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He, Ying Surveying & Spatial Information Systems Faculty of Engineering UNSW. "Spatial data quality management." Publisher:University of New South Wales. Surveying & Spatial Information Systems, 2008. http://handle.unsw.edu.au/1959.4/43323.
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The applications of geographic information systems (GIS) in various areas have highlighted the importance of data quality. Data quality research has been given a priority by GIS academics for three decades. However, the outcomes of data quality research have not been sufficiently translated into practical applications. Users still need a GIS capable of storing, managing and manipulating data quality information. To fill this gap, this research aims to investigate how we can develop a tool that effectively and efficiently manages data quality information to aid data users to better understand and assess the quality of their GIS outputs. Specifically, this thesis aims: 1. To develop a framework for establishing a systematic linkage between data quality indicators and appropriate uncertainty models; 2. To propose an object-oriented data quality model for organising and documenting data quality information; 3. To create data quality schemas for defining and storing the contents of metadata databases; 4. To develop a new conceptual model of data quality management; 5. To develop and implement a prototype system for enhancing the capability of data quality management in commercial GIS. Based on reviews of error and uncertainty modelling in the literature, a conceptual framework has been developed to establish the systematic linkage between data quality elements and appropriate error and uncertainty models. To overcome the limitations identified in the review and satisfy a series of requirements for representing data quality, a new object-oriented data quality model has been proposed. It enables data quality information to be documented and stored in a multi-level structure and to be integrally linked with spatial data to allow access, processing and graphic visualisation. The conceptual model for data quality management is proposed where a data quality storage model, uncertainty models and visualisation methods are three basic components. This model establishes the processes involved when managing data quality, emphasising on the integration of uncertainty modelling and visualisation techniques. The above studies lay the theoretical foundations for the development of a prototype system with the ability to manage data quality. Object-oriented approach, database technology and programming technology have been integrated to design and implement the prototype system within the ESRI ArcGIS software. The object-oriented approach allows the prototype to be developed in a more flexible and easily maintained manner. The prototype allows users to browse and access data quality information at different levels. Moreover, a set of error and uncertainty models are embedded within the system. With the prototype, data quality elements can be extracted from the database and automatically linked with the appropriate error and uncertainty models, as well as with their implications in the form of simple maps. This function results in proposing a set of different uncertainty models for users to choose for assessing how uncertainty inherent in the data can affect their specific application. It will significantly increase the users' confidence in using data for a particular situation. To demonstrate the enhanced capability of the prototype, the system has been tested against the real data. The implementation has shown that the prototype can efficiently assist data users, especially non-expert users, to better understand data quality and utilise it in a more practical way. The methodologies and approaches for managing quality information presented in this thesis should serve as an impetus for supporting further research.
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Yang, Ting Surveying & Spatial Information Systems Faculty of Engineering UNSW. "VISUALISATION OF SPATIAL DATA QUALITY FOR DISTRIBUTED GIS." Awarded by:University of New South Wales. School of Surveying and Spatial Information Systems, 2007. http://handle.unsw.edu.au/1959.4/27434.
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Nowadays a substantial trend occurs that vast amounts of geospatial data are supplied, managed, and processed over distributed GIS. It is important to provide users with the capability of visualising spatial data quality information in a meaningful way for distributed GIS, since it will significantly enhance user understanding of data quality and aid them in assessing the data fitness for their application requirements. This thesis investigates the issue of visualisation of spatial data quality for distributed GIS. Based on a review of core concepts associated with spatial data quality, metadata standards, and major research areas related to data quality, the limitations of current data quality presentation are highlighted. To overcome some of these limitations, the research topic of this thesis is proposed, namely, adding visualisation functionality to the presentation of spatial data quality to convey uncertainty information to users in an interactive and graphical manner. Based on a review of the theories on visualisation and the frameworks developed for visualisation of spatial data quality in literature, an extended framework is developed incorporating several aspects of visualisation such as contexts, contents, and techniques, where the hierarchical nature of data quality and error models are two main parts of the visualisation contents. A brief framework of visualisation of spatial data quality for distributed GIS is proposed, where data storage with quality information and web services for visualising data quality are two key components. To satisfy a series of requirements for representing spatial data quality, a new object-oriented data model is proposed based on the review of developments of data models. This data model can specifically deal with the hierarchical nature of data quality and error propagation, recognising data quality as a dynamic process. Further, The implementation of the data model using GML and SVG is discussed. The details of a web service for visualising spatial data quality are addressed. After proposing the requirements on building a system for spatial data quality visualisation for distributed GIS, the design of a prototype visualisation system for distributed GIS is addressed in detail. The prototype visualisation system for spatial data quality is developed and implemented with an example data set, where SVG and JavaScript are used to illustrate how various graphic methods such as animation, data quality filters, and colour gradients can be used for distributed GIS. In addition to the visualisation of positional accuracy at the feature level, in this pilot system, the hierarchical structure of data quality information is also presented. Limitations of the research in this thesis are also addressed. However, in general, this research is of great significance for the contributions made to a relatively new research area in terms of theories, procedures, and software developments.
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Mohamed-Ghouse, Mohamed Zaffar Sadiq. "Modeling spatial variation of data quality in databases /." Connect to thesis, 2008. http://repository.unimelb.edu.au/10187/3544.
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Li, Yang. "The spatial data quality analysis in the environmental modelling." Thesis, University of East London, 2001. http://roar.uel.ac.uk/1305/.
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The spatial data quality analysis is essential in environmental modelling for efficiently addressing the environmental change. As the complexity of data sets and the modelling capability of computer systems increase, the need to address the quality of both data and models is increasingly important. Integration with environmental modelling, the spatial data quality analysis and the geocomputation paradigm have been three important areas of GIS research. In this research they are brought together in the context of coastal oil spill modelling. The research covers the issues of measurement, modelling and management of spatial data quality. Coupling GIS and environmental modelling, the systematic solution is developed for coastal oil spill modelling which is representative of complex environmental models. The procedures of geospatial data quality analysis were implemented not only with existing GIS funLionality but also with various Geocomputation techniques. Spatial data quality analyses of inputs and model performances, which include sensitivity analyses, error propagation analyses and fitness-for-use analyses, were carried out for the coastal oil spill modelling. The results show that in coastal oil spill modelling, a better understanding and improvement of spatial data quality can be achieved through such analyses. The examples illustrate both the diversity of techniques and tools required when investigating spatial data quality issues in environmental modelling. The evidence of feasibility and practicality are also provided for these flexible analysis approaches. An overall methodology is developed at each stage of a project; with particular emphasis at inception to ensure adequate data quality on which to construct the models. Furthermore, the coupling strategy of GIS and environmental modelling is revised to include a geo-data quality analysis (GQA) engine. With growing availability of proprietary and public domain software suitable for spatial data quality analysis, GQA engines will be formed with the evolution of such software into tightly-coupled collection of tools external to GIS. The GQA engine would itself be tightly-coupled with GIS and environmental models to form a modelling framework.
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Ralphs, Martin P. "Towards the evaluation and management of spatial data quality." Thesis, University of East London, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282737.
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Khalil, Arya Farid. "Temporal and Spatial Analysis of Water Quality Time Series." University of Akron / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=akron1446027770.
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Näkne, Henrik. "Video Quality Metric improvement using motion and spatial masking." Thesis, Uppsala universitet, Avdelningen för visuell information och interaktion, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-275114.
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Objective video quality assessment is of great importance in video compression and other video processing applications. In today's encoders Peak Signal to Noise Ratio or Sum of Absolute Differences are often used, though these metrics have limited correlation to perceived quality. In this paper other block-based quality measures are evaluated with superior performance on compression distortion when evaluating correlation with Mean Opinion Scores. The major results are that Block-based Visual Information Fidelity with optical flow and intra-frame Gaussian weighting outperforms PSRN, VIF, and SSIM. Also, a block-based weighted Mean Squared Error method is proposed that performs better than PSRN and SSIM, however not VIF and BB-VIF, with the advantage of high locality, which is useful in video encoding. The previously mentioned weighting methods have not been evaluated with SSIM, which is proposed for further studies.
