Search Results (2,519)

This chapter offers a conceptual and philosophical analysis of the ontological, epistemological, and ethical issues associated with the design, development, and use of Agentic AI in moral and legal decision-making. Its aim is to map, classify, and bring into focus the principal philosophical problems raised by the autonomous operation of artificial agents in contexts of moral and legal judgement. The chapter contributes to the existing literature by distinguishing between two levels of AI autonomy. Advisory systems possess limited autonomy and provide recommendations that remain subject to human evaluation, whereas regulatory systems exercise a greater degree of autonomy and are entrusted with final decision-making authority. Adopting a sceptical perspective, the analysis examines the conceptual fragility and epistemological difficulties surrounding proposals to employ Agentic AI in significant domains. Particular attention is given to the risk that ostensibly advisory systems may become tacitly regulatory in practice, especially under the influence of widespread assumptions concerning the objectivity, accuracy, and effectiveness of AI. The inquiry proceeds through a step-by-step branching structure organised around three central questions concerning the moral values on the basis of which such systems should be designed and developed, the extent to which they can understand the concepts of ethics and justice, and the attribution of responsibility for their decisions and outputs. Each question opens onto alternative lines of analysis, thereby providing a systematic map of the principal philosophical challenges involved. Its purpose is to provide a synthetic overview of the relevant philosophical issues while highlighting both their breadth and their plurality. To organise these issues systematically, the chapter adopts the schema of an algorithm, offering a clear and ordered account of the possible interconnections among the problems examined and of the ways in which alternative answers generate distinct yet interrelated lines of philosophical inquiry. Full article

This paper presents the kinematic design and experimental validation of a two-degree-of-freedom ankle mechanism based on stepper motor actuation and ball-screw transmission. The proposed system employs a hybrid architecture, combining actively controlled motion in the sagittal plane with passively compliant motion in the frontal plane. Experimental evaluation under no-load laboratory conditions demonstrated a strong linear relationship between motor steps and joint angle within an operating range of approximately ±22°, with coefficients of determination exceeding 0.97. The results confirm the predictability and repeatability of the kinematic transformation while revealing minor hysteresis effects associated with mechanical transmission. The proposed mechanism is intended as a validation platform for studying motion transformation in multi-DoF (degree-of-freedom) ankle systems, providing a basis for future work on load analysis, torque modeling, and closed-loop control. Full article

Thermodynamic concepts are increasingly used in nonlinear photonics to describe Rayleigh–Jeans thermalization, optical wave turbulence, condensation, negative-temperature states, and statistical mode locking. We ask how far this reasoning can be extended to localized structures maintained far from equilibrium by gain, loss, dispersion, and nonlinearity, using strongly chirped dissipative solitons (DSs) of the complex cubic–quintic Ginzburg–Landau equation as a model system. Their internal energy flows and separation of correlation scales connect coherent solitary waves with semi-incoherent wave kinetics, driven-open systems, and Bose–Einstein-condensation analogies. We review thermodynamic-like indicators based on spectral entropy, internal energy, effective temperature, and spectral condensation, and we relate them to dissipative-soliton resonance (DSR), stochastic mode-locking self-start, and redistribution between single- and multipulse attractors. Normal and anomalous group-delay dispersion provide complementary cases. In normal dispersion, DSR is accompanied by spectral localization, increasing scale separation, and growing multipulse accessibility; the statistical degree-count interpretation becomes meaningful only after the two scales separate and still requires ensemble calibration. In anomalous dispersion, the spectrum has extended wings, and noisy calculations reveal finite robust regions inside a larger existence domain, without an analogous thermodynamic turnover along the continuation tested. Thus, the unification is strongest at the level of the adiabatic solution and state-selection diagnostics, not an equilibrium thermodynamics. DSs thereby provide a photonic platform linking nonequilibrium thermodynamics, wave turbulence, driven condensates, and statistical phase-transition concepts. Full article

