721 |
Casting Spells Or; Exploring The Hollow : Differences and similarities in the artistic- and architectural creative processes and their implicationsWettainen, Sofia January 2022 (has links)
This thesis rest upon a distinction between the artistic creative process on the one hand and the architectural creative process on the other. This distinction rest upon the writers own experiences of both fields. The thesis aim to discuss similarities and discrepancies between the two and ground this reasoning in theoretical texts. Starting out by analyzing the introduction of photography into the realm of architecture, this thesis makes the claim that our processes has since this introduction been increasingly ruled by the point of view of the camera and decreasingly ruled by our experiences as physical bodies in space. Arguing that this has a negative impact on both the spaces we create and on the quality and joy of our creative processes the thesis connects this to the never ending aim for efficiency, an aim facilitated by computer software. The thesis proceeds by stating that this negative impact ought to be more analysed, and that architects might have things to gain by welcoming in parts that might seem evident for an artist in their processes i.e. time for reflection, a valuing of mistakes as holders of potential and knowledge, the notion of play, and the possibility to fail and perhaps even perceive those failures as treasures rather then perceive them as failed perfectionism. In a fragment of my case study, accounted for in the appendix to this written report, the thesis dives in to one of the mistakes created during the architectural project of the thesis. Aiming to prove the point that no mistake is without potential, I let this case study illustrate how this specific mistake came to be a founding part of the whole project. The thesis argues that when one person sees and/or experiences what another might deem as a mistake, their interpretation might lead to new ideas and possibilities. Hence, in order for a project or an art piece to reach its full potential, the thesis concludes that no one should perform processes of architecture, nor art, completely alone.
|
722 |
Radio Wave Propagation Measurements and Modeling for Land Mobile Satellite SystemsMousselon, Laure 09 December 2002 (has links)
The performance of a mobile satellite communications link is conditioned by the characteristics of the propagation path between a satellite and mobile users. The most important propagation effect in land mobile satellite system is roadside attenuation of the signals due to vegetation or urban structures. System designers should have the most reliable information about the statistics of the propagation channel to build reliable systems that can compensate for bad propagation conditions.
In 1998, the Virginia Tech Antenna Group developed a simulator, PROSIM, to simulate a propagation channel in the case of roadside tree attenuation in land mobile satellite systems. This thesis describes some improvements to PROSIM, and the adaptation and validation of PROSIM for Digital Audio Radio Satellite systems operating at S-band frequencies. The performance of the simulator for S-band frequencies was evaluated through a measurement campaign conducted with the XM Radio signals at 2.33 GHz in various propagation environments. Finally, additional results on dual satellite systems and fade correlation are described. / Master of Science
|
723 |
Investing in the Future: The Performance of Green Bonds Compared to Conventional Bonds and StocksSöderman, Mats, Haglund, Markus January 2024 (has links)
As the world faces unprecedented environmental challenges, there is an urgent need for largescale investments in green infrastructure and technologies. If we are going to achieve carbon neutrality, significant investments are necessary, and therefore must the entire financial system unite and endorse sustainable investment activities in a market-oriented manner. A green bond is a relatively new type of bond. It was first introduced in 2007 by the European Investment Bank (EIB). This was followed up by a collaboration between Skandinaviska Enskilda Banken (SEB) and the World Bank, a group of Swedish investors, pension funds, and SRI-focused investors. They issued their first green bond in 2008 intending to attract more investors. However, this attempt to increase the interest did not work, green bonds were almost nonexistent until 2013. One explanation for the slow development of the green bond market was the financial crisis in 2008. Further, the reason for the low interest in green bonds during this period was that traditional investors deemed these risky and non-profitable. Using a deductive approach, this thesis investigates how green bonds perform compared to conventional bonds and stocks from the issuing company. The authors sampled green and conventional bonds from 33 companies that matured from 2018 to 2023. The sample data set contains bonds from Asia, Europe, South America, North America, and Australia. The data was tested using multiple hypotheses. This thesis sets out to answer the research question: How do green bonds perform compared to conventional bonds and stocks? The results indicated there is a significant difference between the three asset types. First, the stocks yield higher returns and higher standard deviations than green and conventional bonds. Second, the authors found no evidence for a difference in return thus a significant difference in standard deviation. The results also suggest there is a difference in modified duration, convexity, maturity, and yield to maturity. These findings indicate that green bonds performed better than conventional bonds, especially regarding risk and volatility. Therefore, could green bonds be useful when diversifying a portfolio. The findings suggested that a portfolio composition that combines the three assets could be in line with both shareholder theory and stakeholder theory. The portfolio theory also provides interesting insights into the potential portfolio optimizations since there are differences between green and conventional bonds. Since no difference in the return was found for green and conventional bonds the authors find no reason to support the idea of herding behavior in the trading of green bonds. However, the difference in standard deviation is interesting from a behavioral perspective, a lower standard deviation indicates that the green bond experiences lower volatility compared to conventional bonds.
