Maan magneettikentän dipolimallin toimivuus inklinaatiojakauman perusteella

The magnetic field of the Earth is 99 % of the internal origin and generated in the outer liquid core by the dynamo principle. In the 19th century, Carl Friedrich Gauss proved that the field can be described by a sum of spherical harmonic terms. Presently, this theory is the basis of e.g. IGRF models (International Geomagnetic Reference Field), which are the most accurate description available for the geomagnetic field. In average, dipole forms 3/4 and non-dipolar terms 1/4 of the instantaneous field, but the temporal mean of the field is assumed to be a pure geocentric axial dipolar field. The validity of this GAD (Geocentric Axial Dipole) hypothesis has been estimated by using several methods. In this work, the testing rests on the frequency dependence of inclination with respect to latitude. Each combination of dipole (GAD), quadrupole (G2) and octupole (G3) produces a distinct inclination distribution. These theoretical distributions have been compared with those calculated from empirical observations from different continents, and last, from the entire globe. Only data from Precambrian rocks (over 542 million years old) has been used in this work. The basic assumption is that during the long-term course of drifting continents, the globe is sampled adequately. There were 2823 observations altogether in the paleomagnetic database of the University of Helsinki. The effect of the quality of observations, as well as the age and rocktype, has been tested. For comparison between theoretical and empirical distributions, chi-square testing has been applied. In addition, spatiotemporal binning has effectively been used to remove the errors caused by multiple observations. The modelling from igneous rock data tells that the average magnetic field of the Earth is best described by a combination of a geocentric dipole and a very weak octupole (less than 10 % of GAD). Filtering and binning gave distributions a more GAD-like appearance, but deviation from GAD increased as a function of the age of rocks. The distribution calculated from so called keypoles, the most reliable determinations, behaves almost like GAD, having a zero quadrupole and an octupole 1 % of GAD. In no earlier study, past-400-Ma rocks have given a result so close to GAD, but low inclinations have been prominent especially in the sedimentary data. Despite these results, a greater deal of high-quality data and a proof of the long-term randomness of the Earth's continental motions are needed to make sure the dipole model holds true.

Words as Events : Cretan Mantinádes in Performance and Composition

Words as Events introduces the tradition of short, communicative rhyming couplets, the mantinádes, which are still sung and recited in a variety of performance situations on the island of Crete. The local focus on communicative economy and artistry is further examined in an in-depth analysis of the processes and ideals of composition. Short genres of oral poetry have been widely neglected in folklore research; however, their demand for structural and semantic coherence as well as their dialogic nature appeals to very different human needs from those of the longer poems. In contemporary Crete, poems also appear in written contexts, they are submitted to modern mass media, and people widely exchange them as text messages. By striving to understand the tradition during a period of change, this study analyzes the larger principles that ground the communication, self-expression and creativity in the genre. The aim of this research is thus twofold: to present this specific register of dialogic oral poetry as well as to create a theoretical approach sensitive to the creativity of such short registers. The study is based on long-term ethnographic fieldwork conducted in Crete between the years 1997 2009. An important aspect of the methodology was to create long-term ties with a number of key-informants who composed mantinádes. The interdisciplinary theoretical and methodological basis for this analysis is in the contemporary Finnish and international research on oral poetry and on anthropological research on communicative speech genres. These theoretical insights are extended by addressing questions of spontaneity and individual agency. Since mantinádes are at the same time a model for composition and a reserve of poems in fixed form, the aesthetics and objectives of performance and composition are also plural. In a traditional singing event, the basic motivation for the singers is to provide a meaningful contribution to a selected theme, which is the shared topic of the poetic dialogue. Consequently, similar topics giving rise to poetic associations can be encountered during various moments of everyday life: the dialogic nature is embodied in the tradition to such degree that it also arises in the performances and composition of single poems and outside of any institutionalized performance arenas. Therefore, as this study discusses in detail, even the apparently non-contextualized poems recited between locals or occurring in the contemporary mass media arenas, are understood and evaluated as utterances that provide an individual perspective within a certain dialogue.

Evaluating the Predictability of the Volatility Smile Using Return Distributions

In this paper, we examine the predictability of observed volatility smiles in three major European index options markets, utilising the historical return distributions of the respective underlying assets. The analysis involves an application of the Black (1976) pricing model adjusted in accordance with the Jarrow-Rudd methodology as proposed in 1982. Thereby we adjust the expected future returns for the third and fourth central moments as these represent deviations from normality in the distributions of observed returns. Thus, they are considered one possible explanation to the existence of the smile. The obtained results indicate that the inclusion of the higher moments in the pricing model to some extent reduces the volatility smile, compared with the unadjusted Black-76 model. However, as the smile is partly a function of supply, demand, and liquidity, and as such intricate to model, this modification does not appear sufficient to fully capture the characteristics of the smile.

