• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.128-129
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• 2000

지금까지 해양생물에 관한 연구로서 갈조류중의 미역(Undaria pinnatifida)의 주성분인 알긴산(alginic acid)의 생리활성을 중심으로 성인병의 예방과 노화 억제효과에 관한 연구가 진행되어 왔다. 미역, 다시마 등 갈조류의 생리활성성분으로서 알긴산은 점성(viscosity)이 매우 커서 음료개발에 많은 문제점을 갖고 있다. 그렇지만, 후코이단 성분은 중성다당인 라미나란(laminaran)과는 달리 황산기(sulfate group)를 가진 산성의 수용성 다당류로서 항혈액응고 작용과 항종양 활성을 나타낸다고 보고되어졌다. (중략)

• Journal of Korean Society of Forest Science
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• v.96 no.1
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• pp.115-123
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• 2007

We investigated the effects of postfire logging on bird populations and communities through 57 point counts in unburned, burned and logged burned plots of coniferous forests in Samcheok, Korea. We found that lower species richness, abundance, and diversity in logged plots where were controlled by a typical postfire management. As results of guild analysis for nest sites and food resources, postfire logging reduced densities of ground-shrub nesters, primary and secondary cavity nesters, but was also related to reduction in densities of some foraging groups such as timber drillers and foliage searchers. These results suggest that snag-retention is essential for birds in burned forests and that postfire logging is incompatible with the maintenance of bird populations and communities. Consequently we need to develope guidelines of postfire management for snag-retention in burned forests through intensive researches focused on some target species such as Great spotted woodpeckers Dendrocopos major.

• Korean Journal of Environment and Ecology
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• v.3 no.1
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• pp.70-80
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• 1989

This study was conducted to investigate the user's effects on the avifauna in Kaya Mountain National Park. The survey was carried over 3 districts which were divided with main trail(valley), subtrail(valley), unused trail(ridge) by line transect method from April to October 1989. The observed birds were 29 species and 527 individuals. these consist of 20 species for residents, 7 species for summer visitor 1 species for winter visitor, 1 species for passage migrant. The average density of birds was 2.44 ea/ha, and main dominant species were Parus major minor, Garrulus gtandarius brandtii, Parus palustris hellmayri, Parus varius and Sitta europaea amurenis in order. The observed frequency of wild birds was 8.42 times/km in average. No. of species, no. of individuals, density, species diversity and observed frequency of summer were lower than spring in 3 survey routes. Therefore, from now, in Kaya Mountain National Park management, the enjoyment oriented activities will be regulated and control of trail use on main trail are necessary during breeding periods for wild birds protection, especially in summer. To investigate the use or not of artificial nests, 35 artificial nests were selected. The results of this survey showed that many wild birds prefered mixed nest in column shaped to wooden nests. The rightful installation and manegement for invitation and increase of wild birds was necessary.

• Journal of Korea Water Resources Association
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• v.55 no.11
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• pp.865-875
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• 2022

Field measurements and numerical simulations using EFDC model were performed to quantify the changes of water circulation near Gusipo coast located in the Yellow Sea of Korea to estimate the impact of the construction of the coastal structures (jetty, groin, Gusipo port and bridge). The model predicted tide and tidal currents agreed reasonably well with the measurements. The maximum currents during spring tide near the Gusipo Beach (GB) have the range of 20~40 cm/sec whereas those off the GB range from 60 to 80 cm/sec. The typical patterns of tidal current show parallel with the local isobath. Tidal currents flow northeastward during the flood tide whereas the currents during the ebb tide flow southwestward. The current speeds at shielded waters after the construction of coastal structures strongly decreased as compared with those before the construction. The tidal volume due to the construction of coastal structures was estimated using the depth averaged velocity for 24 hours of spring tide. Tidal volume after construction of coastal structures was compared with initial state (before construction). Tidal volume at present state (after construction of jetty, groin, Gusipo port and bridge) decreased by 28.4% as compared with that of the initial state. The volume after construction of jetty and groin decreased by 21.3%, and the volume after construction of Gusipo port and bridge decreased by 9.8%.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.5
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• pp.430-434
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• 2001

The algicidal activity of Shewanella (formerly Alteromonas) sp. SR-14 against diatom, Chaetoceros calcitrans was reported in our previous papers. In this study, the effect of Vibrio alginolyticus on the algicidal activity of Shewanelia sp, SR-14 was examined under the optimum algicidal conditions, i.e., temperature ($21\pm1^{\circ}C$), light intensity (4,000 lux), and light: dark cycle (12 hour: 12 hour). Shewanella sp. SR-14 grew well in the presence or the absence of V. alginolyticus in Conwy medium. Algal growth was only inhibited by Shewanella sp. SR-14. V. alginolyticus did not show the algicidal activity, Growth of C. calcitrans increased synergistically with growth of V. alginolyticus. When the initial inoculum of V. alginolyticus was only 1 log cycle higher than that of Shewanella sp. SR-14, the effect of V. alginolyticus on the algicidal activity of Shewanella sp. SR-14 was insignificant during incubation of mixed culture, i.e., two bacterial species and the alga. However, when V. alginolyticus dominated Shewanella sp. SR-14 by 3 log cycles of bacterial counts, it was found that the strain SR-14 could not inhibited growth of C. calcitrans up to 5 days of incubation.

