• Korean Journal of Ichthyology
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• v.11 no.1
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• pp.52-61
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• 1999

Seasonal variation in species composition of fish with depth was determined by analysis of bimonthly samples collected by a beach seine at the shallow water (St. 1 < 1.5m) and by beam trawl at the two stations (St. 2, 5~7m and St. 3 > 15 m) from October 1997 to August 1998 off Ippa-do in Asan Bay. Of forty species identified, 13 species at St. 1,28 species at the St. 2 and 30 species at the St. 3 were collected. The fish density was also increased with depth. Favonigobius gymnauchen occupied 55.7% at St. 1 and 38.9% of the number of individuals at St. 2. Almost of fish collected at these two stations were juveniles, and they were principally collected in August and in November. At St. 3, relatively large fishes were collected. Among them Pholis fangi and Chaeturichthys stigmatias predominated in the number of individuals. Abundance was low, but a large number of species were collected in winter. Principal component analysis revealed that the species composition at the shallower stations was different from that at the deeper station. The number of species and abundance of fish in Asan Bay was lower than in the other western coastal waters of Korea. Species composition in the study area of sandy bottom was different from that in the inner Asan Bay of mud bottom.

• Korean Journal of Environmental Biology
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• v.19 no.4
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• pp.282-291
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• 2001

The distribution and standing crop of phytoplankton were investigated seasonally at 6 stations in the nearby streams of Suwon sewage disposal plant. It turned out to be total of 176 taxa, and classified as 4 phylums, 4 classes, 11 orders, 6 suborders, 22 families, 54 genera, 155 species, 20 varieties and 1 form by Engler's classification system. Among 176 taxa, 22 including Microcystis Aphanizomenon flos-aquae were identified as indicators of water pollution. Standing crops of all stations investigated appeared to be relatively high as in other streams through the center of the city, such as Kyoungan-chon of Youngin-si and Gulpo-chon of Buchon-si. In station 1,2,4 and 6, the highest number of standing crop were shown in summer, while in station 3 and 5, it was high in winter. Based on the present study upon the distribution and standing crop of phytoplankton, it is regarded as the state of the eutrophication in the nearby streams of Suwon sewage disposal plant.

• Journal of the Korean Society for Marine Environment & Energy
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• v.7 no.1
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• pp.13-21
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• 2004

Temporal changes of Chl-α, physical and chemical factors were investigated by diurnal observation at 2-hour interval at three fixed stations in the western Chinhae Bay from 12 Aug. to 13 Aug. 1999. Difference of dissolved oxygen between surface and bottom layer was maximum when the thermocline were strong. Organic distribution such as COD was affected by the growth of phytoplankton. Limitting factor was nitrogen, that is, inorganic nitrogen plays a significant role on regulating the algal growth. Surface distribution of dissolved inorganic nitrogen was very low compared to bottom layer by uptake of organisms. Maximum value of Chl-α at station C2 and C11 were observed from subsurface layer, ranges of which exceeded possibility concentration of red tide outbreak, 10 mg/㎥. On the other hand, that of C15 exist at surface layer. In this area, DIN and DIP concentrations increased by input sources such as rainfall and benthic flux before the bloom of phytoplankton. Accumulation of phytoplankton occurred at subsurface layer by the rapid uptake of DIN, especially nitrate ion, when strong thermocline existed as approach to the afternoon, which led to the increase of organics in water column and oxygen deficiency water mass at bottom layer until late at evening. Since then, DIN increases gradually as water temperature decrease to minimum. The quantitative understanding of nitrogen of fluxed to and from the various sources is necessary for environmental management.

