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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
401

The use of portfolio management with target costed process oriented products under conditions of uncertainty

Horton, Kevin G. 02 February 2010 (has links)
The present trend towards shorter product lives means that manufacturers are faced with less time whereby production costs can be controlled and reduced. As a result many companies are turning towards the use of Systems Engineering and cost management techniques that are intended to reduce product costs during the design phases of the product life. <p>One of the many cost management tools that are presently in use is target costing. An iterative process, target costing attempts to reduce the cost of manufacturing products by using value engineering techniques so that identified target costs can be realized. As a step improvement program, the ability of a company to obtain its target cost in not always certain. Target profits from individual products are grouped together into portfolios and then managed according to company strategic profit plans. <p>This report investigates methods used for identifying the uncertainties that can exist in the target costing process and suggests the potential use efficient portfolio techniques for the management of process oriented or continuous products. The report also suggests a number of follow-on projects that could encompass the use of specific decision support systems for the examination of both target costing uncertainties and portfolio management. / Master of Science
402

The Efficiency of Financial Markets Part II : A Stochastic Oscillator Approach

Netzén Örn, André January 2019 (has links)
Over a long period of time, researchers have investigated the efficiency of financial markets. The widely accepted theory of the subject is the Efficient Market Hypothesis, which states that prices of financial assets are set efficiently. A common way to test this hypothesis is to analyze the returns generated by technical trading rules which uses historical prices in an attempt to predict future price development. This is also what this study aims to do. Using adjusted daily closing prices ranging over 2007 to 2019 for 5120 stocks listed on the U.S stock market, this study tests a momentum trading strategy called the stochastic oscillator in an attempt to beat a buy and hold strategy of the Russel 3000 stock market index. The stochastic oscillator is constructed in three different ways, the Fast%K, the Fast%D and the Slow%D, the difference being that a smoothing parameter is used in the Fast%D and Slow%D in an attempt to reduce the number of whiplashes or false trading signals. The mean returns of the technical trading strategies are tested against the mean returns of the buy and hold strategy using a non-parametric bootstrap methodology and also, the risk adjusted returns in terms of Sharpe Ratios are compared for the different strategies. The results find no significance difference between the mean returns of the buy and hold strategy and any of the technical trading strategies. Further, the buy and hold strategy delivers a higher risk adjusted return compared to the technical trading strategies, although, only by a small margin. Regarding the smoothing parameter applied to the strategies, it seems to fulfill its purpose by reducing the number of trades and slightly increasing the mean returns of the technical trading strategies. Finally, for deeper insight in the subject, a reading of "The efficiency of financial markets: A dual momentum trading strategy on the Swedish stock market" by Netzén Örn (2018) is recommended.
403

Exploration of carbon nanotube and copper-carbon nanotube composite for next generation on-chip energy efficient interconnect applications / Exploration de nanotubes de carbone et de composites de nanotubes-cuivre pour des applications d'interconnexion sur puce de la prochained génération efficacité energitique

