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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.
301

Studium interakce houby Pleurotus ostreatus a bakteriálních kultur na abiotickém nosiči - morfologická, biochemická a proteomická analýza / Study of the interaction between fungus Pleurotus ostreatus and bacterial cultures on the abiotic surfaces - morphological, biochemical and proteomic analysis

Kozická, Barbora January 2015 (has links)
Ligninolytic fungi are well known for their ability to degrade a wide range of xenobiotics contaminating the environment, including synthetic industrial dyes. In this work Pleurotus ostreatus was used for decolorization of a synthetic textile dye Remazol Brilliant Blue R (RBBR). To set up a model fungal "fixed-bed" bioreactor the fungus was immobilized on a polyurethane foam and artificially contaminated with a model bacterium Rhodococcus erythropolis. The development of bacterial contamination can be expected during a real application of fungal bio filters in wastewater treatment. The main aim of the work was to study interspecies interactions in the model bioreactors during the dye decolorization. Ligninolytic enzyme activities were followed in the bioreactor cultures as markers of fungal biodegradation ability. In contrast to the controls, no bacterial growth was observed in the P. ostreatus bioreactor culture liquid. The results showed that fungal laccase, pH of the culture liquid, and glucose consumption by the fungus had no effect on the bacterial growth. However, 4*105 - 1,3*106 CFU/ml of R. erythropolis was detected to be associated with the fungal solid support. The presence of these bacteria had no effect on the decolorization performance of the bioreactors. Dye decolorization efficiency...
302

Gynnas kvinnor när icke-kognitiv förmåga värdesätts högre? : En kvantitativ studie över effekten av ökad efterfrågan på icke-kognitiva förmågor på kvinnors relativlöner inom den svenska arbetsmarknaden.

von Beckerath, Lova, Lilja, Emma January 2023 (has links)
Sedan 2000-talets början har avkastningen på icke-kognitiva förmågor ökat på arbetsmarknaden till följd av bland annat skill-biased technological change. Grupper som besitter höga icke-kognitiva förmågor bör därför gynnas på arbetsmarknaden. Givet att ett antal studier finner evidens för att kvinnor har högre icke-kognitiva förmågor än män, undersöker uppsatsen i vilken grad detta återspeglas i kvinnors relativlön. Syftet är att se om kvinnor gynnas av att avkastningen på icke-kognitiva förmågor har ökat i termer av att deras relativlön har ökat. För att undersöka detta tillämpas en regressionsanalys med fixa effekter på en komunpanel, där två olika mått på icke-kognitiv förmåga förekommer. Måtten grundar sig i mönstringsdata respektive O’net-data (Occupational information network). Effekten på kvinnors relativlön studeras under tidsperioden 2008–2018 samt 2014–2018 för Sveriges samtliga 290 kommuner. Resultaten uppvisar ett negativt samband mellan ökad efterfrågan på icke-kognitiv förmåga och kvinnors relativlön, vilket innebär att när efterfrågan ökar så minskar kvinnors relativlön. / Since the beginning of the 21st century, there has been a surge in the returns to non-cognitive abilities in the labor market, due to the influence of skill-biased technological change. This has led to a preference for groups with higher non-cognitive skills in the labor market. In light of some studies revealing that women exhibit greater non-cognitive skills than men, this study aims to investigate whether this phenomenon translates into a corresponding increase in women’s salaries, thus examining whether women are beneficiaries of the amplified returns to non-cognitive skills. To achieve this objective, a fixed-effects regression analysis is employed, using two different metrics to assess non-cognitive capacity, across one municipal panel. The research examines the effect on women's relative salaries from 2008–2018 and 2014–2018, encompassing all 290 municipalities in Sweden. The results demonstrate a negative association between increased demand for non-cognitive skills and women's relative salaries, indicating that as demand increases, women's relative salaries decrease.
303

The effects of budget deficit on fixed investment in selected African Countries

Seshoka, Pretty January 2022 (has links)
Thesis (M.Com. (Economics)) -- University of Limpopo, 2022 / The primary goal of this study was to investigate the effects of budget deficit on fixed investment using annual data for the period 1990-2017 in selected African countries namely, Cameroon, Namibia, Ghana, Egypt, Seychelles, Mauritius, Botswana, Lesotho and South Africa. The study employed panel unit root tests including the Augmented Dickey-Fuller test, Philips Perron test and Levin Lin and chu test. The tests revealed that all the variables are integrated at 1st difference. The study further employed the Panel ARDL bounds test to examine the relationship between budget deficit, fixed investment, money supply and inflation. The empirical findings indicated that a long run relationship exists between the variables of interest. Furthermore, the results revealed that the budget deficit has a negative and statistically significant effect on fixed investment. A one percent increase in the budget deficit, ceteris paribus, leads to a reduction in fixed investment by 44 percent in the long run. The findings further postulated a bidirectional causal relationship between budget deficit and fixed investment, between money supply and fixed investment and between fixed investment and inflation. It was evident in the research that indeed the budget deficit is a problematic macroeconomic policy in African countries. Policy makers should limit high government expenditures as they contribute to increased and persistent budget deficits which crowd out private investment.
304

