• Title/Summary/Keyword: Adaptive mechanism

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Adaptively Secure Anonymous Identity-based Broadcast Encryption for Data Access Control in Cloud Storage Service

  • Chen, Liqing;Li, Jiguo;Zhang, Yichen
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.3
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    • pp.1523-1545
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    • 2019
  • Cloud computing is now a widespread and economical option when data owners need to outsource or share their data. Designing secure and efficient data access control mechanism is one of the most challenging issues in cloud storage service. Anonymous broadcast encryption is a promising solution for its advantages in the respects of computation cost and communication overload. We bring forward an efficient anonymous identity-based broadcast encryption construction combined its application to the data access control mechanism in cloud storage service. The lengths for public parameters, user private key and ciphertext in the proposed scheme are all constant. Compared with the existing schemes, in terms of encrypting and decrypting computation cost, the construction of our scheme is more efficient. Furthermore, the proposed scheme is proved to achieve adaptive security against chosen-ciphertext attack adversaries in the standard model. Therefore, the proposed scheme is feasible for the system of data access control in cloud storage service.

Multimedia Process Scheduling Mechanism with Adaptive Rate Monotonic Algorithm (Adaptive Rate Monotonic 알고리즘을 이용한 멀티미디어 프로세서 스케줄링 기법)

  • ;Felix M. Villarreal
    • Proceedings of the Korean Information Science Society Conference
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    • 1998.10a
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    • pp.95-97
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    • 1998
  • 본 논문에서는 멀티미디어 프로세서의 특성을 반영한 프로세서 스케줄러를 설계하고 실제 구현을 통해 성능을 분석하였다. 제안한 프로세서 스케줄링 기법은 주기가 짧은 프로세서에 높은 우선순위를 부여하지만 우선 순위를 결정하기 위한 주기를 이전 작업의 주기에 위해 동적으로 계산하고 프로세서의 수행 중의 중단을 제한함으로써 Rate Monotonic 알고리즘을 동적이고 비중단적으로 수정하였다. 제안한 스케줄링 기법은 BSD를 기초로 한 운영체제인 FreeBSD 상에서 구현하여 스케줄링의 성능을 평가하였다. 제안한 스케줄러에 대한 실험에서 FreeBSD 스케줄러에 비해 멀티미디어의 실시간적인 특성을 만족하면서 수행 중의 동적인 상황 변화에 적응된 결과를 보인다.

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PAQM: an Adaptive and Proactive Queue Management for end-to-end TCP Congestion Control

  • Ryu Seung Wan
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2003.05a
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    • pp.417-424
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    • 2003
  • In this paper, we introduce and analyze a feedback control model of TCP/AQM dynamics. Then, we propose the Pro-active Queue Management (PAQM) mechanism, which can provide proactive congestion avoidance and control using an adaptive congestion indicator and a control function for wide range of traffic environments. The PAQM stabilizes the queue length around a desired level while giving smooth and low packet loss rates independent of the traffic load level under a wide range of traffic environment. The PAQM outperforms other AQM algorithms such as Random Early Detection (RED) [1] and PI-controller [2]

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On Adaptive Learning HMM Classifiers Using Splitting-Merging Techniques (분할-합병기법을 이용한 HMM 분류기의 적응학습)

  • 오수환;김상운
    • Proceedings of the IEEK Conference
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    • 2003.11b
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    • pp.99-102
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    • 2003
  • In this paper we propose an adaptive learning method for HMM classifiers by using splitting and merging techniques to overcome the problem of the conventional teaming, where one HMM classifier per class has been trained, individually. The experimental results demonstrate a possibility that the proposed mechanism could be applied for applications of having multiple clusters in a class.

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Adaptive Bulk Retransmission Mechanism for Wireless TCP (무선 TCP를 위한 효율적인 재전송 기법)

  • Kang, Jae-Sin;Hong, Choong-Seon;Lee, Dae-Yong
    • Annual Conference of KIPS
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    • 2003.11b
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    • pp.939-942
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    • 2003
  • TCP Westwood[1]는 송신측에 수신된 ACK를 통해서 대역폭을 계산하여 데이터를 전송하는 기법이다. 위성망 같이 손실률이 매우 높은 환경을 위해 TCP Westwood에서는 기존의 Bu]k Retransmission[2] 기법을 보안 하였다. 하지만 Bulk 재 전송 기법은 불필요한 데이터도 함께 재전송하기 때문에 성능이 저하되게 된다. 이 논문에서는 재 전송 패킷의 수를 적절히 조절하는 Adaptive Bulk Retransmission 기법을 제안하고자 한다.

