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This study presents the design and evaluation of an autonomous landing system for rotary-wing unmanned aerial vehicles (UAVs) targeting moving platforms. The proposed system leverages the UAV’s onboard positional data and the moving platform’s position, velocity and orientation information to execute high-precision landings. By incorporating the GPS coordinates provided by the mobile platform, the operational envelope of the landing procedure is significantly extended. A Kalman filter is employed to fuse the platform’s GPS data with the UAV’s inertial orientation measurements, enabling accurate estimation of a dynamic rendezvous point along the platform’s trajectory. This facilitates the generation of an optimised landing trajectory that minimises path length and enhances energy efficiency.
A YOLOv8-based object detection model is integrated into the system to detect the landing pad in real time. The effectiveness of the proposed method is validated through scenario-based simulations designed to evaluate landing performance under variable altitudes, crosswind disturbances and limited visibility due to fog.
Across 30 independent runs, the proposed method reduced total autonomous landing time by 12% (191 ± 2.0 s → 168 ± 1.6 s, p < 0.001), halved the landing phase (22.9 ± 0.7 s → 11.1 ± 0.7 s), shortened the path by ≍152 m (2035 ± 6.8 m → 1883 ± 3.1 m), and lowered battery consumption from 5.0 ± 0.1% to 4.0 ± 0.1%. The system maintained successful landings under variable wind (up to 6 m/s) and fog with a 7 m detection range, achieving sub-meter touchdown accuracy (RMSE ≍ 0.15 m); at a 5 m detection limit, landings failed, indicating a robustness boundary.
Compared to existing literature, the developed system introduces a novel 3D trajectory planning approach involving altitude variations and dynamic target prediction. The framework is modular and compatible with various UAV and ground vehicle platforms, making it suitable for diverse mission profiles in both civilian and defense applications.
This paper presents the design and analysis of the Triple band Circular Quarter Mode Substrate Integrated Waveguide (QMSIW) 1 × 2 MIMO antenna for sub-6 GHz 5 G wireless applications. The antenna operates at three distinct frequencies those are 3.57GHz, 4.41GHz and 5.43 GHz respectively. The 3.57 GHz used to operate for WiMAX, 5 G, and Fixed Wireless Access, the 4.41 GHz, is often used for specific satellite uplink/downlink operations, Radar Systems and the third one 5.43 GHz is used for Wi-Fi, DSRC, and WLAN systems. The proposed architectural design underwent simulation utilizing electromagnetic (EM) tools to the extract results, followed by antenna fabrication and measured results, it was observed that there is a close match between the simulation, measured results and validated results. The measured, simulation gain values are 5.092dBi,4.98dBi at 3.57 GHz, 4.51dBi,4.6dBi at 4.41 GHz and 3.075dBi,3.06dBi at 5.43 GHz frequency, while also demonstrating satisfactory isolation between the ports, quantified as being less than −15 dB. The characteristic parameters of the MIMO antenna, including a diversity-gain (DG) surpassing 9.95 dB (>9.95 dB), alongside an envelope-correlation-coefficient (ECC) of less than 0.0001, Mean effective gain (MEG) lies between − 3 dB to − 4 dB, among any two radiating elements at every operational frequency, indicate that the antenna has been meticulously designed.
Although it is far from uncharted territory, some contemporary thinkers have been pushing the idea that imagination plays a central role in perception; specifically, as that which explains the phenomenon of perceptual presence. I agree with this general idea. However, there is a tendency among thinkers to place the vague notion of mental imagery at the core of their understanding of what it is to imagine; and attempts to explain perceptual presence in imagistic terms are incompatible with the phenomenology. I will consider another view that attempts to explain perceptual presence in terms of our possession of a form of implicit bodily knowledge of the ways one can access the world. Although it does not encounter the same issues as the imagery view, I will argue that there is much more to the phenomenon of presence than can be accounted for on the access view. I will propose an alternative that can be attributed to Merleau-Ponty. This alternative involves both appeal to a form of bodily knowledge and an imaginative capacity for entertaining the possibility of being situated otherwise; that, when exercised, gives rise to the presence of objects in experience as the objects that they are.
