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Today, buildings consume 40% of total energy demand in the EU and are responsible for 36% of GHG emissions. For this reason, and due to the delicate situation of climate change that planet Earth is experiencing, solutions are being sought to make the building sector more sustainable. In the current project, the use of natural materials has been chosen as a solution in line with the EU 2050 long-term strategy. This research broadens the knowledge on sustainable building with natural materials as an alternative to conventional construction. To this end, first, an extensive state of the art has been carried out to gather information and identify research gaps on natural building materials and energy efficiency, proving the suitability of natural construction materials. Special emphasis has been put on straw bale construction and rammed earth construction, which have been studied individually. In addition, geometrically identical building models of both building techniques have been developed and simulated in Stockholm and Valencia in order to see how they would perform in different climates. Total energy demand for the straw-bale building of 140.22 kWh/(m2·year) in the case of Stockholm and 37.05 kWh/(m2·year) in the case of Valencia has been obtained. For the rammed earth building, a total demand of 301.82 kWh/(m2·year) has been obtained in Stockholm and 78.66 kWh/(m2·year) in Valencia. Once passive measures are applied in the different models, a reduction in demand for the straw bale building of 77.8% and 36.3% has been achieved for Stockholm and Valencia, respectively. In the rammed earth building, in contrast, the demand has been reduced by 86.3% in Stockholm and 73.9% in Valencia. Heat recovery ventilation and high insulation level have been identified as imperative needs in Stockholm, in contrast to Valencia. Other improvement strategies such as windows substitution, air permeability improvement, or natural ventilation for cooling have been implemented. Apart from that, better performance of the straw-bale buildings has been identified for both climates. Additionally, focusing on thermal inertia, its influence has been identified as not completely significant in terms of annual demand in the simulated climates.

Floating solar technology is relatively new, and it comes with its own set of challenges and opportunities. This master thesis focuses on understanding how Floating Photovoltaic (FPV) projects perform compared to Ground-Based Photovoltaic (GPV) projects, in specific weather conditions. The following work is based on a case study: a floating power plant run by Akuo Energy, where sensors have been installed in order to measure the evolution of relevant physical and weather parameters on-site. Akuo Energy is a French independent renewable energy producer and developer founded in 2007. The company specializes in the development, financing, construction, and operation of renewable energy projects, including wind, solar and storage power plants. It is committed to producing clean, affordable, and reliable energy while promoting sustainable development and supporting local communities. The thesis is conducted within the Solar Technology Team, which centralizes the solar expertise of the company and implements innovative technologies to improve their Photovoltaic (PV) projects’ performances. As the number of FPV projects increases, the team raised the need for better evaluation of their performance compared to a standard GPV project, in terms of output power and energy yield. As it appears in the literature, FPV installations can differ from GPV, due to different operating conditions: power plant designs, module cooling, weather conditions, or degradation rates. These parameters need to be taken into account in the expected energy yield analysis, especially module cooling, since operating temperature has a proved impact on module efficiency. Today, technological and economic considerations on FPV specific design are therefore essential. However, the main solar projects development software PVsyst used at Akuo Energy does not include a default floating solar library. Experimental measurements are a good starting point for understanding how the numerical model needs to evolve to adapt to the FPV system. By examining a practical case and processing historical data, insights on FPV systems and how weather affects their efficiency can be provided. The objective of this thesis is then to better model the FPV array thermal losses due to the cooling effect and better estimate the yield for future Akuo Energy FPV projects during the development phase. / Flytande solteknik är relativt ny och kommer med sina egna utmaningar och möjligheter. Denna masteruppsats fokuserar på att förstå hur FPV-projekt presterar jämfört med GPV-projekt, under specifika väderförhållanden. Följande arbete är baserat på en fallstudie: ett flytande kraftverk som drivs av Akuo Energy, där sensorer har installerats för att mäta utvecklingen av relevanta fysiska parametrar och väderparametrar på plats. Akuo Energy är en fransk oberoende producent och utvecklare av förnybar energi som grundades 2007. Företaget är specialiserat på utveckling, finansiering, konstruktion och drift av projekt för förnybar energi, inklusive vind-, sol- och lagringskraftverk. Det är engagerat i att producera ren, prisvärd och pålitlig energi samtidigt som man främjar hållbar utveckling och stödjer lokala samhällen. Examensarbetet genomförs inom Solar Technology Team, som centraliserar företagets solexpertis och implementerar innovativa teknologier för att förbättraderas PV-projekts prestanda. När antalet FPV-projekt ökar, tog teamet upp behovet av bättre utvärdering av deras prestanda jämfört med ett standard GPV-projekt, vad gäller uteffekt och energiutbyte. Som det framgår av litteraturen kan FPV-installationer skilja sig från GPV på grund av olika driftsförhållanden: kraftverkskonstruktioner, modulkylning, väderförhållanden, eller nedbrytningshastigheter. Dessa parametrar måste beaktas ta hänsyn till den förväntade energiutbytesanalysen, särskilt modulkylning, eftersom driftstemperaturen har en bevisad inverkan på modulens effektivitet. Idag är därför tekniska och ekonomiska överväganden om FPV specifik design viktiga. Emellertid innehåller den huvudsakliga utvecklingsmjukvaran PVsyst för solenergiprojekt som används på Akuo Energy inte ett flytande solcellsbibliotek som standard. Experimentella mätningar är en bra utgångspunkt för att förstå hur den numeriska modellen behöver utvecklas för att anpassa sig till FPV-systemet. Genom att undersöka ett praktiskt fall och bearbeta historiska data kan insikter om FPV-system och hur vädret påverkar deras effektivitet ges. Syftet med denna avhandling är sedan att bättre modellera FPV-matrisens termiska förluster på grund av kyleffekten och bättre uppskatta avkastningen för framtida Akuo Energy FPV-projekt under utvecklingsfasen.