Liang, Jie 17 June 2019 (has links)
Améliorer uniquement les performances et l'efficacité énergétique des transistors n'est pas suffisant pour les futurs systèmes sur puce. Les interconnexions sont également essentielles et ont de graves répercussions sur les performances globales du circuit et l'efficacité énergétique. Le cuivre (Cu) est le matériau d'interconnexion conventionnel qui a aujourd’hui atteint ses limites par suite de l’effet de la miniaturisation. Les effets de barrière et de dispersion induisent une résistivité élevée et une forte éléctromigration aggravent la fiabilité d'interconnexion. Les Nanotubes de carbone (CNT) et les composites de Cuivre et Nanotube de carbone (Cu-CNT) sont intéressants grâce à leur transport balistique, à la grande évolutivité, à la conductivité thermique élevée et à la densité de courant élevée. Dans ce travail, nous étudions les propriétés physiques fondamentales et électriques des CNT et des composite de Cu-CNT de l’échelle atomique à l’échelle macroscopique pour les applications d’interconnexions locales et globales. Nous évaluons les différentes sources de variabilité et leurs impacts sur les performances d'interconnexion des CNT et l'efficacité énergétique. Le dopage basé sur le transfert de charge des CNT est également étudié en tant que moyen important de réduire davantage sa résistivité et d’atténuer les variations de chiralité des CNT ainsi que d’alléger les effets sur la résistance de contact. Les résultats des mesures expérimentales sont utilisés pour démontrer la validité et la précision de nos modèles établis. Les modèles d'interconnexion sont enfin appliqués aux études à l’échelle de portes et de circuits en tant qu'interconnexions locales et globales pour évaluer leurs performances. / Improving only the performance and energy efficiency of transistors is not sufficient for future systems-on-chip. On-chip interconnects have become equally critical to transistors and can detriment the system’s performance and energy efficiency. Copper (Cu) is the state-of-the-art interconnect material and is reaching its physical limitations due to scaling. Barrier and scattering effects induce high resistivity and electromigration exacerbates interconnect reliability. Carbon Nanotubes (CNTs) and Copper-Carbon Nanotube (Cu-CNT) composite materials are of interest due to ballistic transport, high scalability, high thermal conductivity, and high current density. We investigate from fundamental atomistic level to macroscopic level the physical understanding and electrical compact modeling on CNT and Cu-CNT composite for on-chip local and global interconnect applications. We evaluate and assess the different sources of variations and their impacts on CNT interconnect performance and energy efficiency. Charge transfer based doping of CNT is also investigated as an alternative method to further reduce its resistivity, mitigate CNT chirality variations and contact resistance drawbacks. Experimental measurement results are used to demonstrate the validity and accuracy of our established models. The interconnect models are finally applied to the gate- and circuit- level studies as local and global interconnects to evaluate their performance.
404

Green Wheel Loader – improving fuel economy through energy efficient drive and control concepts

Schneider, Markus, Koch, Oliver, Weber, Jürgen January 2016 (has links)
The drive train components and the machine control system significantly influence the fuel consumption of mobile machinery. The demonstrator vehicle “Green Wheel Loader” developed within the joint research project “TEAM” combines the most promising drive concepts currently available for mobile machines with an innovative operating strategy. The developed drive and control system proved its functionality and performance under realistic operation conditions in a gravel pit. Reference test showed 10 – 15 % fuel savings of the prototype vehicle compared to a state-of-the-art series machine.
405

Modelování výsledků fotbalového zápasu a hypotéza efektivního trhu u sportovního sázení / Modeling of football matches results and efficient-market hypothesis in sports betting

Augustin, Michael January 2020 (has links)
01 Abstract Betting on sporting events can be perceived by the general public as a game of chance. In the professional literature, however, betting on football matches is treated in the same way as other financial markets, where in the event of a violation of the theory of efficient markets due to the occurrence of inefficiency, there are opportunities for investors to obtain abnormal returns. The main goal of this work is to create a model capable of predicting the results of football matches on the basis of historical data better than bookmakers are able to do and test the effectiveness of the Czech betting market for football matches of the Czech highest football league. The first part of the thesis contains a more detailed presentation of the theory of efficient markets, a comparison of financial and betting markets and sources of possible inefficiency in betting markets. The second and third parts present data, models and their possible modification to increase the accuracy of estimates. The fourth part describes the results of testing individual models and subsequent simulations of betting strategies. The fifth part contains a conclusion and discussion of the results, including an indication of possible alternatives to follow-up research. The results of simulations of betting strategies confirm...
406

Energy savings and maintenance optimization of energy-efficient lighting retrofit projects incorporating lumen degradation

