Dissertations / Theses on the topic 'Git modelling'
To see the other types of publications on this topic, follow the link: Git modelling.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Git modelling.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Déhaye, Vincent. "Characterisation of a developer’s experience fields using topic modelling." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-171946.
Full textAbstract:
Finding the most relevant candidate for a position represents an ubiquitous challenge for organisations. It can also be arduous for a candidate to explain on a concise resume what they have experience with. Due to the fact that the candidate usually has to select which experience to expose and filter out some of them, they might not be detected by the person carrying out the search, whereas they were indeed having the desired experience. In the field of software engineering, developing one's experience usually leaves traces behind: the code one produced. This project explores approaches to tackle the screening challenges with an automated way of extracting experience directly from code by defining common lexical patterns in code for different experience fields, using topic modeling. Two different techniques were compared. On one hand, Latent Dirichlet Allocation (LDA) is a generative statistical model which has proven to yield good results in topic modeling. On the other hand Non-Negative Matrix Factorization (NMF) is simply a singular value decomposition of a matrix representing the code corpus as word counts per piece of code.The code gathered consisted of 30 random repositories from all the collaborators of the open-source Ruby-on-Rails project on GitHub, which was then applied common natural language processing transformation steps. The results of both techniques were compared using respectively perplexity for LDA, reconstruction error for NMF and topic coherence for both. The two first represent how well the data could be represented by the topics produced while the later estimates the hanging and fitting together of the elements of a topic, and can depict human understandability and interpretability. Given that we did not have any similar work to benchmark with, the performance of the values obtained is hard to assess scientifically. However, the method seems promising as we would have been rather confident in assigning labels to 10 of the topics generated. The results imply that one could probably use natural language processing methods directly on code production in order to extend the detected fields of experience of a developer, with a finer granularity than traditional resumes and with fields definition evolving dynamically with the technology.
2
Herron, Fiona Michelle. "A study of digesta passage in rabbits and ringtail possums using markers and models." Thesis, The University of Sydney, 2002. http://hdl.handle.net/2123/483.
Full textAbstract:
The common ringtail possum (Pseudocheirus peregrinus), a member of the family Pseudocheiridae, is an arboreal folivorous marsupial that feeds predominantly on Eucalyptus foliage. Contrary to the expectation that small body size would inhibit utilisation of a diet containing such high levels of lignified fibre because of relatively low gut volume to body mass ratios and relatively high mass-specific metabolic rates and nutrient requirements (Hume 1999), the ringtail possum is able to survive solely on a diet of Eucalyptus foliage. The rabbit (Oryctolagus cuniculus) is a terrestrial herbivore and is a member of the family Leporidae that feeds predominantly on grasses. The rabbit was proposed as a digesta flow model for the ringtail possum since both are caecotrophic (periodically re-ingest caecal contents) and both are proposed to exhibit a colonic separation mechanism (CSM) where fluids and small, easily digested particles are preferentially returned to the caecum. The rabbit is of value for the modelling process since it is more accessible for experimental manipulation than the ringtail possum. This study investigated a proposal to use digesta passage through the gastrointestinal tract (GIT) of the rabbit as a model of digesta passage for the ringtail possum on the basis that both are caecotrophic caecum fermenters. A number of potential problems were identified with this proposal and investigation of these problems formed the basis for the research described in this thesis. Two main areas were identified as being potentially problematic: 1) fundamental flaws with the particulate markers used in digesta rate of passage studies; and 2) differences in animal behaviour and natural diet between the two subject species which suggested different digestive strategies and hence different patterns of digesta flow through the GIT. The proposed digesta passage markers were lanthanide metals (Dy, Tm, Eu and Yb) attached to either fibrous particles (1200 - 600�m) or formalin-fixed rumen bacteria (20 � 0.2�m). These markers were shown to not be of the assumed size classes and the extent of lanthanide metal binding differed between the four metals used. An effect due to method of dosing was also observed. The findings of marker inconsistencies caused major limitation to model development and further research is necessary to clarify these markers. The proposal to use digesta flow in the rabbit GIT as a model for digesta flow in the ringtail possum was shown to be idealistic due to the differences in anatomy and behaviour observed between the two herbivores. Laboratory observations, time series analysis and compartmental modelling confirmed the differences between the animals. This study showed: 1) the GIT of the rabbit was more complex both anatomically and functionally than that of the ringtail possum; 2) behaviour affecting digesta passage of the rabbit and ringtail were different and; 3) compartmental models confirmed the anatomical and behavioural findings. Digesta passage in the rabbit could not be modelled mathematically using data on digesta passage due to complexities of the system. In contrast, a basic model was constructed for digesta passage in the ringtail possum. On the basis of these findings, the research hypothesis "that digesta passage in rabbits is similar to that in ringtail possums" was rejected.
3
Herron, Fiona Michelle. "A study of digesta passage in rabbits and ringtail possums using markers and models." University of Sydney. Biology, 2002. http://hdl.handle.net/2123/483.
Full textAbstract:
The common ringtail possum (Pseudocheirus peregrinus), a member of the family Pseudocheiridae, is an arboreal folivorous marsupial that feeds predominantly on Eucalyptus foliage. Contrary to the expectation that small body size would inhibit utilisation of a diet containing such high levels of lignified fibre because of relatively low gut volume to body mass ratios and relatively high mass-specific metabolic rates and nutrient requirements (Hume 1999), the ringtail possum is able to survive solely on a diet of Eucalyptus foliage. The rabbit (Oryctolagus cuniculus) is a terrestrial herbivore and is a member of the family Leporidae that feeds predominantly on grasses. The rabbit was proposed as a digesta flow model for the ringtail possum since both are caecotrophic (periodically re-ingest caecal contents) and both are proposed to exhibit a colonic separation mechanism (CSM) where fluids and small, easily digested particles are preferentially returned to the caecum. The rabbit is of value for the modelling process since it is more accessible for experimental manipulation than the ringtail possum. This study investigated a proposal to use digesta passage through the gastrointestinal tract (GIT) of the rabbit as a model of digesta passage for the ringtail possum on the basis that both are caecotrophic caecum fermenters. A number of potential problems were identified with this proposal and investigation of these problems formed the basis for the research described in this thesis. Two main areas were identified as being potentially problematic: 1) fundamental flaws with the particulate markers used in digesta rate of passage studies; and 2) differences in animal behaviour and natural diet between the two subject species which suggested different digestive strategies and hence different patterns of digesta flow through the GIT. The proposed digesta passage markers were lanthanide metals (Dy, Tm, Eu and Yb) attached to either fibrous particles (1200 - 600�m) or formalin-fixed rumen bacteria (20 � 0.2�m). These markers were shown to not be of the assumed size classes and the extent of lanthanide metal binding differed between the four metals used. An effect due to method of dosing was also observed. The findings of marker inconsistencies caused major limitation to model development and further research is necessary to clarify these markers. The proposal to use digesta flow in the rabbit GIT as a model for digesta flow in the ringtail possum was shown to be idealistic due to the differences in anatomy and behaviour observed between the two herbivores. Laboratory observations, time series analysis and compartmental modelling confirmed the differences between the animals. This study showed: 1) the GIT of the rabbit was more complex both anatomically and functionally than that of the ringtail possum; 2) behaviour affecting digesta passage of the rabbit and ringtail were different and; 3) compartmental models confirmed the anatomical and behavioural findings. Digesta passage in the rabbit could not be modelled mathematically using data on digesta passage due to complexities of the system. In contrast, a basic model was constructed for digesta passage in the ringtail possum. On the basis of these findings, the research hypothesis "that digesta passage in rabbits is similar to that in ringtail possums" was rejected.
4
Berglund, Svante. "GIS in Transport Modelling." Doctoral thesis, KTH, Infrastructure and Planning, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3257.
Full text
5
Deluzio, Kevin John. "Modelling and analysis of gait waveforms." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/nq22455.pdf.
