The numerous man-made disasters and natural catastrophes that menace major communities accentuate the need for proper planning for emergency evacuation. Transportation networks in cities evolve over long time spans in tandem with population growth and evolution of travel patterns. In emergencies, travel demand and travel patterns drastically change from the usual everyday volumes and patterns. Given that most US and Canadian cities are already congested and operating near capacity during peak periods, network performance can severely deteriorate if drastic changes in Origin-Destination (O-D) demand patterns occur during or after a disaster. Also, loss of capacity due to the disaster and associated incidents can further complicate the matter. Therefore, the primary goal when a disaster or hazardous event occurs is to coordinate, control, and possibly optimize the utilization of the existing transportation network capacity. Emergency operation management centres face multi-faceted challenges in anticipating evacuation flows and providing proactive actions to guide and coordinate the public towards safe shelters. Numerous studies have contributed to developing and testing strategies that have the potential to mitigate the consequences of emergency situations. They primarily investigate the effect of some proposed strategies that have the potential of improving the performance of the evacuation process with modelling and optimization techniques. However, most of these studies are inherently restricted to evacuating automobile traffic using a certain strategy without considering other modes of transportation. Moreover, little emphasis is given to studying the interaction between the various strategies that could be potentially synergized to expedite the evacuation process. Also, the absence of an accurate representation of the spatial and temporal distribution of the population and the failure to identify the available modes and populations that are captive to certain modes contribute to the absence of multimodal evacuation procedures. Incorporating multiple modes into emergency evacuation has the potential to expedite the evacuation process and is essential to assuring the effective evacuation of transit-captive and special-needs populations . This dissertation presents a novel multimodal optimization framework that combines vehicular traffic and mass transit for emergency evacuation. A multi-objective approach is used to optimize the multimodal evacuation problem. For automobile evacuees, an Optimal Spatio-Temporal Evacuation (OSTE) framework is presented for generating optimal demand scheduling, destination choices and route choices, simultaneously. OSTE implements Dynamic Traffic Assignment (DTA) techniques coupled with parallel distributed genetic optimization to guarantee a near global optimal solution. For transit evacuees, a Multi-Depots, Time Constrained, Pick-up and Delivery Vehicle Routing Problem (MDTCPD-VRP) framework is presented to model the use of public transit vehicles in evacuation situations. The MDTCPD-VRP implements constraint programming and local search techniques to optimize certain objective functions and satisfy a set of constraints. The OSTE and MDTCPD-VRP platforms are integrated into one framework to replicate the impact of congestion caused by traffic on transit vehicle travel times. A proof-of-concept prototype has been tested; it investigates the optimization of a multimodal evacuation of a portion of the Toronto Waterfront area. It also assesses the impact of multiple objective functions on emergency evacuation while attempting to achieve an equilibrium state between transit modes and vehicular traffic. Then, a large-scale application, including a demand estimation model from a regional travel survey, is conducted for the evacuation of the entire City of Toronto. This framework addresses many limitations of existing evacuation planning models by: 1) synergizing multiple evacuation strategies; 2) utilizing robust optimization and solution algorithms that can tackle such multi-dimensional non deterministic problem; 3) estimating the spatial and temporal distribution of evacuation demand; 4) identifying the transit-dependent population; 5) integrating multiple modes in emergency evacuation. The framework presents a significant step forward in emergency evacuation optimization.

