This paper examines whether the phenomena of price drift around quarterly earnings re-leases exist among firms listed on the large cap. list at the Stockholm Stock Exchange for a time period ranging from the first quarter of 2003 to the second quarter of 2006. It fur-thermore examines the ability of the variables forecast error, relative to analyst’s estimates, and firms’ size to explain the variation in price drift among firms. A sample of some 30 firms were drawn in the first three quarters of each year between 2003 and 2005, for the year of 2006 only the fist two quarters were included in the study. For each quarter all firms were classified into three different portfolios on the basis of earnings deviations relative to mean analyst’s estimates (forecast error). The returns for each firm in all portfolios were investigated during 20 days post- and pre quarterly earnings release date, resulting in an event window totaling 41 days. In order to clear out effects from general market movements the Capital Asset Pricing Model, CAPM, was used in which betas were estimated for all firms each quarter. The findings from this study indicate that price drift, measured by cumulative abnormal re-turn, occur for firms with both negative forecast error as well as positive. For firms with positive error, statistically significant positive price drift was found for both the pre- and post period. As for the firms with earnings below analyst’s mean estimates, negative prean-nouncement drift was statistically supported. The ability of firms size and forecast error to explain the variation in price drift on a stock level was very weak, R2 measures of below 5% was reported. However, forecast error was a strongly significant independent variable in the context of the regressions run for both pre- and post-announcement drift. The firms below the lower market cap. quartile in the sample show, on average, lower pre-announcement drift than the firms belonging in the largest quartile. Concerning market efficiency among the large cap. firms the price drift found is an indica-tion of market inefficiency both it terms of the semi strong and the strong form. However, care should be taken before generalizing the results from this study but. Possible misspeci-fication of the equilibrium return model will skew the price drift measurement. Moreover, speculation is not explicitly controlled for in this test. Finally, this study is done within a li-mited time span; hence generalization over time is not possible

Post earnings announcement drift (PEAD) is defined as the drift that occurs in a company’s share priceafter their earnings announcement. A company that reports earnings above (below) the analysts’expectations should, according to previous studies of PEAD, continue to drift upwards (downwards)after the announcement. (Ball & Brown, 1968) The thesis purpose is to investigate if PEAD existed onthe Swedish market between 2006-2010. We test PEAD’s existences through; (i) creating portfolios inwhich companies’ abnormal return (AR) we expect to decline or increase, (ii) doing a multiple regressionanalysis to test if the drift is statistically significant. From the results of our study, we can neither acceptnor reject the hypothesis that PEAD existed on the Swedish market, although the multiple regressionanalysis prove a statistically significant result for companies’ AR that we expect to decline have drifted3,11% in a negative direction compared to our total sample.

Concept drift refers to a problem that is caused by a change in the data distribution in data mining. This leads to reduction in the accuracy of the current model that is used to examine the underlying data distribution of the concept to be discovered. A number of techniques have been introduced to address this issue, in a supervised learning (or classification) setting. In a classification setting, the target concept (or class) to be learned is known. One of these techniques is called “Ensemble learning”, which refers to using multiple trained classifiers in order to get better predictions by using some voting scheme. In a traditional ensemble, the underlying base classifiers are all of the same type. Recent research extends the idea of ensemble learning to the idea of using committees, where a committee consists of diverse classifiers. This is the main difference between the regular ensemble classifiers and the committee learning algorithms. Committees are able to use diverse learning methods simultaneously and dynamically take advantage of the most accurate classifiers as the data change. In addition, some committees are able to replace their members when they perform poorly. This thesis presents two new algorithms that address concept drifts. The first algorithm has been designed to systematically introduce gradual and sudden concept drift scenarios into datasets. In order to save time and avoid memory consumption, the Concept Drift Introducer (CDI) algorithm divides the number of drift scenarios into phases. The main advantage of using phases is that it allows us to produce a highly scalable concept drift detector that evaluates each phase, instead of evaluating each individual drift scenario. We further designed a novel algorithm to handle concept drift. Our Dynamic Committee for Concept Drift (DCCD) algorithm uses a voted committee of hypotheses that vote on the best base classifier, based on its predictive accuracy. The novelty of DCCD lies in the fact that we employ diverse heterogeneous classifiers in one committee in an attempt to maximize diversity. DCCD detects concept drifts by using the accuracy and by weighing the committee members by adding one point to the most accurate member. The total loss in accuracy for each member is calculated at the end of each point of measurement, or phase. The performance of the committee members are evaluated to decide whether a member needs to be replaced or not. Moreover, DCCD detects the worst member in the committee and then eliminates this member by using a weighting mechanism. Our experimental evaluation centers on evaluating the performance of DCCD on various datasets of different sizes, with different levels of gradual and sudden concept drift. We further compare our algorithm to another state-of-the-art algorithm, namely the MultiScheme approach. The experiments indicate the effectiveness of our DCCD method under a number of diverse circumstances. The DCCD algorithm generally generates high performance results, especially when the number of concept drifts is large in a dataset. For the size of the datasets used, our results showed that DCCD produced a steady improvement in performance when applied to small datasets. Further, in large and medium datasets, our DCCD method has a comparable, and often slightly higher, performance than the MultiScheme technique. The experimental results also show that the DCCD algorithm limits the loss in accuracy over time, regardless of the size of the dataset.

