• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.5
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• pp.776-796
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• 2010

Integrated RFID-WSNs (wireless sensor networks) have recently been researched to provide object identities, sensing information, mobile service, and network functionalities. In integrated RFID-WSNs, the reader collision is one of the critical problems. Above all, due to the absence of universally applicable anti-collision protocols and the channel capture phenomenon, the medium access control protocols in integrated RFID-WSNs suffer from reader collision and starvation problems. In this paper, we propose an efficient MAC protocol, called EMP, to avoid the above problems in integrated RFID-WSNs. EMP is a CSMA-based MAC protocol which is compatible with sensor networks operating on integrated nodes which consist of an RFID reader and a senor node. EMP resolves not only the reader collision problem, but also the starvation problem using a power control mechanism. To verify the performance of EMP, we compared it with other anti-reader collision MAC protocols using simulations. As a result, the performance of EMP showed improvements in throughput, system efficiency, and energy consumption compared to the single data channel protocols (CSMA/CA, Pulse, and DiCa) in dense deployment environments.

• Journal of Digital Convergence
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• v.14 no.2
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• pp.235-243
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• 2016

Legacy data centers are transforming toward cloud data centers according to the advance of mobile and Internet of Things technology, processing of big data, and development of cloud computing technology. The goal of cloud data centers is to efficiently manage energy and facility, and to rapidly provide service demands to users by operating virtualized ICT(Information and Communication Technology) resources. Accordingly, it requires to configure and operate networks for efficiently providing virtualized ICT resources. This paper analyzes networking technologies suitable for cloud data centers and presents ways to efficiently operate the data center.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.5
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• pp.50-58
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• 2013

In this paper, we present the implementation result of an UWB terminal for mobile tactical networks. Considering the major characteristics of the terminals of tactical networks, i) targeting voice service, ii) pedestrian users, and iii) demanding high network fidelity, we designed all protocol layers from physical layer to applications layer. The designed terminal is implemented in forms of software and hardware with RF ASIC, FPGA, DSP, and GPP. The functionality of the implemented terminal is validated by successfully performing 1 to 1 and multi-hop voice communication test.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.1048-1050
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• 2013

Mobile devices or smartphones are rapidly becoming the central computer and communication network device. Recently, smartphones are programmable and come with a growing set of cheap powerful embedded sensors, such as an accelerometer, digital compass, gyroscope, GPS, microphone, and camera. In this paper, we discuss the wireless gas sensing service architectural and develope the gas sensor monitoring services using smartphone and web server.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.321-324
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• 2018

Recently, the evolution of V2X (Vehicle to Everything) technology is accelerating. In particular, it can be seen that C-V2X (Cellular V2X) technology and services combined with mobile telecommunication network are developing rapidly. However, in Korea, e-Call and emergency communication services are inferior to the developed communication technologies and the proportion of vehicles arriving at Golden Hour is considerably low. Therefore, this paper designed the communication architecture with C-V2X and Android operating systems, and presented ways to improve existing e-Call services using V2N (Vehicle to Nomadic Device) communication based on it.

• International Journal of Internet, Broadcasting and Communication
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• v.7 no.1
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• pp.42-48
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• 2015

Generally, the current commercial cloud system is hosted by the centralization large datacenter. However, the other clouding forms existed and one of them is the P2P cloud. The P2P Cloud is a distributed systems, is freedom to join and leave and is possible to provide the IaaS. Commonly, P2P Cloud System is based on Pure-P2P System. Since a number of connection paths exist, it has a high reliability and easily scalability of the network. However, there are disadvantages of the slow rate of route because of looking up the all peers in order to search for the peer. In this paper, it proposes the P2P cloud system based on super-peer P2P. Super-peer P2P system has fast routing time, because of searching for cluster unit and it also can has high reliability and high scalability. We designs the super Peer cloud service and proposes the system model and Resource Allocation Algorithm for IaaS in Super peer P2P environment.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04b
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• pp.853-856
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• 2002

인터넷이라는 거대한 네트워크에 연결되어 있는 시스템의 보안 상태를 주기적으로 점검하여 외부로부터의 공격에 취약한 부분을 보완하여 주는 일은 공격에 대한 방어를 위하여 가장 기본적인 일이다. 그러나 수많은 호스트가 상호 연결된 네트워크 관리 시스템에서 관리자가 각 시스템의 보안상 취약점을 전부 인지하고 이에 대한 보완을 수행하는 것은 상당히 어려운 일이다. 따라서 관리자의 수작업에 의한 취약점 분석 작업보다는 자동화된 관리 도구에 의한 취약점 분석이 효율적이다. 이에 본 논문에서는 네트워크 서비스인 HTTP, SMTP의 취약점을 원격에서 분석하는 시스템을 설계 및 구현하였다. WAVAMS는 에이전트와 독립된 mobile 코드의 이동에 의한 동적 분석 모듈의 추가로 가장 최근의 취약점을 신속하게 분석 할 수 있으며 확장성이 높다. 또한 웹 기반으로 설계되어 관리자가 용이하게 관리할 수 있다.

• IE interfaces
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• v.20 no.2
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• pp.216-226
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• 2007

In code-division multiple-access (CDMA) systems with soft handoff, mobile station (MS) within soft handoff region can use multiple radio channels and receive their signals from multiple base stations (BSs) simultaneously. In this paper, the effects of soft handoff region ratio (SHRR) on reverse link of a CDMA cellular system are analytically investigated. In order to analyze the network performance and quality of service (QoS) perceived by users more realistically, both the soft capacity increasing factor and the traffic load variation affected by SHRR are jointly considered and a two-dimensional continuous time Markov chain (CTMC) model is built. In the numerical example, it is observed that the optimal guard channel exists according the variations of the traffic load and propagation conditions when the proper value of SHRR is determined.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.7
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• pp.1275-1282
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• 2007

With the rapid spread of smart mobile products and practical use of wireless network, it became possible to offer the computing environment people can use anytime anywhere and it is predicted that portable computer as the next generation computing is to be put to practical use. This computer will be expected to have the new interface which provides realistic service through human's five senses as well as the interface through the visual and auditory senses. Accordingly, in this study, we are going to talk about the technology that expresses and reproduces what is based on olfactory information - closely related with memory among honan's five senses - in order to embody the lifelike user interface.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.1
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• pp.131-138
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• 2007

Plain old Web Services came true a services integration with use the XML that will be able to define a platform-independent document format in basic document format. Hut, the XML document decreases the efficiency of the whole application program with connects frequently in relatively slow communication media like network environment, embedded system or use the resource limited small-sized instrument like mobile. In this paper, we implemented the algorism of Fast Infoset, which can convert XML into Fast XML using the Fast Inoset method and PER encoding rules in ASN.1 and constructs Test Bed. Also, it is compared with the existing pure XML message method in difference of process performance after encoding SOAP messages of XML basis when constructing web service.