Feature Map Filtering: Improving Visual Place Recognition with Convolutional Calibration

Convolutional Neural Networks (CNNs) have recently been shown to excel at performing visual place recognition under changing appearance and viewpoint. Previously, place recognition has been improved by intelligently selecting relevant spatial keypoints within a convolutional layer and also by selecting the optimal layer to use. Rather than extracting features out of a particular layer, or a particular set of spatial keypoints within a layer, we propose the extraction of features using a subset of the channel dimensionality within a layer. Each feature map learns to encode a different set of weights that activate for different visual features within the set of training images. We propose a method of calibrating a CNN-based visual place recognition system, which selects the subset of feature maps that best encodes the visual features that are consistent between two different appearances of the same location. Using just 50 calibration images, all collected at the beginning of the current environment, we demonstrate a significant and consistent recognition improvement across multiple layers for two different neural networks. We evaluate our proposal on three datasets with different types of appearance changes - afternoon to morning, winter to summer and night to day. Additionally, the dimensionality reduction approach improves the computational processing speed of the recognition system.Comment: Accepted to the Australasian Conference on Robotics and Automation 201

SpiNNaker - A Spiking Neural Network Architecture

20 years in conception and 15 in construction, the SpiNNaker project has delivered the world’s largest neuromorphic computing platform incorporating over a million ARM mobile phone processors and capable of modelling spiking neural networks of the scale of a mouse brain in biological real time. This machine, hosted at the University of Manchester in the UK, is freely available under the auspices of the EU Flagship Human Brain Project. This book tells the story of the origins of the machine, its development and its deployment, and the immense software development effort that has gone into making it openly available and accessible to researchers and students the world over. It also presents exemplar applications from ‘Talk’, a SpiNNaker-controlled robotic exhibit at the Manchester Art Gallery as part of ‘The Imitation Game’, a set of works commissioned in 2016 in honour of Alan Turing, through to a way to solve hard computing problems using stochastic neural networks. The book concludes with a look to the future, and the SpiNNaker-2 machine which is yet to come

SpiNNaker - A Spiking Neural Network Architecture

20 years in conception and 15 in construction, the SpiNNaker project has delivered the world’s largest neuromorphic computing platform incorporating over a million ARM mobile phone processors and capable of modelling spiking neural networks of the scale of a mouse brain in biological real time. This machine, hosted at the University of Manchester in the UK, is freely available under the auspices of the EU Flagship Human Brain Project. This book tells the story of the origins of the machine, its development and its deployment, and the immense software development effort that has gone into making it openly available and accessible to researchers and students the world over. It also presents exemplar applications from ‘Talk’, a SpiNNaker-controlled robotic exhibit at the Manchester Art Gallery as part of ‘The Imitation Game’, a set of works commissioned in 2016 in honour of Alan Turing, through to a way to solve hard computing problems using stochastic neural networks. The book concludes with a look to the future, and the SpiNNaker-2 machine which is yet to come

Deep neural network generation for image classification within resource-constrained environments using evolutionary and hand-crafted processes

Constructing Convolutional Neural Networks (CNN) models is a manual process requiringexpert knowledge and trial and error. Background research highlights the following knowledge gaps. 1) existing efficiency-focused CNN models make design choices that impact model performance. Better ways are needed to construct accurate models for resourceconstrained environments that lack graphics processing units (GPU’s) to speed up model inference time such as CCTV cameras and IoT devices. 2) Existing methods for automatically designing CNN architectures do not explore the search space effectively for the best solution and 3) existing methods for automatically designing CNN architectures do not exploit modern model architecture design patterns such as residual connections. The lack of residual connections means the model depth is limited owing to the vanishing gradient problem. Furthermore, existing methods for automatically designing CNN architectures adopt search strategies that make them vulnerable to local minima traps. Better techniques to construct efficient CNN models, and automated approaches that can produce accurate deep model constructions advance many areas such as hazard detection, medical diagnosis and robotics in both academia and industry. The work undertaken during this research are 1) the proposal of an efficient and accurate CNN architecture for resource-constrained environments owing to a novel block structure containing 1x3 and 3x1 convolutions to save computational cost, 2) proposed a particle swarm optimization (PSO) method of automatically constructing efficient deep CNN architectures with greater accuracy by proposing a novel encoding and search strategy, 3) proposed a PSO based method of automatically constructing deeper CNN models with improved accuracy by proposing a novel encoding scheme that employs residual connections, in novel search mechanism that follows the global and neighbouring best leaders. The main findings of this research are 1) the proposed efficiency-focused CNN model outperformed MobileNetV2 by 13.43% in respect to accuracy, and 39.63% in respect to efficiency, measured in floating-point operations. A reduction in floating-point operations means the model has the potential for faster inference times which is beneficial to applications within resource-constrained environments without GPU’s such as CCTV cameras. 2) the proposed automatic CNN generation technique outperformed existing methods by 7.58% in respect to accuracy and a 63% improvement in search time efficiency owing to the proposal of more efficient architectures speeding up the search process and 3) the proposed automatic deep residual CNN generation method improved model accuracy by 4.43% when compared against related studies owing to deeper model construction and improvements in the search process. The proposed search process embeds human knowledge of constructing deep residual networks and provides constraint settings which can be used to limit the proposed models depth and width. The ability to constrain a models depth and width is important as it ensures the upper bounds of a proposed model will fit within the constraints of resource-constrained environments

Proceedings of the European Conference on Agricultural Engineering AgEng2021

This proceedings book results from the AgEng2021 Agricultural Engineering Conference under auspices of the European Society of Agricultural Engineers, held in an online format based on the University of Évora, Portugal, from 4 to 8 July 2021. This book contains the full papers of a selection of abstracts that were the base for the oral presentations and posters presented at the conference. Presentations were distributed in eleven thematic areas: Artificial Intelligence, data processing and management; Automation, robotics and sensor technology; Circular Economy; Education and Rural development; Energy and bioenergy; Integrated and sustainable Farming systems; New application technologies and mechanisation; Post-harvest technologies; Smart farming / Precision agriculture; Soil, land and water engineering; Sustainable production in Farm buildings

Learning in the Real World: Constraints on Cost, Space, and Privacy

The sheer demand for machine learning in fields as varied as: healthcare, web-search ranking, factory automation, collision prediction, spam filtering, and many others, frequently outpaces the intended use-case of machine learning models. In fact, a growing number of companies hire machine learning researchers to rectify this very problem: to tailor and/or design new state-of-the-art models to the setting at hand. However, we can generalize a large set of the machine learning problems encountered in practical settings into three categories: cost, space, and privacy. The first category (cost) considers problems that need to balance the accuracy of a machine learning model with the cost required to evaluate it. These include problems in web-search, where results need to be delivered to a user in under a second and be as accurate as possible. The second category (space) collects problems that require running machine learning algorithms on low-memory computing devices. For instance, in search-and-rescue operations we may opt to use many small unmanned aerial vehicles (UAVs) equipped with machine learning algorithms for object detection to find a desired search target. These algorithms should be small to fit within the physical memory limits of the UAV (and be energy efficient) while reliably detecting objects. The third category (privacy) considers problems where one wishes to run machine learning algorithms on sensitive data. It has been shown that seemingly innocuous analyses on such data can be exploited to reveal data individuals would prefer to keep private. Thus, nearly any algorithm that runs on patient or economic data falls under this set of problems. We devise solutions for each of these problem categories including (i) a fast tree-based model for explicitly trading off accuracy and model evaluation time, (ii) a compression method for the k-nearest neighbor classifier, and (iii) a private causal inference algorithm that protects sensitive data