• Korean Journal of Optics and Photonics
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• v.14 no.2
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• pp.166-168
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• 2003

By using gain saturation of semiconductor optical amplifiers (SOAs), an all-optical AND gate at 10 Gb/s has been successfully demonstrated. Firstly, Boolean (equation omitted) has been obtained using the first SOA with signal B and clock injection. Then, the all-optical AND gate is achieved using the second SOA with signals A and (equation omitted) injection.

• Journal of Korean Philosophical Society
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• v.145
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• pp.381-407
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• 2018

Gilles Deleuze presents his distinctive logic of sensation in "Francis Bacon: The Logic of Sensation" with his own approach to Bacon's paintings. What matters here is the sensation of 'haptic' that is 'one possibility of the eyes' but different from optical perception. The concept of 'haptic' has been translated into Korean variously, and Gilles Deleuze adopted this concept from Austrian art historian, Alois Riegl. Alois Riegl had used the concept of 'haptic' to mean proximate view (Nahsicht in German) as in seeing Egyptian bas-relief. Gilles Deleuze was in succession to Alois Riegl's way of thinking and used the concept of 'haptic' to discuss Bacon's paintings. By the way, Alois Riegl had adopted this concept anyway to read Egyptian bas-reliefs, but Gilles Deleuze applies this concept to paintings. Actually, this concept in Gilles Deleuze's theory of painting has more meanings than Alois Riegl'. That is to say, when we intend to understand "The Logic of Sensation" as a new logic of sensation to be represented more than just a discussion about Bacon's paintings, we would say that key word is the concept of 'haptic' being symbolic of Bacon's paintings. Yet, what kind of sensation is the 'haptic'? And, what is Deleuze's theory of sensation? I want to interpret "Francis Bacon: The Logic of Sensation" as a work being developed through his own theory of sensation, and further more I should like to draw special attention to the sensation of 'haptic' in order to make his theory of sensation with admirable clarity.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.2 no.3
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• pp.194-197
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• 2002

This paper considers the problem of routing connections in a optical multi tree networks using WDM (Wavelength Division Multiplexing), where each connection between a pair of nodes in the network is assigned a path through the network and a wavelength on that path, so that connections whose paths share a common link in the network are assigned different wavelengths. The problem of optimal coloring of the paths on the optical multi-networks is NP-hard[1], but if that is the coloring of all paths, then there exists efficient polynomial time algorithm. In this paper, using a "divide & conquer" method, we give efficient algorithm to assign wavelengths to all the paths of a tree network based on the theory of [7]. Here, our time complexity is 0(n4log n).

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.1
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• pp.30-35
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• 2004

In a switched reluctance motor drive, it is important to synchronize the stator phase excitation with the rotor position, Therefore the position of rotor is an essential information. Although high resolution optical encoder/resolvers we used to provide a precise position information, these sensors are expensive. And switching angles synchronizing using sensorless technique has some problems like a reliability and fluctuating of the preset value in the high-speed region, which is caused by the sampling period of the microprocessor. In this paper, a low cost analog encoder suitable for practical applications is proposed. And the control algorithm to generate switching signals using a simple digital logic is presented. The validity of the proposed analog encoder with a proper logic controller is verified from the experiments.

• KSBB Journal
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• v.15 no.1
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• pp.14-21
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• 2000

In this study, algae cultivation using the photobioreactor has been applied to remove the nitrogen and phosphorus compounds in the wastewater of the livestock industry. The optimal ratio of nitrate and ortho-phosphate concentration was found for the enhancement of removal efficiency. To achieve the high density culture of algae, the photobioreactor consisted of optical fibers wes developed to get the sufficient light intensity. The light could be illuminated uniformly from light source to the entire reactor by the optical fibers. The structured kinetic model was proposed to describe the growth rate, consumption rate of nitrates and ortho-phosphates in algae culture. The self-organizing fuzzy logic controller incorporated with genetic algorithm was constructed to control the semi-continuous wastewater treatment system. The proposed fuzzy logic controller was applied to maintain the nitrated concentration at the given set-point with the control of wastewater feeding rate. The experimental results showed that the self-organizing fuzzy logic controller could keep the nitrate concentration and enhance algae growth.

