Dissertations / Theses on the topic 'Track'
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1
Risberg, Patrik. "IT Track or People Track?" Thesis, University of Gävle, Department of Business Administration and Economics, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-73.
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This thesis deals with knowledge management at companies in the Falun-Borlänge region. The purpose is to create better understanding of which path companies have chosen and why, respectively. A qualitative survey seeks to discover if companies have chosen IT track or people track. This is a practical and useful model for an evaluative study. In the same context, a number of important models for evaluating knowledge management are presented.
The result shows that the companies provide a multitude of training within several frameworks. Education is mostly provided in a traditional manner but there are many examples of interactive state-of-the-art training. Furthermore, most of the companies primarily focus upon people and processes, but some focus at technical facilities as well. In some cases are the technical frameworks used for support of core processes.
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Poon, Chun-hin. "An RFID-based track-and-trace anti-counterfeiting system." Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/HKUTO/record/B39556906.
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潘俊軒 and Chun-hin Poon. "An RFID-based track-and-trace anti-counterfeiting system." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B39556906.
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Hawari, Haitham M. "Minimising track degradation through managing vehicle/track interaction." Thesis, Queensland University of Technology, 2007. https://eprints.qut.edu.au/16366/1/Haitham_Hawari_Thesis.pdf.
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The rate at which a railway track deteriorates depends on the response of the track
under different static and repeated dynamic forces. These wheel/rail forces lead to
imperfections in the rail surface and deviation in track geometry alignment. The
wheel/rail forces are dependent upon the quality of maintenance of the
characteristics of both train and track. If train components such as wheelsets and
suspensions are maintained to a high standard, less dynamic forces are generated
at the wheel/rail interface and less damage is caused over time. Therefore, the
amount and cost of maintenance of track are reduced. However, there is little
known about how the characteristics of train components affect time-dependent
track degradation.
Track degradation through deviation of track from its ideal position has the most
effect on maintenance costs. Therefore, the present research aims to investigate
this track degradation and improve understanding of the effects of train
characteristics (such as train mass and speed, suspension stiffness and damping)
on railway tracks. The research is conducted by looking into the relationship
between wheel/rail forces and track degradation on one hand and between
wheel/rail forces and train characteristics on the other hand, with the objective of
assisting in managing vehicle/track interaction in order to minimise track
degradation. This aim is achieved by investigating the above two relationships to
attain the desired relationship between track degradation and train characteristics.
The research focuses on wheel/rail vertical forces (both amplitudes and
frequencies), vertical track alignment (longitudinal vertical profile), and rail head
defects.
The study started by collecting wheel/rail vertical forces data in addition to data
on vertical track degradation under sustained traffic loads on a heavy haul railway section of track in Central Queensland. Also, five years of degradation and
maintenance history data were collected on three other test sections of railway
track under variety of traffic conditions and loads in Central Queensland. There
were four main analyses of this data employed to probe the study. The first
analysis was performed by examining the track degradation history data. The
standard deviation method was used in this first analysis to acquire the rate of
deterioration in terms of its relationship to track profile (roughness). The second
analysis was accomplished by correlating the vertical wheel/rail forces to both
vertical track profile and rail roughness using signal processing principles and a
function know as coherence. The third analysis was carried out by using the
computer simulation software NUCARS to obtain the link between wheel/rail
forces and the deterioration of the vertical track profile. The fourth analysis was
achieved by combining the results obtained from the above three analyses to
acquire the rate of track deterioration in terms of its relationship to varying train
characteristics.
The first analysis mentioned above quantified the relationship between the level of
roughness of the track and rate at which that roughness deteriorated. An important
outcome of this relationship is that there is a threshold of roughness below which
track deterioration is minimal. The track maintenance planners can now use that
threshold for cost effective targeting of tamping activities. The correlation study
between track roughness and wheel/rail forces using the coherence function
found, surprisingly, that the overall deterioration of the track roughness, in the
absence of frequencies of forces above 30 Hz, is due to the so-called quasi-static
lower frequency oscillations of dynamic forces. This conclusion together with the
relationship between vehicle characteristics and track forces, established in the
analyses above, has significant implications for the design of wagon bogies and
for charges track owners might levy on trains using their tracks.
This research is part of a larger Rail CRC project 11/4 called 'Enhancing the
Optimisation of Maintenance/Renewal' being carried out in the School of Urban
Development in Queensland University of Technology.
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Hawari, Haitham M. "Minimising track degradation through managing vehicle/track interaction." Queensland University of Technology, 2007. http://eprints.qut.edu.au/16366/.
Full textAbstract:
The rate at which a railway track deteriorates depends on the response of the track under different static and repeated dynamic forces. These wheel/rail forces lead to imperfections in the rail surface and deviation in track geometry alignment. The wheel/rail forces are dependent upon the quality of maintenance of the characteristics of both train and track. If train components such as wheelsets and suspensions are maintained to a high standard, less dynamic forces are generated at the wheel/rail interface and less damage is caused over time. Therefore, the amount and cost of maintenance of track are reduced. However, there is little known about how the characteristics of train components affect time-dependent track degradation. Track degradation through deviation of track from its ideal position has the most effect on maintenance costs. Therefore, the present research aims to investigate this track degradation and improve understanding of the effects of train characteristics (such as train mass and speed, suspension stiffness and damping) on railway tracks. The research is conducted by looking into the relationship between wheel/rail forces and track degradation on one hand and between wheel/rail forces and train characteristics on the other hand, with the objective of assisting in managing vehicle/track interaction in order to minimise track degradation. This aim is achieved by investigating the above two relationships to attain the desired relationship between track degradation and train characteristics. The research focuses on wheel/rail vertical forces (both amplitudes and frequencies), vertical track alignment (longitudinal vertical profile), and rail head defects. The study started by collecting wheel/rail vertical forces data in addition to data on vertical track degradation under sustained traffic loads on a heavy haul railway section of track in Central Queensland. Also, five years of degradation and maintenance history data were collected on three other test sections of railway track under variety of traffic conditions and loads in Central Queensland. There were four main analyses of this data employed to probe the study. The first analysis was performed by examining the track degradation history data. The standard deviation method was used in this first analysis to acquire the rate of deterioration in terms of its relationship to track profile (roughness). The second analysis was accomplished by correlating the vertical wheel/rail forces to both vertical track profile and rail roughness using signal processing principles and a function know as coherence. The third analysis was carried out by using the computer simulation software NUCARS to obtain the link between wheel/rail forces and the deterioration of the vertical track profile. The fourth analysis was achieved by combining the results obtained from the above three analyses to acquire the rate of track deterioration in terms of its relationship to varying train characteristics. The first analysis mentioned above quantified the relationship between the level of roughness of the track and rate at which that roughness deteriorated. An important outcome of this relationship is that there is a threshold of roughness below which track deterioration is minimal. The track maintenance planners can now use that threshold for cost effective targeting of tamping activities. The correlation study between track roughness and wheel/rail forces using the coherence function found, surprisingly, that the overall deterioration of the track roughness, in the absence of frequencies of forces above 30 Hz, is due to the so-called quasi-static lower frequency oscillations of dynamic forces. This conclusion together with the relationship between vehicle characteristics and track forces, established in the analyses above, has significant implications for the design of wagon bogies and for charges track owners might levy on trains using their tracks. This research is part of a larger Rail CRC project 11/4 called 'Enhancing the Optimisation of Maintenance/Renewal' being carried out in the School of Urban Development in Queensland University of Technology.
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Yang, Bo, and 楊波. "Implementation issues in RFID-based track-and-trace anti-counterfeiting." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/208016.
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Counterfeit products, particularly pharmaceuticals, electronic devices, and apparels, are widespread. They threaten consumer safety and cause huge economic losses to licit supply chain partners and governments.
Although a number of traditional anti-counterfeiting technologies, such as holograms and chemical tags, are available to combat counterfeiting, they are vulnerable to imitation or being reused. Besides, these technologies are intended to protect individual items, rather than to safeguard an entire supply chain. As such, fake products may likely be injected into the supply chain to hurt end-consumers.
