• Journal of the Society of Naval Architects of Korea
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• v.36 no.4
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• pp.37-47
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• 1999

A Finite Volume Method for the discretization of the two-dimensional incompressible Navier-Stokes equation is used to analyse water entry & exit problems in a generalized coordinate system. The free-surface deformations generated by the water entry or exit of a rigid body are simulated by the Level-Set scheme[11]. In the water entry problems for a wedged section and a flared-ship section, the calculation results of water impact force are compared with the experimental results[5] and the time varying free-surface deformations and flow characteristics of the water exit of a cylinder are investigated.

• Geomechanics and Engineering
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• v.13 no.2
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• pp.333-352
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• 2017

A comparison study is made between the dynamic properties of an argillaceous siltstone and its grouting-reinforced body. The purpose is to investigate how grout injection can help repair broken soft rocks. A slightly weathered argillaceous siltstone is selected, and part of the siltstone is mechanically crushed and cemented with Portland cement to simulate the grouting-reinforced body. Core specimens with the size of $50mm{\times}38mm$ are prepared from the original rock and the grouting-reinforced body. Impact tests on these samples are then carried out using a Split Hopkinson Pressure Bar (SHPB) apparatus. Failure patterns are analyzed and geotechnical parameters of the specimens are estimated. Based on the experimental results, for the grouting-reinforced body, its shock resistance is poorer than that of the original rock, and most cracks happen in the cementation boundaries between the cement mortar and the original rock particles. It was observed that the grouting-reinforced body ends up with more fragmented residues, most of them have larger fractal dimensions, and its dynamic strength is generally lower. The mass ratio of broken rocks to cement has a significant effect on its dynamic properties and there is an optimal ratio that the maximum dynamic peak strength can be achieved. The dynamic strain-softening behavior of the grouting-reinforced body is more significant compared with that of the original rock. Both the time dependent damage model and the modified overstress damage model are equally applicable to the original rock, but the former performs much better compared with the latter for the grouting-reinforced body. In addition, it was also shown that water content and impact velocity both have significant effect on dynamic properties of the original rock and its grouting-reinforced body. Higher water content leads to more small broken rock pieces, larger fractal dimensions, lower dynamic peak strength and smaller elastic modulus. However, the water content plays a minor role in fractal dimensions when the impact velocity is beyond a certain value. Higher impact loading rate leads to higher degree of fragmentation and larger fractal dimensions both in argillaceous siltstone and its grouting-reinforced body. These results provide a sound basis for the quantitative evaluation on how cement grouting can contribute to the repair of broken soft rocks.

• Journal of the Korean Institute of Navigation
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• v.20 no.3
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• pp.127-135
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• 1996

This study investigated the correlation of physique factor( standing height, body weight, chest girth, body surface ) and vital capacity upon records of swimming discipline at sea water. The subjects are 194 sophomore students of Korea Maritime University who participated in the swimming discipline. The swimming records were divided into three groups - higher, middle and lower group. The results from this investigation are as follow ; 1. The standing height was above the average on the A, B+ record, body weight was above on the A+, A record, and vital capacity was above on the A+, A, B+, C record respectively. 2. The standing height, body weight, chest girth, body surface, vital capacity was significantly correlated between record P < 0.05 and P < 0.01. Therefore the higher record group has better physique factor and vital capacity than the middle or lower record group. 3. The standing higher of the higher record group was significantly correlated with body weight(0.514), body surface(0.768) and vital capacity(0.427), and body weight was significantly correlated with chest girth(0.525), body surface(0.940) and vital capacity. This standing heiht of the middle record group was sigificantly correlated with body weight(0.509) and body surface(0.779), and body weight was significantly orrelated with chest grith(0.618) and body surface(0.927). The standing height of the lower record group was significantly correlated with body weight(0.595), chest grith(0.363), body surface(0.802) and vital capacity(0.250), and body weight was significantly correlated with chest grith(0.678) and body surface(0.952).

• The Journal of Pediatrics of Korean Medicine
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• v.28 no.2
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• pp.1-22
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• 2014

Objectives The purpose of this study is to investigate the relationship between weak children and growth indices. Methods One hundred twenty-six of the first and the second grade elementary school students who didn't have to develop yet their secondary sexual characteristics answered the questionnaire. Their bone age and body composition were measured. Results 1. According to the Weak Children questionnaire analysis, respiratory problem was one of the biggest problems in the weak children group (35.7%), followed by digestive problems (23.0%), psycho-neurological problems (22.2%), neuromotor problems (9.5%), and urogenital problems (8.7%). 2. From the comparison between growth indices of weak children and that of normal children are as follows: 1) The group of children who had problem in their digestive system had lower growth indices than the normal average children group. The growth indices includes mean height, weight, total body water, protein mass, mineral mass, body fat, skeletal muscle mass, body fat percentage, body mass index (BMI), and basal metabolic rate (BMR). 2) The children who had urogenital weakness had lower mean height, RH (Recent Height), RH - MPH {Recent Height(%) - Mid-Parental Height(%)}, RUS (Radius, Ulna and Short bone) score, weight, protein mass, body fat, BMI, and visceral fat than the normal children group. 3. The results of the multiple comparisons of growth indices and weak children groups are as follows: 1) Digestive weak children were the lowest in total body water, protein mass, mineral mass, skeletal muscle mass, and basal metabolic rate. 2) Urogenital weak children were the lowest in height, RH, RH - MPH, RUS score, and weight. Conclusion These results showed that children's growth is strongly correlated to their own growth problems, especially to those children who have digestive and urogenital problems. Therefore, this may be an effective way for children growth treatment in Korean medicine to treat weak symptoms.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.347-352
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• 2003

