DSDS 20
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Item Open Access Defence and Security Doctoral Symposium Flyer 2020(Cranfield University, 2020-07-24 10:38) Cranfield UniversityFlyer promoting the Defence and Security Doctoral Symposium 2020.Item Open Access Reflections and Their Real Space Significance(Cranfield University, 2020-11-27 10:01) Arnold, EmilyBone is a complex composite material made up of three main components, the most abundant of which is the mineral hydroxyapatite. Within many species, hydroxyapatite naturally occurs as a nanocrystalline material, making accurate analysis difficult. Brilliant X-ray sources are used to allow measurement of a much wider range of angular data (from Q = 0.05 to 60 Å-1) than a traditional laboratory X-ray diffractometer (from Q = 0.1 to 8 Å-1). Shown here is diffraction data collected at Diamond Light Source on the dedicated total scattering beamline I15-1. Debye-Scherrer rings can be seen, allowing measurement of crystallographic parameters within reciprocal space. Shadows are seen from the sample changer and an additional detector. This beamline allows for the observation of local coordination of atoms from 0.1nm to 5 nm (through pair distribution function analysis) while simultaneously measuring average crystallite structure.Item Open Access Structure of an Insensitive High Explosive formulation under a microscope(Cranfield University, 2020-11-27 10:07) Gutierrez Carazo, EncinaIMX-104 is an Insensitive High Explosive containing a mixture of 3-Nitro-1,2,4-triazol-5-one (NTO), 2,4- dinitroanisole (DNAN) and cyclotrimethylenetrinitramine (RDX). Due to its novelty, little is known about its potential toxicity and persistence in the environment and which has raised questions regarding its behaviour.Small flakes were placed under a Leica DM LM microscope to observe their microscopic structure and investigate the formulation process. The picture was taken using a ten times lense (10x) and reflected light. The scale shows the size of the flakes (in mm) and the fragments in focus were approximately 70 µm.Item Open Access The Utility of Gait in Forensic Human Identification: An Empirical Investigation Using Biomechanical and Anthropological Principals(Cranfield University, 2020-11-27 12:06) Macoveciuc, IoanaForensic gait analysis is generally defined as the analysis of walking features of individuals from video footage, to assist in criminal investigations. Although an attractive approach to detecting suspects since data can be collected from a distance without their knowledge (e.g. from public CCTV cameras), this field of study currently lacks validation and quality standards not only due to insufficient research, but also because certain scientific foundations, such as the assumption of gait uniqueness, have not been adequately investigated. To test the scientific basis of this premise, a suitable dataset replicating an ideal forensic gait analysis scenario was compiled from the Karlsruhe Institute of Technology (Germany) database. Biomechanical analyses (i.e. joint angles) of human walking motion (i.e. gait cycles) in the left and right shoulder, elbow, hip, knee, and ankle joints of twenty participants was conducted using the R program. The purpose of these analyses was to investigate the degree to which differences between walking activities of the same participant (i.e. intraindividual variation) impact differences amongst participants (i.e. interindividual variation), according to the following aims: (1) to better understand the relationship between form (anatomy) and function (physiology) of human gait, (2) to investigate the basis of gait uniqueness by examining similarities and differences in joint angles, and (3) to build upon current theoretical foundations of gait-based human identification. The findings indicate different degrees of gait asymmetry given anatomical body region and gait sub-phase (i.e. component of a given cycle), thereby challenging previous methods employing interchangeable use of gait data irrespective of body side, and the use of ‘average’ gait cycles to represent the gait of an individual irrespective of body side. Furthermore, interindividual variability in all five joints is influenced by body side to different extents depending on gait sub-phase and body region, thereby challenging the claim of holistic uniqueness of gait features across all body regions and gait sub-phases. The results therefore underline that previously held assumptions may not hold true, and that their continued use irrespective of innumerable recommendations previously made and in light of novel research, may be detrimental to judicial situations where guilt or innocence is established based on such evidence. Given the findings of this research and paucity regarding empirical basis to support expertise, exerting caution when evaluating gait-based evidence admissibility in the courtroom is highly recommended, since the utility of gait in identification is currently limited.Item Open Access Efficient Space-Time Finite Elements for Thermo-Mechanical Problems(Cranfield University, 2020-11-27 12:47) Quaine, KieranThis talk discusses efficient and reliable Finite Element Methods to simulate the thermo-mechanical response of high explosives. A key motivation is the modelling of the initiation of shear