• 한국환경과학회지
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• 제25권5호
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• pp.655-671
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• 2016

The distribution characteristics of functional feeding groups and biological evaluation of water quality with benthic macroinvertebrates were investigated from 2013 to 2014 in the mountain streams of Jirisan National Park. Both quantitative and qualitative collection had been performed six times during study periods in twelve sites located at upstream, midstream and downstream of four valleys, Chilsungol, Baemsagol, Daesunggol and Piagol of freshwater ecosystem in Jirisan National Park. As results, the total collected benthic macroinvertebrates were 3 phyla, 4 classes, 11 orders, 37 families, 107 species and 4,028 individuals. In 2013, 3 phyla, 4 classes, 10 orders, 32 families, 89 species and 1,829 individuals were collected. And in 2014, 3 phyla, 4 classes, 9 orders, 31 families, 80 species and 2,199 individuals were identified. The total dominant species was Ecdyonurus kibumensis, and EPT groups occupied 80.39% of total species number. Biotic indices were also compared to site and to season. The dominant index (DI) was highest at the downstream of Baemsagol in the spring of 2013, and the evenness index (J') was highest at the downstream of Daesunggol in the summer of 2013. Both diversity index (H') and richness index (RI) were highest at the upstream of Baemsagol in the summer of 2014. The correlation between altitude above sea level and functional feeding groups of benthic macroinvertebrates was also researched in this study. As a result, the species number of shredders and predators have significantly increased according to the increase of the altitude of their habitat. On the other hand, individuals of gathering collectors have increased according to the increase of altitude. The biological water quality was evaluated and compared with several methods in this study, and we suggest that ESB and GPI are more appropriate than KSI and BMI to evaluate biological water quality of mountain stream water.

• Journal of Ecology and Environment
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• 제32권3호
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• pp.197-206
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• 2009

Benthic macroinvertebrate communities were collected from six different sites in the Dobong Stream in Seoul, Korea to investigate spatial and temporal changes in benthic macroinvertebrate communities in response to natural disturbances such as floods and droughts. We collected samples monthly or semimonthly with a Surber net ($30cm{\times}30cm$), and measured environmental factors, including stream temperature, discharge, width, conductivity, dissolved oxygen and pH at each sampling site. Benthic macro invertebrates were strongly affected by floods as well as droughts. In addition, benthic macroinvertebrate communities displayed different responses to the onset of the rainy season in summer 2006 and 2007, apparently due to differences in the intensity and amount of precipitation. Chironomids were particularly sensitive to heavy rain. Floods and droughts also affected the proportions of functional feeding groups during the survey period: the proportion of scrapers was high right after heavy rains, while the proportion of predators tended to increase in intermittent-type streams as the riffle zone decreased. Finally, although species richness and abundance were strongly influenced by heavy rain, they recovered to background levels for within one month, and varied consistently among stream types, indicating habitat stability.

• 국제초고층학회논문집
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• 제5권2호
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• pp.95-103
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• 2016

One of the key problems in the design of high-rise commercial complex is how to guide reasonable pedestrian distribution in commercial space. In this study, pedestrian distribution in three high-rise commercial complexes in Shanghai and Hong Kong was studied using spatial configuration analysis software Space Syntax and quantification of physical elements in commercial spaces, such as functional attractiveness, entrances, escalators, level variations and passage width. Additionally, in an attempt to integrate functions with spatial integration and spatial depth, two combination variables, the spatial coefficient of function (IF) and spatial depth coefficient of function (F/D), were proposed. The results of the correlation analysis and multiple regression analyses reflected the following: (1) Regarding the influence on pedestrian distribution, there was a synergistic and complementary relationship between function and space; (2) The comprehensive flow distribution analytic model could successfully interpret flow distribution in high-rise commercial complexes and its R Square ranged up to about 70% in the three cases; (3) The spatial coefficient of function (IF) and spatial depth coefficient (F/D) could effectively integrate functions and spatial configuration, which could help close the gap between over-emphasis on function in commercial research and the lack of consideration of function in space-syntax analysis.

• ETRI Journal
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• 제44권3호
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• pp.389-399
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• 2022

Wireless sensor networks (WSNs) are one of the basic building blocks of Internet of Things (IoT) systems. However, the wireless sensing nodes in WSNs suffer from energy constraint issues because the replacement/recharging of the batteries of the nodes tends to be difficult. Furthermore, a number of realistic IoT scenarios, such as habitat and battlefield monitoring, contain mobile sensing elements, which makes the energy issues more critical. This research paper focuses on realistic WSN scenarios that involve mobile sensing elements with the aim of mitigating the attendant energy constraint issues using the concept of radio-frequency (RF) energy extraction. The proposed technique incorporates a cluster head election workflow for WSNs that includes mobile sensing elements capable of RF energy harvesting. The extensive simulation analysis demonstrated the higher efficacy of the proposed technique compared with the existing techniques in terms of residual energy, number of functional nodes, and network lifetime, with approximately 50% of the nodes found to be functional at the 4000th, 5000th, and 6000th rounds for the proposed technique with initial energies of 0.25, 0.5 and 1 J, respectively.

