• Title/Summary/Keyword: synchronization problem

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Finding State Transition Functions of One-Dimensional Cellular Automata by Evolutionary Algorithms (일차원 셀룰러 오토마타 상에서 진화 알고리즘을 이용한 상태전이함수 찾기)

  • Park, Jongwoo;Wang, Sehee;Wee, Kyubum
    • KIPS Transactions on Software and Data Engineering
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    • v.8 no.5
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    • pp.187-192
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    • 2019
  • Majority problem and synchronization problem on cellular automata(CA) are hard to solve, since they are global problems while CA operate on local information. This paper proposes a way to find state transition rules of these problems. The rules of CA are represented as CMR(conditionally matching rules) and evolutionary algorithms are applied to find rules. We find many solution rules to these problems, compared the results with the previous studies, and demonstrated the effectiveness of CMR on one-dimensional cellular automata.

Design and Evaluation of a Distributed Multimedia synchronization Algorithm based on the Fuzzy Logic

  • Oh, Sun-Jin;Bae, Ihn-Han
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1998.06a
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    • pp.246-251
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    • 1998
  • The basic requirement of a distributed multimedia system are intramedia synchronization which asks the strict delay and jitter for the check period of media buffer and the scaling duration with periodic continuous media such as audio and video media, and intermedia synchronization that needs the constraint for relative time relations among them when several media are presented in parallel. In this paper, a distributed multimedia synchronization algorithm based on the fuzzy logic is presented and the performance is evaluated through simulation. Intramedia synchronisation algorithm uses the media scaling techniques and intermedia synchronization algorithm uses variable service rates on the basis of fuzzy logic to solve the multimedia synchronization problem.

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The Study on Distribution Clock Synchronization of EtherCAT Communication System (이더캣 통신시스템에서 분산 클럭 동기화에 관한 연구)

  • Moon, Yongseomn;Vo, Trong Tuan Anh;Lee, Youngpil;Cha, Hyunrok
    • The Journal of the Korea institute of electronic communication sciences
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    • v.4 no.4
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    • pp.293-300
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    • 2009
  • In this paper, we describe a method for synchronization protocol method used in control system based on network and IEEE 1599 synchronization method which used for implementation of synchronization technology of advanced industrial Ethernet. We also implement and perform the experiment for synchronization technology of EtherCAT communication which is one of the industrial Ethernet technology used IEEE 1599 synchronization technology based on time. And we describe an evaluation for experiment result, improve the problem and future plan.

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A synchronization algorithm of migrating service object using Server Cooling algorithm (Server Cooling 알고리즘울 이용한 서비스 객체 이주시의 동기화 알고리즘)

  • Lee, Jun-Yeon;Kim, Chang-Min
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.3
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    • pp.953-961
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    • 2000
  • In this paper, we propose the algorithm which solve synchronization problem happened migrating service objects. Load imbalance is occurred due to allocate different amount of load to be proposed to each node in distribute system. To solve this problem, the service objects have to be migrated from heavily loaded node to lightly loaded node. And in such a process, the synchronization problem may occur when client request a service object migrated incompletely. Therefore, we describe the environment of executing service objects, the importer/exporter/trader model compatible with migration of service objects, and appropriate migration algorithm, Finally, we analyze the conditions of problems, and propose the solution of each situations. Also, the performance advantages of using proposed algorithms are quantified through a simulation study.

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A Synchronization Tracking Algorithm to Compensate the Drift of Satellite in FH-FDMA Satellite Communication System (FH-FDMA 위성 통신 시스템에서 위성 드리프트 보정 동기추적 알고리즘)

  • Bae, Suk-Neung;Kim, Su-Il;Choi, Young-Kyun;Jin, Byoung-Il
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.2A
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    • pp.159-166
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    • 2008
  • In this paper, we proposed an algorithm to solve the problem that can't maintain hop synchronization using only early-late gate tracking loop due to the drift of geo-stationary satellite in frequency hopping satellite communication system. When the signal is transferred to downlink through DRT(Dehop-Rebop Transponder), the problem with synchronization loss is occurred periodically when using only early-late gate tracking loop, because of energy loss in each side portion of hop due to orbital variation of the satellite. To solve this problem, we have developed Anti-Shrink synchronization tracking algorithm which uses the prediction value of transmission timing and the structure of inner-outer gate instead of early-late gate with the ranging information. Through simulations, we showed that the performance of the Anti-Shrink algorithm is better than that of simple inner-outer energy ratio algorithm and similar to that of conventional early-late tracking loop algorithm with ranging information. No synchronization failure in the proposed algorithm was occurred because of less energy loss and robustness without the ranging information.

