Country
Measuring General Relational Structure Using the Block Modularity Clustering Objective
Anthony, Adam Paul (University of Maryland Baltimore County) | desJardins, Marie (University of Maryland Baltimore County) | Lombardi, Michael (University of Maryland Baltimore County)
The performance of all relational learning techniques has an implicit dependence on the underlying connectivity structure of the relations that are used as input. In this paper, we show how clustering can be used to develop an efficient optimization strategy can be used to effectively measure the structure of a graph in the absence of labeled instances.
Analyzing Team Actions with Cascading HMM
White, Brandyn Allen (University of Central Florida) | Blaylock, Nate (IHMC) | Bรถlรถni, Ladislau (University of Central Florida)
While team action recognition has a relatively extended literature, less attention has been given to the detailed realtime analysis of the internal structure of the team actions.ย This includes recognizing the current state of the action, predicting the next state, recognizing deviations from the standard action model, and handling ambiguous cases. The underlying probabilistic reasoning model has a major impact on the type of data it can extract, its accuracy, and the computational cost of the reasoning process. In this paper we are using Cascading Hidden Markov Models (CHMM) to analyze Bounding Overwatch, an important team action in military tactics. The team action is represented in the CHMM as a plan tree. Starting from real-world recorded data, we identify the subteams through clustering and extract team oriented discrete features. In an experimental study, we investigate whether the better scalability and the more structured information provided by the CHMM comes with an unacceptable cost in accuracy. We find the a properly parametrized CHMM estimating the current goal chain of the Bounding Overwatch plan tree comes very close to a flat HMM estimating only the overall Bounding Overwatch state (a subset of the goal chain) at a respective overall state accuracy of 95% vs 98%, making the CHMM a good candidate for deployed systems.
Improving Biomedical Document Retrieval by Mining Domain Knowledge
Wang, Shuguang (University of Pittsburgh) | Hauskrecht, Milos (University of Pittsburgh)
When research articles introduce new findings or concepts they typically relate them only to knowledge and domain concepts of immediate relevance. However, many domain concepts relevant for the article and its findings are omitted in the text. This may prevent us from retrieving articles of interest when executing a search query. Approaches such as probabilistic latent semantic indexing (PLSI) overcome this limitation by projecting terms in articles to a lower dimensional latent space and best possible matches in this space are identified. Nevertheless, this approach may not perform well enough if the number of explicit knowledge concepts in the articles is too small compared to the amount of knowledge in the domain. The objective of this paper is to address the problem by exploiting a domain knowledge layer: a rich network of associations among knowledge concepts in the domain of interest. We present a new document retrieval framework that i) extracts associations among knowledge concepts from many documents in the literature corpus; ii) and exploits them to improve the retrieval of relevant documents. We test our approach on the problem of retrieval of biomedical documents and show that it outperforms standard Lucene and BM25 information-retrieval methods.
Memory Based Goal Schema Recognition
Tecuci, Dan G. (University of Texas at Austin) | Porter, Bruce (University of Texas at Austin)
We propose a memory-based approach to the problem of goal-schema recognition. We use a generic episodic memory module to perform incremental goal schema recognition and to build the plan library. Unlike other case-based plan recognizers it does not require complete knowledge of the planning domain or the ability to record intermediate planning states. Similarity of plans is computed incrementally using a semantic matcher that considers the type and parameters of the observed actions.ย We evaluate this approach on two datasets and show that it is able to achieve similar or better performance compared to a statistical approach, but offers important advantages: plan library is acquired incrementally and the memory structure it builds is multi-functional and can be used for other tasks such as plan generation or classification.
Multiple Answer Extraction for Question Answering with Automated Theorem Proving Systems
Sutcliffe, Geoff (University of Miami) | Yerikalapudi, Aparna (University of Miami) | Trac, Steven (University of Miami)
The Multiple ANSwer EXtraction system is a framework for interpreting a conjecture with outermost existentially quantified variables as a question, and extracting multiple answers to the question by repetitive calls to a base system that can report the bindings for the variables in one proof of the conjecture. This paper describes the framework and demonstrates its use on an illustrative example.
Responding to Sneaky Agents in Multi-agent Domains
Seymour, Richard S. (Air Force Institute of Technology) | Peterson, Gilbert L (Air Force Institute of Technology)
This paper extends the concept of trust modeling within a multi-agent environment.ย Trust modeling often focuses on identifying the appropriate trust level for the other agents in the environment and then using these levels to determine how to interact with each agent.ย However, this type of modeling does not account for sneaky agents who are willing to cooperate when the stakes are low and take selfish, greedy actions when the rewards rise.ย Adding trust to an interactive partially observable Markov decision process (I-POMDP) allows trust levels to be continuously monitored and corrected enabling agents to make better decisions.ย The addition of trust modeling increases the decision process calculations, but solves more complex trust problems that are representative of the human world.ย The modified I-POMDP reward function and belief models can be used to accurately track the trust levels of agents with hidden agendas.ย Testing demonstrates that agents quickly identify the hidden trust levels to mitigate the impact of a deceitful agent.
Spyglass: A System for Ontology Based Document Retrieval and Visualization
Rushing, John (University of Alabama in Huntsville) | Berendes, Todd (University of Alabama in Huntsville) | Lin, Hong (University of Alabama in Huntsville) | Buntain, Cody (University of Alabama in Huntsville) | Graves, Sara (University of Alabama in Huntsville)
This paper describes the Spyglass tool, which is designed to help analysts explore very large collectionsย of unstructured text documents. Spyglass uses a domain ontology to index documents, and provides retrievalย and visualization services based on the ontology and the resulting index. The ontology based approach allows analysts to share information and helps to ensure consistency of results. The approach is alsoย scalable and lends itself very well to parallel computation. The Spyglass system is described in detail and indexing and query results using a large set of sample documents are presented.
Reasoning about Changes of Corpus of Documents: Reasoning on Association Rules
Perrussel, Laurent (IRIT - Universitรฉ de Toulouse)
Evaluating changes in documentation of technical products is a key issue in knowledge management. A product may be declined in different versions and one way to evaluate changes is to compare the sets of documents which describe each version. The aim of this paper is to propose a framework for exhibiting changes between sets of documents. This framework is based on the representation of the sets of documents in terms of association rules and on the definition of first order predicates for reasoning with these association rules. The aim of the reasoning stage is to exhibit the differences between the sets of documents. These predicates show what rules are specific to a corpus or how differs the usage of concepts appearing in the associations rules. The framework isย experimented with the comparison of two corpuses of documents which describe documentation about two different versions of a spatial component.
A Large Margin Approach to Anaphora Resolution for Neuroscience Knowledge Discovery
A discriminative large margin classifier based approach to anaphora resolution for neuroscience abstracts is presented. The system employs both syntactic and semantic features. A support vector machine based word sense disambiguation method combining evidence from three methods, that use WordNet and Wikipedia, is also introduced and used for semantic features. The support vector machine anaphora resolution classifier with probabilistic outputs achieved almost four-fold improvement in accuracy over the baseline method.
Coinductive Logic Programming and its Application to Boolean SAT
Min, Richard (The University of Texas at Dallas) | Gupta, Gopal
Coinduction has recently been introduced into logic programming by Simon et al. The resulting paradigm, termed coinductive logic programming (co-LP), allows one to model and reason about infinite processes and objects. Co-LP extended with negation has many interesting applications: for instance in developing top-down, goaldirected evaluation strategies for Answer Set Programming. In this paper we show yet another application of co-LP, namely, elegantly realizing Boolean SAT solvers