A number of interventional procedures such as cardiac catheterization, angiography and the deployment of endovascular devices are routinely performed using x-ray fluoroscopy. To minimize the patient’s exposure to ionizing radiation, each fluoroscopic image is acquired using a very low x-ray exposure (~ 1 uR at the detector). At such an exposure, most semiconductor-based digital flat panel detectors (FPD) are not x-ray quantum noise limited (QNL) due to the presence of electronic noise which substantially degrades their imaging performance. The goal of this thesis was to investigate how a FPD based on amorphous selenium (a-Se) with internal avalanche multiplication gain could be used for QNL fluoroscopic imaging at the lowest clinical exposures while satisfying all of the requirements of a FPD for interventional radiology. Towards this end, it was first determined whether a-Se can reliably provide avalanche multiplication gain in the solid-state. An experimental method was developed which enabled the application of sufficiently large electric field strengths across the a-Se. This method resulted in avalanche gains as high as 10000 at an applied field of 105 V/um using optical excitation. This was the first time such high avalanche gains have been reported in a solid-state detector based on an amorphous material. Secondly, it was investigated how the solid-state a-Se avalanche detector could be used to image X-rays at diagnostic radiographic energies (~ 75 kVp). A dual-layered direct-conversion FPD architecture was proposed. It consisted of an x-ray drift region and a charge avalanche multiplication region and was found to eliminate depth-dependent gain fluctuation noise. It was shown that electric field strength non-uniformities in the a-Se do not degrade the detective quantum efficiency (DQE). Lastly, it was determined whether the solid-state a-Se avalanche detector satisfies all of the requirements of interventional radiology. Experimental results have shown that the total noise produced by the detector is negligible and that QNL operation at the lowest fluoroscopic exposures is indeed possible without any adverse effects occurring at much larger radiographic exposures. In conclusion, no fundamental obstacles were found preventing the use of avalanche a-Se in next-generation solid-state QNL FPDs for use in interventional radiology.

Paskutiniais metais aktualiu klausimu tampa inovacijų modeliavimas. Pasirodant kiekvienai naujovei, verslininkams reikia suprasti ir prognozuoti rinkos vystymąsi, kad galėtų numatyti pardavimų eigą, planuoti pardavimų kiekius ir atlikti finansinį planavimą. Šiame darbe tyrinėsime kompiuterių skverbties koeficientus (penetration rate) 23 skirtingose pasaulio šalyse ir mėginsime parinkti geriausiai prognozavimui tinkantį modelį. Skverbties koeficientas paprastai parodo prekės ženklo ar produkto kategorijos populiarumą. Jis apskaičiuojamas dalinant žmonių, kurie perka kažkokią prekę ar paslaugą, skaičių iš tos rinkos visos populiacijos skaičiaus tam tikru periodu. Taigi, skverbties koeficientas yra procentas žmonių populiacijoje, kurie per stebimą periodą nusipirko tam tikrą prekę ar paslaugą. Marketinge dažnai yra spendžiama problema: didinti pardavimus stengiantis privilioti klientus iš konkurentų ar plečiant potencialių pirkėjų populiaciją, t.y. einant į naujas rinkas. Darbo pradžioje bus pristatyti panelinių duomenų vertinimo būdai, analizei reikalinga teorinė dalis, kai kurių reikalingų statistikų skaičiavimas. Vėliau pereisime prie pagrindinės darbo dalies - geriausio modelio parinkimo. Pirmiausia bus nagrinėjami paprasčiausi tiesinio trendo modeliai, įtraukiant autoregresijos procesą bei egzogeninius kintamuosius. Toliau įvairiais metodais mėginsime modeliuoti difuzijos procesą. Bandysime jį aproksimuoti kvadratiniu trendu, taikyti logistinį bei Gompertz modelius ir... [toliau žr. visą tekstą] / Lately the modelling of innovation process is a constantly recurring problem. As with any new service for managers it is important to understand and to able to forecast the market developement for strategic, capacity and financial planning purposes. This master thesis analyses computer penetration data in 23 different countries and tries to propose the best fitting model for forcasting. Penetration rate usually shows the popularity of a brand or a product. It is given as a percentage of the countries’ households who have bought that particular brand or product at least once within a defined period of time. In marketing there is a decision to make: enlarge sales by trying to attract more costumers in the sales region or by expanding the population of potential buyers, i.e. by expanding to other emerging markets. In the beginning of this thesis we will introduce some basic information about the panel data and some approaches of the theory needed for estimation. Later on we will pass to the main part of the work which is devoted to choosing the model. At first, we analyze some linear trend models with autoregression terms and exogenous variables. Then we examine a diffusion process by approximating it with a quadratic trend, logistic and Gompertz models. Also some basic information about the Bass diffusion model will be provided.