|
724 |
Performance optimization mechanisms for fault-resilient VLIW processors / Mécanismes d'optimisation des performances des processeurs VLIW à tolérance de fautesPsiakis, Rafail 21 December 2018 (has links)
Les processeurs intégrés dans des domaines critiques exigent une combinaison de fiabilité, de performances et de faible consommation d'énergie. Very Large Instruction Word (VLIW) processeurs améliorent les performances grâce à l'exploitation ILP (Instruction Level Parallelism), tout en maintenant les coûts et la puissance à un niveau bas. L’ILP étant fortement dépendant de l'application, le processeur n'utilise pas toutes ses ressources en permanence et ces ressources peuvent donc être utilisées pour l'exécution d'instructions redondantes. Cette thèse présente une méthodologie d’injection fautes pour processeurs VLIW et trois mécanismes matériels pour traiter les pannes légères, permanentes et à long terme menant à trois contributions.La première contribution présente un schéma d’analyse du facteur de vulnérabilité architecturale et du facteur de vulnérabilité d’instruction pour les processeurs VLIW. Une méthodologie d’injection de fautes au niveau de différentes structures de mémoire est proposée pour extraire les capacités de masquage architecture / instruction du processeur. Un schéma de classification des défaillances de haut niveau est présenté pour catégoriser la sortie du processeur. La deuxième contribution explore les ressources inactives hétérogènes au moment de l'exécution, à l'intérieur et à travers des ensembles d'instructions consécutifs. Pour ce faire, une technique d’ordonnancement des instructions optimisée pour le matériel est appliquée en parallèle avec le pipeline afin de contrôler efficacement la réplication et l’ordonnancement des instructions. Suivant les tendances à la parallélisation croissante, une conception basée sur les clusters est également proposée pour résoudre les problèmes d’évolutivité, tout en maintenant une pénalité surface/énergie raisonnable. La technique proposée accélère la performance de 43,68% avec une surcoût en surface et en énergie de ~10% par rapport aux approches existantes. Les analyses AVF et IVF évaluent la vulnérabilité du processeur avec le mécanisme proposé.La troisième contribution traite des défauts persistants. Un mécanisme matériel est proposé, qui réplique au moment de l'exécution les instructions et les planifie aux emplacements inactifs en tenant compte des contraintes de ressources. Si une ressource devient défaillante, l'approche proposée permet de relier efficacement les instructions d'origine et les instructions répliquées pendant l'exécution. Les premiers résultats de performance d’évaluation montrent un gain de performance jusqu’à 49% sur les techniques existantes.Afin de réduire davantage le surcoût lié aux performances et de prendre en charge l’atténuation des erreurs uniques et multiples sur les transitoires de longue durée (LDT), une quatrième contribution est présentée. Nous proposons un mécanisme matériel qui détecte les défauts toujours actifs pendant l'exécution et réorganise les instructions pour utiliser non seulement les unités fonctionnelles saines, mais également les composants sans défaillance des unités fonctionnelles concernées. Lorsque le défaut disparaît, les composants de l'unité fonctionnelle concernés peuvent être réutilisés. La fenêtre de planification du mécanisme proposé comprend deux ensembles d'instructions pouvant explorer des solutions d'atténuation lors de l'exécution de l'instruction en cours et de l'instruction suivante. Les résultats obtenus sur l'injection de fautes montrent que l'approche proposée peut atténuer un grand nombre de fautes avec des performances, une surface et une surcharge de puissance faibles. / Embedded processors in critical domains require a combination of reliability, performance and low energy consumption. Very Long Instruction Word (VLIW) processors provide performance