This study used multilevel measurement modeling to examine the differential difficulties of math and reading items for Grade 6 students participating in Ontario’s provincial assessment in 2005-2006, in relation to whether they received a setting accommodation, had a learning disability (LD), and spoke a language in addition to English. Both differences in difficulty between groups of students for all items (impact) and for individual items (differential item functioning) were examined. Students’ language backgrounds (whether they spoke a language in addition to English) were not significantly related to item difficulty. Compared to non-accommodated students with LD, math and reading items were relatively difficult for accommodated students with LD. Moreover, the difference in overall impact on math items was larger than on reading items for accommodated and non-accommodated students with LD. Overall, students without LD and who did not receive a setting accommodation outperformed students with LD and/or who received a setting accommodation as well as accommodated students without LD. It is important to note that, because this was an operational test administration, students were assigned to receive accommodations by their schools based on their individual needs. It is, therefore, not possible to separate the effect of the setting accommodation on item difficulty from the effects of other differences between the accommodated and non-accommodated groups. The differences in math and reading item difficulties between accommodated and non-accommodated students with LD may be due in part to factors such as comorbidity of LD and attention deficit hyperactivity disorder (ADHD) or a possible mismatch between the setting accommodation and the areas of disabilities. Moreover, the results of the present study support the underarousal/optimal stimulation hypothesis instead of the premise of the inhibitory control and attention for the use of setting accommodation. After controlling for the impact across all items of setting accommodation and LD, several math and reading items were found to exhibit differential item functioning (DIF). The possible sources of DIF were (1) math items that were not adherent to specific item-writing rules and (2) reading items targeting different types of comprehension. This study also found that the linguistic features of math items (total words, total sentences, average word length, monosyllabic words for math) and reading items (word frequency, average sentence length, and average words per sentence for reading) were associated with math and reading item difficulties for students with different characteristics. The total sentences and average word length in a math item as well as total words in a reading item significantly predicted the achievement gap between groups. Therefore, the linguistic features should be taken into account when assessments are developed and validated for examinees with varied characteristics.

This thesis deals with the design of multivariable controllers for stable linear time-invariant multi-input multi-output systems, with an unknown mathematical model, subject to constant reference/disturbance signals and actuator saturation constraints. A new controller parameter optimization approach, which can be carried out experimentally with no knowledge of the plant model nor of the order of the system, is proposed. The approach has the advantage that controllers can be optimized by perturbing only the initial conditions of the servocompensator, and that the order of the resulting controller obtained can be specified by the designer. Implementation of the proposed controller design approach is described, and an experimental application study of the proposed method applied to a multivariable system with industrial sensor/actuator components is presented to illustrate the feasibility of the design method in an industrial environment.

This thesis deals with the design of multivariable controllers for stable linear time-invariant multi-input multi-output systems, with an unknown mathematical model, subject to constant reference/disturbance signals and actuator saturation constraints. A new controller parameter optimization approach, which can be carried out experimentally with no knowledge of the plant model nor of the order of the system, is proposed. The approach has the advantage that controllers can be optimized by perturbing only the initial conditions of the servocompensator, and that the order of the resulting controller obtained can be specified by the designer. Implementation of the proposed controller design approach is described, and an experimental application study of the proposed method applied to a multivariable system with industrial sensor/actuator components is presented to illustrate the feasibility of the design method in an industrial environment.

I Remember…, a series of drawings, is based on personal social experiences starting from the age of thirteen. This series begins with a memory of the first time I had to speak to a room full of people and the unexpected events of that followed. My own relationship with one of the primary subjects, the chair refers to memories of being raised in a home where certain furnishings were “off-limits.” Even more important is the presence of a cryptic narrative, fractured and dreamlike, similar to the style of writing created by Alain Robbe-Grillet. It has been a lifetime goal to create drawings that are interactive with the viewer. The baroque embellished chairs and piano provide a point of departure encouraging contemplative involvement by the viewer conceptually through imagery and physically through scale. Also, showing multiple viewpoints of the object simultaneously creates an atmosphere that is dreamlike and ghostly.