Track-and-trace technology based on Radio Frequency Identification (RFID) has recently emerged as a promising tool to combat counterfeiting, because of its automatic and non-line-of-sight capability to identify massive product items. By maintaining an electronic pedigree (e-pedigree) that records the transaction information of product items along the supply chain, this approach stands out for protecting the supply chain against infiltration, eliminating theft and fraud, facilitating recall of defective products, and supporting remote authentication.
However, a number of technical and critical issues have yet to be solved for practical implementation of RFID-based track-and-trace anti-counterfeiting. These include generation of accurate initial product e-pedigree in fast moving manufacturing lines, precise e-pedigree updating in batch product distributing and receiving, and fast e- pedigree queries for remote and real-time product authentication from end-customers. Without fully addressing these issues, the accumulated product e-pedigree data would be untrustworthy, rendering any subsequent operations of track-and-trace and product authentication unreliable.
This thesis investigates the crucial implementation issues in RFID-based track-and-trace anti-counterfeiting. It firstly presents an innovative track-and-trace anti-counterfeiting system, based on which a TDPS algorithm is proposed for generation of initial product e-pedigree in fast moving production lines. The TDPS overcomes many practical issues, such as tag writing error and tag locking failure, and helps identify the bottleneck of initial product e-pedigree generation. To tackle the bottleneck, the TDPS is further optimized by incorporating a block writing method to enhance the tag EPC writing efficiency and an integration method to balance the overhead of RFID equipment.
In product distributing and receiving, a mechanized 3D scanning method is proposed to improve bulk item identification rate and enhance the accuracy and completeness of product e-pedigree. Indeed, RFID-based track-and-trace anti-counterfeiting mandates a relatively high bulk item identification rate for product authentication and e-pedigree updating. Experimental results demonstrate that the mechanized 3D scanning can achieve a bulk item reading rate of up to 98.9%, which largely outperforms the widely documented bulk reading rate (70%) in real applications.
In retailing level, the efficiency of e-pedigree queries would hugely impact on customer shopping experience and the effectiveness of track-and-trace anti-counterfeiting. A partition-based method is therefore developed to cluster product e-pedigree data to improve the speed of e-pedigree queries. This approach partitions the accumulated e-pedigree data into fixed and dynamic groups, such that queries are conducted mainly on active data, rather than on the whole historical data sets.
By addressing the above key issues, this thesis contributes to making implementation of RFID-based track-and-trace anti-counterfeiting practically viable and reliable.published_or_final_version
Industrial and Manufacturing Systems Engineering
Master
Master of Philosophy
7
Zhang, Yu-Jiang. "An integrated rail track degradation model." Thesis, Queensland University of Technology, 2000. https://eprints.qut.edu.au/36110/7/36110_Digitised%20Thesis.pdf.
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There has been a worldwide trend to increase axle loads and train speeds. This means that railway track degradation will be accelerated, and track maintenance costs will
be increased significantly. There is a need to investigate the consequences of increasing traffic load. The aim of the research is to develop a model for the analysis of physical
degradation of railway tracks in response to changes in traffic parameters, especially increased axle loads and train speeds. This research has developed an integrated track degradation model (ITDM) by integrating several models into a comprehensive framework. Mechanistic
relationships for track degradation hav~ ?een used wherever possible in each of the models contained in ITDM. This overcc:mes the deficiency of the traditional statistical track models which rely heavily on historical degradation data, which is generally not available in many railway systems. In addition statistical models lack the flexibility of incorporating future changes in traffic patterns or maintenance practices. The research starts with reviewing railway track related studies both in Australia and overseas to develop a comprehensive understanding of track performance under various traffic conditions. Existing railway related models are then examined for
their suitability for track degradation analysis for Australian situations. The ITDM model is subsequently developed by modifying suitable existing models, and
developing new models where necessary. The ITDM model contains four interrelated submodels for rails, sleepers, ballast and subgrade, and track modulus. The rail submodel is for rail wear analysis and is developed from a theoretical concept. The sleeper submodel is for timber sleepers damage prediction. The submodel is developed by modifying and extending an existing model developed elsewhere. The submodel has also incorporated an analysis
for the likelihood of concrete sleeper cracking. The ballast and subgrade submodel is evolved from a concept developed in the USA. Substantial modifications and
improvements have been made. The track modulus submodel is developed from a conceptual method. Corrections for more global track conditions have been made. The integration of these submodels into one comprehensive package has enabled the interaction between individual track components to be taken into account. This is done by calculating wheel load distribution with time and updating track conditions
periodically in the process of track degradation simulation.
A Windows-based computer program ~ssociated with ITDM has also been developed. The program enables the user to carry out analysis of degradation of individual track components and to investigate the inter relationships between these
track components and their deterioration.
The successful implementation of this research has provided essential information for prediction of increased maintenance as a consequence of railway trackdegradation. The model, having been presented at various conferences and seminars, has attracted wide interest. It is anticipated that the model will be put into practical use among Australian railways, enabling track maintenance planning to be optimized and potentially saving Australian railway systems millions of dollars in operating costs.
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Sárik, Veronika. "Decision-making model for track system of high-speed rail lines : Ballasted track, ballastless track or both?" Thesis, KTH, Byggvetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-226308.
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During the 50 years of existence of high speed railways, the track structure solutions have developed both in number and in type. As of today, in case of conventional railway, there are 2 main types one could mention: ballasted and ballastless track solutions. However, there is no standardized procedure for choosing between these systems and between their respective variants, the decision is made on a case-by-case basis. This thesis aims to create a generic framework for decision making, primarily taking into account technical details. The model, the input parameters and variables can be easily adjusted and customized based on national standards, practices or other considerations, but the primary focus in the thesis have been the current Swedish regulations. The thesis has an overview on the influencing factors and attempts to include the most crucial ones of these into a decision-making model. This model compares 3 alternatives, namely the ballastless alternative, the ballasted alternative and the alternating system option, in which case the track system selection happens based on local factors, such as geotechnical conditions. These are considered and evaluated through Fuzzy logic, which supports the system selection affected by various sources of uncertainty. The decision is finally made through an LCC calculation. In order to handle the great uncertainties in the data used in the LCC, a Monte Carlo simulation is performed. The main added value of the thesis is considered to be the methodology for choosing the systems based on life-cycle cost after careful technical evaluation. This approach might provide basis for decision for track systems of high speed rail lines.
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Southcott, Michael L. "Radar track association /." Title page, table of contents and abstract only, 1998. http://web4.library.adelaide.edu.au/theses/09PH/09phs726.pdf.
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Dongue, Dongue Dietrich Kevin, and Lorenzo Grosso. "The Speed-Track." Thesis, KTH, Maskinkonstruktion (Inst.), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-142612.
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The Speed-Track is a prototype of tracked vehicle made for material transportation on yards andgalleries. It was realized in 2011 and during the past two years has been employed mainly forload transportation on mountains. The main innovations adopted by the vehicle are about thesuspension system and the hydrostatic transmission; the combination of both allows acomfortable driving up to a maximum speed of 20 km/h.First of all, the present thesis aims to quantitatively evaluate the performances of the vehiclefrom the point of view of the suspension system and the transmission. The design of the vehicle,in fact, has been driven by the designer’s experience and no preliminary simulations and sizingcomputations have been performed.According to the outcomes of the first step as well as the feedback, some improvements to thecurrent configuration are designed and evaluated. The feedback has been submitted to theprototype’s users through a questionnaire. Improvements are supposed to be easily implementedon the existing vehicle.The outcomes of the previous steps as well as the communication with employees andentrepreneurs and the knowledge of the state of the art in terms of construction and earthmovingmachines drive the last step of the present work.The employees and entrepreneurs consulted mainly work in the agricultural sector and they havebeen contacted through web-based forums. In addition, the participation to the fair Bauma 2013allowed us to get a more complete picture of the state of the art.New solutions, starting from scratch, are designed in the last part.Keywords:Speed-Track är en prototyp av en spårfarkost utvecklad för materialtransport på gårdar och igallerior. Den konstruerades 2011 och under de senaste två åren har den främst använts för tungatransporter på berg.De huvudsakliga innovationerna av vilka farkosten använder sig av är kopplade tillsuspensionssystemet och den hydrostatiska transmissionen; kombinationen av dessa möjliggören bekväm resa i hastigheter upp till 20 km/h.Målet med detta examensarbete är framför allt att utvärdera prestandan hos farkosten medhänsyn till suspensionssystemet och transmissionen. Designen av farkosten har utformats baseratpå utvecklarens erfarenheter och inga preliminära simuleringar eller beräkningar har utförts.Baserat på resultaten från, och utvärdering av det första steget har vissa förbättringar till denrådande uppbyggnaden framtagits och utvärderats. Utvärderingen har lämnats till användare avprototypen genom ett frågeformulär.Förbättringarna skall vara lätta att tillämpa på den existerande farkosten.Resultaten från de föregående stegen tillsammans med en dialog med anställda och entreprenörersamt teknisk kunskap med avseende på konstruktion och jordfraktande maskiner driva det sistasteget av det presenterade arbetet.Medarbetare och entreprenörer härstammar framför allt från arbete inom jordbrukssektorn ochhar blivit kontaktade genom web-forum.Dessutom har medverkan under mässan Bauma 2013 givit en mer komplett bild av den rådandetekniken.Nya lösningar skapade från början utvecklas i arbetets sista del.
