• Title/Summary/Keyword: synchronization mechanism

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Construction of a Bidding System Using SyncML Data Synchronization Mechanism (SyncML 자료 동기화 방법을 이용한 이동무선통신 환경에서의 경매 시스템 구축)

  • Park, Kee-Hyun;Yoo, Sang-Jin
    • Information Systems Review
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    • v.6 no.1
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    • pp.155-166
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    • 2004
  • As the necessity of such mobile wireless terminals as PDAs or Cellular phones drastically increases, the terminals play important role in various business areas. In this paper, a bidding system in mobile wireless environments is constructed. However, with many mobile wireless terminals modifying at the same time their (duplicated) bidding values for a given data item, data coherency for the data item becomes essential. Therefore, in this paper, a bidding system using SyncML data synchronization mechanism is proposed and constructed. SyncML is one of data synchronization mechanisms proposed by the SyncML Initiative, a consortium of mobile wireless mobile technology leaders for universal data synchronization. The bidding system is implemented and tested in LINUX, C++, and PocketPC 2000 emulator programming environments.

Data-Synchronization Gateway based on SyncML for an ActiveSync Data Transformation (ActiveSync 자료 변환을 위한 SyncML 자료동기화 게이트웨이)

  • Jang Dae-Jin;Park Kee-Hyun;Ju Hong-Taek;Woo Jong-Jung
    • Journal of Internet Computing and Services
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    • v.7 no.3
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    • pp.61-69
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    • 2006
  • Data synchronization between data stored in mobile communication terminals and a central server is one of essential tasks for efficient mobile communication environments. Since, however, manufacturers of mobile terminals have their proprietary data synchronization mechanisms, data interoperability can hardly be achieved. Therefore, SyncML data synchronization mechanism in mobile communication environments was proposed as an open standard by OMA(Open Mobile Alliance). In this paper, a SyncML-based data synchronization gateway is designed and implemented which can process ActiveSync data also. In other words, by constructing a combined data synchronization gateway which can transform ActiveSync data into SyncML data, data interoperability between mobile terminals which use two different data synchronization mechanisms can be achieved, In addition, mobile communication experiments between ActiveSync-based terminals and a SyncML-based central server show that the data synchronization gateway constructed in this paper, works correctly.

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Research on Event Mechanism for Reducing Power Overheads in Cache Memory Synchronization (캐시 메모리 동기화 전력 감소를 위한 이벤트 메커니즘에 대한 연구)

  • Pak, Young-Jin;Jeong, Ha-Young;Lee, Yong-Surk
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.48 no.3
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    • pp.69-75
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    • 2011
  • In this paper, we propose an anycast event driven synchronization mechanism to reduce power overheads. Our proposed mechanism can reduce unnecessary polling operations on SHI(Snoop Hit Invalidate) or SHR(Snoop Hit Read) states. It prevents waisting bandwidth and reduces power overheads on polling operation. Also it decreases transition power of state change compared to broadcast model. Simulation results indicated that the proposed architecture had about 15.3% of power decrease compared to spin-lock model and about 4.7% of power decrease compared to broadcast model. Overall results indicated that proposed synchronization mechanism could increase power efficiency of multi-core system by reducing power overheads.

A Study on Ticket-Based AAA Mechanism Including Time Synchronization OTP in Global Roaming Environment (글로벌 로밍 환경에서 시간 동기화 OTP를 포함한 티켓 기반 AAA 메커니즘에 관한 연구)

