39 research outputs found
Recovery Capacity: To Build Back Better
No full textThe ambition to Build Back Better after a serious flood disaster is a complex challenge. A comprehensive, multi-disciplinary redevelopment planning process is required to reduce the flood risk and meanwhile create sustainable solutions that bring added value to society every day. General planning principles can be formulated on how to develop the physical conditions for flood resilience, while building a better place to live and work. Scoping and the charrette method are to be applied for pairing and integrating disciplinary results, to co-create Better plans in an interdisciplinary planning process. Two disaster recovery cases in Japan, after the 2011 Tohoku tsunami, and one case on Grand Bahama, after 2019 hurricane Dorian, were studied by multidisciplinary teams of students and staff to investigate in how far Building Back Better was, or is to be, realized. This was done by confronting the practice of the reconstruction process and the resulting plans with the guiding principles for the physical concepts and interdisciplinary planning approach. Practice shows that Building Back Better is suffering from a lack of integration of disciplinary solutions, guided by existing planning regulations and practices and driven by the need for flood safety and by the urgency of the reconstruction works.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Water ResourcesEnvironmental Technology and Desig
The effect of Q on performance: Evidence from US M&A deals
No full textThis thesis investigates the influence of firm valuation, measured by Tobin's Q, on U.S. M&A performance. Contrary to traditional Q-theory, our findings reveal that high-Q acquirers consistently underperform in both short-term market reactions and long-term operating profitability. This could suggests high valuations may be linked to managerial overconfidence and capital misallocation, leading to value-destroying acquisitions.
Furthermore, mergers involving jointly high-Q firms or those within the same industry did not consistently yield superior outcomes. Notably, Q-value mismatches in same-industry mergers negatively impacted long-term performance. This thesis also find that large deal values in high-Q to low-Q transactions did not signal successful capital reallocation and were associated with poorer long-term results.
These findings underscore that managerial discipline and effective post-merger integration are crucial for M&A success rather than only firm valuation or industry overlap. This thesis cautions against uncritically interpreting high valuations or large deal sizes. Future research should explore nuanced measures and qualitative factors impacting M&A outcomes
Grand Bahama after Hurricane Dorian: Interdisciplinary approach to Build Back Better
No full textIn collaboration with the University of the Bahamas, we used the Charette model, the Three-point Approach and the conceptual framework: Build Back Better to propose a solution that involves several aspects: Reduced risk overall, increased social cohesion on the island, improved life quality and reduced costs during reconstruction in the aftermath of a hurricane event. Based on the analysis of the island, the hurricane and the important physical processes, a division between protection method is proposed based on the location on the island: collective andindividual protection.The main vision for the reconstruction of Grand Bahama is to Build Back Better. This is done by taking an interdisciplinary approach and connecting engineering to spatial planning and design. The proposed strategy reduces the risk by taking into account exposure and vulnerability of the general risk approach. The main point of the strategy is to create a resilient urban environment in which vital infrastructure like the airport remains functional. This is done by making a collective protection zone of the economic and social city centre of Freeport, a zone that also offers shelter. Individual protection and evacuation shelters will be given to residents, buildings and facilities in the less densely built areas, east and west of the city.MP31
Wing deformation measurements of the DelFly II in different flight conditions
No full textThis study investigates the wing deformation of the flapping-wing micro air vehicle (MAV) DelFly II in various flight configurations. Experiments were carried out with the MAV tethered in a windtunnel test section. To determine the best suited measurement approach, a trade-off study was carried out which showed that a point tracking approach with background illumination is most suitable. The therefore used high-speed camera pair and illumination were mounted on the same rotating frame with the DelFly, which allowed adequate viewing axes of the wings at for all pitch angles. Processing was done a purpose-build algorithm, allowing 136 points per wing to be measured simultaneously with an average lost point ratio of 3.4 % and an estimated accuracy of 0.25 mm. Results of hovering flight show some previously unnoticed behaviors. First, it was noted that the upper and lower wing on each side do not deform purely symmetric but show some considerable asymmetric behavior like heave and camber production. Furthermore, the upper wing shows a torsional wave and recoil behavior at faster flapping frequencies, which was shown to be beneficial in insect flight. Lastly, it was found that an air-buffer remains present between the wing surfaces