• Geotechnical Engineering
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• v.13 no.6
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• pp.45-60
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• 1997

In this research the behavior of a new type of a single pile under lateral loading and against slope sliding is studied. Especially, the section of a new pile is determined throughout experiments, and the single pile behavior under lateral loading and the effect of improvement in slope stability by using new type of pile (gear-shaped) were studied. As a result, it is known that maximum deflection of gear-shaped pile is far smaller than that of traditional PC circular pile for the same lateral loading. And lateral load of gear-shaped pile at allowable deflection was bigger than that of PC circular pile. From the comparison between two hypes of piles, it can be seen that the degree of improvement of safety factor in slope was higher in gear-shaped pile than that of PC pile under the same condition, and it results in the reduction of the number of stabilizing piles in a slope.

• Journal of the Korea Society of Computer and Information
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• v.25 no.5
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• pp.117-126
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• 2020

In this study, a 3D simulation program was used to produce a bodice prototype of a middle-aged male in their 40s and 50s and then analyze the appearance evaluation and airgap, sectional view, color distribution through virtual wearing to compare and analyze the differences between patterns. Through this, it was intended to provide basic data necessary for pattern development to companies that manufacture and produce clothing for middle-aged men. As a result of analyzing, J pattern was analyzed as the most suitable body shape pattern for middle-aged men. E pattern was too tight and L pattern and N pattern had too much spaces. However, J patternt was analyzed that correction was necessary in setting center back and center front length. The aging phenomenon in which the back is slightly bent forward and shoulders are also inclined is expected to appear, so it is necessary to adjust the front-to-back length, shoulder angle, and shoulder length. It is considered that after developing the research pattern by modifying J pattern, it is necessary to develop a body shape prototype for middle-aged men through actual clothing experiments on middle-aged men.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.6
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• pp.112-118
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• 2015

These days, there are lots of skyscrapers being constructed in downtown areas. However, it requires columns which have a way heavier load. and far more extensive cross sections of column as well. Therefore, it is hard to lay the foundation in downtown areas. This being the case, composite columns such as CFT column are primarily being used. However, CFT column is occurred of difficult beam-column connection development and lower performance since CFT column is closed cross-section. Especially, the result of the study concerning development of connection details with CFT column and exterior diaphragms are very low in current state. In this study, through developing CFT column-H shape steel beam applicating Y shape plate, set width and depth of Y shape plate which affect structural performance of connection details applicating Y shape plate as main variables, and evaluate structural performance through experiments. And also, design Y shape plate used at experiments as setting allowable stress for tension suggested at design criteria lower than axial force of tension side flange connected Y shape plate, through shape of destruction, verify the structural safety and performance of Y shape plate.

• Journal of IKEEE
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• v.15 no.4
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• pp.299-304
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• 2011

In this paper, the circular polarized horn antenna composed of circular polarizer and impedance transformer is designed, and fabricated. For the circular polarizer, two types of the polarizer are designed and the electrical performance of them is compared; rectangular waveguide polarizer with $45^{\circ}$-inclined dielectric slab and oval shaped one. Straight type mode converter has a stepped impedance structure and plays a role of converting waveguide TE mode into coaxial TEM mode, and the proposed antenna is designed to directly connect with active components using the feed-through in the input port of the mode converter. Fabricated antenna has the wideband performance, VSWR<1.5 and Axial ratio < 1.0dB, ranging from 30.085 to 30.885 GHz, and the antenna gain is 6.7~7.0 dBi.

• Journal of the Earthquake Engineering Society of Korea
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• v.15 no.2
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• pp.35-42
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• 2011

The seismic design of solid reinforced concrete bridge columns has been committed to, based on accumulated research and design specifications. The rational confinement model and seismic performance evaluation, however, are insufficient because of the lack of domestic and foreign design specifications about the experimental and analytical difficulties in the case of circular hollow reinforced concrete columns. In this paper, the seismic behavior of circular hollow reinforced concrete columns and its dependence on design variables are understood and explained. These research results can be used to derive the rational and economical design specifications for circular hollow sectional columns based on the result from the nonlinear analysis program, named RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology).