Full text
6
Jani, Janmaizatulriah. "A GIS-based method for groundwater modelling." Thesis, University of Sheffield, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.574558.
Full textAbstract:
Groundwater is important and precious freshwater found under the earth's surface. Groundwater is used for human consumption: for drinking, farming and for maintaining surface water system (rivers) especially during low flow periods. For effective groundwater management, quantitative and qualitative status of groundwater is usually assessed using various groundwater models. These models (for example numerical models) are capable of modelling complex and heterogeneous groundwater conditions. However, due to the requirement of extensive and detailed ground water data, these models are not suitable to be applied in all groundwater systems (major and minor aquifers). Therefore, scientific studies in areas of insignificant groundwater resource (minor aquifers) have been underplayed. However, since all groundwater bodies are significantly important, a new groundwater model was developed in this study. GIS functionality was explored and a GIS-based groundwater model was developed using minimal and accessible input data. GIS was used to represent the subsurface geology particularly the aquifer system and to model groundwater flow. The first model, a GIS based geological model was tested by reconstructing the geology map for the Slea catchment, in the United Kingdom and thickness of the Lincolnshire Limestone aquifer was predicted. The advantage of this model is its capability in predicting an aquifer's thickness without referring to point data like those obtained from boreholes. Then, the second model that is based on topographical and groundwater resistance analysis was used to model natural ground water discharge. Although there is discrepancy between estimated and measured spring discharge, the model has confirmed the usefulness of using GIS tool in modelling groundwater exploring minimal input data and basic modelling procedures. The developed models were not a replacement for numerical groundwater models. However, they would be useful to screen ground water status especially in areas that lack ground water data.
7
Gilman, Joanne. "GIS based wave modelling for coastal management." Thesis, University College London (University of London), 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.396283.
Full textAbstract:
The effective management of the Coastal Zone requires an appreciation of the complex nature of the processes at work. Decisions relating to its management require the modelling of these processes which in turn calls upon a large number of disparate data sets. The most effective way to relate these data to each other, to facilitate their subsequent analysis, and to allow clear visualisation, is by geographical position. This thesis describes work aimed at improving the efficiency and applicability of coastal process models in shoreline management decisions by integrating spatial data and coastal processes in a GIS environment. A Geographic Information System has been integrated with a coastal wave model. The resulting system is shown to simplify the modelling procedures, to facilitate the generation of input data and incorporate functionality for the visualisation and analysis of model results. Increased automation makes coastal process modelling less complicated and more accessible to non- specialists. The integrated system developed has extended the capability of the wave model to generate wave data. Wave height, period, and direction can be generated for discrete points at any density along an inshore contour. These results are visualised and analysed in the GIS. The system has been further developed to demonstrate its decision support capabilities. It is adapted for a typical dredging application. New tools allow the bathymetry to be `excavated' simulating sediment removal; and subsequent modelling quantifies its impact on the inshore wave conditions, which are then reported back to the user. The system and tools are assessed using two test areas. The benefits of using the integrated system are evaluated by comparison with the experience of using wave models in isolation when investigating coastal management issues. Finally, directions and suggestions for further work are discussed.
8
Collins, James Joseph. "Joint mechanics - modelling of the lower limb." Thesis, University of Oxford, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.276573.
Full text
9
Wang, Xuyan. "Landscape dynamic modelling with vector map algebra in GIS /." [St. Lucia, Qld.], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18161.pdf.
Full text
10
Jenkins, Sian M. "Lower limb modelling for children in clinical gait analysis." Thesis, University of Oxford, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.400179.
Full text
11
Collins, Susan. "A GIS approach to modelling traffic related air pollution." Thesis, University of Huddersfield, 1998. http://eprints.hud.ac.uk/id/eprint/4843/.
Full textAbstract:
There is increased concern regarding the effect of traffic related pollution on public heath. As the number of vehicles on the roads continues to rise, it is becoming increasingly more important to identify areas where the population may be at a greater risk to raised levels of pollution and areas where the implementation of policy to control and monitor levels of pollution would be beneficial. Traditionally, levels of air pollution have been established through dispersion modelling or monitoring. However, for modelling traffic related pollution for large populations, these methods have proved inappropriate. Three new approaches have been developed to model traffic related air pollution and are reported in this thesis. The approaches have been developed in a Geographical Information System (GIS) and involve generating detailed maps of the pollution surface from monitored data and information about the pollution sources. The new methods are compared against the geostatistical technique kriging. The first approach combines spatial interpolation from monitoring sites and dispersion modelling, linking the dispersion model to the GIS, the second combines GIS techniques for filtering data and spatial interpolation, and the third uses a combination of GIS techniques for filtering and statistical techniques. The three approaches are tested and validated by predicting levels of pollution at monitoring sites not used to develop the models. It was found that the new approaches provided more reliable estimates of pollution at unsampled locations than kriging, with the last of these proving to be the most effective. The adjusted r2 values for kriging, interpolation and dispersion, interpolation and filtering, and filtering and statistics were found to be 0.44, 0.63, 0.67 and 0.82 respectively. The approaches therefore have clear potential in the areas of air pollution management and epidemiology, where the maps can be used to help identify locations where levels of pollution exceed air quality standards, assess the relationship between air pollution and health outcome and examine the risk of exposure to raised levels of pollution.
12
Martin, Timothy C. "Geospatial modelling of flood dynamics using synthetic aperture radar." Thesis, University of Nottingham, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251747.
Full textAbstract:
Most approaches for modelling flood inundation and depth in lowland settings involve laborious parameterisation of stream channel and floodplain hydraulic characteristics and most require intensive inputs to set up and maintain. Such an approach is unrealistic in Bangladesh with its highly complex and dynamic hydrological network and sparse data collection system. This needs-driven research develops techniques that could be used in an operational, national system for monitoring and assessing floods and for monitoring riverbank erosion and dynamics of river channel morphology. Satellite synthetic aperture radar (SAR) images are used in a consistent, multitemporal data set for the 1998 monsoon flood season. The SAR images are processed and analysed with digital elevation models (DEM) and other spatial data for monitoring floodplain water levels. Compared water levels for the 24-day image acquisition cycle compare with field data by average absolute value difference of 33 cm and with regression coefficient of 0.86. Daily floodwater elevations are simulated through regression relation of the floodplain with conventional river gauge recordings. Flood depth is derived by difference with a DEM and used to create a series of daily flood depth maps that compare with field data by less than 40 cm absolute value difference. Because of the unusually high water levels during the 1998 flood, it is possible that there may have been an unusually direct hydrologic connectivity between the river and the floodplain. Such a relation has yet to be extended to other flood seasons or to other floodplain areas. A series of spatial data products demonstrates the uses of these daily flood data for flood risk and vulnerability mapping, flood damage assessment, river erosion monitoring, and other applications. Before the methods can become operational, data processing, modelling, and analysis will need to become more quantitative and more efficient. Furthermore, institutional linkages and multi-stakeholder co-operation and involvement will need to be ensured. Bangladesh lacks the financial resources for implementing and maintaining an operational system, however, it has the technical capability and the commitment of development partners.
13
Wilde, Bryn. "A geographic information system approach to distributed hydrological modelling." Thesis, Cardiff University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327722.
Full text
14
Evans, Barry. "A multilayered approach to two-dimensional urban flood modelling." Thesis, University of Exeter, 2010. http://hdl.handle.net/10036/117891.
