The financial crisis of 2008 highlighted problems with the accounting standard IAS 39, with claims of high complexity, introduction of procyclicality in the financial statements and a proposed role of contributing to the financial crisis. The International Accounting Standard Board issued the predecessor, IFRS 9, which became effective on January 1st, 2018. IFRS 9 introduces a forward-looking Expected Credit Loss model, which significantly change the accounting of loss provisions. With the objective to provide high accounting quality, the International Accounting Standard Board and Financial Accounting Standard Board develop accounting standards based on the conceptual framework, consisting of qualitative characteristics. The study addresses the accounting quality of IFRS 9 through the research question; What implications does IFRS 9 have for equity analysts?  In order to capture the implications, a survey is designed, to reach out to accessible equity analysts of European banks. The results show that the Expected Credit Loss model under IFRS 9 implicate difficulties for equity analysts. Three themes of implications are identified, Time aspect, Complexity and Comparison. Although IFRS 9 provides useful information for the respondents, there are tendencies of a trade-off between relevance and faithful representation. The accounting quality of faithful representation is valued low due to high complexity and low comparability, which might be derived from that IFRS 9 is newly implemented. Despite the implications of IFRS 9, respondents find impairments, today, to be low and a non-vital part of the valuation process of the banking industry.

The subject of this thesis is the development of localization algorithms for target localization in wireless sensor networks using received signal strength (RSS) measurements or Quantized RSS (QRSS) measurements. In chapter 3 of the thesis, target localization using RSS measurements is investigated. Many existing works on RSS localization assumes that the shadowing components are uncorrelated. However, here, shadowing is assumed to be spatially correlated. It can be shown that localization accuracy can be improved with the consideration of correlation between pairs of RSS measurements. By linearizing the corresponding Maximum Likelihood (ML) objective function, a weighted least squares (WLS) algorithm is formulated to obtain the target location. An iterative technique based on Newtons method is utilized to give a solution. Numerical simulations show that the proposed algorithms achieves better performance than existing algorithms with reasonable complexity. In chapter 4, target localization with an unknown path loss model parameter is investigated. Most published work estimates location and these parameters jointly using iterative methods with a good initialization of path loss exponent (PLE). To avoid finding an initialization, a global optimization algorithm, particle swarm optimization (PSO) is employed to optimize the ML objective function. By combining PSO with a consensus algorithm, the centralized estimation problem is extended to a distributed version so that can be implemented in distributed WSN. Although suboptimal, the distributed approach is very suitable for implementation in real sensor networks, as it is scalable, robust against changing of network topology and requires only local communication. Numerical simulations show that the accuracy of centralized PSO can attain the Cramer Rao Lower Bound (CRLB). Also, as expected, there is some degradation in performance of the distributed PSO with respect to the centralized PSO. In chapter 5, a distributed gradient algorithm for RSS based target localization using only quantized data is proposed. The ML of the Quantized RSS is derived and PSO is used to provide an initial estimate for the gradient algorithm. A practical quantization threshold designer is presented for RSS data. To derive a distributed algorithm using only the quantized signal, the local estimate at each node is also quantized. The RSS measurements and the local estimate at each sensor node are quantized in different ways. By using a quantization elimination scheme, a quantized distributed gradient method is proposed. In the distributed algorithm, the quantization noise in the local estimate is gradually eliminated with each iteration. Simulations show that the performance of the centralized algorithm can reach the CRLB. The proposed distributed algorithm using a small number of bits can achieve the performance of the distributed gradient algorithm using unquantized data.

