With the ever increasing amount of digital information, information workers desire more screen real estate to process their daily desktop work. Thanks to the quick advance in display technology, big screens are increasingly affordable and have been gradually adopted in desktop computing environments. A large wall-size high resolution display, a recent emerging class of display which possesses a huge visualization surface, could potentially benefit information processing work. In this dissertation we investigate such a large display as the primary working space for information processing work. We firstly conducted a longitudinal diary study and three control experiments investigating effects of a large display on information processing work. The longitudinal diary study investigates large display use in a personal desktop computing context by comparing it with single- and dual-monitor. The three controlled experiments further investigate the effects of two factors determining resolution of a display—physical size and pixel-density on users’ performance and behaviors. The diary study reveals the distinct behavior patterns of large display users in partitioning screen space and managing windows, while the control experiments deeply reveal the effects of the physical size and pixel density of a display on different information processing tasks. Aside from studying a continuous large display, we also articulate how interior bezels within a tiled-monitor large display affect users’ performance and behaviors in basic visual search and action tasks via a series of controlled experiments. Based on the understanding of large display effects and users’ behavior patterns, we then design new interaction techniques to address a big challenge of working on a large display: managing overflowing windows. We design and implement a large display oriented window management system prototype: WallTop. It includes a set of interaction techniques that provide greater flexibility for managing windows. Usability tests show that users can quickly and easily learn the new techniques and apply them to realistic window management tasks with increased efficiency on a large display.

With the ever increasing amount of digital information, information workers desire more screen real estate to process their daily desktop work. Thanks to the quick advance in display technology, big screens are increasingly affordable and have been gradually adopted in desktop computing environments. A large wall-size high resolution display, a recent emerging class of display which possesses a huge visualization surface, could potentially benefit information processing work. In this dissertation we investigate such a large display as the primary working space for information processing work. We firstly conducted a longitudinal diary study and three control experiments investigating effects of a large display on information processing work. The longitudinal diary study investigates large display use in a personal desktop computing context by comparing it with single- and dual-monitor. The three controlled experiments further investigate the effects of two factors determining resolution of a display—physical size and pixel-density on users’ performance and behaviors. The diary study reveals the distinct behavior patterns of large display users in partitioning screen space and managing windows, while the control experiments deeply reveal the effects of the physical size and pixel density of a display on different information processing tasks. Aside from studying a continuous large display, we also articulate how interior bezels within a tiled-monitor large display affect users’ performance and behaviors in basic visual search and action tasks via a series of controlled experiments. Based on the understanding of large display effects and users’ behavior patterns, we then design new interaction techniques to address a big challenge of working on a large display: managing overflowing windows. We design and implement a large display oriented window management system prototype: WallTop. It includes a set of interaction techniques that provide greater flexibility for managing windows. Usability tests show that users can quickly and easily learn the new techniques and apply them to realistic window management tasks with increased efficiency on a large display.

An important consideration in energy efficient building design is the management of solar gain, as it is the largest and most variable gain in a building. The design of buildings with highly glazed facades, as well as decreased energy transfer rates through better insulated and tighter envelopes are causing interior spaces to become highly sensitive to solar gain. Shading devices such as operable slat-type louver blinds are very effective in controlling solar gain, yet their impact on peak cooing loads and annual energy consumption is poorly understood. With the ever-increasing role of building energy simulation tools in the design of energy efficient buildings, there is a clear need to model windows with shading devices to assess their impact on building performance. Recent efforts at the University of Waterloo’s Advanced Glazing Systems Laboratory (AGSL) in window shading research have produced a set of flexible shading models. These models were developed with emphasis on generality and computational efficiency, ideally suited for integration into building simulation. The objective of the current research is to develop a complex fenestration facility within a general purpose integrated building simulation software tool, ESP-r, using the AGSL shading models. The strategy for implementation of the AGSL shading models is the addition of a new multi-layer construction within ESP-r, the Complex Fenestration Construction (CFC). The CFC is based on the standard ESP-r multi-layer nodal structure and finite control volume numerical model, with additional measures for coping with the complexities that arise in the solar, convective and radiant exchanges between glazing/shading layers, the interior zone and exterior surroundings. The CFC algorithms process the solar, convective and radiant properties of the glazing/shading system at each time-step, making it possible to add control (e.g., changing the slat angle of a slat-type blind) at the time-step level. Thermal resistances of sealed cavities between glazing/shading layers are calculated at each time-step for various fill gases and mixtures. In addition to modeling glazing/shading layer combinations, the CFC type also provides an alternate method of modeling unshaded windows without relying on third party software to supply the solar optics and cavity resistances. To build confidence in the CFC code implementation, two comparison studies were carried out to compare the CFC type against other models. The first study compared the CFC models for unshaded windows with the standard ESP-r transparent multi-layer construction (TMC) models. The second study compared the CFC slat-type blind models with EnergyPlus 2.0. Good agreement was seen in the simulation results in both studies. The successful implementation of the Complex Fenestration Construction within ESP-r has been demonstrated in the current research. In order for ESP-r users to fully exploit the capabilities of the CFC framework, it is recommended that the current models be extended to include a facility for dynamic shading control as well as the treatment of other types of shading layers. The coupling of daylighting models with the CFC type would provide a useful tool for modeling luminance control in combination with shading control strategies. With these enhancements, it is anticipated that the CFC implementation will be of significant value to practitioners.

