156 resultados para isomorphism
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Methods for representing equivalence problems of various combinatorial objects as graphs or binary matrices are considered. Such representations can be used for isomorphism testing in classification or generation algorithms. Often it is easier to consider a graph or a binary matrix isomorphism problem than to implement heavy algorithms depending especially on particular combinatorial objects. Moreover, there already exist well tested algorithms for the graph isomorphism problem (nauty) and the binary matrix isomorphism problem as well (Q-Extension). ACM Computing Classification System (1998): F.2.1, G.4.
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2000 Mathematics Subject Classification: 35P25, 35R30, 58J50.
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2010 Mathematics Subject Classification: Primary 18G35; Secondary 55U15.
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This paper addresses the issues of hotel operators identifying effective means of allocating rooms through various electronic channels of distribution. Relying upon the theory of coercive isomorphism, a think tank was constructed to identify and define electronic channels of distribution currently being utilized in the hotel industry. Through two full-day focus groups consisting of key hotel electives and industry practitioners, distribution channels wen identified as were challenges and solutions associated with each
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This paper addresses the issues of hotel operators identifying effective means of allocating rooms through various electronic channels of distribution. Relying upon the theory of coercive isomorphism, a think tank was constructed to identify and define electronic channels of distribution currently being utilized in the hotel industry. Through two full-day focus groups consisting of key hotel executives and industry practitioners, distribution channels were identified as were challenges and solutions associated with each.
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This study examines the triple bottom line of sustainability, in the context of both profit-oriented and non-profit oriented organizations. Sustainability is a compound result of interaction between economic, environmental, and social dimensions. Sustainability cannot be achieved without balance between all three dimensions, which has implications for measuring sustainability and prioritizing goals. This study demonstrates a method for measuring organizational sustainability achievement in these three dimensions of sustainability. Content analysis of the annual reports of corporations from the United States, Continental Europe (and Scandinavia), and Asia reveals that the economic dimension remains the preeminent aspect, and corporations still have a long way to go to reach comprehensive sustainability by maintaining a balance between the three dimensions of sustainability. The analysis also shows a high level of isomorphism in the sustainability practices of corporations, suggesting that even the most sustainable corporations are taking a somewhat passive role in prioritizing sustainability goals. A list of 25 terms for each dimension of sustainability (economic, environmental, and social) has been developed which can be used by corporations to develop and communicate their sustainability practices most effectively to the maximum number of their stakeholders. In contrast, botanical gardens demonstrate more balance among the three dimensions of sustainability.
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This paper examines the international diffusion of one business practice, project management, through the prism of prior literature and data on the diffusion of ISO 9000. The study took an inductive approach, building theory through the iterative collection and analysis of quantitative and qualitative data. The findings problematise the central position accorded to the S-curve model and neo-institutional theory in explaining technology diffusion. The research posits three distinct processes driving the diffusion process: utility, institutional isomorphism, and competitive isomorphism, with the latter consisting of three primary mechanisms: competitive imitation, trendslators and fashion retailers. Contrary to prior literature, national, quasi-professional associations are found to be central to the diffusion process and play a key role in advocating and containing management technologies.
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There has been private sector involvement in the delivery of public services in the Irish State since its foundation. This involvement was formalised in 1998 when Public Private Partnership (PPP) was officially introduced. Ireland is a latecomer to PPP and, prior to the credit crisis, was seen as a ‘rapid follower’ relying primarily on the UK PPP model in the procurement of infrastructure in transport, education, housing/urban regeneration and water/wastewater. PPP activity in Ireland stalled during the credit crisis, and some projects were cancelled, but it has taken off again recently with part of the Infrastructure and Capital Investment Plan 2016 – 2021 to be delivered through PPP showing continuing political commitment to PPP. Ireland’s interest in PPP cannot be explained by economic rationale alone, as PPP was initiated during a period of prosperity. We consider three alternative explanations: voluntary adoption – where the UK model was closely followed; coercive adoption – where PPP policy was forced upon Ireland; and institutional isomorphism – where institutional creation and change was promoted to aid public sector organisations in gaining institutional legitimacy. We find evidence of all three patterns, with coercive adoption becoming more relevant in recent years. Ireland’s rapid uptake of PPP differs from other European countries, mostly because when PPP was introduced in 1998, the Irish State was in an economic position where it could have directly procured necessary infrastructure. This paper therefore asks why PPP was adopted and how this adoption pattern has affected the sustainability of PPP in Ireland. This paper defines PPP; examines the background to the PPP approach adopted in Ireland; outlines the theoretical framework of the paper: transfer theory and institutional theory; discusses the methodology; reports on findings and gives conclusions.
