• Journal of the Korean Society of Environmental Restoration Technology
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• v.19 no.3
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• pp.45-57
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• 2016

This study was focused on the northernmost limit of the distribution changing of Daphniphyllum macropodum and studied characteristic of plant communities of natural monument No. 91 in Najangsan national park, Korea. The results of this study were as follows : 1. The highest importance percentage(I.P.) value at tree layer in Quercus. mongolica community was Q. mongolica, 37.8%. But the highest value of mean importance percentage(M.I.P.) was D. macropodum, 32.8%. 2. The highest I.P. value at tree layer in Carpinus laxiflora community was C. laxiflora, 47.4%. The highest M.I.P. value was C. laxiflora, 28.8% and M.I.P. value of D. macropodum was 24.0%. 3. The highest I.P. value at tree layer in D. macropodum community was D. macropodum, 55.6%. C. laxiflora and Q. mogolica I.P. value was 14.8% and 6.8%, respectively. The highest M.I.P. value was D. macropodum, 47.9%. Sapium japonicum and C. laxiflora M.I.P. value was 11.4% and 10.7%, respectively. 4. The highest I.P. value at tree layer in Quercus variabilis community was C. laxiflora, 20.8%. Q. variabilis and Acer pseudosieboldianum I.P. value was 15.3% and 12.5%, respectively. The highest M.I.P. value was D. macropodum, 21.5%. It needs to the continuous monitoring of vegetation and importance percentage change in tree layer and subtree layer of D. macropodum. The researching results of D. macropodum distribution, the distribution range of D. macropodum showed expanded more than range of Lim and Oh' result(1999). In other words, it was distributed low density level between Najangsa temple and Byeokryeonam, and distributed in upper Keumsun waterfall and Wonjeok upper valley. D. macropodum was appeared on hiking trails around from Wonjeokam to Bulchulbong. Especially, it was found in this study that D. macropodum was distributed on Seoraebong's north which placed outside area of Naejangsa region. In this study, it was considered that distribution range of D. macropodum was expanded. Also, it is expected to be used as a result of the field study of changing distribution study of broad leaved evergreen forest due to global warming.

• Journal of Korean Society for Geospatial Information Science
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• v.24 no.1
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• pp.25-33
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• 2016

In order to visualize point based Location-Based Social Network Services(LBSNS) data on multi-scaled tile map effectively, it is necessary to apply tile-based clustering method. Then determinating reasonable numbers and size of tiles is required. However, there is no such criteria and the numbers and size of tiles are modified based on data type and the purpose of analysis. In other words, researchers' subjectivity is always involved in this type of study. This is when Modifiable Areal Unit Problem(MAUP) occurs, that affects the results of analysis. Among LBSNS, geotagged Twitter data were chosen to find the influence of MAUP in scale effects perspective. For this purpose, the degree of spatial autocorrelation using spatial error model was altered, and change of distributions was analyzed using Morna's I. As a result, positive spatial autocorrelation showed in the original data and the spatial autocorrelation was decreased as the value of spatial autoregressive coefficient was increasing. Therefore, the intensity of the spatial autocorrelation of Twitter data was adjusted to five levels, and for each level, nine different size of grid was created. For each level and different grid sizes, Moran's I was calculated. It was found that the spatial autocorrelation was increased when the aggregation level was being increased and decreased in a certainpoint. Another tendency was found that the scale effect of MAUP was decreased when the spatial autocorrelation was high.

• Journal of KIISE:Software and Applications
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• v.29 no.1_2
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• pp.80-90
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• 2002

Clustering is a useful technique for grouping data points such that points within a single group/cluster have similar characteristics. Many clustering algorithms have been developed and used in engineering applications including pattern recognition and image processing etc. Recently, it has drawn increasing attention as one of important techniques in data mining. However, clustering algorithms such as K-means and Fuzzy C-means suffer from difficulties. Those are the needs to determine the number of clusters apriori and the clustering results depending on the initial set of clusters which fails to gain desirable results. In this paper, we propose a new clustering algorithm, which solves mentioned problems. In our method we use evolutionary algorithm to solve the local optima problem that clustering converges to an undesirable state starting with an inappropriate set of clusters. We also adopt a new measure that represents how well data are clustered. The measure is determined in terms of both intra-cluster dispersion and inter-cluster separability. Using the measure, in our method the number of clusters is automatically determined as the result of optimization process. And also, we combine heuristic that is problem-specific knowledge with a evolutionary algorithm to speed evolutionary algorithm search. We have experimented our algorithm with several sets of multi-dimensional data and it has been shown that one algorithm outperforms the existing algorithms.

