1,392 research outputs found

    The European UMTS-auction

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    In this paper we review, and draw some lessons from, the UMTS-auctions that have taken place in Europe during 2000 and 2001.We address several design issues and, in particular, focus attention on asymmetries between the bidders and on possibilities for collusion.An outlook is provided to several other auctions in which the stakes may not be so high, but the design issues perhaps somewhat more complex.

    The Evil Demon Inside

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    This paper examines how new evil demon problems could arise for our access to the internal world of our own minds. I start by arguing that the internalist/externalist debate in epistemology has been widely misconstrued---we need to reconfigure the debate in order to see how it can arise about our access to the internal world. I then argue for the coherence of scenarios of radical deception about our own minds, and I use them to defend a properly formulated internalist view about our access to our minds. The overarching lesson is that general epistemology and the specialized epistemology of introspection need to talk---each has much to learn from each other

    Matching and Price Competition

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    We develop a model in which firms set impersonal salary levels before matching with workers. Salaries fall relative to any competitive equilibrium while profits rise by almost as much, implying little inefficiency. Furthermore, the best firms gain the most from the system while wages become compressed. We discuss the performance of alternative institutions and the recent antitrust case against the National Residency Matching Program in light of our results.

    The physics of wind-blown sand and dust

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    The transport of sand and dust by wind is a potent erosional force, creates sand dunes and ripples, and loads the atmosphere with suspended dust aerosols. This article presents an extensive review of the physics of wind-blown sand and dust on Earth and Mars. Specifically, we review the physics of aeolian saltation, the formation and development of sand dunes and ripples, the physics of dust aerosol emission, the weather phenomena that trigger dust storms, and the lifting of dust by dust devils and other small-scale vortices. We also discuss the physics of wind-blown sand and dune formation on Venus and Titan.Comment: 72 journal pagers, 49 figure

    Modeling the Martian dust cycle 1. Representations of dust transport processes

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    A dust transport scheme has been developed for a general circulation model of the Martian atmosphere. This enables radiatively active dust transport, with the atmospheric state responding to changes in the dust distribution via atmospheric heating, as well as dust transport being determined by atmospheric conditions. The scheme includes dust lifting, advection by model winds, atmospheric mixing, and gravitational sedimentation. Parameterizations of lifting initiated by (1) near-surface wind stress and (2) convective vortices known as dust devils are considered. Two parameterizations are defined for each mechanism and are first investigated offline using data previously output from the non-dust-transporting model. The threshold-insensitive parameterizations predict some lifting over most regions, varying smoothly in space and time. The threshold-sensitive parameterizations predict lifting only during extreme atmospheric conditions (such as exceptionally strong winds), so lifting is rarer and more confined to specific regions and times. Wind stress lifting is predicted to peak during southern summer, largely between latitudes 15° and 35°S, with maxima also in regions of strong slope winds or thermal contrast flows. These areas are consistent with observed storm onset regions and dark streak surface features. Dust devil lifting is also predicted to peak during southern summer, with a moderate peak during northern summer. The greatest dust devil lifting occurs in early afternoon, particularly in the Noachis, Arcadia/Amazonis, Sirenum, and Thaumasia regions. Radiatively active dust transport experiments reveal strong positive feedbacks on lifting by near-surface wind stress and negative feedbacks on lifting by dust devils

    Degree of explanation

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    Partial explanations are everywhere. That is, explanations citing causes that explain some but not all of an effect are ubiquitous across science, and these in turn rely on the notion of degree of explanation. I argue that current accounts are seriously deficient. In particular, they do not incorporate adequately the way in which a cause’s explanatory importance varies with choice of explanandum. Using influential recent contrastive theories, I develop quantitative definitions that remedy this lacuna, and relate it to existing measures of degree of causation. Among other things, this reveals the precise role here of chance, as well as bearing on the relation between causal explanation and causation itself

    The European UMTS-auction

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    In this paper we review, and draw some lessons from, the UMTS-auctions that have taken place in Europe during 2000 and 2001.We address several design issues and, in particular, focus attention on asymmetries between the bidders and on possibilities for collusion.An outlook is provided to several other auctions in which the stakes may not be so high, but the design issues perhaps somewhat more complex.auctions;telecommunications;game theory

    Datives with psych nouns and adjectives in Basque

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    This paper explores the formal expression of two Basque dative argument types in combination with psych nouns and adjectives, in intransitive and transitive clauses: (i) those that express the experiencer, and (ii) those that express the stimulus of the psychological state denoted by the psych noun and adjective . In the intransitive structure involving a dative experiencer (DatExpIS), the stimulus is in the absolutive case, and the intransitive copula izan ‘be’ shows both dative and absolutive agreement. This construction basically corresponds to those built upon the piacere type of psychological verbs typified in Belletti & Rizzi’s (1988) three-way classification of Italian psych verbs. In the intransitive structure involving a dative stimulus (DatStimIS), the experiencer is marked by absolutive case, and the same intransitive copula shows both absolutive and dative agreement (with the latter corresponding to the dative stimulus and not to the experiencer). We show that the behavior of the dative argument in the two constructions is just the opposite of each other regarding a number of morphosyntactic tests, including agreement, constituency, hierarchy and selection. Additionally, we explore two parallel transitive constructions that involve either a dative experiencer and an ergative stimulus (DatExpTS) or a dative stimulus and an ergative experiencer (DatStimTS), which employ the transitive copula *edun ‘have’. Considering these configurations, we propose an extended and more fine-grained typology of psych predicates

    Nese : a diminishing speech variety of northwest Malakula (Vanuatu)

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