• Journal of Institute of Control, Robotics and Systems
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• v.8 no.3
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• pp.256-263
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• 2002

Optical Multistage Interconnection Networks(OMINs) comprising photonic switches have been studied extensively as important interconnecting building blocks for communication networks and parallel computing systems. A basic element of photonic switching networks is a 2$\times$2 directional coupler with two inputs and two outputs. This paper is concerned with the diagnosis of cross-talk-faults in OMINs. As the size of today's network becomes very large, the conventional diagnosis methods based on tests and simulation have become inefficient, or even more, impractical. In this paper, we propose a simple and easily implementable algorithm for detection and isolation of the single crosstalk-fault in OMINs. Specifically, we develope an algorithm fur the isolation of the source fault in switching elements whenever the single crosstalk-fault is detected in OMINS. The proposed algorithm is illustrated by an example of 16$\times$16 banyan network.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.12C
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• pp.1197-1206
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• 2002

Recently, the research on the construction of optical Internet backbone networks using WDM has been actively progressed. In this paper, we propose the offset based service-differentiation scheme in optical burst switching (OBS) networks. We classify the services into two classes; high class and low class. The proposed scheme decides the offset time of high class so as to satisfy the required burst loss rate (BLR) of services according to the service-differentiation ratio (SDR). The SDR may be set depending on the environment of OBS network and user's requirements, our scheme decides the BLR of high class by using the required SDR and conservation law. Finally, we use the offset time decision (OTD) algorithm to determine the offset time of high class. The proposed scheme is evaluated through simulation. The result of simulation is compared with that of analysis to verify the proposed scheme.

• The KIPS Transactions:PartC
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• v.12C no.3 s.99
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• pp.449-456
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• 2005

Optical burst switching (OBS) overcomes the inefficient resource usage of optical circuit switching and minimizes the optical buffering requirement of optical packet switching. General switch management protocol (GSMP) is an open interface between a label switch and a controller, and it provides connection, configuration, performance, event management and synchronization. GSMP open interface in the OBS network allows the implementation of OBS switch to be simple by separating the data forward plane from the control plane. We defined managed objects to support connection, configuration, performance, and fault management for the management of OBS network in the GSMP open interface. We proposed the network management model, in which the above managed objects are distributed in a controller and an OBS switch according to network management functions. We verified the possibility of connection management using distributed network management model in the GSMP open interface of OBS network by implementing GSMP and network management functions with managed objects of OBS.

• Journal of Digital Convergence
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• v.10 no.11
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• pp.351-358
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• 2012

This study is aimed at suggesting optical communication equipment that can deliver high quality video information in high speed, to efficiently handle the flood and water pollution in the river basin. This system is cheaper than existing equipment, and can monitor optical Internet as well as the condition of equipment. Generally, the communication equipment to prevent flood is installed in an unmanned control box and operated by the flood control office situated at the fiver mouth in a long distance section. Therefore, it is hard to promptly cope with communication interruptions, which occur by the cutting or aging of the optical cable. Under the circumstances, this study suggested an efficient system that can deliver high quality video information in high speed (Optical Transmission Convert System) by using optical fiber. The system also solves problems by making use of automatic protection switching (APS) when an accident happens. Its real-time monitoring function gives notice of the problem-occurring points. The system is expected to be widely used in various areas such as intelligent traffic systems.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.11
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• pp.1736-1742
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• 1989

In this thesis, to verify input-output characteristics of GaAs MESFET, light is illuminated to C-band oscillator which already designed and manufactured, thus input-output variation of GaAs MESFET is to be shown. Experimental results of two kinds of optical effects, optical tuning and opticla switching, of GaAs MESFET Oscillators are presented. For optical tuning, the Oscillation frequency decreases with optical illumination and the Oscillator power output generally increases with optical illumination, the increase being around 1 to 3 dBm at 1mW/mm\ulcornerlight intensity. While the DC-lingt illuminated Oscillator response data provide information of the optical senditivity of GaAs-MESFET Oscillators. Pulse-light illuminated transient response data can be invoked to understand the detailed optical-electrical interaction mechanisms response. Thus, it is shown that direct control of micro-devices is realisable, if we use optical effect of GaAs semiconductor compound.