This study has confirmed the existence of a distinct mineralogical component in the upper part of the Yorkville Till Member of the Wedron Formation of Wisconsinan age in northeastern Illinois. This upper till unit occurs within the area of, but is not bounded by, the older Marseilles Morainic System and the younger, overriding Minooka Moraine. The analyses of samples from 79 locations that were used to identify, compare, and differentiate the two tills were: matrix grain size, clay mineral composition, carbonate content, and color.The upper till is a grayish brown, silty clay till with 76% illite and a dolomite-calcite ratio of 2:1. The lower till is an olive gray, silty clay till with 81% illite and a dolomite-calcite ratio of4:1. Results of this study indicate that (1) the two tills are separable and mappable units with the aid of laboratory data; (2) the lower till composes the bulk of the Marseilles Morainic System; (3) the upper till is thin between the moraines and constitutes the till of the Minooka Moraine; and (4) the upper till apparently represents a minor readvance and a concurrent change in source material.Ball State UniversityMuncie, IN 47306

Although higher correlation between gauge and radar at hourly or daily accumulations are reported, it is rarely observed at higher time resolution (e.g. 10 -minute). This study investigates six major rainfall events in year 2000 in the greater Winnipeg area with durations varying from four to nine hours. The correlation between gauge and radar measurements of precipitation is found to be only 0.3 at 10-minute resolution and 0.55 at hourly resolution using Marshall-Palmer’s Z-R relationship (Z=200R1.6). The rainfalls are classified into convective and stratiform regions using Steiner et al. (1995)’s algorithm and two different Z-R relationships are tested to minimize the error associated with the variability of drop-size-distribution, however no improvement is observed. The performance of the artificial neural network is explored as a reflectivity-rainfall mapping function. Three different types of neural networks are explored: the back propagation network, the radial basis function network, and the generalized regression neural network. It is observed that the neural network’s performance is better than the Z-R relationship to estimate the rainfall events which was used for training and validation (correlation 0.67). When this network is tested on a new rainfall its performance is found quite similar to that obtained from the Z-R relationship (correlation 0.33). Based on this observation neural network may be recommended as a post-processing tool but may not be very useful for operational purposes - at least as used in this study. Variability in weather and precipitation scenarios affects the radar measurements which apparently makes it impossible for the neural network or the Z-R relationship to show consistent performance at every rainfall event. To account for variability in weather and rainfall scenarios conventional correction schemes for attenuation and hail contamination are applied and a trajectory model is developed to account for rainfall advection due to wind drift. The trajectory model uses velocity obtained from the single-doppler observation. A space-time interpolation technique is applied to generate reflectivity maps at one-minute resolution based on the direction obtained from the correlation based tracking algorithm. The trajectory model uses the generated reflectivity maps having one-minute resolution which help to account for the travel time by the rainfall mass to reach to the ground. It was found that the attenuation correction algorithm adversely increases the reflectivity. This study assumes that the higher reflectivity caused by hail contaminated regions is one reason for the overestimation in the attenuation correction process. It was observed that the hail capping method applied prior to the attenuation correction algorithm helps to improve the situation. A statistical expression to account for radome attenuation is also developed. It is observed that the correlation between the gauge and the radar measurement is 0.81 after applying the various algorithms. Although Marshall-Palmer’s relationship is recommended for stratiform precipitation only, this study found it suitable for both convective and stratiform precipitation when attenuation is properly taken into account. The precipitation processing model developed in this study generates more accurate rainfall estimates at the surface from radar observations and may be a better choice for rainfall-runoff modellers. / February 2006

