The proceedings contain 66 papers. The topics discussed include: T-RATE: a framework for the trace-driven evaluation of 802.11 rate adaptation algorithms;assessing the impact of concurrent replication with canceling i...
The proceedings contain 66 papers. The topics discussed include: T-RATE: a framework for the trace-driven evaluation of 802.11 rate adaptation algorithms;assessing the impact of concurrent replication with canceling in parallel jobs;preserving user behavior characteristics in trace-based simulation of parallel job scheduling;FlexStore: a software defined, energy adaptive distributed storage framework;WORMStore: a specialized object store for write-once read-many workloads;local maximum routing recovery in underwater sensor networks: performance and trade-offs;a domain-specific framework for creating early trusted underwater systems relying on enterprise architecture;provisioning of computing resources for web applications under time-varying traffic;FT-SOA: a failure-prediction technique in service-oriented systems;a versatile traffic and power aware performability analysis of server virtualized systems;and comparative analysis of page cache provisioning in virtualized environments.
For real-time systems we need time-predictable processors. This paper presents a method cache as a time-predictable solution for instruction caching. The method cache caches whole methods (or functions) and simplifies...
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ISBN:
(纸本)9781479944309
For real-time systems we need time-predictable processors. This paper presents a method cache as a time-predictable solution for instruction caching. The method cache caches whole methods (or functions) and simplifies worst-case execution time analysis. We have integrated the method cache in the time-predictable processor Patmos. We evaluate the method cache with a large set of embedded benchmarks. Most benchmarks show a good hit rate for a method cache size in the range between 4 and 16 KB.
Active diagnosis aims at significantly improving system reliability by computing diagnostic information at run-time for fault isolation and online error recovery. The presented work extends semantic techniques, usuall...
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ISBN:
(纸本)9781479944309
Active diagnosis aims at significantly improving system reliability by computing diagnostic information at run-time for fault isolation and online error recovery. The presented work extends semantic techniques, usually used in large-scale IT systems, for active diagnosis in open embedded realtime systems. Open embedded systems (e.g., ambient assisted living for elderly care, critical infrastructures, health management and medical systems) exhibit real-time and reliability requirements, while the constituent components are unknown at design time. time-triggered diagnostic inference supports the incremental generation of symptoms, which result from the temporal and spatial decomposition of the diagnostic analysis process. The methods and algorithms are prototypically implemented, as well as experimentally evaluated. The paper demonstrates that dynamic semantic web services in combination with time-triggered scheduling techniques are suitable to enable active diagnosis in open embedded systems with reliability and real-time requirements.
In this work, we present the design and implementation of distributed visualization and collaboration for an immersive 3D visualizer in a component-oriented fashion. The design follows an MVC approach, isolating all t...
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ISBN:
(纸本)9781479944309
In this work, we present the design and implementation of distributed visualization and collaboration for an immersive 3D visualizer in a component-oriented fashion. The design follows an MVC approach, isolating all the business objects in the lowest level of the application, making it modular and extensible, therefore providing an easier prototyping of functionality and the isolation of complex business logic algorithms. This design as a solution came from the necessity of an existing visualizer with a monolithic implementation, whose maintainability and improvement are impaired due to the coupling between the business logic and the diverse visualization and distribution algorithms. Our design may be reused as an inspiration for other visualizers that wish to reduce the complexity and cost of the development of new business functionality. We implemented the designed visualizer, where we verified both the synchronism of the distributed visualization and the consistency of the collaboration among multiple nodes. We also evaluated the performance impact caused by the distributed visualization.
Embedded control systems such as automotive form large-scale distributed ones which consist of numerous CPUs and devices, including plants and various hardware components. The complexity of such systems has increased ...
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ISBN:
(纸本)9781479944309
Embedded control systems such as automotive form large-scale distributed ones which consist of numerous CPUs and devices, including plants and various hardware components. The complexity of such systems has increased for sophisticated control using numerous types of sensor data. Meanwhile, market pressures lead to reducing development periods for the large-scale distributed embedded control systems. A model-based design becomes popular to solve the above problems, especially automotive industries. In this paper, we describe a wide-area distributed integrated test environment based on the model-based design. The key features are communication middleware to enable wide-area distributed test with integrating the programs in widely distributed sites and control program execution with models of multiple abstraction levels in the model-based design. Furthermore, we developed a model agent simulation. Instead of a plant model that might be located and simulated by MATLAB/Simulink in a remote site, a model agent behaves like the model in a local computer. The model agent simulation significantly reduces the test execution time in a prototype evaluation.
This work is motivated by the needs to synchronize task executions where tasks might use semaphores to protect their critical sections and run over accelerators. In particular, the Priority Ceiling Protocol is extende...
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ISBN:
(纸本)9781479944309
This work is motivated by the needs to synchronize task executions where tasks might use semaphores to protect their critical sections and run over accelerators. In particular, the Priority Ceiling Protocol is extended to manage priority inversion caused by accelerator usages. By recognizing the difference between an accelerator and a semaphore, higher-priority tasks are less likely blocked by lower-priority tasks, due to their requests for an accelerator. In particular, blocking that will not contribute to any deadlock and/or chained blocking is allowed in a managed way, with an objective to maximize the utilization of accelerators. A series of experiments is then conducted to derive insights to task synchronization when accelerators might be used.
Cyber-physical systems increasingly rely on distributedcomputing platforms where sensing, computing, actuation, and communication resources are shared by a multitude of applications. Such 'cyber-physical cloud co...
