Search Results (1,279)

This paper presents an observer-based strategy for controlling the horizontal trajectories of a hummingbird robot from on-board inertial measurements (MEMS). The centrifugal acceleration resulting from sharp turns is responsible for the dynamic coupling between the roll axis and the pitch and yaw axes. This coupling cannot be accounted for with independent control loops for the three axes; the problem can be solved with a modified state observer (MSO) introduced on the roll axis. Numerical simulations are presented to confirm the idea. The limited additional computational burden allows for real-time implementation. The MSO allows the robot to mimic the behavior of birds that lean towards the inside when turning. Under steady-state conditions (uniform longitudinal velocity and constant yaw rate), the pitch angle is such that the longitudinal component of the gravity vector balances the longitudinal drag force and the roll angle is such that the lateral component of the gravity vector balances the centrifugal acceleration. Full article

This study addresses the lack of quantitative understanding regarding vent-gas combustion feedback in thermal runaway propagation of manganese-based prismatic battery modules. We develop a coupled multiphysics model integrating solid heat transfer, runaway kinetics, gas ejection, and turbulent combustion, informed by constant-volume reactor tests on a single cell that yield a total gas release of 10.6 mol per cell, with H₂ and CO comprising about 49% of combustibles. Model predictions are validated against three-cell module propagation experiments, capturing sequential failure with simulated inter-cell intervals matching experimental repeats that range from 71 to 105 s. The combustion model assumes auto-ignition-based initiation and therefore does not address the stochastic ignition delays observed in the experiments. It is intended for quantifying propagation acceleration once combustion has commenced. Quantitative heat-flow analysis reveals that gas-phase convective and radiative heating contributes substantially to the total heat flux on adjacent cells during venting, and direct comparison between simulations with and without combustion shows that combustion reduces inter-cell propagation intervals by 8–11%, confirming that combustion actively accelerates propagation. Simulations further resolve the combustion zone extending up to 0.4 m laterally. This framework provides a predictive tool and mechanistic basis for vent-gas management and flame-mitigation strategies in battery energy storage systems. Full article

The discovery of energy materials increasingly couples high-throughput computation with machine learning, but the data and models behind a given study are rarely left in a state that lets others, or the original authors months later, re-run or extend the work. IEMAP, Italian Energy Materials Acceleration Platform, was built within the Italian Mission Innovation programme to support the management, analysis and reuse of heterogeneous experimental and computational data on energy materials, with electrochemical storage as its primary use case. Data are organized as projects, each described by structured metadata kept in MongoDB and linked to raw files held in a Ceph object store by content hash. The platform offers interactive access through a web interface and programmatic access through an open-source Python client (iemap-mi) that lets a researcher script ingestion, query and inference together. A trained graph neural network (geoCGNN) is served as an endpoint returning the formation energy and redox potential of a candidate crystal, so the model runs against the same store that holds its inputs. We report a component-level FAIR (Findable, Accessible, Interoperable, Reusable) assessment of the platform, publish the domain ontology that underpins its interoperability, and outline a roadmap towards native semantic querying and knowledge-graph integration. As a demonstration, we reproduce a study of Ni/Ti-doped P2-NaMnO₂ sodium-ion cathodes as a single, openly accessible IEMAP workflow that screens a large compositional space, identifies promising chemistries, and stores all intermediate and final results for reuse. The contribution is the infrastructure that turns a one-off computation-and-ML study into a reusable resource for energy-materials research. Full article

Prolonged sitting and poor posture are linked to musculoskeletal discomfort, higher spinal loading, and lower study and work efficiency. An Arduino-based distributed system combining a multi-sensor was developed for low-cost, camera-free sitting posture monitoring. It comprises a wearable sensing board (WSB), a main control board (MCB), and a host computer. The WSB measures trunk inclination—that is, the forward pitch and lateral roll of the upper trunk relative to the upright reference—using an ADXL345 acceleration sensor, whereas the MCB measures the user-to-desk distance using a US-100 ultrasonic ranging unit; NRF24L01 Wireless Communication Units connect them. Rule-based thresholds classify six states: “normal”, “slouching”, “leaning left”, “leaning right”, “too close”, and “too far”. The Sound Audio Unit and Liquid Crystal Display Unit provide local voice alerts and visual feedback. Using a 4G Unit, the MCB uploads user ID, timestamp, ambient temperature, distance, and posture state to a cloud platform. Cloud-generated text files support host retrieval and display, with accounts for two users and one administrator. The system can determine sitting-distance states within a range of 40–2000 mm and output trunk inclination information over a range of 0–90°. Under the current test conditions, the wireless communication distance between the MCB and WSB exceeds 3 m. In addition, the auditory reminder, time and temperature display, and PC-side data retrieval functions all operate as intended. With a total hardware cost of USD 18.39, the system provides a viable prototype for low-cost, camera-free sitting posture monitoring and remote data management in educational and home settings. Full article