Full textAbstract:
With urbanisation continuing to encroach upon flood plains, the constant replacement of permeable land with impermeable surfaces and with the changes in global climate, the need for improved flood modelling is ever more apparent. A wide range of methods exist that simulate surface flow; most commonly in one-dimensional (1D) or twodimensional (2D), and more recently on smaller scales in three-dimensional (3D) models. In urban flood modelling, 2D models are often the preferred choice as they can simulate surface flow more accurately than their 1D model counterparts; they are, however, more computationally demanding and thereby usually require greater simulation time. With the vast amount of information used in flood modelling, generalisation techniques are often employed to reduce the computational load within a simulation. The objective of this thesis is to improve 2D flood modelling in urban environments by introducing a new and novel approach of representing fine scale building features within coarse grids. This is achieved by creating an automated approach that data-mines key features such as buildings and represents their effects numerically within a multiple layer grid format. This new approach is tested in comparison to two other, already established generalising techniques which are single layer based. The effectiveness of each model is assessed by its ability to accurately represent surface flow at different grid resolutions and how each copes with varying building orientations and distributions within the test datasets. The performance of each generalising approach is determined therefore by its accuracy in relation to the fine scale model and the difference in the computational time required complete the simulation. Finally the multilayered methodology is applied to a real case scenario to test its applicability further. Overall it revealed, as predicted, that the multilayered approach enables far greater accuracies at routing surface flow within coarse grids whilst still greatly reducing computational time. As a further benefit in urban flood modelling, this thesis shows that using a multilayered data format it is possible to simulate the influence of features that have a grid resolution finer than the initial terrain topology data, thus enabling, for example, the routing of surface water through alleyways between buildings that have a width less than one meter.
15
Cheesman, Joanne E. "Modelling long-term runoff from upland catchments." Thesis, Manchester Metropolitan University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389290.
Full textAbstract:
The aim of the research contained in this thesis was to develop a model of long-term upland catchment runoff that can be used for ungauged catchments. This is a problem due to the complex spatial and temporal nature of runoff and the main contributing processes, precipitation (P) and evapotranspiration (Et). It is also a problem due to the lack of suitable data on which to base and test models of these processes, particularly in remote upland areas such as the north-west of England, the study area of this research. Long-term runoff is important since it represents the maximum rate at which water is available for human use and management, for assessment of water resource yield and for prediction of extreme events that are particularly important in respect to climate change. Methods currently in use by water companies in the UK, such as North West Water Limited (NWW), are inadequate since they fail to account for the spatial and temporal nature of runoff. New more reliable methods are therefore required which will equip water managers with flexible and responsive runoff modelling tools based upon routinely available data and that are sensitive to the complex physical nature of the processes involved. A physically based distributed runoff model was developed using GIS technology and spatial data to interpolate and extrapolate available point-based hydrometeorological data. The strategy required the development of models to derive areal representations of P and Et. For the P modelling several interpolation techniques and artificial neural network models were investigated. The results were evaluated against an independent data set. The results showed that a geostatistical interpolation technique, detrended Kriging, which uses pointbased precipitation and spatial elevation data provided the most accurate estimates when compared to other methods. The models of Et involved extrapolation of point-based Et values derived from the Penman-Monteith formula (Monteith, 1965), using spatial land cover data. A point-based temperature function model (Wright and Harding, 1993) that reduces the Penman estimates of Et for upland sites was spatially implemented using spatial temperature and elevation data. No independent data were available for model evaluation but first estimates of errors were gained through comparison of errors of runoff and precipitation estimates. Overall it was found that the most accurate E, model results were derived when the temperature function model was not implemented. Evidence of whether or not a lumped or heterogeneous land cover representation provided the more accurate results was unclear. Error evaluation and sensitivity analysis of the modelled runoff was carried out using measured runoff records and the results were compared to those produced using the North West Water model. It was found that the GIS-based model provided improved estimates of long-term average annual runoff for upland catchments. The largest component of the errors of the GIS-based method were associated with the Et estimates. This was principally a result of poor quality and limited availability of data for the study area. The research highlights many wider issues related to the use of GIS and spatial data for hydrological modelling.
16
Wheatley, David. "The application of geographic information systems to archaeology : with case studies from Neolithic Wessex." Thesis, University of Southampton, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295576.
Full text
17
Balram, Shivanand. "Collaborative GIS process modelling using the Delphi method, systems theory and the unified modelling language (UML)." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=85881.
Full textAbstract:
Efforts to resolve environmental planning and decision-making conflicts usually focus on participant involvement, mutual understanding of the problem situation, evaluation criteria identification, data availability, and potential alternative solutions. However, as the alternatives become less distinct and participant values more diverse, intensified negotiations and more data are usually required for meaningful planning and decision-making. Consequently, questions such as "What collaborative spatial decision making design is best for a given context?" "How can the values and needs of stakeholders be integrated into the planning process?" and "How can we learn from decision making experiences and understanding of the past?" are crucial considerations. Answers to these questions can be developed around the analytic and discursive approaches that transform diffused subjective judgments into systematic consensus-oriented resolutions.This dissertation examines the above issues through the design, implementation, and assessment of the Collaborative Spatial Delphi (CSD) Methodology. The CSD methodology facilitates spatial thinking and discursive strategies to describe the complex social-technical dynamics associated with the knowledge-structuring-consensus nexus of the participation process. The CSD methodology describes this nexus by synthesizing research findings from knowledge management, focus group theory, systems theory, integrated assessment, visualization and exploratory analysis, and transformative learning all represented within a collaborative geographic information system (GIS) framework.
The CSD methodology was implemented in multiple contexts. Its use in two contexts - strategic planning and management of urban green spaces in Montreal (Canada); and priority setting for North American biodiversity conservation - are reported in detail in this dissertation. The summative feedbacks from all the CSD planning workshops help incrementally improve the design of the CSD process. This dissertation also reports on the design and use of questionnaire surveys to incorporate local realities into planning, as well as the development of an evaluation index to assess the face validity and effectiveness of the CSD process from the perspective of workshop participants.
The accumulated evidence from the CSD implementations suggests that many core issues exist across spatial problem solving situations. Thus, the design and specification of a core collaborative process model provides benefits for knowledge exchange. General systems theory was used to classify the core technical components of the collaborative GIS design, and soft systems theory was used to characterize the human activity dynamics. Object oriented principles enabled the generation of a flexible domain model, and the unified modelling language (UML) visually described the collaborative process. The CSD methodology is used as a proof of concept.
This dissertation contributes to knowledge in the general areas of Geography, Geographic information systems and science, and Environmental decision making. The specific contributions are threefold. First, the CSD provides a synthesis of multi-disciplinary theories and a tested tool for environmental problem solving. Second, the CSD facilitates a fusion of local and technical knowledge for more realistic consensus planning outcomes. Third, an empirical-theoretical visual formalism of the CSD allows for process knowledge standardization and sharing across problem solving situations.
18
Dorren, Lucas Karel Agnes. "Mountain geoecosystems GIS modelling of rockfall and protection forest structure /." [S.l. : Amsterdam : s.n.] ; Universiteit van Amsterdam [Host], 2002. http://dare.uva.nl/document/64355.
Full text
19
Gulliver, John. "Space-time modelling of exposure to air pollution using GIS." Thesis, University of Northampton, 2002. http://nectar.northampton.ac.uk/2810/.
Full textAbstract:
This thesis develops, tests and applies methods for space-time modelling of exposure to air pollution using GIS. This involves linkage of five main sub-models: a traffic model, a model of urban air pollution - combining local and ‘background’ pollution models - a network analysis tool for modelling exposure during journeys, and a time-activity model. The model can provide exposure estimates for individuals or population groups. The study took place entirely within Northampton, UK. The model used to estimate hourly PM10 concentrations at outdoor locations gave a moderate fit to monitored data. Results were shown to be comparable with the best results from other studies. This research also found a strong, linear relationship between concentrations of PM10 during simultaneous monitoring of walking and in-car concentrations. This relationship was used to calibrate modelled outdoor pollution levels to give in-car concentrations. Modelled journey- time exposures for walking performed equally with predictions made using a fixed- site monitor located close to journey routes. The model did not perform as well as the fixed-site monitor in predicting in-car exposures. The application of the model to a walk-to-school policy, in which modelled local traffic levels were reduced by 20%, demonstrated that the benefits of the reduction were not spread evenly across a sample of schoolchildren, but varied depending on the route used to school and the location of homes and schools. For those switching between car and walk there may be positive or negative effects of the policy in terms of savings in average hourly exposures, depending on their specific journey and time activity patterns. The results from this research showed that, although the model worked reasonably well in estimating exposures, a number of improvements are needed. These include better models of background concentrations, more detailed models of in-car conditions, and extending exposure modelling to include dose-response estimates
20
Di, Marco Roberto. "Kinematic modelling of the foot-ankle complex for gait analysis." Thesis, University of Sheffield, 2016. http://etheses.whiterose.ac.uk/17583/.
