Most wetlands worldwide have suffered from extensive human exploitation. Unfortunately they have been less explored compared to river and lake ecosystems despite their ecological importance and economic values. This is the same case in Korea. This study was aimed to estimate the assemblage attributes and distribution characteristics of benthic macroinvertebrates for fifty wetlands distributed throughout subtropical Jeju Island in 2021. A total of 133 taxa were identified during survey periods belonging to 53 families, 19 orders, 5 classes and 3 phyla. Taxa richness ranged from 4 to 31 taxa per wetland with an average of 17.5 taxa. Taxa richness and abundance of predatory insect groups such as Odonata, Hemiptera and Coleoptera respectively accounted for 67.7% and 68.2% of the total. Among them Coleoptera were the most diverse and abundant. Taxa richness and abundance did not significantly differ from each wetland type classified in accordance with the National Wetland Classification System. There were three endangered species (Clithon retropictum, Lethocerus deyrolli and Cybister (Cybister) chinensis) and several restrictively distributed species only in Jeju Island. Cluster analysis based on the similarity in the benthic macroinvertebrate composition largely classified 50 wetlands into two major clusters: small wetlands located in lowland areas and medium-sized wetlands in middle mountainous regions. All cluster groups displayed significant differences in wetland area, long axis, percentage of fine particles and macrophyte composition ratio. Indicator Species Analysis selected 19 important indicators with the highest indicator value of Ceriagrion melanurum at 63%, followed by Noterus japonicus (59%) and Polypylis hemisphaerula (58%). Our results are expected to provide fundamental information on the biodiversity and habitat environments for benthic macroinvertebrates in wetland ecosystems, consequently helping to establish conservation and restoration plans for small wetlands relatively vulnerable to human disturbance.

벽계천의 어류군집 특성 및 멸종위기 4종의 서식 양상을 밝히기 위해 2020년 4월부터 9월까지 조사를 실시하였다. 조사기간 동안 7개 지점을 선정하여 조사한 결과, 채집된 어류는 9과 31종 3,415개체였다. 출현종 중 우점종은 참갈겨니 (Zacco koreanus, 31.2%), 아우점종은 피라미(Z. platypus, 15.0%), 다음으로 돌고기(Pungtungia herzi, 11.7%), 줄납자 루(Acheilognathus yamatsutae, 5.4%), 납자루(A. lanceolata intermedia, 4.8%), 밀어(Rhinogobius brunneus, 4.4%), 가는돌고기(Pseudopungtungia tenuicorpa, 4.3%) 등의 순으로 우세하였다. 출현종 중 한국고유종은 19종(고유화율 61.3%)이었고, 기후변화민감종(냉수성 어종)은 금강모치(Rhynchocypris kumgangensis)와 둑중개(Cottus koreanus) 2종이 확인되었다. 법정보호종은 환경부지정 멸종위기 야생생물 II급인 묵납자루(A. signifer)와 가는돌고기, 한강납줄 개(Rhodeus pseudosericeus), 둑중개 4종이 출현하였으며, 주로 묵납자루와 가는돌고기는 중·하류에, 한강납줄개는 중류에, 둑중개는 최상류에 서식하고 있었다. 이중 가는돌고기는 출현개체수가 가장 많았고, 전장빈도분포도로 연령을 추정한 결과, 7월기준 전장 24~35㎜는 당년생, 54~75㎜는 1년생, 82~97㎜는 2년생, 104~109㎜는 3년생 이상으로 추정되었다. 군집분석 중 우점도는 상류에서 높고 하류로 갈수록 낮아지는 경향을 보이나 다양도와 균등도, 풍부도는 상류에서 낮고 하류로 갈수록 높아지는 경향을 보였다. 하천건강성(FAI)은 매우 좋음 5개 지점, 좋음 2개 지점으로 나타나 양호하였다. 벽계천은 비교적 서식지가 잘 보존되고 있었으나 멸종위기종이 많이 서식하는 중·하류부 일부는 하천공사가 진행되면서 서식지가 교란되고 있어 보존대책이 요구되었다.

