Long period nodal motion of sun synchronous orbits

An approximative model is formulated for assessing these perturbations that significantly affect long term modal motion of sun synchronous orbits. Computer simulations with several independent computer programs consider zonal and tesseral gravitational harmonics, third body gravitational disturbances induced by the sun and the moon, and atmospheric drag. A pendulum model consisting of evenzonal harmonics through order 4 and solar gravity dominated nodal motion approximation. This pendulum motion results from solar gravity inducing an inclination oscillation which couples into the nodal precession induced by the earth's oblateness. The pendulum model correlated well with simulations observed flight data

Development of Japanese elementary curriculum that emphasises spoken-ness

This paper discusses the curriculum development which aims to enhance the spoken-ness or naturalness of two-way spoken conversation in Japanese. There are many special features in Japanese spoken conversation, such as particle omission, sentence-final particles, response tokens, fillers, repeat/repair and inversion. Being special characteristics of spoken Japanese, these features are indispensable to �natural� Japanese, and should be included in Japanese learning process if the goal of the Japanese education is to acquire natural Japanese. Despite their significance, these features have not sufficiently and systematically been taught in the current Japanese education. This is due to the fact that these features have not been recognised as formal learning objectives by Japanese teachers. However, there is no theoretical or empirical evidence that these features are too difficult for beginners and should not be taught at the elementary level. The study will discuss the curriculum development in the elementary courses of Japanese program at the Australian National University (ANU), which systematically adopts these features at the early stage of learning process. It will detail the development background, curriculum contents, and assessment of the special features. Since the curriculum was first implemented in the Japanese elementary courses at the ANU five years ago, no students or teachers have provided negative comments about learning/teaching these features. It is crucial that teachers first recognise those features as formal learning objectives and include in their Japanese courses

Delta launch vehicle inertial guidance system (DIGS)

The Delta inertial guidance system, part of the Delta launch vehicle improvement effort, has been flown on three launches and was found to perform as expected for a variety of mission profiles and vehicle configurations

Inflation Dynamics and Inflation Regimes

In this paper we develop and estimate a new-Keynesian model of inflation and use it to investigate the hypothesis that prices in the UK are re-set more frequently during periods of high inflation. In the model, firms are assumed to condition their expectations on an optimally-selected but incomplete information set and we further assume that the probability that they will reset their price in any quarter depends upon the prevailing inflationary regime. The model implies more complex inflation dynamics than conventional new-Keynesian models predict. We find that we cannot reject the formal restrictions implied by the model (using UK quarterly data) and we estimate that the mean time before prices were reset was around eight months during the 'high' inflationary regime and approximately two years when mean inflation was 'low'.Rational expectations, incomplete information, macroeconomic dynamics, regime switching

Demographic Change and the UK Savings Rate

We use microeconomic data to explore the effects of a changing age-structure on the UK's aggregate personal savings rate. Our findings suggest that changes to the population's age structure age have had detectable, sustained, but, relative to the yearly changes observed in the savings rate over the previous century, modest effects on aggregate personal sector savings. We estimate that the projected changes to the UK's age structure over the next 40 years are likely to raise the UK's savings rate but by no more than 2 percentage points. We find no basis for the view that the aggregate savings rate will decline as a result of the anticipated ageing of the UK population.Saving, ageing population

Optimally Rational Expectations and Macroeconomics

This paper provides an alternative to the theory of rational expectations (RE). Its central idea is that the information set on which agents will choose to condition their expectations will not, in general, include all the available information. Our alternative has many of the attractive features of RE; it emerges from an explicit choice-theoretic framework; it has wide applicability; and it can in principle explain the failure of models incorporating RE to account for the dynamics of many macroeconomic relationships.Rational expectations, incomplete information, macroeconomic dynamics

Weak measurement of the Goos-Hanchen shift

It is well known from quantum mechanics that weak measurements offer a means of amplifying and detecting very small phenomena. We present here the first experimental observation of the Goos-Hanchen shift via a weak measurement approach

The Pauli Exclusion Principle and SU(2) vs. SO(3) in Loop Quantum Gravity

Recent attempts to resolve the ambiguity in the loop quantum gravity description of the quantization of area has led to the idea that j=1 edges of spin-networks dominate in their contribution to black hole areas as opposed to j=1/2 which would naively be expected. This suggests that the true gauge group involved might be SO(3) rather than SU(2) with attendant difficulties. We argue that the assumption that a version of the Pauli principle is present in loop quantum gravity allows one to maintain SU(2) as the gauge group while still naturally achieving the desired suppression of spin-1/2 punctures. Areas come from j=1 punctures rather than j=1/2 punctures for much the same reason that photons lead to macroscopic classically observable fields while electrons do not.Comment: This paper received an "honorable mention" in the 2003 Essay Competition of the Gravity Research Foundation and should be appearing in a special issue of Int. J. Mod. Phys.