Relevant bibliographies by topics / Track dynamics

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  2. Dissertations / Theses
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Academic literature on the topic 'Track dynamics'

Author: Grafiati
Published: 4 June 2021
Last updated: 18 February 2022

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Journal articles on the topic "Track dynamics"

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Zeng, Yong. "Effects of Track Elasticity on Wheel-Rail Dynamic Performance of Heavy Haul Railway." Applied Mechanics and Materials 744-746 (March 2015): 1249–52. http://dx.doi.org/10.4028/www.scientific.net/amm.744-746.1249.

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Two vehicle-track dynamics models on heavy haul railway are established in two conditions of rigid track and elastic track. And the impact of track elasticity on the wheel-rail dynamics performance was analyzed using models. The results show that the critical speed of heavy vehicles and wheel-rail dynamic indexes, such as wheel-rail lateral force and wheel-rail vertical force decreased on elastic track compared with rigid track. However, other dynamic indexes, including derailment coefficient and lateral displacement of wheelsets increased on elastic track. And the wheel-rail wear indexes are some differences on two tracks.
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Kaewunruen, Sakdirat, Chayut Ngamkhanong, and Xin Liu. "Spectro-Temporal Responses of Curved Railway Tracks with Variable Radii of Arc Curves." International Journal of Structural Stability and Dynamics 19, no. 04 (2019): 1950044. http://dx.doi.org/10.1142/s0219455419500445.

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On curved railway tracks, wheel/rail interface can usually cause a traveling source of sound and vibration, which constitutes high-pitch or tonal noise pollution causing considerable concern to rail asset owners, commuters and people living or working along the railway corridor. The sound and vibration can be in various forms and spectra. The undesirable tonal sound on curves caused by excessive lateral wheel/rail dynamics in resonance with falling friction states are often called ‘squeal noises’. This paper evaluates the transient effect of curve radii on the possible occurrence of lateral track resonances, which is a principal cause of dynamic wheel/rail mode coupling that could trigger ‘curve squeal’. This study is devoted to systems thinking approach and better insight into dynamic phenomena of railway tracks that could resolve the railway curve noise problems. Curved track models in three-dimensional space have been developed using a finite element package, STRAND7. The dynamic responses of curved track have been simulated by applying a moving train load. The transient loading model of a common wheel/rail slip has been adopted. The simulations of railway tracks with different curve radii have been carried out to develop state-of-the-art understanding of lateral track dynamics, including rail dynamics, cant dynamics and overall track responses. Parametric studies have been conducted to evaluate lateral displacements, velocities and accelerations of rail over sleeper and rail at midspan, both in static and dynamic conditions. The study firstly reveals that the lateral resonance of tangent tracks is relatively rare and the mode coupling behavior is unlikely to occur on moderately curved tracks. The lateral vibration responses have been presented in terms of time histories and spectro-temporal responses (also called “Spectogram”). The dynamic lateral responses of the track are found to be sensitive to the change of curved radii. The resonance peak in the lateral direction is related to the agreement of corresponding natural frequencies of rail and the vibration excitation frequencies under an individual rolling velocity. The outcome of this study establishes new insight into the dominant influences of different track parameters to track lateral dynamic behaviors.
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Hubbard, Mont, Michael Kallay, and Payam Rowhani. "Three-Dimensional Bobsled Turning Dynamics." International Journal of Sport Biomechanics 5, no. 2 (1989): 222–37. http://dx.doi.org/10.1123/ijsb.5.2.222.

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We have developed a mathematical model and computer simulation of three-dimensional bobsled turning. It is based on accurate descriptions of existing or hypothetical tracks and on dynamic equations of motion including gravitational, normal, lift, drag, ice friction, and steering forces. The three-dimensional track surface model uses cubic spline geometric modeling and approximation techniques. The position of the sled on the track is specified by the two variables α and β in the along-track and cross-track directions, differential equations for which govern the possible motions of the sled. The model can be used for studies involving (a) track design, (b) calculation of optimal driver control strategies, and (c) as the basis for a real-time bobsled simulator. It can provide detailed quantitative information (e.g., splits for individual turns) that is not available in runs at actual tracks. The model also allows for comparison of driver performance with the numerically computed optimum performance, and for safe experimentation with risky driving strategies.
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SADEGHI, J., and M. FESHARAKI. "IMPORTANCE OF NONLINEARITY OF TRACK SUPPORT SYSTEM IN MODELING OF RAILWAY TRACK DYNAMICS." International Journal of Structural Stability and Dynamics 13, no. 01 (2013): 1350008. http://dx.doi.org/10.1142/s0219455413500089.

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Attention is drawn to the fact that the recent increase in axle loads, speed and traffic volume in railway tracks, as well as concerns over passengers' riding comfort and safety have resulted in fresh challenges that are needed to be addressed. These challenges can only be successfully tackled with a more accurate modeling of the dynamic behavior of railway tracks. Although a significant amount of research involving mathematical modeling of railway track dynamics has been conducted in the last two decades, the nonlinearity of track support systems has not been given sufficient attention. This paper is concerned with the effect of nonlinearity of the support sub-layers on the dynamic responses of the railway track. To this end, a railway track model that considers the nonlinear properties of the track sub-layers is developed. Then, a field investigation into the dynamic responses of the railway track system under moving trains is conducted. The effect of the nonlinearity properties of the track support system on the track responses is investigated by comparing the results obtained by the numerical model, with or without consideration of track support nonlinearity, with those from the field tests. It is illustrated that consideration of the nonlinear properties of the track support system improves the accuracy of the calculated responses by a factor of three. It is also shown that the train axle loads and track accumulative loading have a significant effect on the nonlinearity of the track support system and, as a result, on the modeling of track responses.
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Chang, Edmund K. M., Sukyoung Lee, and Kyle L. Swanson. "Storm Track Dynamics." Journal of Climate 15, no. 16 (2002): 2163–83. http://dx.doi.org/10.1175/1520-0442(2002)015<02163:std>2.0.co;2.

