Catálogo de publicaciones - libros

Grid workflows can be seen as special scientific workflows involving high performance and/or high throughput computational tasks. Much work in grid workflows has focused on improving application performance through schedulers that optimize the use of computational resources and bandwidth. As high-end computing resources are becoming more of a commodity that is available to new scientific communities, there is an increasing need to also improve the design and reusability “performance” of scientific workflow systems. To this end, we are developing a framework that supports the design and reuse of grid workflows. Individual workflow components (e.g., for data movement, database querying, job scheduling, remote execution etc.) are abstracted into a set of generic, reusable tasks. Instantiations of these common tasks can be functionally equivalent atomic components (called ) or composite components (so-called or ). In this way, a grid workflow designer does not have to commit to a particular Grid technology when developing a scientific workflow; instead different technologies (e.g. GridFTP, SRB, and ) can be used interchangeably and in concert. We illustrate the application of our framework using two real-world Grid workflows from different scientific domains, i.e., cheminformatics and bioinformatics, respectively.

The paper is concerned with supporting natural patterns of scientific collaboration in Access Grid environments. We reveal that no current approach to Access Grid allows dynamic session invocation within on-going Access Grid sessions nor workflow driven session triggering among users involved in that workflow. A model for a lightweight signaling architecture integrated within Access Grid is proposed that allows transparent demand-driven session management. The architecture is configurable both in terms of dynamically changing user preferences and resource requirements. The core of the architecture is the advanced SIP stack embedded both within Access Grid nodes and heterogenous end nodes. This is important in order to allow maximum flexibility of audio,video and workflow presentation to the end users.

Many model-based fault diagnosis approaches have been proposed so far and some of them have been put into industrial practices. But for modern complex processes, due to the variable nature of faults and model uncertainty, no single approach can diagnose all faults and meet different contradictory criteria. In this paper, the importance of integration of different fault diagnostic schemes in a common framework is emphasised. A service-oriented architecture for the integration is proposed based on Grid technologies. As an implementation, a decision support system for the gas turbine engine fault diagnosis is presented and some deployed services are discussed.

In this paper, we present a new extension and reinterpretation of one of the most successful models of awareness in Computer Supported Cooperative Work (CSCW), called the Spatial Model of Interaction (SMI), which manages awareness in Collaborative Virtual Environments (CVEs) through a set of key concepts. This work, carried out at the Universidad Politécnica de Madrid, proposes a couple of special features: the management of the data information from the user point of view and the co-ordinated sharing of computational resources in a virtual organisation. The final awareness model allows users to be aware of the data grid information in a grid computing infrastructure.

In this paper, we propose an architecture of accounting and payment services for service-oriented grid computing systems. The proposed accounting and payment services provide the mechanisms for service providers to be paid for authorized use of their resources. It supports the recording of usage data, secure storage of that data, analysis of that data for purposes of billing and so forth. It allows a variety of payment methods, it is scalable, secure, convenient, and reduce the overall cost of payment processing while taking into account requirements of Grid computing systems.

Grid technologies enable the sharing and coordinated use of diverse resources distributed all over the world. These resources are owned by different organizations having different policies and objectives which need to be considered in making the resource allocation decisions. In such complex environments market-based resource allocation protocols are a better alternative to the classical ones because they take into consideration the policies and preferences of both users and resource owners. The only suitable solution for investigating the effectiveness of these resource allocation protocols over a wide range of scenarios with reproducible results is to consider simulations. Thus in this paper we present Mercatus, a simulation toolkit that facilitates the simulation of market-based resource allocation protocols. We describe the model and the structure of Mercatus and present experimental results obtained by simulating three types of auction-based resource allocation protocols.

The Semantic Grid is an extension of the current Grid in which information will be given well-defined meaning, better enabling computers and resources to work in cooperation and coordination. The architecture of Semantic Grid adopts a service-oriented perspective in which distinct entities are represented as software agents, provide services to one another. Traditionally Grid management frameworks are based upon fixed management functionality and fixed interaction interfaces that cannot satisfy the flexibility and complexity that the dynamic Semantic Resource Grid demands. Agent technology is promising in this domain since it facilitates automatic negotiation of services contracts a dynamic configuration of those services, thus enhancing the provisioning for semantic grid services. In this paper we propose an infrastructure for resource monitoring and management in Semantic resource Grid. Our architecture unifies sharing and managing of heterogeneous resources across the Grid. The resources will be able to actively find and advertise services. The resources will be arranged into groups which will enable the resource to have common understanding. We used agents in our architecture which enable the resources to have effective negotiation, support dynamic services and services utilization and advertisement. In this way we can achieve self-controllability and self-coordinability among Grid resource. We argue that semantics is a key to autonomy of the operation and management in emerging complex dynamic systems, such as Semantic Grid. Our architecture could be a part of resource monitoring and management middleware in the Semantic Resource Grid.

Intelligent Transportation System (ITS) refers to the use of information technologies to address and alleviate transportation problems. The challenges of ITS exist mainly in synthesizing information from geographically distributed, dynamic and heterogeneous databases, specialized sensors and other systems. This synthesis process is computation and communication intensive. Computational Grid is a promising platform for such large-scale data-intensive applications. Building on grid computing technologies, this paper presents a novel infrastructure referred to as Traffic Information Grid (TIG) for ITS development and deployment. The service-oriented and layered system architecture of TIG is introduced and described. Two implementation modes-request/response mode and subscribe/notify mode are presented and evaluated with real traffic data respectively. In addition, an example application is given to illustrate how the TIG works. Based on the practice of TIG, Grid computing is proved to be an effective solution for data-intensive applications.