22 research outputs found
MUNICIPAL OWNERSHIP. How municipalities in Helgeland practice ownership in corporations and enterprises.
Master in Business Adminstration (MBA) - Nord universitet 201
The energy transition: the behavior of renewable energy stock during the times of energy security uncertainty
The global energy sector is experiencing a transition towards renewable energy primarily driven by issues related to climate change and energy security. In this paper, we investigate the impact of uncertainties and potential drivers connected to energy security on the volatilities and returns of renewable energy stocks. Further, we examine how uncertainty and potential drivers connected to energy security affect the volatilities and returns of renewable energy stocks. By applying the MS-GARCH (1,1) and MS-GJR-GARCH (1,1) approach we calculate the Value at Risk (VaR) and Conditional Value-at Risk (CVaR). In addition, we estimate a fixed effects model to determine the impact of the uncertainty variables on the estimated conditional volatility and returns. Our findings indicate that economic policy uncertainty (EPU) positively impacts the returns of renewable stocks, attributing to an increased engagement towards a renewable transition. However, the prices of crucial green metals were found to have a negative impact on renewable stocks suggesting that the transition to renewable energy might impose implications regarding energy security if not managed correctly. The findings of this study have important implications for policymakers, market participants, and governmental agencies in devising a roadmap to promote the transition process to renewable energy sources
"Does god play dice with corrugations?": environmental effects on growth
Corrugation growth has perplexed many researchers for several decades with remaining challenges including its reliable prediction in the field. In the present paper, the effect of environmental variations on corrugation growth is investigated using field measurements and mechanics-based modelling. Statistically significant relationships between average daily rainfall, humidity and the growth of rail corrugation were investigated using meterological and railway site field monitoring of a metropolitan network test site with a recurring rail corrugation of about 95mm wavelength. Corrugation growth rate (G) was determined by systematically measuring the longitudinal rail profile with a Corrugation Analysis Trolley (CAT) on the 240m radius, narrow gauge, concrete-sleepered curve. Both roughness generated and weld initiated profile growths were investigated. The weather data was obtained from records held by the Bureau of Meteorology. The modelling is developed to provide insight and mechanics based analysis of the field corrugation growth under changes in environmental conditions and vehicle speed variability. Results show a strong correlation between variations in rainfall and corrugation growth that is consistent with changes in steady state wear. Changes in contact patch geometry and the damage mechanism as the corrugation amplitude grows are shown to have substantial but slower effects on growth. The results are used to explain observed changes in corrugation growth rate under variable speed control at the same site
Investigation into rail corrugation in high-speed railway tracks from the viewpoint of the frictional self-excited vibration of a wheel–rail system
Dynamic Train/Track Interaction: Simulation of Railhead Corrugation Growth under a Moving Bogie Using Mathematical Models Combined with Full-Scale Measurements
Heavier trains and higher speeds have increased the need for high-quality tracks and vehicles in order to fulfill safety and environmental requests. The phenomena involved in dynamic train/track interaction lead to noise radiation, induce ground-borne vibrations and degrade the track structure and the railcar wheels. Increased axle-loads and higher train speeds also accentuate the influence on the dynamic train/track interaction of imperfections appearing in the track structure and on the wheel tread. A special type of track imperfection is the so-called rail corrugation, which is a periodic vertical irregularity on the railhead. The present thesis is concerned with the vertical dynamic interaction between the moving train and the track, and, in particular, with the modelling of corrugation growth on tangent tracks. Models of increasing complexity are developed, in-field measurements are performed, and realistic track parameters are sought for. The influence of different imperfections, such as rail corrugation, a hung sleeper or a wheelflat, on the wheel/rail contact force and on the track response is investigated. Physical explanations of the calculated interaction behaviour are given. The importance of including both of the two wheelsets in the bogie model is demonstrated and clarified. By use of factorial design methods, the influences of changes in some track parameters on the wheel/rail contact force when a wheelset passes a track having a random railhead irregularity are studied. The calculated results are compared to experimental results from full-scale measurements. A new ballast/subgrade model is suggested where measured frequency response functions together with an optimization routine are used to find the best values of the track parameters. The corrugation growth model is based on the assumption that, on tangent tracks, the damage mechanism is wear from longitudinal slip due to driven, or braked, wheels. Setting out from an initial random railhead irregularity distribution, the corrugation growth is calculated as a function of the wave number of the irregularity. The results clearly show that, for a fixed train speed, the amplitude of irregularities of certain wavelengths will grow while the amplitudes of other irregularities will be smoothened. Comparisons between different corrugation models are carried out. The distribution of the wear within the contact area and also the shift of contact point is found to be important for the corrugation growth. The track models