• 한국항해학회지
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• 제13권3호
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• pp.21-36
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• 1989

The submarine played an active part in military operation during the last of nineteenth century. Today, as an aid to science and technology and technology m the submarine is being utilized in the fields of deep sea investigation and sight-seeing as well as military activities. When the stability and the maneuverability of a submarine is studied, the problems arise on the vertical plane as well as the horizontal plane. However, the horizontal plane has been dealt with in the study of surface vessels. The author attempts to look into the hydrodynamic directional stability at high speeds (above 10knots) on the vertical plane, and to clarify the submarine's depth-rate as related to the factors that affect it : the distance from the center of buoyancy to the center of gravity, the speed of the submarine, and the position and the area ratio of hydroplane. In this study, the author considered the two groups of dimensionless derivatives of submarine. It is confirmed that the depth-rate of a submarine is decreased when the length, of BG is increased under the continuous submerging status. But the depth-rate is increased when the area ratio of hydroplane is enlarged. It is also confirmed that a submarine has only one critical speed in accordance with the shape of its hull, but unconcerned with its speeds.

• 대한조선학회논문집
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• 제49권3호
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• pp.222-226
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• 2012

When ship blocks are erected or pre-erected, most blocks will be at outdoors where they are not protected from weather and exposed to ray of the sun. A deck plate compared to those in radiation heat transfer from the sun will have higher temperature than it of ambient air, and will expand more than lower laying structures whose temperatures are similar with air. But deck plates and under-structures are connected, so the deck plate will be under out-of-plane deformation rather than expand in length. In this study, we considered the temperature difference between air and plate as a major parameter of out-of-plane deformation, and analyzed how much additional deformation would take place. In addition, when a deformation could take place was also analyzed based on the initial deformed shape of deck plate. Because the accuracy inspections of deck plate will be done during daytime, conventional accuracy check results on sunny day could make us feel unfair. Thus resonable datum about momentary additional out-of-plane deformation due to environmental effects have been determined. The real deformation values can be specified even under enlarged deformations by radiation-expansion.

• 한국농촌건축학회논문집
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• 제13권1호
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• pp.1-8
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• 2011

This aim of the study is to investigate the plan and elevation types of existing way stations built in the early 20th century Korea, focused on Choong-ang, Donghae-nambu, and Kyung-jeon line of the railroad tracklines. The plans and elevations are drawn up and analyzed based on literature data and aerial photographs through the survey. These way stations are classified into various types by room layout and front elevation. The basic plan types are composed of waiting room, station service room, and administration. The station service room has a train operation room in the projecting part of corner. This room has windows on every side to see in and out of train. There are the enlarged, extended waiting room types, and linear types in the other plan types. The waiting room is lied on the right side, and has a gable roof in elevation. The elevation types are classified with side and centralized, and so on by the placement and shape of gable roofs. The basic elevation types have gable roofs in sides lied on the waiting room, and these types are transformed into centralized types by extension of waiting room The others are the linear types without gable roofs and the unusual roof types in appearance.

• 소성∙가공
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• 제28권6호
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• pp.335-346
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• 2019

Thick plate forming is presented to manufacture a large and curved member of steam turbine diaphragm. Due to three-dimensional asymmetry of target geometry, it is hard to consistently keep the blank position in die cavity between forming punch and die. In order to relieve the position instability of the blank during the thick plate forming, a blank support structure is proposed to be composed of guide pins and linear bearing, and blank guide arm enlarged from both longitudinal ends of the thick blank. In this study, parametric investigations with regard to the geometric position and width of the blank guide arm are carried out. As main geometric parameters, 2 positions such as maximum curvature region and minimum one on a curved cross-section profile of the target shape are selected, and 14 widths of the blank guide arm are considered. Using 28 variable combinations, three-dimensional numerical simulations are performed to predict the appropriate range of the process parameters. The compatibility and validity of the blank support structure with the blank guide arm for the thick plate forming is verified through the thick plate forming experiments.

• 대한치과교정학회지
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• 제22권2호
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• pp.309-325
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• 1992

The purpose of this study was to evaluate the effect of intrinsic factor and extrinsic factor for growth of the mandibular condylar cartilage of 4 day-old rats in a serum-free medium for 1, 4, 7, 14 days. They were compared with normal growth in vivo and with growth of spheno-occipital synchondrosis in serum-free medium. The cellular kinetics of cartilages were evaluated by auto-radiography of tritiated thymidine. 1. Condylar cartilage was enlarged with rounded head on day 14 of experiment while in vivo the rounded-headed shape changed into functionally flattened appearance. 2. On day 14 of experiment, a severe reduction of the proliferative zone and a considerable increase of the hypertrophic zone were observed while in normal control group endochondrol bone formation and bone marrow were observed. 3. The proliferative activity in the proliferative zone of condylar cartilage detected by $^3H-thymidine$ incorporation was lower than that of normal control group and decreased more than that of spheno-occipital synchondrosis, but it continued during the 14 days of culture. 4. The continued maintenance of condylar cartilage and morphologic change were disturbed in this culture system, but cell division within the proliferative zone was continued and probably linked to intrinsic factor.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.383-387
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• 2004

