Scania works continuously to develop internal combustion engines and after treatment systems which can achieve low pollutant emissions and high efficiency. A major principal that Scania adopted for this goal is the Simulation Driven Development (SDD) process. Here computer aided simulations aid to develop designs and improve characteristics all the while reducing the iterative prototyping and testing process. Currently, parametric modelling and Design of Experiments (DoE) is a proven and major mode of exploring designs within the various stakeholder fields of development; namely structural, fluid mechanics and acoustics.  Topology optimisation in fluid flow is a new field which promises quick exploration of design spaces. The result of topology optimisation are unintuitive designs that could serve as baseline designs which can further reduce the design process. The objective of the thesis was to explore topology optimisation and investigate a way to incorporate topology optimisation in the design process at Scania CV AB. For this task Tosca Fluid by Dassault Systèmes was chosen for its optimisation capabilities, which uses back-flow as the criteria of optimisation. The case study was conducted based on the MTX diesel one box inlet end-plate which was used as reference. The dimensional constraints of the reference product were used to model and utilise the developed workflow. Since this task involved the use of substrates for exhaust gas filtration, it was imperative to explore uniformity of flow over the substrate as an additional optimisation criterion. The project studied modelling design spaces to satisfy the design criteria and the shortcoming the software currently poses have been documented in this report. The report also mentions the tasks involved in setting up simulation cases to work well with Tosca Fluid. In the current stage of the thesis work it was not possible to incorporate uniformity as an additional criterion and hence fails in using Tosca Fluid to optimise topology for turn volumes involving the use of substrates. / Scania arbetar kontinuerligt med att utveckla förbränningsmotorer och efterbehandlings system som kan uppnå låga föroreningar och hög effektivitet. En viktig princip som Scania antog för detta mål är processen Simulation Driven Development (SDD). Här hjälper datorstödda simuleringar att utveckla mönster och förbättra egenskaper samtidigt som den iterativa prototyp- och testprocessen reduceras. För närvarande är parametrisk modellering och Design of Experiments (DoE) ett beprövat och viktigt sätt att utforska konstruktioner inom de olika intressenternas utvecklingsområden; nämligen konstruktion, fluidmekanik och akustik. Topologioptimering i vätskeflöde är ett nytt område som lovar snabb utforskning av designutrymmen. Resultatet av topologioptimering är icke-intuitiva konstruktioner som kan fungera som baslinjedesigner som ytterligare kan minska designprocessen. Syftet med avhandlingen var att utforska topologioptimering och undersöka ett sätt att integrera topologioptimering i designprocessen på Scania CV AB. För denna uppgift valdes Tosca Fluid av Dassault Systèmes för sina optimeringsmöjligheter, som använder återflöddet som kriterier för optimering. Fallstudien genomfördes baserat på MTX diesel först låda inloppsändplatta som användes som referens. Referensproduktens dimensionella begränsningar användes för att modellera och använda det utvecklade arbetsflödet. Eftersom denna uppgift innebar användning av substrat för avgas filtrering, var det absolut nödvändigt att undersöka flödets enhetlighet som ett ytterligare optimerings kriterium. Projektet studerade modellerings designutrymmen för att uppfylla design kriterierna och den brist programvaran för närvarande har dokumenterats i denna rapport. Rapporten nämner också de uppgifter som är involverade i att skapa simuleringsfall för att fungera bra med Tosca Fluid. I det aktuella skedet av avhandlings arbetet var det inte möjligt att införliva enhetlighet som ett ytterligare kriterium och misslyckas därför med att använda Tosca Fluid för att optimera topologi för sväng volymer som involverar användning av substrat.

