GLATARD , Tristan

Grids are interesting platforms for supporting the development of medical image analysis applications: they enable data and algorithms sharing and provide huge amounts of computing power and data storage. In this thesis, we investigate a medical image analysis problem that turns out to be a typical dimensioning application for grids, thus...

Report on the operations of the biomed VO

In this paper, the expressiveness of the simple Scufl data-flow language is studied by showing how it can be used to implement Turing machines. To do that, several non trivial Scufl patterns such as self-looping or sub-workflows are required and we precisely explicit them. The main result of this work is to show how a complex workflow can be...

This paper presents a method to optimize the timeout value of grid computing jobs. It relies on a model of the job execution time that considers the job management system latency through a random variable. It also takes into account a proportion of outliers to model either reliable clusters or production grids characterized by faults causing...

In this paper, we present a generic wrapper that enables the optimization of legacy codes assembled in application workflows on grid infrastructures. We first describe advantages of a service-based approach for job management. We then introduce our wrapper, that works at execution time, thus allowing service grouping strategies to optimize the...

Medical image registration is pre-processing needed for many medical image analysis procedures. A very large number of registration algorithms are available today, but their performance is often not known and very difficult to assess due to the lack of gold standard. The Bronze Standard algorithm is a very data and compute intensive statistical...

Grid are promising tools to tackle massively parallel medical applications such as medical image databases indexation but their complexity make the optimization of computation tasks and the design of computing models difficult. We tackle this complexity by a probabilistic approach. We have shown that a probabilistic model of the computing tasks...

Evaluating registration algorithms is difficult due to the lack of gold standard in most clinical procedures. The bronze standard is a real-data based statistical method providing an alternative registration reference through a computationally intensive image database registration procedure. We propose in this paper an efficient implementation...

In this paper, we study grid job submission latencies. The latency highly impacts performances on production grids, due to its high values and variations as well as the presence of outliers. It is particularly prejudicial for determining the status and expected duration of jobs. In a previous work, a probabilistic model of the latency is...

In this paper, we study grid job submission latencies. The latency highly impacts performances on production grids, due to its high values and variations as well as the presence of outliers. It is particularly prejudicial for determining the status and expected duration of jobs. In a previous work, a probabilistic model of the latency is...

Workflow engines are powerful tools to implement data- intensive scientific applications exploiting parallel grid resources transparently. We discuss the advantages of impelmenting applications as workflows of services when dealing with large data sets. We show how the graph of services associated with data composition operators enable the...

This paper presents a method to optimize the timeout value of grid computing jobs. It relies on a model of the job execution time that considers the job management system latency through a random variable. It also takes into account a proportion of outliers to model either reliable clusters or production grids characterized by faults causing...

This paper presents a method to optimize the timeout value of computing jobs. It relies on a model of the job execution time that considers the job management system latency through a random variable. It also takes into ac- count a proportion of outliers to model either reliable clus- ters or production grids characterized by faults causing...

Production grids have a potential for parallel execution of a very large number of tasks but also introduce a high overhead that significantly impacts the execution of short tasks. In this work, we present a strategy to optimize the partitioning of jobs on a grid infrastructure. This method takes into account the variability and the difficulty...

Operating a large production-level distributed computing infrastructures today still requires a costly human intervention to reach acceptable quality of service. This cost may be acceptable for scientific communities with solid IT support, but it often remains a show-stopper for others. The Life-Science Grid Community (LSGC) gathers five...