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  • Open Access
    Authors: 
    Rachel Bezner Kerr;
    Publisher: Scholarship@Western
    Country: Canada

    This article examines household food security in the Ekwendeni region of northern Malawi using the concept of entitlements, set within a broader world historical framework. The bargaining approach to household gender relations is critiqued through an examination of the data. Historical relations created a gendered experience of food security in northern Malawi. Qualitative research carried out in the Ekwendeni region indicates that women have fewer entitlements within the household, at least in part due to the modified patrilineal system of the Tumbuka-speaking people with Ngoni heritage in the region. They have a higher workload in terms of household reproduction as well as agricultural and market activities. Women are responsible for caring for sick relatives within and beyond the household, which affects household food security. Wives are less likely to receive support for kin in the form of seeds, cash, land or food, in comparison to husbands, who in turn do not always give these resources to the household. Women do not have much decision-making power over major production issues. There is evidence for high levels of spousal abuse, as well as excessive use of alcohol by husbands, which also affects household food security. Wives' unequal position is thus due to a lack of entitlements, such as land, access to employment, support from kin and the state. Some differences between this area of northern Malawi and other studies from central and southern Malawi are due to the different entitlements, particularly control over land and income, which speaks to the enduring implications of different lineage systems in the region. Food security is thus affected by women's unequal access to entitlements in northern Malawi, set within a world historical framework, which is essential for understanding the broader causes of food insecurity.

  • Open Access English
    Authors: 
    Hilland, Rainer V.J.;
    Publisher: Scholarship@Western
    Country: Canada

    Surface temperature plays a key role in many micro-scale urban processes. Walls comprise a significant percentage of the urban surface, yet are under-represented by many methods of thermal remote sensing and not considered in detail by micro-scale surface temperature mod- els. This thesis presents a novel method of mobile thermal observation performed in urban street canyons in London, ON that uses a thermal imager as well as a visual spectrum camera to provide dense spatial and temporal resolution of micro-scale wall temperature distributions. Images are manually classified by a series of nominal variables and the resulting data set discusses the influence of micro-scale wall geometry on shading patterns and temperature distributions. Results show that micro-scale geometry both cools and heats walls, that small amounts of geo- metric complexity significantly affect temperature distributions, and that micro-scale structure may warm facets at night. Implications for temperature and wind applications are discussed.

  • Open Access
    Authors: 
    Weis, Tony;
    Publisher: Scholarship@Western
    Country: Canada

    The productivity of industrial capitalist agriculture is central to dominant development narratives. It is also highly unstable, with intractable biophysical problems created in the substitution of labour, skill and knowledge with technology, and overridden with unsustainable ‘technological fixes’ and masked by a host of externalized costs. Relatively cheap oil is central to this, effectively subsidizing the low-priced industrial grains and oilseeds on which global food security has come to hinge. However, the chronic biophysical contradictions of industrial capitalist agriculture are accelerating, at the same time as the surge in biofuels has augmented the still-rising demand of livestock feed to embolden industrial producers. A period of acute and ominously regressive food price volatility looms in the short term, with more ruinous outcomes ahead. But this might also widen openings for rebuilding biodiverse food systems and remaking and valorizing agricultural work, which will involve rethinking agriculture's place in conceptions of development and modernity.

  • Open Access
    Authors: 
    Young, Andrew D;
    Publisher: Scholarship@Western
    Country: Canada

