Comments on “general failure of logic programs”

The paper [1] purports to present a classification of the general failure sets of logic programs and a simple proof of the theorem on the soundness and completeness of the negation-as-failure rule. In this note we clarify some conflicting terminology between [1] and the papers [2, 3] to which it predominantly refers. Our main purpose, however, is to point out major errors, in particular, one in the proof of the above mentioned theorem.     

Is the success of fuzzy logic really paradoxical?: Toward the actual logic behind expert systems

The formal concept of logical equivalence in fuzzy logic, while theoretically sound, seems impractical. The misinterpretation of this concept has led to some pessimistic conclusions. Motivated by practical interpretation of truth values for fuzzy propositions, we take the class (lattice) of all subintervals of the unit interval [0, 1] as the truth value space for fuzzy logic, subsuming the traditional class of numerical truth values from [0, 1]. The associated concept of logical equivalence is stronger than the traditional one. Technically, we are dealing with much smaller set of pairs of equivalent formulas, so that we are able to check equivalence algorithmically. The checking is done by showing that our strong equivalence notion coincides with the equivalence in logic programming. © 1996 John Wiley & Sons, Inc.     

Implementing the ‘Fool's model’ of combinatory logic

This paper studies Fool's models of combinatory logic, and relates them to Hindley's D-completeness problem. A fool's model is a family of sets of formulas, closed under condensed detachment. Alternatively, it is a model ofCL in naive set theory. We examine Resolution; and the P-W problem. A sequel shows T is D-complete; also, its extensions. We close with an implementation FMO of these ideas.     

Notes on automata theory based on quantum logic

The main results are as follows: (1) it deals with a number of basic operations (concatenation, Kleene closure, homomorphism, complement); (2) due to a condition imposed on the implication operator for discussing some basic issues in orthomodular lattice-valued automata, this condition is investigated in detail, and it is discovered that all the relatively reasonable five implication operators in quantum logic do not satisfy this condition, and that one of the five implications satisfies such a condition iff the truth-value lattice is indeed a Boolean algebra; (3) it deals further with orthomodular lattice-valued successor and source operators; (4) an example is provided, implying that some negative results obtained in the literature may still hold in some typical orthomodular lattice-valued automata.     

Theory of truth degrees of propositions in the logic system L_n~*

Approximate reasoning based on the idea of fuzzy sets was firstly proposed by Zadeh[1] in 1973, which differs from the one advocated in Artificial Intelligence. Indeed, Artificial Intelligence emphasizes symbolic manipulation and roots itself in logic, em…     

Older females in the workforce – the effects of age on psychophysical estimates of maximum acceptable lifting loads

Abstract

The number of older workers in the workforce is increasing substantially, and advanced age is associated with factors that could influence musculoskeletal injury risk and work capacity. This study’s goals were to test whether psychophysical estimates of maximum acceptable weight of lift (lift_max) differed between younger and older workers, and to examine potential explanatory factors. Twenty-four female workers (half 50 + years; half 20–32 years) self-adjusted a box’s mass to their perceived lift_max during four lifting tasks. Older workers’ lift_max values were significantly lower (by approximately 24%) than their younger counterparts. There were no age-related differences in resting heart rate, or peak joint angles and final heart rate during the lifting trials. However, the older group demonstrated lower grip strength (by 24%), and lower heart rate reserve during the trials (by 18%). These results question whether current maximum acceptable lifting weights based on psychophysical information are appropriately protective for female workers greater than 50 years of age.

Practitioner Summary: This psychophysical study demonstrated that older female workers (aged 50–63 years) selected maximum acceptable lift masses that were (on average) 24% lower than younger workers (aged 20–32 years), which corresponded with lower grip strength and heart rate reserve. Current maximum acceptable lifting weights based on psychophysical information may not protect female workers greater than 50 years of age.     

An algebraic axiomatization of the Ewald’s intuitionistic tense logic

Ewald (J Symbolic Logic 51(1):166–179, 1986) considered tense operators \(G\) , \(H\) , \(F\) and \(P\) on intuitionistic propositional calculus and constructed an intuitionistic tense logic system called IKt. The aim of this paper is to give an algebraic axiomatization of the IKt system. We will also show that the algebraic axiomatization given by Chajda (Cent Eur J Math 9(5):1185–1191, 2011) of the tense operators \(P\) and \(F\) in intuitionistic logic is not in accordance with the Halmos definition of existential quantifiers. In this paper, we will study the IKt variety of IKt-algebras. First, we will introduce some examples and we will prove some properties. Next, we will prove that the IKt system has IKt-algebras as algebraic counterpart. We will also describe a discrete duality for IKt-algebras bearing in mind the results indicated by Or?owska and Rewitzky (Fundam Inform 81(1–3):275–295, 2007) for Heyting algebras. We will also get a general construction of tense operators on a complete Heyting algebra, which is a power lattice via the so-called Heyting frame. Finally, we will introduce the notion of tense deductive system which allowed us both to determine the congruence lattice in an IKt-algebra and to characterize simple and subdirectly irreducible algebras of the IKt variety.     

Conformity on the Internet – The role of task difficulty and gender differences

Conformity and the effects of social influence have been studied for a long time in face-to-face situations but have received less attention in contexts of computer-mediated communication (CMC) such as the Internet. The purpose of this study was to investigate conformity behavior in use of the Internet. The social context for the participants was the Internet communities from which they were recruited. Four hypotheses were tested by a survey containing knowledge and logic questions. Half the participants were subjected to conformity manipulations and the result showed a clear conformity to erroneous majority alternatives. Of the participants in the Conformity group (n = 477) 52.6% conformed at least once, with an average 13.0% of participants conforming on each critical question. The conformity increased with higher task difficulty, both subjective and objective. The fourth hypothesis, that women would conform to a higher degree than men, received no support. Instead, the results showed higher conformity for men on both difficult and logical questions. Reasons for conformity on the Internet such as turning to the group for guidance, avoiding social isolation and protecting one’s self-esteem are discussed with reference to theory and earlier research.     

