• Journal of Conservation Science
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• v.31 no.2
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• pp.87-94
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• 2015

Plastic artwork can be appeared crack, change of color and whitening event by various environment conditions. A large scale plastic artwork often exhibits in outside it will be directly degraded by physical and chemical degradation factor such as strong sunlight, high humidity and rainfall. We should know degradation characteristic of plastics to prevent these damages. In this study, we studied degradation characteristic of plastics (5 types of wide use plastics; polypropylene, polystyrene, polyethylene, polyvinyl chloride, polyurethane) depending on various artificial degradation conditions such as high temperature, ultraviolet and these complex conditions (high temperature and ultraviolet). As a result, polypropylene, polystyrene and polyethylene show the most visible change especially polypropylene, polystyrene. Polypropylene didn't show a great change degree of tensile strength and contact angle, on the other hand polystyrene did. Polypropylene and polystyrene weakened by photo degradation, polyvinyl chloride and polyurethane had relatively good light stability. Also the high temperature and complex conditions were most degradation characteristic. High temperature worked for degradation catalyst because its energy can not enough worked for cut off binding energy of plastics while ultraviolet condition effected as directly degradation condition. Though following results, we expect it can be applied to investigation of degradation factor depending on plastic artwork materials and basic result of plastic artworks conservation.

• Journal of the Korean Society of Hazard Mitigation
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• v.6 no.3 s.22
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• pp.69-76
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• 2006

An hydraulic and hydrologic analysis procedure was proposed to reduce the inundation damage of highway in urban stream, that could contribute the EAP and Traffic control planning of Dongbu highway in the Jungrang stream basin which is one of the representative urban area in Korea. We performed the HEC-HMS runoff analysis, and the UNET unsteady flow modeling to decide the inundation reaches and their characteristics. The high inundation risk areas were of Emoon railway bridge and the Wollueng bridge, which are inundated in the case of 10 year and 20 year frequency flood respectively. We also analyze the inundation characteristics under the various conditions of the accumulation rainfall and the duration. Flood elevation at the Wolgye-1 bridge exceed over Risk Flood Water Level(EL.17.84 m) when the accumulation rainfall is over 250 mm and shorter duration than 7 hr. When neglecting backwater effect from the Han river, inundation risk are highly at the reach C2(Wolgye-1 br. ${\sim}$Jungrang br., left bank), C1(Wolgye-1 br. ${\sim}$Jungrang br., right bank), D(Jungrang br. ${\sim}$Gunja br.) in order, but when consider the effect, the inundation risk are higher than the others at the reach D2(Jungrang br. ${\sim}$Gunja br., left bank) and E(Gunja br. ${\sim}$Yongbi br.), which are located downstream near confluence.

• Journal of Korean Society of Forest Science
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• v.88 no.3
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• pp.364-373
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• 1999

This study aims to clarify the effect of forest management practices(thinning and pruning) on soil physical properties and water quality to get the fundamental information on the facility of purifying water quality after forestry practices. Rainfall, throughfall, stemflow, soil and stream water were sampled at the study sites which consist of Abies holophylla and Pinus koraiensis, in Kwangnung Experimental Forest for 6 months from March 1 to August 7, 1998. Average tree height of the management site increased by 1.8m and 0.6m more than that of the non-management site in Abies holophylla and Pinus koraiensis, respectively. Increment of average D.B.H. at the management site showed 4.7cm and 1.4cm more in Abies holophylla and Pinus koraiensis compared with that at non-management sites. Coarse(less than pF2.7) and total porosities of A layer soil at the management site increased more than those at the non-management sites in both stands. Otherwise, soil bulk density resulted in being reversely. Water qualities of throughfall, stemflow and soil water were buffered more by the management practice in both.

• Journal of The Korean Association of Information Education
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• v.22 no.5
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• pp.509-517
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• 2018

As the necessity of maker education is being emphasized and the app generation is now entering school, expectations concerning the impact of app development education are rising in the field of education. The introduction and rise in popularity of a new type of education, such as app development education, requires a change in attitude among teachers. Therefore, this study focused on the concerns of in-service teachers regarding app development education by applying the Concerns-Based Adoption Model (CBAM) of Hall and Hord (2015). For this purpose, the data was collected from 23 in-service teachers who attended a short teacher training session that introduced app development training. The data was converted to the relative intensity based on the stage of concerns questionnaire (SoCQ) scoring device and was expressed as the SoCQ profile. The results of the survey concerning app development education showed that the stage 0 concern (unconcerned) was reported most frequently by teachers and the stage 4 concern (consequence) was reported least frequently. This kind of result, which is typical at the beginning of the introduction of a new education program, indicates that teachers recognize app development education but do not have sufficient information regarding it. Qualitative results also showed that teachers understand the educational possibilities of app development education, but they were worried about the difficulties expected to be applied in the field. Based on these results, we suggest that more detailed information on app development education be provided through teacher training.

