4,190 research outputs found

    The RobotCub Approach to the Development of Cognition

    Get PDF
    This paper elaborates on the workplan of an initiative in embodied cognition: RobotCub. Our goal here is to provide background and to motivate our long-term plan of empirical research including brain and robotic sciences following the principles of epigenetic robotics

    New mobilities across the lifecourse: a framework for analysing demographically-linked drivers of migration

    No full text
    Migration, along with fertility and mortality, is one of the fundamental drivers of population change. Taking the lifecourse as the central concern, the authors set out a theoretical framework and define some key research questions for a programme of research that explores how the linked lives of mobile people are situated in time-space within the economic, social and cultural structures of contemporary society. Drawing on methodologically innovative techniques, these perspectives can offer conceptually significant and policy relevant insights into the changing nature and meanings of migration across the lifecourse

    Automated detection of asteroids in real-time with the Spacewatch telescope

    Get PDF
    The Spacewatch telescope on Kitt Peak is being used to survey for near-earth asteroids using a Tektronix TK2048 CCD in scanning mode. We hope to identify suitable low delta v candidates amongst the near-earth asteroid population as possible exploration targets, to identify those objects which pose a danger to life on earth, and to study the physical properties of the objects in near-earth space. Between Sep. 1990 and Jun. 1991, 14 new earth-approaching asteroids including 1 Aten, 9 Apollo, and 4 Amor type asteroids were detected by automated software and discriminated by their angular rates from the rest of the detected asteroids in near-real time by the observer. The average of about 1.5 earth-approaching asteroids per month is comparable to the total number found by all other observatories combined. One other Apollo type asteroid was detected by the observer as a long trailed image. The positions of this last object were measured and the object was tracked by the observer in real time. This object was determined to be a 5-10 meter diameter object which passed within 170,000 kilometers of earth. Of the 14 automatically detected earth-approaching asteroids, 10 have been found at distances in excess of 0.5 AU from earth. An average of more than 2000 asteroids are detected each month. Positions, angular rates, and brightnesses are determined for each of these asteroids in real-time

    Radio Spectrum and the Disruptive Clarity OF Ronald Coase.

    Get PDF
    In the Federal Communications Commission, Ronald Coase (1959) exposed deep foundations via normative argument buttressed by astute historical observation. The government controlled scarce frequencies, issuing sharply limited use rights. Spillovers were said to be otherwise endemic. Coase saw that Government limited conflicts by restricting uses; property owners perform an analogous function via the "price system." The government solution was inefficient unless the net benefits of the alternative property regime were lower. Coase augured that the price system would outperform the administrative allocation system. His spectrum auction proposal was mocked by communications policy experts, opposed by industry interests, and ridiculed by policy makers. Hence, it took until July 25, 1994 for FCC license sales to commence. Today, some 73 U.S. auctions have been held, 27,484 licenses sold, and 52.6billionpaid.Thereformisatextbookexampleofeconomicpolicysuccess.WeexamineCoasesseminal1959paperontwolevels.First,wenotetheimportanceofitsanalyticalsymmetry,comparingadministrativetomarketmechanismsundertheassumptionofpositivetransactioncosts.Thisfundamentalinsighthashadenormousinfluencewithintheeconomicsprofession,yetisoftenlostincurrentanalyses.Thisanalyticalinsighthaditsbeginninginhisacclaimedearlyarticleonthefirm(Coase1937),andcontinuedintohissubsequenttreatmentofsocialcost(Coase1960).Second,weinvestigatewhyspectrumpolicieshavestoppedwellshortofthepropertyrightsregimethatCoaseadvocated,consideringrentseekingdynamicsandtheemergenceofnewtheorieschallengingCoasespropertyframework.Oneconclusioniseasilyrendered:competitivebiddingisnowthedefaulttoolinwirelesslicenseawards.Byruleofthumb,about52.6 billion paid. The reform is a textbook example of economic policy success. We examine Coase‘s seminal 1959 paper on two levels. First, we note the importance of its analytical symmetry, comparing administrative to market mechanisms under the assumption of positive transaction costs. This fundamental insight has had enormous influence within the economics profession, yet is often lost in current analyses. This analytical insight had its beginning in his acclaimed early article on the firm (Coase 1937), and continued into his subsequent treatment of social cost (Coase 1960). Second, we investigate why spectrum policies have stopped well short of the property rights regime that Coase advocated, considering rent-seeking dynamics and the emergence of new theories challenging Coase‘s property framework. One conclusion is easily rendered: competitive bidding is now the default tool in wireless license awards. By rule of thumb, about 17 billion in U.S. welfare losses have been averted. Not bad for the first 50 years of this, or any, Article appearing in Volume II of the Journal of Law & Economics.

