983 resultados para relational theory


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Computation of the dependency basis is the fundamental step in solving the membership problem for functional dependencies (FDs) and multivalued dependencies (MVDs) in relational database theory. We examine this problem from an algebraic perspective. We introduce the notion of the inference basis of a set M of MVDs and show that it contains the maximum information about the logical consequences of M. We propose the notion of a dependency-lattice and develop an algebraic characterization of inference basis using simple notions from lattice theory. We also establish several interesting properties of dependency-lattices related to the implication problem. Founded on our characterization, we synthesize efficient algorithms for (a): computing the inference basis of a given set M of MVDs; (b): computing the dependency basis of a given attribute set w.r.t. M; and (c): solving the membership problem for MVDs. We also show that our results naturally extend to incorporate FDs also in a way that enables the solution of the membership problem for both FDs and MVDs put together. We finally show that our algorithms are more efficient than existing ones, when used to solve what we term the ‘generalized membership problem’.

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Classical relational databases lack proper ways to manage certain real-world situations including imprecise or uncertain data. Fuzzy databases overcome this limitation by allowing each entry in the table to be a fuzzy set where each element of the corresponding domain is assigned a membership degree from the real interval [0…1]. But this fuzzy mechanism becomes inappropriate in modelling scenarios where data might be incomparable. Therefore, we become interested in further generalization of fuzzy database into L-fuzzy database. In such a database, the characteristic function for a fuzzy set maps to an arbitrary complete Brouwerian lattice L. From the query language perspectives, the language of fuzzy database, FSQL extends the regular Structured Query Language (SQL) by adding fuzzy specific constructions. In addition to that, L-fuzzy query language LFSQL introduces appropriate linguistic operations to define and manipulate inexact data in an L-fuzzy database. This research mainly focuses on defining the semantics of LFSQL. However, it requires an abstract algebraic theory which can be used to prove all the properties of, and operations on, L-fuzzy relations. In our study, we show that the theory of arrow categories forms a suitable framework for that. Therefore, we define the semantics of LFSQL in the abstract notion of an arrow category. In addition, we implement the operations of L-fuzzy relations in Haskell and develop a parser that translates algebraic expressions into our implementation.

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Resumen tomado de la publicaci??n

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Cognitive complexity and control theory and relational complexity theory attribute developmental changes in theory of mind (TOM) to complexity. In 3 studies, 3-, 4-, and 5-year-olds performed TOM tasks (false belief, appearance-reality), less complex connections (Level 1 perspective-taking) tasks, and transformations tasks (understanding the effects of location changes and colored filters) with content similar to TOM. There were also predictor tasks at binary-relational and ternary-relational complexity levels, with different content. Consistent with complexity theories: (a) connections and transformations were easier and mastered earlier than TOM; (b) predictor tasks accounted for more than 80% of age-related variance in TOM; and (c) ternary-relational items accounted for TOM variance, before and after controlling for age and binary-relational items. Prediction did not require hierarchically structured predictor tasks.

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Major infrastructure assets are often governed by a mix of public and private organizations, each fulfilling a specific and separate role i.e. policy, ownership, operation or maintenance. This mix of entities is a legacy of Public Choice Theory influenced NPM reforms of the late 20th century. The privatization of the public sector has resulted in agency theory based ‘self-interest’ relationships and governance arrangements for major infrastructure assets which emphasize economic efficiency but which do not do not advance non-economic public values and the collective Public Interest. The community is now requiring that governments fulfill their stewardship role of also satisfying non-economic public values such as sustainability and intergenerational responsibility. In the 21st century governance arrangements which minimize individual self-interest alone and look to also pursue the interests of other stakeholders have emerged. Relational contracts, Public-Private Partnerships (PPP’s) and hybrid mixes of organizations from the state, market and network modes (Keast et al 2006) provide options for governance which better meet the interests of contractors, government and the community there is emerging a body of research which extends the consideration of the immediate governance configuration to the metagovernance environment constituted by hierarchy, regulation, industry standards, trust, culture and values. Stewardship theory has reemerged as a valuable aid in the understanding of the features of governance configurations which establish relationships between principal and agent which maximize the agent acting in the interests of the principal, even to the detriment of the agent. This body of literature suggests that an improved stewardship outcome from infrastructure governance configurations can be achieved by the application of the emerging options as to the immediate governance configuration, and the surrounding metagovernance environment. Stewardship theory provides a framework for the design of the relationships within that total governance environment, focusing on the achievement of a better, complete stewardship outcome. This paper explores the directions future research might take in seeking to improve the understanding of the design of the governance of major, critical infrastructure assets.

