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international symposium on object-oriented real-time distributed computing

作者： Juan Ricardo Rios Martin Schoeberl Department of Informatics and Mathematical Modeling Technical University of Denmark Lyngby Denmark

Memory management in Safety-Critical Java (SCJ) is based on time bounded, non garbage collected scoped memory regions used to store temporary objects. Scoped memory regions may have different life times during the execution of a program and hence, to avoid leaving dangling pointers, it is necessary to check that reference assignments are performed only from objects in shorter lived scopes to objects in longer lived scopes (or between objects in the same scoped memory area). SCJ offers, compared to the RTSJ, a simplified memory model where only the immortal and mission memory scoped areas are shared between threads and any other scoped region is thread private. In this paper we present how, due to this simplified model, a single scope nesting level can be used to check the legality of every reference assignment. We also show that with simple hardware extensions a processor can see some improvement in terms of execution time for applications where cross-scope references are frequent. Our proposal was implemented and tested on the Java Optimized Processor (JOP).

关键词： Hardware Arrays Java Software Memory management object oriented modeling Sensors

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Agent-Based Modeling and Simulation of Artificial Immune Systems

Agent-Based Modeling and Simulation of Artificial Immune Sys...

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ieee international symposium on object/Component/Service-oriented real-time distributed computing Workshops (ISORCW)

作者： Norma Montealegre Franz J. Rammig Design of Distributed Embedded Systems Group Heinz Nixdorf Institute Paderborn Germany

Agent-based modeling and simulation is a way to model the behavior of populations of components and their interactions within a system. the key of this approach is to model the components of the system as autonomous agents and to simulate their behavior for evaluating the system as a whole. that is very useful for observing the emergence of properties in social, biological, environmental or financial systems, among others. Artificial immune systems, which is a sub field of artificial intelligence, comprises systems modeled by simplifying models from the biological immune system. If agent-based modeling and simulation is used as a laboratory for understanding the biological immune system then, it can also be used for transferring the observed principles into artificial immune system models or for evaluating models that have been already adapted for solving technical problems. this paper presents first, a methodology for transferring principles of the biological immune system into the field of artificial immune systems. then, it presents a brief explanation of the behavior of the cells of the biological immune system, which are treated as internal agents inside a biological organism. Afterwards, the modeling of some selected type of cells and the simulation of the whole simplified system are presented. In the end, the principles of that simplified system are transferred into the design of an alarm management system for the smart grid.

关键词： Immune system Pathogens Biological system modeling Adaptation models object oriented modeling Computational modeling

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An Optimized Compilation of UML State Machines

An Optimized Compilation of UML State Machines

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international symposium on object-oriented real-time distributed computing

作者： Asma Charfi Chokri Mraidha Pierre Boulet LIST Laboratory of model driven engineering for embedded systems CEA Gif-sur-Yvette France Sciences et Technologies Cité scientifique Université Lille Villeneuve d'Ascq France

Due to the definition of fUML (Foundational Subset for Executable UML Models) along with its action language Alf (Action Language for fUML), UML (Unified Modeling Language) allows the production of executable models on which early verification and validation activities can be conducted. Despite this effort of standardization and the large use of UML in industry, developers still hand tune the code generated from models to correct, enhance or optimize it. this results in a gap between the model and the generated code. Manual code tuning except from being error prone can invalidate all the analysis and validations already done in the model. To avoid the code hand tuning drawbacks and, since UML is becoming an executable language, we propose a new Model Based Development (MBD) approach that skips the code generation step by compiling directly UML models. the biggest challenge for this approach - tackled in this paper is to propose a model compiler that is more efficient than a code compiler for UML models. Our model compiler performs optimizations that code compilers are unable to perform resulting in a more compact assembly code.

