适合遥感影像处理的网格计算环境研究

网格计算是近几年来发展迅速的一种网络资源共享模型,其目的是网络资源的完全共享。网格计算相对于传统的C／S及Web GIS来说,它在网络计算、数据处理、资源共享、任务协同等方面都有了进一步的发展。在适感影像处理与理解应用方面,由于涉及大量的网络计算及网络传输等耗时操作,应用网格计算思想进行适感图像处理就更有实际意义。结合网格计算的网络计算及资源共享的优势,设计并开发适合适感影像处理的网格计算环境及软件,是解决当前适感影像海量数据处理的有效途径之一,同时也是适感图像处理软件的一个发展趋势之一。本文结合实际研究成果,首先给出了基于网格计算思想的适感影像处理的设计流程,并对其具体实现技术进一步进行了讨论。在分析其在图像处理方面应用的基础上,对面向网络的智能化适感图像网格处理系统进行了分析与设计,并给出了其实现的一些关键技术。     

遥感网格的数据压缩与任务分配方法研究

网格计算作为分布式计算在科学计算领域的发展方向,可以为对地观测数据的处理提供强大的计算力。在分析遥感信息服务网格节点(Remote Sensing Information Service Grid Nodes,RSSN)中网络数据传输和负载均衡两个关键问题的基础上,提出了一种有效的基于游程编码和Huffman编码的数据压缩方法和基于"计算端元"的任务分配策略,该方法针对遥感影像特点进行有效数据压缩,具有较好的压缩比,达到了17%,且能实现任务负载均衡。并在遥感信息服务网格节点计算平台上,以中国范围内1km分辨率气溶胶光学厚度(Aerosol Optical Depth,AOD)反演计算为例,从压缩率和计算时间效率方面验证和分析了上述方法的有效性。     

网格GIS体系结构研究及应用

网格GIS(地理信息系统)是GIS在网格技术支持下,用以构建空间信息服务体系的技术系统。在分析传统GIS技术和网格技术的基础上,提出了一种在网格平台下,借助于OGSA-DAI构建的跨区域的、异构的GIS模型,并初步实现了在GLOBUS平台上的一个GIS应用。实验表明该系统能够有效地集成异地GIS资源,提高了传统GIS运算速度。     

Distributed computing model for processing remotely sensed images based on grid computing

With advances in remote-sensing technology, the large volumes of data cannot be analyzed efficiently and rapidly, especially with arrival of high-resolution images. The development of image-processing technology is an urgent and complex problem for computer and geo-science experts. It involves, not only knowledge of remote sensing, but also of computing and networking. Remotely sensed images need to be processed rapidly and effectively in a distributed and parallel processing environment. Grid computing is a new form of distributed computing, providing an advanced computing and sharing model to solve large and computationally intensive problems. According to the basic principle of grid computing, we construct a distributed processing system for processing remotely sensed images. This paper focuses on the implementation of such a distributed computing and processing model based on the theory of grid computing. Firstly, problems in the field of remotely sensed image processing are analyzed. Then, the distributed (and parallel) computing model design, based on grid computing, is applied. Finally, implementation methods with middleware technology are discussed in detail. From a test analysis of our system, TARIES.NET, the whole image-processing system is evaluated, and the results show the feasibility of the model design and the efficiency of the remotely sensed image distributed and parallel processing system.     

The application hosting environment: Lightweight middleware for grid-based computational science

Grid computing is distributed computing performed transparently across multiple administrative domains. Grid middleware, which is meant to enable access to grid resources, is currently widely seen as being too heavyweight and, in consequence, unwieldy for general scientific use. Its heavyweight nature, especially on the client-side, has severely restricted the uptake of grid technology by computational scientists. In this paper, we describe the Application Hosting Environment (AHE) which we have developed to address some of these problems. The AHE is a lightweight, easily deployable environment designed to allow the scientist to quickly and easily run legacy applications on distributed grid resources. It provides a higher level abstraction of a grid than is offered by existing grid middleware schemes such as the Globus Toolkit. As a result, the computational scientist does not need to know the details of any particular underlying grid middleware and is isolated from any changes to it on the distributed resources. The functionality provided by the AHE is ‘application-centric’: applications are exposed as web services with a well-defined standards-compliant interface. This allows the computational scientist to start and manage application instances on a grid in a transparent manner, thus greatly simplifying the user experience. We describe how a range of computational science codes have been hosted within the AHE and how the design of the AHE allows us to implement complex workflows for deployment on grid infrastructure.     

