Europe
A Heuristic Method for Solving the Problem of Partitioning Graphs with Supply and Demand
Jovanovic, Raka, Bousselham, Abdelkader, Voss, Stefan
In this paper we present a greedy algorithm for solving the problem of the maximum partitioning of graphs with supply and demand (MPGSD). The goal of the method is to solve the MPGSD for large graphs in a reasonable time limit. This is done by using a two stage greedy algorithm, with two corresponding types of heuristics. The solutions acquired in this way are improved by applying a computationally inexpensive, hill climbing like, greedy correction procedure. In our numeric experiments we analyze different heuristic functions for each stage of the greedy algorithm, and show that their performance is highly dependent on the properties of the specific instance. Our tests show that by exploring a relatively small number of solutions generated by combining different heuristic functions, and applying the proposed correction procedure we can find solutions within only a few percent of the optimal ones.
A Multi-Heuristic Approach for Solving the Pre-Marshalling Problem
Jovanovic, Raka, Tuba, Milan, Voss, Stefan
Minimizing the number of reshuffling operations at maritime container terminals incorporates the Pre-Marshalling Problem (PMP) as an important problem. Based on an analysis of existing solution approaches we develop new heuristics utilizing specific properties of problem instances of the PMP. We show that the heuristic performance is highly dependent on these properties. We introduce a new method that exploits a greedy heuristic of four stages, where for each of these stages several different heuristics may be applied. Instead of using randomization to improve the performance of the heuristic, we repetitively generate a number of solutions by using a combination of different heuristics for each stage. In doing so, only a small number of solutions is generated for which we intend that they do not have undesirable properties, contrary to the case when simple randomization is used. Our experiments show that such a deterministic algorithm significantly outperforms the original nondeterministic method when the quality of found solutions is observed, with a much lower number of generated solutions.
The Chimeria Platform: An Intelligent Narrative System for Modeling Social Identity-Related Experiences
Harrell, D. Fox (Massachussets Institute of Technology) | Kao, Dominic (Massachussets Institute of Technology) | Lim, Chong-U (Massachussets Institute of Technology) | Lipshin, Jason (Massachussets Institute of Technology) | Sutherland, Ainsley (Massachussets Institute of Technology) | Makivic, Julia (Wellesley College)
We demonstrate the Chimeria Platform that computationally models aspects of social identity dynamics for use in digital media such as in videogames and social networks. The Engine models users’ degrees of membership across multiple categories as gradient values, enabling more representational nuance than binary statuses of member/nonmember. The Application Interface handles user interaction and visuals for experiencing the narratives. Domain Epistemologies specify domain-specific ontologies that describe cultural knowledge and beliefs for each narrative. Our Visual Narrative Editor GUI is being developed to make authoring more accessible to a wider audience.
Telling the Difference Between Asking and Stealing: Moral Emotions in Value-based Narrative Characters
Battaglino, Cristina (Università di Torino) | Damiano, Rossana (Università di Torino) | Dias, Joao (INESC-ID, Instituto Superior Tecnico)
In this paper, we translate a model of value-based emo- tional agents into an architecture for narrative characters and we validate it in a narrative scenario. The advantage of using such model is that different moral behaviors can be obtained as a consequence of the emotional ap- praisal of moral values, a desirable feature for digital storytelling techniques.
Opportunistic Storytelling: An Experience-Oriented Strategy for Playable Interactive Narratives
Tomai, Emmett (University of Texas - Pan American)
AI research in interactive narrative often lacks specificity as to the player experience it is trying to enable. In this paper, we consider a set of desirable elements from narrative and interactive experiences, and show by looking at playable experiences from industry and academia that combining them has the potential to be limited or self-defeating. To address these issues, we propose opportunistic storytelling , a set of design principles for near-term playable interactive narratives.
