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When Did You Start Doing that Thing that You Do? Interactive Activity Recognition and Prompting

AAAI Conferences

We present a model of interactive activity recognition and prompting for use in an assistive system for persons with cognitive disabilities. The system can determine the user’s state by interpreting sensor data and/or by explicitly querying the user, and can prompt the user to begin or end tasks. The objective of the system is to help the user maintain a daily schedule of activities while minimizing interruptions from questions or prompts. The model is built upon an option-based hierarchical POMDP. Options can be programmed and customized to specify complex routines for prompting or questioning. Novel aspects of the model include (1) the introduction of adaptive options, which employ a lightweight user model and are able to provide near-optimal performance with little exploration; (2) a restricted-inquiry dual-control algorithm that can appeal for help from the user when sensor data is ambiguous; and (3) a combined filtering / most likely-sequence algorithm for activities determining the beginning and ending time points of the user’s activities. Experiments show that each of these features contributes to the robustness of the model.


Adding Affective Argumentation to the GenIE Assistant

AAAI Conferences

The strategies seem designed to mitigate guilt over the parents' role in their The GenIE Assistant is an implemented proof-of-concept child's inheritance of a genetic condition. The names used computational model of normative biomedical argument to refer to the strategies in this paper and examples of generation informed by study of a corpus of letters each are listed below. All four apply to cases of written by genetic counselors to their clients (Green et al. autosomal recessive inheritance, while only the first two 2011). The goal of the model is to generate transparent apply to cases of autosomal dominant inheritance.


Error Identification and Correction in Human Computation: Lessons from the WPA

AAAI Conferences

Human computing promises new capabilities that cannot be easily provided by computing machinery. However, humans are less disciplined than their mechanical counterparts and hence are liable to produce accidental or deliberate mistakes. As we start to develop regimes for identifying and correcting errors in human computation, we find an important model in the computing groups that operated at the start of the 20th century.


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.


An Intelligent Load Balancing Algorithm Towards Efficient Cloud Computing

AAAI Conferences

MapReduce provided a novel computing model for complex job decomposition and sub-tasks management to support cloud computing with large distributed data sets. However, its performance is significantly influenced by the working data distributions over those data sets. In this paper, we put forward a novel model to balance data distribution to improve cloud computing performance in data-intensive applications, such as distributed data mining. By extending the classic MapReduce model with an agent-aid layer and abstracting working load requests for data blocks as tokens, the agents can reason from previously received tokens about where to send other tokens in order to balance the working tasks and improve system performance. Our key contribution lies in building an efficient token routing algorithm in spite of agents' unknowing to the global state of data distribution in cloud. We also built a prototype of our system, and the experimental results show that our approach can significantly improve the efficiency of cloud computing.


Human Intelligence Needs Artificial Intelligence

AAAI Conferences

Crowdsourcing platforms, such as Amazon Mechanical Turk, have enabled the construction of scalable applications for tasks ranging from product categorization and photo tagging to audio transcription and translation. These vertical applications are typically realized with complex, self-managing workflows that guarantee quality results. But constructing such workflows is challenging, with a huge number of alternative decisions for the designer to consider. We argue the thesis that “Artificial intelligence methods can greatly simplify the process of creating and managing complex crowdsourced workflows.” We present the design of CLOWDER, which uses machine learning to continually refine models of worker performance and task difficulty. Using these models, CLOWDER uses decision-theoretic optimization to 1) choose between alternative workflows, 2) optimize parameters for a workflow, 3) create personalized interfaces for individual workers, and 4) dynamically control the workflow. Preliminary experience suggests that these optimized workflows are significantly more economical (and return higher quality output) than those generated by humans.


Markov Games of Incomplete Information for Multi-Agent Reinforcement Learning

AAAI Conferences

Partially observable stochastic games (POSGs) are an attractive model for many multi-agent domains, but are computationally extremely difficult to solve. We present a new model, Markov games of incomplete information (MGII) which imposes a mild restriction on POSGs while overcoming their primary computational bottleneck. Finally we show how to convert a MGII into a continuous but bounded fully observable stochastic game. MGIIs represents the most general tractable model for multi-agent reinforcement learning to date.


Towards the Integration of Multi-Attribute Optimization and Game Theory for Border Security Patrolling Strategies

AAAI Conferences

The goal for attackers is to move from one side of the graph to the Border security is a key element of national security policy other (represented by sets of source and target nodes); this for any sovereign nation. In the United States, the Border represents a typical scenario of crossing an open region from Patrol deploys thousands of agents integrated with technology one side of the border to destination points in the interior of (e.g., vehicles, cameras, sensors) and infrastructure the county. The paths between the source and target nodes (e.g., fences, checkpoints) to prevent illegal entry of people may represent major or minor roads, or paths suitable for and goods into the country along vast land borders with travel on foot. We use weights on the edges to represent Canada and Mexico. The problem of border security is incredibly the relative speed/cost of transit on the different paths (for complex, due to the diversity and volume of illegal example, it may be must slower and more difficult to use activity that must be controlled, the variety of resources that a foot path than a major highway). Nodes may represent can be deployed to secure the border, and the differences in intersections, checkpoints, or other important waypoints.


Multi-Label Classification of Short Text: A Study on Wikipedia Barnstars

AAAI Conferences

A content analysis of Wikipedia barnstars personalized tokens of appreciation given to participants reveals a wide range of valued work extending beyond simple editing to include social support, administrative actions, and types of articulation work. Barnstars are examples of short semi-structured text characterized by informal grammar and language. We propose a method to classify these barnstars which contain items of interest into various work type categories.We evaluate several multilabel text categorization classifiers and show that significant performance can be achieved by simple classifiers using features which carry context extracted from barnstars. Although this study focused specifically on work categorization via barnstar content for Wikipedia, we believe that the findings are applicable to other similar collaborative systems


Language Models for Semantic Extraction and Filtering in Video Action Recognition

AAAI Conferences

The paper addresses the following issues:  (a) how to represent semantic information from natural language so that a vision model can utilize it?  (b) how to extract the salient textual information relevant to vision?  For a given domain, we present a new model of semantic extraction that takes into account word relatedness as well as word disambiguation in order to apply to a vision model. We automatically process the text transcripts and perform syntactic analysis to extract dependency relations. We then perform semantic extraction on the output to filter semantic entities related to actions. The resulting data are used to populate a matrix of co-occurrences utilized by the vision processing modules.  Results show that explicitly modeling the co-occurrence of actions and tools significantly improved performance.