SpikeSEG : Spiking segmentation via STDP saliency mapping

Taking inspiration from the structure and behaviourof the human visual system and using the Transposed Convo-lution and Saliency Mapping methods of Convolutional NeuralNetworks (CNN), a spiking event-based image segmentationalgorithm, SpikeSEG is proposed. The approach makes use ofboth spike-based imaging and spike-based processing, where theimages are either standard images converted to spiking images orthey are generated directly from a neuromorphic event drivensensor, and then processed using a spiking fully convolutionalneural network. The spiking segmentation method uses the spikeactivations through time within the network to trace back anyoutputs from saliency maps, to the exact pixel location. Thisnot only gives exact pixel locations for spiking segmentation,but with low latency and computational overhead. SpikeSEGis the first spiking event-based segmentation network and overthree experiment test achieves promising results with 96%accuracy overall and a 74% mean intersection over union forthe segmentation, all within an event by event-based framework

Perception understanding action : adding understanding to the perception action cycle with spiking segmentation

Traditionally the Perception Action cycle is the first stage of building an autonomous robotic system and a practical way to implement a low latency reactive system within a low Size, Weight and Power (SWaP) package. However, within complex scenarios, this method can lack contextual understanding about the scene, such as object recognition-based tracking or system attention. Object detection, identification and tracking along with semantic segmentation and attention are all modern computer vision tasks in which Convolutional Neural Networks (CNN) have shown significant success, although such networks often have a large computational overhead and power requirements, which are not ideal in smaller robotics tasks. Furthermore, cloud computing and massively parallel processing like in Graphic Processing Units (GPUs) are outside the specification of many tasks due to their respective latency and SWaP constraints. In response to this, Spiking Convolutional Neural Networks (SCNNs) look to provide the feature extraction benefits of CNNs, while maintaining low latency and power overhead thanks to their asynchronous spiking event-based processing. A novel Neuromorphic Perception Understanding Action (PUA) system is presented, that aims to combine the feature extraction benefits of CNNs with low latency processing of SCNNs. The PUA utilizes a Neuromorphic Vision Sensor for Perception that facilitates asynchronous processing within a Spiking fully Convolutional Neural Network (SpikeCNN) to provide semantic segmentation and Understanding of the scene. The output is fed to a spiking control system providing Actions. With this approach, the aim is to bring features of deep learning into the lower levels of autonomous robotics, while maintaining a biologically plausible STDP rule throughout the learned encoding part of the network. The network will be shown to provide a more robust and predictable management of spiking activity with an improved thresholding response. The reported experiments show that this system can deliver robust results of over 96 and 81% for accuracy and Intersection over Union, ensuring such a system can be successfully used within object recognition, classification and tracking problem. This demonstrates that the attention of the system can be tracked accurately, while the asynchronous processing means the controller can give precise track updates with minimal latency

CubeSat-based passive bistatic radar for space situational awareness : a feasibility study

This paper proposes a low budget solution to detect and possibly track space debris and satellites in Low Earth Orbit. The concept consists of a space-borne radar installed on a cubeSat flying at low altitude and detecting the occultations of radio signals coming from existing satellites flying at higher altitudes. The paper investigates the feasibility and performance of such a passive bistatic radar system. Key performance metrics considered in this paper are: the minimum size of detectable objects, considering visibility and frequency constraints on existing radio sources, the receiver size and the compatibility with current cubeSat's technology. Different illuminator types and receiver altitudes are considered under the assumption that all illuminators and receivers are on circular orbits

Triple Aims Healthcare Policy Voices of Graduate Student Interprofessional Team Members

The purpose of this study is to share the voices of healthcare graduate students participating in an interprofessional course experience, particularly as their voice relate to fundamental healthcare issues care embodied in the Triple Aims. Two research questions guided study efforts: (1) how do graduate students perceive the value of interprofessional learning experiences for their professional development as future healthcare providers? and (2) based on these experiences, how do students perceive the potential for interprofessional teams to address the Triple Aims of health care? This study was based on the qualitative approach of inductive thematic coding (Braun & Clarke, 2006). Findings indicated that course experiences led to favorable perspectives towards interprofessional practice, with students citing particular benefits regarding more effective and efficient patient service. Students also perceived that interprofessional healthcare would advance current practice regarding the first two triple aims (patient healthcare outcomes and patient satisfaction) due its focus on patient-centered care, improved provider communication, and better-informed treatment decisions. Regarding the third triple aim (reduced costs), students noted that healthcare cost savings were possible, but these must be viewed with a macro lens from a long-term perspective

