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Investigating Twitter as a Source for Studying Behavioral Responses to Epidemics
Lamb, Alex (Johns Hopkins University) | Paul, Michael J. (Johns Hopkins University) | Dredze, Mark (Johns Hopkins University)
Recent studies have shown an ability to track influenza rates from Twitter since Twitter users tweet illnesses (“i am home sick with the flu”). However, users may also tweet concerned awareness of illness (“don’t want to get sick, need a flu shot”). Identifying these messages can support computational epidemic response models. We present preliminary results for mining concerned awareness of influenza tweets. We describe our data set construction and experiments with binary classification of data into influenza versus general messages and classification into concerned awareness and existing infection.
Learning and Detecting Patterns in Multi-Attributed Network Data
Levchuk, Georgiy (Aptima, Inc.) | Roberts, Jennifer (Aptima, Inc.) | Freeman, Jared (Aptima, Inc.)
Network analysis is a growing field across many domains, including computer vision, social media marketing, transportation networks, and intelligence analysis. The growing use of digital communication devices and platforms, as well as persistent surveillance sensors, has resulted in explosion of the quantity of data and stretched the abilities of current technologies to process this data and draw meaningful conclusions. Current tools either require significant levels of manual intervention (e.g., to prepare the data, to define patterns, or to draw conclusions from data) or are unable to generalize to new data sources and analysis needs. In this paper, we present automated solutions to two major problems in network analysis: (a) finding patterns in the network data that contains high levels of noise and irrelevant information; and (b) learning repetitive patterns and dependencies between entities and attributes. Our modeling framework represents network data using multi-attributed graphs that can encode various discrete and continuous features and relationships between network entities. The pattern search and learning model is based on probabilistic multi-attributed graph matching, and implemented using distributed message passing algorithms. Our algorithms achieved high accuracy rates in learning and finding patterns in the data, are flexible to new domains and data types, and scale to large datasets using the Map-Reduce framework.
Semantic Role Labeling for Biological Transport
Tan, He (Jönköping University) | Chowdari, Srikanth (Linköping University)
Semantic role labeling (SRL) is a technique of semantic interpretation of text on the sentence level. In this paper, we present a corpus that is labeled with semantic roles for biological transport events. The corpus was built using domain knowledge provided by ontologies. We also report on a word-chunking approach for identifying semantic roles of biomedical predicates describing transport events. We trained a first-order Conditional Random Fields (CRF) for chunking applications with the traditional role labeling features and also domain-specific features. The results show that the system performance varies between different roles and the performance was not improved for all roles by introducing domain specific features.
Training Wheels for the Robot: Learning from Demonstration Using Simulation
Koenig, Nathan (Open Source Robotics Foundation) | Mataric' (University of Southern California) | , Maja
Learning from demonstration (LfD) is a promising technique for instructing/teaching autonomous systems based on demonstrations from people who may have little to no experience with robots. An important aspect to LfD is the communication method used to transfer knowledge from an instructor to a robot. The communication method affects the complexity of the demonstration process for instructors, the range of tasks a robot can learn, and the learning algorithm itself. We have designed a graphical interface and an instructional language to provide an intuitive teaching system. The drawback to simplifying the teaching interface is that the resulting demonstration data are less structured, adding complexity to the learning process. This additional complexity is handled through the combination of a minimal set of predefined behaviors and a task representation capable of learning probabilistic policies over a set of behaviors. The predefined behaviors consist of finite actions a robot can perform, which act as building blocks for more complex tasks.
Robotic Swarm Connectivity with Human Operation and Bandwidth Limitations
Nunnally, Steven (University of Pittsburgh) | Waler, Phillip (University of Pittsburgh) | Kolling, Andreas (Carnegie Mellon University) | Chakraborty, Nilanjan (Carnegie Mellon University) | Lewis, Michael (University of Pittsburgh) | Sycara, Katia (Carnegie Mellon University)
Human interaction with robot swarms (HSI) is a young field with very few user studies that explore operator behavior. All these studies assume perfect communication between the operator and the swarm. A key challenge in the use of swarm robotic systems in human supervised tasks is to understand human swarm interaction in the presence of limited communication bandwidth, which is a constraint arising in many practical scenarios. In this paper, we present results of human-subject experiments designed to study the effect of bandwidth limitations in human swarm interaction. We consider three levels of bandwidth availability in a swarm foraging task. The lowest bandwidth condition performs poorly, but the medium and high bandwidth condition both perform well. In the medium bandwidth condition, we display useful aggregated swarm information (like swarm centroid and spread) to compress the swarm state information. We also observe interesting operator behavior and adaptation of operators’ swarm reaction.