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Xu, Qingyuan, Hao Sun, Lexuan Wang, Lei Xu, Wei Chen, and Ping Lou. "Influence of Vehicle Number on the Dynamic Characteristics of High-Speed Train-CRTS III Slab Track-Subgrade Coupled System." Materials 14, no. 13 (2021): 3662. http://dx.doi.org/10.3390/ma14133662.

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In this paper, a high-speed train–CRTS III slab track–subgrade coupled dynamic model is established. With the model, the influence of vehicle number on the dynamic characteristics of a train–CRTS III slab track–subgrade coupled system with smooth and random track irregularity conditions for conventional and vibration-reduction CRTS III slab tracks are theoretically studied and analyzed. Some conclusions are drawn from the results: (1) the largest dynamic responses of the coupled system for all items and cases are no longer changed when the vehicle number exceeds three, and three vehicles are adequate to guarantee the simulation precision to investigate the dynamic responses of the coupled system. (2) The acceleration of the car body has almost no relation with the vehicle number, and only one vehicle is needed to study the vehicle dynamics using the train–CRTS III slab track–subgrade coupled dynamic model. (3) For the conventional CRTS III slab track on a subgrade, the vehicle number has a negligible influence on the accelerations of the rail, slab, and concrete base, the positive and negative bending moments of the rail, the compressive force of the fastener, and the positive bending stress of slab, but it has a large influence on the tension force of the fastener, and the negative bending stresses of the slab and concrete base. Only one vehicle is needed to study track dynamics without considering the tension force of the fastener, the negative bending stresses of the slab and concrete base, otherwise, two or more vehicles are required. (4) For vibration reduction of the CRTS III slab track on a subgrade, the number of vehicles has some influence on the dynamic responses of all track components, and at least two vehicles are required to investigate the track dynamics.
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Chapman, Christopher C., Andrew McC Hogg, Andrew E. Kiss, and Stephen R. Rintoul. "The Dynamics of Southern Ocean Storm Tracks." Journal of Physical Oceanography 45, no. 3 (2015): 884–903. http://dx.doi.org/10.1175/jpo-d-14-0075.1.

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AbstractThe mechanisms that initiate and maintain oceanic “storm tracks” (regions of anomalously high eddy kinetic energy) are studied in a wind-driven, isopycnal, primitive equation model with idealized bottom topography. Storm tracks are found downstream of the topography in regions strongly influenced by a large-scale stationary meander that is generated by the interaction between the background mean flow and the topography. In oceanic storm tracks the length scale of the stationary meander differs from that of the transient eddies, a point of distinction from the atmospheric storm tracks. When the zonal length and height of the topography are varied, the storm-track intensity is largely unchanged and the downstream storm-track length varies only weakly. The dynamics of the storm track in this idealized configuration are investigated using a wave activity flux (related to the Eliassen–Palm flux and eddy energy budgets). It is found that vertical fluxes of wave activity (which correspond to eddy growth by baroclinic conversion) are localized to the region influenced by the standing meander. Farther downstream, organized horizontal wave activity fluxes (which indicate eddy energy fluxes) are found. A mechanism for the development of oceanic storm tracks is proposed: the standing meander initiates localized conversion of energy from the mean field to the eddy field, while the storm track develops downstream of the initial baroclinic growth through the ageostrophic flux of Montgomery potential. Finally, the implications of this analysis for the parameterization and prediction of storm tracks in ocean models are discussed.
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Yuan, Xuancheng, Shengyang Zhu, Lei Xu, Wanming Zhai, and Huailong Li. "Investigation of the vibration isolation performance of floating slab track with rubber bearings using a stochastic fractional derivative model." Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit 234, no. 9 (2019): 992–1004. http://dx.doi.org/10.1177/0954409719883552.

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Floating slab track is an effective countermeasure to mitigate undesirable vibrations caused by metro trains. In this work, a stochastic fractional derivative model is proposed for simulating the dynamic behavior of rubber bearings in floating slab tracks. The stochastic fractional derivative model is based on the Grünwald representation of fractional calculus, the number theoretical method, and the probability density evolution method (PDEM). It considers the viscoelastic characteristics of the rubber bearings, as well as randomness in mechanical behavior due to manufacturing tolerances, aging, and fatigue. The stochastic fractional derivative model is then implemented into a vehicle–floating slab track coupled dynamics model to investigate the vibration isolation performance of the floating slab track with rubber bearings. The characteristics and advantages of the stochastic fractional derivative model with deterministic parameters are illustrated by comparing the results with the conventional Kelvin model. Finally, stochastic analyses of the dynamic response and the vibration isolation performance of the floating slab track are carried out using the coupled vehicle–floating slab track system dynamics model. Results show that the stochastic simulation of the vehicle–floating slab track system using PDEM is efficient and reliable compared with the Monte Carlo method. Thus, the proposed model is effective and useful for evaluating the vibration levels in floating slab tracks with uncertain parameters, and for predicting the reliability of the vibration isolation performance.
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Zhu, Shengyang, Jun Luo, Mingze Wang, and Chengbiao Cai. "Mechanical characteristic variation of ballastless track in high-speed railway: effect of train–track interaction and environment loads." Railway Engineering Science 28, no. 4 (2020): 408–23. http://dx.doi.org/10.1007/s40534-020-00227-6.

