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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.
471

Isolation, Purification and Characterization of Photosynthetic Membrane Proteins from Galdieria sulphuraria and Chlamydomonas reinhardtii

January 2010 (has links)
abstract: In oxygenic photosynthesis, Photosystem I (PSI) and Photosystem II (PSII) are two transmembrane protein complexes that catalyze the main step of energy conversion; the light induced charge separation that drives an electron transfer reaction across the thylakoid membrane. Current knowledge of the structure of PSI and PSII is based on three structures: PSI and PSII from the thermophilic cyanobacterium Thermosynechococcus elonagatus and the PSI/light harvesting complex I (PSI-LHCI) of the plant, Pisum sativum. To improve the knowledge of these important membrane protein complexes from a wider spectrum of photosynthetic organisms, photosynthetic apparatus of the thermo-acidophilic red alga, Galdieria sulphuraria and the green alga, Chlamydomonas reinhardtii were studied. Galdieria sulphuraria grows in extreme habitats such as hot sulfur springs with pH values from 0 to 4 and temperatures up to 56°C. In this study, both membrane protein complexes, PSI and PSII were isolated from this organism and characterized. Ultra-fast fluorescence spectroscopy and electron microscopy studies of PSI-LHCI supercomplexes illustrate how this organism has adapted to low light environmental conditions by tightly coupling PSI and LHC, which have not been observed in any organism so far. This result highlights the importance of structure-function relationships in different ecosystems. Galdieria sulphuraria PSII was used as a model protein to show the amenability of integral membrane proteins to top-down mass spectrometry. G.sulphuraria PSII has been characterized with unprecedented detail with identification of post translational modification of all the PSII subunits. This study is a technology advancement paving the way for the usage of top-down mass spectrometry for characterization of other large integral membrane proteins. The green alga, Chlamydomonas reinhardtii is widely used as a model for eukaryotic photosynthesis and results from this organism can be extrapolated to other eukaryotes, especially agricultural crops. Structural and functional studies on the PSI-LHCI complex of C.reinhardtii grown under high salt conditions were studied using ultra-fast fluorescence spectroscopy, circular dichroism and MALDI-TOF. Results revealed that pigment-pigment interactions in light harvesting complexes are disrupted and the acceptor side (ferredoxin docking side) is damaged under high salt conditions. / Dissertation/Thesis / Ph.D. Biochemistry 2010
472

Visual saliency computation for image analysis

Zhang, Jianming 08 December 2016 (has links)
Visual saliency computation is about detecting and understanding salient regions and elements in a visual scene. Algorithms for visual saliency computation can give clues to where people will look in images, what objects are visually prominent in a scene, etc. Such algorithms could be useful in a wide range of applications in computer vision and graphics. In this thesis, we study the following visual saliency computation problems. 1) Eye Fixation Prediction. Eye fixation prediction aims to predict where people look in a visual scene. For this problem, we propose a Boolean Map Saliency (BMS) model which leverages the global surroundedness cue using a Boolean map representation. We draw a theoretic connection between BMS and the Minimum Barrier Distance (MBD) transform to provide insight into our algorithm. Experiment results show that BMS compares favorably with state-of-the-art methods on seven benchmark datasets. 2) Salient Region Detection. Salient region detection entails computing a saliency map that highlights the regions of dominant objects in a scene. We propose a salient region detection method based on the Minimum Barrier Distance (MBD) transform. We present a fast approximate MBD transform algorithm with an error bound analysis. Powered by this fast MBD transform algorithm, our method can run at about 80 FPS and achieve state-of-the-art performance on four benchmark datasets. 3) Salient Object Detection. Salient object detection targets at localizing each salient object instance in an image. We propose a method using a Convolutional Neural Network (CNN) model for proposal generation and a novel subset optimization formulation for bounding box filtering. In experiments, our subset optimization formulation consistently outperforms heuristic bounding box filtering baselines, such as Non-maximum Suppression, and our method substantially outperforms previous methods on three challenging datasets. 4) Salient Object Subitizing. We propose a new visual saliency computation task, called Salient Object Subitizing, which is to predict the existence and the number of salient objects in an image using holistic cues. To this end, we present an image dataset of about 14K everyday images which are annotated using an online crowdsourcing marketplace. We show that an end-to-end trained CNN subitizing model can achieve promising performance without requiring any localization process. A method is proposed to further improve the training of the CNN subitizing model by leveraging synthetic images. 5) Top-down Saliency Detection. Unlike the aforementioned tasks, top-down saliency detection entails generating task-specific saliency maps. We propose a weakly supervised top-down saliency detection approach by modeling the top-down attention of a CNN image classifier. We propose Excitation Backprop and the concept of contrastive attention to generate highly discriminative top-down saliency maps. Our top-down saliency detection method achieves superior performance in weakly supervised localization tasks on challenging datasets. The usefulness of our method is further validated in the text-to-region association task, where our method provides state-of-the-art performance using only weakly labeled web images for training.
473

