Search

Purpose: To compute reference centiles for 5- and 30-m sprint times relative to chronological and skeletal age in youth soccer players. Subsequently, to compare individual's sprint performance scores derived from the chronological and skeletal age reference centiles. Methods: Sprint times were collected for a sample of male U11 to U19 soccer players (n = 1745 data points). Skeletal age data were available for a subsample (n = 776 data points). Reference centiles were fitted using generalized additive models for location, scale, and shape. Individual z scores relative to chronological and skeletal age reference centiles were computed and compared for each maturity group (late, on-time, early, and very early) using standardized mean differences (SMD). Results: Reference centiles for chronological age increased more rapidly between 10.5 and 15.5 years, while reference centiles for skeletal age increased more rapidly between 13.0 and 16.5 years. Differences in chronological and skeletal z scores for very early (SMD: −0.73 to −0.43) and late (SMD: 0.58 to 1.29) maturing players were small to large, while differences for early (SMD: −0.30 to −0.19) and on-time (SMD: 0.16 to 0.28) were trivial to small. Conclusion: Reference centiles provide a valuable tool to assist the evaluation of sprint performance in relation to chronological and skeletal age for talent identification purposes in youth soccer players. [ABSTRACT FROM AUTHOR]

A standing wave induced in front of the ionization-front of a millimeter-wave discharge was numerically investigated to develop an interferometric discharge structure identification method. The time-varying waveform of the standing-wave intensity obtained at a distant observation point was smooth when a continuous comb-shaped structure was formed, whereas it was noisy with high-frequency components when a discrete structure was formed. The peak frequency of the Fourier spectrum of the time-varying waveform was proportional to the ionization-front propagation speed. The rapid time-variation of the waveform was caused by an increase in millimeter-wave absorption in a new plasma spot formation in the discrete structure. The results suggest that discharge structure identification, measurement of ionization-front propagation, and timing of plasma spot formation can be conducted experimentally without using a high-speed camera. [ABSTRACT FROM AUTHOR]

Purpose: Postactivation performance enhancement (PAPE), which refers to the phenomena associated with the attainment of enhanced performance in sport-specific tasks after a conditioning activity, is an important objective of warming-up practices in many sports. This is even more relevant for sprinters, as potential increases in sprinting speed will directly influence their competitive results. This systematic review with meta-analysis evaluated the effects of different PAPE protocols (ie, using plyometrics, strength-power exercises, and resisted/assisted sprints) on the sprinting performance (ie, sprint time or sprint speed) of competitive sprinters. Methods: Initially, 1205 records published until last December 18 were identified, using the following databases: PubMed/MEDLINE, Scopus, and Clarivate Web of Science. After removing duplicates and screening titles and abstracts, 14 high-quality studies met the inclusion criteria for the meta-analysis. Results: Overall, there were no significant changes in sprint performance after implementing various types of conditioning activities (standardized mean difference [SMD] = 0.16 [95% CI, −0.02 to 0.33]; Z = 1.78; P =.08; I2 = 0%). In addition, when comparing prechanges and postchanges between experimental, control, and other conditions, no significant differences were found in sprint speed or time across all studies (SMD = 0.09 [95% CI, −0.10 to 0.28]; Z = 0.92; P =.36; I = 0%). Conclusions: Results revealed that different types of conditioning activities may not be capable of acutely enhancing the sprint speed of competitive sprinters. This aligns with previous observations indicating that sprinting is a highly stable physical capacity, a phenomenon that is even more consistent among elite sprinters. Coaches and sport scientists should collaborate to develop more efficient PAPE protocols for these highly specialized athletes, with special attention to study design and individualization, while considering their effects on acceleration versus top speed. [ABSTRACT FROM AUTHOR]

This study aimed to determine the acute effects of static stretching of the hamstrings on maximal sprint speed and its spatiotemporal variables and lower-limb kinematics during the late swing phase, as well as the relationship with Nordic hamstring strength. The study had a within-participant experimental design. Sixteen healthy male college sprinters were asked to sprint 80 m without static stretching and with static stretching of the hamstrings for 4 x 30 s per leg before the sprint: both conditions were counterbalanced. The knee ftexion peak torque was measured using the Nordic hamstring. The differences between no static stretching and static stretching as well as their relationship with Nordic hamstri ng strength were investigated. The results showed that the touchdown distance (p = .036) significantly increased following static stretching. Although not significant. maximal sprint speed decreased (p = .086), and the theoretical hamstring length (difference between knee angle and hip angle) at ipsilateral touchdown was greater (p =.069) following static stretching. In addition, a lower peak torque of the Nordic hamstring resulted in a more significant decrease in maximal sprint speed following static stretching. Therefore, static stretching of the hamstring just before sprinting may increase the theoretical hamstring length during the late swing phase at maximal sprint speed and induce kinematics that increases the hamstring strain injury risk. Moreover, it is suggested that improving the Nordic hamstring strength may help minimize the negative effects of static stretching on the hamstrings. [ABSTRACT FROM AUTHOR]

This work extends the energy-efficient job shop scheduling problem with transport resources by considering speed adjustable resources of two types, namely: the machines where the jobs are processed on and the vehicles that transport the jobs around the shop-floor. Therefore, the problem being considered involves determining, simultaneously, the processing speed of each production operation, the sequence of the production operations for each machine, the allocation of the transport tasks to vehicles, the travelling speed of each task for the empty and for the loaded legs, and the sequence of the transport tasks for each vehicle. Among the possible solutions, we are interested in those providing trade-offs between makespan and total energy consumption (Pareto solutions). To that end, we develop and solve a bi-objective mixed-integer linear programming model. In addition, due to problem complexity we also propose a multi-objective biased random key genetic algorithm that simultaneously evolves several populations. The computational experiments performed have show it to be effective and efficient, even in the presence of larger problem instances. Finally, we provide extensive time and energy trade-off analysis (Pareto front) to infer the advantages of considering speed adjustable machines and speed adjustable vehicles and provide general insights for the managers dealing with such a complex problem. [ABSTRACT FROM AUTHOR]

