• Journal of the Society of Naval Architects of Korea
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• v.37 no.3
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• pp.11-20
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• 2000

The flow characteristics around the stern region of two VLCCs with the same forebody and slightly different afterbody are investigated along with propulsive performance of the ship. The local mean flow measurements and the resistance and self-propulsion tests are carried out in the towing tank for the two VLCC hull forms. The measured results clearly show the formation of bilge vortices and their effect on propulsive efficiency. The comparisons are made for the two VLCC hull forms and the relation between stern framelines and bilge vortex strength is explored. Experimental data can provide a good test case to validate the accuracy of numerical methods and turbulence model of CFD codes for ship flow calculation.

• Journal of Korean Academy of Nursing
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• v.42 no.3
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• pp.333-341
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• 2012

Purpose: The purpose of this study was to test whether pre-operative visual information and parental presence had positive effects on anxiety, delirium, and pain in pediatric patients who awoke from general anesthesia in a post-surgical stage. Methods: This study used a non equivalent control-group post test design (n=76). Independent variables were provision of pre-operative visual information and parental presence for post-surgical pediatric patients in PACU (post anesthesia care unit). Dependent variables were anxiety, delirium, and pain in the pediatric patients measured three times at 10 minute intervals after extubation in the PACU. Measurements included Numerical Rating Scale for assessing state anxiety, Pediatric Anesthesia Emergence Delirium Scale by Sikich & Lerman (2004) for delirium, and Objective Pain Scale by Broadman, Rice & Hannallah (1988) for pain. Results: Experimental group showed significantly decreased state anxiety at time points-10, 20, and 30 minutes after extubation. Delirium was significantly lower at 10 minutes and 30 minutes after extubation in the experimental group. Pain was significantly lower at 10 minutes after extubation in the experimental group. Conclusion: The results of this study suggest that this intervention can be a safe pre-operative nursing intervention for post-surgical pediatric patients at PACU.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.7
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• pp.1244-1254
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• 1992

This paper investigates the vibrational damping characteristics of laminated plates composed of elastic, viscoelastic and elastic layers by theoretical and experimental methods. Laminated plates are in cylindrical bending and visco-elastic adhesive layer is assumed as the visco-elastic spring which takes damping effect through both shear and normal deformations. Governing equations oof laminated plates are derived in the form of simultaneous first order differential equations, which account for the longitudinal displacements, rotary inertia and shear deformations of elastic base plate and elastic constraining plate. The numerical calculations of the equations are illustrated by the applications to the cantilever beam in transverse vibration. The results of the solutions agree well with the experimental measurements in general. The damping effects due to the shear and thickness deformations in the adhesives are analyzed and it is shown that for thicker adhesives, the damping effect due to thickness deformation becomes significant and for thinner adhesives, due to shear deformation.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.3
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• pp.221-228
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• 2011

The large-area crystallization of amorphous silicon thin films on glass backplanes is one of the key technologies in the manufacture of flat-panel displays. Joule-heating induced crystallization (JIC) is a recently introduced crystallization technology. It is considered a highly promising technique for fabricating OLEDs, because the film of amorphous silicon on glass can be crystallized in tens of microseconds, minimizing thermal and structural damage to the glass. In this study, we theoretically and experimentally investigated the temperature variation during the phase transformation. The critical temperatures for crystallization were determined for both solid-solid and solid-liquidsolid transitions, by carrying out in-situ temperature measurements and numerical analysis of the JIC.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.3
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• pp.325-333
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• 2012

An experimental study was carried out to determine the correlation between the internal flow in a circular nozzle and elliptical nozzles with the external flow. The flow rate, spray angle and drop size were measured under various conditions of the injection pressure. Numerical simulations were attempted to investigate the internal flow structure in the elliptical nozzles, because the experimental study was limited in its measurements of flow velocity and pressure distributions in the relatively small orifice. In the case of the elliptical nozzles, the disintegration characteristics of the liquid jet were significantly different from those of the circular nozzle. Surface breakup was observed at the jet issued from the elliptical nozzles with injection pressure. This is due to the internal flow structure, which is reattached to the orifice wall at the minor axis plane of the elliptical nozzle, unlike that observed with the circular nozzle.

