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Two-Stream Contextualized CNN for Fine-Grained Image Classification
Liu, Jiang (Chongqing University of Posts and Telecommunications) | Gao, Chenqiang (Chongqing University of Posts and Telecommunications) | Meng, Deyu (Xi'an Jiaotong University) | Zuo, Wangmeng (Harbin Institute of Technology)
Human's cognition system prompts that context information provides potentially powerful clue while recognizing objects. However, for fine-grained image classification, the contribution of context may vary over different images, and sometimes the context even confuses the classification result. To alleviate this problem, in our work, we develop a novel approach, two-stream contextualized Convolutional Neural Network, which provides a simple but efficient context-content joint classification model under deep learning framework. The network merely requires the raw image and a coarse segmentation as input to extract both content and context features without need of human interaction. Moreover, our network adopts a weighted fusion scheme to combine the content and the context classifiers, while a subnetwork is introduced to adaptively determine the weight for each image. According to our experiments on public datasets, our approach achieves considerable high recognition accuracy without any tedious human's involvements, as compared with the state-of-the-art approaches.
Social Emotion Classification via Reader Perspective Weighted Model
Li, Xin (Sun Yat-sen University) | Rao, Yanghui (Sun Yat-sen University) | Chen, Yanjia (Sun Yat-sen University) | Liu, Xuebo (Sun Yat-sen University) | Huang, Huan (Sun Yat-sen University)
With the development of Web 2.0, many users express their opinions online. This paper is concerned with the classification of social emotions on varied-scale datasets. Different from traditional models which weight training documents equally, the concept of emotional entropy is proposed to estimate the weight and tackle the issue of noisy documents. The topic assignment is also used to distinguish different emotional senses of the same word. Experimental evaluations using different data sets validate the effectiveness of the proposed social emotion classification model.
Handling Class Imbalance in Link Prediction Using Learning to Rank Techniques
Li, Bopeng (University of Michigan) | Chaudhuri, Sougata (University of Michigan) | Tewari, Ambuj ( University of Michigan )
We consider the link prediction (LP) problem in a partially observed network, where the objective is to make predictions in the unobserved portion of the network. Many existing methods reduce LP to binary classification. However, the dominance of absent links in real world networks makes misclassification error a poor performance metric. Instead, researchers have argued for using ranking performance measures, like AUC, AP and NDCG, for evaluation. We recast the LP problem as a learning to rank problem and use effective learning to rank techniques directly during training which allows us to deal with the class imbalance problem systematically. As a demonstration of our general approach, we develop an LP method by optimizing the cross-entropy surrogate, originally used in the popular ListNet ranking algorithm. We conduct extensive experiments on publicly available co-authorship, citation and metabolic networks to demonstrate the merits of our method.
Connecting the Dots Using Contextual Information Hidden in Text and Images
Kader, Md Abdul (The University of Texas at El Paso) | Naim, Sheikh Motahar (The University of Texas at El Paso) | Boedihardjo, Arnold P. (U. S. Army Corps of Engineers, Alexandria, VA) | Hossain, M. Shahriar (The University of Texas at El Paso)
Creation of summaries of events of interest from multitude of unstructured data is a challenging task commonly faced by intelligence analysts while seeking increased situational awareness. This paper proposes a framework called Storyboarding that leverages unstructured text and images to explain events as sets of sub-events. The framework first generates a textual context for each human face detected from images and then builds a chain of coherent documents where two consecutive documents of the chain contain a common theme as well as a context. Storyboarding helps analysts quickly narrow down large number of possibilities to a few significant ones for further investigation. Empirical studies on Wikipedia documents, images and news articles show that Storyboarding is able to provide deeper insights on events of interests.
Structure Aware L1 Graph for Data Clustering
Han, Shuchu (Stony Brook Univsersity) | Qin, Hong (Stony Brook Univsersity)
In graph-oriented machine learning research, L1 graph is an efficient way to represent the connections of input data samples. Its construction algorithm is based on a numerical optimization motivated by Compressive Sensing theory. As a result, It is a nonparametric method which is highly demanded. However, the information of data such as geometry structure and density distribution are ignored. In this paper, we propose a Structure Aware (SA) L1 graph to improve the data clustering performance by capturing the manifold structure of input data. We use a local dictionary for each datum while calculating its sparse coefficients. SA-L1 graph not only preserves the locality of data but also captures the geometry structure of data. The experimental results show that our new algorithm has better clustering performance than L1 graph.
Authorship Attribution Using a Neural Network Language Model
Ge, Zhenhao (Purdue University) | Sun, Yufang (Purdue University) | Smith, Mark J. T. (Purdue University)
In practice, training language models for individual authors is often expensive because of limited data resources. In such cases, Neural Network Language Models (NNLMs), generally outperform the traditional non-parametric N-gram models. Here we investigate the performance of a feed-forward NNLM on an authorship attribution problem, with moderate author set size and relatively limited data. We also consider how the text topics impact performance. Compared with a well-constructed N-gram baseline method with Kneser-Ney smoothing, the proposed method achieves nearly 2.5% reduction in perplexity and increases author classification accuracy by 3.43% on average, given as few as 5 test sentences. The performance is very competitive with the state of the art in terms of accuracy and demand on test data.
Robust Execution Strategies for Probabilistic Temporal Planning
Dietrich, Sam (Harvey Mudd College) | Lund, Kyle (Harvey Mudd College) | Boerkoel, James C. (Harvey Mudd College)
A critical challenge in temporal planning is robustly dealing with non-determinism introduced by the environment, e.g., the durational uncertainty of an action taken by a robot in the physical world due to slippage or other unexpected influences. Recent advances show that robustness, which accounts for uncertainty in predicting schedule success, is a better measure of solution quality than traditional metrics such as flexibility. This paper introduces the Robust Execution Problem (REP) for finding maximally robust dispatch strategies for general probabilistic temporal planning problems. While the REP is generally intractable in practice, we introduce approximate solution techniques—one that can be computed statically prior to the start of execution while providing robustness guarantees and one that dynamically adjusts to opportunities and setbacks during execution. We show empirically that dynamically optimizing for robustness improves the likelihood of execution success.
Predicting Prices in the Power TAC Wholesale Energy Market
Chowdhury, Moinul Morshed Porag (The University of Texas at El Paso)
The Power TAC simulation emphasizes the strategic problems that broker agents face in managing the economics of a smart grid. The brokers must make trades in multiple markets and to be successful, brokers must make many good predictions about future supply, demand,and prices. Clearing price prediction is an important part of the broker’s wholesale market strategy because it helps the broker to make intelligent decisions when purchasing energy at low cost in a day-ahead market. I describe my work on using machine learning methods to predict prices in the Power TAC wholesale market, which will be used in future bidding strategies.
A CP-Based Approach for Popular Matching
Chisca, Danuta Sorina (University College Cork) | Siala, Mohamed (University College Cork) | Simonin, Gilles (University College Cork) | O' (University College Cork) | Sullivan, Barry
Different formulations are proposed, distinguishing The notion of popular matching was introduced by (Gardenfors between one-sided matching (Garg et al. 2010) and twosided 1975), but this notion has its roots in the 18th century matching, e.g. the stable marriage (SM) problem (Gale and the notion of a Condorcet winner.