Full textAbstract:
The functional role of the foot-ankle complex is critical in terms of providing support and mobility to the whole human body. Besides those associated with common lesions or damages of its structures (e.g. sprains, bone fractures), impairments in the foot may also cause secondary chronic pathologies. Thus, a quantitative assessment of the mechanical behaviour of the joints within the foot-ankle complex is certainly of clinical value. Gait analysis is used to assess lower limb joint kinematics during walking, and is usually performed using stereophotogrammetric systems. Conventionally, the foot is considered as a rigid segment. This oversimplification has been overcome with the use of multi-segment models to describe foot kinematics. However, these models have been only partially validated, limiting their widespread adoption. This Thesis aims at filling the gap of a repeatability and reproducibility analysis of the outcomes of the available foot modelling techniques, providing guidelines and reference values to be used in future applications, and establishing a standard for the kinematic assessment of the foot-ankle complex in gait analysis. As a first step, different indices to quantify repeatability and reproducibility of model outcomes have been critically compared and investigated, including Linear Fit Method coefficients (LFM), Coefficient of Multiple Correlation (CMC), Mean Absolute Variability (MAV), and Root Mean Square Error (RMSE). A sensitivity analysis was performed to this purpose using artificially created curves, which were varied by imposing a set of realistic alterations in their shapes, joints’ range of motion, sample by sample amplitude variability, offset, and time shift. The CMC values were found to be sensible to different curve shapes, and, as well as the LFM coefficients, were independent from the range of motion. Complex values of the CMCs were observed when large offset and time shift occurred. The LFM coefficients worsened with the time shift, invalidating the assumption of linear relationship among curves. Nonetheless, these coefficients, when used with measurement of absolute differences (e.g., MAV or RMSE), were found to be the most suitable to be used for gait curve comparisons. The instrumental error associated with different procedures that can be adopted to calibrate a stereophotogrammetric system has then been assessed for two different systems. The results of this part of the Thesis showed that the errors are independent on the adopted calibration. In fact, the between-calibration CMC of joint kinematics were never lower than 0.93. The average differences between measured and known values of distances between pair of markers were lower than 1.7 mm. Instead, the average differences between measured and known values of angles between markers 0.7°. These findings suggest that relevant procedures do not affect the metrological performance of the systems under test and the associated errors can be neglected. As a following step, the experimental error associated to the marker placement was quantified for the four most adopted multi-segment models of the foot. The repeatability and reproducibility of the relative measurements were assessed by comparing joint sagittal kinematics obtained when: a) the same operator placed the markers on thirteen young healthy adults in two different sessions; b) three operators placed the markers for three times on three randomly selected participants, respectively. The two most repeatable and reproducible models, according to the validated similarity and correlation indices (i.e., the LFM coefficient), displayed averaged correlation higher than 0.72, with the lowest values obtained for the between-subject comparison of the midfoot kinematics (0.69 and 0.55). Results showed that foot kinematics have low overall repeatability when evaluated with the existing models, and normative bands should be adopted with caution when used for comparison with patient data, especially when dealing with joints that interacts with the mid-foot and display range of motions smaller than 10°. Finally, to overcome the limitations highlighted by the assessment of the existing models, a novel kinematic model of the foot-ankle complex has been designed, and the repeatability and reproducibility of the relevant sagittal kinematics have also been quantified. Results showed an improvement, especially for the joint enclosed between the mid-foot and the hindfoot, with correlation higher than 0.82. In conclusion, the new model paves the way to a more reliable modelling of the foot and, represents an improvement with respect to the existing techniques.
21
Guo, Danni. "Contributions to spatial uncertainty modelling in GIS : small sample data." Doctoral thesis, University of Cape Town, 2007. http://hdl.handle.net/11427/19031.
Full textAbstract:
Includes bibliographical references.Environmental data is very costly and difficult to collect and are often vague (subjective) or imprecise in nature (e.g. hazard level of pollutants are classified as "harmful for human beings"). These realities in practise (fuzziness and small datasets) leads to uncertainty, which is addressed by my research objective: "To model spatial environmental data with .fuzzy uncertainty, and to explore the use of small sample data in spatial modelling predictions, within Geographic Information System (GIS)." The methodologies underlying the theoretical foundations for spatial modelling are examined, such as geostatistics, fuzzy mathematics Grey System Theory, and (V,·) Credibility Measure Theory. Fifteen papers including three journal papers were written in contribution to the developments of spatial fuzzy and grey uncertainty modelling, in which I have a contributed portion of 50 to 65%. The methods and theories have been merged together in these papers, and they are applied to two datasets, PM10 air pollution data and soil dioxin data. The papers can be classified into two broad categories: fuzzy spatial GIS modelling and grey spatial GIS modelling. In fuzzy spatial GIS modelling, the fuzzy uncertainty (Zadeh, 1965) in environmental data is addressed. The thesis developed a fuzzy membership grades kriging approach by converting fuzzy subsets spatial modelling into membership grade spatial modelling. As this method develops, the fuzzy membership grades kriging is put into the foundation of the credibility measure theory, and approached a full data-assimilated membership function in terms of maximum fuzzy entropy principle. The variable modelling method in dealing with fuzzy data is a unique contribution to the fuzzy spatial GIS modelling literature. In grey spatial GIS modelling, spatial predictions using small sample data is addressed. The thesis developed a Grey GIS modelling approach, and two-dimensional order-less spatially observations are converted into two one-dimensional ordered data sequences. The thesis papers also explored foundational problems within the grey differential equation models (Deng, 1985). It is discovered the coupling feature of grey differential equations together with the help of e-similarity measure, generalise the classical GM( 1,1) model into more classes of extended GM( 1,1) models, in order to fully assimilate with sample data information. The development of grey spatial GIS modelling is a creative contribution to handling small sample data.
22
Sivaraman, Vivekanandan Murugan. "GIS and hydrological modelling for the Upper Scioto River Basin." The Ohio State University, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=osu1409229797.
Full text
23
Hedenäs, Helge. "GIS-modellering av potentiellt drivgods i Ljungan baserat på LIDAR-data." Thesis, Stockholms universitet, Institutionen för naturgeografi och kvartärgeologi (INK), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-105851.