    Mallards (Anas platyrhynchos; n = 339) and Blue-winged Teal (A. discors; n = 213; hereafter teal) were collected from western (1986) and eastern (1987) Saskatchewan grassland and parkland habitats during egg formation to examine body composition, diets and digestive organ size with respect to hypotheses concerning habitat (this study) and the use of body fat (Drobney 1980; Rohwer 1986a; Ankney and Afton 1988). I predicted that ducks breeding in grassland habitats would rely upon more stored body nutrients, whereas parkland ducks would rely more upon dietary nutrients to form eggs. Body composition including fat, protein and mineral reserves and digestive organ sizes and diets (used to index food consumption) did not differ due to habitat in Mallards or teal. Female Mallards breeding at the western grassland site used 60% less body fat during clutch formation compared with females from other sites. Two potential explanations for this are: (A) food resources at this site were annually most predictable so less fat is needed as insurance against bad years or (B) females breeding at this site were unable to build up sufficient fat reserves during spring migration because they were subordinates and were excluded from food resources.;Body protein of female Mallards and teal did not decline as predicted by the protein-limitation hypothesis (Drobney 1980). Body fat declined seasonally among western female Mallards, eastern male Mallards and male teal just initiating RFG, and remained constant among all other samples. These data do not support Rohwer's (1986a) migration-uncertainty hypothesis because arrival in Mallards and teal is likely not synchronous. Agricultural grains (hereafter grains) and seeds were important components in the diet of breeding mallards whereas aquatic invertebrates, especially gastropods and insects, dominated the diet of teal. I argue that because grains were recently introduced, and energy extraction from seeds is likely inefficient, the diet of Mallards and teal support the lipid-limitation hypothesis (Ankney and Afton 1988), that reliance on stored body fat supplements a lipid poor diet.;Body fat acquired prior to arrival, contributed 41% of clutch fat requirements in female teal and 60%-150% in female Mallards. Male Mallards used stored body fat during the egg formation period whereas male teal used fat only prior to this period. Female Mallards from three of four collection sites used stored minerals to supplement dietary calcium intake, ca. 11-13 grams for a 10 egg clutch, enough for about 1 egg, whereas female teal relied upon dietary sources of calcium.

  • Open Access English
    Authors: 
    Shankar, Bhairavi;
    Publisher: Scholarship@Western
    Country: Canada

    Hypervelocity collisions of asteroids onto planetary bodies have catastrophic effects on the target rocks through the process of shock metamorphism. The resulting features, impact craters, are circular depressions with a sharp rim surrounded by an ejecta blanket of variably shocked rocks. With increasing impact energy, the inner crater cavity can preserve complex morphologies including terraced walls, central uplifts, and melted rocks. The lack of erosion due to the absence of water or an atmosphere makes the Moon the perfect target to study impact crater processes, in particular the distribution of highly shocked materials within impact craters of different sizes. This study focuses on the characterization and distribution of highly shocked impact melt deposits using multispectral satellite datasets around three complex craters on the farside of the Moon. The study sites have varying morphologies of central uplifts on the crater floor: 1) the 81 km Olcott crater has a cluster of peak hills; 2) Kovalevskaya crater is a 113 km diameter complex crater with a central peak; and 3) Schrodinger basin has a central peak ring. Models propose that the collapse of crater walls and central uplifts during the final stages of crater formation determine where much of the melt rich rocks are eventually emplaced. The results of this study indicate that for increasing crater sizes, the volume of melt-rich rocks generated also increases – at rates greater than model estimates. Impact melt deposits are emplaced beyond the crater rims at each of the sites and preserve a range of morphologies, including melt veneers, melt sheet, and ponded deposits. The regional and local topography, together with crater modification processes greatly affect where the impact melts are finally emplaced. The compositional analyses of the farside crust, using multispectral reflectance spectroscopy in the UV-VIS-NIR range, indicates that there is increasing evidence of highly mafic compositions (i.e., rocks rich in high-Ca pyroxene, olivine, spinel) intercalated within the original crustal highlands (rocks rich in plagioclase feldspar, and low-Ca pyroxenes) on the lunar farside, proving that the lunar farside is a far more geologically complicated terrain than originally assumed.