We investigate the center problem for analytic maps implicitly defined by algebraic equations of the form ${\displaystyle F(x,y)=x+y+{\displaystyle \sum _{i+k=2}^n}{\alpha }_{i,k}{x}^i{y}^k=0}$. Previous studies of homogeneous analytic maps of even degree and of mixed terms of degrees 2 and 4 revealed two recurring algebraic families characterizing the existence of a center at the origin: mirror-symmetry conditions and alternating-sum conditions. In this paper, we resolve the next open case involving mixed terms of degrees 2 and 6 and show that the same algebraic structure extends to mixed terms of degrees 2 and arbitrary even number. Using an approach based on the involutive identity $f\left(f\right(x\left)\right)=x$, we prove that these two families of algebraic conditions completely characterize the existence of a center at the origin. The proof combines algebraic and structural arguments and avoids the use of explicit higher-order focus quantity computations in the general case. Full article

For the first time, for oxidative cross-linking of chitosan with a natural polyphenol, ferulic acid, the so-called small two-domain bacterial laccase, was used. Recombinant Streptomyces carpinensis laccase (ScaSL) has been shown to oxidize ferulic acid in neutral and alkaline environments, which is important for subsequent nucleophilic reactions of chitosan with oxidation products. The selected conditions (pH 7.0, molar ratio FA/NH₂ = 1:10) provide a cross-linking degree of more than 80%, which significantly exceeds the indicators previously achieved using other laccases. Based on the results of quantum chemical modeling and experimental studies using FTIR spectroscopy and XPS, as well as thermogravimetric and differential scanning calorimetry, a new mechanism for laccase-catalyzed cross-linking of chitosan with ferulic acid without the formation of Schiff bases is proposed. The resulting hydrogels have a uniform smooth microstructure, high oxygen permeability, a significant degree of swelling (270%), and stability over a wide pH range. The material neutralizes up to 95% of ABTS^+• cation radicals. Quantum chemical analysis within the framework of the Marcus theory has demonstrated that the chitosan–ferulic acid conjugate is superior in antioxidant capacity to ferulic acid dimers, despite the decrease in the matrix element of the bond. Application of two-domain bacterial laccase for modifying chitosan hydrogels with ferulic acid opens the way to the creation of environmentally friendly biomaterials with antioxidant protection. Full article

Comparing metro-station service at national scale is hindered by the scarcity of consistent ridership or mobile-phone data across cities. We propose MetroVFE, a topology-based framework for diagnosing metro-station structural service potential. It combines three coupled subsystems—vitality (network centrality, transfer capacity, and feeder-bus connectivity), function (route-type diversity, destination reachability, directional coverage, and operator diversity), and spatial coverage equity (station-spacing uniformity). All indicators are derived from publicly available transit-network topology. Each subsystem is aggregated by entropy weighting, and the three are combined through a coupling coordination degree (CCD) model that penalizes unbalanced development. We instantiate the framework on the CPTOND-2025 national bus–metro vector dataset, computing indicators for 7057 unique metro stations in 45 Chinese cities, with 42,796 feeder bus routes spatially joined to 500 m station catchments. The empirical analysis yields four main findings: (i) Coupling coordination is moderate and has positive skew: the mean station CCD is $0.46$, with $58.5\%$ of stations in antagonistic or transitional bands and only $1.5\%$ highly coordinated. (ii) vitality is the dominant lagging subsystem ($66.4\%$ of stations), and this share rises monotonically from large to small networks ($63.7\%\to 69.3\%\to 78.2\%$). (iii) Unsupervised clustering recovers five interpretable diagnostic typologies, dominated by vitality-deficient ($48.3\%$) and function-developing ($24.8\%$) stations, with only $12.3\%$ balanced–coordinated. (iv) Spatial coverage equity modestly moderates the function→vitality relationship (interaction $p=1\times {10}^{-4}$, robust to controls): the marginal contribution of functional diversity to vitality is about $25\%$ larger in high-coverage-equity than low-coverage-equity station areas ($0.207$ vs. $0.165$). Mean coordination does not differ significantly across network-size tiers (ANOVA $p=0.12$), but typology composition does (${\chi }^2$$p<{10}^{-58}$). Ablation and sensitivity analyses confirm that the coordination feature and the full V-F-E feature set are necessary for stable typologies. MetroVFE is fully reproducible from open data and provides an actionable, mathematically grounded tool for prioritizing station-level interventions. Full article

