unsupervised classifier
Unsupervised Classifiers, Mutual Information and 'Phantom Targets
We derive criteria for training adaptive classifier networks to perform unsu(cid:173) pervised data analysis. The first criterion turns a simple Gaussian classifier into a simple Gaussian mixture analyser. The second criterion, which is much more generally applicable, is based on mutual information. This'firm but fair' criterion can be applied to any network that produces probability-type outputs, but it does not necessarily lead to useful behavior. One of the main distinctions made in discussing neural network architectures, and pattern analysis algorithms generally, is between supervised and unsupervised data analysis.
Two Computational Models for Analyzing Political Attention in Social Media
Hemphill, Libby, Schöpke-Gonzalez, Angela M.
Understanding how political attention is divided and over what subjects is crucial for research on areas such as agenda setting, framing, and political rhetoric. Existing methods for measuring attention, such as manual labeling according to established codebooks, are expensive and can be restrictive. We describe two computational models that automatically distinguish topics in politicians' social media content. Our models---one supervised classifier and one unsupervised topic model---provide different benefits. The supervised classifier reduces the labor required to classify content according to pre-determined topic list. However, tweets do more than communicate policy positions. Our unsupervised model uncovers both political topics and other Twitter uses (e.g., constituent service). These models are effective, inexpensive computational tools for political communication and social media research. We demonstrate their utility and discuss the different analyses they afford by applying both models to the tweets posted by members of the 115th U.S. Congress.
- North America > United States > Michigan > Washtenaw County > Ann Arbor (0.14)
- Asia > Middle East > Iran (0.04)
- North America > United States > Texas (0.04)
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- Law (1.00)
- Government > Regional Government > North America Government > United States Government (1.00)
- Information Technology > Services (0.93)
- Government > Voting & Elections (0.93)
Deep Matching Autoencoders
Mukherjee, Tanmoy, Yamada, Makoto, Hospedales, Timothy M.
Increasingly many real world tasks involve data in multiple modalities or views. This has motivated the development of many effective algorithms for learning a common latent space to relate multiple domains. However, most existing cross-view learning algorithms assume access to paired data for training. Their applicability is thus limited as the paired data assumption is often violated in practice: many tasks have only a small subset of data available with pairing annotation, or even no paired data at all. In this paper we introduce Deep Matching Autoencoders (DMAE), which learn a common latent space and pairing from unpaired multi-modal data. Specifically we formulate this as a cross-domain representation learning and object matching problem. We simultaneously optimise parameters of representation learning auto-encoders and the pairing of unpaired multi-modal data. This framework elegantly spans the full regime from fully supervised, semi-supervised, and unsupervised (no paired data) multi-modal learning. We show promising results in image captioning, and on a new task that is uniquely enabled by our methodology: unsupervised classifier learning.
Finding Bottlenecks: Predicting Student Attrition with Unsupervised Classifier
Sajjadi, Seyed, Shapiro, Bruce, McKinlay, Christopher, Sarkisyan, Allen, Shubin, Carol, Osoba, Efunwande
Policy makers, the public, university administrators, students and their families are concerned about low graduation rates and lengthy times to degree in higher education. The median time to graduation is six years at CSUN (1). The fouryear and the six-year graduation rates are 13% and 50%, respectively (2). With an enrollment of over 6000 undergraduate students, CoBaE is one of largest business schools in the nation. CoBaE confers the second most undergraduate degrees at CSUN (behind the College of Social and Behavioral Science), and it has three of the top ten most popular majors (Management, Finance, and Marketing) at CSUN.
- North America > United States > California > Alameda County > Oakland (0.04)
- Asia > Middle East > Jordan (0.04)
- Information Technology > Artificial Intelligence > Machine Learning > Statistical Learning > Clustering (0.98)
- Information Technology > Artificial Intelligence > Machine Learning > Performance Analysis > Accuracy (0.96)
- Information Technology > Artificial Intelligence > Machine Learning > Statistical Learning > Regression (0.72)