Goto

Collaborating Authors

 Genre


Semi-supervised Bayesian Deep Multi-modal Emotion Recognition

arXiv.org Machine Learning

In emotion recognition, it is difficult to recognize human's emotional states using just a single modality. Besides, the annotation of physiological emotional data is particularly expensive. These two aspects make the building of effective emotion recognition model challenging. In this paper, we first build a multi-view deep generative model to simulate the generative process of multi-modality emotional data. By imposing a mixture of Gaussians assumption on the posterior approximation of the latent variables, our model can learn the shared deep representation from multiple modalities. To solve the labeled-data-scarcity problem, we further extend our multi-view model to semi-supervised learning scenario by casting the semi-supervised classification problem as a specialized missing data imputation task. Our semi-supervised multi-view deep generative framework can leverage both labeled and unlabeled data from multiple modalities, where the weight factor for each modality can be learned automatically. Compared with previous emotion recognition methods, our method is more robust and flexible. The experiments conducted on two real multi-modal emotion datasets have demonstrated the superiority of our framework over a number of competitors.


From Language to Programs: Bridging Reinforcement Learning and Maximum Marginal Likelihood

arXiv.org Machine Learning

Our goal is to learn a semantic parser that maps natural language utterances into executable programs when only indirect supervision is available: examples are labeled with the correct execution result, but not the program itself. Consequently, we must search the space of programs for those that output the correct result, while not being misled by spurious programs: incorrect programs that coincidentally output the correct result. We connect two common learning paradigms, reinforcement learning (RL) and maximum marginal likelihood (MML), and then present a new learning algorithm that combines the strengths of both. The new algorithm guards against spurious programs by combining the systematic search traditionally employed in MML with the randomized exploration of RL, and by updating parameters such that probability is spread more evenly across consistent programs. We apply our learning algorithm to a new neural semantic parser and show significant gains over existing state-of-the-art results on a recent context-dependent semantic parsing task.


Linear Convergence of Accelerated Stochastic Gradient Descent for Nonconvex Nonsmooth Optimization

arXiv.org Machine Learning

In this paper, we study the stochastic gradient descent (SGD) method for the nonconvex nonsmooth optimization, and propose an accelerated SGD method by combining the variance reduction technique with Nesterov's extrapolation technique. Moreover, based on the local error bound condition, we establish the linear convergence of our method to obtain a stationary point of the nonconvex optimization. In particular, we prove that not only the sequence generated linearly converges to a stationary point of the problem, but also the corresponding sequence of objective values is linearly convergent. Finally, some numerical experiments demonstrate the effectiveness of our method. To the best of our knowledge, it is first proved that the accelerated SGD method converges linearly to the local minimum of the nonconvex optimization.


Joint Spatial-Angular Sparse Coding for dMRI with Separable Dictionaries

arXiv.org Machine Learning

Diffusion MRI (dMRI) provides the ability to reconstruct neuronal fibers in the brain, $\textit{in vivo}$, by measuring water diffusion along angular gradient directions in $q$-space. High angular resolution diffusion imaging (HARDI) can produce better estimates of fiber orientation than the popularly used diffusion tensor imaging, but the high number of samples needed to estimate diffusivity requires lengthy patient scan times. To accelerate dMRI, compressed sensing (CS) has been utilized by exploiting a sparse dictionary representation of the data, discovered through sparse coding. The sparser the representation, the fewer samples are needed to reconstruct a high resolution signal with limited information loss, and so an important area of research has focused on finding the sparsest possible representation of dMRI. Current reconstruction methods however, rely on an angular representation $\textit{per voxel}$ with added spatial regularization, and so, the global level of sparsity can be no less than the number of voxels. Therefore, state-of-the-art dMRI CS frameworks may have a fundamental limit to the rate acceleration that can be achieved. In contrast, we propose a joint spatial-angular representation of dMRI that will allow us to achieve levels of global sparsity that are below the number of voxels. A major challenge, however, is the computational complexity of solving a global sparse coding problem over large-scale dMRI. In this work, we present novel adaptations of popular sparse coding algorithms that become better suited for solving large-scale problems by exploiting spatial-angular separability. Our experiments show that our method achieves significantly sparser representations of HARDI than the state-of-the-art which has the potential to increase HARDI acceleration to new levels.


