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Generative adversarial evasion and out-of-distribution detection for UAV cyber-attacks
No full textAs UAVs are increasingly integrated into civilian airspace, the need for resilient intrusion detection system (IDS) frameworks grow, as traditional anomaly detection methods often struggle to detect novel threats. A common strategy is to treat the unfamiliar attacks as out-of-distribution (OOD) samples; hence, inadequate mitigation responses can leave systems vulnerable, granting adversaries the capability to cause potential damage. Furthermore, conventional OOD detectors frequently fail to discriminate the stealthy adversarial attacks from OOD samples. This paper proposes a conditional generative adversarial network (cGAN)-based framework specifically designed to craft stealthy adversarial attacks that effectively evade IDS mechanisms. Initially, we construct a robust multi-class classifier as IDS which classifies the benign UAV telemetry data from known cyber-attack types, including Denial of Service (DoS), false data injection (FDI), man-in-the-middle (MiTM), and replay attacks. Leveraging this classifier, our proposed cGAN strategically perturbs known attack features, generating sophisticated adversarial samples engineered to evade detection through benign misclassification. Then, the generative stealthy adversarial samples are refined to match the distribution of the OOD samples while ensuring high attack success. To effectively detect these stealthy adversarial perturbations, a conditional variational autoencoder (CVAE) is implemented, using negative log-likelihood as a metric to distinguish adversarial samples from genuine OOD samples. Comparative analyses between CVAE-based regret analysis and traditional Mahalanobis distance-based detectors demonstrate that the CVAE’s negative log-likelihood significantly outperforms in detecting stealthy adversarial attacks from OOD samples. Our findings highlight the necessity of advanced probabilistic modeling techniques to reliably detect and adapt the existing IDS against novel, generative-model-based stealthy cyber threats.This work was supported by the Royal Academy of Engineering and the Office of the Chief Science Adviser for National Security under the UK Intelligence Community Postdoctoral Research Fellowship programme2025 IEEE International Conference on Systems, Man, and Cybernetics (SMC
The complex formation mechanism between β-cyclodextrin and organic micropollutants in water, studied by molecular dynamics simulations
No full textCyclodextrins are cage molecules with a hydrophilic exterior that promotes their solubility in water, while their hydrophobic cavity allows the encapsulation of low-molecular-weight organic molecules. Thus, cyclodextrin is a promising compound for removing micropollutant molecules from water. The binding mechanism of ligand molecules to the cavity of the cyclodextrin is driven by the physicochemical properties of the ligand such as its hydrophilic/hydrophobic balance and by its number of hydrogen bond donors and acceptors. In the present study, the free binding energies of nine different organic micropollutant molecules (bisphenol A, the charged and the uncharged forms of trimethoprim, the predominant forms of tetracycline at pH 1, pH 4, and pH 8, caffeine, theobromine, and atenolol) to β-cyclodextrin are calculated by molecular dynamics simulations using steered molecular dynamics and umbrella sampling analysis. Steered molecular dynamics and umbrella sampling analysis are shown to yield similar values for the free binding energy of the complexes, close to the experimental values. Then, the contributions of the electrostatics and van der Waals interactions to the free binding energy of the complexes are investigated, highlighting the major impact of van der Waals interactions. Finally, the effect of the number of hydrogen bonds between β-cyclodextrin and ligand molecules on their free binding energy is shown to depend on the octanol/water partition coefficients, log D, of the ligands. In particular, a correlation between the number of hydrogen bonds and the free binding energy of the complexes is demonstrated in the case of ligand molecules with log D values comprised in the range -0.55 - 0.92.The Leverhulme Trust Research Leadership Awards (RL-2022-041)Langmui
Fundamentals of cooling rate and Its thermodynamic interactions in material extrusion
Get PDFMaterial Extrusion (ME) is a layer-by-layer additive manufacturing technique that has gained prominence due to its simplicity, cost-effectiveness, design freedom, and adaptability to a wide range of thermoplastic materials. However, the mechanical performance of ME-printed parts often remains suboptimal, primarily due to complex thermal phenomena that govern microstructural development during the printing process, which are key determinants of mechanical strength. As a result, optimizing thermodynamic printing parameters has become essential for improving the overall quality of the printed parts. Extensive research articles and reviews have been published to explore the effect of many ME printing parameter settings on the resultant product characteristics. Despite this focus, the effect of cooling rate, a critical thermodynamic parameter of the process, has been largely overlooked in current research when they are critically reviewed. Cooling rate plays a central role in determining the thermal history of printed material, which in turn influences polymer chain mobility and microstructural features of the extruded material, all of which are crucial to the mechanical integrity of the printed part. Thus, it has been concluded by this review that analytical and empirical investigations into the influence of cooling rate on the microstructural properties of ME parts represent a valuable and novel contribution to the academic field.Journal of Manufacturing and Materials Processin