An important consideration in energy efficient building design is the management of solar gain, as it is the largest and most variable gain in a building. The design of buildings with highly glazed facades, as well as decreased energy transfer rates through better insulated and tighter envelopes are causing interior spaces to become highly sensitive to solar gain. Shading devices such as operable slat-type louver blinds are very effective in controlling solar gain, yet their impact on peak cooing loads and annual energy consumption is poorly understood. With the ever-increasing role of building energy simulation tools in the design of energy efficient buildings, there is a clear need to model windows with shading devices to assess their impact on building performance. Recent efforts at the University of Waterloo’s Advanced Glazing Systems Laboratory (AGSL) in window shading research have produced a set of flexible shading models. These models were developed with emphasis on generality and computational efficiency, ideally suited for integration into building simulation. The objective of the current research is to develop a complex fenestration facility within a general purpose integrated building simulation software tool, ESP-r, using the AGSL shading models. The strategy for implementation of the AGSL shading models is the addition of a new multi-layer construction within ESP-r, the Complex Fenestration Construction (CFC). The CFC is based on the standard ESP-r multi-layer nodal structure and finite control volume numerical model, with additional measures for coping with the complexities that arise in the solar, convective and radiant exchanges between glazing/shading layers, the interior zone and exterior surroundings. The CFC algorithms process the solar, convective and radiant properties of the glazing/shading system at each time-step, making it possible to add control (e.g., changing the slat angle of a slat-type blind) at the time-step level. Thermal resistances of sealed cavities between glazing/shading layers are calculated at each time-step for various fill gases and mixtures. In addition to modeling glazing/shading layer combinations, the CFC type also provides an alternate method of modeling unshaded windows without relying on third party software to supply the solar optics and cavity resistances. To build confidence in the CFC code implementation, two comparison studies were carried out to compare the CFC type against other models. The first study compared the CFC models for unshaded windows with the standard ESP-r transparent multi-layer construction (TMC) models. The second study compared the CFC slat-type blind models with EnergyPlus 2.0. Good agreement was seen in the simulation results in both studies. The successful implementation of the Complex Fenestration Construction within ESP-r has been demonstrated in the current research. In order for ESP-r users to fully exploit the capabilities of the CFC framework, it is recommended that the current models be extended to include a facility for dynamic shading control as well as the treatment of other types of shading layers. The coupling of daylighting models with the CFC type would provide a useful tool for modeling luminance control in combination with shading control strategies. With these enhancements, it is anticipated that the CFC implementation will be of significant value to practitioners.

Due to rising energy prices as well as supply and ecological concerns, there is a strong interest in reducing the energy used in buildings. As such, it is desirable to model the operation of a building and predict its future energy use. In predicting the energy use of a building, the heat gain/loss through windows is an important factor. In order to accurately model this heat gain/loss, the convective heat transfer coefficient of any insect screens mounted adjacent to the windows needs to be known. This thesis describes an investigation into the heat transfer from insect screens mounted towards the indoor side of a window. The convective heat transfer coefficient of an insect screen varies based on several parameters. For implementation in building energy modelling software, it is desirable to be able to predict the convective heat transfer coefficient for an arbitrary insect screen. Due to the number of variables and the large dynamic range of the details required for modelling, direct simulation of a range of whole insect screens was not completed. Instead, a range of numerical models representing small sections of an insect screen were created. By comparing results from these to available correlations for simpler geometries, such as cylinders and flat plates, estimates for the heat transfer coefficient of a screen can be obtained. The results were non-dimensionalized for analysis and different methodologies for the prediction of heat transfer from an indoor window insect screen are described.

none

Wave propagation in unbounded media is a topic widely studied in different science and engineering fields. Global and local absorbing boundary conditions combined with the finite element method or the finite difference method are the usual numerical treatments. In this dissertation, an alternative is investigated based on the dynamic stiffness and the exponential window method in the space-wave number domain. Applying the exponential window in the space-wave number domain is equivalent to introducing fictitious damping into the system. The Discrete Fourier Transform employed in the dynamic stiffness can be properly performed in a damped system. An open boundary in space is thus created. Since the equation is solved by the finite difference formula in the time domain, this approach is in the time-wave number domain, which provides a complement for the original dynamic stiffness method, which is in the frequency-wave number domain. The approach is tested through different elasto-dynamic models that cover one-, two- and three-dimensional problems. The results from the proposed approach are compared with those from either analytical solutions or the finite element method. The comparison demonstrates the effectiveness of the approach. The incident waves can be efficiently absorbed regardless of incident angles and frequency contents. The approach proposed in this dissertation can be widely applied to the dynamics of railways, dams, tunnels, building and machine foundations, layered soil and composite materials.

