• Korean Journal of Environment and Ecology
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• v.32 no.2
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• pp.185-202
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• 2018

Many ecological studies regarding forest succession, which is the process of arriving at climax forest through ecological changes, have suggested that Carpinus laxiflora is the leading tree type of the climax forest of temperate zone in South Korea. However, most of these studies on C. laxiflora forest have focused on vegetation structure and succession process in specific areas or regional physiognomical forest communities, and thus some may question whether it is rational to consider C. laxiflora forest as the climax forest in South Korea's temperate forest zone. The purpose of this study was to analyze the vegetation classification, species composition, and stratum structure and to investigate the succession tendency with the vegetation data collected from C. laxiflora forests in 75 quadrates in 17 mountains between 2014 and 2017. We used the phytosociological method to analyze the vegetation structure and the importance value to analyze the stratum structure. The results showed the floristic composition of 6 vegetation units and 9 species groups. The hierarchy of the C. laxiflora community group was represented by the Ulmus laciniata community, Corylus heterophylla community (subdivided Quercus aliena group and Corylus heterophylla typical group), and Rhododendron schlippenbachii community (subdivided Fraxinus chiisanensis group, Carpinus tschonoskii group, and Rhododendron schlippenbachii typical group). Successional tendency of C. laxiflora forest based on the importance of each layer is predicted to be the total of three types such as to maintain the stand (vegetation units 2, 3, and 6), to success the Carpinus cordata forest (vegetation units 1 and 4), and to success Quercus acuta forest (vegetation unit 5).

• 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.

• Journal of Applied Biological Chemistry
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• v.55 no.4
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• pp.227-234
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• 2012

We observed that oil began to accumulate at 25 seed days after flowering (DAF) and reached the maximum potential at 35 seed DAF of oilseed rape, and the greatest weight of 100 seeds was obtained at 35 seed DAF. To survey a broad analysis of gene expression in developing embryos of Brassica napus, the Bn 300k microarray have been constructed. The Bn 300k Microarrary was designed from 80,696 unigenes clustered from 543,448 ESTs and 780 cDNA at NCBI. These arrays have been hybridized in a series of experiments with probes derived from seeds and leaf of B. napus. Approximately 8.5% of the 7,000 genes were expressed as ratios 2-fold higher in seed (25 DAF) than leaves and 0.4% at ratios 10. Also we observed that storage and cell differentiation-related genes were highly expressed at 10 DAF, whereas energy-related genes including fatty acid metabolism were increased up depending on seed maturation using Microarray, which was confirmed by reverse transcriptase polymerase chain reaction. These results suggest that B. napus arrays provide a very useful data set of seed-specific expression that can be further analyzed by examination of the promoter regions of these genes and help our understanding of the complex regulatory network in developing seeds.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.416-416
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• 2019

육상 담수는 대기중 이산화탄소($CO_2$) 배출의 중요한 발생원으로 주목되고 있다. 하천 및 강에서 대기중으로 배출되는 $CO_2$는 전 세계 탄소순환의 핵심요소이며, 대부분의 하천과 강은 $CO_2$로 과포화 되어있다. 세계적으로 하천 및 강의 $CO_2$ 배출량은 호수 및 저수지의 배출량보다 약 5배 많은 것으로 보고되고 있으나, 국내연구에서는 연구사례가 드물다. 따라서 본 연구의 목적은 낙동강 중하류에 위치해있는 강정고령보(GGW), 달성보(DSW), 합천창녕보(HCW), 창녕함안보(CHW)에서 발생되는 순 대기 배출 플럭스(Net Atmospheric Flux, NAF)의 동적 변동 특성을 분석하고, 데이터마이닝 기법을 적용하여 쉽게 수집할 수 있는 물리적 및 수질 변수로 $CO_2$ NAF를 추정하는데 사용할 수 있는 간략한 예측 모델을 개발하는데 있다. $CO_2$ NAF는 대기-수면 경계면에서의 $CO_2$ 부분압($pCO_2$)의 차에 기체전달속도를 곱하여 산정하였으며, 기체전달속도는 Cole and Caraco(1998)가 제안한 식을 사용하였다. 담수와 해수의 탄산염 시스템에서 열역학적 화학평형을 모두 고려한 $CO_2$SYS 프로그램을 사용하여 수중의 $pCO_2$를 산정하였고, $CO_2$ NAF는 Henry의 법칙과 Fick의 1차 확산법칙을 사용하여 계산하였다. $CO_2$ NAF의 시간적 변동성에 영향을 미치는 환경요인을 평가하기 위해서 상관분석, 주성분분석(Principal Component Analysis; PCA), 단계적다중회귀모델(Step-wise Multiple Linear Regression; SMLR), 랜덤포레스트(Random Forest; RF)방법을 사용하였다. SMLR 모델은 R package인 olsrr, RF 모델은 R package인 caret, randomForest를 이용하여 분석하였다. 연구 결과, 4개 보 상류 하천구간은 조류의 성장이 활발한 일부 기간을 제외한 대부분의 기간에서 $CO_2$를 대기로 배출하는 종속영양시스템(Heterotrophic system)을 보였다. $CO_2$ NAF의 중위값은 HCW에서 최소 $391.5mg-CO_2/m^2day$, DSW에서 최대 $1472.7mg-CO_2/m^2day$였다. 모든 보에서 NAF는 pH와 강한 음의 상관관계를 보였으며, $pCO_2$와 Chl-a도 음의 상관관계를 보였다. 이는 조류가 수중에서 $CO_2$를 소비하고 pH를 증가시키기 때문이다. PCA 분석 결과, NAF와 $pCO_2$가 높은 공분산을 보였으며, pH와 Chl-a는 반대 방향으로 군집되어 상관분석과 동일한 결과를 보였다. 이 연구를 통해 개발된 SMLR 모델과 RF 모델의 Adj. $R^2$ 값은 모든 보에서 0.77 이상으로 나왔으며, $pCO_2$ 측정 데이터가 없더라도 하천의 $CO_2$ NAF를 추정하는 방법으로 사용될 수 있을 것으로 평가된다.

