Performance Analysis
Testing Analogical Proportions with Google using Kolmogorov Information Theory
Prade, Henri (Institut de Recherche en Informatique de Toulouse) | Richard, Gilles (British Institute of Technology and E-Commerce)
Analogical reasoning is considered as one of the main mechanisms underlying creativity. "Thinking out of the box" allows the paradigm shift essential to a creative process. More common is the concept of analogical proportion ("2 is to 4 as 4 is to 8") which can be described within an algebraic framework. When it comes to concepts ("engine is to the car as heart is to the human"), we need to investigate a new way to understand this analogical ratio. In this paper, we take inspiration from the formal framework of information theory for proposing a new approach to the evaluation of analogy between concepts. Using Kolmogorov complexity as a backbone providing a clear semantics, we give a practical interpretation for analogy between words viewed as labeling concepts. Making use of Google as a linguistic resource, we provide an implementation of our definitions: experiments show that the accuracy of our definition is quite acceptable and justify the approach.
Mapping Grounded Object Properties across Perceptually Heterogeneous Embodiments
Kira, Zsolt (Georgia Institute of Technology)
As robots become more common, it becomes increasingly useful for them to communicate and effectively share knowledge that they have learned through their individual experiences. Learning from experiences, however, is often-times embodiment-specific; that is, the knowledge learned is grounded in the robot’s unique sensors and actuators. This type of learning raises questions as to how communication and knowledge exchange via social interaction can occur, as properties of the world can be grounded differently in different robots. This is especially true when the robots are heterogeneous, with different sensors and perceptual features used to define the properties. In this paper, we present methods and representations that allow heterogeneous robots to learn grounded property representations, such as that of color categories, and then build models of their similarities and differences in order to map their respective representations. We use a conceptual space representation, where object properties are learned and represented as regions in a metric space, implemented via supervised learning of Gaussian Mixture Models. We then propose to use confusion matrices that are built using instances from each robot, obtained in a shared context, in order to learn mappings between the properties of each robot. Results are demonstrated using two perceptually heterogeneous Pioneer robots, one with a web camera and another with a camcorder.
Automatic Analysis of Author Judgment in Scientific Articles Based on Semantic Annotation
Bertin, Marc (University of Paris-Sorbonne) | Atanassova, Iana (University of Paris-Sorbonne) | Descles, Jean-Pierre (University of Paris-Sorbonne)
In this paper we describe how the annotation methodology adopted in our approach allows us to explain the organization of indexed references in scientific research articles. We identify the semantic values of author judgments in the text segments containing indexed references. We use an automated semantic annotation platform to annotate our corpora. Exploiting this result, we obtain a representation of the annotation distribution on different scales. Finally, we present two evaluations of the annotation.
Multivariate Time Series Classification with Temporal Abstractions
Batal, Iyad (University of Pittsburgh) | Sacchi, Lucia (University of Pavia) | Bellazzi, Riccardo (University of Pavia) | Hauskrecht, Milos (University of Pittsburgh)
The increase in the number of complex temporal datasets collected today has prompted the development of methods that extend classical machine learning and data mining methods to time-series data. This work focuses on methods for multivariate time-series classification. Time series classification is a challenging problem mostly because the number of temporal features that describe the data and are potentially useful for classification is enormous. We study and develop a temporal abstraction framework for generating multivariate time series features suitable for classification tasks. We propose the STF-Mine algorithm that automatically mines discriminative temporal abstraction patterns from the time series data and uses them to learn a classification model. Our experimental evaluations, carried out on both synthetic and real world medical data, demonstrate the benefit of our approach in learning accurate classifiers for time-series datasets.
