E-Portfolio to Promote Virtual Learning Group Communities on the Grid

In Vocational and Educational Training (VET), new trends are toward social learning and, more precisely, toward informal learning. In such settings, this article introduces a process — the e-Qualification — to manage informal learning on the ELeGI “Learning Grid Infrastructure.” It argues that this process must occur in a social context, such as virtual communities. On the one hand, it describes their necessary characteristics and proprieties that lead to the creation of a new kind of virtual community: the Virtual Learning Grid Community (VLGC). On the other hand, e-Qualification cannot occur without the help of a kind of user’s profile, called e-portfolio. Moreover, the e-portfolio is also a process, used to manage the Virtual Learning Grid Communities. The e-Qualification and Virtual Learning Grid Communities’ management will probably rely on the cooperation of different distributed, autonomous, goal-oriented entities, called Mobile Peer-to-Peer (P2P) Agents. Furthermore, we hope that implementing these services will decrease the lack of informal learning treatment on the grid and will become the basis for new services on the Learning Grid.

Distributed Scheduling Protocols for Energy Efficient Large-Scale Wireless Sensor Networks

A major design challenge in wireless sensor network application development is to provide appropriate middleware service protocols to control the energy consumption according to specific application scenarios. In common application scenarios such as in monitoring or surveillance systems, it is usually necessary to extend the system monitoring area as large as possible to cover the maximal area. The two issues of power conservation and maximizing the coverage area have to be considered together with both the sensors’ communication connectivity and their power management strategy. In this chapter,the authors proposed novel enhanced sensor scheduling protocols to address the application scenario of typical surveillance systems. Their protocols take into consideration of both power conservation and coverage ratio to search for the balance between the different requirements. They proposed both centralized and de-centralized sensor scheduling versions, and compared the performance of different algorithms using several metrics. The results provide evidence of the advantages of our proposed protocols comparing with existing sensor scheduling protocols.

Achieving QoS in Highly Unreliable Grid Environments

Grids can form the basis for pervasive computing due to their ability of being open, scalable, and flexible to various changes (from topology changes to unpredicted failures of nodes). However, such environments are prone to failures due to their nature and need a certain level of reliability in order to provide viable and commercially exploitable solutions. This is causing nowadays a significant research activity which is focused on the topic of achieving certain levels of Quality of Service (QoS) in highly unreliable environments (such as mobile and ad hoc Grids). This study will focus on the state-of-the-art analysis of the QoS aspects in Grids and how this is achieved in terms of technological means. A small survey and related work will be also presented. A more detailed analysis on the features of unreliable environments such as mobile Grids will be described. An innovative and efficient mechanism will be described, which is especially designed for such environments, in order to enhance them with the QoS attributes of reliability (fault tolerance through replication of tasks) and service differentiation to the Grid users through a simple task prioritization scheme. The results that this recent research work is presenting are promising for the future advancement of Grid commercialization in such environments.

Grid Workflows with Encompassed Business Relationship

This chapter focuses on presenting and describing an approach that allows the mapping of workflow processes to Grid provided services by not only taking into account the quality of service (QoS) parameters of the Grid services but also the potential business relationships of the service providers that may affect the aforementioned QoS parameters. This approach is an integral part of the QoS provisioning, since this is the only way to estimate, calculate, and conclude to the mapping of workflows and the selection of the available service types and instances in order to deliver an overall quality of service across a federation of providers. The added value of this approach lays on the fact that business relationships of the service providers are also taken into account during the mapping process.

Providing Quantitative Scalability Improvement of Consistency Control for Large-Scale, Replication-Based Grid Systems

Consistency control is important in replication-based-Grid systems because it provides QoS guarantee. However, conventional consistency control mechanisms incur high communication overhead and are ill suited for large-scale dynamic Grid systems. In this chapter, the authors propose CVRetrieval (Consistency View Retrieval) to provide quantitative scalability improvement of consistency control for large-scale, replication-based Grid systems. Based on the observation that not all participants are equally active or engaged in distributed online collaboration, CVRetrieval differentiates the notions of consistency maintenance and consistency retrieval. Here, consistency maintenance implies a protocol that periodically communicates with all participants to maintain a certain consistency level; and consistency retrieval means that passive participants explicitly request consistent views from the system when the need arises in stead of joining the expensive consistency maintenance protocol all the time. The rationale is that it is much more cost-effective to satisfy a passive participant’s need on-demand. The evaluation of CVRetrieval is done in two parts. First, by analyzing its scalability and the result shows that CVRetrieval can greatly reduce communication cost and hence make consistency control more scalable. Second, a prototype of CVRetrieval is deployed on the Planet-Lab test-bed and the results show that the active participants experience a short response time at expense of the passive participants that may encounter a longer response time.