The phenomenon of climate change has exerted an escalating degree of pressure on coastal livelihoods in Bangladesh. In this region, communities find themselves confronted with a dual challenge, being exposed to both rapid-onset hazards, including cyclones, storm surges, and floods, and slow-onset stresses, such as salinity intrusion and sea-level rise. These hazards have ramifications for agriculture, aquaculture, food security, and livelihood sustainability. However, extant studies frequently examine individual risks, livelihood sectors, or disaster responses in isolation. Consequently, there is a paucity of research that comprehensively examines the influence of multiple climate-related hazards on coastal livelihoods and the adaptation options that are locally feasible in overcoming institutional, community, and financial constraints. This study synthesizes evidence from the published literature and is complemented by qualitative evidence from 30 open-ended questionnaires with farmers in selected coastal areas of Bangladesh. The objective of this synthesis is to validate and contextualize the current livelihood conditions, climate-related challenges, and locally adopted adaptation practices. The analysis examines four interconnected dimensions. The following elements are to be considered: (i) climate-related hazards and their sectoral impacts, (ii) livelihood opportunities and vulnerabilities, (iii) adaptation practices, and (iv) institutional, community, and financial constraints. These elements are to be complemented by a SWOT assessment of livelihood adaptation options. The findings indicate that a combination of factors, including salinity intrusion, cyclones, storm surges, flooding, sea-level rise, drought, and changing temperature and rainfall patterns, collectively impose constraints on agricultural and aquaculture productivity, thereby exacerbating livelihood insecurity. Concurrently, practices such as salt-tolerant crop cultivation, sorjan farming, freshwater conservation, pond-dyke vegetable cultivation, tower cultivation, composite agriculture, and environmentally responsible aquaculture offer promising pathways for livelihood adaptation. However, the limited availability of infrastructure, inadequate institutional coordination and stakeholder participation, and insufficient financial resources act as constraints on their broader adoption. The manuscript makes a similar observation regarding infrastructure, institutional support, and funding, which are identified as significant constraints. Concurrently, it acknowledges technological development, stakeholder participation, and climate-resilient livelihood opportunities as crucial avenues for enhancement. This study thus posits a series of recommendations for enhancing the resilience and sustainability of coastal livelihoods in Bangladesh. These recommendations encompass the implementation of hazard-specific and livelihood-oriented adaptation measures, the facilitation of access to climate-resilient technologies and financial resources, and the establishment of a more robust coordination framework among diverse stakeholders. The proposed framework involves collaboration between agriculture, fisheries, water management, disaster management, local government, non-governmental organizations (NGOs), academic institutions, and community organizations. These recommendations align with the manuscript’s proposed measures for communities dependent on salinity, cyclones, storm surges, floods, agriculture, and aquaculture. Additionally, the manuscript places emphasis on cross-sectoral governance. Full article

This study examines differences between monolingual and bilingual students’ self-reported 21st-century skills in higher education, with attention to the contributions of demographic and academic factors. Drawing on data from a linguistically and socioeconomically diverse sample of higher education students, the study considers these skills as part of broader educational concerns related to students’ preparation for academic, social, and labor market demands. Data were collected through an online questionnaire completed by 564 Israeli undergraduate students. The analysis focused on differences between monolingual and bilingual students and on the role of socioeconomic indicators, including family income and mother’s education, as well as academic degree, year of study, and employment status. Results showed that bilingual students reported higher levels in selected subscales, including cognitive processes such as critical thinking and problem-solving, intellectual openness, and interpersonal skills such as teamwork. No significant differences were found for creativity. Hierarchical regression analyses showed that demographic, socioeconomic, academic, and employment variables were associated with perceived skill levels, with different patterns for monolingual and bilingual students. Overall, the findings point to domain-specific differences between bilingual and monolingual students and highlight the importance of contextual and demographic factors. They suggest that bilingual experience may be associated with specific cognitive, intrapersonal, and interpersonal skill domains, although these associations should be interpreted with caution, given the cross-sectional, self-report design. The findings also suggest the value of creating structured opportunities for multilingual engagement in educational settings as one possible way to support 21st-century skills among students from diverse linguistic and socioeconomic backgrounds. Full article