This study used multilevel measurement modeling to examine the differential difficulties of math and reading items for Grade 6 students participating in Ontario’s provincial assessment in 2005-2006, in relation to whether they received a setting accommodation, had a learning disability (LD), and spoke a language in addition to English. Both differences in difficulty between groups of students for all items (impact) and for individual items (differential item functioning) were examined. Students’ language backgrounds (whether they spoke a language in addition to English) were not significantly related to item difficulty. Compared to non-accommodated students with LD, math and reading items were relatively difficult for accommodated students with LD. Moreover, the difference in overall impact on math items was larger than on reading items for accommodated and non-accommodated students with LD. Overall, students without LD and who did not receive a setting accommodation outperformed students with LD and/or who received a setting accommodation as well as accommodated students without LD. It is important to note that, because this was an operational test administration, students were assigned to receive accommodations by their schools based on their individual needs. It is, therefore, not possible to separate the effect of the setting accommodation on item difficulty from the effects of other differences between the accommodated and non-accommodated groups. The differences in math and reading item difficulties between accommodated and non-accommodated students with LD may be due in part to factors such as comorbidity of LD and attention deficit hyperactivity disorder (ADHD) or a possible mismatch between the setting accommodation and the areas of disabilities. Moreover, the results of the present study support the underarousal/optimal stimulation hypothesis instead of the premise of the inhibitory control and attention for the use of setting accommodation. After controlling for the impact across all items of setting accommodation and LD, several math and reading items were found to exhibit differential item functioning (DIF). The possible sources of DIF were (1) math items that were not adherent to specific item-writing rules and (2) reading items targeting different types of comprehension. This study also found that the linguistic features of math items (total words, total sentences, average word length, monosyllabic words for math) and reading items (word frequency, average sentence length, and average words per sentence for reading) were associated with math and reading item difficulties for students with different characteristics. The total sentences and average word length in a math item as well as total words in a reading item significantly predicted the achievement gap between groups. Therefore, the linguistic features should be taken into account when assessments are developed and validated for examinees with varied characteristics.

The numerous man-made disasters and natural catastrophes that menace major communities accentuate the need for proper planning for emergency evacuation. Transportation networks in cities evolve over long time spans in tandem with population growth and evolution of travel patterns. In emergencies, travel demand and travel patterns drastically change from the usual everyday volumes and patterns. Given that most US and Canadian cities are already congested and operating near capacity during peak periods, network performance can severely deteriorate if drastic changes in Origin-Destination (O-D) demand patterns occur during or after a disaster. Also, loss of capacity due to the disaster and associated incidents can further complicate the matter. Therefore, the primary goal when a disaster or hazardous event occurs is to coordinate, control, and possibly optimize the utilization of the existing transportation network capacity. Emergency operation management centres face multi-faceted challenges in anticipating evacuation flows and providing proactive actions to guide and coordinate the public towards safe shelters. Numerous studies have contributed to developing and testing strategies that have the potential to mitigate the consequences of emergency situations. They primarily investigate the effect of some proposed strategies that have the potential of improving the performance of the evacuation process with modelling and optimization techniques. However, most of these studies are inherently restricted to evacuating automobile traffic using a certain strategy without considering other modes of transportation. Moreover, little emphasis is given to studying the interaction between the various strategies that could be potentially synergized to expedite the evacuation process. Also, the absence of an accurate representation of the spatial and temporal distribution of the population and the failure to identify the available modes and populations that are captive to certain modes contribute to the absence of multimodal evacuation procedures. Incorporating multiple modes into emergency evacuation has the potential to expedite the evacuation process and is essential to assuring the effective evacuation of transit-captive and special-needs populations . This dissertation presents a novel multimodal optimization framework that combines vehicular traffic and mass transit for emergency evacuation. A multi-objective approach is used to optimize the multimodal evacuation problem. For automobile evacuees, an Optimal Spatio-Temporal Evacuation (OSTE) framework is presented for generating optimal demand scheduling, destination choices and route choices, simultaneously. OSTE implements Dynamic Traffic Assignment (DTA) techniques coupled with parallel distributed genetic optimization to guarantee a near global optimal solution. For transit evacuees, a Multi-Depots, Time Constrained, Pick-up and Delivery Vehicle Routing Problem (MDTCPD-VRP) framework is presented to model the use of public transit vehicles in evacuation situations. The MDTCPD-VRP implements constraint programming and local search techniques to optimize certain objective functions and satisfy a set of constraints. The OSTE and MDTCPD-VRP platforms are integrated into one framework to replicate the impact of congestion caused by traffic on transit vehicle travel times. A proof-of-concept prototype has been tested; it investigates the optimization of a multimodal evacuation of a portion of the Toronto Waterfront area. It also assesses the impact of multiple objective functions on emergency evacuation while attempting to achieve an equilibrium state between transit modes and vehicular traffic. Then, a large-scale application, including a demand estimation model from a regional travel survey, is conducted for the evacuation of the entire City of Toronto. This framework addresses many limitations of existing evacuation planning models by: 1) synergizing multiple evacuation strategies; 2) utilizing robust optimization and solution algorithms that can tackle such multi-dimensional non deterministic problem; 3) estimating the spatial and temporal distribution of evacuation demand; 4) identifying the transit-dependent population; 5) integrating multiple modes in emergency evacuation. The framework presents a significant step forward in emergency evacuation optimization.