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AbstractDue to the fact that ballastless tracks in high-speed railways are not only subjected to repeated train–track dynamic interaction loads, but also suffer from complex environmental loads, the fundamental understanding of mechanical performance of ballastless tracks under sophisticated service conditions is an increasingly demanding and challenging issue in high-speed railway networks. This work aims to reveal the effect of train–track interaction and environment loads on the mechanical characteristic variation of ballastless tracks in high-speed railways, particularly focusing on the typical interface damage evolution between track layers. To this end, a finite element model of a double-block ballastless track involving the cohesive zone model for the track interface is first established to analyze the mechanical properties of the track interface under the loading–unloading processes of the negative temperature gradient load (TGL) followed by the same cycle of the positive TGL. Subsequently, the effect of wheel–rail longitudinal interactions on the nonlinear dynamic characteristics of the track interface is investigated by using a vehicle-slab track vertical-longitudinal coupled dynamics model. Finally, the influence of dynamic water pressure induced by vehicle dynamic load on the mechanical characteristics and damage evolution of the track interface is elucidated using a fluid–solid coupling method. Results show that the loading history of the positive and negative TGLs has a great impact on the nonlinear development and distribution of the track interface stress and damage; the interface damage could be induced by the wheel–rail longitudinal vibrations at a high vehicle running speed owing to the dynamic amplification effect caused by short wave irregularities; the vehicle dynamic load could produce considerable water pressure that presents nonlinear spatial–temporal characteristics at the track interface, which would lead to the interface failure under a certain condition due to the coupled dynamic effect of vehicle load and water pressure.
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Клубничкин, Evgeniy Klubnichkin, Клубничкин, Vladislav Klubnichkin, Бухтояров, and Leonid Bukhtoyarov. "Investigation of the kinematics and dynamics of propulsor of track harvester." Forestry Engineering Journal 4, no. 4 (2015): 179–90. http://dx.doi.org/10.12737/8471.

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The research of multilink mechanism on the example of propulsor track harvester ЛЗ-5 was made. Propulsor of track harvester (CH) is a multilink mechanism, as it consists of track tracks, including a large number of tracks hingedly connected to each other. For research, we selected the program UM Tracked Vehicles, as it is most appropriate for the task. At the stage of development of the design documentation, such virtual testing in economic terms is more favorable than the natural prototype testing.
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Dissertations / Theses on the topic "Track dynamics"

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Lukes, Richard Angus. "Improving track cycling performance using computational fluid dynamics." Thesis, University of Sheffield, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.505805.

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Elm, Dahlman Rasmus, and Emil Lundberg. "Parametric Studies of Train-Track-Bridge Interaction : An evaluation of the dynamic amplification due to track irregularities for freight transport." Thesis, KTH, Bro- och stålbyggnad, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-301309.

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In this thesis a train-track-bridge interaction (TTBI) model is developed in order to study the dynamic amplification from track irregularities on railway bridges traversed by freight trains. These simulations are of great importance since rail freight transport is expected to increase in order to meet the climate goals. The shift of the freight industry is however not accomplished without complications, because of the heavier and more frequent transportation higher demand is put on the infrastructure supporting the railways. In order to adequately assess the bearing capacity of the railway bridges, more detailed models assessing the dynamic behavior of the bridges are needed. The research underlying the current model in Eurocode were made during the 1970s (ORE, 1976) and the 1990s (ERRI, 1999) which were based on very simplified relations of the interaction and irregularities. Two research questions are therefore established in this thesis. The first one is if the current dynamic amplification factor in Eurocode which accounts for track irregularities is over conservative and secondly if the same factor is suitable to utilize for both section forces and deflections. The model developed in order to answer the stated research questions is a 2D model (considering only vertical excitation) with a linearized Hertz contact spring coupling the vehicle subsystem to the track-bridge system. The bridges examined in the thesis are limited to simply supported bridges with a span length between 4-20 m carrying a ballasted track. The studied train speeds vary between 60 - 120 km/h in order to replicate the speed range utilized by freight trains. The quality of the track (irregularities) is varied between a standard variation of 0.5-5 mm and is generated based on the German power spectral density (PSD) function. Research have previously been carried out in the field of TTBI system but have mostly been focusing on high-speed railway engineering and few studies have been performed on heavy transportation. One of the pioneers in the field of TTBI modelling is Wanming Zhai and the model developed in this thesis is validated against one of his 2D models. Based on the simulations performed in this thesis it is evident that the current model in Eurocode EN 1991-2 is over conservative and in great need of a revision. The model presented in this thesis is for the case with the largest dynamic amplification (120 km/h and a 4 m span length) significantly lower than the model presented in Eurocode. From the sensitivity analysis it is possible to conclude that many of the parameters in the system have low influence on the dynamic amplification while others have considerable influence. The parameters that have a considerable influence might be more suitable with a probabilistic approach instead of a deterministic which was utilized in this thesis.<br>I denna avhandling upprättas en tåg-spår-bro interaktionsmodell i syfte att studera den dynamiska förstorningsfaktorn som uppkommer av ojämnheter från spåret för järnvägsbroar trafikerade av godståg. Dessa typer av simuleringar är viktiga då järnvägstransporter förväntas öka för att klara av att möta de klimatmål som fastställts. Denna ökning av järnvägstransporter genomförs dock inte utan problem. Ökningen medför fler och tyngre transporter vilket skapar problem för järnvägsinfrastrukturen (främst broarna). För att med säkerhet kunna fastställa bärförmågan hos broarna, behövs mer avancerade modeller än de som idag finns i Eurokod. Modellerna som finns angivna i Eurokod bygger på forskning genomförd under 70- (ORE, 1976) och 90-talet (ERRI, 1999), där det användes väldigt förenklade interaktions- och ojämnhets-modeller. På grund av detta har två frågeställningar upprättats. Den första är om den dynamiska förstoringsfaktorn som används i Eurokod för att ta hänsyn till ojämnheterna i spåret är överdrivet konservativ och den andra är om samma faktor är lämplig att använda för både snittkrafter och nedböjning. Modellen som upprättats för att besvara dessa forskningsfrågor är en 2D modell (vertikalt led) med en linjäriserad Hertz kontaktfjäder för att koppla samman fordonet med spår-bro systemet. Broarna som har studerats i denna avhandling är endast fritt upplagda broar med en spannlängd mellan 4-20 m med ballasterat spår. Tåg-hastigheten har varierats mellan 60-120 km/h i syfte att simulera relevanta hastigheter för godståg. Spårkvalitén (ojämnheterna) har beskrivits m.h.a. standardavvikelsen från det perfekta spårläget och har varierats mellan 0.5-5 mm. Dessa ojämnheter har genererats baserat på den tyska power spectral density (PSD) funktionen. Tidigare forskning har utförts inom ämnet tåg-spår-bro interaktion men med huvudsaklig fokus på höghastighetståg/resonans-beteenden och få studier har genomförts på godståg. En av föregångsmännen inom ämnet är Wanming Zhai, och modellen som upprättas i denna avhandling har därav validerats mot hans 2D modell. Baserat på simuleringarna i denna avhandling är det tydligt att den nuvarande modellen som används i Eurokod EN 1991-2 är överdrivet konservativ och i stort behov av en uppdatering. Det fall med stört dynamisk förstoringsfaktor (120 km/h och en spannlängd på 4 m) som behandlas i denna rapport är avsevärt lägre än det som återfinns i Eurokod. Från känslighetsanalysen som genomfördes kunde det fastställas att många av parametrarna i systemet har en låg inverkan på förstoringsfaktorn. För parametrarna som dock hade inflytande skulle ett probabilistiskt angreppssätt kunna vara mer passande än det deterministiska som använts i denna avhandling.
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Hunt, Geoffrey A. "Dynamic analysis of railway vehicle/track interaction forces." Thesis, Loughborough University, 1986. https://dspace.lboro.ac.uk/2134/7492.

