5,774 research outputs found

    A gravity term from spontaneous symmetry breaking

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    In this model, the gravity term in the Lagrangean comes from spontaneous symmetry breaking of an additional scalar quadruplet field Υ\Upsilon. The resulting gravitational field is approximate to one of the models of coframe gravity with parameters ρ1+4ρ2=0\rho_1 + 4 \rho_2 = 0, ρ3=0\rho_3 = 0. This article includes an exact solution of coframe gravity with model parameters ρ10\rho_1 \neq 0, ρ2\rho_2 any, ρ3=0\rho_3 = 0, which is Newtonian at infinity. An iteration process is given to construct a solution for a given matter-radiation stress-energy tensor.Comment: 23 page

    The importance of reverse logistics for retail activity

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    Reverse logistics (RL) refers to a set of programs or competencies aimed at moving products in the reverse direction in the supply chain (i.e., from consumer to producer). It entails more than the mere re-use of containers and the recycling of packaging materials. It is the process of moving a product from the point of consumption to another point for the purpose of recapturing the remaining value, or for the eventual proper disposal of the product. The state of development of RL is analogous to that of inbound logistics between 10 and 20 years ago. The scope of RL has, since, expanded from service parts management to include other areas and has attracted significant attention of a great majority of companies. The reverse logistics process can generate periodic negative cash flows that are difficult to predict and account for, but are important when managing retailer liquidity. Uncertainties surrounding reverse logistics create the possibility that the retailer may be strained in meeting short-run financial obligations or opportunities.reverse logistics, retail activity, product recovery, network design, liquidity

    Generalized Sums over Histories for Quantum Gravity II. Simplicial Conifolds

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    This paper examines the issues involved with concretely implementing a sum over conifolds in the formulation of Euclidean sums over histories for gravity. The first step in precisely formulating any sum over topological spaces is that one must have an algorithmically implementable method of generating a list of all spaces in the set to be summed over. This requirement causes well known problems in the formulation of sums over manifolds in four or more dimensions; there is no algorithmic method of determining whether or not a topological space is an n-manifold in five or more dimensions and the issue of whether or not such an algorithm exists is open in four. However, as this paper shows, conifolds are algorithmically decidable in four dimensions. Thus the set of 4-conifolds provides a starting point for a concrete implementation of Euclidean sums over histories in four dimensions. Explicit algorithms for summing over various sets of 4-conifolds are presented in the context of Regge calculus. Postscript figures available via anonymous ftp at black-hole.physics.ubc.ca (137.82.43.40) in file gen2.ps.Comment: 82pp., plain TeX, To appear in Nucl. Phys. B,FF-92-

    Impact on the fate of the euro area economy

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    Regarding the impact of EMU on euro area firms' competitiveness and their capacity to play an important role in international markets, recent research indicates Euro contribution to increasing the competitiveness of firms by facilitating trade between countries in the eurozone and by promoting the single market integration EU. Euro zone countries are considered to be the best export base, attracting a larger number of companies from neighboring countries. Euro area enlargement and better integrate it, in addition to allowing firms to diversify their operations to lower marginal costs, also tend to be more closely associated with competition and thus a higher variety of products, higher productivity and lower pricescompetitiveness, financial integration, market integration, foreign direct investment

    INFRASTRUCTURE FOR INTEROPERABILITY OF THE E-GOVERNMENT APPLICATIONS BASED ON SEMANTIC WEB SERVICES

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    The e-Government interoperability is the ability of ICT components/applications to work together, in other words it is the ability of two or more diverse government (ICT) systems or components to sharing and re-use of information-services, inter-linking of administrative tasks, within and between sectors are essential factors for the delivery of high quality, innovative, seamless and customer-centric e-services. The organizational interoperability refers to the cooperation way of the public administrations processes, by defining the communication interfaces between processes. This approach addresses the interoperability of e-government applications at organizational and semantic level, adopting Web services (WS) and Semantic Web Services (SWS) as technological solutions. The e-Government interoperability is becoming an increasingly crucial issue, especially for developing countries that have committed to the achievement of the Millennium Development Goals (MDGs) by 2015 . Enhanced government efficiency and effectiveness coupled with the delivery of basic public services to all citizens are essential components required to achieve such goals. In this context, most governments have finalized the design of national e-government strategies and are busy implementing priority programmes. Today the data needed by policy makers to make better decisions is available but inaccessible. Policy makers are faced not only with overlapping and uncoordinated data sources, but also with the absence of common terms of reference and means of representing these data. This results in the time consuming and complex cost of comparing data that is represented differently. Interoperability will allow data compiled by different agencies to be used together to make faster and better decisions. An important goal of governance is to enable the citizenry to have easier and faster access to government information and services. The seamless flow of data from one government office to another provides the policy maker with the information needed to draft sound policy and deliver better services. In this paper we present an approach, which addresses the interoperability of e-government applications at organizational and semantic level, adopting Web services (WS) and Semantic Web Services (SWS) as technological solutions. The main objective of this work consists in designing and developing a distributed network of semantic registries in order to publish, find and execute the Web services. The publishing in registries of the Web services consists in the execution of syntactic and semantic matching algorithms between the attributes of the registries and the attributes of Web services.e-government application, interoperability, semantic registries, WSDL standard

    Robust Control and Monetary Policy Delegation.

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    This paper adapts in a simple static context the Rogoff's (1985) analysis of monetary policy delegation to a conservative central banker to the robust control framework. In this framework, uncertainty means that policymakers are unsure about their model, in the sense that there is a group of approximate models that they also consider as possibly true, and their objective is to choose a rule that will work under a range of di¤erent model specifications. We find that robustness reveals the emergence of a precautionary behaviour in the case of unstructured model uncertainty, reducing thus government's willingness to delegate monetary policy to a conservative central banker.Robust control, Monetary policy delegation, Central bank conservativeness.

    Central Bank Independence, Speed of Disinflation and the Sacrifice Ratio.

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    This paper examines the impact of central bank independence on inflation persistence. Our theoretical analysis predicts that a higher degree of central bank independence leads to a lower inflation persistence and therefore to a higher speed of disinflation. The empirical results, provided using a 18 OECD countries sample, show that central bank independence is negatively related to the degree of inflation persistence. In addition, as there is a positive correlation between inflation persistence and the sacrifice ratio, we conclude that central bank independence, through its influence on inflation persistence, is negatively correlated to the sacrifice ratio.central bank independence, inflation persistence, speed of disinflation, sacrifice ratio.

    The policy mix in a monetary union under alternative policy institutions and asymmetries

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    In this paper we study the monetary and fiscal policy making in a monetary union when authorities face asymmetries in the countries constructing this monetary union. We analyze this problem in an asymmetric environment using a two-country theoretical model and by introducing two alternative types of national asymmetries : asymmetric shocks and the asymmetric transmission mechanism. The central issue of the paper is the design of the appropriate monetary and fiscal policy institutions. In this respect, we investigate which of the two alternative types of monetary policymakers (country representatives or governors) facing to two alternative types of fiscal policy (decentralized or centralized) contributes to better resolve the problem of the trade-off between credibility and flexibility. Our results show that delegate the monetary policy to a council of union-wide governors with decentralized fiscal policies is the appropriate institutional design that would reduce the iinflation bias and stabilize better the regional idiosyncratic shocks in a monetary union in the cases of perfectly asymmetric and perfectly symmetric shocks. In addition, in the case of asymmetric transmission, the monetary union would be better off with a council of monetary policy governors and centralized fiscal policies.EMU, Policy-Mix, Asymmetric shocks, Asymmetric transmission
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