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Spectral Graph Convolutional Networks With Lifting-based Adaptive Graph Wavelets

arXiv.org Artificial Intelligence

Spectral graph convolutional networks (SGCNs) have been attracting increasing attention in graph representation learning partly due to their interpretability through the prism of the established graph signal processing framework. However, existing SGCNs are limited in implementing graph convolutions with rigid transforms that could not adapt to signals residing on graphs and tasks at hand. In this paper, we propose a novel class of spectral graph convolutional networks that implement graph convolutions with adaptive graph wavelets. Specifically, the adaptive graph wavelets are learned with neural network-parameterized lifting structures, where structure-aware attention-based lifting operations are developed to jointly consider graph structures and node features. We propose to lift based on diffusion wavelets to alleviate the structural information loss induced by partitioning non-bipartite graphs. By design, the locality and sparsity of the resulting wavelet transform as well as the scalability of the lifting structure for large and varying-size graphs are guaranteed. We further derive a soft-thresholding filtering operation by learning sparse graph representations in terms of the learned wavelets, which improves the scalability and interpretablity, and yield a localized, efficient and scalable spectral graph convolution. To ensure that the learned graph representations are invariant to node permutations, a layer is employed at the input of the networks to reorder the nodes according to their local topology information. We evaluate the proposed networks in both node-level and graph-level representation learning tasks on benchmark citation and bioinformatics graph datasets. Extensive experiments demonstrate the superiority of the proposed networks over existing SGCNs in terms of accuracy, efficiency and scalability.


Exemplars-guided Empathetic Response Generation Controlled by the Elements of Human Communication

arXiv.org Artificial Intelligence

The majority of existing methods for empathetic response generation rely on the emotion of the context to generate empathetic responses. However, empathy is much more than generating responses with an appropriate emotion. It also often entails subtle expressions of understanding and personal resonance with the situation of the other interlocutor. Unfortunately, such qualities are difficult to quantify and the datasets lack the relevant annotations. To address this issue, in this paper we propose an approach that relies on exemplars to cue the generative model on fine stylistic properties that signal empathy to the interlocutor. To this end, we employ dense passage retrieval to extract relevant exemplary responses from the training set. Three elements of human communication -- emotional presence, interpretation, and exploration, and sentiment are additionally introduced using synthetic labels to guide the generation towards empathy. The human evaluation is also extended by these elements of human communication. We empirically show that these approaches yield significant improvements in empathetic response quality in terms of both automated and human-evaluated metrics. The implementation is available at https://github.com/declare-lab/exemplary-empathy.


Small company beats Elon Musk's Neuralink in race to test brain chips in humans

#artificialintelligence

A small company developing an implantable brain computer interface to help treat conditions like paralysis has received the go-ahead from the Food and Drug Administration (FDA) to kick off clinical trials of its flagship device later this year. New York-based Synchron announced Wednesday it has received FDA approval to begin an early feasibility study of its Stentrode implant later this year at Mount Sinai Hospital with six human subjects. The study will examine the safety and efficacy of its motor neuroprosthesis in patients with severe paralysis, with the hopes the device will allow them to use brain data to "control digital devices and achieve improvements in functional independence." "Patients begin using the device at home soon after implantation and may wirelessly control external devices by thinking about moving their limbs. The system is designed to facilitate better communication and functional independence for patients by enabling daily tasks like texting, emailing, online commerce and accessing telemedicine," the company said in a release.


Advances in machine learning and AI unlock myriad of applications

#artificialintelligence

The July 2021 issue of IEEE/CAA Journal of Automatica Sinica features six articles that showcase the potential of machine learning in its various forms. The applications described in the studies range from advanced driver assistance systems and computer vision to image processing and collaborative robotics. Automation of technology has reshaped both the way in which we work and how we tackle problems. Thanks to the progress made in robotics and artificial intelligence (AI) over the last few years, it is now possible to leave several tasks in the hands to machines and algorithms. To highlight these advances, the IEEE and the Chinese Association of Automation (CAA) decided to join forces, in the first issue of IEEE/CAA Journal of Automatica Sinica.


AI system can blow the whistle if people can't keep their distance

#artificialintelligence

Researchers have developed an artificial intelligence monitoring system to keep track of whether people are social distancing in public spaces, and alerting local authorities if they are not. Griffith University researchers developed the system to monitor the movement of crowds of people in real-time and then applied it to look for instances of people not maintaining social distancing. An AI system which can detected social distancing breaches in real time has been praised by its creators, but raised worries with privacy advocates.Credit:Paul Jeffers Lead researcher Professor Dian Tjondronegoro, an expert in the integration of AI and business innovation, said they moved to allay any privacy concerns around the system by ensuring that no data was stored by it at any time. "We knew we couldn't keep everything on the server because it would be very slow in processing and there are also privacy concerns," he said.


