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Blockchain: The Economic and Financial Institution for Autonomous AI?
No full textThis paper examines how the combination of artificial intelligence (AI) and blockchain technology can enable autonomous AI agents to engage and execute economic and financial transactions. We critically examine the constraints on AI agents in achieving predefined objectives independently, especially due to their limited access to economic and financial institutions. We argue that AI’s access to these institutions is vital in enhancing its capabilities to augment human productivity. Drawing on the theory of institutional economics, we propose that blockchain provides a solution for creating digital economic and financial institutions, permitting AI to engage with these institutions through the management of private keys. This extends AI’s capabilities to form and execute contracts, participate in marketplaces, and utilize financial services autonomously. The paper encourages further research on AI as a general-purpose technology and blockchain as an institutional technology that can unlock the full capabilities of autonomous AI agents
Substantial grain refinement of Al-Mn-Si alloys mediated by collaborative effect of Al-5Ti-1B refiner and sub-rapid solidification
No full textThe mechanical properties of as-cast metallic materials depend strongly on the size and shape of grains, which are critical microstructural parameters dictated by the interplay of nucleation and growth of crystalline solids during solidification. In our experiments, the microstructure transition from coarse columnar crystals into fine equiaxed crystals for dilute Al-Mn-Si alloys was achieved by using sub-rapid solidification with the addition of Al-5Ti-1B grain refiner. The average grain size of Al alloy was reduced from a millimeter size to 73 µm. Through temperature gradient calculation, we found that the acquisition of fine equiaxed crystals could be attributed to the existence of a high number density of TiB2, acting as effective nucleation sites with an increase in total undercooling. Furthermore, the curvature supercooling, constitutional undercooling, thermal undercooling, and kinetic undercooling during sub-rapid solidification were quantitatively determined for given solidification rates. Our results showed that constitutional undercooling, rather than thermal undercooling, was primarily responsible for the formation of fine equiaxed grains, with the assistance of Al-5Ti-1B grain refiner. This work provides a new insight into the grain refining mechanism under sub-rapid solidification
Characterizing fibril morphological changes by spirooxindoles for neurodegenerative disease application
No full textFibrillation of proteins and polypeptides, which leads to the deposition of plaques in cells and tissues has been widely associated with many neuropathological diseases. Inhibition of protein misfolding and aggregation is crucial for the prevention and treatment of these conditions. The growing interest in identifying inhibitor molecules to prevent the formation of fibrils in vivo has led to the results highlighted in this study. Due to their hydrophobic structure and potential to readily cross the blood brain barrier, a library of spirooxindole compounds were synthesized with those labelled Hd-63, Hd-66 and Hd-74 proving to be the most potent against fibril formation. Our spectroscopic analysis provides detailed insight, that the introduction of these spirooxindole compounds leads to morphological changes in the mechanism of fibril formation which prevent the formation of highly ordered fibrils, instead results in the formation of disordered aggregates which are not fibrillar in nature
Windowing-Based Factor Graph Optimization with Anomaly Detection Using Mahalanobis Distance for Underwater INS/DVL/USBL Integration
No full textFactor graph optimization (FGO) provides a new means for asynchronous data fusion of integrated underwater vehicle navigation in a plug-and-play unified framework. However, in complex underwater environments, FGO suffers from observation anomalies, leading to deteriorated navigation solutions. This article proposes an improved factor graph with anomaly detection using Mahalanobis distance to overcome the above issue for inertial navigation system/Doppler velocity log/ultra-short baseline (INS/DVL/USBL) integrated underwater vehicle navigation. This method constructs a new factor graph model embedded with the node of anomaly detection for INS/DVL/USBL integration. Since the standard FGO computational load is increased with the number of the factor nodes, a sliding window technique is established to restrict the factor node number to improve the FGO computational efficiency. Based on above, a scheme of anomaly detection and regulation is presented for handling the disturbance of observation anomaly on system state estimation via the concept of Mahalanobis distance. Results of simulation and ground test experimentation show that the proposed methodology not only has the real-time performance but also has a strong robustness against observation anomaly for INS/DVL/USBL integrated navigation of underwater vehicles
