• Annual Conference of KIPS
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• 2015.10a
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• pp.1593-1596
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• 2015

실시간 영상회의 시스템은 네트워크 및 버퍼링의 지연으로 사용자 정보의 전달이 시스템 간에 효율적으로 이루어지지 않고 있어 실시간성이 완벽하게 보장되지 않고 있는 것이 현실이다. 하지만, 네트워크 인프라의 보강과 지터 지연에 대한 연구는 활발하지만, 버퍼링에 대한 연구는 미흡한 상태이다. 본 논문에서는 버퍼링 지연에 따른 문제 해결을 위한 FRCB(Frame-Rate Control Buffer) 관리 기법을 제안하고자 한다. FRCB는 버퍼의 Overflow와 Underflow를 방지하기 위한 FTH(Fist-play THreshold)와 STH(Slow-play THreshold)로 구성되며, CPU 부하가 높은 상황에서도 좋은 성능을 보여 고품질의 실시간 영상회의에 적합함을 보였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.6A
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• pp.667-667
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• 2004

We must design the buffer algorithm that protects traffic congestion and decreasing throughput at satellite communication network. It is important that buffer algorithm is satisfied with the good performance of transmission packet, responsibility of many connecting traffic and the QOS for connecting character. Old buffer algorithms are not the suitable algorithms when we have the satellite communication network environment. RED buffer algorithm is proposed by Floyd. It has a better performance than old buffer algorithm. But this algorithm is not well adapted a number of connecting TCP packet and changing network, so this algorithm has a bad performance on satellite communication network that is many of connecting user at same time. This paper propose the TARED(Target Adaptive RED). It has a good performance, adaptation and stability on satellite communication network and has not overflow and underflow of the buffer level.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.6A
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• pp.666-676
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• 2004

We must design the buffer algorithm that protects traffic congestion and decreasing throughput at satellite communication network. It is important that buffer algorithm is satisfied with the good performance of transmission packet, responsibility of many connecting traffic and the 005 for connecting character. Old buffer algorithms are not the suitable algorithms when we have the satellite communication network environment. RED buffer algorithm is proposed by Floyd. It has a better performance than old buffer algorithm. But this algorithm is not well adapted a number of connecting TCP packet and changing network, so this algorithm has a bad Performance on satellite communication network that is many of connecting user at same time. This paper Propose the TARED(Target Adaptive RED). It has a good performance, adaptation and stability on satellite communication network and has not overflow and underflow of the buffer level.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.4
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• pp.940-949
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• 1998

The paper proposes an effective mechanism hiring the adaptive buffer control schemes on the mobile seceiver's side that can resolve the problems of delay spikes caused by the handover process onthe cell boundaries when they transmit real-time moving images through the high speed wireless channels. to confirm the effectiveness of the proposed schemes, we have modeled the characteristics of the random errors on the wireless channels, the burst errors and that of the transmission delay by the handover. We also compared the rate of the delay-adaptation of the receive buffers caused by the delay and delay spikes. the comparison was done by testing the suggested schemes against the existing schemes by applying tehm to the packet delay model. We also could identify the noticable reduction of the casesof buffer delay and overflow compared with the conventional schemes, by applying the suggested algorithm to the video image compressed by H.263.

• Journal of Digital Convergence
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• v.16 no.5
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• pp.399-406
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• 2018

Much research has been done using the KDDCup99 data set to study intrusion detection using artificial intelligence. Previous studies have shown that the performance of the SMO (SVM) algorithm is superior. However, intrusion detection studies of new intrusion types not used in training are insufficient. In this paper, a model was created using the instances of weka's SMO and KDDCup99 training data set, kddcup.data.gz. We tested existing instances(292,300) of the corrected.gz file and new intrusions(18,729). In general, intrusion labels not used in training are not tested, so new intrusion labels were changed to normal. Of the 18,729 new intrusions, 1,827 were classified as intrusions. 1,827 instances classified as new intrusions are buffer_overflow. Three, neptune. 392, portsweep. 164, ipsweep. 9, back. 511, imap. 1, satan. Dogs, 645, nmap. 102.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.9
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• pp.3502-3509
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• 2010

