• 제목/요약/키워드: 호네트

검색결과 853건 처리시간 0.032초

Performance Analysis for ABR Congestion Control Algorithm of ATM Switch using Self-Similar Traffic (자기 유사한 트래픽을 이용한 ATM 스위치의 ABR 혼잡제어 알고리즘의 성능분석)

  • Jin, Sung-Ho;Yim, Jae-Hong
    • The KIPS Transactions:PartC
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    • 제10C권1호
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    • pp.51-60
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    • 2003
  • One of the most important matters in designing network and realizing service, is to grip on the traffic characteristics. Conventional traffic prediction and analysis used the models which based on the Poisson or Markovian. Recently, experimental research on the LAN, WAN and VBR traffic properties have been pointed rut that they weren't able to display actual real traffic specificities because the models based on the Poisson assumption had been underestimated the long range dependency of network traffic and self-similar peculiarities, it has been lately presented that the new approach method using self-similarity characteristics as similar as the real traffic models. Therefore, in this paper, we generated self-similar data traffic like real traffic as background load. On the existing ABR congestion control algorithm, we analyzed by classify into ACR, buffer utilization. cell drop rate, transmission throughput with the representative EFCI, ERICA, EPRCA and NIST twitch algorithm to show the efficient reaction about the burst traffic.

A Bayesian Inference Model for Landmarks Detection on Mobile Devices (모바일 디바이스 상에서의 특이성 탐지를 위한 베이지안 추론 모델)

  • Hwang, Keum-Sung;Cho, Sung-Bae;Lea, Jong-Ho
    • Journal of KIISE:Computing Practices and Letters
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    • 제13권1호
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    • pp.35-45
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    • 2007
  • The log data collected from mobile devices contains diverse meaningful and practical personal information. However, this information is usually ignored because of its limitation of memory capacity, computation power and analysis. We propose a novel method that detects landmarks of meaningful information for users by analyzing the log data in distributed modules to overcome the problems of mobile environment. The proposed method adopts Bayesian probabilistic approach to enhance the inference accuracy under the uncertain environments. The new cooperative modularization technique divides Bayesian network into modules to compute efficiently with limited resources. Experiments with artificial data and real data indicate that the result with artificial data is amount to about 84% precision rate and about 76% recall rate, and that including partial matching with real data is about 89% hitting rate.

The Hybrid Model using SVM and Decision Tree for Intrusion Detection (SVM과 의사결정트리를 이용한 혼합형 침입탐지 모델)

  • Um, Nam-Kyoung;Woo, Sung-Hee;Lee, Sang-Ho
    • The KIPS Transactions:PartC
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    • 제14C권1호
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    • pp.1-6
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    • 2007
  • In order to operate a secure network, it is very important for the network to raise positive detection as well as lower negative detection for reducing the damage from network intrusion. By using SVM on the intrusion detection field, we expect to improve real-time detection of intrusion data. However, due to classification based on calculating values after having expressed input data in vector space by SVM, continuous data type can not be used as any input data. Therefore, we present the hybrid model between SVM and decision tree method to make up for the weak point. Accordingly, we see that intrusion detection rate, F-P error rate, F-N error rate are improved as 5.6%, 0.16%, 0.82%, respectively.

Selective On-demand Zone Routing Protocol for Large Scale Mobile Ad-hoc Networks (대규모 Ad-hoc 네트워크 환경에서 트래픽 감소를 위한 선택적 on-demand 라우팅 기법에 관한 연구)

  • Lee, Jae-Ho;Eom, Doo-Seop
    • The Journal of Korean Institute of Communications and Information Sciences
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    • 제37권6B호
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    • pp.443-452
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    • 2012
  • In Mobile Ad-hoc Networks, previous routing protocols classified into proactive and reactive approach respectively have pros and cons under the use of applications and environment. Moreover, to integrate their advantages in case by case, hybrid approach is consistently researched, and Zone Routing Protocol (ZRP) was motivating many recent hybrid protocols. ZRP uses proactive routing to the node located within the zone defined by the specific number of hops, while it uses reactive routing to other nodes. However, in ZRP, because proactive routing is applied only within the zone defined by the number of hops, the zone is formed regardless of whether real data communication occurred frequently or not. In this paper, we propose a new hybrid routing scheme which employs the zone method but forms customized zone considering traffic load and number of hops, by a new decision method named Dynamic Zone Decision (DZD). Additionally, we analyze the performance of the proposed scheme, comparing with the previous proactive, reactive, and hybrid routings.

Message Delivery and Energy Consumption Analysis on Pocket Switched Network Routing Protocols (Pocket Witched Network 라우팅 프로토콜의 메시지 전송 및 에너지 소비 분석)

  • Cabacas, Regin;Ra, In-Ho
    • Journal of the Korean Institute of Intelligent Systems
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    • 제23권6호
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    • pp.571-576
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    • 2013
  • Despite the development of the Internet, both in terms of technology and coverage, there are still remote areas and scenarios where connectivity is very difficult to achieve. Pocket Switched Network is a network paradigm that takes the advantage of human mobility to disseminate data. Factors such as mobility of nodes, link failures, discharged batteries, are among the challenges that may compromise connectivity in these networks. This paper presents a performance analysis of existing routing schemes for PSN in terms of delivery probability, overhead ratio, average latency and average residual energy when the number of nodes is increased. We seek to identify a scheme that maximizes data delivery while minimizing communication overhead and thus extending the network lifetime.

