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Heuristic Planning in Adversarial Dynamic Domains
Chamberland, Simon (Université) | Kabanza, Froduald (de Sherbrooke)
Agents in highly dynamic adversarial domains, such as RTS games, must continually make time-critical decisions to adapt their behaviour to the changing environment. In such a context, the planning agent must consider his opponent's actions as uncontrollable, or at best influenceable. In general nondeterministic domains where there is no clear turn-taking protocol, most heuristic search methods to date do not explicitly reason about the opponent's actions when guiding the state space exploration towards goal or high-reward states. In contrast, we are investigating a domain-independent heuristic planning approach which reasons about the dynamics and uncontrollability of the opponent's behaviours in order to provide better guidance to the search process of the planner. Our planner takes as input the opponent's behaviours recognized by a plan recognition module and uses them to identify opponent's actions that lead to low-utility projected states. We believe such explicit heuristic reasoning about the potential behaviours of the opponent is crucial when planning in adversarial domains, yet is missing in today's planning approaches.
Dynamic Batch Mode Active Learning via L1 Regularization
Chakraborty, Shayok (Arizona State University) | Balasubramanian, Vineeth (Arizona State University) | Panchanathan, Sethuraman (Arizona State University)
Active learning algorithms strategy to simultaneously decide the batch size as well as automatically select the exemplar data instances from identify the informative points to be selected for manual annotation, an unlabeled set and thereby reduce human annotation effort through a single framework. Our method has the in training a classifier. Conventional methods of active same complexity as the state-of-the-art static BMAL technique, learning have focused on the pool-based strategy where the where the batch size is pre-specified by the user.
Provoking Opponents to Facilitate the Recognition of their Intentions
Bisson, Francis (Université) | Kabanza, Froduald (de Sherbrooke) | Benaskeur, Abder Rezak (Université) | Irandoust, Hengameh (de Sherbrooke)
Possessing a sufficient level of situation awareness is essential for effective decision making in dynamic environments. In video games, this includes being aware to some extent of the intentions of the opponents. Such high-level awareness hinges upon inferences over the lower-level situation awareness provided by the game state. Traditional plan recognizers are completely passive processes that leave all the initiative to the observed agent. In a situation where the opponent's intentions are unclear, the observer is forced to wait until further observations of the opponent's actions are made to disambiguate the pending goal hypotheses. With the plan recognizer we propose, in contrast, the observer would take the initiative and provoke the opponent, with the expectation that his reaction will give cues as to what his true intentions actually are.
Reconstructing the Stochastic Evolution Diagram of Dynamic Complex Systems
Bazzazzadeh, Navid (University of Heidelberg) | Brors, Benedikt (University of Heidelberg) | Eils, Roland (University of Heidelberg)
The behavior and dynamics of complex systems are in focus of many research fields. The complexity of such systems comes not only from the number of their elements, but also from the unavoidable emergence of new properties of the system, which are not just a simple summation of the properties of its elements. The behavior of complex systems can be fitted with a number of well developed models, which, however, do not incorporate the modularity and the evolution of a system simultaneously. In this work, we propose a generalized model that addresses this issue. Our model is developed within the Random Set Theoryโs framework and allows for reconstructing the stochastic evolution diagrams of complex systems.
Ad Hoc Teamwork in Variations of the Pursuit Domain
Barrett, Samuel (The University of Texas at Austin) | Stone, Peter (The University of Texas at Austin)
In multiagent team settings, the agents are often given a protocol for coordinating their actions. When such a protocol is not available, agents must engage in ad hoc teamwork to effectively cooperate with one another. A fully general ad hoc team agent needs to be capable of collaborating with a wide range of potential teammates on a varying set of joint tasks. This paper extends previous research in a new direction with the introduction of an efficient method for reasoning about the value of information.ย Then, we show how previous theoretical results can aid ad hoc agents in a set of testbed pursuit domains.
Solving 4x5 Dots-And-Boxes
Barker, Joseph Kelly (University of California, Los Angeles) | Korf, Richard E. (University of California, Los Angeles)
Dots-And-Boxes is a well-known and widely-played combinatorial game. While the rules of play are very simple, the state space for even small games is extremely large, and finding the outcome under optimal play is correspondingly hard. In this paper we introduce a Dots-And-Boxes solver which is significantly faster than the current state-of-the-art: over an order-of-magnitude faster on several large problems. We describe our approach, which uses Alpha-Beta search and applies a number of techniquesโboth problem-specific and generalโto reduce the number of duplicate states explored and reduce the search space to a manageable size. Using these techniques, we have determined for the first time that Dots- And-Boxes on a board of 4x5 boxes is a tie given optimal play. This is the largest game solved to date.
Controlling Selection Bias in Causal Inference
Bareinboim, Elias (University of California, Los Angeles) | Pearl, Judea (University of California, Los Angeles)
Selection bias, caused by preferential exclusion of units (or samples) from the data, is a major obstacle to valid causal inferences, for it cannot be removed or even detected by randomized experiments. This paper highlights several graphical and algebraic methods capable of mitigating and sometimes eliminating this bias.
Medical Treatment Conflict Resolving in Answer Set Programming
Bao, Forrest Sheng (Texas Tech University) | Zhang, Zhizheng (Southeast University) | Zhang, Yuanlin (Texas Tech University)
Medical treatment decision making is a good application of knowledge representation and reasoning. We are particularly interested in using it to resolve treatment conflicts, a complicated condition when two treatments cannot be given simultaneously to a patient of multiple symptoms. The logic system is required to reason on cases with and without treatment conflicts. Thanks to the nonmonotonicity of Answer Set Programming (ASP), we elegantly automate medical treatment conflict resolving on an example problem and show the importance of nonmonotonicity in medical reasoning.
Assessing Quality in the Web of Linked Sensor Data
Baillie, Chris Colin (University of Aberdeen) | Edwards, Peter (University of Aberdeen) | Pignotti, Edoardo (University of Aberdeen)
We also require a generic model of provenance The Web has evolved from a collection of hyperlinked documents in order to support the diverse ecosystem of sensor to a complex ecosystem of interconnected documents, platforms and data. We have investigated a number of existing services and devices. Due to the inherent open nature of the models for representing provenance information but Web, data can be published by anyone or any'thing'. As a found many of these to be tailored to specific domains result of this, there is enormous variation in the quality of (e.g.
Learning Compact Representations of Time-Varying Processes
Bachman, Philip (McGill University) | Precup, Doina (McGill University)
We seek informative representations of the processes underlying time series data. As a first step, we address problems in which these processes can be approximated by linear models that vary smoothly over time. To facilitate estimation of these linear models, we introduce a method of dimension reduction which significantly reduces error when models are estimated locally for each point in time. This improvement is gained by performing dimension reduction implicitly through the model parameters rather than directly in the observation space.