Asia
Adaptive Metric Dimensionality Reduction
Gottlieb, Lee-Ad, Kontorovich, Aryeh, Krauthgamer, Robert
Linear classifiers play a central role in supervised learning, with a rich and elegant theory. This setting assumes data is represented as points in a Hilbert space, either explicitly as feature vectors or implicitly via a kernel. A significant strength of the Hilbert-space model is its inner-product structure, which has been exploited statistically and algorithmically by sophisticated techniques from geometric and functional analysis, placing the celebrated hyperplane methods on a solid foundation. However, the success of the Hilbert-space model obscures its limitations -- perhaps the most significant of which is that it cannot represent many norms and distance functions that arise naturally in applications.
Rotation-invariant convolutional neural networks for galaxy morphology prediction
Dieleman, Sander, Willett, Kyle W., Dambre, Joni
Measuring the morphological parameters of galaxies is a key requirement for studying their formation and evolution. Surveys such as the Sloan Digital Sky Survey (SDSS) have resulted in the availability of very large collections of images, which have permitted population-wide analyses of galaxy morphology. Morphological analysis has traditionally been carried out mostly via visual inspection by trained experts, which is time-consuming and does not scale to large ($\gtrsim10^4$) numbers of images. Although attempts have been made to build automated classification systems, these have not been able to achieve the desired level of accuracy. The Galaxy Zoo project successfully applied a crowdsourcing strategy, inviting online users to classify images by answering a series of questions. Unfortunately, even this approach does not scale well enough to keep up with the increasing availability of galaxy images. We present a deep neural network model for galaxy morphology classification which exploits translational and rotational symmetry. It was developed in the context of the Galaxy Challenge, an international competition to build the best model for morphology classification based on annotated images from the Galaxy Zoo project. For images with high agreement among the Galaxy Zoo participants, our model is able to reproduce their consensus with near-perfect accuracy ($> 99\%$) for most questions. Confident model predictions are highly accurate, which makes the model suitable for filtering large collections of images and forwarding challenging images to experts for manual annotation. This approach greatly reduces the experts' workload without affecting accuracy. The application of these algorithms to larger sets of training data will be critical for analysing results from future surveys such as the LSST.
Accuracy of Latent-Variable Estimation in Bayesian Semi-Supervised Learning
Hierarchical probabilistic models, such as Gaussian mixture models, are widely used for unsupervised learning tasks. These models consist of observable and latent variables, which represent the observable data and the underlying data-generation process, respectively. Unsupervised learning tasks, such as cluster analysis, are regarded as estimations of latent variables based on the observable ones. The estimation of latent variables in semi-supervised learning, where some labels are observed, will be more precise than that in unsupervised, and one of the concerns is to clarify the effect of the labeled data. However, there has not been sufficient theoretical analysis of the accuracy of the estimation of latent variables. In a previous study, a distribution-based error function was formulated, and its asymptotic form was calculated for unsupervised learning with generative models. It has been shown that, for the estimation of latent variables, the Bayes method is more accurate than the maximum-likelihood method. The present paper reveals the asymptotic forms of the error function in Bayesian semi-supervised learning for both discriminative and generative models. The results show that the generative model, which uses all of the given data, performs better when the model is well specified.
Exploiting Semantics for Big Data Integration
Knoblock, Craig A. (University of Southern California Information Sciences Institute) | Szekely, Pedro (University of Southern California Information Sciences Institute)
There is a great deal of interest in big data, focusing mostly on data set size. The use of semantics in this integration descriptions and then integrating the data within process is key to building an approach that scales this unified framework. Finally, we conclude by to large numbers of heterogeneous sources. For example, in and (4) integrate the data across sources using this our museum use case, we received data in spreadsheets model. Karma has been used on a variety of types of (figure 1), comma-separated values (CSV), data, including biological data, mobile phone data, JSON (figure 3), XML, and relational databases (figure geospatial data, and cultural heritage data. In order to illustrate the approach to integrating One challenge in integrating diverse data sources is data in Karma, we will use an example from the cultural the ability to import different data formats into a heritage domain.