  • Open Access
    Authors: 
    Prannay R. Malu; Utkarsh S. Sharma; Joshua M. Pearce;
    Publisher: Elsevier BV
    Countries: France, Canada

    Abstract Aggressive growth of land-based solar photovoltaic (PV) farms can create a land use conflict with agricultural production. Fortunately, this issue can be resolved using the concept of agrivoltaics, which is co-development of land area for both solar PV and agriculture. To investigate and quantify PV generation potential, without significantly harming agriculture output, this study explores the viability of agrivoltaic farms deployment on existing grape farms in India. Considering the shade tolerance of grapes, an techno-economicanalysis is run for the installation of PV systems in the area available between the trellises on a grape farm. The electrical energy generation potential is determined per unit area and economic benefits for the cultivators is quantified over a number of design options. The results show the economic value of the grape farms deploying the proposed agrivoltaic systems may increase more than 15 times as compared to conventional farming, while maintaining approximately the same grape production. If this dual use of land is implemented nationwide, it can make a significant impact by generating over 16,000 GWh electricity, which has the potential of meeting the energy demands of more than 15 million people. In addition, grape-based agrivoltaics can be implemented in rural areas to enable village electrification.

  • Open Access
    Authors: 
    Jennifer L. Braid; Daniel Riley; Joshua M. Pearce; Laurie Burnham;
    Publisher: Scholarship@Western
    Country: Canada

    Modeling and predicting snow-related power loss is important to economic calculations, load management and system optimization for all scales of photovoltaic (PV) power plants. This paper describes a new method for measuring snow shedding from fielded modules and also describes the application of this method to a commercial scale PV power plant in Vermont with two subsystems, one with modules in portrait orientation and the other in landscape. The method relies on time-series images taken at 5 minute intervals to capture the dynamics of module-level snow accumulation and shedding. Module-level images extracted from the full-field view are binarized into snow and clear areas, allowing for the quantification of percentage snow coverage, estimation of resulting module power output, and temporal changes in snow coverage. Preliminary data from the Vermont case study suggests that framed modules in portrait orientation outperform their framed counterparts in landscape orientation by as much as 24% energy yield during a single shedding event. While these data reflect a single event, and do not capture snow shedding behavior across diverse temperature and other climatic conditions, the study nonetheless demonstrates that 1) module orientation and position in the array influence shedding patterns; 2) the start of power production and bypass diode activation differ for portrait and landscape module orientations at similar percentages and orientations of snow coverage; and 3) system design is an important factor in snow mitigation and increased system efficiency in snowy climates.

  • Publication . Presentation . 2019
    Open Access
    Authors: 
    Belton, Tom;
    Publisher: Scholarship@Western
    Country: Canada
  • Open Access English
    Authors: 
    Delavar, Mohammad;
    Publisher: Scholarship@Western
    Country: Canada

    The effective adoption and implementation of Building Information Modeling (BIM) is still challenging for the construction industry. However, studies and reports show a significant increase in the rate of BIM implementation and adoption in mainstream construction activities over the last five years. In contrast, Pre-Engineered Building (PEB) construction, a specialized construction system which provides a very efficient approach for construction of primarily industrial buildings, has not seen the same uptake in BIM implementation and adoption. The thesis reviews the benefits and the main applications of BIM for the PEB industry as well as challenges of its practical implementation. To facilitate the implementation of BIM in the PEB industry, a BIM framework is adapted from Pre-fabrication (Pre-fab) industry and new workflows, process maps, and data-exchange strategies are developed. As the PEB industry traditionally makes significant use of automation in its design and fabrication process, accordingly this work investigates the technical challenges of incorporating automation into the proposed BIM process. Two new BIM concepts, “Planar Concept” and “Floating LOD”, are then developed and implemented as a solution to these challenges. To define the proper input/output criteria for automated BIM design processes, a numerical study was performed to identify an “Optimum LOD”. A software implementation embodying the research outcomes was developed to illustrate the feasibility of the results. Its step-by-step deployment is analyzed and discussed using an example industry PEB design project. Further, the impact of this work is extended by integrating the developed BIM framework and automated design process with wind engineering design activities and tools and procurement systems. The study concludes that the deployment of the proposed BIM framework could significantly address existing issues in project design through to operation processes found in the PEB industry. Also, the results indicate the developed concepts have the potential for supporting the application of automation in the other sectors of the general construction industry. This thesis is written using the "Integrated Article" format and includes various complementary studies.

