King's College London
Towards an Argumentation System for Supporting Patients in Self-Managing Their Chronic Conditions
Kokciyan, Nadin (King's College London) | Sassoon, Isabel (King's College London) | Young, Anthony P. (King's College London) | Chapman, Martin (King's College London) | Porat, Talya (King's College London) | Ashworth, Mark (King's College London) | Curcin, Vasa (King's College London) | Modgil, Sanjay (King's College London) | Parsons, Simon (King's College London) | Sklar, Elizabeth (King's College London)
CONSULT is a decision-support framework designed to help patients self-manage chronic conditions and adhere to agreed-upon treatment plans, in collaboration with healthcare professionals. The approach taken employs computational argumentation, a logic-based methodology that provides a formal means for reasoning with evidence by substantiating claims for and against particular conclusions. This paper outlines the architecture of CONSULT, illustrating how facts are gathered about the patient and various preferences of the patient and the clinician(s) involved. A logic-based representation of official treatment guidelines by various public health agencies is presented. Logical arguments are constructed from these facts and guidelines; these arguments are analysed to resolve inconsistencies concerning various treatment options and patient/clinician preferences. The claims of the justified arguments are the decisions recommended by CONSULT. A clinical example is presented which illustrates the use of CONSULT within the context of blood pressure management for secondary stroke prevention.
User Interfaces and Scheduling and Planning: Workshop Summary and Proposed Challenges
Freedman, Richard G. (University of Massachusetts Amherst) | Chakraborti, Tathagata (Arizona State University) | Talamadupula, Kartik (IBM Research) | Magazzeni, Daniele (King's College London) | Frank, Jeremy D. (NASA Ames Research Center)
The User Interfaces and Scheduling and Planning (UISP) Workshop had its inaugural meeting at the 2017 International Conference on Automated Scheduling and Planning (ICAPS). The UISP community focuses on bridging the gap between automated planning and scheduling technologies and user interface (UI) technologies. Planning and scheduling systems need UIs, and UIs can be designed and built using planning and scheduling systems. The workshop participants included representatives from government organizations, industry, and academia with various insights and novel challenges. We summarize the discussions from the workshop as well as outline challenges related to this area of research, introducing the now formally established field to the broader user experience and artificial intelligence communities.
Situated Planning for Execution Under Temporal Constraints
Cashmore, Michael (King's College London ) | Coles, Andrew (King's College London ) | Cserna, Bence (University of New Hampshire) | Karpas, Erez (Technion) | Magazzeni, Daniele (King's College London) | Ruml, Wheeler (University of New Hampshire)
One of the original motivations for domain-independent planning was to generate plans that would then be executed in the environment. However, most existing planners ignore the passage of time during planning. While this can work well when absolute time does not play a role, this approach can lead to plans failing when there are external timing constraints, such as deadlines. In this paper, we describe a new approach for time-sensitive temporal planning. Our planner is aware of the fact that plan execution will start only once planning finishes, and incorporates this information into its decision making, in order to focus the search on branches that are more likely to lead to plans that will be feasible when the planner finishes.
Combining Experts’ Causal Judgments
Alrajeh, Dalal ( Imperial College London ) | Chockler, Hana (King's College London) | Halpern, Joseph Yehuda (Cornell University)
Consider a policymaker who wants to decide which intervention to perform in order to change a currently undesirable situation. The policymaker has at her disposal a team of experts, each with their own understanding of the causal dependencies between different factors contributing to the outcome. The policymaker has varying degrees of confidence in the experts’ opinions. She wants to combine their opinions in order to decide on the most effective intervention. We formally define the notion of an effective intervention, and then consider how experts’ causal judgments can be combined in order to determine the most effective intervention. We define a notion of two causal models being compatible , and show how compatible causal models can be combined. We then use it as the basis for combining experts causal judgments. We illustrate our approach on a number of real-life examples.
