• Title/Summary/Keyword: rocky

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A Survey of the Rocky Intertidal Biota in Uldolmok, Korea (울돌목 암반조간대 부착생물상 연구)

  • Park Ja-Yang;Lim Byung-Jin;Lee Jae-Il
    • 한국신재생에너지학회:학술대회논문집
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    • 2005.06a
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    • pp.502-506
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    • 2005
  • 2003년 11월과 2004년 4월의 2회에 걸쳐 상용조류발전소 건설 예정지인 울돌목에서 발전소 건설로 인해 야기될 주변생태환경의 변화를 파악하기 위해 4개 지점의 주변 암반조간대에 형성된 기존의 부착생물상 조사가 수행됐다. 울돌목 주변의 암반조간대에 형성된 부착생물상은 서식 형태에 따라 크게 대형해조류(Macroalgae)를 포함한 고착생물, 소 이동성 부착동물, 이동성 소형 무척추동물 등으로 구분된다 부착생물상은 서식양상에 있어 각각의 정점별 특이성이 관찰되었으며, 이는 각기 다른 비생물학적 요인에 따라 지역 특유의 서식환경이 조성되어 있음을 시사하는 간접적인 결과로 간주된다. 이같은 지역 간 생물상 차이는 조위에 따른 수직분포 분석결과 주로 중부조간대를 중심으로 형성된 생물상에 따라 대별되고 있음이 발견되었다.

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A New Record of Sea Urchin (Echinoidea: Echinoida) from Jejudo Island, Korea

  • Shin, Sook
    • Animal Systematics, Evolution and Diversity
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    • v.24 no.3
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    • pp.323-326
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    • 2008
  • Some sea urchins were collected from the subtidal rocky bottom of Munseom near Seogwipo, Jejudo Island by SCUBA diving from April to May, 2008 and identified on the basis of their morphological characteristics. Among them, Tripneustes gratilla (Linnaeus, 1758) of Family Toxopneustidae was newly recorded from Korea and redescribed on the specimen collected at a depth of 25 m between Munseom and Sekkiseom. The detailed morphological description was presented with the photographs. This species was characterized by the very naked median areas of ambulacral and interambulacral portions and this genus was the first record in Korea. Eighteen echinoids are so far recorded in Jejudo Island, Korea.

The Vegetation of Seogno Island (序毛島의 植生)

  • Kil, Bong-Seop;Jeong-Un Kim
    • The Korean Journal of Ecology
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    • v.7 no.4
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    • pp.208-232
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    • 1984
  • A survey was conducted on the vegetation of Seogmo island, which is small island (ca. 41 okm2) located about 1km west of Kanghwa island in the central Korea, from Aug. 1983 to May 1984. Based on the field data, actual vegetation map and potential natural vegetation map were made. The island is covered with broad-leaved trees dominated with Quercus variabilis. The dominance diversity curves obtaiend in different associations are grouped in two types, lognormal distribution forms at the undisturbed vegetation and geometric series at the disturbed or rocky sites. It seems that the curves show to us the nature of their ecocline by the hypothesis of some investigators, i.e. Random niche boundary hypothesis, niche preemption hypothesis, lognormal distribution and logarithmic series. Total numbers of vascular plant species of the island were recorded 108 families, 348 genera, 475 species, 73 variaties and 7 forma. And Pte.-Q Index, 0.93, and Fisher's Index, 589.8, were higher than those in neighboring islands.

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Rock fall on tunnel portals

  • OGGERI, Claudio;PEILA, Daniele;PELIZZA, Sebastiano;KIM, Sanghwan
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.6 no.4
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    • pp.357-365
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    • 2004
  • Tunnel portals are often located in areas where the risk of rock fall and/or detachement of rock fragments from rocky slopes is high. In this case it is necessary to design the portals so as to protect the road (i.e. using an artificial tunnel) or to instal structures that are able to intercept falling blocks on the slope. This paper deals with the design problems of these structures and includes a special analysis of net fences which have undergone a remarkable technological improvement over recent years.

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Two unrecorded marine nematode species of Paracanthonchus (Nematoda: Cyatholaimidae) from the East Sea of Korea

  • Lee, Hyo Jin;Jung, Jongwoo;Rho, Hyun Soo
    • Journal of Species Research
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    • v.5 no.3
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    • pp.503-513
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    • 2016
  • Two unrecorded marine nematode species, belonging to genus Paracanthonchus Micoletzky, 1924, are described on the basis of the specimens collected from rocky intertidal seagrass bed on the eastern coast of Korea. Paracanthonchus macrodon (Ditlevsen, 1918) is characterized by presence of cuticular differentiation, strongly dilated gubernaculum with numerous cusps, three post-cloacal setae, and arrangement of six (4+2) precloacal supplement. Paracanthonchus kamui Kito, 1981 is distinguished from other species of the genus by having the 4.25 turns amphideal fovea, six tubular supplement, rib-shaped gubernaculums with proximally hook-shaped and distally broaden. In this study, we provide taxonomic description and illustration of two unrecorded species of the genus Paracanthonchus by differential interference contrast microscopy. This is the first report on the species of the genus Paracanthonchus from Korea.

