• Proceedings of the Korean Information Science Society Conference
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• 2000.04b
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• pp.393-395
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• 2000

CSCW 시스템은 효율적인 공동작업의 인지를 위해 텔리포인팅, 스냅샷, 문서/프로젝트 추적등과 같은 기능들을 제공한다. 이 중 텔리포인팅은 지역 시스템의 공유윈도우에서 텔리포인터를 통해 발생한 이벤트를 원격지 시스템의 공유윈도우에 동기적으로 표현하는 기법이다. 텔리포인팅은 여러 연구들에서 응용된 바 있으나, 텔리포인팅의 프로토콜에 관한 연구는 미흡하다. 본 논문은 RTP(Real-Time Transport Protocol) 기반의 텔리포인팅을 위한 RTP 페이로드 형식을 정의한다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.01a
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• pp.405-406
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• 2023

일반적으로 네트워크 장비는 원활한 장비 관리를 위해 SNMP라는 프로토콜을 활용한다. SNMP를 활용함에 있어, 각 장비 제조사에서는 고유 기능을 정의하여 사용하기도 하는데 이를 Private MIB이라고 한다. 본 연구에서는 이러한 Private MIB을 대상으로 하는 퍼징(Fuzzing) 기술을 고안하였다. 본 논문에서는 특정 제조사의 Private MIB에 대해 페이로드를 만드는 전략과 실제 페이로드의 생성을 보인다. 이는 수많은 소프트웨어 혹은 장비들의 초기 안전성 평가를 수행하는 데 응용될 수 있을 것으로 기대한다.

• The KIPS Transactions:PartC
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• v.17C no.1
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• pp.99-108
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• 2010

The traffic classification is a preliminary but essentialstep for stable network service provision and efficient network resource management. While various classification methods have been introduced in literature, the payload signature-based classification is accepted to give the highest performance in terms of accuracy, completeness, and practicality. However, the collection and maintenance of up-to-date signatures is very difficult and time consuming process to cope with the dynamics of Internet traffic over time. In this paper, We propose an automatic payload signature generation mechanism which reduces the time for signature generation and increases the granularity of signatures. Furthermore, We describe a signature update system to keep the latest signatures over time. By experiments with our campus network traffic we proved the feasibility of our mechanism.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.7
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• pp.1339-1346
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• 2015

The traffic identification is a preliminary and essential step for stable network service provision and efficient network resource management. While a number of identification methods have been introduced in literature, the payload signature-based identification method shows the highest performance in terms of accuracy, completeness, and practicality. However, the payload signature-based method's processing speed is much slower than other identification method such as header-based and statistical methods. In this paper, we first classifies signatures by matching type based on range, order, and direction of packet in a flow which was automatically extracted. By using this classification, we suggest a novel method to improve processing speed of payload signature-based identification by reducing searching space.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.9B
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• pp.1287-1294
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• 2010

The traffic classification is a preliminary and essential step for stable network service provision and efficient network resource management. While a number of classification methods have been introduced in literature, the payload signature-based classification method shows the highest performance in terms of accuracy, completeness, and practicality. However, the payload signature-based method has a significant drawback in high-speed network environment that the processing speed is much slower than other classification method such as header-based and statistical methods. In this paper, We describes various design options to improve the processing speed of traffic classification in design of a payload signature based classification system and describes our selections on the development of our traffic classification system. Also the feasibility of our selection was proved through experimental evaluation on our campus traffic trace.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.3
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• pp.575-585
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• 2015

The traffic classification is a preliminary and essential step for stable network service provision and efficient network resource management. However, the payload signature-based method has significant drawbacks in high-speed network environment that the processing speed is much slower than other methods such as header-based and statistical methods. In addition, as signature numbers are increasing, traffic analysis speed also declines because of signature matching method that does not consider analytic efficiency of each signature and traffic occurrence feature. In this paper, we propose a signature list reordering method in order by analytic value of each signature. When we reordered the signature list by the proposed method, we achieved about 30% improvement in speed of the traffic analysis compared with random signature list.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.2
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• pp.213-225
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• 2022

Containerization, a lightweight virtualization technology, enables agile deployments of enterprise-scale microservices in modern cloud environments. However, containerization also opens a new window for adversaries who aim to disrupt the cloud environments. Since microservices are composed of multiple containers connected through a virtual network, a single compromised container can carry out network-level attacks to hijack its neighboring containers. While existing solutions protect containers against such attacks by using network access controls, they still have severe limitations in terms of performance. More specifically, they significantly degrade network performance when processing packet payloads for L7 access controls (e.g., HTTP). To address this problem, we present BPFast, an eBPF/XDP-based payload inspection system for containers. BPFast inspects headers and payloads of packets at a kernel-level without any user-level components. We evaluate a prototype of BPFast on a Kubernetes environment. Our results show that BPFast outperforms state-of-the-art solutions by up to 7x in network latency and throughput.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.6
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• pp.2421-2427
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• 2012

This paper is discussed the design on non-linear adaptive attitude controller for quadrotor UAV. Quadrotor UAV featured to have four rotor, required the special controller to compensate for the model parameter uncertainties as the unstable nonlinear system. In this research, we designed the adaptive controller to compensate for the payload changes even though it is changed with industrial applications. Especially, based on the mathematical model of UAV, non-linear adaptive controller is suggested and the stability is verified using the Lyapunov function and finally proved its performance and effectiveness of update laws with various payload by simulation.

• Journal of Korea Multimedia Society
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• v.9 no.2
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• pp.197-207
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• 2006

When the latency of a flow in a fair packet scheduler, which is determined by its rate, violates its required delay bound, the scheduler should reduce the latency with even raising the rate being reserved for the flow. The excessively reserved rate win enforce some outgoing link bandwidth be lost. This loss can not be, unfortunately, evaluated by the three metrics of latency, fairness and implementation complexity used in previous works. This paper is aimed to first introduce the metric of bandwidth utilization to investigate the bandwidth loss in a scheduler and then evaluate the timestamp based schedulers in terms of the bandwidth and payload utilizations. The results show that the bandwidth utilization increases with loosing the required delay bound and, in particular, schedulers with the latency property of WFQ have much better payload utilization by up to 50% than that in the SCFQ one.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.807-808
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• 2010

To insert payload to the orbit over the 200km-altitude using launch vehicle which has 300sec the Isp, multi staging technique for launch is necessary. The range between the sea-level to the transfer orbit about 200~250km is for operation of 1st and 2nd rocket engines and the higher altitude is for propulsion system of the acceleration block and satellite. The upper stage rocket engine should have the high technology for entering the payload into the orbit precisely more than the performance for high thrust level. With this investigation of the upper stage rocket engines which have been used, we want to understand their development trend and prospect which is going to be references for the development of ours.