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Methods of predicting the dynamic forces are developed for the cases of vehicles negotiating vertical and lateral track irregularities. The bounds of validity of various models of the track are evaluated, from single degree of freedom, lumped parameter models to the case of a two layered beam on elastic foundation with a moving dynamic load. For the case of the lateral response of a vehicle negotiating a track switch, a finite element model of the track is also developed. The vehicle model developed for-the vertical case contains all the rigid body modes of a four axle vehicle for which primary and secondary suspension can be included with viscous or friction suspension damping. Solution of the vehicle/track interaction problem for these non-linear models is obtained by numerical integration, vehicle and track being connected by the non-linear wheel/rail contact stiffness. The most significant forces are shown to arise from the interaction of the unsprung mass and track resilience, with the vehicle modes also making a significant contribution, particularly in friction damped cases. For the lateral case use is made of an existing model of transient vehicle behaviour containing the wheel/rail contact non-linearities, to which track resilience is added in order to predict the track forces. The model is used to predict the forces which would be anticipated at discrete lateral irregularities such as those to be found at track switches. Once again the interaction with the track introduces modes of vibration which are significant in terms of wheel/rail forces. Comparison is made with experimental results obtained from full scale tests in the field. In one experiment the vertical track forces due to a range of vehicles negotiating a series of dipped welds in the track were measured, and in a second the lateral forces were recorded at the site of an artificially introduced lateral kink. A particular application of the results is in the prediction of the rate of deterioration of vertical and lateral geometry due to dynamic forces. This is to offer an improved understanding of the deterioration mechanism in order to influence the future design of vehicles and track to reduce maintenance costs.
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Rabone, Jeremy Andrew Leslie. "Molecular dynamics of fission track annealing in apatite minerals." Thesis, Birkbeck (University of London), 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.499138.

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Bezin, Yann. "An Integrated Flexible Track System Modelfor Railway Vehicle Dynamics." Thesis, Manchester Metropolitan University, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.502435.

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This thesis describes the development and validation of a versatile and Flexible Track System Model (FTSM) and its integration into a commercial railway vehicle dynamics software tool. The work was initiated to fill a gap in current disciplines and tools used to investigate problems relating to vehicle and railway track dynamics due to a lack of correlation between Finite Element (FE) and MuItibody System (MBS) based models. The. FTSM track model was validated against results from laboratory testing and compared with existing models. It was then used to study several aspects of the deterioration of ballasted track under the dynamic loading of passing vehicles at speeds, including consideration of the non-linear nature of the track support condition such as sleeper voiding and variable sleeper support stiffness. . The research contributes to the fundamental understanding of the vehicl~-track interaction forces and particularly to the relation that exists between wheel-rail contact forces and track forces. It shows that.in order to accurately predict track degradation forces, a detailed flexible track model is essential. The major differences in terms of wheel-rail contact condition and forces obtained from the conventional simplified track models and from the FTSM are also highlighted. The presence of higher frequency modes of vibration of the flexible track proves essential for those studies involving local and sudden track events. The model was also applied to the analysis and design development of innovative track structures that seem to offer several advantages with respect to conventional ballasted tracks, most importantly a more consistent or continuous support to the rail. This characteristic is shown to be essential for minimising the interactive cycle of dynamic interaction forces and track deformation leading to track settlement and deterioration.
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Witt, Stephen. "The Influence of Under Sleeper Pads on Railway Track Dynamics." Thesis, Linköping University, Department of Management and Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-12232.