Parameter Estimation & Validation of Volume-delay Function based on Traffic Survey Data (교통조사를 통한 도로통행비용함수 구축 및 검증)

  • Kim, Ju-Yeong;Chu, Sang-Ho;Gang, Min-Gu;Heo, Heon
    • Journal of Korean Society of Transportation
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    • 제28권1호
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    • pp.115-124
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    • 2010
  • VDF(volume-delay function) is one of the most important factor to improve the reliability of traffic demand estimation because it is for estimation of link travel time based on the traffic volume variation. Because VDF of link except for freeway is applied as the parameter of BPR(bureau of public road) of U.S., it causes to deteriorate the accuracy of traffic demand estimation. The purpose of this paper is to establish new parameter of VDF based on the real-surveyed traffic data in order to improve the problem of the existing VDF. We suggest the reclassification of road hierarchy, the approach of traffic survey, the estimating method of VDF parameter, and the improvements of new VDF application. The new VDF allows us to estimate more realistic traffic situation in parts of demand, travel time and path between origin-destination.

Designing a Simulation Framework for Vehicular Ad hoc Network Applications (애드혹 네트워크 기반 교통 시스템을 위한 컴퓨터 모의실험 환경 설계)

  • Kim, Hyoung-Soo;Shin, Min-Ho;Nam, Beom-Seok;Lovell, David J.
    • Journal of Korean Society of Transportation
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    • 제26권6호
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    • pp.93-101
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    • 2008
  • With a spread of mobile devices, the growing trend of integrating wireless communications technologies into transportation systems is advanced. In particular, vehicular ad hoc networks (VANETs) enable vehicles to share traffic information that they have through intervehicle communications. This research focused on the design of an integrated transportation and communication simulation framework to build an environment that is more realistic than previous studies developed for studying VANETs. Developing a VANET-based information model, this research designed an integrated transportation and communication simulation framework in which these independent simulation tools not supporting High Level Architecture (HLA) were tightly coupled and finely synchronized. As a case study, a VANET-based traffic information system was demonstrated based on a real road network and real traffic data. The experiment results showed that the simulation framework was well integrated. The simulation framework designed in this study is expected to contribute to developing the environment to experiment a wide range of VANET applications.

Security Enhanced User Authentication Scheme with Key Agreement based on Fuzzy Extraction Technology (보안성이 향상된 퍼지추출 기술 기반 사용자 인증 및 키 동의 스킴)

  • Choi, Younsung;Won, Dongho
    • Journal of Internet Computing and Services
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    • 제17권3호
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    • pp.1-10
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    • 2016
  • Information and network technology become the rapid development, so various online services supplied by multimedia systems are provided through the Internet. Because of intrinsic open characteristic on Internet, network systems need to provide the data protection and the secure authentication. So various researchers including Das, An, and Li&Hwang proposed the biometric-based user authentication scheme but they has some security weakness. To solve their problem, Li et al. proposed new scheme using fuzzy extraction, but it is weak on off-line password attack, authentication without biometrics, denial-of-service and insider attack. So, we proposed security enhanced user authentication scheme with key agreement to address the security problem of authentication schemes.

Efficient DBA Algorithm for Supporting CBR Service on EPON with Traffic Burstiness (트래픽이 급증하는 EPON 환경에서 고정비트율 서비스를 효율적으로 지원하는 DBA 알고리즘)

  • Lee, Jin-Hee;Lee, Tae-Jin;Chung, Min-Young;Lee, You-Ho;Choo, Hyun-Seung
    • Journal of Internet Computing and Services
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    • 제9권4호
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    • pp.61-68
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    • 2008
  • Ethernet passive optical network (EPON) is the next-generation technology mitigating the bottleneck between high-capacity local area networks (LANs) and a backbone network. The bottleneck is aggrevated depending on burstiness and long range dependence (LRD) of traffic characteristics as well as amount of outgoing traffic from the high-capacity LANs. The proposed scheme decreases average packet delay for data upstreaming by considering such traffic characteristics to dynamically allocate bandwidth to multiple optical network units (ONUs). In addition, it can appropriately support delay-sensitive traffic such as constant bit ratio (CBR) traffic by making maximum cycle time fix regardless of the number of ONUs. The comprehensive simulation results indicate that the proposed scheme acheives up to 77% and 82% lower than previous schemes in terms of average packet delay and average queue size while it limits the maximum cycle time to twice of the basic cycle time.

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Efficient Radio Resource Measurement System in IEEE 802.11 Networks (IEEE 802.11 네트워크에서 효율적인 라디오 자원 측정 시스템 연구)

  • Yang, Seung-Chur;Lee, Sung-Ho;Kim, Jong-Deok
    • Journal of the Korea Institute of Information and Communication Engineering
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    • 제16권11호
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    • pp.2437-2445
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    • 2012
  • This paper presents the efficient measurement method of radio resource by analyzing various medium occupied elements. The medium occupied time consists of 802.11 frames, wireless interference, and protocol waiting time from a wireless node on a current channel. And it is used to performance metric. Existing research is only measured partial occupied elements, and is lack of validation of measurement unit and scalability on various IEEE 802.11 radio. This paper presents the measurement method of classified occupied elements. To achieve this, we modified 802.11n based OpenHAL device driver to collect the register information of wireless chipset, and to analyze receiving frames in an virtual monitor mode. We conclude accurate medium occupied time measurement system from various validation methods.