The wheel-rail contact is at the core of all research related to vehicletrackinteraction. This tiny interface governs the dynamic performanceof rail vehicles through the forces it transmits and, like any high stressconcentration zone, it is subjected to serious damage phenomena. Thus,a clear understanding of the rolling contact between wheel and rail is keyto realistic vehicle dynamics simulation and damage analysis. In a multi-body dynamics simulation, the demanding contact problemshould be evaluated at about every millisecond for several wheel-rail pairs.Hence, a rigorous treatment of the contact is highly time-consuming.Simplifying assumptions are therefore made to accelerate the simulationprocess. This gives rise to a trade-o between the accuracy and computationaleciency of the contact model in use. Conventionally, Hertz+FASTSIM is used for calculation of the contactforces thanks to its low computational cost. However, the elliptic patchand pressure distribution obtained by Hertz' theory is often not realisticin wheel-rail contact. Moreover, the use of parabolic traction bound inFASTSIM causes considerable error in the tangential stress estimation.This combination leads to inaccurate damage predictions. Fast non-elliptic contact models are proposed by others to tacklethis issue while avoiding the tedious numerical procedures. The studiesconducted in the present work show that the accuracy of these models iscase-dependent. To improve the accuracy of non-elliptic patch and pressure estimation,a new method is proposed. The method is implemented in an algorithmnamed ANALYN. Comparisons show improvements in patch and, particularly,pressure estimations using ANALYN. In addition, an alternative to the widely-used FASTSIM is developed, named FaStrip. Unlike FASTSIM, it employs an elliptic traction boundand is able to estimate the non-linear characteristic of tangential stressdistribution. Comparisons show more accurate estimation of tangentialstress and slip velocity distribution as well as creep forces with FaStrip. Ultimately, an ecient non-elliptic wheel-rail contact model consistingof ANALYN and FaStrip is proposed. The reasonable computationalcost of the model enables it to be used on-line in dynamics simulationand its accuracy can improve the damage predictions. / <p>QC 20160202</p>

Research in radiotherapy for cancer treatment focuses on finding methods that can improve the compromise between tumour cell inactivation versus damage to the surrounding healthy tissue. As new radiation modalities such as proton therapy become accessible for everyday clinical practice, a better understanding of the variation in biological response of the tumour and healthy tissues would improve treatment planning to achieve optimal outcome. The development of radiobiological models capable of accurate predictions of biological effectiveness is needed. Existing radiation quality descriptors such as absorbed dose and LET are insufficient to explain variation in biological effectiveness for different treatment modalities. The stochastic nature of ionizing radiation creates discrete patterns of energy deposition (ED) sites which can now be analysed through sophisticated computer simulations (e.g. Monte Carlo track structure codes). This opens the possibility to develop a nanometre characterization of radiation quality based on the spatial cluster patterns of ED. The aim of this thesis is to investigate the track structure (ED spatial pattern) properties of several radiation qualities at a micro- and nanometric scale while exploring their influence in biological response through correlations with published experimental data. This work uses track structure data simulated for a set of 15 different radiation qualities: 4 commonly used brachytherapy sources, 6 different proton energies, 4 different carbon ion energies, and 60Co photons used as reference radiation for quantification of biological effectiveness. At a micrometre level, the behaviour of the microdosimetric spread in energy deposition for target sizes of the order of cell nuclei was analysed. The degree of the influence it had in the biological response was found to be negligible for photon sources but for protons and carbon ions the impact increased with decreasing particle energy suggesting it may be a confounding factor in biological response. Finally, this thesis outlines a framework for modelling the relative biological effectiveness based on the frequency distribution of cluster order as a surrogate for the nanometre classification for the physical properties of radiation quality. The results indicate that this frequency is a valuable descriptor of ionizing radiation. The positive correlation across the different types of ionizing radiation encourages further development of the framework by incorporating the behavior of the microdosimetric spread and expanding tests to other experimental datasets.

The Swedish Transport Administration has been giving the task to set up a new standard for concrete slabs for the new high-speed railway in Sweden. They are demanding that the concrete slabs must be dimensioned according to the German Beton Kalender 2000. This report will explore the results when dimensioning a slab track, according to the German Beton Kalender 2000. Moment capacity, deformation, and crack width are calculated according to two structural theories, namely slab and beam theory, and a comparison between the two methods is presented.

International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, Nevada / Magnetic tape is the primary medium used to capture and store unprocessed data from remote sensing satellites. Recent advances in digital cassette recording technology have resulted in the introduction of a range of data recorders which are equally at home working alongside conventional recorders or as part of more advanced data capture strategies. This paper shows how users are taking advantage of the convenience, economy and efficiency of this new generation of cassette-based equipment in a range of practical applications.