bands in materials such as HMX. The localised plastic deformation associated with a shear band leads to the formation of hot spots and can subsequently lead to thermal runaway. Standard finite element methods struggle to accurately resolve the sharp variations associated with these thermal and mechanical features which may lead to unphysical predictions of the numerical models. The numerical methods presented in this talk aim to provide efficient and reliable tools towards modelling the initiation of shear banding and thermal runaway. We consider two approaches: adaptively generated meshes based on mathematically rigorous estimates of the numerical errors, and enriched finite elements. They are illustrated for thermal and elastic problems, as they arise in reduced models. First, we present results based on adaptive finite elements for non-linear thermal problems. Steep temperature gradients are resolved by appropriate mesh refinement procedures. Steered by indicators for the accuracy of the solution, the algorithm automatically resolves hot spots on a refined mesh, significantly reducing computational costs, see for example [2]. Secondly, we con-sider enriched space-time finite elements (also known as generalised finite elements) which include a priori physical information into the numerical method. This a priori information could represent localised of wave-like features, which are added to a coarse approximation space. The modelling can effectively capture features occurring at different spatial and temporal scales [4, 5]. Here we consider a first order formulation of the wave equation [1] and choose plane-wave enrichments [6]. Future work aims to address the full, coupled thermo-mechanical system, as well as to combine the adaptive and enriched approaches of Iqbal et al. [3].[1] H. Barucq, H. Calandra, J. Diaz, and E. Shishenina. Space-Time Trefftz - Discontinuous Galerkin Approximation for Elasto-Acoustics. (RR-9104), 2017.[2] Heiko Gimperlein and Jakub Stocek. Space–time adaptive finite elements for nonlocal parabolic variational inequalities. Computer Methods in Applied Mechanics and Engineering, 352:137 – 171, 2019.[3] M. Iqbal, D. Stark, H. Gimperlein, M.S. Mohamed, and O. Laghrouche. Local adaptive q-enrichments and generalized finite elements for transient heat diffusion problems. Computer Methods in Applied Mechanics and Engineering, 372:113359, 2020.[4] O. Laghrouche, P. Bettess, E. Perrey-Debain, and J. Trevelyan. Wave interpolation finite elements for Helmholtz problems with jumps in the wave speed. Computer Methods in Applied Mechanics and Engineering, 194(2):367 – 381, 2005.[5] E. Perrey-Debain, J. Trevelyan, and P. Bettess. On wave boundary elements for radiation and scattering problems with piecewise constant impedance. IEEE Transactions on Antennas and Propagation, 53(2):876–879, 2005[6] Steffen Petersen, Charbel Farhat, and Radek Tezaur. A space–time discontinuous galerkin method for the solution of the wave equation in the time domain. International Journal for Numerical Methods in Engineering, 78(3):275–295, 2009Item Open Access Development of a Smart Sniffer Device for the Detection of Illicit Drugs, Homemade Explosives, and their Precursor Chemicals(Cranfield University, 2020-11-30 13:29) Hardy, IonaThe controlled drug market in the UK alone is worth £9.4 billion a year (£19 billion a year cost to society) and is used to finance other crimes, including terrorism with enormous social-economical costs. The threat continues to change and exploitation of the latest scientific and technical advances to enhance operation capabilities for an early detection of terrorist and criminal activities, is at the core of Law Enforcement Agencies (LEAs) operational requirements. Among the detection technologies currently used/explored by UK and International market, a portable sniffer device that can detect multiple illicit substances, in a non-destructive, rapid, and accurate manner, would offer a valid alternative to LEAs.The CRIM-TRACK sniffer device was developed by Cranfield and Danish Technical University (EU FP7 project) and is currently at TRL 4. See attached file for the full abstract.Item Open Access Probing the Structure and Evolution of Anode Materials in Thermal Batteries(Cranfield University, 2020-11-30 13:39) Azad, AtiaHigh-temperature thermal batteries use lithium-silicon alloys as the anode material. Li13Si4, Li7Si3 and Li12Si7 alloys are studied to determine if phase transitions occur or if the alloys become amorphous between room temperature and 500◦C (the typical operating temperature of thermal batteries). These alloys are synthesised by reacting lithium metal and silicon powder at elevated temperature inside an evacuated quartz ampoule. The samples’ structural changes are investigated at elevated temperatures using in situ powder neutron diffraction. This is carried out on the Polaris diffractometer at ISIS facility, Rutherford Appleton Laboratory, UK. The results of the neutron scattering experiment seem to imply that the alloys do not become amorphous at 500◦C and no phases transitions occur in the temperature range. Further work is required to determine if phase transitions occur below room temperature. The work so far has presented a simple method of synthesising these alloys and gives information on the lack of phase