• Water for future
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• v.29 no.3
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• pp.217-228
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• 1996

A new routing computer model for the symmetric compound channel called the ASFMCS (Apparent Shear Force Muskingum-Cung Method in Symmetry) is developed. The Muskingum-Cunge routing method is adapted. The Apparent Shear Force(ASF) between the deep main channel and shallow floodplain flow is introduced while the flow is routed. The nonlinear parameter method is applied. The temporal and spatial increments are varied according to the flow rate. The adaptation of above schemes is tested against the routed hydrographs using the DAMBRK model. The results of general routing practice of Muskingum-Cunge Method (GFMC) are also compared with those of the above two models. The results of the new model match remarkably well with those of DAMBRK. The routed hydrographs show smooth variation from the inflow boundary condition without any distortions caused by the difference of cross-section shape. However, the results of GPMC, showing earlier rising and falling of routed hydrograph, have considerable differences from those of the ASFMCS and DAMBRK.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.5
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• pp.517-523
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• 2003

We studied the physical properties of silk fabrics after degumming, the dyeability and the color fastness of silk fabrics after degumming and sericin fixing. As the sericin was removed from silk fabrics, the rate of weight loss increased and both the abrasion resistance and the drape coefficient decreased. This means that the amount of the sericin remained in silk fabrics significantly affects the physical properties of silk fabrics. On the surface and the cross-section of silk fabrics, the silk fibers enclosed by the sericin seemed to be in a lump shape. Each fibroin strand, however, got scattered, as the process of degumming went through. The dyeability of silk fabrics degummed decreased at between 20$^{\circ}C$∼80$^{\circ}C$ the dyeing temperature, on the other hand, it significantly increased over 80$^{\circ}C$. The dyeability of the sericin-fixed silk fabrics was lower than that of the non-serin-fixed silk fabrics, to a little extent. The colorfastness of crocking in the dyed-silk fabrics was a little low and that of the sweat was much lower in a basic sweat. Especially, the colorfastness of the partially degummed silk fabrics was low, because the sericin was not stable in the condition of sweat. Therefore, the process of sericin fixing is essentially required, for the partially degummed silk fabrics and the process of degumming itself.

• Journal of the Korean Society of Clothing and Textiles
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• v.23 no.2
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• pp.335-342
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• 1999

This study is aimed at providing useful data which can be utilized for the design of their dress forms and enhancing the fitness of their apparels. To this end 330 pre-school children living in the capital area and aged from 4 to 6 were sampled to be subject to the measurement of their somatotypes. The results of this study can be summarized as follows ; 1 By the analysis of overlapped cross section diagram and silhouette diagram of each somatotype both had a common shape of lean-backed upper troso. 2. The type 1 showed less dimensions in most scales than type 2 while their shoulder were less developed. The type 2 showing more development in each element. 3. As a result of comparing the dress forms designed in reference with classified somatotypes and the commercial ones it was found that the former ones had the upper body part slanted slightly backwards and the belly part extruded forwards while the latter had a straight posture with large shoulder parts. After all the commercial dress forms were found not to reflect the actual somatotypes of Pre-School children's.

• Journal of Korea Foundry Society
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• v.19 no.5
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• pp.427-432
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• 1999

Most investment castings contain some porosities and microcavities. In this study, we investigated the elimination trends of various internal defects in IN738LC investment castings for industrial gas turbine blade by hot isostatic pressing. The results showed that cylindrical defects which are under $0.6mm{\Phi}{\times}7mm$ size are mostly eliminated and aspect ratio of defects is more sensitive factor than their cross section shape in removing these defects. Increasing hot isostatic pressure and holding time doesn't affect the elimination trend of cylindrical defects over $0.6mm{\Phi}{\times}7mm$ size because first step(plastic deformation) of HIP densification doesn't occur under these HIPping conditions.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.3
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• pp.55-60
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• 2002

