• Title/Summary/Keyword: COMMUNITY STRUCTURE

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Distribution characteristics and community structure of picophytoplankton in the northern East China Sea in 2016-2017 (2016~2017년 동중국해 북부해역의 초미소식물플랑크톤 분포 특성)

  • Park, Kyung Woo;Yoo, Man Ho;Oh, Hyun Ju;Youn, Seok Hyun;Kwon, Kee Young;Moon, Chang Ho
    • Korean Journal of Environmental Biology
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    • v.37 no.1
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    • pp.93-108
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    • 2019
  • To investigate the temporal-spatial distribution of picophytoplankton in relation to different water masses in the northern East China Sea (ECS), picophytoplankton abundance were investigated using flow cytometry with environmental factors in 2016-2017. The results from the analysis of flow cytometer data showed that Synechococcus appeared across all seasons, exhibiting its minimum abundance in winter and maximum abundance in summer. Furthermore, high abundance was detected in the surface mixed layer during spring and summer when vertical stratification occurs; in particular, Synechococcus exhibited maximum abundance in thermocline layer, indicating a close correlation to water temperature and thermocline formation. In addition, the abundance of Synechococcus indicated a decrease in the western seas in 2017 compared to 2016 under the strong influence of the Changjiang Diluted Water (CDW). This was determined by the significant influence of the CDW on the abundance of Synechococcus during summer in the northern waters of the ECS. In contrast, Prochlorococcus did not appear during winter and spring, and its distribution was limited during summer and autumn in the eastern seas under the influence of the Kuroshio current. The largest range of Prochlorococcus distribution was confirmed during autumn without the influence of the CDW. Thus, the distribution pattern of each picophytoplankton genus was found to be changing in accordance to the extension and reduction of sea current in different seasons and periods of time. This is anticipated to be a useful biological marker in understanding the distribution of sea currents and their influence in the northern waters of the ECS.

Seasonal phytoplankton dynamics in oligotriphic offshore water of Dokdo, 2018 (2018년 독도 주변 빈영양 수괴에서 계절별 식물플랑크톤 동태)

  • Lee, Minji;Kim, Yun-Bae;Kang, Jung Hoon;Park, Chan Hong;Baek, Seung Ho
    • Korean Journal of Environmental Biology
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    • v.37 no.1
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    • pp.19-30
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    • 2019
  • To investigate the characteristics of seasonal environment and phytoplankton community structure in the coastal area of Dokdo, a survey of Dokdo around waters was conducted during the four seasons. Phytoplankton of 4 phylum 72 species in four seasons were collected in Dokdo around water. The seasonal mean abundance of phytoplankton were $3.32{\times}10^4cells\;L^{-1}$ in winter, $1.04{\times}10^4cells\;L^{-1}$ in spring, $0.28{\times}10^4cells\;L^{-1}$ in summer, and $4.86{\times}10^4cells\;L^{-1}$ in autumn in Dokdo around water. During winter, the diatoms Chaetoceros spp. had dominated. During spring, when the nutrients in the euphotic layer were depleted, the nano-flagellates and Cryptomonas appeared at surface layer. In summer, the abundance of phytoplankton was relatively low, which lead to occurrence of diatoms such as genus of Chaetoceros, Rhizosolenia, and Skeletonema. In autumn, Pseudo-nitzschia spp. was the most dominant species and tropical species such as Amphisolenia sp. and Ornithocercus magnificus were observed, implying that they may have introduced within warm water current such as Kurosiwo Current. Therefore, although natural phytoplankton communities in the vicinity water of Dokdo are mainly influenced by Tsushima Warm Current branched Kurosiwo Current, their population dynamics was affected on the spatio-temporal change of physicochemical factors by short-term wind events, namely "island effect". Long-term survey research is needed to facilitate food-web response in marine ecosystem associated with phytoplankton biomass and physicochemical factors including the warm water current in oligotrophic offshore water of Dokdo, which may have significant role for sustainable use of Dokdo.