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Woodward, Tim. "Variation in 'Hayward' kiwifruit quality characteristics." The University of Waikato, 2007. http://hdl.handle.net/10289/2640.
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Quantify the magnitude, sources and distribution of variation in fruit quality traits within kiwifruit populations and identify opportunities for the management of this variation. Near-infrared (NIR) grading was used as a tool for monitoring fruit quality, and measurements combined with orchard/vine information to investigate opportunities for the management of the variation in fruit quality traits with a particular focus on fruit DM. NIR enabled non-destructive assessment of the quality characteristics of individual fruit from 96 commercial orchards, comprising 550 fruit-lines, across four consecutive seasons, resulting in a dataset of measurements made on 146.7 million individual fruit. The distribution of quality traits within fruit populations and the relationships between quality traits were examined. The spatial component of variation in fruit quality was investigated to assess the potential for zonal management practices. Finally, the effects of growth temperatures on fruit quality were studied. Significant variation in fruit quality was observed between-seasons, between-orchards, and between-vines within an orchard. From comparison of CVs between quality traits, cropload was more variable than fruit weight which varied more than fruit DM, independent of the production scale considered (between-orchard or between-vine). Across a hierarchy of fruit populations (individual vine, fruit-line and orchard), the majority of fruit quality distributions demonstrated significant deviations from normality. However, departures from normality can be tolerated for estimation of the proportion of fruit with specific quality criteria. The sources of variation in fruit weight and DM populations were investigated at both a between-orchard scale and a within-orchard scale. Between-orchard variation was significant, however, the majority of variation occurred within-fruitlines, within-orchards and within seasons. The within-fruitline component of variation was investigated separately. Both between-vine and within-vine variation were significant, but within-vine variation was dominant. The focus of management should be on reducing variation occurring within-fruitlines within-orchards, which is largely attributable to variation occurring within the individual vine. Higher croploads per vine have negative consequences for fruit weight but variable effects on DM. Increasing croploads reduce both FW and DW allocations for each fruit, therefore the effect of cropload on DM is dependent on the relative reductions in FW and DW. The DW allocations to fruit are not limited by DW production, at least up to the croploads observed in this study (≤65 fruit m-2). The potential for zonal management was investigated. Variation in fruit quality characteristics between-orchards across the Te Puke growing region, and between-vines within an individual orchard area were investigated using geostatistics. A spatial component to variation was identified both between-orchard and between-vine. However, the effect of spatial variation was diluted by that of non-spatial variation and therefore, zonation between orchards or between areas within-orchards should not be where the effort in managing variation is concentrated. Orchard altitude correlated with some aspects of fruit quality. Mean fruit weight declined 0.5g and within-orchard variation in fruit weight declined 0.25 units with a 25m increase in orchard altitude. Mean fruit DM was independent of orchard altitude and within-orchard variability in DM declined 0.023 units per 25m increase in orchard altitude. Differences in orchard altitude equated with differences in growth temperatures. Warm spring and cool summer temperatures favour the growth of high DM fruit. The effects of spring temperatures on canopy development and maturation were investigated to elucidate potential physiological mechanisms for temperatures effects on fruit growth. Higher spring growth temperatures increased the rate of total leaf area development and promoted development of leaf photosynthesis. Higher spring growth temperatures favoured a more positive carbon balance, which has beneficial effects on the development of fruit quality characteristics. Post-harvest, the traditional practice of grading fruit into count sizes generally also segregates for DM, and large count size fruit will often have higher DM than small sized fruit. Between fruit populations, a positive correlation was identified between fruit DM and acidity; therefore, segregation of the inventory by DM will also segregate for acidity. High DM fruit are also more acidic with a higher, more favourable brix/acid ratio when ripe. It is recommended that fruit DM status be managed in the inventory, not by maturity area as is the current practice, but by groups of similar count sizes within maturity areas.
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Beaton, Duncan. "Integration of data description and quality information using metadata for spatial data and spatial information systems." Thesis, University of Newcastle Upon Tyne, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321263.
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Berg, Jan. "Systematic evaluation of perceived spatial quality in surround sound systems /." Luleå : School of Music, Division of Sound Recording, 2002. http://epubl.luth.se/1402-1544/2002/17/index.html.
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Asratyan, Albert. "Performance Analysis of Distributed Spatial Interpolation for Air Quality Data." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-296339.
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Deteriorating air quality is a growing concern that has been linked to many health- related issues. Its monitoring is a good first step to understanding the problem. However, it is not always possible to collect air quality data from every location. Various data interpolation techniques are used to assist with populating sparse maps with more context, but many of these algorithms are computationally expensive. This work presents a three- step chain mail algorithm that uses kriging (without any modifications to the kriging algorithm itself) and achieves up to ×100 execution time improvement with minimal accuracy loss (relative RMSE of 3%) by parallelizing the load for the locally tested data sets. This approach can be described as a multiple- step parallel interpolation algorithm that includes specific regional border data manipulation for achieving greater accuracy. It does so by interpolating geographically defined data chunks in parallel and sharing the results with their neighboring nodes to provide context and compensate for lack of knowledge of the surrounding areas. Combined with the cloud serverless function architecture, this approach opens doors to interpolating data sets of huge sizes in a matter of minutes while remaining cost- efficient. The effectiveness of the three- step chain mail approach depends on the equal point distribution among all regions and the resolution of the parallel configuration, but in general, it offers a good balance between execution speed and accuracy.Försämrad luftkvalitet är en växande oro som har kopplats till många hälsorelaterade frågor. Övervakningen är ett bra första steg för att förstå problemet. Det är dock inte alltid möjligt att samla in luftkvalitetsdata från alla platser. Olika interpolationsmetoder används för att hjälpa till att fylla i glesa kartor med mer sammanhang, men många av dessa algoritmer är beräkningsdyra. Detta arbete presenterar en trestegs ‘kedjepostalgoritm’ som använder kriging (utan några modifieringar av själva krigingsalgoritmen) och uppnår upp till × 100 förbättring av exekveringstiden med minimal noggrannhetsförlust (relativ RMSE på 3%) genom att parallellisera exekveringen för de lokalt testade datamängderna. Detta tillvägagångssätt kan beskrivas som en flerstegs parallell interpoleringsalgoritm som inkluderar regional specifik gränsdatamanipulation för att uppnå större noggrannhet. Det görs genom att interpolera geografiskt definierade databitar parallellt och dela resultaten med sina angränsande noder för att ge sammanhang och kompensera för bristande kunskap om de omgivande områdena. I kombination med den molnserverfria funktionsarkitekturen öppnar detta tillvägagångssätt dörrar till interpolering av datamängder av stora storlekar på några minuter samtidigt som det förblir kostnadseffektivt. Effektiviteten i kedjepostalgorithmen i tre steg beror på lika punktfördelning mellan alla regioner och upplösningen av den parallella konfigurationen, men i allmänhet erbjuder den en bra balans mellan exekveringshastighet och noggrannhet.
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De, Stefano Antonio. "Wavelet-based reduction of spatial video noise." Thesis, University of Southampton, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342855.
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Weir, Michael John Charlesworth. "Ensuring and maintaining data quality in geographical information systems for forest land management." Thesis, Birkbeck (University of London), 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.325336.
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wennmyr, hugo leonardo alexander. "ini." Thesis, KTH, Arkitektur, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-146069.