Higher Radix Floating-Point Representations for FPGA-Based Arithmetic

Catanzaro, Bryan Christopher 22 April 2005 (has links) (PDF)
Field Programmable Gate Arrays (FPGAs) are increasingly being used for high-throughput floating-point computation. It is forecasted that by 2009, FPGAs will provide an order of magnitude greater sustained floating-point throughput than conventional processors. FPGA implementations of floating-point operators have historically been designed to use binary floating-point representations, as do general purpose processors. Binary representations were chosen as the standard over three decades ago because they provide maximal numerical accuracy per bit of floating-point data. However, the unique nature of FPGA-based computation makes numerical accuracy per unit of FPGA resources a more important measure of the usefulness of a given floating-point representation. From this viewpoint, higher radix floating-point representations are well suited to FPGA-based computations, especially high precision calculations which require the support of denormalized numbers. This work shows that higher radix representations lead to more efficient use of FPGA resources. For example, a hexadecimal floating-point adder provides a 30% lower Area-Time product than its binary counterpart, and a hexadecimal floating-point multiplier has a 13% lower Area-Time product than its binary counterpart. This savings occurs while still delivering equal worst-case and better average-case numerical accuracy. This work presents a family of higher radix floating-point representations that are designed specifically to interoperate with standard IEEE floating-point, allowing the creation of floating-point datapaths which operate on standard binary floating-point data, yet use higher radix representations internally. Such datapaths provide higher performance by any measure: they are more accurate numerically, consume less FPGA resources and have shorter latencies. When taking into consideration the unique nature of FPGA-based computing systems, this work shows that binary floating-point representations are not optimal for most FPGA-based arithmetic computations. Higher radix representations can therefore be a useful tool for building efficient custom floating-point datapaths on FPGAs.
305

Har inflationen någon relation till den ekonomiska tillväxten? : En paneldata analys över 19 OECD länder / Does inflation have any relation on economic growth? : A panel data analysis of 19 OECD countries

Jareke, Emelie, Hyyppä Bennet, Katarina January 2022 (has links)
Det finns olika aspekter som påverkar den ekonomiska tillväxten, där ibland inflation. Det har under många år pågått diskussioner om hur förhållandet mellan dessa två variabler ser ut. Denna uppsats analyserar sambandet mellan ekonomisk tillväxt och inflation. Utöver detta besvarar studien om inflation har någon statistisk signifikant relation till den ekonomiska tillväxten. I studien används paneldata från 19 OECD-medlemsländer från 1976 till 2020. För att analysera data utformas en regressionsmodell genom att använda BNP per capita som beroende variabel samt inkludera sju oberoende variabler (inflation, utländska direktinvesteringar, inhemska sparande, bytesvillkor, befolkningstillväxt, humankapital samt initial BNP). Resultatet från regressionsanalysen som utfördes genom fixed effects least squares dummy variable modellen tyder på ett negativt samband mellan inflation och BNP per capita. Däremot är resultatet enbart statistiskt signifikant om inte länder-, perioddummies eller initial BNP inkluderas. / There are various aspects that affect economic growth, including inflation. For many years, there have been discussions about the relationship between these two variables. This thesis analyzes the relation between economic growth and inflation. In addition, the study answers whether inflation has any statistically significant relation to economic growth. The study uses panel data from 19 OECD member countries from 1976 to 2020. To analyze the data, a regression model is designed by using ln GDP per capita as a dependent variable and including seven independent variables (inflation, foreign direct investment, domestic savings, terms of trade, population growth, human capital and initial GDP). The results of the regression analysis are conducted using the fixed effects least squares dummy variable model indicate a negative relationship between inflation and GDP per capita. However, the result is only shown to be statistically significant unless countries-, period dummies or initial GDP are included.
306

