This paper presents an efficient approach for generating suitable system architectures for embedded systems efficiently. Thereby, we focus on a joint generation of schedules and deployment for mixed-criticality multic...
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ISBN:
(纸本)9780769549910
This paper presents an efficient approach for generating suitable system architectures for embedded systems efficiently. Thereby, we focus on a joint generation of schedules and deployment for mixed-criticality multicore architectures using shared memory. The presented approach computes task and message schedules that are optimized with respect to a global discrete time base. As part of the solution, our approach generates an optimized assignment of tasks to computation resources (cores) concerning local memory constraints of cores and criticality constraints of tasks. This approach is integrated into the AUTOFOCUS 3 tool-chain, using a formally defined model of computation with explicit data-flow and discrete-time semantics to develop multi-criticality embedded systems. Our approach relies on a symbolic encoding scheme, based on a system model that is derived from the system architecture. This paper provides a formalization describing the scheduling problem as a satisfiability problem using boolean formulas and linear arithmetic constraints. A state-of-the-art satisfiability modulo theory (SMT) solver is used to compute the joint schedule and deployment for such architectures. This paper demonstrates that state-of-the art satisfiability modulo theory solvers can be used to efficiently compute (safety-oriented) deployments including real-time task and communication schedules for mixed-criticality applications.
This paper is talking about temporal logics with semantics based on intervals of time. Interval operators allow wide choice of temporal operators which includes unary operators with semantics and binary operators are ...
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ISBN:
(纸本)9780769541877
This paper is talking about temporal logics with semantics based on intervals of time. Interval operators allow wide choice of temporal operators which includes unary operators with semantics and binary operators are considered.
We are proud to present a Special Issue on Refinement, originating from the 11th BCS-FACS Refinement Workshop, held at Macao in October 2006. This workshop was organised by the EPSRC RefineNet network and co-located w...
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We are proud to present a Special Issue on Refinement, originating from the 11th BCS-FACS Refinement Workshop, held at Macao in October 2006. This workshop was organised by the EPSRC RefineNet network and co-located with ICFEM. The workshop proceedings have appeared in Electronic Notes in Theoretical Computer Science vol. 187. After the workshop, presenters were invited to submit significantly extended papers for inclusion in this special issue; seven of these were accepted and have been included here. The first two papers are concerned with Unifying Theories of programming (UTP). "A UTP semantics for Circus" by Oliveira, Cavalcanti and Woodcock presents a denotational semantics in UTP of the language Circus which allows the proof of meta-theorems such as refinement laws for Circus. "Mutation testing in UTP" by Aichernig and He shows how UTP provides a foundation for testing and test case generation based on the deliberate introduction of faults.
We introduce an operational rewriting-based semantics for strictly positive nested higher-order (co)inductive types. The semantics takes into account the "limits" of infinite reduction sequences. This may be...
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We introduce an operational rewriting-based semantics for strictly positive nested higher-order (co)inductive types. The semantics takes into account the "limits" of infinite reduction sequences. This may be seen as a refinement and generalization of the notion of productivity in term rewriting to a setting with higher-order functions and with data specified by nested higher-order inductive and coinductive definitions. Intuitively, we interpret lazy data structures in a higher-order functional language by potentially infinite terms corresponding to their complete unfoldings. We prove an approximation theorem which essentially states that if a term reduces to an arbitrarily large finite approximation of an infinite object in the interpretation of a coinductive type, then it infinitarily (i.e. in the "limit") reduces to an infinite object in the interpretation of this type. We introduce a sufficient syntactic correctness criterion, in the form of a type system, for finite terms decorated with type information. Using the approximation theorem, we show that each well-typed term has a well-defined interpretation in our semantics.
In most programminglanguages, type abstraction is guaranteed by syntactic scoping in a single program, but is not preserved by marshalling during distributed communication. A solution is to generate hash types at com...
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In most programminglanguages, type abstraction is guaranteed by syntactic scoping in a single program, but is not preserved by marshalling during distributed communication. A solution is to generate hash types at compile time that consist of a fingerprint of the source code implementing the data type. These hash types can be tupled with a marshalled value and compared efficiently at unmar-shall time to guarantee abstraction safety. In this paper, we extend a core calculus of ML-like modules, functions, distributed communication, and hash types, to integrate structural subtyping, user-declared subtyping between abstract types, and bounded existential types. Our semantics makes two contributions: (1) the explicit tracking of the interaction between abstraction boundaries and subtyping;(2) support for user-declared module upgrades with propagation of the resulting subhashing relation throughout the network during communication. We prove type preservation, progress, determinacy, and erasure for our system.
Hardware security studies, discovers, and classifies hardware attacks as well as defense strategies such as prevention and protection methods along the entire hardware production chain. Hardware Trojans represents a h...
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Hardware security studies, discovers, and classifies hardware attacks as well as defense strategies such as prevention and protection methods along the entire hardware production chain. Hardware Trojans represents a hardware attack model that emerged in the last decades in the hardware security community. In this paper, we present a methodology for achieving a scalable approach to detect hardware Trojans at the design stage using program transformation in a rewrite-based environment. We note that the hardware Trojan attack considered here assumes the vulnerability introduction during the hardware design stage while the payload is obtained as information leakage during the hardware usage. The main contribution in our work is the methodology correctness proof for a high security evaluation assurance level. We also benchmark the effectiveness of our methodology on industrial hardware designs, e.g., Advanced Encryption Standard cores, which is widely used and deployed for numerous devices and applications. (c) 2022 Published by Elsevier Inc.
In this paper we investigate the fixed points of functions that can be obtained by continuous fixed point operators in Pω. We also introduce an operator Cgn that generates all of these fixed points for any continuous...
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In this paper we investigate the fixed points of functions that can be obtained by continuous fixed point operators in Pω. We also introduce an operator Cgn that generates all of these fixed points for any continuous function. In the last two sections of the paper we study the fixed points of λa.a∘a (retracts) and of λy λf.f((y)(f)) (fixed point operators).
A layered object-oriented programminglanguage (OOPL) is defined using a simple functional notation that has been equipped with a collection of features common to many OOPLs. The I resulting language provides a framew...
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A layered object-oriented programminglanguage (OOPL) is defined using a simple functional notation that has been equipped with a collection of features common to many OOPLs. The I resulting language provides a framework within which existing OOPLs can be analysed and new OOPLs can be constructed.
Step-indexed semantic interpretations of types were proposed as an alternative to purely syntactic proofs of type safety using subject reduction. The types are interpreted as sets of values indexed by the number of co...
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Step-indexed semantic interpretations of types were proposed as an alternative to purely syntactic proofs of type safety using subject reduction. The types are interpreted as sets of values indexed by the number of computation steps for which these values are guaranteed to behave like proper elements of the type. Building on work by Ahmed, Appel and others, we introduce a step-indexed semantics for the imperative object calculus of Abadi and Cardelli. Providing a semantic account of this calculus using more 'traditional', domain-theoretic approaches has proved challenging due to the combination of dynamically allocated objects, higher-order store, and an expressive type system. Here we show that, using step-indexing, one can interpret a rich type discipline with object types, subtyping, recursive and bounded quantified types in the presence of state.
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