网格计算经济中的信誉度体系结构

针对网格资源管理中计算经济模型的资源信誉度、资源提供者信誉度和服务消费者信誉 度,提出并实现了信誉度评价体系结构以及信誉度评价中的一些处理策略。详细讨论了信誉度评价 的模块组成和实现模型,对信誉度评价所需的资源使用记录进行了定义,由此对RUR(ResourceUsage Record)基本组成的扩展进行了研究。最后通过仿真实验对信誉度评估体系完成了验证,证明体系结 构的设计和实现是有效的。     

Customizable execution environments for evolutionary computation using BOINC + virtualization

Evolutionary algorithms (EAs) consume large amounts of computational resources, particularly when they are used to solve real-world problems that require complex fitness evaluations. Beside the lack of resources, scientists face another problem: the absence of the required expertise to adapt applications for parallel and distributed computing models. Moreover, the computing power of PCs is frequently underused at institutions, as desktops are usually devoted to administrative tasks. Therefore, the proposal in this work consists of providing a framework that allows researchers to massively deploy EA experiments by exploiting the computing power of their instituions’ PCs by setting up a Desktop Grid System based on the BOINC middleware. This paper presents a new model for running unmodified applications within BOINC with a web-based centralized management system for available resources. Thanks to this proposal, researchers can run scientific applications without modifying the application’s source code, and at the same time manage thousands of computers from a single web page. Summarizing, this model allows the creation of on-demand customized execution environments within BOINC that can be used to harness unused computational resources for complex computational experiments, such as EAs. To show the performance of this model, a real-world application of Genetic Programming was used and tested through a centrally-managed desktop grid infrastructure. Results show the feasibility of the approach that has allowed researchers to generate new solutions by means of an easy to use and manage distributed system.     

一种基于内存服务的内存共享网格系统

内存密集型应用对运行环境的物理内存要求严格,在物理内存不足时将会引发大量磁盘IO,降低系统性能．传统的网络内存致力于在集群内部通过共享空闲节点的物理内存解决该问题,但受集群负载和内部网络影响较大．通过结合网络内存和服务计算、网格计算等技术,提出一种基于内存服务的内存共享网格系统——内存网格,并分析和讨论了实现内存服务的关键技术和算法．内存网格弥补了网络内存的不足,扩展了网格计算的应用范围．通过基于真实应用运行状态的模拟,证明了内存网格与网络内存相比具有性能的提高．     

基于网格计算的QoS模型的研究

随着网格技术和应用的不断深入，对网格提出了严格的服务质量（quality of service，简称QoS）要求，网格计算中的QoS成为研究应用的焦点．缺乏QoS保证逐渐成为制约网格应用的瓶颈之一。论文对网格计算的质量服务进行了研究，描述了网格QoS定义，网格QoS需求和网格QoS的层次模型。同时也介绍了当前研究思路度以后的发展趋势。     

Enhancing Availability of Grid Computational Services to Ubiquitous Computing Applications