The aim of this thesis is to design a kilowatt three-phase step-down rotary transformer for a permanent magnet DC motor. The permanent magnet DC motor has an on-rotor drive system, and therefore requiring a power supply that can transfer power to its drive unit without mechanical contact. The rotary transformer has a detached magnetic coupling structure that qualifies it as a potential method for the wireless power transfer. This thesis studies the rotary transformer as a static device, focusing on its core loss. By using a transient finite element analysis of COMSOL Multiphysics and an iron loss prediction model, the rotary transformer was optimized in terms of efficiency and power density for the on-rotor drive system through proper material selection and geometry exploration. After this, a mechanical design, which based on a literature review of the influences of manufacturing processes on electrical steels, was proposed for realizing the core fabrication and the rotary transformer assembly. The results show that the rotary transformer can step down 400 V/50 Hz three-phase voltage to 13.15V in a Delta-wye connection and output 1.17kW power over an air-gap of 0.3mm with 95.94% overall efficiency. The proposed mechanical design enables the transformer to minimize the core loss and the manufacturing cost. Without using resonant inductive coupling, this transformer design simplifies the power supply for the motor, thereby decreasing the motor manufacturing and maintenance cost.

VHF står för "Very High Frequency" och är ett frekvensband som ligger i området 30 - 300 MHz. Maritim VHF är standard för Sjöfartsverket och fungerar över hela världen. Det är ett kommunikationssystem som bidrar till ökad säkerhet och kan rädda liv på sjön. Andra vanliga kommunikationssystem som mobiltelefoni fungerar inte tillförlitligt. Idag fungerar mobiltelefoni i stora delar av skärgården och längs kusterna men när det gäller kommunikation mellan fartyg längre ut till havs är den maritima VHF-kommunikationen överlägsen. Sjöfartsverket driver för sitt eget och kunders behov ett mobilradionätverk kallat kustradionätverket. Radiotrafiken i nätet sker både på Very High Frequency (VHF) och Medium frequency (MF). VHF-systemet är ett internationellt system som bland annat används till att kommunicera till sjöss och den trafiken befinner sig i frekvensbandet 155.5 - 162.025 MHz. Inom VHF-bandet finns det 55 kanaler. Kanalerna vid kustradiostationen kallas för duplexkanaler och innebär att kustradiostationerna sänder och tar emot signaler på två olika frekvenser. Radioutbredningen hos antennen som är installerad på basstationen har riktverkan i vissa riktningar och dämpningar i andra. Detta kan ses i strålningsdiagrammet under kapitlet "Täckningsmodell" och avsnittet antennen. Andra faktorer som kan påverka radioutbredningen är förluster i basstationenssystemet, topologin hos området mellan sändare och mottagare samt väderberoende utbredningsegenskaper. Genom att hitta de tänkbara faktorer som påverkar signalutbredningen kan en täckningsmodell förutses. Det är förluster som finns i basstationen, radiolänken samt förluster vid mottagarantennen.

The world is heading towards an energy crisis and desperate efforts are being made to find an alternative, reliable and clean source of energy. Solar Energy is one of the most clean and reliable source of renewable energy on earth. Conventionally, extraction of solar power for electricity generation was limited to PV farms, however lately Distributed Generation form of Solar Power has emerged in the form of residential and commercial Grid Tied Micro-Inverters. Grid Tied Micro-Inverters are costly when compared to their string type counterparts because one inverter module is required for every single or every two PV panels whereas a string type micro-inverter utilizes a single inverter module over a string of PV panels. Since in micro-inverter every panel has a dedicated inverter module, more power per panel can be extracted by performing optimal maximum power tracking over single panel rather than over an entire string of panels. Power per panel extracted by string inverters may be lower than its maximum value as few of the panels in the string may or may not be shaded and thereby forming the weaker links of the system. In order to justify the higher costs of Micro-Inverters, it is of utmost importance to convert the available power with maximum possible efficiency. Typically, a microinverter consists of two important blocks; a Front End DC-DC Converter and Output DCAC Inverter. This thesis proposes efficiency optimization techniques for both the blocks of the micro-inverter. iv Efficiency Optimization of Front End DC-DC Converter This thesis aims to optimize the efficiency of the front end stage by proposing optimal design procedure for resonant parameters of LLC Topology as a Front End DC-DC Converter for PV Applications. It exploits the I-V characteristics of a solar panel to design the resonant parameters such that resonant LLC topology operates near its resonant frequency operating point which is the highest efficiency operating point of LLC Converter. Efficiency Optimization of Output DC-AC Inverter Due to continuously variable irradiance levels of solar energy, available power for extraction is constantly varying which causes the PV Inverter operates at its peak load capacity for less than 15% of the day time. Every typical power converter suffers through poor light load efficiency performance because of the load independent losses present in a power converter. In order to improve the light load efficiency performance of Three Phase Inverters, this thesis proposes Phase Skipping Control technique for Three Phase Grid Tied Micro-Inverters. The proposed technique is a generic control technique and can be applied to any inverter topology, however, in order to establish the proof of concept this control technique has been implemented on Three Phase Half Bridge PWM Inverter and its analysis is provided. Improving light load efficiency helps to improve the CEC efficiency of the inverter.