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Preporsition for bachelor thesis project, working from the inside and out. Emphasising spatial quality and experience, More or less ignoring form and program. I’ve had issues with these aspects in earlier project, the form or the program takes alot of place in the project. I haven’t tried this approach before, it’s an attractive thought to allow the project take a form of it’s own, enclosing those spaces i create. The initial concept was to place the pools on the ground (not digging them into the ground) making them volumes that divide and define spaces. Also shifting the interaction between those in the water and those walking alongside the edges. The ceiling should mirror the spaces created by the pool. sinking down over some areas and opening up above others. My process is usually exploratory, I find something i can’t undestand or something where i can’t image the outcome. I play with this until patterns emerge or i feel i can control it. In that stage the inspiration vains. It’s magical to experiencing new things and constantly learning. When i come to that state the project tends to generate itself. During this thesis project I want to define my own process. I want to put it into words in order to understand it myself, but also in order to communicate it to others. Map it all out and hopefully find what makes a project selfgenerating. Filter everything and find the essence of what i’ve learned from my education.
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Dill, Robert W. "Data warehousing and data quality for a Spatial Decision Support System." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1997. http://handle.dtic.mil/100.2/ADA336886.
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Thesis (M.S. in Information Technology Management) Naval Postgraduate School, Sept. 1997.Thesis advisors, Daniel R. Dolk, George W. Thomas, and Kathryn Kocher. Includes bibliographical references (p. 203-206). Also available online.
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Rönnbäck, Britt-Inger. "Are uncertain uncertainties useful?: towards improved quality assessment of spatial data /." Luleå, 2004. http://epubl.luth.se/1402-1544/2004/013.
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Carlisle, Bruce Hendry. "Digital elevation model quality and uncertainty in DEM-based spatial modelling." Thesis, University of Greenwich, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.399349.
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Pennerstorfer, Dieter. "Can Competition Keep the Restrooms Clean? Price, Quality and Spatial Competition." Elsevier, 2017. http://dx.doi.org/10.1016/j.regsciurbeco.2017.02.005.
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This article investigates the influence of competition on price and product quality among Austrian camping sites, a market characterized by both horizontal (spatial) and vertical product differentiation. Theoretically, the effect of competition on quality is ambiguous and depends on the degree of cost substitutability between output and quality. Estimating a system of equations shows that intense competition has a positive impact on product quality and a negative effect on prices (conditional on quality). As high quality is associated with high prices, the total effect of competition on prices is rather small.
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Tuck, Joanne Michelle. "Effects of spatial heterogeneity on the ecology of terrestrial isopods." Thesis, University of East Anglia, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368185.
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Franklin, Hannah Mayford. "Understanding Variation in Water Quality using a Riverscape Perspective." Thesis, University of Canterbury. Biological Sciences, 2010. http://hdl.handle.net/10092/5197.
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With the increasing degradation of rivers worldwide, an understanding of spatial and temporal patterns in freshwater quality is important. Water quality is highly variable in space and time, yet this is largely overlooked at the scale of stream catchments. I employed a landscape ecology approach to examine the spatial patterning of water quality in complex, impacted stream networks on the Canterbury Plains of the South Island of New Zealand, with the goal of understanding how land-use effects proliferate through stream systems.
In particular, I used “snapshot” sampling events in conjunction with spatial modelling and longitudinal profiles to investigate the ways in which spatial and environmental factors influence the variability of water quality in stream networks. Spatial eigenfunction analyses showed that distance measures, which took into account variable connectivity by flow and distance along the stream between sites, explained more spatial variance in water quality than traditional distance metrics. Small upstream reaches were more spatially and temporally variable than main stems (under summer base-flow conditions). The extent of spatial variation in water quality differed between stream networks, potentially depending on linkages to groundwater and the surrounding landscape. My results indicated that the water quality of headwater streams can have a disproportionate influence over water quality throughout an entire network.
I investigated spatio-temporal patterns in water quality more intensively in one stream network, the Cam River, in which I found consistent spatial pattern through time. The relative balance between nutrient inputs (pollution and groundwater) and in-stream conditions influenced the spatial pattern of water quality, as well as that of several ecosystem processes which I measured simultaneously. The spatially intensive and explicit approach has allowed identification of key factors controlling water quality and ecosystem processes throughout the Cam River. This research highlights the importance of taking a spatially explicit approach when studying stream water quality and that such an approach could be insightful and will contribute to solving current stream management problems.
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Miralha, Lorrayne. "ACCOUNTING FOR SPATIAL AUTOCORRELATION IN MODELING THE DISTRIBUTION OF WATER QUALITY VARIABLES." UKnowledge, 2018. https://uknowledge.uky.edu/geography_etds/55.
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Several studies in hydrology have reported differences in outcomes between models in which spatial autocorrelation (SAC) is accounted for and those in which SAC is not. However, the capacity to predict the magnitude of such differences is still ambiguous. In this thesis, I hypothesized that SAC, inherently possessed by a response variable, influences spatial modeling outcomes. I selected ten watersheds in the USA and analyzed them to determine whether water quality variables with higher Moran’s I values undergo greater increases in the coefficient of determination (R²) and greater decreases in residual SAC (rSAC) after spatial modeling. I compared non-spatial ordinary least squares to two spatial regression approaches, namely, spatial lag and error models. The predictors were the principal components of topographic, land cover, and soil group variables. The results revealed that water quality variables with higher inherent SAC showed more substantial increases in R² and decreases in rSAC after performing spatial regressions. In this study, I found a generally linear relationship between the spatial model outcomes (R² and rSAC) and the degree of SAC in each water quality variable. I suggest that the inherent level of SAC in response variables can predict improvements in models before spatial regression is performed. The benefits of this study go beyond modeling selection and performance, it has the potential to uncover hydrologic connectivity patterns that can serve as insights to water quality managers and policy makers.
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Kumar, Aditya. "GeoExpert - An Expert System Based Framework for Data Quality in Spatial Databases." TopSCHOLAR®, 2006. http://digitalcommons.wku.edu/theses/290.
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Usage of very large sets of historical spatial data in knowledge discovery process became a common trend, and in order to obtain better results from this knowledge discovery process the data should be of high quality. In this thesis we proposed a framework 'GeoExpert' for data quality assessment and cleansing tool for spatial data that integrates the spatial data visualization and analysis capabilities of the ARCGIS, the reason and inference capability of an expert system. In this thesis we implemented the proposed framework both stand-alone and web versions using ArcGIS Engine and ArcGIS Server, respectively. We used JESS expert system shell for the expert system part of the GeoExpert. Use of expert system shell separates the application logic from the actual framework which makes the framework easily updatable and domain independent. In this thesis we implemented the GeoExpert on the spatially referenced water quality data.
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Segers, Magrieta. "Spatial variation of coke quality in the non-recovery beehive coke ovens." Diss., Pretoria : [s.n.], 2004. http://upetd.up.ac.za/thesis/available/etd-02082006-154944.
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Trapenskas, Donatas. "Binaural technology and issues related to sound quality analysis and spatial hearing /." Luleå, 2002. http://epubl.luth.se/1402-1544/2002/24.
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Moghadam, Manoochehr Salahi. "Yield and quality of cereals in response to inputs and spatial variability." Thesis, University of Reading, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270926.
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Aragon, Jennifer M. "Spatial and temporal trends in water quality in the Alafia River watershed." [Tampa, Fla] : University of South Florida, 2009. http://purl.fcla.edu/usf/dc/et/SFE0003163.
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Kim, Yong Sang. "Effects of luminance, color, and spatial frequency variations on perceived image quality." Diss., Virginia Tech, 1993. http://hdl.handle.net/10919/40190.