The Grid is an integrated infrastructure that can play the dual roles of a coordinated resource consumer as well as a donator in distributed computing environments. The enormous growth in the use of mobile and embedded devices in ubiquitous computing environment and their interaction with human beings produces a huge amount of data that need to be processed efficiently anytime anywhere. However, such devices often have limited resources in terms of CPU, storage, battery power, and communication bandwidth. Thus, there is a need to transfer ubiquitous computing application services to more powerful computational resources. In this paper, we investigate the use of the Grid as a candidate for provisioning computational services to applications in ubiquitous computing environments. In particular, we present a competitive model that describes the possible interaction between the competing resources in the Grid Infrastructure as service providers and ubiquitous applications as subscribers. The competition takes place in terms of quality of service (QoS) and cost offered by different Grid Service Providers (GSPs). We also investigate the job allocation of different GSPs by exploiting the noncooperativeness among the strategies. We present the equilibrium behavior of our model facing global competition under stochastic demand and estimate guaranteed QoS assurance level by efficiently satisfying the requirement of ubiquitous application. We have also performed extensive experiments over Distributed Parallel Computing Cluster (DPCC) and studied overall job execution performance of different GSPs under a wide range of QoS parameters using different strategies. Our model and performance evaluation results can serve as a valuable reference for designing appropriate strategies in a practical grid environment.     

基于GMA的分布式目录服务的设计与实现

网格监测已经成为网格正常运行的基础设施,目录服务对网格监测系统中的大量信息进行组织和管理。本文设计了一种基于网格监测体系结构GMA(Grid Monitoring Architecture)的分布式目录服务,内容包括体系结构、局部模块组成、存储的信息内容、数据传输格式和信息查询方式等。     

A Taxonomy of Workflow Management Systems for Grid Computing

With the advent of Grid and application technologies, scientists and engineers are building more and more complex applications to manage and process large data sets, and execute scientific experiments on distributed resources. Such application scenarios require means for composing and executing complex workflows. Therefore, many efforts have been made towards the development of workflow management systems for Grid computing. In this paper, we propose a taxonomy that characterizes and classifies various approaches for building and executing workflows on Grids. We also survey several representative Grid workflow systems developed by various projects world-wide to demonstrate the comprehensiveness of the taxonomy. The taxonomy not only highlights the design and engineering similarities and differences of state-of-the-art in Grid workflow systems, but also identifies the areas that need further research.     

Data discovery algorithm for scientific data grid environment

In modern scientific computing communities, scientists are involved in managing massive amounts of very large data collections in a geographically distributed environment. Research in the area of grid computing has given us various ideas and solutions to address these requirements. Data grid mostly deals with large computational problems and provides geographically distributed resources for large-scale data-intensive applications that generate large data sets. Peer-to-peer (P2P) networks have also become a major research topic over the last few years. In a distributed P2P system, a discovery algorithm is required to locate specific information, applications, or users within the system. In this research work, we present our scientific data grid as a large P2P-based distributed system model. By using this model, we study various discovery algorithms for locating data sets in a data grid system. The algorithms we studied are based on the P2P architecture. We investigate these algorithms using our Grid Simulator developed using PARSEC. In this paper, we illustrate our scientific data grid model and our Grid Simulator. We then analyze the performance of the discovery algorithms relative to their average number of hop, success rates and bandwidth consumption.     

论Web服务与网格

网格是网络与异构环境中基于Web服务的分布式网络计算系统。从计算机网络体系结构的观点来探讨网格与计算机网络和Web服务的关系,通过对基于Web服务的网格服务体系结构和OSI/RM框架的对比分析,提出了将实现开放式网格服务结构（OGSA）的计算机系统划分为OSI/RM域内的部分和对OSI/RM不可见部分,从而理清了网格服务体系结构的层次结构与计算机网络层次结构的异同。     

e-Robot网格-仿人机器人研究与应用基础设施

目前仿人机器人的研究与应用碰到了诸如:大计算量、海量存储的需求、实验设备投入大、科研人员的协作和成果融合困难等问题。而网格具有超级计算能力、海量的存储容量、能做到网格中所有软件资源、硬件资源、人力资源的协同工作和全面共享。若能基于网格技术构建一个仿人机器人研究与应用的平台,就能解决仿人机器人研究和应用中的众多障碍。这里提出的e-Robot网格就是这样一个仿人机器人研究与应用的基础设施,它采用OGSA体系结构的基础网格,并在其基础上构建庞大的仿人机器人研究与应用服务软件集合。e-Robot网格将给仿人机器人领域的研究、应用带来变革性的进步。     