The Character of Bogamni group and trends in the surrounding area seen through the stone chamber (석실로 본 나주 복암리 세력과 주변 지역의 동향)

  • Kim, Nak jung
    • Korean Journal of Heritage: History & Science
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    • v.49 no.1
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    • pp.44-67
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    • 2016
  • This article studied the character of Bogamri group and trends in the surrounding area through recently excavated stone chambers. The first type of stone chamber constructed at Bogamni cemetry was Northen Kyushu style stone chamber tomb with corridor. However, According to recent survey Wa style vertical stone lined tomb had constructed earlier than these stone chamber along the southwest cost. It is likely that the background of these Wa style stone tomb was the beginning of formal diplomatic relations between Baekje and Wa. At first, grave goods as well as burial had been Wa style, but gradually local burial element and mortuary practices added. And large tomb had beginning to appear. The representative tombs are Yeongam Okyari Jangdong tomb and Naju Gaheugni Shinhueng tomb. They were built in the middle of the fifth century. It is most likely that the location was selected with regard to the use or securing of inland waterway. But the next step, Yeongsangang river style stone chamber with corridor had constructed at Jeongchon tomb. That tomb is very close to Bogamni tombs and structure and grave goods are very similar also. So these two groups were considered to be the same community. Hereby, It is believed that the inland waterway using power had been turned over to Bogamni group. Bogamni group had constantly constructed stone chamber until seventh century. This represent that Bogamni group had thrived as a leading force in the Yeongsangang river basin. After under the direct control of Baekje, Bogamni group had continued the close relationship with Wa. For this reason, Bogamni group had influenced southwest cost as well as Yeongsangang river basin. It can be estimated by the Bogamni style stone chamber founded at islands of Shinan.

Performing dramaturgy of director as a theatrical director : In terms of researching practice and documentation on the creative quadrilogy on Crime and Punishment ('연극의 작가'로서 연출가의 드라마투르그적 수행 - <죄와벌> 4부작 창작에 관한 '리서치적 실천'과 기록)

  • Kim, Weon Cuk
    • (The) Research of the performance art and culture
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    • no.32
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    • pp.549-594
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    • 2016
  • This research focuses on 'dramaturgical' performance among all the acts of a director who constructs an artistic structure. This is, specifically, the dramaturgical acts that a director comes to perform in the process of dramatizing a novel. This paper aims to suggest a new kind of approach for productive interaction between drama theory and practice, not only by documenting the process of creation but also by moulding theoretical basis on acts of a director. As you all know, creative acts in practice so far have rarely been considered as subject and purpose of academic study. Even some lucky plays and directors had to settle for fragmentary review. That's mainly because Korean theatrical circles confine the way of recording the whole process of drama in practice only to a piecemeal review of performance. As a result, there have been very few cases of observing comtemporary plays under the historical background of drama. In this regard, this paper desires to raise a question, 'is productive interaction between drama theory and creative practice possible?' and to find the answer. If what is described in this paper can have worth beyond a mere record of creative acts, it may establish theoretical grounds on interpreting the play stage of this era by reading, in the contexts of drama history, a director's dramaturgical performing acts to dramatize a novel. The researcher of this paper, as a director of a theater troupe like a human and artistic community, adapted "Crime and Punishment" by Dostoevsky into four plays. They are , , , , and completed in 2009, 2011, 2012, and 2014, respectively as an independent theatric work having no connections to each other in story. Not only because the four plays share the same novel as its origin but also because an identical system is applied to dramatization of the novel, it gives an opportunity to focus on and perceive the role of the director. During the process of dramatiztion, the director, the researcher of this paper, carried all the duties, such as selecting a text, approaching the text theoretically and academically, adapting it for drama, picking out appropriate episodes. This paper defines all these acts as dramaturgical performing acts. In this sense, this paper can also be seen as a documentary of 'acts' performed during the process of dramatization.