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Chaar, Nizar. "Wheelset Structural Flexibility and Track Flexibility in Vehicle-Track Dynamic Interaction." Doctoral thesis, Stockholm : Farkost och flyg, Kungliga Tekniska högskolan, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4345.
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Collins, M. J. "Improvements in track to train communications for railway jointless track circuits." Thesis, University of Bath, 1997. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362264.
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Shaker, Genevieve. "Off the track the full-time nontenure-track faculty experience in English /." [Bloomington, Ind.] : Indiana University, 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3387054.
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Thesis (Ph.D.)--Indiana University, Dept. of Educational Leadership and Policy Studies, 2008.Title from PDF t.p. (viewed on Jul 19, 2010). Source: Dissertation Abstracts International, Volume: 70-12, Section: A, page: 4598. Adviser: Nancy V. N. Chism.
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Dujmović, Vida. "Track layouts of graphs." Thesis, McGill University, 2003. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=84234.
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Graph drawing problems originate from diverse application domains. In some, such as software engineering and cartography, graphs are required to be visualized or drawn in ways that are easy to read and understand. In others, such as VLSI design, graphs are required to be laid out while satisfying some physical constraint. For example, when a drawing is to be displayed on a page or a computer screen, or is to be used for VLSI design, it is important to keep its area/volume small to avoid wasting space.More often than not however, the idea of a good drawing, regardless of its purpose, coincides with having no edge crossings or having very few crossings. Unfortunately, whichever of the numerous drawing styles one considers, a problem requiring a crossing minimization of sorts will, almost certainly, be NP -hard. The theory of fixed parameter tractability (FPT) provides a new and promising approach for coping with intractable problems. In the first part of this thesis we apply algorithmic techniques developed in this theory to well-known graph drawing problems. In particular, we contribute efficient FPT algorithms for crossing minimization and planarization problems concerning the 2-layer drawing style.
In the second part of this thesis we introduce and comprehensively study so-called track layouts of graphs and their subdivisions. A relationship between this combinatorial structure and several well-known types of graph layouts is established, leading to a number of new results. For example, our study of track layouts of bounded treewidth graphs settles an open problem due to Ganley and Heath (2001) regarding queue layouts of such graphs. Moreover, the study also establishes that graphs of bounded treewidth have three-dimensional straight-line grid drawings with linear volume.
Through the study of track layouts of subdivisions, we determine that every graph with n vertices and m edges has a three-dimensional polyline grid drawing with the vertices on a rectangular prism, O (n + m log n) volume and O (log n) bends per edge.
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Underwood, Lindsey. "Aerodynamics of Track Cycling." Thesis, University of Canterbury. Mechanical Engineering, 2012. http://hdl.handle.net/10092/7804.
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The aim of this thesis was to identify ways in which the velocity of a track cyclist could be increased, primarily through the reduction of aerodynamic drag, and to determine which factors had the most significant impact on athlete performance. An appropriate test method was set up in the wind tunnel at the University of Canterbury to measure the aerodynamic drag of different cycling positions and equipment, including helmets, skinsuits, frames and wheels, in order to measure the impact of specific changes on athlete performance.
A mathematical model of the Individual Pursuit (IP) event was also created to calculate the velocity profile and finishing time for athletes competing under different race conditions. The model was created in Microsoft Excel and used first principles to analyse the forces acting on a cyclist, which lead to the development of equations for power supply and demand. The mathematical model was validated using SRM data for eleven, elite track cyclists, and was found to be accurate to 0.31s (0.16%). An analysis of changes made to the bike, athlete, and environmental conditions using the mathematical model showed that the drag area and air density had the greatest impact on the finishing time. The model was then used to predict the finishing times for different pacing strategies by generating different power profiles for a given athlete with a fixed stock of energy (the work done remained the same for all generated power profiles) in order to identify the optimal pacing strategy for the IP. The length of time spent in the initial acceleration phase was found to have a significant impact on the results, although all strategies simulated with an initial acceleration phase resulted in a faster finishing time than all other strategies simulated.
Results from the wind tunnel tests showed that, in general, changes made to the position of the cyclist had the greatest impact on the aerodynamic drag compared to changes made to the equipment. Multiple changes in position had a greater impact on drag than individual changes in position, but the changes were not additive; the total gain or loss in drag for multiple changes in position was not the sum of individual gains or losses in drag. Actual gains and losses also varied significantly between athletes, primarily due to differences in body size and shape, riding experience, and reference position from which changes were made from. Changes in position that resulted in a reduction of the frontal area, such as lowering the handlebars and head, were the most successful at reducing the aerodynamic drag, and a change in skinsuit was found to have the greatest impact on drag out of all equipment changes, primarily due to the choice of material and seam placement. The mathematical model was used to quantify the impact of changes in position and equipment made in the wind tunnel on the overall finishing time for a given athlete competing in an IP event. Time savings of up to 8 seconds were seen for multiple changes in position, and up to 5 seconds for changes to the equipment.
Overall this thesis highlights the significance of aerodynamics on athlete performance in track cycling, suggesting that it is worthwhile spending time and money on research and technology to find new ways to reduce the aerodynamic drag and maximise the speed of cyclists. Although this thesis primarily concentrates on the Individual Pursuit event in track cycling, the same principles can be applied to other cycling disciplines, as well as to other sports.
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Fitzek, Frank H. P. "Network & Cloud Track." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-211634.
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Blanco, Blas. "Railway track dynamic modelling." Licentiate thesis, KTH, Farkost och flyg, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-207180.
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The railway vehicles are an increasing mean of transportation due to, its reduced impact on environment and high level of comfort provided. These reasons have contributed to settle a positive perception of railway traffic into the European society. In this upward context, the railway industrial sector tackles some important challenges; maintaining low operational costs and controlling the nuisance by-products of trains operation, the most important being railway noise. Track dynamic plays a main role for both issues, since a significant part of the operational costs are associated with the track maintenance tasks and, the noise generated by the track can be dominant in many operational situations. This explains why prediction tools are highly valued by railway companies. The work presented in this licentiate thesis proposes methodologies for accurate and efficient modelling of railway track dynamics. Two core axes have led the development of this task, on one hand, the rail modelling and, on the other hand, the characterisation of the finite length nature of track supports. Firstly, concerning the rail modelling technique, it has evolved under two major premises. On one hand, regarding the frequency domain, it should describe high frequency behaviour of the rail. In order to accomplish with this first premise, a model based on Timoshenko beam theory is used, which can accurately account for the vertical rail behaviour up to 2500 Hz. On the other hand, with respect to the time domain, the response should be smooth and free of discontinuities. This last condition is fulfilled by implementation of the Timoshenko local deformation. Secondly, a model of support that considers its finite length nature is sought. For this purpose, a Timoshenko element over elastic foundation is formulated. Thus, the common model of support, which is based on a concentrated connection, is substituted by a distributed model of support. In this way, several enhancements are achieved; the temporal contact force response is smoothed and a more realistic shape is obtained, the amplitude of the displacement due to the parametric excitation is reduced and the magnitude associated to the ‘pin-pin’ frequency is not overestimated.QC 20170522
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Berggren, Eric. "Dynamic track stiffness measurement : a new tool for condition monitoring of track substructure /." Stockholm, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-341.