transitions between room temperature and 500◦C.Item Open Access Novel Ceramic Armour for Land Vehicles: Identifying the Chink in our Knowledge(Cranfield University, 2020-11-30 16:58) Powell, DanielVehicle armour is a complex multi-material system, typically comprising of both ceramics and metals. It must meet highly demanding performance criteria; resistance to penetration (often at incredibly high strain rates) must be maximised whilst weight and encumbrance must be minimised. The principles of armour are well-established, although much of the science is under-researched. Some notable knowledge gaps are the adjoining between the ceramic and metal at the interface, the transmission of energy through this interface and how this contributes to armour being defeated. This project aims to further investigate and understand what happens at this interface, ultimately intending to optimise future armour systems. This is to be achieved through computational modelling, initially investigating different combinations of materials and interlayer thicknesses. These models can then be validated against basic ballistic test data, replicating the conditions of the simulations. Once validated, the models can test innovative and non-conventional interlayer geometries, thickness and material combinations, highlighting promising avenues of further research. Whilst still in the infancy of this research, a spreadsheet has been created to allow the visualisation of damaging shock waves through user-defined materials, layer thicknesses and projectile materials. Once validated, it is intended to make this accessible to the wider scientific community.Item Open Access ASP Triangles: Sketching the Artificial Intelligence of a Mobile Platform(Cranfield University, 2020-12-01 08:49) Di Fraia, MarcoASP triangles are a tool that we introduced to structure the design process of the on-board Artificial Intelligence (AI) of a mobile platform. Their value lies in taking into account the couplings and interactions between macroelements characterizing the platform and the mission context, in analogy to the paradigm shift introduced in aerospace structures by the development of aeroelasticity.Item Open Access Meteorological Wind Effect on the Ballistic Trajectory of a Medium Calibre System(Cranfield University, 2020-12-02 10:52) Knight, DanielModern systems use a single wind sensor onboard the vehicle to measure and capture meteorological wind data to calculate a weapon systems ballistic offset. The most calculations assumes constant wind between firing point and target for the offset. Meteorological wind is not constant being effect by wind gradient, terrain height and other surface changes. Using trial and test data from multiple wind sensors on a firing range, the wind can be modelled across the full flight of a rounds trajectory. Using modelling and analytical approaches to test known and experimental theories around meteorological wind offset to ballistic trajectory. The modelling provides a cost effective approach alongside practical real data from testing.Item Open Access Boron Carbide-Silicon Carbide Nanocomposites for Next Generation Armour(Cranfield University, 2020-12-07 13:40) Payne, HenryMotivation for this Work:Modern warfare is developing rapidly; technology is becoming more advanced and the modern soldier requires more of it. With the increase in equipment there is an increase in weight which reduces mobility. Threats have also developed, in such environments greater protection can be required. Combining these two results in a need to produce lighter armour with a higher level of protection. Boron Carbide (B4C) has shown great potential for use in armours. It has a high hardness and low density, but unfortunately it sometimes fails prematurely. This has been explained by a phase transformation involving polytype collapse. This research aims to mitigate structural breakdown by microstructural design. It is hypothesised that a composite containing nano grains of B4C and Silicon Carbide (SiC) can mitigate the polytype breakdown, whilst combining the low density of B4C with the ballistic reliability of SiC.This poster will:• Outline the materials being investigated for use in new ceramic armours. Specifically those under investigation by Imperial College London, joint with DSTL• Give the breakdown of the method and aims of the project• Outline some basic results from initial studies. This will give the reader an idea of the final goal.Item Open Access Interactive Methods for Improving Robustness of Neural Networks Against Adversarial Attacks(Cranfield University, 2020-12-07 14:10) McCarthy, AndrewNeural network based Machine Learning Systems are improving the efficiency of real-world tasks including, speech recognition, network intrusion detection, and autonomous vehicles. For example, network intrusion detection systems are well suited to machine learning, giving highly accurate classification. However, nefarious actors, ranging from lone hackers to advanced persistent threats seek to fool classifiers through influencing the output of the model. Unfortunately, most well trained neural network models may be fooled using gradient descent attacks algorithmically producing perturbed images known as adversarial examples.Bad actors wish to fool classifiers across application domains including