Modeling long-range interactions across the visual field in stereo correspondence

When the eyes are converged, most objects in the visual scene will have a significant vertical disparity as measured at the retina. The pattern of vertical disparity across the retina is largely independent of object depth, depending mainly on the particular eye position adopted. Recently, Phillipson and Read (2010, European Journal of Neuroscience, doi:10.1111/j.1460-9568.2010.07454.x) showed that humans are better at achieving stereo correspondence when the vertical disparity field indicated infinite viewing distance, even when the physical viewing distance was just 30cm. They interpreted this as indicating that disparity encoding is optimized for long viewing distances, and is not updated to reflect changes in eye posture. Their results also indicated a significant effect of the visual periphery. Performance was better when the vertical disparity across the entire visual field was consistent with a given binocular eye position – even when this was not the eye position actually adopted – than when the vertical disparity beyond 20o eccentricity indicated a different eye position than that within 20o eccentricity. This is a surprising result, since (i) the task was to detect a target 8o in diameter, extending from 10o to 18o eccentricity, so information beyond 20o was completely irrelevant to the task, and (ii) many previous results indicate that the visual system detects and uses vertical disparity in local regions, even when the global vertical disparity field is not consistent with any single binocular eye position. Here, I show that this effect can be explained by a template-matching model in which the response of a population of disparity-detectors is compared with stored templates of the response expected to stimuli of known disparity

The political economy of trade protection: the determinants and welfare impact of the 2002 US emergency steel safeguard measures

This paper analyses the political economy of trade protection in the context of the factors determining the US Emergency Safeguard Measures for steel imposed March 2002. The paper identifies several factors in addition to the official justification stated problems of global over-capacity and the penetration of imports in the US market, namely the continued failure to restructure poorly performing firms, failure of previous attempts at protection and the influence of the domestic steel lobby and short-term political gains to the Bush Administration of protectionist action. The paper also reviews several ex ante and ex post empirical studies of the impact of the steel Safeguards on the steel industry and downstream steel-consuming activities. All of these studies find that the costs of the Safeguard Measures outweighed their benefits in terms of aggregate GDP and employment as well as having an important redistributive impact. The paper provides a brief summary of the subsequent WTO steel case and the final resolution of the dispute. The evidence suggests that the steel Safeguards owed more to political expediency than justification for protection under the WTO rules.

Trade dispute settlement mechanisms: the WTO dispute settlement understanding in the wake of the GATT

A critical feature of the GATT Uruguay Round negotiations was the establishment of a new and more effective system of dealing with international trade disputes, known as the WTO Dispute Settlement Understanding (DSU). The original GATT dispute settlement system comprised rudimentary remnants of a more thorough framework contained in the defunct Havana Charter of the International Trade Organization (ITO). By the time of the start of the Uruguay Round negotiations in Punta del Este in 1986, the effectiveness and credibility of the GATT dispute settlement system was being very seriously questioned. The primary reason for the increasing lack of confidence in the system was the propensity of GATT contracting countries to ignore the findings of Panels, resulting in a stalemate in a number of high profile trade disputes. Several trade disputes between the EU and the United States discussed were initiated under the GATT dispute settlement system but remained unresolved. These disputes became increasingly acrimonious as a direct consequence of the failure of the GATT system to enforce a satisfactory resolution. This paper provides an outline of the workings of the GATT and WTO dispute settlement systems underlie several recent trade disputes. The first two sections deal with the GATT system of settling trade disputes. The first details the key elements of the GATT dispute settlement system while the second considers its performance in resolving disputes. Section 3 outlines the origins of the WTO DSU and summarises its principal Articles. The WTO DSU is appraised on the basis of its first nine years of operation in Section 4 followed by a brief discussion of the key issues that have arisen from its operation. The final Section makes some concluding comments on the relative efficacy of the GATT and WTO dispute settlement systems.

Backpack carrier Patent

Backpack carrier with retractable legs suitable for lunar exploration and convertible to rescue vehicl

The XMM-Newton EPIC Background and the production of Background Blank Sky Event Files

We describe in detail the nature of XMM-Newton EPIC background and its various complex components, summarising the new findings of the XMM-Newton EPIC background working group, and provide XMM-Newton background blank sky event files for use in the data analysis of diffuse and extended sources. Blank sky event file data sets are produced from the stacking of data, taken from 189 observations resulting from the Second XMM-Newton Serendipitous Source Catalogue (2XMMp) reprocessing. The data underwent several filtering steps, using a revised and improved method over previous work, which we describe in detail. We investigate several properties of the final blank sky data sets. The user is directed to the location of the final data sets. There is a final data set for each EPIC instrument-filter-mode combination.Comment: Paper accepted by A&A 22 December 2006. 14 pages, 8 figures. Paper can also be found at http://www.star.le.ac.uk/~jac48/publications

The X-ray Evolution of Merging Galaxies

We present here the first study of the X-ray properties of an evolutionary sample of merging galaxies. Both ROSAT PSPC and HRI data are presented for a sample of eight interacting galaxy systems, each believed to involve a similar encounter between two spiral discs of approximately equal size. The mergers span a large range in age, from completely detached to fully merged systems. A great deal of interesting X-ray structure is seen, and the X-ray properties of each individual system are discussed in detail. Along the merging sequence, several trends are evident: in the case of several of the infrared bright systems, the diffuse emission is very extended, and appears to arise from material ejected from the galaxies. The onset of this process seems to occur very soon after the galaxies first encounter one another, and these ejections soon evolve into distorted flows. More massive extensions (perhaps involving up to 1e10 solar masses of hot gas) are seen at the `ultraluminous' peak of the interaction, as the galactic nuclei coalesce. The amplitude of the evolution of the X-ray emission through a merger is markedly different from that of the infrared and radio emission however, and this, we believe, may well be linked with the large extensions of hot gas observed. The late, relaxed remnants, appear relatively devoid of gas, and possess an X-ray halo very different from that of typical ellipticals, a problem for the `merger hypothesis', whereby the merger of two disc galaxies results in an elliptical galaxy. However, these systems are still relatively young in terms of total merger lifetime, and they may still have a few Gyr of evolution to go through, before they resemble typical elliptical galaxies.Comment: 30 pages, 15 figures, accepted by MNRA

Tool for use in lifting pin supported objects

A tool for use in lifting a pin-supported, electronic package mounted in juxtaposition with the surface of an electronic circuit board is described. The tool is configured to be received beneath a pin-supported package and is characterized by a manually operable linkage, including an elongated, rigid link is supported for axial reciprocation and a pivotal link pinned to the body and supported for oscillation induced in response to axial motion imparted to the rigid link. A lifting plate is pivotally coupled to the distal end of the pivotal link so that oscillatory motion imparted to the pivotal link serves to move the plate vertically for elevating the plate into lifting engagement with the electronic package positioned thereabove