Developing tools and models for evaluating geospatial data integration of official and VGI data sources

PhD ThesisIn recent years, systems have been developed which enable users to produce, share and update information on the web effectively and freely as User Generated Content (UGC) data (including Volunteered Geographic Information (VGI)). Data quality assessment is a major concern for supporting the accurate and efficient spatial data integration required if VGI is to be used alongside official, formal, usually governmental datasets. This thesis aims to develop tools and models for the purpose of assessing such integration possibilities. Initially, in order to undertake this task, geometrical similarity of formal and informal data was examined. Geometrical analyses were performed by developing specific programme interfaces to assess the positional, linear and polygon shape similarity among reference field survey data (FS); official datasets such as data from Ordnance Survey (OS), UK and General Directorate for Survey (GDS), Iraq agencies; and VGI information such as OpenStreetMap (OSM) datasets. A discussion of the design and implementation of these tools and interfaces is presented. A methodology has been developed to assess such positional and shape similarity by applying different metrics and standard indices such as the National Standard for Spatial Data Accuracy (NSSDA) for positional quality; techniques such as buffering overlays for linear similarity; and application of moments invariant for polygon shape similarity evaluations. The results suggested that difficulties exist for any geometrical integration of OSM data with both bench mark FS and formal datasets, but that formal data is very close to reference datasets. An investigation was carried out into contributing factors such as data sources, feature types and number of data collectors that may affect the geometrical quality of OSM data and consequently affect the integration process of OSM datasets with FS, OS and GDS. Factorial designs were undertaken in this study in order to develop and implement an experiment to discover the effect of these factors individually and the interaction between each of them. The analysis found that data source is the most significant factor that affects the geometrical quality of OSM datasets, and that there are interactions among all these factors at different levels of interaction. This work also investigated the possibility of integrating feature classification of official datasets such as data from OS and GDS geospatial data agencies, and informal datasets such as OSM information. In this context, two different models were developed. The first set of analysis included the evaluation of semantic integration of corresponding feature classifications of compared datasets. The second model was concerned with assessing the ability of XML schema matching of feature classifications of tested datasets. This initially involved a tokenization process in order to split up into single words classifications that were composed of multiple words. Subsequently, encoding feature classifications as XML schema trees was undertaken. The semantic similarity, data type similarity and structural similarity were measured between the nodes of compared schema trees. Once these three similarities had been computed, a weighted combination technique has been adopted in order to obtain the overall similarity. The findings of both sets of analysis were not encouraging as far as the possibility of effectively integrating feature classifications of VGI datasets, such as OSM information, and formal datasets, such as OS and GDS datasets, is concerned.Ministry of Higher Education and Scientific Research, Republic of Iraq

Transportation linear referencing toolboxes : a 'reflective practitioner's' design approach

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 2000."September, 2000."Includes bibliographical references (p. 395-407).Seventy percent of the data of a typical transportation agency (e.g., bridges, accidents, etc.) has location as a primary reference. A Linear Referencing System (LRS) is the main way of identifying the location of this data and providing a storage key for it in a database. LRS is based on a one-dimensional offset on a predefined network. In theory, it is one of the simplest spatial cases. In reality, it can be spatially and analytically quite complex. LRS to quite recent date has been little formally researched. That research which has occurred has been the construction of large and comprehensive conceptual data models. This thesis is not primarily aimed at new "tool building research". The existing models have been based to only a limited extent on a fuller analysis of the nature of transportation and spatial data; they have not considered relevant field and wider methodological concerns (i.e., they followed a "model-driven" approach). The goal here is to create a more appropriate foundation and base from which LRS tools may be most appropriately built (i.e., a 'field-driven" approach). A "practitioners perspective" view of LRS was sought. Such a more holistic understanding was sought through the adoption of a "layered methodology" of research that involved gaining the perspectives of a variety of disciplinary viewpoints. This research framework was developed especially for this thesis based on the ideas and work of Schon and Reich. The approach involved in short a desk exercise in fundamental consideration of the nature of LRS, a deeper, cross-field synthesis and literature research, four in-depth state DOT LRS case studies, a panel of transportation field experts, a panel of national data model experts, and a limited object-orientated modeling exercise. The conclusion reached is that while LRS in the simple case can be modeled in general forms, it is also an "exception-driven" field. Thus, a "toolkit approach" may be more appropriate for LRS. It is inferred that this may hold for other similar application areas in transportation and planning. Further research would further develop the holistic layered methodology adopted here and further define the proposed LRS transportation application toolboxes.by Simon Lewis.Ph.D