Social inequalities often persist despite widespread endorsement of universal norms such as fairness and equality. One explanation is that actors interpret these principles differently in practice, generating divergent forms of action within the same institutional setting. This study examines this process in the context of gender equity in STEM education by analysing how teachers organise beliefs, awareness, pedagogical practices, responsibility, and the perceived value of gender equality when reasoning about pedagogical fairness. Using an exploratory case study with a theory-guided, person-centred typological classification approach, questionnaire data from teachers in a Portuguese school cluster (Grades 1–12) were analysed through quantitative classification and interpretive analysis of open-ended responses. Rather than differing only in degree of commitment to equality, teachers’ reported reasoning was organised into three theory-guided orientations: Procedural Impartiality (fairness as identical treatment), Compensatory Intervention (fairness as corrective action), and Reflexive Professional Responsibility (fairness as situated professional judgement). The resulting profiles showed differentiated configurations across the five analytical dimensions, particularly in the relative organisation of awareness, pedagogical practices, responsibility, and the perceived value of gender equality. Descriptive subgroup distributions also suggested tentative variation across disciplinary field, sex, and teaching experience, although these patterns should not be interpreted as systematic or generalisable associations. The findings indicate that teachers’ reported reasoning can be organised into distinct theory-guided orientations and suggest that shared commitments to gender equality may coexist with different professional interpretations of fairness and legitimate pedagogical intervention. The study therefore proposes a framework for examining how equity is interpreted as a professional category in educational contexts, while recognising that further research is needed to examine how such orientations relate to observed classroom practices and student outcomes. Full article

Physiological signal emulators support the calibration, validation, and stress testing of cardiovascular monitoring devices. However, many existing systems generate electrocardiography (ECG) or photoplethysmography (PPG) independently and offer limited control over arrhythmia detection and ECG–PPG coupling. This study presents a programmable physiological signal emulator that integrates a unified event-driven ECG–PPG model with synchronized multichannel hardware. The model represents atrial pacing, atrioventricular conduction, and ventricular activation as separate functional blocks, enabling normal sinus rhythm, first-degree atrioventricular block, second-degree atrioventricular block Mobitz I, complete atrioventricular block, atrial tachycardia, and ventricular tachycardia. A Gaussian-based ECG is generated from the atrial and ventricular event sequences, while a multi-Gaussian PPG waveform is derived from ventricular activation using a beat-class-dependent electromechanical delay. The same processing architecture supports playback of recorded 12-lead clinical ECG data through an inverse lead transformation. The hardware uses an STM32F407VET6 microcontroller and MCP4921 digital-to-analog converters (DACs) to generate 10 synchronized analog outputs, comprising 09 ECG electrodes and 01 PPG channel. Validation covered physiological timing, analog-chain performance, and end-to-end signal reproduction. PR interval errors relative to a commercial electrocardiograph were 1.23 ms for normal sinus rhythm and 1.66 ms for first-degree atrioventricular block. The measured beat-to-beat PR increment during Mobitz I conduction was $40.02\pm 0.04$ ms for a programmed value of 40 ms. At commanded amplitudes of at least 800 mV, both output channels achieved absolute amplitude errors below 0.60%, total harmonic distortion below 1%, and signal-to-noise ratios (SNRs) above 30 dB. Inter-channel R-peak skew remained below the 2 ms sampling interval, and all monitored metrics varied by less than 1.5% during 60 min of continuous operation. Reproduction of a clinical 12-lead recording yielded per-lead $R^2$ values of 0.967–0.986 and a cycle-to-cycle correlation of 0.996. The emulator also reproduced amplitude-dependent bias in automated interval measurements and interpretation labels. These results demonstrate a low-cost, open-source platform for reproducible device calibration, algorithm stress testing, medical training, and physiological signal processing research. Full article

