• Electronics and Telecommunications Trends
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• v.16 no.6 s.72
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• pp.19-28
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• 2001

본 고에서는 최근 광인터넷망의 제어 프로토콜 기술로서 많은 관심을 끌고 있는 GMPLS 기술을 소개하고 표준화 및 연구개발 동향을 분석 고찰한다. MPLS 기술은 비연결형으로 동작하는 IP 망 내에 논리 채널인 LSP를 구성하여 연결형으로 동작하도록 함으로써 IP 트래픽의 흐름을 제어할 수 있게 한 기술로서 최근 ISP 망에 적용되기 시작했다. GMPLS는 MPLS 기술을 확장 보완하여 WDM이나 SDH 망 등의 일반적인 IP 전달망에 적용할 수 있도록 한 기술인데, 특히 광인터넷망에 적용하는 것을 가장 큰 목표로 하고 있다. GMPLS는 라우팅과 시그널링 및 광인터넷 링크 관리를 포함하는 제어 프로토콜 기술과 레이블을 이용한 사용자 평면의 데이터 전달 기술로 구성되며, 이에 대한 표준화는 IETF에서 추진하고 있다.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04d
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• pp.472-474
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• 2003

최근의 인터넷은 트래픽과 서비스 품질에 대한 요구사항이 지속적으로 중대함에 따라 이를 원활히 수용할 수 있는 광인터넷으로 급속히 전환되고 있으며, 향후의 광인터넷 환경에서 사용하기 위한 광인터넷 관련 요소 기술들이 개발 중에 있다. 그러나 광인터넷에 적용될 각 개발 요소 기술들은 단계적으로 개발되고 있고, 기존 네트워크 서비스와의 연동을 고려해야 하므로 각 요소 시스템들이 지닌 기능 및 성능을 검증하기 위해서는 광인터넷을 모델링하고 분석 할 수 있는 광인터넷 시뮬레이터가 필요하게 된다. 이 논문에서는 확장성이 뛰어난 시뮬레이션 엔진인 SSF(Scalable Simulation Framework)를 이용하여, 용이한 광인터넷 모델의 구성과 시뮬레이션 수행 결과에 대한 분석을 제공할 수 있는 광인터넷 시뮬레이터를 설계한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.441-444
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• 2014

공장 사업장 등에서 발생되는 매연은 대기오염의 원인이 될 뿐만 아니라 인체에도 나쁜 영향을 미친다. 따라서 대기오염방지를 위해 배출되는 대기오염물질을 측정하고 이를 관리하여 대기오염을 신속히 파악하고 사전에 방지하기 위한 서비스가 필요하다. 본 논문에서는 광학센싱을 이용해 굴뚝연기의 혼탁도를 측정하고 이를 다양한 모바일 운영체제에서 측정결과를 실시간으로 검색할 수 있는 모바일 웹앱을 설계하고 구현한다. 구현된 시스템에서 사용자는 다양한 모바일기기를 이용하여 굴뚝연기의 혼탁도와 VOC 오염도에 대하여 여러 가지 조건으로 검색할 수 있으며 사용자 정의값을 설정하고 이를 초과하는 경우에 지정된 번호로 알림 서비스를 제공 받을 수 있다. 또한 모바일 운영체제에 독립적인 웹앱의 형태로 제공되어 사용자의 다양한 모바일 기기에서 운영될 수 있으며 실시간으로 유지보수를 제공할 수 있는 장점이 있다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.4
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• pp.221-228
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• 2021

With the advent of the IoT (internet of things) era, there has been discussion on how to efficiently use various information from daily life. In academic and industrial society, various smart devices such as smart watches, smart phones, and smart glasses have been developed and commercialized for narrowing the physical/psychological distance with user information. According to recent developments of smart devices, the contemporary people have desired to check their body information and treat disease by themselves. According to the needs of the time, biological researches by phototherapy/monitoring have been actively conducted. Among various light sources, microLEDs have been spotlighted due to their superior optoelectric properties and stability. In this paper, we would like to review the state-of-the research results on the next-generation biological therapy devices via microLEDs.

• Journal of KIISE:Information Networking
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• v.36 no.4
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• pp.286-296
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• 2009

A major challenge in next generation optical Internet (NGOI) networks based on dense-wavelength division multiplexing (DWDM) is the provision of guaranteed quality-of-service (QoS) for a wide variety of multimedia applications. One of the critical issues in NGOI is the routing and wavelength assignment problem that is embossed as very important and plays a key role in improving the global efficiency for capacity utilization. But the previous researches had the delay problem, and the path routed by higher priority nodes may be congested and interfere with potential future multicast session requests. To overcome these problems, in this research we suggest a Priority-based Minimum Interference Path Multicast Routing (PMIPMR) algorithm, a new routing algorithm which finds alternative routes based on node priorities and Virtual Source (VS) nodes that has both splitting and wavelength conversion, and then chooses a path that does not interfere with potential future multicast session requests when congestions occur in the network. The PMIPMR algorithm reduces blocking rate significantly and increases the wavelength utilization by avoiding congestion in future multicast session requests.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.1
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• pp.161-170
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• 2019