关键词： Unified modeling language Optimization Assembly Semantics object oriented modeling Switches

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Towards a Rigorous Modeling Formalism for Systems of Systems

Towards a Rigorous Modeling Formalism for Systems of Systems

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ieee international symposium on object/Component/Service-oriented real-time distributed computing Workshops (ISORCW)

作者： Tayfun Gezgin Christoph Etzien Stefan Henkler Achim Rettberg Institute for Information Technology (OFFIS) Oldenburg Germany Carl von Ossietzky University슠of슠Oldenburg Oldenburg Germany

the scope of this paper is collaborative, distributed safety critical systems which build up a larger scale system of systems (SoS). Systems participating in an SoS follow both global as well as individual goals, which may be contradicting. Both the global and local goals of the overall SoS may change over time. Hence, self-adaptive ness, i.e., reconfiguration of the SoS as a reaction on changes within its context is a major characteristic of this systems. the aim of this paper is to describe first steps towards a modeling formalism for SoS in a safety critical context. the challenge is to address on the one hand the required flexibility to adapt the system during run-time and on the other hand to guarantee that the system reacts still in a safe manner. To address these challenges, we propose an approach which guarantees that the system still reacts in a safe manner while adaption to uncertainty including context changes. this adaption has to be assumed as unsafe during design time. the key for having success is to define the interaction between the systems as well as its goals as basic elements of the design. Based on our former work, we propose a well-defined modeling approach for the interaction based on components as basic structural elements, the contract paradigm for the design of the interaction, and graph transformations, which addresses the adaptivity of system of systems. the component model is additionally explicitly enriched by goals, which supports so called evaluation functions to determine the level of target achievement.

关键词： Fires Adaptation models Context Protocols real time systems Unified modeling language object oriented modeling

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DMSS: A Dynamic Memory Scheduling System in Server Consolidation Environments

DMSS: A Dynamic Memory Scheduling System in Server Consolida...

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ieee international symposium on object/Component/Service-oriented real-time distributed computing Workshops (ISORCW)

作者： Lanzheng Liu Rui Chu Yongchun Zhu Pengfei Zhang Liufeng Wang National Laboratory for Parallel and Distributed Processing National University of Defense Technology Changsha China Systems and Technology Group IBM China Beijing China

As the foundation of cloud computing, Server consolidation allows multiple computer infrastructures running as virtual machines in a single physical node. It improves the utilization of most kinds of resource but memory under x86 architecture. Because of inaccurate memory usage estimate and the lack of memory resource management, there is much service performance degradation in data centers, even though they have occupied a large amount of memory. Furthermore, memory becomes insufficient for a physical server when a lot of virtual machines depend on it. In order to improve this, we present a dynamic memory scheduling system called DMSS, which can manage memory resources in server consolidation environments and allocate memory among virtual machines on demand. We have designed and implemented the corresponding memory scheduling policy based on Xen virtualization platform to enhance memory efficiency and achieve service level agreement. the benchmark shows that DMSS can make an accurate and rapid response to memory changes and save more than 30% physical memory with less than 5% performance degradation. DMSS actually brings in economic benefits to cloud service providers because more virtual machines can be accommodated at lower costs.

关键词： Memory management Virtual machine monitors Monitoring Resource management Servers Dynamic scheduling Degradation

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ISORC 2010 - 2010 13th ieee international symposium on object/Component/ Service-oriented real-time distributed computing: Message from the symposium Co-chairs

ISORC 2010 - 2010 13th IEEE International Symposium on Objec...

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ISORC 2010 - 2010 13th ieee international symposium on object/Component/Service-oriented real-time distributed computing 2010年 1卷 viii页

作者： De Miguel, Miguel Selic, Bran Dillon, tharam Technical University of Madrid Spain Malina Software Corp. Canada Curtin University of Technology Australia

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ISORC 2010 - 2010 13th ieee international symposium on object/Component/ Service-oriented real-time distributed computing: Message from the program Co-chairs

ISORC 2010 - 2010 13th IEEE International Symposium on Objec...