This thesis focuses on the relationship between trade and FDI in the SADC. While FDI is seen as a stimulus for growth and development, Africa is lagging behind other regions in attracting FDI. Whilst a number of reasons have been explored in the literature, the potential link between trade and FDI has not been explored in the African context. This may be potentially important, since African governments have been engaging in trade liberalisation and trade promotion over the past two decades. In this thesis, gravity modelling is used to investigate the trade-FDI relationship. Two single equation regression models are used in a preliminary investigation to evaluate aggregate trade and FDI. The third model consists of six panel regressions that evaluate the different relationships between the individual SADC countries and their individual major trading partners. A causality test is also carried out to confirm the relevance of trade as a determinant of FDI in the SADC. Overall results indicate that, in the specific case of the SADC, SADC exports significantly cause FDI. Distance from home countries and political instability are the most significant negative forces that affect FDI inflows. Home country exports deliver mixed results and these results suggest that the United States and the United Kingdom have a different FDI-trade relationship with the SADC than continental Europe, whereas Japan's exports prove insignificant. The policy implications are that the SADC will need to focus on attracting investment from countries that provide for complementary FDI and trade as this is optimal for poverty alleviation and job creation. Further research should focus on these policy areas and take into account the relevance of trade as a determinant of FDI. / Thesis (Ph.D. (Economics))--North-West University, Potchefstroom Campus, 2007.

A number of interventional procedures such as cardiac catheterization, angiography and the deployment of endovascular devices are routinely performed using x-ray fluoroscopy. To minimize the patient’s exposure to ionizing radiation, each fluoroscopic image is acquired using a very low x-ray exposure (~ 1 uR at the detector). At such an exposure, most semiconductor-based digital flat panel detectors (FPD) are not x-ray quantum noise limited (QNL) due to the presence of electronic noise which substantially degrades their imaging performance. The goal of this thesis was to investigate how a FPD based on amorphous selenium (a-Se) with internal avalanche multiplication gain could be used for QNL fluoroscopic imaging at the lowest clinical exposures while satisfying all of the requirements of a FPD for interventional radiology. Towards this end, it was first determined whether a-Se can reliably provide avalanche multiplication gain in the solid-state. An experimental method was developed which enabled the application of sufficiently large electric field strengths across the a-Se. This method resulted in avalanche gains as high as 10000 at an applied field of 105 V/um using optical excitation. This was the first time such high avalanche gains have been reported in a solid-state detector based on an amorphous material. Secondly, it was investigated how the solid-state a-Se avalanche detector could be used to image X-rays at diagnostic radiographic energies (~ 75 kVp). A dual-layered direct-conversion FPD architecture was proposed. It consisted of an x-ray drift region and a charge avalanche multiplication region and was found to eliminate depth-dependent gain fluctuation noise. It was shown that electric field strength non-uniformities in the a-Se do not degrade the detective quantum efficiency (DQE). Lastly, it was determined whether the solid-state a-Se avalanche detector satisfies all of the requirements of interventional radiology. Experimental results have shown that the total noise produced by the detector is negligible and that QNL operation at the lowest fluoroscopic exposures is indeed possible without any adverse effects occurring at much larger radiographic exposures. In conclusion, no fundamental obstacles were found preventing the use of avalanche a-Se in next-generation solid-state QNL FPDs for use in interventional radiology.

Universiẗat, Diss.--Erlangen-Nürnberg.

Sverige är ett av de länderna som har haft en väldigt kraftig uppgång på bostadspriserna de senaste åren enligt Statistiska centralbyråns (SCB) siffror. Utvecklingen har inte endast påverkat huvudstaden utan även andra städer i landet. Faktorerna bakom prisuppgången må vara många men studiens syfte är att uppskatta sambandet mellan bestämningsfaktorerna: befolkningstäthet, förvärvsinkomst, nyproducerade bostadsrätter i förhållande till folkmängd, bolåneränta samt arbetslöshet med bostadsrättspriserna. Fokus kommer ligga på storstadsregionerna Stor-Stockholm, Stor-Göteborg och Stor-Malmö mellan år 2008-2016. Bostadspriserna analyseras ur ett grundläggande nationalekonomiskt perspektiv och undersökningen har formats med hänsyn till det statistiska materialet som funnits åtkomligt, för att testas med hjälp av paneldata där fixed effect har innefattas. Studien omfattar 45 kommuner med en tidsperiod på 9 år och mängden observationer uppgår till 405, där datamaterialet bedöms vara komplett utan några bortfall under tidsperioden, det vill säga balanserad. Studiens resultat visar ett positivt samband mellan befolkningstäthet och bostadsrättspriserna, en ökning med en invånare per ökar bostadspriserna med 15,8 kr per kvm, såvida de andra variablerna hålls konstanta (modell 7). Regressionresultatet visar på att befolkningstätheten är den faktor som har den främsta påverkan på bostadsrättspriserna i jämförelse med studiens övriga faktorer. Resultatet påvisar även ett positivt samband mellan förvärvsinkomst och bostadspriserna samt ett negativt samband mellan faktorerna arbetslöshet och ränta på bostadsrättspriserna i samtliga modeller. Däremot visar nyproduktionen ett oväntat resultat. Studien skall bland annat bidra till en ökad förståelse för sambandet mellan de utvalda bestämningsfaktorerna och dess inverkan på bostadspriserna. Vidare är studiens källor tillförlitliga och har en stark validitet som ger en ökad förståelse för sambandet. / Sweden is one of the countries that has had a very strong increase in the housing prices during the recent years according to SCB’s calculations. The development has not only been seen in Stockholm but it has also affected the smaller cities as well. The factors behind the massive price increases may be many, but the purpose of the essay has been to estimate the relationship between the factors: population density, income, new constructed condominiums in relation to the population, interest rate and unemployment have on condominiums rates. The main focus will lay on the following big cities, Stockholm, Gothenburg and Malmö from the years of 2008-2016. The housing prices will be analyzed from an economic perspective. Further, the study has been formed by the statistical material that has been accessible and then been tested using panel data that includes fixed effect. The study encompasses 45 municipalities with a time period of 9 years (2008-2016) which comprises to 405 observations, where the data is strongly balanced, meaning that the database is complete. The result of the essay shows a positive correlation between population density and housing prices, an increase of one inhabitant per increases housing prices by 15.8 kr per square meter, if all the other variables are hold constant (model 7). The regression results indicate that population density is the factor that has the main impact on housing prices in comparison to all other factors. The results also shows a positive correlation between income and housing prices, as well as a negative correlation between the factors unemployment and the interest rate on housing prices in all models. On the other hand, new production shows an unexpected result. Furthermore, the essay considered to contribute to a better understanding of the relationship between the selected factors and its impact on the housing prices in Sweden's three largest cities, Stockholm, Gothenburg and Malmö during the period 2008-2016.

