Deep Learning
Estimation of Body Mass Index from Photographs using Deep Convolutional Neural Networks
Pantanowitz, Adam, Cohen, Emmanuel, Gradidge, Philippe, Crowther, Nigel, Aharonson, Vered, Rosman, Benjamin, Rubin, David M
Obesity is an important concern in public health, and Body Mass Index is one of the useful (and proliferant) measures. We use Convolutional Neural Networks to determine Body Mass Index from photographs in a study with 161 participants. Low data, a common problem in medicine, is addressed by reducing the information in the photographs by generating silhouette images. Results present with high correlation when tested on unseen data.
Conditional Density Estimation Tools in Python and R with Applications to Photometric Redshifts and Likelihood-Free Cosmological Inference
Dalmasso, Niccolรฒ, Pospisil, Taylor, Lee, Ann B., Izbicki, Rafael, Freeman, Peter E., Malz, Alex I.
It is well known in astronomy that propagating non-Gaussian prediction uncertainty in photometric redshift estimates is key to reducing bias in downstream cosmological analyses. Similarly, likelihood-free inference approaches, which are beginning to emerge as a tool for cosmological analysis, require the full uncertainty landscape of the parameters of interest given observed data. However, most machine learning (ML) based methods with open-source software target point prediction or classification, and hence fall short in quantifying uncertainty in complex regression and parameter inference settings such as the applications mentioned above. As an alternative to methods that focus on predicting the response (or parameters) $\mathbf{y}$ from features $\mathbf{x}$, we provide nonparametric conditional density estimation (CDE) tools for approximating and validating the entire probability density $\mathrm{p}(\mathbf{y} \mid \mathbf{x})$ given training data for $\mathbf{x}$ and $\mathbf{y}$. As there is no one-size-fits-all CDE method, the goal of this work is to provide a comprehensive range of statistical tools and open-source software for nonparametric CDE and method assessment which can accommodate different types of settings and which in addition can easily be fit to the problem at hand. Specifically, we introduce CDE software packages in $\texttt{Python}$ and $\texttt{R}$ based on four ML prediction methods adapted and optimized for CDE: $\texttt{NNKCDE}$, $\texttt{RFCDE}$, $\texttt{FlexCode}$, and $\texttt{DeepCDE}$. Furthermore, we present the $\texttt{cdetools}$ package, which includes functions for computing a CDE loss function for model selection and tuning of parameters, together with diagnostics functions. We provide sample code in $\texttt{Python}$ and $\texttt{R}$ as well as examples of applications to photometric redshift estimation and likelihood-free cosmology via CDE.
TGG: Transferable Graph Generation for Zero-shot and Few-shot Learning
Zhang, Chenrui, Lyu, Xiaoqing, Tang, Zhi
Zero-shot and few-shot learning aim to improve generalization to unseen concepts, which are promising in many realistic scenarios. Due to the lack of data in unseen domain, relation modeling between seen and unseen domains is vital for knowledge transfer in these tasks. Most existing methods capture seen-unseen relation implicitly via semantic embedding or feature generation, resulting in inadequate use of relation and some issues remain (e.g. domain shift). To tackle these challenges, we propose a Transferable Graph Generation (TGG) approach, in which the relation is modeled and utilized explicitly via graph generation. Specifically, our proposed TGG contains two main components: (1) Graph generation for relation modeling. An attention-based aggregate network and a relation kernel are proposed, which generate instance-level graph based on a class-level prototype graph and visual features. Proximity information aggregating is guided by a multi-head graph attention mechanism, where seen and unseen features synthesized by GAN are revised as node embeddings. The relation kernel further generates edges with GCN and graph kernel method, to capture instance-level topological structure while tackling data imbalance and noise. (2) Relation propagation for relation utilization. A dual relation propagation approach is proposed, where relations captured by the generated graph are separately propagated from the seen and unseen subgraphs. The two propagations learn from each other in a dual learning fashion, which performs as an adaptation way for mitigating domain shift. All components are jointly optimized with a meta-learning strategy, and our TGG acts as an end-to-end framework unifying conventional zero-shot, generalized zero-shot and few-shot learning. Extensive experiments demonstrate that it consistently surpasses existing methods of the above three fields by a significant margin.
A Queuing Approach to Parking: Modeling, Verification, and Prediction
Tavafoghi, Hamidreza, Poolla, Kameshwar, Varaiya, Pravin
We present a queuing model of parking dynamics and a model-based prediction method to provide real-time probabilistic forecasts of future parking occupancy. The queuing model has a non-homogeneous arrival rate and time-varying service time distribution. All statistical assumptions of the model are verified using data from 29 truck parking locations, each with between 55 and 299 parking spots. For each location and each spot the data specifies the arrival and departure times of a truck, for 16 months of operation. The modeling framework presented in this paper provides empirical support for queuing models adopted in many theoretical studies and policy designs. We discuss how our framework can be used to study parking problems in different environments. Based on the queuing model, we propose two prediction methods, a microscopic method and a macroscopic method, that provide a real-time probabilistic forecast of parking occupancy for an arbitrary forecast horizon. These model-based methods convert a probabilistic forecast problem into a parameter estimation problem that can be tackled using classical estimation methods such as regressions or pure machine learning algorithms. We characterize a lower bound for an arbitrary real-time prediction algorithm. We evaluate the performance of these methods using the truck data comparing the outcomes of their implementations with other model-based and model-free methods proposed in the literature.