Ikuzwe, Alice January 2020 (has links)
The lighting retrofit method is adopted as one of the solutions to reduce lighting energy consumption and improve lighting quality in existing buildings. Lighting controls and energy-efficient light sources are used to achieve the goals of the lighting retrofit. Nowadays, Light-Emitting Diodes (LEDs) are replacing traditional lighting technology owing to their high efficiency and longevity. One of the advantages of LEDs is the controllability function, which allows users to set the light level according to their preferences. This saves more energy and satisfies users’ lighting needs. However, over time, the performance of lighting retrofit projects deteriorates subject to failure of the retrofitted lights. Therefore, to maintain the performance of lighting retrofit projects, maintenance must be planned and performed. The impacts of the users’ lighting level requirements on LEDs’ life characteristics and lighting system performance are investigated by using lighting controls. Light and occupancy sensors adjust artificial light to the light level required by users and detect the presence of users in the zones, respectively. Light sensors measure the average illuminance in the zones. The measured illuminance is compared to the users’ set illuminance; if the measured illuminance is higher than the users’ set illuminance, lamps are dimmed to meet users’ lighting preference, when the measured illuminance is less than the users’ set illuminance, lamps in the zone are replaced by new ones. The dimming level in each zone at each sampling interval is used to estimate the operating junction temperature, thereafter the degradation rate and luminous flux are calculated. Light levels at workspace are modelled using the lumen method. This model helps to quantify energy savings and predict when lamps will fail to deliver the required light levels. In existing studies, users’ lighting level requirements are neglected when investigating the lifetime of the lighting system; however, users’ profile and driving schemes affect the operating conditions of a lighting system. From the simulation results, it is noted that lumen output degradation increases when the user’s set illuminance is above the illuminance required under normal operating conditions and decreases when the user’s set illuminance is below the illuminance required under normal operating conditions. Increased lumen output degradation shortens the lifetime of LEDs and reduces energy savings, while decreased lumen output degradation extends the lifetime and increases energy savings. Generally, lighting retrofit projects contain a large lighting population; investigating when each lamp will fail can be time-consuming and costly. In this research, a mathematical model is formulated to model LEDs’ failure by analysing the statistical properties of the lumen degradation rates. Based on the statistical properties of the degradation rates, the cumulative probability of failure distribution and the survival function are modelled. The formulated survival function is incorporated into the lighting maintenance optimization problem to balance energy savings and maintenance costs. A case study carried out shows that, in 10 years, the optimal lighting maintenance plan would save up to 59% of lighting energy consumption with acceptable maintenance costs. It is found that the proposed maintenance plan is more cost-effective than full maintenance. It is concluded that lumen degradation failure should be considered when investigating the performance of lighting retrofit projects, as this may not only affect energy savings but also reduce the level of illumination, which can cause visual discomfort. The initial investment costs of LEDs are still a barrier to the implementation of LED lighting systems in residential buildings. Energy-efficiency projects often face hurdles to access capital investments because decision-makers and funders do not have enough information about operational savings the project can provide and specific financial requirements applied to efficiency investment. In this research, an optimization model is formulated to give decision-makers and funders detailed information about the performance and operational savings that a LED lighting retrofit project can offer and its economic viability. The lumen degradation failure model developed is used to monitor and estimate the energy savings, and the optimal maintenance plan is scheduled to replace failed lamps. In the existing studies, the economic analysis of the lighting retrofit projects is assessed based on lighting population decay due to burnout failure while in this research economic analysis is assessed by considering the lumen degradation failure. The case study results show that the substitution of halogen light bulbs with LED light bulbs could save up to 291.4 GWh of energy consumption, and reduce 273:92 103 tons of CO2 emissions over 10-year period. The optimization model formulated is effective to help the decision-makers and funders to quantify the savings and assess the economic viability of the LED lighting retroïnˇA˛t project. This optimization model can help the decision-makers and funders to make an informed decision. / Thesis (PhD (Electrical Engineering))--University of Pretoria, 2020. / Electrical, Electronic and Computer Engineering / PhD (Electrical Engineering) / Unrestricted
407

Coherent Optical & Electro-Optical Signal Processor Circuit Architectures for Photonic Integration