Image recognition, speech recognition, and network intrusion detection. Humans and computers perceive the same data in different ways. Humans generally overlook minor differences in data. For example, minor changes in pixel size and colour. People easily overlook the visual difference between colour codes rgb(255,0,255) and rgb(254,0,254); whereas the numeric difference is strongly evident in computers algorithms, even within large quantities of data. Adversarial examples exploit this difference. Humans have difficulty detecting anything improper in a successful attack, because the perturbations are so small.Consequentially successful attacks against neural networks mean systems are vulnerable and therefore dangerously deployed in application domains. For example, incorrect classifications of road signs in autonomous could have dire consequences. Moreover, the increasing size of data being processed by neural networks enlarges the attack surface available to attackers whilst obfuscating the attack to humans. If unaddressed future mature attack methods will facilitate more destructive attacks. I therefore address the urgent research need in this area. My research explores the robustness of neural networks, aiming to understand the principles behind successful attacks and consider mitigations in key domains of network intrusion detection and image and speech recognition. I am designing tools to aid visualization of weak points in training datasets, and neural network models, to unearth attacks. Discovering ways to improve robustness of neural network models whilst retaining acceptable classification accuracy. Improving robustness of neural networks enables safe deployment across a wider range of domains.Item Open Access Bohmian Molecular Dynamics Simulations of Warm Dense Matter(Cranfield University, 2020-12-07 14:23) Campbell, ThomasThe computational demands of modelling large numbers of coupled electrons and ions have long been considered insurmountable, despite advances and refinements in density functional theory (DFT) calculations. However, a different approach to modelling quantum interactions, via application of the Bohmian trajectories formalism, can overcome this hurdle. We present further results from a new Bohm - molecular dynamics approach (Bohm MD). The static results of our simulations are validated by DFT results – our static ion-ion structure factor of aluminium at 5.2 g cm-3and 3.5 eV shows excellent agreement with both orbital free and Kohn Sham DFT. We then use Bohm MD to extract dynamic results, not only the ion-ion dynamic structure factor which provides a direct link to experimental observables, but also, unprecedentedly, the ion-electron and electron-electron dynamic structure factors.Thus Bohm MD provides a self-consistent approach to non-adiabatic investigation of dynamic modes in systems of thousands of particles.Item Open Access When Multipetawatt Lasers Strike! The Physics and Applications of Laser Beams Hitting Solids(Cranfield University, 2020-12-07 16:34) Morris, StuartWhen we talk about extremely powerful lasers, it's easy to conjure up images of spies strapped to tables, Sci-Fi guns and planet destroyers, but facts are often stranger than fiction. Modern lasers on the intensity frontier are capable of focussing huge amounts of light energy into tiny, micron-scale focal spots over less than a trillionth of a second in duration - creating an incredibly high energy density. When such a pulse strikes something solid, we end up with a bright flash of X-rays, ion beams and even antimatter can be generated in the extreme fields - but how? And what applications can such exotic particles provide?Item Open Access The Security Implications of AI-Enabled Technology in the Military(Cranfield University, 2020-12-07 16:40) Ertan, AmySeveral world leaders and defence secretaries across the world have referred to a current ‘AI arms race’ in which militaries vie for technological superiority across artificial intelligence-enabled technologies. Concurrently, active research highlights a significant range of security risks, misuse cases, and concerns on the ethics and strategic implications of using AI-enabled technologies without sufficient validation and oversight. My research focuses on exploring this tension within the military AI innovation landscape, in particular within the UK and the US. Through highlighting the technical, institutional, market and strategic dynamics of the design and deployment of AI-enabled technology for defence I map out likely unforeseen or unintended security consequences of current practices. My research also looks at potential options to mitigate the dynamics most likely to lead to 'irresponsible' AI including the role of international norms as well as industry frameworks. The 3M presentation will conclude by drawing the attention of listener's to a 'so what'? Military innovation has historically fed into the civic space (with drones or facial recognition being more recent examples) and so the norms and constraints on emerging technologies at this stage set a precedent for future deployment. By offering an overview of current gaps and mitigations in the field, I hope to communicate the importance of effective norms-setting as an urgent task to prevent the proliferation of technology with a net negative impact.