• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.1
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• pp.32-39
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• 2018

Repairing timing and the extended service life with repairing are very important for cost estimation during operation. Conventionally used model for repair cost shows a step-shaped cost elevation without consideration of variability of extended service life due to repairing. In the work, RC(Reinforced Concrete) Column is considered for probabilistic evaluation of repairing number and cost. Two mix proportions are prepared and chloride behavior is evaluated with quantitative exterior conditions. The repairing frequency and cost are investigated with varying service life and the extended service life with repairing which were derived from the chloride behavior analysis. The effect of COV(Coefficient of Variation) on repairing frequency is small but the 1st repairing timing is shown to be major parameter. The probabilistic model for repairing cost is capable of reducing the number of repairing with changing the intended service life unlike deterministic model of repairing cost since it can provide continuous repair cost with time.

• The Journal of the Korea Contents Association
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• v.12 no.9
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• pp.211-216
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• 2012

In this study, the relationship between the organizational characteristics of police officers and the level of post-traumatic stress disorder in the comparative analysis was to check for post-traumatic stress disorder, according to the organizational characteristics affect. To accomplish this, a way ANOVA analysis of variance(One-way ANOVA) was conducted. The department in post-traumatic stress disorder level, a significant difference was found. It was more likely to be exposed to a traumatic experience if who is working in the front-line department. Post-traumatic stress disorder according to the work unit, a significant difference was found. The level of Post-traumatic stress disorder in outside job unit officers was higher than that of desk job unit offcers. Post-traumatic stress disorder according to the rank and duration of employment and the administrative district level, a significant difference was not found.

• Journal of Conservation Science
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• v.28 no.1
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• pp.75-86
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• 2012

Iksan Mireuksaji Stone pagoda was built A.D. 639 when King Moo was governing Baekje, in which Sarira has been enshrined in a hole dug in the stereobate for 1,370 years. In South Korea, about 150 cases of Sarira have been found so far. In this connection, many studies have been conducted on how to manage it and on its genesis, but there have been no data on environments to which it has been exposed. In this study, accordingly, researches were made into environments to which Sarira has been exposed as well as into how much it has been damaged under the environments. Sarira in wooden pagodas was influenced greatly by water, but that in stone pagodas by saturated relative humidity. Thus, Sarira in the containers was significantly influenced by the outside temperature for 1 to 2 days, but had no any reaction to humidity. The time it took for the humidity in a Sarira container to reach its maximum, varied depending upon the humidity of the day when Sarira was enshrined. In the case of this pagoda, the humidity reached its maximum 30 days later.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.4
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• pp.316-322
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• 2019

A probabilistic approach considering uncertainties was employed to investigate the effects on the material characteristics and strength of nuclear bio-logical shield concrete walls, when exposed to long-term radiation during the entire service life. Time-dependent compressive and tensile strengths were estimated by conducting the neutron fluence analysis. For the contaminated concrete, individual compressive and tensile failure probabilities can be possibly evaluated by not only establishing limit-state function withthe predefined critical values but also performing Monte Carlo Simulation. Nuclear power plant types similar to the Kori Unit 1, which was shut off permanently in 2017 after the 40-year operation, were herein selected for an illustrative purpose. Consequently, the probability-based performance assessment and prediction of contaminated concrete walls were well demonstrated.

• Environmental Analysis Health and Toxicology
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• v.23 no.4
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• pp.291-299
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• 2008

