Search Results (20)

In car–pedestrian collisions (CPC), most studies have focused on injury analysis using youth models. However, the mechanical performance of bones and muscles naturally deteriorates with age. Compared with younger people, the elderly are more vulnerable to bone fracture when subjected to the same impact. In this study, a digital twin model of the elderly lower limb (DTM-ELL) and a digital twin model of the youth lower limb (DTM-YLL) for Chinese 50th-percentile males were developed based on CT images, in which 150 material properties were assigned to the bones according to their Hounsfield units. The digital twin model of the lower limb (DTM-LL) was validated through quasi-static three-point bending simulation and dynamic lateral loading simulation of the knee joint. A family-car lateral impact simulation was used to verify the consistency between the developed model and THUMS (Total HUman Model for Safety). Through collision simulations between each of three car models and the DTM-LL, it was found that the maximum average stress in the femur of the DTM-ELL is 62.64% of that of the DTM-YLL under the same CPC conditions. Surrounding soft tissues, acting as effective cushioning during CPC, reduce the maximum femoral stress by 29.56% relative to the model without surrounding soft tissues. Finally, a real CPC accident was reconstructed in finite element software using the DTM-LL developed from the CT images. The reconstruction results showed that the DTM-LL had acceptable biofidelity and can be used to study femoral injuries in elderly pedestrians involved in CPC. Full article

Ice hockey puck impacts combine high velocity, oblique loading, and spatially variable contact, yet conventional helmet assessments rely primarily on global head kinematics. This study quantified how puck impact velocity, angle, and location affect skull stress and brain tissue strain. A commercially available ice hockey helmet was reconstructed from three-dimensional scans and coupled with the Total Human Model for Safety (THUMS) Version 7.1 head model. Helmet response was benchmarked against standardized drop-test data at top, lateral, and rear locations. Eighteen nominal puck-impact conditions combined two velocities (30 and 40 m/s), three angles (0°, 45°, and 60°), and three locations; additional ±10% velocity runs assessed sensitivity. Peak skull von Mises stress (skull stress) and brain maximum principal strain (MPS) were compared descriptively. Benchmark peak linear acceleration differed from reference data by 0.5–5.8%. The greatest skull stress occurred at 40 m/s, 0°, lateral impact (0.556 MPa), whereas the greatest MPS occurred at 40 m/s, 0°, top impact (0.175). These different worst-case locations show that local skull loading and brain tissue deformation are not captured by a single metric. Multi-metric, location-specific evaluation may improve ice hockey helmet assessment and regional optimization. Full article

Under high-speed frontal impact, occupants in zero-gravity seats restrained by a three-point seatbelt are at risk of head injury, lumbar spine injury, and submarining. To reduce occupant injury, this study systematically investigated the protective effects of active seatback repositioning strategies on occupants under 56 km/h frontal impact. First, the THUMS (Total Human Model for Safety)-based finite element assembly consisting of a regular seat model and a 3-point seat belt system was verified by comparing thoracic acceleration, head acceleration, lap belt force, and shoulder belt force with PMHS test data. On this basis, a zero-gravity seat model with an active seatback repositioning function was established. Using this model, the effects of seatback repositioning timing and seatback rotational speed on occupant kinematic responses and injury protection performance were investigated. The results showed that with the introduction of active seatback repositioning before the crash, occupant head and lumbar spine injuries, as well as submarining tendency, can be significantly reduced. Particularly, with respect to the repositioning time analysis, the seatback repositioning with 100 ms precrash setting provided the best protective performance and compared with the fixed-seatback condition, the occupant head injuries of HIC₁₅, BrIC, CSDM(0.25), injury probability of lumbar spine and pelvic forward excursion was reduced by 66.4%, 65%, 99.8%, 34.1%, and 48%, respectively. Furthermore, the influence of seatback repositioning speed on occupant injury protection was examined. The results indicated that an excessively high seatback rotational speed increased head and neck injury, thoracolumbar flexion, as well as risk of rib injury. Full article

Introduction: Pedestrians lying on the road—collapsed through medical emergency, intoxication, or displacement following a prior collision—represent a disproportionately lethal and underaddressed category in road traffic safety. Forensic database analyses derived from Japan’s national police records document a fatality rate of 33.0% for collisions involving pedestrians lying on the road, more than double the rate for upright pedestrian collisions. Standard Advanced Driver-Assistance Systems (ADAS) yield a True Positive Rate (TPR) of only 21.4% for detecting pedestrians lying on the road under night conditions—a classification gap of 73.3 percentage points. Methods: In simulation trials, we evaluated the Advanced Falling Object Detection System (AFODS—where “falling object” denotes the low-profile human form at road level, distinguishing the prone pedestrian from the upright postures addressed by conventional ADAS) on a composite dataset of 3200 annotated fall events and 12,000 negative samples (training/validation), with 320 independent controlled simulation trials used for performance evaluation, spanning real-world, forensic-reconstruction, and Total Human Body Model for Safety (THUMS)-validated synthetic scenarios. No physical prototype has been evaluated; all performance data are derived from simulation, and 37.5% of positive samples are synthetically generated. These simulation conditions represent a first feasibility demonstration pending real-world hardware validation. This paper introduces three original contributions absent from prior work: a three-stage quantitative injury-risk model, a formal ISO 26262 Hazard Analysis and Risk Assessment (HARA), and a medicolegal SHAP interpretability framework. The injury-risk model translated detection latency via impact velocity to Head Injury Criterion (HIC) and estimated fatal injury probability (AIS ≥ 5); these model outputs should be interpreted as exploratory estimates pending ATD validation. Reporting follows principles consistent with the TRIPOD statement. Results: Under clear daytime conditions, AFODS demonstrated a TPR of 98.2% (95% CI: 97.4–98.8%) in simulation, decreasing to 95.6% under night dry-road conditions and 89.4% under night rain. The system achieved an AUC of 0.981 and a mean end-to-end latency of 46.5 ms, representing a 76.8 percentage-point improvement in simulation over the monocular RGB baseline (p < 0.001). The injury-risk model projects a reduction in estimated fatal head injury probability from 66.2% (Monte Carlo mean) (no detection, 50 km/h full-speed impact) to 0.7% under AFODS worst-case night/rain conditions, and to ≈0% under clear daytime simulation conditions. Conclusions: A 73.3 percentage-point classification gap places pedestrians lying on the road outside the effective detection envelope of current ADAS, compounded by the systematic exclusion of non-upright postures from regulatory test protocols and benchmark datasets. AFODS supports proof-of-concept feasibility under simulation conditions. Three translational steps are required: prototype validation on real-world hardware using instrumented Anthropomorphic Test Devices (ATDs); prone-posture biomechanical injury modelling using HIC and BrIC criteria; and regulatory extension of pedestrian AEB test standards to non-upright scenarios. Full article