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Wehbi, Mohamed. "Developing a novel technique to extract track stiffness information from track geometry measurement." Thesis, University of Birmingham, 2016. http://etheses.bham.ac.uk//id/eprint/6722/.
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Railway tracks deteriorate over time due to the combined effects of train loads and environment. To carry out appropriate maintenance, it is necessary to measure the condition of the track. There are two broad categories of condition measures namely: function and structural measures of conditions. Functional measures of condition assess the condition of the track from the point of view of the user. An example of a commonly used functional measure of condition is track geometry. In the UK, track geometry is measured by the track recording coach and it is carried frequently on the entire network. On the other hand, structural measures of condition assess the structural integrity of the track. Example of a commonly used structural measure of condition is track stiffness. In the UK, track stiffness is measured using the Falling Weight Deflectometer (FWD) and it is carried out less frequently on specific railway track sections as it is very slow, requires closure of the track and is expensive to operate. The aim of this research is to investigate the feasibility of using track geometry measurement to extract track stiffness information and ultimately develop a prototype automated system to achieve this.
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Frohling, Robert Desmond. "Deterioration of railway track due to dynamic vehicle loading and spatially varying track stiffness." Thesis, Pretoria : [s.n.], 1997. http://upetd.up.ac.za/thesis/available/etd-01122009-160350.
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Revathi, Palaniappan Natchammai. "Forest Machine Track-Soil Interaction." Thesis, KTH, Maskinkonstruktion (Inst.), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-142428.
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I många västeuropeiska länder har metoden för skogsavverkning ändrats från användning av motorsåg till ett mekaniserat skogsavverkningssystem känt som kortvirkesmetoden. Denna metod är baserad på en tvåmaskinslösning – en skördare som fäller, grenar och sågar träden enlig fördefinierade längder, och en skotare som transporterar stockarna till en lastplats för vidare transport till en bearbetningsanläggning. För att utveckla skogsmaskiner som är skonsammare för marken behövs en djupare förståelse av interaktionen mellan terrängen och dragfordonet. Huvudfokus i detta projekt ligger på bandgående skotare.Inom detta projekt, innefattar interaktionen mellan bandet och marken spårbildning, sammanpressning, marktryck, skjuvning, grepp och dragkraft. Spårdjupet är en av de viktiga faktorerna för att bestämma fordonets prestanda och skadeåverkan på mark och vegetation. Mätning och karakterisering av de mekaniska egenskaperna för flersiktade jordlager är en komplex uppgift. De två oftast använda metoderna för att mäta jordens mekaniska egenskaper är Bevametertekniken och Konpenetrometertekniken, där Bevametertekniken är jämförelsevis mindre effektiv för att karakterisera den nordiska skogsträngen eftersom skogsjorden inte är homogen.Olika semiempiriska WES-modeller och parametriska modeller används för bestämmandet av marktryck, spårdjup, dragkraft, rörelsemotstånd och kraften i dragkroken för hjul- och bandfordonen. Beräkningarna utfördes för en skotare av mediumstorlek utrustad med tre olika typer av band monterade på boggihjulen. Detta gjordes för tre olika typer av terrängförhållanden och både med och utan last. Även en jämförelse mellan hjul- och bandfordon gjordes. Resultatet från de teoretiska beräkningarna jämfördes med testdata från ett fullskaligt fältprov. Fältprovet inkluderade data för marktryck, nerträngning i jorden och spårdjup mätt på en skotare, både med och utan last.Adams for Tracked Vehicles (ATV) plugin är ett verktyg primärt utvecklat för dynamiska simuleringar av bandfordon. Fördelar och nackdelar med mjukvaran och dess lämplighet för användning för modellering av interaktionen mellan band och jord for skogsmaskiner diskuteras i denna rapport.In many Western European countries, the method of timber harvesting has changed from the use of chain saws to a mechanized harvesting system known as Cut-To-Length method. This cut to length method is based on a two-machine solution – a harvester that folds, branches and cuts trees according to pre-defined lengths, and a forwarder that transports logs to a loading area from where it is further transported to a processing facility. In order to develop forest machines that is gentler to the ground, a thorough understanding of the terrain and the vehicle’s traction unit is required. The main focus of this project is on the tracked forest forwarders.In this project, the track soil interaction covers issues like rutting, compaction, ground pressure, shearing, traction and drawbar pull. The rut depth is one of the important factors to determine the vehicle performance and damages caused to the ground and vegetation. Measurement and characterization of the mechanical properties of a multilayer soil is quite a complex task. The two most commonly used methods to measure the soil mechanical properties are the Bevameter technique and the Cone penetrometer technique, of which the Bevameter technique is comparatively less efficient for characterizing the Nordic forest terrain as the forest soil is not homogenous.Different semi-empirical WES models and parametric models are used for the determining the ground pressure, rut depth, tractive force, motion resistance and drawbar pull for the wheeled and tracked vehicles. The calculations were performed for a medium sized forwarder equipped with three different types of tracks mounted on bogie wheels on three types of terrain conditions under loaded and unloaded conditions. A comparison of the wheeled and tracked vehicle performance is also made. The results obtained from the theoretical calculations are compared with the test data from a full scale field test. The field test data include ground pressure, soil penetration and rut depth data measured on the forwarder with and without load.Adams for Tracked vehicles (ATV) plugin is a tool primarily developed for performing dynamic simulations of tracked equipment. The pros and cons of the software and it’s suitability to be used for the track soil interaction modeling of forestry machines is discussed in this report.
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Noyes, Stephen P. "Radar track extraction in clutter." Thesis, University of Sussex, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.400009.
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Kayes, Edwin. "Micro-Track Digital Cassette Recording." International Foundation for Telemetering, 1993. http://hdl.handle.net/10150/611878.
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International Telemetering Conference Proceedings / October 25-28, 1993 / Riviera Hotel and Convention Center, Las Vegas, NevadaThe increasing availability of powerful yet relatively inexpensive data acquisition and processing techniques has precipitated a radical reappraisal of the methods used to capture, manipulate and store data of all kinds. Some of the recently introduced recording systems can be used both for fast data capture and for high capacity archival/back-up applications - effectively bridging a long-standing divide between these two formerly diverse aspects of data recording and processing. This paper offers a brief overview of a new technology known as micro-track recording, and suggests ways in which system designers and integrators may take full advantage of its important new facilities and features.
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Zhang, Xianying. "Modelling of track sound radiation." Thesis, University of Southampton, 2016. https://eprints.soton.ac.uk/397349/.
