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1. BACKGROUND AND THE STUDY The US economy grew almost six times faster than total delivered energy since 1972, during a period when the standard of living improved dramatically within [...]

Dual-polarization weather radars have evolved significantly in the last three decades culminating in operational deployment by the National Weather Service. In addition to operational applications in the weather service, dual-polarization radars have shown significant potential in contributing to the research fields of ground-based remote sensing of rainfall microphysics, the study of precipitation evolution, and hydrometeor classification. Microphysical characterization of precipitation and quantitative precipitation estimation are important applications that are critical in the validation of satellite-borne precipitation measurements and also serve as valuable tools in algorithm development. This paper presents the important role played by dual-polarization radar in validating spaceborne precipitation measurements. Examples of raindrop size distribution retrievals and hydrometeor-type classification are discussed. The quantitative precipitation estimation is a product of direct relevance to spaceborne observations. During the Tropical Rainfall Measuring Mission (TRMM) program substantial advancement was made with ground-based polarization radars collecting unique observations in the tropics, which are noted. The scientific accomplishments of relevance to spaceborne measurements of precipitation are summarized. The potential of dual-polarization radars and opportunities in the era of the global precipitation measurement mission is also discussed.

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jedc.2007.01.020 Byline: Eric Smith (a), Duncan K. Foley (b) Abstract: A long history of analogy making between neoclassical economics and physical thermodynamics has unfortunately served to obscure two important relations between the two fields: their definitions of equilibria stem from essentially the same three axioms for the mathematical representations of systems, while the classes of transformation each has chosen to emphasize, and their responses to the problem of path dependence, have led them to very different interpretations of duality in those representations. Despite these conventional differences, we show that economies in which all agents have preferences quasi-linear in some good have a trading-constraint structure isomorphic to the structure of physical systems with classical thermodynamic equations of state. Exact equivalents of thermodynamic potentials, including entropy, can be constructed, and function as the economic counterparts to free energies. Quasi-linear economies are the most general in which the Walrasian idea of price formation as an analog of force balance can be realized. More general economic models raise the same methodological problems as more complex physical models that exhibit path-dependence. We show how the degree of aggregatability of an economic model corresponds to which properties of equilibria retain path-independence, and to the extent to which a social-welfare function exists. A new contour money-metric utility defines the maximal generalization of social-welfare functions in arbitrary economies, but depends on the endowments and composition of the economy in non-quasi-linear cases, and is limited to one-dimensional contours of equilibria in non-aggregatable cases. The differences between economic and thermodynamic methodology lies in the economic focus on the irreversible movement from initial disequilibrium endowments to equilibrium through voluntary trade, in contrast to the thermodynamic recognition that only reversible transformations lead to measurement of system structure. The consequences of respecting reversibility for economic method are sketched, and alternative interpretations of the Walrasian notion of wealth preservation are presented. Author Affiliation: (a) Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, NM 87501, USA (b) Department of Economics, Graduate Faculty, New School University, 65 Fifth Avenue, New York, NY 10003, USA Article History: Received 1 May 2005; Revised 1 December 2006; Accepted 26 January 2007

To purchase or authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1468-2354.2007.00440.x Byline: James Albrecht ([dagger]), Axel Anderson ([dagger]), Eric Smith ([dagger]), Susan Vroman (1) Abstract: We construct a model of the housing market in which agents differ in their flow values while searching. Agents enter the market relaxed (with high flow values) but move to a desperate state (low flow values) at a Poisson rate if they have not already transacted. We characterize the equilibrium steady-state matching pattern and the joint distribution of price and time to sale (for sellers). The expected price conditional on time to sale falls with time spent on the market, whereas the conditional variance of price first rises and then falls with time on the market. Author Affiliation: ([dagger])Georgetown University, U.S.A.; Georgetown University, U.S.A.; University of Essex, U.K.; Georgetown University, U.S.A.

Assessment of water quality conditions as required by Section 303d of the Clean Water Act must rely on limited monitoring data. Because data are limited there will always be the potential for error when deciding if water quality standards are being met. However, the informed, use of statistical procedures makes it possible to describe and manage these errors. We make the case for using such procedures in water quality assessment and draw the implications for the monitoring data for water quality standard setting, arguing that standard setting must accommodate the limits of the monitoring data and the statistical procedures that will be used for water quality assessment. CE Database subject headings: Water quality control; Statistics; Standards.