Full textAbstract:
Drivgods utgör ett hot mot dammsäkerheten vid vattenkraftsverk eftersom det ökar risken för blockering av kraftverkens utskov vilket i sin tur kan resultera i överströmning av dammen och dammbrott. Fram till idag har drivgods inte ansetts vara ett problem i Sverige. Flera allvarliga drivgodsincidenter utomlands i kombination med en prognostiserad ökning av flödesintensiteter och översvämningstillfällen i Svenska vattendrag har dock lett till ett ökat intresset hos Svenska dammägare. Det saknas idag tillförlitliga metoder för prognostisering av potentiella drivgodsmängder vid extremflöden, vilket försvårar planering av preventiva åtgärder. Denna studie har som mål att utveckla specifika metoder för automatiserad kvantifiering och geografisk analys av drivgods. En modell har utvecklats i ArcGIS Modelbuilder för (i) avgränsning och klassificering av riskområden längs ett vattendrag baserat på identifierade riskfaktorer för drivgods-bildning, (ii) kvantitativ estimering av trädvolym utifrån höjdrasterdataset framtagna från LIDAR punktmoln, och (iii) identifiering av trädindivider baserat på lokalisering av lokala maxpunkter i en digital ytmodell skapad från laser-data. I syfte att utvärdera metodens tillämpbarhet samt undersöka förekomsten av eventuella geografiska mönster i utbredningen av potentiella drivgodskvantiteter appliceras modellen på utvalda dammanläggningar längs med älven Ljungan i Sverige. Modellens noggrannhet i uppskattningen av trädindivider valideras i en fältkontroll. Resultaten indikerar en mycket god överrensstämmelse mellan modellerade och fältkontrollerade värden på trädantal, dock med något underestimerade modellerade värden. Ett större antal träd som riskerar att falla i älven identifierades vid högre vattenflöden som ett resultat av en generellt större geografisk omfattning på översvämmade ytor. Stora vegetationsvolymer identifierades främst i riskområden med en stor andel höga träd men även i riskområden med ett stort antal träd. I vissa riskområden erhölls större relativa vegetationsvolymer trots ett betydligt mindre relativt antal träd vilket antyder att både trädhöjd och trädantal styr vegetationsvolymers storlek. Resultaten av utförda statistiska och geografiska analyser förbättrar överblicken över drivgodsets volym och geografiska fördelning längs vattendrag vilket i sin tur även leder till en bättre förståelse för drivgodsproblemets magnitud för specifika dammanläggningar. Den automatiserade metoden genererar reproducerbara resultat som är jämförbara mellan olika dammanläggningar och vattendrag över tid. Metoden har stor potential för framtida drivgodsanalyser då den erbjuder möjligheten att identifiera riskområden och estimera drivgodskvantiteter inom dessa.Floating debris poses a threat to dam safety at hydropower dams as it increases the risk of spillways becoming blocked, which can in turn result in dam overflow and failure. Until now it has not been considered a problem in Sweden. However, the occurrence of several major international incidents, together with a projected future increase in streamflow intensities and flood events in Swedish rivers has raised the interest of Swedish dam owners. Presently there is a lack of robust methods for forecasting potential magnitudes of floating debris in extreme streamflow scenarios, which limits planning of preventive measures. This study aims to develop explicit methods for automated quantification and geographical analysis of floating debris. A model is developed in ArcGIS Modelbuilder for (i) identification and classification of risk areas along a river based on identified risk factors for floating debris formation, (ii) quantitative estimation of vegetation volume from elevation raster datasets derived from LIDAR point clouds, and (iii) identification of trees within risk areas based on locating local maxima in a digital surface raster derived from laser-data. In order to evaluate the applicability of the method as well as to investigate the existence of geographical patterns in potential floating debris quantities, the model is applied on selected dam facilities along the Ljungan River in Sweden. The accuracy of modeled tree amounts is validated in a field study. The results indicate high correlation between modeled number of trees and ground truth data, though modeled values are slightly underestimated. A greater number of trees at risk of falling into the river were identified during higher streamflow events as a result of larger areas being flooded. Large volumes of vegetation were identified in risk areas with a high proportion of tall trees as well as in risk areas with a large number of trees. In some risk areas, greater relative vegetation volumes were obtained despite a significantly smaller relative number of trees. This suggests that vegetation volume as a factor depends both upon the number of trees as well as tree height. The results of performed statistical and geographical analyses provide a better overview of floating debris distribution along rivers, leading to a better understanding of potential magnitudes of the problem for specific dam facilities. The automated method generates reproducible results that are comparable between different dam facilities and rivers over time. The method has significant potential for future floating debris analyses as it offers the possibility to identify risk areas and estimate floating debris quantities within them.
24
Berardi, Andrea. "Biophysical modelling of the Astroni Nature Reserve, Naples, Italy." Thesis, University College London (University of London), 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321946.
Full text
25
Bofakos, Petros. "An object-oriented approach to geo-referenced data modelling." Thesis, Keele University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386632.
Full text
26
Accad, Arnon. "Vegetation communities modelling using GIS-Integrated statistical, ecological and data models /." St. Lucia, Qld, 2003. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17703.pdf.
Full text
27
Jordan, Gyözö. "Terrain Modelling with GIS for Tectonic Geomorphology : Numerical Methods and Applications." Doctoral thesis, Uppsala universitet, Miljö- och landskapsdynamik, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4635.
Full textAbstract:
Analysis of digital elevation models (DEMs) by means of geomorphometry provides means of recognising fractures and characterising the morphotectonics of an area in a quantitative way. The objective of the thesis is to develop numerical methods and a consistent GIS methodology for tectonic geomorphology and apply it to test sites. Based on the study of landforms related to faults, geomorphological characteristics are translated into mathematical and numerical algorithms. The methodology is based on general geomorphometry. In this study, the basic geometric attributes (elevation, slope, aspect and curvatures) are complemented with the automatic extraction of ridge and valley lines and surface specific points. Evan’s univariate and bivariate methodology of general geomorphometry is extended with texture (spatial) analysis methods such as trend, autocorrelation, spectral, wavelet and network analysis. Digital terrain modelling is carried out by means of (1) general geomorphometry, (2) digital drainage network analysis, (3) digital image processing, (4) lineament extraction and analysis, (5) spatial and statistical analysis and (6) DEM specific digital methods such as shaded relief models, digital cross-sections and 3D surface modelling. Geological data of various sources and scales are integrated in a GIS database. Interpretation of multi-source information confirmed the findings of digital morphotectonic investigation. A simple shear model with principal displacement zone in the NE-SW direction can explain most of the morphotectonic features associated with structures identified by geological and digital morphotectonic investigations in the Kali Basin. Comparison of the results of the DTA with the known geology from NW Greece indicated that the major faults correspond to clear lineaments. Thus, DTA of an area in the proposed way forms a useful tool to identify major and minor structures covering large areas. In this thesis, numerical methods for drainage network extraction and aspect analysis have been developed and applied to tectonic geomorphology.
28
Al-Hussein, Salem. "GIS modelling of land degradation in northern Jordan using satellite imagery." Thesis, University of Leicester, 2000. http://hdl.handle.net/2381/30386.
Full textAbstract:
Northern Jordan has undergone tremendous land cover change during the last three decades. This study tried to answer the following question: How have population growth and socio-economic influences affected soil quality in northern Jordan? The underlying factors that have led to the changes in land use and land cover are poorly documented, but efforts in this area started to be effective with the creation of the Badia Research and Development Programme. However, there has been little effort to spatially correlate the land cover changes with soil quality. An empirical model based on high resolution spatial and temporal remotely sensed data offers the ability to assess the degradation impacts of changes in land cover in a spatial context. In an attempt to assess the impacts of changing land cover on soil, a GIS-based erosion model has been developed to predict annual soil loss by water in northern Jordan. This model uses the Revised Universal Soil Loss Equation (RUSLE). Spatially distributed static (topographic and soil) parameters for this model are extracted from a regional GIS developed specifically for the Badia Programme area. The dynamic (vegetation cover) parameter is estimated from the land cover maps, derived by digital processing of multi-resolution, multi temporal Landsat MSS (14.9. 1972, 16. 7. 1985) and TM (28. 8. 1992). Mapping of vegetation cover was carried out by applying TM-Linear Mixture Modelling and NDVI, while mapping of fallow lands was carried out by both on-screen digitizing and sketch mapping in the field. The image difference technique was used in the change detection analysis. The erosion model predicts an increase in the amount of soil loss in the study area from 1972 to 1992, as a result of land cover changes. It was concluded that the degradation of the soil in the study area, observed during the last two decades, was caused by effects of these land cover changes.
29
Oberhofer, Katja. "Anatomically-based, subject-specific modelling of lower limb motion during gait." Thesis, University of Auckland, 2009. http://hdl.handle.net/2292/5444.
Full text
30
McGuckin, Sara Olivia. "Modelling phosphorus losses from agricultural catchments to surface waters using GIS." Thesis, Queen's University Belfast, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314181.