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The primary objective of this dissertation was to investigate the effects of varying levels of luminance, color, and spatial frequency content on the perceived image quality of a soft-copy color image. A secondary objective was to test the robustness of selected image quality metrics (MTFA, SQRI, and ICS) to the color variations as measured by the change in correlations between the perceived quality ratings and the values of the image quality metrics. To accomplish these objectives, a color image was selected and its luminance, color, and spatial frequency components were attenuated systematically using image processing software. With the manipulated images, an experiment was conducted in which subjects were asked to rate, on a 0.0 - 9.0 continuous scale, the perceived quality of a displayed image in comparison to the original image. Results of the statistical analysis of the collected data were characterized by the highly significant main effects and interaction effects. However, the magnitudes of the interactions were small.
The effect of the luminance component on perceived quality was found to be dominant and consistent across all the levels of the other two variables. As the luminance increased, the perceived quality increased at a decreasing rate. The luminance main effect was modeled well (R2 = 0.9968) by the second-order polynomial of the luminance attenuation level, or, equivalently, by the relative amount of the luminance contained in the image. The range of variation of perceived quality produced by the six luminance levels was about five units on a 0.0 - 9.0 continuous scale. It was concluded that perceived quality of the color image was determined primarily by the luminance component of the image.
The effect of color on perceived quality was found to be smaller than expected. The range of variation in perceived quality produced by the six color levels was only a little over one unit on a 0.0 - 9.0 continuous scale. Perceived qualities increased at a decreasing rate as the level of color increased. However, the slope of the curve representing the color effect was smaller than that of the luminance effect The main effect of color was modeled well (R2 = 0.9972) by the second-order polynomial of the color attenuation level, or, equivalently, by the relative amount of color contained in the image. Based on the findings of the color effect, two different roles of color in image perception are suggested. At extremely low luminance, color acts primarily as a facilitator of the luminance by providing more cues on the content of the image. At sufficiently high luminance, the increased perceived quality stems from the aesthetic characteristics of the color.
Both highpass and lowpass filtering, on the average, caused about 1.5 units of degradation as compared to the unfiltered image in perceived image quality on a 0.0 - 9.0 continuous scale. The perceived quality of the unfiltered image was greater than that of the filtered images across all the levels of luminance and color attenuation except at a low luminance level. There was no significant difference between the perceived qualities of the highpass and lowpass filtered images.
The R2 of the second-order polynomial for image qUality metrics (MTFA, SQRI, and ICS) and the mean perceived qualities did not vary across the color variations in the image manipulations. That is, these image quality metrics were robust to the color variations when the relationship between the quality metric values and the actual perceived qualities was represented by the second-order polynomial. However, with the first-order model, the R2 increased as the color level increased. The SQRI yielded higher R2 values than did the MTFA and ICS metrics when the first-order model was used. Also, the range of variation of R2 for the SQRI was smaller than that for the other two metrics. Therefore, it appears that the robustness of an image quality metric to the color variation is affected by the degree of non-linearity correction in the metric if the robustness is tested in the context of the straight-line relationship.Ph. D.
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Song, Chang-Shik. "Effects of Spatial Structure on Air Quality Level in U.S. Metropolitan Areas." Cleveland State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=csu1370284273.
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Franks, Jessica L. "Spatial and Temporal Influences of Water Quality on Zooplankton in Lake Texoma." Thesis, University of North Texas, 2000. https://digital.library.unt.edu/ark:/67531/metadc2532/.
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Seventy-one aquatic species including the copepodids and nauplii were identified from Lake Texoma from August 1996 to September 1997. Zooplankton community structure, abundance and spatial and temporal distributions were compared among five lake zones delineated a priori based on chloride concentration. The zones, in order of decreasing chloride concentration, are the Red River zone (RRZ), Red river Transition zone (RRTZ), Main Lake zone (MLZ), Washita River Transition zone (WRTZ) and Washita River zone (WRZ). Bray Curtis Similarity Index showed community structure was most similar in the two Red River arm zones, the two Washita River arm zones and the MLZ. Zooplankton abundance was greatest in the Red River arm (312 org/L), intermediate in the Washita River arm (217 org/L) and least in the Main Lake body (103 org/L). A significant increase in the abundance of a deformed rotifer, Keratella cochlearis, was observed mainly in the Red River arm during a second study from March 1999 to June 1999. Seasonal dynamics, rather than spatial dynamics, were more important in structuring the zooplankton community, especially in the two river arms. Spatial variance was solely attributed to station and zone effects independent of time for a few crustacean species and many of the water quality parameters supporting the presence of longitudinal gradients of differing water quality. Three independent models (Red River arm, Washita River arm, Main Lake body) rather than a single model for the entire reservoir, best describe patterns in the zooplankton community and its relationship to seasonal, physical and chemical factors. Statistical power, sample size and taxonomic resolution were examined. When monitoring seasonal and annuals trends in abundance, the greatest statistical power was achieved by analyzing count data at taxonomic levels above genus. Taxonomic sufficiency was assessed to determine if costs could be reduced for zooplankton identifications. For water quality monitoring purposes only, it is recommended that genus identifications are sufficient if supplemented with quarterly species identifications.
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Pretorius, Liaan Marié. "Spatial and temporal variability in water quality characteristics of the Swartkops Estuary." Thesis, Nelson Mandela Metropolitan University, 2015. http://hdl.handle.net/10948/4176.
Full textAbstract:
Water quality characteristics of the heavily urbanised and industrialised Swartkops River catchment in the Eastern Cape has been the focus of several studies since the 1970s. Overloaded and poorly maintained wastewater treatment works (WWTW), polluted stormwater runoff and solid waste have had a negative impact on the water quality status of the Swartkops River and estuary. Past studies have revealed that a distinct relationship exists between land use activities and the water quality of the Swartkops Estuary, which in turn has raised concerns pertaining to the ecological, economic, recreational, and cultural value of the estuaryThe Swartkops Estuary has a Present Ecological State (PES) of Category D(1) and a Recommended Ecological Category (REC)(2) of a C (Van Niekerk et al., 2014). It is known that effective management of anthropogenic impacts on coastal systems requires a thorough understanding of the system’s biological responses to wastewater discharges and to hydrologic changes. For this reason, the objective of this study was to determine the current water quality status of the Swartkops Estuary, and to gain greater insight into factors controlling eutrophication. This was important as outdated water quality information was used in the Swartkops Integrated Environmental Management Plan (Enviro-Fish Africa, 2011) due to a lack of current data. To determine the current water quality status of the Swartkops Estuary the present study investigated spatial and temporal variability in physico-chemical parameters, nutrients, phytoplankton biomass and community composition, faecal bacteria, and “where possible” related this to historical water quality data. In general, points of entry into the estuary were investigated for their impact on nutrient enrichment and the bacteriological status of the estuary. Water quality surveys were completed in September 2012, November 2012, February 2013, May 2013 and August 2013The present study found evidence to suggest that water is not flushed as efficiently from the estuary as was previously the case, and that the natural hydrology of the estuary has been modified. These changes appear to be the effect of large volumes of wastewater discharges from the wastewater treatment works (WWTW), which has led to the additional stresses of increased vertical stratification and reduced vertical mixing. A build-up of dissolved inorganic nutrients has given rise to persistent eutrophic conditions and phytoplankton blooms occurring from the middle reaches to the tidal limit of the estuary. These findings were associated with a generally well oxygenated estuary; however, bottom water hypoxic conditions were recorded in the upper reaches of the estuary on two occasions and were generally associated with bloom.forming flagellates. Elevated concentrations of inorganic nutrients stimulated phytoplankton to attain high biomass ranging from 0 to 248 g l-1 (31.8 6.56 g l-1). All nutrients displayed positive linear gradients from the mouth to the tidal limit, showed significant (p < 0.05) temporal and spatial variability, and were significantly (p < 0.05) correlated with phytoplankton biomass. Phytoplankton blooms (> 10 000 cells ml-1) of several different groups were recorded from the middle reaches of the estuary to the tidal limit. Diatoms were the dominant group during increased freshwater inflow (at mean daily flow rate of 2.14 m3 s-1) and low DIP levels, whereas flagellates were generally the dominant group during reduced flow and under higher nutrient levels. Although the different tidal stages had no effect on phytoplankton biomass per se, it did support co-existance between phytoplankton groups. This was noted during the spring ebb tide in September 2012 (i.e. flagellates, diatoms and dinoflagellate) and in February 2013 (i.e. dinoflagellates, diatoms and chlorophytes). Phytoplankton blooms have become persistent in the middle to upper reaches of the estuary where chlorophyll-a was > 20 µg l-1 and cell density exceeded 10 000 cells ml-1; a situation not reported in previous studies. The Motherwell Canal was and still is the main source of nitrogen (generally in the form of ammonium) to the estuary, whereas the Swartkops River is still the primary source of phosphorus to the estuary. Since the stormwater canal services the large residential area of Motherwell where leaks in the sewer system, the dumping of night soil buckets, and faulty pumps are often reported, polluted discharges from the Motherwell Canal can enter the canal at any given point. In contrast to the canal, DIP loading from the Swartkops River to the estuary generally occurred under conditions of low flow, whereas nitrogen showed no apparent relationship. Faecal bacteria originating from the Motherwell Canal had the most profound effect on the bacteriological status in the middle reaches of the estuary, whereas the Swartkops River had an intermediate effect due to bacteria die-offs occurring between the point of release from the WWTW to the riverine reaches and the tidal limit of the estuary. Nevertheless, Escherichia coli and enterococci levels are still high, especially in the summer months rendering the estuary unsafe for recreation during this season. Historical data on trace metals in the water column were limited and thus observations from the present study could not be concluded with much confidence. However, preliminary data suggest that levels of copper, zinc, iron and cadmium have increased by at least 90% in the estuary, at the tidal limit of the estuary and in the Markman and Motherwell canals. High inputs of nutrients, trace metals and faecal bacteria to the estuary from land-use activities indicate the necessity for remedial actions with the main objective being to conserve and protect the estuary’s recreational, ecological and economic functions.