Bakgrund: En ny reglering har införts den 1 januari 2018, vilket är IFRS 9 finansiella instrument som ersätter IAS 39. Värdering och redovisning förändras från en objektiv till en subjektiv bedömning av kreditförluster. Syfte: Syftet med studien är att undersöka vilken effekt IFRS 9 har på svenska banker efter införandet. Studien undersöker även om effekten varierar beroende av bankers storlek. Metod: För att uppnå studiens syfte har en kvantitativ studie med deduktiv ansats tillämpats. Sekundärdata har inhämtats ur bankernas årsredovisningar för 2018 från respektive hemsida. Banker som ingår i studien är 43 svenska banker som står under Finansinspektionens tillsyn. Studiens tre hypoteser testades med hjälp av ttest, där parvis observation gjordes mellan åren 2017 och 2018. Resultat och slutsats: Resultatet visade en signifikant förändring av totala kapitalrelationen och kärnprimärkapitalrelationen i de större bankerna, vilka nyckeltalen var lägre efter införandet av IFRS 9. Egna kapitalet, kreditförlusterna och soliditeten kunde inte visa någon signifikant förändring. Slutsats av studiens resultat är att införandet av IFRS 9 haft en marginell effekt på svenska banker. / Background: The new regulation IFRS 9 has replaced IAS 39. The new regulation is subjective, forward-looking, compared with the old, objective model. Purpose: The purpose of our study was to investigate the effect IFRS 9 has on Swedish banks after the transition. Another aim is to study the effect of IFRS 9 on different bank sizes. Method: To achieve the purpose of the study, a quantitative method has been applied. Data has been obtained from annual reports for the year of 2018. The data consist of shareholders equity, balance sheet total and reported loan losses. Hypothesis testing has been done by using t-test Result and conclusion: The results can support a week significant positive effect on Tier 1 capital and capital adequacy ratio from large banks. No results could be found for Shareholders equity, Credit loss or Solidity.

Thermal and chemical recovery processes are important EOR methods used often by the oil and gas industry to improve recovery of heavy oil and high viscous oil reservoirs. Knowledge of underlying mechanisms and their modeling in numerical simulation are crucial for a comprehensive study as well as for an evaluation of field treatment. EOS-compositional, thermal, and blackoil reservoir simulators can handle gas (or steam)/oil/water equilibrium for a compressible multiphase flow. Also, a few three-phase chemical flooding reservoir simulators that have been recently developed can model the oil/water/microemulsion equilibrium state. However, an accurate phase behavior and fluid flow formulations are absent in the literature for the thermal chemical processes to capture four-phase equilibrium. On the other hand, numerical simulation of such four-phase model with complex phase behavior in the equilibrium condition between coexisting phases (oil/water/microemulsion/gas or steam) is challenging. Inter-phase mass transfer between coexisting phases and adsorption of components on rock should properly be modeled at the different pressure and temperature to conserve volume balance (e.g. vaporization), mass balance (e.g. condensation), and energy balance (e.g. latent heat). Therefore, efforts to study and understand the performance of these EOR processes using numerical simulation treatments are quite necessary and of utmost importance in the petroleum industry. This research focuses on the development of a robust four-phase reservoir simulator with coupled phase behaviors and modeling of different mechanisms pertaining to thermal and chemical recovery methods. Development and implementation of a four-phase thermal-chemical reservoir simulator is quite important in the study as well as the evaluation of an individual or hybrid EOR methods. In this dissertation, a mathematical formulation of multi (pseudo) component, four-phase fluid flow in porous media is developed for mass conservation equation. Subsequently, a new volume balance equation is obtained for pressure of compressible real mixtures. Hence, the pressure equation is derived by extending a black oil model to a pseudo-compositional model for a wide range of