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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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.
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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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.
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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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.
Cyber-physical systems are integrations of computation, communication networks, and physical dynamics. Although time plays a central role in the physical world, all widely used software abstractions lack temporal sema...
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Cyber-physical systems are integrations of computation, communication networks, and physical dynamics. Although time plays a central role in the physical world, all widely used software abstractions lack temporal semantics. The notion of correct execution of a program written in every widely-used programming language today does not depend on the temporal behavior of the program. But temporal behavior matters in almost all systems. Even in systems with no particular real-time requirements, timing of programs is relevant to the value delivered by programs, and in the case of concurrent programs, also affects the functionality. In cyber-physical systems, temporal behavior affects not just the value delivered by a system but also its correctness. In this talk, I will argue that time can and must become part of the semantics of programs for a large class of applications. To illustrate that this is both practical and useful, we will describe two recent efforts at Berkeley in the design and implementation of timing-centric software systems. On the implementation side, I will describe PRET machines, which redefine the instruction-set architecture (ISA) of a microprocessor to include temporal semantics. On the design side, I will briefly describe PTIDES, a programming model for distributedreal-time systems. PTIDES leverages clock synchronization to deliver a deterministic model of computation for distributedreal-time systems.
Part of the KOMOBAR project aims to support agricultural production processes in rural areas. These processes are subject to frequent disturbances that need to be accounted for. KOMOBAR proposes to reduce the (human t...
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ISBN:
(纸本)9781479948451
Part of the KOMOBAR project aims to support agricultural production processes in rural areas. These processes are subject to frequent disturbances that need to be accounted for. KOMOBAR proposes to reduce the (human to human) communication overhead by deploying a distributed system that allows for soft real-time monitoring of the respective processes in execution. Further, KOMOBAR considers a major requirement that is found in the targeted market: A majority of the subcontractors that conduct the harvest are small to medium sized businesses that are unlikely to accept larger investments in IT infrastructure. KOMOBAR addresses this by employing Commercial Of-The-Shelf hardware and a cross platform software approach.
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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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.
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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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.
The proceedings contain 37 papers. The topics discussed include: an invariant preserving transformation for PLC models;product model derivation by model transformation in software product lines;component-based hazard ...
ISBN:
(纸本)9780769543772
The proceedings contain 37 papers. The topics discussed include: an invariant preserving transformation for PLC models;product model derivation by model transformation in software product lines;component-based hazard analysis for mechatronic systems;model-based hardware generation and programming - the MADES approach;architectural design patterns for flight software;abstract infrastructure for real systems: reflection and autonomy in realtime;knowledge representation and awareness in autonomic service-component ensembles - state of the art;developing mechanisms for determining 'good enough' in SORT systems;a lazy algorithm for distributed priority assignment in real-time systems;a service discovery approach for testing dynamic SOAs;middleware support for a self-configurable wireless sensor network;and using transactional memory to synchronize an adaptive garbage collector in real-time Java.
The proceedings contain 32 papers. The topics discussed include: real-time multicast and memory replication channels with delay bounded error detection and retry capabilities;scheduling multi clock realtime systems: ...
ISBN:
(纸本)9780769543680
The proceedings contain 32 papers. The topics discussed include: real-time multicast and memory replication channels with delay bounded error detection and retry capabilities;scheduling multi clock realtime systems: from requirements to implementation;modeling MARTE sequence diagram with timing Pi-calculus;a model-based transformation process to validate and implement high-integrity systems;modeling interface definition language extensions (IDL3+) using domain-specific modeling languages;a generalized model to control the throughput in a processor for real-time applications;modeling and analyzing real-time data streams;a time-predictable object cache;refactoring real-time java profiles;the design of middleware support for real-time SOA;accurate measurement-based WCET analysis in the absence of source and binary code;and determining actual response time in P-FRP using idle-period game board.
Many big data applications receive and process data in realtime. These data, also known as data streams, are generated continuously and processed online in a low latency manner. Data stream is prone to change dramati...
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ISBN:
(纸本)9781479936168
Many big data applications receive and process data in realtime. These data, also known as data streams, are generated continuously and processed online in a low latency manner. Data stream is prone to change dramatically in volume, since its workload may have a variation of several orders between peak and valley periods. Fully provisioning resources for stream processing to handle the peak load is costly, while over-provisioning is wasteful when to deal with lightweight workload. Cloud computing emphasizes that resource should be utilized economically and elastically. An open question is how to allocate query task adaptively to keeping up the input rate of the data stream. Previous work focuses on using either local or global capacity information to improve the cluster CPU resource utilization, while the bandwidth utilization which is also critical to the system throughput is ignored or simplified. In this paper, we formalize the operator placement problem considering both the CPU and bandwidth usage, and introduce the Elastic Allocator. The Elastic Allocator uses a quantitative method to evaluate a nodes capacity and bandwidth usage, and exploit both the local and global resource information to allocate the query task in a graceful manner to achieve high resource utilization. The experimental results and a simple prototype built on top of Storm finally demonstrate that Elastic Allocator is adaptive and feasible in cloud computing environment, and has an advantage of improving and balancing system resource utilization.
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