• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.17 no.2
• /
• pp.412-434
• /
• 2023

This study discusses the high-order diffusion method in the wavelet domain. It aims to improve the edge protection capability of the high-order diffusion method using wavelet coefficients that can reflect image information. During the first step of the proposed diffusion method, the wavelet packet decomposition is a more refined decomposition method that can extract the texture and structure information of the image at different resolution levels. The high-frequency wavelet coefficients are then used to construct the edge detection function. Subsequently, because accurate wavelet coefficients can more accurately reflect the edges and details of the image information, by introducing the idea of state weight, a scheme for recovering wavelet coefficients is proposed. Finally, the edge detection function is constructed by the module of the wavelet coefficients to guide high-order diffusion, the denoised image is obtained. The experimental results showed that the method presented in this study improves the denoising ability of the high-order diffusion model, and the edge protection index (SSIM) outperforms the main methods, including the block matching and 3D collaborative filtering (BM3D) and the deep learning-based image processing methods. For images with rich textural details, the present method improves the clarity of the obtained images and the completeness of the edges, demonstrating its advantages in denoising and edge protection.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 1995.06a
• /
• pp.97-100
• /
• 1995

In transmission of image sequences over ATM networks, the packet loss problem and channel sharing efficiency are important. As a possible solution two-layer video coding methods have been proposed. These methods transmit video information over the network with different levels of protection with respect to packets loss. In this paper, a two-layer coding method using pyramid structure is proposed and several realizations of two-layer video coding methods are presented and their performances are compared.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2011.07a
• /
• pp.563-564
• /
• 2011

본 논문에서 우리는 unequal loss protection(ULP) 알고리즘을 기반으로 패킷이 손실될 수 있는 망 환경에서 인지적으로 재구성된 영상의 왜곡을 최소화하는 방법을 제안한다. 알고리즘에는 2가지의 주요 요인이 있다. 첫째, 인간 시각 체계의 균일하지 않은 분포의 함수로 압축된 영상에 가중치를 준다. 둘째, 패킷은 오류 전파가 일어나지 않도록 하면서 각각의 group of picture(GOP)내에서 시간적인 중요성이 할당된다. 프레임의 인지적인 중요성과 GOP의 계층적인 중요성을 동시에 고려하여, 제안하는 ULP알고리즘은 인간 시각적으로 가장 중요한 지역의 크기를 식별하여 효율적인 forword error correction(FEC) 알고리즘을 수행한다.

• Convergence Security Journal
• /
• v.13 no.2
• /
• pp.155-163
• /
• 2013

Connection hijacking attack using the vulnerability of the TCP protocol to redirect TCP stream goes through your machine actively (Active Attack). The SKEY such as one-time password protection mechanisms that are provided by a ticket-based authentication system such as Kerberos or redirection, the attacker can bypass.Someone TCP connection if you have access on TCP packet sniffer or packet generator is very vulnerable. Sniffer to defend against attacks such as one-time passwords and token-based authentication and user identification scheme has been used. Active protection, but these methods does not sign or encrypt the data stream from sniffing passwords over insecure networks, they are still vulnerable from attacks. For many people, an active attack is very difficult and so I think the threat is low, but here to help break the illusion successful intrusion on the UNIX host, a very aggressive attack is presented. The tools available on the Internet that attempt to exploit this vulnerability, known as the recent theoretical measures is required. In this paper, we propose analysis techniques on a wireless network intruder detection.

• ETRI Journal
• /
• v.24 no.4
• /
• pp.311-322
• /
• 2002

Presently, optical burst switching (OBS) technology is under study as a promising solution for the backbone of the optical Internet in the near future because OBS eliminates the optical buffer problem at the switching node with the help of no optical/electro/optical conversion and guarantees class of service without any buffering. To implement the OBS network, there are a lot of challenging issues to be solved. The edge router, burst offset time management, and burst assembly mechanism are critical issues. In addition, the core router needs data burst and control header packet scheduling, a protection and restoration mechanism, and a contention resolution scheme. In this paper, we focus on the burst assembly mechanism. We present a novel data burst generation algorithm that uses hysteresis characteristics in the queueing model for the ingress edge node in optical burst switching networks. Simulation with Poisson and self-similar traffic models shows that this algorithm adaptively changes the data burst size according to the offered load and offers high average data burst utilization with a lower timer operation. It also reduces the possibility of a continuous blocking problem in the bandwidth reservation request, limits the maximum queueing delay, and minimizes the required burst size by lifting up data burst utilization for bursty input IP traffic.

