• Computers and Concrete
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• 제21권6호
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• pp.669-679
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• 2018

In this paper the behavior of reinforced concrete (RC) beam-column connections under cyclic loading was analyzed. The specimens, manufactured in a reduced-scale were made of (a) recycled aggregate concrete (RAC) by replacing 30% of natural coarse aggregate (NCA) with recycled coarse aggregate (RCA) and (b) RAC incorporating Polyethylene terephthalate (PET) fiber i.e., PET fiber-reinforced concrete (PFRC) at the joint region. PET fiber (aspect ratio=25) of 0.5% by weight of concrete used in the PFRC mix was obtained by hand cutting of post-consumer PET bottles. A reference specimen was also prepared using 100% of NCA and subjected to similar loading sequence. Comparing the results the structural behavior under cyclic loading of RAC specimens are quite similar to the reference specimens. Damage tolerance, load resisting capacity, stiffness degradation, ductility, and energy dissipation of the RAC specimens enhanced due to addition of PET fibers at the joint region. PFRC specimens also presented a lower damage indices and higher principal tensile stresses as compared to the RAC specimens. The results obtained gave experimental evidence on the feasibility of RAC for structural use. Using PET fibers as a discrete reinforcement is recommended for improving the seismic performance of RAC specimens.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 가을 학술논문 발표대회
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• pp.49-50
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• 2022

There are continuous cases of fire expansion due to fire door problems around the world, including the 2010 Shanghai Apartment Fire, the 2017 Grenfell Tower Fire in England, and the 2020 Ul-san Residential and Commercial Complex Fire. In order to prevent such fire damage, the country has strengthened the performance standards of fire doors, and recently, efforts have been made to ensure the best performance of fire doors by introducing a quality recognition system. Securing the performance of fire doors is a very important aspect. However, there is a concern that old fire doors may not function normally in the event of fire due to natural deterioration, corrosion, and damage during the use process, but countermeasures are insufficient. Therefore, from a management perspective, it is very important to maintain fire doors and secure an appropriate replacement time. Therefore, the purpose of this study is to determine whether the fire door has durability to prevent fire spread in the process of use through operation probability analysis and expert surveys, and to propose an appropriate useful life of the fire door.

• 한국산림과학회지
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• 제103권4호
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• pp.528-536
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• 2014

최근 기후변화로 인해 관심이 증대되는 도시 녹지 내 난대상록활엽수의 동해피해 현황을 조사하여 그 특성을 분석하였다. 각 개체목의 주요 부위별 피해빈도를 분석한 결과, 줄기 피해는 동백나무가 59.6%로 가장 낮았으며, 후피향나무가 83.3%로 가장 많은 피해를 입은 것으로 나타났다. 피해도는 지역별로 진주지역이 가장 피해가 심하였으며(p<0.001), 식재구역의 경우 생태공원이 가장 높은 피해도를 보였다(p<0.001). 식재 환경별로 수하식재지(p<0.01), 단목식재(p<0.001), 평탄지(p<0.001) 및 유기물이 많은 곳(p<0.05)에서 피해도가 낮았다. 생육인자와 피해도와 간의 상관분석 결과 수고, 수관폭의 상관계수가 각각 -0.432, -0.470으로 피해도와 부의 상관관계로 나타났다. 따라서 효율적인 난대상록활엽수의 도시녹지 조성을 위해서는 수종, 입지환경 특성을 충분히 고려하여야 할 것으로 사료된다.

• 한국도로학회논문집
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• 제20권1호
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• pp.35-45
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• 2018

