398,306 research outputs found
Implementing Multi-Periodic Critical Systems: from Design to Code Generation
This article presents a complete scheme for the development of Critical
Embedded Systems with Multiple Real-Time Constraints. The system is programmed
with a language that extends the synchronous approach with high-level real-time
primitives. It enables to assemble in a modular and hierarchical manner several
locally mono-periodic synchronous systems into a globally multi-periodic
synchronous system. It also allows to specify flow latency constraints. A
program is translated into a set of real-time tasks. The generated code (\C\
code) can be executed on a simple real-time platform with a dynamic-priority
scheduler (EDF). The compilation process (each algorithm of the process, not
the compiler itself) is formally proved correct, meaning that the generated
code respects the real-time semantics of the original program (respect of
periods, deadlines, release dates and precedences) as well as its functional
semantics (respect of variable consumption).Comment: 15 pages, published in Workshop on Formal Methods for Aerospace
(FMA'09), part of Formal Methods Week 2009
Feedback Control Goes Wireless: Guaranteed Stability over Low-power Multi-hop Networks
Closing feedback loops fast and over long distances is key to emerging
applications; for example, robot motion control and swarm coordination require
update intervals of tens of milliseconds. Low-power wireless technology is
preferred for its low cost, small form factor, and flexibility, especially if
the devices support multi-hop communication. So far, however, feedback control
over wireless multi-hop networks has only been shown for update intervals on
the order of seconds. This paper presents a wireless embedded system that tames
imperfections impairing control performance (e.g., jitter and message loss),
and a control design that exploits the essential properties of this system to
provably guarantee closed-loop stability for physical processes with linear
time-invariant dynamics. Using experiments on a cyber-physical testbed with 20
wireless nodes and multiple cart-pole systems, we are the first to demonstrate
and evaluate feedback control and coordination over wireless multi-hop networks
for update intervals of 20 to 50 milliseconds.Comment: Accepted final version to appear in: 10th ACM/IEEE International
Conference on Cyber-Physical Systems (with CPS-IoT Week 2019) (ICCPS '19),
April 16--18, 2019, Montreal, QC, Canad
15 years of experience with mechatronics research and education
This paper describes the experiences with mechatronic research projects and several educational structures in the University of Twente since 1989. Education took place in a two-year Mechatronic Designer programme, in specialisations in Electrical and Mechanical Engineering and in an (international) MSc programme. There are two-week mechatronic projects in the BSc curricula of EE and ME. Many of the PhD and MSc projects were done in projects sponsored by the industry or by application-oriented research programs. Research topics included modelling and simulation (learning) control, embedded systems and mechatronic design
Introduction to the Selected Papers from ICCPS 2016
Since their inception more than a decade ago, terms such as “cyber-physical systems” (CPS) or
“cooperating objects” have come to describe research and engineering efforts that tightly conjoin
real-world physical processes and computing systems. The integration of physical processes and
computing is not new; embedded computing systems have been in place for decades controlling
physical processes. The revolution is steaming from the extensive networking of embedded computing devices and the holistic cyber-physical co-design that integrates sensing, actuation, computation, networking, and physical processes. Such systems pose many broad scientific and technical
challenges, ranging from distributed programming paradigms to networking protocols, as well as
systems theory that combines physical models and networked embedded systems. Notably, as the
physical interactions imply that timing requirements are considered, real-time computing systems methodologies and technologies are also pivotal in many of those systems. Moreover, many
of these systems are often safety-critical, and therefore it is fundamental to guarantee other nonfunctional properties (such as safety, security, and reliability), which often interplay among them
and with timeliness requirements.
CPS is a growing key strategic research, development, and innovation area, and it is becoming
pivotal for boosting the development of the future generation of highly complex and automated
computing systems, which will be pervasive in virtually all application domains. Notable examples
are aeronautics, aerospace and defence systems, robotics, autonomous transportation systems, the
Internet of Things, energy-aware and green computing, smart factory automation, smart grids,
and advanced medical devices and applications.
This special issue contains a selection of extended versions of the best papers presented at the
Seventh ACM/IEEE International Conference on Cyber-Physical Systems (ICCPS 2016), which was
held with the Cyber-Physical Systems Week in Vienna, Austria, on 11–14 April 2016. This selection
reflects effectively the growing pervasiveness of these systems in various applications domains.
These papers excel at describing the diversity of methodologies used to design and verify various
non-functional properties of these complex systems.info:eu-repo/semantics/publishedVersio
Social Embeddedness and Agent Development
Two different reasons for using agents are distinguished: the `engineering' perspective and the `social simulation' perspective. It is argued that this entails some differences in approach. In particular the former will want to prevent unpredictable emergent features of their agent populations whilst the later will want to use simulation to study precisely this phenomena. A concept of `social embeddedness' is explicated which neatly distinguishes the two approaches. It is argued that such embedding in a society is an essential feature of being a truly social agent. This has the consequence that such agents will not sit well within an `engineering' methodology
Beyond 'Global Production Networks': Australian Fashion Week's Trans-Sectoral Synergies
When studies of industrial organisation are informed by commodity chain, actor network, or global production network theories and focus on tracing commodity flows, social networks, or a combination of the two, they can easily overlook the less routine trans-sectoral
associations that are crucial to the creation and realisation of value. This paper shifts attention to
identifying the sites at which diverse specialisations meet to concentrate and amplify mutually reinforcing circuits of value. These valorisation processes are demonstrated in the case of Australian Fashion Week, an event in which multiple interests converge to synchronize different expressions
of fashion ideas, actively construct fashion markets and enhance the value of a diverse range of fashionable commodities. Conceptualising these interconnected industries as components of a trans-sectoral fashion complex has implications for understanding regional development, world cities, production location, and the manner in which production systems “touch down” in different
places
Embedded model discrepancy: A case study of Zika modeling
Mathematical models of epidemiological systems enable investigation of and
predictions about potential disease outbreaks. However, commonly used models
are often highly simplified representations of incredibly complex systems.
Because of these simplifications, the model output, of say new cases of a
disease over time, or when an epidemic will occur, may be inconsistent with
available data. In this case, we must improve the model, especially if we plan
to make decisions based on it that could affect human health and safety, but
direct improvements are often beyond our reach. In this work, we explore this
problem through a case study of the Zika outbreak in Brazil in 2016. We propose
an embedded discrepancy operator---a modification to the model equations that
requires modest information about the system and is calibrated by all relevant
data. We show that the new enriched model demonstrates greatly increased
consistency with real data. Moreover, the method is general enough to easily
apply to many other mathematical models in epidemiology.Comment: 9 pages, 7 figure
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