남조류의 체외 대사부산물이 다른 조류의 광합성에 미치는 타감작용

김범철,허우명,황길순,안태석,심재형 江原大學校 附設 環境硏究所 1994 環境硏究 Vol.11 No.-

The effect of cyanobacterial extracellular byproducts upon the aIgal photosynthesis was assessed to elucidate the allelopathic effect of algal blooms in eutrophic lake. Algal cultures were filtered with 0.2μm membrane filters to remove algal cells and sterilized. 0 to 30m1aliquots of filtrate were added to 25m1 culture suspensions of other algal species, and the (14)^C uptake rates wert measured. The filtrates of cyanobacterial cultures(Anabaena flos-aquae, Phormidium sp.) inhibited the photosynthesis of green algae(Selenastrum capricornutum and Scenedesmus brasiliensis), while the filtrate of Selenastrum capricornutum and Scenedesmuns brasiliensis did not inhibit Anabaena flos-aqiae. In the autoinhibition test Anabaena flos-aquae, Selenastrum capricornutum, and Scenedesmus brasiliensis showed positive, negative, and no effects, respectively.

식물플라크톤의 세포외배출유기물을 고려한 소양호의 1차생산과 유기물 부하

남궁현,김범철,황길순,최광순,김철구 江原大學校 附設 環境硏究所 2001 環境硏究 Vol.18 No.-

The autochthonous and allochthonous organic carbon loading were measured in Lake Soyang, to estimate the amount of carbon loading into the lake and the contribution of their sources to the lake's carbon loading. Autochthonous carbon loading was estimated from phytoplankton primary production with the extracellular organic carbon(EOC). Allochthonous loding was determined by measuring dissolved organic carbon(DOC) and particulate organic carbon(POC) concentration in the main inflowing Soyang River. Both autochthonous and allochthonous organic carbon loading were high during the summer, from July to September, and accounted for 43.2% and 71.7% of the annual loading, respectively. Primary productivity was elevated up to 1,000 mgCm^(-2)d^(-1)during summer and lowest in winter. EOC production from phytoplankton was also large in summer, resulting in a high DOC concentration in the lake water. Primary production of phytoplankton and allochthonous organic matter loading from the watershed contributed to 53.6% and 46.4% of total loading, respectively. The EOC production accounted for 4.4~21.2% of POC primary production, implying that EOC production of phytolankton must be considered in estimation of primary production.

소양호에서 인의 존개 형태별 분포에 관하여 : The Distribution of Phosphorus Fractions in Lake Soyang

김범철,허우명,황길순,김동섭,최광순 江原大學校 附設 環境硏究所 1996 環境硏究 Vol.13 No.-

The distribution of phosphorus in Lake Soyang from January 1985 to August 1992 was surveyed by the measurement of soluble reactive phosphorus(SRP), total dissolved phosphorus(DTP), and total phosphorus(TP) concentration. SRP concentration was in the range of 2~7㎎/㎥ in epilimnion, and 4~200㎎P/㎥ in hypolimnion. The vertical distribution pattern of SRP showed a large difference with the season. SRP concentration decereased during the growing season of phytoplankton in the epilimnion of Lake Soyang and increased in hypolimnion during the oxygen depletion. Higher concentration near the bottom implies they are diffused from the bottom sediment where organic particles are settled and degraded. SRP, DOP, POP and TP concentration was higher in the meralimnion of Lake Soyang in rainy season It might be related with storm runoff. General trend of TP variation is that the TP concentration of water column is increasing substantially from yeat to year. TP concentration in the surface water increased from 5㎎P/㎥ at 1985 to 20㎎P/㎥ at 1992.

낙동강 수계의 인, 질소 및 Chl.a 농도 분포 : The distributions of phosphorus, nitrogen, and chlorophyll a concentration in the Nakdong River

허우명,김범철,황길순,최광순,박원규 江原大學校 附設 環境硏究所 1996 環境硏究 Vol.13 No.-

The longitudinal variations of water quality along the mainstream of the Nak-ding River from May 1994 to October was surveyed by the measurement of chl-orophyll a, total phosphorus, total nitrogen, dissolved inorganic phosphorus, nitrate-nitrogen, ammonia-nitrogen concentration, and secchi disc transparancy. Chl. a, TP, TN, DIP, NO_(3) and NH_(3)-N concentration was maintained at high level during the investigation period. And they also showed the peak after the input of Kumho River. Chl. a concentration was increased from 14.2㎎/㎥ in May to 95.2 in October. TP ane TN concentration was maintained always above 100㎎/㎥ and 3~4㎎N/l, respectively. TN/TP ratio were less than 16 from June to September with a few exceptions. Therefore, nitrogen is the limit-ing nutrient in the Nakdong River. Trophic states were in the range of eutrophic to hypertrophic, from 60 to80.

