Uncertainty
A Variational Inference Procedure Allowing Internal Structure for Overlapping Clusters and Deterministic Constraints
Geiger, D., Meek, C., Wexler, Y.
We develop a novel algorithm, called VIP*, for structured variational approximate inference. This algorithm extends known algorithms to allow efficient multiple potential updates for overlapping clusters, and overcomes the difficulties imposed by deterministic constraints. The algorithm's convergence is proven and its applicability demonstrated for genetic linkage analysis.
Intelligent Multiobjective Optimization of Distribution System Operations
Sarfi, Robert J., Solo, Ashu M. G.
A hybrid fuzzy knowledge-based system with crisp and fuzzy rules as well as numerical methods was developed for multiobjective optimization of power distribution system operation. The development process and knowledge-acquisition process for the fuzzy knowledge-based system are described in detail. After a heuristic preprocessor proposes a list of switch openings that would seem to reduce system losses, network radiality rules consider whether to open a particular switch and find a corresponding switch that can be closed to maintain radiality. Network performance rules find the degree of desirability of proposed switching combinations for enhancing multiple objectives.
Automating the Underwriting of Insurance Applications
Aggour, Kareem S., Bonissone, Piero P., Cheetham, William E., Messmer, Richard P.
An end-to-end system was created at Genworth Financial to automate the underwriting of long-term care (LTC) and life insurance applications. Relying heavily on artificial intelligence techniques, the system has been in production since December 2002 and in 2004 completely automates the underwriting of 19 percent of the LTC applications. A fuzzy logic rules engine encodes the underwriter guidelines and an evolutionary algorithm optimizes the engine's performance. Finally, a natural language parser is used to improve the coverage of the underwriting system.
Intelligent Multiobjective Optimization of Distribution System Operations
Sarfi, Robert J., Solo, Ashu M. G.
Also, it provides a means for conflict resolution of multiple criteria and better assessment of options. This system provides identification, recognition, optimization, a very powerful solution methodology by permitting and control. The algorithmic methods optimization of power distribution system provide updates to the system status operation (Sarfi and Solo 2005a). Sarfi, Salama, and Chikhani (1994a) as well as system with a coupling between knowledgebased Sarfi and Solo (2002c) demonstrate that fuzzy and numerical methods combines the logic is not an asset in all power systems planning advantages of both methods for multiobjective and operation scenarios. Some rules do optimization of power distribution system not involve any uncertainty or can be represented operation. One must to ensure that the best methods are employed. An extensive study of software effectively optimizes a power distribution network tools used in real-time power system for multiple system-performance objectives, applications concluded that electric utility including system loss reduction, transformer companies were not satisfied with conventional load balancing, reduction of transformer approaches based on numerical methods in aging to decrease the failure rate and 50 percent of the cases examined (Sarfi, Salama, increase continuity of service, maintenance of and Chikhani 1994a). Dissatisfied parties a satisfactory voltage profile throughout the cited two major shortcomings in techniques network, reactive power compensation, and based on numerical methods: (1) lack of flexibility conservative voltage reduction (CVR) practice in system modeling, and (2) exclusion of to achieve peak shaving.
Convexity Arguments for Efficient Minimization of the Bethe and Kikuchi Free Energies
Loopy and generalized belief propagation are popular algorithms for approximate inference in Markov random fields and Bayesian networks. Fixed points of these algorithms have been shown to correspond to extrema of the Bethe and Kikuchi free energy, both of which are approximations of the exact Helmholtz free energy. However, belief propagation does not always converge, which motivates approaches that explicitly minimize the Kikuchi/Bethe free energy, such as CCCP and UPS. Here we describe a class of algorithms that solves this typically non-convex constrained minimization problem through a sequence of convex constrained minimizations of upper bounds on the Kikuchi free energy. Intuitively one would expect tighter bounds to lead to faster algorithms, which is indeed convincingly demonstrated in our simulations. Several ideas are applied to obtain tight convex bounds that yield dramatic speed-ups over CCCP.
A Logic for Reasoning about Evidence
We introduce a logic for reasoning about evidence that essentially views evidence as a function from prior beliefs (before making an observation) to posterior beliefs (after making the observation). We provide a sound and complete axiomatization for the logic, and consider the complexity of the decision problem. Although the reasoning in the logic is mainly propositional, we allow variables representing numbers and quantification over them. This expressive power seems necessary to capture important properties of evidence.
Scalable Algorithms for Aggregating Disparate Forecasts of Probability
Predd, Joel B., Kulkarni, Sanjeev R., Osherson, Daniel N., Poor, H. Vincent
In this paper, computational aspects of the panel aggregation problem are addressed. Motivated primarily by applications of risk assessment, an algorithm is developed for aggregating large corpora of internally incoherent probability assessments. The algorithm is characterized by a provable performance guarantee, and is demonstrated to be orders of magnitude faster than existing tools when tested on several real-world data-sets. In addition, unexpected connections between research in risk assessment and wireless sensor networks are exposed, as several key ideas are illustrated to be useful in both fields.
A Continuation Method for Nash Equilibria in Structured Games
Blum, B., Shelton, C. R., Koller, D.
Structured game representations have recently attracted interest as models for multi-agent artificial intelligence scenarios, with rational behavior most commonly characterized by Nash equilibria. This paper presents efficient, exact algorithms for computing Nash equilibria in structured game representations, including both graphical games and multi-agent influence diagrams (MAIDs). The algorithms are derived from a continuation method for normal-form and extensive-form games due to Govindan and Wilson; they follow a trajectory through a space of perturbed games and their equilibria, exploiting game structure through fast computation of the Jacobian of the payoff function. They are theoretically guaranteed to find at least one equilibrium of the game, and may find more. Our approach provides the first efficient algorithm for computing exact equilibria in graphical games with arbitrary topology, and the first algorithm to exploit fine-grained structural properties of MAIDs. Experimental results are presented demonstrating the effectiveness of the algorithms and comparing them to predecessors. The running time of the graphical game algorithm is similar to, and often better than, the running time of previous approximate algorithms. The algorithm for MAIDs can effectively solve games that are much larger than those solvable by previous methods.
Using Educational Robotics to Motivate Complete AI Solutions
Greenwald, Lloyd, Artz, Donovan, Mehta, Yogi, Shirmohammadi, Babak
Robotics is a remarkable domain that may be successfully employed in the classroom both to motivate students to tackle hard AI topics and to provide students experience applying AI representations and algorithms to real-world problems. This article uses two example robotics problems to illustrate these themes. We show how the robot obstacle-detection problem can motivate learning neural networks and Bayesian networks. We also show how the robot-localization problem can motivate learning how to build complete solutions based on particle filtering. Since these lessons can be replicated on many low-cost robot platforms they are accessible to a broad population of AI students. We hope that by outlining our educational exercises and providing pointers to additional resources we can help reduce the effort expended by other educators. We believe that expanding handson active learning to additional AI classrooms provides value both to the students and to the future of the field itself.
Unifying Undergraduate Artificial Intelligence Robotics: Layers of Abstraction over Two Channels
From a computer science and artificial intelligence perspective, robotics often appears as a collection of disjoint, sometimes antagonistic subfields. The lack of a coherent and unified presentation of the field negatively affects teaching, especially to undergraduates. This article presents an alternative synthesis of the various subfields of AI robotics and shows how these traditional subfields fit into the whole. Finally, it presents a curriculum based on these ideas.