• 한국패류학회지
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• 제9권2호
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• pp.68-84
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• 1993

A study on the distribution and seasonal changes of the benthic macroinvertebrate community was performed on the 4 intertidal rocky shores of Biyang-do in Chehu Island throughout four seasons from January 1992 to january 1993. The macroinvertebrates composed of 8 phyla, 15 classes, 31 orders, 71 families, 168 species. The seasonal appearing species were 135 species in summer, 127 species in spring, 124 species in winter and 121 species in autumn, respectively. The dominant species of the upper zones were Nodilittorina exigua, Nerita japonica, Pollicipes mitella, the middle zones were Turbo coronata coreensis, Monodonta neritoides, petrolisthes japonicus and the lower zones were Pagurus samuelis, Chthamalus pilsbryi, Chlorostoma argyrostoma lischkei. The community dominance indices of the upper zones were much higher than the middle and lower zones. The seasonal appearnace in species in the lower zones were remarkable, but individual numbes were not. Species diversity and evenness in all investigated zones were highest in spring and lowest in winter. But species richness was highest in summer, lowest in autumm.

• 대한전기학회논문지:전력기술부문A
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• 제48권3호
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• pp.294-303
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• 1999

To improve the visual servoing performance, several strategies were proposed in the past such as redundant feature points, using a point with different height and weighted selection of image features. The performance of these visual servoing methods depends on the configuration between the camera and object. And redundant feature points require much computation efforts. This paper proposes the visual servoing method based on the disturbance obsever, which compensates the upper off-diagonal component of image feature jacobian to be the null. The performance indices such as sensitivity for a measure of richness, sensitivity of the control to noise, and comtrollability are shown to be improved when the image feature Jacobian is given as a block diagonal matrix. Computer simulations are carried out for a UUMA560 robot and show some results to verify the effectiveness of the proposed method.

• 대한조선학회논문집
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• 제43권1호
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• pp.50-58
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• 2006

Free running model tests gives us only maneuvering indices not hydrodynamic derivatives. For this reason, system identification method has been applied to the measured data to identify mathematical model describing hydrodynamic force. However It is difficult to obtain complete set of maneuvering derivatives because of strong correlation of sway velocity and yaw rate. Therefore, in this paper, we assumed that sway velocity related coefficients would be obtained by oblique towing test. and then proposed new procedure to estimate yaw related coefficients. To do this, correlation and regression analyses were carried out to establish modified model and estimate maneuvering derivatives. Also D-optimal rudder input scenario was found based on the modified model and confirmed the validity of its sufficient richness as a input scenario.

• Journal of Ecology and Environment
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• 제30권4호
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• pp.325-330
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• 2007

Recognizing the ecological importance of forest gap formation for forest community structure, we examined the differences in species diversity between forest gaps and closed canopy areas for trees and shrubs in three developmental stages (seedling, sapling I, and sapling II) in a typical mixed broadleaved-Korean pine forest. We randomly placed 100 sample plots ($2{\times}2m$ for seedling and sapling I, and $5{\times}5m$ for sapling II) in forest gap and closed canopy areas of a 9 ha permanent sample plot for vegetation surveys of plants of each developmental stage in each habitat type. Even though the formation of forest gaps encouraged the occurrence of gap-dependent species and increased overall species diversity, there were no significant differences in species richness among the three developmental stages for both tree and shrub species (p>0.05). Comparing the two types of sites, statistical tests revealed no difference in species richness for trees, but highly significant differences (p<0.01) between forest types for shrubs for seedlings and sapling I, but not sapling II. Analysis of variance test indicated that there were no significant differences in species diversity among the three developmental stages of tree species (p>0.05) for both Simpson and Shannon indices. The variance for shrub seedlings was significantly different between forest gaps and closed canopy areas, but not for sapling I and sapling II. The analysis showed that the species diversity in forest gaps was significantly different from that of closed canopy areas for seedling and sapling I (p<0.01), but not for sapling II (p>0.05).