Whether energy-supply crises accelerate decarbonisation or reinforce fossil-fuel dependence remains an open empirical question, particularly in the Middle East and North Africa (MENA). This study examines the 2011 collapse of Egyptian natural gas exports to Jordan, caused by repeated attacks on the Arab Gas Pipeline, as a sudden and largely exogenous energy-security shock. Using harmonised annual electricity-generation data from Ember for six MENA and Mediterranean countries from 2000 to 2022, a panel difference-in-differences framework estimated by two-way fixed effects assesses how Jordan’s renewable electricity share evolved relative to a comparison group. The evidence indicates a delayed rather than immediate response. Event-study estimates show little change between 2012 and 2016, followed by a marked divergence reaching approximately 16 percentage points by 2022. The full-period average difference is 4.22 percentage points (95% CI −2.93 to 11.37), while the later divergence persists across leave-one-country-out specifications and when renewable generation is normalised by pre-crisis system size. Fuel concentration changed little, because Jordan replaced a gas-and-oil generation mix with a gas-and-renewables mix, a shift consistent with a compositional improvement in energy security through reduced fossil-fuel import exposure rather than greater diversification. Energy crises may, therefore, open opportunities for renewable transitions, but their realisation appears contingent on institutional capacity. Full article

Rock–ice avalanches and repeated freeze–thaw cycles pose coupled challenges to baffle-type mitigation structures in high-altitude cold regions. This study used controlled small-scale pull-out tests to quantify changes in baffle–soil friction over 0–30 freeze–thaw cycles and then calibrated a discrete element method (DEM) model to the terminal 30-cycle condition to evaluate baffle geometry, particle size, interparticle cohesion, and pull-out velocity. Moisture redistribution approached equilibrium after approximately 7–10 cycles, whereas the friction response stabilized only after approximately 16 cycles, indicating that hydraulic stabilization preceded mechanical and interfacial stabilization. The friction coefficient decreased from 0.83 before cycling to 0.48 after 30 cycles, corresponding to an attenuation of 42.17%, and the friction force decreased from 130 to 75 N. The decay showed three stages: limited change over 0–3 cycles, accelerated degradation over 3–16 cycles, and a near-plateau thereafter. The DEM results indicate that lateral prop-root projections can increase pull-out resistance by enlarging the mobilized soil volume and enhancing mechanical interlocking; the response also depends nonlinearly on particle size and cohesion. The proposed baffle is therefore presented as a preliminary structural concept rather than a field-ready design. Because the experiments were not performed under complete geometric, kinematic, or dynamic similitude and the DEM calibration represents only one post-freeze–thaw state, the numerical values should be interpreted as laboratory-scale comparative results. Full article

The Chang 7 Member in the Zhidan area of the Ordos Basin is a strategic target for the exploration and development of continental shale oil. However, a systematic understanding of high-resolution sequence stratigraphic division, the spatial distribution of sand bodies and sedimentary facies, sedimentary evolution, and its controlling factors remains insufficient. Guided by high-resolution sequence stratigraphy, this study integrates core observations, well logging, and mud logging data from the Zhidan area. By employing signal processing techniques such as synthetic prediction error filtering analysis and well-to-well profile correlation, a high-precision sequence stratigraphic framework was established. Based on this framework, the spatial distribution of sand bodies and sedimentary facies was meticulously characterized, and the sedimentary evolution process along with its controlling factors was thoroughly discussed. The results indicate that the Chang 7 Member in the Zhidan area was deposited within a complete third-order cycle, which can be further subdivided into two fourth-order cycles. The sedimentary facies are predominantly characterized by a meandering river delta front–lake–turbidite fan system. From the Chang 7₃ to the Chang 7₁ depositional periods, the delta front prograded from north to south toward the center of the lake basin. Concurrently, the sand bodies evolved from thin-bedded deposits to multi-layered stacked and laterally extensive continuous deposits. The sedimentary infilling of the Chang 7 Member was synergistically controlled by tectonic subsidence, paleogeomorphology, paleoclimate, provenance supply, and base-level changes. As the base level transitioned from an accelerated rise to a decelerated rise, the depositional process shifted from retrogradation to progradation. This study not only provides significant insights into the sequence stratigraphy and sedimentary evolution of the Zhidan area but also holds great implications for promoting the exploration and development of continental shale oil and gas. Full article

