of lightly-reinforced existing walls strengthened with thick RC jacket was investigated. The thick RC jacket with a thickness of 500 mm was placed at one side of the thin existing wall with a thickness of 150 mm. At the interface between the wall and RC jacket, a tee-shaped steel section with a number of anchor bolts and dowel bars was used as the shear connector. To investigate the connection performance and strengthening effects, the cyclic loading tests of four jacketed wall specimens were performed. The tests showed that the flexural strength of the jacketed walls under out-of-plane loading was significantly increased. During the initial behavior, the tee shear connector transferred forces successfully at the interface without slip. However, as the cracking, spalling, and crushing of the concrete increased in the exiting walls, the connection performance at the interface was significantly degraded and, consequently, the strength of the jacketed walls was significantly decreased. The flexural strength of the jacketed walls with tee shear connector was estimated considering the full and partial composite actions of the tee shear connector.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.8
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• pp.77-86
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• 2018

The purpose of this study is to examine the condition of the architectural location and the history of Yeongbojeong and investigate the motivation which formed the YuSik space and the poetical circles of it. And another purpose of the study is to discover how Yeongbojeong, located in a military camp in Western coast, displayed the poetic scenery so to be the poetic summer house among so many Nujeongs in Joseon. Yeongbojeong is currently located in Soseong-ri, Ocheon-myeon, Boryeong City, Chungnam. Yeongbojeong has the biggest size among all the summer houses in the country with 24 architectural rooms. And Yeongbojeong is not only the summer house in which people could simply see its scenery, but beyond the poetic space of Joseon, it was the unique poetic summer house which enables poets and calligraphers to enjoy imaginary freedom. The time range of the study was from the building of Yeongbojeong in 1504 to its demolish in 1901, and its space range was taken focused on the particular scenery which was seen from around Yeongbojeong. To investigate the architectural aspect of Yeongbojeong, the existing records about the summer houses, "OcheonGoonJi" and the landscape paintings etc. were referred. The travel records and poems in the work collection of the famous poets who explored Yeongbojeong were referred to examine the formation of the Yeongbojeong poetical circles. The result of the study shows the process that Yeongbojeong had become the famous national place with scenery and how it became the most visited YuSik space. And this study figured out the full account of Yeongbojeong poetical circles which had been formed by so many poets of the country for 4 hundred years.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.2
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• pp.105-114
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• 2019

Yeongbojeong was a famous pavilion of Joseon, which was located in Chungcheong-Suyeong, Ocheon-myeon, Boryeong-si. It was an open place for poets and calligraphers to freely visit during 400 years. Until today, it is widely said that Yeongbojeong was newly built by LeeRyang in 1504, who was Sugunjeoldosa(naval forces officer). The researcher investigated Gyujanggak to search Lee Maenghyu's "Asulrok-Book", and it was determined that Yeongbojeong was created by Gang Soon, 36 years earlier than LeeRyang. Accordingly, this research aimed at determining the appropriateness of the creation of Yeongbojeong. "Asulrok-Book", which said, "Yeongbojeong was Wonjeong(園亭) of Gang Soon during Yejong's reign", however this research could settle imperfection of Geungeo Gimun which was not clearly explained. Yeongbojeong was created due to Gang Soon's Wonjeong in 1468, however he was also a traitor and was executed, so that nobody wanted to mention about it. Therefore, it was determined that no phrase related to the record of creation of Yeongbojeong by Gang Soon out of lots of Yongbojeong Jeyoungsi and Gimun. Lee Maenghyu was a brave scholar who recorded 'Yeongbojeong was Gang Soon's Wonjeong' confidently, breaking such taboo. This research intended to clearly investigate the year of foundation of Yeongbojeong and establish the history of Chungcheong-Suyeong by thoroughly analyzing newly discovered "Asulrok-Book", existing "Ocheong GoonJi", and "Chungcheongsaryejib" and considering the fact relevance. As the result of this research, it was determined that Yeongbojeong was Gang Soon's Wonjeong through "Asulrok-Book". The point that Yeongbojeong was forfeited reverted to neighboring Chungcheong-Suyeong after Gang Soon was executed due to his participation in a conspiracy also was a newly discovered fact. LeeRyang, Sugunjeoldosa, can be said a brave commander, since he put up the original Yeongbojeong instead of abandoning the name Yeongbojeong of Gang soon. So far, Yeongbojeong is widely accepted as 'new construction of Yeongbojeong by LeeRyang in 1504'. However, since the record of Gang Soon's Wonjeong was discovered, and as the result of diversified analysis and examination, it is proper to correct the foundation year of Yeongbojeong as 1468.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.1
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• pp.53-60
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• 2018