Developing a traffic control device maintenance management system interfacing with Gis

Roadway systems contain a wide variety of spatially distributed physical features which require installation, maintenance and replacement. These features include traffic control devices such as signs, signals, pavement markings and streetlights. Several technologies exist that can be utilized by the transportation sector to improve program management of a number of these features. Geographic Information Systems (GIS) technology provides a powerful environment for the capture, storage, retrieval, analysis, and display of spatial (locationally defined) data. A need exists to provide an inventory of the transportation physical plant to interface with a work management system. Information pertaining to the number and condition of such features is required for planning, operating, maintaining, managing and budgeting needs. This thesis summarizes the development of a user-friendly, computerized process to establish a graphical interface between a roadway inventory database and GIS; Evaluation of existing technologies and a survey of current literature will provide a basis for the design of a Traffic Control Device Maintenance Management System. This system will provide a consistent form of technology transfer on a common platform. This system will manage resources by integrating work-orders and the database. The system will utilize GIS technology to integrate a work-order system and a database reporting system for resource management. The work order interface capabilities will include maintenance work-order management, project cost and progress tracking, and program planning and policy analysis; The key is to develop a user-friendly system useful to both the field-level installation crews and planning-level management. A case study in Clark County, Nevada, will be used to evaluate alternative methods of collecting and data on traffic control devices and to illustrate the development of a GIS-based management system. This system is intended to improve the efficiency and effectiveness of operational practices as well as serve as a vital decision support tool for planning and management

Fabricate

Bringing together pioneers in design and making within architecture, construction, engineering, manufacturing, materials technology and computation, Fabricate is a triennial international conference, now in its third year (ICD, University of Stuttgart, April 2017). Each year it produces a supporting publication, to date the only one of its kind specialising in Digital Fabrication. The 2017 edition features 32 illustrated articles on built projects and works in progress from academia and practice, including contributions from leading practices such as Foster + Partners, Zaha Hadid Architects, Arup, and Ron Arad, and from world-renowned institutions including ICD Stuttgart, Harvard, Yale, MIT, Princeton University, The Bartlett School of Architecture (UCL) and the Architectural Association