Scania and TuSimple Pilot Self-Driving Trucks in Sweden

#artificialintelligence

Scania, the Swedish manufacturer of heavy lorries, trucks and buses, is testing L4 level self-driving trucks on the E4 motorway between Södertälje and Jönköping, in collaboration with San Diego-based company TuSimple. Participating truck provides actual commercial services to The Scania Transport Laboratory, loading materials required for production operations. The truck is controlled by the TuSimple's unmanned driving system, with a safety officer and test engineer onboard for monitoring. Scania has been testing self-driving trucks for mining transportation in Australia since 2017. TuSimple has also partnered with companies like Volkswagen and Navistar to test commercial vehicles.


Goal Recognition for Deceptive Human Agents through Planning and Gaze

Journal of Artificial Intelligence Research

Eye gaze has the potential to provide insight into the minds of individuals, and this idea has been used in prior research to improve human goal recognition by combining human's actions and gaze. However, most existing research assumes that people are rational and honest. In adversarial scenarios, people may deliberately alter their actions and gaze, which presents a challenge to goal recognition systems. In this paper, we present new models for goal recognition under deception using a combination of gaze behaviour and observed movements of the agent. These models aim to detect when a person is deceiving by analysing their gaze patterns and use this information to adjust the goal recognition. We evaluated our models in two human-subject studies: (1) using data collected from 30 individuals playing a navigation game inspired by an existing deception study and (2) using data collected from 40 individuals playing a competitive game (Ticket To Ride). We found that one of our models (Modulated Deception Gaze Ontic) offers promising results compared to the previous state-of-the-art model in both studies. Our work complements existing adversarial goal recognition systems by equipping these systems with the ability to tackle ambiguous gaze behaviours.


SINGA-Easy: An Easy-to-Use Framework for MultiModal Analysis

arXiv.org Artificial Intelligence

Deep learning has achieved great success in a wide spectrum of multimedia applications such as image classification, natural language processing and multimodal data analysis. Recent years have seen the development of many deep learning frameworks that provide a high-level programming interface for users to design models, conduct training and deploy inference. However, it remains challenging to build an efficient end-to-end multimedia application with most existing frameworks. Specifically, in terms of usability, it is demanding for non-experts to implement deep learning models, obtain the right settings for the entire machine learning pipeline, manage models and datasets, and exploit external data sources all together. Further, in terms of adaptability, elastic computation solutions are much needed as the actual serving workload fluctuates constantly, and scaling the hardware resources to handle the fluctuating workload is typically infeasible. To address these challenges, we introduce SINGA-Easy, a new deep learning framework that provides distributed hyper-parameter tuning at the training stage, dynamic computational cost control at the inference stage, and intuitive user interactions with multimedia contents facilitated by model explanation. Our experiments on the training and deployment of multi-modality data analysis applications show that the framework is both usable and adaptable to dynamic inference loads. We implement SINGA-Easy on top of Apache SINGA and demonstrate our system with the entire machine learning life cycle.


On the Exploitability of Audio Machine Learning Pipelines to Surreptitious Adversarial Examples

arXiv.org Artificial Intelligence

Machine learning (ML) models are known to be vulnerable to adversarial examples. Applications of ML to voice biometrics authentication are no exception. Yet, the implications of audio adversarial examples on these real-world systems remain poorly understood given that most research targets limited defenders who can only listen to the audio samples. Conflating detectability of an attack with human perceptibility, research has focused on methods that aim to produce imperceptible adversarial examples which humans cannot distinguish from the corresponding benign samples. We argue that this perspective is coarse for two reasons: 1. Imperceptibility is impossible to verify; it would require an experimental process that encompasses variations in listener training, equipment, volume, ear sensitivity, types of background noise etc, and 2. It disregards pipeline-based detection clues that realistic defenders leverage. This results in adversarial examples that are ineffective in the presence of knowledgeable defenders. Thus, an adversary only needs an audio sample to be plausible to a human. We thus introduce surreptitious adversarial examples, a new class of attacks that evades both human and pipeline controls. In the white-box setting, we instantiate this class with a joint, multi-stage optimization attack. Using an Amazon Mechanical Turk user study, we show that this attack produces audio samples that are more surreptitious than previous attacks that aim solely for imperceptibility. Lastly we show that surreptitious adversarial examples are challenging to develop in the black-box setting.


Electrical peak demand forecasting- A review

arXiv.org Artificial Intelligence

The power system is undergoing rapid evolution with the roll-out of advanced metering infrastructure and local energy applications (e.g. electric vehicles) as well as the increasing penetration of intermittent renewable energy at both transmission and distribution level, which characterizes the peak load demand with stronger randomness and less predictability and therefore poses a threat to the power grid security. Since storing large quantities of electricity to satisfy load demand is neither economically nor environmentally friendly, effective peak demand management strategies and reliable peak load forecast methods become essential for optimizing the power system operations. To this end, this paper provides a timely and comprehensive overview of peak load demand forecast methods in the literature. To our best knowledge, this is the first comprehensive review on such topic. In this paper we first give a precise and unified problem definition of peak load demand forecast. Second, 139 papers on peak load forecast methods were systematically reviewed where methods were classified into different stages based on the timeline. Thirdly, a comparative analysis of peak load forecast methods are summarized and different optimizing methods to improve the forecast performance are discussed. The paper ends with a comprehensive summary of the reviewed papers and a discussion of potential future research directions.