This study aims to analyze the effects of a training program based on practice variability on the speed and accuracy of the tennis forehand approach to the net shot. The study sample consisted of 35 players of both genders, 22 men and 13 women Cage 44 ± 10.9 years, height 1.73 ± 0.8 cm, and weight 74.7 ± 8,4 kg) Players were randomly distributed into two groups (control group = 18 and experimental group = 17). Both training groups worked a total volume of 4 weeks, seven sessions, and 15 min per session of forehand approach shot. Control group performed traditional training while experimental group trained with variability using wristband weights. The data obtained showed a large Group x Time interaction in the accuracy of the forehand approach shot, F(1, 16) = 28.034, p <.001. η =.637. Only the experimental group increased significantly in the accuracy after the program (51.4%. effect size = 1.3. p < .001). while no changes were achieved regarding hitting speed (1.2%, effect size =0.12, p=.62). The control group did not improve iii any of the tested variables. These results indicate that variability of training using wrist weights is a valid option to improve forehand approach shot accuracy in recreational-level players. Although stroke speed was not increased. this type of training may be interesting as accuracy and technical control is commonly the main goal of training at this level. [ABSTRACT FROM AUTHOR]

Purpose: To compare the effects between resisted sled sprint training (RSS) and unresisted sprint training (URS) on sprint and acceleration performance, vertical jump, and maximal strength during an 8-week period of preseason training. Methods: Twenty-six recreational active rugby players were randomly divided into either RSS or URS training groups and then performed 8 weeks of training, 2 sessions/wk of sprint-specific training program. The RSS group performed sprints by towing a sled overloaded with 12.6% of body mass for 2 of the 3 sets of 3 × 20-m sprints, plus one set was carried out with unresisted modality. The URS groups performed 3 sets of 3 × 20-m unresisted sprints. The measures of 10- and 30-m sprint times, vertical jump, and 3-repetition-maximum (3-RM) squat tests were performed at baseline and after 8 weeks. Results: Ten- and 30-m sprint times (P <.05 and η p 2 >.44) improved significantly more in RSS than in URS. Both groups improved significantly in vertical jump and 3-RM squat tests; however, no significant differences (P >.1 and η p 2 <.11) between groups were found. Conclusions: Our findings indicate that an 8-week program of RSS is more effective than URS for enhancing sprint time performance in male recreational active rugby players. In addition, these data suggest that a sled overload corresponding to 12.6% of body mass can induce positive effects on both acceleration and speed performance in recreational active rugby players. [ABSTRACT FROM AUTHOR]

We report on efforts to improve the speed of low-G far-infrared transition-edged-sensed bolometers. We use a fabrication process that does not require any dry etch steps to reduce heat capacity on the suspended device and measure a reduction in the detector time constant. However, we also measure an increase in the temperature-normalized thermal conductance (G) and a corresponding increase in the noise-equivalent power (NEP). We employ a new near-IR photon-noise technique using a near-IR laser to calibrate the frequency-domain multiplexed AC system and compare the results to a well-understood DC circuit. We measure an NEP white noise level of 0.8 aW/rtHz with a 1/f knee below 0.1 Hz and a time constant of 3.2 ms. [ABSTRACT FROM AUTHOR]

Taking advantage of the gradual change characteristic of the curvature of the conventional conic ellipse, this paper proposes a method of fitting a non-uniform rational B-spline (NURBS) curve with an elliptical arc and, thereafter, performing speed planning and interpolation of the elliptical arc itself. First, the method of elliptical arc fitting is introduced and then proven by simulation with comparative previous linear and arc fittings to obtain better fitting accuracy with fewer segments. Subsequently, the tangent vector of any point of an ellipse is used to complete the speed planning and interpolation of that ellipse. In terms of speed planning, the maximum acceleration of any point in the elliptical arc can be obtained by using a tangent vector, and the time speed curve in this work is completed based on this phenomenon. In the interpolation stage, the longest axis of the current point is determined by using the tangent vector of any point of the elliptical arc, according to which the pulse is sent, thereby completing the interpolation operation via this iterative cycle. This method unifies the processing model of the interpolation algorithm, the simplicity and efficiency of which is verified by subsequent simulation data. This method can also be universally applied to processing most other types of curve. [ABSTRACT FROM AUTHOR]

High‐time‐resolved mapping results of two rare reactivation processes following a negative return stroke are discovered and analyzed. At first, the discharges prior to the reactivation process were dominated by positive discharges lasting for tens of milliseconds in a limited space in the vicinity of a decayed negative leader channel. The positive discharges produced no detectable electric field change. Then, negative discharges started and propagated along the decayed downward negative leader channels at a speed exceeding 106 m/s for a few microseconds and produced negative electric field changes. The analysis reveals that the processes are physically distinct from recoil leaders and side discharges in terms of propagation behaviors, electromagnetic characteristics, and time scale. The possible mechanisms of the processes are discussed. The observation suggests that the reactivation processes of the negative leaders may lead to subsequent return strokes. Plain Language Summary: A hot topic in lightning research is how extinguished leader channels are reactivated. In recent years, the process of recoil leader reactivating the decayed positive leader channel has been extensively discussed. However, the reactivation process of the negative leader channel is not yet well understood. This paper reports the observation results of two reactivation processes of decayed negative leader channels following a negative return stroke. The discharges prior to the reactivation processes developed continuously for several tens of milliseconds and were dominated by positive discharges. Then, negative discharges started and transferred negative charges to the decayed grounding stroke channel within tens of microseconds. We describe the fact that the process is a new discharge process that does not fall within the scope of recoil leader or side discharge. However, the negative reactivation process may lead to subsequent return stroke, which has a similar effect to the recoil leader. Key Points: Two reactivation processes of decayed negative leaders were triggered following a negative return strokePositive discharges prior to the reactivation process lasted for tens of milliseconds and produced weak VHF radiationsThe negative discharges propagated along decayed negative leader channels for a few microseconds and produced electric field change [ABSTRACT FROM AUTHOR]

Raindrop fall speed increases with raindrop size. Because larger raindrops fall through a given layer of the atmosphere more quickly compared to smaller raindrops, they spend less time in the layer and, therefore, have less time to be acted on and advected by the storm‐relative winds. This results in hydrometeor size sorting which impacts the polarimetric radar variables such as differential reflectivity ZDR $\left({Z}_{DR}\right)$ and specific differential phase KDP $\left({K}_{DP}\right)$. Previous work has shown a strong correlation between the mean storm‐relative wind in the sorting layer and the separation between regions of enhanced ZDR ${Z}_{DR}$ and KDP ${K}_{DP}$ at the bottom of the sorting layer. This study leverages this finding, along with a simple size sorting model, to construct radar‐derived estimates of the storm‐relative wind profile. The radar‐derived "pseudo‐hodographs" are well‐correlated with the magnitude and direction of the corresponding storm‐relative wind profiles. Further, these radar‐derived estimates of the storm‐relative winds are used to calculate estimates of shear and storm‐relative helicity, which also exhibit a strong correlation. Plain Language Summary: Large raindrops fall through a given layer of the atmosphere more quickly and, therefore, spend less time in the layer compared to small drops. This impacts weather radar variables and two of them are featured in this study. A simple model of raindrop fallout and motion is used to show that the change in a radar signature between two heights serves as a good estimate for the wind between those two heights. Additionally, these estimated winds can be used to calculate estimates of metrics related to the vertical wind profile. Key Points: The storm‐relative wind profile can be estimated by analyzing hydrometeor size sorting signaturesThe change in the size sorting signature between two heights is highly correlated with the storm‐relative wind between those heightsMetrics such as shear and storm‐relative helicity can be estimated using the radar‐derived estimates of the storm‐relative wind profile [ABSTRACT FROM AUTHOR]