Chloride ingress is a critical durability concern for cement-based construction materials exposed to marine environments and other chloride-containing conditions, as it can accelerate material degradation and reduce service life. To improve the chloride ingress resistance of mortar containing pre-wetted porous fine aggregate, the effects of internal curing provided by the porous fine aggregate and ion adsorption by calcined layered double hydroxides (CLDHs) on mortar performance were investigated. Compressive strength, pore structure, water-soluble chloride profiles, X-ray diffraction (XRD), and scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM-EDS) were employed to analyze chloride transport and fixation in mortars with different porous fine aggregate replacement ratios and CLDHs contents. The results showed that the pre-wetted porous fine aggregate was beneficial to later-age strength development, which may be associated with its internal water storage and release characteristics, although its effect varied with the replacement ratio. At a replacement ratio of 10%, the pore structure of the mortar remained relatively stable, and the increase in water-soluble chloride content relative to the reference mortar was mainly confined to the near-surface region. By contrast, higher replacement ratios increased the total porosity and the proportions of larger pores and pore throats, thereby promoting chloride migration into the intermediate and deeper regions. CLDHs did not significantly improve the overall pore structure of the mortar, but may have reduced the water-soluble chloride content through structural reconstruction and interlayer fixation. Among the investigated mixtures, the mortar containing 3% CLDHs exhibited the lowest water-soluble chloride content at all tested depths. The pre-wetted porous fine aggregate primarily regulated the pore structure and chloride transport conditions, whereas CLDHs mainly reduced water-soluble chloride content and may contribute to chloride binding. Their combined contributions helped retard chloride migration into the mortar and improve its resistance to chloride ingress. Full article

This paper addresses the lateral path tracking problem for autonomous vehicles operating over a wide speed range by proposing a speed-adaptive horizon model predictive control (SAH-MPC) strategy. Unlike conventional fixed-horizon MPC, the proposed approach schedules both the prediction horizon ${\mathrm{N}}_{\mathrm{p}}$ and the control horizon ${\mathrm{N}}_{\mathrm{c}}$ as explicit functions of the longitudinal speed. This design maintains high tracking accuracy at low speeds while enhancing stability and suppressing oscillations at high speeds. The controller is formulated using a bicycle-model representation of the lateral-yaw dynamics, with online linearization, forward-Euler discretization, and a quadratic programming solver enforcing hard constraints on steering angle and its increment, as well as soft stability constraints on sideslip angle, lateral acceleration, and tire slip angles. A co-simulation framework is established in MATLAB/Simulink and CarSim, and the algorithm is evaluated under double lane-change and slalom maneuvers at speeds from 36 to 90 km/h, with a fixed-horizon MPC (${\mathrm{N}}_{\mathrm{p}}=20$, ${\mathrm{N}}_{\mathrm{c}}=5$) as the baseline. Quantitative comparisons show that at 90 km/h, SAH-MPC reduces the peak lateral error by 33% (from 0.42 m to 0.28 m) and lowers the peak yaw-rate oscillation by 18%. Moreover, it helps maintain the sideslip angle within the prescribed ±4° safety bound, whereas the baseline exceeds this limit with a peak of 5.2°. These results demonstrate that SAH-MPC effectively improves the tracking-stability trade-off across a wide speed range without altering the core MPC structure, offering a simple yet practical enhancement for speed-varying autonomous driving. Full article