This study aimed to develop a disaster triage training program designed to enhance knowledge, skills, and resilience for disasters among nurses.
Method
A randomized controlled trial was conducted at two government hospitals in Indonesia. One hundred and eight nurses were randomly assigned in equal numbers to the experimental and control groups. The experimental group received a 4-hour triage training focused on mass casualty incidents. Disaster triage knowledge, skills, and resilience were assessed at three time points: before, immediately after, and 1 month following the intervention. Generalized Estimating Equations were used to evaluate the effectiveness of the training program.
Results
The results of this study revealed that nurses in the experimental group showed significantly greater improvements in disaster triage knowledge, skills, and resilience compared to those in the control group at 2 post-test time points. In addition, feedback from trained nurses emphasized its relevance to local disaster scenarios, such as earthquakes and floods, and highlighted the value of hands-on practice and easily accessible learning materials.
Conclusions
The study demonstrates that disaster triage training can effectively enhance nurses’ preparedness for disasters. It is recommended that health care institutions integrate disaster-related content into regular on-the-job training programs for nurses and assess its effectiveness.
We develop a weakly nonlinear theory to revisit the water hammer phenomenon resulting from slow valve manoeuvres. The hydraulic head at the valve is known to be nonlinearly coupled with the flow velocity via a relation derived from Bernoulli’s principle, so that solutions have been so far obtained only via numerical models. The governing equations and boundary conditions indeed yield a nonlinear boundary-value problem, which is here solved using a perturbation approach, Laplace transform and complex analysis. We obtain space- and time-dependent analytical solutions in all of the pipe and validate our results by comparison with standard numerical methods (i.e. Allievi’s method) for determining the exact behaviour of the hydraulic head at the valve. Additionally, we derive algebraic practically relevant closed form expressions for predicting the maximum and minimum hydraulic head values during both valve closure and opening manoeuvres.
An understanding of bird movement and habitat use in breeding and non-breeding areas is critical for the conservation of migratory birds. Latham’s Snipe Gallinago hardwickii breeds in Japan and Russia then migrates more than 6,000 km to its non-breeding sites in Australia. It is at risk because it favours areas under pressure from urban development. We investigated the movement patterns of Latham’s Snipe at a key non-breeding site – Jerrabomberra Wetlands, in Canberra, Australia. We tracked 32 Latham’s Snipe using GPS telemetry devices in the 2022/3 and 2023/4 seasons. The tracked birds remained at Jerrabomberra Wetlands for their non-breeding season and formed distinctive and predictable patterns of roosting and foraging. The distance range between roosting and foraging sites was similar across both the 2022/3 and 2023/4 seasons, with 75% of birds travelling less than 2.5 km and the majority of birds travelling <6 km. Approximately one third (31%) of birds travelled up to 30 km overnight before returning to the wetlands, and two birds (6%) travelled up to 140 km for up to three days. Home range sizes averaged 19 ha and did not significantly differ among individuals in either season. The relatively small size of the home ranges and short foraging trip distances suggest that conservation of non-breeding habitat in urbanised areas can be achieved through the protection of small areas, providing the habitat is suitable. However, individuals varied in their use of the broader landscape and therefore their susceptibility to threats may vary. From an urban planning perspective, habitat protection should prioritise roost sites while ensuring a diversity of foraging habitat within 6 km.