• Journal of the Korean Geotechnical Society
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• v.36 no.12
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• pp.35-43
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• 2020

Currently, cofferdams of circular cross section are widely applied as temporary facilities for the installation of bridge foundations in river/sea bridge construction in Korea. Existing caisson, sheet pile, and cell type cofferdam are widely used, but these methods take a lot of time and cost for installation and dismantling. In the case of the existing sheet pile construction method, attention is needed to secure internal and external stability because of the damage to the sheet pile due to ground penetration and difficulty in connecting element members. In this study, penetration design of circular steel pipes using suction pressure was performed on the soft ground of the west coast, and it was confirmed that penetration construction using suction pressure was possible through field tests. It was confirmed that applying the ground analysis results using the cone penetration test (CPT) to the design rather than the standard penetration test (N value) results more similar to the field test results. In addition, it was confirmed that local failure of the inside of the cofferdam was induced when a suction pressure higher than the upper limit suction pressure was applied in the silty sand.

• Journal of KSNVE
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• v.9 no.3
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• pp.600-606
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• 1999

A reactive type acoustic filter is developed based on the phase cancellation effect which is occurring in the plane wave propagation through the two paths where the cross sectional areas are reversely changing. The theory is experimentally validated by the use of a cylindrical duct and an inserted hollowed cone of which vertex part is eliminated. Noise attenuation and the filtered frequency are dependent on the area variation and the effective length of the filter. Experimental comparison shows that the filtered frequencies of 1st and 2nd mode are lower than the analytical prediction due to the mass loading effects, and the 3rd mode is in good agreement. The proposed filter can be applied as an in-duct noise filter for improving the sound quality in a narrow space for various industrial applications.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.1
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• pp.19-28
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• 2021

In rotating detonation engine(RDE), only the detonation wave is moving around the outer wall of the combustor. Neither a mechanical part nor flow is rotating in RDE. Thus, the RDE cross section is not necessary to be circular, but arbitrary closed section is possible. A RDE of tri-arc cross section is designed and As an example of an arbitrary cross sectioned RDE, a RDE of tri-arc cross section is designed in this study, and operational and performance characteristics were examined experimentally. The rotation of the detonation wave is confirmed by dynamic pressure sensor and high-speed camera, while the characteristics of the detonation wave were investigated at the concave and convex surfaces. In the present study, the thrust level of 17.0 N to 96.0 N was obtained depending on the mass flow rate.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.25 no.1
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• pp.37-49
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• 2012

A structural model of the SNF(spent nuclear fuel) disposal canister for the PWR(pressurized water reactor) for about 10,000 years long term deposition at a 500m deep granitic bedrock repository has been developed through various structural safety evaluations. The SNF disposal baskets of this canister model have the array type whose four square cross section baskets stand parallel to each other and symmetrically with respect to the center of the canister section. However, whether this developed structural model of the SNF disposal canister is optimal is not determinable yet. Especially, there is still a problem in weight-reduction of the canister. The cross section shape of the SNF basket should be changed to solve this problem. There are two ways in changing the cross section shape of the SNF basket; the one is to rotate the cross section itself and the other is to change the cross section shape as other shape different from the square cross section. The previous study shows that the canister with $30{\sim}35^{\circ}$ rotated basket array is structurally more stable than the canister with un-rotated parallel basket array. However, whether this canister with rotated basket array is optimal is not either determinable as yet, because it is not revealed that the canister with other cross section different from the square cross section is structurally more stable than other canisters. Therefore, the structural analysis of the SNF disposal canister with other cross section shape which is also symmetric with respect to the canister center planes is very necessary. The structural analysis of the canister with various cross section shape basket array in which each basket is arrayed symmetrically with respect to the center planes is carried out in this paper. The structural analysis result shows that the SNF disposal canister with circular cross section shape baskets located symmetrically with respect to the center of the canister section is structurally more stable than the previously developed SNF disposal canister with the parallel basket array.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.6
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• pp.73-83
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• 2016

Bearing stress near anchor plates is usually very high due to prestressing force in anchorage zone of concrete structure used post-tensioned prestressed method. In order to effective utilization of cross section and crack control, appropriate size of anchorage plates should be used to prevent crack initiation and failure of concrete structures eventually. This study aims to suggest equation for effective area of bearing plate of rectangle type and circular type by Highway Bridge Design Specification and PTI etc. A shape factor according to bearing plate shape is suggested based on numerical analysis, and it can be used suitability for design of special anchorage plate dimension.