• The Journal of Engineering Geology
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• v.22 no.1
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• pp.49-58
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• 2012

Anchor heads a recommonly exposed to surface weathering processes that cause physical damage by vibration and external forces. This study presents a new method of anchor-head installation that uses near-surface embedding based on analyses of concrete block failure. ABAQUS 3D numerical modeling performed to compare this method with the standard technique and to analyze the distribution of displacement and the stress pattern. In addition, application of the method to a real-world case was tested by in-situ measurements. The results show a maximum vertical stress of 9.73 MPa and vertical displacement of 1.34 mm. Field tests indicated that displacement of a concrete block was 3 to 4 times greater than that of an embedded bearing plate.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.7
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• pp.609-618
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• 2015

This paper discusses the attitude determination of the CNUSAIL-1 cube-satellite. The primary mission of the CNUSAIL-1 is sail deployment and operation in low Earth orbit, and the secondary mission is to look into influence of the sail deployment on satellite attitude and orbit. The attitude determination strategy is proposed depending on three mission phases, and its performance and applicability are verified through numerical simulations. This study considers the following sensors: Sun sensors and a three-axis magnetometer as attitude reference sensors, and a three-axis MEMS gyroscope as an inertial attitude sensor. Because sensors used for cube satellites have relatively low performances and worse noise characteristics, an Extended Kalman filter (EKF) is applied to attitude determination. Additionally, it has the merits to deal with the Gaussian noises and to predict the attitude even with no measurements from reference attitude sensors, especially in the eclipse of the cube satellite. The performance of the EKF is compared to a deterministic attitude determination technique, QUEST(QUaternion ESTimation).

• The Korean Journal of Food And Nutrition
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• v.28 no.1
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• pp.153-159
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• 2015

This study was conducted to develop food for the elderly, which are well-shaped and easy to chew and swallow. The amounts of water and gelatin were adjusted to facilitate breaking down of the food with the tongue. In the aging society, it is necessary to support the development of a variety of products that can ease the intake functions of swallowing and chewing, while complementing with the essential nutrients supplements; such products can be actively commercialized in the elderly industry. Various types of food, for elderly with difficulties in chewing and swallowing, were used for sensory assessment. Sensory panel consisted of 10 dietitians (10 women) in nursing care facilities. The sensory optimal composite recipes were determined by central composite design (CCD). The sensory measurements were significantly different in the appearance (p<0.01), saltiness (p<0.01) and overall quality (p<0.01). The optimum formulation of pan fried flat fish, calculated by numerical and graphical method, was 8.54 g of salt and 6.34 g of olive oil. Moisture content, hardness, and adhesiveness of pan fried flat fish were 84.77%, 250, and -1.20, respectively. The result showed that easily chewable and swallowable pan fried flat fish for the elderly will have sufficient competitiveness, considering its safety, taste, and preference. This study may provide the basic materials for the development of easily chewable and swallowable foods for elderly.

• The Korean Journal of Food And Nutrition
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• v.27 no.6
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• pp.1175-1181
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• 2014

This study was conducted to develop for the elderly food that is safe, well-shaped, and easy to chew and swallow, using gelification. Gelatin, which has low adhesiveness, thereby lowering the possibility of being swallowed wrongly into the respiratory track, was used as a viscosity agent for the gelification. Water and gelatin amounts were adjusted to facilitate breaking the food with the tongue. Various foods for the elderly with chewing and swallowing difficulties were used for sensory assessment. Sensory panel consisted of 10 dietitians (10 women) in nursing care facilities. The sensory optimal composite recipes were determined by central composite design (CCD). The sensory measurements were significantly different in appearance (p<0.05), saltiness (p<0.05), sweetness (p<0.01), and overall quality (p<0.05). The optimum formulation of the Korean barbecue beef calculated by numerical and graphical method was 3.71 g of sugar and 19.53 g of soy sauce. Moisture content, hardness and adhesiveness of the Korean barbecue beef were 78.85%, 2.40, -1.87, respectively. The result shows that food for the elderly, which is easy to chew and swallow, using gelification will have sufficient competitiveness in terms of safety, taste, and preference. The development of food for the elderly that take into account the difficulties in chewing and swallowing among the elderly, reflects their preference, and has sufficient nutrients, is important to enable the elderly to enjoy their meals. Also, as the Korean society is getting older, it remains one of the biggest social challenges.

• Water for future
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• v.28 no.5
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• pp.151-162
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• 1995

A two-dimensional stream tube dispersion model is developed to simulate accurately transverse dispersion processes of pollutants in natural channels. Two distinct features of the stream tube dispersion model derived herein are that it employs the transverse cumulative discharge as an independent variable replacing the transverse distance and that it is developed in a natural coordinate system which follows the general direction of the channel flow. In the model studied, Eulerian-Lagrangian method is used to solve the stream tube dispersion equation. The stream tube dispersion equation is decoupled into two components by the operator-splitting approach; one is governing advection and the other is governing dispersion. The advection equation has been solved using the method of characteristics and the results are interpolated onto Eulerian grid on which the dispersion equation is solved by centered difference method. In solving the advection equation, cubic spline interpolating polynomials is used. In the present study, the results of the application of this model to a natural channel are compared with a steady-state flow measurements. Simulation results are in good accordance with measured data.