Revising Z: Part I – logic and semantics

This is the first of two related papers. We introduce a simple specification logic Z _C comprising a logic and a semantics (in ZF set theory) within which the logic is sound. We then provide an interpretation for (a rational reconstruction of) the specification language Z within Z _C . As a result we obtain a sound logic for Z, including a basic schema calculus. Received March 1998 / Accepted in revised form April 1999     

A modal contrastive logic: The logic of ‘but’

In this paper we present a modal approach to contrastive logic, the logic of contrasts as these appear in natural language conjunctions such as but. We use a simple modal logic, which is an extension of the well-knownS5 logic, and base the contrastive operators proposed by Francez in [2] on the basic modalities that appear in this logic. We thus obtain a logic for contrastive operators that is more in accord with the tradition of intensional logic, and that, moreover — we argue — has some more natural properties. Particularly, attention is paid to nesting contrastive operators. We show that nestings of but give quite natural results, and indicate how nestings of other contrastive operators can be done adequately. Finally, we discuss the example of the Hangman's Paradox and some similarities (and differences) with default reasoning. But but us no buts, as they say.Also partially supported by Nijmegen University, Toernooiveld, 6525 ED Nijmegen, The Netherlands.     

Blind-friendly user interfaces – a pilot study on improving the accessibility of touchscreen interfaces

Multimedia Tools and Applications - Touchscreen devices such as a smartphone, smartwatch, and tablets are essential assistive devices for visually impaired and blind people in performing activities...     

A fuzzy logic system based on Schweizer-Sklar t-norm

In recent years, the basic research of fuzzy logic and fuzzy reasoning is growing ac- tively day by day, such as the basic logic system BL proposed by Hajek[1]; fuzzy logic system MTL proposed by Esteva and Godo[2]; fuzzy reasoning, implication operators …     

Smart home – digitally engineered domestic life

The purpose of the Smart Home Project is to devise a set of intelligent home appliances that can provide an awareness of the users' needs, providing them with a better home life experience without overpowering them with complex technologies and intuitive user interfaces. Our main aim for the project is to improve day-to-day home life with smart computer technologies while still keeping the home life as normal as possible – we refer to this as digitally engineering analogue home life.     

Applying Approximate Counting for Computing the Frequency Moments of Long Data Streams

This paper takes up a remark in the well-known paper of Alon, Matias, and Szegedy (J. Comput. Syst. Sci. 58(1):137–147, 1999) about the computation of the frequency moments of data streams and shows in detail how any F _k with k≥1 can be approximately computed using space O(km ^1−1/k (k+log m+log log  n)) based on approximate counting. An important building block for this, which may be interesting in its own right, is a new approximate variant of reservoir sampling using space O(log log  n) for constant error parameters.     

The light side of interval temporal logic: the Bernays-Schönfinkel fragment of CDT

Decidability and complexity of the satisfiability problem for the logics of time intervals have been extensively studied in the recent years. Even though most interval logics turn out to be undecidable, meaningful exceptions exist, such as the logics of temporal neighborhood and (some of) the logics of the subinterval relation. In this paper, we explore a different path to decidability: instead of restricting the set of modalities or imposing severe semantic restrictions, we take the most expressive interval temporal logic studied so far, namely, Venema’s CDT, and we suitably limit the negation depth of modalities. The decidability of the satisfiability problem for the resulting fragment, called CDT_BS, over the class of all linear orders, is proved by embedding it into a well-known decidable quantifier prefix class of first-order logic, namely, Bernays-Schönfinkel class. In addition, we show that CDT_BS is in fact NP-complete (Bernays-Schönfinkel class is NEXPTIME-complete), and we prove its expressive completeness with respect to a suitable fragment of Bernays-Schönfinkel class. Finally, we show that any increase in the negation depth of CDT_BS modalities immediately yields undecidability.     

Inventing the future – The vision of the Jericho Forum

The world of the future will be very different from today. We can expect to encounter radical changes as the Information Age transforms business, society and security. Information Security professionals must look ahead, embrace the challenges and develop new forward-looking security solutions. This paper explains why and how this can be done, and explains the vision and work of the Jericho Forum, a new group that is setting out to do just that.     

LectureLounge – experience education beyond the borders of the classroom

Capturing presentations (lectures, seminars, etc.) on video is on the brink of becoming a normal event in educational environments. However, a breakthrough has yet to occur. Why is this so? First, it seems that capturing purely video is not enough to capture the whole educational experience [4]. Second, while equipment is relatively cheap, the amount and quality of manual work needed to operate capturing and publication systems is very high, and thus so are the costs. Third, systems that support the capturing process by including additional metadata tend to be intrusive on the presenter’s way of working.We would like to introduce LectureLounge [3], a presentation capturing, management, and publication system that shows that it does not have to be this way.     

The impact of the nature of globally distributed work arrangement on work–life conflict and valence: the Indian GSD professionals’ perspective

While there is a rich literature exploring the various facets of Globally Distributed Systems Development (GSD), there is scant attention given to the human resource issues such as work–life conflict (WLC) faced by GSD professionals and their valence toward globally distributed work. In this study, we attempt to identify factors that influence offshore GSD workers’ WLC and their valence toward globally distributed work. Specifically, we focus on factors related to the nature of the distributed work arrangements as experienced by offshore Indian workers involved in GSD. On the basis of survey data, we find support for the impact of a number of distribution-related variables on WLC and valence.