Thesis (PhD (Sport Sc)) -- University of Stellenbosch, 2004. / ENGLISH ABSTRACT: This study investigated the effects of a relaxation, self-talk, goal-setting, imagery, and concentration training package on the performance of six athletes in the 1500- meter event. Subjects were four female and two male high school middle distance athletes. The dependent measure was time taken to complete the 1500-meter nm in competition settings. A mental skills training package was developed, implemented and evaluated using a single subject, multiple baseline design. Performance scores were plotted for each 1500-meter nm and subjects' graphs were assessed for intervention-related change against mean performance change and established split-middle analysis criteria. Visual inspection of plotted values was supplemented by quantitive analysis using repeated measures analysis of variance (RANOV A). This study also included procedural reliability checks to ensure that the athletes did in filet utilize the mental skills they received training in. Visual analysis indicated the mental skills package to be effective in enhancing performance times (1500-meter) in the case of four of the athletes. Overall, repeated measures analysis of variance revealed significant improvement in 1500- meter performance times for subjects across phases. However, a split-middle analysis of within subject variation indicated that a significant intervention effect was not observed in two of the six subjects. The social validity assessment by athletes and their two coaches provided further confirmation of the overall effectiveness of the intervention. Social validation checks indicated all participants to have perceived the intervention to be successful and all were satisfied with the delivery and content of the training package. The results support the usefulness of single-subject research designs for assessing the impact of mental training. The present study demonstrated that a mental skills training package combining relaxation, self-ta1k, goal setting, imagery, and concentration skills was effective in enhancing athletic performance. / AFRIKAANSE OPSOMMING: Die effek van "n sportsielkundige opleidingspakket, bestaande uit ontspanningsvaardighede, effektiewe selfspraak, doelwitstelling, beelding en konsentrasievaardighede op die prestasie van sportlui in die 1500-meter wedloop, is in die onderhawige navorsing ondersoek. Die proefpersone wat aan die navorsingprojek deelgeneem het, was vier vroulike en twee manlike hoërskool middelafstand-atlete. Die afhanklike veranderlike is gedefinieer as die tyd wat dit elke proefpersoon neem om die 1500-meter wedloop in kompetisie-situasies te voltooi. 'n Sportsielkundige opleidingspakket is ontwikkel, geïmplementeer en die effek daarvan op prestasietyd is geëvalueer deur gebruik te maak van "n enkelproefpersoon-, meervoudige basislynontwerp oor individue. Wedlooptyd in die 1500- meter is graftes ten opsigte van elke proefpersoon voorgestel en volgens kriteria vir visuele inspeksie en die "split-middle" -tegniek geanaliseer. Visuele analise van die data is deur middel van kwantitatiewe herhaalde waameming;analise van die variansie uitgebrei. Die ondersoek het ook kontrole vir prosedurelebetroubaarheid ingesluit om te verseker dat die betrokke sportsielkundige vaardighede waarin proefpersone opgelei is, inderdaad deur hul gebruik word Visuele analise van die navorsingdata het aangedui dat die sportsielkundige opleidingsprogram wel effektiefwas om presf.asietyd (l500-meter) by vier van die ses atlete te verbeter. Die herhaalde waamemingsanalise van die variansie het oor die algemeen beduidende verbetering in presf.asietyd in die 1500-meter vir proefpersone vanaf die basislyn:fase na die intervensiefase aangetoon. "n "Split-miádle" analise van intra-proefpersoon variasie het egter aangedui dat "n beduidende intervensie-effek nie by twee van die ses proefpersone waargeneem kon word nie. 'n Gunstige sosiale validering is van die betrokke proefpersone en hul afrigters ontvang wat verdere bevestiging bied vir die effektiwiteit van die intervensie oor die algemeen. Resultate met betrekking tot die sosiale validering het aangedui dat al die deelnemers by die navorsingprojek die intervensie as suksesvol beskou het en tevrede was met die toepassing en inhoud van die opleidingspakket. In die onderhawige ondersoek is aangedui dat "n sportsielkundige opleidingsprogram wat ontspanningsvaardighede, selfspraak, doelwitstelling, beelding en konsentrasievaardighede kombineer, weloor die algemeen effektief was om sportlui se prestasie te verbeter.