Economics‐inspired decentralized control approach for adaptive grid services and applications

Grid technologies facilitate innovative applications among dynamic virtual organizations, while the ability to deploy, manage, and properly remain functioning via traditional approaches has been exceeded by the complexity of the next generation of grid systems. An important method for addressing this challenge may require nature‐inspired computing paradigms. This technique will entail construction of a bottom‐up multiagent system; however, the appropriate implementation mechanism is under consideration in order for the autonomous and distributed agents to emerge as a controlled grid service or application. A credit card management service in economic interactions is considered in this article for a decentralized control approach. This consideration is based on a preliminarily developed ecological network‐based grid middleware that has features desired for the next generation grid systems. The control scheme, design, and implementation of the credit card management service are presented in detail. The simulation results show that (1) agents are accountable for their activities such as behavior invocation, service provision, and resource utilization and (2) generated services or applications adapt well to dynamically changing environments such as agent amounts as well as partial failure of agents. The approach presented herein is beneficial for building autonomous and adaptive grid applications and services. © 2006 Wiley Periodicals, Inc. Int J Int Syst 21: 1269–1288, 2006.     

网格服务可管理性模型及策略研究

随着网格技术和应用的不断发展,一些关键领域或业务应用场景要求网格系统提供更好的服务质量(QoS),而具有较高可管理性的服务管理策略可以在提供较高服务质量的同时减小系统的开销.文中提出了网格服务的干扰和可管理性的形式化描述及量化计算方法,并建立了描述干扰发生过程的网格系统随机Petri网(SPN)模型.之后文章对服务管理策略进行了分类研究,并根据SPN模型的仿真计算结果,对各类策略对网格服务的干扰情况的影响以及对网格服务可管理性的量化评价结果进行了比较和分析,为具有高可管理性的策略的设计提供依据.     

基于Web服务的网格体系结构及其支撑环境研究

网格技术是当前网络计算的前沿领域,基于Web服务技术构建网格系统有助于提高网格系统的可扩展性和互操作能力,是这一领域中的最新热点.但现有的工作尚未明确界定基于Web服务的网格的功能模型和实现机制.首先讨论了网格功能模型,基于OGSA(open grid service architecture)框架提出了基于Web服务的网格层次体系结构,并将Web服务工作流引入到网格任务描述中,给出一种Web服务与网格技术相融合的机制,介绍了基于Web服务的网格支撑环境WebSASE4G的总体结构和设计原理,为基于Web     

Reliability of grid service systems

Grid computing system is different from conventional distributed computing systems by its focus on large-scale resource sharing, where remote accessing and information communication have great influence on grid computing. As an important metric for services, the grid service reliability is studied in this paper. There are some earlier studies on the reliability analysis of conventional small-scale distributed systems, which ignored the communication time and processing time when studying the reliability, but it is not practical in the reliability analysis of grid services due to the wide-area property of the network. Thus, this paper presents a model for the grid services and develops an approach to analyze the grid service reliability. Detailed algorithms to compute the grid service reliability are presented and a self-sensing technology is proposed for parameterization and monitoring. A numerical example is used for the purpose of illustration. Finally, the new model is compared with different types of conventional models, through which this model is verified more suitable for grid service reliability.     

网格计算技术及应用综述

Grid computing is a new kind of distributed computing technology and computing environment ,and also an attentive hot point of information technology in the world. It launches a space for new generation internal application,due to its supporting the complicated service efficiently and useable resource in the Internet. This paper sums up the results and applications instance in the grid computing in the world during recent years ,and then analyzes emphatically the system architecture ,components ,working principle in the grid computing and some typical grid systems ,and then discusses the problems of the large scale science computing and network service in grid computing in China,and alsopoints out the future trends.