Jožef Stefan Institute

About: Jožef Stefan Institute is a facility organization based out in Ljubljana, Slovenia. It is known for research contribution in the topics: Liquid crystal & Dielectric. The organization has 3828 authors who have published 12614 publications receiving 291025 citations.

Asynchrony in parallel computing: from dataflow to multithreading

Abstract: The paper presents an overview of the parallel computing models, architectures, and research projects that are based on asynchronous instruction scheduling. It starts with pure dataflow computing models and presents an historical development of several ideas (i.e. single-token-per-arc dataflow, tagged-token dataflow, explicit token store, threaded dataflow, large-grain dataflow, RISC dataflow, cycle-by-cycle interleaved multithreading, block interleaved multithreading, simultaneous multithreading) that resulted in modern multithreaded superscalar processors. The paper shows that unification of von Neumann and dataflow models is possible and preferred to treating them as two unrelated, orthogonal computing paradigms. Today's dataflow research incorporates more explicit notions of state into the architecture, and von Neumann models using many dataflow techniques to improve the latency hiding aspects of modern multithreaded systems.

A MRI spatial mapping technique for microvascular permeability and tissue blood volume based on macromolecular contrast agent distribution

Abstract: A rapid and automated method for two-dimensional spatial depiction (mapping) of quantitative physiological tissue characteristics derived from contrast enhanced MR imaging was developed and tested in disease models of cancer, inflammation, and myocardial reperfusion injury. Specifically, an established two-compartment kinetic model of unidirectional mass transport was implemented on a pixel-by-pixel basis to generate maps of tissue permeability surface area product (PS) and fractional blood volume (BV) based on dynamic MRI intensity data after administration of albumin-(Gd-DTPA)30, a prototype macromolecular contrast medium (MMCM) designed for blood pool enhancement. Maps of PS and BV in disease models of adenocarcinoma, intramuscular abscess inflammation, and myocardial reperfusion injury clearly depicted zones of increased permeability (up to approximately 500 microl/cc/h--compared to inflammation > tumors. A rapid, automated mapping technique derived from dynamic contrast-enhanced MRI data can be used to facilitate the identification and characterization of pathophysiologic abnormalities, specifically relative increases in blood volume and/or microvascular permeability.