• 한국해양학회지
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• v.25 no.2
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• pp.106-116
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• 1990

The dynamics and seasonal succession of dinoflagellate community, and their correlations with environmental parameters were investigated during the period from April, 1986 to March, 1987 at 6 selected stations in Masan Bay, Korea. The dinoflagellate standing crops varied extensively with months and stations: ranging from 44 to 2,789,900 cella/ l at surface layer and from 52 to 165,714 cells/ l at bottom layer, respectively. The distribution of standing crops by size class of dinoflagellate species showed that a group of 20-um size class was predominant throughout the present survey, since the most of dominant species have belonged to the size category. Among dominant species, Gyrodinium fissum was most dominant throughout the year in all sampling stations, particulary in June. Scripsiella trochoidea was predominant in May, Protoperidinium bipes and Prorocentrum minimum from June to September, Prorocentrum triestinum, P micans and Ceratium fusus from September to December, and Heterocapsa triquetra from December to April. The stepwise multiple regression analysis between dinoflagellate and environmental parameters revealed that salinity, nitrate-N, pH, and transparency were correlated with the variations of standing crops of dinoflagellate.

• Korean Journal of Environmental Biology
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• v.23 no.3 s.59
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• pp.238-249
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• 2005

The present study was carried out to apprehend that the pollutants originating from Jinhae Industrial Complex affect benthic polychaetous community in the northern Jinhae bay. An investigation on the macrobenthic community in Jinhae bay was conducted in September, December of 2002 and March of 2003. The benthic fauna showed mean density of 2,151 ind. $m^{-2}$ in September of 2002, 2,427 ind. $m^{-2}$ in December of 2002 and 2,394 ind. $m^{-2}$ in March of 2003. Major faunal groups are polychaetes, crustaceans and mollusks, corresponding to $73.7\%,\;12.0\%\;and\;11.7\%,$ in total mean density during all of the sampling season, respectively. The most abundant species was Lumbrineris longifolia $(24.85\%),$ followed by Tharyx sp. $(21.70\%),$ Mesochaetopterus sp. $(6.20\%),$ Heteromastus filiformis $(5.39\%),$ Prionospio sp. $(5.18\%),$ Clycinde sp. $(4.29\%),$ etc. Tharyx sp. was the highest abundant species in September of 2002, and Lumbrineris longifolia was the dominant species in another sampling seasons. The density and the species number of polychaetes were high around Chori Is. and poor near Jinhae Industrial Complex area. Cluster analysis based on the species composition showed that Jinhae bay could be divided into three regions except in March of 2003. In December of 2002, there are very distinct regions by the cluster analysis. The density of benthic polychaetes in Jinhae bay was higher than that in the other coastal area of Korea, due to the predominance by some of opportunistic species, such as Lumbrineris longifolia, Tharyx sp. and Heteromastus filiformis, etc. It means that the study area were in the process of organic enrichment.

