Diese Arbeit beschäftigt sich dem Thema Studienfinanzierung. Zuerst richtet sich der Fokus auf die Analyse des Gutes Hochschulausbildung. Anschließend werden die Finanzierungsmöglichkeiten der Studierenden aufgezeigt, wobei den Krediten eine besondere Aufmerksamkeit zukommt. Die Analyse der Finanzierungssysteme in den USA und Australien ist ebenfalls Bestandteil der vorliegenden Arbeit. Hier richtet sich das Augenmerk auf die Entwicklung der Studiengebühren und die angebotenen Finanzierungsmöglichkeiten. Daran anschließend erfolgt eine Darstellung der Auswirkungen des jahrelang gebührenfrei angebotenen Hochschulstudiums in Deutschland. In diesem Zusammenhang werden die Finanzierungsstruktur deutscher Hochschulen, die soziale Zusammensetzung der Studierenden und die Akademikerquote beleuchtet. Zum Abschluss erfolgt eine empirische Untersuchung der Lebenseinkommen verschiedener Bildungsgruppen in Deutschland und damit verbunden eine Berechnung der Bildungsrenditen bestimmter Ausbildungsniveaus. / This work is directed at the theme financing of higher education. The first view goes to the analysis of the good higher education. Following, the ways of financing higher Education will be presented, in which the loans play a particular role. The breakdown of the financing schemes in the USA and Australia is a part of this work as well. In this section the history of tuition fees and the offered financing proposals are disclosed. Afterwards a presentation of the impacts of the long lasting tuition free higher education in Germany occurs. In this context the financing structure in German universities, the social composition of students at German universities and the percentage of graduates are outlined. An empirical analysis of the lifetime income from different education groups and the calculation of education returns of particular education levels in Germany conclude this work.

The paper is based on an individual life-cycle model, which describes the purely economic components of human capital. The present value of human capital is determined by all future income flows, which at the same time constitute the individual as well as the total tax base of a nation. Therefore, the income of the productive population determines the total tax revenue, which is spent for public goods (including education) and transfers (for poverty reduction). The efficient design of the education system (by private and public education investments) determines the quality of the human capital stock as well as the future gross income flows. The costs of public goods and the transfer expenditures have to be financed from the total tax revenue, which also affects the individual tax burden via the specific tax bases and tax rates. Especially the redistribution of income is connected with serious disincentives, influencing the preferences for work and leisure as well as for consumption and saving. An efficient tax and transfer system being accompanied by an education system financed in public private partnership, which treats equally labor and capital income, sets positive incentives for the formation of human, financial, and real capital. An important prerequisite for a sustainable growth process is the efficient design of the social security system, being based on the family as well as a collective risk equalization scheme. If that system is diminishing absolute poverty in an appropriate time period by transfers and vocational education measures for the grown-up as well as high quality primary, secondary and tertiary education programs for the children, the transfer expenditure would decrease and the tax bases (income and consumption) increase, lowering the burden on the productive population. For the first time, this micro model presented in this paper pools all the relevant variables for development within a simple life-cycle model, which can also be used for a powerful analysis of the current failures in existing tax and transfer schemes and fruitful empirical investigations. Hence, an efficient tax and transfer scheme strongly contributes to an improved national position in the global competition.

Cu(In,Ga)Se2 (CIGS) is one of the most promising semiconductor compounds for large-scale production of efficient, low-cost thin film solar cells, and several research institutes have announced their plans for CIGS production lines. But for the CIGS technology to become a commercial success, a number of issues concerning manufacturability, product definition, and long-term stability require further attention. Several studies indicate that CIGS-based modules are stable over many years in field operation. At the same time, it is shown in the present work that they may have difficulties in passing standard accelerated lifetime test procedures like the IEC 1646 damp heat test. In particular, CIGS modules are sensitive to humidity penetrating through the module encapsulation, which will increase the resistive losses in the front contact and cause severe corrosion of the back contact. It is also shown that cells experience degradation in both voltage and fill factor, and the causes of these effects are addressed. By concentrating the light falling onto a solar cell, the device will deliver a higher power output per illuminated absorber area, which can lower the electricity production costs. For CIGS-based solar cells, low-concentrated illumination could be an economically viable approach. In this work it is shown that the yearly performance of a photovoltaic system with CIGS modules can be significantly improved at a moderate cost by using parabolic aluminum mirrors as concentrating elements. However, in order to avoid detrimental power losses due to high temperatures and current densities, the modules need to be designed for the higher light intensity and to be sufficiently cooled during operation. A design where the front contact of the module is assisted by a metal grid has shown promising results, not only for concentrated illumination but also for normal operation. The benefits are enhanced window processing tolerance and throughput, as well as improved degrees of freedom of the module geometry.