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Wang, Annie Yi. "A spatial and temporal analysis of neighborhood air quality in downtown Vancouver." Thesis, University of British Columbia, 2017. http://hdl.handle.net/2429/62591.
Full textAbstract:
Rapid urban densification and an enhanced understanding of the health consequences of intra-urban air pollution exposure variability has led to a need for accurate estimation of traffic-related air pollution (TRAP) exposures, including temporal and spatial variability. To address this goal, a wireless real-time air pollution monitor was evaluated and the effect of street canyon geometry on TRAP levels was assessed. The AQMesh wireless monitor (with sensors for CO, NO, NO₂, O₃ and SO₂)—was evaluated in a co-location study with regulatory air quality monitoring stations in London, England and Vancouver, Canada. The amount of variability (R²) explained by AQMesh sensors (algorithm version 3.0) ranged from 0.02% to 34.5% in Vancouver and 1.5% to 82.3% in London. Sensors for NO₂ and O₃ displayed the highest accuracy while the CO sensor accuracy was much weaker. AQMesh, as examined in this co-location, was not sufficiently robust for use in regulatory applications. A simple GIS-based model for the identification of potential street canyons where TRAP levels may be elevated was created using 3D building information, aspect ratio and the prevailing wind direction. The model was evaluated in a mobile monitoring campaign in which particulate matter smaller than 2.5 micrometers (PM2.5) and particle number concentration (PNC) were measured along 4 road segments: canyon high traffic (C HT), canyon low traffic (C LT), non-canyon high-traffic (NC HT) and non-canyon low traffic (NC LT). A linear mixed effects model found the effect estimates for C LT (i.e. the effect of canyon) to be 8% higher for PM2.5 and 17% higher for PNC when compared to the reference road segment category, NC LT. In comparison, the effect estimates for NC HT (i.e. the effect of traffic) was 16% higher for PM2.5 and 34% higher for PNC when compared to NC LT. This research suggests that the impact of traffic may be greater than the impact of street canyons in determining TRAP exposures.Medicine, Faculty of
Occupational Science and Occupational Therapy, Department of
Graduate
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Shi, Tianji. "Air-quality model evaluation through the analysis of spatial-temporal ozone features." Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/54707.
Full textAbstract:
Legislative actions regarding ozone pollution use air quality models (AQMs) such as the Community Multiscale Air Quality (CMAQ) model for scientific guidance, hence the evaluation of AQM is an important subject. Traditional point-to-point comparisons between AQM outputs and physical observations can be uninformative or even misleading since the two datasets are generated by discrepant stochastic spatial processes. I propose an alternative model evaluation approach that is based on the comparison of spatial-temporal ozone features, where I compare the dominant space-time structures between AQM ozone and observations. To successfully implement feature-based AQM evaluation, I further developed a statistical framework of analyzing and modelling space-time ozone using ozone features. Rather than working directly with raw data, I analyze the spatial-temporal variability of ozone fields by extracting data features using Principal Component Analysis (PCA). These features are then modelled as Gaussian Processes (GPs) driven by various atmospheric conditions and chemical precursor pollution. My method is implemented on CMAQ outputs during several ozone episodes in the Lower Fraser Valley (LFV), BC. I found that the feature-based ozone model is an efficient way of emulating and forecasting a complex space-time ozone field. The framework of ozone feature analysis is then applied to evaluate CMAQ outputs against the observations. Here, I found that CMAQ persistently over-estimates the observed spatial ozone pollution. Through the modelling of feature differences, I identified their associations with the computer model's estimates of ozone precursor emissions, and this CMAQ deficiency is focused on LFV regions where the pollution process transitions from NOx-sensitive to VOC-sensitive. Through the comparison of dynamic ozone features, I found that the CMAQ's over-prediction is also connect to the model producing higher than observed ozone plume in daytime. However, the computer model did capture the observed pattern of diurnal ozone advection across LFV. Lastly, individual modelling of CMAQ and observed ozone features revealed that even under the same atmospheric conditions, CMAQ tends to significantly over-estimate the ozone pollution during the early morning. In the end, I demonstrated that the AQM evaluation methods developed in this thesis can provide informative assessments of an AQM's capability.Science, Faculty of
Statistics, Department of
Graduate
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Conetta, Robert. "Towards the automatic assessment of spatial quality in the reproduced sound environment." Thesis, University of Surrey, 2011. http://epubs.surrey.ac.uk/39628/.
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The research in this thesis describes the creation and development of a method for the prediction of perceived spatial quality. The QESTRAL1 model is an objective evaluation model capable of accurately predicting changes to perceived spatial quality. It uses probe signals and a set of objective metrics to measure changes to low-level spatial attributes. A polynomial weighting function derived from regression analysis is used to predict data from listening tests, which employed spatial audio processes (SAPs) proven to stress those low-level attributes. A listening test method was developed for collecting listener judgements of impairments to spatial quality. This involved the creation of a novel test interface to reduce the biases inherent in other similar audio quality assessment tests. Pilot studies were undertaken which established the suitability of the method. Two large scale listening tests were conducted using 31 Tomneister students from the Institute of Sound Recording (IoSR), University of Surrey. These tests evaluated 48 different SAPs, typically encountered in consumer sound reproduction equipment, when applied to 6 types of programme material. The tests were conducted at two listening positions to determine how perceived spatial quality was changed. Analysis of the data collected from these listening tests showed that the SAPs created a diverse range of judgements that spanned the range of the spatial quality test scale and that listening position, programme material type and listener each had a statistically significant influence upon perceived spatial quality. These factors were incorporated into a database of 308 responses used to calibrate the model. The model was calibrated using partial least-squares regression using target specifications similar to those of audio quality models created by other researchers. This resulted in five objective metrics being selected for use in the model. A method of post correction using an exponential equation was used to reduce non-linearity in the predicted results, thought to be caused by the inability of some metrics to scrutinise the highest quality SAPs. The resulting model had a correlation (r) of 0.89 and an error (RMSE) of 11.06% and performs similarly to models developed by other researchers. Statistical analysis also indicated that the model would generalise to a larger population of listeners.