Die fortschreitende Urbanisierung resultiert in zunehmenden Mobilitätsbedürfnissen und infrastrukturellen Herausforderungen für Städte und ländliche Räume. Auf Basis dessen sind Überlegungen entstanden, die das bestehende Mobilitäts- und Transportsystem in Richtung des Luftraums erweitern wollen, was unter der Begrifflichkeit Advanced Air Mobility zusammengefasst werden kann. Dabei werden elektrisch betriebene, senkrecht start- und landende (eVTOL-)Fluggeräte für die Personenbeförderung vorgesehen. Die bevorstehende Integration derartiger Fluggeräte erfordert Infrastrukturen in urbanen und ruralen Gebieten, welche die Schnittstelle zwischen der Land- und Luftseite bilden, analog zu Flughäfen der konventionellen Luftfahrt. Aufgrund fehlender praktischer Erfahrungswerte hinsichtlich operationeller Fähigkeiten der Fluggeräte, betrieblicher Anforderungen der benötigten Bodeninfrastruktur, des Umfangs eines möglichen Flugtaxibetriebs und resultierender Netzwerkgestaltung werden diese spezifischen Herausforderungen innerhalb dieser Arbeit analysiert. Die Netzwerkentwicklung basiert auf drei verschiedenen Datengrundlagen (Verkehrs-/Mobilitätsdaten, bestehende Verkehrsinfrastrukturen in Sachsen und kombinierte Betrachtung von Verkehrs-/Mobilitätsdaten im Kontext bestehender Infrastrukturen), die in jeweils eigenständige Nachfrageschätzungen überführt werden. Die resultierenden Erkenntnisse fließen innerhalb eines p-Hub Single Allocation Problems zusammen, so dass unterschiedliche Netzwerkentwürfe am Beispiel Sachsen in Abhängigkeit der geschätzten Passagierströme entstehen. Für diese Netzwerke werden zukünftige Einsatzmöglichkeiten der genannten Fluggeräte auf Basis bestimmter Energiebedarfe je Netzwerkkante diskutiert. Abschließend erfolgt eine Schätzung maximaler Reichweiten für die Kategorien Vectored Thrust, Lift & Cruise und Multicopter in Abhängigkeit zu Abfluggewichten (Auslastung), vertikalen Verweildauern der Fluggeräte und möglichen spezifischen Energiedichten der Batterieeinheiten in den Fluggeräten. Diese Arbeit liefert erste nachvollziehbare Erkenntnisse zur Vorbereitung eines zukünftigen Flugtaxibetriebs und thematisiert durch die Berücksichtigung von bereits versiegelten (Verkehrs-)Flächen gleichzeitig eine möglichst bedarfs- und stadtgerechte Integration dieses neuen Verkehrsträgers in bestehende Mobilitätssysteme. / The advancing process of urbanization leads to increasing mobility demands and infrastructural challenges for both urban and rural areas. Consequently, considerations have emerged to expand the existing mobility and transportation system towards the airspace, encapsulated under the term Ädvanced Air Mobility'(AAM). This involves the provision of electrically powered, vertical take-off and landing (eVTOL) aircraft for passenger transportation. The forthcoming integration of such aircraft necessitates infrastructures in urban and rural areas, serving as the interface between the land and air domains, akin to airports in conventional aviation. Due to the lack of practical experience regarding the operational capabilities of these aircraft, operational requirements of the necessary ground infrastructure, the scale of potential air taxi operations, and resulting network design, these specific challenges are analyzed within this study. The network development relies on three different sets of data (traffic/mobility data, existing transportation infrastructures in Saxony, and combined analysis of traffic/mobility data in the context of existing infrastructures), each translated into independent demand estimations. The resulting insights are synthesized within a p-Hub Single Allocation Problem framework, generating various network designs for the case of Saxony depending on estimated passenger flows. For these networks, future applications of the mentioned aircraft are discussed based on specific energy requirements per network edge. Finally, maximum range estimations are provided for Vectored Thrust, Lift & Cruise, and Multicopter categories, depending on takeoff weights (occupancy), vertical dwell times of the aircraft, and potential specific energy densities of battery units in the aircraft. This study delivers initial comprehensible insights to prepare for future air taxi operations, simultaneously addressing, through the consideration of already sealed (transport) areas, the most demand- and city-appropriate integration of this new mode of transportation into existing mobility systems.