PURPOSES : This study examines the performance changes of road networks according to the strength of a disaster, and proposes a method for estimating the quantitative resilience according to the road-network performance changes and damage scale. This study also selected high-influence road sections, according to disasters targeting the road network, and aimed to analyze their hazard resilience from the network aspect through a scenario analysis of the damage recovery after a disaster occurred. METHODS : The analysis was conducted targeting Sejong City in South Korea. The disaster situation was set up using the TransCAD and VISSIM traffic-simulation software. First, the study analyzed how road-network damage changed the user's travel pattern and travel time, and how it affected the complete network. Secondly, the functional aspects of the road networks were analyzed using quantitative resilience. Finally, based on the road-network performance change and resilience, priority-management road sections were selected. RESULTS : According to the analysis results, when a road section has relatively low connectivity and low traffic, its effect on the complete network is insignificant. Moreover, certain road sections with relatively high importance can suffer a performance loss from major damage, for e.g., sections where bridges, tunnels, or underground roads are located, roads where no bypasses exist or they exist far from the concerned road, including entrances and exits to suburban areas. Relatively important roads have the potential to significantly degrade the network performance when a disaster occurs. Because of the high risk of delays or isolation, they may lead to secondary damage. Thus, it is necessary to manage the roads to maintain their performance. CONCLUSIONS : As a baseline study to establish measures for traffic prevention, this study considered the performance of a road network, selected high-influence road sections within the road network, and analyzed the quantitative resilience of the road network according to scenarios. The road users' passage-pattern changes were analyzed through simulation analysis using the User Equilibrium model. Based on the analysis results, the resilience in each scenario was examined and compared. Sections where a road's performance loss had a significant influence on the network were targeted. The study results were judged to become basic research data for establishing response plans to restore the original functions and performance of the destroyed and damage road networks, and for selecting maintenance priorities.

• 한국환경보건학회지
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• 제46권5호
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• pp.588-598
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• 2020

Objectives: Human indices were developed to determine returning point of residents and damage restoration after the chemical accident Methods: To determine the returning point of residents after the chemical accident, a new concept, the standard man model was introduced as a human index, in which both H-code and its acute effects were main idea. To evaluate the applicability, a hydrogen fluoride leakage accident in Gumi was applied. The returning point were suggested as the conservative remission period of acute effects among relevant hazard effects and compared with actual returning point. The coverage of each age group were considered with reflecting average daily dose expected for actual residents. In addition, a relief-index as a social-scientific approach was reflected as well to apply the damage restoration Results: Actual returning point of residents in Gumi was 88 days; and that of standard man model suggested was 84 days. The expected amount of exposure at aged 12 or under was at least 2.35 times greater than that of this model, 40s, theoretically. However, their population ratio was less than 1%, so 99% of residents could be applied when the standard man model was applied. The relief-index was as an objective and quantitative methodology to apply the qualitative aspect. Conclusions: Although evaluated as a relatively positive result, there was a limitation such as the number of accident applied to the verification of standard man model. The relief index was also considered, but further research should be carried out to find threshold level for the relief.

• 패션비즈니스
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• 제12권6호
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• pp.11-22
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• 2008

The goal of this study is to provide beauticians with the fundamental material to use effectively heat permanent wave in beauty industry as well as their customer's satisfaction. It carried out an experiment with damaged hair of a woman in her late twenties to investigate the change of physical and morphological characteristics by its water content when performing heat permanent wave. After spreading 0g, 1g, 2g, 3g, and 4g of water on damaged hair respectively, heat permanent wave was treated and the change of hair was observed. The change of physical characteristic was compared through permanent wave form of hair, tensile strength and elongation. The change of morphological characteristic was observed through Scanning Electron Microscope(SEM) and Transmission Electron Microscope(TEM). The result of experiment on the physical specificity revealed that permanent wave form was the most ideal when the water content was 2g, also 3g. Though the materials with much moisture content formed the results were not satisfied. The material with 0g of water content didn't make the wave. In terms of tensile strength and elongation, tensile strength was generally reduced as per the damaged degree of hair. On the contrary, elongation was increased. It observed the changes of morphological characteristic that the damage on hair cuticle was deepen, as its moisture content was decreased, and cuticle's surface was worn away. The observation of fine structure on hair section by transmission electronic microscope also certainly showed the result that damaged hair having experience with chemical treatment had got much damaged to hair cuticle as well as hair cortex. Generally chemical treatment makes hair damaged. Under consideration of this aspect, the ultimate goal of this thesis is to minimize the damage of hair caused by chemical treatment and get the satisfaction on the hair style. According to the result of experiment, the damaged hair whose moisture content was 3g showed the best permanent wave form.

