• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.2
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• pp.99-104
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• 2024

In the deficiency of an exact solution yielding algorithm, approximate algorithms remain as a solely viable option to the Minimum Linear Arrangement(MinLA) problem of Binary tree. Despite repeated attempts by a number of algorithm on k = 10, only two of them have been successful in yielding the optimal solution of 3,696. This paper therefore proposes an algorithm of O(n) complexity that delivers the exact solution to the binary tree. The proposed algorithm firstly employs an In-order search method by which n = 2^k - 1 number of nodes are assigned with a distinct number. Then it reassigns the number of all nodes that occur on level 2 ≤ 𝑙 ≤ k-2, (k = 5) and 2 ≤ 𝑙 ≤ k-3, (k = 6), including that of child of leaf node. When applied to k=5,6,7, the proposed algorithm has proven Chung[14]'s S^(k)_min=2^k-1+4+S^(k-1)_min+2S^(k-2)_min conjecture and obtained a superior result. Moreover, on the contrary to existing algorithms, the proposed algorithm illustrates a detailed assignment method. Capable of expeditiously obtaining the optimal solution for the binary tree of k > 10, the proposed algorithm could replace the existing approximate algorithms.

• Journal of IKEEE
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• v.13 no.1
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• pp.87-93
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• 2009

The paper introduces a silicon controlled rectifier (SCR)-based device with high holding voltage for ESD power clamp. The holding voltage can be increased by extending a p+ cathode to the first n-well and adding second n-well wrapping around n+ cathode. The increase of the holding voltage above the supply voltage enables latch-up immune normal operation. In this study, the proposed device has been simulated using synopsys TCAD simulator for electrical characteristic, temperature characteristic, and ESD robustness. In the simulation result, the proposed device has holding voltage of 3.6V and trigger voltage of 10.5V. And it is confirmed that the device could have holding voltage of above 4V with the size variation of extended p+ cathode and additional n-well.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.4
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• pp.93-97
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• 2015

In this Paper, we proposed optimization of system performance, optimal splitting factor applied to power splitting protocol with relay in the cooperative communication undergo co-channel interference. We can possible to optimize and maximize the channel capacity of the receiver through optimal factor of splitting protocol. So, we can solve inability in system, and to increase the efficiency of the network. Finally, performance of the proposed protocol is analyzed in terms of outage probability, capacity of system.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.1
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• pp.56-61
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• 2011

This paper describes design of a programmable frequency synthesizer for RF PLL with $0.18{\mu}m$ silicon CMOS technology being used as an application of the UWB system like MBOA. To get good performance of speed and noise super dynamic circuits was used, and to get programmable division ratio switching circuits was used. Especially to solve narrow bandwidth problem of the dynamic circuits load resistance value of unit divider block was varied. Simulation results of the designed circuit shows very fast and wide operation characteristics as 1~14GHz frequency range.

• Journal of Satellite, Information and Communications
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• v.6 no.1
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• pp.6-11
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• 2011

In this paper presents a new approach to evaluate reliability indices of electric distribution systems using genetic Algorithm (GA). The use of reliability evaluation is an important aspect of distribution system planning and operation to adjust the reliability level of each area. In this paper, the reliability model is based on the optimal load transferring problem to minimize load generated load point outage in each sub-section. This approach is one of the most difficult procedures and become combination problems. A new approach using GA was developed for this problem. GA is a general purpose optimization technique based on principles inspired from the biological evolution using metaphors of mechanisms such as natural selection, genetic recombination and survival of the fittest. Test results for the model system with 24 nodes 29 branches are reported in the paper.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.4
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• pp.821-828
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• 2012

In this paper, we report that the differences between RF power levels can be improved in wavelength division multiplexing - radio over fiber (WDM-RoF) system by using a photonic crystal fiber. In a WDM-RoF system, each WDM channel experiences different received RF power level fluctuation in remote node (RN) because of wavelength-dependent dispersion. Since each WDM channel experiences different power fluctuation, the RF power fluctuation acts as a design constraint in viewpoint of network design. We designed a photonic crystal fiber to improve the effect of wavelength- dependent dispersion on RF power fluctuation. Also, we analyzed the wavelength-dependent difference of inter-channel RF power fluctuations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.2
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• pp.280-286
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• 2009