Phenomenological Studies on Composite Higgs Models

El Faham, Hesham January 2018 (has links)
Composite Higgs Models (CHMs) are formulated in terms of strongly coupled theories. They often predict fermionic top partners with a mass around the TeV scale. Going beyond minimality enriches the spectrum of the theory with additional hypothetical scalars that significantly change the phenomenology. In this thesis, we explore an SO(6)/SO(5) CHM with an additional pseudo-scalar custodial singlet. The latter has anomalous couplings to the Standard Model vector bosons. We study the phenomenology of the singlet, including bounds from the available ATLAS and CMS searches in the relevant channels with di-boson and fermionic final states. We used HiggsBounds tool to test the model theoretical predictions against the current exclusion limits. The study is performed at the 8 and 13 TeV experiments at the LHC. We present a model parameter space from which the bounds on the (most sensitive) signal cross sections of the hypothetical singlet can be easily extracted.
474

Alkali Circulation in the Blast Furnace - Process Correlations and Counter Measures

Carlsson, Joel January 2018 (has links)
In blast furnace ironmaking one major challenge is to control and measure the alkalis circulating and accumulating in the blast furnace (BF). Alkali enter the BF with the primary raw material and will form a cycle where it is first reduced to metal at the lower parts forming gas. Alkali then follows the gas flow up where it oxidizes and solidies as the oxide form has a higher melting and volatilization temperature. Condensation then occurs on burden material and in their pores and by that it is following the burden downwards. The circular nature of the reactions leads to a build-up of alkali in the form of potassium in the BF that is hard to control or measure. Condensation of alkali compounds can also occur on the BF walls functioning like a glue to which particles attach, forming scaffolds that can rapidly increase and disturb the burden descent. The increased alkali catalyzes gasication of coke with CO2 that increasescoke consumption and leads to disintegration of coke. A common method today to control alkali is by varying the basicity in the BF. As lower basicity increases the amount alkali removed through slag while at the same time reducing the amount of sulfur that can be removed with the slag. This project was divided into two parts. The first part was a continuation of a previous study performed at Swerea MEFOS. Where to control the effect of alkali on coke gasication a method was tested using coke ash modication to inhibit the catalyzing properties of alkali bound on coke. The method has previously shown that alkalis are bound in the desired form but the added amount was not sufficient for inhibition of all picked-up alkalis. In this study, additional trials with higher additions of kaolin was performed. 2 wt% kaolin was added to the coal blend for producing coke that was then added to LKAB's experimental blast furnace (EBF) as basket samples in the end of a campaign. The excavated samples were analyzed using XRF, XRD, SEM-EDS and TGA to find if the alkali was bound in aluminum silicates in the coke ash, if the addition was sufficient for binding all alkalis and if the catalytic effect in coke gasication had been achieved. The second part was a novel approach with a statistical process analysis using SIMCA to connect top gas composition of SSAB Oxelösund's BF No. 4 to alkali content using process data. The approach investigated the correlation between NH3(g) and HCN(g) in the top gas to alkali content. Expanding on the possibility to measure alkali content quickly for the operators using top gas measurements. Top gas composition was measured using a mass spectrometer (MS) and where complimented with process and tap data provided by SSAB. Data was analyzed using the multivariate analysis tool SIMCA 15 to find possible correlations. Results from the first part showed that the alkali that was found was present as alkali aluminum silicates independent of kaolin addition after the EBF. As temperature along gas composition was the main factors behind alkali uptake in coke. Main differences in alkali uptake and development of coke properties in the BF was linked to the temperature and gas composition profile during tests campaigns compared. Results from TGA showed that the reaction rate of coke with CO2 increases with increasing K2O and that start of reaction was lower with increasing alkali. The results from the second approach did not find a correlation between HCN(g) and K2O in slag. Positive correlation could be seen between HCN(g) and increased SiO2 in slag and that H2O(g) would affect HCN(g) negatively.
475

