150 research outputs found
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SPIN-ning Software Architectures: A Method for Exploring Complex Systems
When designing complex software systems that provide multiple non-functional properties, it is usual to try to reuse (and finally compose) simpler existing designs, which deal with each of these properties in solitude. The paper describes a method for automatically and quickly identifying all the different ways one can compose such designs, with the aid of a model checke
Interim research assessment 2003-2005 - Computer Science
This report primarily serves as a source of information for the 2007 Interim Research Assessment Committee for Computer Science at the three technical universities in the Netherlands. The report also provides information for others interested in our research activities
Technological roadmap on AI planning and scheduling
At the beginning of the new century, Information Technologies had become basic and indispensable
constituents of the production and preparation processes for all kinds of goods and services and
with that are largely influencing both the working and private life of nearly every citizen. This
development will continue and even further grow with the continually increasing use of the Internet
in production, business, science, education, and everyday societal and private undertaking.
Recent years have shown, however, that a dramatic enhancement of software capabilities is required,
when aiming to continuously provide advanced and competitive products and services in all these
fast developing sectors. It includes the development of intelligent systems – systems that are more
autonomous, flexible, and robust than today’s conventional software.
Intelligent Planning and Scheduling is a key enabling technology for intelligent systems. It has
been developed and matured over the last three decades and has successfully been employed for a
variety of applications in commerce, industry, education, medicine, public transport, defense, and
government.
This document reviews the state-of-the-art in key application and technical areas of Intelligent Planning
and Scheduling. It identifies the most important research, development, and technology transfer
efforts required in the coming 3 to 10 years and shows the way forward to meet these challenges in
the short-, medium- and longer-term future.
The roadmap has been developed under the regime of PLANET – the European Network of Excellence
in AI Planning. This network, established by the European Commission in 1998, is the co-ordinating
framework for research, development, and technology transfer in the field of Intelligent Planning and
Scheduling in Europe.
A large number of people have contributed to this document including the members of PLANET non-
European international experts, and a number of independent expert peer reviewers. All of them are
acknowledged in a separate section of this document.
Intelligent Planning and Scheduling is a far-reaching technology. Accepting the challenges and progressing
along the directions pointed out in this roadmap will enable a new generation of intelligent
application systems in a wide variety of industrial, commercial, public, and private sectors
Modeling and Analyzing Cyber-Physical Systems Using Hybrid Predicate Transition Nets
Cyber-Physical Systems (CPSs) are software controlled physical devices that are being used everywhere from utility features in household devices to safety-critical features in cars, trains, aircraft, robots, smart healthcare devices. CPSs have complex hybrid behaviors combining discrete states and continuous states capturing physical laws. Developing reliable CPSs are extremely difficult. Formal modeling methods are especially useful for abstracting and understanding complex systems and detecting and preventing early system design problems. To ensure the dependability of formal models, various analysis techniques, including simulation and reachability analysis, have been proposed in recent decades. This thesis aims to provide a unified formal modeling and analysis methodology for studying CPSs.
Firstly, this thesis contributes to the modeling and analysis of discrete, continuous, and hybrid systems. This work enhances modeling of discrete systems using predicate transition nets (PrTNs) by fully realizing the underlying specification through incorporating the first-order logic with set theory, improving the type system, and providing incremental model composition. This work enhances the technique of analyzing discrete systems using PrTN by improving the simulation algorithm and its efficient implementation. This work also improves the analysis of discrete systems using SPIN by providing a more accurate and complete translation method.
Secondly, this work contributes to the modeling and analysis of hybrid systems by proposing an extension of PrTNs, hybrid predicate transition nets (HPrTNs). The proposed method incorporates a novel concept of token evolution, which nicely addresses the continuous state evolution and the conflicts present in other related works. This work presents a powerful simulation capability that can handle linear, non-linear dynamics, transcendental functions through differential equations. This work also provides a complementary technique for reachability analysis through the translation of HPrTN models for analysis using SpaceEx
Formal modelling and analysis of broadcasting embedded control systems
PhD ThesisEmbedded systems are real-time, communicating systems, and the effective
modelling and analysis of these aspects of their behaviour is regarded as essential
for acquiring confidence in their correct operation. In practice, it is important
to minimise the burden of model construction and to automate the analysis,
if possible. Among the most promising techniques for real-time systems are
reachability analysis and model-checking of networks of timed automata. We
identify two obstacles to the application of these techniques to a large class of
distributed embedded systems: firstly, the language of timed automata is too
low-level for straightforward model construction, and secondly, the synchronous,
handshake communication mechanism of the timed automata model does not fit
well with the asynchronous, broadcast mechanism employed in many distributed
embedded systems. As a result, the task of model construction can be unduly
onerous.
This dissertation proposes an expressive language for the construction of
models of real-time, broadcasting control systems, and demonstrates how effi-
cient analysis techniques can be applied to them.
The dissertation is concerned in particular with the Controller Area Network
(CAN) protocol which is emerging as a de facto standard in the automotive
industry. An abstract formal model of CAN is developed. This model is adopted
as the communication primitive in a new language, bCANDLE, which includes
value passing, broadcast communication, message priorities and explicit time.
A high-level language, CANDLE, is introduced and its semantics defined by
translation to bCANDLE. We show how realistic CAN systems can be described
in CANDLE and how a timed transition model of a system can be extracted for
analysis. Finally, it is shown how efficient methods of analysis, such as 'on-the-
fly' and symbolic techniques, can be applied to these models. The dissertation
contributes to the practical application of formal methods within the domain
of broadcasting, embedded control systemsSchool of Computing and Mathematics at the University of Northumbri
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