Accurate prediction of the future trajectories of traffic agents is a critical aspect of autonomous vehicle navigation. However, most existing approaches focus on predicting trajectories from a static roadside perspective, ignoring the influence of autonomous vehicles' future plans on neighboring traffic agents. To address this challenge, this paper introduces EPG‐MGCN, an ego‐planning‐guided multi‐graph convolutional network. EPG‐MGCN leverages graph convolutional networks and ego‐planning guidance to predict the trajectories of heterogeneous traffic agents near the ego vehicle. The model captures interactions through multiple graph topologies from four distinct perspectives: distance, visibility, ego planning, and category. Additionally, it encodes the ego vehicle's planning information via the planning graph and a planning‐guided prediction module. The model is evaluated on three challenging trajectory datasets: ApolloScape, nuScenes, and next generation simulation (NGSIM). Comparative evaluations against mainstream methods demonstrate its superior predictive capabilities and inference speed. [ABSTRACT FROM AUTHOR]

Existing segmentation-based text detection methods generally face the problems of insufficient receptive fields, insufficient text information filtering, and difficulty in balancing detection accuracy and speed, limiting their ability to detect arbitrary-shaped text in complex backgrounds. To address these problems, we propose a new text detection method fusing the pure ConvNet model InceptionNeXt and the multi-scale attention mechanism. Firstly, we propose a text information reinforcement module to fully extract effective text information from features of different scales while preserving spatial position information. Secondly, we construct the InceptionNeXt Block module to compensate for insufficient receptive fields without significantly reducing speed. Finally, the INA-DBNet network structure is designed to fuse local and global features and achieve the balance of accuracy and speed. Experimental results demonstrate the efficacy of our method. Particularly, on the MSRA-TD500 and Total-text datasets, INA-DBNet achieves 91.3% and 86.7% F-measure while maintaining real-time inference speed. Code is available at: https://github.com/yuyu678/INANET. [ABSTRACT FROM AUTHOR]

This paper is concerned with the propagation phenomena for the nonlocal reaction-diffusion monostable equation with delay of the form ∂ u (t , x) ∂ t = d Δ u (t , x) + f (u (t , x) , ∫ R J (x − y) u (t − τ , y) d y) , t > 0 , x ∈ R. It is well-known that if we take J (x) = δ (x) and τ = 0 , there exists a minimal wave speed c ⁎ > 0 , such that this equation has no traveling wave front for 0 < c < c ⁎ and a traveling wave front for each c ≥ c ⁎ , which is unique up to translation and is globally asymptotically stable. Furthermore, when J is symmetry and exponentially bounded and τ > 0 , Wang et al. (2008) [27] considered the effects of delay and nonlocality on the spreading speed and proved that (i) if ∂ 2 f (0 , 0) > 0 , then the delay can slow the spreading speed of the wave fronts and the nonlocality can increase the spreading speed; and (ii) if ∂ 2 f (0 , 0) = 0 , then the delay and nonlocality do not affect the spreading speed. However, when J is asymmetry or exponentially unbounded , the question was left open. In this paper we obtain a rather complete answer to this question. More precisely, we show that for exponentially bounded kernels the minimal speed of traveling waves exists and coincides with the spreading speed. We also investigate the case of exponentially unbounded kernels where we prove the non-existence of traveling wave solutions and obtain upper and lower bounds for the position of any level set of the solutions. These bounds allow us to estimate how the solutions spread, depending on the kernels. [ABSTRACT FROM AUTHOR]

Racing performance traits are the main indicators for evaluating the performance and value of sport horses. The aim of this study was to identify the key genes for racing performance traits in Yili horses by performing a genome-wide association study (GWAS). Breeding values for racing performance traits were calculated for Yili horses (n = 827) using an animal model. Genome-wide association analysis of racing performance traits in horses (n = 236) was carried out using the Blink, and FarmCPU models in GAPIT software, and genes within the significant regions were functionally annotated. The results of GWAS showed that a total of 24 significant SNP markers (P < 6.05 × 10− 9) and 22 suggestive SNP markers (P < 1.21 × 10− 7) were identified. Among them, the Blink associated 16 significant SNP loci and FarmCPU associated 12 significant SNP loci. A total of 127 candidate genes (50 significant) were annotated. Among these, CNTN6 (motor coordination), NIPA1 (neuronal development), and DCC (dopamine pathway maturation) may be the main candidate genes affecting speed traits. SHANK2 (neuronal synaptic regulation), ISCA1 (mitochondrial protein assembly), and KCNIP4 (neuronal excitability) may be the main candidate genes affecting ranking score traits. A common locus (ECA1: 22698579) was significantly associated with racing performance traits, and the function of the genes at this locus needs to be studied in depth. These findings will provide new insights into the detection and selection of genetic variants for racing performance and will help to accelerate the genetic improvement of Yili horses. [ABSTRACT FROM AUTHOR]

Superior ultraviolet photodetectors (UVPDs) with fast response speed and high responsivity are essential for UV communication, intelligent sensing, advanced manufacturing, and more. Various studies have demonstrated the excellent performance of traditional UVPDs based on wide bandgap semiconductors (WBSs). However, these devices often suffer from a relatively slow response speed due to the defect states within WBSs. In this work, a new short channel non‐WBS UVPD is developed using the vertically stacked short channel PtSe2/ultrathin‐Si UVPD. The heterojunction is stacked by the 200 nm thick Si flake that exfoliates from a Silicon‐on‐Insulator (SOI) wafer by wet etching and the wafer‐scale CVD ‐grown PtSe2 via the mature PDMS stamp transfer protocols. The absorption in the Si layer, which depends on the incident wavelength, shows a strong correlation with the device photocurrent response. Under 365 nm illumination, the vertical device exhibits a fast UV response speed up to 51.8/73.6 µs. This performance outperforms that of conventional lateral structures and many WBS‐based UVPDs, largely attributed to the extremely short transport distances of photogenerated carriers and the superior physical characteristics of Si. This study shows that ultrathin‐Si is a promising building block for fast speed UVPDs, which are vital for UV optoelectronic applications. [ABSTRACT FROM AUTHOR]