Multi-product mass production small and medium enterprise factories have a wide variety of products and a large number of products, wasting manpower and expenses for inventory management. In addition, there is no way to check the status of inventory in real time, and it is suffering economic damage due to excess inventory and shortage of stock. There are many ways to build a real-time data collection environment, but most of them are difficult to afford for small and medium-sized companies. Therefore, smart factories of small and medium enterprises are faced with difficult reality and it is hard to find appropriate countermeasures. In this paper, we implemented the contents of extension of existing inventory management method through character extraction on label with barcode and QR code, which are widely adopted as current product management technology, and evaluated the effect. Technically, through preprocessing using OpenCV for automatic recognition and classification of stock labels and barcodes, which is a method for managing input and output of existing products through computer image processing, and OCR (Optical Character Recognition) function of Google vision API. And it is designed to recognize the barcode through Zbar. We propose a method to manage inventory by real-time image recognition through Raspberry Pi without using expensive equipment.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.3
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• pp.35-45
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• 2008

Realtime visibility measurement using camera is a new method which can collect some realtime visibility data similar to those of the human eyes, and can replace the existing methods using the expensive optical equipment. There have been a few attempts to measure visibility by extracting depth and three-dimensional structure under bad weather conditions. However, if there are many movements of objects in the image, these approaches seem to be inappropriate. In addition, the realtime visibility measurement will require a relatively simple and fast processing. Typically the contrast degrades exponentially in the bad weather. Therefore, in this paper we propose an easy and quick method that extract contrast from images using a moving area filter and measure visibility by mathematically modelling of the relationship between image contrast and visibility. The moving area filter is used for removing the area of the sky and moving objects that affect visibility measurement on images. The method proposed here can make possible not only realtime visibility measurement from images taken by CCD cameras, but also steady visibility measurement by using the moving area filter in case of much traffic on the road.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.6
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• pp.1492-1511
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• 2013

A novel, chaotic map that is based on concatenated torus automorphisms is proposed in this paper. As we know, cat map, which is based on torus automorphism, is highly chaotic and is often used to encrypt information. But cat map is periodic, which decreases the security of the cryptosystem. In this paper, we propose a novel chaotic map that concatenates several torus automorphisms. The concatenated mechanism provides stronger chaos and larger key space for the cryptosystem. It is proven that the period of the concatenated torus automorphisms is the total sum of each one's period. By this means, the period of the novel automorphism is increased extremely. Based on the novel, concatenated torus automorphisms, two application schemes in image encryption are proposed, i.e., 2D and 3D concatenated chaotic maps. In these schemes, both the scrambling matrices and the iteration numbers act as secret keys. Security analysis shows that the proposed, concatenated, chaotic maps have strong chaos and they are very sensitive to the secret keys. By means of concatenating several torus automorphisms, the key space of the proposed cryptosystem can be expanded to $2^{135}$. The diffusion function in the proposed scheme changes the gray values of the transferred pixels, which makes the periodicity of the concatenated torus automorphisms disappeared. Therefore, the proposed cryptosystem has high security and they can resist the brute-force attacks and the differential attacks efficiently. The diffusing speed of the proposed scheme is higher, and the computational complexity is lower, compared with the existing methods.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.261-267
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• 2015

The eigenvalue problems involving the diffraction of waves by multi-layered grating configurations can be explained by rigorous modal expansion terms. Such a modal solution can be represented by equivalent transmission-line networks, which are generalized forms of simple conventional circuits. This approach brings considerable physical insight into the grating diffraction process of the fields everywhere. In particular, the transmission-line representation can serve as a template for computational algorithms that systematically evaluate dispersion properties, radiation effects and other optical characteristics that are not readily obtained by other methods. To illustrate the validity of the present rigorous approach, the previous research works are numerically confirmed and the results agree well each other.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.6
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• pp.2711-2733
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• 2018

Minimizing power consumption in bandwidth limited optical traffic grooming networks is presented as a two-objective optimization problem. Since the main objective is to route a connection, the network throughput is maximized first, and then the minimum power consumption solution is found for this maximized throughput. Both transparent IP over WDM (Tp-IPoWDM) and translucent IP over WDM (Tl-IPoWDM) network may be applied to examine such bi-objective algorithms. Simulations show that the bi-objective algorithms are more energy-efficient than the single objective algorithms where only the throughput is optimized. For a Tp-IPoWDM network, both link based ILP (LB-ILP) and path based ILP (PB-ILP) methods are formulated and solved. Simulation results show that PB-ILP can save more power than LB-ILP because PB-ILP has more path selections when lightpath lengths are limited. For a Tl-IPoWDM network, only PB-ILP is formulated and we show that the Tl-IPoWDM network consumes less energy than the Tp-IPoWDM network, especially under a sparse network topology. For both kinds of networks, it is shown that network energy efficiency can be improved by over-provisioning wavelengths, which gives the network more path choices.