4,889 research outputs found

    The finite representation property for composition, intersection, domain and range

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    We prove that the nite representation property holds for rep- resentation by partial functions for the signature consisting of composition, intersection, domain and range and for any expansion of this signature by the antidomain, xset, preferential union, maximum iterate and opposite opera- tions. The proof shows that, for all these signatures, the size of base required is bounded by a double-exponential function of the size of the algebra. This establishes that representability of nite algebras is decidable for all these signatures. We also give an example of a signature for which the nite repre- sentation property fails to hold for representation by partial functions

    Representations of (2,n)(2,n)-semigroups by multiplace functions

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    We describe the representations of (2,n)(2,n)-semigroups, i.e. groupoids with nn binary associative operations, by partial nn-place functions and prove that any such representation is a union of some family of representations induced by Schein's determining pairs.Comment: 17 page

    Traversable Wormholes in Geometries of Charged Shells

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    We construct a static axisymmetric wormhole from the gravitational field of two charged shells which are kept in equilibrium by their electromagnetic repulsion. For large separations the exterior tends to the Majumdar-Papapetrou spacetime of two charged particles. The interior of the wormhole is a Reissner-Nordstr\"om black hole matching to the two shells. The wormhole is traversable and connects to the same asymptotics without violation of energy conditions. However, every point in the Majumdar-Papapetrou region lies on a closed timelike curve.Comment: 9 pages, LaTeX, 1 figur

    Representations of Menger (2,n)(2,n)-semigroups by multiplace functions

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    Investigation of partial multiplace functions by algebraic methods plays an important role in modern mathematics were we consider various operations on sets of functions, which are naturally defined. The basic operation for nn-place functions is an (n+1)(n+1)-ary superposition [][ ], but there are some other naturally defined operations, which are also worth of consideration. In this paper we consider binary Mann's compositions \op{1},...,\op{n} for partial nn-place functions, which have many important applications for the study of binary and nn-ary operations. We present methods of representations of such algebras by nn-place functions and find an abstract characterization of the set of nn-place functions closed with respect to the set-theoretic inclusion

    Inverse monoids and immersions of 2-complexes

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    It is well known that under mild conditions on a connected topological space X\mathcal X, connected covers of X\mathcal X may be classified via conjugacy classes of subgroups of the fundamental group of X\mathcal X. In this paper, we extend these results to the study of immersions into 2-dimensional CW-complexes. An immersion f:DCf : {\mathcal D} \rightarrow \mathcal C between CW-complexes is a cellular map such that each point yDy \in {\mathcal D} has a neighborhood UU that is mapped homeomorphically onto f(U)f(U) by ff. In order to classify immersions into a 2-dimensional CW-complex C\mathcal C, we need to replace the fundamental group of C\mathcal C by an appropriate inverse monoid. We show how conjugacy classes of the closed inverse submonoids of this inverse monoid may be used to classify connected immersions into the complex

    More than a cognitive experience: unfamiliarity, invalidation, and emotion in organizational learning

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    Literature on organizational learning (OL) lacks an integrative framework that captures the emotions involved as OL proceeds. Drawing on personal construct theory, we suggest that organizations learn where their members reconstrue meaning around questions of strategic significance for the organization. In this 5-year study of an electronics company, we explore the way in which emotions change as members perceive progress or a lack of progress around strategic themes. Our framework also takes into account whether OL involves experiences that are familiar or unfamiliar and the implications for emotions. We detected similar patterns of emotion arising over time for three different themes in our data, thereby adding to OL perspectives that are predominantly cognitive in orientation

    Corporate Culture and Its Connection with External and Internal Public Relations

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    The main aim of this article is to present the influence of corporate culture on company's stakeholders. This paper signalises the tendency in corporate communication with its internal and external publics. It is focused on two issues: corporate social responsibility and employer branding. Those two categories are consequences of corporate culture model.Głównym celem artykułu jest zaprezentowanie wpływu jaki wywiera charakter kultury korporacyjnej na związanych z przedsiębiorstwem interesariuszy (stakeholders). W artykule zasygnalizowane zostały główne tendencje wyznaczające charakter komunikacji między organizacją a jej wewnętrznym i zewnętrznym otoczeniem. Tekst koncentruje się na dwóch kwestiach: społecznej odpowiedzialności przedsiębiorstwa (corporate social responsibilty) i budowanie wizerunku pracodawcy (employer branding), które zaprezentowane zostały jako efekty określonego modelu kultury organizacyjnej

    Psychological climates in action learning sets: A manager’s perspective

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    Action Learning (AL) is often viewed as a process that facilitates professional learning through the creation of a positive psychological climate (Marquart, 2000; Schein, 1979). An psychological climate that fosters an environment in which learning set members feel psychologically safe enough to reflect upon both the successes, and failures in their professional life without any form of repercussion. However, there has been little attention given to the ways that that psychological climate develops, and the differing facets that create that climate. In response to such deficit, this paper reports the outcomes of interviews with eleven managers, all of whom are former AL set members on their experiences of action learning set membership. Drawing upon an interpretivist philosophy, the paper explores the key themes that emerged from the analysis of those interviews. The analysis serves to illustrate the differing facets that collectively contribute creation of a positive psychological climate that is conducive for learning. Analysis points to the relative importance of such facets as: trust, honesty, vulnerability, reciprocity, confidentiality and personal disclosure, all of which have the capacity to lead to a positive psychological climate in action learning sets. This paper is useful for developing an understanding of the differing facets in AL sets that create a psychological climate conducive for learning. As such, it has utility for action learning facilitators, set members, academics and educational consultants

    Psychological Safety and Norm Clarity in Software Engineering Teams

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    In the software engineering industry today, companies primarily conduct their work in teams. To increase organizational productivity, it is thus crucial to know the factors that affect team effectiveness. Two team-related concepts that have gained prominence lately are psychological safety and team norms. Still, few studies exist that explore these in a software engineering context. Therefore, with the aim of extending the knowledge of these concepts, we examined if psychological safety and team norm clarity associate positively with software developers' self-assessed team performance and job satisfaction, two important elements of effectiveness. We collected industry survey data from practitioners (N = 217) in 38 development teams working for five different organizations. The result of multiple linear regression analyses indicates that both psychological safety and team norm clarity predict team members' self-assessed performance and job satisfaction. The findings also suggest that clarity of norms is a stronger (30\% and 71\% stronger, respectively) predictor than psychological safety. This research highlights the need to examine, in more detail, the relationship between social norms and software development. The findings of this study could serve as an empirical baseline for such, future work.Comment: Submitted to CHASE'201
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