• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.275-278
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• 2013

Log is a file system, a system that uses all remaining data. Want situation now being issued in the IT, media Nate on information disclosure, the press agency server hack by numbness crime occurred. Hacking crisis that's going through this log analysis software professionally for professional analysis is needed. The present study, about APT attacks happening intelligently Log In case of more than traceback in advance to prevent the technology to analyze the pattern for log analysis techniques.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.6
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• pp.494-505
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• 1990

This paper reports on the development of a DPSK demodulator of DS spread spectrum communications that use one SAW convolver. The spreading code chip pattern is changed from bit to bit in data portion of packet. And code chip is PSK modulated. Compared with simulation, experiment shows that the DPSK signal spreaded can be demodulated by using only one SAW convolver. And the theoretical performance of this DPSK demudulator is equal to CSK demodulator wich uses two SAW convolvers.

• Journal of Communications and Networks
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• v.10 no.1
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• pp.98-107
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• 2008

In mobile ad hoc networks, packet loss is unavoidable due to MAC contention, link failure or the inherent characteristics of wireless link. Since TCP relies on the timely reception of TCP ACK packets to progress the transmission of the TCP DATA packets, ACK loss obviously affects the performance due to two main problems: (a) Frequent occurrence of spurious retransmissions caused by timeout events and (b) impairment of the fast retransmit mechanism caused by the lack of a sufficient number of duplicate ACK packets. In particular, since most reactive routing protocols force the packets buffered over a path to be discarded while performing a route recovery, the performance degradation becomes more serious due to such ACK loss. In this paper, therefore, TCP with two piggybacking schemes (called TCP-pgy) is proposed in order to resolve the above-mentioned problems over reactive routing protocols. Through extensive simulations using the ns-2 simulator, we prove that our proposed schemes contribute to TCP performance improvements.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.1
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• pp.414-435
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• 2017

As network adaptive streaming technology becomes increasingly common, transport protocol also becomes important in guaranteeing the quality of multimedia streaming. At the same time, because of the appearance of high-quality video such as Ultra High Definition (UHD), preventing buffering as well as preserving high quality while deploying a streaming service becomes important. The Internet Engineering Task Force recently published Multipath TCP (MPTCP). MPTCP improves the maximum transmission rate by simultaneously transmitting data over different paths with multiple TCP subflows. However, MPTCP cannot preserve high quality, because the MPTCP subflows slowly increase the transmission rate, and upon detecting a packet loss, drastically halve the transmission rate. In this paper, we propose a new multipath congestion control scheme for high-quality multimedia streaming. The proposed scheme preserves high quality of video by adaptively adjusting the increasing parameter of subflows according to the network status. The proposed scheme also increases network efficiency by providing load balancing and stability, and by supporting fairness with single-flow congestion control schemes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.3 no.3
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• pp.251-265
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• 2009

VoIP service is the transmission of voice data using SIP protocol on an IP-based network. The SIP protocol has many advantages, such as providing IP-based voice communication and multimedia service with low communication cost. Therefore, the SIP protocol disseminated quickly. However, SIP protocol exposes new forms of vulnerabilities to malicious attacks, such as message flooding attack. It also incurs threats from many existing vulnerabilities as occurs for IP-based protocol. In this paper, we propose a new virtual proxy to cooperate with the existing Proxy Server to provide state monitoring and detect SIP message flooding attack with IP/MAC authentication. Based on a proposed virtual proxy, the proposed system enhances SIP attack detection performance with minimal latency of SIP packet transmission.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2002.11a
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• pp.59-65
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• 2002

Recently, lots of researchers work focused on the intrusion detection system. Pattern matching technique is commonly used to detect the intrusion in the system, However, the method requires a lot of time to match between systems rule and inputted packet data. This paper proposes a new intrusion detection system based on the pattern matching technique. Proposed system reduces the required time for pattern matching by using classified system rule. The classified rule is implemented with a general tree for efficient pattern matching. Thereby, proposed system could perform network intrusion detection efficiently.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2469-2471
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• 2002

MMI 시스템은 제철 공정에서 발생되는 다양한 데이터를 조업자에게 쉽고 빠르게 전달하기 위해, real time operating system에서 동작하는 제철공정의 주된 제어 프로세스와 인터페이스 한다. 따라서 MMI 시스템은 제철 공정의 주된 제어 프로세스와 ethernet network을 통해 공유 데이터들을 통신하도록 개발되고, MMI 시스템은 M/S window operating system과 DDE(Dynamic Data Exchange) 라이브러리 환경을 기반으로 개발된다. 수 개의 MMI client PC와 1 개의 MMI server로 구성되는 MMI 시스템은 MMI client들 사이의 공유 데이터가 동기화될 수 있도록 최적 packet 양을 도출하고, 신뢰성 높은 데이터 전송을 위한 특별한 데이터 핸들링 방법을 사용한다. MMI 시스템은 GUI(Graphic User Interface)를 사용하여 조업자에게 친숙한 window 화면을 제공하므로, MMI 시스템의 화면 수정, 첨가 및 삭제가 비용 부담없이 용이하게 진행되므로, 기존 제철 공정에서 사용하던 OCP(Operating Control Panel)들이 MMI 시스템으로 대체되고 있다.

• Journal of the Korea Society of Computer and Information
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• v.20 no.6
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• pp.29-35
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• 2015

The heterogeneous LTE (Long Term Evolution)-Advanced networks comprising a macrocell and femtocells can provide an efficient solution not only to extend macrocell coverage but also to deal with packet traffics increasing explosively within macrocells. An efficient resource management scheme is necessary to maintain the QoS (Quality of Service) of mobile multimedia services because the LTE-Advanced system should support not only voice but also mobile applications such as data, image and video. This paper proposes a resource management scheme to guarantee QoS continuity of multimedia services and to maximize the resource utilization in OFDMA (Orthogonal Frequency Division Multiple Access) based LTE-Advanced systems. This scheme divides the resources into several service blocks and allocates those resources based on the competition between macrocell and femtocell. Simulation results show that it provides better performances than the conventional one in respect of handover failure rate and blocking rate.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.1
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• pp.79-86
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• 2013

In this paper which it is relating to the DSRC system based road side equipment, we propose the protocol stack architecture of road side equipment and the process structure of the main RM, L7 and LLC layers which is road side equipment device as well. And also we design the signal flow and data-transfer process as well between road side equipment and on board equipment to describe the installation process between road side equipment and von board equipment based on DSRC system. Thus, it is possible to provide various application services between intelligent transportation systems of road side equipment and local server, as well as it enables the local server managing the memorys of on board equipment which entry in service area thru the road side equipment.

• Journal of Fisheries and Marine Sciences Education
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• v.17 no.2
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• pp.270-280
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• 2005

Many researchers have proposed the various methods to detect illegal intrusion in order to improve internet environment. Among these researches, IDS(Intrusion Detection System) is classified the most common model to protect network security. In this paper, we propose new log format instead of Apache log format for SSL integrity verification. We translate file-DB log format into R-DB log format. Using these methods we can manage Web server's integrity, and log data is transmitted verification system to be able to perform both primary function of IDS and Web server's integrity management at the same time. The proposed system in this paper is also able to use for wire and wireless environment based on PDA.