An Empirical Study of the Mixture of Time and Movements in Prices

This paper investigates the persistent pattern in the Helsinki Exchanges. The persistent pattern is analyzed using a time and a price approach. It is hypothesized that arrival times are related to movements in prices. Thus, the arrival times are defined as durations and formulated as an Autoregressive Conditional Duration (ACD) model as in Engle and Russell (1998). The prices are defined as price changes and formulated as a GARCH process including duration measures. The research question follows from market microstructure predictions about price intensities defined as time between price changes. The microstructure theory states that long transaction durations might be associated with both no news and bad news. Accordingly, short durations would be related to high volatility and long durations to low volatility. As a result, the spread will tend to be larger under intensive moments. The main findings of this study are 1) arrival times are positively autocorrelated and 2) long durations are associated with low volatility in the market.

Pricing Index Options with Stochastic Volatility

The objective of this paper is to investigate the pricing accuracy under stochastic volatility where the volatility follows a square root process. The theoretical prices are compared with market price data (the German DAX index options market) by using two different techniques of parameter estimation, the method of moments and implicit estimation by inversion. Standard Black & Scholes pricing is used as a benchmark. The results indicate that the stochastic volatility model with parameters estimated by inversion using the available prices on the preceding day, is the most accurate pricing method of the three in this study and can be considered satisfactory. However, as the same model with parameters estimated using a rolling window (the method of moments) proved to be inferior to the benchmark, the importance of stable and correct estimation of the parameters is evident.

Experimental approach for studying structural changes in axonal membrane upon nerve excitation

The Hodgkin and Huxley (HH) model of action potential has become a central paradigm of neuroscience. Despite its ability to predict action potentials with remarkable accuracy, it fails to explain several biophysical findings related to the initiation and propagation of the nerve impulse. The isentropic heat release and optical phenomena demonstrated by various experiments suggest that action potential is accompanied by a transient phase change in the axonal membrane. In this study a method was developed for preparing a giant axon from the crayfish abdominal cord for studying the molecular mechanisms of action potential simultaneously by electrophysiological and optical methods. Also an alternative setup using a single-cell culture of an Aplysia sensory neuron is presented. In addition to the description of the method, the preliminary results on the effect of phloretin, a dipole potential lowering compound, on the excitability of a crayfish giant axon are presented.

“Aivan sama vaikkei ne olis edes pelannut” – Jalkapallo elämyskulutuksen kohteena