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In most situations the dominant source of noise from the railway system for conventional speeds is rolling noise. This is radiated by the wheels, the rails which dominate the important mid-frequency region between 400 and 2000 Hz, and, at low frequencies, also the sleepers. The acoustic properties of the rails, sleepers and ballast are investigated in this thesis. The sound radiation of a rail in close proximity to a ground (both rigid and absorptive) is predicted by the boundary element method (BEM) in two dimensions (2D). Results are given in terms of the radiation ratio for both vertical and lateral motion of the rail, when the effects of the acoustic boundary conditions due to the sleepers and ballast are taken into account in the numerical models. Allowance is made for the effect of wave propagation along the rail by applying a correction in the 2D modelling. The numerical predictions of the sound radiation from a rail are verified by comparison with experimental results obtained using a 1:5 scale rail model in different configurations. The sound radiation from the sleepers has been calculated using a three-dimensional boundary element model including the effect of both reflective and partially absorptive ground. When the sleeper flexibility and support stiffness are taken into account, it is found that the radiation ratio of the sleeper can be approximated by that of a rigid half-sleeper. When multiple sleepers are excited through the rail, their sound radiation is increased as they form a composite source. This effect has been calculated for cases where the sleeper is embedded in a rigid or partially absorptive ground. It is shown that it is sufficient to consider only three sleepers in determining their radiation ratio when installed in track. At low frequencies the vibration of the track is localised to the three sleepers nearest the excitation point whereas at higher frequencies the distance between the sleepers is large enough compared with the acoustic wavelength for them to be treated independently. Measurements on a 1:5 scale model railway track are used to verify the numerical predictions with good agreement being found for all configurations. Not only can ballast absorb noise to some extent due to the gaps between the ballast particles but it can also vibrate and reradiate noise during a train pass-by. Experiments have been performed using 1:5 scale ballast to investigate this. The basic properties of the ballast, as a porous material, are measured initially, in particular the flow resistivity and porosity. The modelling of the ballast absorption is then implemented based on the corresponding measured parameters and this is compared with the measured absorption. The effects of ballast absorption on the rail and sleeper radiation are also measured, and are compared with the numerical predictions. Moreover, the vibration of the ballast is obtained experimentally. The influence of the ballast vibration on the sleeper radiation is then estimated and shown to increase the noise radiation below 200 Hz. Finally, the sound radiation from the whole track is predicted, and compared with the corresponding measured results on the 1:5 scale model. The sound radiation models for the rail and the sleeper, are used with the TWINS software to give revised predictions of the track sound radiation. Prediction differences are shown between the original TWINS and the updated models.
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Muinde, Michael. "Railway track geometry inspection optimization." Thesis, Luleå tekniska universitet, Drift, underhåll och akustik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-71280.
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Railway transportation plays a vital role in modern societies. Due to increasing demands for transportation of passengers and goods, higher speed trains with heavier axle loads are introduced to the railway system, and it is expected to continue in the future. Therefore, track geometry bears huge static and dynamic forces that accelerate degradation process. As a result, railway track should be inspected regularly to detect geometry faults and to plan for maintenance actions in advance. Track geometry inspection has a profound impact on railway track availability and maintenance cost. Although there have been improvements in safety performance and maintenance planning of railway tracks, still infrastructure managers expect a more effective maintenance planning and scheduling regime. This thesis proposes a simulation-based model for optimization of track geometry inspection intervals. To simulate the track geometry evolution a linear model is used to model track geometry degradation in a maintenance cycle. It is assumed that the parameters of degradation model are random variables following lognormal distribution. Using the proposed model, the track geometry behaviour is simulated under different inspection intervals. Later, different inspection intervals are compared with respect to the cost function and the optimal range of inspection intervals is obtained.
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Wu, Wendy Xiaohui. "The corrugation of railway track." Thesis, London South Bank University, 1997. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245157.
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Taylor, Teresa Brooks. "Service-Learning/Civic Engagement Track." Digital Commons @ East Tennessee State University, 2017. https://dc.etsu.edu/etsu-works/3632.
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Gely, Pierre. "High frequency vehicle-track interactionsimulation : Coupling of an advanced track model with a multi-bodysystem." Thesis, KTH, Järnvägsteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-159277.
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The forces caused by the high frequency vehicle-track interaction have a great impact on thetrack maintenance. They should be represented in vehicle-track models in order to predicttheir impact. As a result, a multi-body system (MBS) should be extended with an advancedtrack model. The MBS represents the vehicle and the wheel-rail contact with a great accuracy.The track will be modeled in two different ways: a moving track model and a continuous trackmodel which is a finite element modeling (FEM). The first one will be a lumped-mass model.The most advanced system will be the second one, which is a MBS-FEM representation andoffers a great precision to represent the high frequency dynamical properties. The system willbe used to simulate pertinent phenomena such as a wheelflats, corrugations and rail joint.Based on the literature and the measurements, the model is validated in a wider frequencyrange than the one currently used (0-20Hz). The results given by both models are close tothe literature and the measurement.
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Romps, John F. (John Francis). "Modelling track maintenance and its effects on the reliability of a single track railroad line." Thesis, Massachusetts Institute of Technology, 1993. http://hdl.handle.net/1721.1/12397.
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White, Darris L. "Statistical Characterization of Vehicle and Track Interaction Using Rail Vehicle Response and Track Geometry Measurements." Thesis, Virginia Tech, 1998. http://hdl.handle.net/10919/36835.
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This study evaluates the dynamic interaction between rail vehicles and the track on which they travel. The measurements were analyzed in the time and frequency domain. The effects of external parameters such as the vehicle design, subgrade stiffness, and degree of curvature were analyzed and compared for both the vehicle response and the track geometry data.
This study was conducted in close cooperation with the Transportation Technology Center, Inc. (TTCI) in Pueblo, Colorado. The track and vehicle response data was collected on the High Tonnage Loop at TTCI over a span of approximately ten years. For the purpose of this study, TTCI provided this data to the Advanced Vehicle Dynamics Laboratories (AVDL) at Virginia Tech.
The analysis of the data was first completed for the vehicle response and track geometry measurements separately. In this manner, the effects of the subgrade stiffness, the degree of curvature, and the vehicle design could be evaluated for each of the measurements. The analysis of the track and rail vehicle response was successfully completed, and the results from this analysis are presented in the following chapters.
The analysis showed that the subgrade stiffness had a significant effect on the vertical wheel loads, the track crosslevel, and the track gauge. For an increase in the degree of curvature, the variation of the crosslevel increased. The dynamic response of the vertical and lateral wheel loads showed a significant dependence on the alignment of the rails. Improvements for future studies of the interaction between the track and rail vehicles have been recommended.Master of Science
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Michas, Georgios. "Slab track systems for high-speed railways." Thesis, KTH, Väg- och banteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-96507.
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In the last 40 years an increase in train speed and axle load around the world and other challenges in the conventional ballasted track system gave birth to ballastless railway track system. This study examines in depth the various slab track systems that are being used today. Their design characteristics as well as the various requirements for efficient use are thoroughly explained. At least 34 different ballastless systems have been recorded in many railway networks throughout the world. The most significant slab track systems are analysed in detail and compared. Slab track designs have significant advantages comparing to ballasted tracks. The most significant are the high stability of the track, the almost non-existent need for maintenance, the long life cycle (60 years) and the reduced weight and height of the track. Their disadvantages against the ballasted tracks are mainly summarized in their higher construction costs. The Finite Element package ABAQUS/CAE is used to model a 3-D slab track design under static traffic loading. The results suggest that slab tracks have profoundly better stability and durability comparing to ballasted tracks mainly due to their higher stiffness and strength. The author underlines the need for further studies to undoubtedly prove the claimed advantages of slab track systems as well as to improve the costs associated with construction.
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Bolte, Nils-Ole, and Daniel Christopher Goll. "Potential analysis of track-and-trace systems in the outbound logistics of a Swedish retailer." Thesis, Jönköping University, Internationella Handelshögskolan, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-48986.
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Supply chain visibility has become a crucial factor for companies in times of globalization and customer satisfaction. Track-and-trace technologies are important tools in order to enhance supply chain visibility. This thesis was written in cooperation with a Swedish retailer and evaluates potential track-and-trace technologies in order to develop a solution to close their current track-and-trace gap in their outbound logistics. Currently the handover point between the retailer and the postal service provider is not clearly defined, so that shipments get lost during the transition. Therefore, a literature review about currently used track-and-trace technologies was carried out. Several technologies with a wide price and applicability range are currently used and have been analysed regarding their strength and weaknesses. A qualitative study in form of interviews was conducted within the Swedish market about how this gap could possibly be closed. Empirical findings show that the existing track-and-trace technologies do not provide a best practice solution. Especially in the field of outbound logistics, several factors and the individual process requirements of a company have to be considered in order to develop an efficient solution, so that the existing track-and-trace gap can be closed. Each company has its unique set of challenges, which have to be solved in order to successfully implement a long- lasting tracking solution. A high dependence from the postal service provider is additionally given since all process steps need to be aligned to guarantee reliability of the data afterwards. In the case of the Swedish retailer, an automatized scanning bow with a separated area for outbound parcels is expected to improve transparency of the handover and lower the total amount of lost shipments. The breakeven point would be reached within the next years, so that operational saving could soon be achieved. Due to the global outbreak of COVID-19, as well as significant problems of the retailer, the practical application could not be tested. It should therefore be part of further academic studies.