Savanna woody plant community and trait responses to bottom-up and top-down controls, with a specific focus on the role of mammalian herbivory / Réponses des traits spécifiques et des communautés ligneuses de savane aux processus de contrôle ascendant et descendant (bottom-up/top-down), avec une emphase sur le rôle des mammifères herbivores

Wigley, Benjamin Joseph 09 September 2013 (has links)
Les savanes sont des écosystèmes complexes pilotées par plusieurs mécanismes ascendant (ex: les nutriments du sol ou pluviométrie) ou descendant (ex: feu ou herbivorie), mais l'importance relative de ces mécanismes reste largement débattue. En particulier, le rôle des herbivores brouteurs (browsers) reste mal compris en tant que source de perturbation, et donc de force de pression descendante influant sur la dynamique des savanes. Dans cette étude, deux approches ont été développées pour aborder le rôle des perturbations dans la dynamique des savanes. Dans un première partie, j'ai utilisé une approche comparative inter-site pour explorer les réponses des communautés de plantes, et des principaux traits de ces plantes associés aux feuilles, branches, architecture et défense, aux variations de quatre facteurs : les nutriments dans le sol, la pluviométrie, la pression d'herbivorie et l'intensité du feu. Seize sites de savane, en Afrique du Sud et au Zimbabwe, ont été sélectionnés sur des gradients de chacun de ces facteurs. Les espèces ligneuses dominantes (>80 % de la biomasse) sur chaque site ont été identifiées et échantillonnées, afin de mesurer les traits des feuilles et des branches associés à l'appétence, architecture, ainsi qu'aux défenses physiques et chimiques de ces plantes. Des mesures ont également été faites pour estimer les effets des meso-brouteurs et mega-brouteurs. Des transects ont permis d'estimer la fréquence et l'intensité du feu sur chaque site, et l'effet sur les plantes. En préambule à l'analyse, et devant le manque de protocole standard pour estimer la fertilité des sols dans la littérature écologique, je propose une méthode et un échantillonnage afin de définir de manière robuste la fertilité des sols sur chaque site. Dans cette partie inter-site, huit traits principaux ont été comparés sur le gradient de qualité de sol et de pluviométrie, et bien que quelques relations statistiques existent entre les traits des feuilles, le sol et la pluviométrie, ces relations sont très faibles comparées à celle trouvées dans les méta analyses inter-biomes publiées dans la littérature. Cependant, ces approches interbiome sont dominées par des sites tempérés qui ont des niveaux de perturbations bien inférieurs à ceux des savanes africaines. L'évaluation des effets des meso-brouteurs et mega-brouteurs le long des gradients de sol et de pluviométrie sur vingt traits associés aux défenses structurelles et chimiques des plantes montre que les défenses structurelles sont plus corrélées aux caractéristiques du sol que les défenses chimiques, mais que seules les défenses structurelles sont fortement corrélées à l'impact par les brouteurs. Le niveau d'utilisation des plantes par les mesobrouteurs apparaît plus prévisible en fonction des traits des plantes que celui par les mégabrouteurs. Dans une deuxième partie présentent des résultats de deux études basées sur des expériences d'exclos. Dans le parc national de Kruger, la composition de la communauté, l'abondance et la démographie des ligneux dominants ont été estimées à l'intérieur et à l'extérieur de trois exclos de 40 ans, et les brouteurs apparaissent comme ayant un impact significatif sur la distribution, la densité et la structure des populations des espèces arbustives et arborées ayant des traits préférés : forte concentration en azote foliaire et faible teneur en défenses chimiques. L'interaction entre les effets des brouteurs et du feu semble aussi affecter le recrutement des juvéniles ligneux dans les grandes classes de taille. Dans le parc de Hluhluwe-iMfolozi, cinq exclos ont été utilisé pour tester l'effet des brouteurs sur l'architecture, la croissance, les défenses chimiques et structurelles des jeunes individus de sept espèces d'acacia. Des différences nettes apparaissent entre les espèces d'acacia de savane semi-aride et plus humide dans les traits associés à l'appétence, l'architecture et les défenses … [etc] / Savannas are complex ecosystems affected by several bottom-up (e.g. soil nutrient availability and rainfall) and top-down (e.g. fire and herbivory) drivers. However, the relative importance of bottom-up vs. top-down drivers in influencing savanna dynamics is still widely debated. Within the top-down (disturbance) category of drivers, the role of mammal browsers in particular in driving savanna functioning is still not well understood. Two approaches were adopted to determine the role of disturbance in savannas. Firstly, by using a comparative approach, I attempted to address the so-called ‘savanna problem’ by investigating how savanna woody plant community compositions and key plant traits relating to the leaves, stems, architecture, and defence are influenced by soil nutrient status, rainfall, fire and browsing. Sixteen sites were selected along gradients of these four drivers from savanna parks throughout South Africa and Zimbabwe. The dominant woody species (species that accounted for >80% of standing biomass) at each site were identified and sampled for the key leaf and stem traits relating to plant functioning, palatability, architecture, physical and chemical defences. Measurements were undertaken for each species in order to determine both meso-browser and mega browser impact. Transects were undertaken in order to determine the relative abundance and the effects of fire on each species at each site. Due to the current lack of standardized soil sampling protocols in the ecological literature, and uncertainty around the definition of what denotes a fertile or infertile soil, I propose a number of standardized protocols and sampled according to these established protocols in order to accurately determine the soil nutrient status at each site. Following this, the relationships between climatic variables and soil nutrients with both species means and community weighted means for eight key leaf traits were explored. Although some significant relationships were found between savanna leaf traits of woody plants, climate, soil nutrients and their interactions, these tended to be weaker than those found in meta-analyses. These broad-scale studies usually include sites from many biome types, many of which are from temperate regions where inherent levels of disturbance are typically much lower than in African savannas. The high levels of disturbance typically found in African savannas are thought to partially account for the high within site variability found in leaf traits and the weak relationships found between leaf traits, soil nutrients and rainfall. To assess the importance of resources vs. disturbance in savannas functioning, the effects of soil nutrients, rainfall, fire and both meso-browser and mega-browser impact on twenty savanna woody plant traits relating to plant palatability, chemical and structural defences were explored. Structural defences were found to be more strongly correlated with soil characteristics than chemical defences, while browser impact was found to be strongly correlated with structural defences but not with chemical defences. Actual browser utilisation tended to be more predictable for meso-browsers than mega-browsers. Secondly using an experimental approach, two sets of herbivore exclosures were utilized to directly test how mammal browsers influenced woody species distributions, abundance, population structure and plant traits relating to palatability and defence. The effects of three longterm herbivore exclosures in the Kruger National Park on savanna woody plant community compositions, population demographics and densities were determined. Browsers were found to have significant impacts on species distributions, densities and population structures by actively selecting for species with favourable traits, particularly higher leaf N. An interaction between browsers and fire which limited the recruitment of seedlings and saplings into larger size classes was also demonstrated… [etc]
476