Bisphenol A diglycidyl ether(BADGE)는 비스페놀 A와 에피클로로하이드린의 축합에 의해 만들어지는 물질로 상업용 액상 에폭시 수지의 주성분이다. 본 연구는 clusterin mRNA 발현이 BADGE의 노출된 생식기계 독성에 연관되어 있는지를 연구하기 위해 수행하였다. BADGE는 SPF Sprague-Dawley 임신 랏트에 임신 6일부터 수유기가지 하루에 한 번 0(대조군)과 375mg/kg/day를 경구 투여하였다. 수컷 새끼는 일반 사항과 몸무게, 일반 발달 지표(예, 항문과 생식기 사이의 거리, 이개개전, 절치붕출, 유두잔류, 안검개열, 고환하강, 포피박리 등)등을 관찰하였다. 대조군과 투여군에서 다섯 마리의 수컷 새끼는 출생 후 3, 6와 9주에 부검하여 부고환의 조직학적 변화 등을 관찰하였다. BADGE 375 mg/kg/day 투여군에서 항문과 생식기 사이의 거리는 대조군보다 길어지는 경향을 보였다. 출생 후 6주와 9주에서 부고환의 상대 무게는 대조군보다 약간 증가하였으나 조직학적인 변화는 관찰되지 않았다. BADGE 투여 군에서 clusterin mRNA 발현량은 대조군에 비해 3주에 56%, 6주에 57% 그리고 9주에 86% 감소하였다. 이런 결과는 랏트의 부고환에서 clusterin은 BADGE에 반응하는 유전자 중 하나일 수 있다는 가능성을 나타낸다.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.181-181
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• 2019

기후변화의 노출분석에서 가장 중요한 인자는 정확한 강우패턴의 파악이다. 시험지구인 경기도 화성시에 위치한 버들저수지 저수지 상류지역 및 수혜구역을 대상으로 기후변화 유발인자(노출)인 강우량의 변화량을 조사 및 분석 하였다. 시험지구에 대한 강우 변화량 분석은 설계당시의 지배관측소인 수원관측소 자료(1967~2015년)를 이용해 기간이동 변화를 위해 월별, 분기별 강우량를 비교하였다(기준: 1967~2000년 평균). 강우의 공간이용은 수원관측소의 인접 강우 관측소간의 상대적 비교(연강우량 평균)를 통해 강우 변화를 분석하였고, 강우이동은 홍수기 최대강우량 비교하여 분석하였다. 분석결과 5년 단위 평균 강수량은 (기준) 1,292mm 대비 (비교1 : 2001~2005년) 1,292mm, (비교2 : 2006~2010년) 1,408mm, (비교3 : 2011~2015년) 1,349mm로 평균 대비 총강수량은 많아지고 있으며, 5년 단위의 분기별 강우기여율 중 강우의 시간적 이동에 대한 지표인 2분기(4~6월) 기준대비(23%) 비교1(25%) 비교2(21%), 비교3(22%)로 비교1 구간에서만 조금 상승했고 그 후에는 차츰 강우량이 적어진 것으로 분석됐다. 강우가 농업생산기반시설에 미치는 영향 정도를 파악하기 위해 강우량 대비 저수지의 저수율을 비교하였다. 연도별로 만수위가 아닐 때 내린 강우량을 저수지에 유효한 강우량(유효강우량)으로 조건을 주어 분석하였다. 만수위상태에서는 강우가 발생해도 하류하천으로 무효 방류된다. 특히 평수기에는 유효강우량이 30~40% 정도이지만 가뭄시기였던 2014~2016년에는 강우 기여율이 72~86%까지 올라 간 것으로 보아 강우량의 변화에 농업생산기반시설인 저수지가 크게 영향을 미치고 있으므로 "강우량- 저수량"은 농업생산기반시설에 영향을 미치는 인자로 기후변화에 대한 민감도 분석의 영향지표로 이용할 수 있다.

• Journal of Environmental Impact Assessment
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• v.30 no.5
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• pp.317-327
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• 2021

Industrial complexes have have been played an important role in various aspects such as national industrial development, economic growth. However, it is a cluster of manufacturing facilities which has a great impact on the surrounding area and the overall domestic environment during the operation of the facility. In this study, environmental influences and siting characteristics of industrial complexes were investigated based on the environmental impact assessment report from 2009 to 2019. The development tendency of industrial complexes is continuous decline, and major development areas are Gyeonggi, Gyeongsang and Chungcheong areas. We also confirmed that the average area of defenestration due to industrial complex is on the decline. Furthermore, the residential area and educational facilities, and the exposed population affected by industrial complex is constantly increased.

