Data privacy has been growing in importance in recent years, especially with the continuous increase of online activity. Researchers study, design, and develop solutions aimed at enhancing users’ data privacy. The wicked problem of data privacy is a continuous challenge that defies straightforward solutions. Since there are many factors involved in data privacy, such as technological, legal, and human aspects, we can only aim at mitigating rather than solving this wicked problem. Our aim was to focus on human aspects for designing usable crypto-based privacy-enhancing solutions.  In this thesis, we followed a user centered design method by using empirical qualitative means for investigating user’s perceptions and opinions of our solutions. Most of our work has focused on redactable signatures in the cloud context within the eHealth use-case. Redactable signatures are  a privacy enhancing scheme allowing to remove parts of a signed document by a specified party for achieving data minimization without invalidating the respective signature. We mainly used semi-structures interviews and focus groups in our investigations. Our results yielded key HCI considerations as well as guidelines of different means for supporting the design of future solutions. / Data privacy has been growing in importance in recent years, especially with the continuous increase of online activity. Researchers continuously study, design, and develop solutions aimed at enhancing users’ data privacy. The wicked problem of data privacy is the continuous challenge that defies straightforward solutions. Since there are many factors involved in data privacy, such as technological, legal, and human aspects, we can only aim at mitigating rather than solving this wicked problem. Our aim was to focus on human aspects for designing usable crypto-based privacy-enhancing solutions.  In this thesis, we followed a user centered design method by using empirical qualitative means for investigating user’s perceptions and opinions of our solutions. Most of our work has focused on redactable signatures in the cloud context within an eHealth use-case. Redactable signatures are a privacy-enhancing scheme, which allow the removal of parts of a signed document by a specified party without invalidating the respective signature. Our results yielded key HCI considerations as well as guidelines of different means for supporting the design of future solutions. / <p>Paper 3 was included as manuscript in the thesis.</p>

As technology geometries have shrunk to the deep sub-micron (DSM) region, the chip density and clock frequency of FPGAs have increased significantly. This makes computer-aided design (CAD) for FPGAs very important and challenging. Due to the increasing demands of portable devices and mobile computing, low power design is crucial in CAD nowadays. In this dissertation, we present a framework to optimize power consumption for technology mapping onto FPGAs. We propose a low-power technology mapping scheme which is able to predict the impact of choosing a subnetwork covering on the ultimate mapping solution. We dynamically update the power estimation for a sequence of options and choose the one that yields the least power consumption. This technique outperforms the best low-power mapping algorithms reported in the literature. We further extend this work to generate mapping solutions with optimal delay. We also propose placement algorithms to optimize the performance of the placed circuit. Net cluster based methodology is designed to ensure closely connected nets will be routed in the same region. Net cluster is obtained by clique partitioning on the net dependency graph. Net positions and consequent cell positions are computed with a force-directed approach which drags nets connected to closer positions. We further study the performance-driven placement problem for high level synthesis. We use the Automatic Design Instantiation (AUDI) high level synthesis system to generate a register-transistor level (RTL) netlist. This RTL netlist is fed into a CAD tool for physical synthesis. We do not necessarily go through the entire physical design process which is usually quite time-consuming. Instead, we have created an accurate wirelength/timing estimator working on the floorplan. If the estimated timing information does not meet the constraints, a guidance is generated and provided to AUDI system. The guidance consists of the estimated timing information and instructions to produce a new netlist in order to improve the performance. Finally the circuit is placed and routed on a satisfying design. This performance-driven placement framework yields better results as compared to a commercial CAD tool.

<p>Software is finding its way into an increasing range of devices (phones, medical equipment, cars...). A challenge is to design <i>verification</i> methods to ensure correctness of software. </p><p>We focus on <i>model checking</i>, an approach in which an abstract model of the implementation and a specification of requirements are provided. The task is to answer automatically whether the system conforms with its specification.We concentrate on (i) timed systems, and (ii) parameterized systems.</p><p><i>Timed systems </i>can be modeled and verified using the classical model of timed automata. Correctness is translated to language inclusion between two timed automata representing the implementation and the specification. We consider variants of timed automata, and show that the problem is at best highly complex, at worst undecidable.</p><p>A <i>parameterized system</i> contains a variable number of components. The problem is to verify correctness regardless of the number of components. <i>Regular model checking</i> is a prominent method which uses finite-state automata. We present a semi-symbolic minimization algorithm combining the partition refinement algorithm by Paige and Tarjan with decision diagrams.</p><p>Finally, we consider systems which are both timed and parameterized: <i>Timed Petri Nets</i> (<i>TPNs</i>), and <i>Timed Networks</i> (<i>TNs</i>). We present a method for checking safety properties of TPNs based on forward reachability analysis with acceleration. We show that verifying safety properties of TNs is undecidable when each process has at least two clocks, and explore decidable variations of this problem.</p>