Sitotroga cerealella (Olivier) (Lepidoptera: Gelechiidae) is one of the most serious pests of rice. The variations in phytoconstituents of rice cultivars (Miniket, Cottondora Sannalu, Gobindobhog, Swarna, and Tulaipanji) that led to differences in population growth of S. cerealella were studied. Fitness of the moth was approximated in terms of mean generation time (Tc), net reproductive rate (NRR or R0), intrinsic rate of population increase (rm), etc. Considering potential fecundity (Pf), growth rates, mortality coefficient (MC), and expected population size in the second generation (PF2), we classified the susceptibility of the rice cultivars to S. cerealella in the order as M > C > G > S > T. This was despite the higher concentrations of all the tested primary metabolites (PMs) in C and T. The least susceptibility of T and lower susceptibility of C than M can be attributed to their higher levels of secondary metabolites (SMs). M was highly susceptible due to its lowest SM content and sufficient levels of PMs. Now, G and S contained lower amounts of SMs, but they were moderately susceptible owing to the lower PM content. This emphasises the role of SMs, such as phenols, flavonoids, tannins, saponins, alkaloids, phytates, and oxalates, in determining the susceptibility of crop cultivars. Although none of the rice cultivars were entirely resistant, it can be stated that Miniket requires more protection measures against S. cerealella during storage than the others.
The crucifer flea beetle, Phyllotreta cruciferae (Goeze), and the striped flea beetle, P. striolata (Fabricius) (Coleoptera: Chrysomelidae), are invasive pests to canola, Brassica napus (Linnaeus) (Brassicaceae), in North America. Understanding how temperature and predators influence flea beetle damage in canola is critical for improving current management strategies, yet these factors are rarely studied. We examined the prevalence (proportion of plants damaged), intensity (defoliation of damaged plants), and overall damage (mean defoliation = prevalence × intensity) caused by flea beetles on canola seedlings at different temperatures, plant densities, and with or without generalist predators. Flea beetles preferred to feed on the abaxial (undersides) of cotyledons rather than the typically assessed adaxial (top) side, regardless of temperature, and produced more stem and cotyledon damage at higher temperatures, regardless of the species. Predators Pardosa spp. (Araneae: Lycosidae) and Pterostichus melanarius (Illiger) (Coleoptera: Carabidae) reduced flea beetle abundance and the intensity of cotyledon defoliation. Pterostichus melanarius also reduced overall stem damage, whereas Pardosa spp. reduced stem damage intensity. Under constant flea beetle densities, canola sustained less damage at a higher plant density. These results suggest that reducing the number of flea beetles per seedling, through predation or higher plant density, may help reduce Phyllotreta damage to canola.
This study quantitatively investigates the two-dimensional pseudosteady shock refraction at an inclined air–water interface, referred to as the water wedge, in the weak and strong incident shock strength groups. Numerical simulations are employed to validate the predicted refraction sequences from a previous study (Anbu Serene Raj et al. 2024 J. Fluid Mech.998, A49). A distinctive irregular refraction pattern, referred to as the bound precursor refraction with a Mach reflection, is numerically validated in the weak shock group. Based on the numerical simulations, an enhanced formulation is proposed to determine the sonic line of the incident flow Mach number ($M_b$) in water, thereby providing an appropriate transition condition for an irregular refraction with a Mach reflection to a free precursor refraction with a Mach reflection transition. Furthermore, comparative studies on solid and water wedges of wedge angle $20^\circ$ reveal discernible differences in the shock reflection patterns. The interplay of the energy dissipation due to the transmitted shock wave and the Richtmyer–Meshkov instability at the air–water interface results in the variation of the triple-point trajectory and transition angles between single Mach reflection (SMR) to transitional Mach reflection (TMR) occurring in air.
Time series of counts often display complex dynamic and distributional characteristics. For this reason, we develop a flexible framework combining the integer-valued autoregressive (INAR) model with a latent Markov structure, leading to the hidden Markov model-INAR (HMM-INAR). First, we illustrate conditions for the existence of an ergodic and stationary solution and derive closed-form expressions for the autocorrelation function and its components. Second, we show consistency and asymptotic normality of the conditional maximum likelihood estimator. Third, we derive an efficient expectation–maximization algorithm with steps available in closed form which allows for fast computation of the estimator. Fourth, we provide an empirical illustration and estimate the HMM-INAR on the number of trades of the Standard & Poor’s Depositary Receipts S&P 500 Exchange-Traded Fund Trust. The combination of the latent HMM structure with a simple INAR$(1)$ formulation not only provides better fit compared to alternative specifications for count data, but it also preserves the economic interpretation of the results.