• Korean Journal of Ecology and Environment
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• v.49 no.4
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• pp.308-319
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• 2016

In order to evaluate the role of macrophytes as refuge of zooplankton on physical distribution (i.e. summer rainfall), we investigated the environmental factors, macrophytes, and zooplankton in waterside zones (macrophytes zones) and open water zones of 17 wetlands from May and August, 2011. In this study, a total of 51 zooplankton species were identified, and Polyarthra sp. and Diaphanosoma brachyurum were found to be the most dominant species. Waterside area of each wetland were occupied by a total of 10 macrophyte species, species composition and biomass (dry weight) were different in the survey sites. Zooplankton was more abundant in waterside zone than open water zones lacking macrophytes (One-way ANOVA, df=2, F=27.1, P<0.05), in particular, waterside zone of 1, 8, 9, 10, and 11 wetland were supported by high zooplankton density after summer rainfall. This wetlands were developed by various macrophyte species than other wetland, and submerged plant commonly presented. Waterside zones with various macrophyte species provides complexity to the habitat structure, should be utilized as refuge to avoid disturbance such as summer rainfall. The results indicate that macrophytes are the key components to enhance bio-diversity include zooplankton, and the inclusion of diverse plant species in wetland construction or restoration schemes will result in ecologically healthy food webs.

• Journal of the Korean Society for Library and Information Science
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• v.49 no.4
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• pp.125-157
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• 2015

In Korean Studies, there have been made many studies for finding the identity as the intrinsic academic field, because the Korean studies have complex intertwined characteristics with other fields. However, previous related studies have been mostly focused on the qualitative content analysis method related to the major Korean Studies, the study applying the bibliometric method was not conducted. Therefore, the purpose of this study is to draw intellectual structures about the domestic and overseas Korean studies academic papers applying the bibliometric methods, and to analyze content of intellectual structures by focus group interview (FGI). As the result of this study, the intellectual structure in the domestic Korean Studies had the characteristics of the Humanities, and the intellectual structure in the foreign Korean Studies had the characteristics of the Social Sciences. Also, the domestic Korean Studies encompassed a wide range of period from ancient to modern times, while the foreign Korean Studies focused on a modern and contemporary times. This study has a significance in the way that it is the first study to draw the intellectual structures in the domestic and foreign Korean Studies applying the bibliometric method, and then to carry out the comprehensive analysis through FGI with specialists in Korean Studies. However, in order to do more meaningful one-to-one comparison studies about the field of the domestic and foreign Korean Studies, many follow-up co-studies reflecting diverse opinions of many researchers in Korean Studies will be necessary.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04b
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• pp.145-147
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• 2004