The electric power sector is undergoing significant changes with the development of Smart Grid technologies and is rapidly influencing the way we consume energy. Demand Response (DR) is an important element in the emerging smart grid paradigm and is paving way for the more sophisticated implementation of Energy Hub Management Systems (EHMSs). Utilities are looking at Demand Side Management (DSM) and DR services that allow customers to make informed decisions regarding their energy consumption which in return, can help the energy providers to reduce their peak demand and hence enhance grid sustainability. Ice rinks are large commercial buildings which facilitate various activities such as hockey, figure skating, curling, recreational skating, public arenas, auditoriums and coliseums. These have a complex energy system; in which an enormous sheet of ice is maintained at a low temperature while at the same time the spectator stands are heated to ensure comfortable conditions for the spectators. Since indoor ice rinks account for a significant share of the commercial sector and are in operation for more than 8 months a year, their contribution in the total demand cannot be ignored. There is significant scope for energy savings in indoor ice rinks through optimal operation of their climate control systems. In this work, a mathematical model of indoor ice rinks for the implementation of EHMS is developed. The model incorporates weather forecast, electricity price information and end-user preferences as inputs and the objective is to shift the operation of climate control devices to the low electricity price periods, satisfying their operational constraints while having minimum impact on spectator comfort. The inside temperature and humidity dynamics of the spectator area are modeled to reduce total electrical energy costs while capturing the effect of climate control systems including radiant heating system, ventilation system and dehumidification system. Two different pricing schemes, Real Time Pricing (RTP) and Time-of-Use (TOU), are used to assess the model, and the resulting energy costs savings are compared. The expected energy cost savings are evaluated for a 8 month period of operation of the rink incorporating the uncertainties in electricity price, weather conditions and spectator schedules through Monte Carlo simulations. The proposed work can be implemented as a supervisory control in existing climate controllers of indoor ice rinks and would play a significant role in the enforcement of EHMS in Smart Grids.

Multi-antenna relay beamforming is a promising candidate in the next generation wireless communication systems. The assumption of sum power constraint at the relay in previous work is often unrealistic in practice, since each antenna of the relay is limited by its own front-end power amplifier and thus has its own individual power constraint. In this thesis, given per-antenna power constraints, we obtain the semi-closed form solution for the optimal relay beamforming design in the two-hop amplify-and-forward relay beamforming and establish its duality with the point-to-point single-input multiple-output (SIMO) beamforming system. Simulation results show that the per-antenna power constraint case has much lower per-antenna peak power and much smaller variance of per-antenna power usage than the sum-power constraint case. A heuristic iterative algorithm to minimize the total power of relay network is proposed.

Multi-antenna relay beamforming is a promising candidate in the next generation wireless communication systems. The assumption of sum power constraint at the relay in previous work is often unrealistic in practice, since each antenna of the relay is limited by its own front-end power amplifier and thus has its own individual power constraint. In this thesis, given per-antenna power constraints, we obtain the semi-closed form solution for the optimal relay beamforming design in the two-hop amplify-and-forward relay beamforming and establish its duality with the point-to-point single-input multiple-output (SIMO) beamforming system. Simulation results show that the per-antenna power constraint case has much lower per-antenna peak power and much smaller variance of per-antenna power usage than the sum-power constraint case. A heuristic iterative algorithm to minimize the total power of relay network is proposed.

Centralized power system planning covers time windows that range from ten to thirty years. Consequently, it is the longest and most uncertain part of power system economics. One of the challenges that power system planning faces is the inability to accurately predict random events; these random events introduce risk in the planning process. Another challenge stems from the fact that, despite having a centralized planning scheme, generation plans are set first and then transmission expansion plans are carried out. This thesis addresses these problems. A joint model for generation and transmission expansion for the vertically integrated industry is proposed. Randomness is considered in demand, equivalent availability factors of the generators, and transmission capacity factors of the transmission lines. The system expansion model is formulated as a two-stage stochastic program with fixed recourse and probabilistic constraints. The transmission network is included via a DC approximation. The mean variance Markowitz theory is used as a risk minimization technique in order to minimize the variance of the annualized estimated generating cost. This system expansion model is capable of considering the locations of new generation and transmission and also of choosing the right mixture of generating technologies. The global tendency is to move from regulated power systems to deregulated power systems. Power pool electricity markets, assuming that the independent system operator is concerned with the social cost minimization, face great uncertainties from supply and demand bids submitted by market participants. In power pool electricity markets, randomness in the cost and benefit functions through random demand and supply functions has never been considered before. This thesis considers as random all the coefficients of the quadratic cost and benefit functions and uses the mean variance Markowitz theory to minimize the social cost variance. The impacts that this risk minimization technique has on nodal prices and on the elasticities of the supply and demand curves are studied. All the mathematical models in this thesis are exemplified by the six-node network proposed by Garver in 1970, by the 21-node network proposed by the IEEE Reliability Test System Task Force in 1979, and by the IEEE 57- and 118-node systems.