Modelling of supersonic top lance and the heat-up stage of the CAS-OB process

Kärnä, A. (Aki) 13 November 2018 (has links)
Abstract The CAS-OB (composition adjustment by sealed argon bubbling - oxygen blowing) process is used in secondary steelmaking to adjust the composition and temperature of the steel melt. The steel melt can be heated by oxidizing aluminium in process which feeds aluminium particles and oxygen to the melt surface. Oxygen is in fed by a top lance, which is an important part of many metallurgical processes and is typically used to deliver oxygen to steel melt surface by supersonic blowing. Because observing and measuring the metallurgical processes is challenging due to the high temperature, numerical models predicting the processes are especially important. In this thesis, both top lances and the heat-up stage of the CAS-OB process were studied, and numerical models were constructed. CFD (computational fluid dynamics) were used to study top lances. A turbulence model was adjusted for supersonic flows with experimental data from literature. The CAS-OB process model involves chemical reactions and fluid flows. In order to keep the computation times reasonable, a full fluid flow calculation is not included in the model but is calculated in advance. Heat and mass transfer correlations are calculated with CFD, and the results are then used in the process simulation model. Chemical reactions are calculated based on the law of mass action and thermodynamics. The results were validated with industrial measurements. The CAS-OB heat-up stage model can be used in its current state in process development, and in the future for online control of the process. The CFD model for the top lance can be applied to a lance in any other process. / Tiivistelmä CAS-OB-prosessia (composition adjustment by sealed argon bubbling - oxygen blowing) käytetään teräksen valmistuksessa sulan teräksen koostumuksen ja lämpötilan säätämiseen. Terässulaa voidaan tarvittaessa lämmittää syöttämällä alumiinikappaleita ja happea sulan pinnalle. Hapen syöttö tapahtuu yliäänilanssilla, jota käytetään monissa metallurgisissa prosesseissa, yleensä toimittamaan happea sulan pinnalle yliäänisellä puhalluksella. Metallurgisten prosessien havainnointi ja mittaaminen ovat haastavia korkeiden lämpötilojen vuoksi, joten numeeriset mallit ovat erityisen tärkeitä prosessien ennustamisessa. Tässä työssä on tutkittu yliäänilansseja ja CAS-OB-prosessin lämmitysvaihetta ja luotu niille numeeriset mallit. Yliäänilanssien tutkimiseen käytettiin numeerista virtauslaskentaa (CFD, computational fluid dynamics). Lanssien mallinnusta varten olemassa olevaa turbulenssimallia muokattiin paremmin yliäänivirtausta kuvaavaksi kirjallisuudesta löytyvän mittaustiedon perusteella. CAS-OB-prosessimallissa huomioidaan virtaus ja kemialliset reaktiot. Koska laskenta-ajat haluttiin pitää käytännöllisinä, virtauslaskentaa ei suoriteta mallissa, vaan se tehdään etukäteen. Aineen- ja lämmönsiirtokertoimet lasketaan CFD-laskennalla, ja tuloksia käytetään prosessimallissa. Kemialliset reaktiot lasketaan perustuen massavaikutuksen lakiin ja termodynamiikkaan. CAS-OB-mallin tulokset on validoitu terästehtaalla tehtyjen kokeiden perusteella. Mallia voidaan käyttää nykyisessä muodossaan prosessin kehityksessä ja tulevaisuudessa myös prosessin ohjauksessa. Yliäänilanssin CFD-mallia voidaan soveltaa myös muihin metallurgisiin prosesseihin.
477

Three empirical studies on the performance of firms involved in M&As and IPOs

Bai, Yang January 2018 (has links)