본 연구는 패류양식업이 밀집한 남해 강진만 해역에서 수하식 및 살포식 양식해역과 비양식해역을 구분하여 양식활동으로 인한 유기물 축적과 저서다모류군집 변화를 파악하고, 어장환경평가 기법을 활용하여 건강도를 평가하고자 수행되었다. 남해 강진만 해역의 평균 입도, 수온, 염분농도, 총유기탄소 등의 시·공간 분포는 정점간에 큰 차이가 없었던 반면, 출현 종수, 개체밀도와 종다양도 등은 살포식 양식 해역의 정점이 다른 해역의 정점과 비교해 상대적으로 낮은 경향을 보였다. 한편 집괴분석과 주요좌표분석 결과에서도 살포식 양식해역 정 점의 저서다모류군집이 나머지 정점의 군집과 뚜렷하게 구분되었다. 수하식 양식해역의 정점과 비양식해역 정점에서는 오염지시종인 Scolectoma longifolia와 Sigambra tentaculata가 우점종으로 출현하였으나, 수심과 해수 유통 등의 물리적인 요인에 의한 영향을 받는 일부 정점 을 제외하면 점유율이 높지 않았다. 강진만 해역의 저서생태계 건강도는 1~2등급으로 양호한 상태였다. 그러나, 다모류군집구조의 시·공간 분 포와 저서생태계 건강도지수를 고려하면 살포식 양식해역의 퇴적환경은 양식으로 인한 물리적인 교란에 영향을 받는 것으로 보여진다.

To understand the spatiotemporal distribution pattern of zooplankton and the environmental factors influencing zooplankton abundance in Gomso Bay, major harvesting area of Manila clam (Venerupis philippinarum) in South Korea, zooplankton sampling was conducted four times in autumn (October 2022), winter (January 2023), early spring (March 2023), and spring (May 2023). Among the environmental factors of Gomso Bay, water temperature, chlorophyll a concentration (Chl-a), dissolved oxygen (DO), and pH observed different patterns, while salinity and suspended particulate matter (SPM) showed no significant statistical differences between the survey periods. The zooplankton in Gomso Bay occurred 33, 29, 27, and 29 taxonomic groups during each respective survey period. In October 2022 and May 2023, arthropod plankton were dominated, while in January and March 2023, protozoa were primarily dominant. Among the Arthropods, copepods including Acartia hongi, Paracalanus parvus s. l., Corycaeus spp., and Oithona spp. commonly found along Korean coastal areas of the Yellow Sea, were dominated. Cluster analysis based on zooplankton abundance indicated a single community (stable condition) in each season, attributed to low dissimilarity distances, while three distinct clusters (autumn, winter-early spring, spring) between seasons indicated a highly seasonal environment in Gomso Bay.

This study investigated the diversity of butterfly communities inhabiting agroecosystems and examined the effect of latitude and longitude. The ecological characteristics of butterflies inhabiting rural ecosystems, such as habitat preference and food plant range, were also examined. This study was conducted from 2019 to 2022, selecting 10 locations nationwide and conducting line transect surveys every two weeks for four years, confirming a total of 112 species and 21,901 individuals. There was no difference in the number of species and individuals by region, but there was a clear difference in community composition. The most abundant species in rural ecosystems were Pieris rapae, Polygonia c-aureum, Zizeeria maha, and Colias erate, in that order. There was no significant difference in the number of species and individuals by latitude and longitude, indicating no peninsula effect. Habitat preference showed that butterflies preferring grasslands and forest edges were much more common than those preferring the forest interior, and the food breadth was mostly oligophagous, followed by monophagous and polyphagous. Butterflies inhabiting agroecosystems had ecological characteristics that preferred open spaces such as grasslands and forest edges or relatively diverse foods, due to the similarity of the environmental characteristics of the survey points. Through this study, we believe that continuous monitoring is necessary to determine whether climate change, which is currently underway and habitat change are affecting butterflies in agroecosystems.

