• Journal of the Korea institute for structural maintenance and inspection
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• v.2 no.4
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• pp.201-208
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• 1998

To observe the confinement effects of Carbon Fiber Sheet(CFS) on the high-strength R/C short columns, Fifteen specimens with CFS were manufactured and tested under uni-axial compressive load. Major variables of this study are amount, spacing, type of CFS and amount of transverse steel. Increasing the amount of transverse steel and CFS, compressive strength and axial rigidity is improved. R/C columns with transverse steel and CFS exhibited less axial stress than columns with only CFS. From the test results, it is shown that the area confined with transverse steel and CFS is considerably important to evaluate axial stress of R/C short columns.

• Journal of the Korea institute for structural maintenance and inspection
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• v.2 no.4
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• pp.148-158
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• 1998

Determining the thickness if concrete lining and detecting of the cavity where is located behind tunnel lining plays an important role in the safety diagnosis of tunnel structure and the quality control. In this study, we made use of GPR and seismic method in order to find the cavity or flaw. Although GPR is very useful method in the concrete lining without rebar, it is difficult to detect the cavity in the reinforced concrete lining. We applied mini-seismic method to the reinforced concrete lining. The obtained seismic data was processed by means of seismic section in time domain and image section of power spectrum in frequency domain using Impact-Echo method as well. The proposed method can accurately show the location and depth of the cavity in the reinforced concrete lining.

• The Journal of the Convergence on Culture Technology
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• v.8 no.6
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• pp.605-614
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• 2022

In this study, oregano was extracted by supercritical extraction and hydrothermal extraction method. In vitro experiments such as antimicrobial and antioxidant activity test were performed. As a result of the disc diffusion method, only the supercritical extracts formed a clear zone. The MIC for S. aureus was found only in the supercritical fluid extracts and it was 1000 ㎍/mL. The hydrothermal extract's MIC is 125 ㎍/mL for C. acnes. Through biofilm inhibition assay, we found that the supercritical fluid oregano extracts inhibit the biofilm of S. aureus by more than 70% even at low concentrations of 125 ㎍/mL. On the other hand, the antioxidant ability of the hydrothermal extract was better than that of the supercritical fluid extracts. Furthermore, we tried to make a skincare ingredient for atopic dermatitis by utilizing the S. aureus biofilm inhibitory ability of oregano supercritical fluid extracts. Liposome was used to overcome the low solubility of the oregano supercritical fluid extracts and increase stability.

• Economic and Environmental Geology
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• v.37 no.3
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• pp.311-324
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• 2004

We investigated the contamination and behavior of heavy metals in stream sediments within the watershed of Juam Reservoir. Many abandoned mines within the reservoir can act as a potential contaminant source for water quality. Heavy metal concentrations (Cr, Cu, Ni, Pb and Zn) in stream sediments from watershed are very low, indicating that content of heavy metals in the sediments probably do not affect the water quality in Juam Reservoir. However Pb concentration in the stream sediments increases downward streams, suggesting the possible diffusion of Pb contamination. According to the leaching ratio for stream sediments at a strong acidic condition in the abandoned mine areas, the relative mobility for metals decreases in the order of Pb＞Zn=Cu＞Ni＞Cr, indicating that Pb can have a bad effect upon the water quality in Jum Reservoir. Moreover, if contaminated sediment is placed in the bottom of reservoir (i.e., reducing condition), the relative mobility of Pb is the highest, indicating that Pb in the bottom sediments can be leached to water at interface between water and sediment with changing in physicochemical conditions.

• The Journal of the Convergence on Culture Technology
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• v.8 no.6
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• pp.615-624
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• 2022

In this study, we assessed anti-oxidant activity, anti-microbial, inhibition of biofilm formation and inflammatory factors(nitric oxide, interleukin-6, interleukin-8) inhibitory effect of Perillae semen hydrothermal extract(PSW) and three kinds of Perillae semen supercritical fluid extract(PSSs) extracted by controlling temperature with no variation of pressure. Compared with PSW, PSSs had significantly lower minimal inhibitory concentrations(MICs) against Staphylococcus aureus(S. aureus) and the ability of PSSs to inhibit formation of biofilm was also superior. PSSs reduce the production of inflammatory mediator and inflammatory cytokines significantly compared to PSW. We suggest, therefore, Perillae semen supercritical fluid 45℃ extract which showed the best anti-microbial, inhibition of biofilm formation, and inhibition of inflammatory factors production among the supercritical fluid extracts could be used for protecting patients with atopic dermatitis from pruritus and transepidermal water loss as a functional ingredient from nature.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.361-362
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• 2021

The meaning of hologram is widely used as a similar hologram. The use of holograms has been proposed in many cases. In this paper, we present an outline of similar holograms using up to 3 or 4 facets, and express the similar holograms using the results produced by 3D modeling of the university headquarters building at Wonkwang University. Through this, a virtual building seen by the human eye can be virtually shown in space through a hologram among various methods shown in a virtual space such as AR / VR / MR. Through this study, it is possible to try to construct a new digital contents utilization area by expressing various materials such as buildings or cultural property buildings through hologram.

