• 한국지반공학회논문집
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• 제29권7호
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• pp.5-15
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• 2013

노후화된 터널에서 배수공의 막힘현상은 중요한 문제점으로 대두되며, 장기적으로는 배수시스템에 폐색현상을 일으킨다. 배수시스템에서의 침전물 방지를 위한 요소기술 검증을 위해 본 연구에서는 도로터널의 토사층 및 라이닝을 모사하여 배수공의 유출수에서의 침전현상을 살펴보았다. 또한 기존의 배수공들은 대부분$5^{\circ}$ 이하로 설치되었기 때문에 배수공의 기울기를 변화시켜가며 시험하였다. 배수공의 기울기를 $2^{\circ}$로 한 경우에는 퀀텀스틱은 스케일의 생성을 방지하는 데 효과가 있었으나 자화장치는 효과가 없는 것으로 나타났다. 배수공의 기울기를 $5^{\circ}$로 한 경우에는 퀀텀스틱과 자화장치 모두 배수공내 스케일의 생성을 방지하는 데 효과가 있었으나, 특히 퀀텀스틱이 자화장치보다 더욱 효과가 있는 것으로 나타났다.

• 조명전기설비학회논문지
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• 제26권4호
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• pp.41-47
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• 2012

This paper deals with the electrical characteristics related to power loss, equivalent resistance, and leakage currents flowing through new and deteriorated zinc oxide(ZnO) arrester elements subjected to the mixed DC and 60[Hz] AC voltages. The test specimens were deteriorated by 8/20[${\mu}s$] impulse current of 2.5[kA]. The leakage current-applied voltage($I-V$) characteristic curves of ZnO surge arrester elements were measured as a parameter of the ratio of the peak of 60[Hz] AC voltage to the peak of total voltage. As a consequence of test results, in case of the same applied voltage, the leakage currents flowing through the deteriorated ZnO arrester elements were higher than those flowing through the new ZnO surge arrester elements. The cross-over phenomenon in $I-V$ curves of ZnO surge arrester elements measured as a parameter of the mixed ratio of DC and AC voltages was observed at the low current domain. The effect of DC voltage on the leakage current flowing through ZnO surge arrester elements is pronounced at the same magnitude of test voltages. In addition, the larger the applied number of 8/20[${\mu}s$] impulse current of 2.5[kA] is, the greater the power loss is, in particular, the more severe the power loss increases at higher applied voltages.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권12호
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• pp.562-567
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• 2003

Lightning arresters are deteriorated by repetition of protective operation against overvoltages or impulse currents in environments of its use. If a deteriorated arrester is left in power lines, it can lead to an accident such as a line to ground fault even in a normal system. Therefore, it is necessary to eliminate the deteriorated arrester in advance by checking the soundness of arresters on a regular basis, and to ensure the reliability of power systems by preventing accidents. Various deterioration diagnostic techniques and devices are suggested, and most of which measure leakage current components as an indicator of arrester ageing. However, the techniques based on the magnitude of leakage current measure simply RMS or peak value of leakage current components and do not provide detailed information needed in the diagnosis. In this study, we found that the wave height distributions of the total leakage currents are remarkably changed or a new wave height are produced with the progress of arrester deterioration. To propose a new technique for the diagnosis, we designed a leakage current detection unit and an analysis program which can measure leakage current magnitudes and analyze wave height distributions. From the experimental results, we confirmed that the proposed technique by analyzing the wave height distribution can simply diagnose the mode of defects such as a partial damage and an existence of punctures in arresters as well as deterioration of arresters.

• Journal of Ginseng Research
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• 제18권1호
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• pp.32-38
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• 1994

Male rats aged 15 months, which had been over-trained with 12 arm radial maze up to the criterion of 1 or 2 errors an average per trial, were divided into two groups and 7 months after the over-training and were studied the effect of red ginseng trial saponin fraction (PT) on the spatial memory function. The rats which could be improved the performance of 9.75$\pm$1.26 (within 185$\pm$8.2 1 sec) were classified into "normal group" (n=4) and the ones, which showed R-maze performance of 7.0$\pm$2.87 within 300 sec, "deteriorated memory group" (n=5). PT was dissolved in distilled water and injected into the deteriorated memory group intraperitoneally at 30 min before R-maze for 3 consecutive days. The injected amount of PT on the 1st day was 10mg/rat, 1mg/rat both on the 2nd the 3rd day. As results, the performance was restored to 9.4$\pm$2.0 after stopping ginseng administration, although the lower performance values (1.4$\pm$0.89, 2.8$\pm$0.83, 3.8$\pm$0.84, respectively) were exerted during the three days of PT administration than before PT administration (7.0$\pm$2.87) since 1 day after administratitan of PT. The restored performance values were continuously maintained up to the level of the "normal group". However, any lower performance values were not observed when PT was administered via intraperitoneal route to the normal group in about of 2 mg/rat except 10mg1ra1. The number of errors when the foods in arms were put at only 6 places was clearly reduced during the 9 days of consecutive administration of PT as compared with untreated control. These results indicated that PT administration may enhance their cognitive function after a long lapse of time not only in the memory deteriorated rats but also in normal ones. The reason exerted lower performance values during PT administration in this paper was discussed as compared with the results of T-maze behavior of another 3-month-aged rats. of another 3-month-aged rats.

