• Korean Journal of Food Science and Technology
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• v.50 no.1
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• pp.55-60
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• 2018

Microbial communities of four commercial Korean nuruks were analyzed by the 454 pyrosequencing method to correlate different characteristics of rice wine fermentation. The total and average sequencing reads of fungi in the four nuruks were 14,800 and 3,494, respectively. At the phylum level, Ascomycota was dominant in three nuruks, namely, SH, SS, and JJ, while Zygomycota was dominant in SJ. Saccharomycopsis was dominant in nuruks subjected to longer fermentation periods, such as SH and SS. The total and average sequence reads for bacteria were 31,485 and 7,871, respectively. Bacteria belonging to the phylum Firmicutes were dominant in all samples. SH showed several genera of lactic acid bacteria, such as Lactobacillus, Leuconostoc, Pediococcus, and other minor bacteria. Staphylococcus and Bacillus were the dominant bacteria in JJ and SJ, respectively.

• Korean Journal of Ecology and Environment
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• v.51 no.2
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• pp.149-159
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• 2018

Twenty-nine wetlands (20 river type and 9 lake type wetlands) in Gyeongsangnam-do were investigated to understand the characteristics of fish assemblages by the wetland type and to suggest management strategies. As a result, $10.3{\pm}4.8$ species were collected from river type wetlands on average (${\pm}SD$) and $9.1{\pm}4.1$ species from lake type wetlands. Thus, there was no significant difference in the number of species between them (Mann-Whitney U test, P>0.05). However, the species that constitute the fish assemblage showed statistically significant differences between the two wetland types (PERMANOVA, Pseudo-F=2.9555, P=0.007). Furthermore, the species that contribute the most to each type of fish assemblage were Zacco koreanus (river type, 28.51%) and Lepomis macrochirus (lake type, 23.21%), respectively (SIMPER). The results of the NMDS analysis using the fish assemblage by place classified the species into three groups (river type, lake type, and others). The current wetland management is only focused on endangered species, but this study shows a difference in fish assemblage by wetland type. Therefore, a management system based information on endemic species, exotic species and major contribution species should be provided. Furthermore, the classification of some types of wetlands based on the present topography was found to be ambiguous, and wetland classification using living creatures can be used as a complementary method. This study has limitations because only two types of wetlands were analyzed. Therefore, a detailed management method that can represent every type of wetland should be prepared through the research of all types of wetlands in the future.

• Journal of the Korean Institute of Gas
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• v.23 no.4
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• pp.19-27
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• 2019

The consumption of liquefied natural gas (LNG) has increased annually due to the strengthening of international environmental regulations. In order to produce stable and efficient LNG, it is essential to divide the global (overall) operating condition and construct a quick and accurate monitoring system for each operation condition. In this study, multi-mode monitoring system is proposed to the LNG plant fractionation process. First, global normal operation data is divided to local (subdivide) normal operation data using global principal component analysis (PCA) and k-means clustering method. And then, the data to be analyzed were matched with the local normal mode. Finally, it is determined the state of process abnormality through the local PCA. The proposed method is applied to 45 fault case and it proved to be more than 5~10% efficient compared to the global PCA and univariate monitoring.

• Korean Journal of Ecology and Environment
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• v.50 no.4
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• pp.470-477
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• 2017

The aims of this study were to analyze the physico-chemical factors and the characteristics of epilithic diatom community from 15 sites of the Naeseongcheon and tributaries located in the upper region of the Nakdong river from May to October 2016. The biological water quality was assessed using DAIpo and TDI. A total of 163 diatom taxa were identified with 2 orders, 3 suborders, 9 families, 35 genera, 145 species, 16 varieties and 2 forms. Cocconeis placentula var. lineata appeared at every examined sites. Achnanthes lanceolata, Nitzschia fonticola, Nitzschia inconspicua and Reimeria sinuata were common taxa of the Naeseongcheon. Nitzschia inconspicua and Achnanthes minutissima were major dominant species. As a result of the CCA, Electrical conductivity and total nitrogen concentration were important factors determining the diatom species composition. In the result of the biological assessment using DAIpo, the Naeseongcheon was rated at class B with an average of 62.38. In the result of assessment using TDI, the Naeseongcheon was rated at class C with an average of 66.12.