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Ireland is a latecomer to Public Private Partnership (PPP) having only adopted it in 1998. Prior to the credit crisis, Ireland followed the UK model with PPPs being implemented in transport, education, housing/urban regeneration and water/wastewater. Having stalled during the credit crisis, PPP has been reactivated recently with the domestic infrastructure stimulus programme . The focus of this paper is on Ireland as a younger participant in PPP and the nexus between adoption patterns and sustainability characteristics of Irish PPP. Using document analysis and exploratory interviews, the paper examines the reasons for Ireland’s interest in PPP which cannot be attributed to economic rationales alone. We consider three explanations: voluntary adoption – where the UK model was closely followed as part of a domestic modernisation agenda; coercive adoption – where PPP policy was forced upon public sector organisations; and institutional isomorphism – where institutional creation and change around PPP was promoted to help public sector organisations gain institutional legitimacy. We find evidence of all three patterns with coercive adoption becoming more relevant in recent years, which is likely to affect sustainability adversely unless incentives for voluntary adoption are strengthened and institutional capacity building is boosted.
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We say that a (countably dimensional) topological vector space X is orbital if there is T∈L(X) and a vector x∈X such that X is the linear span of the orbit {Tnx:n=0,1,…}. We say that X is strongly orbital if, additionally, x can be chosen to be a hypercyclic vector for T. Of course, X can be orbital only if the algebraic dimension of X is finite or infinite countable. We characterize orbital and strongly orbital metrizable locally convex spaces. We also show that every countably dimensional metrizable locally convex space X does not have the invariant subset property. That is, there is T∈L(X) such that every non-zero x∈X is a hypercyclic vector for T. Finally, assuming the Continuum Hypothesis, we construct a complete strongly orbital locally convex space.
As a byproduct of our constructions, we determine the number of isomorphism classes in the set of dense countably dimensional subspaces of any given separable infinite dimensional Fréchet space X. For instance, in X=ℓ2×ω, there are exactly 3 pairwise non-isomorphic (as topological vector spaces) dense countably dimensional subspaces.
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We consider Sklyanin algebras $S$ with 3 generators, which are quadratic algebras over a field $\K$ with $3$ generators $x,y,z$ given by $3$ relations $pxy+qyx+rzz=0$, $pyz+qzy+rxx=0$ and $pzx+qxz+ryy=0$, where $p,q,r\in\K$. this class of algebras has enjoyed much attention. In particular, using tools from algebraic geometry, Feigin, Odesskii \cite{odf}, and Artin, Tate and Van Den Bergh, showed that if at least two of the parameters $p$, $q$ and $r$ are non-zero and at least two of three numbers $p^3$, $q^3$ and $r^3$ are distinct, then $S$ is Artin--Schelter regular. More specifically, $S$ is Koszul and has the same Hilbert series as the algebra of commutative polynomials in 3 indeterminates (PHS). It has became commonly accepted that it is impossible to achieve the same objective by purely algebraic and combinatorial means like the Groebner basis technique. The main purpose of this paper is to trace the combinatorial meaning of the properties of Sklyanin algebras, such as Koszulity, PBW, PHS, Calabi-Yau, and to give a new constructive proof of the above facts due to Artin, Tate and Van Den Bergh. Further, we study a wider class of Sklyanin algebras, namely
the situation when all parameters of relations could be different. We call them generalized Sklyanin algebras. We classify up to isomorphism all generalized Sklyanin algebras with the same Hilbert series as commutative polynomials on
3 variables. We show that generalized Sklyanin algebras in general position have a Golod–Shafarevich Hilbert series (with exception of the case of field with two elements).
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This work aims to describe how is occurring through the process of institutionalizing the Administration distance course of UFRN. To this end, structured into two parts: through research and analysis of content, sought to impound as if gave historic process of creation, as well as identify variables isomórficas, proposed by Powell and DiMaggio (1991), on the actions undertaken, and still present, institutional actors-having been found three typologies; then investigated the process itself, analyzing the factors of institutionalization suggested Esman (1966-1972), internal structure doctrine, leadership programme, resources, links and exchanges, from the political plan educational course. As the research methodology was defined as qualitative, even though I used survey to collect, reviewed the second ANOVA. The results found in this step pointed out that only the doctrine and internal structure variables are consistent with the assumptions of model; we found for other, discharged indicated a gap between the political acts contemplated in teaching and the actions taken so far, unfavourable element to its legitimacy. However, although the implications found in the analysis of these factors suggest that this course can derive one more discontinuous Government proposal of distance course, this study believes that are still reasonable assistance to facilitate and promote the process aimed at strengthening the progress achieved so far in the success of its institutionalization
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An earlier Case-based Reasoning (CBR) approach developed by the authors for educational course timetabling problems employed structured cases to represent the complex relationships between courses. Previous solved cases represented by attribute graphs were organized hierarchically into a decision tree. The retrieval searches for graph isomorphism among these attribute graphs. In this paper, the approach is further developed to solve a wider range of problems. We also attempt to retrieve those graphs that have common similar structures but also have some differences. Costs that are assigned to these differences have an input upon the similarity measure. A large number of experiments are performed consisting of different randomly produced timetabling problems and the results presented here strongly indicate that a CBR approach could provide a significant step forward in the development of automated system to solve difficult timetabling problems. They show that using relatively little effort, we can retrieve these structurally similar cases to provide high quality timetables for new timetabling problems.