Since 1988, the states of Armenia and Azerbaijan have been engaged in conflict over the enclave of Nagorno Karabakh. The conflict has developed into one of the most intractable and complicated disputes in the international arena, with the main parties being the two rivalling sovereign states plus the 'unrecognised state' of Nagorno Karabakh. Despite the optimistic statements and claims by the OSCE and after many years of negotiations and talks, the peace process remains in stalemate. The research argues the virtues of Track Two diplomacy and highlights the successful instances where it has made important contributions to the 'official' or Track One diplomatic process. It also explores the potential of a 'no war no peace' situation by discerning the factors influencing the progress of the conflict. The research shows that a deeper understanding of the obstacles to peace is achieved by appreciating the significance of historical events as well as recognising the motives and interests of the different parties. The study reviews all major factors which have led to the failure of resolution efforts, particular the negative role played by Russia. It concludes that the scholars in the field of conflict resolution can bring about a lasting peace to this region, provided there is a fundamental change in the structure of the co-chairs of the OSCE.

Repeat track analysis is one tool that can be used to derive parameters describing elevation changes from elevation data collected from a satellite with a near-repeat groundtrack. While initially developed to study ocean topography, it was then applied to ice sheet data. This study expands upon that previous research by testing the method’s ability to estimate parameters using different amounts of data, different grid sizes and types, and different elevation models containing different parameters to be estimated. In all cases, ICESat-derived elevations were used as input data, as ICESat has a near-repeat groundtrack with extensive coverage of the Greenland and Antarctica ice sheets. Results were compared using the differences between modeled and ICESat-derived elevations, correlation of estimated parameters to known physical features, and differences between known and estimated parameter values for simulated elevation data. It was found that there should be data from at least as many distinct time periods (or, in the case of ICESat, laser campaigns) as parameters being estimated, grids centered on and aligned with the reference groundtrack should be used, and that elevation models containing a constant elevation change rate, slopes, an initial elevation at the grid center, and annual terms should be used. Crossover analysis is a different method to determine elevation change rate with elevation data and serves as an independent verification of the repeat track analysis method. It was found that the hdot values determined from crossover and repeat track analyses agreed to within 5 cm/yr in most areas of the ice sheets, with differences greater than 40 cm/yr along the coasts. While repeat track analysis provides greater coverage than crossover analysis, it is uncertain which method provides the most accurate results. / text

<p>Active secondary suspension in trains has been studied for a number of years, showing promising improvements in ride comfort. However, due to relatively high implementation and maintenance costs, active technology is not being used in service operation to a large extent. The objective of this study is to develop an active lateral secondary suspension concept that offers good ride comfort improvements and enables centring of the carbody above the bogies when negotiating curves at unbalanced speed. Simultaneously, the active suspension concept should be a cost-effective solution for future series production. The thesis consists of an introductory part and three appended papers.</p><p>The introductory part describes the concept of active secondary suspension together with different actuator types and control methods. Further, the present simulation model and applied comfort evaluation methods are presented. The introductory part also comprises a summary of the appended papers, an evaluation of track forces and suggestions for further work.</p><p>Paper A presents the initial development of an active lateral secondary suspension concept based on sky-hook damping in order to improve vehicle dynamic performance, particularly on straight tracks. Furthermore, a Hold-Off-Device (HOD) function has been included in the suspension concept in order to centre the carbody above the bogies in curves and hence avoid bumpstop contact. Preparatory simulations as well as the subsequent on-track tests in the summer of 2007 showed that the active suspension provides improved passenger ride comfort and has significant potential to be a cost-effective solution for future implementation.</p><p>In Paper B, measurement results from on-track tests performed in 2008 are presented. The active secondary suspension concept was slightly modified compared to the one presented in the first paper. One modification was the implementation of a gyroscope in order to enable detection of transition curves and to switch off the dynamic damping in these sections. Ride comfort in the actively suspended carbody was significantly improved compared to that in the passively suspended car. The satisfactory results led to implementation of the active suspension system in long-term tests in service operation in the beginning of 2009.</p><p>In Paper C, a quarter-car model in MATLAB has been used to investigate a more advanced control algorithm: <em>H</em>_∞ instead of sky-hook. <em>H</em>_∞ control provides more flexibility in the design process due to the possibility to control several parameters. In particular, this is done by applying weight functions to selected signals in the system. When comparing the two control strategies through simulations, the results show that <em>H</em>_∞ control generates similar carbody accelerations at the same control force as sky-hook; however, the relative displacement displacement is somewhat lower.</p>

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