In this paper, we propose a novel voxel-based 3D single object tracking (3D SOT) method called Voxel Pseudo Image Tracking (VPIT). VPIT is the first method that uses voxel pseudo images for 3D SOT. The input point cloud is structured by pillar-based voxelization, and the resulting pseudo image is used as an input to a 2D-like Siamese SOT method. The pseudo image is created in the Bird's-eye View (BEV) coordinates; and therefore, the objects in it have constant size. Thus, only the object rotation can change in the new coordinate system and not the object scale. For this reason, we replace multi-scale search with a multi-rotation search, where differently rotated search regions are compared against a single target representation to predict both position and rotation of the object. Experiments on KITTI [1] Tracking dataset show that VPIT is the fastest 3D SOT method and maintains competitive Success and Precision values. Application of a SOT method in a real-world scenario meets with limitations such as lower computational capabilities of embedded devices and a latency-unforgiving environment, where the method is forced to skip certain data frames if the inference speed is not high enough. We implement a real-time evaluation protocol and show that other methods lose most of their performance on embedded devices; while, VPIT maintains its ability to track the object. [ABSTRACT FROM AUTHOR]

Armed conflicts, pandemics or natural disasters often necessitate rapid, coordinated responses by international organisations (IOs) to avoid escalation or loss of life. However, effective analytical tools to assess and compare the speed of these responses are lacking. This paper introduces a framework for evaluating IO crisis response speed, with the aim of better understanding which IOs are best equipped to offer rapid crisis responses and which are not. I propose a three-stage model that measures the time for IOs to (a) recognise a crisis, (b) decide on measures and (c) implement these measures, while also accounting for variations in levels of precision and obligation. Using empirical insights from the 2014 Ebola outbreak in West Africa, I demonstrate how this model can generate data that can improve our understanding of the performance of IOs as crisis managers and foster discussions on enhancing the speed and efficiency of multilateral responses during crises. [ABSTRACT FROM AUTHOR]

Introduction: This observational study investigated: (1) potential changes in female football players' in-season training load, intensity and physical performance, and (2) if in-season accumulated training load, intensity, or their progression are associated to changes in physical performance. Methods: Thirty-five national level female players (∼21 years, n = 35) from three top-teams of the Finnish national league participated. Players performed tests at the beginning and at the end of the 27-week in-season. Tests were: 30-m sprint, countermovement jump (CMJ) and 1,200-m shuttle run, used to calculate maximal aerobic speed (MAS). Players' external and internal training load and intensity were monitored in all on-field training sessions and official matches (3,941 data samples) using Polar Team Pro system. Results: Training load decreased towards the end of the in-season (p < 0.05), but intensity remained stable. No changes in physical performance test results occurred from before to after in-season tests at a group level. Change of CMJ correlated negatively with accumulated training load, intensity and progression of total distance (TD) and low-intensity running distance (LIRD) (r = −0.398 to −0.599, p < 0.05). Instead, development of MAS correlated positively with progression of TD and LIRD intensities (r = 0.594 and 0.503, p < 0.05). Development of both CMJ and MAS correlated positively with intensity progression of very-high-intensity running distance (VHIRD) and number of accelerations and decelerations (r = 0.454–0.588, p < 0.05). Discussion: Reduced training load over the in-season is not detrimental for players' physical performance when training intensity progressively increases. Intensity progression of VHIRD, moderate- and high-intensity accelerations and decelerations are indicators of both MAS and CMJ development, respectively. [ABSTRACT FROM AUTHOR]

Linear induction motors (LIMs) are positioned head-to-tail in medium and low-speed maglev (MLSM) trains, and the interaction due to small spacing between two LIMs is not yet clear. In this work, based on the 2D electromagnetic field theory, the vector magnetic potential (VMP) of each region was solved, and the traction forces of two adjacent LIMs were derived. Subsequently, the correctness of the theoretical model was verified by simulation. Finally, the effects of the spacing, wiring type, pole pitch, speed, etc., on the traction forces of two adjacent LIMs were analyzed. The results show that the traction force of LIM1 (arranged in front) is almost unaffected by LIM2 (arranged behind LIM1), while that of LIM2 fluctuates periodically with the spacing, and the smaller the spacing, the greater the fluctuation amplitude. Meanwhile, the larger the pole pitch, the more the pole number, the greater the slip frequency, and the lower the speed, the smaller the effect of LIM1 on LIM2. When the spacing takes 1.1 to 1.6 times the pole pitch, the traction force of LIM2 is larger than that of LIM1. The achievements can provide technical support for enhancing the traction performance of the LIMs in the MLSM trains. [ABSTRACT FROM AUTHOR]

In two experiments, we explored whether cross-modal cues can be used to improve foraging for multiple targets in a novel human foraging paradigm. Foraging arrays consisted of a 6 × 6 grid containing outline circles with a small dot on the circumference. Each dot rotated from a random starting location in steps of 30°, either clockwise or counterclockwise, around the circumference. Targets were defined by a synchronized rate of rotation, which varied from trial-to-trial, and there were two distractor sets, one that rotated faster and one that rotated slower than the target rate. In Experiment 1, we compared baseline performance to a condition in which a nonspatial auditory cue was used to indicate the rate of target rotation. While overall foraging speed remained slow in both conditions, suggesting serial scanning of the display, the auditory cue reduced target detection times by a factor of two. In Experiment 2, we replicated the auditory cue advantage, and also showed that a vibrotactile pulse, delivered to the wrist, could be almost as effective. Interestingly, a visual-cue to rotation rate, in which the frame of the display changed polarity in step with target rotation, did not lead to the same foraging advantage. Our results clearly demonstrate that cross-modal cues to synchrony can be used to improve multitarget foraging, provided that synchrony itself is a defining feature of target identity. [ABSTRACT FROM AUTHOR]

A vortex pair solution of the incompressible 2 d Euler equation in vorticity form ω t + ∇ ⊥ Ψ ⋅ ∇ ω = 0 , Ψ = (− Δ) − 1 ω , in R 2 × (0 , ∞) is a travelling wave solution of the form ω (x , t) = W (x 1 − c t , x 2) where W (x) is compactly supported and odd in x 2. We revisit the problem of constructing solutions which are highly concentrated around points (0 , ± q) , more precisely with approximately radially symmetric, compactly supported bumps with radius ε and masses ± m. Fine asymptotic expressions are obtained, and the smooth dependence on the parameters q and ε for the solution and its propagation speed c are established. These results improve constructions through variational methods in [14] and in [5] for the case of a bounded domain. [ABSTRACT FROM AUTHOR]