Data integration for urban transport planning

Urban transport planning aims at balancing conflicting challenges by promoting more efficient transport systems while reducing negative impacts. The availability of better and more reliable data has not only stimulated new planning methodologies, but also created challenges for efficient data management and data integration. The major focus of this study is to improve methodologies for representing and integrating multi-source and multi-format urban transport data. This research approaches the issue of data integration based on the classification of urban transport data both from a functional and a representational perspective. The functional perspective considers characteristics of the urban transport system and planning requirements, and categorises data into supply, demand, performance and impact. The representational perspective considers transport data in terms of their spatial and non-spatial characteristics that are important for data representation. These two perspectives correspond to institutional and methodological data integration respectively, and are the foundation of transport data integration. This research is based on the city of Wuhan in China. The methodological issues of transport data integration are based on the representational perspective. A framework for data integration has been put forward, in which spatial data are classified as point, linear and areal types, and the non-spatial data are sorted out as values and temporal attributes. This research has respectively probed the integration of point, linear and areal transport data within a GIS environment. The locations of socio-economic activities are point-type data that need to be spatially referenced. A location referencing process requires a referencing base, source address units and referencing methods. The referencing base consists of such spatial features as streets, street addresses, points of interest and publicly known zones. These referencing bases have different levels of spatial preciseness and have to be kept in a hierarchy. Source addresses in Chinese cities are usually written as one sentence, which has to be divided into address units for automatic geo-coding. As it is difficult to separate from the sentences, the address units have to be clearly identified in survey forms. Depending on the types of address units, the referencing process makes use of either semantic name matching or address matching to link source addresses to features in the referencing base. The name-based and road-based referencing schemes constitute a comprehensive location referencing framework that is applicable to Chinese cities. The relationship between two sets of linear features can be identified with spatial overlay in the case of independent representation, or with internal linkage in a dependent representation. The bus line is such a feature that runs on the street network and can be dependently referenced by streets. In the heavily bus-oriented city of Wuhan, bus lines constitute a large public transit network that is important to transport planning and management. This research has extended conventional bus line representation to a more detailed level. Each bus line has been differentiated as two directional routes that are defined separately with reference to the street network. Accordingly, individual route stops are also represented in the database. These stop sites are spatial features with geometry that are linked to street segments and bus routes by linear location referencing methods. A data model linking base street network, bus lines and routes, line and route stops, and other bus operations data has been constructed. The benefits of the detailed model have been demonstrated in several transport applications. Zonal data transitions include three types of operations, i.e. aggregation, areal interpolation and disaggregation. This study focuses on disaggregating data from larger zones to smaller zones. In the context of Wuhan, zonal data disaggregation involves the allocation of statistical data from statistical units to smaller parcels. Given the availability of land use data, a weighted approach reflecting spatial variations has been applied in the disaggregation process. Two technical processes for disaggregation have been examined. Weighted area-weighting (WAW) is an adaptation of the classic area-weighting method, and Monte Carlo simulation (MC) is a stochastic process based on a raster data model. The MC outcome is more convenient for subsequent re-aggregation, and is also directly available for micro-simulation. An important contribution arising from this zonal integration study is that two standardised disaggregation tools have been developed within a GIS environment. The research has also explored the institutional aspect of data integration. The findings of this study show that there is generally a good institutional transport structure in the city of Wuhan and that there is also a growing awareness of using information technology. Professional cooperation exists among transport organisations, but not yet at a level for data sharing. An integrated data support framework requires data sharing. In such a framework, it should be possible to know where to get data for specific transport studies, or which kind of research an institution supports

Wet spinning fibres from imogolite and carbon nanotubes

As 1D materials with high intrinsic strength and stiffness, nanotubes are promising building blocks for the next generation of fibres in structural composites. This thesis explores wet spinning techniques for assembling macroscale fibres from nanotubes. Carbon nanotubes (CNTs) are an obvious target material to compete with commercial carbon fibres, based on their excellent intrinsic mechanical properties and low density, alongside high electrical conductivity for multifunctional applications. However, studying CNT materials is challenging due to their intrinsically high optical absorbance and low X-ray scattering cross-section, as well as the dispersity of typical feedstocks in both size and helicity. Imogolite nanotubes (INTs) are an inorganic analogue that offers an opportunity to observe the assembly of nanotubes into fibres using both polarised optical microscopy (POM) and X-ray scattering (XRS). In contrast to CNTs, INTs are optically transparent and can be synthesised at low temperature to provide feedstocks that are uniform in structure and diameter. In this work, the first known pure INT fibres have been produced and used to understand the nanotube wet spinning process. In situ POM demonstrated that in cylindrical spinnerets the spinning dope undergoes plug flow with inhomogeneous alignment due to the shear thinning nature of the solutions. The use of a tapered spinneret enables good alignment of the spinning dope, due to the induced extensional flow. Using this information, CNT fibres were spun from reduced CNT solutions and the wet spinning process was refined using a combination of in situ observation and statistical experimental design. The dissolution of negatively-charged CNTs (nanotubides) was examined both from a theoretical perspective and experimentally to identify the key conditions required to obtain homogeneous spinning dopes. The optimal dissolution depended upon both degree of charging and effective stirring. The optimised CNT dope was then wet spun using a variety of coagulating systems to identify the accessible process window and optimum parameters for spinning from these reactive charged solutions. Further improvement of the CNT fibre properties is predicted to arise through the use of higher aspect ratio CNT feedstocks. However, challenges still remain in the liquid phase processing of longer CNTs. In order to create CNT fibres competitive with commercial CFs, future research should focus on how to process these longer feedstocks following the guidance in this thesis.Open Acces

Longing to Return and Spaces of Belonging. Iraqis’ Narratives in Helsinki and Rome

Siirretty Doriast