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Cyber Physical Systems: Design Challenges
"... Cyber-Physical Systems (CPS) are integrations of computation and physical processes. Embedded computers and networks monitor and control the physical processes, usually with feedback loops where physical processes affect computations and vice versa. The economic and societal potential of such system ..."
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Cited by 181 (9 self)
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Cyber-Physical Systems (CPS) are integrations of computation and physical processes. Embedded computers and networks monitor and control the physical processes, usually with feedback loops where physical processes affect computations and vice versa. The economic and societal potential of such systems is vastly greater than what has been realized, and major investments are being made worldwide to develop the technology. There are considerable challenges, particularly because the physical components of such systems introduce safety and reliability requirements qualitatively different from those in generalpurpose computing. Moreover, physical components are qualitatively different from object-oriented software components. Standard abstractions based on method calls and threads do not work. This paper examines the challenges in designing such systems, and in particular raises the question of whether today’s computing and networking technologies provide an adequate foundation for CPS. It concludes that it will not be sufficient to improve design processes, raise the level of abstraction, or verify (formally or otherwise) designs that are built on today’s abstractions. To realize the full potential of CPS, we will have to rebuild computing and networking abstractions. These abstractions will have to embrace physical dynamics and computation in a unified way. 1
The case for the precision timed (PRET) machine
, 2006
"... Copyright © 2006, by the author(s). ..."
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Heterogeneous Concurrent Modeling and Design in Java (Volumes 1: Introduction to Ptolemy II)
, 2005
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Towards semantic services for sensor-rich information systems
, 2005
"... Abstract — This paper describes the architecture and programming model of a semantic-service-oriented sensor information system platform. We argue that the key to enabling scalable sensor information access is to define an ontology and associated sensor information hierarchy for interpretation of ra ..."
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Cited by 59 (4 self)
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Abstract — This paper describes the architecture and programming model of a semantic-service-oriented sensor information system platform. We argue that the key to enabling scalable sensor information access is to define an ontology and associated sensor information hierarchy for interpretation of raw data streams. The ontological abstraction allows a sensing system to optimize its resource utilization in collecting, storing, and processing data. We describe the SONGS architecture that uses an automatic service planning to convert declarative user queries into a service composition graph, and performs compile-time and run-time optimizations for resource-aware execution of the service composite in a sensor network, building on the sensor information hierarchy. We motivate and demonstrate the SONGS platform using a parking garage example. I.
Flexible and Formal Modeling of Microprocessors with Application to Retargetable Simulation
- Design, Automation and Test in Europe Conference and Exhibition
, 2003
"... Given the growth in application-specific processors, there is a strong need for a retargetable modeling framework that is capable of accurately capturing complex processor behaviors and generating efficient simulators. We propose the operation state machine (OSM) computation model to serve as the fo ..."
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Cited by 48 (5 self)
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Given the growth in application-specific processors, there is a strong need for a retargetable modeling framework that is capable of accurately capturing complex processor behaviors and generating efficient simulators. We propose the operation state machine (OSM) computation model to serve as the foundation of such a modeling framework. The OSM model separates the processor into two interacting layers: the operation layer where operation semantics and timing are modeled, and the hardware layer where disciplined hardware units interact. This declarative model allows for direct synthesis of micro-architecture simulators as it encapsulates precise concurrency semantics of microprocessors. We illustrate the practical benefits of this model through two case studies- the StrongARM core and the PowerPC-750 superscalar processor. The experimental results demonstrate that the OSM model has excellent modeling productivity and model efficiency. Additional applications of this modeling framework include derivation of information required by compilers and formal analysis for processor validation.
Exposición General
- Revista Internacional del Trabajo
, 1995
"... Twitter offers an explicit mechanism to facilitate information diffusion and has emerged as a new medium for communication. Many approaches to find influentials have been proposed, but they do not consider the temporal order of information adoption. In this work, we propose a novel method to find in ..."
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Cited by 28 (1 self)
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Twitter offers an explicit mechanism to facilitate information diffusion and has emerged as a new medium for communication. Many approaches to find influentials have been proposed, but they do not consider the temporal order of information adoption. In this work, we propose a novel method to find influentials by considering both the link structure and the temporal order of information adoption in Twitter. Our method finds distinct influentials who are not discovered by other methods.
SYSTEMCODESIGNER -- An Automatic ESL Synthesis Approach by Design Space Exploration and Behavioral Synthesis for Streaming Applications
, 2009
"... With increasing design complexity, the gap from ESL (Electronic System Level) design to RTL synthesis becomes more and more crucial to many industrial projects. Although several behav-ioral synthesis tools exist to automatically generate synthesizable RTL code from C/C++/SystemC-based input descript ..."
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Cited by 27 (12 self)
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With increasing design complexity, the gap from ESL (Electronic System Level) design to RTL synthesis becomes more and more crucial to many industrial projects. Although several behav-ioral synthesis tools exist to automatically generate synthesizable RTL code from C/C++/SystemC-based input descriptions and software generation for embedded processors is automated as well, an efficient ESL synthesis methodology combining both is still missing. This article presents SYS-TEMCODESIGNER, a novel SystemC-based ESL tool to automatically optimize a hardware/software SoC (System on Chip) implementation with respect to several objectives. Starting from a SystemC behavioral model, SYSTEMCODESIGNER automatically extracts the mathematical model, performs a behavioral synthesis step, and explores the multiobjective design space using state-of-the-art mul-tiobjective optimization algorithms. During design space exploration, a single design point is eval-uated by simulating highly accurate performance models, which are automatically generated from the SystemC behavioral model and the behavioral synthesis results. Moreover, SYSTEMCODESIGNER permits the automatic generation of bit streams for FPGA targets from any previously optimized SoC implementation. Thus SYSTEMCODESIGNER is the first fully automated ESL synthesis tool pro-viding a correct-by-construction generation of hardware/software SoC implementations. As a case study, a model of a Motion-JPEG decoder was automatically optimized and implemented using SYSTEMCODESIGNER. Several synthesized SoC variants based on this model show different tradeoffs between required hardware costs and achieved system throughput, ranging from software-only solutions to pure hardware implementations that reach real-time performance for QCIF streams on a 50MHz FPGA.
Model-driven configuration and deployment of component middleware publish/subscribe services
- of Lecture
"... Quality of service (QoS)-enabled publish/subscribe services are available in component middleware platforms, such as the CORBA Component Model (CCM). Today, however, these platforms lack a simple and intuitive way to integrate publish/subscribe service configurations and deployments. This paper illu ..."
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Cited by 18 (10 self)
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Quality of service (QoS)-enabled publish/subscribe services are available in component middleware platforms, such as the CORBA Component Model (CCM). Today, however, these platforms lack a simple and intuitive way to integrate publish/subscribe service configurations and deployments. This paper illustrates how generative model-driven techniques and tools can automate many service configuration and deployment tasks associated with integrating publish/subscribe services into QoS-enabled component-based systems. We evaluate these techniques in the context of a real-time avionics mission computing problem involving a system with over 50 components. Our evaluation finds that an automated model-driven configuration of a reusable component middleware framework not only significantly reduces handwritten code and but also simultaneously achieves high reusability and composability of CCM components.