Background: Dissemination and implementation science is an evolving field that focuses on the strategies and mechanisms by which scientific evidence is adopted, used, and sustained in clinical and community practice. Main body: Implementation scientists are confronted by the challenge to balance rigor and generalizability in their work while also attempting to speed the translation of evidence into clinical and community practice. Hybrid Effectiveness-Implementation studies and the RE-AIM framework were conceptualized to address these challenges. Hybrid Effectiveness-Implementation (HEI) studies provide methods of examining the effectiveness of health promoting interventions while concurrently assessing the utility of dissemination and implementation strategies designed to enhance the application of evidence-based principles in practice. RE-AIM provides a set of planning and evaluation dimensions that can be assessed with a goal to balance internal and external validity. The purpose of this commentary is to provide clarity on definitions of each approach and how to effectively use them together to answer research questions that will advance dissemination and implementation science for health promotion. Conclusions: We provide examples of concerted use of RE-AIM within HEI studies from the literature and focus on language to provide a clarity and consistency across research questions, designs, and settings. We share how to operationalize RE-AIM dimensions in HEI studies for both dissemination and implementation strategies. Future directions include refining, defining, and evaluating each RE-AIM dimension within hybrid studies. [ABSTRACT FROM AUTHOR]

Abrupt changes in speed due to external disturbances can occur during human gait. Insight into the gait compensation mechanism is necessary to examine gait stability in the context of unexpected speed changes. The present study investigated the effect of speed changes on overall gait patterns under three different walking speed conditions. Dynamic time warping (DTW) and cross-correlation techniques were used, revealing that similarity of gait kinematics decreased at slower gait speed compared to preferred and faster speeds. These results suggest that individuals may encounter difficulties in maintaining gait stability at slower speed than normal and faster speeds. Additionally, at the moment when speed changes occur, the similarity of gait patterns significantly decreases, as indicated by higher DTW and cross-correlation values. This insight could assist clinicians and physical therapists in gaining an understanding of overall gait patterns during unexpected speed changes and developing assistive devices to prevent slips, trips, and falls. [ABSTRACT FROM AUTHOR]

Dependency between the conventional imbalance diagnostic feature and the shaft rotational speed makes imbalance diagnosis challenging for variable-speed machines. This paper focuses on an investigation of this dependency and on a proposal for a novel imbalance diagnostic feature and a novel simplified version for this feature, which are independent of shaft rotational speed. An equivalent mass–spring–damper system is investigated to find a closed-form expression describing this dependency. By normalizing the conventional imbalance diagnostic feature by the obtained dependency, a diagnostic feature is proposed. By conducting comprehensive experimental trials with a wind turbine with a permissible imbalance, it is justified that the proposed simplified version of imbalance diagnostic feature is speed-invariant. [ABSTRACT FROM AUTHOR]

Smartphone-based location estimation technology is becoming increasingly important across various fields. Accurate location estimation plays a critical role in life-saving efforts during emergency rescue situations, where rapid response is essential. Traditional methods such as GPS often face limitations in indoors or in densely built environments, where signals may be obstructed or reflected, leading to inaccuracies. Similarly, fingerprinting-based methods rely heavily on existing infrastructure and exhibit signal variability, making them less reliable in dynamic, real-world conditions. In this study, we analyzed the strengths and weaknesses of different types of wireless signal data and proposed a new deep learning-based method for location estimation that comprehensively integrates these data sources. The core of our research is the introduction of a 'matching-map image' conversion technique that efficiently integrates LTE, WiFi, and BLE signals. These generated matching-map images were applied to a deep learning model, enabling highly accurate and stable location estimates even in challenging emergency rescue situations. In real-world experiments, our method, utilizing multi-source data, achieved a positioning success rate of 85.27%, which meets the US FCC's E911 standards for location accuracy and reliability across various conditions and environments. This makes the proposed approach particularly well-suited for emergency applications, where both accuracy and speed are critical. [ABSTRACT FROM AUTHOR]

Anomaly detection has significant importance for the development of autonomous monitoring systems. Real-world anomalous events are complicated due to diverse human behaviors and class variations. Anomalous activities depend upon speed, length of activity, and motion features to comprehend suspicious behaviors. Fast activities are captured quickly within a few video frames, whereas slow actions may take several hundred video frames to define an anomalous action. Furthermore, a video is more than just a stack of frames with spatiotemporal representations. Most of the existing approaches suffer from learning variable speed fast and slow activities simultaneously and primarily focus on learning spatiotemporal features only. Modeling the spatiotemporal and motion relationships between frames together can help understand the actions better. Motion features when combined with spatiotemporal representations perform higher. Our contribution is two-fold in this research work. Firstly, a novel dynamic frame-skipping approach is proposed to duly generate meaningful representations of spatiotemporal frames and optical-flow-based motion representations for variable speed anomalous actions. Secondly, AnomalyNet, as a new end-to-end deep architecture, is designed to simultaneously learn both spatiotemporal and motion features in image sequences. AnomalyNet is evaluated on the challenging real-world anomaly detection datasets. The results confirm that the proposed model has achieved a competitive AUC of 86.1% on the real-world UCF-Crime dataset and has achieved a superior AUC score of 99.87% compared to state-of-the-art methods on challenging ShanghaiTech dataset in the domain of unsupervised, weakly-supervised, and fully-supervised anomaly detection. Furthermore, the model achieved the highest F1 score for both fast and slow variable speed anomalous activities, such as explosions, road accidents, robbery, and stealing for real-world autonomous surveillance. [ABSTRACT FROM AUTHOR]

We propose an automatic layout method for indoor scenes that effectively satisfies specific constraints. Our approach involves enhancing the existing scene representation method to accommodate complex constraints, including the precise placement of doors, windows, and user-specified furniture. To achieve this, we construct a conditional vector that encapsulates the necessary constraints. Moreover, our automatically constrained layout approach is implemented by training a conditional variational autoencoder model. Given the constraints and randomly sampled vectors, the decoder module can generate diversified reasonable indoor layout results. Evaluations show that our model outperforms the existing methods. Furthermore, our model exhibits a lower parameter count and faster execution speed compared with the existing approaches. [ABSTRACT FROM AUTHOR]

The exact solutions for the Navier–Stokes–Fourier equations in the case of plane shock waves for dilute monatomic gases with constant transport coefficients were found by Becker in 1922. The solutions obtained are limited for a Prandtl's number given by Pr=3/4$Pr=3/4$. Besides the solutions for the speed and temperature, profiles were given in an implicit way. In this paper, we consider Becker's model to find some exact explicit solutions for dilute polyatomic gases. [ABSTRACT FROM AUTHOR]