This PhD thesis consists of three empirical papers. Each paper can be read independently. However, all three papers investigate different factors affecting the performance of firms involved in mergers and acquisitions (M&As) and initial public offerings (IPOs). A private firm seeking to become listed and who also wish to grow through acquisition can do so with an IPO followed by acquisitions or a reverse takeover (RT). In a RT, a private firm is acquired by a public firm, but the private firm controls the combined public entity after completion of the deal. Chapter 2, 'Post-acquisition performance when firms list and acquire simultaneously versus sequentially: Reverse takeover versus IPO-M&As', examines the differential performance of firms conducting an IPO prior to undertaking follow-on acquisitions (IPO-M&As) versus firms that combine the process of obtaining the listing and acquiring another firm by conducting a RT. I investigate how acquirers' choices affect their post-acquisition performances. In this paper, I also investigate the impact of board structure changes on firm performance in IPO-M&A and RT deals. This event study covers RTs and acquisition-motived IPOs listed on the London Stock Exchange during 1995-2012. Challenging the theoretical expectation that IPOs increase the likelihood of optimal exercise of acquisition options by reducing valuation uncertainty, my results show that an IPO does not alleviate the stock market underperformance of acquirers within 3 years post-acquisition. Private firms seem to self-select into different listing-and-acquisition routes depending on firm-specific characteristics and the board members keep the same level of control preference. However, the choice of listing-and-acquisition does not appear to significantly affect performance. I find no significant difference in the post-acquisition performance of firms undertaking IPO-M&As or RTs. Chapter 3, 'Post-acquisition performance of target firms: The impact of management turnover', investigates the efficiency of the takeover market and the impact of management turnover on target firm performance. Investigating separately the operating performance of targets and acquirers in U.K. domestic acquisitions during 2006-2014, I find that the post-acquisition peer-adjusted profits significantly improve in the unprofitable targets but do not change significantly in profitable targets. Both profitable and unprofitable targets experienced high management turnovers, but the improvement in profits does not appear to be driven by the management turnover. The reason of management turnovers is more complex than the acquisitions' market discipline function or resource-based management hypothesis. However, a complete turnover of top management in target firms seems to hurt the post-acquisition performance of acquirers, suggesting target management team may possess valuable information to facilitate the integration process. This study sheds light on the post-acquisition restructuring of target firms and their management teams, especially in private targets. Chapter 4, 'Identifying leaders among IPO firms: a content analysis of analyst coverage reports', investigates how analysts identify firms as a leader and whether leader firms go on to generate superior operating performance to non-leaders. Using a content analysis approach, I extract sentences including the keyword 'lead' from initial coverage reports and pick out sentences where the IPO firm is identified as either an 'industry leader' or 'partial leader'. I examine the textual content of initial coverage reports on U.S. IPOs during 1999-2012 and find that lead-underwriter analysts appear not to be more optimistic than non-lead-underwriters in their leadership identification of IPO firms, however, nor are they more accurate than non-lead-underwriters in identifying leader firms. I find that neither firms identified by analysts as industry leaders nor firms identified as having partial leadership advantages tend to generate superior peer-adjusted net sales or profit margins compared to non-leaders. The Global Settlement in 2003 significantly reduced the likelihood, frequency and intensity of partial leadership identification. Although there is no explicit regulation requirement on the text content in analyst reports, analysts have become more conservative in identifying a firm as a leader after the Global Settlement. This study helps investors to understand the incremental information of leadership identification in analyst reports, beyond the quantitative outputs such as stock recommendations.
478