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<p>In this work the influence of Under Sleeper Pads on the dynamic forces on a railway track is investigated. A special interest is devoted to the effect of using Under Sleeper Pads in a railway track with changing vertical stiffness. The contact force between wheel and rail and the ballast contact forces are examined. For the investigation a finite element model with the length of thirty sleepers is created and calculations are performed with the software LS-DYNA. Three different cases of varying vertical track stiffness are studied: the transition from an embankment to a bridge, a randomly varying track stiffness along the railway track and hanging sleepers.</p>
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Gong, Cencen. "The interaction between railway vehicle dynamics and track lateral alignment." Thesis, University of Huddersfield, 2013. http://eprints.hud.ac.uk/id/eprint/19755/.

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This thesis examines the effect of vehicle dynamics on lateral deterioration of the track alignment. As rail traffic runs along a route, the forces imposed upon the track cause the ballast to settle, and hence the track geometry deteriorates. At a specified value of deterioration the track geometry needs to be restored by tamping or other methods. As the deterioration is mainly in the vertical direction, this aspect has been more widely studied and models have been developed to predict vertical track geometry deterioration. On the other hand, lateral track deterioration is not as well understood, and this thesis aims to fill the gap in this knowledge. However, the understanding of the lateral deterioration mechanisms becomes more important as speed and capacity increase. This thesis describes statistical studies of track lateral deterioration, as well as the development and validation of a vehicle-track lateral dynamic interaction model. This work is undertaken to contribute to the fundamental understanding of the mechanisms of track lateral deterioration, therefore making the effective control and reduction of the lateral deterioration achievable. The statistical analysis provides a better understanding of three aspects of track lateral irregularities, namely: the relationship between vertical and lateral irregularities, the relationship between track curvature and track lateral irregularity and the change in track lateral deterioration over time. The vertical and lateral track irregularity magnitudes are clearly correlated. The track quality in the vertical direction is generally worse than in the lateral direction, however the number of track sections with lateral quality significantly worse than the vertical is non-negligible. The lateral irregularities tend to be larger on curves. It is notable that less than ten percent of the track studied has a constant lateral deterioration due to frequent maintenance activities and bidirectional lateral dynamic forces. Unlike vertical settlement, lateral deterioration develops exponentially in both magnitude and wavelength, and the major influences are found from the irregularities with wavelength longer than 10 m. The change in track lateral irregularity with different curve radii and the lateral deterioration rate are described in separate exponential power functions due to the limitation of the available track data. The parameters for these empirical equations do not remain constant due to the change in track conditions. Current track lateral models mainly focus on lateral failures such as buckling and lateral sliding. The development of lateral track irregularities tends to be studied using representative values of net lateral forces and net L/V (Lateral/Vertical) load ratios. Unlike other track lateral deterioration models, the model developed in this thesis focuses on the development of lateral irregularities based on the dynamic interactions between the vehicles and the track system. This model makes it possible to carry out more integrations and analysis of the track lateral deterioration in a realistic dynamic simulation, using vehicle models, contact conditions, track initial irregularities, and traffic mix more close to the reality. The vehicle-track lateral dynamic interaction model was validated against track geometry data measured on the West Coast Mainline (WCML) in England. It has been found that the model gives a reasonably accurate prediction of the development of lateral track irregularities. However, it also tends to predict a short wavelength deterioration that is not seen in the actual track deterioration. Improvements to the model are suggested by either adding more factors or simplifying the model depending on specific target application. Enhancing the model by including more details, such as longitudinal forces, temperature effect, more layered track systems, uneven track bed conditions and more representative wheel-rail contact conditions etc., may help understand the reason of the additional short wavelength. A sensitivity analysis was performed in order to identify the critical factors that influence lateral track deterioration. The track damage caused by specific vehicles can be controlled by understanding different vehicle dynamics behaviour on a particular track section or route. Vehicles with simple suspension design and heavy axle loads tend to cause more lateral track damage. Within a certain speed range, there will be a critical speed that generates the largest lateral deterioration. Vehicles with different dynamic behaviours can generate a potential offset of the lateral deterioration, so it is possible to design the traffic mix to cancel out the peak deterioration. However, it may not be very practical to redesign the traffic mix due to different traffic requirements. Subsequently, actions can be taken to effectively reduce track lateral deterioration, such as optimise the suspension design, vehicle weight, the selection of an optimal operation speed, and enhance the traffic mix design. As the most important interface between vehicle and track, the wheel-rail contact condition has an extremely large influence on lateral deterioration. Wheel and rail profiles with different wear conditions can cause altered vehicle-track lateral dynamic interaction. It is found that increasingly worn wheel/rail profiles within an acceptable tolerance can effectively reduce the lateral deterioration. Lateral deterioration can also be reduced by increasing all the track stiffness values, damping values and the mass of rails and sleepers, or alternatively, by decreasing the sleeper spacing. The sleeper-ballast interface is found to play the most important role in lateral deterioration. The interfaces between the sleeper and ballast shoulder, crib and base determines the non-linear characteristic such as hysteresis and sliding features. Improving the strength of the sleeper-ballast interface can improve the elastic limits and hysteresis characteristics, hence reducing the lateral deterioration. The findings of the investigation indicate that the model provides in-depth knowledge of the mechanisms influencing lateral deterioration and provides effective solutions with consideration of vehicles, wheel-rail contact and the track system. Further work would include track data with sufficient information in order to develop a more comprehensive empirical model that describes the lateral deterioration, inclusion of more potentially influential factors such as: temperature, ground condition, traffic etc. The model can be improved by taking into account additional factors such as the influence of longitudinal forces from the wheels to the rails, different weather and temperatures, subgrade and ground conditions, etc. The reason for the high frequency noise in the deterioration prediction is not understood yet and it should be discussed in terms of more accurate vehicle simulation results and more comprehensive rail and wheel worn profiles measured on the target track and vehicles. Furthermore, the sleeper-ballast lateral characteristics are not well understood and the previous research in this area is quite limited. To improve on the present work it would be useful to carry out laboratory tests in order to capture more accurately track lateral stiffness and damping values as well as the comprehensive non-linear characteristic of track lateral residual resistance behaviour.
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Leiviskä, Albin. "Load generation on a CV90 track system using multibody dynamics." Thesis, Umeå universitet, Institutionen för fysik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-187750.