A multirotor unmanned aerial vehicle (UAV) slung load system (SLS) is a nonlinear dynamics with eight degrees of freedom and four inputs that can be used for load transportation. The suspended payload can be modelled as a two degree-of-freedom pendulum attached to the UAV. This paper presents a path-following control (PFC) for an SLS. The PFC renders motions along any smooth Jordan curve in $ {\mathbb R}^3 $ R 3 for payload position controlled-invariant. This property has practical benefits over traditional time-based trajectory tracking. Furthermore, the PFC prescribes UAV yaw and a desired payload speed profiles along the path. The PFC adopts dynamic extension and input-output state feedback linearisation. The closed-loop has a 1-dimensional zero-dynamics which is shown to be bounded. Hence, the PFC error dynamics is exponentially stable. Simulations are provided to validate the design. [ABSTRACT FROM AUTHOR]

A unique oscillating wind-driven triboelectric nanogenerator (OWTENG) based on the sphere's vortex-induced vibration (VIV) behavior is proposed in this study, which can harvest wind energy across a multitude of horizontal directions. With the Euler-Lagrange method, the coupled governing equations of the OWTENG are established and subsequently validated by experimental tests. The vibrational properties and output performance of the OWTENG for varying wind speeds are analyzed, demonstrating its effectiveness in capturing wind energy across a broad range of wind speeds (from 2.20 m/s to 8.84 m/s), and the OWTENG achieves its peak output power of 106.3 µW at a wind speed of 5.72 m/s. Furthermore, the OWTENG maintains a steady output power across various wind directions within the speed range of 2.20 m/s to 7.63 m/s. Nevertheless, when the wind speed exceeds 7.63 m/s, the vibrational characteristics of the sphere shift based on the wind direction, leading to fluctuations in the OWTENG's output power. This research presents an innovative approach for designing vibrational triboelectric nanogenerators, offering valuable insights into harvesting wind energy from diverse directions and speeds. [ABSTRACT FROM AUTHOR]

In a sweep cover problem, points of interest (PoIs) are required to be visited by mobile sensors periodically. The time span between two consecutive visits of a PoI is the sweep-period of that PoI. In this paper, we study the min sweep-period sweep cover problem with a distance constraint (MinSPSC DC ). Given M mobile sensors with speed a , K base stations and a distance constraint D , the goal of MinSPSC DC is to design routes for the mobile sensors such that the maximum sweep-period is minimized under the condition that every mobile sensor has to visit a base station before traveling distance D. We present an M M − K + 1 ⋅ 2 D D − 2 d max -approximation algorithm for MinSPSC DC , where d max is the maximum distance between a PoI and a base station. [ABSTRACT FROM AUTHOR]

Detecting defects on photovoltaic panels using electroluminescence images can significantly enhance the production quality of these panels. Nonetheless, in the process of defect detection, there often arise instances of missed detections and false alarms due to the close resemblance between embedded defect features and the intricate background information. To tackle this challenge, we propose an Adaptive Complementary Fusion (ACF) module designed to intelligently integrate spatial and channel information. This module is seamlessly integrated into YOLOv5 for detecting defects on photovoltaic panels, aiming primarily to enhance model detection performance, achieve model lightweighting, and accelerate detection speed. In order to validate the efficacy of the proposed module, we conducted experiments using a dataset comprising 4500 electroluminescence images of photovoltaic panels. Compared to the cutting-edge detection capability of YOLOv8, our YOLO-ACF method exhibits enhancements of 5.2, 0.8, and 2.3 percentage points in R, mAP50, and mAP50-95, respectively. In contrast to the lightest and fastest YOLOv5, YOLO-ACF achieves reductions of 12.9%, 12.4%, and 4.2% in parameters, weight, and time, respectively, while simultaneously boosting FPS by 5%. Through qualitative and quantitative comparisons with various alternative methods, we demonstrate that our YOLO-ACF strikes a good balance between detection performance, model complexity, and detection speed for defect detection on photovoltaic panels. Moreover, it demonstrates remarkable versatility across a spectrum of defect types. [ABSTRACT FROM AUTHOR]

Group differences in test scores are a key metric in education policy. Response time offers novel opportunities for understanding these differences, especially in low‐stakes settings. Here, we describe how observed group differences in test accuracy can be attributed to group differences in latent response speed or group differences in latent capacity, where capacity is defined as expected accuracy for a given response speed. This article introduces a method for decomposing observed group differences in accuracy into these differences in speed versus differences in capacity. We first illustrate in simulation studies that this approach can reliably distinguish between group speed and capacity differences. We then use this approach to probe gender differences in science and reading fluency in PISA 2018 for 71 countries. In science, score differentials largely increase when males, who respond more rapidly, are the higher performing group and decrease when females, who respond more slowly, are the higher performing group. In reading fluency, score differentials decrease where females, who respond more rapidly, are the higher performing group. This method can be used to analyze group differences especially in low‐stakes assessments where there are potential group differences in speed. [ABSTRACT FROM AUTHOR]

Purpose: This study investigated whether a running-adapted version of the cycling-based "step–ramp–step" (SRS) protocol would improve prediction of V ˙ O2 in treadmill exercise compared to the traditional prescriptive approach. Methods: Fourteen healthy individuals (6 females; 25 ± 6 years; 66.1 ± 12.7 kg) performed a treadmill-based SRS protocol including a ramp-incremental test to task failure followed by two constant-speed bouts within the moderate-(MODstep—below estimated lactate threshold; θLT), and heavy-intensity domains (HVYstep—between θLT and respiratory compensation point; RCP). Using the uncorrected V ˙ O2-to-speed relationship from the ramp exercise, three constant-speed bouts were performed at 40–50% between: baseline and θLT (CSEMOD); θLT and RCP (CSEHVY); and RCP and peak (CSESEV). For CSEMOD, CSEHVY, and CSESEV measured end-exercise V ˙ O2 was compared to predicted V ˙ O2 based on the: (i) "SRS-corrected" V ˙ O2-to-speed relationship (where MODstep and HVYstep were used to adjust the V ˙ O2 relative to speed); and (ii) linear "uncorrected" data. Results: Average treadmill speeds for CSEMOD and CSEHVY were 7.8 ± 0.8 and 11.0 ± 1.4 km·h−1, respectively, eliciting end-exercise V ˙ O2 of 1979 ± 390 and 2574 ± 540 mL·min−1. End-exercise V ˙ O2 values were not different compared to SRS-predicted V ˙ O2 at CSEMOD (mean difference: 5 ± 166 mL·min−1; p = 0.912) and CSEHVY (20 ± 128 mL·min−1; p = 0.568). The linear "uncorrected" estimates were not different for CSEMOD (− 91 ± 172 mL·min−1; p = 0.068) but lower for CSEHVY (− 195 ± 146 mL·min−1; p < 0.001). For CSESEV (running speed: 13.8 ± 1.7 km·h−1), the end-exercise V ˙ O2 was not different from peak V ˙ O2 achieved during the ramp (3027 ± 682 vs. 2979 ± 655 mL·min−1; p = 0.231). Conclusion: In healthy individuals, the SRS protocol more accurately predicts speeds for a target V ˙ O2 compared to traditional approaches. [ABSTRACT FROM AUTHOR]