• Journal of Aquaculture
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• v.6 no.3
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• pp.133-146
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• 1993

Monthly variation of fatness index of the shortnecked clam was investigated at Moonhangri in Namhaedo of the southern coast of Korea from April 1991 to March 1992. The standing crops of umbo stage larvae and spats of this bivalve were also investigated. The results are as follows: The ranges of a monthly average water temperature and salinity were $6.9\~23.5^{\circ}C$ and $29.6\~33.1%o$ during the investigation period. Fatness index of the shortnecked clam decreased suddenly from June to September, which seemed to be spawning season. The umbo stage larvae of the clam were observed from May to November. The standing crops of the larvae were $883\;inds./m^3$ in August and$68\;inds./m^3$ in November. The observed number per ~ of the spats varied with the month and the different exposure time zones. The highest density $(1,508\;inds./m^3)$ was observed 1 hour exposure zone in August, and the lowest one $(28 inds./m^3)$ at 1 hour exposure station in April. Even the observed number of the spats below 4 mm in shell length were high in 1 and 3 hour exposure zones, the spats above 4 mm in shell length were observed mainly at 3 hour exposure zone.

• The Journal of Korean Academy of Prosthodontics
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• v.48 no.1
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• pp.8-15
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• 2010

Purpose: The purpose of this study was to evaluate the effect of various methods of dentin bonding agent application and air abrasion pretreatment on microtensile bond strength between dentin and resin, using a self-etching adhesive system. Material and methods: Thirty freshly extracted human molars were obtained and divided into 6 groups of 5 teeth. A 2-step self etching adhesive system (Clearfil SE Bond) was used for all groups. The control specimens were prepared using a direct immediate bonding technique. The delayed dentin sealing specimens were prepared using an indirect approach without dentin prebonding. The immediate dentin sealing specimens were prepared using dentin prebonding immediately following preparation. Immediate dentin sealing teeth and delayed dentin sealing teeth had provisional restorations using Fermit for two weeks. Then all specimens of each group were divided into two groups of three, depending on air abrasion pretreatment. Composite "crowns" were incrementally built on and specimens were stored in water for 24 hours. All teeth were prepared for a microtensile bond strength test. Bond strength data were analyzed with a one-way ANOVA test, and post hoc comparison was done using the Scheffe's test. Results: The mean microtensile bond strengths of all groups were not statistically different from each other. Conclusion: When preparing teeth for indirect restorations, IDS and DDS with Clearfil SE bond, have no difference on the microtensile bond strength between dentin and resin. Air abrasion pretreatment did not affect the microtensile bond strength when using IDS and DDS with Clearfil SE bond.

• Korean Journal of Ecology and Environment
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• v.40 no.2
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• pp.173-183
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• 2007

The Ministry of Environment plans to introduce the Whole Effluent Toxicity (WET) system in Korea. The WET test is well established in developed countries with recognizing of the limitations of physicochemical analysis method and potential risk of chemicals in water medium. Therefore, it is essential to build the ecotoxicity infrastructure for the induction of WET test. In this study, we extensively collected the domestic and foreign toxicity test methods which employ native test species to Korea. And we suggested that the domestic ecotoxicity test methods with domestic test species in Korea through extracting the range of test conditions. Five domestic fish species selected were Carassiu auratus (Crucian carp), Cyprinus carpio(Common carp), Gasterosteus aculeatus (Three spine stickleback), Misgurnus anguillicaudatus (Oriental weather fish) and Oryzias latipes (Japanese medaka), The toxicity test methods with native test species to Korea were collected from the standard methods (OECD, U.S. EPA, ASTM), government reports, SCI papers and domestic papers. We collected the 32 test methods, and suggested the suitable aquatic toxicity test methods for fish. It is expected that this study could prove a useful information to establish the ecotoxicity test methods with domestic aquatic organisms in Korea henceforth.