• 한국광학회지
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• 제16권3호
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• pp.196-200
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• 2005

[ $0.75delta\%$ ]의 평판광회로(PLC;Planar Lightwave Circuit)소자의 설계 및 제작기술을 가지고 저손실과 높은 누화율을 가진 파장 다중화 및 역다중화 소자를 개발하였다. C-band AWG(Arrayed Waveguide Grating)에서의 삽입손실은 2.503이하, 누화율은 35dB이상, 균일도는 1dB이하이며 L-band에서는 Vernier 디자인을 적용하여 ITU-T의 파장 정확도가 0.04nm이하가 되도록 제작하였다.

• Journal of electromagnetic engineering and science
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• 제3권1호
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• pp.17-21
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• 2003

In this paper, we design an optimal planar array geometry for maximum side-lobe reduction. The concept of thinned array is applied to obtain an optimal two dimensional(2-D) planar array structure. First, a 2-D rectangular array with uniform spacing is used as an initial planar array structure. Next, we modify the initial planar array geometry with the aid of thinned array theory in order to reduce the maximum side-lobe level. This is implemented by a genetic algorithm under some constraint, minimizing the maximum side-lobe level of the 2-D planar array. It is shown that the optimized planar array structure can achieve low side-lobe level without optimizing the excitations of the array antennas.

• 제어로봇시스템학회논문지
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• 제20권11호
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• pp.1153-1163
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• 2014

An efficient 3D SLAM (Simultaneous Localization and Map Building) method is developed for urban building environments using a tilted 2D LRF (Laser Range Finder), in which a 3D map is composed of perpendicular/horizontal planar polygons. While the mobile robot is moving, from the LRF scan distance data in each scan period, line segments on the scan plane are successively extracted. We propose an "expected line segment" concept for matching: to add each of these scan line segments to the most suitable line segment group for each perpendicular/horizontal planar polygon in the 3D map. After performing 2D localization to determine the pose of the mobile robot, we construct updated perpendicular/horizontal infinite planes and then determine their boundaries to obtain the perpendicular/horizontal planar polygons which constitute our 3D map. Finally, the proposed SLAM algorithm is validated via extensive simulations and experiments.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 방전 플라즈마 유기절연재료 초전도 자성체연구회
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• pp.19-22
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• 2004

The resonant planar transformer, which had power capacity of 300 W, input voltage of 220 V, output voltage of 15 V, and switching frequency of 500 kHz, was designed and manufactured by using the planar core with large effective area and the flat copper lead frames for miniaturization and high efficiency of the switching mode power supply (SMPS). As well as, a resonant converter equipped with the above mentioned planar transformer was manufactured and electromagnetic characteristics were investigated. The numerical value of turns for 1st and 2nd winding were 12 and 2 respectively. The self inductance of 1st winding was 33.2 ${\mu}H$, very low leakage inductance of 1.27 ${\mu}H$, and the coupling factor of 0.98 were obtained at switching frequency of 300 kHz. The high efficiency of 88.21 % for the SMPS equipped with planar transformer was obtained at power capacity of 300 W.

• International Journal of Precision Engineering and Manufacturing
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• 제8권2호
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• pp.64-69
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• 2007

Aerostatic planar XY stages are frequently used as the main frames of precision positioning systems. The machining and assembly process of the rails and bed of the stage is one of first processes performed when the system is built. When the system is complete, the 2D position, motion, and stage flatness errors are measured in tests. If the stage errors exceed the application requirements, the stage must be remachined and the assembly process must be repeated. This is difficult and time-consuming work. In this paper, a method for estimating the errors of a planar XY stage is proposed that can be applied when the rails and bed of the stage are evaluated. Profile measurements, estimates of the motion error, and 2D position estimation models were considered. A comparison of experimental results and our estimates indicated that the estimated errors were within $1{\mu}m$ of their true values. Thus, the proposed estimation method for 2D position and flatness errors of an aerostatic planar XY stage is expected to be a useful tool during the assembly process of guideways.

