104 research outputs found

    WG1N5315 - Response to Call for AIC evaluation methodologies and compression technologies for medical images: LAR Codec

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    This document presents the LAR image codec as a response to Call for AIC evaluation methodologies and compression technologies for medical images.This document describes the IETR response to the specific call for contributions of medical imaging technologies to be considered for AIC. The philosophy behind our coder is not to outperform JPEG2000 in compression; our goal is to propose an open source, royalty free, alternative image coder with integrated services. While keeping the compression performances in the same range as JPEG2000 but with lower complexity, our coder also provides services such as scalability, cryptography, data hiding, lossy to lossless compression, region of interest, free region representation and coding

    New architecture for heterogeneous real-time simulation

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    This thesis investigates a new architecture for modeling and simulating complex distributed real-time systems. Modeling adequately a large distributed real time system may involve, due to its complexity, several different theoretical vehicles such as queuing theory, finite state machines, and others. Currently there are no software tools, which would offer combining such heterogeneous features into a single comprehensive simulation environment. This study involves integrating 3 tools, SES/workbench, an offline simulator using queuing theory as its modeling discipline, ObjecTime as a real-time simulator based on finite state machines as its modeling discipline, and VxWorks real-time kernel used for free modeling in the VMEbus environment. We developed an architecture, which connects all 3 simulators into an integrated system, in which parameters and simulation results can be freely exchanged between tools. In addition, the system is enhanced by a web-based interface, which can be used to provide input and obtain output of the entire system and help in distributing the simulation over the Internet. The new architecture was extensively tested and applied to a large-scale distributed embedded simulation in a military environment

    Locally Adaptive Resolution (LAR) codec

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    The JPEG committee has initiated a study of potential technologies dedicated to future generation image compression systems. The idea is to design a new norm of image compression, named JPEG AIC (Advanced Image Coding), together with advanced evaluation methodologies, closely matching to human vision system characteristics. JPEG AIC thus aimed at defining a complete coding system able to address advanced functionalities such as lossy to lossless compression, scalability (spatial, temporal, depth, quality, complexity, component, granularity...), robustness, embed-ability, content description for image handling at object level... The chosen compression method would have to fit perceptual metrics defined by the JPEG community within the JPEG AIC project. In this context, we propose the Locally Adaptive Resolution (LAR) codec as a contribution to the relative call for technologies, tending to fit all of previous functionalities. This method is a coding solution that simultaneously proposes a relevant representation of the image. This property is exploited through various complementary coding schemes in order to design a highly scalable encoder. The LAR method has been initially introduced for lossy image coding. This efficient image compression solution relies on a content-based system driven by a specific quadtree representation, based on the assumption that an image can be represented as layers of basic information and local texture. Multiresolution versions of this codec have shown their efficiency, from low bit rates up to lossless compressed images. An original hierarchical self-extracting region representation has also been elaborated: a segmentation process is realized at both coder and decoder, leading to a free segmentation map. This later can be further exploited for color region encoding, image handling at region level. Moreover, the inherent structure of the LAR codec can be used for advanced functionalities such as content securization purposes. In particular, dedicated Unequal Error Protection systems have been produced and tested for transmission over the Internet or wireless channels. Hierarchical selective encryption techniques have been adapted to our coding scheme. Data hiding system based on the LAR multiresolution description allows efficient content protection. Thanks to the modularity of our coding scheme, complexity can be adjusted to address various embedded systems. For example, basic version of the LAR coder has been implemented onto FPGA platform while respecting real-time constraints. Pyramidal LAR solution and hierarchical segmentation process have also been prototyped on DSPs heterogeneous architectures. This chapter first introduces JPEG AIC scope and details associated requirements. Then we develop the technical features, of the LAR system, and show the originality of the proposed scheme, both in terms of functionalities and services. In particular, we show that the LAR coder remains efficient for natural images, medical images, and art images

    Safe-guarded multi-agent control for mechatronic systems: implementation framework and design patterns

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    This thesis addresses two issues: (i) developing an implementation framework for Multi-Agent Control Systems (MACS); and (ii) developing a pattern-based safe-guarded MACS design method.\ud \ud The Multi-Agent Controller Implementation Framework (MACIF), developed by Van Breemen (2001), is selected as the starting point because of its capability to produce MACS for solving complex control problems with two useful features:\ud • MACS is hierarchically structured in terms of a coordinated group of elementary and/or composite controller-agents;\ud • MACS has an open architecture such that controller-agents can be added, modified or removed without redesigning and/or reprogramming the remaining part of the MACS

    GRAAL: A Framework for Low-Power 3D Graphics Accelerators

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    Active suspension simulation through software interfacing.