Full text
31
Stocks, Christopher Eugene. "Environmental modelling with GIS : an assessment and a possible development strategy." Thesis, University of Sheffield, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301425.
Full text
32
Matandirotya, Electdom. "Measurement and modelling of geomagnetically induced currents (GIC) in power lines." Thesis, Cape Peninsula University of Technology, 2016. http://hdl.handle.net/20.500.11838/2459.
Full textAbstract:
Thesis (DTech (Electrical Engineering))--Cape Peninsula University of Technology, 2016.Geomagnetically induced currents (GIC) are currents induced in ground-based conductor networks in the Earth's surface. The GIC are driven by an electric eld induced by geomagnetic variations which are a result of time-varying magnetospheric-ionospheric currents during adverse space weather events. Several studies have shown that there is a likelihood of technological damage (the power grid) in the mid- and low-latitude regions that could be linked to GIC during some geomagnetic storms over the past solar cycles. The effects of GIC in the power system can range from temporary damage (e.g. protective relay tripping) to permanent damage (thermal transformer damage). Measurements of GIC in most substations are done on the neutral-to-ground connections of transformers using Hall-effect transducers. However, there is a need to understand the characteristics of GIC in the power lines connected to these transformers. Direct measurements of GIC in the power lines are not feasible due to the low frequencies of these currents which make current measurements using current transformers (CT) impractical. This thesis discusses two techniques that can be employed to enhance understanding GIC characteristics in mid-latitude regions. The techniques involve the measurement of GIC in a power line using differential magnetometer measurements and modelling GIC using the finite element method. Low frequency magnetometers are used to measure magnetic felds in the vicinity of the power lines and the GIC is inferred using the Biot-Savart law. A finite element model, using COMSOL-Multiphysics, is used to calculate GIC with the measured magnetic field and a realistic Earth conductivity profile as inputs. The finite element model is used for the computation of electric field associated with GIC modelling.
33
MacFarlane, Robert Hywel. "Integrating behavioural models with GIS for land-use policy impact modelling." Thesis, University of Aberdeen, 1994. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU067330.
Full textAbstract:
In this project, a range of characteristics describing farmers as decision-makers and details of their land holdings are integrated within a Geographic Information System (GIS) and used to predict overall farm response to defined policy scenarios, for a study area in the upland fringe of Grampian Region. Agriculture has undergone considerable adjustments over the past 40 years, characterised by the processes of intensification and specialisation of farming systems. These changes have been essentially policy-driven, although the precise interaction of policy, technological and macro-economic forces are not entirely understood. Further to this, rural areas are subject to an increasing range of consumption demands which has stimulated a new range of land-use policy schemes, and constraints, on farmers and landowners. From a position of assured government support which was enjoyed by the majority of farmers until the mid-1980s, the policy situation has developed into one of uncertainty and some confusion over the requirements and responsibilities placed on individual farmers. This research links spatial, behavioural and economic elements which combine to condition farm-level response to policy change. The complexity of individuals' decision environments, coupled with the diversity of individuals' values, objectives and resources is immense. The focus is on individual farms, and the implications of change at the individual level in developing a model of farm-level response to policy and market shifts.
34
Carriero, Alessandra. "Modelling gait abnormalities and bone deformities in children with cerebral palsy." Thesis, Imperial College London, 2009. http://hdl.handle.net/10044/1/4649.
Full textAbstract:
Cerebral palsy (CP) is a neuromuscular disorder that affects the motor control of muscles. CP children exhibit abnormal walking patterns and frequently develop lower limb, long bone deformities. To improve functionality and guide orthopaedic treatments effectively, it is critical to elucidate the relationship existing between bone morphology and movement of the lower limbs CP children. The hypothesis of this study is that gait abnormalities result in bone deformities. The investigation of this complex relationship represents the core of this thesis. The examination of magnetic resonance images and gait analysis of healthy and CP children showed different development in femoral and tibial morphology and varied gait characteristics between them. Similarly, different correlations between bone morphology and gait characteristics resulted in healthy and CP children. Gait characteristics also varied between CP children. An objective and quantitative graphical classification method of CP gait patterns was developed. This classified the CP children in overlapping clusters according to their gait patterns, confirming the presence of multiple gait abnormalities on the same lower limb for CP children. With the intention to define the effect of the walking characteristics on the bone structure, femoral muscle and hip contact forces in healthy and CP children with different walking strategies were estimated by using inverse dynamic analysis. The different gait styles resulted in different loadings on the developing femur bone. These constituted the loading conditions for bone growth analysis. A three-dimensional finite element model for femoral growth was developed and mechanobiological theories applied in order to predict femur changes over time in healthy and CP children. The models predicted higher femoral anteversion and neck3 shaft angle formation in children with CP, emphasizing how different gait characteristics can influence bone morphology. This information has potential to explain and eventually prevent or treat the development of bone deformities in CP children.
35
Wood, Graham John. "Auditing and modelling environmental impact assessment errors using geographical information systems." Thesis, Oxford Brookes University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.364099.
Full text
36
Lu, Tung-Wu. "Geometric and mechanical modelling of the human locomotor system." Thesis, University of Oxford, 1997. https://ora.ox.ac.uk/objects/uuid:789d619c-f32e-4efa-9935-6ec8ce82ece4.
Full textAbstract:
A critical review of studies related to the modelling of the human locomotor system is given. Kinematic and dynamic modelling and analysis of the pelvis-leg apparatus as an ensemble of four rigid body segments are described. Experiments were performed on two patients with custom-made instrumented massive proximal femoral prostheses implanted after tumour resection. Telemetered axial forces transmitted along the prostheses, together with kinematic, force plate and electromyographic data, were recorded synchronously during level walking, single and double leg stance, and isometric tests of the hip muscles. A sagittal plane model of the locomotor system, with an anatomical model of the knee joint, was developed from an existing model and used for a comparative study of methods for the calculation of the internal forces. A three-dimensional computer graphics-based animated model of the locomotor system was developed, with the hip as a ball-and-socket joint, the knee as a parallel spatial mechanism and the ankle as a two-hinge complex. Thirty-four muscles or muscle groups were included. A method for the determination of the orientation of multi-joint systems from surface markers was developed to take account of measurement errors including skin movement artefacts. Both the 2D and 3D models of the locomotor system were evaluated and validated quantitatively with the telemetered femoral axial forces. It is concluded that (a) a significant part of the bending moments along limbs are transmitted by a combination of tensile forces in muscles and compressive forces in bones so that moments transmitted by the bones are much less than the limb moments, (b) bi-articular muscles play a major role in modulating forces in bones, (c) appropriate simulation of muscle forces is important in experimental or theoretical studies of load transmission along bones, (d) computer graphics-based modelling and animation are important tools in bridging the gap between clinical users and biomechanists.
37
Rubiano, Mejia Jorge ElieÌcer Rubiano Mejia. "Mapping and modelling landscape stakeholders' visions in Sherwood Natural Area." Thesis, University of Nottingham, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288763.
Full text
38
Xia, Jianhong, and not supplied. "Modelling the spatial-temporal movement of tourists." RMIT University. Mathematical and Geospatial Sciences, 2007. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20080110.161021.