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Despite its importance in the development of competitive advantage, attempts to unify diverse classifications of business-to-business relational exchange have been largely unsuccessful. We used 18 semi-structured, in-depth interviews with managers from a wide range of industries to explain the business-to-business relational exchange construct. Analysis of the data revealed that business-to-business relational exchange comprises five key dimensions. These are communication, compatibility, commitment, trust and power symmetry. The research highlights the importance of personal interaction in business relationships and provided additional insights into the importance of affective commitment. In addition we reveal a number of negative consequences of affective commitment, which have been previously unexplored. A new conceptual model of business-to-business relational exchange is presented, which synthesises these findings and directs future research.

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This chapter introduces the reader to the relational approach to information literacy, its evolution and use in contemporary research and emerging directions. It presents the relational approach, first introduced by Australian information literacy researchers, as an integration of experiential, contextual and transformational perspectives. The chapter opens with a reflection on the wider information literacy domain. It then addresses the development of the approach, its fundamental elements and characteristics, and explores the adoption of the approach in key contexts including education, workplace and community settings. The chapter explores significant studies that have contributed to its evolution and reflects on the impact of the development of the relational framework and related research. The chapter concludes with a focus on directions emerging from the relational understanding ofinformation literacy and potential implications.

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The openness and compassion implicit in the social transaction of recent philosophies of cosmopolitanism is reflected in the aims of the body of interpersonal, process-driven artworks commonly referred to as relational art. In attempting to bring art into life, specifically as a point of intervention in the lives of its spectators, the affective power required to realize the communal and participatory aims of many of these artworks is central. Relational art practices invite the individualising distinctiveness of the spectator yet ultimately seek the collective affect of the artwork’s formulated community. Like cosmopolitanism, this is a felt community where the obligatory affective investment is imagined as open and empathic built on mutual exchange and generosity. They suggest that it doesn’t matter so much what we feel about art but what and how we feel through art. The artworld’s public spheres have become increasingly affective worlds, where the artwork’s coerced and managed human relations are conceived as interstices for a more open exchange with art and each other. With reference to Sydney Biennale’s recent All My Relations exhibition, this paper will interrogate how worldly feelings are made material by the requisite emotional and aesthetic labour of feeling for and with others in relational art.

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Purpose In the mainstream relationship management literature, critical appraisal of the relationship paradigm in an international setting is virtually non-existent. The extant literature reveals a gap in terms of linking relationship management theories with international management. Furthermore, little research attention has been paid to synthesise the existing theories in a cohesive manner towards developing a theoretical paradigm in the interface of the importer-supplier relationship dyad. Thus, the purpose of this paper is to strengthen the theoretical grounds of relationship marketing in an international setting in an importer-exporter relationship context. Design/methodology/approach The paper follows a comprehensive review approach and applies the fundamental theory of trust and commitment to identify the relational factors. More precisely, the paper identifies and applies other relevant theories such as internationalisation process theory, resource-based theory of the firm, dependence theory and transaction cost theory in developing an innovative theoretical paradigm. Findings Based on the integration of extant theories, this paper proposes a new direction in the theoretical realm of the trust and commitment building process within an importer and supplier relationship management paradigm. The research concludes that trust and commitment are the focal factors within the international relational paradigm. Research limitations/implications The proposed research direction suggests an emerging framework integrating mainstream theoretical variables of trust and commitment in importer and foreign-supplier context. This novel framework has the potential for use in further research. Originality/value This paper advances a grounded theoretical exploration within an international management domain in the context of importers and foreign-suppliers.

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Functional dependencies in relational databases are investigated. Eight binary relations, viz., (1) dependency relation, (2) equipotence relation, (3) dissidence relation, (4) completion relation, and dual relations of each of them are described. Any one of these eight relations can be used to represent the functional dependencies in a database. Results from linear graph theory are found helpful in obtaining these representations. The dependency relation directly gives the functional dependencies. The equipotence relation specifies the dependencies in terms of attribute sets which functionally determine each other. The dissidence relation specifies the dependencies in terms of saturated sets in a very indirect way. Completion relation represents the functional dependencies as a function, the range of which turns out to be a lattice. Depletion relation which is the dual of the completion relation can also represent functional dependencies and similarly can the duals of dependency, equipotence, and dissidence relations. The class of depleted sets, which is the dual of saturated sets, is defined and used in the study of depletion relations.

