Asia
Gene Selection and Clustering of Breast Cancer Data
Bhuiyan, Farzana Ahamed (Tennessee Technological University) | Sharif, MD Bulbul (Tennessee Technological University) | Tinker, Paul Joshua (Tennessee Technological University) | Eberle, William (Tennessee Technological University) | Talbert, Douglas A. (Tennessee Technological University) | Ghafoor, Sheikh Khaled (Tennessee Technological University) | Frey, Lewis (Medical University of South Carolina)
In this work, we first attempt to replicate an earlier study on gene selection and clustering, and then we extend this work by applying a different type of hierarchical clustering to dis- cover interesting subsets of genes from breast cancer data. Replication of such studies is a known challenge and an ac- tive area of research in bioinformatics. The work presented in this paper is three-fold. First, we replicate a study conducted at the University of North Carolina to generate an initial set of genes. Second, we apply an approach called Distance Weighted Discrimination to fuse multiple, disparate breast cancer datasets into a single validation set. Third, we per- form hierarchical clustering and k-means clustering on this validation set to discover natural groupings and compare the clusters generated by both methods. While applying the hi- erarchical clustering is part of the reproduction step, we ex- tend the research by trying two different forms of hierarchi- cal clustering. We also apply k-means clustering for the same purpose and compare all three methods using Kaplan-Meier estimation and Cox proportional hazards regression. We dis- cover that among the three methods, k-means clustering gives us the best results.
Using EEG Features and Machine Learning to Predict Gifted Children
Ghali, Ramla (Université de Montréal) | Tato, Ange (Université de Montréal) | Nkambou, Roger (Université de Montréal)
Gifted students have a higher capabilities of understanding and learning. They are characterized by a high level of attention and a high performance in the classroom. Gifted children are defined in this paper as children who have a performance higher than the average group (59.64%). In order to predict gifted students from normal students, we conducted an experiment where 17 pupils have voluntarily participated in this study. We collected different types of data (gender, age, performance, initial average in math and EEG mental states) in a web platform to learn mathematics called NetMath. Participants were invited to respond to top-level exercises on the four basic operations in decimals. We trained different machine learning algorithms to predict gifted students. Our first results show that the decision tree could predict gifted students with an accuracy of 76.88%. Using J48 trees, we noticed also that two relevant features could determine gifted children: the relaxation extracted from EEG headset and the characteristic of strong student. A strong student is defined as a student who obtained a mean higher than the group’s mean in the first step evaluation in class.
Visual Attention Model for Cross-Sectional Stock Return Prediction and End-to-End Multimodal Market Representation Learning
Zhao, Ran (Carnegie Mellon University) | Deng, Yuntian (Harvard University) | Dredze, Mark (Johns Hopkins University) | Verma, Arun (Bloomberg) | Rosenberg, David (Bloomberg) | Stent, Amanda (Bloomberg)
Technical and fundamental analysis are traditional tools used to analyze individual stocks; however, the finance literature has shown that the price movement of each individual stock correlates heavily with other stocks, especially those within the same sector. In this paper we propose a general-purpose market representation that incorporates fundamental and technical indicators and relationships between individual stocks. We treat the daily stock market as a ‘market image’ where rows (grouped by market sector) represent individual stocks and columns represent indicators. We apply a convolutional neural network over this market image to build market features in a hierarchical way. We use a recurrent neural network, with an attention mechanism over the market feature maps, to model temporal dynamics in the market. We show that our proposed model outperforms strong baselines in both short-term and long-term stock return prediction tasks. We also show another use for our market image: to construct concise and dense market embeddings suitable for downstream prediction tasks.
Classification of Semantic Relations between Pairs of Nominals Using Transfer Learning
Zhang, Linrui (University of Texas at Dallas) | Moldovan, Dan (University of Texas at Dallas)
The representation of semantic meaning of sentences using neural network has recently gained popularity, due to the fact that there is no need to specifically extract lexical syntactic and semantic features. A major problem with this approach is that it requires large human annotated corpora. In order to reduce human annotation effort, in recent years, researchers made several attempts to find universal sentence representation methods, aiming to obtain general-purpose sentence embeddings that could be widely adopted to a wide range of NLP tasks without training directly from the specific datasets. InferSent, a supervised universal sentence representation model proposed by Facebook research, implements 8 popular neural network sentence encoding structures trained on natural language inference datasets, and apply to 12 different NLP tasks. However, the relation classification task was not one of these. In this paper, we re-train these 8 sentence encoding structures and use them as the starting points on relation classification task. Experiments using SemEval-2010 datasets show that our models could achieve comparable results to the state-of-the-art relation classification systems.