Active Learning for Domain Classification in a Commercial Spoken Personal Assistant
Chen, Xi C., Sagar, Adithya, Kao, Justine T., Li, Tony Y., Klein, Christopher, Pulman, Stephen, Garg, Ashish, Williams, Jason D.
We describe a method for selecting relevant new training data for the LSTM-based domain selection component of our personal assistant system. Adding more annotated training data for any ML system typically improves accuracy, but only if it provides examples not already adequately covered in the existing data. However, obtaining, selecting, and labeling relevant data is expensive. This work presents a simple technique that automatically identifies new helpful examples suitable for human annotation. Our experimental results show that the proposed method, compared with random-selection and entropy-based methods, leads to higher accuracy improvements given a fixed annotation budget. Although developed and tested in the setting of a commercial intelligent assistant, the technique is of wider applicability.
Deep Learning for Estimating Synaptic Health of Primary Neuronal Cell Culture
Kormilitzin, Andrey, Yang, Xinyu, Stone, William H., Woffindale, Caroline, Nicholls, Francesca, Ribe, Elena, Nevado-Holgado, Alejo, Buckley, Noel
Understanding the morphological changes of primary neuronal cells induced by chemical compounds is essential for drug discovery. Using the data from a single high-throughput imaging assay, a classification model for predicting the biological activity of candidate compounds was introduced. The image recognition model which is based on deep convolutional neural network (CNN) architecture with residual connections achieved accuracy of 99.6$\%$ on a binary classification task of distinguishing untreated and treated rodent primary neuronal cells with Amyloid-$\beta_{(25-35)}$.
Smaller Models, Better Generalization
Sharma, Mayank, Tripathi, Suraj, Dubey, Abhimanyu, Jayadeva, null, Guruju, Sai, Goalla, Nihal
Reducing network complexity has been a major research focus in recent years with the advent of mobile technology. Convolutional Neural Networks that perform various vision tasks without memory overhaul is the need of the hour. This paper focuses on qualitative and quantitative analysis of reducing the network complexity using an upper bound on the Vapnik-Chervonenkis dimension, pruning, and quantization. We observe a general trend in improvement of accuracies as we quantize the models. We propose a novel loss function that helps in achieving considerable sparsity at comparable accuracies to that of dense models. We compare various regularizations prevalent in the literature and show the superiority of our method in achieving sparser models that generalize well.
On the rate of convergence of fully connected very deep neural network regression estimates
Kohler, Michael, Langer, Sophie
Recent results in nonparametric regression show that deep learning, i.e., neural networks estimates with many hidden layers, are able to circumvent the so-called curse of dimensionality in case that suitable restrictions on the structure of the regression function hold. One key feature of the neural networks used in these results is that they are not fully connected. In this paper we show that we can get similar results also for fully connected multilayer feedforward neural networks with ReLU activation functions, provided the number of neurons per hidden layer is fixed and the number of hidden layers tends to infinity for sample size tending to infinity. The proof is based on new approximation results concerning fully connected deep neural networks.
Deep Neural Network Ensembles against Deception: Ensemble Diversity, Accuracy and Robustness
Liu, Ling, Wei, Wenqi, Chow, Ka-Ho, Loper, Margaret, Gursoy, Emre, Truex, Stacey, Wu, Yanzhao
We develop a three - step diversity ensemble creation algorithm: (1) Creating a pool of candidate ensemble member models, or so called base models; (2) Creating a pool of candidate ensemble teams with their diversity scores higher than the pre - defined minimum diversity threshold; and (3) Developing robust ensemble consensus methods, which can effectively combine, rank and integrate predictions from members of an ensemble committee to produce high accuracy ensemble prediction output again st adversarial examples. D ifferent ensemble creation methods tend to have varying level of diversity. A. Creating Ensemble s of Type 1 diversity We want to construct a pool of N redundant DNN models trained on the same learning task as the base classifiers. Preferably, the best ensemble committee members are those base classifiers that are relatively diverse and have high individual test accuracy. T he type 1 diversity ensemble creation algorithm requires that every base model in the pool meet s the type 1 dive rsity and ha s high benign test accuracy comparable to that of the target model under protection. One approach is to add one member model to the pool at a time. Assume that we initialize the pool with a privately trained DNN model. We only allow the next mo del to be added to the pool if it is trained independently using different hyper - parameters or different neural network structures or algorithms and it meet s the high benign test accuracy requirement.
DeepBbox: Accelerating Precise Ground Truth Generation for Autonomous Driving Datasets
Rathore, Govind, Lin, Wan-Yi, Kim, Ji Eun
DeepBbox: Accelerating Precise Ground Truth Generation for Autonomous Driving Datasets Govind Rathore, Wan-Yi Lin and Ji Eun Kim Abstract -- Autonomous driving requires various computer vision algorithms, such as object detection and tracking. Precisely-labeled datasets (i.e., objects are fully contained in bounding boxes with only a few extra pixels) are preferred for training such algorithms, so that the algorithms can detect exact locations of the objects. However, it is very time-consuming and hence expensive to generate precise labels for image sequences at scale. In this paper, we propose DeepBbox, an algorithm that "corrects" loose object labels into right bounding boxes to reduce human annotation efforts. We use Cityscapes [1] dataset to show annotation efficiency and accuracy improvement using DeepBbox. Experimental results show that, with DeepBbox, we can increase the number of object edges that are labeled automatically (within 1% error) by 50% to reduce manual annotation time.