Adaptação e aceleração do middleware Ginga-NCL para o sistema-em-chip do SBTVD

Freitas, Bruno Policarpo Toledo January 2014 (has links)
Este trabalho tem por finalidade aprimorar o Sistema-em-Chip (SoC) desenvolvido para um "Set-Top Box"de Televisão Digital com a capacidade de executar aplicações segundo o Sistema Brasileiro de Televisão Digital (SBTVD) e melhorar o desempenho do novo sistema. A "Rede H.264"e o "GingaCDN", dois projetos desenvolvidos anteriormente relacionados à Televisão Digital, foram utilizados como base para esse trabalho. A Rede H.264 teve como principal objetivo o desenvolvimento de codificadores e decodificadores para o padrão brasileiro. O resultado foi um SoC para "Set-Top Box"que inclui uma interface de usuário, um processador e os decodificadores de áudio e vídeo com suas respectivas interfaces de saída. Por outro lado, o GingaCDN criou uma implementação de referência para o middleware do SBTVD, denominado Ginga. O primeiro passo foi adicionar regras para compilar o Ginga no ambiente de desenvolvimento do SoC, sendo necessárias diversas mudanças na infraestrutura do middleware. O desempenho do sistema é melhorado através de hardware-software codesign onde as primitivas do Ginga que consomem maior tempo de processamento e de processador foram implementadas em hardware. O ganho obtido ocorre devido a dois fatores: o sistema se torna mais rápido e os recursos da CPU são liberados para outras aplicações. Neste trabalho, o alvo foi o subsistema gráfico do middleware, onde o impacto é mais significativo. Um estudo das características do hardware do sistema foi realizado e, então, uma função gráfica foi escolhida e implementada em hardware. Todas as etapas para substituir uma função em software por outra equivalente em hardware são descritas no texto. Entre as contribuições deste trabalho, abre-se espaço para dar continuidade à expansão das capacidades do "Set-Top Box"por meio de módulos de hardware, melhorando a eficiência do SoC para esta aplicação, dito então "Ginga-ready". A experiência pode ser estendida também para auxiliar a geração de middleware para outras plataformas. / This work aims to enhance a System-on-Chip (SoC) designed for Digital Television Set-Top Box in order to run applications according to the Brazilian Television standard (SBTVD) and to increase the performance by hardware. Two previous projects related to the Digital Television, "Rede H.264" and "GingaCDN", were used as base for this work. The "Rede H.264" had as main objective the development of codecs for the Brazilian standard. The result was a SoC for a Set-Top Box which includes a processor, audio and video decoders with output drivers, and user interface. Otherwise, the "GingaCDN" created a reference implementation for the middleware of the SBTVD, called Ginga. The first step was to add rules to compile Ginga on the development environment of the SoC, for which some configuration of the Ginga middleware needed to be changed. Performance improvement was obtained by hardware-software codesign where Ginga primitives that are time and processor consuming could be implemented in hardware. The gain is twofold: the system becomes faster and CPU resources are freed for other applications. In this work, the target was the graphical subsystem primitives of the middleware, where the impact is more significant. A study of the hardware characteristics of the system was made, and then a graphical function was chosen and implemented on hardware. All the steps needed to substitute a software function by an equivalent one implemented in hardware are described in the text. Among the contributions of this work, the way is openned to continue the expansion of the capabilities of the Set-Top Box by efficient hardware modules on a so called "Ginga-ready" SoC. The experience may be useful also to help the generation of the middleware for other platforms.
479

