• Journal of the Society of Naval Architects of Korea
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• v.33 no.1
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• pp.19-26
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• 1996

An experimental and computational study of the pressure fluctuation induced by a propeller on a hull surface was carried out with three ship models and seven model propellers. The fluctuation of pressure on a flat plate was measured at KRISO cavitation tunnel and calculated by a panel and lifting surface method(XForShip code). To extend the measurement data on the flat plate into that on complex hull forms, the correction factor was determined as a ratio of the solid boundary factor(SBF). The computation of pressure fluctuation around complex hull forms was also performed to make the full scale prediction and compared with the corrected experimental data. The calculated values agreed well with the compensated experimental data and it was found that the correction factor was about 0.65-0.7.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.8
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• pp.25-30
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• 2004

In this paper, we suggest a new front panel structure with ridged front panel dielectric layer and hollow gap. The proposed structure can decrease a driving voltage and increase Xe content due to strong electric fields. In the experiment, we have used 6" test panel with 10 %, 15 %, 20 %, 30 % and 50 % Xe contents and 450 torr gas pressure. When comparing with a conventional structure in Xe 10 %, the proposed structure with same Xe content decreased a firing and sustain voltage by about 74 V and 79 V, also the luminance and luminous efficacy of proposed structure with 50 % Xe content were improved by about 33 % and 50.9 %..9 %.

• Journal of the Korea Institute of Building Construction
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• v.16 no.6
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• pp.579-585
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• 2016

3D laser scanning can be used for scanning the freeform surface and building a model from which the measurements could be taken, in order to solve the difficulty with getting access to the exact freeform shape and position data of the complex building envelope. The shape making process using 3D scanning is as follows: point cloud, mesh surface segmentation, NURBS(Non-Uniform Rational B-spline) surface generation, and parametric solid model generation. In this research, we review previous studies, reverse engineering notion, importance of reverse engineering usage for freeform envelope, and previous cases in order to identify the detail reverse engineering process for prefabrication and construction of freeform panels using 3D laser scanning technology. Therefore, the purpose of this research is to present a basic information which should be considered during design and construction phase and improve quality and constructibility of freeform building by analyzing the reverse engineering process and case study for prefabrication and construction of freeform panels using 3D laser scanning. The research results will enable 3D shape engineering and design parameterization using reverse engineering to be used in various construction projects.

• Journal of Korean Society of Steel Construction
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• v.26 no.2
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• pp.133-142
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• 2014

Double split tee connection is a full strength-partial restrained connection that suitable for ordinary moment frame and special moment frame which demonstrates behavior characteristics depending on the stiffness ratio of columns and beams, changes in the geometric shape of the T-stub, number of fasteners and effect of panel zone. For the double split tee connection to ensure structurally safe behavior, it needs to exhibit sufficient strength, stiffness and ductile capacity. This study sought to investigate the effects of the moment-rotation angle relationship of the double split tee connection and to evaluate the initial rotational stiffness of the double split tee connection depending on changes in the geometric shape of the T-stub. To this end, two different double split tee connection specimens are experimented which designed to change geometric parameter values (${\alpha}^{\prime}$) of the T-stub, and a three-dimensional finite element analysis was performed.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.1
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• pp.106-114
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• 2001

In this study, a shape optimization of stiffener was conducted to increase buckling load or failure load in each case with a different design value and a different objective function for stiffened laminated composite panel of I-type under compression loading. Regarding each of buckling load or failure load as objective function, optimum design was carried out. In respect of optimum design, the effects of relative length of web and cab of stiffener on buckling load or failure load of postbuckling were investigated.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.9 s.252
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• pp.866-872
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• 2006

A numerical study on the propulsive characteristics of a biomimetic foil is done by developing an unsteady linearly-varying strength vortex method. A biomimetic foil is represented as a deforming foil with a tail fin. Present method is verified by comparing the simulated results with results using finite element and finite volume methods. A new boundary condition is imposed by considering the relative rotational velocity, which has not been included in the previous published literature. It is found that the undulation amplitude increases the thrust while maximum thickness is stepping down the thrust. It is also shown that there exists an optimal frequency for maximum thrust generation. It is believed that present results can be used in the investigation of the propulsive characteristics of the biomimetic deforming foil.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.10a
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• pp.277-284
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• 2001

Recently, with development of mechanics of materials, as pursuing the high speed of the ships, a demanding of composite construction which satisfies high strength and low weight at the same time is iner casing. A sandwich element is a type of composite construction, which is composed of thin, strong, stiff and relatively high density faces and a think, light, and weaker core material. As 2nd moment is increased by faces is separated from the neutral axis farther, a sandwich element is most effective light structural form. In this paper, the make a comparative study Aluminum Honeycomb Sandwich Panel(AHSP) and Aluminum Pyramid Sandwich Panel(APSP).

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.83-84
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• 2019

Free-form buildings refer to geometric external structures in curved form, unlike conventional structures with straight lines. The development of construction technologies for the implementation of these Free-form buildings is ongoing. However, there are still many restrictions on the construction technology of Free-form buildings, resulting in problems such as increased construction period and increased construction costs. Therefore, it is urgent to develop building technology for the construction of Free-form building in order to secure competitiveness in the global Free-form building market. Accordingly, this study proposes Two-sided multi-point press technology that can solve problems of existing technology and implement FCP(Free-form Concrete Panel).

• Journal of Korean Institute of Fire Investigation
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• v.3 no.1
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• pp.43-46
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• 2003

In this experimental report, We introduce an idea of thermal corrosion in sandwich panel. In brief, Because the structures of sandwich panel are easily collapsed by thermal damage caused by a fire, it is very difficult to investigate a point and origin of fire. Therefore, If the shapes of thermal corrosion are reconstructed according to change of temperature and lapse time by experiment in sandwich panel, it is very simple task that fire scene investigators search for a point and origin of fire. As a result, we present the difference of thermal corrosion between samples which are applied heat by many-sided variable, such as temperature, heating time, lapse time, humidity, and others.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.8-9
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• 2021

FCP requires different curvatures and shapes according to the method of division, and it is necessary to manufacture a formwork accordingly. FCP production equipment consists of CNC equipment and side shape control equipment. This can be implemented in various shapes of upper, lower, and side surfaces. In the side shape control equipment, it is implemented as a variable side formwork. Among the required performance of the variable side formwork, there is stiffness against side pressure, which needs to be verified. Therefore, in this study, the FCP fabrication experiment is conducted with the developed variable side formwork. By analyzing the error in the shape of the fabricated FCP, the lateral pressure resistance capability of the side form is measured and verified.