We consider the problem of providing spelling corrections for misspelled queries in Email Search using user’s own mail data. A popular strategy for general query spelling correction is to generate corrections from query logs. However, this strategy is not effective in Email Search for two reasons: 1) query log of any sin- gle user is typically not rich enough to provide potential corrections for a new query 2) corrections generated us- ing query logs of other users are not particularly useful since the mail data as well as search intent are highly specific to the user. We address the challenge of design- ing an effective spelling correction algorithm for Email Search in the absence of query logs. We propose SpEQ, a Machine Learning based approach that generates cor- rections for misspelled queries directly from the user’s own mail data.

Modern technical devices are often too complex for many users to be able to use them to their full extent. Based on planning technology, we are able to provide advanced user assistance for operating technical devices. We present a system that assists a human user in setting up a complex home theater consisting of several HiFi devices. For a human user, the task is rather challenging due to a large number of different ports of the devices and the variety of available cables. The system supports the user by giving detailed instructions how to assemble the theater. Its performance is based on advanced user-centered planning capabilities including the generation, repair, and explanation of plans.

Scheduling is integral to many real-world logistics problems. It can be as simple as catching the bus in the morning, or as complex as assembling a commercial airliner. While simple applications render scheduling tools trivial, these tools have not been widely adopted for complex scenarios either. The larger the scenario, the greater the temporal uncertainty throughout the system, and many schedulers do not consider the probabilistic uncertainty in actions' durations. Figure 1: The role of scheduling in a plannning and execution This makes them brittle to temporal disturbances or architecture. In this architecture, the planner and scheduler first generate Figure 1 diagrams the layers of reasoning for a planning executive a plan and scheduling policy offline, which the dispatcher to map logistical goals into real-world actions.

Markov logic networks (MLNs) combine the power of first-order logic and probabilistic graphical models and as a result are ideally suited for solving large, complex problems in application domains that have both rich relational structure and large amount of uncertainty. However, inference in these rich, relational representations is quite challenging. The aim of this thesis is to advance the state-of-the-art in MLN inference, enabling it to solve much harder and more complex tasks than is possible today. To this end, I will develop techniques that exploit logical structures and symmetries that are either explicitly or implicitly encoded in the MLN representation and demonstrate their usefulness by using them to solve hard real-world problems in the field of natural language understanding.

It is known that we can aggregate the opinions of different agents to find high-quality solutions to complex problems. However, choosing agents to form a team is still a great challenge. Moreover, it is essential to use a good aggregation methodology in order to unleash the potential of a given team in solving complex problems. In my thesis, I present two different novel models to aid in the team formation process. Moreover, I propose a new methodology for extracting rankings from existing agents. I show experimental results both in the Computer Go domain and in the building design domain.

Argumentation Theory and Answer Set Programming (ASP) are two prominent theories in the field of knowledge representation and non-monotonic reasoning,where Argumentation Theory stands for a variety of approaches following similar ideas.The main difference between Argumentation Theory and ASP is that the former focusses on representing knowledge and reasoning about it in a way that resembles human reasoning, neglecting the efficiency of the reasoning procedure,whereas the latter is concerned with the efficient computation of solutions to a reasoning problem, resulting in a less human-understandable process. In recent years, ASP has been frequently applied for the computation of reasoning problems represented in argumentation-theoretical-terms and has been found an efficient method for determining solutions to problems in Argumentation Theory. My research is concerned with the opposite direction, i.e. with applying Argumentation Theory to ASP in order to explain the solutions to an ASP reasoning problem in a more human-understandable way.Developing such an explanation method also involves to investigate both the exact relationship between different approaches in Argumentation Theory in order to find the most suitable one for explanations and their connection with ASP, in particular with respect to their semantics.

In a heterogeneous multiagent system it can be useful to have knowledge about the different types of agents in the system. Agent modeling develops agent models based on interactions between agents, then predicts agent actions. This approach is effective in small domains but does not scale well. We develop an approach where an agent can learn using an abstract model identification or stereotype rather than an explicit and unique model for each agent. We associate each agent with a stereotype and learn a policy incorporating this knowledge. The benefits of this approach are that it is simple, scalable, and degrades gracefully with misidentification.

My research focuses on developing innovative ways to control Heating, Ventilation, and Air Conditioning (HVAC) and schedule occupancy flows in smart buildings to reduce our ecological footprint (and energy bills). We look at the potential for integrating building operations with room booking and meeting scheduling. Specifically, we improve on the effectiveness of energy-aware room-booking and occupancy scheduling approaches, by allowing the scheduling decisions to rely on an explicit model of the building's occupancy-based HVAC control. From computational standpoint, this is a challenging topic as HVAC models are inherently non-linear non-convex, and occupancy scheduling models additionally introduce discrete variables capturing the time slot and location at which each activity is scheduled. The mechanism needs to tradeoff minimizing energy cost against addressing occupancy thermal comfort and control feasibility in a highly dynamic and uncertain system.

Today’s data centers are designed with multi-core CPUs where multiple virtual machines (VMs) can be co-located into one physical machine or distribute multiple computing tasks onto one physical machine. The result is co-tenancy, resource sharing and competition. Modeling and predicting such co-run interference becomes crucial for job scheduling and Quality of Service assurance. Co-locating interference can be characterized into two components, sensitivity and pressure, where sensitivity characterizes how an application’s own performance is affected by a co-run application, and pressure characterizes how much contentiousness an application exerts/brings onto the memory subsystem. Previous studies show that with simple models, sensitivity and pressure can be accurately characterized for a single machine. We extend the models to consider cross-architecture sensitivity (across different machines).

For my dissertation I am focusing on non-classical planning for robotic applications. Much classical planning research relies on assumptions that do not hold in real world robotics applications. In many cases the entire world state is not known in advance and the events that occur in the future can not be known with certainty. Robots operating in the real world also need to be responsive and react to dynamic obstacles and events.