Minimal Narrative Annotation Schemes and Their Applications
Rahimtoroghi, Elahe (University of California, Santa Cruz) | Corcoran, Thomas (University of California, Santa Cruz) | Swanson, Reid (University of California, Santa Cruz) | Walker, Marilyn A. (University of California, Santa Cruz) | Sagae, Kenji (Institute for Creative Technologies, University of Southern California) | Gordon, Andrew (Institute for Creative Technologies, University of Southern California)
The increased use of large corpora in narrative research has created new opportunities for empirical research and intelligent narrative technologies. To best exploit the value of these corpora, several research groups are eschewing complex discourse analysis techniques in favor of high-level minimalist narrative annotation schemes that can be quickly applied, achieve high inter-rater agreement, and are amenable to automation using machine-learning techniques. In this paper we compare different annotation schemes that have been employed by two groups of researchers to annotate large corpora of narrative text. Using a dual-annotation methodology, we investigate the correlation between narrative clauses distinguished by their structural role (orientation, action, evaluation), their subjectivity, and their narrative level within the discourse. We find that each simple narrative annotation scheme captures a structurally distinct characteristic of real-world narratives, and each combination of labels is evident in a corpus of 19 weblog narratives (951 narrative clauses). We discuss several potential applications of minimalist narrative annotation schemes, noting the combination of label across these two annotation schemes that best support each task.
Use of Patient Generated Data from Social Media and Collaborative Filtering for Preferences Elicitation in Shared Decision Making
Parimbelli, Enea (University of Pavia) | Quaglini, Silvana (University of Pavia) | Napolitano, Carlo (IRCCS Fondazione Salvatore Maugeri) | Priori, Silvia (IRCCS Fondazione Salvatore Maugeri) | Bellazzi, Riccardo (University of Pavia, IRCCS Fondazione Salvatore Maugeri) | Holmes, John (University of Pennsylvania)
With the increasing demand for personalization in clinical decision support system, one of the most challenging tasks is effective patient preferences elicitation. In the context of the MobiGuide project, within a medical application related to atrial fibrillation, a decision support system has been developed for both doctors and patients. In particular, we support shared decision-making, by integrating decision tree models with a dedicated tool for utility coefficients elicitation. In this paper we focus on the decision problem regarding the choice of anticoagulant therapy for low risk non-valvular atrial fibrillation patients. In addition to the traditional methods, such as time trade-off and standard gamble, an alternative way for preferences elicitation is proposed, exploiting patients’ self-reported data in health-related social media as the main source of information.
Nonverbal Behavior Modeling for Socially Assistive Robots
Admoni, Henny (Yale University) | Scassellati, Brian (Yale University)
The field of socially assistive robotics (SAR) aims to build robots that help people through social interaction. Human social interaction involves complex systems of behavior, and modeling these systems is one goal of SAR. Nonverbal behaviors, such as eye gaze and gesture, are particularly amenable to modeling through machine learning because the effects of the system—the nonverbal behaviors themselves—are inherently observable. Uncovering the underlying model that defines those behaviors would allow socially assistive robots to become better interaction partners. Our research investigates how people use nonverbal behaviors in tutoring applications. We use data from human-human interactions to build a model of nonverbal behaviors using supervised machine learning. This model can both predict the context of observed behaviors and generate appropriate nonverbal behaviors.
Knowledge Extraction from Learning Traces in Continuous Domains
Doncieux, Stephane (Sorbonne Universités and The National Center for Scientific Research (CNRS))
A method is introduced to extract and transfer knowledge between a source and a target task in continuous domains and for direct policy search algorithms. The principle is (1) to use a direct policy search on the source task, (2) extract knowledge from the learning traces and (3) transfer this knowledge with a reward shaping approach. The knowledge extraction process consists in analyzing the learning traces, i.e. the behaviors explored while learning on the source task, to identify the behavioral features specific to successful solutions. Each behavioral feature is then attributed a value corresponding to the average reward obtained by the individuals exhibiting it. These values are used to shape rewards while learning on a target task. The approach is tested on a simulated ball collecting task in a continuous arena. The behavior of an individual is analyzed with the help of the generated knowledge bases.
A Few AI Challenges Raised while Developing an Architecture for Human-Robot Cooperative Task Achievement
Lemaignan, Séverin (École Polytechnique Fédérale de Lausanne) | Alami, Rachid (LAAS-CNRS, Université de Toulouse)
Over the last five years, and while developing an architecture for autonomous service robots in human environments, we have identified several key decisional issues that are to be tackled for a cognitive robot to share space and tasks with a human. We introduce some of them here: situation assessment and mutual modelling, management and exploitation of each agent (human and robot) knowledge in separate cognitive models, natural multi-modal communication, "human-aware" task planning, and human and robot interleaved plan achievement. As a general "take home" message, it appears that explicit knowledge management, both symbolic and geometric, proves to be a successful key while attempting to address these challenges, as it pushes for a different, more semantic way to address the decision-making issue in human-robot interactions.