• Korean Journal of Ecology and Environment
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• v.34 no.3 s.95
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• pp.199-205
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• 2001

This study was investigated to the assessment of organic pollution using attached diatom assemblages in the Shinchon stream on April, June, September and December 1999. Diatoms were identified total 74 taxa which composed of 68 species, 4 varieties and 2 unidentified species. The Centrales were 5 taxa and Pennales were 69 taxa. Dominant species were Navicula subminuscula, Navicula saprophila and Nitzschia palea which were saprophilous taxa to organic pollution. N. palea was dominant species at st. $1{\sim}3$ on April, June and September and N. subminuscula was recorded as dominant species at st. 4 on June, September and December. N. saprophila was dominated only at station 4 on April. DAIpo values were ranged $0.4{\sim}15.3$ at all stations from April to December and the water qualities were polysaprobic states except to ${\alpha}-mesosaprobic$ state at st. 1 on June. If Navicula sp. was identified as saprophilous taxa, DAIpo value of this station will be 3.5 and water quality of the station will be polysaprobic state. This stream was assessed the water qualities of polysaprobic states.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.1
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• pp.1-13
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• 2003

To investigate the community structure and meiofaunal density in seagrass/bare non-seagrass beds, a survey was conducted at three seagrass bed locations in Doomoojin of Baegryongdo, inner harbor of Eocheongdo in May 1999, and Yulim of Dolsando for every month from February to July 1999. Meiobenthic samples were collected from sediments within seagrass beds (SB) and non-seagrass bed (or adjacent to barren sand area, NSB). Nematodes were the most dominant group among representative 13 meiofaunal groups. The sub-dominant groups were benthic for-aminiferans, benthic harpacticoids, and annelids. The highest density of meiofauna was recorded at a seagrass bed of Yulim (7,244 ind/10 $\textrm{cm}^2$ in June), and lowest density was recorded at a non-seauass bed of Baegryoungdo (438 ind/ 10 $\textrm{cm}^2$ in May). For vertical distribution, the highest density of meiofauna was recorded at 0-2 cm depth, and the density abruptly decreased with depth in all stations. The density of meiofauna in size between 0.125 m and 0.25 mm was maximum. Sediment types for the study areas ranged from sandy to sandy mud by the Folk's classification. The density of total meiofauna, the number of taxa, and the density of the dominant groups (nematodes, benthic for-aminiferans, benthic harpacticoids, annelids) between SB and NSB were significantly different. The results clearly showed the importance of seagrass bed as suitable habitat for meiofauna.

• Journal of the Korea Computer Graphics Society
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• v.17 no.3
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• pp.43-50
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• 2011

We present a trade-off technique for fast but qualitative planar shape deformation using a layered mesh. We construct a layered mesh that is embedding a planar input shape; the upper-layer is denoted as a control mesh and the other lower-layer as a shape mesh that is defined by mean value coordinates relative to the control mesh. First, we try to preserve some shape properties including user constraints for the control mesh by means of a known existing nonlinear least square optimization technique, which produces deformed positions of the control mesh vertices. Then, we compute the deformed positions of the shape mesh vertices indirectly from the deformed control mesh by means of simple coordinates computation. The control mesh consists of a small number of vertices while the shape layer contains relatively a large number of vertices in order to embed the input shape as tightly as possible. Since the time-consuming optimization technique is applied only to the control mesh, the overall execution is extremely fast; however, the quality of deformation is sacrificed due to the sacrificed quality of the control mesh and its relativity to the shape mesh. In order to change the deformation behavior and consequently to compensate the quality sacrifice, we present a method to control the deformation stiffness by incorporating the orientation into the user constraints. According to our experiments, the proposed technique produces a planar shape deformation fast enough for real-time applications on limited embedded systems such as cell phones and tablet PCs.

• Journal of Broadcast Engineering
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• v.2 no.2
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• pp.136-145
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• 1997

As a 3D mesh model consists of a lot of vertices and polygons and each vertex position is represented by three 32 bit floating-point numbers in a 3D coordinate, the amount of data needed for representing the model is very excessive. Thus, in order to store and/or transmit the 3D model efficiently, a 3D model compression is necessarily required. In this paper, a 3D model compression method using PRVQ (predictive residual vector quantization) is proposed. Its underlying idea is based on the characteristics such as high correlation between the neighboring vertex positions and the vectorial property inherent to a vertex position. Experimental results show that the proposed method obtains higher compression ratio than that of the existing methods and has the advantage of being capable of transmitting the vertex position data progressively.

