• Title/Summary/Keyword: Island Length

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Community Structure and Productivity of Phytobenthos in Juckdo (Eastern Coast of Korea) II. Seasonal Changes of Algal Vegetation in Relation to Annual Growth of Large Brown Algae (저서식물의 군집구조와 생산성(동해안, 죽도) II. 해조류 식생의 계절변화와 대형갈조류 성장상태의 관계)

  • 고철환
    • Journal of Plant Biology
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    • v.26 no.4
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    • pp.181-190
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    • 1983
  • Seasonal occurrence of benthic algae and changes of subtidal vegetation were studied for their species composition, diversity and biomass during 1982 and 1983 at several selected sites at Juckdo Island (38$^{\circ}$12'N, 128$^{\circ}$32'E), eastern coast of Korea. Three large brown algae which played a role in change of algal vegetation through their great biomass were investigated with regard to their seasonal growth. Large brown algae such as Undaria pinnatifida, Costaria costata, Laminaria japonica, Agarum cribrosum, Sargassum confusum and S. hornerii constitute the major portion of vegetation in this area throughout the year. Algal vegetation in spring time is characterized by dominance of species U. pinnatifida and C. costata, whereas the summer vegetation by S. confusum and S. hornerii. In autumn large brown algae are shedded and only small algae, such as Chondrus ocellatus and Grateloupia filicina, remain. The vegetation in winter is dominated by the growth of U. pinnatifida and C. costata. Monthly changes in mean length and weight of randomly collected U. pinnatifida, C. costata and S. confusum are as follows; U. pinnatifida occurs from December to June and shows their maximum growth during March (120 cm in length, 201 g/individual in wet weight), its maximum growth rate is 1.4 cm/day, 3.3 g/day in this month. The growth season of C. costata is very similar to U.pinnatifida, but their average maximum length(110 cm) and weight (106 g/ind.) are lower than U. pinnatifida. The greatest growth rate is during March (1.8 cm/day, 2.0g/day). S. confusum is present throughout the year and reaches the maximum growth (102 cm, 63g/ind.) in July. Maximum growth rate (1.5 cm/day, 1.2 g/day) occurs also during this month. U. pinnatifida and C. costata show different months of maximum growth evidently during the two year. This seems to be caused by a considerable damage to the local vegetation followed by heavy storm in February 1983.

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Morphology of Digestive Tract and Its Goblet Cells of Giurine Goby Rhinogobius giurinus

  • Hur Sang-Woo;Song Young-Bo;Lee Chi-Hoon;Lim Bong-Soo;Lee Young-Don
    • Fisheries and Aquatic Sciences
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    • v.8 no.2
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    • pp.83-89
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    • 2005
  • Morphology, histology, and histochemical characteristics of the digestive tract of the guirine goby (Rhinogobius giurinus: Gobiidae), collected from the coast of Jeju Island, Korea, were investigated. The digestive tract of R. giurinus, which is a brackish water species, has a short (relative length of gut=0.42), simple, and narrow gut. The gastric glands are well developed in the stomach, but pyloric caeca are absent. The mucosal folds are regularly branched, and the muscularis extern a is thickest in the esophagus, which also contained the most mucus-secreting goblet cells (P<0.05). In R. giurinus, digestive function occurs in the anterior portion of the digestive tract, where mucus protects the tract from the actions of digestive enzymes and functions to activate digestion.

Numerical Simulation for Local Circulation of Urban Area and Deposition Phenomenon (도시지역의 국지순환과 침적현상에 관한 수치모의)

  • 이화운;오은주;노순아;반수진
    • Journal of Korean Society for Atmospheric Environment
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    • v.19 no.6
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    • pp.773-787
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    • 2003
  • There are variations in the temperature Held due to urban heat island and anthropogenic heating so that regional scale meteorological field is changed. Therefore we simulate and predict the regional climate change according to surface characteristics through regional meteorological model. This study investigates the regional meteorological field by urbanization that influences in local circulation system using CSU-RAMS and simulates dry deposition velocity (V$_{d}$) using PNU/DEM which includes surface characteristics (such as albedo, surface hydrology and rough-ness length etc.) with calculated meteorological field. During the summer, horizontal distributions of V$_{d}$ were simulated using CSU-RAMS and PNU/DEM at Busan metropolitan area. The estimated values of V$_{d}$ were larger in forest and agricultural areas than water areas since ozone with low water solubility is destroyed slowly at wet surface or water.water.

New Record of a Naidid Oligochaete Species, Ripistes parasita (Annelida: Clitellata: Naididae) from Korea

  • Jung, Jong-Woo
    • Animal Systematics, Evolution and Diversity
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    • v.28 no.2
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    • pp.137-139
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    • 2012
  • An aquatic oligochaete species, $Ripistes$ $parasita$ (Schmidt, 1847) collected from Ganghwado Island in Korea, is described and illustrated. Specimens inhabiting on aquatic vegetation at the edge of the streams were collected with a plankton hand net. Morphological features of present specimens such as the number of long hair chaetae per bundle and their length in VI-VIII, and shape and size of ventral chaetae are concordant with those of previous reports on this species. The genus $Ripistes$ contains one species, $R.$ $parasite$ which is distributed over, Europe, North America and eastern part of Asia including China and Japan. This is the first record of $R.$ $parasita$ in Korea.