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He, Hong, and s3094261@student rmit edu au. "Nightscapes on open space." RMIT University. Architecture and Design, 2006. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20080715.142827.
Full textAbstract:
The initial concept of my project started from my experience in China. The domestic increase of productivity, heavier workloads and longer working hours have provoked an urgent desire for an increased quality of leisure, which has triggered an enormous basic demand for comfortable houses with gardens in Chinese societies. But most Chinese people do not have a backyard or a garden to themselves due to the high population density. Public open space has to compensate for this demand. Meanwhile, with the quickening tempo of modern life and prolonged working hours, most people have to enjoy their entertainment and social activities after daytime. Therefore, these public open spaces are even more highly used than during the day, people use them as their backyard and for social gatherings. How these open spaces operate at night has had an enormous impact on nightlife and its importance has been gradually recognized. The Chinese government is spending large amounts of money constructing and upgrading the lighting in open space. But most of these projects do not address key issues associated with lighting. For example, what the government considers 'good lighting' many people consider to be over-lighting or functional lighting and even some lighting projects leave many functions of the space unlit, For instance, pathways or sidewalks are not lit but the plazas and squares are. Those types of issues occur in many open spaces due to a traditional approach to the lighting design process which tends to occur separately to the design process. Obviously most lighting projects do not really consider the relation of light, space and people's use. When I came to Melbourne I found out that the City of Melbourne has a specific lighting strategy, which is more about electricity saving and technical requirements rather than spatiality. In addition, many lighting companies deal with lighting effect on surrounding landscape and architecture but are also not about spatiality. So in order to understand the spatial qualities of lighting, my original research questions were: 1. Instead of traditional building materials how lighting can be used to transform space and spatial quality in open space? 2. How does lighting spatially bridge between site and street, site and building, site and context, eventually site and city? 3. I also wanted to consider the site's identity at various scales.
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von, Brandis RG, and BK Reilly. "Spatial variation in trophy quality of popular hunted ungulate species in South Africa." Southern African Wildlife Management Association, 2008. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1000760.
Full textAbstract:
Adatabase of approximately 9000 trophy measurements of ungulates hunted in South Africa
between 1993 and 2001 was analysed in order to detect species-specific, regional variation in
mean trophy quality. Blesbok (Damaliscus dorcas), eland (Taurotragus oryx), impala
(Aepyceros melampus), kudu (Tragelaphus strepsiceros), mountain reedbuck (Redunca
fulvorufula) and springbok (Antidorcas marsupialis) showed statistically significant
variation in trophy quality. A number of other species including blue wildebeest
(Connochaetus taurinus), black wildebeest (Connochaetus gnou), bushbuck (Tragelaphus
angusticeps), common reedbuck (Redunca redunca), gemsbok (Oryx gazella), red
hartebeest (Alcelaphus buselaphus), nyala (Tragelaphus angasii) and waterbuck (Kobus
ellipsiprymnus) were insignificant. The manipulation of trophy quality on ranches is speculated
to be the major cause of these significant regional variations. It is recommended that
species-specific baselines of trophy quality and associated levels of ‘acceptable manipulation’be
established and incorporated into a national trophy quality monitoring programme to
provide some level of protection to an industry that contributes significantly to the South African
economy.
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Yang, Mengwei. "STUDY OF SPATIAL DISTRIBUTION OF WATER QUALITY AND LANDSCAPE TYPES IMPACT ON STREAM WATER QUALITY IN BUTLER COUNTY, OH." Miami University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=miami1501262013874623.
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Cobb, Charles Evan. "Spatial and temporal variations of PM2.5 mass and composition in Atlanta ASACA 1999-2006 /." Thesis, Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-11172006-161408/.
Full textAbstract:
Thesis (M. S.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2007.Dr. Armistead Russell, Committee Chair ; Dr. James Mulholland, Committee Member ; Dr. Michael Bergin, Committee Member.
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Mendes, Pedro Mota. "Correction of spatial distortion in magnetic resonance imaging." Master's thesis, Faculdade de Ciências e Tecnologia, 2011. http://hdl.handle.net/10362/6333.
Full textAbstract:
Dissertation to Obtain the Degree of Master
in Biomedical EngineeringMagnetic Resonance Imaging (MRI) has been a major investigation and research focus among scientific and medical communities. So, new hardware with superior magnetic fields and faster sequences has been developed. However, these improvements result in intensity and spatial distortions, particularly in fast sequences, as Echo Plana Imaging (EPI), used in functional and diffusion-weighed MRI (fMRI and DW-MRI). Therefore, correction of spatial distortion is useful to obtain a higher quality in this kind of images. This project contains two major parts. The first part consists in simulating MRI data required for assessing the performance of Registration methods and optimizing parameters. To assess the methods five evaluation metrics were calculated between the corrected data and an undistorted EPI, namely: Root Mean Square (RMS); Normalized Mutual Information (NMI), Squared Correlation Coefficient(SCC); Euclidean Distance of Centres of Mass (CM) and Dice Coefficient of segmented images. In brief, this part validates the applied Registration correction method. The project’s second part includes correction of real images, obtained at a Clinical Partner. Real images are diffusion weighted MRI data with different b-values (gradient strength coefficient), allowing performance assessment of different methods on images with increasing b-values and decreasing SNR. The methods tested on real data were Registration, Field Map correction and a new proposed pipeline, which consists in performing a Field Map correction after a registration process. To assess the accuracy of these methods on real data, we used the same evaluation metrics, as for simulated data, except RMS and Dice Coefficient. At the end, it was concluded that Registration-based methods are better than Field Map, and that the new proposed pipeline produces some improvements in the registration. Regarding the influence of b-value on the correction, it is important to say that the methods performed using images with higher b’s showed more improvements in regarding metric values, but the behaviour is similar for all b-values.
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Ochandio, Mario Roberto. "Spatial Analysis of Atrazine in the Elm Fork Watershed." Thesis, University of North Texas, 2000. https://digital.library.unt.edu/ark:/67531/metadc2510/.
Full textAbstract:
This study assessed the water quality of the Elm Fork Watershed with regards to the herbicide Atrazine. Atrazine is a potential environmental endocrine disruptor and carcinogen. Overall, concentrations were lower than the four-quarter drinking water average of 3 µg/Lthe Maximum Contaminant Level set by the USEPA. However, three creek stations had four-quarter average concentrations greater than 3 µg/L, and virtually all samples exceeded the 0.1 µg/L standard set in Europe [1,2]. Statistically significant differences in concentrations were detected between the 27 sampling stations and areas of high concentrations were identified. However correlations between Atrazine concentrations and land-use and precipitation were not statistically significant. Further analysis with more detailed data should be conducted before any relationships are discarded.
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Boulil, Kamal. "Une approche automatisée basée sur des contraintes d’intégrité définies en UML et OCL pour la vérification de la cohérence logique dans les systèmes SOLAP : applications dans le domaine agri-environnemental." Thesis, Clermont-Ferrand 2, 2012. http://www.theses.fr/2012CLF22285/document.