• The Korean Journal of Physiology and Pharmacology
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• 제2권5호
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• pp.549-553
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• 1998

Using the planar lipid bilayer method, we investigated the effect of d-tubocurarine (dTC) on the extracellular side of large-conductance $Ca^{2+}-activated\;K^+$ channel from rat brain. When the initial open probability (Po) of the channel was relatively high, dTC decreased channel activity in a concentration dependent manner. In contrast, when the initial Po was lower, sub-micro molar dTC increased channel activity by destabilizing the closed states of the channel. Further addition of dTC up to micro molar range decreased channel activity. This dual effect of dTC implicates that there exist at least two different binding sites for dTC.

• 한국정보전자통신기술학회논문지
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• 제16권6호
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• pp.499-508
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• 2023

본 논문에서는 3차원 공간 내에서 동일 평면 상에 존재하는 특징점들의 좌표를 추정하기 위한 기법을 제안한다. 제안된 방법은 카메라 영상만을 이용하여 3차원 공간 내에 존재하는 다수의 특징점들을 검출한 다음 동일 평면 상에 위치하지 않는 특징점들은 제거시킨다. 이를 위해서 3차원 공간 내의 평면 객체와 2차원 카메라 영상 평면 사이의 평면 호모그래피(homography) 관계를 추정한 다음 각 특징점들의 평면 객체 상에서의 역사영 오차를 계산하고 오차값이 기준 값보다 큰 특징점들은 좌표값 추정 과정에서 제외시킨다. 제안된 방법은 별도의 센서 또는 최적화 알고리즘 없이 카메라 영상으로부터 추정된 평면 호모그래피 만을 이용한다. 실험 결과를 통해서 초당 40프레임 이상의 처리 속도를 보인다는 것을 확인할 수 있었으며, 또한 RGB-D 카메라를 이용하는 경우와 비교해도 처리 속도에 큰 차이를 보이지 않았으며, 특히 제안된 방법은 검출되는 특징점의 수가 지속적으로 증가하는 조건에서도 처리 속도가 거의 영향을 받지 않음을 알 수 있었다.

• Journal of electromagnetic engineering and science
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• 제12권2호
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• pp.155-160
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• 2012

A wideband circularly polarized pinwheel-shaped planar monopole antenna fed by a wideband feeding network is presented in this paper. The proposed antenna is formed by four wideband planar monopole antenna elements with aquadruple feeding network in order to improve the performance of circular polarization. Additionally, the antenna, which is introduced here, has a high gain in the z axis direction because of its folded antenna structure. The attractive characteristics of the proposed antenna are the wide impedance bandwidth of 87.3 % (1 GHz to 2.55 GHz), the 3 dB axial ratio (AR) bandwidth of 92.3 % (1.05 GHz to 2.85 GHz), and the maximum gain within the 3 dB AR bandwidth is about 8.24 dBic.

• Journal of applied mathematics & informatics
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• 제10권1_2호
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• pp.27-40
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• 2002

For two integers m, n with m $\leq$ n, an [m,n]-factor F in a graph G is a spanning subgraph of G with m $\leq$ d$\_$F/(v) $\leq$ n for all v ∈ V(F). In 1996, H. Enomoto et al. proved that every 3-connected Planar graph G with d$\_$G/(v) $\geq$ 4 for all v ∈ V(G) contains a [2,3]-factor. In this paper. we extend their result to all 3-connected locally finite infinite planar graphs containing no unbounded faces.

• Journal of Computational Design and Engineering
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• 제2권2호
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• pp.96-104
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• 2015

Aluminum die casting is an important manufacturing process for mechanical components. Die casting is known to be more accurate than other types of casting; however, post-machining is usually necessary to achieve the required accuracy. The goal of this investigation is to develop machining- free aluminum die casting. Improvement of the accuracy of planar and cylindrical parts is expected by correcting metal molds. In the proposed method, the shape of cast aluminum made with the initial metal molds is measured by 3D scanning. The 3D scan data includes information about deformations that occur during casting. Therefore, it is possible to estimate the deformation and correction amounts by comparing 3D scan data with product computer-aided design (CAD) data. We corrected planar and cylindrical parts of the CAD data for the mold. In addition, we corrected the planar part of the metal mold using the corrected mold data. The effectiveness of the proposed method is demonstrated by evaluating the accuracy improvement of the cast aluminum made with the corrected mold.