Spiking Neural Networks for event-based action recognition: A new task to understand their advantage

Spiking Neural Networks (SNN) are characterised by their unique temporal dynamics, but the properties and advantages of such computations are still not well understood. In order to provide answers, in this work we demonstrate how Spiking neurons can enable temporal feature extraction in feed-forward neural networks without the need for recurrent synapses, showing how their bio-inspired computing principles can be successfully exploited beyond energy efficiency gains and evidencing their differences with respect to conventional neurons. This is demonstrated by proposing a new task, DVS-Gesture-Chain (DVS-GC), which allows, for the first time, to evaluate the perception of temporal dependencies in a real event-based action recognition dataset. Our study proves how the widely used DVS Gesture benchmark could be solved by networks without temporal feature extraction, unlike the new DVS-GC which demands an understanding of the ordering of the events. Furthermore, this setup allowed us to unveil the role of the leakage rate in spiking neurons for temporal processing tasks and demonstrated the benefits of "hard reset" mechanisms. Additionally, we also show how time-dependent weights and normalization can lead to understanding order by means of temporal attention.Comment: New article superseding the one in previous version

Simple and complex spiking neurons: perspectives and analysis in a simple STDP scenario

Spiking neural networks (SNNs) are largely inspired by biology and neuroscience and leverage ideas and theories to create fast and efficient learning systems. Spiking neuron models are adopted as core processing units in neuromorphic systems because they enable event-based processing. The integrate-and-fire (I&F) models are often adopted, with the simple Leaky I&F (LIF) being the most used. The reason for adopting such models is their efficiency and/or biological plausibility. Nevertheless, rigorous justification for adopting LIF over other neuron models for use in artificial learning systems has not yet been studied. This work considers various neuron models in the literature and then selects computational neuron models that are single-variable, efficient, and display different types of complexities. From this selection, we make a comparative study of three simple I&F neuron models, namely the LIF, the Quadratic I&F (QIF) and the Exponential I&F (EIF), to understand whether the use of more complex models increases the performance of the system and whether the choice of a neuron model can be directed by the task to be completed. Neuron models are tested within an SNN trained with Spike-Timing Dependent Plasticity (STDP) on a classification task on the N-MNIST and DVS Gestures datasets. Experimental results reveal that more complex neurons manifest the same ability as simpler ones to achieve high levels of accuracy on a simple dataset (N-MNIST), albeit requiring comparably more hyper-parameter tuning. However, when the data possess richer Spatio-temporal features, the QIF and EIF neuron models steadily achieve better results. This suggests that accurately selecting the model based on the richness of the feature spectrum of the data could improve the whole system's performance. Finally, the code implementing the spiking neurons in the SpykeTorch framework is made publicly available

Chapter 7: History

This chapter provides the following: The principles of teaching and learning history in the primary school curriculum and the way in which children develop their understanding of the past, including a consideration of how misconceptions can affect teaching and learning. The chapter provides an appreciation of approaches and resources to support learning primary history. It concludes by emphasising the importance of enquiry based learning,developing a framework of the past and exploring different stories, events and people within it

Frameworks for SNNs: a Review of Data Science-oriented Software and an Expansion of SpykeTorch

Developing effective learning systems for Machine Learning (ML) applications in the Neuromorphic (NM) field requires extensive experimentation and simulation. Software frameworks aid and ease this process by providing a set of ready-to-use tools that researchers can leverage. The recent interest in NM technology has seen the development of several new frameworks that do this, and that add up to the panorama of already existing libraries that belong to neuroscience fields. This work reviews 9 frameworks for the development of Spiking Neural Networks (SNNs) that are specifically oriented towards data science applications. We emphasize the availability of spiking neuron models and learning rules to more easily direct decisions on the most suitable frameworks to carry out different types of research. Furthermore, we present an extension to the SpykeTorch framework that gives users access to a much broader choice of neuron models to embed in SNNs and make the code publicly available