Redescriptions of Two Thalestrid Copepods, Phyllothalestris sarsi Sewell, 1940 and Dactylopusia falcifera Willey, 1935(Copepoda, Harpacticoida, Thalestridae)in Korea (한국산 요각류, Phyllothalestris sarsi Sewell, 1940와 Dactylopusia falcifera Willey, 1935(요각아강, 갈고리노벌레목, Thalestridase과)의 재기재)

  • Song, Sung-Joon;Kim, Won;Chang, Cheon-Young
    • Animal Systematics, Evolution and Diversity
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    • v.17 no.2
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    • pp.229-243
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    • 2001
  • Two marine harpacticoid species, Phyllothalestris sarsi Sewell, 1940 and Dactylopusia falcifera Willey, 1935 belonging to family Thalestridae are redescribed from South Korea, on the basis of the specimens of both sexes mainly from the washings of macroalgae at littoral rocky shore or sublittoral bottom sediments during the period from 1994 to 2000. They are new to Korean fauna, and this report is the first record for them in the Pacific Ocean.

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Bottom sediments of the Asan bay, west coast of Korea (아산만일대(牙山灣一帶) 해저퇴적물(海底堆積物)에 대(對)하여)

  • Kim, Sung-woo;Chang, Jeong-hae;Park, Yong-ahn
    • Economic and Environmental Geology
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    • v.11 no.2
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    • pp.81-88
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    • 1978
  • Nearly 300 bottom sediments and 20 box-cores were sampled from the Asan bay. The central portion of the Asan bay is covered by sand, slightly gravelly sand and gravelly muddy sand. Between the central and marginal zones gravelly mud and slightly gravelly sandy mud are characteristically distributed. The gravel population in the sediments seems to be originated from the rocky bottom on the area near the bay because the gravel is angular and composed of the schist and gneiss. The quartz/feldspar ratio is about 3/2. It is considered to be that the amount of feldspar in this bay is much higher than that of any other areas in the Yellow Sea. This is considerd to be comparatively short distance of transport ion of these sediment from the provenance.

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A Clinical Consideration of Orthodontic Force (교정력에 관한 임상적인 소고)

  • Kim, Il-Bong;Ku, Ok-Kyung;Sung, Jae-Hyun;Kim, Yung-Soo
    • The Journal of the Korean dental association
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    • v.11 no.2
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    • pp.123-129
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    • 1973
  • The authors measured orthodontic force using the orthodontic materials of the Rocky Mountain Products Company. The results were as follows : ① Use latex of wide diameter in long distance, and when the latex of wide diameter activated by four or five times, we obtained a optimal force. ② The authors obtained canine retractions with sectional arch. Activation of sectional arch began at 1mm and had to do not activations of 3mm more. ③ The leveling started from .014 green round wire and finished to. 0.16" green Elgiloy round wire. Permit only a mild force in ideal arch form, in rectangular wire. ④ Fundamentaly, elastic thread obtained maximum force by activating as two times. ⑤ Coil spring obtained more heavy force from short distance than long distance.

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Mobility Analysis of Planar Mobile Robots and The Rough-Terrain Mobile Robot via The Representative Screw (대표 스크류를 이용한 평면형 및 험로 주행 로봇의 모빌리티 분석)

  • 김희국;이승은;이병주
    • Journal of Institute of Control, Robotics and Systems
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    • v.8 no.10
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    • pp.881-889
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    • 2002
  • Mobility analysis for various mobile mechanisms including mechanisms with lack of geometric generality is performed. Joint screws are employed to find the sire of feasible joint motion space or each of independent loops of mobile mechanisms. Particularly, the concept of "representative screws" is introduced to represent the feasible motion spaces for subsets of joints belonging to either a loop or a sub-system consisting of several closed loops. Firstly. simplified joint model for each of low different typical wheels popularly employed in mobile robots is described. Then. mobility analysis fir various types of planar mobile robots and the Mars Rover mobile robot for navigation on the rocky road on Mars arc performed. It is confirmed that the obtained results in this study coincide with the previous ones which were obtained by suing imaginary Joints approach(1)pproach(1)

A new record of Acanthogorgia species(Octocorallia: Alcyonacea: Holaxonia: Acanthogorgiidae) from Korea

  • Cho, In-Young;Hwang, Sung-Jin
    • Journal of Species Research
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    • v.7 no.1
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    • pp.92-96
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    • 2018
  • In 2017, during a survey of the anthozoan fauna in the Hallyeohaesang National Park in the South Sea, several Acanthogorgia specimens were collected from the subtidal zone. Through taxonomic analysis, one species, Acanthogorgia densiflora $K{\ddot{u}}kenthal$ & Gorzawsky, 1908, was found to be previously unreported from Korea, and was, therefore, newly added to the list of Korean anthozoan fauna. This species is distributed on the slopes of the rocky substratum between depths of 14 and 24 m. Including the findings from this study, ten species of the genus Acanthogorgia have thus been reported from the Korean waters until now.