This thesis deals with the construction proposal of the combustion chamber of Stirling engine. The introduction briefly describes the history and practical application of Stirlinova engine today. The following section explains the differences between theoretical and real cycle and the principle of beta Stirling engine modifications. The next section is devoted to the calculation of fuel and air consumption and fuel compared to each other. The proposed design is based not only on the calculation of fuel and air, but also heat transfer between flue gas and preheated air. The last part is devoted to calculating the flow of LPG and flow model of the combustion chamber.

The primary purpose of this dissertation is to develop the arguments for reporting directly on a company's cash flows in its published financial statements. Specifically, the Free Cash Flow (FCF) model of economist Joel Stern is analyzed and critiqued as a basis for a revised reporting scheme.

Software systems are today a part of more or less every organization. The varieties of software used in organizations are ranging from simple log-keeping applications to advanced decision support systems. The task of a priori valuation of software investments has attracted a lot of research for a long time. One of the main themes of this research has been which types of consequences software investments result in and how these consequences can be incorporated in the a priori valuation of the investment. Much of this research has stated the problem as how to incorporate intangible consequences in the valuation since intangible costs and benefits are assumed to represent a large part of the consequences from a software investment. These consequences are therefore highly relevant in the appraisal of software investments. This thesis is concerned with the question of how intangible consequences can be incorporated in the a priori valuation of a software investment. To answer this question, this thesis presents a theoretical model for the valuation of a software investment based upon a discounted cash flow model in continuous time. The general model argued for in this thesis is that usage results in consequences which must be translated into cash flows to be incorporated in a discounted cash flow model. The software usage is chosen as the underlying value creating function since it is the basic underlying function that creates all consequences specific to the software investment. This thesis develops a stochastic cash flow model to incorporate the uncertainty and characteristics of when the intangible conse quences have an effect on the cash flow by adopting a Brownian motion into the valuation model. To find an analytic model for the problem, the expectations of the future cash flows is transformed into risk-neutral expectations. This allows us to use the risk-free rate of return as a discount factor in the model.

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Syftet med studien är att skapa förståelse för hur snabb omställning till distansarbete i samband med pandemin har påverkat kommunikation och samarbete inom en organisation. I studien kommer medarbetarnas upplevelser av den informella och formella kommunikationen samt samarbeten att undersökas, för att se om det finns några skillnader före och under pandemin. Teorin Communicative constitution of organisation (CCO) och McPhee och Zaugs fyra-flödesmodell har använts för att skapa en djupare förståelse för kommunikationens betydelse inom organisationen. Modellen lyfter fram begrepp som informell och formell kommunikation samt samarbete, dessa utgör tre viktiga byggstenar för en organisation. I studien används ett kvalitativt tillvägagångssätt och det empiriska materialet samlas in genom sju semistrukturerade intervjuer. Respondenterna i studien är individer som under pandemin varit tvungna att ställa om till distansarbete hemifrån och som inte hade tidigare erfarenhet av distansarbete. Resultatet i studien visar hur viktig kommunikationen inom en organisation är för både enskilda medarbetare och arbetsgrupper. Den informella kommunikationen har minskat, däremot har respondenterna hittat sätt för att behålla en del av det informella. Resultatet visar även att antalet formella möten har ökat samt blivit mer effektiva. När det kommer till samarbeten är upplevelsen hos respondenterna att det blivit svårare digitalt men att de fått en bättre struktur och högre grad av flexibilitet.