Coexistence of Wireless Systems for Spectrum Sharing

Kim, Seungmo 28 July 2017 (has links)
Sharing a band of frequencies in the radio spectrum among multiple wireless systems has emerged as a viable solution for alleviating the severe capacity crunch in next-generation wireless mobile networks such as 5th generation mobile networks (5G). Spectrum sharing can be achieved by enabling multiple wireless systems to coexist in a single spectrum band. In this dissertation, we discuss the following coexistence problems in spectrum bands that have recently been raising notable research interest: 5G and Fixed Satellite Service (FSS) at 27.5-28.35 GHz (28 GHz); 5G and Fixed Service (FS) at 71-76 GHz (70 GHz); vehicular communications and Wi-Fi at 5.85-5.925 GHz (5.9 GHz); and mobile broadband communications and radar at 3.55-3.7 GHz (3.5 GHz). The results presented in each of the aforementioned parts show comprehensively that the coexistence methods help achieve spectrum sharing in each of the bands, and therefore contribute to achieve appreciable increase of bandwidth efficiency. The proposed techniques can contribute to making spectrum sharing a viable solution for the ever evolving capacity demands in the wireless communications landscape. / Ph. D. / Sharing a band of frequencies in the radio spectrum among multiple wireless systems has emerged as a viable solution for alleviating the severe capacity crunch in next-generation wireless mobile networks such as 5th generation mobile networks (5G). Spectrum sharing can be achieved by enabling multiple wireless systems to coexist in a single spectrum band. In this dissertation, we discuss the following coexistence problems in spectrum bands that have recently been raising notable research interest: 5G and Fixed Satellite Service (FSS) at 27.5-28.35 GHz (28 GHz); 5G and Fixed Service (FS) at 71-76 GHz (70 GHz); vehicular communications and Wi-Fi at 5.85-5.925 GHz (5.9 GHz); and mobile broadband communications and radar at 3.55-3.7 GHz (3.5 GHz). The results presented in each of the aforementioned parts show comprehensively that the coexistence methods help achieve spectrum sharing in each of the bands, and therefore contribute to achieve appreciable increase of bandwidth efficiency. The proposed techniques can contribute to making spectrum sharing a viable solution for the ever evolving capacity demands in the wireless communications landscape.
307

Elitishockeyns anpassning till arbetsrätten : Föräldraledig som elitishockeyspelare?  "Nej, det går inte, helt omöjligt"

Åkerlund, Carl January 2016 (has links)
The sports in Sweden has previously been self-regulated with its own rules and provisions. As the commercialisation and professionalization have increased the common legal system has a greater impact on sports. The purpose of this study is to investigate the professional ice hockey adjustments to the labour law regulation. Furthermore the purpose is to illuminate possible advantage and disadvantage with the professional ice hockey player’s conditions of employment. To answer the purpose and the research questions of this study the legal dogmatic method, the legal sociology method and qualitative method with interviews has been used. The study shows how the professional ice hockey has adapted the labour law regulations with collective agreement due to the semi-dispositive provisions found in Swedish labour law. In Swedish professional ice hockey only the fixed-term contract is applied and most of the provisions about employment security are not available for the ice hockey players. In return the players has a stronger protection during the employment. As an employee and a parent the right to have a parental leave is statutory. The study shows a complex of problems with ice hockey player’s opportunity to have a parental leave, which is a right as an employee. This raises questions about equality between men and women in the labour market of ice hockey.
308

The Rasch Sampler

Verhelst, Norman D., Hatzinger, Reinhold, Mair, Patrick 22 February 2007 (has links) (PDF)
The Rasch sampler is an efficient algorithm to sample binary matrices with given marginal sums. It is a Markov chain Monte Carlo (MCMC) algorithm. The program can handle matrices of up to 1024 rows and 64 columns. A special option allows to sample square matrices with given marginals and fixed main diagonal, a problem prominent in social network analysis. In all cases the stationary distribution is uniform. The user has control on the serial dependency. (authors' abstract)
309

Calculation of the average age of fixed assets and its behaviour under different conditions

