Tobias Beisel

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We present a new version of STIR (Software for Tomographic Image Reconstruction), an open source object-oriented library implemented in C++ for 3D positron emission tomography reconstruction. This library has been designed such that it can be used for many algorithms and scanner geometries, while being portable to various computing platforms. This second(More)
This paper presents an extension of the Completely Fair Scheduler (CFS) to support cooperative multitasking with time-sharing for heterogeneous processing elements in Linux. We extend the kernel to be aware of accelerators, hold different run queues for these components and perform scheduling decisions using application provided meta information and a(More)
Todays computer systems increasingly comprise heterogenous computing elements like multi-core processors, graphics processing units, and specialized co-processors, which allow parallel processing. Programming applications to utilize such systems is a complex process and needs good knowledge about the hardware architecture. Automatic and transparent use of(More)
To accelerate image reconstruction of positron emission tomography (PET) data, we introduced an approach for parallel architectures by applying the message passing paradigm to an existing implementation of the ordered-subsets expectationmaximization (OSEM) algorithm for twoor three-dimensional (2D/3D) PET. To reduce the amount of time needed to complete a(More)
We present a new version of STIR, an Open Source object-oriented library implemented in C++ for 3D PET reconstruction. This library has been designed such that it can be used for many algorithms and scanner geometries, while being portable to various computing platforms. This second release enhances its flexibility and modular design and includes additional(More)
Computer systems increasingly integrate heterogeneous computing elements like graphic processing units and specialized co-processors. The systematic programming and exploitation of such heterogeneous systems is still a subject of research. While many efforts address the programming of accelerators, scheduling heterogeneous systems, i. e., mapping parts of(More)
The use of heterogeneous computing resources, such as Graphic Processing Units or other specialized coprocessors, has become widespread in recent years because of their performance and energy efficiency advantages. Approaches for managing and scheduling tasks to heterogeneous resources are still subject to research. Although queuing systems have recently(More)
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