Helmet weight simulator

A device for providing acceleration cues to the helmet of a simulator pilot is described. Pulleys are attached to both shoulders of the pilot. A cable is attached to both sides of the helmet and extends through the pulleys to a takeup reel that is controlled by a torque motor. Control signals are applied to a servo system including the torque motor, the takeup reel and a force transducer which supplies the feedback signal. In one embodiment of the invention the force transducer is in the cable and in another it is in the takeup reel

Coherent states and the quantization of 1+1-dimensional Yang-Mills theory

This paper discusses the canonical quantization of 1+1-dimensional Yang-Mills theory on a spacetime cylinder, from the point of view of coherent states, or equivalently, the Segal-Bargmann transform. Before gauge symmetry is imposed, the coherent states are simply ordinary coherent states labeled by points in an infinite-dimensional linear phase space. Gauge symmetry is imposed by projecting the original coherent states onto the gauge-invariant subspace, using a suitable regularization procedure. We obtain in this way a new family of "reduced" coherent states labeled by points in the reduced phase space, which in this case is simply the cotangent bundle of the structure group K. The main result explained here, obtained originally in a joint work of the author with B. Driver, is this: The reduced coherent states are precisely those associated to the generalized Segal-Bargmann transform for K, as introduced by the author from a different point of view. This result agrees with that of K. Wren, who uses a different method of implementing the gauge symmetry. The coherent states also provide a rigorous way of making sense out of the quantum Hamiltonian for the unreduced system. Various related issues are discussed, including the complex structure on the reduced phase space and the question of whether quantization commutes with reduction

Regional business cycles in New Zealand:Do they exist? What might drive them?

We use National Bank of New Zealand Regional Economic Activity data, to identify and characterise classical business cycle turning points, for New Zealand’s 14 regions and aggregate New Zealand activity. Using Concordance statistic measures, logistic model and GMM estimation methods, meaningful regional business cycles have been identified and a number of significant associations established. All regions exhibit cyclical asymmetry for both durations and amplitudes, and synchronisations between aggregate NZ activity and each region are contemporaneous. The regional cycles rarely die of old age but are terminated by particular events. The regions most highly synchronised with the NZ activity cycle are Auckland, Canterbury, and Nelson- Marlborough; those least so are Gisborne and Southland. Noticeably strong co-movements are evident for certain regions. Geographical proximity matters, and unusually dry conditions can be associated with cyclical downturns in certain regions. There is no discernable evidence of association with net immigration movements, and no significant evidence of regional cycle movements being associated with real national house price cycles. The agriculture-based nature of the New Zealand economy is highlighted by the strong influence of external economic shocks on rural economic performance. In particular, there is considerable evidence of certain regional cycles being associated with movements in New Zealand’s aggregate terms of trade, real prices of milksolids, real dairy land prices and total rural land prices.Classical business cycle; Turning Points; Regional business cycles; Concordance statistics; New Zealand

Surface roughness detector Patent

Roughness detector for recording surface pattern of irregularitie

Regional Business Cycles in New Zealand: Do they exist? What might drive them?

We use National Bank of New Zealand Regional Economic Activity data, to identify and characterise classical business cycle turning points, for New Zealand’s 14 regions and aggregate New Zealand activity. Using Concordance statistic measures, logistic model and GMM estimation methods, meaningful regional business cycles have been identified and a number of significant associations established. All regions exhibit cyclical asymmetry for both durations and amplitudes, and synchronisations between aggregate NZ activity and each region are contemporaneous. The regional cycles rarely die of old age but are terminated by particular events. The regions most highly synchronised with the NZ activity cycle are Auckland, Canterbury, and Nelson-Marlborough; those least so are Gisborne and Southland. Noticeably strong co-movements are evident for certain regions. Geographical proximity matters, and unusually dry conditions can be associated with cyclical downturns in certain regions. There is no discernable evidence of association with net immigration movements, and no significant evidence of regional cycle movements being associated with real house price cycles. The agriculture-based nature of the New Zealand economy is highlighted by the strong influence of external economic shocks on rural economic performance. In particular, there is considerable evidence of certain regional cycles being associated with movements in New Zealand’s aggregate terms of trade, real prices of milksolids, real dairy land prices and total rural land prices. JEL Classification: C22, E32, R11, R12, R15 Keywords: Classical business cycle; Turning Points; Regional business cycles; Concordance statistics; New Zealand

Status of coral reefs of Little Cayman, Grand Cayman and Cayman Brac, British West Indies in 1999 and 2000. (Part 1: Stony corals and algae)

A benthic assessment of the isolated Cayman Islands was completed at 42 sites. Major changes in the reef community structure were documented by comparison with earlier studies. Acropora palmata and A. cervicornis, once abundant as shallow framework builders, were uncommon. Diseased stony corals were seen in \u3e90% of the study sites, with the highest averages in Little Cayman, especially at Bloody Bay which is one of the most highly regulated marine parks in the Cayman Islands. The Montastraea annularis species complex accounted for two-thirds of the diseased corals which, along with other massive species, were affected largely by white-plague disease. Recent partial-colony mortality was particularly high in Grand Cayman. However, small- to intermediate-sized (M. annularis complex) suggest a strong potential for population regeneration. Algal competition generally did not appear to be a problem for stony corals, and bleaching was insignificant, yet more prevalent, in the deeper (\u3e10 m) sites

Study of behavioral modifications resulting from exposure to high let radiation

Animal irradiations, behavioral studies, neurological studies, and nuclear medicine studies are discussed

Non-radial Oscillation Modes of Compact Stars with a Crust

Oscillation modes of isolated compact stars can, in principle, be a fingerprint of the equation of state (EoS) of dense matter. We study the non-radial high-frequency l=2 spheroidal modes of neutron stars and strange quark stars, adopting a two-component model (core and crust) for these two types of stars. Using perturbed fluid equations in the relativistic Cowling approximation, we explore the effect of a strangelet or hadronic crust on the oscillation modes of strange stars. The results differ from the case of neutron stars with a crust. In comparison to fluid-only configurations, we find that a solid crust on top of a neutron star increases the p-mode frequency slightly with little effect on the f-mode frequency, whereas for strange stars, a strangelet crust on top of a quark core significantly increases the f-mode frequency with little effect on the p-mode frequency.Comment: 10 pages, 6 figure

The Bargmann representation for the quantum mechanics on a sphere

The Bargmann representation is constructed corresponding to the coherent states for a particle on a sphere introduced in: K. Kowalski and J. Rembielinski, J. Phys. A: Math. Gen. 33, 6035 (2000). The connection is discussed between the introduced formalism and the standard approach based on the Hilbert space of square integrable functions on a sphere S^2.Comment: LaTe

Coherent states on spheres

We describe a family of coherent states and an associated resolution of the identity for a quantum particle whose classical configuration space is the d-dimensional sphere S^d. The coherent states are labeled by points in the associated phase space T*(S^d). These coherent states are NOT of Perelomov type but rather are constructed as the eigenvectors of suitably defined annihilation operators. We describe as well the Segal-Bargmann representation for the system, the associated unitary Segal-Bargmann transform, and a natural inversion formula. Although many of these results are in principle special cases of the results of B. Hall and M. Stenzel, we give here a substantially different description based on ideas of T. Thiemann and of K. Kowalski and J. Rembielinski. All of these results can be generalized to a system whose configuration space is an arbitrary compact symmetric space. We focus on the sphere case in order to be able to carry out the calculations in a self-contained and explicit way.Comment: Revised version. Submitted to J. Mathematical Physic