In deepwater open-loop drilling of ultra-shallow high-build-rate horizontal wells, the drill string spans the exposed seawater section, the mudline transition, and the constrained downhole section. Existing studies have not yet established a unified coupled dynamic model covering the full string, and the response patterns and parameter-control mechanisms remain insufficiently understood. This study examines a surface-hole operation in a block of the South China Sea. A six-degree-of-freedom spatial Euler–Bernoulli beam finite element model was established from the measured wellbore trajectory. Structural and fluid inertia, geometric stiffness due to axially varying force, Morison-type current loading, a wake-oscillator model for vortex-induced vibration (VIV), wellbore contact and friction, and bit loads were coupled within one framework. The generalized-alpha method was used for time discretization, and the nonlinear dynamic equilibrium equations were solved by within-step iteration for multiple operating conditions. Under the baseline condition, the peak in-line displacement was 6.3–6.4 m and occurred in the middle of the seawater section; the peak cross-flow displacement was approximately 0.43 m, the maximum bending moment was approximately 36 kN m, and the maximum equivalent stress was approximately 230 MPa. The high internal-force values were concentrated in the mudline transition and the upper BHA, demonstrating spatial separation between deformation and internal force. Surface current velocity controlled the in-line response amplitude: increasing the velocity from 0.4 to 0.8 m/s increased the peak in-line displacement by approximately 230%. WOB had a limited effect on global deformation and acted mainly on the local near-bit section. These results provide numerical reference for mechanistic analysis and parameter control of drill-string dynamics in comparable deepwater open-loop drilling operations. Full article

Multi-phase permanent magnet synchronous generators (PMSGs) are increasingly adopted in renewable energy systems and isolated microgrids due to their improved fault tolerance, reduced per-phase current stress, and enhanced power density compared to conventional three-phase machines. This article presents a systematic performance comparison between 15-phase and 9-phase PMSGs under four distinct operating conditions: healthy mode, single-phase open-circuit fault (Phase 1), and two fault-tolerant control (FTC) strategies. The first FTC technique involves opening a second phase with approximately 90-degree phase displacement from the faulty phase to attenuate power oscillations and reduce current amplitude imbalances. The second technique involves isolating a complete three-phase set containing the faulty phase without adapting the machine model. Both machines are modeled using the vector space decomposition (VSD) approach under field-oriented control (FOC), and simulations are performed in MATLAB/Simulink. Performance metrics include power efficiency, power losses, power ripple factor, electromagnetic power ripple, stator RMS current evolution, and stator current balance. Results demonstrate that the 15-phase PMSG consistently exhibits lower power ripple (6.5% vs. 15.54% under open-circuit fault), higher efficiency (89.02% vs. 87.44%), and reduced power losses across all fault scenarios. The first fault-tolerant strategy improves performance in both machines but is more effective in the 15-phase configuration. To validate the findings beyond offline simulation, hardware-in-the-loop (HIL) experiments are conducted on an OPAL-RT real-time platform, where the complete system—the PMSG and converter models together with the FOC and fault-tolerant control algorithms—is implemented within its FPGA framework. The HIL results for electromagnetic power and d–q axis stator currents show close agreement with the MATLAB/Simulink results across all operating conditions, confirming the FPGA implementability of the proposed control strategies under real-time constraints. These findings provide actionable insights for the design and control of high-phase-count generators in grid-connected and isolated power systems. Full article