Lane-Keeping Assist Systems (LKAS) are widely used in modern passenger vehicles to support lateral vehicle control and reduce the risk of unintended lane departure. Although LKAS performance is commonly evaluated in relation to perception, control, and sensor fusion, the observable vehicle response may also depend on the mechanical condition of the chassis. This study presents a qualitative, measurement-based evaluation of the influence of intentionally introduced front-wheel toe misalignment on the observable response of a production LKAS under controlled proving-ground conditions. Experimental tests were conducted on the highway module of the ZalaZONE proving ground using a Lexus RX 450h equipped with a factory-installed LKAS function. Three front-wheel toe configurations were investigated: factory-specified alignment, single-wheel toe misalignment, and severe toe misalignment affecting both front wheels. Measurements were performed at 70, 90, and 110 km/h on straight and curved road sections. Vehicle speed, steering angle, lateral acceleration, and GNSS-based position data were recorded using CAN- and GNSS/IMU-based data acquisition. The qualitative comparison of the measured signal profiles indicated that the misaligned configurations were associated with a shifted steering-angle operating range and less uniform steering and lateral-acceleration responses. The most pronounced visible differences occurred under the severe toe-misalignment condition, particularly at higher speeds and in the curved section. As the analysis did not include quantitative effect measures or statistical comparisons, these observations are interpreted as exploratory tendencies rather than statistically validated changes in LKAS performance. The findings suggest that front-wheel toe condition should be considered in the measurement-based assessment, maintenance, and calibration of ADAS-equipped vehicles. Full article

Hydrogen-powered heavy-duty vehicles (HHDVs) operating under multiple driving conditions are subjected to coupled longitudinal, vertical, and lateral dynamic excitations, which significantly affect their dynamic performance and rollover stability. To investigate these characteristics, a coupled vehicle dynamic model consisting of a vertical dynamic model and a yaw–roll dynamic model was established, and numerical simulations were conducted under multiple operating conditions. The effects of operating condition, road roughness, initial braking speed, and braking deceleration on ride comfort and dynamic tire load were systematically analyzed. Furthermore, rollover stability was evaluated under J-turn, Fishhook, and Double Lane Change (DLC) maneuvers using yaw rate, slip angle, lateral acceleration, and lateral load transfer ratio (LTR) as evaluation indices. The simulation results show that braking causes the greatest deterioration in ride comfort, with the peak human–seat vertical acceleration increasing by 33.10% compared with the constant-speed condition, while acceleration results in a 27.55% increase. Road roughness substantially affects both ride comfort and dynamic tire load. Under braking, the peak front and rear tire dynamic loads on a Class D road are approximately 3.1 and 2.9 times those on a Class B road, respectively. Increasing the initial braking speed intensifies dynamic responses, whereas increasing the braking deceleration effectively suppresses tire dynamic load fluctuations. Among the three steering maneuvers, the Fishhook maneuver exhibits the highest rollover propensity, with the maximum absolute LTR approaching 0.8. These simulation-based findings provide insights into chassis parameter optimization, vehicle dynamic performance evaluation, and rollover prevention of HHDVs under multiple operating conditions. The present study is limited by the lack of experimental validation of the developed dynamic models, and experimental or hardware-in-the-loop validation will be considered in future work. Full article

Flood forecasting often depends on upstream hydrographs that are unavailable, incomplete, or unreliable. Reverse Flood Routing (RFR) addresses this gap by reconstructing upstream inflows from downstream observations, yet its operational use remains limited by numerical instability, observational uncertainty, and the ill-posed nature of the inverse problem. This review critically synthesizes RFR methodologies across a physics–fidelity continuum, ranging from storage-based and simplified hydraulic models to full hydrodynamic inversions, optimization-based techniques, Bayesian approaches, and emerging data-driven methods. The reviewed approaches are compared in terms of physical realism, numerical stability, computational demand, data requirements, uncertainty treatment, and field applicability. The synthesis indicates that storage-based methods remain attractive for data-limited and computationally constrained applications, whereas full hydrodynamic models are better suited to complex flow conditions involving backwater effects and detailed channel hydraulics. Optimization-based and Bayesian approaches can improve parameter estimation and uncertainty representation, while hybrid AI–physics methods offer promise for computational acceleration but still require stronger physical constraints and broader operational validation. Across all methodological families, error amplification, lateral inflow, transmission losses, and inconsistent benchmarking remain persistent limitations. An integrated framework is therefore proposed to connect observations, model selection, regularization, uncertainty quantification, hybrid computational methods, and operational decision support, providing a roadmap for more reliable and scalable RFR applications. Full article