• Journal of Korea Water Resources Association
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• v.51 no.5
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• pp.425-438
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• 2018

Existing studies that analyze the causes and effects of water circulation use mostly rainfall - runoff models, which requires much effort in model development, calibration and verification. In this study, hydrological sensitivity analysis which can separate quantitatively the impacts by natural factors and anthropogenic factor was applied to the Hwacheon dam upper basin from 1967 to 2017. As a result of using various variable change point detection methods, 1999 was detected as a statistically significant change point. Especially, based on the hydrological sensitivity analysis using 5 Budyko based functions, it was estimated that the average inflow reduction amount by Imnam dam construction was $1.890\;billion\;m^3/year$. This results in this study was slightly larger than the those by existing researchers due to increase of rainfall and decrease of Hwacheon dam inflow. In future, it was suggested that effective water management measures were needed to resolve theses problems. Especially, it can be suggested that the monthly or seasonal analysis should be performed and also the prediction of discharge for future climate change should be considered to establish resonable measures.

• Journal of Korean Society of Forest Science
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• v.89 no.2
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• pp.223-231
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• 2000

This study aims to clarify the effect of forest management practices(thinning and pruning) on water quality to get the fundamental information on the facility of cleansing water quality after forest operation. Rainfall, throughfall and stemflow were sampled at the study sites which consist of Abies holophylla and Pinus koraiensis in Kwangnung Experimental Forest for 6 months from May 4, to November 1, 1999. Average tree height in the management sites increased by 0.5m more than that in the non-management sites in Abies holophylla and Pinus koraiensis, respectively. Increment of average D.B.H. at the management sites grew 3.5cm and 2.6cm more in Abies holophylla and Pinus koraiensis compared with that at non-management sites. Average pH of the total amount for the event in throughfall and stemflow was higher than that of throughfall and stemflow of the beginning of the event at the management and non-management sites. Average electrical conductivity of throughfall and stemflow at the beginning of the event was higher than that of the total amount for the event at management and non-management sites. Water qualities of throughfall and stemflow were buffered more by the management practice in both. The forest management may affect purification of water quality of throughfall and stemflow in Abies holophylla and Pinus koraiensis.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.5
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• pp.1435-1443
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• 2016

This study evaluated the sanitary state of seawater and shellfish in Yeoja bay from January 2014 to June 2016. The sampling stations for sanitary survey in Yeoja Bay was composed of 50 stations for seawater and 4 stations for ark shell and the samples have been collected monthly at a stated date. The total and fecal coliforms in seawater and Escherichia coli (E. coli) in shellfish were investigated as sanitary indicator bacteria, respectively. The geometric mean and the estimated 90th percentile ranges of total and fecal coliforms for seawater were <1.8-3.9, <1.8-2.6 and <1.8-29.7, <1.8-9.3 MPN/100 mL, respectively. The range of E. coli levels for ark shell were <20~330 MPN/100 g. The sanitary state in Yeoja bay was evaluated clean area according Korea criteria and conditionally approved area according US criteria and Class B area according EU criteria.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1991.06a
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• pp.32-32
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• 1991