In this work, we focus on enhancing the efficacy of predictive modeling in operational management decision making in two different settings: Essay 1 focuses on demand forecasting for the companies and the second study utilizes longitudinal data to analyze the illicit drug seizure and overdose deaths in the United States. In Essay 1, we utilize an operational system (newsvendor model) to evaluate the forecast method outcome and provide guidelines for forecast method (the exponential smoothing model) performance assessment and judgmental adjustments. To assess the forecast outcome, we consider not only the common forecast error minimization approach but also the profit maximization at the end of the forecast horizon. Including profit in our assessment enables us to determine if error minimization always results in maximum profit. We also look at the different levels of profit margin to analyze their impact on the forecasting method performance. Our study also investigates how different demand patterns influence maximizing the forecasting method performance. Our study shows that the exponential smoothing model family has a better performance in high-profit products, and the rate of decrease in performance versus demand uncertainty is higher in a stationary demand environment.In the second essay, we focus on illicit drug overdose death rate. Illicit drug overdose deaths are the leading cause of injury death in the United States. In 2017, overdose death reached the highest ever recorded level (70,237), and statistics show that it is a growing problem. The age adjusted rate of drug overdose deaths in 2017 (21.7 per 100,000) is 9.6% higher than the rate in 2016 (19.8 per 100,000) (U. S. Drug Enforcement Administration, 2018, p. V). Also, Marijuana consumption among youth has increased since 2009. The magnitude of the illegal drug trade and its resulting problems have led the government to produce large and comprehensive datasets on a variety of phenomena relating to illicit drugs. In this study, we utilize these datasets to examine how marijuana usage among youth influence excessive drug usage. We measure excessive drug usage in terms of drug overdose death rate per state. Our study shows that illegal marijuana consumption increases excessive drug use. Also, we analyze the pattern of most frequently seized illicit drugs and compare it with drugs that are most frequently involved in a drug overdose death. We further our analysis to study seizure patterns across layers of heroin and cocaine supply chain across states. This analysis reveals that most active layers of the heroin supply chain in the American market are retailers and wholesalers, while multi-kilo traffickers are the most active players in the cocaine supply chain. In summary, the studies in this dissertation explore the use of analytical, descriptive, and predictive models to detect patterns to improve efficacy and initiate better operational management decision making.

The present thesis addresses the issue of the impact of two independent variables - speech rate and interpreters' experience - on the length of time lag in simultaneous interpreting from English to Czech. Time lag, or ear-voice-span (EVS), in simultaneous interpreting is the time difference between the input in source language and the output in target language. The study comprises of two parts. The first, theoretical part summarises the current state of research on the subject. The second, empirical part compares the average EVS in excerpts of sixty simultaneous interpreting renditions uttered by forty-nine subjects divided into two speech rate categories and three experiential categories. The aim is to find out, firstly, whether there are any differences in EVS length based on speech rate, and, secondly, how the interpreters' level of experience influences their EVS length. The first main finding is that a higher speech rate leads, on average, to a shorter EVS than an optimal speech rate; this does not, however, apply in the case of professional interpreters - their EVS length is not affected by speech rate. The second main finding is that the interpreters' level of experience influences EVS length significantly: the more experienced the subjects, the shorter their EVS on average. While evaluating...