improvements through Instruction Level Parallelism (ILP) exploitation, while keeping cost and power in low levels. Since the ILP is highly application dependent, the processor does not use all its resources constantly and, thus, these resources can be utilized for redundant instruction execution. This thesis presents a fault injection methodology for VLIW processors and three hardware mechanisms to deal with soft, permanent and long-term faults leading to three contributions. The first contribution presents an Architectural Vulnerability Factor (AVF) and Instruction Vulnerability Factor (IVF) analysis schema for VLIW processors. A fault injection methodology at different memory structures is proposed to extract the architectural/instruction masking capabilities of the processor. A high-level failure classification schema is presented to categorize the output of the processor. The second contribution explores heterogeneous idle resources at run-time both inside and across consecutive instruction bundles. To achieve this, a hardware optimized instruction scheduling technique is applied in parallel with the pipeline to efficiently control the replication and the scheduling of the instructions. Following the trends of increasing parallelization, a cluster-based design is also proposed to tackle the issues of scalability, while maintaining a reasonable area/power overhead. The proposed technique achieves a speed-up of 43.68% in performance with a ~10% area and power overhead over existing approaches. AVF and IVF analysis evaluate the vulnerability of the processor with the proposed mechanism.The third contribution deals with persistent faults. A hardware mechanism is proposed which replicates at run-time the instructions and schedules them at the idle slots considering the resource constraints. If a resource becomes faulty, the proposed approach efficiently rebinds both the original and replicated instructions during execution. Early evaluation performance results show up to 49\% performance gain over existing techniques.In order to further decrease the performance overhead and to support single and multiple Long-Duration Transient (LDT) error mitigation a fourth contribution is presented. We propose a hardware mechanism, which detects the faults that are still active during execution and re-schedules the instructions to use not only the healthy function units, but also the fault-free components of the affected function units. When the fault faints, the affected function unit components can be reused. The scheduling window of the proposed mechanism is two instruction bundles being able to explore mitigation solutions in the current and the next instruction execution. The obtained fault injection results show that the proposed approach can mitigate a large number of faults with low performance, area, and power overhead.
|
725 |
Parní turbina jako točivá redukce / Steam turbine for steam reductionBrabec, Vít January 2011 (has links)
The dissertation analyses a possibility to install a steam turbine for steam reduction in the heating plant with a combined cycle, Červený Mlýn. In the first part of this work the constituent parts of Červený Mlýn plant are briefly described. Basic information is included about two considered solutions to the steam turbine for steam reduction. Then the thermic diagram of the whole heating plant and the heat exchanger station itself is presented. On the basis of the given values of the heat required in the hydrothermal system, duration of the steam flow through both variants of the steam turbine for steam reduction is determined. The thermodynamic calculation of the steam turbine for steam reduction is aimed at determination of the power output and its comparison with the power outputs of the steam turbines for steam reduction considered. In the economical profitability calculation, basic economical quantities are given for both the solutions and the more suitable solution is recommended.