Full textAbstract:
Les systèmes d'Entrepôts de Données et OLAP spatiaux (EDS et SOLAP) sont des technologies d'aide à la décision permettant l'analyse multidimensionnelle de gros volumes de données spatiales. Dans ces systèmes, la qualité de l'analyse dépend de trois facteurs : la qualité des données entreposées, la qualité des agrégations et la qualité de l’exploration des données. La qualité des données entreposées dépend de critères comme la précision, l'exhaustivité et la cohérence logique. La qualité d'agrégation dépend de problèmes structurels (e.g. les hiérarchies non strictes qui peuvent engendrer le comptage en double des mesures) et de problèmes sémantiques (e.g. agréger les valeurs de température par la fonction Sum peut ne pas avoir de sens considérant une application donnée). La qualité d'exploration est essentiellement affectée par des requêtes utilisateur inconsistantes (e.g. quelles ont été les valeurs de température en URSS en 2010 ?). Ces requêtes peuvent engendrer des interprétations erronées des résultats. Cette thèse s'attaque aux problèmes d'incohérence logique qui peuvent affecter les qualités de données, d'agrégation et d'exploration. L'incohérence logique est définie habituellement comme la présence de contradictions dans les données. Elle est typiquement contrôlée au moyen de Contraintes d'Intégrité (CI). Dans cette thèse nous étendons d'abord la notion de CI (dans le contexte des systèmes SOLAP) afin de prendre en compte les incohérences relatives aux agrégations et requêtes utilisateur. Pour pallier les limitations des approches existantes concernant la définition des CI SOLAP, nous proposons un Framework basé sur les langages standards UML et OCL. Ce Framework permet la spécification conceptuelle et indépendante des plates-formes des CI SOLAP et leur implémentation automatisée. Il comporte trois parties : (1) Une classification des CI SOLAP. (2) Un profil UML implémenté dans l'AGL MagicDraw, permettant la représentation conceptuelle des modèles des systèmes SOLAP et de leurs CI. (3) Une implémentation automatique qui est basée sur les générateurs de code Spatial OCL2SQL et UML2MDX qui permet de traduire les spécifications conceptuelles en code au niveau des couches EDS et serveur SOLAP. Enfin, les contributions de cette thèse ont été appliquées dans le cadre de projets nationaux de développement d'applications (S)OLAP pour l'agriculture et l'environnementSpatial Data Warehouse (SDW) and Spatial OLAP (SOLAP) systems are Business Intelligence (BI) allowing for interactive multidimensional analysis of huge volumes of spatial data. In such systems the quality ofanalysis mainly depends on three components : the quality of warehoused data, the quality of data aggregation, and the quality of data exploration. The warehoused data quality depends on elements such accuracy, comleteness and logical consistency. The data aggregation quality is affected by structural problems (e.g., non-strict dimension hierarchies that may cause double-counting of measure values) and semantic problems (e.g., summing temperature values does not make sens in many applications). The data exploration quality is mainly affected by inconsistent user queries (e.g., what are temperature values in USSR in 2010?) leading to possibly meaningless interpretations of query results. This thesis address the problems of logical inconsistency that may affect the data, aggregation and exploration qualities in SOLAP. The logical inconsistency is usually defined as the presence of incoherencies (contradictions) in data ; It is typically controlled by means of Integrity Constraints (IC). In this thesis, we extends the notion of IC (in the SOLAP domain) in order to take into account aggregation and query incoherencies. To overcome the limitations of existing approaches concerning the definition of SOLAP IC, we propose a framework that is based on the standard languages UML and OCL. Our framework permits a plateforme-independent conceptual design and an automatic implementation of SOLAP IC ; It consists of three parts : (1) A SOLAP IC classification, (2) A UML profile implemented in the CASE tool MagicDraw, allowing for a conceptual design of SOLAP models and their IC, (3) An automatic implementation based on the code generators Spatial OCLSQL and UML2MDX, which allows transforming the conceptual specifications into code. Finally, the contributions of this thesis have been experimented and validated in the context of French national projetcts aimming at developping (S)OLAP applications for agriculture and environment
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Kuo, Yun-Ching. "Determination of image quality for added noise as a function of spatial frequency /." Online version of thesis, 1989. http://hdl.handle.net/1850/11527.
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Flesch, Aaron D., Richard L. Hutto, Leeuwen Willem J. D. van, Kyle Hartfield, and Sky Jacobs. "Spatial, Temporal, and Density-Dependent Components of Habitat Quality for a Desert Owl." Public Library of Science, 2015. http://hdl.handle.net/10150/621328.
Full textAbstract:
UA Open Access Publishing FundSpatial variation in resources is a fundamental driver of habitat quality but the realized value of resources at any point in space may depend on the effects of conspecifics and stochastic factors, such as weather, which vary through time. We evaluated the relative and combined effects of habitat resources, weather, and conspecifics on habitat quality for ferruginous pygmy-owls (Glaucidium brasilianum) in the Sonoran Desert of northwest Mexico by monitoring reproductive output and conspecific abundance over 10 years in and around 107 territory patches. Variation in reproductive output was much greater across space than time, and although habitat resources explained a much greater proportion of that variation (0.70) than weather (0.17) or conspecifics (0.13), evidence for interactions among each of these components of the environment was strong. Relative to habitat that was persistently low in quality, high-quality habitat buffered the negative effects of conspecifics and amplified the benefits of favorable weather, but did not buffer the disadvantages of harsh weather. Moreover, the positive effects of favorable weather at low conspecific densities were offset by intraspecific competition at high densities. Although realized habitat quality declined with increasing conspecific density suggesting interference mechanisms associated with an Ideal Free Distribution, broad spatial heterogeneity in habitat quality persisted. Factors linked to food resources had positive effects on reproductive output but only where nest cavities were sufficiently abundant to mitigate the negative effects of heterospecific enemies. Annual precipitation and brooding-season temperature had strong multiplicative effects on reproductive output, which declined at increasing rates as drought and temperature increased, reflecting conditions predicted to become more frequent with climate change. Because the collective environment influences habitat quality in complex ways, integrated approaches that consider habitat resources, stochastic factors, and conspecifics are necessary to accurately assess habitat quality.
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Yan, Yao. "Development of Methods for Spatial Modeling of Sediments Quality in Lake Okeechobee, Florida." FIU Digital Commons, 2011. http://digitalcommons.fiu.edu/etd/385.
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The major objectives of this dissertation were to develop optimal spatial techniques to model the spatial-temporal changes of the lake sediments and their nutrients from 1988 to 2006, and evaluate the impacts of the hurricanes occurred during 1998-2006.
Mud zone reduced about 10.5% from 1988 to 1998, and increased about 6.2% from 1998 to 2006. Mud areas, volumes and weight were calculated using validated Kriging models. From 1988 to 1998, mud thicknesses increased up to 26 cm in the central lake area. The mud area and volume decreased about 13.78% and 10.26%, respectively. From 1998 to 2006, mud depths declined by up to 41 cm in the central lake area, mud volume reduced about 27%. Mud weight increased up to 29.32% from 1988 to 1998, but reduced over 20% from 1998 to 2006. The reduction of mud sediments is likely due to re-suspension and redistribution by waves and currents produced by large storm events, particularly Hurricanes Frances and Jeanne in 2004 and Wilma in 2005.
Regression, kriging, geographically weighted regression (GWR) and Regression-Kriging models have been calibrated and validated for the spatial analysis of the sediments TP and TN of the lake. GWR models provide the most accurate predictions for TP and TN based on model performance and error analysis. TP values declined from an average of 651 to 593 mg/kg from 1998 to 2006, especially in the lake’s western and southern regions. From 1988 to 1998, TP declined in the northern and southern areas, and increased in the central-western part of the lake. The TP weights increased about 37.99% - 43.68% from 1988 to 1998 and decreased about 29.72% - 34.42% from 1998 to 2006.