Background/Objectives: Population aging has emerged as a major global challenge, particularly in Asian countries experiencing rapid demographic transitions. Among them, South Korea represents one of the fastest aging societies in the world, having rapidly transitioned into a super-aged society. As aging populations expand worldwide, increasing attention has been directed toward well-dying as an important component of quality of life, end-of-life care, and social well-being in later life. This study aims to identify the major research trends and knowledge structures of well-dying studies by applying text net-work analysis and LDA-based topic modeling. Methods: A total of 91 Korean academic studies related to well-dying published between 2016 and March 2026 were collected from publicly accessible scholarly databases and analyzed via keyword frequency, degree centrality, and community detection analyses, as well as LDA-based topic modeling. Results: The results showed that keywords such as “death,” “awareness,” “education,” “older adults,” “medical care,” and “life-sustaining treatment” played central roles in the knowledge network. Community analysis revealed that well-dying research has evolved into interconnected domains involving psychological preparations for death, hospice and palliative care, legal and ethical decision-making, and community-based aging policies. Topic modeling further identified four major themes: (1) psychological well-being and death preparation in later life, (2) social and policy approaches to well-dying, (3) well-dying education and healthcare perceptions, and (4) legal and ethical issues surrounding life-sustaining treatment decisions. Conclusions: The findings suggest that well-dying research is expanding from individual psychological adaptation to broader social, medical, legal, and policy dimensions. As one of the world’s fastest-aging societies, the Korean case provides meaningful implications for other countries facing accelerated population aging and highlights the importance of integrated well-dying policies and community-based support systems in super-aged societies. Full article

Mainstream airport runway roughness indices and aircraft–runway coupled vibration studies are constructed under the implicit centreline taxi assumption, leaving the random lateral deviation of the actual aircraft trajectory outside the coupled vibration framework. Existing studies have revealed the importance of lateral deviation from the perspectives of wheel track distribution and cumulative damage; however, these approaches mainly treat lateral deviation as an exogenous statistical input for damage evaluation without embedding it into the aircraft–runway coupled vibration equations to resolve the joint probability evolution of the aircraft, wheel load and pavement responses. Unlike existing centreline- or fixed-wheel-path aircraft–runway coupled vibration models, this study embeds aircraft lateral deviation as a random variable into the wheel–pavement contact coordinates and the displacement–compatibility relation so that the three-dimensional runway roughness input varies randomly with the actual wheel path and further solves the probability distributions of the aircraft-side and pavement-side responses through PDEM. The IPDEM solution was cross-validated against 10,000 Monte Carlo simulations, with PDF shape deviations within 5% and mean/standard deviation within 3%. Results show that the centre-of-gravity acceleration reaches a coefficient of variation (COV) of 47.99% (about 3.7 times the 12.98% induced by aircraft weight randomness alone), and the main-landing-gear dynamic load coefficient COV reaches 1.84% (again, 2.9 times the 0.63% for weight randomness); the pavement bottom strain and vertical displacement attain COVs of 1.50% and 2.03%, respectively. Within the cases and comparison scope of this study, lateral deviation randomness is an important source of dispersion in the aircraft-side responses, and the CGA and DLC variability this induces is higher than that under aircraft weight randomness alone, providing a probabilistic baseline for reliability-based runway design and full-cross-section roughness evaluation. Full article

Numerical simulations are conducted to investigate the near-bed flow behaviors of submarine canyons with periodic ridge-valley topography on continental slopes. In the numerical simulation, two topographic parameters are defined: α represents the basal slope angle of the continental slope, and β denotes the side slope angle of the submarine canyon. The topographic modulation of these two parameters on near-bed flow velocity and pipeline on-bottom stability is explored. The results show that the ribbed slope exerts two distinct modulation mechanisms on near-bed flow fields, which are governed by the relative angle between incoming flow and ridge-valley structures. When the flow is perpendicular to the canyon axis (θ = 0°), local topographic contraction and expansion accelerate flow over ridge crests and reduce near-bed velocity in valleys as β increases. In contrast, when the flow is parallel to the canyon (θ = 90°), lateral confinement by bilateral ridges forms a topographic channel, leading to persistent flow acceleration throughout the entire valley area. Moreover, such directional velocity differences substantially alter the on-bottom stability of pipelines deployed within the canyon. Two pipe-soil interaction models are employed in the stability analysis: the Verley-Lund model for a flat clayey seabed and the Slope-Silt model for a sloping silty seabed. The sensitivity of their predictions to soil undrained shear strength is further evaluated. Full article