Influence of Environmental Characteristics on the Community Structure of Benthic Macroinvertebrates in Stream-type Waterways Constructed at Upper Reaches of Guem River (금강 상류 구간 내 샛강형 수로의 서식환경 특성이 저서성 대형무척추동물 군집 구조에 미치는 영향)

  • Son, Se-Hwan;Choi, Jong-Yun
    • Korean Journal of Ecology and Environment
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    • v.54 no.1
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    • pp.24-38
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    • 2021
  • Microhabitat In the upper stream is created by various environment variables such as the bottom substrate and the physicochemical factors, and may influence the distribution of benthic macroinvertebrates. We investigated the bottom substrate and environmental variables influencing the distribution of benthic macroinvertebrate in 26 stream-type waterways established at upper reaches of Geum River. During study period, total 85 families, 160 species, 9305 individuals of benthic macroinvertebrates were recorded. The stream-type waterways, where the bottom substrates consist mainly of pebble (16~64 mm) and cobble (64~256 mm) or with rapid water velocity (more than 0.2 m/s) and high dissolved oxygen (more than 120%), were supported by high species diversity of benthic macroinvertebrate. Hierological cluster analysis and the nonparametric multidimensional scale (NMDS) divided 26 stream-type waterways into a total of three clusters. In Cluster 1, the invertebrate species, such as Branchiura sowerbyi, Cloeon dipterum, Ischnura asiatica, Paracercion calamorum, and Radix auricularia, closely related to aquatic macrophytes, and Chironomidae spp., Limnodrilus gotoi, and Tanypodinae sp. were abundant in waterways, with high coverage of silt and clay as well as high turbidity and total nitrogen. The benthic macroinvertebrate species (Cheumatopsyche brevilineata, Drunella ishiyamana, Dugesia japonica, Ephemera orientalis, Gumaga KUa, Macrostemum radiatum, Potamanthus formosus, Semisulcospira libertine, Stenelmis vulgaris, and Teloganopsis punctisetae) included in Cluster 2 were dominated in sites with high cover rates of pebble and gravel. Cluster 3 was predominantly covered by the Cobbles, was supported by Simulium sp. Such a clear distinction in the study sites means that each stream-type waterways is governed by a clear habitat environment. In the case of some sites with low species diversity, improvement measures are required to restore nature, such as improving the function of inflows and outflows, creating meandering channel, and inducing the settlement of littoral vegetation.

Prediction of Distribution Changes of Carpinus laxiflora and C. tschonoskii Based on Climate Change Scenarios Using MaxEnt Model (MaxEnt 모델링을 이용한 기후변화 시나리오에 따른 서어나무 (Carpinus laxiflora)와 개서어나무 (C. tschonoskii)의 분포변화 예측)

  • Lee, Min-Ki;Chun, Jung-Hwa;Lee, Chang-Bae
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.23 no.1
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    • pp.55-67
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    • 2021
  • Hornbeams (Carpinus spp.), which are widely distributed in South Korea, are recognized as one of the most abundant species at climax stage in the temperate forests. Although the distribution and vegetation structure of the C. laxiflora community have been reported, little ecological information of C. tschonoskii is available. Little effort was made to examine the distribution shift of these species under the future climate conditions. This study was conducted to predict potential shifts in the distribution of C. laxiflora and C. tschonoskii in 2050s and 2090s under the two sets of climate change scenarios, RCP4.5 and RCP8.5. The MaxEnt model was used to predict the spatial distribution of two species using the occurrence data derived from the 6th National Forest Inventory data as well as climate and topography data. It was found that the main factors for the distribution of C. laxiflora were elevation, temperature seasonality, and mean annual precipitation. The distribution of C. tschonoskii, was influenced by temperature seasonality, mean annual precipitation, and mean diurnal rang. It was projected that the total habitat area of the C. laxiflora could increase by 1.05% and 1.11% under RCP 4.5 and RCP 8.5 scenarios, respectively. It was also predicted that the distributional area of C. tschonoskii could expand under the future climate conditions. These results highlighted that the climate change would have considerable impact on the spatial distribution of C. laxiflora and C. tschonoskii. These also suggested that ecological information derived from climate change impact assessment study can be used to develop proper forest management practices in response to climate change.