No description available.

The growing acceptance of B-ISDN (Broadband Integrated Services Digital Network) requires entirely new switching support a wide range of service demands including voice, video and data. At the same time, advances in the field of VLSI have enabled new principles to the design and architecture high-performance switching fabrics. Direct binary switch fabrics are a suitable candidate for future B- switches. Binary hypercubes have regular topology, are highly fault and have multiple paths for routing cells which help avoid performance penalties due to congestion and faults. In addition, these switches can adopt the novel, distributed, and adaptive routing scheme called 'deflection routing'. In normal routing, cells are routed along shortest paths to their destinations; in case of multiple cells contending for a single outgoing channel, the rest of the contending cells are either buffered or dropped to avoid congestion. In the case of deflection routing, cells can be routed along non-shortest paths. As a result, deflection routing helps avoid dropping cells. The scheme may be implemented with and without queuing buffers at the routers. In order to properly provision, control, and design these hypercube switches, it is essential that their performance capabilities be completely understood. Researchers have used both analytical model and simulations to evaluate performance of hypercube switches. The presence of distributed logic, multi-path routing, deflection routing, and queuing buffers make modeling tasks highly challenging. Building a reasonably accurate model of a hypercube switch with queuing buffers and deflection routing and using that model to gain practical insights into some of the important design parameters of the switch has been the major motivation of this thesis. An approximate Markov model of a single switching element is built to capture the behavior of a d-dimension switch. The numerical model is solved iteratively. Accuracy of the model is established by validating against simulation results. One disadvantage of having multiple paths, queuing buffers, and deflection motion of cells in hypercube switches is that the cells belonging to a particular traffic stream may not be delivered at their destinations in sequence. This phenomenon is known as 'out-of-orderness' of cells. An additional goal of this thesis has been development of a model to capture out-of-orderness phenomenon. The model is validated by comparing model results against simulation. Results show that the model is accurate and reveals significant insight into switch's behavior that can be used to design and engineer d-dimension hypercube switches.

Der Asynchronous Transfer Mode (ATM) stellt die zukünftige und einheitliche Basistechnologie für das Breitband-ISDN dar. Da nahezu alle wesentlichen Protokollfunktionen in Hardware realisierbar sind, soll nachfolgend ein Überblick über bereits angebotene VLSI-Schaltkreise gegeben werden. Eine Systematisierung und Einordnung vorhandener ATM-Chips hinsichtlich ihrer Leistungsfähigkeit und ihres Funktionsumfangs erfolgt in Hinblick auf das sogenannte B-ISDN-Referenzmodell. Dieses Schichtenmodell definiert die notwendigen Protokolle und Schnittstellen für den Asynchronous Transfer Mode. Zum grundlegenden Verständnis wird einleitend eine kurze Einführung in die Basisprinzipien von ATM gegeben.