Abstract Syntax Networks for Code Generation and Semantic Parsing

arXiv.org Machine Learning

Tasks like code generation and semantic parsing require mapping unstructured (or partially structured) inputs to well-formed, executable outputs. We introduce abstract syntax networks, a modeling framework for these problems. The outputs are represented as abstract syntax trees (ASTs) and constructed by a decoder with a dynamically-determined modular structure paralleling the structure of the output tree. On the benchmark Hearthstone dataset for code generation, our model obtains 79.2 BLEU and 22.7% exact match accuracy, compared to previous state-of-the-art values of 67.1 and 6.1%. Furthermore, we perform competitively on the Atis, Jobs, and Geo semantic parsing datasets with no task-specific engineering.


Fisher consistency for prior probability shift

arXiv.org Machine Learning

We introduce Fisher consistency in the sense of unbiasedness as a desirable property for estimators of class prior probabilities. Lack of Fisher consistency could be used as a criterion to dismiss estimators that are unlikely to deliver precise estimates in test datasets under prior probability and more general dataset shift. The usefulness of this unbiasedness concept is demonstrated with three examples of classifiers used for quantification: Adjusted Classify & Count, EM-algorithm and CDE-Iterate. We find that Adjusted Classify & Count and EM-algorithm are Fisher consistent. A counter-example shows that CDE-Iterate is not Fisher consistent and, therefore, cannot be trusted to deliver reliable estimates of class probabilities.


How Artificial Intelligence enhances education

#artificialintelligence

In the past years, a collection of hardware, software and online service have managed to bring changes and reforms to classrooms and teaching methods. But the true disruption of education is yet to arrive. Artificial Intelligence has proven its role as a game changing factor in an increasing number of fields, causing transformations unimaginable in the past. It's now showing glimmers of how it might forever change the learning process, one of the oldest skills that mankind has mastered. We've teamed up with Product Hunt to offer you the chance to win an all expense paid trip to TNW Conference 2017!


Open Source Deep Learning Frameworks and Visual Analytics

@machinelearnbot

Deep Learning gets more and more traction. It basically focuses on one section of Machine Learning: Artificial Neural Networks. This article explains why Deep Learning is a game changer in analytics, when to use it, and how Visual Analytics allows business analysts to leverage the analytic models built by a (citizen) data scientist. Deep Learning is the modern buzzword for artificial neural networks, one of many concepts and algorithms in machine learning to build analytics models. A neural network works similar to what we know from a human brain: You get non-linear interactions as input and transfer them to output. A neural network is a supervised algorithm in most cases, which uses historical data sets to learn correlations to predict outputs of future events, e.g. for cross selling or fraud detection.


The Best AI Conferences to Attend in 2017

#artificialintelligence

And we'd like to help. Since we've already done a crapload of research (and gotten a lot of customer and expert feedback) on which AI events are likely to be the must-attends of the next year, we thought we'd do you a solid and let you know which conferences we're headed to in the coming months. We've also listed other top contenders we won't make it to but may interest you. Hope to see you at a show or two next year! Explore how deep learning will impact healthcare, manufacturing, search & transportation." Where do the challenges still lie in research and application? We're exploring the convergence of software & hardware to create safer, smarter and more efficient transport."


OpsVeda Announces Participation at SAPPHIRE NOW 2017

#artificialintelligence

OpsVeda today announced that it will participate at SAPPHIRE NOW and ASUG Annual Conference being held May 16–18 in Orlando, Florida. The company will be showcasing its platform that leverages machine learning techniques for proactive detection and remediation of potential operational disruptions. OpsVeda presents the full stack real-time operational intelligence platform, to power automated operational decision making in the enterprise. It helps the operations team to re-capture an estimated 10-20% of the revenue and margin leakage due to out of stocks, chargebacks, changes in customer buying behavior, expedites, missed deliveries and inventory obsolescence. Many of these issues go undetected until it is too late for any corrective action.