at all times of the clap-and-peel motion (apart from the root trailing edge). This air-buffer increases once freestream velocity is added, which is investigated during the climbing flight study. Here, the reduced angle of attack of the wing is assumed to reduce the wing loading at faster climb, resulting in lower deformations outside the clap-and-peel motion. The isolated effect of a body pitch angle is also studied. Here, the asymmetrical freestream direction results in larger asymmetries such as wing alignment with the freestream direction and reduced camber and even camber reversal during the upstroke. In forward flight the pitch angle is changed simultaneously with the flapping frequency and freestream velocity. Due to the non-linear properties the wing deforms not directly as a superposition of the individual effects. Deviations are mostly present in increased asymmetry in incidence angle, while the camber behaves more linear and the clap-and-peel motion also remains relatively unchanged. The torsional wave and recoil are here however reduced. Descending flight was also tested. Velocities below 1m/s result in relatively minor deformation changes, while faster descent leads to large flapping frequency fluctuations, making interpretation of the results impossible.Aerospace Engineerin
New Trends and Challenges for Energy Geographies: Introduction to the Special Issue
No full textabstract: In 1961, the Canadian geographer John D. Chapman recognized the rapid growth in demand for inanimate energy and the role geographers could be playing in explaining its patterns and importance in the growing world economy (Chapman, 1961). Fifty years later, Karl Zimmerer (2011) introduced a Special Issue of the Annals of the Association of American Geographers by noting that not only had Chapman’s prediction come true but that geographers were studying even a wider spectrum of energy challenges than Chapman could ever have imagined (see e.g. Dorian et al., 2006; Florini, Sovaccol, 2009)
Reconstructing Beethoven: Mauricio Kagel’s Ludwig van
No full textThe subject of this dissertation is Ludwig van, Mauricio Kagel’s tribute to Beethoven on the occasion of the 200th anniversary of the latter’s birth, which consists of three separate, but closely related, versions: a film, a musical score and a recording. The main aim of this project is to analyse the performance problems that musicians have to face when realising the score Ludwig van, which is an entirely indeterminate collage of Beethoven’s music, and to suggest ways of tackling them. For this purpose, all three versions of the work are studied in this thesis. The film is examined in terms of the issues it raises concerning Beethoven’s reception and of the function of its music, which consists of unusual performances of Beethoven’s works. The score is analysed from the perspective of postmodern theory and 20th-century art movements, while the roles of the composer and the performer are discussed and redefined. The recording is studied as a sample of how Kagel himself chose to realise his own score. Finally, the difficulties I encountered in my own attempts to realise Ludwig van are discussed, and the ways in which I dealt with them are presented. The conclusion at which this dissertation arrives is that, in works of such indeterminacy as Ludwig van, the performers are required to step outside their conventional role and act partly as composers. Compared to works that are considered challenging to the performer in the conventional sense, of requiring technical virtuosity, this work presents a more fundamental challenge, which has to do with overcoming personal boundaries: it asks the performer not to execute a pre-composed work, but to create their own version of Ludwig van. Since very little has been written about Ludwig van by performers with an academic background, this thesis can offer valuable assistance to prospective performers of the work in their attempt to balance between the highly charged conceptual aspect of the composition and the practical need to achieve its successful performance
Effects of asymmetrical inflow in forward flight on the deformation of interacting flapping wings
No full textThis study investigates the wing deformation of a flapping-wing micro air vehicle (MAV) in climbing and forward flight conditions. A measurement setup was developed that maintains adequate viewing axes of the wings for all pitch angles. Recordings of a high-speed camera pair are processed using a point tracking algorithm, allowing 136 points per wing to be measured simultaneously with an estimated accuracy of 0.25mm. Results of the climbing flight study show that although inflow is symmetric, the wing deformations are slightly asymmetric. Furthermore, it was found that an air-buffer remains present between the wing surfaces at all times, especially with increased freestream velocity. Apart from a minor camber reduction, the clapand- peel motion remains mostly unchanged for changing velocities, while during the remaining cycle the incidence angle and camber ratio are reduced, together with the angle of attack. In forward flight the clap-and-peel motion is twisted around its contact area to align with the inflow direction, while the general deformation remains unchanged, suggesting similar effectiveness as in hover. Positive mean incidence angles are present for the entire cycle, especially for fast forward flight and stroke reversals. Furthermore, camber is positive during downstroke, while approaching zero for the upstroke in fast forward flight, which suggests low loading during the upstroke.AerodynamicsControl & Simulatio