• Journal of Korea Game Society
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• v.9 no.2
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• pp.135-142
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• 2009

Mesh denoising is a method to remove noise applying various filters. However, those methods usually spend much time since filtering is performed on CPU. Because GPU is specialized for floating point operations and faster than CPU, real-time processing for complex operations is possible. Especially mesh denoising is adequate for GPU parallel processing since it repeats the same operations for vertices or triangles. In this paper, we propose mesh denoising algorithm based on bilateral filtering using GPU parallel processing to reduce processing time. It finds neighbor triangles of each vertex for applying bilateral filter, and computes its normal vector. Then it performs bilateral filtering to estimate new vertex position and to update its normal vector.

• Korean Journal of Applied Biomechanics
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• v.13 no.3
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• pp.355-366
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• 2003

본 연구의 목적은 뛰어 내리기 동작 시 신발과 뛰어 내리는 높이가 지면반력과 충격감소에 미치는 영향을 연구하였다. 10명의 건강한 피험자가 신발 또는 맨발로 네 가지 다른 높이에서 (30, 45, 60 &75 cm) 다섯 번의 뛰어 내리기를 시도하였다. 수직지면반력(VGRF), 영상분석, 경골과 앞이마의 가속도가 함께 측정되었다. 첫 번째 정점의 수직지면반력 (VGRF1)은 75cm의 높이에서 맨발보다는 신발을 신은 상황에서 더 큰 값을 보여 주었다. 두 번째 정점의 수직지면반력 (VGRF2)은 신발을 신은 것보다는 맨발의 조건에 더 큰 값을 보여 주었다. 앞 이마의 가속도 (AccHead)는 높이와 지면에 거의 변화를 보이지 않았다. 첫 번째 정점의 경골 가속도 (AccHead)는 높이와 지면에 거의 변화를 보이지 않았다. 첫 번째 정점의 경골 가속도 (AccTibia1)는 맨발의 조건보다 신발을 신은 조건에서 더 크게 나타났다. 반면에 두 번째 정점의 경골 가속도 (AccTibia2)는 특히 60 그리고 75cm조건에서 신발을 신었을 때 보다 맨발일 때 더 큰 값을 보여 주었다. 충격감소지수 (AtteIndex)는 모든 높이에서 맨발의 조건이 신발을 신은 조건 보다 통계적으로 유의하게 높게 나타났다. 결론적으로 뛰어 내리기 동작 시 신발이 지면반력을 최소화시키고 충격을 감소시키는데 부가적인 완충물로 제공되었음을 뒷받침 해준다.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.1579-1580
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• 2015

본 논문에서는 3차원 메쉬 모델의 중요 영역을 표현하는 메쉬 돌출맵(mesh saliency map)을 생성하기 위하여 다중 스케일 평균 곡률 (multi-scale mean curvature)을 기반으로 정의된 전역 희소치(global rarity)를 이용하는 방법을 제안한다. 제안 방법에서는 우선, 메쉬 모델의 지역 영역 특성을 정의하기 위하여 기존 관련 연구들에서 많이 사용하고 있는 가우시안 가중치 평균곡률(Gaussian-weighted mean curvature)을 5단계 서로 다른 스케일에서 정의하고, 메쉬의 각 정점(vertex)에 대하여 중심주변 연산자(center-surround operator)를 적용하여 5단계 지역 돌출특성(local saliency)을 정의한다. 주어진 메쉬 모델의 전역 희소치를 구하기 위하여 메쉬의 모든 정점쌍 (vertex pair)에 대하여 5단계 지역 돌출 특성 공간에서의 거리를 계산하고, 각 정점별로 5단계 지역 돌출 특성 공간에서의 다른 정점과의 거리의 합으로 전역 희소치를 정의한다. 이러한 전역 희소치를 각 정점의 메쉬 돌출치로 정의한다. 서로 다른 형태의 3차원 모델에 대하여 제안방법에 의한 메쉬 돌출맵과 지역 특성만을 고려한 기존 메쉬 돌출맵을 생성하여 중요 영역 표현 결과를 비교 분석한다.