Scientific evaluation of open-pit slope stability under the disturbance of underground goaf is critical to the safe production of open-pit coal mines. Taking an open-pit coal mine in Inner Mongolia as the engineering background, this study investigates the influence mechanism of underground goaf on slope stability. With discrete element numerical simulation, the movement law of overlying strata above the goaf is revealed, and the heights of the “three zones” and boundary movement angles are determined. Furthermore, limit-equilibrium theory is adopted to analyze slope stability affected by goafs from three perspectives: goaf span, occurrence position and inter-goaf spacing. The results indicate that under partial extraction conditions, goaf span is positively correlated with the height of the caving zone and negatively correlated with the boundary movement angle. As the goaf width increases, the mining-induced deformation field expands progressively, and a distinct bending-subsidence zone develops in the 50 m wide single-goaf case, resulting in a complete caving–fractured–bending-subsidence zonation. For adjacent goafs, smaller inter-goaf spacing promotes overlap of the mining-induced deformation fields and generally enhances overburden disturbance. As the spacing increases, the interaction between adjacent goafs tends to weaken, although the degree of reduction depends on goaf width and the deformation parameter considered. Therefore, the spacing of approximately 50 m observed in the present simulations is interpreted as a site-specific transition range rather than a universal critical threshold. Two landslide modes are identified in the Baozhixil open-pit mine: circular arc sliding and composite sliding controlled by the weak interlayer of No. 1 coal seam. Slope stability is negatively correlated with goaf span and positively correlated with the horizontal distance between the goaf and the slope face. For the analysis of inter-goaf spacing, slope stability shows a positive correlation with the proportion of non-collapse deformation area within the sliding mass. Full article

Tailless underactuated hypersonic glide vehicles rely on elevons alone to control both roll and yaw. The dual-loop cascade architecture, in which differential elevon deflection regulates sideslip and the resulting sideslip response drives roll, exploits the high roll-to-yaw ratio to address lateral–directional underactuation. However, because the inner loop relies on sideslip angle feedback, its performance is sensitive to composite measurement bias. This study first analyzes lateral–directional open-loop divergence, the high roll-to-yaw ratio, and adverse yaw induced by differential elevons using a six-degree-of-freedom model and linearizations at multiple trim points, and then develops a baseline cascade controller employing stability-axis yaw-rate feedback. A first-order Gauss–Markov process with a constant offset is subsequently used to represent sideslip angle measurement bias. A linear extended state observer is introduced only in the velocity–bank angle outer loop to jointly estimate and compensate for the equivalent effect propagated by the bias, aerodynamic perturbations, center-of-mass offsets, and residual inner-loop dynamics. Observer parameters are selected through input direction identification, hierarchical two-dimensional parameter sweeps, and local grid verification. Local stability and boundedness near the design operating point are analyzed under bounded-input assumptions at the levels of the observer error, velocity–bank angle tracking error, and complete attitude control closed loop. Strictly paired Monte Carlo simulations and ablation experiments show that the proposed method effectively attenuates the propagation of sideslip angle measurement bias into the roll channel, improves velocity–bank angle tracking accuracy and response consistency under random uncertainties, and does not appreciably increase the required elevon position command envelope. Full article

This study addresses the thermodynamic analysis of the thermal decomposition of solid compounds under a linear temperature increase. Starting from the Gibbs free energy formulation developed for isothermal–isobaric systems, a generalised description is derived for dynamic regimes by combining thermodynamic considerations with the three-parameter equation. The proposed approach enables the identification of temperature-invariant Gibbs free energy nodes and establishes a direct relationship between Gibbs free energy, conversion degree and heating rate. The application of the equilibrium criterion yielded insights into the enthalpy and entropy changes associated with the heating rate diagrams. This investigation utilises empirical findings on the high-temperature decomposition of calcite (case 1) and the low-temperature dehydration of calcium oxalate monohydrate (case 2), applying local thermodynamic analysis to an extensive experimental dataset of the relationship. The analysis shows that the thermodynamic behaviour of these systems depends strongly on heating rate and on the selection of the thermodynamic reference state. For calcite, increasing heating rate leads to a quasi-equilibrium condition characterised by $\Delta G$ approaching zero, whereas for calcium oxalate monohydrate, the observed behaviour reflects the coupled contributions of the chemical dehydration reaction and water-vapour transport. The proposed formulation also reveals the role of the enthalpy–entropy compensation effect in the interpretation of dynamic thermodynamic functions and provides a direct link between phenomenological thermodynamics and thermo-kinetic descriptions. The novelty of the approach lies in demonstrating how fundamental thermodynamic considerations can be transitioned into thermokinetic formulations, thereby opening up new paths for extending the analysis to determine Arrhenius parameters. Full article