River estuaries are dynamic and productive ecosystems with high regional biodiversity. Environmental DNA (eDNA) has become a useful approach to assessing biodiversity in aquatic ecosystems. This study was conducted to investigate fish community characteristics and species diversity in two river estuary ecosystems, the Taehwa River and Changwon Stream. We further compared conventional and eDNA metabarcoding analyses of the fish communities. The conventional survey was performed in May, July, and October 2022, while the eDNA analysis was conducted only in May. We observed various fish species with different life histories, including carp, goby, and marine fish. We also found that migratory fish, such as dace Tribolodon hakonensis, sweetfish Plecoglossus altivelis, and eel Auguilla japonica, occurred in the Taehwa River, suggesting high river connectivity. Marine fish species were predominant in the Changwon Stream, as this river is located close to the sea. The diversity indices showed that the Taehwa River generally had higher species richness, evenness, and diversity values than the Changwon Stream. A total of 9-19 species were detected in the conventional survey for the three sites, whereas 11-18 species were found from eDNA analysis. The findings indicate that the sensitivity of eDNA was similar to or higher than that of the conventional method. Our study findings suggest the efficiency and efficacy of eDNA-based fish community monitoring, although with some shortcomings in applying the genetic marker to Korean fish, including no clear-cut distinction for Korean endemic species and/or genetically closely related species groups.

This study conducted an investigation into the effects of fruit type and cultivation practices (organic and conventional) on soil characteristics and soil arthropod communities within apple, blueberry, grape, peach, and pear orchards. The collection of soil arthropod communities was achieved through the utilization of pitfall traps, with concurrent measurements taken for soil moisture content, electrical conductivity, and temperature. The findings of this study unveiled substantial impacts attributed to fruit type and cultivation practices on soil characteristics. Specifically, within organic apple orchards, discernibly higher levels of soil moisture content, electrical conductivity, and temperature were observed when compared to their conventional counterparts. The investigation into soil arthropod communities yielded a total of 1,527 individuals, classified in to five phyla and 15 orders. The range of abundance, species richness, and diversity indices varied across conventional and organic orchards. Cultivation practices were found not to exert a significant influence on soil arthropod community characteristics. However, Non-metric Multidimensional Scaling (NMDS) analysis indicated a significant differentiation in soil arthropod community structure based on cultivation practices. This study underscores the importance of considering vegetation structure and environmental characteristics that may influence soil arthropod communities comprehensively when assessing the impact of cultivation practices on soil arthropods. Furthermore, it emphasizes the need to account for both the characteristics and structure of soil arthropod communities in understanding the implications of cultivation practices on these organisms.

본 연구는 백두대간보호지역에 서식하는 포유류와 등산객의 일중 활동 주기의 비교를 통해 시간적 규모에 따른 포유류 군집의 잠재적 위험성 검증을 위해 수행되었다. 이를 위해 2015년부터 2019년까지 백두대간보호지역의 능선부 를 대상으로 무인센서카메라를 활용하여 등산객과 포유류의 활동 주기를 분석하였다. 조사 결과 담비와 다람쥐의 활동 주기는 연중 등산객의 활동 주기와 높게 중첩되었다. 또한, 노루와 고라니는 봄에 등산객의 활동 주기와 높게 중첩되며, 멧돼지는 겨울에 등산객의 활동 주기와 높게 중첩되었다. 삵과 너구리, 오소리의 일중 활동 주기는 전체기간 동안 등산객의 활동 주기와 중첩되지 않았다. 포유류의 일중 활동 주기는 종 특이적 행동 패턴과 계절에 따라 차이를 보이며, 그에 따라 등산객의 활동 주기와 중첩에 차이를 보였다. 종 특이적 행동 특성과 계절에 따른 행동의 차이로 인해 백두대간보호지역에 서식하는 포유류는 인간의 활동에 의한 간섭에 대한 영향은 차이가 발생할 것으로 예상된다. 본 연구 결과 백두대간보호지역에 서식하는 포유류의 종 특이적 행동 특성에 관한 기초자료의 제공과 더불어 종과 계절에 따른 포유류 군집의 안정성 확보를 위한 관리 및 보전 방안의 수립을 위한 기초자료로써 의미를 가진다고 판단된다.