• The Journal of the Korea Contents Association
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• v.22 no.1
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• pp.172-187
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• 2022

In the era of 'Experience Economy' user experience has emerged as a core value of a product, affecting the sustainability of the product and the long-term market viability. However, studies on product user experience factors (PUX factors) that affect the sustainability of the product still limited. Therefore, the purpose of this study is to investigate the relationship between the PUX factors and the continuance usage intention with wireless earphones, which is a wearable product that is widely used to enjoy music in everyday life. The study uses three types of wireless earphones as the target product to insight into the differentiation of this relationship represents in different types of product. The research process consisted of four steps: 1) "Investigation on the current status of wireless earphones market", 2) "User survey and derivation of PUX factors", 3 "Analyzing the relationship between PUX factors and continuance usage intention", 4) "Output of analysis results and direction of product experience design". Through this research process, it was found that the core PUX factors that influence product sustainability were different depending on the type of wireless earphone. According to the differentiation of the core PUX factors, a variety of design methods for improving product experience and product sustainability was presented.

• Korean Journal of Remote Sensing
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• v.38 no.5_2
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• pp.661-667
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• 2022

As remote sensing and GIS have been considered to be essential technologies for disasters information production, researches on developing methods for analyzing spatial data, and developing new technologies for such purposes, have been actively conducted. Especially, it is assumed that the use of remote sensing and GIS for disaster management will continue to develop thanks to the launch of recent satellite constellations, the use of various remote sensing platforms, the improvement of acquired data processing and storage capacity, and the advancement of artificial intelligence technology. This spatial issue presents 10 research papers regarding ship detection, building information extraction, ocean environment monitoring, flood monitoring, forest fire detection, and decision making using remote sensing and GIS technologies, which can be applied at the disaster prediction, monitoring and response stages. It is anticipated that the papers published in this special issue could be a valuable reference for developing technologies for disaster management and academic advancement of related fields.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.19 no.4
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• pp.272-286
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• 2014

This study was performed to investigate the community structure and health assessment of macrobenthic assemblages in Cheonsu Bay, West Coast of Korea. Total species number was 224 and mean density was $1,940ind./m^2$, both of which were dominated by polychaete worms (111 species and $1,213ind./m^2$). In terms of density, the major dominant species were the bivalve Theora fragilis ($280{\pm}213ind./m^2$), the polychaetes Heteromastus filiformis ($254{\pm}218ind./m^2$), Lumbrineris longifolia ($216{\pm}41ind./m^2$), Mediomastus californiensis ($158{\pm}97ind./m^2$) and the amphipod Eriopisella sechellensis ($167{\pm}100ind./m^2$). As a result of community statistics (cluster analysis and nMDS ordination), the macrobenthic community structure was classified two major groups (inner and mouth of bay) and two stations (station 2 near Ganwol dyke in spring and summer). The Benthic Pollution Index (BPI) and AZTI's Marine Biotic Index (AMBI) were applied to assess the benthic ecological status. During the sampling periods, the BPI Index values varied between 11 (bad status) and 92 (high status). On the other hand, the AMBI Index values was ranged between 1.34 (good status) and 4.39 (poor status). In conclusion, in terms of the mean BPI and AMBI Index values, the ecological status of Cheonsu Bay were moderate status (ecotone stage) and good status, respectively.

• Journal of Korean Society of Forest Science
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• v.101 no.3
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• pp.526-537
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• 2012

The study was carried out to classify forest vegetation structure of Mt. Guryong which is located in Bonghwa-gun, Gyeongsangbuk-do province. 72 plots(quadrat) were investigated from July to August in 2010 using phytosociological analysis methodology of Z-M schools. The forest vegetation of the study area was classified as Quercus mongolica community group that was further divided into 5 communities; Pinus densiflora for. erecta community, Acer mono community, Quercus mongolica typical community, Larix leptolepis community and Pinus koraiensis community. Pinus densiflora for. erecta community was subdivided into Quercus variabilis group and Pinus densiflora for. erecta typical group. Acer mono community was also subdivided into Prunus maackii group and Deutzia glabrata group. The vegetation of the study areas could be described as 1 community group, 5 communities and 4 groups and 7 units in total. Classified vegetation units were highly correlated with altitude and topography. It was considered that forest tending operations for maintaining need to be continuously practiced for Quercus spp. with highly relative dominance value in the Pinus densiflora for. erecta community (vegetation units 1, 2).