The NGN(Next-Generation Network) structure has been considered from various points of view as all If wireless-wired integration network and its performance is one of the main issue in these days. In this paper, various wired and wireless integrated networks with voice service are designed and simulated to obtain problems and factors affects the network performance using OPnet simulator. The characteristics only showed in the wired and wireless integrated networks are measured and analyzed compared with the single networks such as a wired or wireless networks. Especially, in the wired and wireless integrated networks showed degrading performance even if there are few transmissions in the network and furthermore, the various networks of increasing numbers of the nodes and transmission are simulated and evaluated.

• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.81-85
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• 2009

본 논문은 VoIP, IPTV, VoD 등의 실시간 서비스 품질을 네트워크 노드에서 모니터링함으로써네트워크에서 발생한 품질이상을 분석할 수 있는 스위치 칩을 설계하였다. 인터넷 서비스의 특성상 단대단 서비스에 기반한 실시간서비스는 품질이상이 발생한 위치를 정확하게 분석할 수 없기 때문에 유지보수에 어려움이 있다. 이러한 문제를 해결하기 위해 본 논문에서는 실시간서비스에 해당하는 플로우를 등록하고 해당 플로우가 장치내에서 발생한 패킷손실, RTP 시퀀스 넘버를 참조하여 이전 장치에서의 패킷손실, 패킷의 IAT(Inter Arrival Time), 대역폭, 그리고 장치내 지연을 실시간으로 측정할 수 있는 기능을 가진 AVB(Audio/Video Bridge)칩을 구현하기 위해 IEEE802.1AS를 기만한 시간동기 프로토콜의 정확성을 시뮬레이션하고, FPGA를 이용하여 구현한 AVB 스위치칩에서 타임스템프의 정확성을 확인함으로써 실시간서비스의 품질을 네트워크에서 실시간으로 모니터링 할 수 있는 가능성을 확인하였다.

• Proceedings of the Korea Contents Association Conference
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• 2010.05a
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• pp.16-18
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• 2010

유비쿼터스 컴퓨팅 환경에서 다양한 위치 기반 서비스(LBS)를 위해 객체 식별은 필수적인 기술이다. 객체 식별을 위해서 영상 분석 식별, 무선 신호(RF: Radio Frequency) 식별, MIT Cricket 시스템의 RF 신호와 초음파를 활용한 객체 식별 등의 시스템들이 제안되었다. 그 중 가장 널리 이용되는 Cricket 시스템은 RF 신호에 객체의 식별 정보를 포함시켜 초음파 신호와 동시에 송신하고, 수신단에서 RF 신호의 정보를 통해 객체를 식별하는 방식을 이용한다. 하지만 유비쿼터스 컴퓨팅 환경에서 이용되는 단말 노드의 소형의 특성을 유지하기위해 다수의 장치 모듈을 내장하기 힘들다. 본 논문에서는 신호의 정확도가 높은 초음파를 활용하여 RF 통신모듈 없이 신호 중첩 분석으로 통해 다중 객체를 인식하기 위한 기술을 제안한다. 본 논문에서 제안하는 알고리즘의 가능성을 시뮬레이션을 통해 입증하였다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.5
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• pp.93-99
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• 2013

We have used SMS to exchange messages between mobile phones. Since the network evolved to the ALL-IP network, the next generation messaging service, RCS, has emerged to the market. Because SMS and RCS coexist, we need to inter-work the messages between SMS users and RCS users. This paper introduces a message inter-working framework(MIWF) that can inter-work SMS and RCS without changing end user's UX. It defines the call flows between the network equipment and MIWF. Also, it shows how MIWF converts messages between 3 protocols. Performance evaluation proves that MIWF does not add loads to the existing network.