Since the advent of nanoscale material based electronic devices, there has been a considerable interest in exploring carbon nanotubes from fundamental science and technological perspectives. In carbon nanotubes, the atoms form a cylindrical structure with a diameter of the order 1nm. The length of the nanotubes can extend up to several hundred micrometers. Carbon nanotubes exhibit a variety of intriguing electronic properties such as semiconducting and metallic behaviour, due to the quantum confinement of the electrons in the circumferential direction. Much of the study dedicated to describe the behaviour of carbon nanotube-based devices assumes for simplicity the nanotube to be a ballistic material. However, in reality the phonon scattering mechanism exists also in nanotubes, of course, and can generally not be neglected, except in very short nanotubes. In this work, we focus attention on exploring the steady-state electron transport properties of semiconducting single-walled carbon nanotubes, including both phonon scattering and defect (vacancy) scattering, using the semi-classical bulk single electron Monte Carlo method.   The electron energy dispersion relations are obtained by applying the zone folding technique to the dispersion relations of graphene, which are calculated using the tight-binding description. The vibrational modes in the carbon nanotubes are studied using a fourth nearest-neighbour force constant model. Both the electron-phonon and the electron-defect interactions are formulated within the tight-binding framework, and their corresponding scattering rates are computed and analyzed. In particular, the dependence of the phonon scattering rate and the defect scattering rate on the diameter of the nanotube, on temperature and on electron energy is studied. It is shown that the differences observed in the scattering rate between different nanotubes mainly stem from the differences in their band structure.   A bulk single electron Monte Carlo simulator was developed to study the electron transport in semiconducting zigzag carbon nanotubes. As a first step, we included only electron-phonon scattering, neglecting all other possible scattering mechanisms. With this scattering mechanism, the steady-state drift velocity and the mobility for the nanotubes (8,0), (10,0), (11,0), (13,0) and (25,0) were calculated as functions of the electric-field strength and lattice temperature, and the results are presented and analysed here. The dependence of the mobility on the lattice temperature can be clearly seen at low electric-field strengths. At such electric-field strengths, the scattering is almost entirely due to acoustic phonons, whereas at high electric-field strengths optical phonon emission processes dominate. It is shown that the saturation of the steady-state drift velocity at high electric-field strengths is due to the emission of high-energy optical phonons. The results indicate the presence of Negative differential resistance for some of the nanotubes considered in this work. The discrepancy found in the literature concerning the physical reason for the appearance of negative differential resistance is clarified, and a new explanation is proposed. It is also observed that the backward scattering is dominant over the forward scattering at high electric-field strengths.                                                                                   We then included also defect scattering, actually electron-vacancy scattering, for the nanotubes (10,0) and (13,0). The steady-state drift velocities for these nanotubes are calculated as functions of the density of vacancies, electric-field strength and the lattice temperature, using three different vacancy concentrations. The results indicate the presence of Negative differential resistance at very low concentration of defects, and how this feature may depend on the concentration of defects. The dependence of the steady-state drift velocity on the concentration of defect and the lattice temperature is discussed. The electron distribution functions for different temperatures and electric field strengths are also calculated and investigated for all the semiconducting nanotubes considered here. In particular, a steep barrier found in the electron distribution function is attributed to the emission of high energy optical phonons.

The Swedish State Road Administration has since 1992 procured operations and maintenance of state roads on the open market. The procurement has been termed “Grundpaket Drift”, GPD, and comprises mostly operational measures for road networks.The clients of GPD, SRA regions, have gradually changed the original documentation in order to adapt it to local conditions. This process has gradually led to that some parts of the documentation are creating problems for contractors interested in procuring jobs.This thesis tries to analyze GPD and clarify the differences that may be essential to the procurement process and to facilitate future joint working projects and processing descriptions.