Office Managing Partners, Non-Audit Services, and Audit Quality

January 2016 (has links)
abstract: This study investigates the relation between the line of service (audit, tax, advisory) of Big Four office managing partners (OMPs) and both non-audit service fees and audit quality. Given that audit quality has been shown to vary across offices and because changes in office-level leadership can impact the office culture, I examine the impact of the OMP’s line of service on non-audit service fees and audit quality. I find that when an accounting firm office changes leadership to an advisory OMP, non-audit service revenues increase while audit quality suffers. This finding is consistent with advisory partners encouraging an office culture that emphasizes selling non-audit services more than conducting quality audits. Overall, this study provides evidence consistent with regulators’ concerns that the recent trend toward greater advisory services at the largest accounting firms reduces their focus on providing high-quality audits, thereby leading to decreased audit quality. / Dissertation/Thesis / Doctoral Dissertation Accountancy 2016
480

Due Diligence in Cross-Border M&As : Top Management Team's human capital affecting the speed of due diligence process

Salakka, Matti, Sabernik, Jürgen January 2018 (has links)
Master Thesis in Business Administration Title:           Due Diligence in Cross-border M&As - Top management team´s human capital affecting speed of due diligence process Authors:       Jürgen Sabernik and Matti Salakka Tutor:          Tommaso Minola, Ph.D. Date:           2018-05-21 Key Terms:   Mergers & Acquisitions, Due Diligence, Speed, Cross-border, Human Capital, Top Management Team   Abstract Problem:       Globalization and market saturation are a constant influence for all the participating businesses in the markets. Therefore, companies of all various sizes are considering mergers & acquisitions to either consolidate the market, use it as a market growth opportunity or entry strategy into a new market or even country. Due to these multidimensional processes, many of the attempted M&As fail. Practitioners tend to focus only on financial or legal characteristics when considering to acquire and afterwards merge the target company, which results into failed M&A process. Accordingly, multifaceted phenomena such as M&As should not be only assessed on two dimensions, they should rather be evaluated as a whole with a dynamic due diligence process along the M&A. Purpose:     The purpose of this thesis is to investigate the speed of dynamic due diligence process in cross-border mergers and acquisitions and what effect the human capital of an organization’s top management has on it. Method:     For this thesis, we utilize a qualitative research based on a multiple case study approach. Therefore, we investigated four case companies within different industries in the Finnish context. The primary empirical data was collected through semi-structured interviews with guidance from a topic guide, in addition we also used company information such as annual reports or the company websites as secondary data. The derived statements are based on the findings, which were categorized and afterwards adopted as a basis for the analysis. Findings:       The findings of this thesis are that the human capital factors affect the speed of the due diligence process in cross-border mergers and acquisitions via four themes; (1) business environment, (2) market knowledge, (3) inter-organizational leadership and (4) individual skills. The themes can affect the speed directly, but more importantly through the interplay of different themes.  Conclusion:    In conjunction with various authors mentioned in this thesis, we also come to the conclusion that a dynamic due diligence process is contributional in order to grasp the multidimensionality of mergers & acquisitions. Additionally, the context where the individual M&A is happening is playing a major role within the evaluation process. Hence, top management team’s human capital has an impact on the speed of dynamic DD process in cross-border M&As via the four above mentioned themes.

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