  • Open Access English
    Authors: 
    Zeng, Chuiqing;
    Publisher: Scholarship@Western
    Country: Canada

    The two-dimensional (2D) footprints and three-dimensional (3D) structures of buildings are of great importance to city planning, natural disaster management, and virtual environmental simulation. As traditional manual methodologies for collecting 2D and 3D building information are often both time consuming and costly, automated methods are required for efficient large area mapping. It is challenging to extract building information from remotely sensed data, considering the complex nature of urban environments and their associated intricate building structures. Most 2D evaluation methods are focused on classification accuracy, while other dimensions of extraction accuracy are ignored. To assess 2D building extraction methods, a multi-criteria evaluation system has been designed. The proposed system consists of matched rate, shape similarity, and positional accuracy. Experimentation with four methods demonstrates that the proposed multi-criteria system is more comprehensive and effective, in comparison with traditional accuracy assessment metrics. Building height is critical for building 3D structure extraction. As data sources for height estimation, digital surface models (DSMs) that are derived from stereo images using existing software typically provide low accuracy results in terms of rooftop elevations. Therefore, a new image matching method is proposed by adding building footprint maps as constraints. Validation demonstrates that the proposed matching method can estimate building rooftop elevation with one third of the error encountered when using current commercial software. With an ideal input DSM, building height can be estimated by the elevation contrast inside and outside a building footprint. However, occlusions and shadows cause indistinct building edges in the DSMs generated from stereo images. Therefore, a “building-ground elevation difference model” (EDM) has been designed, which describes the trend of the elevation difference between a building and its neighbours, in order to find elevation values at bare ground. Experiments using this novel approach report that estimated building height with 1.5m residual, which out-performs conventional filtering methods. Finally, 3D buildings are digitally reconstructed and evaluated. Current 3D evaluation methods did not present the difference between 2D and 3D evaluation methods well; traditionally, wall accuracy is ignored. To address these problems, this thesis designs an evaluation system with three components: volume, surface, and point. As such, the resultant multi-criteria system provides an improved evaluation method for building reconstruction.

search
Include:
The following results are related to Canada. Are you interested to view more results? Visit OpenAIRE - Explore.
293 Research products, page 1 of 30
  • Open Access
    Authors: 
    Rachel Bezner Kerr;
    Publisher: Scholarship@Western
    Country: Canada

    This article examines household food security in the Ekwendeni region of northern Malawi using the concept of entitlements, set within a broader world historical framework. The bargaining approach to household gender relations is critiqued through an examination of the data. Historical relations created a gendered experience of food security in northern Malawi. Qualitative research carried out in the Ekwendeni region indicates that women have fewer entitlements within the household, at least in part due to the modified patrilineal system of the Tumbuka-speaking people with Ngoni heritage in the region. They have a higher workload in terms of household reproduction as well as agricultural and market activities. Women are responsible for caring for sick relatives within and beyond the household, which affects household food security. Wives are less likely to receive support for kin in the form of seeds, cash, land or food, in comparison to husbands, who in turn do not always give these resources to the household. Women do not have much decision-making power over major production issues. There is evidence for high levels of spousal abuse, as well as excessive use of alcohol by husbands, which also affects household food security. Wives' unequal position is thus due to a lack of entitlements, such as land, access to employment, support from kin and the state. Some differences between this area of northern Malawi and other studies from central and southern Malawi are due to the different entitlements, particularly control over land and income, which speaks to the enduring implications of different lineage systems in the region. Food security is thus affected by women's unequal access to entitlements in northern Malawi, set within a world historical framework, which is essential for understanding the broader causes of food insecurity.

  • Open Access English
    Authors: 
    Hilland, Rainer V.J.;
    Publisher: Scholarship@Western
    Country: Canada

    Surface temperature plays a key role in many micro-scale urban processes. Walls comprise a significant percentage of the urban surface, yet are under-represented by many methods of thermal remote sensing and not considered in detail by micro-scale surface temperature mod- els. This thesis presents a novel method of mobile thermal observation performed in urban street canyons in London, ON that uses a thermal imager as well as a visual spectrum camera to provide dense spatial and temporal resolution of micro-scale wall temperature distributions. Images are manually classified by a series of nominal variables and the resulting data set discusses the influence of micro-scale wall geometry on shading patterns and temperature distributions. Results show that micro-scale geometry both cools and heats walls, that small amounts of geo- metric complexity significantly affect temperature distributions, and that micro-scale structure may warm facets at night. Implications for temperature and wind applications are discussed.