• 한방안이비인후피부과학회지
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• 제28권3호
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• pp.126-134
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• 2015

Objectives : The purpose of this study is to report that Korean medical treatment is good for deteriorated moderate allergic skin after taking lotus root while getting treatment for contact dermatitis by pain relieving patch.Methods : A 54-year-old woman patient with allergic contact dermatitis received treatment with acupuncture, herbal medicine, etc. We used observation and Visual Anologue Scale(VAS) to evaluate recovery from erythema, pruritus and skin damages.Results : A visible symptoms to the naked eye and VAS scale were effectively decreased after Korean medicine treatments.Conclusions : Korean medical treatments were effective for allergic contact dermatitis deteriorated by lotus root while getting treatment contact dermatitis by pain relieving patch.

• 대한건축학회연합논문집
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• 제20권6호
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• pp.121-129
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• 2018

The present study analyzed what policies are being executed for deteriorated apartments in Japan and what characteristics each policy had in order to examine policy direction and implications for the improvement of vitalization of remodeling business of deteriorated apartments in Korea. The study results are as follows. Japan recognized social problems of deteriorated apartments and pushed forward a national level remodeling actively by preparing financial support of central government and supporting plan by city and province. First, Japan maintained initial performance of buildings through phased maintenance for deterioration of buildings and aimed to reduce environmental load and maintain asset values of buildings through enlarging durability of buildings by responding to lifestyle according to social changes. To this end, they promoted the long life of buildings through the establishment of systematic long term repair plan from the stage of moving in the buildings. Second, in order to reduce the risk of remodeling projects, they prepared an environment where business could be carried out with an easy mind in various aspects by introducing remodeling business registration system and large scale repair construction defect insurance system. Third, they reduced economic burden of main agents of remodeling business with tax preferential treatment and financial support policies. Fourth, they have established remodeling support system based on overall social issues and connected it with social effect that could be obtained through this. The remodeling policies of Japan were carried out in the direction of solving social problems and considering economic aspect rather than just improving individuals' residence environment.

• Nuclear Engineering and Technology
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• 제55권9호
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• pp.3441-3449
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• 2023

We determined the radiation shielding properties for 10CaO-xPbO-(90-x) deteriorated silica gel (DSG) glass system (x = 20, 25, 30, 35, 40, and 45 mol.%). The mass attenuation coefficient (MAC) has been estimated at photon energies of 74.23, 97.12, 122, 662, 1173, and 1332 keV using a narrow beam X-ray attenuation and transmission experiment, the XCOM program, and a PHITS simulation. The obtained MAC values were applied to estimate the half value layer (HVL), mean free path (MFP), effective atomic number, and effective electron density. Results show that the MAC value of the studied glasses ranges between 0.0549 and 1.4415 cm²/g, increases with the amount of PbO, and decreases with increasing photon energy. The HVL and MFP values decrease with increasing PbO content and increase with increasing photon energy. The recycled glass, with the addition of PbO content (20-45 mol.%), exhibited excellent radiation shielding capabilities compared to standard barite and ferrite concretes and some glass systems. Moreover, the experimental radiation shielding parameters agree with the XCOM and PHITS values. This study suggests that this new waste-recycled glass is an effective and cost-saving candidate for X-ray and gamma-ray shielding applications.

• 대한불안의학회지
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• 제18권2호
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• pp.80-91
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• 2022

