• Journal of the Korean Society of Safety
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• v.14 no.2
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• pp.32-41
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• 1999

If the Leak-Before-Break (LBB) concept is applicable to the nuclear piping design, it is not necessary to consider the dynamic effect due to pipe rupture. Therefore, the construction cost can be significantly reduced by eliminating unnecessary pipe whip restraints and jet impingement devices. The objective of this paper is to develop the Piping Evaluation Diagram (PED) for efficient application of LBB concept to piping system at an initial piping design stage. For this purpose, the 3-D finite element analyses were performed to evaluate the crack stability. And the stress-strain curve based on the pipe material tests were used to calculate the detectable leakage crack length. Finally, the present PED which was composed as a function of NOP load and allowable SSE load, was developed for an application of LBB concept to the safety injection and shutdown cooling line in Korean Next Generation Reactor (KNGR).

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.5
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• pp.1106-1116
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• 1994

Leak Before Break(LBB) design concept is applied to piping systems of newly-built Yonggwang 3, 4 nuclear generating stations as a design alternative to the provision of pipe whip restraints, in recognition of the questionable benefits of providing such restraints. The objective of this paper is to evaluate the material properties (tensile and fracture toughness) of SA312 TP316 stainless steel and their associated welds manufactured for shutdown cooling system of Yonggwang 3, 4 nuclear generating stations. Effect of various parameters such as specimen orientation, test temperature, welding on material properties were examined.

• Structural Engineering and Mechanics
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• v.2 no.2
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• pp.141-156
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• 1994

In this paper, the effect of material elasticity was evaluated through a simple model as proposed by Wang and Yu (1991), for yield mechanisms of a cantilever beam under tip pulse loading. The beam was assumed rigid-perfectly plastic but instead of the usual fully clamped constraints at its root, an elastic-perfectly plastic rotational spring was introduced there so the system had a certain capacity to absorb elastic energy. Compared with a rigid-perfectly plastic beam without a spring root, the present beam-spring model showed differences in the initial plastic hinge position and the minimum magnitude of the dynamic force needed to produce a plastic failure. It was also shown that various failure responses may happen while the hinge travels along the beam segment towards the root, rather than a unique response mode as in a rigid perfectly plastic analysis.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.4
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• pp.748-755
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• 2001

This paper concerns rotor vibration reduction using magnetic damper system. The fuzzy control logic is utilized to fulfill desired motion. The fuzzy system structure and membership function were first determined by simulation results. The researched control logic contains two fuzzy controller : reference position variation according to the rotor whirling status and error compensation algorithm to minimize the rotor vibration due to unbalance and unstable fluid film force. The Sugeno type output membership function was utilized by several trials and optimized membership function constants were selected from experiments. The experimental results show that the proposed method effectively control and reduce the rotor vibration with fluid film bearings.

• Journal of Mechanical Science and Technology
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• v.14 no.2
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• pp.215-225
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• 2000

The structural integrity of the fuel test loop (FTL) in a Korean experimental reactor is evaluated when the FTL, submerged in a water environment, is subjected to a postulated pipe rupture. The analyses are performed under static and dynamic conditions, imposing the thrust force history at each postulated pipe rupture section. Through analysis the following results are found: l) A double ended guillotine can not be expected based on the toughness of the material, 2) the structural integrity of the chimney surrounding the FTL would not impede the structural integrity by the pipe whip. All analyses are performed by finite element methods.

• Journal of the Korean Society of Costume
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• v.57 no.10
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• pp.11-23
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• 2007

The purpose of this study is to express the sexuality of feminism in the modern fashion. As for the methods of research, literary research was carried out using reference based on feminism history and sexuality concept and demonstrative analysis was undertaken using 2000's collections photographs. In the results of that, the sexuality of gender resistance feminism is featured by three key words: sado-masochism sexuality, bi sexuality and hetero sexuality. First, sado-masochism sexuality shows fetish look and dominatrix look shown in the strong attitudes. Sado-masochism sexuality is setting fetishes such as mask, whip, chain, metallic materials and tight leather boots. Second, bi sexuality presents mannish look of soft and feminie style's slim pants suit with ruffle, flounce and decorated detail blouse. and fetish look wearing of sexual symbol clothes such as corset and bustier. Third, hetero sexuality represent glamour look which exposure and emphasis of breasts, hips and other sexual symbols.

• Structural Engineering and Mechanics
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• v.3 no.5
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• pp.445-462
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• 1995

Previous studies of a stepped cantilever with two straight segments under a suddenly applied constant force (a step load) applied at its tip have shown that the validity of deformation mechanisms is governed by certain geometrical restrictions. Single and double-hinge mechanisms have been proposed and it is shown in this paper that for a stepped cantilever with a stronger tip segment, i.e. $M_{0.1}$ > $M_{0.2}$, where $M_{0.1}$ and $M_{0.2}$ are the dynamic fully plastic bending moments of the tip and root segments, respectively, the family of possible yield mechanisms is expanded by introducing new double and triple-hinge mechanisms. With the aid of these mechanisms, it is shown that all initial deformations can be derived for a stepped cantilever regardless of its geometry and the magnitude of the dynamic force applied.

• Structural Engineering and Mechanics
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• v.3 no.5
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• pp.463-474
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• 1995

When a tubular cantilever beam is loaded by a dynamic force applied transversely at its tip, the strain hardening of the material tends to increase the load carrying capacity and local buckling and cross-sectional overlization occurring in the tube section tends to reduce the moment carrying capacity and results in structural softening. A theoretical model is presented in this paper to analyze the deformation of a tubular beam in a dynamic response mode. Based on a large deflection analysis, the hardening/softening M-${\kappa}$ relationship is introduced. The main interest is on the curvature development history and the deformed configuration of the beam.

• Journal of KSNVE
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• v.5 no.2
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• pp.235-246
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• 1995

Experiment on the modal balancing of a flexible rotor supported on two kinds of fluid film bearings is performed to verify the modal balancing theory. The fluid film bearings are a tilting pad bearing and a two axial grooved journal bearing. One is inherently stable, but the other is not. The experimental result shows that the modal balancing method is effective for balancing of a high speed flexible rotor system. Besides, the critical speeds and mode shapes measured experimentally are in good coincidence with the results of rotordynamic analysis. Oil whip, which is the instability phenomenon due to fluid film force, is also observed during the experiment.

• Journal of the Korean Association of Geographic Information Studies
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• v.3 no.3
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• pp.69-76
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• 2000

This study deals with development GIS application using web-based CAD, this application serves to user, designer, manager that more convenient and various functions. Development to this application, collect attribute data from fieldwork and geographic data from cadastral map and aerial survey map and then development to user interface using HTML, JavaScript, ASP, Whip ActiveX control. This application's characters are as follows ; First, system designer designed that anyone who have basic knowledge about web and CAD can develop this application. A system structure simplification by 2-Tier. Geographic information use DWF(drawing web format) file and attribute information use DBMS in consideration of extension. Second, system manager can service independently GIS in Web need not high priced GIS engine, so more economical. Third, internet user get service GIS information and function that search of information, zoom in/out, pan, print etc., if you need more functions, add function without difficultly. Developed application as above, not only save volume but fast of speed as use vector data exclude character and image data. Also, this application can used by means of commercial and travel information service but also various GIS service of public institution and private in web.