• 국제초고층학회논문집
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• 제5권3호
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• pp.155-165
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• 2016

A much higher level of seismic performance is needed for supertall buildings due to increased demands for their functional continuities and the recognized needs for their continuing emergence in metropolitan areas. This paper analyzes, compares, and contrasts responses recorded during the 2011 Tohoku-oki Earthquake of different supertall buildings featuring conventional and vibration-controlled engineering systems. The superior performance and advantage of the latter are pointed out, and the typical dynamic properties, response characteristics, and effects on the secondary system are discussed. Ongoing efforts to enhance vibration control performance are described, covering the development of specifications, use of performance curves and targeted displacement design, and methods to find appropriate locations of damper installation resulting in a minimized amount of dampers.

• Journal of the korean society of oceanography
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• 제34권3호
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• pp.172-178
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• 1999

An overview of the spatial and seasonal patterns of phytobenthic communities is described from the intertidal zone at Hawon-Pando on the southwestern coast of Korea based on quantitative and qualitative estimates of macroalgae. There were considerable variations of macroalgal diversity and cover value with the intertidal levels. Tn general, the number of species decreased with increasing intertidal height. The upper region was dominated by Sargassum thunbergii. S. thunbergii and crustose red algae were dominant in the mid intertidal habitat. In the lower intertidal Corallina pilulifera and crustose red algae were the conspicuous dominants. Macroalgal community structure at Hawon-Pando is discussed in the context of functional-form groups. The Hawon-Pando intertidal is characterized as consisting of a relatively high cover of species assigned to the thick leathery, crustose and jointed calcareous groups, and is distinguished by a paucity of the filamentous group.

• 한국환경복원기술학회지
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• 제2권2호
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• pp.1-8
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• 1999

This study is one of the processes to build the artificial wetlands in the urban area. The purpose of this study was to survey biotic or physical environments, and to review modelling techniques to find out the ecological structure and function. Case study site was the Bangdong wetland in the north west side of Taejon metropolitan city. The number of species of insects decreased during monitoring. But the number of individuals of insects decreased abruptly after increasing. And then biodiversity index dropped and dominance index increased. So the structure of biotopes was affected by weather conditions. And in the restricted area such as urban area, the changes of insects were affected sensitively by not physical but environmental changes. As for birds, the number of species was reduced a little, but the number of individuals increased abruptly. And dominance index increased slowly. The changes of water depth and increase of temperature affected the habitat condition of vegetations and birds, so the dominance index of specific species increased. In urban areas it is necessary to continue management for water environmental changes, such as the depth and area of water. The number of species of fishes was reduced a little, but the number of individuals increased abruptly. And dominance index and biodiversity index decreased slowly. But the water environments was so changeable that it is difficult to explain current status as some specific trends. The number of species of reptiles and amphibians changed little, but the number of individuals increased abruptly. And dominance and biodiversity were not changed. The changes of water depth and temperature affected the habitat of every species the environmental changes affected.

• Journal of Ecology and Environment
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• 제35권3호
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• pp.177-188
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• 2012

We analyzed crown development in Aucuba japonica Thunb. var. japonica resulting from the responses of phytoelements to habitat light conditions over a long period of time. Over the years, the degree of extension unit (EU) dimorphism and the degree of anisophylly were higher under shaded conditions than in brighter conditions. An overall temporally increasing pattern in the degree of EU dimorphism was found while no clear-cut trend was found in the case of anisophylly. EU length and number of leaves per EU co-varied in a spatio-temporal context. The number of terminal buds and their sizes acted as the key initiators of morphological differences of phytoelements which were further amplified following bud break. Leaf area density was displayed mostly in the apex peripheral layer of the crown and the apex layer received most of the incident light. There was a tradeoff between annual leaf production and mean leaf size. Depending on the heterogeneity of irradiance level within a crown, correlative growth inhibition caused higher EU mortality at brighter sites. Due to high mortality, shorter EUs had a mere role in the construction of structural framework of the crown except for the formation of some gaps. There was a strong convergence of EU dimorphism, anisophylly, EU extension growth and variations in leaf size towards formation of functional crown to reduce potential self-shading. Depending on the irradiance level, Aucuba japonica Thunb. var. japonica showed two different modes of crown expansion. At the brighter sites, individual crown expansion was progressive while at the darker sites, individual crown expanded in a diminishing manner and maintained a stable size. A plant's "growth diminishing phase" appeared earlier at shaded sites than brighter sites.