Molecular and metabolic response of ‘Piccolo’ cherry tomato to Graduated Controlled Atmosphere
Get PDFControlled atmosphere (CA) is used to extend the postharvest life of climacteric fruit by suppressing respiration and delaying ethylene mediated ripening. However, sudden exposure to low oxygen conditions can induce hypoxic stress, triggering metabolic and hormonal disruptions that negatively impact fruit quality. This study aimed to understand the mechanisms underlying ethylene sensitivity under low oxygen conditions through the application of a novel approach to CA, called Graduated Controlled Atmosphere (GCA), in ‘Piccolo’ cherry tomato. Compared to standard CA, GCA treatment resulted in greater suppression of respiration and improved firmness retention, indicating reduced physiological stress and slower cell wall degradation. Gene expression analysis revealed downregulation of NCED1, ACS, and ACO genes under GCA, indicating delayed ethylene-associated transcriptional activity. These hormonal adjustments were also reflected in lower abscisic acid (ABA) concentrations, implying a more stable ripening trajectory. Besides hormonal modulation, GCA-treated fruit exhibited alterations in primary metabolism. Sucrose accumulation and changes in malate levels under GCA conditions suggest a shift in energy metabolism, consistent with improved hypoxia tolerance. However, a notable trade-off was observed in reduced lycopene accumulation, potentially due to lower oxidative signalling and shared precursors between carotenoid and ABA biosynthesis. These findings demonstrate that GCA promotes a more controlled physiological and molecular response to hypoxic storage by reducing stress-associated metabolic and hormonal activity. GCA, as an advanced postharvest strategy, enhances texture retention and may reduce quality losses during storage. This work provides new mechanistic insights into hypoxia adaptation in fruit and supports the use of gradual atmosphere modification to optimise CA protocols.The work was supported by the Biotechnology and Biological Sciences Research Council (BBSRC; BB/P00492X/1).Postharvest Biology and Technolog
Probing the influence of water on silica surface modification during amine grafting for enhancing CO2 adsorption
Get PDFAmine-grafted adsorbents are promising materials for carbon capture, but their adsorption efficiency and hydrothermal stability still require improvement. This study examines how water addition influences silica surface modification during amine grafting with (3-aminopropyl)triethoxysilane (APTES). We used 29/Si cross-polarization magic-angle spinning (CPMAS) and direct-observation 29/Si NMR spectroscopy with proton decoupling to test the common assumption that water increases the surface silanol content of silica-based sorbents. Our findings indicate a different mechanism. BET analysis and NMR results show that water promotes the hydrolysis of APTES ethoxy groups. This accelerates condensation with surface silanol sites and enables a more complete reaction between APTES and the silica surface. A reduction in Q/4 sites further supports this mechanism, suggesting that water induces structural rearrangement of surface siloxane bonds, generating additional reactive silanol groups for grafting. These mechanistic insights explain previously reported improvements observed in wet-grafted sorbents, including enhanced sorption kinetics, better thermal stability, improved regenerability, stronger CO₂ interaction, and increased selectivity. The enhanced performance is linked to the formation of more uniform siloxane bridges through hetero- and homo-condensation reactions of hydrolysed APTES molecules. Overall, this work highlights the central role of water in tuning the silica surface during amine grafting. By clarifying how water shapes the grafting mechanism, the study provides a pathway for designing more efficient and durable sorbents that can support scalable carbon-capture technologies and broader decarbonisation goals.Petroleum Technology Development Fund (PTDF), Nigeria, (Award Number: PTDF/ED/OSS/PHD/BOO/1710/20) and Imo State University, Owerri, NigeriaChemical Engineering Journa
Perceptions of flight crew resilience among commercial pilots: evaluation of pilots’ acceptance of CBTA across China, the United States, Europe, and the Asia Pacific
Get PDFAirline pilots play a critical role in ensuring safety in aviation. This study investigates commercial pilots' perceptions of flight crew resilience, and their acceptance of Competency-Based Training and Assessment (CBTA) utilizing revised questionnaires from the Flight Management Attitude and Safety Survey (FMASS). The research included pilots from China, the United States, Europe, and the Asia Pacific, aiming to assess their understanding, acceptance, and application of resilience concepts and CBTA methods in daily operations. The study uses a questionnaire that includes open questions for pilots to share their suggestions for CBTA training. This advantage allows the study to apply both quantitative and qualitative approaches. The mixed methods of SPSS v.26 and NVivo provide valuable insights. The findings indicate that pilots possess a better understanding of, and more positive attitudes toward, Crew Resource Management (CRM) and Threat and Error Management (TEM). The study advocates for fostering a supportive cockpit environment, emphasizing the importance of airline culture and cockpit climate in building resilience. It also highlights the necessity of incorporating resilience training into initial pilot education and during CBTA programs. Recognizing that humans are critical to the aviation system, the study concludes that resilience training for flight crews should be introduced from the very first lesson in pilot training. Additionally, successful pilot training outcomes will benefit from collaboration between researchers and industry practitioners.2025 8th International Conference on Transportation Information and Safety (ICTIS
