• Journal of information and communication convergence engineering
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• 제10권4호
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• pp.359-364
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• 2012

Harvesting energy from the environment is essential for many applications to slow down the deterioration of energy of the devices in sensor networks and in general, the network itself. Energy from the environment is an inexhaustible supply which, if properly managed and harvested from the sources, can allow the system to last for a longer period - more than the expected lifetime at the time of deployment, or even last indefinitely. The goal of this study is to develop a simple algorithm for ns-2 to simulate energy harvesting in wireless sensor network simulations. The algorithm is implemented in the energy module of the simulator. Energy harvesting algorithms have not yet been developed for ns-2. This study will greatly contribute to the existing knowledge of simulating wireless sensor networks with energy harvesting capabilities in ns-2. This paper will also serve as a basis for future research papers that make use of energy harvesting.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2001년도 The Seoul International Simulation Conference
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• pp.136-140
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• 2001

The 3rd generation mobile telecommunication fields are being standardized and developed in two parts, 3GPP and 3GPP2. These two parts have established each Network Architecture Models to achieve the goals basically required in the 3rd generation and to make it progress to IP network in the future. To achieve these goals many system architectures are proposed. Not only functional aspects but also performance aspects are considered as major factors. This paper proposes a new method of performance evaluation modeling and simulation that improved the existing way. The method proposed in this paper is Aspect oriented logical performance analysis Modeling and Simulation method. This proposed method is expected to improve efficiency of performance analysis modeling and simulation on the 3rd generation mobile telecommunication system.

• ETRI Journal
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• 제31권3호
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• pp.263-270
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• 2009

This paper investigates linear soft combination schemes for cooperative spectrum sensing in cognitive radio networks. We propose two weight-setting strategies under different basic optimality criteria to improve the overall sensing performance in the network. The corresponding optimal weights are derived, which are determined by the noise power levels and the received primary user signal energies of multiple cooperative secondary users in the network. However, to obtain the instantaneous measurement of these noise power levels and primary user signal energies with high accuracy is extremely challenging. It can even be infeasible in practical implementations under a low signal-to-noise ratio regime. We therefore propose reference data matrices to scavenge the indispensable information of primary user signal energies and noise power levels for setting the proposed combining weights adaptively by keeping records of the most recent spectrum observations. Analyses and simulation results demonstrate that the proposed linear soft combination schemes outperform the conventional maximal ratio combination and equal gain combination schemes and yield significant performance improvements in spectrum sensing.

• 정보통신설비학회논문지
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• 제10권4호
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• pp.148-154
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• 2011

This paper presents u-COEX, Ubiquitous-Collaborative Online shopping EXecution system, for small- and mediam- sized business enterprises, based on EPCglobal network. The system is taking advantage of RFID technology promises to optimize the critical processes in the Supply Chain Management. The system consists of five major functions: integrated order management, realtime monitoring and analysis system of sales and inventory, decision support system, integrating with EPCglobal and RFID technology, and u-catalog feature. The prototype implementation was developed for mass electronic market complex and the result revealed the feasibility to be applicable to real market.

• 정보통신설비학회논문지
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• 제9권3호
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• pp.102-106
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• 2010

Recently process industries from oil and gas procedures and mining companies to manufactures of chemicals, foods, and beverages has been exploring the USN (Ubiquitous Sensor Networks) technology to improve safety of production processes. However, to apply the USN technology in the large-scale plant industry, reliability and security issues are not fully addressed yet, and the absence of the industrial sensor networking standard causes a compatibility problem with legacy equipment and systems. Although this situation, process industry such as energy plants are looking for the secure wireless plant solution to provide detailed, accurate safety monitoring from previously hard-reach, unaccordable area. In this paper, SPSF (Smart Plant Safety Framework based on Reliable-Secure USN) is suggested to fulfill the requirements of high-risk industrial environments for highly secure, reliable data collection and plant monitoring that is resistant to interference. The SPSF consists of three main layers: 1) Smart Safety Sensing Layer, 2) Smart Safety Network Layers, 3) Plant Network System Layer.

• 한국컴퓨터산업학회논문지
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• 제3권7호
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• pp.851-860
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• 2002

다양한 통신 네트워크를 관리함에 따라 통합되고, 효율적인 통신 네트워크 오퍼레이션 및 유지 관리를 목적으로 한 TMN(Telecommunication Management Network)을 개발하였다. 그러나 TMN은 구현과정에서 서로 다른 플랫폼상에서 개발되어 왔기 때문에 TMN 시스템 에이전트의 클래스를 개발하고 유지하는 단계에서 여러 가지 문제점이 발견되었다. 이러한 문제점을 해결하기 위해서 본 논문에서는 CBD(Component Based Development.)를 기반으로 한 컴포넌트 아웃소싱 모델을 제안한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권5호
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• pp.2203-2217
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• 2016

To prevent structured peer to peer (P2P) overlay networksfrom being attacked by malicious nodes, a symmetric lookup-based routing algorithm referred to as Symmetric-Chord is proposed in this paper. The proposed algorithm determines the precision of routing lookup by constructing multiple paths to the destination. The selective routing algorithm is used to acquire information on the neighbors of the root. Authenticity of the root is validated via consistency shown between the information ascertained from the neighbors and information from the yet-to-be-verified root, resulting in greater efficiency of resource lookup. Simulation results demonstrate that Symmetric-Chordhas the capability of detecting malicious nodes both accurately and efficiently, so as to identify which root holds the correct key, and provides an effective approach to the routing security for the P2P overlay network.

• Journal of Communications and Networks
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• 제4권4호
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• pp.314-320
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• 2002

The various sectors of the International Telecommunication Union (ITU) have been addressing the evolution of thirdgeneration and future wireless systems in the context of a comprehensive International Mobile Telecommunications 2000 (IMT-2000) project, and within the ITU’s Telecommunication Standardization Sector (ITU-T) a Special Study Group on “IMT-2000 and Beyond” has been established to address the network aspects of these emerging wireless systems. The Special Study Group (SSG) is playing a global role in this general area, in which a number of regional standards development organizations and a variety of industry forums are also active. This paper provides background information on the SSG and describes the SSG’s ongoing work addressing medium-term issues relating to convergence of fixed and mobile systems and the harmonization of evolving IMT-2000 systems. The paper also addresses related mobility management aspects.

• 정보통신설비학회논문지
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• 제2권3호
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• pp.9-16
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• 2003

In this paper, we propose the burst error reduction (BER) algorithm for VoIP service in the wireless LAN network. In end point device, this BER algorithm can be achieved packet loss bounded QoS provisioning using interleaving in buffering and FEC (Forward Error Correction) through transmitting voice packet. BER algorithm can reduced the voice packet loss rate 5.5%-60% in VoIP network using wireless LAN.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 B
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• pp.928-930
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• 1995

The power telecommunication network is a important base construction of power company. The requirements of power plant operation, office automation, subscriber services make it to go on evolution for new structure and advanced services. For these reasons its evolution strategy establishment is needed for systematical improvement. In this paper, we established the structure of power integrated information network which will be able to adapt international standard trends, to support original power prodection, to have competitive power in the telecommunication service market, and suggest evolution strategy schemes for stepwise development.