Dynamic Network Optimization for Effective Qos Support in Large Grid Infrastructures

In the past decade there has been a remarkable change from mainframe-based centralized computing to a distributed client/server approach. In the coming decade this trend is likely to continue with further shifts towards network centric collaborative computing. At the state of the art, the key technology in collaborative computing is the computational grid paradigm. Like an electrical power grid, the computational Grid will aim to provide a steady, reliable source of computing power. More precisely, the term grid is now adopted to designate a common computational and/or data processing infrastructure built on distributed resources, highly heterogeneous (in their role, computing power and architecture), interconnected by heterogeneous communication networks and communicating through some basic services realized by a middleware stratum that offers a reliable, simple, uniform and often transparent interface to its resources such that an unaware user can submit jobs to the Grid just as if he/she was facing a large virtual supercomputer, so that large computing endeavors, consisting of one or more related jobs or tasks, are then transparently distributed over the network on the available computing resources. Such a workload distribution strategy, that is, to balance the tasks on different idle computers on the underlying networks, is the most important functionality in computational Grids, usually provided at the service level of the grid software infrastructure.

Ontology-Based Construction of Grid Data Mining Workflows

This chapter introduces an ontology-based framework for automated construction of complex interactive data mining workflows as a means of improving productivity of Grid-enabled data exploration systems. The authors first characterize existing manual and automated workflow composition approaches and then present their solution called GridMiner Assistant (GMA), which addresses the whole life cycle of the knowledge discovery process. GMA is specified in the OWL language and is being developed around a novel data mining ontology, which is based on concepts of industry standards like the predictive model markup language, cross industry standard process for data mining, and Java data mining API. The ontology introduces basic data mining concepts like data mining elements, tasks, services, and so forth. In addition, conceptual and implementation architectures of the framework are presented and its application to an example taken from the medical domain is illustrated. The authors hope that the further research and development of this framework can lead to productivity improvements, which can have significant impact on many real-life spheres. For example, it can be a crucial factor in achievement of scientific discoveries, optimal treatment of patients, productive decision making, cutting costs, and so forth.

Karma2

The increasing ability for the sciences to sense the world around us is resulting in a growing need for datadriven e-Science applications that are under the control of workflows composed of services on the Grid. The focus of our work is on provenance collection for these workflows that are necessary to validate the work-flow and to determine quality of generated data products. The challenge we address is to record uniform and usable provenance metadata that meets the domain needs while minimizing the modification burden on the service authors and the performance overhead on the workflow engine and the services. The framework is based on generating discrete provenance activities during the lifecycle of a workflow execution that can be aggregated to form complex data and process provenance graphs that can span across workflows. The implementation uses a loosely coupled publish-subscribe architecture for propagating these activities, and the capabilities of the system satisfy the needs of detailed provenance collection. A performance evaluation of a prototype finds a minimal performance overhead (in the range of 1% for an eight-service workflow using 271 data products).

Reputation Evaluation Framework Based on QoS in Grid Economy Environments

This chapter mainly introduces some recent researches of reputation evaluation methods in Grid economy. The GRACE (Grid Architecture for Computational Economy architecture) is adopted to explain some mechanisms in the Grid economy for its clearly inner modules architecture. In addition, several new developed modules based on GRACE architecture are detailed discussed and two of them are laid morn emphasis on by us, which are the RCM (Reputation Control Module) and distributed reputation control architectures based on VOD (Virtual Organizational Domain). The inner communication and workflow of them are shown in this chapter. Furthermore, through experiments results, the authors discover the profit of Grid nodes and tasks execution success rate are all improved by adding these new modules.

Implementation and QoS for High-performance GIServices in Special Information Grid

With the development of grid technology, the spatial information grid researches are also in progress. In China, the spatial information grid platform (abbreviation to SIG) not only can provide geo-spatial data services (GDS) for handling terabytes of geospatial data, but also can present processing functionality services (PFS) encapsulated from several Remote Sensing (RS) software to solve RS computing problems remotely. In particular, the spatial user can utilize some provided high-performance PFS to achieve those computing intensive tasks that lacking of the high-performance computing facility such as cluster or Condor platform. Unfortunately, the existing SIG paid litter attention to Geographic Information Science (GIS) field, as a result, the constitution of PFS related to GIS, especially the high-performance GIServices (HP-GIServices), are becoming the main issues for SIG’s next research. Lacking of GIServices mainly resulted from the limitations of SIG architecture, difficulty of extracting parallel GIS functionalities modules, as well as the complexity for services implementation and encapsulation. Based on existing SIG platform, this chapter proposes the improved architecture for SIG, upon which the constituted GIS nodes can provide GIServices. Within the new architecture, some parallel GRASS GIS (Geographic Resources Analysis Support System) 1 algorithms programs, which are built by different parallelization patterns and can run in cluster with better efficiency, are encapsulated to high-performance GIServices guiding by certain generic mode. Lastly, the QoS (quality of services) indexes are proposed to evaluate the quality of the constituted HP-GIServices in SIG. From the tentative experiments and analyses, the facts demonstrate that this approach can reach our aims. In all, the chapter firstly gives an overview of existing SIG platform. Facing to the problem of lacking of HP-GIServices, the improved architecture, various parallelization patterns to extract parallel GIS algorithms based on GRASS GIS are proposed. Furthermore, the encapsulation guidance and QoS for evaluating HP-GIServices are also discussed.