• 수산해양교육연구
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• 제19권1호
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• pp.129-136
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• 2007

The component parts of the shell plate of a ship are steel. but the screw propeller or the bow thruster is a compound of bronze, nickel and aluminum. On account of the these different components between metals of the shell plate, the screw propeller and the bow thruster, which are underwater, the shell plate of a ship is corroded by the action of ionization. Authors investigated the corrosion loss of the zinc anodes which were attached to the bottom shell of the training ship Kaya for about two years. The obtained results were as follows:1. In case of the shell plate the difference of the corrosion loss according to port and starboard was almost nothing. But the corrosion loss of the forward part was more than that of the aftward part.2. There was little difference in the corrosion loss between the forward and the aftward part on the bilge keel.3. The corrosion loss of the fore, midship and aft part on the false keel were 24.7%, 22.4% and 23.9% respectively.4. The corrosion loss of the fore and the aft part on the false keel was more than that of the midship part.5. The corrosion loss of the bow thruster was greater than any other parts.6. The nearer the zinc anode to the screw propeller the more the corrosion loss on the stern frame, and the situation was also same as on the rudder.

• Journal of Ecology and Environment
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• 제41권1호
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• pp.9-18
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• 2017

Background: Species in the heterokont genus Synura are colonial and have silica scales whose ultrastructural characteristics are used for classification. We examined the ultrastructure of silica scales and molecular data (nuclear SSU rDNA and LSU rDNA, and plastid rbcL sequences) to better understand the taxonomy and phylogeny within the section Petersenianae of genus Synura. In addition, we report the first finding of newly recorded Synura species from Korea. Results: We identified all species by examination of scale ultrastructure using scanning and transmission electron microscopy (SEM and TEM). Three newly recorded species from Korea, Synura americana, Synura conopea, and Synura truttae were described based on morphological characters, such as cell size, scale shape, scale size, keel shape, number of struts, distance between struts, degree of interconnections between struts, size of base plate pores, keel pores, base plate hole, and posterior rim. The scales of the newly recorded species, which belong to the section Petersenianae, have a well-developed keel and a characteristic number of struts on the base plate. We performed molecular phylogenetic analyses based on sequence data from three genes in 32 strains (including three outgroup species). The results provided strong statistical support that the section Petersenianae was monophyletic, and that all taxa within this section had well-developed keels and a defined number of struts on the base plate. Conclusions: The phylogenetic tree based on sequence data of three genes was congruent with the data on scale ultrastructure. The resulting phylogenetic tree strongly supported the existence of the section Petersenianae. In addition, we propose newly recorded Synura species from Korea based on phylogenetic analyses and morphological characters: S. americana, S. conopea, and S. truttae.

• 대한기관식도과학회:학술대회논문집
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• 대한기관식도과학회 1981년도 제15차 학술대회연제순서 및 초록
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• pp.5.2-5
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• 1981

후두의 Anterior glottic web에 대한 수술적 치료방법은 1924년 Haslinger가 처음으로 Web의 성공적인 Correction예를 보고한 이래 1935년 Iglauer, 1950년 Mc Naught, 1969년 Pennington, 1970년 Montgomery등이 각기 다른 치료법을 소개하였으나 그 치료목적이 전연합부의 상피화와 동시에 Denuded Vocal Cord에 형성되는 유착을 방지하는 데에 있었다. 저자등은 최근 후두유두종 3례에서 2∼3회의 제거술후에 유발된 Anterior glottic web를 경험하여 Stainless Steel Plate를 이용한 Keel을 제작하여 사용한 결과 만족할 만한 결과를 얻었기에 문헌적 고찰을 가하여 보고하는 바이다.

• Ocean Systems Engineering
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• 제1권4호
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• pp.285-296
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• 2011