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Visando analisar a Formação Inicial de Professores (FIP) do Ensino Básico em Moçambique, no intuito de captar como concorre para a construção da representação de profissionalidade na atividade docente, este estudo descritivo e interpretativo estrutura-se em duas dimensões complementares (extensiva e intensiva). Através dessas duas dimensões procurou-se explicitar os pontos críticos do objeto de estudo e produzir conhecimento sobre o mesmo. E, nessa linha, nas conclusões do estudo ficarão disponíveis possíveis contributos para a melhoria da sustentação e eficácia da formação inicial. Na dimensão extensiva, em função de descritores de profissionalidade associados ao reconhecimento social de uma atividade como profissional, definidos na literatura investigativa da sociologia das profissões e da educação, analisou-se a noção de profissionalidade que norteia a FIP. Essa análise foi desenvolvida com recurso ao estudo de documentos legais e curriculares, inquéritos por questionário a 289 formadores e por entrevista a 7 agentes-chave da formação de professores (gestores, académicos e formadores de professores). Na dimensão intensiva, concretizada num estudo multicaso (4 estudos de caso) envolvendo, essencialmente, 16 formadores de 4 instituições de formação de professores (polos), aprofundou-se a compreensão da visão de formadores de professores sobre profissionalidade, com recurso à observação de atividade docente e respetiva planificação, entrevistas semi-estruturadas a 4 gestores da Prática Pedagógica e estágio nesses polos, à luz do quadro teórico fundamentador dos caraterizadores de profissionalidade referenciais do estudo e dos resultados obtidos na dimensão extensiva. Os resultados do estudo denotam falta de sintonia entre o conceito de ensinar patenteado nos documentos e discursos dos agentes-chave da Formação de Professores (a indicar que ensinar é fazer aprender) e a prática letiva dos formadores, a denunciar que ensinar é entendido como expôr conteúdos/transmitir conhecimentos. Quanto aos caraterizadores de profissionalidade, discursivamente destacam-se como atributos reconhecidos ao professor: ser educador e profissional; possuir conhecimento específico para ensinar; ter a função e a responsabilidade de ensinar; ser inovador e investigador; e agir de acordo com o quadro deontológico associado à profissão. No entanto, estas representações entram em choque com a realidade, marcada por falta de poder dos professores sobre o currículo e sobre o conhecimento profissional, que não produzem nem controlam; baixas qualificações (possuem nível correspondente à 10ª classe); inexistência de um quadro deontológico específico e por uma prática docente dos formadores inscrita na racionalidade técnica e mais alinhada com uma dinâmica de funcionarização do que de profissionalização. Na esteira do isomorfismo pedagógico, da chamada naturalização das práticas de ensino, e da força da gramática escolar, o tipo de prática docente que marca a ação dos formadores tenderá a ser replicada pelos formandos quando professores. Aliás, os documentos curriculares parecem resumir o ser profissional ao facto de se possuir formação para professores. O estudo fundamenta a possibilidade de, nas políticas, se reforçar uma maior coerência entre discursos e práticas na visão de profissionalidade construída na FIP, aprofundar os pontos de descontinuidade detetados no estudo ou outros relevantes e trabalhar no sentido da clarificação do conceito de profissionalidade pretendida na Formação de Professores do Ensino Básico em Moçambique.
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We show how to reconstruct a graded ample Hausdorff groupoid with topologically principal neutrally-graded component from the ring structure of its graded Steinberg algebra over any commutative integral domain with 1, together with the embedding of the canonical abelian subring of functions supported on the unit space. We deduce that diagonal-preserving ring isomorphism of Leavitt path algebras implies $C^*$-isomorphism of $C^*$-algebras for graphs $E$ and $F$ in which every cycle has an exit. This is a joint work with Joan Bosa, Roozbeh Hazrat and Aidan Sims.