|
726 |
Risk-adjusted Earned Value and Earned Duration Management models for project performance forecastingApostolidou, Ilektra-Georgia, Karmiris, Georgios January 2019 (has links)
Project control is essential to ensure that the investment on a project is providing the intended benefits and is valuable to the customers. Previous methods offer project performance monitoring and forecasting tools, but they lack accuracy and the associated techniques omit the project financial risk (any unplanned event that has an impact on schedule and budget); the main factor of project failure. Poor project execution, and particularly failure to control and accurately forecast the project performance, may lead to increased costs, upset customers and eventually loss of market share. These gaps have been filled in this study by the development of novel models that use statistical analysis of the previous project performance, including risk evaluation techniques. The proposed models succeeded in providing remarkably improved forecasts in three project dimensions: duration, cost and resources. The robustness of the models has been verified by testing them on real projects. The results show superiority in terms of accuracy and easy application compared to any existing method, proving that the risk inclusion provides improvement compared to previous studies. The most important features of the models are: risk-based adjustment of the forecasted values, periodic and completion forecasts, statistical processing and holistic approach. The greatest advancements have been made in the cost forecast, for which the risk adjustment inclusion is examined for the first time. The resources (man-hours) forecast is another pioneer element of the proposed models. All the above provide a complete image of the project status and paint the picture of future performance. The models results are fed in a Decision Support System, which highlights the overperforming and underperforming areas of the project. This confirms the proposition that the model results can be used to initiate restorative action. The contribution of this study to the project management field is easy-to-use and accurate models, which include the financial risk and facilitate the project manager’s decisions and actions. Anticipation of the project performance, by considering the risk, can result to significant time and cost savings, crucial for project success.
|
727 |
Long term seasonal and annual changes in rainfall duration and magnitude in Luvuvhu River Catchment, South AfricaMashinye, Mosedi Deseree 18 May 2018 (has links)
MESHWR / Department of Hydrology and Water Resources / This study was aimed at investigating the long term seasonal and annual changes in rainfall duration and magnitude at Luvuvhu River Catchment (LRC). Rainfall in this catchment is highly variable and is characterised of extreme events which shift runoff process, affect the timing and magnitude of floods and drought, and alter groundwater recharge. This study was motivated by the year to year changes of rainfall which have some effects on the availability of water resources. Computed long term total seasonal, annual rainfall and total number of seasonal rainy days were used to identify trends for the period of 51 years (1965- 2015), using Mann Kendal (MK), linear regression (LR) and quantile regression methods. The MK, LR and quantile regression methods have indicated dominance of decreasing trends of the annual, seasonal rainfall and duration of seasonal rainfall although they were not statistically significant. However, statistical significant decreasing trends in duration of seasonal rainfall were identified by MK and LR at Matiwa, Palmaryville, Levubu, and Entabeni Bos stations only. Quantile regression identified the statistically significant decreasing trends on 0.2, 0.5 and 0.7 quantiles only in the Palmaryville, Levubu and Entabeni Bos, respectively. Stations with non-statistically significant decreasing trends of annual and seasonal rainfall had magnitude of change ranging from 0.12 to 12.31 and 0.54 to 6.72 mm, respectively. Stations with non-statistically increasing trends of annual and seasonal rainfall magnitude had positive magnitude of change ranging from 1.51 to 6.78 and 2.05 to 6.51 mm, respectively. The Study recommended further studies using other approaches to determine the duration of rainfall to improve, update and compare the results obtained in the current study. Continuous monitoring and installation of rain gauges are recommended on the lower reaches of the catchment for the findings to be of complete picture for the whole catchment and to also minimize the rainfall gaps in the stations. Water resources should be used in a sustainable way to avoid water crisis risk in the next generations. / NRF
|
728 |
La distinction entre la formation et l’exécution du contrat : contribution à l’étude du contrat dans le temps / Distinction between the stage of formation and execution at the contract : contribution to the study on the contract of durationVan Haecke-Lepic, Sabine 07 December 2017 (has links)