• The Journal of Information Technology
• /
• v.7 no.4
• /
• pp.9-20
• /
• 2004

Result Dos that materialization KNU Virus Wall to solve serious problem Hurtfulness Virus is present network chiefly in this research to do not become and do correct disposal in situation such as internet and Multiple Protocol that is done intelligence anger for ESM, CIS and MIS side as secondary to solve this problem about out log analysis system embody. As a result, could use comprehensively, and can click by Site Design, Packet transmission, and used to interior internet (GroupWare) in information protection aspect because intelligence enemy to face each other ESM's various hacking and virus uses Enterprise Security Management system and CIS, whole web through Smart View and relation of security could do monitoring.

• Journal of the Korea Society of Computer and Information
• /
• v.10 no.5 s.37
• /
• pp.217-226
• /
• 2005

In today's cyberworld, network performance is affected not only by an increased demand for legitimate content request, but also by an increase in malicious activity. In this Paper, we research that network performance was affected by an increase in malicious Hacker who make DoS Attack, DDoS Attack, SYN Flooding, IP Spoofing, etc. in using TCP/IP. We suggest that Packet filtering in Network Level, Gateway Level, Application Level against to Protect by Hacker's attack. Also, we suggest that content distribution in Web Server approaches to mitigate Hacker's activity using Cache Sever, Mirror Sever, CDN. These suggests are going to use useful Protection methode of Hacker's attack.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.9 no.12
• /
• pp.5150-5169
• /
• 2015

Mobile Ad hoc NETworks (MANETs) are the best choice when mobility, scalability, and decentralized network infrastructure are needed. Because of critical mission applications of MANETs, network security is the vital requirement. Most routing protocols in MANETs assume that every node in the network is trustworthy. However, due to the open medium, the wide distribution, and the lack of nodes' physical protection, attackers can easily compromise MANETs by inserting misbehaving nodes into the network that make blackhole attacks. Previous research to detect the misbehaving nodes in MANETs used the overhearing methods, or additional ACKnowledgement (ACK) packets to confirm the reception of data packets. In this paper a special lightweight acknowledgement-based method is developed that, contrary to existing methods, it uses ACK packets of MAC layer instead of adding new ACK packets to the network layer for confirmations. In fact, this novel method, named PIGACK, uses ACK packets of MAC 802.11 to piggyback confirmations from a receiver to a sender in the same transmission duration that the sender sends a data packet to the receiver. Analytical and simulation results show that the proposed method considerably decreases the network overhead and increases the packet delivery ratio compared to the well-known method (2ACK).

• Journal of the Korea Society of Computer and Information
• /
• v.13 no.3
• /
• pp.123-130
• /
• 2008

To avoid some protection systems such as firewall, P2P applications have recently used to apply dynamic port numbers. Reliable estimates of P2P traffic require examination of packet payload, a methodological land mine from legal, privacy technical, logistic, and fiscal perspectives. Indeed, access to user payload is often rendered impossible by one of these factors, inhibiting trustworthy estimation of P2P growth and dynamics. Despite various methods such as port-based and signature-based techniques, it still dose not satisfy the method which uses both qualitative and quantitative aspects. In this paper, a method using SVM mechanism which discriminate the P2P traffic from non-P2P traffics using differences between P2P and other application traffics is suggested. This is a systematic methodology to identify P2P networks, and without relying on packet payload.

• Journal of Korea Multimedia Society
• /
• v.14 no.11
• /
• pp.1431-1437
• /
• 2011

This paper proposes a novel watermarking algorithm that protects digital copyrights and is robust to attacks. Watermarks are embedded in the subband including the significant part of the signal such as a pitch. Generally, the subband containing the pitch has the biggest energy. In order to find this subband, wavelet packet transform is used to decompose the subbands and their energy are calculated. The signal of the selected subbands is transformed in frequency domain using FFT. The watermarks are embedded using QIM for samples higher than a certain threshold. The blind detection uses the Euclidean distance. The proposed method shows less than 5% BER in the audio watermark benchmarking.