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Arasteh, khouy Iman. "Optimization of track geometry maintenance : a study of track geometry degradation to specify optimal inspection intervals." Licentiate thesis, Luleå tekniska universitet, Drift, underhåll och akustik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-17885.
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Railway infrastructure is a complex system which comprises different subsystems. Long useful life span is one of the important aspects of this prime mode of transport. The useful life length of its assets is highly dependent on the maintenance and renewal strategy used during its life cycle. Today’s demands on the railway industry call for increased capacity, including more trains, travelling at higher speeds with higher axle loads. This increased usage will result in higher degradation of railway asset and higher maintenance costs. However, due to the competitive environment and limited budgets, railway infrastructure managers are compelled to optimize operation and maintenance procedures to decrease operation and maintenance costs while meeting high safety standards. To assure track safety and maintain high quality, a cost effective track maintenance strategy is required, one based not only on technical and/or safety limits but also on cost-effective maintenance thresholds. RAMS (Reliability, Availability, Maintainability and Safety) and LCC (Life Cycle Cost) analyses, which are derived from reliable track condition data, provide an approach to specify cost effective maintenance strategy to lessen corrective maintenance actions and downtimes.One of the main parameters to assure railway safety and comfortable railway service is to maintain high quality of track geometry. Poor track geometry quality, directly or indirectly, may result in safety problems, speed reduction, traffic disruption, greater maintenance cost and higher degradation rate of the other railway components (e.g. rails, wheels, switch, crossings etc.). The aim of this study is to develop a methodology to optimize track geometry maintenance by using historical geometry data. The methodology is based on reliability and cost analysis and supports the maintenance decision-making process to identify cost-effective inspection interval. An important phase of track geometry maintenance optimization is to estimate the track degradation rate. Obtaining knowledge about degradation helps to properly schedule maintenance activities such as inspection and tamping.The thesis provides a methodology to identify a cost-effective inspection interval based on track degradation rate and cost drivers. It contains state-of-the-art track geometry maintenance optimization. It describes Trafikverket’s (Swedish Transport Administration) maintenance strategy regarding measurements, reporting on and improving track quality, and it evaluates the efficiency of this strategy. Finally, it includes a case study carried out on the iron ore line in north of Sweden that runs from Boden to Gällivare to evaluate track geometry degradation and analyze the probability distributions of failures. A cost model is developed in order to find optimal inspection interval.Keywords: Track geometry degradation, Track maintenance optimization, Maintenance planning, TampingGodkänd; 2011; 20110516 (iman); LICENTIATSEMINARIUM Ämnesområde: Drift och underhållsteknik/Operation and Maintenance Engineering Examinator: Professor Uday Kumar, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Diskutant: Adjungerad Professor, Per-Olof Larsson-Kråik, Trafikverket, Luleå Tid: Måndag den 13 juni 2011 kl 10.00 Plats: F1031, Luleå tekniska universitet
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Faiz, Rizwan Bin. "An empirical rail track degradation model based on predictive analysis of rail profile and track geometry." Thesis, Loughborough University, 2010. https://dspace.lboro.ac.uk/2134/6455.
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It is generally observed that the condition of rail tracks degrades rapidly over time until and unless effective maintenance is carried out. In the rail industry, rail maintenance actions are usually reactive, which means that maintenance is carried out after a defect has been identified. Unfortunately, this approach can lead to general safety concerns and may result in costly maintenance. Predictive maintenance, which aims to predict the future behaviour of track degradation based on the analysis of already recorded data, can be used to identify defects in advance, thus providing a solution for the above safety and cost concerns. Two important questions for which answers are sought in predictive maintenance of rail track are: where does the fault occur and when. The aim of the research presented in this thesis is to develop a novel predictive rail track degradation model that answers the above questions. The proposed model consists of an alignment component for effective alignment of data and a degradation component for understanding rail track degradation based on rail profile and track geometry parametric analysis. The thesis takes an incremental approach to data alignment proposing three different algorithms namely, distance alignment, fixed window based alignment and parameter based alignment. It is proven that the latter approach provides the most accurate data alignment algorithm. The degradation component of the proposed model is based on a comprehensive multivariate and univariate analysis. In multivariate analysis, parameters of a base file i.e. a file consisting of parameters belonging to the same segment of the rail track at a given time of measurement are predicted using all other parameters of the same file. In univariate analysis, every parameter of a given base file is predicted, temporally, from the corresponding parameters in the previous base files. Such contribution analysis manifests the level to which each parameter contributes in predicting other parameters and over time. Subsequent to univariate and iii multivariate analysis the predictive errors are thresholded into either exceedences i.e. they exceed the threshold line, needing immediate maintenance, or normal i.e. they are below the threshold line, needing no immediate maintenance. The research presented in this thesis shows that in multivariate analysis, rail profile parameters were predicted with 97% prediction accuracy below threshold, whereas track geometry parameters were predicted with 99% prediction accuracy below threshold. Both univariate and multivariate analysis will serve as the basis in monitoring track conditions and thus finding track degradation problems. This will greatly aid in planning predictive track degradation by providing an objective means of evaluating track conditions and hence the over all life of the rail track will increase.
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Gardner, Andrew S. "Power output of track sprint cyclists /." [St. Lucia, Qld.], 2005. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18973.pdf.
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Grimm, Henrik. "Environment simulation of track-based systems." Thesis, University of Skövde, Department of Computer Science, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-525.
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Simulation means running a model of a system with suitable input and observing the corresponding output. Real-time environment simulation is a special kind of simulation used to simulate a control system's environment in real-time. This is done to test the control system before it is used in its real environment. In this project, computer simulation of a certain kind of environments, called track-based systems, is studied and a general model for track-based systems is developed. In this model, track layouts are represented by graphs, which is a flexible and extensible representation and a method for visualizing these layouts is presented. The model also includes representation of switches, sensors, and trains. In addition, a configurable prototype simulator is designed and implemented for a model railroad system. The experience gained in this project is documented in the report and is presented as guidelines for developing simulators for track-based systems.
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Maithripala, Diyogu Hennadige Asanka. "Radar deception through phantom track generation." Texas A&M University, 2005. http://hdl.handle.net/1969.1/3169.
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This thesis presents a control algorithm to be used by a team of ECAVs (Electronic Combat
Air Vehicle) to deceive a network of radars through the generation of a phantom track.
Each ECAV has the electronic capability of intercepting and introducing an appropriate
time delay to a transmitted pulse of a radar before transmitting it back to the radar, thereby
deceiving the radar into seeing a phantom target at a range beyond that of the ECAV. A radar
network correlates targets and target tracks to detect range delay based deception. A team of
cooperating ECAVs, however, precisely plans their trajectories in a way all the radars in the
radar network are deceived into seeing the same phantom. Since each radar in the network
confirms the target track of the other, the phantom track is considered valid. An important
feature of the algorithm achieving this is that it translates kinematic constraints on the
ECAV dynamic system into constraints on the phantom point. The phantom track between
two specified way points then evolves without violating any of the system constraints. The
evolving phantom track in turn generates the actual controls on the ECAVs so that ECAVs
have flyable trajectories. The algorithms give feasible but suboptimal solutions. The main
objectives are algorithm development for phantom track generation through a team of cooperating
ECAVs, development of the algorithms to be finite dimensional searches and
determining necessary conditions for feasible solutions in the immediate horizon of the
searches of the algorithm. Feasibility of the algorithm in deceiving a radar network through
phantom track generation is demonstrated through simulation results.
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Coghill, Matthew Taylor. "Radiobiological modeling using track structure analysis." Thesis, Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/44731.