In this thesis, multiple on-road vehicle tracking problem is explored, with greater consideration of road constraints and interactions between vehicles. A comprehensive method for tracking multiple on-road vehicles is proposed by making use of domain knowledge of on-road vehicle motion. Starting with raw measurements provided by sensors, bias correction methods for sensors commonly used in vehicle tracking are briefly introduced and a fast but effective bias correction method for airborne video sensor is proposed. In the proposed method, by assuming errors in sensor parameter measurements are close to zero, the bias is separately addressed in converted measurements of target position by a linear term of errors in sensor parameter measurements. Based on this model, the bias is efficiently estimated by addressing it while tracking or using measurements of targets that are observed by multiple airborne video sensors simultaneously. The proposed method is compared with other airborne video bias correction methods through simulations. The numerical results demonstrate the effectiveness of the proposed method for correcting bias as well as its high computational efficiency. Then, a novel tracking algorithm that utilizes domain knowledge of on-road vehicle motion, i.e., road-map information and interactions among vehicles, by integrating a car-following model into a road coordinate system, is proposed for tracking multiple vehicles on single-lane roads. This algorithm is extended for tracking multiple vehicles on multi-lane roads: The road coordinate system is extended to two-dimension to express lanes on roads and a lane-changing model is integrated for modeling lane-changing behavior of vehicles. Since the longitudinal and lateral motions are mutually dependent, the longitudinal and lateral states of vehicles are estimated sequentially in a recursive manner. Two estimation strategies are proposed: a) The unscented Kalman filter combined with the multiple hypothesis tracking framework to estimate longitudinal and lateral states of vehicles, respectively. b) A unified particle filter framework with a specifically designed computationally-efficient joint sampling method to estimate longitudinal and lateral states of vehicles jointly. Both of two estimation methods can handle unknown parameters in motion models. A posterior Cramer-Rao lower bound is derived for quantifying achievable estimation accuracy in both single-lane and multi-lane cases, respectively. Numerical results show that the proposed algorithms achieve better track accuracy and consistency than conventional multi-vehicle tracking algorithms, which assumes that vehicles move independently of one another. / Thesis / Doctor of Philosophy (PhD)

The purpose of this research is to develop methodologies for applying traffic flow theories to various ITS categories through the utilization of evolving surveillance technologies. This integration of theory, measurement and application has been overlooked since the advent of ITS because of the number of disciplines involved. In this context, the following illustrative methodologies are selected, developed and presented in this study: - a methodology for automatic measurement of major spatial traffic variables for the present and the future implementation of various ITS functional areas, in general; and - a methodology for real-time link and incident specific freeway diversion in conjunction with freeway incident management, in particular. The first methodology includes the development of a dynamic flow model based on stochastic queuing theory and the principle of conservation of vehicles. An inductive modeling approach adapted here utilizes geometric interpretations of cumulative arrival-departure diagrams which have been drawn directly from surveillance data. The advantages of this model are real-time applicability and transportability as well as ease of use. Analysis results show that the estimates are in qualitative and quantitative agreement with the empirical data measured at 30-second intervals. The analytical expression for link travel times satisfies traffic dynamics where the new form of the equation of conservation of vehicles has been derived. This methodology has potential applicable to automatic traffic control and automatic incident detection. The methodology is then applied to freeway diversion in real-time in conjunction with freeway incident management. The proposed new form of the equation of conservation of vehicles is applied to detect recurring or non-recurring congestion analytically. The principle of conservation of vehicles is applied to develop the concept of progression and retrogression of incident domain, which turns out to be compatible with traditional shock wave traffic mechanism during incidents. The link and incident specific diversion methodology is achieved by using a delay diagram and volume-travel time curves, which can be plotted per link per incident. The use of such graphic aids makes problem solving much easier and clearer. The dynamic traffic flow model developed here can also be applied to estimate travel times during incidents as a function of time. The development of a computer program for freeway diversion concludes this research. / Ph. D.

Due to increasing penetration of solar power generation, distribution grids are facing a number of challenges. Frequent reverse active power flows can result in rapid fluctuations in voltage magnitudes. However, with the revised IEEE 1547 standard, smart inverters can actively control their reactive power injection to minimize voltage deviations and power losses in the grid. Reactive power control and globally optimal inverter coordination in real-time is computationally and communication-wise demanding, whereas the local Volt-VAR or Watt-VAR control rules are subpar for enhanced grid services. This thesis uses machine learning tools and poses reactive power control as a kernel-based regression task to learn policies and evaluate the reactive power injections in real-time. This novel approach performs inverter coordination through non-linear control policies centrally designed by the operator on a slower timescale using anticipated scenarios for load and generation. In real-time, the inverters feed locally and/or globally collected grid data to the customized control rules. The developed models are highly adjustable to the available computation and communication resources. The developed control scheme is tested on the IEEE 123-bus system and is seen to efficiently minimize losses and regulate voltage within the permissible limits. / Master of Science