국내 주요호수의 육수학적 조사 (1) : 옥정호

김범철,박주현,이병진,허우명,황길순,최광순,채기숙 江原大學校 附設 環境硏究所 1998 環境硏究 Vol.15 No.-

The limnological survey of Lake Okjong was conducted for one year from June 1993 to May 1994 on the monthly basis. The loading of phosphorus, nitrogen and organic carbon from the watershed into the lake were monitored at the main in flowing sites. Secchi disc transparency , epilimnetic chlorophyll a, total nitrogen, total phosphorus concentration and primary production were in the range of 1.3~4.H m, 2.4~ 18.7 mg Chl/m³. 1.25~2.87 mg N/l, 7~65 mg P/m³, 325~2,113 mg C/m²/day, respectively. TN/Tl atomic ratio varled from 129 to 443. N/P ratio decreased in summer because phosphorus concentration was higher than in winter, while nitrogen did not vary much. The seasonal succession of phytoplankton was distinct. In winter and spring, diatoms, Aulacoseira granulata var. angustissima and Aulacoseira italica were dominant while cyanobacteria, Microcystis sp.,M. ichthyovlabe, Phormidium sp. and P.valderianum var. tenuis were dominant in warm seasons. The dominant zooplankton species were Thertmocyclops taihokuensis in warm seasons while Boosmina longirostris were dominant in cold seasons. The organic carbon, nirtogen and phosphorus content of lake sediment were 8.0~14.8, 0.59~0.71, 1.14~1.87 ng N/g, respectively. The sediment of Lake Okjong can be classified as oligohumic based on C/N ratio. The total phosphorus loading from the watershed and fishfarm were estimated to be 2.7g P/m²/yr, which far exceeded the critical loading for eutrophication. The organic carbon loading from the watershed and primary production were determined to be 998t C/yr, 6,348t C/yr, respectively. Most of organic carbon was contributed by autochthonous primary production of phytoplankton. Trophic state of Lake Okjong can be classified as eutrophic

국내 주요 호수의 육수학적 조사(4): 주암호

김범철,박주현,허우명,임병진,황길순,최광순,최종수 江原大學校 附設 環境硏究所 2001 環境硏究 Vol.18 No.-

In this study limnological characteristics of Lake Juam was surveyed from June 1993 to May 1994 in order to provides important information regarding water resources. Seschi disc transparency, epilimnetic chlorophyll a(chl-a), tatal nitrogen(TN), total phosphorus(TP) concentration and primary productivity were in the range of 2.0~4.5 m, 0.9~13.6 mgChl/㎥, 0.78~2.32N/l, 11~56 mgP/㎥, 270~2,160mgCm^(-2)day^(-1), respectively. On the basis of TP, Chl-a and Secchi disc depth, the trophic state of Lake Juam can be classified as mesotrophic lake. The phosphorus inputs from non-point sources are concentrated in heavy rain episodes during the monsoon season. As a result, phosphorus concentration are higher in summer than in winter. TP loading from the watershed were estimated to be 0.9 gPm^(-2)yr(-1), which correspond to a boundary of the critical loading (1.0 gPm^(-2)yr(-1), which correspond to a boundary of the critical loading (1.0 gPm^(-2)yr(-1)) for eutrophication. From the results of the algal assay, both phosphous and nitrogen act as limiting nutrients in algal growth. The seasonal succession of phytoplankton community structure in Lake Juam was similar to that observed in other temperate lakes. Diatoms(Asterionella formosa and Aulacoseira granulata var. angustissima) were dominant in spring and winter, cyanobacteria (Microcystis aeruginosa, M. sp. and M. viridis) were dominant in warm season. The organic carbon, nitrogen and phosphorus content of lake sediment were 9.5~14.0 mgC/g, 1.01~1.82 mgN/g, and 0.51~0.65 mgP/g, respectively. The allochthonous organic carbon loading from the watershed and autochthonous organic carbon loading by primary production of phytoplankton were determined to be 1,122 tC/yr and 6,718 tC/yr, respectively. To prevent eutrophication of Lake Juam, nutrient management of watershed should be focus on reduction of fertilizer application, proper treatment of manure, and conservation of topsoil as well as point source.

