Publications

Drivers' Awareness, Knowledge, and Use of Autonomous Driving Assistance Systems (ADAS) and Vehicle Automation
Kelly Selina Bronson
Sophie Le Page
Katherine M. Robinson
Shalaleh Rismani
Jason Millar
Advanced driver assistance systems (ADAS) technologies in vehicles (e.g. park assist, lane change assist, emergency braking, etc.), which ta… (see more)ke over parts of the driving task of human drivers, are advancing at a disruptive pace and hold the potential to deliver many benefits to society. However, public understanding of ADAS systems, and driver training and licensing for using them, are lagging behind the fast-paced technological development, which could raise safety issues or slow the deployment of ADAS, thus offsetting their potential benefits. There is, therefore, a need to investigate issues related to public perception of ADAS in order to develop appropriate policies and governance structures which support innovation, and result in the smooth deployment and acceptance of appropriate ADAS for society. In this work we perform a quantitative public survey to better understand how the public's awareness and knowledge of ADAS technologies in their vehicles correlate to their use or engagement of those technologies. We find that up to 67% of participants never or rarely use optional ADAS in their vehicles (e.g. adaptive cruise control), where women were less likely than men to use ADAS even though women reported more awareness of ADAS in their vehicles, better training, and more willingness to pay for ADAS. By performing this analysis we hope to raise awareness around the public perception of current state-of-the-art in ADAS technologies. We also hope to flag concerns that answers to these questions might raise for the regulatory agencies, and manufacturers, responsible for bringing these technologies to market.
JANOS: An Integrated Predictive and Prescriptive Modeling Framework
David Bergman
Teng Huang
Philip A. Brooks
A. Raghunathan
Business research practice is witnessing a surge in the integration of predictive modeling and prescriptive analysis. We describe a modeling… (see more) framework JANOS that seamlessly integrates the two streams of analytics, allowing researchers and practitioners to embed machine learning models in an end-to-end optimization framework. JANOS allows for specifying a prescriptive model using standard optimization modeling elements such as constraints and variables. The key novelty lies in providing modeling constructs that enable the specification of commonly used predictive models within an optimization model, have the features of the predictive model as variables in the optimization model, and incorporate the output of the predictive models as part of the objective. The framework considers two sets of decision variables: regular and predicted. The relationship between the regular and the predicted variables is specified by the user as pretrained predictive models. JANOS currently supports linear regression, logistic regression, and neural network with rectified linear activation functions. In this paper, we demonstrate the flexibility of the framework through an example on scholarship allocation in a student enrollment problem and provide a numeric performance evaluation. Summary of Contribution. This paper describes a new software tool, JANOS, that integrates predictive modeling and discrete optimization to assist decision making. Specifically, the proposed solver takes as input user-specified pretrained predictive models and formulates optimization models directly over those predictive models by embedding them within an optimization model through linear transformations.
Deep Active Learning: Unified and Principled Method for Query and Training
Changjian Shui
Fan Zhou
Boyu Wang
In this paper, we are proposing a unified and principled method for both the querying and training processes in deep batch active learning. … (see more)We are providing theoretical insights from the intuition of modeling the interactive procedure in active learning as distribution matching, by adopting the Wasserstein distance. As a consequence, we derived a new training loss from the theoretical analysis, which is decomposed into optimizing deep neural network parameters and batch query selection through alternative optimization. In addition, the loss for training a deep neural network is naturally formulated as a min-max optimization problem through leveraging the unlabeled data information. Moreover, the proposed principles also indicate an explicit uncertainty-diversity trade-off in the query batch selection. Finally, we evaluate our proposed method on different benchmarks, consistently showing better empirical performances and a better time-efficient query strategy compared to the baselines.
Nonlinear chance-constrained problems with applications to hydro scheduling
Enrico Malaguti
Giacomo Nannicini
Dimitri Thomopulos
SST'19 - Software and Systems Traceability
Jan-Philipp Steghöfer
Nan Niu
Anas Mahmoud
Traceability is the ability to relate di erent artifacts during the development and operation of a system to each other. It enables program … (see more)comprehension, change impact analysis, and facilitates the cooperation of engineers from di erent disciplines. The 10th International Workshop on Software and Systems Traceability (former International Workshop on Traceability in Emerging Forms of Software Engineering, TEFSE), explored the role and impact of traceability in modern software and systems development. The event brought together researchers and practitioners to examine the challenges of recovering, maintaining, and utilizing traceability for the myriad forms of software and systems engineering artifacts. SST'19 was a highly interactive working event focused on discussing the main problems related to software traceability in particular in the context of opportunities and challenges posed by the recent progress in Arti cial Intelligence techniques and proposing possible solutions for such problems.
