• International Journal of Internet, Broadcasting and Communication
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• 제10권4호
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• pp.70-74
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• 2018

In order to ensure the flow of goods available and more flexible, reduce labor costs, many factories and industrial zones around the world are gradually moving to use automated solutions. One of them is to use Automated guided vehicles (AGV). Currently, there are a line tracing method as an AGV operating method, and a method of estimating the current position of the AGV and matching with a factory map and knowing the moving direction of the AGV. In this paper, we propose ceiling Light and guided line based moving direction estimation algorithm using multi-camera on the AGV in smart factory that can operate stable AGV by compensating the disadvantages of existing AGV operation method. The proposed algorithm is able to estimate its position and direction using a general - purpose camera instead of a sensor. Based on this, it can correct its movement error and estimate its own movement path.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.743-746
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• 2006

We have demonstrated a transflective liquid crystal display (LCD) with a single cell gap in a patterned vertically aligned mode. In our configuration, the different electrode structure in a transmissive and a reflective part was suggested to compensate an optical path difference of each region. As the result, the similar electro-optic characteristic of each region was obtained which results in an enhanced performance of the device. Moreover, suggested technique can be highly effective to realize the practical transflective LCD due to the simple fabrication process.

• Journal of Communications and Networks
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• 제7권4호
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• pp.499-508
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• 2005

In this paper, we address the problem of efficient routing and wavelength assignment (RWA) in multi-fiber wavelength division multiplexing (WDM) networks without wavelength translation, under dynamic traffic. We couple Dijkstra's shortest path algorithm with a suitable weight function which chooses optical paths based both on wavelength availability and multi-fiber segments. We compare our approach with other RWA schemes both for regular and irregular WDM multi-fiber network topologies in terms of blocking probability and overall link utilization.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 영호남학술대회 논문집
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• pp.128-130
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• 2000

A new type ac plasma display panels(PDPs) cells are designed and tested electrically and optically. One cells have the structure of sin discharge path shape and small electrode area. The other cells have the non-symmetric structure with a same electrode area. They show a higher luminous efficienccy and a lower power consumption about 30% improvement than the conventional standard ac PDP cells.

• ETRI Journal
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• 제24권5호
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• pp.373-380
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• 2002

This paper presents a new method for a visual cryptography scheme that uses phase masks and an interferometer. To encrypt a binary image, we divided it into an arbitrary number of slides and encrypted them using an XOR process with a random key or keys. The phase mask for each encrypted image was fabricated nuder the proposed phase-assignment rule. For decryption, phase masks were placed on any path of the Mach-Zehnder interferometer. Through optical experiments, we confirmed that a secret binary image that was sliced could be recovered by the proposed method.

• Journal of Advanced Marine Engineering and Technology
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• 제38권2호
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• pp.169-174
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• 2014

This paper proposes a novel beehive-shaped reflector for application to light-emitting diode (LED) transceivers for illumination and bi-directional visible light communication (VLC). By using a diffuse propagation model extended to line-of-sight and direct signals, the distribution of illuminance and the path loss of the transceiver are investigated to evaluate the performance of the beehive-shaped reflector. To verify bi-directional communication, a VLC-based image capture system, comprising a complementary metal-oxide semiconductor (CMOS) image sensor and video processor unit, is demonstrated. Real-time images captured by the CMOS camera are successfully transmitted to the monitoring system via a free-space channel at a rate of 115.2 kbps.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 춘계학술대회 논문집
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• pp.264-270
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• 1996

In this paper, a computer automated system has been developed for measuring the focal length of camera lens using the MTF(Modurar Transfer Function) based on the signal processing around a line CCD and autocollimator. An optical Path for the focal length measurement system has been designed around thelight sourec, collimator, camera, mirror and the line CCD. The eyepiece of the collimator is replaced byline CCD, and the mirror is moved along the focal axis by a PC driven step motor. An efficient method has been designed for finding the optimum MTF value for the focal length based on the least squares approach. The developed system is fullycomputer automated: signal transmission to and from the camera, MTF evaluation based on the line CCD, step motor contorl, etc. The developed system has been applied to a practical camera manufacturing process and demonstrated its performance

• 전자공학회논문지B
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• 제32B권5호
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• pp.710-719
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• 1995

In LD driver with HBT's. the speed characteristics of HBT's are deteriorated very much mainly due to the source resistance(Rs) of the signal applied to the LD driving HBT. We improved the bandwidth of LD driver by 2-5GHz with modifications of EF buffer. Because the modified buffers are composed of EF structure, their bandwidths are decreased rapidly as Rs is increased. When Rs is large these buffers decrease the bandwidth of the LD driver rather than increase it. To solve this problem, we propose a new buffer structure which contaings new charging and discharging path for the parasitic collector capacitance of the HBT. For Rs>100${\Omega}$, it shows superior characteristics of improving bandwidth to the EF buffers. It also shows good gain characteristics.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2000년도 추계학술대회 논문집
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• pp.47-50
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• 2000

대기 중에 존재하는 오염물질들을 광학적 원리에 기초하여 open path 방식으로 관측할 수 있는 Differential Optical Absorption Spectroscopy (이하 DOAS) 시스템은 대기오염관측의 기본적인 관념을 타파할 수 있는 하나의 대안으로 떠오르고 있다 (Lindqvist et al., 1990). 비록 아직까지 이러한 시스템으로 분석가능한 모든 관측대상물질들에 대한 검정방식의 객관성이 확보되지는 않고 있지만, $SO_2$, $O_3$, $NO_2$를 포함하는 일부 기준성 항목들의 경우 미국의 EPA나 독일의 TUV와 같은 기관들에 의해 공인받았을 정도로 측정방식의 객관성을 인정받는 추세에 있다. (중략)

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2000년도 추계학술대회 논문집
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• pp.308-309
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• 2000

대기 중에 존재하는 오염물질들에 의한 빛의 흡수가 파장에 따라 달라지는 광학적 원리에 기초한 open path 방식의 Differential Optical Absorption Spectroscopy(이하 DOAS) 시스템은 대기오염측정에 있어 새로운 장을 개척하고 있다. 기존의 측정방식과 비교할 때 DOAS방식은 여러 오염물질의 실시간 동시 측정을 통해 오염물질의 거동을 파악할 수 있게 함으로써 측정시간의 제약을 극복할 수 있으며, 시료 채취와 실험실 분석으로 나뉘어진 기존 화학적 방식의 기술적 어려움과 비효율성을 극복할 수 있다. (중략)