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ISBN:
(纸本)9781479944309
Cyber-physical systems increasingly rely on distributedcomputing platforms where sensing, computing, actuation, and communication resources are shared by a multitude of applications. Such 'cyber-physical cloud computing platforms' present novel challenges because the system is built from mobile embedded devices, is inherently distributed, and typically suffers from highly fluctuating connectivity among the modules. Architecting software for these systems raises many challenges not present in traditional cloud computing. Effective management of constrained resources and application isolation without adversely affecting performance are necessary. Autonomous fault management and real-time performance requirements must be met in a verifiable manner. It is also both critical and challenging to support multiple end-users whose diverse software applications have changing demands for computational and communication resources, while operating on different levels and in separate domains of security. The solution presented in this paper is based on a layered architecture consisting of a novel operating system, a middleware layer, and component-structured applications. The component model facilitates the construction of software applications from modular and reusable components that are deployed in the distributed system and interact only through well-defined mechanisms. The complexity of creating applications and performing system integration is mitigated through the use of a domain-specific model-driven development process that relies on a domain-specific modeling language and its accompanying graphical modeling tools, software generators for synthesizing infrastructure code, and the extensive use of model-based analysis for verification and validation.
Middleware designed for use in distributedreal-time and Embedded (DRE) systems enable cost and development time reductions by providing simple communications abstractions and hiding operating system-level networking ...
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ISBN:
(纸本)9781479944309
Middleware designed for use in distributedreal-time and Embedded (DRE) systems enable cost and development time reductions by providing simple communications abstractions and hiding operating system-level networking API details from developers. While current middleware technologies can hide many low-level details, designers must provide a static configuration for the system's underlying network in order to achieve required performance characteristics. This has not been a problem for many types of DRE systems where the configuration of the system is relatively fixed from the factory (e.g., aircraft or naval vessels). However for truly open systems (i.e., systems where end users can add or substract components at runtime) the standard static network configuration approach cannot guarantee that required performance will be met because network resource demands are not fully known a priori. Open systems with stringent performance requirements need middleware that can dynamically manage the underlying network configuration automatically in response to changing demands. Fortunately, recent trends in networking have resulted in a wide variety of networking equipment that expose a standardized low-level interface to their configuration via the OpenFlow protocol. In this paper we discuss how OpenFlow can be leveraged by DRE middleware to automatically provide performance guarantees. In order to make the discussion concrete, we describe the architecture of our prototype middleware MIDAS as well as the details of one example network resource management strategy. We demonstrate the feasibility of our approach via performance assesment of a simple DRE application using our MIDAS and commerically available OpenFlow hardware.
Autonomous adaptation in self-adapting embedded real-time systems introduces novel risks as it may lead to unforeseen system behavior. An anomaly detection framework integrated in a real-time operating system can ease...
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ISBN:
(纸本)9781479944309
Autonomous adaptation in self-adapting embedded real-time systems introduces novel risks as it may lead to unforeseen system behavior. An anomaly detection framework integrated in a real-time operating system can ease the identification of such suspicious novel behavior and, thereby, offers the potential to enhance the reliability of the considered self-x system. However, anomaly detection is based on knowledge about normal behavior. When dealing with self-reconfiguring applications, normal behavior changes so that the knowledge base requires adaptation or even (re-)construction at runtime. The stringent restrictions of real-time systems in terms of runtime and memory consumption assign this task to be a really challenging problem. In this paper, we present our idea for online construction of application behavior knowledge that does not rely on any training phase. The applications' behavior is defined by the application's system call invocations. For the knowledge base, we exploit Suffix Trees as they offer potentials to represent application behavior patterns and their associated information in a compact manner. We apply the online algorithm provided by Suffix Trees as a basis to construct the knowledge base with low computational effort. However, we integrate anomaly detection and classification into the online construction method. We ensure thereby that new behavioral patterns do not unconditionally update the behavior knowledge base, but beforehand, have been evaluated in a context-related manner inspired by Danger Theory, a special discipline of Artificial Immune Systems.
In recent vehicles, multifunctional displaying of various data from Electronic Control Units (ECUs) and multimedia devices is required for monitoring or for safe driving. Control Area Network (CAN) is generally used f...
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ISBN:
(纸本)9781467380140
In recent vehicles, multifunctional displaying of various data from Electronic Control Units (ECUs) and multimedia devices is required for monitoring or for safe driving. Control Area Network (CAN) is generally used for transmitting status data such as diagnostic information of a vehicle. For automotive audio/video data, either Media oriented Systems Transport (MOST) or 1Gbps synchronous Ethernet is used. And also, several types of out-vehicle and in vehicle cameras are attached to be used for infotainment, logging and intelligent safe driving. In this paper, a real-time streaming system for multifunctional displaying of two types of vehicle information is presented. The first data type is the vehicle status information from an ECU via CAN. The second one is the Motion JPEG (MJPEG) video data from an Ethernet camera device. After gathering CAN and MJPEG frames, the streaming system combines them into messages in a new frame format and streams them to a multifunction display device in real-time. In order to provide timeliness of streaming of two different types of frames with different bandwidths, several real-time data acquisition tasks and a real-time streaming task are necessary. Of course, a suitable deadline-driven real-time scheduling for each task is also required according to the timing characteristic of the task. For the modeling of the timeliness-guaranteed system, the time-triggered Message triggered object (TMO), a well-known real-timedistributedobject model, was used in modeling the system. As an execution engine for TMOs, a middleware for real-timedistributedcomputing on Linux, named Linux TMO System (LTMOS) v2.0, was used. Considering that 1Gbps Synchronous Ethernet is emerging as a next-generation backbone for automotive networks, the developed system is expected to be used widely in the developments of multifunction displays for vehicles in the near future.
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