Trends in QA/QC of Phytoplankton Data for Marine Ecosystem Monitoring (해양생태계 모니터링을 위한 식물플랑크톤 자료의 정도 관리 동향)

  • YIH, WONHO;PARK, JONG WOO;SEONG, KYEONG AH;PARK, JONG-GYU;YOO, YEONG DU;KIM, HYUNG SEOP
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.26 no.3
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    • pp.220-237
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    • 2021
  • Since the functional importance of marine phytoplankton was firstly advocated from early 1880s massive data on the species composition and abundance were produced by classical microscopic observation and the advanced auto-imaging technologies. Recently, pigment composition resulted from direct chemical analysis of phytoplankton samples or indirect remote sensing could be used for the group-specific quantification, which leads us to more diversified data production methods and for more improved spatiotemporal accessibilities to the target data-gathering points. In quite a few cases of many long-term marine ecosystem monitoring programs the phytoplankton species composition and abundance was included as a basic monitoring item. The phytoplankton data could be utilized as a crucial evidence for the long-term change in phytoplankton community structure and ecological functioning at the monitoring stations. Usability of the phytoplankton data sometimes is restricted by the differences in data producers throughout the whole monitoring period. Methods for sample treatments, analyses, and species identification of the phytoplankton species could be inconsistent among the different data producers and the monitoring years. In-depth study to determine the precise quantitative values of the phytoplankton species composition and abundance might be begun by Victor Hensen in late 1880s. International discussion on the quality assurance of the marine phytoplankton data began in 1969 by the SCOR Working Group 33 of ICSU. Final report of the Working group in 1974 (UNESCO Technical Papers in Marine Science 18) was later revised and published as the UNESCO Monographs on oceanographic methodology 6. The BEQUALM project, the former body of IPI (International Phytoplankton Intercomparison) for marine phytoplankton data QA/QC under ISO standard, was initiated in late 1990. The IPI is promoting international collaboration for all the participating countries to apply the QA/QC standard established from the 20 years long experience and practices. In Korea, however, such a QA/QC standard for marine phytoplankton species composition and abundance data is not well established by law, whereas that for marine chemical data from measurements and analysis has been already set up and managed. The first priority might be to establish a QA/QC standard system for species composition and abundance data of marine phytoplankton, then to be extended to other functional groups at the higher consumer level of marine food webs.

An Exploration of MIS Quarterly Research Trends: Applying Topic Modeling and Keyword Network Analysis (MIS Quarterly 연구동향 탐색: 토픽모델링 및 키워드 네트워크 분석 활용)

  • Kang, Eunkyung;Jung, Yeonsik;Yang, Seonuk;Kwon, Jiyoon;Yang, Sung-Byung
    • Journal of Intelligence and Information Systems
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    • v.28 no.2
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    • pp.207-235
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    • 2022
  • In a knowledge-based society where knowledge and information industries are the main pillars of the economy, knowledge sharing and diffusion and its systematic management are recognized as essential strategies for improving national competitiveness and sustainable social development. In the field of Information Systems (IS) research, where the convergence of information technology and management takes place in various ways, the evolution of knowledge occurs only when researchers cooperate in turning old knowledge into new knowledge from the perspective of the scientific knowledge network. In particular, it is possible to derive new insights by identifying topics of interest in the relevant research field, applied methodologies, and research trends through network-based interdisciplinary graftings such as citations, co-authorships, and keywords. In previous studies, various attempts have been made to understand the structure of the knowledge system and the research trends of the relevant community by revealing the relationship between research topics, methodologies, and co-authors. However, most studies have compared two or more journals and been limited to a certain period; hence, there is a lack of research that looked at research trends covering the entire history of IS research. Therefore, this study was conducted in the following order for all the papers (from its first issue in 1977 to the first quarter of 2022) published in the MIS Quarterly (MISQ) Journal, which plays a leading role in revealing knowledge in the IS research field: (1) After extracting keywords, (2) classifying the extracted keywords into research topics, methodologies, and theories, and (3) using topic modeling and keyword network analysis in order to identify the changes from the beginning to the present of the IS research in a chronological manner. Through this study, it is expected that by examining the changes in IS research published in MISQ, the developing patterns of IS research can be revealed, and a new research direction can be presented to IS researchers, nurturing the sustainability of future research.