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The purpose of this thesis is to present data pertinent to and propose conclusions regarding the coordination
of radiobiologic effectiveness (RBE) and linear energy transfer (LET). RBE is a quantity relating the effectiveness
of different radiations in causing cell death. LET is a measure of the rate of energy transferred to material by an
ionizing particle. This relationship of these values varies for different particles. The reason for this is still inconclusive. The petitioner has made use of a toolkit for Geant4, known as Geant4-DNA, to perform track-structure analysis on a chromosome model. Geant4 is an object-oriented program for the "simulation of the passage of particles through matter" developed by CERN that makes use of Monte Carlo methods and is expanded by Geant4-DNA to handle low-energy electron physics as well as physic-chemical effects. The chromosome model, in this case, has been developed by the petitioner as a nucleus with a basic, uniform distribution of chromatin. Radiation damage to DNA, in the form of aberrations, lesions and strand breaks, can be coordinated to energy deposited or number of ionizations occurring in the target (in this case DNA or chromatin fiber). Certain threshold values have been established as indicate of different types of DNA damage. The ultimate goal of this work is to score these clusters of events against the threshold values to determine the severity of DNA damage. The final comparison of the results for different particles will provide for a better understanding of the RBE-LET relationships by improving the understanding of the underlying nanodosimetric qualities.
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Cornelissen, Thijs Gerrit. "Track fitting in the ATLAS experiment." [S.l. : Amsterdam : sn.] ; Universiteit van Amsterdam [Host], 2006. http://dare.uva.nl/document/37742.
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Eijk, Rutger Mark van der. "Track reconstruction in the LHCb experiment." [S.l. : Amsterdam : s.n.] ; Universiteit van Amsterdam [Host], 2002. http://dare.uva.nl/document/66446.
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Goldberg, Ilfra Charlotte. "Why is there fast-track promotion?" Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=56909.
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This thesis seeks an explanation for the existence of corporate "fast tracks". Part One surveys four existing fast track models from the literature. In tournament theory, fast tracks have been viewed as a response to the adverse selection problem. In models where the firm uses junior positions for on-the-job screening, they may be a possibility permitted by a particular technology. Alternatively, they may arise from the signalling engaged in by workers when there is asymmetric information. Finally, they can be used as a way of overcoming a lack of precise information on worker ability.In the second part of the thesis an alternative explanation is proposed. A firm is considered to consist of two levels: production workers and managerial workers. If a worker is an able manager, the firm will lose valuable production time by slow promotion. However, slower promotion allows more information to be revealed for a given expenditure. Different track lengths are created depending on the firm's initial assessment of managerial competence.
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Austin, Robert Brendon. "Successful delivery of flash track projects." Diss., Georgia Institute of Technology, 2016. http://hdl.handle.net/1853/54990.
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This research explores a higher order of fast tracking, called Flash Tracking, in response to increasing calls for faster, more reliable project deliveries. Flash Tracking is defined as a time-driven project, which by necessity requires a heightened degree of concurrency between engineering, procurement, and construction. In contrast to fast tracking, which entails a level of concurrency between engineering, procurement, and construction that has become a staple of the construction industry, Flash Tracking extends the envelope by requiring a series of innovative practices across the project delivery spectrum. The specific research questions pursued include: 1) identifying which innovative improvements in project delivery methodology could be made to compress project durations, while maintaining safety, quality, and risk tolerance, and 2) addressing how project teams can best overcome barriers to delivering shorter project durations. A multi-method research project was undertaken to address these questions, which entailed an extensive review of the literature, structured case study interviews, and multiple group decision-making exercises. The literature review focused on the construction industry, as well as manufacturing, shipbuilding, and software development, to identify practices and techniques potentially relevant to Flash Tracking that could be extended to the construction industry. Group decision-making exercises included a modified Delphi method study, an Analytic Hierarchy Process, and a series of research charrettes or focus groups. These studies produced a prioritized, two-tiered listing of 47 essential Flash Track practices, providing practitioners with both a measure to assess their readiness for undertaking a Flash Track project and strategies for increasing their readiness. A subsequent study--a semantic network analysis--refined and buttressed the research team’s earlier findings. This two-year study, conducted in concert with industry experts, led to a re-engineered engineering, procurement, and construction (EPC) model which embraces relational contract strategies, improved communications, and the early engagement of key stakeholders.
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Khadem, Sameni M. "Railway track capacity : measuring and managing." Thesis, University of Southampton, 2012. https://eprints.soton.ac.uk/348816/.
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This thesis adopts a holistic approach towards railway track capacity to develop methodologies for different aspects of defining, measuring, analysing, improving and controlling track capacity utilisation. Chapter 1 presents an overview of the concept of capacity and the railway capacity challenge is explained. Chapter 2 focuses on past approaches to defining and analysing the concept of railway capacity. Existing methods for estimating capacity utilisation are studied in four categories: analytical methods, parametric models, optimisation and simulation. Chapter 3 examines various factors affecting capacity utilisation. Chapter 4 develops the systems engineering foundation toward railway capacity. From process improvement methods, Six Sigma and its Define, Measure, Analyse, Improve and Control (DMAIC) cycle is chosen as the underlying framework of the thesis. Chapter 5 defines lean, micro and macro capacity utilisation based on the discrete nature of railway capacity. Data Envelopment Analysis (DEA) is used to develop two novel methodologies to analyse lean capacity utilisation. A DEA model analyses relative efficiency of train operating companies based on their efficiency to transform allocated train paths (timetabled train kilometres) and franchise payments to passenger-kilometres while avoiding delays. A case study demonstrates its application to 16 train operating companies in the UK. The operational efficiency of stations is benchmarked from similar studies for ports and airports. Two models are developed for analysing technical efficiency and service effectiveness. 96 busiest stations in Great Britain are analysed by this method. For analysing capacity utilisation in the freight sector, the concept of ‘profit-generating capacity’ is introduced in chapter 6. It is applied in an American freight case study to choose between bulk and intermodal trains in a heterogeneous traffic. DEA is also used in another case study for identifying the most profitable commodities. Chapter 7 suggests using variation reduction and failure mode and effect analysis (FMEA) to control capacity utilisation. For improving railway capacity utilisation it is suggested to find and improve the weakest line section, the weakest trains and the weakest station. A real world case study of the South West Main Line in Great Britain, demonstrates applying these aspects. For finding the weakest line section two existing methods of the UIC 406 and the CUI method are compared with each other. For finding the weakest trains a meso index is suggested. It can identify which trains can be removed to free up some capacity in the busiest section of the line. Simulating delays and removing the highest delay causing trains is another method suggested. The weakest stations are identified by applying the DEA methodology developed in chapter 5. Target values for train stops at each station are suggested to be fed to the tactical timetabling. It is concluded that developing methodologies to analyse, improve and control railway capacity utilisation is needed and the methodologies proposed in this thesis can be a stepping stone towards them.
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Wang, Chen-Shan. "Moving object detection by track analysis." Thesis, Monterey, California : Naval Postgraduate School, 1990. http://handle.dtic.mil/100.2/ADA241007.
Full textAbstract:
Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, September 1990.Thesis Advisor(s): Lee, Chin-Hwa. Second Reader: Hippenstiel, Ralph. "September 1990." Description based on title screen as viewed on December 18, 2009. DTIC Identifier(s): Underwater Object Locators, Underwater Tracking, Underwater Targets, Acoustic Detection, Computerized Simulation, Acoustic Data. Author(s) subject terms: Hough Transform, ILS, LAS, Sorting, Modification, Similarity. Includes bibliographical references (p. 76). Also available in print.
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Chen, Tung-Sheng. "Simulated annealing in sonar track detection." Thesis, Monterey, California : Naval Postgraduate School, 1990. http://handle.dtic.mil/100.2/ADA241785.
Full textAbstract:
Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, December 1990.Thesis Advisor(s): Lee, Chin-Hwa. Second Reader: Therrien, Charles W. "December 1990." Description based on title screen as viewed on April 02, 2010. DTIC Descriptor(s): Simulation, optimization, detection, sonar, edges, theses, sensitivity, noise, annealing, detectors DTIC Identifier(s): Sonar tracking, edge detectors, signal to noise ratio, combinatorial optimization, simulation. Author(s) subject terms: Simulated annealing, sonar track detection, combinatorial optimization Includes bibliographical references (p. 59). Also available in print.