For test on flooring board laminated with PVC decoration materials in order to replace the current surface materials such as HPL in decoration wood-based flooring board. the Results of comparison and analysis are as follows: For thermal conductivity, flooring board decorated with PVC did not show huge differences when temperature was rising and lowering compared to the flooring materials laminated with the existing HPL surface materials. It seems the most meaningful results for using it as indoor flooring materials. That is, in Korea where there is the culture focusing on ondol heating, use amount of heat energy and efficiency of flooring materials are very important and sensitive issues, involving immediately with household economy of final consumers, and it might be a criteria to judge basic performances required as flooring materials. As a result of the analysis on mandatory durability test items such as abrasion resistance, absorption width expansion rate, impact resistance, surface hardness, and impact absorption for flooring materials, compared to flooring board laminated with general HPL surface decoration materials, decoration wood-based flooring board laminated with PVC surface decoration materials which is higher abrasion resistance with smaller transformation and has better durability and impact absorption of the surface, is available for actual application as indoor flooring board, and for replacing surface decoration materials impregnated with heat-hardened resion such as HPL.

• Journal of the Korean Society of Clothing and Textiles
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• v.44 no.6
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• pp.1037-1052
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• 2020

This study evaluates the comfort and suitability of safety clothing. We made three safety clothes 'y', 'lg', 'lgH'. Only 'y' made with fluorescence fabric has passed International Standards (ISO 20471). A wearing test investigated the physiological response and subjective sensations at 30℃ and 50% RH, six men participated. Mean skin temperature and tympanic temperature showed significant difference with experimental course (p<.05). The micro-temperature (Tm) showed significant differences between three garments on the thigh (p<.01). When wearing 'lg', Tm was the highest. Micro-humidity indicated the interaction between clothing and the experimental course on the chest with no significant difference; however, there was a low tendency when wearing 'lgH' after the second half of exercise. The sweat rate indicated a significant difference between 'lg' and 'lgH' at 20 minutes of exercise (p<.05). Three sensations showed significant differences with the time (p<.01), there was also a tendency to feel hotter and more humid when wearing 'lg'. Skin sensation showed significant differences between pre-experiment and post-experiment (p<.05), 'y' was the most preferred. The 'lg' with long-sleeved currently worn in Korea tended to feel hotter, more humid and more uncomfortable than 'y'. It indicates that there is room for improvement in Korean safety clothing.

• Journal of Korean Society on Water Environment
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• v.27 no.2
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• pp.147-158
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• 2011

This study analyzed the linkage characteristics between road runoff and the nearest streams in mountain regions using a discriminant analysis. The road-to-stream linkage is an important characteristic to evaluate whether the contaminant on road surface is transported directly into the nearby channel system. This study evaluated a total of 51 drainage outlets of mountain roads near the Soyanggang Dam. The linkage between road and stream, slope and width of road, and other information necessary for the discriminant analysis have been collected by in situ investigation and by analyzing the Digital Elevation Model. Finally, as independent variables in the discriminant analysis, the contributing road representing the road characteristics (similar to the runoff from the road drainage outlet) and the distance and slope of the connecting channel between road and nearest stream were selected. Among these three, the distance was found to have the highest discriminant power, the contributing road the lowest. Using the discriminant function derived, 40 out of 51 cases (78.4%) were correctly discriminated and the remaining 11 cases (21.6%) were wrongly discriminated. Reasons of wrongly discriminated cases were mainly due to change in drainage outlet direction, excessive runoff, change in road-to-stream path, etc. This result also indicates that the road-to-stream linkage can be introduced or prohibited by exactly the same way.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.18 no.1
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• pp.1-11
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• 2022

As abnormal climates occur due to the increase in greenhouse gases at home and abroad, various problems such as human casualties, crop damage, energy depletion, and economic loss due to heat diseases, which are one of the extreme climate phenomena, are following one after another. In response, the government has established the 'Climate Crisis Response Special Committee' since 2018, when it recorded the greatest damage in history due to heat waves, and has been carrying out budget formation and reform of laws and systems every year to respond to heat waves. However, in relation to the heat wave damage reduction facility that is being expanded with a large budget, there is no prior research related to the degree of heat loss due to the use of the facility, the difference in effects between specific groups, and the economic effect that comes back compared to the invested budget. Therefore, from a midto long-term perspective, it is expected that it will be difficult to establish a clear direction for policy making. Therefore, in this study, representative facilities were selected according to the principle of heat reduction among the currently expanded heat damage reduction facilities, and a questionnaire survey was conducted for users of each reduction facility (waterfall, awning, pond, and elastic pavement). Accordingly, the change in the sense of heat according to the use of the heat damage reduction facility was checked, and the change in the sense of heat according to the group characteristics (gender, age, metabolic rate) was analyzed to examine the characteristics of the relationship between the facility and the users.