VipBoost: A More Accurate Boosting Algorithm
Su, Xiaoyuan (Florida Atlantic University) | Khoshgoftaar, Taghi M | Greiner, Russell
Boosting is a well-known method for improving the accuracy of many learning algorithms. In this paper, we propose a novel boosting algorithm, VipBoost (voting on boosting classifications from imputed learning sets), which first generates multiple incomplete datasets from the original dataset by randomly removing a small percentage of observed attribute values, then uses an imputer to fill in the missing values. It then applies AdaBoost (using some base learner) to produce classifiers trained on each of the imputed learning sets, to produce multiple classifiers. The subsequent prediction on a new test case is the most frequent classification from these classifiers. Our empirical results show that VipBoost produces very effective classifiers that significantly improve accuracy for unstable base learners and some stable learners, especially when the initial dataset is incomplete.
Confidence-based Tuning of Nomogram Predictions
Mancill, Tony (Washington State University Vancouver) | Wallace, Scott A (Washington State University Vancouver)
Instance classification using machine learning techniques has numerous applications, from automation to medical diagnosis. In many problem domains, such as spam filtering, classification must be performed quickly across large datasets. In this paper we begin with machine learning techniques based on the naive Bayes classification and attempt to improve classification performance by taking into account attribute confidence intervals. Our prediction functions operate over nominal datasets and retain the asymptotic complexity of one-pass learning and prediction functions. We present preliminary results indicating a modest, albeit inconsistent improvement over the naive Bayes classifier alone.
Mining Meaning from Wikipedia
Medelyan, Olena, Milne, David, Legg, Catherine, Witten, Ian H.
Wikipedia is a goldmine of information; not just for its many readers, but also for the growing community of researchers who recognize it as a resource of exceptional scale and utility. It represents a vast investment of manual effort and judgment: a huge, constantly evolving tapestry of concepts and relations that is being applied to a host of tasks. This article provides a comprehensive description of this work. It focuses on research that extracts and makes use of the concepts, relations, facts and descriptions found in Wikipedia, and organizes the work into four broad categories: applying Wikipedia to natural language processing; using it to facilitate information retrieval and information extraction; and as a resource for ontology building. The article addresses how Wikipedia is being used as is, how it is being improved and adapted, and how it is being combined with other structures to create entirely new resources. We identify the research groups and individuals involved, and how their work has developed in the last few years. We provide a comprehensive list of the open-source software they have produced.
Quality Classifiers for Open Source Software Repositories
Tsatsaronis, George, Halkidi, Maria, Giakoumakis, Emmanouel A.
Open Source Software (OSS) often relies on large repositories, like SourceForge, for initial incubation. The OSS repositories offer a large variety of meta-data providing interesting information about projects and their success. In this paper we propose a data mining approach for training classifiers on the OSS meta-data provided by such data repositories. The classifiers learn to predict the successful continuation of an OSS project. The `successfulness' of projects is defined in terms of the classifier confidence with which it predicts that they could be ported in popular OSS projects (such as FreeBSD, Gentoo Portage).
Sentence Compression as Tree Transduction
This paper presents a tree-to-tree transduction method for sentence compression. Our model is based on synchronous tree substitution grammar, a formalism that allows local distortion of the tree topology and can thus naturally capture structural mismatches. We describe an algorithm for decoding in this framework and show how the model can be trained discriminatively within a large margin framework. Experimental results on sentence compression bring significant improvements over a state-of-the-art model.
Online prediction of ovarian cancer
Zhdanov, Fedor, Vovk, Vladimir, Burford, Brian, Devetyarov, Dmitry, Nouretdinov, Ilia, Gammerman, Alex
In this paper we apply computer learning methods to diagnosing ovarian cancer using the level of the standard biomarker CA125 in conjunction with information provided by mass-spectrometry. We are working with a new data set collected over a period of 7 years. Using the level of CA125 and mass-spectrometry peaks, our algorithm gives probability predictions for the disease. To estimate classification accuracy we convert probability predictions into strict predictions. Our algorithm makes fewer errors than almost any linear combination of the CA125 level and one peak's intensity (taken on the log scale). To check the power of our algorithm we use it to test the hypothesis that CA125 and the peaks do not contain useful information for the prediction of the disease at a particular time before the diagnosis. Our algorithm produces $p$-values that are better than those produced by the algorithm that has been previously applied to this data set. Our conclusion is that the proposed algorithm is more reliable for prediction on new data.