본 논문에서는 무선인터넷 환경에 적합한 개인화된 상품추천에이전트를 제안한다. 기존에 유선인터넷상의 많은 개인화 추천시스템에서는 초기 사용자 모델링을 위해 사용자에게 수많은 질의를 하고 응답을 요구하였다. 그러나 이러한 방식은 무선인터넷 환경에서 정보 전송량에 따른 높은 사용요금을 고려할 때 적용하기 힘든 방식이다. 본 제안 시스템은 사용자의 Social data률 이용하여 사용자를 비슷한 연령과 성별 그룹으로 나누고, 해당 그룹에서 구매율이 높은 상품을 우선 제시한 후, 사용자 행동을 모니터링 하여 암시적(Implicit)피드백을 통해 프로파일을 생성함으로써, 번거로운 질의-응답 과정 없이도 초기 사용자 모델링을 수행할 수 있다. 프로파일 생성 이후에는 이를 기반으로 하여 사용자몰 유사한 취향을 가진 그룹으로 다시 군집화한 후 협력적 추천을 하게 되며, 프로파일에는 해당 상품의 최종 카테고리명과 키워드를 수집함으로써, 상품의 브랜드와 규격정보를 반영한 추천이 가능하다. 또한 추천 상품과 사용자의 구매데이터와의 비교를 수행하여 사용자가 해당상품을 구매하였을 경우, 상품에 대한 취향정보는 그대로 유지하고 관련 상품을 추천하되, 구매한 상품이 중복 추천되지 않도록 하였다. 시스템 평가를 위해 프로토타입을 구현하여, 다수의 사용자에게 시스템을 이용하며 관심품목을 체크하도록 하였고. 추천횟수가 반복되며 히트율이 증가하는 결과를 통해 시스템의 학습속도와 성능을 평가하였다. 그리고 쇼핌몰에서 구매경험이 있는 사용자의 기존 구매데이터와 Social data를 이용한 초기 제시상품을 역으로 비교하여 오랜 시간과 비용 발생 없이도 초기 프로파일 생성의 유효성을 증명하였다. 포함하는 XML 질의에 대해서도 웹에서 캐쉬를 이용한 처리가 효율적임을 확인하였다.키는데 목적이 있다.RED에 비해 향상된 성능을 보여주었다.웍스 네트워크상의 다양한 디바이스들간의 네트워크 다양화와 분산화 기능을 얻을 수 있었고, 기존의 고가의 해외 솔루션인 Echelon사의 LonMaker 소프트웨어를 사용하지 않고도 국내의 순수 솔루션인 리눅스 기반의 LonWare 3.0 다중 바인딩 기능을 통해 저 비용으로 홈 네트워크 구성 관리 서버 시스템 개발에 대한 비용을 줄일 수 있다. 기대된다.e 함량이 대체로 높게 나타났다. 점미가 수가용성분에서 goucose대비 용출함량이 고르게 나타나는 경향을 보였고 흑미는 알칼리가용분에서 glucose가 상당량(0.68%) 포함되고 있음을 보여주었고 arabinose(0.68%), xylose(0.05%)도 다른 종류에 비해서 다량 함유한 것으로 나타났다. 흑미는 총식이섬유 함량이 높고 pectic substances, hemicellulose, uronic acid 함량이 높아서 콜레스테롤 저하 등의 효과가 기대되며 고섬유식품으로서 조리 특성 연구가 필요한 것으로 사료된다.리하였다. 얻어진 소견(所見)은 다음과 같았다. 1. 모년령(母年齡), 임신회수(姙娠回數), 임신기간(姙娠其間), 출산시체중등(出産時體重等)의 제요인(諸要因)은 주산기사망(周産基死亡)에 대(對)하여 통계적(統計的)으로 유의(有意)한 영향을 미치고 있어 $25{\sim}29$세(歲)의 연령군에서, 2번째 임신과 2번째의 출산에서 그리고 만삭의 임신 기간에, 출산시체중(出産時體重) $3.50{\sim}3.99kg$사이의 아

• Korean Journal of Social Welfare Studies
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• v.45 no.3
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• pp.71-95
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• 2014

The purpose of this study is to examine the effects of household income types and sources on the depressions and self-respect of the old aged. Although household income types and sources are supposed to be important to the mental health of the old aged as well as income level, there have been little policy interests to them. This study analyze the relationship between the household income types & sources and the mental health of the old aged, using the 8th data from the Korean Welfare Panel Study. Major findings are as follows. First, we find that there are considerable variations in the household income sources composition among the old aged, and that types of household income are related to the individual and family features of the old aged. Second, the results of regression analyses show that the household income types are associated with the depression and self-respect of the old aged. And, we find that some income sources affects the mental health of the old aged. The results of this study suggest that there should be policy attentions to the mental health effects of the household income sources so as to increase the adequacy of the income security system for the aged in Korea.

• Korean Journal of Social Welfare Studies
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• v.49 no.2
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• pp.5-38
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• 2018

The purpose of this study is to examine work-life balance by analyzing time schedules of married couple. The 2014 Korea Time Use Survey dataset was used for the analysis. Finally, 6,262 time diaries of 3,131 households were included in the analysis. The study used sequence analysis in particular, by applying the Lesnard(2014)'s dynamic hamming matching (DHM) method, which is useful for the time diary analysis where timing is a key factor. This study explored daily schedules of each man and woman according to 9 types of couple-combined work-schedules, which had been already derived by cluster analysis. The daily schedules were identified according to the activities divided as labor, housework, sleep, self-management, active leisure, passive leisure, and others. Here, time allocation was analyzed through various graphs showing average time amount and modal states by time period. Based on the analysis, it summarized that "long working hours as a main factor of work-life imbalance", "gender inequality of time use", "non-standard hours work impairing quality of life and "poverty of leisure time"as characteristics of work-life imbalance. Finally this study discussed the social policy implications to support work-life balance.

