A simple algorithm for clock synchronization in transputer networks

In a distributed system based on Transputer components there is one clock for each processing element, and the definition of the global system time requires the choice of a hardware or software synchronization method. This paper describes the RING_SYNC algorithm, based on a ring-structured synchronization scheme. RING_SYNC has no provision for fault tolerance, but it introduces little overhead, thanks to the optimization of both the number of messages exchanged at sync time and the resynchronization frequency. The implementation of the algorithm together with the tests performed for measuring the synchronization error and their results are discussed extensively, and some typical applications are pointed out.     

A distributed synchronization mechanism for interacting processes

Reliable synchronization is intended to ensure a graceful degradation of the system in the event of a failure. Solutions to synchronization problems of this kind under constant space conditions are presented. Lamport's bakery algorithm and generalized critical region have been modified and extended for application to this problem.     

基于无线HART网络的时钟同步算法研究

无线HART是一种适用于过程自动化领域的TDMA无线通信网络,全网节点的时钟同步是通信安全、可靠、无冲突的前提。本文首先分析了无线HART通信协议以及IEEE STD 802.15.4标准,并在其基础上设计并实现适用于无线HART通信网络的时钟同步算法。     

基于多作用体的FMS调度仿真系统

该文使用多作用体（Ｍｕｌｔｉ－ａｇｅｎｔ）的概念开发了一个ＦＭＳ调度仿真系统。该系统使用合同网（ＣｏｎｔｒａｃｔＮｅｔ）算法，通过多作用体之间的相互作用，较为真实地反映了ＦＭＳ运行的实际情况，并为调度软件的实际运行提供了基础。     

面向对象方法在FMS仿真系统中的应用

该文主要以面向对象的程序设计方法为研究工具，描述了ＦＭＳ仿真系统中的基本活动和程序设计方法。     

On self-synchronization and controlled synchronization

An attempt is made to give a general formalism for synchronization in dynamical systems encompassing most of the known definitions and applications. The proposed set-up describes synchronization of interconnected systems with respect to a set of functionals and captures peculiarities of both self-synchronization and controlled synchronization. Various illustrative examples are given.     

802.16d协议OFDM接入同步误差影响研究

本文首先对802.16协议以及物理层正交频分复用(OFDM)接入方式的协议规范进行了简单介绍。然后在阐述了OFDM的原理和实现技术之后重点针对同步误差的对802.16d物理层OFDM接入方式的影响进行了研究与仿真,并得出结论。     

Multimedia group and inter-stream synchronization techniques: A comparative study

This paper presents the most comprehensive analysis and comparison of the most-known multimedia group and inter-stream synchronization approaches. Several types of multimedia synchronization are identified but only inter-stream and group synchronization algorithms are considered. This is the first survey including group synchronization techniques. A classification of the main synchronization techniques included in most of the analyzed algorithms complements the paper. Finally, a table is presented summarizing the main characteristics of each analyzed algorithm according to those techniques and other critical issues.     

An accurate on-demand time synchronization protocol for wireless sensor networks

Time synchronization is a critical component in any wireless sensor network (WSN). In terms of energy consumption, on-demand time synchronization is better than continuous synchronization. However, currently existing on-demand time synchronization protocols have a very low accuracy and very strong spatial accumulative effect. These features are not suitable for several types of WSN applications, such as applications with stringent temporal requirements, or applications that have a large spatial region of interest. In this paper, we propose an on-demand time synchronization protocol, named AOTSP (Accurate On-demand Time Synchronization Protocol), which differs from other protocols of the same category by having the following advantages, as shown in our theoretical analysis and simulation results: (1) weak spatial accumulative effect; (2) fairly low communication cost; (3) low computational complexity; (4) high accuracy; (5) high scalability. Such features make AOTSP a suitable time synchronization protocol for a broad range of WSN applications.     

Concurrent communication and synchronization mechanisms

The concepts of process and guarded command have become the basic building blocks in concurrent programming language design. In this paper we deal with many of the proposed communication and synchronization primitives and we compare them from the perspective of their implementability. Our evaluation treats four basic criteria: the length of synchronization, process termination, deadlock and protocol complexity.     