성대의 점막하 조직의 부종을 특징으로 하는 폴립양 성대는 음성의 남용 및 상기도에 대한 다양한 자극 요인들에 의하여 발생된다고 보고되어 있으며, 현재까지 부종의 기전 및 병태에 대하여도 혈괴의 유리화 현상(hyalinization), 또는 단순한 혈관의 투과력 증대 등의 논란이 많은 실정에 있어 치료방법 역시 학자에 따라 견해를 달리하고 있다. 이에 저자들은 폴립양 성대의 치료에 도움을 얻고자 최근 5년간 본 교실에서 경험한 폴립양 성대 34례(남자 18예, 여자 16예, 평균연령 53.7세)에 대한 임상 소견 및 저자들의 치료 성적을 분석 검토하여 다음과 같은 결과를 얻었다. 1. 측별로는 총 34예중 양측 23예(67.6%), 편측 11예(32.4%)이었다. 2. 동반질환으로 성대에 타 질환이 있었던 예가 9예(후두용 5예, 과각화증 3예, 성대마비 1예 ; 26.5%), 수면무호흡증 5예(14.7 %)이었으며 전신질환이 있었던 예가 4예(기관지 천식 2예, 폐결핵 2예 ; 11.8%)이었다. 3. 유발요인으로는 음성남용 7예(20.6%), 상기도감염 3예(8.8%), 흡연 26 예 (76.5%)이었다. 4. 공기역학검사 및 청각심리검사가 가능하였던 14예에서 최대발성지속시간이 정상이하이었던 예가 10예(71.4%), 발성율이 정상이상이었던 예가 9예 (64.3%)이었으며, 애성의 특징도 조호성(rough)이 10예(71.4%)로 가장 많았다. 5. 총 34예를 sucking technique를 적용하여 수술적 치료를 하였는데 음성이 호전된 경우는 32예(정상 15예, 호전 17예 : 94.1%)이었으며 호전되는데 걸린 평균 기간은 2.8개월이었다. 이상의 성적으로 보아 폴립양 성대는 국소 또는 전신적으로 동반질환이 많고 흡연 등의 만성 자극 요인이 있으며 술후 음성 호전에 걸리는 기간이 길어 보다 복합적인 측면에서 치료에 임하여야 할 것으로 사료된다. with such configuration.trap with 2.88[eV] deep of injected space charge from the chathode in the crystaline regions. The origin of ${\alpha}$$_2$ peak was regarded as the detrapping process of ions trapped with 0.9[eV] deep originated from impurity-ion remained in the specimen during production process of the material, in the crystalline regions. The origin of ${\beta}$ peak was concluded to be due to the depolarization process of "C=0"dipole with the activation energy of 0.75[eV] in the amorphous regions. The origin of ${\gamma}$ peak was responsible to the process combined with the depolarization of "CH$_3$", chain segment, with the activation energy of carriers from the shallow trap with 0.4[eV], in he amorphous regions.의 증발산율은 우기의 기상자료를 이용하여 구한 결과 0.05 - 0.10 mm/hr 의 범위로서 이로 인한 강우손실량은 큰 의미가 없음을 알았다.재발이 나타난 3례의 환자를 제외한 9례 (75%)에서는 현재까지 재발소견을 보이지 않고 있다. 이러한 결과는 다른 보고자들과 유사한 결과를

• Journal of Korea Water Resources Association
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• v.39 no.5 s.166
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• pp.383-394
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• 2006

This study is for the inundation damage analysis caused by levee break, and for the applicability of GIS tool to make inundation map in the Jungrang stream basin which is one of the representative urbanized area in Korea. The FLDWAV was applied to the actual flood in 1998 to calibrate the parameters, and was used under the flood conditions of 100, 200 years and PMF for the analysis of inundation caused by the levee breach. As the conditions of the levee break, the duration of break(10, 30, 60 min), the width of break(10, 20, 30m) and the location of the break are considered. We found out that the range and the volume of the inundation are strongly influenced by the location of the levee break, the break width in order. And, we compared the two processes of making the inundation map using WMS and ArcView model. The Process 1 which use only WMS has the benefit by its simplicity but there could be considerable errors in making the inundation map, while Process 2 where the ArcView model is introduced to WMS has the capability of making detailed topography map but needs more process time. This study could contribute to levee breach flood analysis and making flood map to establish the EAP(Emergency Action Plan) in the urban basin.

• Journal of Korea Water Resources Association
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• v.36 no.2
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• pp.161-172
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• 2003

This study has evaluated the stream gauge network with the main emphasis on if the current stream gauge network can catch the runoff characteristics of the basin. As the evaluation of the stream gauge network in this study does not consider a special purpose of a stream gauge, nor the effect from a hydraulic structure, it becomes an optimization of current stream gauge network under the condition that each stream gauge measures the natural runoff volume. This study has been applied to the Nam-Han River Basin for the optimization of total 31 stream gauge stations using the entropy concept. Summarizing the results are as follows. (1) The unit hydrograph representing the basin response from rainfall can be transferred into a probability density function for the application of the entropy concept to optimize the stream gauge network. (2) Accurate derivation of unit hydrographs representing stream gauge sites was found the most important part for the evaluation of stream gauge network, which was assured in this research by comparing the measured and derived unit hydrographs. (3) The Nam-Han River Basin was found to need at least 28 stream gauge stations, which was derived by considering both the shape of the unit hydrograph and the runoff volume. If considering only the shape of the unit hydrograph, the number of stream gauges required decreases to 23.