components (water, oil, surfactant, polymer, anion, cation, alcohol, and gas). Mass balance equations are then solved for each component in order to compute volumetric concentrations. In this formulation, we consider interphase mass transfer between oil and gas (steam and water) as well as microemulsion and gas (microemulsion and steam). These formulations are derived at reservoir conditions. These new formulations are a set of coupled, nonlinear partial differential equations. The equations are approximated by finite difference methods implemented in a chemical flooding reservoir simulator (UTCHEM), which was a three-phase slightly compressible simulator, using an implicit pressure and an explicit concentration method. In our flow model, a comprehensive phase behavior is required for considering interphase mass transfer and phase tracking. Therefore, a four-phase behavior model is developed for gas (or steam)/ oil/water /microemulsion coexisting at equilibrium. This model represents coupling of the solution gas or steam table methods with Hand’s rule. Hand’s rule is used to capture the equilibrium between surfactant, oil, and water components as a function of salinity and concentrations for oil/water/microemulsion phases. Therefore, interphase mass transfer between gas/oil or steam/water in the presence of the microemulsion phase and the equilibrium between phases are calculated accurately. In this research, the conservation of energy equation is derived from the first law of thermodynamics based on a few assumptions and simplifications for a four-phase fluid flow model. This energy balance equation considers latent heat effect in solving for temperature due to phase change between water and steam. Accordingly, this equation is linearized and then a sequential implicit scheme is used for calculation of temperature. We also implemented the electrical Joule-heating process, where a heavy oil reservoir is heated in-situ by dissipation of electrical energy to reduce the viscosity of oil. In order to model the electrical Joule-heating in the presence of a four-phase fluid flow, Maxwell classical electromagnetism equations are used in this development. The equations are simplified and assumed for low frequency electric field to obtain the conservation of electrical current equation and the Ohm's law. The conservation of electrical current and the Ohm's law are implemented using a finite difference method in a four-phase chemical flooding reservoir simulator (UTCHEM). The Joule heating rate due to dissipation of electrical energy is calculated and added to the energy equation as a source term. Finally, we applied the developed model for solving different case studies. Our simulation results reveal that our models can accurately and successfully model the hybrid thermal chemical processes in comparison to existing models and simulators. / text

Redovisning av finansiella instrument har varit omtalat de senaste åren, framför allt gällandebanker. Mellan år 2017 och 2018 skedde en övergång mellan två standarder, från IAS 39 tillIFRS 9. Anledningen till den nya standarden IFRS 9 var, dels att IAS 39 blev hårt kritiserad,och dels på grund av dess komplexitet. Kritiken gentemot IAS 39 blev som mest omtalad efterfinanskrisen 2007–2009, speciellt avseende sättet som kreditförluster redovisades. Bland destörsta skillnaderna mellan standarderna var en ny modell för redovisning av kreditförluster iIFRS 9, antalet värderingskategorier minskade samt att upplysningskraven utökades.Ytterligare en förändring var att IFRS 9 är en principbaserad standard, till skillnad från IAS 39som är regelbaserad. Detta kan leda till problematik gällande både subjektiva bedömningar ochharmonisering.Syftet med studien var att undersöka de övergångseffekter som uppstod för banker vidövergången till IFRS 9. Genom en kvalitativ dokumentstudie har tolv banker studerats,uppdelade i tre olika bankkategorier, där vi genom resultatet ämnat att finna eventuella mönster,likheter eller skillnader i bankernas övergångseffekter. Med utgångspunkt i årsredovisningarnafrån 2017 och 2018 från respektive bank, har fokus varit på hur redovisningen av kreditförlusterpåverkade de finansiella rapporterna vid övergången.Av resultatet framgår att alla banker i