• 한국산림과학회지
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• 제97권2호
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• pp.171-180
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• 2008

The characterization of tree species and forest stand conditions is useful in the planning of activities aimed to conserve biodiversity. The main objective of this study was to describe tree species diversity, species composition and stand structure of tropical deciduous forests distributed in three regions in Myanmar. Forest inventory was conducted in the Oktwin teak bearing forest, the Letpanpin community forest and Alaungdaw Kathapa National Park. According to the Jackknife estimator of species richness, 85 species (${\pm}18.16$), 70 species (${\pm}5.88$) and 186 species (${\pm}17.10$) belonging to 31 families were found in the Oktwin teak bearing forest, 33 families in Letpanpin community forest and 53 families in Alaungdaw Kathapa national park, respectively. Shannon's diversity indices were significantly different among the forests (p<0.05). It ranged from 3.36 to 4.36. Mean tree density (n/ha) of the Oktwin teak bearing forest, Letpanpin community forest and Alaungdaw Kathapa National Park were 488 (${\pm}18.6$), 535 (${\pm}15.6$) and 412 (${\pm}14.1$), while basal areas per hectare were $46.96m^2({\pm}3.23),\;49.01m^2({\pm}5.08)\;and\;60.03m^2({\pm}3.88)$, respectively. At the family level, Verbenaceae, Myrtaceae and Combretaceae occupied the highest importance value index, while at the species level it was Tectona grandis, Lagerstoremia speciosa and Xylia xylocarpa.

• 한국패류학회지
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• 제17권1호
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• pp.63-70
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• 2001

1999년 9월부터 2000년 8월까지 제주도 안덕면 화순리 화순화력발전소 인접 5개 지점 조간대의 대형저서무척추동물의 분포와 군집구조에 관한 연구결과는 다음과 같다. 화순화력발전소 인접 조간대에 분포하는 대형무척추동물은총 6 문, 13 강, 24 목, 49 과, 97 종이 출현하였다. 조간대 상부구역의 제 1 우점종은 좁쌀무늬총알고둥, 제 2우점종은 군부 (Liolophura japonica), 테두리고등 (Patelloida saccharina), 배무래기 (Notoarmea schrenckii) 이였다. 중부구역의 제 1 우점종은 울타리고등 (Monodonta labio), 작은조무래기따개비 (Chthamalus challengeri), 고랑딱개비 (Siphonalia japonica), 군부 (L. japonica), 울타리고등 (M. labio)이였으며, 제 2 우점종은 배무래기 (N.schrenckii), 울타리고등 (M. labio), 진주담치 (Mytilus edulis), 거북손 (Mitella mitella), 군부 (L. japonica) 이였다. 하부구역의 제 1 우절종은 꽃고랑딱개비 (Siphonalia sirius), 작은조무래기따개비 (C. challengeri), 해변말미잘(Actinia mesembryanthemum), 테두리고등 (P. saccharina), 울타리고등 (M. labio) 이였으며, 제 2 우점종은 배무래기 (N. schrenckii), 군부 (L. japonica), 석회관갯지렁이(Serpula vermicularis), 울타리고등 (M. labio)이였다. 조간대 종다양도지수나 균등도, 풍부도는 하부구역이 상부구역이나 중부구역에 비하여 컸다.

• ALGAE
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• 제23권2호
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• pp.151-162
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• 2008

Marine algal flora and community structure were seasonally examined at three sites in the vicinity of the Wolseong nuclear power plant in Korea from February to November 2006. A total of 126 seaweeds including 25 green, 31 brown, 70 red algae, and 1 marine plant were identified. The greatest number of species occurred at Jeonchonri (101 species) followed by intake (88 species) and discharge (29 species) during the study period. Of 126 seaweeds, 76 annuals and 13 warm tolerance species were recorded. Dominant species based on important value (IV > 10) were Ulva pertusa and Enteromorpha linza at intake, U. pertusa and Padina arborescens at discharge, and Sargassum horneri and Corallina pilulifera at Jeonchonri shore. Annual average biomass exhibited a wide range of variations, from 40.67g m-2 in dry weight at discharge to 133.69g m-2 at Jeonchonri. Among six functional groups, dominant group was coarsely-branched form at intake and Jeonchonri, but it was different at discharge site as filamentous form. Seaweed community structures of discharge site were distinguishable in decreasing species richness, biomass, species diversity index (H’), richness index (R), and evenness index (J’). Also, the ratios of green algae, warm tolerance species, annual algae, filamentous form and dominance index (DI) remarkably increased. Such phenomenons of discharge site are usually found under environmentally stressful conditions such as high disturbance. Thus, I can conclude that the heated effluents of nuclear power plant act as environmental stress influencing seaweed community structures and it can be detected with various community indices.