• 한국환경생태학회지
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• 제30권4호
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• pp.712-723
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• 2016

본 논문은 생명공학기술을 통해 생산된 LM벼에 대한 비표적 생물체 중 곤충을 중심으로 한 환경위해성 평가방법을 제시하고자 작성하였다. 자료조사를 위해 농업 해충관련 도감 및 서적을 활용하였고 참고문헌과 환경위해성 평가 관련 홈페이지를 참조하였으며, 논문이나 벼와 관련된 서적들을 통해 국내 현황을 참조하였다. 조사결과, 벼에 서식하는 곤충은 약 140여종으로 조사되었고, 초식성 곤충 분류군은 각각 수액섭식자, 곡물섭식자, 잎섭식자, 화분섭식자로 세분화하였다. LM벼에 피해가능성이 큰 비표적 곤충은 12종, 중간인 비표적 곤충은 28종, 경미한 비표적 곤충은 101종으로 조사되었으며, 바이러스를 매개하는 종은 11종, 잠재적 해충으로 분류되는 종은 9종으로 나타났다. 위해가설 가설적립단계 모식도를 작성하기 위하여 LM벼에 악영향을 받기 쉬운 곤충의 지리적 분포, 서식지의 특수화, 확산정도, 종풍부도 등을 이용하여 순위를 매겼으며, 10종(벼총채벌레, 애멸구, 벼멸구, 멸강나방, 혹명나방, 우리가시허리노린재, 먹노린재, 벼멸구붙이, 벼메뚜기, 벼잎굴파리)을 추려내었다. 이후 위해가설 가설정립단계 모식도를 작성하였으며 LM벼의 비표적 생물에 대한 영향을 추론하였다. 본 논문은 국내 자연생태계의 지속가능한 이용 및 보존에 기여하고, LMO의 환경위해성 평가, 심사를 통해 사전위해성을 차단할 수 있는 방법을 제시하고자 작성되었으며, 결과적으로 국민의 건강 및 생물다양성유지, 자연 생태계 보전을 위한 사후 안전관리 체계구축에 활용될 연구 자료를 제공하고자 한다.

• 환경생물
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• 제40권4호
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• pp.363-373
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• 2022

본 연구는 2021년 4월부터 8월까지 3차례에 걸쳐 제주도 봉개동에 위치한 물장오리오름 습지의 저서성 대형무척추동물상 및 군집구조를 파악하기 위해 수행되었다. 조사지점은 물장오리오름 습지를 4개의 구역으로 구분하였으며, 접근이 가능한 3개 구역(1 area~3 area)에서 조사를 실시하였다. 물장오리오름 습지의 서식지 환경을 분석한 결과, 월 평균기온은 7~8월에 가장 높고, 12~2월에 가장 낮은 양상이 2017년부터 2021년까지 반복되었다. 월 강수량은 2017년을 제외하고 2018년부터 2021년까지 장마철인 6월부터 9월에 가장 높은 것으로 분석되었다. 위성영상 분석을 통해 식생면적과 수 면적의 변동을 분석한 결과, NDVI는 2월부터 7월까지 증가하고 이후 감소하는 양상을 나타내었으며, NDWI는 반비례의 관계를 나타내는 것으로 분석되었다. 조사기간 동안 채집된 저서성 대형무척추동물은 총 2문 3강 8목 17과 26종이 출현하였으며, 정성조사 시 13과 21종, 정량조사 시 15과 24종 412개체가 출현하였다. 우점종은 깔따구류(Chronomidae spp.)가 132개체(32.04%)로 확인되었으며, 자색물방개(Noterus japonicus)가 71개체(17.23%)로 아우점하였다. 본 연구와 문헌에서 확인된 출현종을 비교·분석한 결과, 딱정벌레목과 잠자리목의 종다양성이 높은 것으로 확인되었으며, 주요 섭식기능군은 Predators, 서식기능군은 Swimmers로 분석되었다. OHC-group은 2021년에 17종(73.91%)이 확인되었으며, 2016년에는 23종(79.31%), 2018년에 26종(86.67%), 2019년에 19종(79.17%)이 출현하였다. 멸종위기야생생물 II급인 물방개(Cybister japonicus)가 문헌에서 서식하는 것으로 확인되었으며, 2021년에도 10개체(2.43%)가 조사되었다. 따라서 물장오리오름 습지에 서식하고 있는 물방개의 서식환경을 유지할 수 있도록 지속적인 관리와 서식지 보호가 필요할 것으로 생각된다.