The Female FTSE Board Report 2018: Busy going nowhere with the female executive pipeline
No full textThis year we see two different pictures emerging in terms of women’s representation on FTSE 100 and FTSE 250 corporate boards. Since October 2017 the percentage of women on FTSE 100 boards has increased from 27.7% to 29%, meaning that if the current pace continues it is possible to reach the targeted 33% by the end of 2020. In total 264 women hold 305 directorships on FTSE 100 boards. The percentage of female Non-Executive Director (NED) positions is at the all-time high of 35.4%, whilst the percentage of female executive positions has flatlined at 9.7%. On a positive note, seven women hold a Chair position and 18 hold Senior Independent Directorships. A further 85 women hold 95 Chair roles on the various committees across FTSE 100 boards. In contrast, the percentage of women on FTSE 250 boards has only increased marginally from 22.8% in October 2017 to 23.7%, the percentage of female executive directorships has dropped from 7.7% to 6.4% and the number of all male boards has increased to ten. These present challenging conditions for meeting the 33% target in 2020
Development and characterisation of integrated wet-spun alginate-Moringa oleifera composite fibers for potential water purification
Get PDFEnsuring access to safe drinking water requires effective materials and technologies to treat contaminated water. In this study, we developed sodium alginate fibre (SAlgF) and their composite fibres functionalised with pulverised Moringa oleifera (MoP) at concentrations of 0.5 %, 1 %, 4 %, and 8 % using the wet-spinning technique. Both SAlgF and MoP are biodegradable, offering eco-friendly alternatives to synthetic polymers in line with green manufacturing. The results showed significant improvements in the mechanical properties, with the 1 % MoP composite fibre exhibiting 6 times the strength of pure SAlgF in terms of ultimate tensile strength (UTS) and Young's modulus (YM). X-ray Diffraction (XRD) analysis revealed enhanced fibres interactions, while Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetric Analysis (TGA) confirmed the successful incorporation of MoP into the alginate matrix and improved thermal stability. Furthermore, the result obtained from the Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDX) indicated morphological changes and the uptake of heavy metal ions when immersed into solutions containing Cu²⁺, Ni²⁺, and Cd²⁺. These findings demonstrate the potential of MoP-modified composite fibres for sustainable and cost-effective water treatment applications, particularly in developing countries.The authors would like to acknowledgment the financial support of Petroleum Technology Development Fund (PTDF) of the Federal republic of Nigeria, through the award of Postgraduate Scholarship at the Ph.D. level, NO. PTDF/ED/OSS/PHD/AOO/1844/2020PHD152.Carbohydrate Polymer Technologies and Application
Modelling real‐world effects in near‐field SAR collections for compressive sensing
Get PDFThe ability to control sidelobes in a SAR image is critical to forming images that are useful for interpretation and exploitation. QinetiQ has developed the RIBI sensing system, which utilises a distributed coherent array of sensors to produce multistatic images. These systems require techniques from outside the traditional radar domain to utilise the theoretical resolution possible in synthesising a coherent aperture from multiple disparate collections. This paper develops previously published work on using compressive sensing techniques to suppress sidelobes in SAR images to develop a higher‐fidelity measurement model. Using Cranfield University's GBSAR System a series, experimental measurements are conducted, and image estimation techniques are applied to this real data. It demonstrates an improvement in recovery performance over an isotropic measurement matrix, and discusses areas which require further development.This work was funded by QinetiQ's sponsorship of PhDresearch.IET Radar, Sonar & Navigatio
Cultural dynamics and ambidextrous innovation: insights from Saudi Arabia’s project-based organizations—a thematic–explorative study
Get PDFThe implementation of ambidextrous innovation in project organizations within the cultures of the Global South, such as Saudi Arabia, is a significant problem. Organizational culture is positioned as a key factor that can help project organizations in cultures such as Saudi Arabia to implement ambidexterity as a key innovation framework. However, knowledge of ambidextrous innovations in such an important cultural and organizational context is highly limited. Thus, the aim of the present research is to explore key cultural aspects and themes based on action and a grounded theory research approach that can help organizations employ projects as a key work structure to implement ambidextrous innovations in project management offices (PMOs) in Saudi Arabia. To achieve this aim, the current study employed in-depth semi-structured interviews with 36 participants. The results, employing open coding procedures as a tool of data analysis using the NVivo 14.0 software package, revealed 62 key cultural aspects that can be critical in implementing the innovation of ambidexterity. To further validate and triangulate the findings, inter-rater reliability was undertaken with the help of two experts, and two sessions of focus group discussions were also conducted. The first session of the focus group helped us critically evaluate and filter the cultural aspects, resulting in the final 56 key cultural aspects. The second focus group session was undertaken with participants with the aim of grouping aspects into theoretical themes, which resulted in 10 themes. The research is novel in that it addresses both project organizations and the culture of the Global South, including Saudi Arabia. Empirical research needs to be conducted to predict and achieve other key outcomes.Administrative Science