The study identifies how different stakeholders perceive service quality improvement initiatives in public higher education institutions in Ethiopia. For this purpose, a mixed research methodology was employed. Furthermore, secondary data were collected from a variety of literature and primary data were collected from academic staff and final year students at public higher education institutions using the SERVQUAL scale and through focus group interviews. The collected data were analysed using both descriptive and inferential statistics. The research findings indicated that all dimensions of the service quality improvement initiatives were perceived by academic staff and studentsto be verypoor. The reasons for these poor or low perceptions were: the high expectationsof the stakeholders, the government’s intention to expand, lack of adequate knowledge regarding the implementation of the BPR process, the lack of motivation by service providers, poor management and the lack of good governance by the universities, inexperienced workers, non-empowered and task specific frontline employees, the low quality of the infrastructure, non-value adding hierarchical structures and approval systems, ethical problems with some service providers, the high staff turnoverand the lack of experienced staff. In addition, at all new universities, construction is underway and as a result,there are problems such as the poor state of the dormitories, classes,bathrooms, recreation areas, lounges, TV rooms, sport fields and internet connectivity, while the libraries are not well stocked with books and periodicals either. This study has recommended that the institutions should have standardised instruments that can be used to measure the status of service quality improvement and deliveryperiodically and to identify the areas that have the highest perceived performance gap scores in order to redeploy some of the resources. It also needs to be pointed out that the service providers lack sufficient knowledge and skillsconcerning the implementation of BPR, thus training is recommended in this regard.It is further recommended that for effective implementation of the BPR process, the importance of the provision of different guiding documents, continuous monitoring of activities and top management support should be kept in mind. / Educational Leadership and Management / D. Ed. (Educational Management)

In order to efficiently utilize the scarce wireless resource as well as keep up with the ever-increasing demand for Quality-of-Service (QoS) of multimedia applications, wireless networks are undergoing rapid development and dramatic changes in the underlying technologies and protocols. The Medium Access Control (MAC) protocol, which coordinates the channel access and data transmission of wireless stations, plays a pivotal role in wireless networks. Performance modelling and analysis has been and continues to be of great theoretical and practical importance in the design and development of wireless networks. This research is devoted to developing efficient and cost-effective analytical tools for the performance analysis and enhancement of MAC protocols in Wireless Local Area Networks (WLANs) under heterogeneous multimedia traffic. To support the MAC-layer QoS in WLANs, the IEEE 802.11e Enhanced Distributed Channel Access (EDCA) protocol has proposed three QoS differentiation schemes in terms of Arbitrary Inter-Frame Space (AIFS), Contention Window (CW), and Transmission Opportunity (TXOP). This research starts with the development of new analytical models for the TXOP scheme specified in the EDCA protocol under Poisson traffic. A dynamic TXOP scheme is then proposed to adjust the TXOP limits according to the status of the transmission queue. Theoretical analysis and simulation experiments show that the proposed dynamic scheme largely improves the performance of TXOP. To evaluate the TXOP scheme in the presence of ii heterogeneous traffic, a versatile analytical model is developed to capture the traffic heterogeneity and model the features of burst transmission. The performance results highlight the importance of taking into account the heterogeneous traffic for the accurate evaluation of the TXOP scheme in wireless multimedia networks. To obtain a thorough and deep understanding of the performance attributes of the EDCA protocol, a comprehensive analytical model is then proposed to accommodate the integration of the three QoS schemes of EDCA in terms of AIFS, CW, and TXOP under Poisson traffic. The performance results show that the TXOP scheme can not only support service differentiation but also improve the network performance, whereas the AIFS and CW schemes provide QoS differentiation only. Moreover, the results demonstrate that the MAC buffer size has considerable impact on the QoS performance of EDCA under Poisson traffic. To investigate the performance of EDCA in wireless multimedia networks, an analytical model is further developed for EDCA under heterogeneous traffic. The performance results demonstrate the significant effects of heterogeneous traffic on the total delay and frame losses of EDCA with different buffer sizes. Finally, an efficient admission control scheme is presented for the IEEE 802.11e WLANs based on analytical modelling and a game-theoretical approach. The admission control scheme can maintain the system operation at an optimal point where the utility of the Access Point (AP) is maximized with the QoS constraints of various users.

<p>Network on Chip is a scalable and flexible communication infrastructure for the design of core based System on Chip. Communication performance of a NoC depends heavily on the routing algorithm. Deterministic and adaptive distributed routing algorithms have been advocated in all the current NoC architectural proposals. In this thesis we make a case for the use of source routing for NoCs, especially for regular topologies like mesh. The advantages of source routing include in-order packet delivery; faster and simpler router design; and possibility of mixing non-minimal paths in a mainly minimal routing. We propose a method to compute paths for various communications in such a way that traffic congestion is avoided while ensuring deadlock free routing. We also propose an efficient scheme to encode the paths.</p><p>We developed a tool in Matlab that computes paths for source routing for both general and application specific communications. Depending upon the type of traffic, this tool computes paths for source routing by selecting best routing algorithm out of many routing algorithms. The tool uses a constructive path improvement algorithm to compute paths that give more uniform link load distribution. It also generates different types of traffics. We also developed a simulator capable of simulating source routing for mesh topology NoC. The experiments and simulations which we performed were successful and the results show that the advantages of source routing especially lower packet latency more than compensate its disadvantages. The results also demonstrate that source routing can be a good routing candidate for practical core based SoCs design using network on chip communication infrastructure.</p>