• Journal of Internet Computing and Services
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• v.14 no.2
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• pp.61-71
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• 2013

Until now, there have been various studies against Internet worms. Most of intrusion detection and prevention systems against Internet worms use detection rules, but these systems cannot respond to new Internet worms. For this reason, a malicious process control system which uses the fact that Internet worms multicast malicious packets was proposed. However, the greater the number of servers to be protected increases the cost of the malicious process control system, and the probability of detecting Internet worms attacking only some predetermined IP addresses is low. This paper presents a security framework that can reduce the cost of the malicious process control system and increase the probability of detecting Internet worms attacking only some predetermined IP addresses. In the proposed security framework, virtual machines are used to reduce the cost of control servers and unused IP addresses are used to increase the probability of detecting Internet worms attacking only some predetermined IP addresses. Therefore the proposed security framework can effectively respond to a variety of new Internet worms at lower cost.

• Journal of Ubiquitous Convergence Technology
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• v.2 no.2
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• pp.88-96
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• 2008

IPTV Content delivery systems over wired networks confront scalability problems due to their high network bandwidth requirement for real-time services. Especially, VoD service provides Trick Mode features such as pause, fast forward and similar operations. However, Trick Mode services are delivered by the method of unicast only for controlling of the stream. With a point of views, this paper propose a new real-time multimedia streaming architecture over IP Networks, which tries to achieve bandwidth efficiency and supporting for mass clients better than traditional unicast services. The proposed methods divide the Transport Stream into a series of segments. After that, this divided partial Transport Stream makes multicast streaming periodically. Meanwhile Set-top Box of a client makes a rearrangement orderly by using Presentation Time Stamp field from the served Transport Stream packets. While the current Transport Stream segment is playing, it should be guaranteed that the next segment is downloaded on time. Consequently, the original video content can be played out continuously. The detail introduction of a new real-time multimedia streaming system with analysis and simulation follows as below.

• Proceedings of the Korea Contents Association Conference
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• 2003.05a
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• pp.231-236
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• 2003

Video conferencing system it is various at internet and uses the reading is become accomplished. Research of like this portion synchronization of audio, the video compression technique and multimedia data, supports the video conference the research of the Mbone of the If multicast for being active, being become accomplished the multimedia service which is various an video from internet, the line speed of communication becomes high-speed anger and to follow leads is become accomplished. The video conference from opening elder brother dispersion internet network environment the problem against the image which is an image conference data and a voice security is serious and it raises its head. To sleep it presents the security method which from the video conference it follows in quality of multimedia data from the dissertation which it sees and it does.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.2 no.1
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• pp.23-35
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• 2008

Mobile IP (MIP) is the solution supporting the mobility of Mobile Nodes (MNs), however, it is known to lack the support for NEtwork MObility (NEMO). NEMO manages situations when an entire network, composed of one or more subnets, dynamically changes its point of attachment to the Internet. NEMO Basic Support (NBS) protocol ensures session continuity for all the nodes in a mobile network, however, there exists a serious pinball routing problem. To overcome this weakness, there are many Route Optimization (RO) solutions such as Bi-directional Tunneling (BT) mechanism, Aggregation and Surrogate (A&S) mechanism, Recursive Approach, etc. The A&S RO mechanism is known to outperform the other RO mechanisms, except for the Binding Update (BU) cost. Although Improved Prefix Delegation (IPD) reduces the cost problem of Prefix Delegation (PD), a well-known A&S protocol, the BU cost problem still presents, especially when a large number of Mobile Routers (MRs) and MNs exist in the environment such as train, bus, ship, or aircraft. In this paper, a solution to reduce the cost of delivering the BU messages is proposed using a multicast mechanism instead of unicasting such as the traditional BU of the RO. The performance of the proposed multicast-based BU scheme is examined with an analytical model which shows that the BU cost enhancement is up to 32.9% over IPDbased, hence, it is feasible to predict that the proposed scheme could benefit in other NEMO RO protocols.

• The Journal of the Korea Contents Association
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• v.9 no.12
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• pp.528-536
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• 2009

Recently, the importance of IPTV providing multimedia service over IP based networks managed to provide the required level of quality of service and experience, security, interactivity and reliability has been gradually increasing by the commercialization of its service. However, the original purposes of IPTV service - contents are produced and consumed anytime, anywhere, and over any device at the same time - have not been satisfied by service providers because most services offered by service providers depend on closed IPTV platform. In this paper, we propose an open IPTV service platform that an individual or small company can easily produce contents and offer IPTV service independently from the existing closed IPTV platform.. The proposed IPTV platform exploits overlay multicast scheme to offer reasonable service under the environment where network bandwidth and processor resource are limited. It also uses CDN-like scheme to ensure the quality of transmitted contents. The performance evaluation shows that the proposed IPTV platform has the possibility of being an open IPTV platform considering its results such as the quality of transmitted contents, the transmission rate, the channel zapping time, and so on. It also shows that proposed IPTV platform could be applied to real IPTV service with continuous enhancement of its functions and user interfaces.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.332-337
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• 2016

