• Journal of Fisheries and Marine Sciences Education
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• v.19 no.1
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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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• v.41 no.1
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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.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1981.05a
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• pp.5.2-5
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• 1981

When the laryngeal web is small it rarely produces significant symptomatology. Large webs may produce stridor on both inspration and expiration, as well as hoarseness in various degrees. We have recently experienced with three cases of post-operative anterior glottic web after removal of the papilloma suffering from dyspnea and hoarseness. Layngeal webs with a definite voice problem or stridor should be managed surgically. And so, thyrotomy and a stainless steel keel insertion at the glottic level for repair of laryngeal web was performed. This technique has produced satisfactory result in all cases.

• Ocean Systems Engineering
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• v.1 no.4
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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.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.52 no.2
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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.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1983.05a
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• pp.8.1-8
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• 1983

An anterior glottic web can be congenital or develop as a result of trauma. The congenital webs indicate failure of normal separation of the two vocal cord primordia and the cicatrical membrane caused by accidental and operative trauma. When the web is small it rarely produces significant sympto-matology but larger webs may produce stridor as well as hoaresness in various degrees. Achievement of epithelialization of the anterior commisure after excision of a web, thus preventing adhesions from forming between the denuded vocal cords, is the principle underlying the surgical treatment of anterior glottic webs. Recently the authors experienced a case of anterior glottic web which occured in a 23 year old man after repeat removal of a papilloma several times in child-hood. The patient received treatment of a web excision followed by placement of a gold keel between the cords in the anterior glottis.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.3
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• pp.244-248
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• 2000

It was investigated and analized on the construction and hull form for the ordinary fishing boat of south coast in Korea, and then analogized on the shipbuilding technology of fishing boat and fishing type around 1900 by B-spline form parameter method. The results obtained can be summarize as follows : (1) It was known that the boats used in this study have more narrow hull form than that of ancient fishing boats and their hull form was improved around 1900. (2) Keel was composed of bar keel with angle cross section. The stem corner have a material of bar stem and makes a sharp pointed stem. (3) Shell plate was jointed by the rabbetted clinker joint method. (4) It was investigated that anchovy drag net fishing boat has high L/B, L/D, B/D value as compared with drift gill net fishing boat. (5) Two boats have a good stability and particularly anchovy drag net fishing boat have a better stability value in comparison to the drift gill net fishing boat.

• International Journal of Ocean System Engineering
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• v.4 no.1
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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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• v.17 no.3
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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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• v.36 no.4
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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.