• Journal of the Optical Society of Korea
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• v.20 no.4
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• pp.470-475
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• 2016

In this paper, the effects of filter parameters on a supercontinuum-based all-optical thresholder are experimentally investigated. By tuning the filter parameters, the power transfer function and power transmission function are tailored. The experimental results show that a thresholder with short center wavelength has a better power function, and the slope in the middle level of the thresholder increases with increasing bandwidth. Through tuning the filter parameters, the thresholder can achieve a steplike power transfer function for optical thresholding, and a steplike power transmission function for optical self-switching. This makes the supercontinuum-based thresholder more flexible, and allows customization of performance to meet different demands in various applications.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.7C
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• pp.712-722
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• 2002

We have investigated a novel optical decoder for a fiber-optic code division multiple access(CDMA) communication systems. The conventional optical encoder and decoder have the advantage of simple structure. However the number of users in the system is limited by the auto- and cross-correlation properties generated in decoding process. In previous studies, to improve the system performance, although they used an optical code that minimize the sidelobe and cross-correlation, could not yet find a novel methods for performance improvement in fiber-optic CDMA system. Thus, it is necessary to investigate the novel optical decode in order to improve the performance of system. In this paper, we schematize the AND gate logic element(AGLE) composed with 1$\times$2 or 1$\times$3 coupler and the optical thyristor and propose the novel optical decoder using K(weight) AGLE. The optical thyristor only passes the overlapped signal and clips other signals. Such a novel concept means that the optical thyristor can operate as a hard-limiter. We analyze the fiber-optic CDMA system using the novel optical decoder with simulation and is found that the novel optical decoder using the AGLE and optical thyristor excludes the sidelobe and cross-correlation intensity between any two sequences.

• Proceedings of the Optical Society of Korea Conference
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• 1998.08a
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• pp.184-185
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• 1998

본 논문은 광/전 변환 소자로서, 단일 모드 광섬유로부터 입력되는 1.3$\mu$m 파장의 광신호를 ECL(Emitter Coupled Logic) 레벌의 전기 신호로 입력된 데이터를 출력 시키는 광수신 모듈에 관한 것으로, 초고속정보통신망 구축을 위한 ATM system, B-NT(Briadband Network Terination) system, 10G 전송 system 등에 직접 사용할수 있는 Clock Recevery 없는 155Mbps 광수신 모듈을 소개한다. 또한 광모듈 원가의 대부분을 차지 하고 있는 광패키징 가격 하락을 위하여 Si기판을 이용한 수동 광정렬 방식의 패키징 방법 을 사용하여 소형화, 저렴한 가격, 그리고 소요공정 시간을 단축하였다[1]. 모듈의 신뢰도를 위하여 신뢰성 시험[2] 및 system 시험을 하였으며 BERT(Bit Error Rate Tester)로 측정한 광수신의 평균 수신감도는 -36dB이다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.13 no.2
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• pp.133-139
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• 2013

This paper proposes a vision-based indoor localization method for autonomous vehicles. A single upward-facing digital camera was mounted on an autonomous vehicle and used as a vision sensor to identify artificial landmarks and any natural corner features. An interest point detector was used to find the natural features. Using an optical flow detection algorithm, information related to the direction and vehicle translation was defined. This information was used to track the vehicle movements. Random noise related to uneven light disrupted the calculation of the vehicle translation. Thus, to estimate the vehicle translation, a Kalman filter was used to calculate the vehicle position. These algorithms were tested on a vehicle in a real environment. The image processing method could recognize the landmarks precisely, while the Kalman filter algorithm could estimate the vehicle's position accurately. The experimental results confirmed that the proposed approaches can be implemented in practical situations.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.11
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• pp.33-38
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• 2011

In this paper, the effect of pulse current and generated heat on characteristics of the LED is measured and evaluated. For experiments, the LED driving circuit and digital logic which determines period and duty ratio of lighting are designed. At rated current, the temperature and optical characteristics of the LED with change in duty ratio and period are compared, and those of the LED with change in duty ratio and existence of cooling fan are also compared at constant average current. As a result, frequency does not affect device temperature and optical characteristic of the LED but duty ratio does. Also, the cooling fan is less effective on those of the LED at rated current.