Full textAbstract:
Tourism is one of the most rapidly developing industries in the world. The study of spatio-temporal movement models of tourists are undertaken in variety of disciplines such as tourism, geography, mathematics, economics and artificial intelligence. Knowledge from these different fields has been difficult to integrate because tourist movement research has been conducted at different spatial and temporal scales. This thesis establishes a methodology for modelling the spatial-temporal movement of tourists and defines the spatial-temporal movement of tourists at both the macro and micro level. At the macro level, the sequence of tourist movements is modelled and the trend for tourist movements is predicted based on Markov Chain theory (MC). Log-linear models are then adopted to test the significance of the movement patterns of tourists. Tourism market segmentation based on the significant movement patterns of tourists is implemented using the EM (Expectation-Maximisation) algorithm. At the micro level, this thesis investigates the wayfinding decision-making processes of tourists. Four wayfinding models are developed and the relationships between the roles of landmarks and wayfinding decision-making are also discussed for each type of the wayfinding processes. The transition of a tourist movement between the macro and micro levels was examined based on the spatio-temporal zooming theory. A case study of Phillip Island, Victoria, Australia is undertaken to implement and evaluate the tourist movement models established in this thesis. Two surveys were conducted on Phillip Island to collect the macro and micro level movement data of tourists. As results show particular groups of tourists travelling with the same movement patterns have unique characteristics such as age and travel behaviours such as mode of transport. Effective tour packages can be designed based on significant movement patterns and the corresponding target markets. Tourists with various age groups, residency, gender and different levels of familiarity with physical environment have different wayfinding behaviours. The results of this study have been applied to tourism management on Phillip Island and the novel methods developed in this thesis have proved to be useful in improving park facilities and services provided to tourists, in designing tour packages for tourism market promotion and in understanding tourist wayfinding behaviours.
39
Avila, Moreno Rodolfo. "Radiocaesium transfer to roe deer and moose : modelling and experimental studies /." Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 1998. http://epsilon.slu.se/avh/1998/91-576-5482-4.gif.
Full text
40
Titidezh, Omid. "Assessing transport accessibility for healthcare facility reconfiguration using GIS and multilevel modelling." Thesis, Loughborough University, 2012. https://dspace.lboro.ac.uk/2134/12355.
Full textAbstract:
Transport accessibility to healthcare facilities is a major issue in the United Kingdom, as recently demonstrated by the shift away from providing healthcare in acute hospitals to care closer to home . Common measures of accessibility focus on the creation of distance or travel time contours around a destination and devote less attention to individual differences such as user perceptions, their transport usage, and area-wide factors including income deprivation, safety and security. Failure to account for such factors may result in imperfect decision making in terms of healthcare relocation and reconfiguration. This thesis therefore aims to develop a user-based accessibility model by focusing on both individual socio-economic (e.g. age, gender, access to transport modes) and area-wide characteristics (e.g. income deprivation, public transport provision, safety and security). In order to identify important factors that affect accessibility and to develop the user-based accessibility model, two revealed preference questionnaire surveys were undertaken at Loughborough and Hinckley. The purpose of the first questionnaire was to understand underlying factors affecting accessibility to a healthcare facility. The results revealed that both individual and area-wide factors affect transport accessibility to a healthcare facility. The purpose of the second questionnaire was conducted to capture data relating to users perception of accessibility and their socio-economic factors so as to develop a user-perception based accessibility model. Network-based travel time and travel distance as well as public transport provision data from a respondent home to a healthcare facility were generated using a GIS technique. Individual-level questionnaire data were then integrated with the other secondary datasets (e.g. Census, Index of Multiple Deprivation, Accidents) using postcodes of survey respondents. Both single-level and multilevel mixed-effects linear regression models were employed to develop a relationship between user-perceptions relating to accessibility and the factors influencing accessibility. Multilevel models that can control data from the two levels (i.e. individuals nested within local areas) provided better goodness-of-fit statistics compared with those of single-level regression models. The results indicate that travel distance by car, number of available direct bus services, age, and destination choices affect user-perceptions of accessibility to a healthcare facility. For instance, if travel distance by car increases by one mile then the perception of accessibility to a healthcare facility decreases by four units (on a scale of 0-100). Surprisingly, many area-wide factors such as security and safety, income deprivation were found to be statistically insignificant. In order to see which healthcare facility is more accessible, calibrated multilevel models along with number of people within the catchment area were then employed to predict the overall accessibility score related to a healthcare facility. This is important for policy makers in healthcare facility relocation and reconfiguration with respect to user perception of transport accessibility. Also it would be valuable to organisations that need to make decisions based on their users perceptions who are the real decision makers as to whether to use a facility or not.
41
Johnston, Peter Rowland. "A GIS supported methodology for air pollution modelling in the minerals industry." Thesis, Imperial College London, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.286410.
Full text
42
Woodman, Patricia E. "Archaeological predictive modelling using GIS : a case study from the Scottish Mesolithic." Thesis, University of Reading, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363659.
Full text
43
Premalal, de Silva Ranjith. "Spatiotemporal hydrological modelling with GIS for the Upper Mahaweli Catchment, Sri Lanka." Thesis, Cranfield University, 1997. http://dspace.lib.cranfield.ac.uk/handle/1826/7841.
Full textAbstract:
Sustainability of water resources is imperative for the continued prosperity of Sri Lanka where the economy is dependent upon agriculture. The Mahaweli river is the longest in Sri Lanka, with the upper catchment covering an area of 3124 sq km. The Mahaweli Development programme, a major undertaking in the upper catchment has been implemented with the aims of providing Mahaweli water to the dry zone of the country through a massive diversion scheme and also for generating hydropower. Under this programme, seven large reservoirs have been constructed across the river and large scale land use changes in the catchment have occurred during the last two decades. Critics now say that the hydrological regime has been adversely affected due to indiscriminate land use changes and, as a result, river flows have diminished during the last two decades, thus jeopardising the expectations of this massive development programme. Reforestation programmes have been recommended because of the benefits of forest in resource conservation and also the water derived from fog interception. Selection of the best sites for these forest plantations for maximum benefits, especially in terms of water yield from fog interception has the utmost importance. This created the need for a comprehensive model to represent the hydrology and to simulate the hydrological dynamics of the catchment In conceptual terms, GIS is well suited for modelling with large and complex databases associated with hydrological parameters. However, hydrological modelling efforts in GIS are constrained by the limitations in the representation of time in its spatial data ,structures. The SPANS GIS software used in this study provided the capability of linking spatially distributed numerical parameters with corresponding tabulated data through mathematical and statistical expressions while implicitly representing temporality through iterative procedures.The spatial distribution of land use was identified through the supervised classification of IRS-IA LISS II imagery. Daily rainfall data for a 30 year period and corresponding gauging locations derived from GPS were managed and retrieved through a Lotus 1-2- 3 database. The fog interception component was estimated based on elevation and the monsoon season. Hydrological processes such as interception and evapotranspiration were derived from individual sub models and finally combined within the overall hydrological model structure. The model was run with daily time steps on numerical 'values of each quad cell of the thematic coverage. The information on flow derived from the model was depicted as a series of thematic maps in addition to the time series of numerical values at subcatchment and catchment outlets. The results confirmed that the model is capable of simulating catchment response of the UMCA successfully. The time dimension was accommodated through a senes of non-interactive REXX programmes in developing the customised version of the model. It is concluded that the software architecture of SPANS GIS is capable of accommodating spatiotemporal modelling implicitly in its spatial data structures although changes in the model structure may necessitate considerable reprogramming. Sensitivity of the model for different spatial interpolation techniques was evaluated. Further, sensitivity of the model for the defined hydrological parameters, spatial 'resolution and land use was also assessed. The model is sensitive to land use changes in the catchment and it shows 15-35% annual increase of runoff when forests are converted to grassland. Further studies are required to develop a more detailed set of hydrological parameters for the model.
44
Zhang, Xiaoyang. "Soil-erosion modelling at the global scale using remote sensing and GIS." Thesis, King's College London (University of London), 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321948.
Full text
45
Frew, Robin. "GIS-based accessibility modelling as a means of evaluating geospatial data usability." Thesis, University of South Wales, 2016. https://pure.southwales.ac.uk/en/studentthesis/gisbased-accessibility-modelling-as-a-means-of-evaluating-geospatial-data-usability(cdd9e8aa-6bb0-470f-8fb2-a012a7d9a49f).html.