Ontarians are producing more waste per capita than previous generations and consuming more bottled water. Using the product policy quadrangle developed by Oosternhuis (1996), the research examines four components of Ontario bottled water packaging policy— policy objectives, policy instruments, product groups and actors. Interviews with Ontario experts reveal stakeholder communication and Extended Producer Responsibility can promote packaging minimization. There was no agreement about whether Ontario has a waste policy framework to support bottled water waste reduction, reuse and recycling. Stakeholders did agree that a policy framework can help to promote packaging minimization. The discussion will examine the following: various concepts to support zero waste, eco-labelling, policy objectives, enforcement, use of language, focus on financial obligations, deposit-return systems, refillable containers, bottle standardization, waste minimization, how waste is measured, an evaluation of the waste hierarchy, reporting waste reduction and reuse, learning from history and alternative methods of encouraging the consumption of municipal water. The research recommends these changes be implemented with the development of the new Waste Diversion Act. The research recommends that Ontario implement Integrated Product Policy and Extended Producer Responsibility to support packaging minimization.

Centralized power system planning covers time windows that range from ten to thirty years. Consequently, it is the longest and most uncertain part of power system economics. One of the challenges that power system planning faces is the inability to accurately predict random events; these random events introduce risk in the planning process. Another challenge stems from the fact that, despite having a centralized planning scheme, generation plans are set first and then transmission expansion plans are carried out. This thesis addresses these problems. A joint model for generation and transmission expansion for the vertically integrated industry is proposed. Randomness is considered in demand, equivalent availability factors of the generators, and transmission capacity factors of the transmission lines. The system expansion model is formulated as a two-stage stochastic program with fixed recourse and probabilistic constraints. The transmission network is included via a DC approximation. The mean variance Markowitz theory is used as a risk minimization technique in order to minimize the variance of the annualized estimated generating cost. This system expansion model is capable of considering the locations of new generation and transmission and also of choosing the right mixture of generating technologies. The global tendency is to move from regulated power systems to deregulated power systems. Power pool electricity markets, assuming that the independent system operator is concerned with the social cost minimization, face great uncertainties from supply and demand bids submitted by market participants. In power pool electricity markets, randomness in the cost and benefit functions through random demand and supply functions has never been considered before. This thesis considers as random all the coefficients of the quadratic cost and benefit functions and uses the mean variance Markowitz theory to minimize the social cost variance. The impacts that this risk minimization technique has on nodal prices and on the elasticities of the supply and demand curves are studied. All the mathematical models in this thesis are exemplified by the six-node network proposed by Garver in 1970, by the 21-node network proposed by the IEEE Reliability Test System Task Force in 1979, and by the IEEE 57- and 118-node systems.

Ontarians are producing more waste per capita than previous generations and consuming more bottled water. Using the product policy quadrangle developed by Oosternhuis (1996), the research examines four components of Ontario bottled water packaging policy— policy objectives, policy instruments, product groups and actors. Interviews with Ontario experts reveal stakeholder communication and Extended Producer Responsibility can promote packaging minimization. There was no agreement about whether Ontario has a waste policy framework to support bottled water waste reduction, reuse and recycling. Stakeholders did agree that a policy framework can help to promote packaging minimization. The discussion will examine the following: various concepts to support zero waste, eco-labelling, policy objectives, enforcement, use of language, focus on financial obligations, deposit-return systems, refillable containers, bottle standardization, waste minimization, how waste is measured, an evaluation of the waste hierarchy, reporting waste reduction and reuse, learning from history and alternative methods of encouraging the consumption of municipal water. The research recommends these changes be implemented with the development of the new Waste Diversion Act. The research recommends that Ontario implement Integrated Product Policy and Extended Producer Responsibility to support packaging minimization.