The current pattern mining algorithms focus on discovering either frequent itemsets or high-utility itemsets. The goal of this research is to study the problem of mining frequent-utility itemsets. To solve this problem, two novel algorithms named FUIMTWU-Tree (Frequent-utility Itemset Mining based on TWU-Tree) and FUIMTF-Tree (Frequent-utility Itemset Mining based on TF-Tree) are presented based on the integration of IHUP and HUI-Miner. The TWU-tree and TF-Tree structures are utilised to avoid the unnecessary utility-list construction of itemsets that do not appear in a transaction dataset. The performance of the proposed algorithms is evaluated on various datasets. The results of the experiments demonstrate that FUIMTWU-Tree and FUIMTF-Tree perform efficiently in terms of speed, pruning performance and scalability. [ABSTRACT FROM AUTHOR]

We study billiards in domains enclosed by circular polygons. These are closed C 1 strictly convex curves formed by finitely many circular arcs. We prove the existence of a set in phase space, corresponding to generic sliding trajectories close enough to the boundary of the domain, in which the return billiard dynamics is semiconjugate to a transitive subshift on infinitely many symbols that contains the full N-shift as a topological factor for any N ∈ N , so it has infinite topological entropy. We prove the existence of uncountably many asymptotic generic sliding trajectories approaching the boundary with optimal uniform linear speed, give an explicit exponentially big (in q) lower bound on the number of q-periodic trajectories as q → ∞ , and present an unusual property of the length spectrum. Our proofs are entirely analytical. [ABSTRACT FROM AUTHOR]

Considering the ambiguous impact of axial pushing speed on tube formability based on free bending technology, the influence of axial pushing speed is investigated. A prediction and compensation model for increased springback angle caused by the axial pushing speed is introduced, and the bending angle compensation equation is proposed. Then, the bending parameter calculation model is modified. Firstly, tube bending experiments were conducted at 20%, 100%, 200%, and 400% of normal pushing speed. According to the experimental results, the influence of axial pushing speed on tube formability was investigated. The results showed that the push speed has a minor effect on the variations in wall thickness and ovality on the arc section of the tube, and the tube bending quality increases with decreasing axial push speed in transition sections S1 and S3. The tube accuracy results showed that as the axial pushing speed increased, so did the bending angle error between the experimental and intended. Based on the research results, the recommended axial pushing speeds are provided for high efficiency and quality of the tube. Subsequently, the effect of different axial pushing speeds on the springback angle in S1 is investigated. The results demonstrated that S1 had a negligible variation in springback angle at different axial pushing speeds, and the difference is mostly in S2. Ultimately, the bending angle compensation equation was introduced, and springback prediction model for different bending angles under various pushing speeds was established and experimentally validated. The results demonstrated a 6.34% reduction in the bending angle error between the designed and optimized. [ABSTRACT FROM AUTHOR]

Rolling technology with rigid arc rollers presents an innovative approach for the rapid manufacturing of three-dimensional surface components. The unique design generates a variable gap between the rollers, applying lateral bending and uneven compression to sheet metal, thus producing components with complex curvatures. Employing finite element simulation and experimental studies, this research investigates the effects of rotational speed variations on the bending deformation and dimensional accuracy of three-dimensional surface parts. The research findings indicate that as the ratio of rotational speeds between the convex and concave rolls increases from 0.75 to 2, the longitudinal curvature of the saddle-shaped parts gradually increases and then stabilizes, while the transverse curvature decreases. In contrast, for spherical parts, the longitudinal curvature shows an initial decrease followed by stabilization, with minimal changes observed in the transverse curvature. The degree to which the roller rotational speed ratio impacts curvature intensifies with increasing sheet metal compression. These findings suggest that the roll rotational speed ratio can be used as a new process parameter to enhance the curvature range and surface precision of formed parts. [ABSTRACT FROM AUTHOR]

This paper analyzes whether the rubber stack traction structure can be applied to 140 km/h metro vehicles from the perspective of vehicle dynamics. The rolling vibration test results indicate that the vehicle Ride Index exceeds the standard limit, the low-frequency vibration of the car body is significantly greater than that of the frame and axle box, and the lateral motion mode of the car body reaches 2.0 Hz. Through the stiffness test, it is found that when the displacement is less than 5.93 mm, the additional stiffness of the rubber stack traction structure exceeds 0.55 MN/m, which is far greater than the stiffness exhibited by the Z-shaped traction rod at the same displacement. The simulation results demonstrate that the excessive additional stiffness of the traction rubber stack is the primary factor for the car body abnormal vibration and does not effectively improve the vehicle stability. It is recommended that this type of metro shall use a rubber stack traction structure with small additional stiffness or Z-shaped traction rod to improve the car body vibration characteristics at 140 km/h. Furthermore, the recommended maximum operating speed for the bogie with the studied rubber stack traction structure is 80 km/h. [ABSTRACT FROM AUTHOR]

The effects of the stress loading rate and maximum servo wall speed on the instability characteristics of granular materials were investigated using stress-controlled biaxial compression simulation. The results indicate that: (1) the stress loading rate affects the destabilization process of the specimen, with a higher stress loading rate making it easier for the sample to destabilize in a shorter time. (2) The maximum servo wall speed impacts the shear behavior of the specimen and can even lead to simulation test failure. It is therefore strongly recommended that this parameter be listed as a key parameter in future studies. (3) Based on the above analysis, a new conceptual framework was proposed to characterise the different cases of stress-controlled tests, which can guide the rational selection of rates. [ABSTRACT FROM AUTHOR]