This study presents an innovative system for upper limb rehabilitation, combining a variable stiffness device, the ReHArm prototype, with a dynamic and engaging user interface, known as Arms Rehabilitation Management System. The proposed system offers a highly customisable approach to rehabilitation, ensuring real-time adaptability to patients’ specific needs while maintaining compactness and ease of use. Key features include a modular design allowing precise stiffness adjustments, a robust control architecture, and interactive rehabilitation phases designed to enhance user engagement. Extensive multidisciplinary analyses, including kinematic, dynamic, and structural evaluations, demonstrate the system’s ability to improve therapy effectiveness through tailored interaction and feedback. Validation tests demonstrated the prototype’s reliability and robustness, and initial usability assessments suggest its potential to improve rehabilitation outcomes. Further clinical studies involving patients will be necessary to fully evaluate its therapeutic effectiveness.
The spatio-temporal evolution of very large-scale coherent structures, also known as superstructures, is investigated in both smooth- and rough-wall boundary layers by means of direct numerical simulations up to a frictional Reynolds number of ${\textit{Re}}_\tau = 3\,150$. One smooth-wall and four rough-wall cases are considered, all developing over a region as long as $\sim$60 times the incoming boundary-layer thickness in the streamwise direction. Bio-inspired, biofouling-type topographies are employed for the rough-wall cases, following the previous work of Womack et al. (2022 J. Fluid Mech. vol. 933, p. A38) and Kaminaris et al. (2023 J. Fluid Mech. vol. 961, p. A23). We utilise three-dimensional time series, as well as multiple two-point correlation functions along the boundary layer to capture the detailed length- and time-scale evolution of the superstructures. The results suggest that the presence of roughness significantly amplifies both the strength and the streamwise growth rate of superstructures. Interestingly, however, their ratios relative to the local boundary-layer thickness, $\mathscr{L}_{\!x}/\delta$ and $\mathscr{L}_z/\delta$, remain constant and independent of the streamwise coordinate, indicating that such scaled length scales might constitute a possible flow invariant. Volumetric correlations revealed that all cases induce structures inclined with respect to the mean-flow direction, with those over the rough-wall topographies exhibiting steeper inclination angles. Finally, via proper orthogonal decomposition, pairs of counter-rotating roll modes were detected and found to flank the high- and low-speed superstructures, supporting the conjecture in the literature regarding the mechanisms responsible for the lateral momentum redistribution. The latter also suggests that the way momentum organises itself in high Reynolds number wall-bounded flows might be independent of the roughness terrain underneath.
Obesity is characterised by chronic low-grade inflammation, which is a key factor in the development of obesity-related co-morbidities. Intake of n-3 long-chain PUFAs are associated with anti-inflammatory effects. Recent studies suggest that also n-11 long-chain MUFAs may reduce the concentrations of inflammatory markers, possibly by increasing the biosynthesis of EPA. The primary aim was to investigate if diets added herring oil containing cetoleic acid (CA, C22:1n-11) or a CA concentrate affected the fatty acid composition in tissues from obese rats with chronic inflammation. Secondary aims included investigating the effects on inflammatory markers. Thirty male obese Zucker fa/fa rats were fed diets containing herring oil (HERO) or a CA concentrate (CECO), containing 0.70 or 1.40 wt% CA, respectively, with a comparable content of EPA (0.17 and 0.20 wt%, respectively), or a control diet with soyabean oil for 5 weeks. Data were analysed using one-way ANOVA. CA from HERO and CECO diets were recovered in liver, adipose tissue, muscle and blood cells. The EPA concentration was similar between HERO and CECO groups in tissues, whereas the hepatic concentrations of fatty acid desaturases were lower or similar to Controls. The concentrations of TNFα, matrix metalloproteinase-3, IL6, monocyte chemotactic protein 1 and integrin alpha M in adipose tissue, and the hepatic concentration of CD68 were lower after CECO intake but were not affected by the HERO diet. To conclude, rats fed the CECO diet had lower concentrations of inflammatory and macrophage infiltration markers, but this effect was probably not mediated through increased EPA biosynthesis.