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Kadari, Kishore Kumar. "Electroplating on 3D Printed Conductive Track." Scholar Commons, 2017. https://scholarcommons.usf.edu/etd/7412.
Full textAbstract:
There are substantial advances in Additive Manufacturing (AM) technologies. The simplest and advantageous technique of AM in terms of cost and scaling of the substrate is Fused Deposition Modeling(FDM). Currently, integration of electronics to a 3D printed structure is done manually after fabrication of the structure. To print electronic circuits directly on a 3D printed structure, copper electroplating process has been studied in this work.
To electroplate on the 3D printed insulating substrate, various materials were studied to make substrate conductive. By using conductive Polylactic Acid (PLA) filaments, a compatible substrate for electroplating was printed. Electroplating was proved to be advantageous in terms of uniform distribution as well as fast deposition rate when performed laterally. The conductive levels of the electrodeposited layers on 3D printed conductive substrates were studied at different voltages in different configurations.
Furthermore, the textures of the electroplated layer were studied using Scanning Electron Microscopy(SEM) method. The resistance of samples was measured using four-point probe resistance setup. The Morphology and roughness of the samples were studied by an optical profilometer system.
In addition, the adhesion strength of the electrodeposited copper on conductive PLA material was tested by a peel test using scotch tape. Thickness and conductivity calculations were performed for uniformly deposited samples. Further study is required for optimizing electroplating process to be used for in situ metallizations of a 3D printed structure.
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Medinaceli, Villegas Eduardo <1976>. "Astroparticle physics with nuclear track detectors." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2008. http://amsdottorato.unibo.it/850/1/Tesi_Medinaceli_Eduardo.pdf.
Full textAbstract:
This thesis is mainly about the search for exotic heavy particles -Intermediate
Mass Magnetic Monopoles, Nuclearites and Q-balls with the SLIM experiment
at the Chacaltaya High Altitude Laboratory (5230 m, Bolivia), establishing
upper limits (90% CL) in the absence of candidates, which are among the best
if not the only one for all three kind of particles. A preliminary study of the
background induced by cosmic neutron in CR39 at the SLIM site, using Monte
Carlo simulations.
The measurement of the elemental abundance of the primary cosmic ray
with the CAKE experiment on board of a stratospherical balloon; the charge
distribution obtained spans in the range 5≤Z≤31.
Both experiments were based on the use of plastic Nuclear Track Detectors,
which records the passage of ionizing particles; by using some chemical reagents
such passage can be make visible at optical microscopes.
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Medinaceli, Villegas Eduardo <1976>. "Astroparticle physics with nuclear track detectors." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2008. http://amsdottorato.unibo.it/850/.
Full textAbstract:
This thesis is mainly about the search for exotic heavy particles -Intermediate
Mass Magnetic Monopoles, Nuclearites and Q-balls with the SLIM experiment
at the Chacaltaya High Altitude Laboratory (5230 m, Bolivia), establishing
upper limits (90% CL) in the absence of candidates, which are among the best
if not the only one for all three kind of particles. A preliminary study of the
background induced by cosmic neutron in CR39 at the SLIM site, using Monte
Carlo simulations.
The measurement of the elemental abundance of the primary cosmic ray
with the CAKE experiment on board of a stratospherical balloon; the charge
distribution obtained spans in the range 5≤Z≤31.
Both experiments were based on the use of plastic Nuclear Track Detectors,
which records the passage of ionizing particles; by using some chemical reagents
such passage can be make visible at optical microscopes.
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Simson, Scott Andrew. "Development of a model for railway track maintenance planning." Thesis, Queensland University of Technology, 1999. https://eprints.qut.edu.au/36116/1/36116_Simson_1999.pdf.
Full textAbstract:
Track maintenance represents over 20 percent of Australian railway operating costs. Thus there is considerable incentive for rail corporations to reduce their maintenance costs. There is considerable research directed at improving track structures and maintenance techniques to reduce the track maintenance expenditure. However, there is little work on the planning of track maintenance that can be applied to Australian railway operations. This research reviews maintenance planning and finds that models currently available are empirical models reliant mainly on historical track condition data
from specific rail organisations. No such models are yet in use Australian railway operations. Leading models utilise expert systems to decide maintenance
activities rather than optimise the net benefits of maintenance. As such, these models are ineffective at assessing what if scenarios of changed track operating
conditions. Internationally, current maintenance practice is to plan maintenance
on professional judgement without the use of models to aid decisions. Currently, only a minority of larger rail corporations record sufficient track and
maintenance data needed for maintenance planning modeling. A new track maintenance model has been formulated based on a mechanistic track degradation approach. This allows the model to operate without historical track maintenance condition data and hence utilise a minimal amount of track maintenance data. The model assesses the net benefit of maintenance by
simulating the costs of planned and unplanned maintenance, as well as train
operating costs as they are affected by track condition.
A prototype computer program has been developed that has shown that the model is capable of assessing a cost efficient intervention level for tamping and
resleepering maintenance. The model's independence from historical data means it is applicable to any rail operator and is capable of assessing what if scenarios
on the impact of changed track, traffic or cost conditions. The model has been subjected to testing that has identified areas for its further development. These areas are the modeling of defective sleeper clusters and of sleeper ages, also the development and inclusion of a ballast degradation and maintenance sub-model. Further work for the developed prototype computer application include improving the program efficiency, expanding the number of iteration cycles used in the simulation and recording a track asset value during degradation and maintenance of the track
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Lindfeldt, Olov. "Quality on single-track railway lines with passenger traffic : Anlytical model for evaluation of crossing stations and partial double-tracks." Licentiate thesis, KTH, School of Architecture and the Built Environment (ABE), 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4560.
Full textAbstract:
Railway transportation is showing a substantial increase. Investments in new infrastructure, new fast and comfortable vehicles, and high frequency of service are important factors behind the increase.
Infrastructure configuration and timetable construction play important roles in the competitiveness of railway transportation. This is especially true on single-track lines where the travel times and other timetable related parameters are severely restricted by crossings (train meetings). The crossings also make the lines’ operation more sensitive to disturbances.
Since the major part of the Swedish railway network is single-track it is of great interest to examine the relationships between operation properties, such as travel times and reliability, and infrastructure configuration on single-track lines. The crossings are the core feature of single-track operation and this thesis focuses on the crossing time, i.e. the time loss that occurs in crossing situations.
A simplified analytical model, SAMFOST, has been developed to calculate the crossing time as a function of infrastructure configuration, vehicle properties, timetable and delays for two crossing trains. The effect of possible surrounding trains is not taken into account and all kinds of congestion effects are thus excluded from evaluation. SAMFOST has been successfully validated against the simulation tool RailSys, which shows that this type of simplified model is accurate in non-congested situations.
A great advantage of disregarding congested situations is that analysis is independent of timetable assumptions. The model also explicitly shows the effect of punctuality, which is of particular importance on single-track lines where the interdependencies between trains are strengthened by the crossings.
For the same reason, the timetable is severely constrained. Nonetheless, there is often a need for changes of the timetable (crossing pattern). The thesis proposes three simple measures of timetable flexibility, all based on assigned crossing time requirements. Together, these measures can be used to evaluate how infrastructure configuration, vehicle properties, punctuality etc affect possibilities to alter the timetable.
As an example of its application, SAMFOST has been used to evaluate the effect of shorter inter-station distance, partial double-track and combined crossing and passenger stop. These measures affect the operational properties quite differently.
More crossing stations result in a minor decrease in travel time (lower mean crossing time) but significantly higher reliability (lower crossing time variance). These effects are independent of punctuality, which is a valuable property.
A partial double-track results in shorter travel times and in some cases also higher reliability. Both effects are strongly dependent on punctuality and high punctuality is needed to achieve high effects.
A combined crossing and passenger stop results in a situation similar to that of a partial double-track. In this case it is important to point out that the assignment of time supplements in the timetable should be directly correlated to punctuality in order to achieve good operation.