Nebulizer which is on sale in our country has many problems like noise and efficiency In order to solve these problems, we used 0.6[kg/$\textrm{cm}^2$] moter in made of the Diaphragm instead of 2.5[kg/$\textrm{cm}^2$] piston type to reduce noise art output power. Nozzle in the core of the Nebulizer was made of the wild collision cross-section and slope of the fluid in detail. It is found that we could be significantly improve remedial value by doing these efforts.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.5
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• pp.968-972
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• 2007

The importance of bumper system lies not only in the styling of vehicles, but also in the protection of vehicles and pedestrians from reasonable impact. In this study, we proceed to search a method for efficient bumper system without using the impact test and the computer simulation to analyze the bumper system. In the process of the research, we proposed the each method that is used to search the shape that satisfy each regulations in first, because bumper's dimensions to satisfy 'vehicle protection' regulations and form's dimensions to satisfy ‘pedestrian protection' regulations are difficult to exist together. After that we proposed the calculate method and design algorithm that is used to search a reasonable point satisfying the two regulations together.

• Journal of Korea Water Resources Association
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• v.34 no.2
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• pp.141-154
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• 2001

An experimental study was performed to investigate the effects of levee crest width and the slope steepness on levee break due to overtopping flow. The phenomenon of bank failure can be described in 4 stages. In this study, the magnitudes of breach width, breach depth peak discharge, and scouring shape at the break site were measured, and the result shows that peak discharge will be reduced and breach duration extended by widening the crown width and lessening the levee slope steepness. The breach width was narrower and the breach depth deeper, as the levee crest width become wider or the slope steeper. And, the bed scour depth was deeper and steeper, as the levee crest crest width become narrower or the slope milder.

• Transactions of Materials Processing
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• v.29 no.6
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• pp.356-361
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• 2020

In general, the drawing process is performed in a multi-pass to meet the required shape and cross section. In the drawn material, the surface strain is relatively higher than the center due to the direct contact with the die. Therefore, a non-uniform strain distribution appears in the surface of the material where the strain is concentrated and the center having a relatively low strain, thus it is difficult to predict the strain in the drawn material. In this study, the non-uniform strain distribution was evaluated using a finite element analysis and the non-uniform strain distribution model based on the upper bound method. In addition, the relationship between the hardness and the strain was established through a simple compression test to evaluate the distribution of the strain in the experimentally multi-pass drawn bar.

• Journal of Ocean Engineering and Technology
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• v.27 no.6
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• pp.1-6
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• 2013

A 25ft class fishing leisure boat is developed, and the resistance performances are investigated by a model test in a high-speed circulating water channel. The design speed of the developed ship is 25 knots using a 150 ps outboard engine. A catamanan type hull form using a planing section is adopted considering the Froude number and large deck area. The effect of a center body attached on the bottom of the cross deck is studied under various conditions. Wave patterns are observed to make clear the relationship between the resistance performance and the wave characteristics. The results show that the shape of the center body and the position of the chine line can have a strong effect on the resistance performance in a certain velocity range.

• International Journal of Naval Architecture and Ocean Engineering
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• v.12 no.1
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• pp.226-240
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• 2020

This paper presents an experimental investigation of asymmetric impact effects on hydroelastic responses. A 1:64 scaled segmented ship model with U-shape open cross-section backbone was newly designed to meet elastic similarity conditions of vertical, horizontal and torsional stiffness simultaneously. Different wave heading angles and wavelengths were adopted in regular wave test. In head wave condition, parametric rolling phenomena happened along with asymmetric slamming forces, the relationship between them was disclosed at first time. The impact forces on starboard and port sides showed alternating asymmetric periodic changes. In oblique wave condition, nonlinear springing and whipping responses were found. Since slamming phenomena occurred, high-frequency bending moments became an important part in total bending moments and whipping responses were found in small wavelength. The wavelength and head angle are varied to elucidate the relationship of springing/whipping loads and asymmetric impact. The distributions of peaks of horizontal and torsional loads show highly asymmetric property.