Spar platforms have several advantages for deploying wind turbines in offshore for depth beyond 120 m. The merit of spar platform is large range of topside payloads, favourable motions compared to other floating structures and minimum hull/deck interface. The main objective of this paper is to present the response analysis of the slack moored spar platform supporting 5MW wind turbine with bottom keel plates in regular and random waves, studied experimentally and numerically. A 1:100 scale model of the spar with sparD, sparCD and sparSD configuration was studied in the wave basin ($30{\times}30{\times}3m$) in Ocean engineering department in IIT Madras. In present study the effect of wind loading, blade dynamics and control, and tower elasticity are not considered. This paper presents the details of the studies carried out on a 16 m diameter and 100 m long spar buoy supporting a 90 m tall 5 MW wind turbine with 3600 kN weight of Nacelle and Rotor and 3500 kN weight of tower. The weight of the ballast and the draft of the spar are adjusted in such a way to keep the centre of gravity below the centre of buoyancy. The mooring lines are divided into four groups, each of which has four lines. The studies were carried out in regular and random waves. The operational significant wave height of 2.5 m and 10 s wave period and survival significant wave height of 6 m and 18 s wave period in 300 m water depth are considered. The wind speed corresponding to the operational wave height is about 22 knots and this wind speed is considered to be operating wind speed for turbines. The heave and surge accelerations at the top of spar platform were measured and are used for calculating the response. The geometric modeling of spar was carried out using Multisurf and this was directly exported to WAMIT for subsequent hydrodynamic and mooring system analysis. The numerical results were compared with experimental results and the comparison was found to be good. Parametric study was carried out to find out the effect of shape, size and spacing of keel plate and from the results obtained from present work ,it is recommended to use circular keel plate instead of square plate.

• 수산해양기술연구
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• 제52권2호
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• pp.79-87
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• 2016

Mobile fish-cage was developed assuming a cage net with an enclosed area, which and estimated the hydrodynamic characteristics of the cage through the model experiment. Flux-shielding plates, installed in the bow were compared with the resistance test carried out by making a hole, bilge keel and stud, and basic block flow rate consisting of the results to a flat surface plate. The experimental results confirmed the improved resistance performance effect of 3~6% in the bilge keel and the stud form. To assess the stability of the fish-cage, evaluation of the stability in accordance with the stability criteria for determining the floating docks had confirmed that it satisfied the static stability performance under operating conditions at sea.

• 대한기관식도과학회:학술대회논문집
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• 대한기관식도과학회 1983년도 제17차 학술대회연제순서 및 초록
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• pp.8.1-8
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• 1983

후두격막증은 이를 선천성 및 후천성 후두격막증으로 분류하며 선천성 후두격막증은 후두의 발생과정에서 특히 태아기 7 ∼ 8주경에 후두개와 양측 피열연골 융기가 서로 합쳐진 T형 초기성문 (primitive glottis)이 태아기 10 주경에 이루어져야 할 전후분리가 장해됨으로서 선천성 후두질환의 약 3 %에서 발생되며 그 중 약 75 %가 성문부에서 발생되고 나머지 약 25 %는 성문상부 및 성문하부에서 발생된다. 한편 후천성 후두격막증은 그의 대부분이 외상이나 수술후의 상흔 등에서 합병되며 선천성에 비해서 격막이 비교적 두껍고 섬유성인 경향을 보인다. 후두격막증의 증상은 그 격막의 상태에 따라서 일정하지 않으나 대체로 그 격막형성이 아주 작은 경우에는 특별한 증상이 없으나 격막이 큰 경우에는 사성이나 호흡곤란을 유발하게 된다. 본 증의 치료 원칙으로서는 격막을 절제한 후 특히 성문의 성대전연합 (Anterior Commissure)부위의 재유착을 예방하는 것인데 현재까지의 시술방법으로서는 1924년 Haslinger가 수술후의 성대전 연합 사이로 엷은 은편(silver plate)을 삽입시켰던 례와 1950년 McNaught가 갑상연골절개술로 탄타룸 편(tantalum keel)을 삽입시켰던 례가 있으며 이밖에도 테후론편 (teflon keel)등이 삽입되거나 점막이식술 등이 시도되어 왔다. 저자들은 최근에 23세 남자 환자로서 유·소아기에 수차의 후두유두종 수술후에 성대 전연합부에 발생한 격막증에 대하여 금편(gold keel)을 삽입하여 치험하였기에 이를 비데오로 소개하고자 한다.