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Feng, Huan. "3D-models of railway track for dynamic analysis." Thesis, KTH, Transportvetenskap, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-52619.

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In recent decades, railway transport infrastructures have been regaining their importance due to their efficiency and environmentally friendly technologies. This has led to increasing train speeds, higher axle loads and more frequent train usage. These improved service provisions have however brought new challenges to traditional railway track engineering, especially to track geotechnical dynamics. These challenges demanded for a better understanding of the track dynamics. Due to the large cost and available load conditions limitation, experimental investigation is not always the best choice for the dynamic effect study of railway track structure. Comparatively speaking, an accurate mathematical modeling and numerical solution of the dynamic interaction of the track structural components reveals distinct advantage for understanding the response behavior of the track structure. The purpose of this thesis is to study the influence of design parameters on dynamic response of the railway track structure by implementing Finite Element Method (FEM). According to the complexity, different railway track systems have been simulated, including: Beam on discrete support model, Discretely support track including ballast mass model and Rail on sleeper on continuum model. The rail and sleeper have been modeled by Euler-Bernoulli beam element. Spring and dashpot has been used for the simulation of railpads and the connection between the sleeper and ballast ground. Track components have been studied separately and comparisons have been made between different models. The finite element analysis is divided into three categories: eigenvalue analysis, dynamic analysis and general static analysis. The eigenfrequencies and corresponding vibration modes were extracted from all the models. The main part of the finite element modeling involves the steady-state dynamic analysis, in which receptance functions were obtained and used as the criterion for evaluating the dynamic properties of track components. Dynamic explicit analysis has been used for the simulation of a moving load, and the train speed effect has been studied. The displacement of the trackbed has been evaluated and compared to the measurement taken in Sweden in the static analysis.
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Thellman, Jonas. "Vehicle Dynamics Testing in Advanced DrivingSimulators Using a Single Track Model." Thesis, Linköpings universitet, Fordonssystem, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-79397.

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The purpose of this work is to investigate if simple vehicle models are realisticand useful in simulator environment. These simple models have been parametrisedby the Department of Electrical Engineering at Linköping University and havebeen validated with good results. The models have been implemented in a simulatorenvironment and a simulator study was made with 24 participants. Eachtest person drove both slalom and double lane change manoeuvres with the simplemodels and with VTI’s advanced model. The test persons were able to successfullycomplete double lane changes for higher velocities with the linear tyre modelcompared to both the non-linear tyre model and the advanced model. The wholestudy shows that aggressive driving of a simple vehicle model with non-linear tyredynamics is perceived to be quite similar to an advanced model. It is noted significantdifferences between the simple models and the advanced model when drivingunder normal circumstances, e.g. lack of motion cueing in the simple model suchas pitch and roll.
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Books on the topic "Track dynamics"

1

Zhai, Wanming. Vehicle–Track Coupled Dynamics. Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-32-9283-3.

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Lei, Xiaoyan. High Speed Railway Track Dynamics. Springer Singapore, 2017. http://dx.doi.org/10.1007/978-981-10-2039-1.

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Samavedam, G. Safety of high speed ground transportation systems: Track lateral shift : fundamentals and state-of-the-art review. U.S. Dept. of Transportation, Federal Railroad Administration, Office of Research and Development, 1996.

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Popp, Karl, and Werner Schiehlen, eds. System Dynamics and Long-Term Behaviour of Railway Vehicles, Track and Subgrade. Springer Berlin Heidelberg, 2003. http://dx.doi.org/10.1007/978-3-540-45476-2.

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Mraṅʻʹ, ʼOṅʻ Maṅʻʺ. Mīʺ rathāʺ samuiṅʻʺ. Cā pe Bimānʻ, 1985.

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International, Workshop Wave 2002 (2002 Okayamaken Japan). Wave propagation, moving load, vibration reduction: Proceedings of the International Workshop WAVE 2002, Okayama, Japan, 18-20 September 2002. Balkema, 2003.

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Ahlbeck, D. R. Development of safety criteria for evaluating concrete tie track in the Northeast Corridor: Volume I., remedial projects assessment. Federal Railroad Administration, Office of Research and Development, 1986.

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United States. Federal Railroad Administration. Fifth quarterly progress report, May 1984 - December 1984, on development of safety criteria for evaluating concrete tie track in the Northeast Corridor. Battelle Columbus Laboratories, 1985.

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Igwemezie, J. O. Calibration of railway track for dynamic loads: Track structure research II, task 2. CIGGT, 1992.

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Docobo, J. A., A. Elipe, and H. McAlister, eds. Visual Double Stars: Formation, Dynamics and Evolutionary Tracks. Springer Netherlands, 1997. http://dx.doi.org/10.1007/978-94-009-1477-3.

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Book chapters on the topic "Track dynamics"

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Schramm, Dieter, Manfred Hiller, and Roberto Bardini. "Single Track Models." In Vehicle Dynamics. Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-540-36045-2_10.