  • Open Access
    Authors: 
    Weis, Tony;
    Publisher: Scholarship@Western
    Country: Canada

    The productivity of industrial capitalist agriculture is central to dominant development narratives. It is also highly unstable, with intractable biophysical problems created in the substitution of labour, skill and knowledge with technology, and overridden with unsustainable ‘technological fixes’ and masked by a host of externalized costs. Relatively cheap oil is central to this, effectively subsidizing the low-priced industrial grains and oilseeds on which global food security has come to hinge. However, the chronic biophysical contradictions of industrial capitalist agriculture are accelerating, at the same time as the surge in biofuels has augmented the still-rising demand of livestock feed to embolden industrial producers. A period of acute and ominously regressive food price volatility looms in the short term, with more ruinous outcomes ahead. But this might also widen openings for rebuilding biodiverse food systems and remaking and valorizing agricultural work, which will involve rethinking agriculture's place in conceptions of development and modernity.

  • Open Access
    Authors: 
    Young, Andrew D;
    Publisher: Scholarship@Western
    Country: Canada

    Mallards (Anas platyrhynchos; n = 339) and Blue-winged Teal (A. discors; n = 213; hereafter teal) were collected from western (1986) and eastern (1987) Saskatchewan grassland and parkland habitats during egg formation to examine body composition, diets and digestive organ size with respect to hypotheses concerning habitat (this study) and the use of body fat (Drobney 1980; Rohwer 1986a; Ankney and Afton 1988). I predicted that ducks breeding in grassland habitats would rely upon more stored body nutrients, whereas parkland ducks would rely more upon dietary nutrients to form eggs. Body composition including fat, protein and mineral reserves and digestive organ sizes and diets (used to index food consumption) did not differ due to habitat in Mallards or teal. Female Mallards breeding at the western grassland site used 60% less body fat during clutch formation compared with females from other sites. Two potential explanations for this are: (A) food resources at this site were annually most predictable so less fat is needed as insurance against bad years or (B) females breeding at this site were unable to build up sufficient fat reserves during spring migration because they were subordinates and were excluded from food resources.;Body protein of female Mallards and teal did not decline as predicted by the protein-limitation hypothesis (Drobney 1980). Body fat declined seasonally among western female Mallards, eastern male Mallards and male teal just initiating RFG, and remained constant among all other samples. These data do not support Rohwer's (1986a) migration-uncertainty hypothesis because arrival in Mallards and teal is likely not synchronous. Agricultural grains (hereafter grains) and seeds were important components in the diet of breeding mallards whereas aquatic invertebrates, especially gastropods and insects, dominated the diet of teal. I argue that because grains were recently introduced, and energy extraction from seeds is likely inefficient, the diet of Mallards and teal support the lipid-limitation hypothesis (Ankney and Afton 1988), that reliance on stored body fat supplements a lipid poor diet.;Body fat acquired prior to arrival, contributed 41% of clutch fat requirements in female teal and 60%-150% in female Mallards. Male Mallards used stored body fat during the egg formation period whereas male teal used fat only prior to this period. Female Mallards from three of four collection sites used stored minerals to supplement dietary calcium intake, ca. 11-13 grams for a 10 egg clutch, enough for about 1 egg, whereas female teal relied upon dietary sources of calcium.