Hall, Barry Charles 12 1900 (has links)
Thesis (MBA)--Stellenbosch University, 2001. / ENGLISH ABSTRACT: Researchers at the Graduate School of Business of the University of Stellenbosch raised their concerns about the accuracy of inflation adjustment estimates. This led to research by Hanekom (1992), Marais (1992), Ozrovech (1992), Laack (1994) and an article by Hamman and Smit (1994). Hanekom, Marais, Ozrovech and Loock investigated alternative methods of calculating the average age of fixed assets for South African companies. They came to the conclusion that approximations of inflation adjustments by means of simplified formulas are inaccurate and should be discontinued. Alternative methods are time-consuming, data dependent and contain various assumptions that may lead to inaccurate results. Based on the findings and recommendations of the above-mentioned authors to develop company-specific inflation adjustment models, this study project will attempt to investigate the behaviour of the average age of fixed assets as calculated by the formula: Average age (year n) = Accumulateddepreciation (n) Depreciation(for year n) Various conditions that influence this specific calculation will be simulated in spreadsheet models. The behaviour of the approximated average age will then be explained by means of the results obtained from the spreadsheet simulations, as well as a mathematical formula that will be deducted from the simulated spreadsheet models. The understanding of the behaviour of the estimation of the average age of fixed assets and the conditions that influence this estimation might help to establish possible patterns that would assist with the development of companyspecific inflation adjustment models. / AFRIKAANSE OPSOMMING: Navorsers aan die Nagraadse Bestuurskool van die Universiteit van Stellenbosch het hulle twyfel uitgespreek oor die akkuraatheid van inflasieregstellingskattings, wat gelei het tot navorsing deur Hanekom (1992), Marais (1992), Ozrovech (1992) en Loock (1994) en 'n artikel deur Hamman en Smit (1994). Hanekom, Marais, Ozrovech en Loock het alternatiewe metodes ondersoek om die berekening van die gemiddelde ouderdom van vaste bates vir Suid Afrikaanse maatskappye te doen. Die slotsom was egter dat die berekening van die waardes met behulp van eenvoudige formules onakkuraat is en eerder gestaak moet word. Alternatiewe metodes is tydrowend, afhanklik van die beskikbaarheid van inligting, en vereis aannames wat tot moontlike onakkurate antwoorde kan lei. Na aanleiding van bogenoemde skrywers se gevolgtrekkings, en aanbevelings om maatskappy-spesifieke modelle te ontwikkel om inflasieaanpassings te doen, sal hierdie studie poog om die gedrag van die gemiddelde ouderdom van vaste bates soos dit bereken word deur die volgende formule, te ondersoek: Gemiddelde ouderdom (jaar n) = Opgehoopte waardevermindering (n) Waardevermindering (vir jaar n) Verskillende toestande wat die berekening beïnvloed sal deur middel van sigblad modelle gesimuleer word. Die gedrag van die geraamde gemiddelde ouderdom sal dan verduidelik word aan die hand van die sigblaaie sowel as 'n afgeleide wiskundige formule vir die berekening van die waarde. lndien die verskillende toestande en faktore wat die berekening van die gemiddelde ouderdom van vaste bates beïnvloed, verstaan en verduidelik kan word, kan moontlike patrone geïdentifiseer word wat sal help met die ontwikkeling van meer spesifieke modelle vir inflasie-aanpassings van maatskappye.
310

Internal Model Control (IMC) design for a stall-regulated variable-speed wind turbine system

Rosmin, Norzanah January 2015 (has links)
A stall-regulated wind turbine with fixed-speed operation provides a configuration which is one of the cheapest and simplest forms of wind generation and configurations. This type of turbine, however, is non-optimal at low winds, stresses the component structure and gives rise to significant power peaks during early stall conditions at high wind speeds. These problems can be overcome by having a properly designed generator speed control. Therefore, to track the maximum power locus curve at low winds, suppress the power peaks at medium winds, limit the power at a rated level at high winds and obtain a satisfactory power-wind speed curve performance (that closely resembles the ideal power-wind speed curve) with minimum stress torque simultaneously over the whole range of the wind speed variations, the availability of active control is vital. The main purpose of this study is to develop an internal model control (IMC) design for the squirrel-cage induction generator (SCIG), coupled with a full-rated power converter of a small (25 kW), stall-regulated, variable-speed wind-turbine (SRVSWT) system, which is subject to variations in the generator speed, electromagnetic torque and rotor flux. The study was done using simulations only. The objective of the controller was to optimise the generator speed to maximise the active power generated during the partial load region and maintain or restrict the generator speed to reduce/control the torque stress and the power-peaking between the partial and full load regions, before power was limited at the rated value of 25 kW at the full load region. The considered investigation involved estimating the proportional-integral (PI) and integral-proportional (IP) controllers parameter values used to track the stator-current producing torque, the rotor flux and the angular mechanical generator speed, before being used in the indirect vector control (IVC) and the sensorless indirect vector control (SLIVC) model algorithms of the SCIG system. The design of the PI and IP controllers was based on the fourth-order model of the SCIG, which is directly coupled to the full-rated power converter through the machine stator, whereas the machine rotor is connected to the turbine rotor via a gearbox. Both step and realistic wind speed profiles were considered. The IMC-based PI and IP controllers (IMC-PI-IP) tuning rule was proven to have smoothened the power curve and shown to give better estimation results compared to the IMC-based PI controllers (IMC-PI), Ziegler-Nichols (ZN) and Tyreus-Luyben (ZN) tuning rules. The findings also showed that for the SRVSWT system that employed the IVC model algorithm with the IMC-PI-IP tuning rule, considering the application of a maintained/constant speed (CS) strategy at the intermediate load region is more profitable than utilizing SRVSWT with the modified power tracking (MoPT) strategy. Besides that, the finding also suggested that, for the IMC-PI-IP approach, the IVC does provide better power tracking performance than the SLIVC model algorithm.

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