Designing inclusive products for everyday environments: the effects of everyday cold temperatures on older adults’ dexterity

This paper focuses on the effect that an everyday cold temperature (5 °C) can have on older adults’ (+65 years) dexterous capabilities and the implications for design. Fine finger capability, power and pinch grip were measured using objective performance measures. Ability to perform tasks using a mobile phone, stylus, touch screen and garden secateurs were also measured. All measures were performed in a climatic cold chamber regulated at 5 °C and in a thermo-neutral environment regulated between 19 °C and 24 °C. Participants were exposed to the cold for a maximum of 40 min. Results from the study showed that older adults’ fine finger dexterity, ability to pick up and place objects and ability to use a mobile phone were significantly (p < 0.05) affected by an everyday cold temperature of 5 °C when compared to performance in the thermo-neutral environment. However, power and pinch grip strength and ability to use the gardening secateurs were not significantly affected by the cold. Based on these findings, the following guidance is offered to designers developing products that are likely to be used outside in an everyday cold environment: (1) minimise the number of product interactions that require precise fine finger movements; (2) try to avoid small controls that have to be pressed in a sequence; (3) maximise the number of product interactions that can be operated through either exerting a gripping action (power or pinch grip) or by gross hand and arm movements.     

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.     

On the Performance of Approximate Equilibria in Congestion Games

We study the performance of approximate Nash equilibria for congestion games with polynomial latency functions. We consider how much the price of anarchy worsens and how much the price of stability improves as a function of the approximation factor ε. We give tight bounds for the price of anarchy of atomic and non-atomic congestion games and for the price of stability of non-atomic congestion games. For the price of stability of atomic congestion games we give non-tight bounds for linear latencies. Our results not only encompass and generalize the existing results of exact equilibria to ε-Nash equilibria, but they also provide a unified approach which reveals the common threads of the atomic and non-atomic price of anarchy results. By expanding the spectrum, we also cast the existing results in a new light.     

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.     

Anticipation – the underlying science of sport. Report on research in progress

Professional sport practitioners intuitively acknowledge anticipation. Sports researchers sometimes discuss it. Still, there is little data-based evidence to characterize the role anticipation plays in human performance. Even less documented is the distinction between reaction and anticipation. This text presents the real-time quantification environment developed as an AnticipationScope?. Based on a very large data harvest from this experimental set-up, hypotheses regarding the role of anticipation in sport are advanced. The conclusion is that while preparation and reaction play an important role in sports performance, in the final analysis anticipation distinguishes the professional from other sport practitioners. Work in progress is presented with the aim of engaging the community of researchers in the design of alternative methods for quantifying anticipation and for processing the data. Generalization from sport to human performance is one of the intended outcomes of this research.     

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.     

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     

Designing electronic feedback – Analyzing the effects of social presence on perceived feedback usefulness

Feedback interventions, i.e. actions taken by (an) external agent(s) to provide information regarding one׳s task performance, are an important element in motivating and raising performance. Especially the perceived feedback usefulness determines its positive effects. In today׳s digitalized world, feedback is more often given electronically, i.e. computer-mediated or even automated by computer systems. Those feedback interventions׳ effect on perceptions resulting from the difference of communication media is essentially considered by the concept of social presence. However, information systems (IS) research lacks a structured evaluation of possible design choices of feedback media, their influence on the social presence and subsequent effect on the perceived feedback usefulness. To close this research gap, we conduct a laboratory experiment with 43 participants in which we analyze six different design choices for feedback media. We applied a 2×3 experimental design covering the feedback source (human, non-human feedback) and media richness (text, audio, and video). We show that social presence directly and mediated by the perceived trustworthiness of feedback on simple IT-based tasks impacts perceived feedback usefulness. Our study concludes by outlining opportunities for future research and practical implications for human and non-human (i.e. automated) feedback.     

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 …     

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.