• Journal of Korea Water Resources Association
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• v.42 no.2
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• pp.149-160
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• 2009

The objective of this study is to suggest parameter regionalization scheme which is integrated two multivariate statistical methods: principal components analysis(PCA) and hierarchical cluster analysis(HCA). This technique is to apply semi-distributed rainfall-runoff model on ungauged catchments. 7 catchment characteristics (area, mean altitude, mean slope, ratio of forest, water content at saturation, field capacity and wilting point) are estimated for 109 mid-sized sub-basins. The first two components from PCA results account for 82.11% of the total variance in the dataset. Component 1 is related to the location of the catchments relevant to the altitude and Component 2 is connected with the area of these. 103 ungauged catchments are clustered using HCA as the following 6 groups: Goesan 23, Andong 6, Imha 5, Hapcheon 21, Yongdam 4, Seomjin 44. SWAT model is used to simulate runoff and the parameters of the model on the 6 gauged basins are estimated. The model parameters were regionalized for Soyang, Chungju and Daecheong dam basins which are assumed as ungauged ones. The model efficiency coefficients of the simulated inflows for these three dams were at least 0.8. These results also mean that goodness of fit is high to the observed inflows. This research will contribute to estimate and analyze hydrologic components on the ungauged catchments.

• Korean Journal of Environment and Ecology
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• v.29 no.4
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• pp.508-515
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• 2015

Post-fire restoration can affect breeding bird communities and species compositions over a long-term period by determining pot-fire succession, and a long-term monitoring is therefore required to understand its impacts on forest birds. This study aimed to document the effects of post-fire restoration methods on breeding bird communities in three areas: unburned and two burned (nonintervention and intervention with clear-cut logging and planting) stands 13 years after the stand-replacing Samcheok forest fire at Mt. Geombong in Samcheok, South Korea. According to 108 point counts during the breeding season from April to June 2013, we found that the number of individuals, observed bird species, and species diversity index in intervention stands with clear-cut logging and planting were lower than that in nonintervention and unburned control stands. Foraging and nesting guild analysis also showed a lower abundance of foliage searchers, timber drillers, primary cavity nesters and secondary cavity nesters in intervention stands than in the other stands, while no significant difference was detected between the nonintervention and unburned stands. These results imply that an interventional restoration method may deter the recovery of avian breeding communities after forest fires, and also suggest that non-interventional restoration methods may be an effective way to benefit the species diversity and density of breeding bird communities.

• Journal of the Korean association of regional geographers
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• v.18 no.4
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• pp.464-472
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• 2012

To assess the space-time clustering of FMD(Foot-and-Mouth Disease) epidemic occurred in Korea between November 2010 to April 2011, geographical information system (GIS)-based spatial analysis technique was used. Farm address and geographic data obtained from a commercial portal site were integrated into GIS software, which we used to map out the color-shading geographic features of the outbreaks through a process called thematic mapping, and to produce a visual representation of the relationship between epidemic course and time throughout the country. FMD cases reported in northern area of Gyounggi province were clustered in space and time within small geographic areas due to the environmental characteristics which livestock population density is high enough to ease transmit FMD virus to the neighboring farm, whereas FMD cases were clustered in space but not in time for southern and eastern area of Gyounggi province. When analyzing the data for 7-day interval, the mean radius of the spatial-time clustering was 25km with minimum 5.4km and maximum 74km. In addition, the radius of clustering was relatively small in the early stage of FMD epidemic, but the size was geographically expanded over the epidemic course. Prior to implementing control measures during the outbreak period, assessment of geographic units potentially affected and identification of risky areas which are subsequently be targeted for specific intervention measures is recommended.

