13,705 research outputs found
A herbrandized functional interpretation of classical first-order logic
We introduce a new typed combinatory calculus with a type constructor that, to each type σ, associates the star type σ^∗ of the nonempty finite subsets of elements of type σ. We prove that this calculus enjoys the properties of strong normalization and confluence. With the aid of this star combinatory calculus, we define a functional interpretation of first-order predicate logic and prove a corresponding soundness theorem. It is seen that each theorem of classical first-order logic is connected with certain formulas which are tautological in character. As a corollary, we reprove Herbrand’s theorem on the extraction of terms from classically provable existential statements.info:eu-repo/semantics/publishedVersio
Elementary Proof of Strong Normalization for Atomic F
We give an elementary proof (in the sense that it is formalizable in Peano arithmetic) of the strong normalization of the atomic polymorphic calculus Fₐₜ (a predicative restriction of Girard’s system F)
Analysis in weak systems
The authors survey and comment their work on weak analysis. They describe the basic set-up of analysis in a feasible second-order theory and consider the impact of adding to it various forms of weak Konig's lemma. A brief discussion of the Baire categoricity theorem follows. It is then considered a strengthening of feasibility obtained (fundamentally) by the addition of a counting axiom and showed how it is possible to develop Riemann integration in the stronger system. The paper finishes with three questions in weak analysis.info:eu-repo/semantics/publishedVersio
Does Gender Matter for Political Leadership? The Case of U.S. Mayors
What are the consequences of electing a female leader for policy and political outcomes? We answer this question in the context of U.S. cities, where women’s participation in mayoral elections increased from negligible numbers in 1970 to about one-third of the elections in the 2000’s. We use a novel data set of U.S. mayoral elections from 1950 to 2005, and apply a regression discontinuity design to deal with the endogeneity of female candidacy to city characteristics. In contrast to most research on the influence of female leadership, we find no effect of gender of the mayor on policy outcomes related to the size of local government, the composition of municipal spending and employment, or crime rates. While female mayors do not implement different policies, they do appear to have higher unobserved political skills, as they have a 6-7 percentage point higher incumbent effect than a comparable male. But we find no evidence of political spillovers: exogenously electing a female mayor does not change the long run political success of other female mayoral candidates in the same city or of female candidates in local congressional elections.
Do Political Parties Matter? Evidence from U.S. Cities
We examine whether partisan political differences have important effects on policy outcomes at the local level using a new panel data set of mayoral elections in the United States. Applying a regression discontinuity design to deal with the endogeneity of the mayor's party, we find that party labels do not affect the size of government, the allocation of spending or crime rates, even though there is a large political advantage to incumbency in terms of the probability of winning the next election. The absence of a strong partisan impact on policy in American cities, which is in stark contrast to results at the state and federal levels of government, appears due to certain features of the urban environment associated with Tiebout sorting. In particular, there is a relatively high degree of household homogeneity at the local level that appears to provide the proper incentives for local politicians to be able to credibly commit to moderation and discourages strategic extremism.
An overview of three decades of mergers and acquisitions research
Mergers and acquisitions (M&A) have long attracted managers’ attention and have been researched in different perspectives and using different theories. In this study we grasp the wealth of extant research in the field of M&As. We conducted a bibliometric study of 635 articles on strategic management and international business research published in 34 highly ranked management journals between 1983 and 2012. We performed citation, co-citation and factor analyses to uncover the issues examined by scholars, the main theoretical approaches and themes researched. The results show a relative shift from economic and financial approaches to knowledge-based and organizational learning perspectives in recent years. There was also an evolution from assessing the performance of firms after an M&A to seeking an understanding of what may drive synergy creation after the integration process. Furthermore we observed an increasing interest in cross-border M&As. We discuss our findings, identifying gaps and suggesting paths for future research.info:eu-repo/semantics/publishedVersio
Technologies may help thinking
The objective of teachers’ personal and professional development is an excellent reason to reflect upon the innovation issues in education and a rare opportunity to implement the use of portfolios in the teaching practices.
The most recent developments of digital technologies allow experiencing new organisational and knowledge building that state the diversity and multiplicity of purposes, both alone and as a group.
From the reflection on these two aspects comes up the present proposal for the analysis and evaluation of the technologies which may easily be accessed by the educational community and may be used in the process of electronic portfolios building.
In what teachers are concerned the use of portfolios can become a powerful means helping the change of the educational practices (Cardoso, Peixoto, Serrano and Moreira, 1996) if it is adopted as a metacognitive and reflexive strategy about teaching about them (Galvão, 2005).
However there is a lack of information about what portfolios are, which technologies can be used, how they are prepared and how to take advantage of them. All these questions point out to the need of a specific training in this field.
Accordingly, this chapter especially aims at helping teachers in that process, providing an analysis and evaluation technologies grid based on their pedagogical potentialities for the building of digital portfolios
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