Reports of the AAAI 2014 Conference Workshops
Albrecht, Stefano V. (University of Edinburgh) | Barreto, André M. S. (Brazilian National Laboratory for Scientific Computing) | Braziunas, Darius (Kobo Inc.) | Buckeridge, David L. (McGill University) | Cuayáhuitl, Heriberto (Heriot-Watt University) | Dethlefs, Nina (Heriot-Watt University) | Endres, Markus (University of Augsburg) | Farahmand, Amir-massoud (Carnegie Mellon University) | Fox, Mark (University of Toronto) | Frommberger, Lutz (University of Bremen) | Ganzfried, Sam (Carnegie Mellon University) | Gil, Yolanda (University of Southern California) | Guillet, Sébastien (Université du Québec à Chicoutimi) | Hunter, Lawrence E. (University of Colorado School of Medicine) | Jhala, Arnav (University of California Santa Cruz) | Kersting, Kristian (Technical University of Dortmund) | Konidaris, George (Massachusetts Institute of Technology) | Lecue, Freddy (IBM Research) | McIlraith, Sheila (University of Toronto) | Natarajan, Sriraam (Indiana University) | Noorian, Zeinab (University of Saskatchewan) | Poole, David (University of British Columbia) | Ronfard, Rémi (University of Grenoble) | Saffiotti, Alessandro (Orebro University) | Shaban-Nejad, Arash (McGill University) | Srivastava, Biplav (IBM Research) | Tesauro, Gerald (IBM Research) | Uceda-Sosa, Rosario (IBM Research) | Broeck, Guy Van den (Katholieke Universiteit Leuven) | Otterlo, Martijn van (Radboud University Nijmegen) | Wallace, Byron C. (University of Texas) | Weng, Paul (Pierre and Marie Curie University) | Wiens, Jenna (University of Michigan) | Zhang, Jie (Nanyang Technological University)
The AAAI-14 Workshop program was held Sunday and Monday, July 27–28, 2012, at the Québec City Convention Centre in Québec, Canada. Canada. The AAAI-14 workshop program included fifteen workshops covering a wide range of topics in artificial intelligence. The titles of the workshops were AI and Robotics; Artificial Intelligence Applied to Assistive Technologies and Smart Environments; Cognitive Computing for Augmented Human Intelligence; Computer Poker and Imperfect Information; Discovery Informatics; Incentives and Trust in Electronic Communities; Intelligent Cinematography and Editing; Machine Learning for Interactive Systems: Bridging the Gap between Perception, Action and Communication; Modern Artificial Intelligence for Health Analytics; Multiagent Interaction without Prior Coordination; Multidisciplinary Workshop on Advances in Preference Handling; Semantic Cities — Beyond Open Data to Models, Standards and Reasoning; Sequential Decision Making with Big Data; Statistical Relational AI; and The World Wide Web and Public Health Intelligence. This article presents short summaries of those events.
Using Semantics and Statistics to Turn Data into Knowledge
Pujara, Jay (University of Maryland, College Park) | Miao, Hui (University of California, Santa Cruz) | Getoor, Lise (Carnegie Mellon University) | Cohen, William W.
Many information extraction and knowledge base construction systems are addressing the challenge of deriving knowledge from text. A key problem in constructing these knowledge bases from sources like the web is overcoming the erroneous and incomplete information found in millions of candidate extractions. To solve this problem, we turn to semantics — using ontological constraints between candidate facts to eliminate errors. In this article, we represent the desired knowledge base as a knowledge graph and introduce the problem of knowledge graph identification, collectively resolving the entities, labels, and relations present in the knowledge graph. Knowledge graph identification requires reasoning jointly over millions of extractions simultaneously, posing a scalability challenge to many approaches. We use probabilistic soft logic (PSL), a recently-introduced statistical relational learning framework, to implement an efficient solution to knowledge graph identification and present state-of-the-art results for knowledge graph construction while performing an order of magnitude faster than competing methods.