Fractal impedance for passive controllers: a framework for interaction robotics
Keyhan Kouhkiloui Babarahmati
Carlo Tiseo
Joshua Smith
Hsiu‐chin Lin
M. S. Erden
Michael Nalin Mistry
Defining ‘actionable’ high- costhealth care use: results using the Canadian Institute for Health Information population grouping methodology
Maureen Anderson
Crawford W. Revie
Henrik Stryhn
Cordell Neudorf
Yvonne Rosehart
Wenbin Li
Meriç Osman
Laura C. Rosella
Walter P. Wodchis
Preventing Posterior Collapse in Sequence VAEs with Pooling
Teng Long
Yanshuai Cao
Variational Autoencoders (VAEs) hold great potential for modelling text, as they could in theory separate high-level semantic and syntactic … (see more)properties from local regularities of natural language. Practically, however, VAEs with autoregressive decoders often suffer from posterior collapse, a phenomenon where the model learns to ignore the latent variables, causing the sequence VAE to degenerate into a language model. Previous works attempt to solve this problem with complex architectural changes or costly optimization schemes. In this paper, we argue that posterior collapse is caused in part by the encoder network failing to capture the input variabilities. We verify this hypothesis empirically and propose a straightforward fix using pooling. This simple technique effectively prevents posterior collapse, allowing the model to achieve significantly better data log-likelihood than standard sequence VAEs. Compared to the previous SOTA on preventing posterior collapse, we are able to achieve comparable performances while being significantly faster.
Adversarial target-invariant representation learning for domain generalization
Isabela Albuquerque
Joao Monteiro
Tiago Falk
In many applications of machine learning, the training and test set data come from different distributions, or domains. A number of domain g… (see more)eneralization strategies have been introduced with the goal of achieving good performance on out-of-distribution data. In this paper, we propose an adversarial approach to the problem. We propose a process that enforces pair-wise domain invariance while training a feature extractor over a diverse set of domains. We show that this process ensures invariance to any distribution that can be expressed as a mixture of the training domains. Following this insight, we then introduce an adversarial approach in which pair-wise divergences are estimated and minimized. Experiments on two domain generalization benchmarks for object recognition (i.e., PACS and VLCS) show that the proposed method yields higher average accuracy on the target domains in comparison to previously introduced adversarial strategies, as well as recently proposed methods based on learning invariant representations.
Generalizing to unseen domains via distribution matching
Isabela Albuquerque
Joao Monteiro
Mohammad-Javad Darvishi-Bayazi
Tiago Falk
Supervised learning results typically rely on assumptions of i.i.d. data. Unfortunately, those assumptions are commonly violated in practice… (see more). In this work, we tackle this problem by focusing on domain generalization: a formalization where the data generating process at test time may yield samples from never-before-seen domains (distributions). Our work relies on a simple lemma: by minimizing a notion of discrepancy between all pairs from a set of given domains, we also minimize the discrepancy between any pairs of mixtures of domains. Using this result, we derive a generalization bound for our setting. We then show that low risk over unseen domains can be achieved by representing the data in a space where (i) the training distributions are indistinguishable, and (ii) relevant information for the task at hand is preserved. Minimizing the terms in our bound yields an adversarial formulation which estimates and minimizes pairwise discrepancies. We validate our proposed strategy on standard domain generalization benchmarks, outperforming a number of recently introduced methods. Notably, we tackle a real-world application where the underlying data corresponds to multi-channel electroencephalography time series from different subjects, each considered as a distinct domain.
Can a Gorilla Ride a Camel? Learning Semantic Plausibility from Text
Ian Porada
Kaheer Suleman
CoQA: A Conversational Question Answering Challenge
Danqi Chen
Christopher D. Manning
Humans gather information through conversations involving a series of interconnected questions and answers. For machines to assist in inform… (see more)ation gathering, it is therefore essential to enable them to answer conversational questions. We introduce CoQA, a novel dataset for building Conversational Question Answering systems. Our dataset contains 127k questions with answers, obtained from 8k conversations about text passages from seven diverse domains. The questions are conversational, and the answers are free-form text with their corresponding evidence highlighted in the passage. We analyze CoQA in depth and show that conversational questions have challenging phenomena not present in existing reading comprehension datasets (e.g., coreference and pragmatic reasoning). We evaluate strong dialogue and reading comprehension models on CoQA. The best system obtains an F1 score of 65.4%, which is 23.4 points behind human performance (88.8%), indicating that there is ample room for improvement. We present CoQA as a challenge to the community at https://stanfordnlp.github.io/coqa.