Hasan, Mehedi 17 December 2020 (has links)
The capacity of optical communications networks continues to grow unabated. Applications for streaming video, social networking and cloud computing, are driving exponential growth of the traffic carried over the world’s ICT networks, which has been sustained thus far through the proliferation of datacenters and efficient, effective use of existing optical fibre. To meet increasing capacity demands requires increasingly sophisticated modulation formats and spectral management to achieve effective use of the available spectrum provided by an optical fibre. Moreover, the technology developed for optical communications is finding broader application to other sectors such as data centres, 5&6 G wireless; lidar and radar. Ultimately, some essential signal processing functions must occur at speeds beyond purely electronic means even when accounting for anticipated technological development. The option is to perform signal processing in the optical domain. Optical signal processors are fundamentally analog and linear in nature. To provide high performance, an analogue processor must be well controlled in a way analogous to the numerous and sophisticated controllers employed by the process industry. Consequently, a further extension of control to deeper levels within the physical layer reaching the optical layer will be necessary. For example, current reconfigurable optical add-drop multiplexers are coloured and directional and the wavelength division multiplexing channel grid, transponders modulation format, and the routing are all fixed. Through optimization of the interface between the physical components, sensors, and processors elastic optical network technology can be achieved by employing colour-, direction-, contention-, grid-less, filter-, gap-less reconfigurable optical add-drop multiplexers, flexible channels centre frequencies and width, flexible sub-carriers in super-channels, flexible modulation formats and forward error control coding transponders, and impairment-aware wavelength routing and spectral assignment. The aim of this thesis is to advance the state-of-the-art in photonic circuits and subsystems via proposing new architecture; study of the feasibility of photonic integration and, proof of concept implementations using available resources. The goal is to introduce new architectural concepts that make effective use of physical components and/or optical processors with reduced energy consumption, reduced footprint and offer speed beyond all-electronic implementations. The thesis presents four case studies based on one or more published papers and supplementary material that advance the goal of the thesis. The first study presents a coherent electro-optic circuit architecture that generates N spatially distinct phase-correlated harmonically related carriers using a generalized Mach-Zehnder Interferometer with its N×1 combiner replaced by an N×N optical Discrete Fourier Transform. The architecture subsumes all Mach-Zehnder Interferometer-based architectures in the prior art given an appropriate selection of output port(s) and dimension N, although the principal application envisaged is phase-correlated subcarrier generation for next-generation optical transmission systems. The theoretical prediction is then verified experimentally using laboratory available photonic integrated circuit fabricated for other applications. Later on, a novel extension of the circuit architecture is introduced by replacing the optical Discrete Fourier Transform network using the combination of a properly chosen phase shifter and single MMI coupler. The second study proposes two novel architectures for an on-chip ultra-high-resolution panoramic spectrometer and presents their design, analysis, integration feasibility, and verification by simulation. The target application is to monitor the power of a wavelength division multiplexed signals in both fixed and flex grid over entire C-band with minimum scan time and better than 1 GHz frequency accuracy. The two architectures combine in synchrony a scanning comb filter stage and channelized coarse filter. The fine filtering is obtained using a ring resonator while the coarse filtering is obtained using an arrayed waveguide grating with appropriate configuration. The fully coherent first architecture is optimised for compactness but relies on a repeatable fabrication processes to match the optical path lengths between a Mach-Zehnder interferometer and a multiple input arrayed waveguide grating. The second architecture is less compact than the first but is robust to fabrication tolerances as it does not require the path length matching. The third study proposes a new circuit architecture for single sideband modulation or frequency conversion which employs a cascade Mach-Zehnder modulator architecture departing from the orthodox dual parallel solution. The theoretical analysis shows that the circuit has 3-dB optical and 3-dB electrical advantage over the orthodox solution. The 3-dB electrical advantage increases the linear operating range of Mach-Zehnder modulator before RF amplifier saturation. An experimental verification of the proposed architecture is provided using an available photonic integrated circuit. The proposed circuit can also perform complex modulation. An alternative implementation based on polarization modulators is also described. The fourth study presents the theoretical modelling of a photonic generation of broadband radio frequency phase shifter. The proposed phase shifter can generate any phase without bound: the complex transmission of the phase shifter follows a trajectory that rotates on a unit circle and may encircle the origin any number of times in either direction, which has great utility in the tuning of RF-photonic systems. The proposed concept is then verified experimentally using off the shelf low frequency electronic components.
408

Reducing GHG emissions from ships in port areas

Winnes, Hulda, Styhre, Linda, Fridell, Erik 21 December 2020 (has links)
Climate change has recently received more attention in the shipping sector. This is mainly due to a growing demand for reduced global emissions and the fact that shipping is one of the fastest growing sectors in terms of greenhouse gas (GHG) emissions. In parallel, ports have started to introduce programmes and policies to address these emissions. This study aims at quantifying potential reductions of ships' emissions of GHG from efforts implemented by ports. Building on a model that calculates GHG emissions from ships in various scenarios for individual ports, different kinds of measures for emission reductions are investigated for diverse types of vessels and parts of the port area. A case study of the ship traffic to the Port of Gothenburg is performed. Projections of ship emissions in the port area for 2030 are made, and three scenarios, ‘1. Alternative fuel’, ‘2. Ship design’ and ‘3. Operation’, are analysed. These scenarios are related to a business as usual development. GHG emissions from ships in the port are projected to increase by 40% to 2030 in a business as usual (BAU) scenario. The highest reductions were seen in the ‘Operation’ scenario where GHG emissions were 10% lower than the BAU level.
409