• 동의생리병리학회지
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• 제31권5호
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• pp.255-263
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• 2017

This article is for understanding relations between the classifications of gastritis and syndrome differentiation types of Korean Medicine through research on syndrome differentiations of clinically applied gastritis and literature of Korean Medicine. Clinical papers were searched in China Academic Journals(CAJ) of China National Knowledge Infrastructure(CNKI) from 1995 to 2015. Conclusions are as follows. First, disease mechanism of chronic gastritis are qi stagnation, damp stagnation, heat obstruction, blood stasis obstruction, yin damage, damage to collaterals with healthy qi deficiency and pathogenic qi. And qi movement stagnation is shown through the status of chronic gastritis. Second, chronic superficial gastritis belongs to qi aspect syndrome and mainly pathogen excess syndrome. And the key mechanisms are congestion and disharmony of stomach qi sometimes combined with liver depression, food accumulation and dampness-heat. Third, chronic atrophic gastritis belongs to qi-blood syndrome and deficiency-excess complex syndrome with the root of spleen qi deficiency and stomach yin deficiency and the tip of blood stasis, qi stagnation. And key mechanism is damage to collaterals with healthy qi deficiency and toxin-blood stasis. Forth, pathogen excess syndromes are shown at the early stage of chronic gastritis and healthy qi deficiency syndromes after the middle stage. Qi deficiency is shown at the beginning of the disease and yin deficiency at the late stage. And qi deficiency is related with superficial gastritis and yin deficiency with atrophic gastritis.

• 대한한의학원전학회지
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• 제21권3호
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• pp.177-258
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• 2008

An Epidemic disease is regarded as warm disease by Korean Medicine. Warm disease is highly contagious and shows an unfavorable condition, and that is characteristic of being widely prevalent. Warm disease study cope with this epidemic disease opportunely. In the Myeong[明] and Cheong[淸] Dynasty, warm disease study got into the region of Korean medicine of today and "The Sections of Warm Disease(溫病條辨)" contributed to the cause of the study was really great. "The Sections of Warm Disease" written by Ohguktong(吳鞠通) in the Cheong Dynasty are divided into the three sections of Upper burner[上焦], Middle burner[中焦] and Lower burner[下焦]. Ohguktong, dealing with the contents of Defense-aspect[衛分], Gi-aspect[氣分], Construction-aspect[營分], Blood-aspect[血分], and so forth in all "Sections of Warm Disease", made use of Seopcheonsa(葉天士)'s Defense Gi[衛氣], Construction, and Blood pattern identification with Triple burner[三焦] pattern identification and six channel pattern identification. And he, having a correct understanding of the nature of medicine, suggested in detail that the directions of medicine and described the processing according to method and the method to take medicine. To conclude, Ohguktong(吳鞠通) Tong in "The Sections of Warm Disease" not only formulated the system of the practical theory of warm disease but also solidified the foundation covering warm disease and its treatment as well, He established the new method of treatment and formula related to warm disease and made a definite distinction between cold damage[傷寒] and warm disease[溫病].

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.431-431
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• 2012

A compact tokamak reactor concept as a 14 MeV neutron source is desirable from an economic viewpoint for a fusion-driven transmutation reactor. LAR (Low Aspect Ratio) tokamak allows a potential of high "see full txt" operation with high bootstrap current fractions and can be used for a compact fusion neutron source. For the optimal design of a reactor, a radial build of reactor components has to be determined by considering the plasma physics and engineering constraints which inter-relate various reactor components and are constrained to use ITER physics and technology. In a transmutation reactor, the blanket should produce enough tritium for tritium self-sufficiency and the neutron multiplication factor, keff should be less than 0.95 to maintain sub-criticality. The shield should provide sufficient protection for the superconducting toroidal field (TF) coil against radiation damage and heating effects of the fusion neutrons, fission neutrons, and secondary gammas. In this work, characteristics of transmutation reactor based on LAR tokamak is investigated by using the coupled system analysis.

• 소음진동
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• 제11권1호
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• pp.104-110
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• 2001

The demand of blasting work in civil engineering work is increasing because of the increasing social infra-structural construction work. The blasting method creates large benefit in regard to the economic aspect and shortening construction period. This method, however, has problems to be solved in respect to the blasting vibration and noise. Blasting vibration and noise have been studied by many workers, regarding to the impact on the structure and human body. This investigation is concerned on the affect of blasting vibration and noise on the animals which is relatively new. In general, animals have inferior mental capacity than human in hearing but have higher sensitivity on the vibration and noise due to blasting. The object of this study is to investigate an appropriate measurement of lessening damage on the animals by vibration and noise due to blasting.