  • Moon, Jong-Sik;Lee, Im-Yeong
    • The KIPS Transactions:PartC
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    • v.14C no.2
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    • pp.129-138
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    • 2007
  • AAA(Aluthentieation, Authorization, Accounting) protocol is an information securitv technology that offer secure and reliable user Authentication, Authorization, Accounting function systematically in various services. protocol and wireless network work as well as win network. Currently IETF(Internet Engineering Task Force) AAA Working Group deal with about AAA protocol and studying with activity, But, recently it exposing much problems side to user's anonymity and privacv violation. Therefore, in this paper, AAAH(Home Authentication Server) authenticaters Mobile device, after that, use ticket that is issued from AAAH even if move to outside network and can be serviced offering authentication in outside network without approaching by AAAH, Also, we study mechanism that can offer user's privacy and anonymousness to when use service. Our mechanism is using Time Synchronization OTP and focusing authentication and authorization. Therefore, our mechanism is secure from third party attack and offer secure and effective authentication scheme. Also only right user can offer services by using ticket. can reduce signal and reduce delay of message exchanged, can offer persistent service and beighten security and efficiency.

The Design of Intramedia Synchronization based QoS (QoS 기반의 미디어내 동기화 설계)

  • Park, Hong-Jin;Lee, Jun-Yeon;Kim, Chang-Min
    • The Transactions of the Korea Information Processing Society
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    • v.6 no.8
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    • pp.2042-2049
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    • 1999
  • In contrast to traditional data communication, the multimedia communication must support variable requirements to multimedia application service. Specially, it is a critical issue that the synchronization supports a continuous and temporal relationship media playout in a distributed environment. But the continuously generated media in source can't guarantee the constant interval on playout for the destination due to the inconsistent network transmission delay and transmission error. In this paper, we introduce a intramedia synchronization mechanism for the continuous and synchronous playout of multimedia stream such as audio and video across a communication network. The proposed mechanism is based on the user defined QoS(Quality of Service) and the playout correction algorithm to guarantee the continuous media playout at the receiver.

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Synchronization of Network Interfaces in System Area Networks (시스템 에어리어 네트?에서의 동기화 기법)

  • Song, Hyo-Jung
    • Journal of KIISE:Computer Systems and Theory
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    • v.32 no.5
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    • pp.219-231
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    • 2005
  • Many applications in cluster computing require QoS (Quality of Service) services. Since performance predictability is essential to provide QoS service, underlying systems must provide predictable performance guarantees. One way to ensure such guarantees from network subsystems is to generate global schedules from applications'network requests and to execute the local portion of the schedules at each network interface. To ensure accurate execution of the schedules, it is essential that a global time base must be maintained by local clocks at each network interface. The task of providing a single time base is called a synchronization problem and this paper addresses the problem for system area networks. To solve the synchronization problem, FM-QoS (1) proposed a simple synchronization mechanism called FBS(Feedback-Based Synchronization) which uses built-in How control signals. This paper extends the basic notion of FM-QoS to a theoretical framework and generalizes it: 1) to identify a set of built-in network flow control signals for synchrony and to formalize it as a synchronizing schedule, and 2) to analyze the synchronization precision of FBS in terms of flow control parameters. Based on generalization, two application classes are studied for a single switch network and a multiple switch network. For each class, a synchroniring schedule is proposed and its bounded skew is analyzed. Unlike FM-QoS, the synchronizing schedule is proven to minimize the bounded skew value for a single switch network. To understand the analysis results in practical networks, skew values are obtained with flow control parameters of Myrinet-1280/SAN. We observed that the maximum bounded skew of FBS is 9.2 Usec or less over all our experiments. Based on this result, we came to a conclusion that FBS was a feasible synchronization mechanism in system area networks.

Study on Synchronization Characteristics of a Variable Nozzle in Environment of Simulated Combustion Pressure (연소압 모사 환경 상태의 가변노즐 동기화 특성 연구)

  • Park, Dong-Chang;Lee, Sang-Youn;Lee, Ju-Young;Cho, Sung-Won;Yun, Su-Jin;Yoon, Hyun-Gull;Lim, Jin-Shik
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2011.11a
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    • pp.919-921
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    • 2011
  • Variable nozzles are used to enhance the effectiveness of aircraft engines at various altitudes. Unsynchronized movements of variable nozzle flaps affect the direction of thrust in case the variable nozzle consists of many flaps. A synchronization test system was developed to verify the synchronization characteristics of variable nozzle mechanism including flaps. The test system has a capability to simulate combustion pressure in variable nozzle space. The test system was used to qualify the synchronization characteristics of a variable nozzle flaps affected by magnitude and uniformity of simulated combustion pressure, and time delay of each nozzle actuators.

