Developing critical systems with PLD components
- Adrian J. Hilton; Jon G. Hall; Walton Hall; Adrian J. Hilton; Jon G. Hall
Abstract. Understanding the roles that rigour and formality can have in the design of critical systems is critical to anyone wishing to contribute to their development. Whereas knowledge of these issues is good in software development, in the use of hardware – specifically programmable logic devices (PLDs) and the combination of PLDs and software – the issues are less well known. Indeed, even in industry there are many differences between current and recommended practice and engineering opinion differs on how to apply existing standards. This has led to gaps in the formal and rigorous treatment of PLDs in critical systems....
Generalizing Term Subsumption Languages to Fuzzy Logic
During the past decade, knowledge representation research in AI has generated a class of languages called term subsumption languages (TSL), which is a knowledge representation formalism with a well-defined logic-based semantics-Due to its formal semantics, a term subsumption system can automatically infer the subsumption relationships between concepts defined in the system. However, these systems are very limited in handling vague concepts in the knowledge base. In contrast, fuzzy logic directly deals with the notion of vagueness and imprecision using fuzzy predicates, fuzzy quantifiers, linguistic variables, and other constructs. Hence, fuzzy logic offers an appealing foundation for generalizing the semantics of...
A system for nonmonotonic rules on the web
- Grigoris Antoniou; Antonis Bikakis
Abstract. Defeasible reasoning is a rule-based approach for efficient reasoning with incomplete and inconsistent information. Such reasoning is, among others, useful for ontology integration, where conflicting information arises naturally; and for the modeling of business rules and policies, where rules with exceptions are often used. This paper describes these scenarios in more detail, and reports on the implementation of a system for defeasible reasoning on the Web. The system (a) is syntactically compatible with RuleML; (b) features strict and defeasible rules and priorities; (c) is based on a translation to logic programming with declarative semantics; and (d) is flexible and...
Semantic Web Verification: Verifying Reasoning in the Logic ALC
- José A. Alonso Jiménez; Joaquín Borrego Díaz; María J. Hidalgo Doblado; Francisco J. Martín Mateos Y; José Luis; Ruiz Reina; Grupo De Lógica Computacional
In the Semantic Web, knowledge is usually structured in the form of ontologies, using the Web Ontology Language (OWL), which is based in part on the Description Logics (DLs). DLs are a family of logical formalisms for representing and reasoning
Checking object system designs incrementally
- Hans-dieter Ehrich; Maik Kollmann; Ralf Pinger
Abstract: We present a method for checking global conditions for object systems in a way that avoids state space explosion. The objects referred to in a global condition are checked step by step against local conditions and communication requirements derived from the global condition. The derivation is automatic, based on information about the system structure contained in the global condition. The approach is demonstrated using model checking, but the idea works for other approaches to verification or testing as well. In our current investigation, a multi-object variant of CTL is used for expressing global conditions. The local conditions and communication...
The Conductor: Gestures for Embodied Agents with Logic Programming
- Zsòfia Ruttkay; Zhisheng Huang; Anton Eliens
Abstract. The paper discusses how distributed logic programming can be used to define and control the hand gestures of embodied agents in virtual worlds, by using the STEP language as an interface between the constructs of logic programming and the humanoid model defined in VRML. By using this framework, different gesture dictionaries can be defined and variants of a hand gesture, according to dynamically changing factors, can be generated on the fly. The approach is tested on the demanding demonstrator of conducting, providing experience, also on time performance of the animation. 1
Characteristic Faults and Spectral Information for Logic BIST
- Xiaoding Chen; Michael S
We present a new method of built-in-self-test (BIST) for sequential circuits and system-on-a-chip (SOC) using characteristic faults and circuitspecific spectral information in the form of one or more Hadamard coefficients. The Hadamard coefficients are extracted from the test sequences for a small set of characteristic faults of the circuit. By extracting a few characteristic faults from the circuit, we show that detection of these characteristic faults is sufficient in detecting a vast majority of the remaining faults in the circuit. The small number of characteristic faults allows us to reduce the coefficients necessary for BIST. State relaxation is performed on...
What awareness isn't: A sentential view of implicit and explicit belief
- Kurt Konolige
In their attempt to model and reason about the beliefs of agents, artificial intelligence (AI) researchers have borrowed from two different philosophical tradi-tions regarding the folk psychology of belief. In one tradition, belief is a relation between an agent and a proposition, that is, a propositional attitude. Formal analyses of propositional attitudes are often given in terms of a possible-worlds semantics. In the other tradition, belief is a relation between an agent and a sen-tence that expresses a proposition (the sentential approach). The arguments for and against these approaches are complicated, confusing, and often obscure and unintelligible (at least to...
Magnetotactic Bacteria and Their Significance for P Systems and Nanoactuators
- Ioan I. Ardelean; Mircea Ignat; Cristina Moisescu
Summary. In the framework of the dialog between P systems and Microbiology, in this paper we focus on the magnetotactic behavior of magnetotactic bacteria, namely the orientation along the Earth’s geomagnetic field lines. Magnetic properties and magnetotactic behavior could be used to obtained micro- and nanoactuators for the desired distribution at nanometer level of either intact magnetotactic bacteria or isolated intact magnetosomes with significant potential application in the construction of magnetic logic gates. Furthermore, (precise) distribution of intact magnetotactic bacteria or isolated intact magnetosomes by carefully using rather strong external magnetic fields could be described by P systems as a...
