No description available.

No description available.

The goal of this thesis was to develop a powertrain model of a vehicle and parametrize itusing non-invasive sensors. The non-invasive sensors available were chassis dynamometer,the pedal robot and the vehicle’s on-board diagnostics which was accessed using a scantool. Non-invasive sensors were used so that the vehicle to model can easily be changed. Aparametrization methodology to parametrize the model for a new vehicle was also developedto facilitate the change of vehicle. The powertrain model is for cars with a combustion engineand a manual gearbox. The engine model consist of two static maps, a pedal map and an engine map. The pedalmap is created using the fact that a constant pedal position and engine speed gives a constantthrottle position. The engine map is created in similar manner using that a constant throttleposition and engine speed gives a constant engine torque. The engine model also uses a firstorder lag element to model the time delay from a change in pedal position to a change inwheel torque. The driveline model is a rigid driveline model that assumes that the clutch,driveshaft and propeller shaft are stiff. The developed parametrization methodology contains information on how to estimate theparameters of the model which are gear ratios, engine and driveline inertias, engine anddriveline losses, engine and pedal maps and the time constant for the time delay. The powertrain model was validated component wise, as standalone and integrated intothe vehicle model against data gathered with the help of the chassis dynamometer. For thestandalone and integrated validation the gathered data were for different driving cases, suchas up and down gear-shifting, engine braking and skipping gears. The standalone validationshowed that the model performed well for the presented driving cases and the results hadgood data fit for 3rd gear and higher. However not for 1st and 2nd gear due to problemsin the pedal map. The pedal map was constructed on the assumption that the same pedalposition for all gears gives the same throttle position, which was not always the case. Thiscaused problems in some areas of the engine and pedal maps however in the validation ofthe maps it was shown that the maps for the most part gave good results.

Previous work by researchers as Eugene F. Fama and Kenneth R. French, show that average return on stocks are related to a firms characteristics like size and book-to-market ratio. These kinds of patterns in average return is not explained by The Capital Asset Pricing Model (CAPM), and are therefore seen as anomalies. Fama and French have proposed a three-factor model, which captures patterns observed in U.S average returns associated with size and value. Since the previous research on this topic is limited in Sweden we find it interesting to study companies listed on the Swedish stock exchange “Nasdaq OMX Stockholm”. This study finds that the average return on Swedish stocks seems to be related to size and value. The two additional variables in the three-factor model help explain the variation on the Swedish stock market for the period 2011-2013.

Many physical systems can be represented by a regular arrangement of molecules in a lattice structure. Knowing how neighboring molecules in the lattice interact with one another can give great insight into a material's macroscopic behavior. A very popular and effective means of investigating these microscopic interactions is the Ising Model. This model, suggested first by Wilhelm Lenz in 1920 and later expanded by Ernst Ising in 1925, is based on the assumptions that each molecule in a lattice structure can be represented by its spin value (+l or -1) and that only nearest neighbors contribute to the total interaction energy. The Ising Model, which was initially used in the study of ferromagnetic systems, can now be used to study a variety of physical systems. Some of these include antiferromagnetic crystals, binary alloys, DNA, and lattice gasses. / Department of Physics and Astronomy