Recently, it has become popular to argue that certain workers have fallen into a trap in which they have poor skills, few job opportunities and a low return on training, while others have not. This paper demonstrates how such a trap can occur within a simple matching model with rent sharing. Rent sharing diminishes the worker's incentive to acquire skills; however, since firms also benefit from training, rent sharing likewise induces job creation. The subsequent improved matching prospects may offset the initial disincentive to invest. However, for this mechanism to be effective, firms and workers must coordinate their actions. If they do not, the trap occurs. JEL classification: J64; E24 Keywords: Search; Matching; Training; Multiple equilbria

An intercomparison of microwave multiple scattering radiative transfer codes used in generating databases for satellite rainfall retrieval algorithms has been carried out to ensure that differences obtained from retrieval techniques do not originate from the underlying radiative transfer code employed for the forward modeling. A set of profiles containing liquid water and ice contents of cloud and rain water as well as snow, graupel and pristine ice were distributed to the participants together with a black box routine providing Mie single scattering, atmospheric background absorption and surface emissivity. Simulations were to be carried out for nadir and off-nadir (53.1 [degrees]) observation angles at frequencies between 10 and 85 GHz. Among the radiative transfer models were two-stream, multiple stream and Monte Carlo models. The results showed that there were two major sources of differences between the codes. 1) If surface reflection/emission was considered isotropic, simulated brightness temperatures were significantly higher than for specular reflection and this effect was most pronounced at nadir observation and over ocean-type surfaces. 2) Flux-type models including delta-scaling could partially compensate for the errors introduced by the two-stream approximation. Largest discrepancies occured at high frequencies where atmospheric scattering is most pronounced and at nadir observation. If the same surface boundary conditions, the same multiple-stream resolution and the same scaling procedures are used, the models were very close to each other with discrepancies below 1 K. Index Terms--Microwave radiative transfer, model intercomparison, precipitation retrieval.

A technique for overcoming the reproducibility problems imposed by Metal Organic Chemical Vapor Deposition due to the absence of stable precursors has been devised. The procedure, which is used in the deposition of high quality high temperature superconductors in a number of semiconductors, allows real time control of the gas phase composition via ultraviolet absorption sensing. The technique permits the very tight control of the deposited material's composition.

A flux compression power unit (FCPU) is being developed to generate tailored millisecond current pulses for ETC gun applications. A propellant mixture is used to accelerate a conducting piston into the magnetic field region within a helical coil. An armature integral to the piston makes sliding contact with the coil through compliant brushes and provides continuous current flow between the coil and a center rod which acts as a return current path. Interaction between the armature and the magnetic field decelerates the piston and transfers the piston's kinetic energy to the magnetic field. The initial current and energy in the helical coil (provided by a 'seed' capacitor bank) are thereby multiplied and delivered to a resistive load. Repetitive operation may be obtained by using the compressed magnetic field to stop the piston at the end of the useful compression stroke and return it to the starting position. FCPU point of departure design parameters for a proof-of-principle experiment include: 120 mm bore diameter, 75 cm coil length, 80 turns/m helical winding, 15 kA seed current (7.2 kJ initial energy), 3.5 kg piston initially accelerated to 300 m/s. Simulations predict a FCPU current multiplication of 40x, 95 kJ delivered to a fixed resistance load, and the stopping of the piston. The simulations include current diffusion and flux trapping. Initial experiments using solid propellants to accelerate the piston are reported.

This paper models trading patterns when marketplaces exist and goods are differentiated. When first visiting the market, a buyer samples a stock of goods. If fortunate, the buyer finds a match, purchases one of these goods and then exits. If not, the buyer can now only match with the flow of new goods. In a steady state, the stock of unmatched traders on one side of the market is trying to match with the flow of new traders on the other side. This behaviour is shown to describe matching patterns between unemployed job seekers and vacancies in U.K. Job Centres.

This paper analyses how the levels of unemployment and vacancies affect the rate at which unemployed workers find employment - the worker-firm 'matching function'. in particular, we test the robustness of previous empirical work by checking whether we obtain the same estimated function using cross-section data rather than aggregate time series data. We find strong evidence of constant returns to scale which is strikingly similar to previous work.

1. Introduction Long-standing customers or workers often receive favourable treatment. London's Royal Opera House has a season subscription plan which not only offers an understandable discount off single ticket prices [...]

The impact of proportional wage and profit taxation was examined in a simple equilibrium search and bargaining model. The model studies how labor market taxes are used to generate government revenue, apportion income, how agents respond to the taxes and the effects of wage and profit taxes on the steady-state equilibrium. Unemployment benefits that are lower than search costs will make workers less particular in their job search. A profit tax may decrease unemployment in the short run, but could increase it in the long run, as wages increase.

The local meteorological events leading up to the launch of the space shuttle Atlantis on 2 August 1991 were captured in full-resolution GOES visible data being archived for the Convection and Precipitation/Electrification Experiment. The postponement of the launch on 1 August, and the successful lift-off on the following day provide a good example of the important role played by nowcasting and short-term forecasting at Cape Canaveral. In this brief article, we discuss the local weather conditions prior to, during, and after the launch and demonstrate the importance of short-term forecasting capabilities around the cape during launch operations.

The premiums for automobile insurance vary according to city. Large numbers of motorists without insurance can lead to high premiums in some cities, while high premiums may cause many motorists to avoid becoming insured in other markets. A noncooperative equilibrium model produces inefficient equilibria with uninsured motorists and high premiums that are actuarially fair. Markets that have low density and high income have a lower probability of poor equilibrium.