Printed in Great Britain PII: S1353-4505(96)00034-8 i353-»505/96 $15.00+0.00 On Opening "Black Boxes " and Looking Inside
- Usa I. Iezzoni
Embedded within many of the best-known initiatives to publicly compare provider performance is an ironic twist. Methodologies used to derive comparative performance figures are increasingly proprietary, with their logic protected as trade secrets. Thus, while demands grow to publicize information on provider performance, details of the specific methods used to produce these figures are withheld; they are a "black box". One area with particularly strong commercial ties involves tools which quantify severity of illness [1-3]. Although severity adjustment appears an arcane methodological pursuit, findings derived from this process, severity-adjusted
Incorporating tables into proofs
- Dale Miller; Vivek Nigam
nigam at lix.inria.fr dale.miller at inria.fr Abstract. We consider the problem of automating and checking the use of previously proved lemmas in the proof of some main theorem. In particular, we call the collection of such previously proved results a table and use a partial order on the table’s entries to denote the (provability) dependency relationship between tabled items. Tables can be used in automated deduction to store previously proved subgoals and in interactive theorem proving to store a sequence of lemmas introduced by a user to direct the proof system towards some final theorem. Tables of literals can be...
Implementing deep inference in TOM
- Pierre-etienne Moreau; Antoine Reilles
Abstract. The calculus of structures is a proof theoretical formalism which generalizes sequent calculus with the feature of deep inference: in contrast to sequent calculus, the calculus of structures does not rely on the notion of main connective and, like in term rewriting, it permits the application of the inference rules at any depth inside a formula. Tom is a pattern matching processor that integrates term rewriting facilities into imperative languages. In this paper, relying on the correspondence between the systems in the calculus of structures and term rewriting systems, we present an implementation of system BV of the calculus...
<<< Back | Print
When semiconductor devices had geometries of 0.18 microns and larger, most defects manifested themselves as static faults. Test strategies based on stuck-at fault-model scan patterns and standard memory BIST (built-in selftest) were effective, and the addition of I DDQ tests and a limited set of functional patterns could improve the test quality even further. But as fabrication processes have shrunk to 130 nm and smaller, these test Memory BIST for at-speed test methods are no longer adequate. High-frequency, heavily integrated devices have physical properties that result in a different distribution of defects. In particular, the number of timing defects has...
- Matt Williams; Jon Williamson
We present a new framework for combining logic with probability, and demonstrate the application of this framework to breast cancer prognosis. Background knowledge concerning breast cancer prognosis is represented using logical arguments. This background knowledge and a database are used to build a Bayesian net that captures the probabilistic relationships amongst the variables. Causal hypotheses gleaned from the Bayesian net in turn generate new arguments. The Bayesian net can be queried to help decide when one argument attacks another. The Bayesian net is used to perform the prognosis, while the argumentation framework
On expressive and model checking power of propositional program logics
- N. V. Shilov; K. Yi
Abstract. We examine when a model checker for a propositional program logic can be used for checking another propositional program logic in spite of lack of expressive power of the first logic. We prove that (1) a branching time Computation Tree Logic CTL, (2) the propositional µ-Calculus of D. Kozen µC, and (3) the second-order propositional program logic 2M of C. Stirling enjoy the equal model checking power in spite of difference in their expressive powers CTL < µC < 2M: every listed logic has a formula such that every model checker for this particular formula for models in a...
A first order theory of planning, knowledge, and action
- Leora Morgenstern
Most AI planners work on the assumption that they have complete knowledge of their problem domain and situation so that planning an action consists of searching for an action sequence that achieves some desired goal. In actual planning situations, we rarely know enough to map out a detailed plan of action when we start out. Instead, we initially draw up a sketchy plan and fill in details as we proceed. This paper presents a formalism based upon a syntactic logic of knowledge which is expressive enough to describe this flexible planning process.
2. G. Gopalakrishnan, & P. Jain “Some Recent Asynchronous System Design Methodologies”
data path are reduced by about 0.5 pF per signal. Thus the saving in power is extended to other surrounding functions. 4. CONCLUSIONS This paper describes an asynchronous implementation of an ARM ALU. The unit exploits the fact that most operations can be completed quickly to discard the hardware typically used in an ALU to speed up a few worst-case operations; these operations are rare and so are allowed to take longer. Although it appears that a typical addition in a real programme is somewhat slower than a completely random distribution would suggest it is still much faster than the...
Manuscript revised November 25, 2006.
- Erkan Ülker; Ahmet Arslan
In this paper, we develop a new hybrid curve fitting model using fuzzy set and rough set theory. The developed method differs from classical curve fitting techniques and algorithms. For produced rule sets of model to create by using fuzzy logic technique and the membership functions of input and output functions, the range of membership functions and the relations between membership functions is utilized from the bezier curve algorithm because of it was base one of parametric curve fitting algorithms in computer graphics and computer aided geometric design. One major disadvantage in the production of parametric curves such as Bezier...
Parametric types for typed attribute-value logic
- Gerald Penn
Parametric polymorphism has been combined with inclusional polymorphism to provide nat-ural type systems for Prolog (DH88), HiLog (YFS92), and cofistraint resolution languages (Smo89), and, in linguistics, by HPSG-tike grammars to classify lists and sets of linguistic objects (PS94), and by phonologists in represen-tations of hierarchical structure (Kle91). This paper summarizes the incorporation of para-metric types into the typed attribute-value logic of (Car92), thus providing a natural extension to the type system for ALE (CP96). Following (Car92), the concern here is not with models of feature terms themselves, but with how to com-pute with parametric types, and what different kinds of...
DEDUCTIVE RETRIEVAL MECHANISMS FOR STATE DESCRIPTION MODELS
This paper presents some programming facili ties for modeling the semantics of a task domain and for describing the situations that occur in that domain as a task is being carried out. Each such description models a "state " of the task envi ronment, and any given state can be transformed into a new state by the occurrence of an event that a Iters the environment. Such modeling systems are vital in many Al systems, particularly those that do question answering and those that do automatic generation and execution monitoring of plans. The modeling mechanisms described are basically exten sions...