Quality Differentiation and the Labour Market Effects of International Trade

This paper offers a new treatment of the labour market effects of international trade, based on a model in which intra-industry trade is explained on Heckscher-Ohlin principles. The model is more consistent with stylised facts about North-South trade than the traditional Heckscher-Ohlin model of inter-industry trade. Applying the model to trade between Italy and ‘non-advanced countries’ and inferring the factor content of intra-industry trade from the inter-sectoral relationship between factor intensity and average unit values of exports, we find that the labour market effects of intra- industry trade add significantly to the estimated factor market impact of trade.intra-industry trade, North-South trade, vertical product differentiation, labour market effects of international trade

EU accession and Poland's external trade policy

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Comment

Summary While agreeing with Deariove's espousal of an eclectic approach to the analysis of political economy — the public choice approach is powerful and has much to offer to social scientists — not all social behaviour can be explained as the actions of rational self?seeking individuals. The fact that the public choice approach has been developed by opponents of state intervention in the market should not deter others from investigating its potential and benefiting from its insights. Resumen Comentario Aunque concuerda con Dearlove en la adopción de un enfoque ecléctico para analizar la economía política, ya que el enfoque de la opción pública es poderoso y tiene mucho que ofrecer a los dentistas sociales, sostiene que no toda la conducta social puede explicarse como resultante de acciones de individuos racionales egocéntricos. El hecho de que el enfoque de la opción pública haya sido desarrollado por los oponentes de la intervención estatal en el mercado no debería impedir la investigación de sus potenciales ni de beneficiarse de sus aportes. Resumé Commentaire Bien qu'en accord avec l'approche éclectique que Mr. Dearlove a choisi pour l'analyse de l'économie politique — la théorie sur ‘le choix publique’ est effective et a beaucoup à offrir aux scientistes sociaux — il n'est pas possible d'affirmer que tous les comportements sociaux peuvent être expliqués comme étant les actions d'individus égoistes et rationels; le fait que la théorie sur ‘le choix publique’ ait été développée par les opposants à l'intervention de l'état sur le marché, ne devrait pas en empêcher d'autres à rechercher ses potentiels et à bénéficier de ses éclaircissements sur le sujet

Experimental demonstration of a light-ray-direction-flipping METATOY based on confocal lenticular arrays

We show, theoretically and experimentally, that a sheet formed by two confocal lenticular arrays can flip one component of the local light-ray direction. Ray-optically, such a sheet is equivalent to a Dove-prism sheet, an example of a METATOY (metamaterial for light rays), a structure that changes the direction of transmitted light rays in a way that cannot be performed perfectly wave-optically.Comment: 5 pages, 6 figure

Efficient Modeling of an Array Antenna and Requirements for Maritime Mobile Reception of Meteorological Satellite Imagery

Wireless communication is an integral part of safety at sea. Direct broadcasts from public weather satellites on L- and X-band provide real-time weather observations and weather product dissemination to end users. These high-bandwidth broadcasts offer enhanced data throughput and require accurate pointing of high-gain antennas. An electronically-steered array antenna can provide high gain and rapid beam steering without moving parts, suitable for deployment on small vessels offshore. Figures of merit, such as array antenna gain and input impedance, vary with the beam steering angle as a consequence of mutual coupling between array elements. The electromagnetic design of an electronically-steered array antenna is more complex than a parabolic dish or a fixed broadside array, requiring an iterative development process and a computationally efficient method of simulating the array. This work addresses the validation of an efficient method for array simulation, a necessary first step in the design process of a deployable array. Starting with a small L-band subarray, a Fourier windowing method is applied to approximate the scan-dependent behavior of an electronically-steered array from an efficient numerical model in a periodic unit cell. Results are validated against experimental measurements of hardware prototypes and explicit numerical models of the subarray. The iterative design of antenna elements in an array environment and construction of a full-size array are left for future work

Efficient Modeling of an Array Antenna and Requirements for Maritime Mobile Reception of Meteorological Satellite Imagery

Wireless communication is an integral part of safety at sea. Direct broadcasts from public weather satellites on L- and X-band provide real-time weather observations and weather product dissemination to end users. These high-bandwidth broadcasts offer enhanced data throughput and require accurate pointing of high-gain antennas. An electronically-steered array antenna can provide high gain and rapid beam steering without moving parts, suitable for deployment on small vessels offshore. Figures of merit, such as array antenna gain and input impedance, vary with the beam steering angle as a consequence of mutual coupling between array elements. The electromagnetic design of an electronically-steered array antenna is more complex than a parabolic dish or a fixed broadside array, requiring an iterative development process and a computationally efficient method of simulating the array. This work addresses the validation of an efficient method for array simulation, a necessary first step in the design process of a deployable array. Starting with a small L-band subarray, a Fourier windowing method is applied to approximate the scan-dependent behavior of an electronically-steered array from an efficient numerical model in a periodic unit cell. Results are validated against experimental measurements of hardware prototypes and explicit numerical models of the subarray. The iterative design of antenna elements in an array environment and construction of a full-size array are left for future work

Fermat's principle with complex refractive indices and local light-ray rotation

We describe local light-ray rotation in terms of complex refractive indices. We show that Fermat's principle holds, and we derive an extended Snell's law. The change in the angle of a light ray with respect to the normal to a refractive-index interface is described by the modulus of the refractive-index ratio, the rotation around the interface normal is described by the argument of the refractive-index ratio.Comment: 3 pages, 2 figure

Effects of depressed pH on survival, growth and reproduction of brook trout, Salvelinus fontinalis (Mitchill)

Brook trout were continuously exposed to depressed pH values from 4.0 to 6.0, at 0.5 unit Intervals during a nine-month partial-chronic bloassay. At all pH levels above 4.0, Juvenile fish exhibited greater than 96 per cent survival. Although a pH of 4.0 was not acutely lethal, juvenile survival was poor. All trout exposed below pH 5.0 showed disturbances In acid-base balance and plasma electrolyte composition. Juveniles did not grow or sexually mature at pH 4.0 and exhibited slower growth at pH 4.5, compared to fish exposed at higher pH's. Inhibition of growth at pH 4.0 was attributed to starvation rather than H-ion concentration. Spawning occurred at all pH levels except 4.0. Eggs produced by females held at pH 4.5 were abnormal In shape and size, compared to those spawned by females held at or above pH 5.0. The total number of eggs produced at pH 4.5, however, did not differ significantly from the higher pH levels. Embryos from parents exposed to pH 4.5 showed low viability and did not hatch. Viability and hatchablllty of eggs held In the pH range, 5.0 to 6.0, was significantly reduced (P < .01) when compared to eggs held at pH 7.0. Poor alevln survival occurred at all pH levels below 7.0. Data on alevln growth at low pH was highly variable and hence Inconclusive. Results of the present Investigation coincide with those of other studies on fathead minnow, brook trout and flagflsh, which Indicate that reproductive success of these species Is affected below pH 6.5