The rapid reconstruction of a transfer path is caused by frequent secession of nodes in many applications using overlay multicast. For this, however, many studies have been proposed, but a study of fast path recovery is required. This paper proposes a new method for fast path recovery to improve the path reconstruction time and for stable path maintain caused by the sudden secession of the parent node on overlay multicast. The proposed method uses the virtual transfer path and the candidate parent node for the fast path recovery. All nodes exchange periodically the RTT (Round Trip Time) information between the other nodes of similar position itself and neighboring node. All nodes have a candidate parent node list, and each node stores the exchanged RTT information on the list. Each node constructs the virtual transfer path to reduce the recovery time after deciding a candidate parent node that is one of them by the RTT order. In this way, when the parent node is seceded, all nodes can recover the transfer path quickly using the virtual transfer path. The simulation result showed that the recovery time of the proposed method is an average 30% faster than the known method.

• Journal of the Institute of Convergence Signal Processing
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• v.8 no.1
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• pp.39-43
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• 2007

In high speed communication networks, the determination of a transmission rate is critical for the stability of a closed-loop network system with the congestion control scheme. In ATM networks, the available bit rate (ABR) service is based on a feedback mechanism, i.e., the network status is transferred to the ABR source by a resource management (RM) cell. RM cells contain the traffic information of the downstream nodes for the traffic rate control. However, the traffic status of the downstream nodes can not be directly transferred to the source node in the IP based networks. In this paper, a new rate-based congestion control scheme using an exponential weighted moving average algorithm is proposed to build an efficient feedback control law for congestion avoidance in high speed communication networks. The proposed congestion control scheme assures the stability of switch buffers and higher link utilization of the network. Moreover, we note that the proposed congestion scheme can flexibly work along with the increasing number of input sources in the network, which results in an improved scalability.

• The Journal of the Convergence on Culture Technology
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• v.4 no.1
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• pp.285-290
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• 2018

Vehicular ad hoc network (VANET) is one of the future communication technologies in which it offers safe-driving information and Internet access for both drivers and passengers by communicating among cars on the road. In case of applying Content Centric Network (CCN) rather than TCP/IP over VANET, called VCCN, it can provide efficient multicast communication of shared information among participating cars as well as offer corresponding one-to-one communications. This paper introduces SUMO for simulating traffic flows, VANET for car-to-car ad hoc communications, and CCN for a future Internet architecture. In addition, it compares and analyses the transmission performance of moving cars over VCCN. According to the simulation results using SUMO and VCCN, the larger the packet size, the better the transmission performance. In addition, VCCN provides higher packet transmission rate than that of TCP/IP when the clients shares the same contents. Furthermore, the overall data reception rate exceeds the physical transmission channel rate.

• Journal of KIISE:Information Networking
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• v.27 no.4
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• pp.418-428
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• 2000

이동호스트를 지원하는 네트워크에서의 멀티캐스트 라우팅은 그룹 멤버의 빈번한 위치 변화를 가져와서 기존의 고정 호스트를 기본으로 설계된 멀티캐스트 라우팅 프로토콜을 적용할 경우 많은 문제점을 발생시킨다. 이런점에서 Mobile-IP를 유니캐스트 라우팅 방식으로 사용하는 이동환경에서의 이동호스트를 위한 몇가지 멀티캐스팅 방법이 제시되었으나 이 방법들 또한 비최적 경로로의 데이터 전송, 비효율적인 데이터 중복 전송, 그리고 빈번한 멀티캐스트 트리의 재구성으로 인한 오버헤드 등의 문제점을 가지고 있다. 따라서 본 논문에서는 이런 문제점들을 구찰하고 이 문제점들을 보와하는 효과적인 멀티캐스트 라우팅 프로토콜을 제안하고자 한다. 제시하는 프로토콜은 Mobile-IP를 사용하는 이동호스트에게 멀티캐스트 서비스를 지원하는 멀티캐스트 에이전트와 이들 멀티캐스트 에이전트들 중에서 선택된 멀티캐스트 포워더를 이용하여 동작한다 이동호스트는 이웃한 멀티캐스트 포워더로부터 데이터를 터널링받거나 또는 로컬네트워크에 위치한 멀티캐스트 라우터로부터 멀티캐스트 데이터를 직접전송받게 된다. 따라서 멀티캐스트 데이터의 전송 경로를 단축시키고 중복되는 데이터 및 터널링으로 전송되는 데이터를 감소시킴으로써 전체 네트워크 트래픽량을 줄이는 효과를 얻을 수 있다. 제시하는 프로토콜의 성능은 다양한 환경의 시뮬레이션을 통하여 확인해 본다.

• Journal of Advanced Navigation Technology
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• v.13 no.5
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• pp.726-735
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• 2009

In this paper, we proposed a novel conditional access system to reduce the overhead transmission rate for messages which verify the entitlement of subscribers in bandwidth-limited system. We adapted a key update system with the tree structure which had been used for IP multicast to a group hierarchy for the subscriber groups or channel groups. We also analyzed the overhead transmission rate for periodic key update and aperiodic one for change in a subscriber. The numerical evaluations show that the proposed system can significantly reduce the overhead transmission rate for dynamic subscriber change up to several hundred thousands times for various system configuration.