A Temporal Relaxed Planning Graph Heuristic for Planning with Envelopes
Coles, Amanda Jane (King's College London) | Coles, Andrew Ian (King's College London)
When planning in temporal domains with required concurrency, envelopes arise where one or more actions need to occur within the execution of another. Starting an envelope action gives rise to an implicit relative deadline: all of the actions that need to occur within the envelope must complete before it ends. Finding effective heuristic guidance in these domains is challenging: the heuristic must not only consider how to reach the goals, but identify when it is not possible to achieve these implicit deadlines to avoid fruitless search. In this paper, we present an adaptation of a Temporal Relaxed Planning Graph heuristic, that accounts for dependencies between facts and actions in the relaxed planning graph; and the envelopes that are open in the state being evaluated. Results show that our new heuristic significantly improves the performance of a temporal planner on benchmark domains with required concurrency.
Grid Pathfinding on the 2 k Neighborhoods
Rivera, Nicolas (King's College London) | Hernández, Carlos (Universidad Andrés Bello) | Baier, Jorge A. (Pontificia Universidad Catolica de Chile)
Grid pathfinding, an old AI problem, is central for the development of navigation systems for autonomous agents. A surprising fact about the vast literature on this problem is that very limited neighborhoods have been studied. Indeed, only the 4- and 8-neighborhoods are usually considered, and rarely the 16-neighborhood. This paper describes three contributions that enable the construction of effective grid path planners for extended 2 k -neighborhoods. First, we provide a simple recursive definition of the 2 k -neighborhood in terms of the 2 k –1 -neighborhood. Second, we derive distance functions, for any k >1, which allow us to propose admissible heurisitics which are perfect for obstacle-free grids. Third, we describe a canonical ordering which allows us to implement a version of A* whose performance scales well when increasing k . Our empirical evaluation shows that the heuristics we propose are superior to the Euclidean distance (ED) when regular A* is used. For grids beyond 64 the overhead of computing the heuristic yields decreased time performance compared to the ED. We found also that a configuration of our A*-based implementation, without canonical orders, is competitive with the "any-angle" path planner Theta$^*$ both in terms of solution quality and runtime.
Deterministic versus Probabilistic Methods for Searching for an Evasive Target
Bernardini, Sara (Royal Holloway University of London) | Fox, Maria (King's College London) | Long, Derek (King's College London) | Piacentini, Chiara (University of Toronto)
Several advanced applications of autonomous aerial vehicles in civilian and military contexts involve a searching agent with imperfect sensors that seeks to locate a mobile target in a given region. Effectively managing uncertainty is key to solving the related search problem, which is why all methods devised so far hinge on a probabilistic formulation of the problem and solve it through branch-and-bound algorithms, Bayesian filtering or POMDP solvers. In this paper, we consider a class of hard search tasks involving a target that exhibits an intentional evasive behaviour and moves over a large geographical area, i.e., a target that is particularly difficult to track down and uncertain to locate. We show that, even for such a complex problem, it is advantageous to compile its probabilistic structure into a deterministic model and use standard deterministic solvers to find solutions. In particular, we formulate the search problem for our uncooperative target both as a deterministic automated planning task and as a constraint programming task and show that in both cases our solution outperforms POMDPs methods.
PDDL+ Planning with Temporal Pattern Databases
Piotrowski, Wiktor Mateusz (King's College London) | Fox, Maria (King's College London) | Long, Derek (King's College London) | Magazzeni, Daniele (King's College London) | Mercorio, Fabio (University of Milano-Bicocca)
The introduction of PDDL+ allowed more accurate representations of complex real-world problems of interest to the scientific community. However, PDDL+ problems are notoriously challenging to planners, requiring more advanced heuristics. We introduce the Temporal Pattern Database (TPDB), a new domain-independent heuristic technique designed for PDDL+ domains with mixed discrete/continuous behaviour, non-linear system dynamics, processes, and events. The pattern in the TPDB is obtained through an abstraction based on time and state discretisation. Our approach combines constraint relaxation and abstraction techniques, and uses solutions to the relaxed problem, as a guide to solving the concrete problem with a discretisation fine enough to satisfy the continuous model's constraints.
