• Journal of the Korean Ceramic Society
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• v.36 no.8
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• pp.820-828
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• 1999

This study suggests the accurate method to calculate dominant wavelength and excitation purity which are used for analyzing color of glass product. Instead of ruler and magnified chromatricity diagram by using the slope of lines by tristimulus measured and achromatic timulus and by monochromatiic stimulus and achromatic stimulus calculating method of dominant wavelength and excitation purity was acquired with the relation between them. When it was applied to products the obtained results were more accurate than those from existing methods.

• The KIPS Transactions:PartB
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• v.9B no.1
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• pp.129-138
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• 2002

In this paper, a distance measuring algorithm for motion capture using color stereo camera is proposed. The color markers attached on articulations of an actor are captured by stereo color video cameras, and color region which has the same color of the marker's color in the captured images is separated from the other colors by finding dominant wavelength of colors. Color data in RGB (red, green, blue) color space is converted into CIE (Commission Internationale del'Eclairage) color space for the purpose of calculating wavelength. The dominant wavelength is selected from histogram of the neighbor wavelengths. The motion of the character in the cyber space is controlled by a program using the distance information of the moving markers.

• International Journal of Fluid Machinery and Systems
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• v.1 no.1
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• pp.10-23
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• 2008

The development of pre-set wavelength G$\ddot{o}$rtler vortices are studied in the boundary-layer flows on concave surfaces of 1.0 and 2.0 m radius of curvature. The wavelengths of the vortices were pre-set by thin wires of 0.2 mm diameter placed 10 mm upstream and perpendicular to the concave surface leading edge. Velocity contours were obtained from velocity measurements using a single hot-wire anemometer probe. The most amplified or dominant wavelength is found to be 15 mm for free-stream velocity of 2.1 m/s and 3.0 m/s on the concave surface of R = 1 m and 2 m, respectively. The velocity contours in the cross-sectional planes at several streamwise locations show the growth and breakdown of the vortices. Three different regions can be identified based on the growth rate of the vortices. The occurrence of a secondary instability mode is also shown in the form of mushroom-like structures as a consequence of the non-linear growth of the G$\ddot{o}$rtler vortices. By pre-setting the vortex wavelength to be much larger and much smaller than the most amplified one, the splitting and merging of G$\ddot{o}$rtler vortices can be respectively observed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05e
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• pp.100-103
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• 2003

고휘도 LED(light emitting diode) 빨강(R), 녹색(G), 파랑(B), 호박색(A), 백색(W) 등의 중요한 광학특성인 광속(luminous flux), 효율(luminous efficacy), 피크 파장(peak wavelength), 가중치 평균 파장(weighted average wavelength), 반치폭 (full width at ha1f maximum), 색도좌표(chromaticity coordinate), 주 파장(dominant wavelength), 자극순도 (excitation purity) 와 휘도순도(colorimetric purity)에 대해서 비교검토하였다. 시험결과로 제시된 LED의 기본적인 특성 데이터는 추후, 새로운 조명용 LED 램프나 등기구(luminaire)를 개발 및 특성연구에 많은 도움을 줄 것으로 사료된다.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.166-169
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• 2007

최근에 정부의 "15/30 LED조명 보급정책"에 힘입어 개발된 8W급 조명용 LED광원의 CIE 색도좌표 (chromaticity coordinate)와 주파장(dominant wavelength)등을 측정 고찰 하였다. 적색(R), 녹색(G), 청색(B), 백색(W)순으로 주파장은 각각 620[nm], 531[nm], 465[nm], 579[nm]이고, 자극순도(excitation purity)는 0.98, 0.82, 0.97, 0.15이며, 휘도순도(colorimetric putity)는 45[%], 16[%], 279[%], 6[%]로 나타났다. Power LED의 최적배치 설계로서, 특히 백색 LED광원의 경우 백열전구(15 lm/W)에 비해 3배 이상의 높은 효율(47.71m/W)을 보였고, 배광측정에서는 78.7%의 효율로 나타났다. 현재 LED광원은 MR16이나 베이스 타입 등의 형태로 제작하여 스탠드, 복도등, 비상유도등, 침실용 등의 용도에 사용되고, 일부는 LED의 원형이나 면(flat)타입으로 가로등이나 투광등으로도 활용되고 있다. 따라서 이들에 대한 각각의 특성들을 제시해 둘 필요성인 인지되어 국내 최초로 개발된 R/G/B/W 8W급 LED광원에 대한 기본적인 광특성 결과를 얻었으며, 이중에서 HB 백색 LED램프의 색도좌표 값을 얻어 CIE표준광과의 색도좌표(x, y) 위치를 비교 검토할 수 가 있었다.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.3
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• pp.313-318
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• 2018