Full textAbstract:
This thesis arose from the recognised lack of previous research into the usability of geospatial data. Whereas considerable study has been made into the usability of devices and their interface, the underlying data has been subject to less consideration, though a substantial literature exists regarding data quality. With the rapid expansion of geospatial data availability through a multitude of platforms (much of it free and crowdsourced), and the increase in creation of such data as mobile devices track location, there is a need to investigate the usability of the data in different contexts and applications. This thesis contends that data quality and data usability, though closely related, are separate characteristics, and that quality is an important element of data usability. Usability of different data types from various sources is examined here in the context of the well-established application of GIS-based accessibility modelling. Sensitivity analysis techniques were utilised in a novel way to highlight usability issues with the data being studied through the use of statistical and visual approaches. Comparisons were made between a variety of proprietary datasets and data from other sources, such as free and open-source software (FOSS) volunteer geographic information (VGI) network data from OpenStreetMap (OSM), and observations made as to their usability, while addressing cross-cutting topical themes, such as examining different sources of locational representation, different sources of network representation, and questioning the effect of supply and demand on accessibility. The use of both an urban and a rural study area enabled comparisons to be drawn in different geographical contexts. Several specific proposals are made with regard to improving usability of the proprietary (Ordnance Survey) and VGI (OSM) datasets. An aide to decision making is also suggested through the use of a usability checklist, enabling sample or trial data to be assessed quickly and simply in any given context. A novel Utility Factor is proposed, which draws together contributions from the quantitative aspects of this study into one figure, and is suggested as a context-based proxy of usability based on measures of data similarity, difference and effect. The results obtained confirm the need for further research to both clarify aspects of data usability and widen the scope of future research into different contexts and applications.
46
Almuzaini, Khalid. "Qualitative modelling of place location on the linked data web and GIS." Thesis, Cardiff University, 2017. http://orca.cf.ac.uk/106368/.
Full textAbstract:
When asked to define where a geographic place is, people normally resort to using qualitative expressions of location, such as north of and near to. This is evident in the domain of social geography, where qualitative research methods are used to gauge people’s understanding of their neighbourhood. Using a GIS to represent and map the location of neighbourhood boundaries is needed to understand and compare people’s perceptions of the spatial extent of their neighbourhoods. Extending the GIS to allow for the qualitative modelling of place will allow for the representation and mapping of neighbourhoods. On the other hand, a collaborative definition of place on the web will result in the accumulation of large sets of data resources that can be considered “location-poor”, where place location is defined mostly using single point coordinates and some random combinations of relative spatial relationships. A qualitative model of place location on the Linked Data Web (LDW) will allow for the homogenous representation and reasoning of place resources. This research has analysed the qualitative modelling of place location on the LDW and in GIS. On the LDW, a qualitative model of place is proposed, which provides an effective representation of individual place location profiles that allow place information to be enriched and spatially linked. This has been evaluated using the application of qualitative spatial reasoning (QSR) to automatic reasoning over place profiles, to check the completeness of the representation, as well as to derive implicit links not defined by the model. In GIS, a qualitative model of place is proposed that provides a basis for mapping qualitative definitions of place location in GIS, and this has been evaluated using an implementation-driven approach. The model has been implemented in a GIS and demonstrated through a realistic case study. A user-centric approach to development has been adopted, as users were involved throughout the design, development and evaluation stages.
47
Heyns, Michael John. "Ensemble estimation and analysis of network parameters: strengthening the GIC modelling chain." Master's thesis, University of Cape Town, 2017. http://hdl.handle.net/11427/25277.
Full textAbstract:
Ensemble Estimation and Analysis of Network Parameters - Strengthening the GIC Modelling Chain - Abstract Large grounded conducting networks on Earth's surface have long been known to be affected by solar activity and geomagnetic storms. Geomagnetically induced currents (GICs) in these quasiantennas are just one of the effects. In modern times, society has become more and more dependent on electrical power and, as a result, power networks. These power networks form extensive grounded conductors and are susceptible to GICs, even at mid-latitude regions. Given a large enough event now, such as the Carrington event of 1859, the direct and knock-on results can be devastating. Such an event is more than just a possibility, it is just a matter of time. With this in mind, the study of the effects of GICs and the modelling of them has become essential to ensure the future security of society in general. GIC modelling makes the assumption that the resultant GIC at a specific node in a power network is assumed to be linearly related to the horizontal vector components of the geoelectric field, which is induced by a plane-wave geomagnetic field. The linear GIC and geoelectric field relation is linked by a pair of network parameters, a and b. These parameters are not easily measurable explicitly but may be estimated empirically. Furthermore, these parameters are traditionally only seen to include network information and remain constant given a stable network. In this work, a new empirical approach to derive estimates for a and b is presented where the linear relation is solved simultaneously for all possible pair of time instances. Given a geomagnetic storm time-series (length n) of simultaneous GIC and geoelectric field data to solve for a and b, taking all possible time instance pairs yields approximately N²/2 estimates for a and b. The resulting ensembles of parameter estimates are analysed and found to be approximately Cauchy-distributed. Each individual estimate resulting from a single pair of time instances being solved is not the true state of the system, but a possible state. Taking the ensemble as a whole though gives the most probable parameter estimate, which in the case of a Cauchy distribution is the median. These ensemble parameter estimates are used in the engineering link of the modelling chain, but the ensembles themselves allow further analysis into the nature of GICs. An improvement is seen when comparing the performance of the ensemble estimates applied to an out-of-sample dataset during the Halloween Storm of 2003 with previous GIC modelling in the South African power network using the same dataset. Analysis of the ensembles has verified certain ground assumptions (specifically the plane-wave assumption and network directionality) made as a first-order approximation in GIC modelling and has also shown that errors from these assumptions are absorbed into empirically derived network parameters. Using a range of estimates from the ensemble, a GIC prediction band is produced. This in itself corresponds to an error estimate in the prediction. For the first time, it has been explicitly shown that empirically derived network parameters show a correlation to the magnitude of the produced GIC. This behaviour is then used to refine the parameter estimation further and allow for real time dynamic network parameter estimation that further improves modelling.
48
Goh, Lina. "Freezing of gait in Parkinson’s disease: rehabilitation and measurement." Thesis, The University of Sydney, 2022. https://hdl.handle.net/2123/29693.
Full textAbstract:
This thesis presents three studies: (1) a systematic review with meta-analyses that evaluates the effects of rehabilitation interventions on freezing of gait in people with Parkinson’s disease; (2) a pilot trial that examines the feasibility and acceptability of a video self-modelling intervention to address freezing of gait; and (3) a study that explores the reliability, validity, and usability of the Ziegler test to measure freezing of gait severity. In study 1, results from meta-analyses show a small effect of physiotherapy/exercise on reducing freezing of gait post-intervention (Hedges’ g=-0.26, 95% CI -0.38 to -0.14), consistent with previous reviews. However, the robust methodology used in study 1 suggests cautious interpretation as the certainty of the evidence is very low and intervention effects are unlikely to be clinically meaningful. It is likely that a comprehensive assessment of freezing of gait triggers and prescription of personalised interventions that is sustained over time will be most effective at addressing freezing of gait. In study 2, evaluation of personalised video self-modelling (delivered via a virtual reality headset) plus physical practice of movement strategies, was shown to be both feasible and acceptable, with 90% retention, 84% adherence to video viewing and most reporting they would use the intervention again. In study 3, the Ziegler test was shown to be a reliable (ICC2,1=0.80; ICC3,1=0.91) and valid freezing of gait severity measure when used by physiotherapists in real time. The Ziegler test duration may also be used as a proxy measure for freezing of gait severity. Taken together, these results help researchers and clinicians determine effective personalised interventions to reduce freezing of gait and improve measurement of freezing of gait severity by using quantitative tools. Reducing freezing of gait could improve mobility, reduce fall risk, and increase health-related quality of life in people with Parkinson’s disease.
49
Hartshorne, James Byng. "Assessing the influence of digital terrain model characteristics on tropical slope stability analysis." Thesis, University of Bristol, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336822.
Full text
50
Harrison, Paula A. "Climate change and wheat production : spatial modelling of impacts in Europe." Thesis, University of Oxford, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310423.
Full text