• Journal of Korean Society of Transportation
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• v.25 no.5
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• pp.161-172
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• 2007

Vehicles transporting hazardous materials can make huge damage to people, properties and environment by traffic accidents. Therefore, transporting hazardous materials is a big issue with the cutting edge technology of communications in these days. However, despite this situation, Korean government gives limited efforts for systematic management, research and investment about hazardous materials. Accordingly, this research suggests the key path finding algorithm about management of real-time schedule and routes for vehicles transporting hazardous materials. Besides, the case study is progressed in transportation networks of Seoul in order to evaluate the reality of algorithm. Specifically, time-space network transformation is performed for time window attributes. In addition, this study proposes the techniques searching for non-dominated paths considering schedule by the multiobjective shortest path algorithm based on dynamic programming in dynamic transportation networks including multiobjective attributes.

• Tunnel and Underground Space
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• v.19 no.1
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• pp.19-30
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• 2009

For the purpose of determining the thickness of concrete lining and detect of the cavity where may be located behind tunnel lining, IE (Impact-Echo) method it effectively useful in the tunnel safety diagnosis and the quality control during the construction. As a part of case study, we applied IE method to various tunnel structure types such as road tunnel and subway tunnel constructed by NATM (New Austrian Tunnelling Method) and ASSM (American Steel Support Method). As tunnel specifications estimated from this method were compared with coring data, design drawing and other survey results, it was very good agreement with each other. In conclusion, we verified that IE method shows an accurate and reliable result. The conventional interpretation of IE method in frequency domain gives only vertical information at a certain point. However, the interpretation using time-frequency analysis and depth section imaging technique from two dimensional profiling surveys can show more reliable information about structure inside.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.3
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• pp.371-377
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• 2007

In this paper, acceleration threshold of perception for the horizontal vibration of tall buildings was estimated. Excessive vibration of tall buildings by wind can give displeasure, such as giddiness and visual insecurity. To provide comfortable environment to residents of tall buildings, acceleration needs to be limited. For tall buildings the first mode of vibration is dominant. To reproduce the first mode of vibration, experiments were performed by generating sine waves by a shaking table. A nitration house was made and forty persons were employed for experiments. The forty persons were organized into five experimental groups, each of which was composed of eight persons, and the threshold of perception for horizontal vibration was measured by increasing acceleration in the range of 0.2Hz through 1.2Hz of frequency, Performance curves were obtained by dividing the distribution of perception for horizontal vibration into the range of $0{\sim}20%,\;21{\sim}40%,\;41{\sim}60%,\;61{\sim}80%\;and\;81{\sim}100%$ and by fitting curves.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.261-261
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• 2015

지금까지 빗물에 대한 일반인들의 인식은 모두 치수에 중심을 두어왔다. 즉, 빗물은 내리자마자 곧바로 하수도를 통해 방류수역으로 신속하게 배제해야한다 것에만 관심을 두어 왔던 것이다. 이러한 문제점을 해결하기 위해 빗물을 버리고 배제하기보다 필요한 곳에서 집수하여 활용하거나 적절히 침투 또는 저류하여 물을 효과적으로 제어 관리해야할 필요성이 대두되고 있다. 안정적인 수자원 확보 및 공급에 대한 사회적 요구가 증가됨에 따라 대체방안으로서의 빗물이용관리가 제기되고 있으며, 이는 도시화 및 인구의 도서집중, 경제활동의 고도화 등 물 사용량이 증대되는 생활방식에 따라 물 공급 중단에 따른 피해 잠재성이 증가되고 있음을 의미하기도 한다. 본 과제에서는 이러한 필요성을 감안하여 대체수자원으로서의 빗물을 이용한 수자원 확보방안에 대해 연구하고, 스마트 워터그리드 관점에서의 빗물이용방안을 제시하여 그 적용성을 평가하고자 한다. 본 연구를 수행하기 위해서는 기존 대체수자원의 확보기술을 조사하고, 이를 바탕으로 다양한 수원을 통한 수자원 확보방안을 제시하고, 이 중 빗물을 이용한 수자원 확보방안에 대하여 스마트워터그리드 관점에서의 적용성을 평가하였다. 스마트워터그리드 내에서의 빗물이용을 통한 대체수자원 적용성 평가는 도서지역의 제한급수 등 물 부족 문제 해결을 위한 방안과 산간 농업지역에서의 물부족으로 인한 농작물 생산활동의 저하문제를 해결하기 위한 방안을 제시하였다. 또한 수자원확보를 위한 적정 빗물이용법 도출을 위해 최근 물 관리 패러다임의 변화를 고려한 정책사업으로의 접근, 중앙정부와 지방정부의 노력, 정부-민간 협동체계 구축을 위한 지역전문가의 활동방법 등을 제시하고자 한다. 본 연구의 결과 스마트워터그리드 체계구축을 위한 여러 요소기술 중 다중수원을 통한 용수확보 방안에서 빗물(우수)을 이용한 대체수자원 확보방안을 정립하고, 이를 이용하여 도서지역에서의 제한급수문제 해결방안과 산간 농업지역에서의 농업용수 확보방안을 제시할 수 있을 것이다.