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Intermedia Synchronization Protocol for Continuous Media Using MPEG-4 in Mobile Distributed Systems

  • Dominguez, Eduardo Lopez;Hernandez, Saul Eduardo Pomares;Gil, Pilar Gomez;Calleja, Jorge De La;Benitez, Antonio;Marin-Hernandez, Antonio
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.6 no.6
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    • pp.1689-1706
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    • 2012
  • The preservation of temporal dependencies among a group of processes that exchange continuous media at runtime is a key issue for emerging mobile distributed systems (MDS), such as monitoring of biosignals and interactive multiuser games. Although several works are oriented to satisfy temporal dependencies, most of them are not suitable for MDSs. In general, an MDS is characterized by the absence of global references (e.g. shared memory and wall clock), host mobility, limited processing and storage capabilities in mobile hosts, and limited bandwidth on wireless communication channels. This paper proposes an asymmetric synchronization protocol to be used at runtime in an MDS without using a common reference. One main aspect of our synchronization protocol is that it translates temporal constraints to causal dependencies of the continuous media data as seen by the mobile hosts. We simulate the protocol by considering a cellular network environment and by using MPEG-4 encoders. The simulation results show that our protocol is effective in reducing the synchronization error. In addition, the protocol is efficient in terms of processing and storage costs at the mobile devices, as well as in the overhead attached per message across the wired and wireless channels.

An Efficient Selective Method for Audio Watermarking Against De-synchronization Attacks

  • Mushgil, Baydaa Mohammad;Adnan, Wan Azizun Wan;Al-hadad, Syed Abdul-Rahman;Ahmad, Sharifah Mumtazah Syed
    • Journal of Electrical Engineering and Technology
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    • v.13 no.1
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    • pp.476-484
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    • 2018
  • The high capacity audio watermarking algorithms are facing a main challenge in satisfying the robustness against attacks especially on de-synchronization attacks. In this paper, a robust and a high capacity algorithm is proposed using segment selection, Stationary Wavelet Transform (SWT) and the Quantization Index Modulation (QIM) techniques along with new synchronization mechanism. The proposed algorithm provides enhanced trade-off between robustness, imperceptibility, and capacity. The achieved watermarking improves the reliability of the available watermarking methods and shows high robustness towards signal processing (manipulating) attacks especially the de-synchronization attacks such as cropping, jittering, and zero inserting attacks. For imperceptibility evaluation, high signal to noise ratio values of above 22 dB has been achieved. Also subjective test with volunteer listeners shows that the proposed method has high imperceptibility with Subjective Difference Grade (SDG) of 4.76. Meanwhile, high rational capacity up to 176.4 bps is also achieved.

A Mechanism of Clock Synchronization for Wireless Networked Control System (무선 네트워크 제어 시스템을 위한 클럭 동기화 메커니즘)

  • Do, Trong-Hop;Quan, Wenji;Yoo, Myungsik
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38B no.7
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    • pp.564-571
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    • 2013
  • Wireless network has been used in many applications due to its advantages such as convenience, mobility, productivity, easy deployment, easy expandability and low cost. When it comes to stability, wireless network still shows its limitation which makes it difficult to be used for real-time control system. One of the first problems of using wireless network for control system is clock synchronization. There have been synchronization schemes proposed for wired networked control system as well as wireless network. But these should not be applied directly in wireless network control system. In this paper, we point out the importance of clock synchronization in wireless network control system. Then based on the characteristic of wireless networked control system, we propose a clock synchronization scheme for it. Furthermore, we simulate our scheme and compare with previous synchronization scheme in wired and wireless environments.