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Subgraph Matching-Based Literature Mining for Biomedical Relations and Events

AAAI Conferences

Extracting important relations between biological components and semantic events involving genes or proteins from literature has become a focus for the biomedical text mining community. In this paper, we review a subgraph matching-based approach proposed in our previous work for mining relations and events in the biomedical literature. Our subgraph matching algorithm is formally presented, along with a detailed analysis of its complexity. We present three different relation/event extraction tasks in which our approach has been successfully applied. Our approach is of considerable value in extracting highly precise, binary relations when appropriate training data is available.


Organizing Committee and Preface

AAAI Conferences

Thee symposium focused on combining human and machine inference. For unique events and data-poor problem, there is no substitute for human judgment. Even for data-rich problems, human input is needed to account for contextual factors. However, human are notorious for underestimating the uncertainty in their forecasts and even the most expert judgments exhibit well-known cognitive biases. The challenge is therefore to aggregate expert judgment such that it compensates for the human deficiencies. We hope that bringing researchers in this venue will provide meaningful discussions and further inspire interesting research in this direction.


An Ontological Representation Model to Tailor Ambient Assisted Interventions for Wandering

AAAI Conferences

Wandering is a problematic behavior that is common among people with dementia (PwD), and is highly influenced by the elders’ background and by contextual factors specific to the situation. We have developed the Ambient Augmented Memory System (AAMS) to support the caregiver to implement interventions based on providing external memory aids to the PwD. To provide a successful intervention, it is required to use an individualized approach that considers the context of the PwD situation. To reach this end, we extended the AAMS system to include an ontological model to support the context-aware tailoring of interventions for wandering. In this paper, we illustrate the ontology flexibility to personalize the AAMS system to support direct and indirect interventions for wandering through mobile devices.


An Intelligent Nutritional Assessment System

AAAI Conferences

Higher life expectancies lead to an increased prevalenceof dementia in older adults, which is projected torise dramatically in the future. The link between malnutritionand dementia highlights the need to closelymonitor nutrition as early as possible. However, currentself-report assessment methods are labor-intensive,time-consuming and inaccurate. Technology has the potentialof assisting in nutritional analysis by alleviatingthe cognitive load of recording food intake and lesseningthe burden of care for the elderly. Therefore, we proposean intelligent nutritional assessment system thatwill monitor the dietary patterns of older adults with dementiaat their homes. Our computer vision-based systemconsists of food recognition and portion estimationalgorithms that, together, provide nutritional analysisof an image of a meal. We create a novel food imagedataset on which we achieve an 87.2% recognition accuracy.We apply several well-known segmentation andrecognition algorithms and analyze their suitability tothe food recognition problem.


Generalized Weighted Model Counting: An Efficient Monte-Carlo Meta-Algorithm

AAAI Conferences

In this paper, we focus on computing the prices of secu- rities represented by logical formulas in combinatorial prediction markets when the price function is represented by a Bayesian network. This problem turns out to be a natural extension of the weighted model counting (WMC) problem (Sang, Bearne, and Kautz 2005), which we call generalized weighted model counting (GWMC) problem. In GWMC, we are given a logical formula F and a polynomial-time computable weight function. We are asked to compute the total weight of the valuations that satisfy F. Based on importance sampling, we propose a Monte-Carlo meta-algorithm that has a good theoretical guarantee for formulas in disjunctive normal form (DNF). The meta-algorithm queries an oracle algorithm that computes marginal probabilities in Bayesian networks, and has the following theoretical guarantee. When the weight function can be approximately represented by a Bayesian network for which the oracle algorithm runs in polynomial time, our meta-algorithm becomes a fully polynomial-time randomized approximation scheme (FPRAS).


Decomposition and Distribution of Humorous Effect in Interactive Systems

AAAI Conferences

We aim to identify and control unintentional humor occurring in human-computer interaction, and recreate it intentionally. In this research we focus on text prediction systems, a type of interactive programs employed in mobile phones, search engines, and word processors. More specifically, we identified two design principles, inspired by humor and emotion theories, and implemented them in a proof-of-concept tool simulating a specific type of text prediction.


Modeling Social Emotions in Intelligent Agents Based on the Mental State Formalism

AAAI Conferences

Emotional intelligence is the key for acceptance of intelligent agents by humans as equal partners, e.g., in ad hoc teams. At the same time, its existing implementations in intelligent agents are mostly limited to basic affects. Currently, there is no consensus in the understanding of complex and social emotions at the level of functional and computational models. The approach of this work is based on the mental state formalism, originally developed as a part of the cognitive architecture GMU BICA and recently extended to include affective building blocks (A.V. Samsonovich, AAAI Technical Report WS-12-06: 109-116, 2012). In the present work, complex social emotions like humor, jealousy, compassion, shame, pride, etc. are identified as emergent patterns of appraisals represented by schemas, that capture the cognitive nature of these emotions and enable their modeling. A general model of complex emotions and emotional relationships is constructed that can be validated by simulations of emotionally biased interactions and emergent relationships in small groups of agents. The framework will be useful in cognitive architectures for designing human-like-intelligent social agents possessing a sense of humor and other human-like emotionally intelligent capabilities.


Selective Sampling of Labelers for Approximating the Crowd

AAAI Conferences

In this paper, we present CrowdSense, an algorithm for estimating the crowd’s majority opinion by querying only a subset of it. CrowdSense works in an online fashion where examples come one at a time and it dynamically samples subsets of labelers based on an exploration/exploitation criterion. The algorithm produces a weighted combination of a subset of the labelers’ votes that approximates the crowd’s opinion. We also present two probabilistic variants of CrowdSense that are based on different assumptions on the joint probability distribution between the labelers’ votes and the majority vote. Our experiments demonstrate that we can reliably approximate the entire crowd’s vote by collecting opinions from a representative subset of the crowd.


Integration of UMLS and MEDLINE in Unsupervised Word Sense Disambiguation

AAAI Conferences

Scarcity of training data for word sense disambiguation argues for the use of knowledge-based disambiguation methods, which rely on information available in terminological resources. Unfortunately, these resources are not generally optimized to perform word sense disambiguation. On the other hand, there are many examples of ambiguous biomedical words with context in MEDLINE. However, these examples of ambiguity are not labeled with their proper sense. We propose the integration of the UMLS and MEDLINE to create concept profiles which are used to perform knowledge-based word sense disambiguation. Our results show an accuracy of 0.8770 on a biomedical word sense disambiguation data set; this represents a statistically significant improvement over other knowledge-based methods based on the UMLS on this data set.


Improving Forecasting Accuracy Using Bayesian Network Decomposition in Prediction Markets

AAAI Conferences

We propose to improve the accuracy of prediction market forecasts by using Bayesian networks to constrain probabilities among related questions. Prediction markets are already known to increase forecast accuracy compared to single best estimates. Our own flat prediction market substantially beat a baseline linear opinion pool during the first year. One way to improve performance is by expressing relationships among the questions. Elsewhere we describe work on combinatorial markets. Here we show how to use Bayesian networks within a flat market. The general approach is to decompose a target question (hypothesis) into a set of related variables (causal factors and evidence), when the relationship among the variables is known with some confidence. Then the marginal probabilities for the variables in the Bayes net are updated using the market estimates, with the Bayes net enforcing coherence. This paper describes the overall concept, shows the results for a particular model of the potential Greek exit from the European Union, and describes the team’s future research plan.