Community composition and abundance of aquatic invertebrates are important for ecological functions. Community characteristics of insects and gastropods were compared in five regions to investigate the effect of geological factors in surveys conducted between June and August to analyze seasonal changes in invertebrate communities. Underwater traps were used to obtain a constant collection effect. Insect communities were dominated by Hydrochara affinis, Rhantus suturalis and Sigara nigroventralis, and nMDS analysis demonstrated the separation of their communities by region. H. affinis and Sternolophus rufipes were not found in Haenam and Cheolwon, respectively. The results showed the effects of regional temperature on the distribution of aquatic insects. Pomacea canaliculata, Hippeutis cantori and Austropeplea ollula were dominant in the gastropod community. The seasonal variation in the abundance of P. canaliculata was the most pronounced, and its abundance in August was 38.2 times higher than in June. The abundances of several species including Hippeutis cantori were negatively correlated with that of P. canaliculata. These results suggest that P. canaliculata is a pivotal factor that drives seasonal changes in gastropod community.

Membrane bioreactor (MBR) provides the benefits on high effluent quality and construction cost without the secondary clarification. Despite of these advantages, fouling, which clogs the pore in membrane modules, affects the membrane life span and effluent quality. Studies on the laboratory scale MBR were focused on the control of particulate fouling, organic fouling and inorganic fouling. However, less studies were focused on the control of biofouling and microbial aspect of membrane. In the full scale operation, most MBR produces high effluent quality to meet the national permit of discharge regulation. In this study, the performance and microbial community analysis were investigated in two MBRs. As the results, the performance of organic removal, nitrogen removal, and phosphorus removal was similar both MBRs. Microbial community analysis, however, showed that Azonexus sp. and Propionivibrio sp. contributed to indirect fouling to cause the chemical cleaning in the DX MBR.

This study explores modern portfolio theory by integrating the Black-Litterman portfolio with time-series clustering, specificially emphasizing K-shape clustering methodology. K-shape clustering enables grouping time-series data effectively, enhancing the ability to plan and manage investments in stock markets when combined with the Black-Litterman portfolio. Based on the patterns of stock markets, the objective is to understand the relationship between past market data and planning future investment strategies through backtesting. Additionally, by examining diverse learning and investment periods, it is identified optimal strategies to boost portfolio returns while efficiently managing associated risks. For comparative analysis, traditional Markowitz portfolio is also assessed in conjunction with clustering techniques utilizing K-Means and K-Means with Dynamic Time Warping. It is suggested that the combination of K-shape and the Black-Litterman model significantly enhances portfolio optimization in the stock market, providing valuable insights for making stable portfolio investment decisions. The achieved sharpe ratio of 0.722 indicates a significantly higher performance when compared to other benchmarks, underlining the effectiveness of the K-shape and Black-Litterman integration in portfolio optimization.

Long term variations of fish assemblage in the coastal waters of Bukchon-ri were determined using samples collected by trammel net from 2012 to 2022. Water temperature increased by 0.4℃ in 2022 that was less then 2012. During the survey period, a total of 95 species (53 families and 15 orders) of fishes were identified, Scorpaeniformes (five families and 22 species) and Perciformes (25 families and 39 species) accounted for 73% of the total number. The number of species was higher in summer than winter, showing a peak in summer at 66 species and lower in winter and autumn at 45 species. The number of individuals and the biomass peaked in summer at 1,238 individuals and 280.1 kg, and were the lowest in autumn at 597 individuals and 155.4 kg. The annual diversity index, evenness index and richness index were appeared 2.11-2.80, 0.64-0.80 and 4.70-7.34 at each years. The dominance index were appeared highest in 2014 while 2021 were appeared the lowest in 2017. The subtropical fishes were identified total of 38 species (40.0%) and the number of species was higher in 2022 at 22 (52.4%) species and lower in 2015-2017 at each 10 (31.3-37.0%) species. The dominant species of subtropical fishes were appeared rabbit fish (Siganus fuscescens), boxfish (Ostracion immaculatus), smallscale blackfish (Girella melanichthys), flag fish (Goniistius zonatus), stripey (Microcanthus strigatus), rock porgy (Oplegnathus punctatus), and bluestriped angelfish (Chaetodontoplus septentrionalis) in study sites.