The topic of this publication is a comparison of insulated sandwich panels and materials of organic origin - wood based materials. There were compared insulative properties, lifetime and finacial costs of these materials.

A utilização de tecnologias construtivas inovadoras, como os painéis pré-fabricados arquitetônicos de concreto (PPAC), tem-se configurado prática frequente do mercado brasileiro por, potencialmente, contribuir para incrementar os níveis de industrialização dos processos de produção, bem como a qualidade do produto final a custos reduzidos. No Brasil, entretanto, não existem ainda normas ou manuais técnicos que balizem a utilização dessa tecnologia construtiva. Por isso, este trabalho sistematiza o conhecimento sobre a tecnologia de PPAC para emprego em fachadas de edifícios de múltiplos pavimentos, por meio da apresentação dos principais fatores que devem ser considerados nas fases de elaboração dos projetos de empreendimentos que utilizem os PPAC em suas fachadas. Fatores esses, que condicionam o desempenho e a eficiência do processo de produção das fachadas. Após o acompanhamento do processo de produção de dois empreendimentos que utilizaram PPAC em suas fachadas, constituindo os estudos de caso, conclui-se que a tecnologia de PPAC apresenta grande potencial para incrementar os níveis de industrialização do processo de produção do edifício, se a elaboração dos seus projetos ocorrer nas fases preliminares da concepção do empreendimento, em que suas funções e interfaces sejam consideradas. / The arquitectural precast concrete panel technology has frequently been used because of its probability of increasing the industrialization levels of the building process and also improve the building product quality. On the other hand, mostly in Brasil, there are no rules ou manual books which guide the utilization of this technology. In addition, this works aims to raise the knowledge about the arquitectural precast concrete panel used as cladding (APCP-PPAC in Portuguese). Therefore, this works presents some factors that must be considered in designs of building facades, using this kind of technology. After the analysis of one study case using APCP, it was concluded that APCP technology has a great potential of increasing the industrialization levels of the building process, if its designs are done as soon as possible and if its performance and interfaces are considered.

The diploma work deals with chemical composition of photovoltaic panels and assessment of their environmental risks. In its introduction part, the characterization of photovoltaic panels, including the composition of their layers and the significance of some specific metals in these facilities, is summarized. The introduction part also mentions the life cycle of photovoltaic panels from production to end of life. The experimental part is focused on chemistry of several different types of photovoltaic panels. In addition to the major elements of the panels (Si, Al, Fe, Na, Ca), the analyzes confirmed the increased content of interest metals (especially Cu, Ag, Sb, Sn, Zn, Pb) at tens to thousands of mg/kg depending on the processed sample. A potentially economically interesting value is Ag. The Ag concentrations range from hundreds to 1,300 mg/kg (~ 1,200 g Ag / t of panels) for some types of processed samples. High concentrations exhibit Cu (up to 16,700 mg/kg), Sb (up to 1,890 mg/kg) or Sn (up to 2050 mg/kg). Leaching experiments (using deionized water and EDTA reagents) were performed at two time intervals (24 and 168 hours). Very low leachability of the metals from the studied samples (in order of per mil or less) has been demonstrated. The studied samples of photovoltaic panels can be classified...

The diploma thesis is focused on the evaluation of a photovoltaic power plant in the company premises. The first chapters briefly discuss the theory of electricity generation using photovoltaic panels. It describes the principle of operation of photovoltaic panels, history, production, etc. In the practical part of the thesis we focus on the evaluation of the company's photovoltaic power plant when comparing real data with simulations.