Tutkielmassa tarkastellaan jalkapallon seuraamista elämyskuluttamisen näkökulmasta. Elämyskulutuksella tarkoitetaan tässä yhteydessä tapahtumia ja hetkiä, jolloin ihminen kokee tavallisuudesta poikkeavan ja mieleenpainuvan tunnetilan. Elämyksiä tarjoavat palvelut ovat lisänneet jatkuvasti suosiotaan, kun arjessa rationaalisuus ylikorostuu ja sille halutaan vastapainoa. Aihetta taustoitetaan elämysyhteiskunnan, yhteisöllisyyden ja kuluttajaheimojen käsitteiden avulla. Erityishuomion saavat kulttuuritapahtumat elämystuotteina, penkkiurheilu yhteiskunnallisena ilmiönä sekä erilaiset jalkapalloon liittyvät kulutustavat. Tutkielma on luonteeltaan fenomenologis-etnografinen kuvaileva tutkimus. Tutkimusmenetelminä on käytetty osallistuvaa havainnointia ja haastatteluita. Tutkimusperinteen mukaisesti ilmiön ymmärtäminen, kuvaaminen ja kirjoittaminen ovat tärkeässä osassa. Havainnointiaineisto on kerätty kolmessa eri tapahtumassa seuraamalla katsojien käyttäytymistä ja tunnelman syntymiseen vaikuttavia tekijöitä. Haastateltavat on valittu harkinnanvaraisesti jalkapalloa aktiivisesti seuraavista henkilöistä ja menetelmänä on käytetty avoimia teemahaastatteluita. Urheilun vetovoima ajanvietteenä perustuu vahvojen tunteiden herättämiseen, joten penkkiurheilu on elämyskulutusta puhtaimmillaan. Urheilu elämystuotteena on oivallinen, sillä sen lukuisten kulutustapojen lisäksi tapahtumat muodostavat päättymättömän jatkumon. Myös oman aineistoni perusteella osoittautui, että menneiden tapahtumien avulla ankkuroidutaan yhteisöön ja tulevien tapahtumien avulla pidetään innostusta yllä. Pettymysten hetkelläkään koukusta ei haluta irti, sillä jokainen kokemus lisää tunteita omaa urheilulajia ja yhteisöä kohtaan. Urheilutapahtumissa katsojan elämys syntyy subjektiivisen kokemuksen kautta, mutta yhteisö luo elämyksen toteutumisen välttämättömät edellytykset. Jalkapalloyleisöön kuuluvissa henkilöissä yhdistyvät halu kuulua ryhmään ja olla samaan aikaan sen ulkopuolella. Peliä voidaan tarkkailla itsekseen ja keskittyneesti suuren joukon keskellä tai hurrata muiden mukana. Aineistoni perusteella jalkapallofanin innostus pulppuaa kahdesta lähteestä: yhteisöllisyydestä ja kiinnostuksesta lajiin. Yhteisöllisyyden tunne syntyy kuulumisesta globaaliin jalkapalloyhteisöön, oman suosikkijoukkueen kannattajiin ja samaa lajia seuraavien kaverien muodostamaan lähipiiriin. Urheilullinen puoli innostuksesta syntyy kiinnostuksesta jalkapalloa kohtaan lajina, aktiivisesti seuratuista säännöllisistä tapahtumista ja oman joukkueen kannattamisesta. Jalkapallon seuraajiin teoria jatkuvasti muuttuvista uusyhteisöistä pätee melko huonosti, sillä lajille ja seuralle ollaan hyvin uskollisia. Faneille on tärkeää sitoutua pieneen lähiyhteisöön, jonka kanssa heillä on yhteinen historia ja mahdollisuus jakaa kokemuksia keskustelemalla ja muistelemalla.

Ideaalin ja todellisuuden välimaastossa - katoavatko perheateriat?

Aims: The recent conversations about disappearing family meals, mental problems of the youngsters and family meals´ protective effect on youngsters problems have been the base of this study. The main aim of this study is to find out, what kind of position family meals do have in the youngsters´lives. Study questions are: 1. What kind of conceptions youngsters have of family meals? 2. What kind of hands-on experience youngsters have about family meals? 3. How youngsters feel family meals on a emotional level? a. Are meals positive moments with the family or do they just limit timetables? b. Do the youngsters need family meals if they do not have those in their families? Why? Why not? Methods: The data was collected using stimulated recall -interviews and basic themed interviews. The data was collected from thirteen 8th graders from Pirkanmaa and Kanta-Häme. The interviews were analyzed with the qualitative content analysis. Results and conclusion: The youngsters´ consepts of the meals and the family meals were quite traditional, assuming that those are warm, varied and eaten with company. The situation of the family meals was good and those were eaten nearly every day in the most of the families. The youngsters thought that the family meals were important social moments with the family and they were able to talk about important things with the family during the meals. They also felt that the daily eating rythm was good and they did not felt that the meals would have been somehow restrictive. Even so that the pupils felt the family meals were important, the pupil whose family did not eat family meals did not long those meals. He felt that he was able to share his thoughts and experiences also in other ways. It is important that youngsters have this channel of communication.

Birth of the European individual : Outline of a theory of legal practice

The modern subject is what we can call a self-subjecting individual. This is someone in whose inner reality has been implanted a more permanent governability, a governability that works inside the agent. Michel Foucault s genealogy of the modern subject is the history of its constitution by power practices. By a flight of imagination, suppose that this history is not an evolving social structure or cultural phenomenon, but one of those insects (moth) whose life cycle consists of three stages or moments: crawling larva, encapsulated pupa, and flying adult. Foucault s history of power-practices presents the same kind of miracle of total metamorphosis. The main forces in the general field of power can be apprehended through a generalisation of three rationalities functioning side-by-side in the plurality of different practices of power: domination, normalisation and the law. Domination is a force functioning by the rationality of reason of state: the state s essence is power, power is firm domination over people, and people are the state s resource by which the state s strength is measured. Normalisation is a force that takes hold on people from the inside of society: it imposes society s own reality its empirical verity as a norm on people through silently working jurisdictional operations that exclude pathological individuals too far from the average of the population as a whole. The law is a counterforce to both domination and normalisation. Accounting for elements of legal practice as omnihistorical is not possible without a view of the general field of power. Without this view, and only in terms of the operations and tactical manoeuvres of the practice of law, nothing of the kind can be seen: the only thing that practice manifests is constant change itself. However, the backdrop of law s tacit dimension that is, the power-relations between law, domination and normalisation allows one to see more. In the general field of power, the function of law is exactly to maintain the constant possibility of change. Whereas domination and normalisation would stabilise society, the law makes it move. The European individual has a reality as a problem. What is a problem? A problem is something that allows entry into the field of thought, said Foucault. To be a problem, it is necessary for certain number of factors to have made it uncertain, to have made it lose familiarity, or to have provoked a certain number of difficulties around it . Entering the field of thought through problematisations of the European individual human forms, power and knowledge one is able to glimpse the historical backgrounds of our present being. These were produced, and then again buried, in intersections between practices of power and games of truth. In the problem of the European individual one has suitable circumstances that bring to light forces that have passed through the individual through centuries.