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Functional dependencies in relational databases are investigated. Eight binary relations, viz., (1) dependency relation, (2) equipotence relation, (3) dissidence relation, (4) completion relation, and dual relations of each of them are described. Any one of these eight relations can be used to represent the functional dependencies in a database. Results from linear graph theory are found helpful in obtaining these representations. The dependency relation directly gives the functional dependencies. The equipotence relation specifies the dependencies in terms of attribute sets which functionally determine each other. The dissidence relation specifies the dependencies in terms of saturated sets in a very indirect way. Completion relation represents the functional dependencies as a function, the range of which turns out to be a lattice. Depletion relation which is the dual of the completion relation can also represent functional dependencies and similarly can the duals of dependency, equipotence, and dissidence relations. The class of depleted sets, which is the dual of saturated sets, is defined and used in the study of depletion relations.

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- Purpose This paper aims to investigate how direct mail consumption contributes to brand relationship quality. Store flyers and other direct mailings continue to play a significant role in many companies’ communication strategies. Research on this topic predominantly investigates driving store traffic and sales. Less is known regarding the consumer side, such as the value that consumers may derive from the consumption of direct mailings and the effects of such a value on brand relationship quality. To address this limitation, this paper tests a causal model of the contribution of direct mail value to brand commitment, drawing on a value framework that integrates social theory of engagement regimes and literature on experiential customer value. - Design/methodology/approach The empirical work of this paper is based on a rigorous four-study mixed methods design, involving qualitative study, confirmatory factor analysis and partial least squares structural modeling. - Findings The authors develop two second-order formatively designed scales – familiar value and planned value scales – that illustrate the role of engagement regimes in consumer behavior. Although both types of value contribute equally to direct mail attachment, they exert contrasting effects on other mediational consumer responses, such as reading and gratitude. Finally, the proposed theoretical model appears to be robust in predicting customers’ brand commitment. - Research limitations/implications This study provides new insights into the research on consumer value and brand relational communication. - Originality/value This study is the first to consider consumer benefits from the social perspective of engagement regimes.

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This study analyses personal relationships linking research to sociological theory on the questions of the social bond and on the self as social. From the viewpoint of disruptive life events and experiences, such as loss, divorce and illness, it aims at understanding how selves are bound to their significant others as those specific people ‘close or otherwise important’ to them. Who form the configurations of significant others? How do different bonds respond in disruptions and how do relational processes unfold? How is the embeddedness of selves manifested in the processes of bonding, on the one hand, and in the relational formation of the self, on the other? The bonds are analyzed from an anti-categorical viewpoint based on personal citations of significance as opposed to given relationship categories, such as ‘family’ or ‘friendship’ – the two kinds of relationships that in fact are most frequently significant. The study draws from analysis of the personal narratives of 37 Finnish women and men (in all 80 interviews) and their entire configurations of those specific people who they cite as ‘close or otherwise important’. The analysis stresses the subjective experiences, while also investigating the actualized relational processes and configurations of all personal relationships with certain relationship histories embedded in micro-level structures. The research is based on four empirical sub-studies of personal relationships and a summary discussing the questions of the self and social bond. Discussion draws from G. H. Mead, C. Cooley, N. Elias, T. Scheff, G. Simmel and the contributors of ‘relational sociology’. Sub-studies analyse bonds to others from the viewpoint of biographical disruption and re-configuration of significant others, estranged family bonds, peer support and the formation of the most intimate relationships into exclusive and inclusive configurations. All analyses examine the dialectics of the social and the personal, asking how different structuring mechanisms and personal experiences and negotiations together contribute to the unfolding of the bonds. The summary elaborates personal relationships as social bonds embedded in wider webs of interdependent people and social settings that are laden with cultural expectations. Regarding the question of the relational self, the study proposes both bonding and individuality as significant. They are seen as interdependent phases of the relationality of the self. Bonding anchors the self to its significant relationships, in which individuality is manifested, for example, in contrasting and differentiating dynamics, but also in active attempts to connect with others. Individuality is not a fixed quality of the self, but a fluid and interdependent phase of the relational self. More specifically, it appears in three formats in the flux of relational processes: as a sense of unique self (via cultivation of subjective experiences), as agency and as (a search for) relative autonomy. The study includes an epilogue addressing the ambivalence between the social expectation of individuality in society and the bonded reality of selves.

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A fundamental problem in the analysis of structured relational data like graphs, networks, databases, and matrices is to extract a summary of the common structure underlying relations between individual entities. Relational data are typically encoded in the form of arrays; invariance to the ordering of rows and columns corresponds to exchangeable arrays. Results in probability theory due to Aldous, Hoover and Kallenberg show that exchangeable arrays can be represented in terms of a random measurable function which constitutes the natural model parameter in a Bayesian model. We obtain a flexible yet simple Bayesian nonparametric model by placing a Gaussian process prior on the parameter function. Efficient inference utilises elliptical slice sampling combined with a random sparse approximation to the Gaussian process. We demonstrate applications of the model to network data and clarify its relation to models in the literature, several of which emerge as special cases.