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    Electronic System-Level Synthesis Methodologies

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    A Compositional Approach to Embedded System Design

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    An important observable trend in embedded system design is the growing system complexity. Besides the sheer increase of functionality, the growing complexity has another dimension which is the resulting heterogeneity with respect to the different functions and components of an embedded system. This means that functions from different application domains are tightly coupled in a single embedded system. It is established industry practice that specialized specification languages and design environments are used in each application domain. The resulting heterogeneity of the specification is increased even further by reused components (legacy code, IP). Since there is little hope that a single suitable language will replace this heterogeneous set of languages, multi-language design is becoming increasingly important for complex embedded systems. The key problems in the context of multi-language design are the safe integration of the differently specified subsystems and the optimized implementation of the whole system. Both require the reliable validation of the system function as well as of the non-functional system properties. Current cosimulation-based approaches are well suited for functional validation and debugging. However, these approaches are less powerful for the validation of non-functional system properties. In this dissertation, a novel compositional approach to embedded system design is presented which augments existing cosimulation-based design flows with formal analysis capabilities regarding non-functional system properties such as timing or power consumption. Starting from a truly multi-language specification, the system is transformed into an abstract internal design representation which serves as basis for system-wide analysis and optimization.Ein wesentlicher Trend im Entwurf eingebetteter Systeme ist die steigende Komplexität der zu entwerfenden Systeme. Neben der zunehmenden Funktionalität hat die steigende Komplexität eine weitere Dimension: die resultierende Heterogenität bezüglich der verschiedenen Funktionen und Komponenten eines eingebetteten Systems. Dies bedeutet, daß Funktionen aus verschiedenen Anwendungsbereichen in einem einzelnen System eng miteinander kooperieren. Es ist in der industriellen Praxis etabliert, daß in jedem Anwendungsbereich spezialisierte Spezifikationssprachen zum Einsatz kommen. Da wenig Hoffnung besteht, daß eine einzige geeignete Sprache diesen heterogenen Mix von Sprachen ersetzen wird, gewinnt der mehrsprachige Entwurf für komplexe eingebettete Systeme an Bedeutung. Die Hauptprobleme im Bereich des mehrsprachigen Entwurfs sind die sichere Integration der verschieden spezifizierten Teilsysteme und die optimierte Implementierung des gesamten Systems. Beide Probleme verlangen eine zuverlässige Validierung der Systemfunktion sowie der nichtfunktionalen Systemeigenschaften. Heutige cosimulationsbasierte Ansätze aus Forschung und Industrie sind gut geeignet für die funktionale Validierung und Fehlersuche, haben aber Schwächen bei der Validierung nichtfunktionaler Systemeigenschaften. In der vorliegenden Arbeit wird ein neuartiger kompositionaler Ansatz für den Entwurf eingebetteter Systeme vorgestellt, der existierende cosimulationsbasierte Entwurfsflüsse um Fähigkeiten zur Analyse nichtfunktionaler Systemeigenschaften ergänzt. Ausgehend von einer mehrsprachigen Spezifikation, wird das System in eine abstrakte homogene interne Darstellung transformiert, die als Grundlage für die systemweite Analyse und Optimierung dient

    Tenth Workshop and Tutorial on Practical Use of Coloured Petri Nets and the CPN Tools Aarhus, Denmark, October 19-21, 2009

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    This booklet contains the proceedings of the Tenth Workshop on Practical Use of Coloured Petri Nets and the CPN Tools, October 19-21, 2009. The workshop is organised by the CPN group at the Department of Computer Science, University of Aarhus, Denmark. The papers are also available in electronic form via the web pages: http://www.cs.au.dk/CPnets/events/workshop0
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