POST-ANNOUNCEMENT-DRIFT : EN KOMBINATION AV PASSIV- OCH AKTIV FÖRVALTNINGSTRATEGI

Forsman, Viktor, Jonsson, Jonathan January 2020 (has links)
Problembakgrund &amp; problemdiskussion: Att som professionell investerare lyckas överavkasta sitt jämförelseindex år efter år är lättare sagt än gjort. Oavsett vilken strategi en förvaltare använder sig av kan det vara svårt att kontinuerligt lyckas prestera bättre än marknaden. Författarna av denna studie har blivit inspirerade av anomalin PEAD, postearnings-announcement-drift. Den visar att om ett bolag överraskar positivt (negativt) har aktiekursen en tendens att stiga (falla) ett tag efter att den nya informationen har presenterats.   Problemformulering: Är det möjligt att kombinera indexplacering med PAD i samband med rapporter för att nå överavkastning gentemot OMXS30-index?  Vilken tidsperiod av tre, fem eller tio dagar är det i genomsnitt mest lukrativt att hålla aktien under rådande strategi? Syfte: Studiens huvudsyfte är att se om en kombination av aktiv förvaltning grundat på PEAD tillsammans med en passiv förvaltning i en börsfond som följer OMXS30, skulle lyckas överavkasta mot OMXS30. Studiens delsyfte är att se vilken av tidsperioderna tre, fem eller tio dagar som kan generera största avkastning. Författarna vill med denna studie kunna ge professionella investerare en stabil strategi som över tid visar sig överavkasta jämförelsebart index på ett kostnadseffektivt sätt och utan att ta allt för stor risk.   Teori: Studien behandlar teorier kopplat till Post Earnings Announcement Drift (PEAD) som sedan sätts i kontext med en genomgång av de etablerade teorierna om den effektiva marknadshypotesen och random walk. Som i sin utformning motsätter sig att en strategi byggd på PEAD ska kunna bringa överavkastning.    Metod: Studien använder sig av en kvantitativ metod med en deduktiv ansats. Aktiedata är inhämtad från bolag som ingått i OMXS30 under perioden 2010–2019. Studien har testat om strategin har överavkastat gentemot studiens utvalda referensindex.    Empiri/analys: Studiens resultat har ett empiriskt stöd för att PAD3 har en signifikant överavkastning gentemot OMXS30. Medan PAD5 och PAD10 visade sig inte ha en statistiskt säkerställd överavkastning mot OMXS30. Författarna har vidare funnit intressanta resultat som starkt pekar mot att strategin presterar starkt under en negativ marknad.   Slutsats: Strategin visade sig ha starka bevis att motsäga random walk då ett återupprepande prismönster gick att finna i studiens resultat. Trots att majoriteten av resultaten av de statistiska testerna inte var signifikanta ställer sig författarna även tveksamma till den effektiva marknadshypotesen. Strategin med den kortaste aktiva förvaltningen överavkastade index med över 150% vilket bör kunna ses som ett tecken på att marknaden inte till fullo lyckas prisa in den nya information som presenteras i samband med då bolagen släpper rapporter.
410

Januarieffekten inom large cap och mid cap bolag : En studie på svenska börsmarknaden / The January effect within large cap and mid cap companies : A study on the Swedish stock market

Malmquist, Hampus, Hansson, Anton January 2020 (has links)
The stock market have received a fair amount of attention in the media recently as a result of the ongoing covid-19 pandemic. The question arouse if there is one month in the year that outperforms all other months in the stock market. A well known anomaly in the world of finance referred to as, the January effect, came up to discussion. Earlier studies of this subject have achieved different results and conclusions. Therefore, this study aims to examine if the January effect exists on mid cap and large cap companies on the Swedish stock market. To achieve this, one large cap portfolio and one mid cap portfolio both equally weighted with ten companies each were created. These two portfolios were analyzed with, among others, a well known regression model for season anomalies. The results of this study concludes that the January effect does not exist in neither of the portfolios.

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