studien påverkades av övergången från IAS 39 till IFRS9. Det uppstod däremot inga tydliga mönster för hur bankerna påverkades, varken mellan deenskilda bankerna eller mellan bankkategorierna, då effekterna kraftigt skiljer sig. Något somframgår är att i genomsnitt ökade kreditförluster, kreditreserveringar och kreditförlustnivån,samt att eget kapital minskade. Studiens resultat indikerar att bakomliggande faktorer kan liggatill grund för den stora variationen av påverkan på bankerna. Faktorer som subjektivabedömningar, affärsmodell och verksamhet. De striktare kraven för upplysningar iårsredovisningarna skulle bidra till ökad transparens och således öka jämförbarheten. Det visarsig dock i studien att det brister i harmoniseringen och därför försvårades jämförbarheten.Vår slutsats är att införandet av IFRS 9 och framför allt dess förändrade regler gällandekreditförlustreserveringar påverkade bankerna. Även att variationen av verksamhet,affärsmodell och subjektiva bedömningar kan ha stor påverkan på redovisningen. Samtligabanker påverkades men förändringen var varierande. Det finns tendens till att storbankerna ochsparbankerna hade liknande övergångseffekter. Det framkom dock inga tydliga mönster förnågon av bankkategorierna. Utifrån dessa faktorer kan det krävas fler riktlinjer för att begränsade tolkningarna som uppstår. Allt för att jämförbarheten ska öka för de finansiella instrumentenmellan olika banker. / Redovisning av finansiella instrument har varit omtalat de senaste åren, framför allt gällandebanker. Mellan år 2017 och 2018 skedde en övergång mellan två standarder, från IAS 39 tillIFRS 9. Anledningen till den nya standarden IFRS 9 var, dels att IAS 39 blev hårt kritiserad, och dels på grund av dess komplexitet. Kritiken gentemot IAS 39 blev som mest omtalad efterfinanskrisen 2007–2009, speciellt avseende sättet som kreditförluster redovisades. Bland destörsta skillnaderna mellan standarderna var en ny modell för redovisning av kreditförluster iIFRS 9, antalet värderingskategorier minskade samt att upplysningskraven utökades. Ytterligare en förändring var att IFRS 9 är en principbaserad standard, till skillnad från IAS 39som är regelbaserad. Detta kan leda till problematik gällande både subjektiva bedömningar och harmonisering.  Syftet med studien var att undersöka de övergångseffekter som uppstod för banker vid övergången till IFRS 9. Genom en kvalitativ dokumentstudie har tolv banker studerats, uppdelade i tre olika bankkategorier, där vi genom resultatet ämnat att finna eventuella mönster, likheter eller skillnader i bankernas övergångseffekter. Med utgångspunkt i årsredovisningarna från 2017 och 2018 från respektive bank, har fokus varit på hur redovisningen av kreditförluster påverkade de finansiella rapporterna vid övergången.  Av resultatet framgår att alla banker i studien påverkades av övergången från IAS 39 till IFRS 9. Det uppstod däremot inga tydliga mönster för hur bankerna påverkades, varken mellan de enskilda bankerna eller mellan bankkategorierna, då effekterna kraftigt skiljer sig. Något som framgår är att i genomsnitt ökade kreditförluster, kreditreserveringar och kreditförlustnivån, samt att eget kapital minskade. Studiens resultat indikerar att bakomliggande faktorer kan ligga till grund för den stora variationen av påverkan på bankerna. Faktorer som subjektiva bedömningar, affärsmodell och verksamhet. De striktare kraven för upplysningar i årsredovisningarna skulle bidra till ökad transparens och således öka jämförbarheten. Det visar sig dock i studien att det brister i harmoniseringen och därför försvårades jämförbarheten.  Vår slutsats är att införandet av IFRS 9 och framför allt dess förändrade regler gällande kreditförlustreserveringar påverkade bankerna. Även att variationen av verksamhet, affärsmodell och subjektiva bedömningar kan ha stor påverkan på redovisningen. Samtliga banker påverkades men förändringen var varierande. Det finns tendens till att storbankerna och sparbankerna hade liknande övergångseffekter. Det framkom dock inga tydliga mönster för någon av bankkategorierna. Utifrån dessa faktorer kan det krävas fler riktlinjer för att begränsa de tolkningarna som uppstår. Allt för att jämförbarheten ska öka för de finansiella instrumenten mellan olika banker.