• Korean Journal of Environment and Ecology
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• v.33 no.5
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• pp.596-604
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• 2019

This study conducted a sediment culture experiment to investigate the effects of sediment oxygen demand (SOD) and environmental factors on sediment and water quality. We installed a leaching tank in the laboratory, cultured it for 20 days, and analyzed the relationship between P and Fe in the sediment. As a result, the dissolved oxygen of the water layer decreased with time, while the oxidation-reduction potential of the sediment progressed in the negative direction to form an anaerobic reducing environment. The SOD was measured to be 0.05 mg/g at the initial stage of cultivation and increased to 0.09 mg/g on the 20th day, indicating the tendency of increasing consumption of oxygen by the sediment. The change is likely to have caused by oxygen consumption from biological-SOD, which is the decomposition of organic matter accumulated on the sediment surface due to the increase of chl-a, and chemical-SOD consumed when the metal-reducing product produced by the reduction reaction is reoxidized. The correlation between SOD and causality for sediment-extracted sediments was positive for Ex-P and Org-P and negative for Fe-P. The analysis of the microbial community in the sediment on the 20th day showed that anaerobic iron-reducing bacteria (FeRB) were the dominant species. Therefore, when the phosphate bonded to the iron oxide is separated by the reduction reaction, the phosphate is eluted into the water to increase the primary productivity. The reduced substance is reoxidized and contributes to the oxygen consumption of the sediment. The results of this study would be useful as the reference information to improve oxygen resin.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.214-214
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• 2019

가뭄이 '심함' 단계 이상 도달 시에는 매주 수문분석을 수행하여 가뭄전망을 수행하여야 한다. 이를 위해서는 기상청의 강수량과 기온 등의 기상예측 자료가 필요하다. 현재 기상청에서는 3개월 기상전망으로 월단위 강수량과 평균기온을 매월 제공하고 있다. 1개월 전망에서 4주의 강수량합과 평균기온을 제공하고 있다. 하지만, 향후 4주간을 전망하는 1개월 전망에서는 1주단위의 강수량과 평균기온이 아닌, 4주간의 강수량합과 평균기온을 1주일 단위로 업데이트해 WINS에 제공하고 있다. 1주단위의 강수량과 평균기온을 취득하기 어려워, 평년 일단위 강수량과 평균기온 자료를 사용하여 4주간의 자료를 1주 단위로 분할하는 방법을 사용하였다. 주간단위 수문자료의 처리를 위해 국제표준기구(ISO)에서 제시하는 기준(ISO 8601)에 따랐다. ISO 8601은 월요일부터 일요일까지를 1주로 정의하며 현재 사용하고 있는 날짜체계와 1대1로 대응되도록 하였다. 예를 들면 1981년 2월 22일은 '1981-W07-7' 또는 '1981W077'로 표시한다. 표시된 형식은 1981년 7번째 주 일요일을 뜻한다. 이 기준에 따라 수문자료를 정리할 수 있도록 프로그램을 개발하였다. 주간 단위 잠재증발산량 계산은 월잠재증발산량 프로그램을 1주단위로 계산할 수 있도록 수정 및 보완하여 개발하였다. 수정 및 보완한 부분은 외기복사(外氣輻射)량 계산부분이다. 외기복사량은 지구가 태양을 1년 주기로 공전하므로 특정 위도에서 특정날짜에 따라 복사량이 달라지므로 주간단위의 월요일부터 일요일에 해당하는 날짜의 외기복사량을 각각 계산하고 이를 평균하여 주간단위 대푯값으로 사용하도록 하였다. 계산된 주간단위 외기복사량과 최고 최저기온을 입력하여 Hargreaves식에 의해 잠재증발산량을 계산한다. 융적설을 포함한 주단위 강우-유출 모형의 매개변수를 추정하기 위해 전국 24개 지점의 수문자료를 사용하였다. abcd 모형과 융적설모듈의 초기값 포함 11개 매개변수를 SCE-UA 전역최적화 알고리즘으로 추정하였다. 추정된 유역의 매개변수는 토양배수, 토양심도, 수문지질, 유역특성인자를 사용한 군집분석 결과에 의해 113개 중권역에 할당하였다. 개발된 주간단위 강우-유출 모형은 비교적 단기 가뭄전망을 위해 사용된다. 계산된 유량은 자연유량이며, 전국 취수장 수량, 하수처리장 방류수, 회귀수를 반영하여 지점별 유량을 계산하여 가뭄전망에 사용되고 있다.