• 한국산학기술학회논문지
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• 제4권3호
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• pp.159-163
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• 2003

본 논문에서는 복합적층 평패널의 최소중량화설계를 수행하기 위하여 길이방향 보강재로 보강된 평패널에 축압축 하중이 작용할 경우 좌굴하중을 구한다. 또한 좌굴에 대한 최소중량화설계를 유한차분에너지법을 이용한 선형좌굴이론과 비선형좌굴이론에 의해서 구하고 비선형 탐색 최적설계기법 ADS를 활용하여 해석한다. 복합적층 평패널의 종횡비는 1, 3, 7에 대하여 고려하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.742-744
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• 2001

Moving flat core LOA consists of iron flat core as a mover and electric magnet as a stator and operated by electromagnetic force between mover and stator. In a moving flat core type, it takes advantage of doing not have to be equipped with power supply device, having a lower manufacturing cost. But it has a lower linearity and precision. In this paper, a static characteristics of LOA were studied and analyzed using FEA. Experiments, electromagnetic force and inductance according to air gap and input currents, were carried by exciting coil. And we compared these results one another.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2011년도 춘계 학술논문 발표대회 2부
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• pp.91-96
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• 2011

The flat slab is well-known as a structural system to reduce the story height, so it is broadly used for recent building. However, the normal RC flat slab is not appropriate for the long span, and the quantity of reinforcement bar and concrete is raised. Recently, the post-tensioning system has been introduced and used widely as an alternative method. Nevertheless, in Korea, it is not used broadly due to lack of the understanding and field experience. Especially, the post-tensioning system is hesitated to use due to uncertainty of construction ability and economics. This paper will introduce applicability to site and economics of unbonded post-tensioning system through construction examples.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.587-590
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• 2003

In flat-plate floors, slab-column connections are broken down with a brittle shear failure. And it can cause the collapse of the whole structures. Thus, the proper method of shear reinforcement in flat plate-column connections must be required. The objective of this study is to compare shear reinforcement specimens using lattice bars to no shear reinforcement specimens in view of shear strength and ductility of the flat plate-column connections. The test results have shown that shear reinforcement specimens varying $\rho$, $b_0$/d and $C_1$/$C_2$ increase in shear strength by 36.85% and in ductility by 9.16 for no shear reinforcement specimens on the average. This results confirm the effectiveness of this type of shear reinforcement in improving shear strength and ductility.

• 소성∙가공
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• 제8권2호
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• pp.178-187
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• 1999

The Cross rolling between flat jaws, as a kind of hot forging, is the forming method to make the axisymmetric multi-step shaft by its rotation and pressure between flat jaws which move in opposite direction. The purpose of this study is to propose the optimal geometric data for shape development of the forward forming region. All data described on this paper are quantified by experiment from initial shape design to final shape development. As the result, proper geometric data are proved that lenth of the first forming area in the forward forming region is 1.5 times larger than circumference of work-piece and the progress angle changes 3 times smoothly.

• 전자공학회논문지D
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• 제35D권3호
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• pp.56-62
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• 1998

One of the key components to accomplish WDM all-optical network is an arrayed waveguide grating router. The spectral characterisitc of the ypeical arrayed waveguide grating rouger has parabolic shape, hence the bandwidth is limited. The spectral response of an optical filter should be as flat as possible for the reliable operation of the syste, because the center frequency of the optical source could be deviated in the actual system. In order to acquire these characteristics, we propose and design a new type of the arrayed waveguide grating router with a flat passband using the Fourier optics concept. The BPM simulation results of the new arrayed waveguide grating router with the flat passband show that the bandwideth is 0.8 nm at -1 dB, instertion loss about 6 dB, and the crosstalk less than -23 dB fro each cnannel, which is 1.6 nm(200 GHz) separated from the adjacent channel around 1550 nm wavelength range.

• 제어로봇시스템학회논문지
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• 제18권2호
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• pp.141-148
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• 2012

This paper proposes fault tolerant gaits of a quadruped robot with feet of flat shape. Fault tolerant gaits make it possible for a legged robot to continue static walking against a leg failure. In the previous researches, it was assumed that a legged robot had feet that have point contact with the surface. When the robot is endowed with feet having flat shape, fault tolerant gaits can show better performance compared with the former gaits, especially in terms of the stride length and gait stability. In this paper, fault tolerant gaits of a quadruped robot against a locked joint failure are addressed in straight-line motion and crab walking, respectively.

• 한국전기전자재료학회논문지
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• 제17권6호
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• pp.647-651
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• 2004

We fabricated the 1-inch diode type flat lamp using CNTs, which were grown directly on soda-lime glass substrate at 600 ∼ 650 $^{\circ}C$ by thermal chemical vapor deposition(CVD) of acetylene gas. Turn- on field was about 2.8 V/${\mu}{\textrm}{m}$. We observed that uniform and high brightness had been obtained. The brightness of CNT flat lamp was measured up to about 14 kcd/$m^2$ at 2000V in spacing of 500 ${\mu}{\textrm}{m}$. The results showed that the CNTs were very good emission source and suitable for application in the lamp.

• 대한수학회보
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• 제50권1호
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• pp.285-303
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• 2013

The asymptotic expansions of the Bergman kernels on the diagonals near the boundary points of exponentially-flat infinite type for pseudoconvex tube domain in $\mathbb{C}^2$ are obtained.

• Kyungpook Mathematical Journal
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• 제60권4호
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• pp.821-830
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• 2020

The object of the present paper is to classify a special type of spacetime, called Lorentzian para-Sasakian type spacetime (4-dimensional LP-Sasakian manifold with a coefficient α) satisfying certain curvature conditions.