본 연구에서는 대학 평생교육체제 사업에 참여하는 성인학습자의 학업중단 현상을 방지하기 위한 토 대를 마련하고자 성인학습자를 심리적 특성별로 집단을 분류하고, 그에 따른 학업지속의향 및 소진의 차 이가 있는지를 확인하였다. 이를 위해 지방소재 A 대학 성인학습자를 대상으로 설문을 진행하였고, 그 결과 108명의 데이터를 수집․분석하였다. 성인학습자의 심리적 특성(대학생활적응, 사회적지지, 학업열 의, 학업목표)으로 집단을 분류하는 군집분석을 실시하였고, 그후 이를 독립변인, 학업지속의향과 학업소 진을 종속변으로 두어 일원분산분석을 진행하였다. 그 결과 고위험집단, 위험잠재집단, 성장가능집단, 고 성장가능집단으로 4개의 군집으로 분류되었다. 그리고 이 군집별 학업지속의향, 학업소진의 차이분석 결과 통계적으로 유의하게 나타났다. 이러한 결과를 바탕으로 성인학습자 개인적 특성에 따른 군집에 따른 맞춤형 지원이 필요하다는 결론을 내렸고, 개인적 특성에 따른 군집유형을 좀 더 다각화하고 위계적으로 분류하며 맞춤형 밀착지원이 필요하다고 제언하였다.

PURPOSES : A model for minimizing cutting loss and determining the optimum layout of blocks in pavements was developed in this study. METHODS : Based on literature review, a model which included constraints such as the amount, volume, overlap, and pattern, was developed to minimize the cutting loss in an irregular pavement shape. The Stach bond, stretcher bond, and herringbone patterns were used in this model. The harmony search and particle swarm algorithms were then used to solve this model. RESULTS : Based on the results of the model and algorithms, the harmony search algorithm yielded better results because of its fast computation time. Moreover, compared to the sample pavement area, it reduced the cutting loss by 20.91%. CONCLUSIONS : The model and algorithms successfully optimized the layout of the pavement and they have potential applications in industries, such as tiling, panels, and textiles.

본 연구는 2003년부터 2022년까지 동해 남서부 해역에서 초미소(0.2-2 ㎛) 식물플랑크톤의 군집, 표층 수온 상승, 그리고 무기 영양염 간의 복잡한 상호작용을 다루었다. 동해에서 관측된 표층 수온의 상승 추세는 전 지구규모의 수온 상승과 일치하며, 여름에는 최 대 온도가 나타나지만 봄에는 최소 온도를 보여 일반적인 온대해역의 계절적 수온 변동과는 다른 양상을 보였다. 표층 무기 영양염의 농 도는 겨울에 증가하며 봄을 거치면서 서서히 감소하는 계절적 변동성을 나타냈다. 식물플랑크톤의 생물량을 대표하는 표층 총 chlorophyll-a 농도는 온대 해역의 전형적인 쌍봉분포(bimodal distribution) 양상을 보였다. 연구 기간 동안 초미소 식물플랑크톤의 기여도는 연평균 0.5%씩 지속적으로 증가하였으나, 총 chlorophyll-a 농도는 약한 감소 추세를 보였다. 초미소 식물플랑크톤의 기여도와 영양염 간에 는 강한 상관관계가 나타났으며, 이는 이러한 변동이 식물플랑크톤의 크기별 영양염의 가용성과 밀접하게 연관되어 있음을 의미한다. 이 러한 분석 결과는 해양 생태계의 변화 조건에서 식물플랑크톤이 어떻게 반응할는지 예측 가능하게 하므로, 생태학적으로 중요한 의미를 갖는다.