The objective of this work is to enhance the awareness of the indoor propagation behaviour, by a set of investigations including simulations and measurements. These investigations include indoor propagation behaviour, local mean power estimation, proposing new indoor path loss model and introducing a case study on 60 GHz propagation in indoor environments using ray tracing and measurements. A summary of propagation mechanisms and manifestations in the indoor environment is presented. This comprises the indoor localization techniques using channel parameters in terms of angle of arrival (AOA), time of arrival (TOA) and received signal strength (RSS). Different models of path loss, shadowing and fast fading mechanisms are explored. The concept of MIMO channels is studied using many types of deterministic channel modelling such as Finite Difference Time Domain, Ray tracing and Dominant path model. A comprehensive study on estimating local average of the received signal strength (RSS) for indoor multipath propagation is conducted. The effect of the required number of the RSS data and their Euclidian distances between the neighbours samples are investigated over 1D, 2D and 3D configurations. It was found that the effect of fast fading was reduced sufficiently using 2D horizontal’s arrangement with larger spacing configuration. A modified indoor path loss prediction model is presented namely effective wall loss model (EWLM). The modified model with wall correction factors is compared to other indoor path loss prediction models using simulation data (for 2.4, 5, 28, 60 and 73.5 GHz) and real-time measurements (for 2.4 and 5 GHz). Different operating frequencies and antenna polarizations are considered to verify the observations. In the simulation part, EWLM shows the best performance among other models. Similar observations were recorded from the experimental results. Finally, a detailed study on indoor propagation environment at 60 GHz is conducted. The study is supported by Line of Sight (LoS) and Non-LoS measurements data. The results were compared to the simulated ones using Wireless-InSite ray tracing software. Several experiments have confirmed the reliability of the modelling process based on adjusted material properties values from measurements.

本研究探討台灣於2011年依據IAS 39進行34號公報之第三次修訂實施，採用已發生損失模型後的兩項議題：（1）放款壞帳費用之提列與盈餘波動性以及資本適足率波動性之關聯性，（2）以歷史成本評價之期末金額及以公允價值評價之期末金額，究竟何者對於未來之帳款沖銷與不良債權較具有關聯性。 實證結果顯示，自2011年採用已發生損失模型後盈餘波動性無顯著之變化，且壞帳費用對於盈餘波動性無解釋能力；而自2011年後資本適足率波動性亦無顯著變化，但壞帳費用對於資本適足率波動性有顯著的影響，顯示銀行明顯透過壞帳費用之提列進行資本管理而非盈餘管理。在未來信用損失預測之部分，以歷史成本評價之期末放款金額對於未來之帳款沖銷及不良債權有顯著的負相關，而以公允價值評價之期末放款金額對於未來之帳款沖銷及不良債權卻無解釋能力，可能係因未來帳款沖銷與未來不良債權之發生與放款之帳齡有顯著的關聯性，而與未來可收取之現金流量無顯著之相關。 / This study aims to investigate how Incurred Loss Model affects the recognition of loan loss provisions and the valuation of loans due to the third revision of SFAS No. 34 which was revised based on IAS 39 in 2011. For the recognition of loan loss provisions, it focuses on the relationship with earnings volatilities and capital adequacy volatilities, and for the valuation of loans, it specializes on whether credit loss predicting is related to historical cost accounting or fair value accounting. The result shows that, since the implementation of Incurred Loss Model in 2011, both the adoption of Incurred Loss Model and the loan loss provisions have no significant impact on earnings volatilities. For capital adequacy volatilities, implementing Incurred Loss Model has no effect on capital adequacy volatilities neither. However, the loan loss provisions since 2011 significantly enhance the volatilities of capital adequacy. It reveals that banks use loan loss provisions to manage capitals instead of earnings. For credit loss predicting, loans evaluated with historical cost accounting have significant negative relations with future charge-offs and non-performing loans while loans evaluated under fair value accounting do not have any explanation power. It may suggests that future charge-offs and non-performing loans are related to the aging of loans, but not the future payoffs of loans.