Image Quality Assessment for Population Cardiac MRI: From Detection to Synthesis

Cardiac magnetic resonance (CMR) images play a growing role in diagnostic imaging of cardiovascular diseases. Left Ventricular (LV) cardiac anatomy and function are widely used for diagnosis and monitoring disease progression in cardiology and to assess the patient's response to cardiac surgery and interventional procedures. For population imaging studies, CMR is arguably the most comprehensive imaging modality for non-invasive and non-ionising imaging of the heart and great vessels and, hence, most suited for population imaging cohorts. Due to insufficient radiographer's experience in planning a scan, natural cardiac muscle contraction, breathing motion, and imperfect triggering, CMR can display incomplete LV coverage, which hampers quantitative LV characterization and diagnostic accuracy. To tackle this limitation and enhance the accuracy and robustness of the automated cardiac volume and functional assessment, this thesis focuses on the development and application of state-of-the-art deep learning (DL) techniques in cardiac imaging. Specifically, we propose new image feature representation types that are learnt with DL models and aimed at highlighting the CMR image quality cross-dataset. These representations are also intended to estimate the CMR image quality for better interpretation and analysis. Moreover, we investigate how quantitative analysis can benefit when these learnt image representations are used in image synthesis. Specifically, a 3D fisher discriminative representation is introduced to identify CMR image quality in the UK Biobank cardiac data. Additionally, a novel adversarial learning (AL) framework is introduced for the cross-dataset CMR image quality assessment and we show that the common representations learnt by AL can be useful and informative for cross-dataset CMR image analysis. Moreover, we utilize the dataset invariance (DI) representations for CMR volumes interpolation by introducing a novel generative adversarial nets (GANs) based image synthesis framework, which enhance the CMR image quality cross-dataset

BEACH MORPHODYNAMICS AND ASSOCIATED HAZARDS IN THE UK

In this thesis the relationship between beach morphodynamics and recreational hazards was investigated for the first time within the United Kingdom (UK). Four field experiments, conducted during 2006-2008 provided new insights into the spatio-temporal dynamics of UK beach types and their associated hazard signatures. The extent of data collection ranged from national (UK beach classification) to regional (temporal morphologic variation) to site specific (macrotidal rip current dynamics). Detailed morphodynamic characteristics of 98 beaches within the UK were collected. Twelve distinct beach groups were identified through cluster analysis, each having a unique morphodynamic signature. Conceptualisation within a relative two-dimensional framework using the dimensionless fall velocity (Q) and the relative tide range (RTR) required an absolute wave energy flux threshold to differentiate between intermediate beaches with (H2T > 5) and without (H2T < 5) three-dimensional bar morphology. The role of geologic control, sediment abundance and drainage characteristics in constraining beach morphodynamics was shown to be significant within the sites studied. Rip currents were responsible for 68% of all recorded incidents between 2005-2007 throughout all 76 beaches patrolled by the Royal National Lifeboat Institution (RNLI). Hazard type and severity varied between morphodynamic beach types. Intermediate beaches with low-tide bar/rip morphology (Q = 2-5 and RTR < 7), including Low-Tide Terrace and Rip (LTT+R) and Low-tide Bar/Rip (LTBR) beaches, presented the greatest risk to the insea beach user. These high risk beaches, representing 59% of the west coast beaches in Devon and Cornwall, also attracted the greatest visitor populations. Seasonal monitoring of hydrodynamics and morphology at LTT+R and LTBR beaches in Devon and Cornwall (annual Hsio% = 3-4 m; mean spring tidal range = 4.2-8.6 m) identified key mechanisms controlling the temporal hazard signature (THS), a term used here to describe the spatio-temporal variation in type and severity o f bathing hazard within a specified region both in the alongshore as well as in the cross-shore (significant in macrotidal environments). The morphological template controlled the presence, extent and intensity of beach rip current systems, where the development of low/tide transverse and inter-tidal bar/rip systems during summer presented the greatest morphological hazard. Typical summer wave forcing by relatively small, long period swell {H, - 0.5-1 m; Tp ~ 6-10 s) over this morphology provided conditions conducive to hazardous rip currents. Under these conditions hazard exposure was increased due to the accessibility of the relatively low energy surf zone. Both spring/neap and semi-diurnal tidal variations were identified as key controls on the THS. Variable tidal excursion modulates rip current activity, and tidal translation rates control the rate of change of the THS. The 'optimum' combination of these mechanisms results in the 'switching' on and off of rip currents during spring low tides and the subsequent rapid alongshore migration of rip channel/hazard location as the surf zone inundates the landward inter-tidal bar system. In conjunction with high insea population, these 'optimum hazard scenarios' drove the high risk, coast-wide 'mass rescue' events identified in the incident records. This work provides a scientific, standardised basis for a beach risk assessment model and lifeguard training programs within the RNLI. Improved understanding of macrotidal rip currents has initiated new field and modelling efforts to further general quantitative understanding of these systems, vital to the improvement of beach safety services.Royal National Lifeboat Institutio

New Fundamental Technologies in Data Mining

The progress of data mining technology and large public popularity establish a need for a comprehensive text on the subject. The series of books entitled by "Data Mining" address the need by presenting in-depth description of novel mining algorithms and many useful applications. In addition to understanding each section deeply, the two books present useful hints and strategies to solving problems in the following chapters. The contributing authors have highlighted many future research directions that will foster multi-disciplinary collaborations and hence will lead to significant development in the field of data mining

Visual and Camera Sensors

This book includes 13 papers published in Special Issue ("Visual and Camera Sensors") of the journal Sensors. The goal of this Special Issue was to invite high-quality, state-of-the-art research papers dealing with challenging issues in visual and camera sensors

Cooperative Radio Communications for Green Smart Environments

The demand for mobile connectivity is continuously increasing, and by 2020 Mobile and Wireless Communications will serve not only very dense populations of mobile phones and nomadic computers, but also the expected multiplicity of devices and sensors located in machines, vehicles, health systems and city infrastructures. Future Mobile Networks are then faced with many new scenarios and use cases, which will load the networks with different data traffic patterns, in new or shared spectrum bands, creating new specific requirements. This book addresses both the techniques to model, analyse and optimise the radio links and transmission systems in such scenarios, together with the most advanced radio access, resource management and mobile networking technologies. This text summarises the work performed by more than 500 researchers from more than 120 institutions in Europe, America and Asia, from both academia and industries, within the framework of the COST IC1004 Action on "Cooperative Radio Communications for Green and Smart Environments". The book will have appeal to graduates and researchers in the Radio Communications area, and also to engineers working in the Wireless industry. Topics discussed in this book include: • Radio waves propagation phenomena in diverse urban, indoor, vehicular and body environments• Measurements, characterization, and modelling of radio channels beyond 4G networks• Key issues in Vehicle (V2X) communication• Wireless Body Area Networks, including specific Radio Channel Models for WBANs• Energy efficiency and resource management enhancements in Radio Access Networks• Definitions and models for the virtualised and cloud RAN architectures• Advances on feasible indoor localization and tracking techniques• Recent findings and innovations in antenna systems for communications• Physical Layer Network Coding for next generation wireless systems• Methods and techniques for MIMO Over the Air (OTA) testin