Papers by Keyword: Distributed System

Abstract: Distributed system has the characteristic of high concurrency, which often leads to deadlock due to the execution of concurrent process. By applying Petri nets model can effectively solve this problem. In this paper, based on Petri nets model, we propose a new efficient deadlock avoidance policy for distributed system by using the Petri reachability graph. At last we analysis the different performance between this algorithm and the traditional method by using Matlab tool.

Abstract: The paper presents possibility of usage the formalism of structural reliability notation with an implementation of directed graphs and reliability functions recorded in accordance with the Perfect Disjunctive Normal Form notation (PDNF). The author presents the mathematical basis used for an identification of internal structures of mechatronic machines and reduction it to the series-connected blocks. The presented method is a hybrid combination of a binary analysis of evaluated reliability functions (stored in the form of matrixes that relate to defined graphs) and blocks with binary inputs and outputs.

Abstract: The article describes an approach dedicated to a hybrid representation of mechatronic systems combining matrix and block notations. The main attention is focused on the identification of relationships between mechatronic machines in respect of functional reliability (analysed in the form of block and digraph notations) and rules that allow for the simplification of the reliability function in the systems of machines connected in parallel, series and complex arrangement. The author has adopted a functional representation based on system demonstration employing a binary function of reliability in which the equation is determined based on the method for setting minimum paths in the graph (structural representation of each subsystem). The introduced assumption allows reducing any structure to a serial connection of functional blocks. The author of the paper has also described a manner of implementation in real systems. This article does not include the description of the method used for determining the reliability function, but only theoretical assumptions used in case of identifying functional dependencies.

Abstract: According to different node data access objects, and based on the idea of behavior-driven development, an interface-oriented node data access tool is designed and implemented. The tool mainly implements an executable node data access tool that is based on MFC, and writes a set of Win32 console application, which improves the node data automation access scripts and encapsulates the module interfaces, thus improving the distributed network data access speed.

Abstract: This article on inter-process communication mechanism has conducted in-depth research and analysis of traditional UNIX system under the environment of the inter process communication mechanism and existing mechanisms for process communication in distributed environment. And on that basis propose new interprocess communication mechanism in distributed environment. Given interprocess communication semaphores and Message Queuing design ideas and implementation details, and compare it with the traditional way, we concluded that in the case of performance does not deteriorate, provides better user interfaces and location transparency and access higher transparency.

Abstract: This paper introduces the service-oriented architecture technology, and proposes the architecture model of Out-trajectory Data Processing in distributed environment. According to the demand and features of Ship-borne Out-trajectory Data Processing flow, it describes how to carry out cross-platform service integration by using the Service Bus Middleware, and provides a kind of typical distributed deployment strategy.

Abstract: This paper presents a differential evolution algorithm with designed greedy heuristic strategy to solve the task scheduling problem. The static task scheduling problem is NP-complete and is a critic issue in parallel and distributed computing environment. A vector consists of a task permutation assigned to each individual in the target population by using DE mutation and crossover operators. A heuristic strategy is used to generate the feasible solutions as there a lot of infeasible solutions in the solution space as the size of the problem increase. And the strategies of the particle swarm algorithm are employed to modify the DE crossover operator for speeding up the search to optimal solution. And then, the individual is replaced with the corresponding target individual if it is global best or local best in terms of fitness. The performance of the algorithm is illustrated by comparing with the existing effectively scheduling algorithms. The performances of the proposed algorithms are tested on the benchmark and compared to the best-known solutions available. The computational results demonstrate that effectively and efficiency of the presented algorithm.

Abstract: For software function verification and performance testing, a test platform was built during the development of large-capacity EPON OLT equipment. The platform was based on distributed system,which using modified TCP/UDP to establish RPC data exchange path between nodes. With Linux as unified operating system, software work in both embedded PowerPC and x86-based PC virtual machines without modification. At last, a group of stress test was executed on the platform and the result was discussed.

Abstract: This paper presents an implemented solution for controlling the access of the users to restricted areas and resources (including machines and robots), based on fingerprint recognition. The proposed distributed system is composed of a number of fingerprint scanning mobile terminals connected to a server net (one or more server instances used for identity confirmation). The proposed server architectures itself was designed to be loosely coupled in order to be able to achieve a highly scalable system.

Abstract: Web search engine based on DNS, the standard proposed solution of IETF for public web search system, is introduced in this paper. Now no web search engine can cover more than 60 percent of all the pages on Internet. The update interval of most pages database is almost one month. This condition hasn't changed for many years. Converge and recency problems have become the bottleneck problem of current web search engine. To solve these problems, a new system, search engine based on DNS is proposed in this paper. This system adopts the hierarchical distributed architecture like DNS, which is different from any current commercial search engine. In theory, this system can cover all the web pages on Internet. Its update interval could even be one day. The original idea, detailed content and implementation of this system all are introduced in this paper.