A multipurpose audio watermarking algorithm with synchronization and encryption

We propose a new multipurpose audio watermarking scheme in which two complementary watermarks are used.For audio copyright protection,the watermark data with copyright information or signature are first encrypted by Arnold transformation.Then the watermark data are inserted in the low frequency largest significant discrete cosine transform(DCT) coefficients to obtain robustness performance.For audio authentication,a chaotic signal is inserted in the high frequency insignificant DCT coefficients to detect tampered regions.Furthermore,the synchronization code is embedded in the audio statistical characteristics to resist desynchronization attacks.Experimental results show that our proposed method can not only obtain satisfactory detection and tampered location,but also achieve imperceptibility and robustness to common signal processing attacks,such as cropping,shifting,and time scale modification(TSM).Comparison results show that our method outperforms some existing methods.     

一类超混沌系统的自适应控制同步算法

本文运用理论分析与仿真实验相结合的手段,研究了一类超混沌系统的自适应控制同步问题。所研究的超混沌系统为一含负电容的四阶自治超混沌电路。运用自适应控制原理,针对所给出的超混沌系统设计了超混沌自适应控制算法。运用线性化方法及稳定性理论,将自适应控制同步问题转化为误差的稳定性问题。对控制算法中关键参数的选取进行了理论分析,在此基础上,对控制算法进行数值仿真验证,结果表明了所设计超混沌自适应控制器的有效性。     

A framework for argument-based task synchronization with automatic detection of dependencies

Synchronization in parallel applications can be achieved either implicitly or explicitly. Implicit synchronization is typical of programming environments that provide predefined, and often simple, patterns of parallelism such as data-parallel libraries and languages and skeletal operations. Nevertheless, more flexible approaches that allow to express arbitrary task-level parallel computations without a predefined structure request in turn that the user explicitly specifies the synchronization needed among the parallel tasks.     

802．16d协议OFDM接入同步误差影响研究

本文首先对802.16协议以及物理层正交频分复用（OFDM）接入方式的协议规范进行了简单介绍.然后在阐述了OFDM的原理和实现技术之后重点针对同步误差的对802.16 d物理层OFDM接入方式的影响进行了研究与仿真,并得出结论.     

Reliable synchronization in distributed systems

In distributed computer systems, processors often need to be synchronized to maintain correctness and consistency. Unlike shared-memory parallel systems, the lack of shared memory and a clock considerably complicates the task of synchronization in distributed systems. The objective of this article is two-fold: (1) We present a new randomized agreement algorithm to synchronize cooperating processors in a distributed system. This algorithm achieves the desired agreement in expected five rounds of message exchanges, tolerating a maximum of one-fifth of the processors failures. The algorithm belongs to the class of broadcast-based synchronization problems. (2) We present a new self-stabilization algorithm for an acyclic directed-graph structured distributed systems. This new fault-tolerant algorithm survives all imaginable faults in distributed systems. The algorithm belongs to arbiter-based and broadcast-based synchronization problems.     

OFDM系统同步算法研究

正交频分复用(OFDM)技术是一种高效的调制技术,其基本思想是把串行高速的数据流分散到正交的子载波上进行并行传输,而同步问题是OFDM技术的一个关键问题。给出OFDM系统的模型,对同步问题进行了具体分析,给出载波频率同步的算法的描述,并对基于CP的同步算法进行仿真,结果表明其具有较好的频率捕获能力和较小的误差。     

New conditions for synchronization in dynamical communication networks

This paper investigates synchronization in a typical multi-agent system in which the communication network changes according to the system state. Through building new relationships between a matrix and its associated graph and estimating the diameter of the communication network, we prove that synchronization can be achieved if the speed of agents is bounded by O(n^−β), where n is the number of agents and β is bounded by a constant independent of n, which is much better than the existing bound O(n⁻ⁿ). Some simulations are provided to illustrate the theoretical results.     

Solving synchronization problems using semaphores

A brief account of certain extensions to the basic definition of semaphores is given. An implementation of semaphores as controllers of buffer queues is described and it is shown how this was used to solve an actual synchronization problem.