Varje dag använder sig miljontals svenskar av någon form av medlems- eller kundklubbskort när de handlar i butik, kontaktar en kundtjäst eller loggar in på ett företags hemsida. Motiven till detta kan förstås vara olika - det kan vara smidigt, lönsamt eller nödvändigt för att överhuvudtaget få den hjälp och service man önskar. För företagen är denna registrering å andra sidan ett effektivt sätt att samla information om sina kunder som ett led i deras lojalitetsskapande arbete mot kund. Tidigare, internationella studier av CRM visar dock på att företagen inte utnyttjar den information de har om kunder för att verkligen styra verksamheten. Syftet med denna uppsats är att studera om detta är ett aktuellt problem även bland svenska företag genom en enkätundersökning riktad till CRM- och kundklubbsansvariga vid svenska företag. Denna undersökning har utarbetats utifrån Cuthbertsons tre kriterier för att avgöra om en organisation är kundorienterade eller ej. Resultat visar att de flesta företag som deltog i studien inte använder informationen man samlar in från kunderna i någon större utsträckning. Däremot visar resulataten att företag med äldre kundklubbar samt med höga medlemsantal generellt är bättre på att sprida och använda den kunskap som kundklubben samlar in. Skälen till att kundinformation inte används i större utsträckning beror enligt vår analys på frånvaron av fungerande intern infrastrauktur för att sprida inhämtad kunddata, kundklubben har för få medlemmar och låg ålder vilket påverkar dess interna status samt att kundklubben främst betraktas som ett register för riktad marknadsföring snarare än som ett redskap för att styra företagens verksamhet i stort.

This study aim at investigating whether income inequality ceteris paribus is a determinant of population health measured by infant mortality rate and average expected lifetime. Earlier research has found results pointing in different directions but the income inequality hypothesis suggests that income inequality alone is something bad for the population. The study uses data on income distribution from the Luxembourg Income Study (LIS) and the World Income Inequality Database (WIID). Data on economic development and health indicators comes from the OECD database. An econometric model which applies country fixed effects is specified and the results indicates no effect from income inequality on infant mortality rate but some indications of a negative effect on average expected lifetime.

Wireless sensor networks are made up of a large number of sensors deployed randomly in an ad-hoc manner in the area/target to be monitored. Due to their weight and size limitations, the energy conservation is the most critical issue. Energy saving in a wireless sensor network can be achieved by scheduling a subset of sensor nodes to activate and allowing others to go into low power sleep mode, or adjusting the transmission or sensing range of wireless sensor nodes. In this thesis, we focus on improving the lifetime of wireless sensor networks using both smart scheduling and adjusting sensing ranges. Firstly, we conduct a survey on existing works in literature and then we define the sensor network lifetime problem with range assignment. We then propose two completely localized and distributed scheduling algorithms with adjustable sensing range. These algorithms are the enhancement of distributed algorithms for fixed sensing range proposed in the literature. The simulation results show that there is almost 20 percent improvement of network lifetime when compare with the previous approaches.

Mn-doped II-VI semiconductor nanocrystals exhibit bright dopant photoluminescence that has potential usefulness for light emitting devices, temperature sensing, and biological imaging. The bright luminescence comes from the 4T1→6A1 transition of the Mn2+ d electrons after the exciton-dopant energy transfer, which reroutes the exciton relaxation through trapping processes. The driving force of the energy transfer is the strong exchange coupling between the exciton and Mn2+ due to the confinement of exciton in the nanocrystal. The exciton-Mn spatial overlap affecting the exchange coupling strength is an important parameter that varies the energy transfer rate and the quantum yield of Mn luminescence. In this dissertation, this correlation is studied in radial doping location-controlled Mn-doped CdS/ZnS nanocrystals. Energy transfer rate was found decreasing when increasing the doping radius in the nanocrystals at the same core size and shell thickness and when increasing the size of the nanocrystals at a fixed doping radius. In addition to the exciton-Mn energy transfer discussed above, two consecutive exciton-Mn energy transfers can also occur if multiple excitons are generated before the relaxation of Mn (lifetime ~10^-4 - 10^-2 s). The consecutive exciton-Mn energy transfer can further excite the Mn2+ d electrons high in conduction band and results in the quenching of Mn luminescence. The highly excited electrons show higher photocatalytic efficiency than the electrons in undoped nanocrystals. Finally, the effect of local lattice strain on the local vibrational frequency and local thermal expansion was observed via the temperature-dependent Mn luminescence spectral linewidth and peak position in Mn-doped CdS/ZnS nanocrystals. The local lattice strain on the Mn2+ ions is varied using the large core/shell lattice mismatch (~7%) that creates a gradient of lattice strain at various radial locations. When doping the Mn2+ closer to the core/shell interface, the stronger lattice strain softens the vibrational frequency coupled to the 4T1→6A1 transition of Mn2+ (Mn luminescence) by ~50%. In addition, the lattice strain also increases the anharmonicity, resulting in larger local thermal expansion observed from the nearly an order larger thermal shift of the Mn luminescence compared to the Mn-doped ZnS nanocrystals without the core/shell lattice mismatch.