<p><strong>Abstract </strong></p><p><strong>Purpose </strong>The purpose of this study is to investigate the methods used for valuating private limited knowledge based companies and if a new approach is required, create or modify a foundation that will constitute as a base within the valuation process.</p><p><strong>Method </strong>This is a qualitative study using interviews to obtain primary data. People working in the valuation industry were contacted and we got eight respondents. The questions were designed to answer our purpose and research questions. Telephone interviews were chosen due to the fact that we believed the response would be higher.      <strong></strong></p><p><strong> </strong></p><p><strong>Frame of References </strong>The theories used in this section is divided into three parts; the financial analysis including traditional valuating methods such as the Discounted Cash Flow model and relative valuating and multiples. The non-financial analysis focus on the underlying analysis consistent of structural- and intellectual capital and also value drivers that are creating value for the firm. In the end other theories concerning the analysis are presented, such as the risk-return trade-off, risk rating systems and analytical hierarchy process.            <strong> </strong></p><p><strong> </strong></p><p><strong>Empirical Findings </strong>In this section the presentations of the respondents’ answers and</p><p><strong>and Analysis </strong>a brief analysis related to each question. After this an extended analysis is presented focusing on the subject and our risk scheme and guidelines we created/modified. The extended analysis is connected to the respondents’ answers. The purpose of this section is to have a better understanding about the risk of transient intellectual capital and give recommendations how to handle it. Also, guidelines of how to weight different value driver are discussed.</p><p><strong>Conclusion </strong>We concluded that all valuations utilize more than one approach in order to estimate the most accurate value for the company. For knowledge based companies the biggest risk with a M&A transaction is the probability of diminishing the intellectual capital. We constructed a model that will manage this risk based on our interviews and established theories.</p><p> </p>

Flood inundation is a major natural hazard that can have very severe socio-economic consequences. This thesis presents an enhanced numerical model for flood simulation. After setting the context by examining recent large-scale flood events, a literature review is provided on shallow flow numerical models. A new version of the hyperbolic horizontal variable density shallow water equations with source terms in balanced form is used, designed for flows over complicated terrains, suitable for wetting and drying fronts and erodible bed problems. Bed morphodynamics are included in the model by solving a conservation of bed mass equation in conjunction with the variable density shallow water equations. The resulting numerical scheme is based on a Godunov-type finite volume HLLC approximate Riemann solver combined with MUSCL-Hancock time integration and a non-linear slope limiter and is shock-capturing. The model can simulate trans-critical, steep-fronted flows, connecting bodies of water at different elevations. The model is validated for constant density shallow flows using idealised benchmark tests, such as unidirectional and circular dam breaks, damped sloshing in a parabolic tank, dam break flow over a triangular obstacle, and dam break flow over three islands. The simulation results are in excellent agreement with available analytical solutions, alternative numerical predictions, and experimental data. The model is also validated for variable density shallow flows, and a parameter study is undertaken to examine the effects of different density ratios of two adjacent liquids and different hydraulic thrust ratios of species and liquid in mixed flows. The results confirm the ability of the model to simulate shallow water-sediment flows that are of horizontally variable density, while being intensely mixed in the vertical direction. Further validation is undertaken for certain erodible bed cases, including deposition and entrainment of dilute suspended sediment in a flat-bottomed tank with intense mixing, and the results compared against semi-analytical solutions derived by the author. To demonstrate the effectiveness of the model in simulating a complicated variable density shallow flow, the validated numerical model is used to simulate a partial dam-breach flow in an erodible channel. The calibrated model predictions are very similar to experimental data from tests carried out at Tsinghua University. It is believed that the present numerical solver could be useful at describing local horizontal density gradients in sediment laden and debris flows that characterise certain extreme flood events, where sediment deposition is important.