19,317 research outputs found

    Tourism development in Kuwait: examining the political-economic challenges in a unique rentier economy

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    This article explores the challenges Kuwait faces to develop tourism due to the particularly unique political-economic system of popular rentierism. Kuwait’s tourism industry is relatively underdeveloped in comparison to other Gulf Cooperation Council countries and has not received much attention by tourists, policy-makers, and scholars. This study provides both a macro-level analysis of the political economic obstacles to tourism development in Kuwait and the more micro-level challenges that have resulted, particularly in relation to proposed mega-development projects. While insights from this study are useful for understanding the role of tourism in the rentier economies, this study also further theorises tourism within the field of international relations and political economy and shows how tourism development is of particular importance for public diplomacy in the current global arena

    ALLY: An operator's associate for satellite ground control systems

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    The key characteristics of an intelligent advisory system is explored. A central feature is that human-machine cooperation should be based on a metaphor of human-to-human cooperation. ALLY, a computer-based operator's associate which is based on a preliminary theory of human-to-human cooperation, is discussed. ALLY assists the operator in carrying out the supervisory control functions for a simulated NASA ground control system. Experimental evaluation of ALLY indicates that operators using ALLY performed at least as well as they did when using a human associate and in some cases even better

    Spatial Degrees of Freedom in Everett Quantum Mechanics

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    Stapp claims that, when spatial degrees of freedom are taken into account, Everett quantum mechanics is ambiguous due to a "core basis problem." To examine an aspect of this claim I generalize the ideal measurement model to include translational degrees of freedom for both the measured system and the measuring apparatus. Analysis of this generalized model using the Everett interpretation in the Heisenberg picture shows that it makes unambiguous predictions for the possible results of measurements and their respective probabilities. The presence of translational degrees of freedom for the measuring apparatus affects the probabilities of measurement outcomes in the same way that a mixed state for the measured system would. Examination of a measurement scenario involving several observers illustrates the consistency of the model with perceived spatial localization of the measuring apparatus.Comment: 34 pp., no figs. Introduction, discussion revised. Material tangential to main point remove

    Holes in the walls: primordial black holes as a solution to the cosmological domain wall problem

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    We propose a scenario in which the cosmological domain wall and monopole problems are solved without any fine tuning of the initial conditions or parameters in the Lagrangian of an underlying filed theory. In this scenario domain walls sweep out (unwind) the monopoles from the early universe, then the fast primordial black holes perforate the domain walls, change their topology and destroy them. We find further that the (old vacuum) energy density released from the domain walls could alleviate but not solve the cosmological flatness problem.Comment: References added; Published in Phys. Rev.

    Global monopole, dark matter and scalar tensor theory

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    In this article, we discuss the space-time of a global monopole field as a candidate for galactic dark matter in the context of scalar tensor theory.Comment: 8 pages, Accepted in Mod. Phys. Lett.

    Differential efficacies of human type I and type II interferons as antiviral and antiproliferative agents.

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    Self-stabilization of extra dimensions

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    We show that the problem of stabilization of extra dimensions in Kaluza-Klein type cosmology may be solved in a theory of gravity involving high-order curvature invariants. The method suggested (employing a slow-change approximation) can work with rather a general form of the gravitational action. As examples, we consider pure gravity with Lagrangians quadratic and cubic in the scalar curvature and some more complex ones in a simple Kaluza-Klein framework. After a transition to the 4D Einstein conformal frame, this results in effective scalar field theories with certain effective potentials, which in many cases possess positive minima providing stable small-size extra dimensions. Estimates made in the original (Jordan) conformal frame show that the problem of a small value of the cosmological constant in the present Universe is softened in this framework but is not solved completely.}Comment: 10 pages, 4 figures, revtex4. Version with additions and corrections, accepted at Phys. Rev.

    The Isomorphism Relation Between Tree-Automatic Structures

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    An ω\omega-tree-automatic structure is a relational structure whose domain and relations are accepted by Muller or Rabin tree automata. We investigate in this paper the isomorphism problem for ω\omega-tree-automatic structures. We prove first that the isomorphism relation for ω\omega-tree-automatic boolean algebras (respectively, partial orders, rings, commutative rings, non commutative rings, non commutative groups, nilpotent groups of class n >1) is not determined by the axiomatic system ZFC. Then we prove that the isomorphism problem for ω\omega-tree-automatic boolean algebras (respectively, partial orders, rings, commutative rings, non commutative rings, non commutative groups, nilpotent groups of class n >1) is neither a Σ21\Sigma_2^1-set nor a Π21\Pi_2^1-set
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