• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.1027-1030
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• 2005

The article introduces developing trends of an adaptive mobile terminal as an interface for use of various network resources, such as public wireless networks and un-licensed wireless networks in ubiquitous sensor network environments, without troublesome settings or operations by users. These adaptive mobile terminals able to provide seamless services that adapt autonomously to the user's movements and changes in the state of wireless resources. Consequently, adaptive mobile terminals should be had respective independent hardware structure of usable wireless networks.

• Journal of KIISE:Information Networking
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• v.30 no.1
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• pp.82-96
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• 2003

The Internet has evolved into the global computer network due to the openness of its protocol, but such evolution brings about new risks and threats. To protect computer networks safely, it is the best way that preventing an attacher from intruding beforehand. However, to provision against all attacks causes the degradation of network performance as well as to prevent unknown attacks is very hard. Secure Combination, the framework which establishes a mutual collaboration and cooperation between the trusted zones, could protect systems from the potential attacks. This frameworks can predict attacks by exchanging security information and cooperating with each zone. It is a dynamic and powerful security architecture that rapidly enables updating security policy and deploying response modules.

• Smart Media Journal
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• v.4 no.4
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• pp.24-32
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• 2015

Recently, SDN is actively used as datacenter networks and gradually increase its applied areas. Along with this change of networking environment, research of deploying network security systems on SDN becomes highlighted. Especially, systems for detecting network flooding attacks by monitoring every packets through ports of OpenFlow switches have been proposed. However, because of the centralized management of a SDN controller which manage multiple switches, it may be substantial overhead that the attack detection system continuously monitors all the flows. In this paper, a sampling based network flooding attack detection and prevention system is proposed to reduce the overhead of monitoring packets and to achieve reasonable functionality of attack detection and prevention. The proposed system periodically takes sample packets of network flows with the given sampling conditions, analyzes the sampled packets to detect network flooding attacks, and block the attack flows actively by managing the flow entries in OpenFlow switches. As network traffic sampler, sFlow agent is used, and snort, an opensource IDS, is used to detect network flooding attack from the sampled packets. For active prevention of the detected attacks, an OpenDaylight application is developed and applied. The proposed system is evaluated on the local testbed composed with multiple OVSes (Open Virtual Switch), and the performance and overhead of the proposed system under various sampling condition is analyzed.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.10b
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• pp.939-942
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• 2001

인터넷 사용자가 급격히 증가함에 따라 정보통신 산업의 발전이 되었지만, 이에 따른 역기능 또한 크게 증가하고 있는 추세이며, 이를 차단하고, 탐지하는 기술이 해킹기술을 앞지르지 못하고 있으며 수동적 입장에서 해킹 사례를 분석하거나, 접근 차체를 차단하는 방법을 택하고 있지만 새로운 해킹 시도에 노출되고, 피해가 계속되고 있다. 따라서 우리가 제안하는 Anomaly IDS는 능동적 입장에서 해킹기법에 대해 대처하고, 새로운 형태의 해킹기술을 탐지함으로써, 보호하려는 시스템에 대한 능동적 보안수단을 제공한다. 본 논문에서는 기존 Anomaly IDS에서의 문제점을 보완하는 다계층적 측면에서 Audit Data를 통계적으로 학습하여 패턴을 생성하고 탐지하는 시스템을 설계 및 구현하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.383-386
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• 2007

Under the circumstance of Ubiquitous Society, service should be provided according to the users' location and environment. When specific service is demanded by user, the technology, which can help to detect whether there are devices performing the requested service in the ubiquitous network, is mandatory. This technology also should guarantee that users have the appropriate service through the most suitable device which is selected by this technology. The priority is an essential factor when multi service are asked by multi users simultaneouslyin the ubiquitous network, The paper focuses on realization of Smart Classroom which provides multi users, such as the professor and the students, with active services based on the Zigbee network and the Mobile platform.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.1
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• pp.33-43
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• 2011

This paper proposes a traffic-aware TXOP adjustment algorithm for the IEEE 802.11e networks. In the proposed algorithm the access point (AP) monitors the network traffics periodically and adjusts the TXOP value of the non-QoS traffic in order to improve the network throughput while maintaining the QoS of video and voice applications. The experimental results show that the proposed algorithm outperforms the legacy IEEE 802.11e in terms of the throughput and the fairness.

• Proceedings of the Korea Contents Association Conference
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• 2005.11a
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• pp.585-589
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• 2005

RFID is a very important interface technology in a ubiquitous computing that is called new computing paradigms. that is, we can handle the data updating, recognizing and processing easily using a integrated the network and RFID technology in a ubiquitous computing. Therefore, we propose a business adminstration system that can able to change the passive management structure to active management structure in a u-business administration using RFID technology of ubiquitous computing. Proposed system has management server function that handle recording and management of information by business administration to improve structure of legacy passive management system actively, so that supply effect of reduce manpower and cost for the manager, and offer easy interface to user at the same time.

• The KIPS Transactions:PartC
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• v.17C no.1
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• pp.129-134
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• 2010

Intelligent Power Switch (IPS) is a semiconductor device which contains a logic circuit in itself. It has received significant attention as a switching component to substitute the fuse and relay components in common automobile since the internal logic provides the controllability on the loads. However, a control system for the IPS status control and a network system to share the status information of IPS are required to fully exploit the capabilities of IPS. In this paper, we propose a control circuit and algorithm using IPS. Also the communication system between the control systems and IPS components using Control Area network (CAN) are proposed.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10d
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• pp.477-481
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• 2006

최근 무선 인터넷을 포함한 다양한 통신기술의 발달로 원격지에서 회의, 교육 및 발표를 위한 여러 가지 솔루션들이 마련되고 있으며, 그 이용영역이 확대되어가고 있는 추세이다. 그러나 대개의 시스템들은 영상이나 정보를 일방적으로 전달하는 방식이기 때문에 참여자가 수동적이 되기 쉬우며, 보다 능동적인 상호작용을 위해서는 참여자 각자에게 카메라와 같은 영상 장비가 양방향으로 설치되어야 하거나 다른 고가의 장비가 필요한 경우가 대부분이다. 본 논문에서는 이미 많은 사용자가 PDA나 Smart Phone을 보유하고 있고 점점 그 보급률이 향상되고 있다는 점에 착안하여, 이를 이용한 보다 능동적인 회의 참여 시스템을 제안하고, 각종 모바일 단말기와 PC간의 무선 통신을 통한 실시간 통신 기술을 바탕으로 하여 프레젠테이션 참여자의 상호작용을 지원하고 협동적인 회의가 가능하도록 하는 시스템을 구현하였다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.6
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• pp.528-537
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• 2002

In this paper, the extended FDTD is used for the analysis of microwave circuits including active elements. Lumped elements such as R, L, C which are inserted into a microstrip line are analyzed with the FDTD lumped element modeling. Parasitic capacitance and inductance could be obtained using network modeling and so it is sure that FDTD lumped element modeling makes it possible to get more accurate data which include parasite components. Moreover, a balanced mixer using two diodes that are modeled by an extended FDTD is designed and the more exact characteristic of the mixer is acquired than in current circuit simulator.