Synchronization of a Complex Dynamical Network with nonidentical Node and Free Coupling Strength (비동일 노드들과 연결정보 제약이 없는 복잡동적 네트워크의 동기화)

  • Yun, Han-O
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.8
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    • pp.292-298
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    • 2013
  • This paper considers synchronization problem of a complex dynamical network with nonidentical nodes. For the problem, the target node is chosen as one of nodes in the complex network instead of an isolate node. Moreover, our synchronization scheme does not need additional conditions and information of coupling matrix comparing with existing works. Based on Lyapunov stability theory, a design criterion for a novel adaptive feedback controller for the synchronization between the target node and another nodes of the complex network is proposed. Finally, the proposed method is applied to a numerical example in orther to show the effectiveness of our results.

Display Synchronization Scheme for Flight Simulator Considering Frame Per Second (프레임률을 고려한 항공기 시뮬레이터의 영상 동기화 방안)

  • Lee, SunYoung;Mun, Dae-Han;Lee, ChungJae;Kim, Ki-Il
    • IEMEK Journal of Embedded Systems and Applications
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    • v.11 no.1
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    • pp.39-46
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    • 2016
  • According to general architecture of flight simulator made up of several independent rendering display systems, display synchronization problem between them naturally happens. In addition, since the flight simulator is usually implemented in the same networks where network delay is not big concern, it is necessary to consider different factors of existing synchronization technique. Among them, in this paper, we propose a new display synchronization scheme for flight simulator where each system has different rendering capacity. In the proposed scheme, each system is synchronized by considering maximum and minimum frames per second (FPS) while considering level of detail and latency. Also, experimental results are given to demonstrate the suitability of the proposed scheme for display synchronization scheme.

A multimedia synchronization mechanism using receiver buffer-level (수신측 버퍼 레벨을 이용한 멀티미디어 동기화 기법)

  • 김승천;박기현;이현태;박재성;이재용;이상배
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.6
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    • pp.1334-1342
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    • 1997
  • The future data communications are expected to support the various andcomplex services withmultimedia. So thispaper has focused on the multimedia synchronization problem which has important position in multimedia presentation. Firstly, this paper consider the suitable layer for multimedia synchronization in the communication structure as transport layer or upper ones, in which we propose synchronization mechanism using fixed length buffer with bufer-lever or upper ones, in which we propose synchronization mechanism using fixed length bufer with buffer-level. The proposed mechansim also supports intra-and inter-media synchronization among media. Through simulation, we prove our analysis of the fixed-length buffersize that theproposed mechanism can provide. Also we show comparisons between our mechanism and other scheme.

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An Implementation of Clock Synchronization in FPGA Based Distributed Embedded Systems Using CDR (CDR을 사용한 FPGA 기반 분산 임베디드 시스템의 클록 동기화 구현)

  • Song, Jae-Min;Jung, Yong-Bae;Park, Young-Seak
    • IEMEK Journal of Embedded Systems and Applications
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    • v.12 no.4
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    • pp.239-246
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    • 2017
  • Time synchronization between distributed embedded systems in the Real Time Locating System (RTLS) based on Time Difference of Arrival (TDOA) is one of the most important factors to consider in system design. Clock jitter error between each system causes many difficulties in maintaining such a time synchronization. In this paper, we implemented a system to synchronize clocks between FPGA based distributed embedded systems using the recovery clock of CDR (clock data recovery) used in high speed serial communication to solve the clock jitter error problem. It is experimentally confirmed that the cumulative time error that occurs when the synchronization is not performed through the synchronization logic using the CDR recovery clock can be completely eliminated.

Implementation of IEEE 1588v2 PTP for Time Synchronization Verification of Ethernet Network (이더넷 네트워크의 시간 동기화 검증을 위한 IEEE 1588v2 PTP 구현)

  • Kim, Seong-Jin;Ko, Kwang-Man
    • The KIPS Transactions:PartA
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    • v.19A no.4
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    • pp.181-186
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    • 2012
  • The distributed measurement and control system require technology to solve complex synchronization problem among distributed devices. It can be solved by using IEEE Standard for a Precision Clock Synchronization Protocol for Networked Measurement and Control Systems to synchronize real-time clocks incorporated within each component of the system. In this paper, we implemented the IEEE 1588v2 PTP emulator on BlueScope BL6000A using a delay request-response mechanism to measure clock synchronization.