C’est au cours de l’étude de la distinction entre la formation et l'exécution du contrat que s’est imposée une réflexion sur une autre alternative au modèle du contrat à exécution instantanée : le contrat de durée. En consacrant un modèle de contrat hors du temps le droit contractuel s’est construit sur une chimère. En effet, en niant l’infiltration du temps dans le contrat, les frontières entre la formation et l’exécution se sont fissurées. Devant cet état de fait, les attentes de clarification de la réforme furent nombreuses. Cependant, la réforme du droit des contrats bien que codifiant les apports épars de la jurisprudence n’en a pas tiré les conséquences de fond en consacrant une possible incomplétude du contrat à sa formation. En continuant à ignorer l’impact de la durée sur les contrats qui s’exécutent dans le temps, la réforme a aggravé l’éclatement des concepts et a empêché le droit commun d’évoluer.L’auteur s’est attaché donc à vouloir englober l’ensemble de la réalité contractuelle en faisant émerger à côté du modèle du contrat échange, le modèle du contrat de durée. La proposition d’un contrat de durée serait donc de nature à réconcilier le droit contractuel entre la culture contractuelle de l’échange et la culture contractuelle de la coopération qui prend naissance dans la durée. La durée du contrat transforme le contrat et émancipe son exécution en permettant au moment de la formation une certaine incomplétude. / While studying the distinction between the preparation and the execution of a contract, a reflection on a new alternative to the contract of instantaneous performance imposed itself: an adjustable circumstance-based contract. Devoted to a timeless model of contract, contract law has built itself on a pipe dream. Indeed, the negation of time’s infiltration in a contract led the boundaries between preparation and execution to crack apart. In front of this situation the expectations for clarification with the reform were numerous. However, the 2016 reform of contract law, although systematising the scattered provisions of case law, did not drew the needed conclusions by sanctioning the possible incompleteness of a contract in its preparation. Still ignoring time’s impact in time-based contracts, the 2016 reform has worsened the splitting of concepts and prevented the evolution of common right. Thus the author focused on embracing the whole of contractual reality and developing alongside the swap contract: the adjustable circumstance-based contract. Contract law has indeed been confronted to types of contract that struggled to integrate duration but which, in the need to happen alongside a unique swap model, distorted its concepts. This is why the offer of an adjustable circumstance-based contract would be able to reconcile, in contract law, the contract culture of swap and the contract culture of cooperation which arise in duration.
|
729 |
Univariate and Bivariate ACD Models for High-Frequency Data Based on Birnbaum-Saunders and Related DistributionsTan, Tao 22 November 2018 (has links)
This thesis proposes a new class of bivariate autoregressive conditional median duration models for matched high-frequency data and develops some inferential methods for an existing univariate model as well as the bivariate models introduced here to facilitate model fitting and forecasting. During the last two decades, the autoregressive conditional mean duration (ACD) model has been playing a dominant role in analyzing irregularly spaced high-frequency financial data. Univariate ACD models have been extensively discussed in the literature. However, some major challenges remain. The existing ACD models do not provide a good distributional fit to financial durations, which are right-skewed and often exhibit unimodal hazard rates. Birnbaum-Saunders (BS) distribution is capable of modeling a wide variety of positively skewed data. Median is not only a robust measure of central tendency, but also a natural scale parameter of the BS distribution. A class of conditional median duration models, the BS-ACD and the scale-mixture BS ACD models based on the BS, BS power-exponential and Student-t BS (BSt) distributions, have been suggested in the literature to improve the quality of the model fit. The BSt-ACD model is more flexible than the BS-ACD model in terms of kurtosis and skewness. In Chapter 2, we develop the maximum likelihood estimation method for the BSt-ACD model. The estimation is performed by utilizing a hybrid of optimization algorithms. The performance of the estimates is then examined through an extensive Monte Carlo simulation study. We also carry out model discrimination using both likelihood-based method and information-based criterion. Applications to real trade durations and comparison with existing alternatives are then made. The bivariate version of the ACD model