Initial State Prediction in Planning
Krivic, Senka (University of Innsbruck) | Cashmore, Michael (King's College London) | Ridder, Bram (King's College London) | Magazzeni, Daniele (King's College London) | Szedmak, Sandor (Aalto University) | Piater, Justus (University of Innsbruck)
While recent advances in offline reasoning techniques and online execution strategies have made planning under uncertainty more robust, the application of plans in partially-known environments is still a difficult and important topic. In this paper we present an approach for predicting new information about a partially-known initial state, represented as a multigraph utilizing Maximum-Margin Multi-Valued Regression. We evaluate this approach in four different domains, demonstrating high recall and accuracy.
Reports of the 2016 AAAI Workshop Program
Albrecht, Stefano (The University of Texas at Austin) | Bouchard, Bruno (Université du Québec à Chicoutimi) | Brownstein, John S. (Harvard University) | Buckeridge, David L. (McGill University) | Caragea, Cornelia (University of North Texas) | Carter, Kevin M. (MIT Lincoln Laboratory) | Darwiche, Adnan (University of California, Los Angeles) | Fortuna, Blaz (Bloomberg L.P. and Jozef Stefan Institute) | Francillette, Yannick (Université du Québec à Chicoutimi) | Gaboury, Sébastien (Université du Québec à Chicoutimi) | Giles, C. Lee (Pennsylvania State University) | Grobelnik, Marko (Jozef Stefan Institute) | Hruschka, Estevam R. (Federal University of São Carlos) | Kephart, Jeffrey O. (IBM Thomas J. Watson Research Center) | Kordjamshidi, Parisa (University of Illinois at Urbana-Champaign) | Lisy, Viliam (University of Alberta) | Magazzeni, Daniele (King's College London) | Marques-Silva, Joao (University of Lisbon) | Marquis, Pierre (Université d'Artois) | Martinez, David (MIT Lincoln Laboratory) | Michalowski, Martin (Adventium Labs) | Shaban-Nejad, Arash (University of California, Berkeley) | Noorian, Zeinab (Ryerson University) | Pontelli, Enrico (New Mexico State University) | Rogers, Alex (University of Oxford) | Rosenthal, Stephanie (Carnegie Mellon University) | Roth, Dan (University of Illinois at Urbana-Champaign) | Sinha, Arunesh (University of Southern California) | Streilein, William (MIT Lincoln Laboratory) | Thiebaux, Sylvie (The Australian National University) | Tran, Son Cao (New Mexico State University) | Wallace, Byron C. (University of Texas at Austin) | Walsh, Toby (University of New South Wales and Data61) | Witbrock, Michael (Lucid AI) | Zhang, Jie (Nanyang Technological University)
The Workshop Program of the Association for the Advancement of Artificial Intelligence’s Thirtieth AAAI Conference on Artificial Intelligence (AAAI-16) was held at the beginning of the conference, February 12-13, 2016. Workshop participants met and discussed issues with a selected focus — providing an informal setting for active exchange among researchers, developers and users on topics of current interest. To foster interaction and exchange of ideas, the workshops were kept small, with 25-65 participants. Attendance was sometimes limited to active participants only, but most workshops also allowed general registration by other interested individuals. The AAAI-16 Workshops were an excellent forum for exploring emerging approaches and task areas, for bridging the gaps between AI and other fields or between subfields of AI, for elucidating the results of exploratory research, or for critiquing existing approaches. The fifteen workshops held at AAAI-16 were Artificial Intelligence Applied to Assistive Technologies and Smart Environments (WS-16-01), AI, Ethics, and Society (WS-16-02), Artificial Intelligence for Cyber Security (WS-16-03), Artificial Intelligence for Smart Grids and Smart Buildings (WS-16-04), Beyond NP (WS-16-05), Computer Poker and Imperfect Information Games (WS-16-06), Declarative Learning Based Programming (WS-16-07), Expanding the Boundaries of Health Informatics Using AI (WS-16-08), Incentives and Trust in Electronic Communities (WS-16-09), Knowledge Extraction from Text (WS-16-10), Multiagent Interaction without Prior Coordination (WS-16-11), Planning for Hybrid Systems (WS-16-12), Scholarly Big Data: AI Perspectives, Challenges, and Ideas (WS-16-13), Symbiotic Cognitive Systems (WS-16-14), and World Wide Web and Population Health Intelligence (WS-16-15).