• ETRI Journal
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• v.24 no.2
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• pp.69-81
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• 2002

This paper reviews the existing research activities on signaling and control procedures for IP over optical networks. We focus on the IP-centric signaling and control architecture based on the generalized multi-protocol label switching (GMPLS) protocol and analyze various scenarios and technical issues for deploying the IP over an optical network. We analyze the signaling and operations and administration and maintenance requirements for integrating an IP network and an optical network in order to cope with the high bandwidth and poor resource granularity of the optical network, including the optical cross-connect system. On the basis of network architecture and a reference configuration model, we investigate the GMPLS-based control architecture and interconnection model appropriate for controlling IP bandwidth and optical lambda resources. The signaling and control procedure based on GMPLS on optical user-network interface and network-network interface are comparatively investigated to provide the optical lightpath. We also study protection and restoration procedures to protect link failure when it applies to generalized MPLS signaling.

• Proceedings of the Optical Society of Korea Conference
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• 2002.07a
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• pp.94-95
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• 2002

Photonic crystal (PC) has special interests for their promising applications in three-dimensional photon control and integrated devices. In a nonlinear photonic crystal (NPC), optical intensity in a defect layer is greatly increased due to the location function of NPC and nonlinearity. The nonliearity of the defect layer is very much enhanced because the group velocity is reduced and the interaction time between light and nonlinear medium in the defect layer is enlarged. (omitted)

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.114-115
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• 2000

Halobacterium halobium에서 추출한 Bacteriorhodopsin(bR)을 고분자 물질에 첨가해 박막화하였다. 이 단백질 박막 소자의 photodynamic특성을 이용하여 광 switching system을 구성하였다. 광 switch system은 pump광을 이용해 B상태와 M상태에서 축퇴4광파 혼합방식으로 구성했다. Red, blue, violet 광원을 사용하여 B상태와 M상태 격자를 형성하고 on-off되는 위상공액신호를 측정했다. (중략)

• Proceedings of the Optical Society of Korea Conference
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• 1991.06a
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• pp.74-79
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• 1991

측뢰 4 광파 혼합법으로 여러 가지 용매와 색소를 매질로 이용하여 위상공파를 발생시키고 발생한 위상공액파를 증폭하였다. 광원은 Q-switching된 루비레이저이다. 위상 공액파의 반사율, R을 증가시키기 위해 여러 가지의 색소와 용매를 이용하여 위상공액파를 방생시키고 이들 중 반사율이 좋은 조합으로 루비봉을 이용한 증폭기를 통과시켜 증폭실험을 수행하였다. 증폭기를 거친 최종적인 반사율은 Renh로 정의하였을 때 실험 결과는 DMSO와 Cryptocyanine의 조합에서 최대 Renh/R = 6.3 $\pm$ 0.38를 얻을 수 있었다.

• Proceedings of the Optical Society of Korea Conference
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• 2001.02a
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• pp.148-149
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• 2001

순광학적 스위치와 logic gate는 초고속 networks와 컴퓨터를 위한 차세대의 기술로 부각되고 있다. 현재 사용되고 있는 전자적인 switching, routing, 신호 처리들은 대용량 고속화에 그 한계를 나타내고 있다. 미래에 요구되는 초고속 광 네트워크의 계획은 광학 스위치와 광 변조장치가 필요하다는 것을 지적하고있다 최근에 전자나 광전자적으로 가능한 것 이상으로 미래에 요구되는 Tera bits/sec에 접근할 수 있는 고속 연산과 신호처리가 가능한 스위칭에 관한 연구가 활발이 진행되고 있다. (중략)