• Journal of the Korean Data and Information Science Society
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• v.23 no.5
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• pp.983-992
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• 2012

Social indicator survey can identify the state of society as a whole. When we create a policy, social indicator survey can reflect the public opinion of the region. Social indicator survey is an important measure of social change. Social indicator survey has been conducted in many municipalities (Seoul, Incheon, Busan, Ulsan, Gyeongsangnamdo, etc.). But, the result of social indicator survey analysis is mainly the basic statistical analysis. In this study, we propose a new data mining methodology for effective analysis. We propose a 3-step complex data mining in society indicator survey. 3-step complex data mining uses three data mining method (intervening association rule, clustering, decision tree).

• Annual Conference on Human and Language Technology
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• 2018.10a
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• pp.115-119
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• 2018

다중 문서 제목 추출은 하나의 주제를 가지는 다중 문서에 대한 제목을 추출하는 것을 말한다. 일반적으로 다중 문서 제목 추출에서는 다중 문서 집합을 단일 문서로 본 다음 키워드를 제목 후보군으로 추출하고, 추출된 후보를 나열하는 형식의 연구가 많이 진행되어져 왔다. 하지만 이러한 방법은 크게 두 가지의 한계점을 가지고 있다. 먼저, 다중 문서를 단순히 하나의 문서로 보는 방법은 전체적인 주제를 반영한 제목을 추출하기 어렵다는 문제점이 있다. 다음으로, 키워드를 조합하는 형식의 방법은 키워드의 단위를 찾는 방법에 따라 추출된 제목이 자연스럽지 못하다는 한계점이 있다. 따라서 본 논문에서는 이 한계점들을 보완하기 위하여 단어 관련성 추정과 Byte Pair Encoding을 이용한 요약 기반의 다중 뉴스 기사 제목 추출 방법을 제안한다. 평가를 위해서는 자동으로 군집된 총 12개의 주제에 대한 다중 뉴스 기사 집합을 사용하였으며 전문 교육을 받은 연구원들이 정성평가를 진행하여 5점 만점 기준 평균 3.68점을 얻었다.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.26-26
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• 2022

본 연구는 하천중심선을 활용하여 Sentinel-1 위성영상기반 중소규모 하천 수체(水體) 추출 방법을 제안한다. 한강 유역의 한탄강 일부를 연구지역으로 선정하였으며, 이 지역을 촬영한 Sentinel-1 위성영상자료를 수집하였다. 여기에 개발한 방법의 검증을 위하여 유사시간대의 고해상도 광학위성 PlanetScope을 함께 수집하였다. 본 연구에서는 하천의 수체를 효과적으로 추출하기 위하여 국토지리정보원에서 제공하는 하천중심선 자료를 활용하였다. 하천중심선을 따라 유클리드 거리를 가중치로 산정한 자료(DST)와 Sentinel-1의 VH, VV 편광을 조합한 k-means 방법을 통해 위성영상의 픽셀을 군집화하였고, 최적의 매개변수 값을 산출하였다. 이 매개변수를 활용하여 Sentinel-1의 VV편광, VH편광 그리고 DST의 상관관계에 따른 타원방정식 형태의 계산식을 도출할 수 있었다. 수집한 자료의 검증결과 평균적으로 정확도는 0.65~0.75, kappa 계수는 0.8 내외를 보여 상당히 일치함을 확인할 수 있었다. 또한, 추가 확보한 30여 개의 Sentinel-1 위성영상을 제안 방법으로 추출한 수체의 면적과 유량 값을 비교해 본 결과, 유사한 변화 양상을 보였다. 본 연구는 하천 중심선자료를 활용하여 참값이 없더라도 수체 면적 추정이 가능함을 확인하였다. 제안한 방법은 현존하는 수체추출 방법보다 간단하고 신속하게 수체를 추출할 수 있을 것으로 보인다. 추후, 딥러닝을 통한 수체 식별을 추가 진행을 통해. 정확도를 높일 수 있을 것으로 기대한다.