• 환경생물
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• 제21권2호
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• pp.101-113
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• 2003

여름철 광양만의 저서환경 상태를 파악하기 위해서 2001년 6뭘 광양만의 38개 조사정점에서 대형저서동물의 분포를 조사하였다. 출현한 대형저서동물은 총 154종 이었고, 다모류가 출현종수와 개체수에서 가장 우점한 동물분류군이었다. 다모류의 Tharyx sp.(44.8%),Lumbrineris longifolia (14.0%), 이매패류의 Mytilus edulis (6.5%), 단각류의 Corophium sinense (4.5%), 다모류의 Heteromastus filiformis(3.6%), Sigambra tentaculata (1.7%)등이 주요 우점종이었다. 광양만의 묘도 서쪽에 위치한 정점들에서 종수와 개체수가 적었고, 광양만의 주수로역에서 풍부한 생물상을 보였다. 저서오염지수 (BPI)와 생물계수(BC)에 의한 저서군집의 건강도지수서는 주수로역의 일부 정점을 제외한 전 정점이 현재 정상상태 또는 약간 오염된 상태에 있었고, 광양만 입구 지역에서는 유기물오염에 잘 적응한 다모류의 대량 출현이 있어서 유기물 오염의 징후로 보여 향후 지속적인 감시가 필요한 것으로 나타났다.

• The Plant Pathology Journal
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• 제32권4호
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• pp.329-339
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• 2016

The short-term effects of low-level contamination by heavy metals (As, Cd, Cu, and Pb) on the soil health were examined by analyzing soil nematode community in soils planted with tomatoes. For this, the soils were irrigated with five metal concentrations ([1, 1/4, $1/4^2$, $1/4^3$, and 0] ${\times}$ maximum concentrations [MC] detected in irrigation waters near abandoned mine sites) for 18 weeks. Heavy metal concentrations were significantly increased in soils irrigated with MC of heavy metals, among which As and Cu exceeded the maximum heavy metal residue contents of soil approved in Korea. In no heavy metal treatment controls, nematode abundances for all trophic groups (except omnivorous-predatory nematodes [OP]) and colonizer-persister (cp) values (except cp-4-5) were significantly increased, and all maturity indices (except maturity index [MI] of plant-parasitic nematodes) and structure index (SI) were significantly decreased, suggesting the soil environments might have been disturbed during 18 weeks of tomato growth. There were no concentration-dependent significant decreases in richness, abundance, or MI for most heavy metals; however, their significant decreases occurred in abundance and richness of OP and cp-4, MI2-5 (excluding cp-1) and SI, indicating disturbed soil ecosystems, at the higher concentrations (MC and MC/4) of Pb that had the most significant negative correlation coefficients for heavy metal concentrations and nematode community among the heavy metals. Therefore, the short-term effects of low-level heavy metal contamination on soil health can be analyzed by nematode community structures before the appearance of plant damages caused by the abiotic agents, heavy metals.

• The Korean Journal of Ecology
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• 제28권2호
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• pp.79-83
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• 2005

한반도 서남해안 상록활엽수림이 우점하고 있는 산림의 대형나방(명나방 포함) 종 다양성을 조사하였다. 조사지역은 해남군 두륜산 일대로 2001년 3월부터 2004년 10월까지 약 4년간 자외선 등을 이용한 야간채집을 통하여 나방 종을 분류, 분석하였다. 조사결과 채집된 나방은 총 18과 489종이었으며, 미소나방과 주간활동성인 나비를 합한다면 이 지역에 분포하는 나비목곤충은 훨씬 더 많을 것으로 예상된다. 채집된 종 중 밤나방과가 181종으로 가장 많았고 다음으로 자나방과(129종), 명나방과(72종) 순이었으며, 개체수로는 자나방과가 가장 많았고 다음으로 밤나방과, 명나방과, 갈고리나방과의 순이었다. 채집된 종의 51%가 2개체 미만의 희귀종을 차지하였다. 월별 종수와 개체수의 변화를 살펴보았고, 이들 수치를 이용한 이질성도와 균등도를 산출하여 계절별 변화를 살펴보았다. 산림생태계 보전 및 이용에 특정 나방 종 및 종 그룹을 이용하는 것에 대하여 간략히 논의하였다.