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Schramm, Dieter, Manfred Hiller, and Roberto Bardini. "Twin Track Models." In Vehicle Dynamics. Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-540-36045-2_11.

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Schramm, Dieter, Manfred Hiller, and Roberto Bardini. "Single Track Models." In Vehicle Dynamics. Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-54483-9_10.

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Schramm, Dieter, Manfred Hiller, and Roberto Bardini. "Twin Track Models." In Vehicle Dynamics. Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-54483-9_11.

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Zhai, Wanming. "Computational Comparison of Vehicle–Track Coupled Dynamics and Vehicle System Dynamics." In Vehicle–Track Coupled Dynamics. Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-32-9283-3_7.

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Zhai, Wanming. "Vehicle–Track Coupled Dynamics Models." In Vehicle–Track Coupled Dynamics. Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-32-9283-3_2.

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Zhai, Wanming. "Introduction." In Vehicle–Track Coupled Dynamics. Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-32-9283-3_1.

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Zhai, Wanming. "Practical Applications of the Theory of Vehicle–Track Coupled Dynamics in Engineering." In Vehicle–Track Coupled Dynamics. Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-32-9283-3_10.

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Zhai, Wanming. "Excitation Models of Vehicle–Track Coupled System." In Vehicle–Track Coupled Dynamics. Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-32-9283-3_3.

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Zhai, Wanming. "Numerical Method and Computer Simulation for Analysis of Vehicle–Track Coupled Dynamics." In Vehicle–Track Coupled Dynamics. Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-32-9283-3_4.

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Conference papers on the topic "Track dynamics"

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Payne, Michael, and Malcolm Cutchins. "Simulation of certain track-following problems." In Dynamics Specialists Conference. American Institute of Aeronautics and Astronautics, 1996. http://dx.doi.org/10.2514/6.1996-1245.

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Mahdavi, Fatemeh, Md Imam Hossain, Hasti Hayati, David Eager, and Paul Kennedy. "Track Shape, Resulting Dynamics and Injury Rates of Greyhounds." In ASME 2018 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/imece2018-87156.

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A challenge for greyhound racing is optimizing the tracks to minimize the risk of injuries. The effects of different track design variables on greyhound injury rates has not been explored sufficiently. The purpose of this paper is to present some preliminary findings on the effect of greyhound racetrack design variables such as the track curvature and lure alignment. An analysis was carried out of two years of greyhound racing injury data from three different tracks in New South Wales, Australia. The data from before and after an intervention was introduced were compared. Variables in the study, which may affect\ the analysis were investigated to minimize the errors. The analysis showed that there is a reduction in injury rates for a longer lure arm in the tracks with short or no straight section. To verify the effect of track design variables on the greyhound dynamics a kinematic simulation of greyhound center of gravity was created. The simulation considered fundamental variables correlating directly with kinematics between the greyhound and the track. The simulation data showed that the rate of change in the rotation of the greyhound heading direction decreases when the track running path has a more gradual curvature. The result of the simulation showed excellent agreement with that of injury data analysis.
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Yang, Jingjing, and Nan Zhang. "TEMPERATURE WARPING AND TRAIN-TRACK DYNAMIC ANALYSIS OF CRTS II SLAB BALLASTLESS TRACK." In 5th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering Methods in Structural Dynamics and Earthquake Engineering. Institute of Structural Analysis and Antiseismic Research School of Civil Engineering National Technical University of Athens (NTUA) Greece, 2015. http://dx.doi.org/10.7712/120115.3491.812.

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Mazilu, T., and M. A. Gheți. "THEORETICAL ASSESSMENT OF VERTICAL INTERACTION BETWEEN A WHEELSET AND TRACK: INFLUENCE OF THE TRACK DAMPING MODEL." In XI International Conference on Structural Dynamics. EASD, 2020. http://dx.doi.org/10.47964/1120.9219.21831.

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Pfeiffer, Friedrich. "Dynamics of Roller Coasters." In ASME 2005 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2005. http://dx.doi.org/10.1115/detc2005-84093.

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Roller coasters are dynamically multibody systems with unilateral contacts due to the usual raceway design including straight parts and bends. In running down such tracks and passing parts of the track with changing curvature impacts with friction are generated in the track-wheel contacts. The impacts are always connected with large overloads of the wheels sometimes leading to damages. To investigate these problems the roller coaster carriages are modelled as a non-smooth multibody system with impacts and stick-slip processes. The results in terms of wheel loads are used to improve wheel design.
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Murat, M., A. Akkerman, and J. Barak. "Ion track structure and dynamics in SiO2." In 2007 9th European Conference on Radiation and Its Effects on Components and Systems (RADECS 2007). IEEE, 2007. http://dx.doi.org/10.1109/radecs.2007.5205478.

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Pasiliao, Eduardo. "Track Fusion for Independent Sensors." In 48th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference. American Institute of Aeronautics and Astronautics, 2007. http://dx.doi.org/10.2514/6.2007-2223.

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Ulianov, Cristian, Francis J. Franklin, Paul Hyde, and Ramy Shaltout. "Experimental investigation of wheel-track interaction characteristics using test track bogie dynamics measurements." In 2016 18th International Wheelset Congress (IWC). IEEE, 2016. http://dx.doi.org/10.1109/iwc.2016.8068379.

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Olivier, Bryan, Olivier Verlinden, and Georges Kouroussis. "A VEHICLE/TRACK CO-SIMULATION MODEL USING EASYDYN." In 7th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering Methods in Structural Dynamics and Earthquake Engineering. Institute of Structural Analysis and Antiseismic Research School of Civil Engineering National Technical University of Athens (NTUA) Greece, 2019. http://dx.doi.org/10.7712/120119.7212.19125.