Streaming service in the wireless mobile network environment has been a very challenging issue due to the dynamic uncertain nature of the channels. Overhead such as congestion, latency, and jitter lead to the problem of performance degradation of an adaptive multi-streaming service. This paper proposes a AMSS (Adaptive Multi-level Streaming Service) mechanism to reduce the performance degradation due to overhead such as variable network bandwidth, mobility and limited resources of the wireless mobile network. The proposed AMSS optimizes streaming services by: 1) use of fuzzy similarity metric, 2) minimization of packet loss due to buffer overflow and resource waste, and 3) minimization of packet loss due to congestion and delay. The simulation result shows that the proposed method has better performance in congestion control and packet loss ratio than the other existing methods of TCP-based method, UDP-based method and VBM-based method. The proposed method showed improvement of 10% in congestion control ratio and 8% in packet loss ratio compared with VBM-based method which is one of the best method.

• Journal of KIISE:Information Networking
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• v.34 no.4
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• pp.276-286
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• 2007

Existing streaming mechanisms have no consideration for the characteristics of streaming applications because they only consider network stability. In this paper, in order to overcome limitations of the previous work on video streaming, we propose a new video streaming mechanism called "HAViS(Hybrid Approach for Video Streaming)". The proposed mechanism includes more sophisticated features that consider both network and user requirements. Therefore, the HAViS mechanism improves the network stability by adjusting the sending rate of video stream based on the network state and it also provides the smooth playback by preventing the buffer underflow or overflow. Moreover, it is designed to take into consideration the streaming video content. Through the simulation, we prove that the HAViS mechanism efficiently uses the buffer resources and provides improved network stability and smooth playback.

• Journal of KIISE
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• v.42 no.8
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• pp.1049-1056
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• 2015

Runtime Intrusion Prevention Evaluator (RIPE), published in 2011, is a benchmark suite for evaluating mitigation techniques against 850 attack patterns using only buffer overflow. Since RIPE is built as a single process, defense and attack routines cannot help sharing process states and address space layouts when RIPE is tested. As a result, attack routines can access the memory space for defense routines without restriction. We separate RIPE into two independent processes of defense and attacks so that mitigations based on confidentiality such as address space layout randomization are properly evaluated. In addition, we add an execution mode to test robustness against brute force attacks. Finally, we extend RIPE by adding 38 attack forms to perform format string attacks and virtual table (vtable) hijacking attacks. The revised RIPE contributes to the diversification of attack patterns and precise evaluation of the effectiveness of mitigations.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.33 no.2
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• pp.345-351
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• 2023

As software development progresses and programs become increasingly complex, the cost of reducing and managing software vulnerabilities has also increased. To address this issue, the Rust programming language, which guarantees Memory Safety, has been suggested as an alternative for more error-prone languages such as traditional C/C++. However, Rust also supports the use of libraries written in C/C++ to enhance compatibility with older languages and avoid redundant development, compromising its original guarantees. For example, memory corruption happened in C/C++ can lead to exploits such as buffer overflow, Use-After-Free and null-pointer dereferecing. To tackle this problem, recent studies have been conducted to secure interactino between Rust and C/C++ by isolation. This paper uncovers areas that have not been fully explored in previous studies, following limitation analysis on each. Finally, this paper suggests the future direction of research on safe interaction between Rust and C/C++.

• Convergence Security Journal
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• v.24 no.3
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• pp.105-115
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• 2024

Since 2015, programming has been included in school curricula to enhance computer literacy and problem-solving skills. C language, widely used for its simplicity, efficiency, and long history, poses significant security risks, particularly in memory vulnerabilities like buffer overflow, pointer errors, format strings, and integer overflow. These vulnerabilities can cause severe system issues and widespread damage. This paper proposes an "Error Detection and Automatic Correction of Memory Vulnerabilities (EDAC)" algorithm to detect and correct these errors, aiming to reduce the impact of C language memory vulnerabilities.