GPS Location Tracker: Collecting data for sports visualisation
No full textA start-up creates videos which users can watch to experience their running or cycling activity all over again. Currently, the company depends on external data sources to generate a video. To be less dependent on these sources the company wants to create their own tracking solution. This solution has to fit in their existing smartphone application available for iOS and Android. The company wants to remain flexible, therefore the tracking application has to be developed in such a way that it can also be used in other products the company might develop in the future. As a goal, the data has to result in visually pleasing videos for a large user base.Based on an experimental app developed during the research phase, raw smartphone GPS data was found to be unsuitable for video rendering. To improve this data, a Kalman Filter is used, in combination with a smoothing algorithm. The system has been designed to allow code sharing between iOS and Android where possible. The system has been implemented in Objective-C, Java, and TypeScript. Separating the system in three blocks enables code reuse which improves maintainability of the system. The filter has been integrated as shared code in the TypeScript implementation, which allows filtering to happen on the device. The user of the React Native Module developed has freedom to retrieve the unprocessed and processed data.The system has been tested by means of unit tests in all three programming languages used. Tests have been executed using a continuous integration server, testing each pull request against the current code base to ensure quality. Part of the testing phase includes the React Native Module to be implemented in the client's smartphone application to demonstrate its use. The application has been sent to a number of test participants to collect data from different routes and activities. The project can be seen as a success since all important requirements have been successfully implemented.<br/
The women from Rhodesia: an auto-ethnographic study of immigrant experience and [Re] aggregration in Western Australia
No full textThis thesis examines the positioning of white, English-speaking, immigrant women from Africa to Australia. I explore the effects that minimal differences have on issues of identity. Notions of identity, memory, and belonging are contrasted with white settlement in Rhodesia in the last century. My personal history and the desire to write a thesis relevant to the Australian experience led me to ask, How do women from a privileged background, from Rhodesia and Zimbabwe, understand their experiences as immigrants to Australia? The relevance lies in the perception that Australia is populated by immigrants and this research interrogates at a deeper level some specific issues presented by this sample group and my interpretation of their experiences augments the literature in this area. I questioned (individually) a small group of immigrants using unstructured interviews; the use of my own experiences and 'long/desk drawer' makes the study significantly autobiographical. Notions of migration into Australia from Southern Africa are explored using theories and themes of rites de passage. I interrogate the meanings attributed to assimilation and integration in immigration and connect these to the theory. Identity, memory, and reflection are discussed in the context of separation from Africa and integration into Australia. The similarities and differences and embodied history (habitus) that shape us, interweave the trope of rites de passage, uncovering a multiplicity of identity-attributed, assumed, and self-determined. I examine the ways in which Australians of Anglo-Saxon and British origin tend to position English-speaking immigrants from non-British backgrounds as outsiders and suggest that this attribution has more to do with similarities than differences. Reflection and discussion of other times and places reveals how memories intersect with 'new' lives in Australia and the complexities of time in migration as rites de passage make possible an exploration of present experience shadowing earlier experience. Finally, I discover that identity and belonging as continually negotiated spaces are illuminated by the contrast I drew between assimilation and integration as conceptual tools in understanding the migrant experience
Maximum-likelihood estimation in ptychography in the presence of Poisson-Gaussian noise statistics
No full textOptical measurements often exhibit mixed Poisson-Gaussian noise statistics,
which hampers image quality, particularly under low signal-to-noise ratio (SNR)
conditions. Computational imaging falls short in such situations when solely
Poissonian noise statistics are assumed. In response to this challenge, we
define a loss function that explicitly incorporates this mixed noise nature. By
using maximum-likelihood estimation, we devise a practical method to account
for camera readout noise in gradient-based ptychography optimization. Our
results, based on both experimental and numerical data, demonstrate that this
approach outperforms the conventional one, enabling enhanced image
reconstruction quality under challenging noise conditions through a
straightforward methodological adjustment.Comment: Contains main and supplementary document