Unsaturated swelling clays are used in engineered barriers for waste disposal facilities due to their self-sealing ability and low hydraulic conductivity. The characterization of unsaturated clay behaviour is required for design of these barriers. In recent years, several small-scale laboratory and full-scale field tests have been conducted to characterize the mechanical and hydraulic behaviour of the unsaturated swelling clay. This focus of the present study is towards the development of constitutive models to simulate hydraulic and mechanical behaviour of precompacted unsaturated swelling clay, called the bentonite-sand buffer (BSB) material. Development, calibration, implementation, and application of the proposed constitutive models form the scope of the study. The results of laboratory triaxial tests with controlled suction and suction measurements are used to calibrate the constitutive models presented. An algorithm, called the PEM (Parameter Evaluation Method), which is useful to estimate constitutive model parameters and evaluate the performance of constitutive models is proposed. This algorithm has been used to estimate the parameters of two elasto-plastic constitutive models (i.e., the BBM (Alonso et al. 1990) and the BGM (Blatz and Graham 2003)) based on the laboratory tests results on the BSB material. New 3-dimensional porosity-dependent permeability model (kwn) and water retention surface (WRS) are developed in this study. The mathematical formulations of these models using parameters calibrated with laboratory tests conducted on the BSB material are provided. Implementation algorithms of the BBM, the BGM, the kwn, and the WRS in 2-phase flow hydraulic-mechanical (H-M) analysis using a 2D-finite difference method are also provided . Three combinations of hydraulic and mechanical constitutive models (linear elastic model, BGM, vanGenuchten (1980) and kwn models) are used to simulate small-scale infiltration processes in the BSB material. Two types of tests, constant volume (CV) and constant mean stress (CMS) tests are simulated using 2D-finite difference H-M analysis. The full-scale isothermal test (ITT) of AECL is modelled using 3 combinations of H-M constitutive models. The ITT experiment comprises of buffer, rock, and concrete materials. The selected combinations of H-M constitutive models are used in three types of analyses: buffer-only (BO); buffer-rock with 20x30m domain (BR); and time-dependent boundary conditions (BCt). The results of the study show that the applications of the elasto-plastic mechanical constitutive models and porosity-dependent permeability (kwn) model are improvements over existing constitutive models to model this class of problem. The rock properties and applied boundary conditions are significant in modelling the ITT experiment. The application of the time-dependent boundary condition can reduce the uncertainty of the rock properties and boundary conditions within the rock, so that it improves the model ability to simulate the hydraulic-mechanical behaviour of unsaturated swelling clay.

One of the impacts of the rising demand for community health services, primarily used by seniors, is that hospitals are often faced with the challenge of having patients finish the acute phase of their treatment and yet are unable to discharge them due to the lack of a bed in a more appropriate community care setting. The frequency of this challenge has led to the designation of “alternative level of care” (ALC) being ascribed to patients who remain in the hospitals due to insufficient capacity downstream. The thesis focuses on a model that seeks to address patient flow through the community care network (CCN) and finding capacity allocation policies for the different facilities that resolves the ALC challenge using scenario analysis. A queuing network model with general routings and nodes’ blocking has been developed and a heuristic approximation method has been employed for solving the model. Blocking probabilities and the number of blocked patients are derived as performance metrics of the CCN. We test the accuracy of the queuing model through a simulation model and the behaviours of the system in different scenarios are investigated in the simulation model and our policy insights and conclusions are provided.

In this thesis, we investigate the impact of channels that have a bursty nature in a cognitive radio network scenario. Our goal is to design a general channel usage model that can handle bursty primary user channel usage. The proposed model describes idle periods with a discrete platoon arrival process and describes busy periods with a discrete phase type distribution. The performance of the proposed model is compared with two more traditionally encountered channel usage models in three different secondary user access schemes. First, we design a reactive access scheme to show the poor performance results an in- vestigator can potentially obtain when ignoring bursty data traffic. We have also analyzed two proactive secondary network access schemes. Numerical results show that the achiev- able utilization and interference probability of the network are affected when traditional channel models are used in a bursty PU channel.

The structure of protein is essentially important for life activities. Proteins can perform their functions only by specific structures. In this thesis, the kink and multi-kink model for protein description are reviewed. It is shown that most of the loop parts in Protein Databank (PDB) can be described by very limited number of kinks within the experimental precision. Furthermore, by applying the model into two well studied real proteins (myoglobin and villin headpiece HP35), it is shown that the multi-kink model gives correct folding pathway and thermal dynamical properties compared with the experimental results for both proteins. In particular, the kink model is computationally inexpensive compared with other existing models. In the last chapter, a new visualization method for the heavy atoms in the side-chain is presented.

No description available.