First Record of Japanese Codling, Physiculus japonica Hilgendorf (Moridae, Gadiformes) from Korea

  • Koh Jeong-Rack;Moon Dae-Yeon
    • Fisheries and Aquatic Sciences
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    • v.6 no.2
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    • pp.97-100
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    • 2003
  • The Japanese codling fish, Physiculus japonica (family Moridae) is recorded as new to the Korean fish fauna. The specimen was fished from the South-Eastern waters off Jeju Island, Korea in March 1999. Standard length of the specimen was 343.2 mm, with a thin barbel on ower jaw, 67 soft second dorsal rays, 71 soft anal rays and 12 lateral-line above scales. Identification key of this specimen as P. japonica in the family Moridae was teethless vomer, chin barbel and well-developed black ventral light organ located on the anterior of anus. We give a new Korean name Dol-dae-gu for P. japonica.

Occurrence of a Thunnus alalunga Juvenile from Korea (날개다랑어(Thunnus alalunga) 치어의 국내 출현)

  • Yoo, Joon-Taek;Kim, Zang-Geun;Kim, Jin-Koo;Ryu, Jung-Hwa
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.45 no.2
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    • pp.180-182
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    • 2012
  • A single juvenile specimen of $Thunnus$ $alalunga$ (8.4 mm in standard length) of the Scombridae was collected from the southeast sea of Jeju Island ($127.7^{\circ}E$, $33.0^{\circ}N$) on August 18, 2011. It was identified as $T.$ $alalunga$ based on the following combination of morphological characters: snout elongated; melanophores focused on the dorsal spiny region, but no melanophores on the dorsal soft fin base, anal fin base or caudal region.

Construction of the Busan-Geoje Fixed Links Immersed tunnel (기획특집 - 거가대교 침매터널의 시공)

  • Cho, Bong-Hyun
    • Journal of the Korean Professional Engineers Association
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    • v.43 no.2
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    • pp.34-38
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    • 2010
  • The Busan-Geoje Fixed Link is an 8.2 km long motorway connecting Busan to the island of Geoje where the Korean big two shipbuilding yard locate on. This motorway includes a 3,300m immersed tunnel which is one of the longest immersed tunnel in the world and two cablestayed bridges each of 2km in length. The site locates in a exposed offshore, which is subjected to strong winds, large swell waves and strong tidal currents. These conditions together with the tunnel being at a deepest immersed tunnel ever built and the foundation condition is consisting of a very soft, normally to slightly over consolidated marine clay, makes the project unique and one of the most challenging immersed tunnels ever built.

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A New Gastrotrich Species of the Genus Ptychostomella (Macrodasyida, Thaumastodermatidae) from South Korea

  • Lee, Ji-Min;Hwang, Ui-Wook;Chang, Cheon-Young
    • Animal cells and systems
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    • v.13 no.1
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    • pp.25-30
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    • 2009
  • A new marine gastrotrich species, Ptychostomella jejuensis n. sp. belonging to the family Thaumastodermatidae, is described on the basis of the specimens from subtidal sand bottom at about 6-7 m depth of Jeju Island, South Korea. Ptychostomella jejuensis n. sp. is distinguished from its congeneric species with smooth cuticular armature by the character combination: (1) small body up to about 160 ${\mu}m$ in length; (2) presence of knob-like cephalic tentacles; (3) absence of dorsal and ventral adhesive tubes; (4) bifid pedicles; (5) pyriform copulatory organ. Under scanning electron microscopy, numerous epidermal gland openings were observed in the new species, characteristically flanking a bristle. Taxonomic accounts on the affinities, some brief remarks on the epidermal gland openings and the cooccurrence with P. orientalis Lee and Chang, 2003 are also presented with detailed illustrations and scanning electron photomicrographs.

Taxonomic Study of Amphiroa rigida Lamouroux (Rhodophyta) in Korea (한국산 홍조 몽우리두층게발에 관한 분류학적 연구)

  • Choi , Do-Sung
    • ALGAE
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    • v.22 no.3
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    • pp.159-165
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    • 2007
  • Morphological and anatomical characters of Amphiroa rigida Lamouroux were investigated with field materials and taxonomic accounts are given to the species. The species grows in the subtidal zone of Cheju island, and is characterized by semiendophytic habit in Hydrolithon onkodes. The species is well defined by about 1 cm height, loosely tufted thallus with irregular branches, two-tiered geniculum with equal length, geniculum tier connecting by oblique end walls, and conceptacles buried in cortices of intergeniculum. Korean isolates have etrasporangial, male and female conceptacles. The structure and developmental patterns of conceptacles are very similar to those shown in previous studies.

A Case Study for the Economic Feasibility Model and Analysis of a GDHS Given Geothermal Temperature (기대지열온도하에서 GDHS의 경제성분석 사례연구)

  • Yang, Moon-Hee;Kim, Tai-Yoo;Lee, Sang-Kyu
    • Journal of Korean Institute of Industrial Engineers
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    • v.23 no.1
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    • pp.115-127
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    • 1997
  • A GDHS(Geothermal District Heating System) is a heating system supplying a group of districts with heat extracted from geothermal sources. The advantages of GDHS include saving fuel consumption as well as reducing air pollution. This paper presents a case study for the economic feasibility model and analysis of a GDHS with which central/individual heating systems are replaced. Configuring to a simplified GDHS which consisits of subsurface systems, surface systems, and transmission/distribution systems, we find out the properties of the system and the model parameters affecting the initial investment/operating costs in order to develop a classical economic feasibility model given geothermal temperature. Based on our model parameter space, we analyzed the geothermal development project of the Jejoo Island probabilistically given prior information such as the expected geothermal power, the demand size and the length of transmission/distribution pipes.

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