Why the Data Train Needs Semantic Rails
Janowicz, Krzysztof (University of California, Santa Barbara) | Harmelen, Frank van (Vrije Universiteit Amsterdam) | Hendler, James A. (Rensselaer Polytechnic Institute) | Hitzler, Pascal (Wright State University)
While catchphrases such as big data, smart data, data-intensive science, or smart dust highlight different aspects, they share a common theme: Namely, a shift towards a data-centric perspective in which the synthesis and analysis of data at an ever-increasing spatial, temporal, and thematic resolution promises new insights, while, at the same time, reducing the need for strong domain theories as starting points. In terms of the envisioned methodologies, those catchphrases tend to emphasize the role of predictive analytics, that is, statistical techniques including data mining and machine learning, as well as supercomputing. Interestingly, however, while this perspective takes the availability of data as a given, it does not answer the question how one would discover the required data in today’s chaotic information universe, how one would understand which datasets can be meaningfully integrated, and how to communicate the results to humans and machines alike. The semantic web addresses these questions. In the following, we argue why the data train needs semantic rails. We point out that making sense of data and gaining new insights works best if inductive and deductive techniques go hand-in-hand instead of competing over the prerogative of interpretation.
Block-Wise MAP Inference for Determinantal Point Processes with Application to Change-Point Detection
Existing MAP inference algorithms for determinantal point processes (DPPs) need to calculate determinants or conduct eigenvalue decomposition generally at the scale of the full kernel, which presents a great challenge for real-world applications. In this paper, we introduce a class of DPPs, called BwDPPs, that are characterized by an almost block diagonal kernel matrix and thus can allow efficient block-wise MAP inference. Furthermore, BwDPPs are successfully applied to address the difficulty of selecting change-points in the problem of change-point detection (CPD), which results in a new BwDPP-based CPD method, named BwDppCpd. In BwDppCpd, a preliminary set of change-point candidates is first created based on existing well-studied metrics. Then, these change-point candidates are treated as DPP items, and DPP-based subset selection is conducted to give the final estimate of the change-points that favours both quality and diversity. The effectiveness of BwDppCpd is demonstrated through extensive experiments on five real-world datasets.
Implementation of a Practical Distributed Calculation System with Browsers and JavaScript, and Application to Distributed Deep Learning
Deep learning can achieve outstanding results in various fields. However, it requires so significant computational power that graphics processing units (GPUs) and/or numerous computers are often required for the practical application. We have developed a new distributed calculation framework called "Sashimi" that allows any computer to be used as a distribution node only by accessing a website. We have also developed a new JavaScript neural network framework called "Sukiyaki" that uses general purpose GPUs with web browsers. Sukiyaki performs 30 times faster than a conventional JavaScript library for deep convolutional neural networks (deep CNNs) learning. The combination of Sashimi and Sukiyaki, as well as new distribution algorithms, demonstrates the distributed deep learning of deep CNNs only with web browsers on various devices. The libraries that comprise the proposed methods are available under MIT license at http://mil-tokyo.github.io/.
Nonparametric Nearest Neighbor Descent Clustering based on Delaunay Triangulation
Abstract: In our physically inspired in-tree (IT) based clustering algorithm and the series after it, there is only one free parameter involved in computing the potential value of each point. In this work, based on the Delaunay Triangulation or its dual Voronoi tessellation, we propose a nonparametric process to compute potential values by the local information. This computation, though nonparametric, is relatively very rough, and consequently, many local extreme points will be generated. However, unlike those gradient-based methods, our ITbased methods are generally insensitive to those local extremes. This positively demonstrates the superiority of these parametric (previous) and nonparametric (in this work) ITbased methods. 1 Introduction In (1), we proposed a physically inspired clustering algorithm, in which an in-tree (IT) structure was first constructed. This IT structure organizes the data points into the clusters with several undesired connections (edges) between them requiring to be removed.