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The Activity-Based Computing Project

AAAI Conferences

This position paper describes the Activity-Based Computing (ABC) project which has been ongoing in Denmark since 2003. Originally, the project took its outset in the design of a pervasive computing platform suited for the mobile, collaborative, and time-critical work of clinicians in a hospital setting. Out of this grew a conceptual framework, a set of six ABC principles, and a programming and runtime framework for the development of activity-based computing infrastructures and applications. Lately, these principles and technologies have been successfully moved to other application areas, and is now used to design and implement activity-based computing support for work in a biology laboratory and for global software development.


A General Perceptual Model for Eldercare Robots

AAAI Conferences

A general perceptual model is proposed for Eldercare Robot implementation that is comprised of audition functionality interconnected with a feedback-driven perceptual reasoning agent. Using multistage signal analysis to feed temporally tiered learning/recognition modules, concurrent access to sound event localization, classification, and context is realized. Patterns leading to the quantification of patient emotion/well being can be inferred using a perceptual reasoning agent. The system is prototyped using a Nao H-25 humanoid robot with an online processor running the Nao Qi SDK and the Max/MSP environment with the FTM, and GF libraries.


What Are Tweeters Doing: Recognizing Speech Acts in Twitter

AAAI Conferences

Speech acts provide good insights into the communicative behavior of tweeters on Twitter. This paper is mainly concerned with speech act recognition in Twitter as a multi-class classification problem, for which we propose a set of word-based and character-based features. Inexpensive, robust and efficient, our method achieves an average F1 score of nearly 0.7 with the existence of much noise in our annotated Twitter data. In view of the deficiency of training data for the task, we experimented extensively with different configurations of training and test data, leading to empirical findings that may provide valuable reference for building benchmark datasets for sustained research on speech act recognition in Twitter.


Learning Adversarial Reasoning Patterns in Customer Complaints

AAAI Conferences

We propose a mechanism to learn communicative action structure to analyze adversarial reasoning patterns in customer complaints. An efficient way to assist customers and companies is to reuse previous experience with similar agents. A formal representation of customer complaints and a machine learning technique for handling scenarios of interaction between conflicting human agents are proposed. It is shown that analyzing the structure of communicative actions without context information is frequently sufficient to advise on complaint resolution strategies. Therefore, being domain-independent, the proposed machine learning technique is a good complement to a wide range of customer response management applications where formal treatment of inter-human interactions is required.


Incorporating Unsupervised Learning in Activity Recognition

AAAI Conferences

Users are constantly involved in a multitude of activities in ever-changing context. Analyzing activities in context-rich environments has become a great challenge in context-awareness research. Traditional methods for activity recognition, such as classification, cannot cope with the variety and dynamicity of context and activities. In this paper, we propose an activity recognition approach that incorporates unsupervised learning. We analyze the feasibility of applying subspace clustering---a specific type of unsupervised learning โ€” to high-dimensional, heterogeneous sensory input. Then we present the correspondence between clustering output and classification input. This approach has the potential to discover implicit, evolving activities, and can provide valuable assistance to traditional classification based methods.


A Formal Systems Approach to Machine Capture, Representation and Use of Activity Context

AAAI Conferences

Britain's trains are not noted for their AAAI Activity Context Representation Workshop. The punctuality and they are deemed on-time within a window first paper, 'Defining and Representing Activity Context of ten or so minutes, so just using the train timetable to for Systems Analysis', summarizes the author's formal predict bad spots is not feasible. Over a number of journeys, Simplified Set Theory (SST) approach and the use of his the user attempts to find journey landmarks that precede PentaVenn diagram. This second paper uses these in a the bad spots by a few minutes ("a few" being less modest, partially worked example to explore the contexts than the predicted time for file transfer). Some landmarks of an activity and how a formal approach can aid systems might be easy to identify, e.g.


FAQ-Learning in Matrix Games: Demonstrating Convergence Near Nash Equilibria, and Bifurcation of Attractors in the Battle of Sexes

AAAI Conferences

This article studies Frequency Adjusted Q-learning (FAQ-learning), a variation of Q-learning that simulates simultaneous value function updates. The main contributions are empirical and theoretical support for the convergence of FAQ-learning to attractors near Nash equilibria in two-agent two-action matrix games.The games can be divided into three types: Matching pennies, Prisoners' Dilemma and Battle of Sexes. This article shows that the Matching pennies and Prisoners' Dilemma yield one attractor of the learning dynamics, while the Battle of Sexes exhibits a supercritical pitchfork bifurcation at a critical temperature, where one attractor splits into two attractors and one repellent fixed point. Experiments illustrate that the distance between fixed points of the FAQ-learning dynamics and Nash equilibria tends to zero as the exploration parameter of FAQ-learning approaches zero.


Untangling Topic Threads in Chat-Based Communication: A Case Study

AAAI Conferences

Analyzing chat traffic has important applications for both the military and the civilian world. This paper presents a case study of a real-world application of chat analysis in support of team training exercise in the military. It compares the results of an unsupervised learning approach with those of a supervised classification approach. The paper also discusses some of the specific challenges presented by this domain.


Lifelong Credit Assignment with the Success-Story Algorithm

AAAI Conferences

Consider an embedded agent with a self-modifying, Turing-equivalent policy that can change only through active self-modifications. How can we make sure that it learns to continually accelerate reward intake? Throughout its life the agent remains ready to undo any self-modification generated during any earlier point of its life, provided the reward per time since then has not increased, thus enforcing a lifelong success-story of self-modifications, each followed by long-term reward acceleration up to the present time. The stack-based method for enforcing this is called the success-story algorithm. It fully takes into account that early self-modifications set the stage for later ones (learning a learning algorithm), and automatically learns to extend self-evaluations until the collected reward statistics are reliable ... a very simple but general method waiting to be re-discovered! Time permitting, I will also briefly discuss more recent mathematically optimal universal maximizers of lifelong reward, in particular, the fully self-referential Goedel machine.


Developing Scripts to Teach Social Skills: Can the Crowd Assist the Author?

AAAI Conferences

The social world that most of us navigate effortlessly can prove to be a perplexing and disconcerting place for individuals with autism. Currently there are no models to assist non-expert authors as they create customized social script-based instructional modules for a particular child. We describe an approach to using human computation to develop complex models of social scripts for a plethora of complex and interesting social scenarios, possible obstacles that may arise in those scenarios, and potential solutions to those obstacles. Human input is the natural way to build these models, and in so doing create valuable assistance for those trying to navigate the intricacies of a social life.