used for the calculations are linear non-proportionally damped beam structures which are longitudinally rigid. Finite elements are employed and, in order to save computational time, the equations of motion for the track model are decoupled by use of complex-valued modal analysis. The vehicle is modelled as a discrete system of masses, springs and viscous dampers, which may be non-linear. Vertically, the wheel/rail contact is assumed to be Hertzian. The longitudinal contact is treated by use of a heuristic model for stationary rolling contact mechanics. The friction force influences the vertical dynamics of the track by applying a bending moment to the rail. Also, the longitudinal creepage depends on the rotation of the cross section of the rail and the angular velocity of the wheel. The friction law used is verified against the so-called exact theory for elastic stationary rolling contact. The system of equations governing the motion of the track, the motion of the vehicle, and the vertical and longitudinal wheel/rail contact is solved by use of a time stepping routine. The wear is taken as proportional to the frictional power and is assigned, at each time step, to the centroid of the wear distribution in the contact patch
Generating Facial Animation With Emotions In A Neural Text-To-Speech Pipeline
This thesis presents the work of incorporating facial animation with emotions into a neural text-to-speech pipeline. The project aims to allow for a digital human to utter sentences given only text, removing the need for video input. Our solution consists of a neural network able to generate blend shape weights from speech which is placed in a neural text-to-speech pipeline. We build on ideas from previous work and implement a recurrent neural network using four LSTM layers and later extend this implementation by incorporating emotions. The emotions are learned by the network itself via the emotion layer and used at inference to produce the desired emotion. While using LSTMs for speech-driven facial animation is not a new idea, it has not yet been combined with the idea of using emotional states that are learned by the network itself. Previous approaches are either only two-dimensional, of complicated design or require manual laboring of the emotional states. Thus, we implement a network of simple design, taking advantage of the sequence processing ability of LSTMs and combines it with the idea of emotional states. We trained several variations of the network on data captured using a head mounted camera, and the results of the best performing model were used in a subjective evaluation. During the evaluation the participants were presented several videos and asked to rate the naturalness of the face uttering the sentence. The results showed that the naturalness of the face greatly depends on which emotion vector was used, as some vectors limited the mobility of the face. However, our best achieving emotion vector was rated at the same level of naturalness as the ground truth, proving our method successful. The purpose of the thesis was fulfilled as our implementation demonstrates one possibility of incorporating facial animation into a text-to-speech pipeline
Education for Democracy : An Idea Analysis of the Educational Philosophy of Natanael Beskow 1920–1932
The purpose of this thesis is to present, contextualize and interpret the educational philosophy of Natanael Beskow between 1920–1932. The examined source material consists of articles published in the journal Studiekamraten which ordinated from Birkagården folk high school (Birkagårdens folkhögskola) where Beskow served as principal. The content of the articles is related to previous research and to a historical context. This historical context deals primarily with the modernization of the Swedish society. The basic theoretical perspectives are theories about Bildung and liberal adult education presented by Bernt Gustavsson. This thesis finds that Beskow regarded education as an inner process that gradually raised and developed the individual’s moral capacity. Such neo-humanist views dominated pedagogical philosophy of the time. In addition, Beskow saw education as an instrument that could initiate a spiritual awakening. A challenging alternative to the established liberal adult education movement (folkbildningsrörelsen) was the class struggle education (klasskampsbildningen) that was formed within SKP. Its advocates regularly attacked Birkagården folk high school. Beskow was critical of the movement. He represented a contrasting ideal built around mutuality and democracy which partly originated from the foreign settlement movement.
Education for Democracy : An Idea Analysis of the Educational Philosophy of Natanael Beskow 1920–1932
The purpose of this thesis is to present, contextualize and interpret the educational philosophy of Natanael Beskow between 1920–1932. The examined source material consists of articles published in the journal Studiekamraten which ordinated from Birkagården folk high school (Birkagårdens folkhögskola) where Beskow served as principal. The content of the articles is related to previous research and to a historical context. This historical context deals primarily with the modernization of the Swedish society. The basic theoretical perspectives are theories about Bildung and liberal adult education presented by Bernt Gustavsson. This thesis finds that Beskow regarded education as an inner process that gradually raised and developed the individual’s moral capacity. Such neo-humanist views dominated pedagogical philosophy of the time. In addition, Beskow saw education as an instrument that could initiate a spiritual awakening. A challenging alternative to the established liberal adult education movement (folkbildningsrörelsen) was the class struggle education (klasskampsbildningen) that was formed within SKP. Its advocates regularly attacked Birkagården folk high school. Beskow was critical of the movement. He represented a contrasting ideal built around mutuality and democracy which partly originated from the foreign settlement movement.