has not received attention due to non-synchronicity. Although some bivariate generalizations of the ACD model have been introduced, they do not possess enough flexibility in modeling durations since they are conditional mean-based and do not account for non-monotonic hazard rates. Recently, the bivariate BS (BVBS) distribution has been developed with many desirable properties and characteristics. It allows for unimodal shapes of marginal hazard functions. In Chapter 3, upon using this bivariate BS distribution, we propose the BVBS-ACD model as a natural bivariate extension of the BS-ACD model. It enables us to jointly analyze matched duration series, and also capture the dependence between the two series. The maximum likelihood estimation of the model parameters and associated inferential methods have been developed. A Monte Carlo simulation study is then carried out to examine the performance of the proposed inferential methods. The goodness-of-fit and predictive performance of the model are also discussed. A real bivariate duration data analysis is provided to illustrate the developed methodology. The bivariate Student-t BS (BVBSt) distribution has been introduced in the literature as a robust extension of the BVBS distribution. It provides greater flexibility in terms of the kurtosis and skewness through the inclusion of an additional shape parameter. In Chapter 4, we propose the BVBSt-ACD model as a natural extension of the BSt-ACD model to the bivariate case. We then discuss the maximum likelihood estimation of the model parameters. A simulation study is carried out to investigate the performance of these estimators. Model discrimination is then done by using information-based criterion. Methods for evaluating the goodness-of-fit and predictive ability of the model are also discussed. A simulated data example is used to illustrate the proposed model as compared to the BVBS-ACD model. Finally, in Chapter 5, some concluding comments are made and also some problems for future research are mentioned. / Thesis / Master of Science (MSc)
|
730 |
A total quality management (TQM) strategic measurement perspective with specific reference to the software industryPohl, Martha Jacoba. 11 1900 (has links)
The dissertation aims to obtain an integrated and comprehensive perspective on measurement issues that play a strategic role in organisations that aim at continuous quality improvement through TQM. The multidimensional definition of quality is proposed to view quality holistically. The definition is dynamic, thus dimensions are subject to evolution. Measurement of the quality dimensions is investigated. The relationship between quality and cost, productivity and profitability respectively is examined. The product quality dimensions are redefined for processes. Measurement is a strategic component ofTQM. Integration of financial measures with supplier-;
customer-; performance- and internal process measurement is essential for synergism. Measurement of
quality management is an additional strategic quality dimension. Applicable research was integrated. Quantitative structures used successfully in industry to achieve quality improvement is important, thus the quality management maturity grid, cleanroom software engineering, software factories, quality function deployment, benchmarking and the ISO 9000 standards are briefly described. Software Metrics Programs are considered to be an application of a holistic measurement approach to quality. Two practical approaches are identified. A framework for initiating implementation is proposed. Two strategic software measurement issues are reliability and cost estimation. Software reliability measurement and modelling are introduced. A strategic approach to software cost estimation is suggested. The critical role of data collection is emphasized. Different approaches
to implement software cost estimation in organisations are proposed. A total installed cost template as the ultimate goal is envisaged. An overview of selected software cost estimation models is provided. Potential research areas are identified. The linearity/nonlinearity nature of the software production function is analysed. The synergy between software cost estimation models and project management techniques is investigated. The quantification aspects of uncertainty in activity durations, pertaining to project scheduling, are discussed. Statistical distributions for activity durations are reviewed and compared. A structural view of criteria determining activity duration distribution selection is provided. Estimation issues are reviewed. The integration of knowledge from dispersed fields leads to new dimensions of interaction. Research and practical experience regarding software metrics and software metrics programs can be successfully applied to address the measurement of strategic indicators in other industries. / Business Management / D. Phil. (Operations Research)
|
Page generated in 0.067 seconds