Design and application of dynamic seabed penetrators in offshore geotechnical engineering: A review
No full textDynamic seabed penetrators are increasingly utilised for offshore site investigation and mooring offshore floating infrastructure. This paper presents a state-of-the-art review of dynamic seabed penetrator designs, performances, and data interpretations developed after the 2000s. The goal of this study is to provide essential insights into dynamic seabed penetrators, aiming to elucidate the strengths and constraints associated with various designs based on applications. This facilitates the prospective common advancements and potential refinements discussion. A brief introduction is provided on existing dynamic seabed penetrator, along with the advantages and drawbacks of their physical design. The dynamic seabed penetrators are grouped and reviewed according to their prototype model investigations, field studies, and practical applications, i.e., free-falling penetrometer (FFP) for offshore site investigation; and dynamically installed anchor (DIA) for mooring offshore infrastructure. The influence of penetrator geometry, weight, instrumentation, and the target soil type and state on the penetrator performances are also presented. Existing data interpretation models are then discussed, which take into consideration the strain rate effects, including consolidation and viscous rate effects, and the non-linear variation in capacity factor. Through the review, some research gaps are identified and highlighted, leading to potential future research opportunities
Co-designing an online treatment decision aid for men with low-risk prostate cancer: Navigate
No full textObjectives: To develop an online treatment decision aid (OTDA) to assist patients with low-risk prostate cancer (LRPC) and their partners in making treatment decisions. Patients and methods: Navigate, an OTDA for LRPC, was rigorously co-designed by patients with a confirmed diagnosis or at risk of LRPC and their partners, clinicians, researchers and website designers/developers. A theoretical model guided the development process. A mixed methods approach was used incorporating (1) evidence for essential design elements for OTDAs; (2) evidence for treatment options for LRPC; (3) an iterative co-design process involving stakeholder workshops and prototype review; and (4) expert rating using the International Patient Decision Aid Standards (IPDAS). Three co-design workshops with potential users (n = 12) and research and web-design team members (n = 10) were conducted. Results from each workshop informed OTDA modifications to the OTDA for testing in the subsequent workshop. Clinician (n = 6) and consumer (n = 9) feedback on usability and content on the penultimate version was collected. Results: The initial workshops identified key content and design features that were incorporated into the draft OTDA, re-workshopped and incorporated into the penultimate OTDA. Expert feedback on usability and content was also incorporated into the final OTDA. The final OTDA was deemed comprehensive, clear and appropriate and met all IPDAS criteria. Conclusion: Navigate is an interactive and acceptable OTDA for Australian men with LRPC designed by men for men using a co-design methodology. The effectiveness of Navigate in assisting patient decision-making is currently being assessed in a randomised controlled trial with patients with LRPC and their partners
Structure of rotating detonation in mixtures of natural gas and oxygen
No full textThe rotating detonation combustor is investigated as a potential implementation of pressure-gain combustion. Achieving net pressure-gain has proven to be extremely challenging in most combustors reported in the literature, regardless of their operating parameters. The performance losses observed in rotating detonation, compared to ideal predictions, can be attributed to mechanisms such as vitiation by residual burnt gases, partial detonation, and pre-combustion of reactants. The literature frequently discusses the impact of these mechanisms on measurable properties such as thrust and wave speed, but their effects on the front structure have not been fully understood. This study proposes using the rotating detonation structure for the first time to evaluate the vitiation quantitatively. The front structure of a compressed natural gas — oxygen-fueled rotating detonation is characterized using broadband chemiluminescence, and properties such as oblique shock angle, expansion angle, and front height are reported. The experimental values are then compared to the ideal predictions derived based on mass flow rates. The experimental front heights are found to be much higher than their ideal predicted counterparts. Analytical calculations that include pre-burning and vitiation show an increase in front height and a reduction in expansion angle, consistent with the chemiluminescence levels observed. The vitiated mass fraction is then deduced from the experimental front height, and the remaining velocity deficit is then used to evaluate the partial detonation mass fraction. Vitiated front angles compare favorably to the predicted values. Novelty and Significance This study reports high-quality chemiluminescence imaging of natural gas/oxygen rotating detonation front enabling the measurement of critical geometrical front features such as the front height, oblique shock angle, and expansion angle. The conventional front mass flow rate balance is extended to account for the re-c
