The WaveGyro

The WaveGyro – A new Concept for Ocean Wave Energy Capture (Master Thesis by Gebhard Waizmann, University of Southampton 22.09.2011) Abstract Climate change, environmental pollution and the proceeding resource depletion give awareness of the necessity towards more sustainable energy economics. Energy from ocean waves may once play a contributing role towards this step but is as yet in its fledgling stages. This is mainly due to the harsh sea environment, which implies the need for simple and robust wave energy converter. The work presented in this thesis picks up this thought when dealing with the so-called WaveGyro. Introductory chapters explain how this novel concept arose, followed by a detailed explanation of the working principle. The WavGyro utilizes gyroscopes to provide an internal reaction moment against the wave excitation. This internal reaction permits designing a completely enclosed and thus environmentally resistant device. The gyroscopic precession is used to convert the wave-induced moment into a moment that accelerates the flywheels. Equations of motion, which describe the gyroscope kinetics, are deduced. The gyroscopic motions and moment is then implemented into the first-order wave hydrodynamics. Two main approaches to describe the wave excitation are presented. The first approach is superposition of radiation and exci-tation and the second approach makes use of the relative motion principle, which relates the excitation to the extent of displacement. Both approaches are employed to deduce the maximum power capture condition in relation to the device’s dimensions and operational parameters. The influence of real sea state, analytically expressed by the Pierson-Moskowitz spec-trum, on the optimum power analysis is considered and implementation methods are de-veloped. Subsequently the spin-up mechanism is explained and examined; this is the mechanism converting the precession moment into torque accelerating the flywheel. It is shown that a simple configuration, composed of an ordinary cogwheel and a sprag-clutch only is not sufficient for this mechanism. Ideas for alternative mechanisms are considered but require further investigation to allow conclusive results. Finally, an approximate plan for the design of model is developed, which includes basic considerations of scaling laws. Recommendations for further theoretical and practical work on the WaveGyro are provided

Scalar Symmetries of the Hubbard Models with Variable Range Hopping

Examples of scalar conserved currents are presented for trigonometric, hyperbolic and elliptic versions of the Hubbard model with non-nearest neighbour variable range hopping. They support for the first time the hypothesis about the integrability of the elliptic version. The two- electron wave functions are constructed in an explicit form.Comment: 9 pages, LaTex2e, no figure

Tax Morale, Tax Evasion, and the Shadow Economy

Under which conditions is moral justification of taxation possible? This question does not only interest philosophers and economists from a scientific point of view, but can have considerable practical relevance as well because the willingness of citizens to pay taxes may depend upon whether they consider taxation to be morally justified or not. We first consider theoretical arguments on the role of tax morale, and when tax evasion might be considered as justified by citizens or not. Then we ask how tax morale can be measured. Next, we discuss the role of tax morale for the shadow economy, before determinants of tax morale and empirical results for the impact of tax morale on tax compliance are discussed. For a high tax morale, institutional and cultural factors are at least as important as economic incentives.Tax morale, tax evasion, principles of taxation, trust, direct democracy, federalism

(Why) Are Economists Different?

After presenting some casual evidence about the difference between economists and the rest of the population, first the survey and experimental evidence which has been presented on this topic during the last 20 years is discussed. But can these results really be transferred to real world situations? To show this, examples of referenda results in Switzerland are presented where the citizens decided against recommendations of most economists. But what is so particular in economic theory that causes these different convictions? Some explanations are given with respect to positive economic theory and with respect to the normative convictions of economists. The paper concludes with possible consequences which economists might draw.cooperative behaviour, indoctrination, self-selection, referenda results, economic model of behaviour, commitment, fairness of the market, economists

Time Series Properties of the German Monthly Production Index

The production index is an important indicator for assessing the cyclical state of the economy. Unfortunately, the monthly time series is contaminated by many noisy components like seasonal variations, calendar and vacation effects. Only part of those nuisance components are explicitly considered in the seasonal adjustment procedures used by statistical agencies. In this paper, we propose a more flexible specification for the seasonal and working day effects and introduce an indicator for the summer vacations effect. We allow for time-varying parameters and show that the resulting Unobserved Components Model delivers more reliable results for the adjusted series.production index, seasonal adjustment, working day effect, business cycles, unobserved components models

The Weak Rationality Principle in Economics

The weak rationality principle is not an empirical statement but a heuristic rule how to proceed in social sciences. It is a necessary ingredient of any understanding’ social science in the Weberian sense. In this paper, first this principle and its role in economic theorizing is discussed. It is also explained why it makes sense to use a micro-foundation and, therefore, employ the rationality assumption in economic models. Then, with reference to the ?bounded rationality’ approach, the informational assumptions are discussed. Third, we address the assumption of self-interest which is often seen as a part of the rationality assumption. We conclude with some remarks of handling the problems of ?free will’ as well as ?weakness of the will’ within the economic approach.Rationality, Self Interest, Micro-Foundation, Bounded Rationality

Uniformizable families of tt-motives

Abelian $t$-modules and the dual notion of $t$-motives were introduced by Anderson as a generalization of Drinfeld modules. For such Anderson defined and studied the important concept of uniformizability. It is an interesting question, and the main objective of the present article to see how uniformizability behaves in families. Since uniformizability is an analytic notion, we have to work with families over a rigid analytic base. We provide many basic results, and in fact a large part of this article concentrates on laying foundations for studying the above question. Building on these, we obtain a generalization of a uniformizability criterion of Anderson and, among other things, we establish that the locus of uniformizability is Berkovich open.Comment: 40 pages, v2: Section 7 rewritten; to appear in Trans. Amer. Math. So

The Effects of Fiscal Institutions on Public Finance: A Survey of the Empirical Evidence

This paper surveys the empirical research on fiscal institutions of the last three decades. The main results are: (i) Constitutional or statutory fiscal limitations have in most cases proved to be effective in cutting down public expenditure, revenue, and debt. (ii) Budgetary proce-dures matter as well. They might be less effective than constitutional or statutory rules, but in a situation where it is impossible to introduce such rules they might present a feasible second-best way to reach fiscal sustainability. (iii) Citizens demand fewer public services and a sounder fiscal policy in systems with direct legislation than in purely parliamentary systems. (iv) There is some evidence that fiscal federalism leads ceteris pari-bus to a smaller size of the government. There are also political institutions which have an impact on the public budg-ets, and there are some interactions between the different institutions.balanced budget, budgetary procedures, fiscal federalism, direct democracy, public expenditure, public debt