The Fuel Test Loop (FTL) consists of In-Pile Test Section (IPS) and Out-of-Pile System (OPS). The test condition in IPS such as pressure, temperature and quality of the main cooling water, can be controlled by the OPS. The FTL has been developed to be able to irradiate three pins to the core irradiation hole (IR1 hole) by considering for its utility and user's irradiation requirement. The IPS vessel assembly (IVA) consists of IPS head, outer pressure vessel, inner pressure vessel, inner assembly and test fuel carrier. The IVA is approximately 5.6 m long and fits within a 74 mm in diameter envelope over the full height of the chimney. Above the top of the chimney, the head of the IPS is enlarged to allow the closure flanges and pipe work connections. IVA was designed to test the CANDU and PWR nuclear fuel pin together. Specially, wished to minimize interference by nuclear fuel change in design and synthesize these items and shape design for IVA.

• 대한기계학회논문집B
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• 제29권9호
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• pp.1032-1041
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• 2005

This study is performed to investigate the heat transfer characteristics of heat exchanger according to the arrangement of fins as well as fin configuration by using the four times enlarged model. Friction factor, Colburn j factor and goodness factors are compared to each other to estimate performance of each case for 4 different kinds of fins, which are plain, single side slit, double side slit and louver fin. Results show that heat transfer would be altered by fin arrangement and that friction loss is more affected by fin configurations than by the fin arrangements. In particular, heat transfer depends more on the shape of front row than that of rear row. The heat transfer rate of combined fin arrangement increases a lot more under the same pressure drop than that of conventional fin arrangement. This indicates that the heat exchanger of higher efficiency would be designed by the proper combination of fins, of different shapes.

• 한국동물위생학회지
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• 제39권1호
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• pp.65-68
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• 2016

Multiple enlarged submandibular nodules were discovered during a routine antimortem examination at slaughter in 3 dairy cows of 20-month-old. Grossly, submandibular nodules were firm, reddish, and oval in shape. On cut surface, multiple yellowish abscesses in the parenchyma were observed. Histopathologically, the nodules were characterized by severe diffuse pyogranulomatous inflammation and chronic fibrosis with multiple eosinophilic clubs of Splendore-Hoeppli material containing central bacterial colonies. Trueperella pyogenes was isolated from the lesions. This case was diagnosed as submandibular pyogranuloma caused by Trueperella pyogenes in slaughtered dairy cows in Korea.

• Applied Microscopy
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• 제43권2호
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• pp.47-53
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• 2013

The trichomes on leaves of three species of Mentha such as M. spicata, M. suaveolens, and M. piperita var were examined by scanning electron microscopy. Simple non-glandular trichomes and peltate glandular trichomes were distinctively occurred on these leaves. In M. spicata, short and sharp non-glandular trichomes were dominantly appeared on adaxial surface, whereas capitate glandular trichomes were commonly localized on abaxial surface. In M. suaveolens, non-glandular trichomes were identified with simple unbranched and branched. Unbranched trichomes which were sharp and pointed in shape occurred on adaxial surface, however, branched and v-shaped trichomes appeared abundantly on abaxial surface. Peltate trichomes consisted of a large eight-celled head. Small capitates trichomes consisted of a cylindrical head with an one-celled uniseriate stalk. In M. piperita var, single non-glandular trichomes and peltate trichomes were present on adaxial surface. Small capitate trichomes consisted of a globose unicellular head with a two- or three-celled uniseriate stalk. Peltate trichomes were distinctly present on abaxial surface, whereas they were not observed on adaxial surface. The trichomes were less dense in this species. Peltate trichomes consisted of a large eight-celled head, with an enlarged secretory cavity, attached to an one-celled short stalk.

• 한국정밀공학회지
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• 제31권12호
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• pp.1121-1126
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• 2014

To compensate location error of ultrasonic horn, the laser scanning system based on the galvanometer scanner is developed. It consists of the 3-Axis linear stage and the 2-Axis galvanometer scanner. To measure surface shape of three-dimensional free form surface, the dynamic focusing unit is adopted, which can maintain consistent focal plane. With combining the linear stage and the galvanometer scanner, the scanning area is enlarged. The scanning CAD system is developed by stage motion teaching and NURBS method. The laser scanning system is tested by marking experiment with the semi-cylindrical sample. Scanning accuracy is investigated by measured laser marked line width with various scanning speed.