A percentage of insulating glass (IG) units break each year due to thermally induced perimeter stresses. The glass industry has known about this problem for many years and an ASTM standard has recently been developed for the design of monolithic glass plates for thermal stresses induced by solar irradiance. It is believed that a similar standard can be developed for IG units if a proper understanding of IG thermal stresses can be developed. The objective of this research is to improve understandings of IG thermal stresses and compare the IG thermal stresses with those that develop in monolithic glass plates given similar environmental conditions. The major difference between the analysis of a monolithic glass plate and an IG unit is energy exchange due to conduction, natural convection, and long wave radiation through the gas space cavity. In IG units, conduction, natural convection, and long wave radiation combine in a nonlinear fashion that frequently requires iterative numerical analyses for determining thermal stresses in certain situations. To simplify the gas space energy exchange, a numerical propagation procedure was developed. The numerical propagation procedure combines the nonlinear effects of conduction, natural convection, and long wave radiation into a single value. Use of this single value closely approximates the nonlinear nature of the gas space energy exchange and simplifies the numerical analysis. The numerical propagation procedure was then coupled with finite element analysis to estimate thermal stresses for both monolithic glass plates and IG units. It is shown that the maximum thermal stresses that develop in IG units increase linearly with input solar irradiance during the transient phase. It is shown that an initial preload stress develops under equilibrium conditions due to the thermal bridge effects of the spacer. It is shown that IG units develop larger thermal stresses than monolithic glass plates under similar environmental conditions. Finally, it is shown that the use of low-e coatings increase IG thermal stresses and that the location of low-e coating as well as environmental conditions affect which glass plate develops larger thermal stresses.

Neurovascular models have played an important role in understanding neuronal function or medical conditions. In the past few decades, only small volumes of neurovascular data have been available. However, huge data sets are becoming available with high throughput instruments like the Knife-Edge Scanning Microscope (KESM). Therefore, fast and robust tracing methods become necessary for tracing such large data sets. However, most tracing methods are not effective in handling complex structures such as branches. Some methods can solve this issue, but they are not computationally efficient (i.e., slow). Motivated by the issue of speed and robustness, I introduce an effective and efficient fiber tracing algorithm for 2D and 3D data. In 2D tracing, I have implemented a Moving Window (MW) method which leads to a mathematical simplification and noise robustness in determining the trace direction. Moreover, it provides enhanced handling of branch points. During tracing, a Cubic Tangential Trace Spline (CTTS) is used as an accurate and fast nonlinear interpolation approach. For 3D tracing, I have designed a method based on local maximum intensity projection (MIP). MIP can utilize any existing 2D tracing algorithms for use in 3D tracing. It can also significantly reduce the search space. However, most neurovascular data are too complex to directly use MIP on a large scale. Therefore, we use MIP within a limited cube to get unambiguous projections, and repeat the MIP-based approach over the entire data set. For processing large amounts of data, we have to automate the tracing algorithms. Since the automated algorithms may not be 100 percent correct, validation is needed. I validated my approach by comparing the traced results to human labeled ground truth showing that the result of my approach is very similar to the ground truth. However, this validation is limited to small-scale real-world data due to the limitation of the manual labeling. Therefore, for large-scale data, I validated my approach using a model-based generator. The result suggests that my approach can also be used for large-scale real-world data. The main contributions of this research are as follows. My 2D tracing algorithm is fast enough to analyze, with linear processing time based on fiber length, large volumes of biological data and is good at handling branches. The new local MIP approach for 3D tracing provides significant performance improvement and it allows the reuse of any existing 2D tracing methods. The model-based generator enables tracing algorithms to be validated for large-scale real-world data. My approach is widely applicable for rapid and accurate tracing of large amounts of biomedical data.

When thinking of renovating the windows of old buildings, the building owner has a lot of decisions to make. These are to keep the window but make it more energy efficient by adding an extra pane or to completely change the whole window. At the same time, the joint between the window frame and wall makes a thermal bridge which depends on how much insulation has been placed in the cavities after installation. Upon the decision of keeping the window, the status of this joint will be unchanged. This thesis deals with finding out the best economical solution for a company that has rental apartments in Gävle in Sweden, Gavlegårdarna AB. To calculate the thermal bridges, which are weak areas of the building envelope in which they significantly increase the energy load of houses, a CDF program called Fluent is used to quantify the heat loss at the joints. Measurements have been performed to validate the CFD model. To simulate the energy savings in the building, the building energy simulation program IDA-ICE is used. Finally, Life Cycle Costing calculations are made to assess the best long term economical option. It is concluded that the most reasonable solution is to add an extra glass in the existing window, but it is not the most ecofriendly. A more ecological solution is to add the extra glass and to perform enhanced insulation at the joints around the window frames and walls, or to replace the old window with a new low energy window – however, these are not profitable so