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Adaptive Control of Robotic Manipulators Using Multiple Models and (다중모델과 스위칭을 이용한 로봇 매니퓰레이터의 적응제어)

  • Rhee, Hyoung-Chan
    • Proceedings of the KIEE Conference
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    • 1997.07b
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    • pp.693-695
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    • 1997
  • This paper deals with the tracking control problem of robotic manipulators with unknown or changing dynamics. The torque input applied to the joint actuators is determined at every instance by the identification model that best approximates the robot dynamics. The best of the identified model is chosen by the proposed switching mechanism with fuzzy inference of the manipulator in an indirect adaptive controller architecture. Simulation results are also included to demonstrate the improvement in the tracking performance when the proposed method is used.

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Radio Resource Metric Estimation (RRME) Mechanism for Multimedia Service Applications based on a CDMA Communication System

  • Lee Yeon-Woo;Cho Kwang-Moon;Hur Kyeong
    • International Journal of Contents
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    • v.2 no.2
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    • pp.10-16
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    • 2006
  • In this paper, we propose a predictive resource metric region (RMR) based radio resource metric estimation (RRME) mechanism, which utilizes a resource metric mapping function (RMMF), both of which permit efficient inter-working between the physical layer and higher layers for envisaging multimedia service applications over a CDMA communication system platform. The RMR can provide the acceptable resource region where QoS and acceptable link quality can be guaranteed with an achievable resource margin to be utilized in terms of capacity margin, the degree of confidence (DCL) of user, second-order statistics of Eb/Io. With predicted capacity margin and variance, DCL can deliver decision parameters with which an adaptive QoS based admission control can perform well taking capacity and resource availability into account in a dynamic and predictive manner. Combined with advanced techniques such as adaptive modulation or rate control and power control, the proposed mechanism can adjust the conventional stringent link quality information efficiently, and deliver accurate information of the resource availability. Thus, these can guarantee the maximization of resource utilization of multimedia service applications.

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Software Design of Packet Analyzer based on Byte-Filtered Packet Inspection Mechanism for UW-ASN

  • Muminov, Sardorbek;Yun, Nam-Yeol;Park, Soo-Hyun
    • Journal of Korea Multimedia Society
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    • v.14 no.12
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    • pp.1572-1582
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    • 2011
  • The rapid growth of UnderWater Acoustic Sensor Networks (UW-ASNs) has led researchers to enhance underwater MAC protocols against limitations existing in underwater environment. We propose the customized robust real-time packet inspection mechanism with addressing the problem of the search for the data packet loss and network performance quality analysis in UW-ASNs, and describe our experiences using this approach. The goal of this work is to provide a framework to assess the network real-time performance quality. We propose a customized and adaptive mechanism to detect, monitor and analyze the data packets according to the MAC protocol standards in UW-ASNs. The packet analyzing method and software we propose is easy to implement, maintain, update and enhance. We take input stream as real data packets from sniffer node in capture mode and perform fully analysis. We were interested in developing software and hardware designed tool with the same capabilities which almost all terrestrial network packet sniffers have. Experimental results confirm that the best way to achieve maximum performance requires the most adaptive algorithm. In this paper, we present and offer the proposed packet analyzer, which can be effectively used for implementing underwater MAC protocols.

A Multi-Priority Service Differentiated and Adaptive Backoff Mechanism over IEEE 802.11 DCF for Wireless Mobile Networks

  • Zheng, Bo;Zhang, Hengyang;Zhuo, Kun;Wu, Huaxin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.7
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    • pp.3446-3464
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    • 2017
  • Backoff mechanism serves as one of the key technologies in the MAC-layer of wireless mobile networks. The traditional Binary Exponential Backoff (BEB) mechanism in IEEE 802.11 Distributed Coordination Function (DCF) and other existing backoff mechanisms poses several performance issues. For instance, the Contention Window (CW) oscillations occur frequently; a low delay QoS guarantee cannot be provided for real-time transmission, and services with different priorities are not differentiated. For these problems, we present a novel Multi-Priority service differentiated and Adaptive Backoff (MPAB) algorithm over IEEE 802.11 DCF for wireless mobile networks in this paper. In this algorithm, the backoff stage is chosen adaptively according to the channel status and traffic priority, and the forwarding and receding transition probability between the adjacent backoff stages for different priority traffic can be controlled and adjusted for demands at any time. We further employ the 2-dimensional Markov chain model to analyze the algorithm, and derive the analytical expressions of the saturation throughput and average medium access delay. Both the accuracy of the expressions and the algorithm performance are verified through simulations. The results show that the performance of the MPAB algorithm can offer a higher throughput and lower delay than the BEB algorithm.