Detecting the Onset of a Network Layer DoS Attack with a Graph-Based Approach
Paudel, Ramesh (Tennessee Technological University) | Harlan, Peter (Western Kentucky University) | Eberle, William (Tennessee Technological University)
A denial-of-service (DoS) attack is a malicious act with the goal of interrupting the access to a computer network. The result of DoS attack can cause the computers on the network to squander their resources to serve illegitimate requests that result in a disruption of the network’s services to legitimate users. With a sophisticated DoS attack, it becomes difficult to distinguish malicious requests from legitimate requests. Since a network layer DoS attack can cause interruptions to a network while causing collateral damage, it is vital to understand the measures to mitigate against such attacks. Generally, approaches that implement distribution charts based on statistical analysis or honeypots have been applied to detect a DoS attack. However, this is usually too late, as the damage is already done. We hypothesize in this work that a graph-based approach can provide the capability to identify a DoS attack at its inception. A graph-based approach will also allow us to not only focus on anomalies within an entity (like a computer) but also allow us to analyze the anomalies that exist in an entity’s relationship with other entities, thus providing a rich source of contextual analysis. We demonstrate our proposed approach using a publicly-available dataset.
An Empirical Evaluation of the Effect of Adversarial Labels on Classifier Accuracy Estimation
Clifford, Alexandra (MIT Lincoln Laboratory) | Corey, Cassian (MIT Lincoln Laboratory) | Holodnak, John T. (MIT Lincoln Laboratory)
This paper examines the effect of providing adversarial labels to several algorithms that use noisy labels from multiple experts to estimate classifier accuracy, referred to hereafter as "estimators." We propose four adversary labeling strategies and use experiments on synthetic data to gauge their impact on the estimators. Our results show that even a single adversary can considerably impact the effectiveness of an estimator. In addition, we find that estimators that weight the input of all experts equally tend to be much more affected by the inclusion of adversaries than those that can separately model each expert and that the impact of adversaries is lessened when the experts have higher accuracy.
Domain Adaptive Transfer Learning for Fault Diagnosis
Wang, Qin, Michau, Gabriel, Fink, Olga
Thanks to digitization of industrial assets in fleets, the ambitious goal of transferring fault diagnosis models fromone machine to the other has raised great interest. Solving these domain adaptive transfer learning tasks has the potential to save large efforts on manually labeling data and modifying models for new machines in the same fleet. Although data-driven methods have shown great potential in fault diagnosis applications, their ability to generalize on new machines and new working conditions are limited because of their tendency to overfit to the training set in reality. One promising solution to this problem is to use domain adaptation techniques. It aims to improve model performance on the target new machine. Inspired by its successful implementation in computer vision, we introduced Domain-Adversarial Neural Networks (DANN) to our context, along with two other popular methods existing in previous fault diagnosis research. We then carefully justify the applicability of these methods in realistic fault diagnosis settings, and offer a unified experimental protocol for a fair comparison between domain adaptation methods for fault diagnosis problems.
Explaining Reward Functions in Markov Decision Processes
Russell, Jacob (Dartmouth College) | Santos, Eugene (Dartmouth College)
Rewards in Markov Decision Processes (MDP) define the behavior of the model. Without a clear interpretation of what the reward function is and is not capturing, one cannot trust their model nor diagnose when the model is giving incorrect recommendations. Increasing complexity of state-of-the-art models used to represent the reward function and model-free methods that attempt to avoid representing this function make trusting the model much more difficult. We map these reward functions onto a standard classification problem where we can explain what factors the model considers in making decisions in local and global contexts and quantify whether the fit of the reward function is likely to be good for explaining the behavior of the model. We evaluate our proof-of-concept on both the standard version and a modified version of the Object World domain to add more nonlinearity.
Convolutional Adversarial Latent Factor Model for Recommender System
Costa, Felipe Soares Da (Aalborg University) | Dolog, Peter (Aalborg University)
The accuracy of Top-N recommendation task is challenged in the systems with mainly implicit user feedback considered. Adversarial training has presented successful results in identifying real data distributions in various domains (e.g. image processing). Nonetheless, adversarial training applied to recommendation is still challenged especially by interpretation of negative implicit feedback causing it to converge slowly as well as affecting its convergence stability. This is often attributed to high sparsity of the implicit feedback and discrete values characteristic from items recommendation. To face these challenges, we propose a novel model named convolutional adversarial latent factor model (CALF), which uses adversarial training in generative and discriminative models for implicit feedback recommendations. We assume that users prefer observed items over generated items and then apply pairwise product to model the user-item interactions. Additionally, the latent features become input data of our convolutional neural network (CNN) to learn correlations among embedding dimensions. Finally, Rao-Blackwellized sampling is adopted to deal with the discrete values optimizing CALF and stabilizing the training step. We conducted extensive experiments on three different benchmark datasets, where our proposed model demonstrates its efficiency for item recommendation.
Multi-Robot Informative Path Planning in Unknown Environments Through Continuous Region Partitioning
Dutta, Ayan (University of North Florida) | Bhattacharya, Amitabh (University of North Florida) | Kreidl, O. Patrick (University of North Florida) | Ghosh, Anirban (University of North Florida) | Dasgupta, Prithviraj (University of Nebraska at Omaha)
Information collection is an important application of multi-robot systems especially in environments that are difficult to operate for humans. The objective of the robots is to maximize information collection from the environment while remaining in their path-length budgets. In this paper, we propose a novel multi-robot information collection algorithm that uses a continuous region partitioning approach to efficiently divide an unknown environment among the robots based on the discovered obstacles in the area, for better load-balancing. Our algorithm gracefully handles situations when some of the robots cannot communicate with other robots due to limited communication ranges.