• Journal of the Korean Geographical Society
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• v.36 no.2
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• pp.111-125
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• 2001

An estuary is semi-inclosed inlets, located between terrestrial and marine environment. Since many estuaries along south-western coasts of Korean peninsula were affected by human settlements and activities, significant changes in sedimentation environments have been observed. The research area is divided into three distinct morpho-stratigraphic units: fluvial dominated area(Area1), mixed area(Area 2), tide-dominated area(Area3). The landform of this area has been changed by reclamation and river channel change. Temporal variations affected by dam construction, periodic freshet was iterrupted. Sediments began to continuously accmulate on estuary banks by tide. Meanwhile, because of the continuous but reduced discharge of fresh water, the salinity of estuarine sediments was declined. That processes made vegetated area( Phregmites lonivalvis and Suaeda japonica) to be expanded. It indicates that the magnitude and frequency of geomorphic processes has been significantly changed.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.8
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• pp.528-532
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• 2012

This study investigated the possibility of phosphogypsum (PG) recycle as an embankment material by eco-toxicity experiments for S. capricornutum, T. suecica and D. magna. The eco-toxicity experiment was studied according to column leachates from PG mixing ratio, and a specific growth rate of S. capricornutum was usually higher than that of T. suecica. For D. magna, 0.3 of toxicity unit was obtained, which indicated the below of toxicity value of 1 at PG50 condition during a 48-hr test. A minor effect of column leachate samples on three organisms was observed. This study suggested that PG was satisfied with the criteria of waste recycle and could be reused at PG30 condition.

• The Korean Journal of Quaternary Research
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• v.5 no.1
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• pp.33-45
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• 1991

Sand bars associated with strong tidal currents are well developed in the subtidal zone near the Kokunsan islands. Tidal currents measured at sand bar in the area show an asymmetry in magnitude between flood and ebb currents. At the southern flank of the sand bar the currents are flood-dominant whereas the currents are ebb-dominant at the northern flank. The asymmetry is more distinctive as the currents become stronger during spring tide. Moreover, the flood-dominance along the southern flank is stronger than the ebb-dominance along the northern flank. Thus the flood current is more affective to the sand bar. The sandy bottom sediment is mostly transported as bedload by the tidal currents. The magnitude asymmetry of the tidal currents results in a net sediment movement in one direction. The direction is onshore in the south and offshore in the north, which may result in a net counterlookwise rotation of the sands around the sand bar. However, the sand bar may migrate towards onshore due to the more affective flood current in the south. The irregular V-shaped outline of the sand bar in the south also seem to reflect the strong effect of flood current.

• Journal of the Microelectronics and Packaging Society
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• v.1 no.1
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• pp.51-60
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• 1994

RuO2 계 후막저항체에 사용된 유리의 입도 및 연화점이 후막저항체의 전기적 특성 에 미치는 영향을 시험하기 위하여 연화점이 서로 다른 두 종류의 유리를 제조하고 이들을 미분쇄하여 각각 세 조류의 평균입도로 분급하였다. 이 유리분말들을 이용하여 여섯 종류의 후막저항체를 제조하고 그 저항체들의 전기적 특성을 평가하고 고찰하였다. 연화점이 높은 유리로 만든 후막저항체들보다 높은 쉬트 저항을 나타냈다. 또한 후막저항체들의 쉬트 저항 및 저항온도계수는 저항체들의 미세조직과 밀접한 관계가 있음을 확인하였다.

• KOREAN POULTRY JOURNAL
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• v.38 no.8 s.442
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• pp.142-143
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• 2006

조류 인플루엔자(Avian influenza, 이하 AI)는 때로는 돼지에서 나타나기도 하지만 주로 가금류에만 감염되는 바이러스성 질병이다 . 본래 “ influenza”는 라 틴 어 의“influential “(영어: influence), “영향을 주다”에서 유래된 말로 옛날 서양인들이 전염병이 돌면 별자리의 영향에 의한 것으로 믿은 것에서 유래됐다 한다. AI는 매우 종특이적(species- specific)이나, 드물게 종을 넘어 인간에게까지도 감염력을 나타내는 것들도 있다. 야생이 아닌 인간이 사육하는 가금류에서는 약독성과 맹독성의 두 종류가 발견되는데 이들은 아주 극단적인 결과를 나타낸다. 약독성은 깃이 곤두서거나 산란율이 저하되는 정도로 미미하게 경과되는 반면, 맹독성은 계군 간의 전파속도가 빠르고 각종 장기들에 감염되어 48시간 이내에 100% 치사율을 보이기도 한다.