Fish Community Characteristics and Inhabiting Status of Endangered Species in the Bukcheon (Stream) of Seoraksan National Park, Korea (설악산국립공원 내 북천의 어류군집 특성 및 멸종위기종의 서식양상)

  • Park, Seong-Cheol;Choi, Kwang-Seek;Han, Mee-Sook;Ko, Myeong-Hun
    • Korean Journal of Environment and Ecology
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    • v.36 no.4
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    • pp.390-401
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    • 2022
  • This study investigated the characteristics of fish communities and inhabiting status of endangered species in the Bukcheon (Stream) of Seoraksan National Park, Korea from April to September 2020. A total of 4,356 fish of 7 families and 22 species were collected from 17 survey stations during the survey period. The dominant species was Zacco koreanus (relative abundance, 41.8%), and subdominant species was Rhynchocypris kumgangensis (relative abundance, 15.1%), followed by Pungtungia herzi (10.1%), Pseudopungtungia tenuicorpa (5.0%), Coreoleuciscus splendidus (4.1%), Zacco platypus (3.8%), Microphysogobio longidorsalis (3.5%), and Hemibarbus mylodon (2.2%). Among the fish species collected, 14 species (63.6%) were identified as Korean endemic species. There was one natural monument species (Hemibarbus mylodon), and four species of class II endangered wildlife that were designated by the Ministry of Environment (Acheilognathus signifer, Pseudopungtungi tenuicorpa, Gobiobotia brevibarba, and Brachymystax lenok tsinlingensis). Among the four species of class II endangered wildlife, B. lenok tsinlingensis inhabited in the upper stream, and A. signifer, P. tenuicorpa and G. brevibarba inhabited mainly in the middle-lower stream. Also, P. tenuicorpa, H. mylodon, and B. lenok tsinlingensis were inhabited in large numbers. Additionally, two cold-water fish species (R. kumgangensis and B. lenok tsinlingensis) and one landlocked species (B. lenok tsinlingensis) were collected. According to the results of cluster analysis, the dominance index decreased from upstream to downstream, but the diversity, evenness, and richness index increased; the cluster structure was divided into the uppermost, upstream, midstream, and downstream. The water quality of Bukcheon was evaluated as good overall since the river health (index of biological integrity) evaluated using fish was evaluated as very good (11 stations), good (2 stations), and normal (4 stations). However, river repair work was being carried out in some areas and some wastewater was flowing in from the midstream, therefore, supplementary measures to preserve fish habitats are required.

Development and Validation of the 'Food Safety and Health' Workbook for High School (고등학교 「식품안전과 건강」 워크북 개발 및 타당도 검증)

  • Park, Mi Jeong;Jung, Lan-Hee;Yu, Nan Sook;Choi, Seong-Youn
    • Journal of Korean Home Economics Education Association
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    • v.34 no.1
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    • pp.59-80
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    • 2022
  • The purpose of this study was to develop a workbook that can support the class and evaluation of the subject, 「Food safety and health」 and to verify its validity. The development direction of the workbook was set by analyzing the 「Food safety and health」 curriculum, dietary education materials, and previous studies related to the workbook, and the overall structure was designed by deriving the activity ideas for each area. Based on this, the draft was developed, and the draft went through several rounds of cross-review by the authors and the examination and revision by the Ministry of Food and Drug Safety, before the final edited version was developed. The workbook was finalized with corrections and enhancements based on the advice of 9 experts and 44 home economics teachers. The workbook consists of 4 areas: the 'food selection' area, with 10 learning topics and 36 lessons, the 'food poisoning and food management' area, with 10 learning topics and 36 lessons, the 'cooking' area, with 11 learning topics and 43 lessons, and the 'healthy eating' area, with 11 learning topics and 55 lessons, resulting in a total of 42 learning topics, 170 lessons. The workbook was designed to evenly cultivate practical problem-solving competency, self-reliance capacity, creative thinking capacity, and community capacity. In-depth inquiry-learning is conducted on the content, and the context is structured so that self-diagnosis can be made through evaluation. According to the validity test of the workbook, it was evaluated to be very appropriate for encouraging student-participatory classes and evaluations, and to create a class atmosphere that promotes inquiry by strengthening experiments and practices. In the current situation where the high school credit system is implemented and individual students' learning options are emphasized, the results of this study is expected to help expand the scope of home economics-based elective courses and contribute to realizing student-led classrooms with a focus on inquiry.