• Journal of the Optical Society of Korea
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• v.13 no.2
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• pp.206-212
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• 2009

This study presents the compact zoom lens with a zoom ratio of 5x for a mobile camera by using a prism. The lens modules and aberrations are applied to the initial design for a four-group inner-focus zoom system. An initial design with a focal length range of 4.4 to 22.0 mm is derived by assigning the first-order quantities and third-order aberrations to each module along with the constraints required for optimum solutions. We separately designed a real lens for each group and then combined them to establish an actual zoom system. The combination of the separately designed groups results in a system that satisfies the basic properties of the zoom system consisting of the original lens modules. In order to have a slim system, we directly inserted the right-angle prism in front of the first group. This configuration resulted in a more compact zoom system with a depth of 8 mm. The finally designed zoom lens has an f-number of 3.5 to 4.5 and is expected to fulfill the requirements for a slim mobile zoom camera having high zoom ratio of 5x.

• Korean Journal of Optics and Photonics
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• v.18 no.2
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• pp.135-141
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• 2007

This paper describes the design technology for a third generation thermal imaging system, which is more compact than before, using a $320\times240$ mid-IR focal plane detector. The third generation non-scanning thermal imaging system was constructed as a compact thermal imaging module as a reconnaissance, surveillance and navigation sensor for helicopter and infantry vehicles in the $1980's\sim1990's$ and now, we designed a new compact infrared camera and studied a new type of non-uniformity correction lens fer this camera.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.5
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• pp.385-390
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• 2012

This paper discusses the applicability of a compact rolling piston refrigeration compressor to portable refrigerators. The capacity of this compressor is 1 cc. Using a 12 V BLDC motor, the compressor is driven from 2500 rpm to 6000 rpm. The height of the compression module and motor is approximately 56 mm, and their weight is approximately 374 g. We confirmed the effective operation of the compressor components by evaluating their compression and cooling performance.

• ETRI Journal
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• v.31 no.5
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• pp.622-624
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• 2009

This letter presents a compact 2.5 Gb/s burst-mode receiver using the first reported monolithic amplifier IC developed with 0.25 ${\mu}m$ SiGe BiCMOS technology. With optimum avalanche photodiode gain, the receiver module can obtain a fast response, high sensitivity and wide dynamic range, satisfying the overhead timing and various power specifications for a 2.5 Gb/s next-generation passive optical network (PON), as well as a legacy 1.25 Gb/s PON in the upstream.

• Bulletin of the Korean Mathematical Society
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• v.52 no.2
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• pp.557-570
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• 2015

Let $\mathbb{G}$ be a von Neumann algebraic locally compact quantum group, in the sense of Kustermans and Vaes. In this paper, as a consequence of a notion of amenability for actions of Lau algebras, we show that $\hat{\mathbb{G}}$, the dual of $\mathbb{G}$, is co-amenable if and only if there is a state $m{\in}L^{\infty}(\hat{\mathbb{G}})^*$ which is invariant under a left module action of $L^1(\mathbb{G})$ on $L^{\infty}(\hat{\mathbb{G}})^*$. This is the quantum group version of a result by Stokke [17]. We also characterize amenable action of Lau algebras by several properties such as fixed point property. This yields in particular, a fixed point characterization of amenable groups and H-amenable representation of groups.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.7
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• pp.1288-1293
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• 2007

In this paper, a compact triplexer has been implemented for Cellular/GPS/USPCS applications. In order to realize the proposed triplexer, we use a low-temperature co-fired ceramic (LTCC) substrate to enable a fully compact integrated module using a multi-layer high-density architecture, and conjugate-match the channels instead of the open matching technique. The three dimensional design capability of LTCC substrates can reduce the overall size of the triplexer, resulting in dimensions on the order of $3.2\;mm\;{\times}\;2.5\;mm\;{\times}\;1\;mm$. The measured result shows that the triplexer has, in Cellular/GPS/USPCS bands, the insertion loss of less than 0.5dB, less than 1.7dB, and less than 0.9dB in order. Also, the triplexer has an isolation of more than 15dB in the cellular and USPCS bands and an isolation of more than 20dB in the GPS band.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.582-584
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• 2006

This paper describes a monocular PSD-based motion capture sensor to employ with commercial video game systems such as Microsoft's XBOX and Sony's Playstation II. The system compact, low-cost, and only requires a one-time calibration at the factory. The system includes a PSD(Position Sensitive Detector) and active infrared (IR) LED markers that are placed on the object to be tracked. The PSD sensor is placed in the focal plane of a wide-angle lens. The micro-controller calculates the 3D position of the markers using only the measured intensity and 2D position on the PSD. A series of experiments were performed to evaluate the performance of our prototype system. From the experimental results we see that the proposed system's compact size, low-cost, ease of installation, and high frame rates are suitable for high speed motion tracking in games.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.1
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• pp.108-114
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• 2004

In this paper we propose the boot system using CF memory card and study the system implementation method. The system that is proposed in this paper basically consist of high performance microprocessor, small amount of program memory and CF memory card. And added LCD module and touch panel for the user interface. This system use the CF memory card and DRAM instead of the Flash memory, so it can reduce the system cost. And system performance is increased because of the system program running in the DRAM.

• Journal of Biomedical Engineering Research
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• v.17 no.4
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• pp.491-498
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• 1996

The development of a compact two-wavelength Nd:YAG laser for dental and ENT applications is presented. The Nd:YAG resonator generates either 1.06$\mu$m or 1.32$\mu$m. The wavelength selection is made at the control panel. The Nd:YAG laser parameters at 1.06$\mu$m are ; the maximum pulse duration of 150$\mu$s, repetition rates of I-100Hz, and the maximum average power of 25W. At 1.32$\mu$m, the pulse duration is the same where the repetition rates and the maximum average power are I-30Hz and lOW respectively. High voltage power supply consists of a simmer module and two identical high voltage DC converters. In order to make a complete medical laser system, an optical fiber delivery unit, foot pedal and water spray handpiece are also developed. The wavelength selection is reliable since no movement of optical or mechanical components is required. The high voltage power supply is compact, easy to be maintained and applicable for other laser systems due to its modular design.

• The Journal of Natural Sciences
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• v.11 no.1
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• pp.11-14
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• 1999

Let G be a compact Lie group and let $\rho$ : G $\rightarrow O(2) be a homomorphism. Denote by V the G-module associated with $\rho$ and by S(V) the unit circle of V. In this paper, we show that if G is abelian, then a real G-vector bundle over S(V) is isomorphic to Whitney sum of real G-line or G-plane bundles.