81,326 research outputs found
Morphological Analysis as Classification: an Inductive-Learning Approach
Morphological analysis is an important subtask in text-to-speech conversion,
hyphenation, and other language engineering tasks. The traditional approach to
performing morphological analysis is to combine a morpheme lexicon, sets of
(linguistic) rules, and heuristics to find a most probable analysis. In
contrast we present an inductive learning approach in which morphological
analysis is reformulated as a segmentation task. We report on a number of
experiments in which five inductive learning algorithms are applied to three
variations of the task of morphological analysis. Results show (i) that the
generalisation performance of the algorithms is good, and (ii) that the lazy
learning algorithm IB1-IG performs best on all three tasks. We conclude that
lazy learning of morphological analysis as a classification task is indeed a
viable approach; moreover, it has the strong advantages over the traditional
approach of avoiding the knowledge-acquisition bottleneck, being fast and
deterministic in learning and processing, and being language-independent.Comment: 11 pages, 5 encapsulated postscript figures, uses non-standard NeMLaP
proceedings style nemlap.sty; inputs ipamacs (international phonetic
alphabet) and epsf macro
Machine Learning in Automated Text Categorization
The automated categorization (or classification) of texts into predefined
categories has witnessed a booming interest in the last ten years, due to the
increased availability of documents in digital form and the ensuing need to
organize them. In the research community the dominant approach to this problem
is based on machine learning techniques: a general inductive process
automatically builds a classifier by learning, from a set of preclassified
documents, the characteristics of the categories. The advantages of this
approach over the knowledge engineering approach (consisting in the manual
definition of a classifier by domain experts) are a very good effectiveness,
considerable savings in terms of expert manpower, and straightforward
portability to different domains. This survey discusses the main approaches to
text categorization that fall within the machine learning paradigm. We will
discuss in detail issues pertaining to three different problems, namely
document representation, classifier construction, and classifier evaluation.Comment: Accepted for publication on ACM Computing Survey
A bagging SVM to learn from positive and unlabeled examples
We consider the problem of learning a binary classifier from a training set
of positive and unlabeled examples, both in the inductive and in the
transductive setting. This problem, often referred to as \emph{PU learning},
differs from the standard supervised classification problem by the lack of
negative examples in the training set. It corresponds to an ubiquitous
situation in many applications such as information retrieval or gene ranking,
when we have identified a set of data of interest sharing a particular
property, and we wish to automatically retrieve additional data sharing the
same property among a large and easily available pool of unlabeled data. We
propose a conceptually simple method, akin to bagging, to approach both
inductive and transductive PU learning problems, by converting them into series
of supervised binary classification problems discriminating the known positive
examples from random subsamples of the unlabeled set. We empirically
demonstrate the relevance of the method on simulated and real data, where it
performs at least as well as existing methods while being faster
Adversarial Attack and Defense on Graph Data: A Survey
Deep neural networks (DNNs) have been widely applied to various applications
including image classification, text generation, audio recognition, and graph
data analysis. However, recent studies have shown that DNNs are vulnerable to
adversarial attacks. Though there are several works studying adversarial attack
and defense strategies on domains such as images and natural language
processing, it is still difficult to directly transfer the learned knowledge to
graph structure data due to its representation challenges. Given the importance
of graph analysis, an increasing number of works start to analyze the
robustness of machine learning models on graph data. Nevertheless, current
studies considering adversarial behaviors on graph data usually focus on
specific types of attacks with certain assumptions. In addition, each work
proposes its own mathematical formulation which makes the comparison among
different methods difficult. Therefore, in this paper, we aim to survey
existing adversarial learning strategies on graph data and first provide a
unified formulation for adversarial learning on graph data which covers most
adversarial learning studies on graph. Moreover, we also compare different
attacks and defenses on graph data and discuss their corresponding
contributions and limitations. In this work, we systemically organize the
considered works based on the features of each topic. This survey not only
serves as a reference for the research community, but also brings a clear image
researchers outside this research domain. Besides, we also create an online
resource and keep updating the relevant papers during the last two years. More
details of the comparisons of various studies based on this survey are
open-sourced at
https://github.com/YingtongDou/graph-adversarial-learning-literature.Comment: In submission to Journal. For more open-source and up-to-date
information, please check our Github repository:
https://github.com/YingtongDou/graph-adversarial-learning-literatur
Optimizing E-Commerce Product Classification Using Transfer Learning
The global e-commerce market is snowballing at a rate of 23% per year. In 2017, retail e-commerce users were 1.66 billion and sales worldwide amounted to 2.3 trillion US dollars, and e-retail revenues are projected to grow to 4.88 trillion USD in 2021. With the immense popularity that e-commerce has gained over past few years comes the responsibility to deliver relevant results to provide rich user experience. In order to do this, it is essential that the products on the ecommerce website be organized correctly into their respective categories. Misclassification of products leads to irrelevant results for users which not just reflects badly on the website, it could also lead to lost customers. With ecommerce sites nowadays providing their portal as a platform for third party merchants to sell their products as well, maintaining a consistency in product categorization becomes difficult. Therefore, automating this process could be of great utilization. This task of automation done on the basis of text could lead to discrepancies since the website itself, its various merchants, and users, all could use different terminologies for a product and its category. Thus, using images becomes a plausible solution for this problem. Dealing with images can best be done using deep learning in the form of convolutional neural networks. This is a computationally expensive task, and in order to keep the accuracy of a traditional convolutional neural network while reducing the hours it takes for the model to train, this project aims at using a technique called transfer learning. Transfer learning refers to sharing the knowledge gained from one task for another where new model does not need to be trained from scratch in order to reduce the time it takes for training. This project aims at using various product images belonging to five categories from an ecommerce platform and developing an algorithm that can accurately classify products in their respective categories while taking as less time as possible. The goal is to first test the performance of transfer learning against traditional convolutional networks. Then the next step is to apply transfer learning to the downloaded dataset and assess its performance on the accuracy and time taken to classify test data that the model has never seen before
A Comparative Study of the Application of Different Learning Techniques to Natural Language Interfaces
In this paper we present first results from a comparative study. Its aim is
to test the feasibility of different inductive learning techniques to perform
the automatic acquisition of linguistic knowledge within a natural language
database interface. In our interface architecture the machine learning module
replaces an elaborate semantic analysis component. The learning module learns
the correct mapping of a user's input to the corresponding database command
based on a collection of past input data. We use an existing interface to a
production planning and control system as evaluation and compare the results
achieved by different instance-based and model-based learning algorithms.Comment: 10 pages, to appear CoNLL9
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