The degradation of aging energy infrastructure systems has the potential to increase the risk of failure, resulting in power outage and costly unplanned maintenance work. Therefore, the development of scientific and cost-effective life cycle management (LCM) strategies has become increasingly important to maintain energy infrastructure. Since degradation of aging equipment is an uncertain process which depends on many factors, a risk-based approach is required to consider the effect of various uncertainties in LCM. The thesis presents probabilistic models to support risk-based life cycle management of energy infrastructure systems. In addition to uncertainty in degradation process, the inspection data collected by the energy industry is often censored and truncated which make it difficult to estimate the lifetime probability distribution of the equipment. The thesis presents modern statistical techniques in quantifying uncertainties associated with inspection data and to estimate the lifetime distributions in a consistent manner. Age-based and sequential inspection-based replacement models are proposed for maintenance of component in a large-distribution network. A probabilistic lifetime model to consider the effect of imperfect preventive maintenance of a component is developed and its impact to maintenance optimization is illustrated. The thesis presents a stochastic model for the pitting corrosion process in steam generators (SG), which is a serious form of degradation in SG tubing of some nuclear generating stations. The model is applied to estimate the number of tubes requiring plugging and the probability of tube leakage in an operating period. The application and benefits of the model are illustrated in the context of managing the life cycle of a steam generator.

The degradation of aging energy infrastructure systems has the potential to increase the risk of failure, resulting in power outage and costly unplanned maintenance work. Therefore, the development of scientific and cost-effective life cycle management (LCM) strategies has become increasingly important to maintain energy infrastructure. Since degradation of aging equipment is an uncertain process which depends on many factors, a risk-based approach is required to consider the effect of various uncertainties in LCM. The thesis presents probabilistic models to support risk-based life cycle management of energy infrastructure systems. In addition to uncertainty in degradation process, the inspection data collected by the energy industry is often censored and truncated which make it difficult to estimate the lifetime probability distribution of the equipment. The thesis presents modern statistical techniques in quantifying uncertainties associated with inspection data and to estimate the lifetime distributions in a consistent manner. Age-based and sequential inspection-based replacement models are proposed for maintenance of component in a large-distribution network. A probabilistic lifetime model to consider the effect of imperfect preventive maintenance of a component is developed and its impact to maintenance optimization is illustrated. The thesis presents a stochastic model for the pitting corrosion process in steam generators (SG), which is a serious form of degradation in SG tubing of some nuclear generating stations. The model is applied to estimate the number of tubes requiring plugging and the probability of tube leakage in an operating period. The application and benefits of the model are illustrated in the context of managing the life cycle of a steam generator.

Advances in micro-sensor and wireless technology enable small but smart sensors to be developed for wide range environment-monitor applications. Since Sensor nodes only have limited power capacity and are difficult to recharge, how to prolong network lifetime is an important issue in wireless sensor networks design. Several topology control algorithms have been proposed to maintain the connectivity of wireless sensor network and reduce the energy consumption. Multi-hop Infrastructure Network Architecture (MINA) is a kind of Multi-layer Architecture for WSN topology, which utilizes hundred of sensors to transmit data to a sink. This architecture partitions sensor nodes into layers based on their distances (calculated by hop count) to BS. In this way, the node connected to more nodes will relay more data for other nodes. This make the node exhaust its battery power quickly and thus reduces the network lifetime. This study proposes an Efficient Energy Time-Slot Allocation (EETA) scheme which distributes time slots in accordance with the energy of neighbor nodes and the number of neighbor nodes. In addition, this work also devises an adaptive time slot size to reduce data packet drop in case when the node buffer is full. The simulation results show that the EETA performs better than the MINA in terms of network lifetime.