In many distributed systems robustness is a major concern since network nodes might fail spontaneously. Such failures can be a major problem when a workflow needs to be run on a set of unreliable and distributed nodes. Replication is a widely used architecture paradigm to increase system reliability. This thesis addresses robustness of workflow execution in distributed systems using replication...

In database query processing, actual run-time conditions (e.g., actual selectivities and actual available memory) very often differ from compile-time expectations of run-time conditions (e.g., estimated predicate selectivities and anticipated memory availability). Robustness of query processing can be defined as the ability to handle unexpected conditions. Robustness of query execution, specifi...

Model predictive control (MPC) is a popular control method that has proved effective for robotics, among other fields. MPC performs re-planning at every time step. Replanning is done with a limited horizon per computational and real-time constraints and often also for robustness to potential model errors. However, the limited horizon leads to suboptimal performance. In this work, we consider th...

Stochastic Optimal Control (SOC) is typically used to plan a movement for a specific situation. While most SOC methods fail to generalize this movement plan to a new situation without re-planning, we present a SOC method that allows us to reuse the obtained policy in a new situation as the policy is more robust to slight deviations from the initial movement plan. In order to improve the robustn...

in spark ignition (si) engines, the accurate control of air fuel ratio (afr) in the stoichiometric value is required to reduce emission and fuel consumption. the wide operating range, the inherent nonlinearities and the modeling uncertainties of the engine system are the main difficulties arising in the design of afr controller. in this paper, an optimization-based nonlinear control law is anal...

Real-world applications of autonomous agents require coordinated groups to work in collaboration. Dependable systems must plan and carry out activities in a way that is robust to failure and uncertainty. Previous work has produced algorithms that provide robustness at the planning phase, by choosing between functionally redundant methods, and the execution phase, by dispatching temporally flexi...