This thesis is a part of a project where a new method, the base descriptor approach, is studied. The purpose of this method is to reduce drift and extract vital information from electronic tongue measurements. Reference solutions, called descriptors, are measured and the measurements are used to find base descriptors. A base descriptor is, in this thesis, a regression vector for prediction of the property that the descriptor represent. The property is in this case the concentration of a chemical substance in the descriptor solution. Measurements from test samples, in this case fruit juices, are projected onto the base descriptors to extract vital and drift-stable information from the test samples. The base descriptors are used to determine the concentrations of the descriptors'chemical substances in the juices and thereby also to classify the different juices. It is assumed that the measurements of samples of juices and descriptors drift the same way. This assumption has to be true in order for the base descriptor approach to work. The base descriptors are calculated by multivariate regression methods like partial least squares regression (PLSR) and principal component regression (PCR). Only two of the descriptors tested in this thesis worked as basis for base descriptors. The base descriptors'predictions of the concentrations of chemical substances in the juices are hard to evaluate since the true concentrations are unknown. Comparing the projections of juice measurements onto the base descriptors with a classification model on the juice measurements performed by principal component analysis (PCA), there is no significant difference in drift of the juice measurements in the results of the two methods. The base descriptors, however, separates the juices for classification somewhat better than the classification of juices performed by PCA.

This report was undertaken at the request of the Management and maintenance department of Swedish National Road Authority (Vägverket Region Sydöst) in Jönköping. In 1992, the management and maintenance of Swedish roads were laid out on external constructors. When putting out a tender for the work, the foundation is from a national set of rules which are in constant change. This report is limited to winter road upkeep. The trend in the invitation for tenders is that it is moving from the more conventional executional demands towards the less controlling demands. The downside of functional, less controlling demands is that it is difficult to articulate how to measure them. The order authority therefore has to find ways to make sure to get what has been paid for. In connection to the invitation for tender of winter road upkeep for 2005, the new set of rules, ATB Vinter 2003 was deployed. The main purpose of this thesis is to see which the big changes in the set of rules are and how these changes affect the organisation and activities of the constructor. It is also studied how the changes in execution is perceived by road users and how it affects the possibilities of the constructor to come as a newcomer to a new area of administration. Interviews and examination of sets of rules has led to a list of a number of changes that the constructors feel affect their work in any sense. Views from road users that have come in to the order authority have been scrutinized to see how they have experienced the change. When selecting which areas of administration to examine, care was taken to ensure that one was where the same constructor secured a renewed contract for the area over the gap of changing rules and the other one was area where the constructor was a newcomer. The result shows a number of changes and how these affect both the constructors and the road users. The report describes how winter road upkeep is maintained in the south of Sweden and the cooperation between buyer and constructor.

Examensarbete - Civilekonomprogrammet. Ekonomihögskolan vid Linnéuniversitetet. Författare: Josefin Pettersson & Robert Håkansson Handledare:  Professor Sven-Olof Yrjö Collin Examinator:  Christopher von Koch Titel: Vad förklarar revisionskvalitet? – En studie om revisorns benägenhet att ge en going concern-varning. Bakgrund och problemdiskussion: Revisionskvalitet har under senare år fått ökat fokus till följd av revisorsskandaler. Kvalitén kan betraktas som låg då ett bolag som gått i konkurs inte fått en varning om fortsatt drift i föregående revisionsberättelse. Det leder till att intressenter kan lida skada till följd av att revisorn medvetet eller på grund av osäkerhet eller svårigheter inte uttryckt en varning. Revisionskvalitén kan påverkas av olika dimensioner när en bedömning av ett företags fortsatta drift ska göras. Dessa har en koppling mot klienten, revisionsbyrån, revisorn, intressenter, relationer och det geografiska läget. Syfte: Uppsatsens syfte är att förklara vad som påverkar revisionskvalitén genom att undersöka revisorernas benägenhet att avge en going concern-varning. Metod: Studien har utgått från tidigare forskning och därmed tillämpat en deduktiv ansats där hypoteser empiriskt har undersökts. Intervjuer har genomförts med fyra revisorer vilka bidrog till en praktisk förståelse för problemområdet. Vidare har en kvantitativ metod använts för att samla in data från svenska konkursbolags årsredovisningar. Data har sedan analyserats med hjälp av statistiska verktyg. Resultat och slutsatser: Revisionskvalitén kan betraktas som låg i Sverige jämfört med andra länder. Vi har funnit att revisorerna i endast 18,9 procent av fallen signalerar en going concern-varning till ett konkursdrabbat företag. Vi fann att revisionskvalitet föreligger när revisionsarvodet och andelen leverantörsskulder är höga då de visar positiva samband gentemot going concern-varningar. Revisionskvalitet föreligger också om klienten är verksam inom informations- och kommunikationsbranschen samt handels- och försäljningsbranschen. Studien tyder på att det finns ett negativt samband mellan styrelsens storlek och going concern-varningar.