  • Open Access English
    Authors: 
    Shankar, Bhairavi;
    Publisher: Scholarship@Western
    Country: Canada

    Hypervelocity collisions of asteroids onto planetary bodies have catastrophic effects on the target rocks through the process of shock metamorphism. The resulting features, impact craters, are circular depressions with a sharp rim surrounded by an ejecta blanket of variably shocked rocks. With increasing impact energy, the inner crater cavity can preserve complex morphologies including terraced walls, central uplifts, and melted rocks. The lack of erosion due to the absence of water or an atmosphere makes the Moon the perfect target to study impact crater processes, in particular the distribution of highly shocked materials within impact craters of different sizes. This study focuses on the characterization and distribution of highly shocked impact melt deposits using multispectral satellite datasets around three complex craters on the farside of the Moon. The study sites have varying morphologies of central uplifts on the crater floor: 1) the 81 km Olcott crater has a cluster of peak hills; 2) Kovalevskaya crater is a 113 km diameter complex crater with a central peak; and 3) Schrodinger basin has a central peak ring. Models propose that the collapse of crater walls and central uplifts during the final stages of crater formation determine where much of the melt rich rocks are eventually emplaced. The results of this study indicate that for increasing crater sizes, the volume of melt-rich rocks generated also increases – at rates greater than model estimates. Impact melt deposits are emplaced beyond the crater rims at each of the sites and preserve a range of morphologies, including melt veneers, melt sheet, and ponded deposits. The regional and local topography, together with crater modification processes greatly affect where the impact melts are finally emplaced. The compositional analyses of the farside crust, using multispectral reflectance spectroscopy in the UV-VIS-NIR range, indicates that there is increasing evidence of highly mafic compositions (i.e., rocks rich in high-Ca pyroxene, olivine, spinel) intercalated within the original crustal highlands (rocks rich in plagioclase feldspar, and low-Ca pyroxenes) on the lunar farside, proving that the lunar farside is a far more geologically complicated terrain than originally assumed.

  • Open Access
    Authors: 
    Prannay R. Malu; Utkarsh S. Sharma; Joshua M. Pearce;
    Publisher: Elsevier BV
    Countries: France, Canada

    Abstract Aggressive growth of land-based solar photovoltaic (PV) farms can create a land use conflict with agricultural production. Fortunately, this issue can be resolved using the concept of agrivoltaics, which is co-development of land area for both solar PV and agriculture. To investigate and quantify PV generation potential, without significantly harming agriculture output, this study explores the viability of agrivoltaic farms deployment on existing grape farms in India. Considering the shade tolerance of grapes, an techno-economicanalysis is run for the installation of PV systems in the area available between the trellises on a grape farm. The electrical energy generation potential is determined per unit area and economic benefits for the cultivators is quantified over a number of design options. The results show the economic value of the grape farms deploying the proposed agrivoltaic systems may increase more than 15 times as compared to conventional farming, while maintaining approximately the same grape production. If this dual use of land is implemented nationwide, it can make a significant impact by generating over 16,000 GWh electricity, which has the potential of meeting the energy demands of more than 15 million people. In addition, grape-based agrivoltaics can be implemented in rural areas to enable village electrification.

  • Open Access
    Authors: 
    Jennifer L. Braid; Daniel Riley; Joshua M. Pearce; Laurie Burnham;
    Publisher: Scholarship@Western
    Country: Canada

    Modeling and predicting snow-related power loss is important to economic calculations, load management and system optimization for all scales of photovoltaic (PV) power plants. This paper describes a new method for measuring snow shedding from fielded modules and also describes the application of this method to a commercial scale PV power plant in Vermont with two subsystems, one with modules in portrait orientation and the other in landscape. The method relies on time-series images taken at 5 minute intervals to capture the dynamics of module-level snow accumulation and shedding. Module-level images extracted from the full-field view are binarized into snow and clear areas, allowing for the quantification of percentage snow coverage, estimation of resulting module power output, and temporal changes in snow coverage. Preliminary data from the Vermont case study suggests that framed modules in portrait orientation outperform their framed counterparts in landscape orientation by as much as 24% energy yield during a single shedding event. While these data reflect a single event, and do not capture snow shedding behavior across diverse temperature and other climatic conditions, the study nonetheless demonstrates that 1) module orientation and position in the array influence shedding patterns; 2) the start of power production and bypass diode activation differ for portrait and landscape module orientations at similar percentages and orientations of snow coverage; and 3) system design is an important factor in snow mitigation and increased system efficiency in snowy climates.