The Effect of Rainfall on the Water Quality of a Small Reservoir (Lake Wangkung, Korea)

( Gil Son Hwang ),( Bom Chul Kim ),( Jae Ok Kim ),( Jai Ku Kim ),( Young Chul Kim ) 한국하천호수학회 2005 생태와 환경 Vol.38 No.S

Primary Productivity of Phytoplankton at the Eutrophic down Reach of a Regulated River (the Han River, Korea)

Namkung, Hyun,Hwang, Gil Son,Kim, Bom Chul,Kim, Kap Soo 한국육수학회 2001 생태와 환경 Vol.34 No.4

수도권의 중심부를 가로지르는 한강의 하류수역은 조수의 영향을 받을 수 있는 하구의 상단부에 위치해 있다. 한강 하류수역은 한강 종합개발사업의 일환으로 이루어진 준설과 수중보 건설에 의해서 강물이 정체되었으며, 또한 지천으로부터 유입되는 많은 오염물질에 의해서 식물플랑크톤의 대량 발생을 촉진할 수 있는 환경으로 변화되었다. 본 연구에서는 부영양한 한강 하류수역에서 식물플랑크톤의 1차생산을 측정하였으며, 더불어 내부생성유기물과 외부기원유기물을 산정하였다. 1차생산력은 C-14 uptake법과 P-I 모델법으로 측정하였다. 1차생산력의 범위는 140∼4,890 mgC m^-2 day^-1(중앙값 1,865 mgC m^-2 day^-1)이었으며, 국내의 부영양한 호수와 유사한 수준이었다. 식물플랑크톤의 생물량 변동은 봄철에 최대치를 보였으며, 유량의 변화와 관련이 있는 것으로 나타났다. 외부기원유기물은 여름철 홍수기를 제외한 연중 내내 지천을 통하여 유입되는 오염물질에 의해서 좌우되었다. 총 유기물 부하량에 대하여 식물플랑크톤의 1차생산이 차지하는 기여도는 40.9%로서, 유수 생태계로서는 높은 수준이었다. The downstream reach of the Han River adjoining Seoul in Korea was the upper boundary of an estuary where tidal effect on the flow rate could be exerted. According to the comprehensive river regulation project, the river was channelized and impounded by two overflow dams, which provided favorable condition for algal growth in this sewage polluted eutrophic reach. In this study primary productivity of phytoplankton was measured in the down reach and the autochthonous and allochthonous organic carbon loadings were estimated. Primary production of phytoplankton measured by C-14 uptake and P-I model method ranged from 140 to 4,890 mgC m^-2 d^-1 (median value 1,865 mgC m^-2 d^-1) showing the level of eutrophic lakes. Phytoplankton density that varied according to water flow rate was highest in spring. Allochthonous organic carbon loading was dominated by sewage input through tributaries in most of days except flood flow period. The average proportion of autochthonous carbon generation by phytoplankton was 40.9%, which is very high proportion for a lotic habitat.

거리에 따른 촉각 정보를 이용한 손가락 기반 가상현실 상호작용

손형기(Hyungki Son),길현재(Hyunjae Gil),황인욱(Inwook Hwang),김진용(Jin Ryong Kim) 한국HCI학회 2018 한국HCI학회 학술대회 Vol.2018 No.1

HMD 기반의 가상현실 기술이 발전하면서 단순한 상호작용이 아닌, 가상의 객체를 직접 조작하는 상호작용이 가능하게 되었다. 하지만 현재의 가상현실 기술에서는 완벽한 공간정보를 시각적으로 전달하기가 어렵기 때문에 사용자는 고유감각(proprioceptive sense)과 시각 정보사이에서의 차이로 인해 가상 객체의 조작이 매우 어려운 것이 현실이다. 본 연구에서는 이러한 가상객체의 조작 (예: 버튼) 시 Distance-to-tactile coding 방식으로 감각치환을 통해 고유감각과 시각정보의 불일치를 보완할 수 있는지를 살펴본다. Fitts’ Law 기반 실험을 통해 3 가지 피드백 조건에서 운동 시간 및 오차율을 측정한 결과, 햅틱 피드백을 제공한 경우 운동 시간 및 오차율에서 향상된 결과를 볼 수 있었다.

Primary Productivity of Phytoplankton at the Entrophic down Reach of a Regulated River (the Han River, Korea)

Hyun, Nam-kung,Hwang, Gil-son,Kim, Bom-chul,Kim, Kap-soo 江原大學校 附設 環境硏究所 2001 環境硏究 Vol.18 No.-

The downstream reach of the Han River adjoining Seoul in Korea was the upper boundary of an estuary where tidal effect on the flow rate could be exerted. According to the comprehensive river regulation project, the river was channelized and impounded by two overflow dams, which provided favorable condition for algal growth in this sewage polluted eutrophic reach. In this study primary productivity of phytoplankton was measured in the down reach and the autochthonous and allochthonous organic carbon loadings were estimated. Primary production of phytoplankton measured by C-14 uptake and P-I model method ranged from 140 to 4,890 mgCm^(-2)d^(-1)(median value 1,865 mgCm^(-2)d^(-1)) showing the level of eutrophic lakes. Phytoplankton density that varied according to water flow rate was highest in spring. Allochthonous organic carbon loading was dominated by sewage input through tributaries in most of days except flood flow period. The average proportion of autochthonous carbon generation by phytoplankton was 40.9%, which is very high proportion for a lotic habitat.