Credal Valuation Networks for Machine Reasoning Under Uncertainty
No full textContemporary undertakings provide limitless opportunities for widespread application of machine reasoning and artificial intelligence in situations characterised by uncertainty, hostility and sheer volume of data. The paper develops a valuation network as a graphical system for higher-level fusion and reasoning under uncertainty in support of the human operators. Valuations, which are mathematical representation of (uncertain) knowledge and collected data, are expressed as credal sets, defined as coherent interval probabilities in the framework of imprecise probability theory. The basic operations with such credal sets, combination and marginalisation, are defined to satisfy the axioms of a valuation algebra. A practical implementation of the credal valuation network is discussed and its utility demonstrated on a small scale example
Feasible trajectory planning for minimum time manoeuvring
No full textPath planning models are often only founded by geometric calculations and do not consider the vehicle's limitations. In critical situations, path following is crucial, as a departure from the trajectory can have significant consequences. It is therefore necessary to define trajectories which the vehicle has the capacity to follow, i.e. feasible trajectories. This paper presents a framework for feasible trajectory generation for use in minimum time manoeuvres (MTM). The feasibility of trajectories is evaluated against a Quasi-Steady-State (QSS) acceleration envelope and jerk constraints. The vehicle's dynamics feasibility is assessed through a new exact relation of vehicle trajectory curvature that is expressed relative to a track reference line. The physical restriction of these constraints, relative to the vehicle's transient capabilities, implies that QSS feasibility assessments also extend to the transient vehicle. Minimum curvature trajectories are also reviewed. Results are presented for four examples. First, a constant radius example highlights differences in the minimum curvature cost models. The second example compares minimum curvature trajectories against MTM solutions for the Tempelhof Airport Street Circuit (Berlin), resulting in a new minimum curvature objective. The last two examples, straight road and Adria International Raceway, show that the feasible trajectory model is a good predictor of the QSS handling limits, indicating its ability to define feasible trajectories. The maximum spread of results is (Formula presented.). A friction ellipse model is additionally presented for comparison against the Normal-Tangential-Acceleration (NTA) surface. Friction ellipse results showed to be comparable if the acceleration envelope alignment is sufficient
Factors Influencing Seniors’ Anxiety in Using ICT
No full textThe ability of older adults to engage with information and communication technologies (ICT) is crucial in today’s more digital and connected world. Anxiety about and failure to adopt and engage with ICT is increasingly likely to be a barrier in daily living for older adults, potentially reducing their freedom as consumers, quality of life, independence, and wellbeing. It may also be a significant factor in social and economic exclusion. Drawing on consumer behaviour, ICT theories and frameworks, and a quantitative survey of 706 older Australian adults, this paper examines factors influencing anxiety in engaging with ICT. Our findings show that perceived anxiety was associated with increased subjective norms or when others placed pressure on older people to engage more with ICT and when older adults perceived increased risks associated with ICT engagement. Conversely, reduced levels of perceived anxiety were correlated with a positive attitude towards ICT and when older people had the technical and cognitive resources to adopt and engage with ICT. The results highlight the importance of building, renewing, and reinforcing digital competencies in older consumers. Understanding factors associated with ICT-related anxiety means that organisations will be better placed to develop campaigns, products, programmes, and policies for older consumers that actively reduce anxiety, increase their use of ICT, and reduce the digital divide.</p