The monocular 6D pose estimation of a noncooperative satellite is essential in various on-orbit automatic operations. Nevertheless, the application of this technology still faces challenges, such as heavy model parameters and high latency. In this study, we comprehensively explored the critical components of satellite pose estimation, including landmark description, localisation, and the PnP algorithm, and we introduce a high-precision, real-time, and robust pipeline. Existing methods adopt external convex landmarks, such as 11 landmarks for the SPEED dataset, which are insufficient to describe the geometric structure of the satellite. This study adopted a wireframe-based landmark description, encompassing all visually prominent satellite joints connected directly into the satellite's wireframe model. In addition, unlike most existing methods that rely on heatmap-based landmark localisation, which incurs high computational costs and quantisation errors, we adopt direct coordinate classification for satellite landmark localisation, which is lightweight, fast, and accurate. Experimental results on the SPEED dataset demonstrate that our method outperforms the current state-of-the-art technique, with an accuracy increase of 28% and parameter number decrease of 78%. In particular, our method is very lightweight and robust, and it runs in real-time, making it well-suited for on-orbit real-time satellite pose estimation. • A lightweight monocular satellite pose estimation method is very important for resource-constrained in-orbit platforms. • The three key processes of satellite pose estimation are studied to achieve the balance between accuracy and efficiency. • A High-accuracy, real-time, and robust pipeline for noncooperative satellite pose estimation is proposed. [ABSTRACT FROM AUTHOR]

The clustering algorithm based on the minimum spanning tree (MST) can identify clusters of different shapes. However, the minimum spanning tree clustering algorithm has a high computational cost due to multiple rounds of traversing required during the construction and edge-breaking clustering phases. To address this issue, a density peak fusion idea is proposed, which utilizes kd-trees to obtain neighborhoods and designs leader nodes to propose an algorithm that reduces the time cost of the minimum spanning tree. The main idea of the algorithm is that nodes with higher density than surrounding nodes are used to replace the nodes participating in the formation of the minimum spanning tree. By using the selection technique of density peaks, the number of points required for initial construction and subsequent traversal of the minimum spanning tree is reduced, thereby reducing the complexity of the minimum spanning tree and achieving faster clustering speed. The algorithm has been tested on various synthetic and real datasets. It has achieved significant improvements in speed and clustering performance. Compared with the most advanced mst-based clustering algorithm, the algorithm has a speed increase of at least 30% and a performance increase of about 5%. [ABSTRACT FROM AUTHOR]

In this paper, we introduce a novel approach to enhance the accuracy and convergence behavior of Self-Organizing Maps (SOM) by incorporating a reweighted zero-attracting term into the loss function. We evaluated two SOM versions: conventional SOM and robust adaptive SOM (RASOM). The enhanced versions, reweighted zero-attracting SOM (RZA-SOM) and reweighted zero-attracting RASOM (RZA-RASOM), include an l 1 norm in the error function to add a zero-attractor term, which improves weight coefficient adjustments while preserving topology. The models were assessed for convergence speed and misadjustment under sparsity assumptions of the true coefficient matrix, and their robustness was tested under conditions of increased non-zero taps. Using six different datasets, we compared the performance of RZA-SOM and RZA-RASOM against conventional SOM and RA-SOM in terms of accuracy, quantization error, and topology preservation. Experimental results consistently demonstrated that RZA-SOM and RZA-RASOM surpassed the performance of conventional SOM and RA-SOM. • Introduction of novel reweighted zero-attractor term in loss function for heightened SOM algorithmic precision. • Heightened convergence rates and improved behavior, marked by earlier error steady-state attainment during training. • Enhanced robustness against outliers and superior handling of imbalanced data in multiclass clustering scenarios. • Rigorous experimental evaluations across six distinct datasets effectively underpin proposed algorithmic enhancements. [ABSTRACT FROM AUTHOR]

Objective: At unsignalized T-intersections, right turning drivers from major or minor roads have to accept or reject the available gap and cross the intersection. Poor judgment may arise risk of collision with the major road conflicting vehicles. Subject drivers intending to cross the intersection encounter wide range of gaps. Drivers accept large gaps and reject small gaps. However, drivers experience dilemma over a wide range of gaps. This study aims to examine dilemma experienced by the right turning drivers by modeling gap acceptance and rejection decisions for estimating dilemma zone boundaries on major road. Methods: Videographic method was considered for collecting traffic movement data at unsignalized T-intersections. Traffic video data was collected at three specific unsignalized T-intersections with varying degree of channelization. After this, accepted and rejected gaps with different traffic characteristics of offending vehicles (subject drivers) and conflicting vehicles such as speed, distance, vehicle type, etc. for right turning movements were extracted from the video data to analyze gap acceptance and rejection decisions of the drivers and estimate dilemma zone boundaries. Results: Gap decisions (acceptance or rejection) were modeled using Generalized Linear Model (GLM) as a function of conflicting vehicle type, speed, and distance from the intersection along with degree of channelization for major and minor roads. The results showed that gap rejection probability increased with increment in conflicting vehicle's speed and decrement in conflicting vehicle's distance from the intersection. Dilemma zone boundaries were obtained using developed GLM models by estimating the conflicting vehicle distance from the intersection for 90% and 10% gap rejection probabilities. Dilemma zone boundaries were observed to shift farther from the intersection with increase in vehicle speed and vehicle size. The analysis revealed that subject drivers experienced more dilemma while accepting a gap from major road as compared to minor road. Conclusions: This study showed that channelization plays a major role in mitigating dilemma of the subject drivers. Overall, the study identified dilemma zone boundaries for unsignalized T-intersections which may assist the right turning subject drivers to cross the intersection safely. [ABSTRACT FROM AUTHOR]

When conducting maneuver target tracking, trajectory initialization plays a crucial role in enhancing the accuracy of tracking algorithms. During maneuver target tracking, the accuracy of the tracking algorithm can be significantly improved through trajectory initialization. However, the traditional trajectory initialization algorithms face issues such as susceptibility to noise interference, lack of universality, and poor robustness in environments with high clutter levels. To address these issues, this study proposes a trajectory initialization algorithm based on multidimensional fuzzy clustering (MDF-clustering). The algorithm utilizes multidimensional feature information of the target, such as speed and irradiance, to determine point trajectory affiliation by assigning weights based on the clustering center of each feature type. Subsequently, it updates the clustering center and weight assignment using the new target features, ultimately deriving the correct trajectory through iterative processes. Experimental results demonstrate that the proposed method achieves an average stable initialization frame number of 3.12 frames, an average correct trajectory initialization rate of 99.59%, an average false trajectory occupancy rate of 0.04%, and an average missed batch rate of 0.06%. These results indicate improvements of at least 0.87 frames, 27.11%, 60.28%, and 6.48%, respectively, in terms of initialization rate, false trajectory rate, and missed batch rate, when compared to traditional methods. The algorithm enhances the accuracy and robustness of trajectory initialization in challenging environments characterized by solid clutter and target maneuvers, offering significant practical value for target tracking in complex scenarios. [ABSTRACT FROM AUTHOR]