Light scattering in random media with wavelength-scale structures : astronomical and industrial applications

Light scattering, or scattering and absorption of electromagnetic waves, is an important tool in all remote-sensing observations. In astronomy, the light scattered or absorbed by a distant object can be the only source of information. In Solar-system studies, the light-scattering methods are employed when interpreting observations of atmosphereless bodies such as asteroids, atmospheres of planets, and cometary or interplanetary dust. Our Earth is constantly monitored from artificial satellites at different wavelengths. With remote sensing of Earth the light-scattering methods are not the only source of information: there is always the possibility to make in situ measurements. The satellite-based remote sensing is, however, superior in the sense of speed and coverage if only the scattered signal can be reliably interpreted. The optical properties of many industrial products play a key role in their quality. Especially for products such as paint and paper, the ability to obscure the background and to reflect light is of utmost importance. High-grade papers are evaluated based on their brightness, opacity, color, and gloss. In product development, there is a need for computer-based simulation methods that could predict the optical properties and, therefore, could be used in optimizing the quality while reducing the material costs. With paper, for instance, pilot experiments with an actual paper machine can be very time- and resource-consuming. The light-scattering methods presented in this thesis solve rigorously the interaction of light and material with wavelength-scale structures. These methods are computationally demanding, thus the speed and accuracy of the methods play a key role. Different implementations of the discrete-dipole approximation are compared in the thesis and the results provide practical guidelines in choosing a suitable code. In addition, a novel method is presented for the numerical computations of orientation-averaged light-scattering properties of a particle, and the method is compared against existing techniques. Simulation of light scattering for various targets and the possible problems arising from the finite size of the model target are discussed in the thesis. Scattering by single particles and small clusters is considered, as well as scattering in particulate media, and scattering in continuous media with porosity or surface roughness. Various techniques for modeling the scattering media are presented and the results are applied to optimizing the structure of paper. However, the same methods can be applied in light-scattering studies of Solar-system regoliths or cometary dust, or in any remote-sensing problem involving light scattering in random media with wavelength-scale structures.

Monetary policy rules and estimated reaction functions for the European Central Bank

This thesis studies the interest-rate policy of the ECB by estimating monetary policy rules using real-time data and central bank forecasts. The aim of the estimations is to try to characterize a decade of common monetary policy and to look at how different models perform at this task.The estimated rules include: contemporary Taylor rules, forward-looking Taylor rules, nonlinearrules and forecast-based rules. The nonlinear models allow for the possibility of zone-like preferences and an asymmetric response to key variables. The models therefore encompass the most popular sub-group of simple models used for policy analysis as well as the more unusual non-linear approach. In addition to the empirical work, this thesis also contains a more general discussion of monetary policy rules mostly from a New Keynesian perspective. This discussion includes an overview of some notable related studies, optimal policy, policy gradualism and several other related subjects. The regression estimations are performed with either least squares or the generalized method of moments depending on the requirements of the estimations. The estimations use data from both the Euro Area Real-Time Database and the central bank forecasts published in ECB Monthly Bulletins. These data sources represent some of the best data that is available for this kind of analysis. The main results of this thesis are that forward-looking behavior appears highly prevalent, but that standard forward-looking Taylor rules offer only ambivalent results with regard to inflation. Nonlinear models are shown to work, but on the other hand do not have a strong rationale over a simpler linear formulation. However, the forecasts appear to be highly useful in characterizing policy and may offer the most accurate depiction of a predominantly forward-looking central bank. In particular the inflation response appears much stronger while the output response becomes highly forward-looking as well.