Objective : Hospital workers' mental health has deteriorated because of the ongoing COVID-19 pandemic. The purpose of this study was to investigate the impact of the prolonged COVID-19 pandemic on the mental health of hospital workers and its determinants. Methods : Two surveys were conducted among employees working in a hospital that received COVID-19 patients from the early phase of the pandemic in South Korea. Data on demographics, perceived threat, workplace evaluation, resilience, and mental health status were collected using the Korean General Health Questionnaire-20 in the initial phase (February 2020) and during the third wave of COVID-19 (December 2020) for 467 and 545 workers, respectively. The mental health of hospital workers in the two phases was compared, and the risk and protective factors during the third wave were investigated. Results : The proportion of patients in the psychiatric high-risk group increased from 2.8% in the initial phase to 11.4% during the third wave. The perceived threat, workplace evaluation, and resilience of respondents deteriorated. Risk factors for mental health during the third wave included the perceived threat items of job stress, loss of control, and considering resignation. Protective factors included presence of children, workplace satisfaction, and hardiness in resilience. Conclusion : Hospital workers' mental health deteriorated as the pandemic progressed. General stress and tension such as job stress, loss of control, considering resignation rather than COVID-19-specific stress had negative effects on mental health of hospital workers. Therefore, care for work stress itself can be helpful to maintain the mental health of hospital workers. Also, governance to improve workplace satisfaction or hardiness in resilience can be a potential protective factor for hospital workers' mental health during the prolonged pandemic.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2009년도 추계학술발표대회 논문집
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• pp.132-137
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• 2009

The purpose of this study was to suggest urban regeneration methods for deteriorated downtown residential area, considering the development condition of urban blocks. Through the research that are based on literature, field survey, urban planning map and local experts consulting, it found out suitable sites for development such as a deteriorated residential zone or a unused site and it was deduced eight development types from analyzing the characters of developable sites. And then it is suggested various housing forms which were applied to eight development types of developable sites. The consequences of this research are summarized as follows. There are various housing forms by eight development types; block housing, low rise-high density court housing, medium low rise-high density housing, urban housing for low-income groups belong to T1-development of urban strategic position; block housing, housing on hilly site, semi-detached house, lodging house, urban housing for low-income groups, elderly housing belong to T2-development for living benefit; block housing, low rise-high density court housing, housing on hilly site, low rise housing, lodging housing, urban housing for low-income groups, elderly housing belong to T3-development of a small-scale rental housing; block housing, low rise-high density court housing, medium low rise-high density housing, terrace-house, housing on hilly site, low rise housing, block-typed detached house, semi-detached house, cluster-typed low rise housing, town house, urban housing for low-income groups belong to T4-residential environment renewal development; terrace-house, housing on hilly site, low rise housing, block housing, semi-detached house belong to T5-development of a small-scale housing; terrace-house, housing on hilly site, low rise housing, cluster-typed low rise housing belong to T6-development to adapt natural environment; block housing, low rise-high density court housing, low rise housing, block-typed detached house, town house belong to T7-development for community; block housing, low rise-high density court housing block housing, medium low rise-high density housing, terrace-house, housing on hilly site, low rise housing, elderly housing belong to T8-development of environment-friendly.

• 보존과학회지
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• 제27권2호
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• pp.191-199
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• 2011

견본 회화 문화재의 보존처리의 보견작업에 적합한 자외선 인공 열화견을 얻기 위해 자외선의 종류, 자외선 조사시간에 따른 열화견의 물리적 특성과 견본 회화 보존처리에의 적용성을 평가하였다. 장파장 자외선(UV-A) 조사 열화견은 단파장 자외선(UV-C) 조사 열화견에 비해 자연상태에서 열화가 일어난 생견과 유사한 표면 손상 형태를 보였다. UV-C 열화견은 자외선 조사와 함께 강도가 급격하게 떨어져 54시간을 조사하였을 때 원래 강도의 12.7%까지 저하한 반면 UV-A 열화견은 168시간 조사하였을 때 원래 강도의 14.2% 수준으로 떨어져 강도 저하가 완만하였다. UV-A 열화견의 수분율은 자외선 조사시간의 증가와 함께 7.3%까지 떨어지다가 증가하지만 UV-C 열화견은 6.0%까지 떨어지다가 다시 증가하였으며 전체적으로 UV-A 열화견의 수분이 높았다. UV-A 열화견은 밝은 황색을 띠며 황변지수가 낮은 반면 UV-C 열화견은 어두운 황갈색이며 황변지수가 높았다. 견본 회화 보존처리에의 적용성을 평가한 결과, UV-A 열화견은 UV-C 열화견에 비해 황변에 의한 색상차가 크지 않아 보견 작업시 염색이나 보채에 크게 문제가 되지 않을 정도이며, 강도면에서 UV-C 열화견은 섬유가 부서지기 쉬운 상태인 것과는 달리, UV-A 열화견은 자연상태에서 열화가 일어난 생견과 유사한 속심이 살아있는 듯한 느낌을 띠었다. 그리고 UV-A 열화견과 UV-C 열화견 모두 친수성을 가져 보채에는 문제가 없었다. 전반적인 평가 결과 UV-C 열화견 보다 UV-A 열화견이 견본 회화의 보견에 사용하기 적합하였다.