A coaxial band rejection filter is designed and fabricated for a beam interacting cavity. The proposed filter has a quarter wavelength choke for the dominant mode of the cavity. The equivalent circuit of the coaxial band rejection filter is presented and the ABCD parameter os each part is derived to obtain the ABCD parameter of the entire filter. The scattering matrix was obtained from the ABCD matrix and the was simulated by MATLAB using the obtained scattering matrix. The coaxial band rejection filter structure was simulated using HFSS, and the results confirmed the simulation using the equivalent circuit was useful. The designed coaxial band rejection filter was fabricated with 6-1/8 flange. The fabricated filter was measured using a transition from 6-1/8 flange to N-type flange. The insertion loss of the fabricated filter is greater than 25 dB in the dominant mode of the cavity and less than 0.25 dB in the first higher order mode. The measurement results are in good agreement with the simulated results and meet the design specification.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.172-175
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• 1999

In this paper, we propose new algorithm to minimize the total cost of overall system in WDM ring networks. The cost of system includes the number of SONET ADMs as well as the number of wavelength. As optical technologies and WDM components are developed, the dominant cost of system is the number of SONET ADMs which is electronic equipment. To reduce the number of SONET ADMs in nonuniform traffic, we propose two algorithms one is the algorithm to construct full circles as many as possible to minimize gaps by cutting and combining the connections. The other is the algorithm to groom circles Into a wavelength to share the maximum number of nodes. The simulation results show that the proposed algorithm is superior to conventional algorithm in nonuniform traffic

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.240-242
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• 2008

In the present article, we analyze airborne Pi-SAR (Polarimetric-Interferometric SAR) X-band images of ocean waves around the Miyake Island at approximately 180 km south from Tokyo, Japan. Two images of a same scene were produced at approximately 40 min. interval from two directions at right angles. One image shows dominant range travelling waves, but the other image shows a different wave pattern. This difference can be caused by the different image modulations of RCS and velocity bunching. We have estimated the dominant wavelength from the image of range waves, and from the wave phase velocity computed from the dispersion relation (though no wave height data were available), the image intensity is computed by using the velocity bunching model. The comparison of the result with the second image at right angle strongly suggests the evidence of velocity bunching.

• Journal of Photoscience
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• v.9 no.2
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• pp.359-361
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• 2002

A green mutant of Rhodobacter sphaeroides 60I was acquired by chemical induction. The blue-shifted of the carotenoid absorption was found in the Light-harvesting complex II (LH2) of the mutant. With the excitation at different wavelength, we observed that the evolution of excited-state dynamics in LH2 of Rhodobacter sphaeroides 60I. The dynamical traces demonstrate a dominant absorption followed concomitantly by an ultrafast transmission increase and decay with 818nm excitation.

• Transactions of Materials Processing
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• v.11 no.2
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• pp.103-107
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• 2002

With the great demand for WDM (Wavelength Division Multiplexing) optical communications, optical switches are expected to become one of the dominant components in future networks. Conventional mechanical switches suffer from poor reliability and large size; however, many micromachined optical switches with moving mirrors have been proposed for high scale OXC (Optical Crossconnect) or ADM (Add/Drop Multiplex) because of the low power consumption and high reliability of these switches. In this paper, we introduce the technological trends of optical switches using MEMS, related micromachining technologies and their characteristics.