  • Publication . Presentation . 2019
    Open Access
    Authors: 
    Belton, Tom;
    Publisher: Scholarship@Western
    Country: Canada
  • Open Access English
    Authors: 
    Delavar, Mohammad;
    Publisher: Scholarship@Western
    Country: Canada

    The effective adoption and implementation of Building Information Modeling (BIM) is still challenging for the construction industry. However, studies and reports show a significant increase in the rate of BIM implementation and adoption in mainstream construction activities over the last five years. In contrast, Pre-Engineered Building (PEB) construction, a specialized construction system which provides a very efficient approach for construction of primarily industrial buildings, has not seen the same uptake in BIM implementation and adoption. The thesis reviews the benefits and the main applications of BIM for the PEB industry as well as challenges of its practical implementation. To facilitate the implementation of BIM in the PEB industry, a BIM framework is adapted from Pre-fabrication (Pre-fab) industry and new workflows, process maps, and data-exchange strategies are developed. As the PEB industry traditionally makes significant use of automation in its design and fabrication process, accordingly this work investigates the technical challenges of incorporating automation into the proposed BIM process. Two new BIM concepts, “Planar Concept” and “Floating LOD”, are then developed and implemented as a solution to these challenges. To define the proper input/output criteria for automated BIM design processes, a numerical study was performed to identify an “Optimum LOD”. A software implementation embodying the research outcomes was developed to illustrate the feasibility of the results. Its step-by-step deployment is analyzed and discussed using an example industry PEB design project. Further, the impact of this work is extended by integrating the developed BIM framework and automated design process with wind engineering design activities and tools and procurement systems. The study concludes that the deployment of the proposed BIM framework could significantly address existing issues in project design through to operation processes found in the PEB industry. Also, the results indicate the developed concepts have the potential for supporting the application of automation in the other sectors of the general construction industry. This thesis is written using the "Integrated Article" format and includes various complementary studies.

  • Open Access English
    Authors: 
    Zeng, Chuiqing;
    Publisher: Scholarship@Western
    Country: Canada

    The two-dimensional (2D) footprints and three-dimensional (3D) structures of buildings are of great importance to city planning, natural disaster management, and virtual environmental simulation. As traditional manual methodologies for collecting 2D and 3D building information are often both time consuming and costly, automated methods are required for efficient large area mapping. It is challenging to extract building information from remotely sensed data, considering the complex nature of urban environments and their associated intricate building structures. Most 2D evaluation methods are focused on classification accuracy, while other dimensions of extraction accuracy are ignored. To assess 2D building extraction methods, a multi-criteria evaluation system has been designed. The proposed system consists of matched rate, shape similarity, and positional accuracy. Experimentation with four methods demonstrates that the proposed multi-criteria system is more comprehensive and effective, in comparison with traditional accuracy assessment metrics. Building height is critical for building 3D structure extraction. As data sources for height estimation, digital surface models (DSMs) that are derived from stereo images using existing software typically provide low accuracy results in terms of rooftop elevations. Therefore, a new image matching method is proposed by adding building footprint maps as constraints. Validation demonstrates that the proposed matching method can estimate building rooftop elevation with one third of the error encountered when using current commercial software. With an ideal input DSM, building height can be estimated by the elevation contrast inside and outside a building footprint. However, occlusions and shadows cause indistinct building edges in the DSMs generated from stereo images. Therefore, a “building-ground elevation difference model” (EDM) has been designed, which describes the trend of the elevation difference between a building and its neighbours, in order to find elevation values at bare ground. Experiments using this novel approach report that estimated building height with 1.5m residual, which out-performs conventional filtering methods. Finally, 3D buildings are digitally reconstructed and evaluated. Current 3D evaluation methods did not present the difference between 2D and 3D evaluation methods well; traditionally, wall accuracy is ignored. To address these problems, this thesis designs an evaluation system with three components: volume, surface, and point. As such, the resultant multi-criteria system provides an improved evaluation method for building reconstruction.