This study attempts to develop the management and control system of water pipe on the footing of database builded by the research on the pipe of water supply equipped over 48.809km within district of Hamyang-up by Hamyang-Gun, and to apply it to the work of self-governing body. And, since the structure and equipment of facilities of underground water supply pipe ate so complex, the maintenance and management of function of facilities are needed for long-term. This study has the purpose to build the database per self-governing body which can be connected with the future NGIS project, and to promote the efficiency of management and control of facilities and equipment.

• Journal of KSNVE
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• v.7 no.2
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• pp.261-272
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• 1997

Recently washing machines are to be in lower vibration and lower sound because of better environment. Vibration problems in washing machines occur in both washing mode and spinning mode, but vibration in spinning mode becomes main problem because of its high rotating speed and continuity. Vibration while spinning is mainly due to rigid body motion of total washing system which includes suspending rods, washing bath, spinning bath, and gear sets. In this study, some researches were done in order to analyze the rigid body motion of washing system and flexible vibration of spinning bath. A basic mathematical model was established, and the effect of position of salt water and shape change of salt water case were considered. And the effect of lengths of suspending rods, attaching angles, vertical and horizontal position, stiffness of spring on the change of vibration were also considered. To identify the effect of salt water on vibration, some measurements were done. When salt water was positioned at upper part, the effect was most and this coincides with the tendency of simulation.

• Water for future
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• v.14 no.2
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• pp.53-62
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• 1981

In the Hydraulic Structure, Such as dam body or levee of river that is constructed with soil, We analyzed a top line of free ground water table. This study is based on the logical reason that the pressure on the free surface is atmospheric and the seepage line is a stream line. In order to research for the unknown seepage line. We analyzed seepage water of steady flow through parous media by Finite Element method based on Galerkin Principle, and compared the comluted value with experimental value. The results show that the computed value was nearly equal to the experimental value. Finally, it noticed that finite Element method was more practical than Experimental Method for Seepage line analysis.

• International Journal of Naval Architecture and Ocean Engineering
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• v.11 no.1
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• pp.70-81
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• 2019

An improved three dimensional Rankine source method is developed to solve numerically water wave problems in time domain. The free surface and body surface are both represented by continuous panels rather than a discretization by isolated points. The integral of Rankine source 1/r on free surface panel is calculated analytically instead of numerical approximation. Due to the exact algorithm of Rankine source integral applied on the free surface and body surface, a space increment free surface source distribution method is developed and much smaller amount of source panels are required to cover the fluid domain surface than other numerical approximation methods. The proposed method shows a higher accuracy and efficiency compared to other numerical methods for various water wave problems.

• The Korean Journal of Physiology and Pharmacology
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• v.25 no.1
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• pp.39-49
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• 2021

High fructose diet is associated with the global metabolic syndrome (MtS) pandemic. MtS develops in early life, depending on prenatal and postnatal nutritional status. We hypothesized that ovariectomy increases the chances of developing MtS in adult offspring following high fructose intake by the mother. Pregnant C57BL/6J mouse dams drank water with or without 20% fructose during pregnancy and lactation. After weaning, the pups were fed regular chow. The offspring were evaluated until they were 7 months of age after the mice in each group, both sexes, were gonadectomized at 4 weeks of age. The offspring (both sexes) of the dams who had high fructose intake developed MtS. In the offspring of dams who drank tap water, orchiectomy increased the body weight gain and body fat accumulation, while ovariectomy increased the body fat accumulation as compared to the sham controls. In the offspring of dams with high fructose intake, orchiectomy decreased the body weight gain, body fat accumulation, visceral adiposity, and glucose intolerance, while ovariectomy exacerbated all of them as compared to the sham operations. These data indicate that ovariectomy encourages the development of MtS in adult offspring after maternal high fructose intake, while orchiectomy prevents the development of MtS. The sex difference indicates that male and female sex hormones play contradictory roles in the development of MtS.

• Journal of the Society of Naval Architects of Korea
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• v.45 no.4
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• pp.345-352
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• 2008

The motion of a projectile initiated by the release of highly pressurized air is simulated presuming the flow field as a two dimensional one. The effects of water compressibility on projectile movements are investigated, comparing results based on the Fluent VOF model where water is treated as an incompressible medium with those from the presently developed VOF scheme. The present model considers compressibility of both air and water. The Fluent results show that the body moves farther and at higher speeds than the present ones. As time proceeds, the relative difference of speed and displacement between the two results drops substantially, after acoustic waves in water traverse and return the full length of the tube several times. To estimate instantaneous accelerations, however, requires implementation of the water compressibility effect as discrepancies between them do not decrease even after several pressure wave cycles.