    Propfan experimental data analysis

    Get PDF
    A data reduction method, which is consistent with the performance prediction methods used for analysis of new aircraft designs, is defined and compared to the method currently used by NASA using data obtained from an Ames Res. Center 11 foot transonic wind tunnel test. Pressure and flow visualization data from the Ames test for both the powered straight underwing nacelle, and an unpowered contoured overwing nacelle installation is used to determine the flow phenomena present for a wind mounted turboprop installation. The test data is compared to analytic methods, showing the analytic methods to be suitable for design and analysis of new configurations. The data analysis indicated that designs with zero interference drag levels are achieveable with proper wind and nacelle tailoring. A new overwing contoured nacelle design and a modification to the wing leading edge extension for the current wind tunnel model design are evaluated. Hardware constraints of the current model parts prevent obtaining any significant performance improvement due to a modified nacelle contouring. A new aspect ratio wing design for an up outboard rotation turboprop installation is defined, and an advanced contoured nacelle is provided

    Status Report on the Low-Energy Demonstration Accelerator (LEDA)

    Get PDF
    The 75-keV injector and 6.7-MeV RFQ that comprise the first portion of the cw, 100-mA proton linac for the accelerator production of tritium (APT) project have been built and operated. The LEDA RFQ has been extensively tested for pulsed and cw output-beam currents <=100 mA. Up to 2.2 MW of cw rf power from the 350-MHz rf system is coupled into the RFQ, including 670 kW for the cw proton beam. The emittance for a 93-mA pulsed RFQ output beam, as determined from quadrupole-magnet-scan measurements, is ex x ey = 0.25 x 0.31 (pi mm mrad)2 [rms normalized]. A follow-on experiment, to intentionally introduce and measure beam halo on the RFQ output beam, is now being installed.Comment: Paper TUD14 for the XX International Linac Conference (LINAC2000), 3 pages, 10 figure

    Price Expectations in Experimental Asset Markets with Futures Contracting

    Get PDF
    A financial bubble is defined as a condition in which the trading price of an asset is above (and increasing relative to) its discounted present value of earnings, i.e., its fundamental value. Consider the data in Figure 1 where an asset was traded over 15 consecutive trading periods. In the figure, we plot the deviation in mean contract price from the net asset value (NAV) of the security for each of the trading periods. Notice that the price grows steadily, peaks, and then "crashes" to its NAV. There is a puzzle concerning the level of premiums and discounts from NAV for closed-end funds, which provides a challenge to a rational expectations theory of asset pricing, since the data in Figure 1 was generated from an experiment in which the fundamental value of the asset was controlled. There were no external market factors to justify the deviation from fundamental value other than the capital gains expectation of the participants (see smith, Suchanek and Williams [1988] hereafter referred to as SSW). The phenomena describe in Figure 1 is a very standard outcome of a specific experimental asset market that has been replicated over 70 times with diverse subject pools

    Measuring Economic Growth from Outer Space

    Get PDF
    GDP growth is often measured poorly for countries and rarely measured at all for cities. We propose a readily available proxy: satellite data on lights at night. Our statistical framework uses light growth to supplement existing income growth measures. The framework is applied to countries with the lowest quality income data, resulting in estimates of growth that differ substantially from established estimates. We then consider a longstanding debate: do increases in local agricultural productivity increase city incomes? For African cities, we find that exogenous agricultural productivity shocks (high rainfall years) have substantial effects on local urban economic activity.economic growth; remote sensing; urbanization; income measurement

    Double Bubbles in Assets Markets with Multiple Generations

    Get PDF
    We construct an asset market in a finite horizon overlapping-generations environment. Subjects are tested for comprehension of their fundamental value exchange environment, and then reminded during each of 25 periods of its declining new value. We observe price bubbles forming when new generations enter the market with additional liquidity and bursting as old generations exit the market and withdrawing cash. The entry and exit of traders in the market creates an M shaped double bubble price path over the life of the traded asset. This finding is significant in documenting that bubbles can reoccur within one extended trading horizon and, consistent with previous cross-subject comparisons, shows how fluctuations in market liquidity influence price paths. We also find that trading experience leads to price expectations that incorporate fundamental value.Asset Markets, Price Bubbles, Laboratory Experiments, Overlapping Generations
    corecore