From 1988 to 1998, TN decreased in most areas, especially in the northern and southern lake regions; western littoral zone had the biggest increase, up to 40,000 mg/kg. From 1998 to 2006, TN declined from an average of 9,363 to 8,926 mg/kg, especially in the central and southern regions. The biggest increases occurred in the northern lake and southern edge areas. TN weights increased about 15%-16.2% from 1988 to 1998, and decreased about 7%-11% from 1998 to 2006.
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Cronk, Julie K. "Spatial water quality and aquatic metabolism in four newly constructed freshwater riparian wetlands /." The Ohio State University, 1992. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487777901660325.
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Müller, Roger André. "Lake Dissolved Organic Matter Quantity and Quality : Variability across Temporal and Spatial Scales." Doctoral thesis, Uppsala universitet, Limnologi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-242335.
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Surface waters receive large amounts of dissolved organic matter (DOM) via runoff from land. The DOM is rich in organic carbon that serves as an energy source for the aquatic biota. During uptake of this energy, aquatic organisms mineralize organic carbon. The resulting inorganic carbon is partially released to the atmosphere as carbon dioxide and methane that are greenhouse gases, and which are of concern for the ongoing global warming. The rate at which organic carbon is mineralized depends strongly on DOM quantity and quality that vary with respect to both time and space. In this thesis, DOM quantity and quality were addressed using spectroscopic methods that build on the absorptive and fluorescent properties of chromophoric DOM (CDOM). New techniques to measure CDOM absorption and fluorescence were applied and further developed that allowed us to present novel CDOM variability patterns. Addressing the lake-rich Scandinavian landscape, strong focus was placed on water retention by lakes that tightly links to lake DOM quantity and quality. An analysis of 24,742 lakes from seven large Swedish river systems indicated that the majority of lakes in Sweden exchange their water within one year. From headwaters to the Sea, summed lake volumes in the catchments of lakes were found to increase at rates comparable to discharge, which indicated effective water renewal along flow. A strong relationship between lake water retention and CDOM was apparent and further investigated based on samples from a lake district to a regional scale. Results from in situ high-frequency monitoring of CDOM absorption in a eutrophic humic lake showed intra-annual variability patterns known from oligotrophic lake systems. The patterns for CDOM absorption contrasted results obtained for synchronously measured partial pressures of carbon dioxide that showed diurnal signals. Measurements of CDOM fluorescence and DOC concentrations indicated lake-internal DOM production. A comparison of these results with results from addressing 560 lakes distributed across Sweden, showed that a well-calibrated CDOM fluorescence measurement captures signals from lake-internal DOM production. I conclude that improved CDOM fluorescence measurements are promising to address lake-internally produced DOM.
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Fournier, John, and Arthur Sullivan. "Addition of Video to Telemetry Tracking System Upgrades Spatial Data to Radar-Quality." International Foundation for Telemetering, 1988. http://hdl.handle.net/10150/615033.
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International Telemetering Conference Proceedings / October 17-20, 1988 / Riviera Hotel, Las Vegas, NevadaTraditionally telemetry trackers have not been required to provide precision space-position data. Such data, when needed, has required expensive radar or optical support. Currently, an increasing number of flight test operations have need of precision spatial data, in conjunction with telemetry data reception, in areas where no radar or optical support is available. To meet this need, EMP has carefully combined existing technologies to upgrade the angle output data accuracy of telemetry trackers to the level expected of precision radars. A TV Boresight Camera and video Tracking Error Detector combined with the EMP Model ACU-6 microprocessor-based Antenna Control Unit provide the means to automatically measure and store all of the systematic bias errors inherent in a telemetry tracking system. The resulting error model is used to provide real-time-data-correction for each error parameter. Video tracking provides correction for dynamic tracking errors in real time. Calibrations utilize boresight and stellar targets. The design goal to reduce dynamic angle data error to <10 arc seconds, RMS, appears to be reasonable.
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Rapp, Joshua. "Spatial analysis of catchment characteristics in relation to water quality using remote sensing and geographic information systems /." Spatial analysis of catchment characteristics in relation to water quality using remote sensing and geographic information systemsRead the abstract of the thesis, 2003. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17469.pdf.
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Ren, Lanbin. "Park-above-Parking Downtown: A Spatial-Based Investigation." Thesis, University of Oregon, 2013. http://hdl.handle.net/1794/12958.
Full textAbstract:
Parking and parks are both crucial to downtown economic development. Many studies have shown that downtown parks significantly contribute to increasing surrounding property values and attract residents, businesses and investment. Meanwhile, sufficient available parking promotes accessibility to downtown that also contributes to increasing tax revenue for local government. However, both downtown parks and parking raise problems. Many downtown parks have become places for drug dealing, shooting and vandalism since the decline of downtowns in the 1960s. At the same time, residents and visitors alike oftentimes complain about the lack of parking while in fact parking spaces occupy a large amount of land in downtown. Parks and parking also compete for space in downtown where land value is higher than the rest of the city. To address these issues, several cities have begun to address the relationship between parking and parks by placing them in one place: park on the ground level and parking underneath. This typology is defined as a park-above-parking project in this research. However, this phenomenon has received little scholarly attention. To justify the existing situation of park-above-parking and to contemplate future projects, this research provides a spatial-based investigation to discuss the empirical relationships between social cultural and political-economic impacts, design quality, and related policy-making processes based on four cases. A longitudinal study that traces the direct and indirect impacts of park-above-parking projects was conducted for each case through both qualitative and quantitative methods. This research provides a set of methods for the measurement of contributions of park-above-parking downtown, connections between park quality, social use and adjacent economic growth, recommendations for land use planning policy-making and guidelines for the design of park-above-parking projects.
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English, April Renee Atkinson Samuel F. "Stream water quality corridor assessment and management using spatial analysis techniques introduction, evaluation and implementation of the WQCM model /." [Denton, Tex.] : University of North Texas, 2007. http://digital.library.unt.edu/permalink/meta-dc-3976.
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Illerstam, Fredrik. "Quality Assurance of the Spatial Accuracy of Large Field of View Magnetic Resonance Imaging." Thesis, KTH, Skolan för teknik och hälsa (STH), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-148815.
Full textAbstract:
In todays Radiotherapy Treatment Planning, RTP, it is common to use Computed Tomography, CT, together with Magnetic Resonance Imaging, MRI, where CT provides electron density information and a geometrical reference, and where MRI provides superior soft tissue contrast. To sim- plify the workflow and improve treatment accuracy, research groups have demonstrated how to exclude CT and use a MRI-only approach. In this thesis, a method for spatial distortion analysis, ultimately enabling quality assurance, QA, of the spatial accuracy of MRI, was defined, tested and evaluated. A phantom was built to cover the entire clinical Field Of View, FOV, and 6mm-diameter fluid filled paintball markers were placed in a well-defined geometrical pattern within the phantom, and used as positive contrast. The phantom was imaged with a 3D Fast Gradient Echo sequence and a 3D Fast Spin Echo sequence. The markers were identified in the image data by a MATLAB-algorithm, and the location of the center of mass was calculated for each marker and compared to a theoretical reference. The location error was defined as the spatial distortion - a measurement of the spatial accuracy. Imaging parameters were altered and the effect on the spatial accuracy was analyzed. The spatial distortions were successfully measured within the entire (maximal) clinical FOV. It was shown that high readout bandwidth reduced distortions in the frequency encoding direction. These distortions could thus be attributed to B0-inhomogeneities. It was also determined that increasing the readout bandwidth to the maximum value reduced the maximum distortions in the frequency encoding direction to the same level as the maximum distortions in the other two phase-encoding directions of the 3D acquisitions. The voxel size had a very small effect on the spatial accuracy, enabling large voxelsize to be used when imaging the phantom, to decrease the scan time. The method was deemed capable of serving as a basis for QA of the spatial accuracy of large FOV MRI, which is needed in future MRI-only RTP approaches.