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Chumyen, Panudech, David Connolly, Kaitai Dong, Pedro Costa, Paulo Soares, and Peter Woodward. "THE USE OF MULTIPLE MODELS TO ANALYSE RAILWAY TRACK GROUND DYNAMICS." In XI International Conference on Structural Dynamics. EASD, 2020. http://dx.doi.org/10.47964/1120.9223.19550.

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Reports on the topic "Track dynamics"

1

Karafiath, Leslie L. Dynamic Track-Terrain Interaction Model. Defense Technical Information Center, 1988. http://dx.doi.org/10.21236/ada196031.

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Clynch, James R., Richard Franke, and Beny Neta. Improvements in Dynamic GPS Positions Using Track Averaging. Defense Technical Information Center, 1999. http://dx.doi.org/10.21236/ada369222.

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Zhou, Songnian. A Trace-Driven Simulation Study of Dynamic Load Balancing. Defense Technical Information Center, 1986. http://dx.doi.org/10.21236/ada619389.

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Sabau, Adrian S., Yuan Lang, Narendran Raghavan, Srdjan Simunovic, John A. Turner, and Vipul K. Gupta. Fluid Dynamics Effects on Microstructure Prediction in Single Laser Tracks for Additive Manufacturing. Office of Scientific and Technical Information (OSTI), 2018. http://dx.doi.org/10.2172/1505324.

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Reader, Grahame, Mark A. Boothe, Russell L. Elsberry, Lester E. Carr, and III. Southern Hemisphere Application of the Systematic Approach to Tropical Cyclone Forecasting Part 4: Sources of Large Track Errors by Dynamical Models. Defense Technical Information Center, 2000. http://dx.doi.org/10.21236/ada384643.

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Bilovska, Natalia. HYPERTEXT: SYNTHESIS OF DISCRETE AND CONTINUOUS MEDIA MESSAGE. Ivan Franko National University of Lviv, 2021. http://dx.doi.org/10.30970/vjo.2021.50.11104.

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In the article we interpret discrete and continuous message as interrupted and constant, limited and continual text, which has specific features and a number of differences between traditional (one-dimensional) text and hypertext (multidimensional). The purpose of this study is to define the concept of “hypertext”, consideration of its characteristics and features of the structure, similarities and differences with the traditional text, including the message in the media and communication. To achieve the goal of the study, we used a number of methods typical of journalism. Empirical analysis enabled a generalized description of the subject of study, which allowed to know it as a phenomenon. With the help of generalization the characteristic and specific regularities and principles of hypertext were studied. The system method is used to identify the dependence of each element of hypertext on its place in the text system as a whole. The retrospective method helped to understand the preconditions for the emergence of hypertext, to trace the dynamics of its development. General scientific methods (analysis, synthesis, induction, deduction) made it possible to formulate the conclusions of the study. Thanks to hypertext and the hypertext systems, the concept of virtual reality has gained tangible meaning. In hypertext space, virtuality organically complements reality. The state of virtuality, in this case, becomes the concept of hyperreality, and all this merges into a single whole in the space of computer text. Due to its volume and multidimensionality, hypertext can arouse scientific interest as an interdisciplinary discipline. In today’s world, the phenomenon of hypertext has been the subject of numerous discussions, conferences and research in the field of social communications, linguistics and psychology. Today, a significant number of organizations conduct large-scale research based on the concepts of hypertext associations and associative navigation.
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Amela, R., R. Badia, S. Böhm, R. Tosi, C. Soriano, and R. Rossi. D4.2 Profiling report of the partner’s tools, complete with performance suggestions. Scipedia, 2021. http://dx.doi.org/10.23967/exaqute.2021.2.023.

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This deliverable focuses on the proling activities developed in the project with the partner's applications. To perform this proling activities, a couple of benchmarks were dened in collaboration with WP5. The rst benchmark is an embarrassingly parallel benchmark that performs a read and then multiple writes of the same object, with the objective of stressing the memory and storage systems and evaluate the overhead when these reads and writes are performed in parallel. A second benchmark is dened based on the Continuation Multi Level Monte Carlo (C-MLMC) algorithm. While this algorithm is normally executed using multiple levels, for the proling and performance analysis objectives, the execution of a single level was enough since the forthcoming levels have similar performance characteristics. Additionally, while the simulation tasks can be executed as parallel (multi-threaded tasks), in the benchmark, single threaded tasks were executed to increase the number of simulations to be scheduled and stress the scheduling engines. A set of experiments based on these two benchmarks have been executed in the MareNostrum 4 supercomputer and using PyCOMPSs as underlying programming model and dynamic scheduler of the tasks involved in the executions. While the rst benchmark was executed several times in a single iteration, the second benchmark was executed in an iterative manner, with cycles of 1) Execution and trace generation; 2) Performance analysis; 3) Improvements. This had enabled to perform several improvements in the benchmark and in the scheduler of PyCOMPSs. The initial iterations focused on the C-MLMC structure itself, performing re-factors of the code to remove ne grain and sequential tasks and merging them in larger granularity tasks. The next iterations focused on improving the PyCOMPSs scheduler, removing existent bottlenecks and increasing its performance by making the scheduler a multithreaded engine. While the results can still be improved, we are satised with the results since the granularity of the simulations run in this evaluation step are much ner than the one that will be used for the real scenarios. The deliverable nishes with some recommendations that should be followed along the project in order to obtain good performance in the execution of the project codes.
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A research program on radiative, chemical, and dynamical feedback progresses influencing the carbon dioxide and trace gases climate effects: Annual progress report, September 1, 1986--July 15, 1989. Office of Scientific and Technical Information (OSTI), 1989. http://dx.doi.org/10.2172/6000810.

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