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ISORC 2010 - 2010 13th ieee international symposium on object/Component/Service-oriented real-time distributed computing 2010年 1卷 ix页

作者： Obermaisser, Roman Tsai, Wei-Tek Nah, Yunmook Shokri, Eltefaat Vienna University of Technology Austria Arizona State University United States Dankook University Korea Republic of Aerospace Corporation United States

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LoCaF: Detecting real-World States with Lousy Wireless Cameras

LoCaF: Detecting Real-World States with Lousy Wireless Camer...

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international Conference on distributed computing in Sensor Systems (DCOSS)

作者： Benjamin Meyer Richard Mietz Kay Romer Institute of Computer Engineering University of Lübeck Germany

the Internet of things (IoT) integrates wireless sensors to provide online and real-time access to the state of things and places. However, many interesting real-world states are difficult to detect with traditional scalar sensors. Tiny wireless camera sensor nodes are an interesting alternative as a single camera can observe a large area in great detail. However, low image resolution, poor image quality, and low frame rates as well as varying lighting conditions in outdoor scenarios make the detection of real-world states using these lousy cameras a challenging problem. In this paper we introduce a framework that addresses this problem by providing an end-to-end solution that includes energy-efficient image capture, image enhancement to mitigate low picture quality, object detection with low frame rates, inference of high-level states, and publishing of these states on the IoT. the framework can be flexibly configured by end-users without programming skills and supports a variety of different applications.

关键词： Cameras Wireless communication Lighting object detection Wireless sensor networks Image resolution

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OASIS: An architecture for dynamic instrumentation of enterprise distributed real-time and embedded systems

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COMPUTER SYSTEMS SCIENCE AND ENGINEERING 2011年第6期26卷 413-423页

作者： Hill, James Sutherlandy, Hunt Staudingery, Paul Silveriaz, thomas Schmidtx, Douglas C. Slabyz, John Visnevskiy, Nikita Indiana Univ Purdue Univ Indianapolis IN 46202 USA GE Global Res Niskayuna Niskayuna NY USA Vanderbilt Univ Nashville Nashville TN USA

Instrumentation is a critical part of evaluating an enterprise distributed real-time and embedded (DRE) system's performance. Traditional techniques for instrumenting enterprise DRE systems require DRE system developers to make design decisions regarding what metrics to collect during early phases of the software lifecycle so these needs can be factored into the system architecture. In many circumstances, however, it is hard for DRE system developers to know this information during early phases of the software lifecycle-especially when metrics come from many heterogeneous sources (such as application-and system-level hardware and software resources) and evaluating performance is traditionally an after-thought. To address these issues, this article presents the design and performance of OASIS, which is SOA-based middleware and tools that dynamically instruments enterprise DRE system without requiring design-time knowledge of which metrics to collect. this article also empirically evaluates OASIS in the context of a representative enterprise DRE system case study from the domain of shipboard computing. Results from applying OASIS to this case study show that its flexibility enables DRE system testers to precisely control instrumentation overhead. We also highlight open challenges in dynamic instrumentation for next-generation enterprise DRE systems.

关键词： dynamic instrumentation enterprise DRE systems service-oriented architecture middleware real-time instrumentation

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A time-predictable object cache

A time-predictable object cache

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ieee international symposium on object, Component, Service-oriented real-time distributed computing

作者： Schoeberl, Martin Department of Informatics and Mathematical Modeling Technical University of Denmark Denmark

ISBN: (纸本)9780769543680

Static cache analysis for data allocated on the heap is practically impossible for standard data caches. We propose a distinct object cache for heap allocated data. the cache is highly associative to track symbolic object addresses in the static analysis. Cache lines are organized to hold single objects and individual fields are loaded on a miss. this cache organization is statically analyzable and improves the performance. In this paper we present the design and implementation of the object cache in a uniprocessor and chip-multiprocessor version of the Java processor JOP. © 2011 ieee.

关键词： real time systems

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