Community Sanctions as Substitutes to Imprisonment in the Nordic Countries

Vortex-induced vibrations (VIV) and wake interference on circular cylinders have reached a lot of research attention over the years. However, most research is done for relativly low Reynold numbers (sub-critical) and does not correspond to real world chimney situations. A real chimney in the south of Sweden has experienced some large vibrations and data gathered from this chimney shows a correlation between these motions and wind directions. Results from 2D CFD simulations used to simulate VIV on a circular cylinder when laying in the wake of another larger, and fix, cylinder at critical Reynold numbers are presented in this thesis. Simulations are done for three cases; one single cylinder, for comparisons, and two simluations for cylinders in tandem arrangement, at 35 and 70 m respectively. Results show that the cylinder when in tandem arrangement experience much larger vibrations than the single cylinder. For velocities above 10 m/s the tandem arrangement can lead to resonance on the cylinder, which is not occuring in the case with a single cylinder. This thesis shows that even at distances of 70 m, wake interference can have a large effect on VIV and more advanced models and simulations would be useful for better predictions of the behaivor of chimneys

Monetary policy, expected inflation and inflation risk premia

Within a New Keynesian business cycle model, we study variables that are normally unobservable but are very important for the conduct of monetary policy, namely expected inflation and inflation risk premia. We solve the model using a third-order approximation that allows us to study time-varying risk premia. Our model is consistent with rejection of the expectations hypothesis and the business-cycle behaviour of nominal interest rates in US data. We find that inflation risk premia are very small and display little volatility. Hence, monetary policy authorities can use the difference between nominal and real interest rates from index-linked bonds as a proxy for inflation expectations. Moreover, for short maturities current inflation is a good predictor of inflation risk premia. We also find that short-term real interest rates and expected inflation are significantly negatively correlated and that short-term real interest rates display greater volatility than expected inflation. These results are consistent with empirical studies that use survey data and index-linked bonds to obtain measures of expected inflation and real interest rates. Finally, we show that our economy is consistent with the Mundell-Tobin effect: increases in inflation are associated with higher nominal interest rates, but lower real interest rates.term structure of interest rates; monetary policy; expected inflation; inflation risk premia; Mundell-Tobin effect

Monetary policy and rejections of the expectations hypothesis

We study the rejection of the expectations hypothesis within a New Keynesian business cycle model. Earlier research has shown that the Lucas general equilibrium asset pricing model can account for neither sign nor magnitude of average risk premia in forward prices, and is unable to explain rejection of the expectations hypothesis. We show that a New Keynesian model with habit-formation preferences and a monetary policy feedback rule produces an upward-sloping average term structure of interest rates, procyclical interest rates, and countercyclical term spreads. In the model, as in U.S. data, inverted term structure predicts recessions. Most importantly, a New Keynesian model is able to account for rejections of the expectations hypothesis. Contrary to earlier work, we identify systematic monetary policy as a key factor behind this result. Rejection of the expectation hypothesis can be entirely explained by the volatility of just two real shocks which affect technology and preferences.term structure of interest rates; monetary policy; sticky prices; habit formation; expectations hypothesis

Guidelines for writing definitions in ontologies

Ontologies are being used increasingly to promote the reusability of scientific information by allowing heterogeneous data to be integrated under a common, normalized representation. Definitions play a central role in the use of ontologies both by humans and by computers. Textual definitions allow ontologists and data curators to understand the intended meaning of ontology terms and to use these terms in a consistent fashion across contexts. Logical definitions allow machines to check the integrity of ontologies and reason over data annotated with ontology terms to make inferences that promote knowledge discovery. Therefore, it is important not only to include in ontologies multiple types of definitions in both formal and in natural languages, but also to ensure that these definitions meet good quality standards so they are useful. While tools such as Protégé can assist in creating well-formed logical definitions, producing good definitions in a natural language is still to a large extent a matter of human ingenuity supported at best by just a small number of general principles. For lack of more precise guidelines, definition authors are often left to their own personal devices. This paper aims to fill this gap by providing the ontology community with a set of principles and conventions to assist in definition writing, editing, and validation, by drawing on existing definition writing principles and guidelines in lexicography, terminology, and logic

Energy landscapes, lowest gaps, and susceptibility of elastic manifolds at zero temperature

We study the effect of an external field on (1+1) and (2+1) dimensional elastic manifolds, at zero temperature and with random bond disorder. Due to the glassy energy landscape the configuration of a manifold changes often in abrupt, ``first order'' -type of large jumps when the field is applied. First the scaling behavior of the energy gap between the global energy minimum and the next lowest minimum of the manifold is considered, by employing exact ground state calculations and an extreme statistics argument. The scaling has a logarithmic prefactor originating from the number of the minima in the landscape, and reads $\Delta E_1 \sim L^\theta [\ln(L_z L^{-\zeta})]^{-1/2}$, where $\zeta$ is the roughness exponent and $\theta$ is the energy fluctuation exponent of the manifold, $L$ is the linear size of the manifold, and $L_z$ is the system height. The gap scaling is extended to the case of a finite external field and yields for the susceptibility of the manifolds $\chi_{tot} \sim L^{2D+1-\theta} [(1-\zeta)\ln(L)]^{1/2}$. We also present a mean field argument for the finite size scaling of the first jump field, $h_1 \sim L^{d-\theta}$. The implications to wetting in random systems, to finite-temperature behavior and the relation to Kardar-Parisi-Zhang non-equilibrium surface growth are discussed.Comment: 20 pages, 22 figures, accepted for publication in Eur. Phys. J.

The Term Structure of Interest Rates: Estimation and Interpretation

This document reports the currently used term structure estimation method at the Bank of Finland and discusses interpretation of the results it generates. We start by introducing two widely used term structure estimation methods: the Cubic Spline Function method and the Nelson-Siegel approach. We compare their results, paying special attention to the smoothness of forward interest rates and distribution of pricing errors. Next, we introduce the Bank of Finland's method, commenting on its strengths and weaknesses. Finally, we discuss interpretation of the term structure of interest rates with emphasis on the inflation expectations and the role of the time-varying risk premia.term structure of interest rates; cubic splines; Nelson-Siegel; forward interest rates; relative value; inflation expectations; time-varying risk premia

Definitions in ontologies

Definitions vary according to context of use and target audience. They must be made relevant for each context to fulfill their cognitive and linguistic goals. This involves adapting their logical structure, type of content, and form to each context of use. We examine from these perspectives the case of definitions in ontologies