The Good Judgment Project: A Large Scale Test of Different Methods of Combining Expert Predictions
Ungar, Lyle (University of Pennsylvania) | Mellers, Barbara (University of Pennsylvania) | Satopää, Ville (University of Pennsylvania) | Tetlock, Philip (University of Pennsylvania) | Baron, Jon (University of Pennsylvania)
Many methods have been proposed for making use of multiple experts to predict uncertain events such as election outcomes, ranging from simple averaging of individual predictions to complex collaborative structures such as prediction markets or structured group decision making processes. We used a panel of more than 2,000 forecasters to systematically compare the performance of four different collaborative processes on a battery of political prediction problems. We found that teams and prediction markets systematically outperformed averages of individual forecasters, that training forecasters helps, and that the exact form of how predictions are combined has a large effect on overall prediction accuracy.
Human-Inspired Techniques for Human-Machine Team Planning
Shah, Julie (Massachusetts Institute of Technology) | Kim, Been (Massachusetts Institute of Technology) | Nikolaidis, Stefanos (Massachusetts Institute of Technology)
Robots are increasingly introduced to work in concert with people in high-intensity domains, such as manufacturing, space exploration and hazardous environments. Although there are numerous studies on human teamwork and coordination in these settings, very little prior work exists on applying these models to human-robot interaction. This paper presents results from ongoing work aimed at translating qualitative methods from human factors engineering into computational models that can be applied to human-robot teaming. We describe a statistical approach to learning patterns of strong and weak agreements in human planning meetings that achieves up to 94% prediction accuracy. We also formulate a human-robot interactive planning method that emulates cross-training, a training strategy widely used in human teams. Results from human subject experiments show statistically significant improvements on team fluency metrics, compared to standard reinforcement learning techniques. Results from these two studies support the approach of modeling and applying common practices in human teaming to achieve more effective and fluent human-robot teaming.
Experimenting with Drugs (and Topic Models): Multi-Dimensional Exploration of Recreational Drug Discussions
Paul, Michael J. (Johns Hopkins University) | Dredze, Mark (Johns Hopkins University)
Clinical research of new recreational drugs and trends requires mining current information from non-traditional text sources. In this work we support such research through the use of multi-dimensional latent text models, such as factorial LDA, that capture orthogonal factors of corpora, creating structured output for researchers to better understand the contents of a corpus. Since a purely unsupervised model is unlikely to discover specific factors of interests to clinical researchers, we modify the structure of factorial LDA to incorporate prior knowledge, including the use of of observed variables, informative priors and background components. The resulting model learns factors that correspond to drug type, delivery method (smoking, injection, etc.), and aspect (chemistry, culture, effects, health, usage). We demonstrate that the improved model yields better quantitative and more interpretable results.
Do Jokes Have to Be Funny: Analysis of 50 “Theoretically Jokes”
Taylor, Julia (Purdue University)
This talk will analyze responses to funniness of five versions of 10 different jokes. The responses of one of them will then be compared to theoretical analysis and representation of the same joke based on Script-based Semantics Theory of Humor, General Theory of Verbal Humor, and Ontological Semantic Theory of Humor.
On Causality Inference in Time Series
Bahadori, Mohammad Taha (University of Southern Califoria) | Liu, Yan (University of Southern California)
Causality discovery has been one of the core tasks in scientific research since the beginning of human scientific history. In the age of data tsunami, the causality discovery task involves identification of causality among millions of variables which cannot be done manually by humans. However, the identification of causality relationships using artificial intelligence and statistical techniques in non-experimental settings faces several challenges. In this work, we address three of the challenges regarding Granger causality, one of the most popular causality inference techniques. First, we analyze the consistency of two most popular Granger causality techniques and show that the significance test is not consistent in high dimensions. Second, we review our nonparametric generalization of the Lasso-Granger technique called Generalized Lasso Granger (GLG) to uncover Granger causality relationships among irregularly sampled time series. Finally, we describe two techniques to uncover the casual dependence in non-linear datasets. Extensive experiments are provided to show the significant advantages of the proposed algorithms over their state-of-the-art counterparts.