• 수산해양기술연구
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• 제36권3호
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• pp.244-248
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• 2000

199년경 한국 남해안 어선의 특징은 독창적이고 견고하여 한반도 주변의 해양조건에 적합하고 우리 선조들의 훌륭한 조선기술을 확인할 수 있었으며, 그 결과를 요약하면 다음과 같다. (1) 본 연구에 사용한 시험대상 어선은 고대 어선에 비하여 비교적 세형으로서 1900년경의 선형이 개량되었음을 알 수 있었다. (2) 용골은 각형단면인 방형용골(bar keel)로 되어 있으며, 선수부는 방형선수재의 구조로서 예리한 pointed stem을 이루고 있다. (3) 외판은 턱붙이 클링커 이음방법으로 접합되어 있었다. (4) 권형망어선의 L/B, L/D, B/D의 값이 자망어선의 값에 비하여 크게 나타났다. (5) 복원성은 두 선박이 양호한 편이며 권형망어선이 자망어선에 비해서 더 우수한 것으로 나타났다.

• International Journal of Ocean System Engineering
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• 제4권1호
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• pp.1-18
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• 2014

Heave plates have been widely used to enhance viscous damping and thus reduces the heave response of Spar platforms. Single heave plate attached to the keel of the Spar has been reported in literature (Tao and Cai 2004). The effect of double heave plates on hydrodynamic response in random waves has been investigated in this study. The influence of relative spacing $L_d/D_d$ ($D_d$-the diameter of the heave plate) on the hydrodynamic response in random waves has been simulated in wave basin experiments and numerical model. The experimental investigation has been carried out using 1:100 scale model of Spar with double heave plates in random waves for different relative spacing and varying wave period. The influence of relative spacing between the heave plates on the motion responses of Spar are evaluated and presented. Numerical investigation has been carried out to investigate effect of relative spacing on hydrodynamic characteristics such as heave added mass and hydrodynamic responses. The measured results were compared with those obtained from numerical simulation and found to be in good agreement. Experimental and numerical simulation shows that the damping coefficient and added mass does not increase for relative spacing of 0.4 and the effect greater than relative spacing on significant heave response is insignificant.

• Journal of Acupuncture Research
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• 제17권3호
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• pp.45-56
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• 2000

Objectives : Meridian Scraping Therapy(MST: Kwal-Sa: 刮痧) has not well known in Korea. But it's a kind of Traditional Physical Therapy wide spreaded in China and Taiwan. So I want to introduce this new Therapy by summarizing the basic theories and practical manipulations. Conclusions : To analyse the meaning of the character Kwal-Sa, Kwal(刮) means scraping the skin by some tools and Sa(痧) means originally the red spots on skin of measles but in this therapy it's the red spot on skin after the treatment. Meridian Scraping Therapy is based on the meridiology and holism which are the basic theory of Oriental Medicine. The main effects of Meridian Scraping Therapy are draining of pathogenic factors, promoring the flow of ki and blood, tonify yang, balancing the harmony of intemal organs and enhancing the immuno-ability in body. Rhinoceros corpus is common matrial of MST-plate which is the tool of manipulation. And by this plate several manipulation is performed according to the symptom and the locations of pain. The merits of MST are that easily learned by practician, the effects of the treatment are very quickly manifest and no significant side-effects. And additionally this therapy performed not only for treat diseases but prevent it and preserve health.

• Animal Systematics, Evolution and Diversity
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• 제36권4호
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• pp.285-295
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• 2020

Adults of Prosimulium kiotoense and Twinnia japonensis were collected and reported from Korea for the first time. Since adult black flies are notorious for morphological homogeneity particularly in female, larval and pupal characters have been mainly used to identify them. Adults of P. kiotoense can be identified by the following combination of characteristics: Adult, wing with radial sector (Rs) branched into R²⁺³ and R⁴⁺⁵; hind leg basitarsus without calcipala; first tarsomere without pedisulcus. Female, claw without basal thumblike lobe; hypogenial valve elongate, convex, heavily sclerotized medially, posterior end touching each other, space between valves rhomboid. Male, claw with basal thumblike lobe; ventral plate keel shaped; gonostylus with 2-3 spinules. Adults and pupa of T. japonensis can be identified by the following combination of characteristics: Adult, antenna with 7 flagellomeres. Female, hypogenial valve broad, posterior end of valve not touching each other; cercus elongate, subquadrate; spermatheca slightly wider and long, round. Male, claw with basal thumblike lobe; gonostylus with 1 spinule; ventral plate flat. Pupa, gill of 16 filaments, arising from 3 swollen stalks; abdominal tergites without spine combs except tergites III and IV with small recurved hooks; terminal spine well developed, wavy shaped.