Background/Objectives: This paper investigates the application of radial basis function (RBF) interpolation to adapt the Toyota Human Model for Safety (THUMS) version 6 finite element (FE) models to diverse anthropometric profiles using ANSUR II data. The research focuses on generating personalized human body models (HBMs) across 50th, 80th, and 98th percentiles for both sexes in standing and seated postures, evaluating mesh quality with quantitative metrics, and assessing posture-dependent transformations. Methods: The geometric accuracy for the standing configuration was quantified using DICE similarity coefficients and the 95th percentile Hausdorff distance (HD95). Results: While global whole-body DICE similarity averaged approximately 0.40 due to an inherent variability in distal limb positioning, regional analysis demonstrated strong volumetric overlap in the critical chest and torso regions with DICE values ranging from 0.80 to 0.88. Regional HD95 values were within 20–30 mm across most of the surface area. Surfaces distance analyses showed that more than 95% of the nodes were within $\pm 20$ mm of the target surfaces with the distribution centered near zero across all the percentiles. The mesh quality for both standing and seated morphs demonstrated low violation rates with the aspect ratio being 28% to 30%, while warpage, skewness and, Jacobian determinants were less than 15%. The seated morphs preserved anatomical alignment and posture despite mesh density differences between the postures. Conclusions: These findings indicate that the morphing process preserves anatomical fidelity while highlighting the need for further optimization to mitigate localized distortions in dynamic simulations. Full article

Detection of brown spot needle blight (BSNB) disease caused by the fungal pathogen Lecanosticta acicola (Thum.) Syd. has increased significantly at commercial loblolly pine (Pinus taeda L.) plantations across the southeastern United States in recent years. Historically, it has been a serious problem in longleaf pine (Pinus palustris Mill) during the grass stage of seedlings, when the environment is more conducive to fungal infection. However, since 2016, confirmed cases of the disease on loblolly pines have increased in several states, including AL, AR, FL, GA, LA, MS, SC, TN, and TX. We investigated the distribution pattern of confirmed cases of BSNB on loblolly pine between 2016 and 2023, identified site-specific factors, and evaluated the historical standardized precipitation index (SPI) value record over the past four decades. Our results showed that extended periods of above-normal SPI values are associated with BSNB spatial distribution patterns, particularly where the disease has been widely reported in AL, AR, LA, and MS. We observed significant reduction in tree height and dbh in severely infected versus healthy trees at the six study sites evaluated in 2023. Excessive rainfall and prolonged water saturation associated with historical 5-Year SPI values suggest that vulnerable loblolly pine seedlings (depending on genetic family) are more likely to be predisposed to L. acicola infection due to persistent stress from reduced soil nutrient flux and other physiological processes of the host. Understanding the effect of precipitation patterns on cases of BSNB is an important step toward preventing or minimizing the future impact of the disease on commercial plantations in the Southeast. Full article

Traumatic brain injury (TBI) is a significant public health concern and its rising prevalence in road traffic accidents underscores the need for deeper understanding and tailored investigation. This study explores the feasibility of employing the female finite element head model (FeFEHM) to analyse biomechanical responses in two distinct road traffic accident scenarios, focusing on strain and stress distribution in critical brain structures. Two collision scenarios from the German In-Depth Accident Study (GIDAS) were reconstructed using validated Total Human Model for Safety (THUMS) simulations. The extracted skull kinematics were applied to the FeFEHM in ABAQUS to compute maximum principal strain, von Mises stress, and intracranial pressure across key brain regions, including the corpus callosum and pituitary gland. Simulations revealed strain concentrations in the parietal and temporal lobes, while the mid-body region was the most affected in the corpus callosum. Pituitary gland deformation was minimal under both loading conditions. Our findings align qualitatively with reported injury sites and injury risk was consistent with those observed in the real-world crashes. The findings highlight the potential of integrating sex-specific biomechanical models into crash biomechanics workflows. Future work should extend this approach across larger datasets and impact scenarios to support its implementation in regulatory and engineering contexts, since the actual sample size prevents conclusions regarding sex-specific biomechanics. Full article

The paper presents the innovative approach to a high-fidelity motorcycle riding simulator based on VR (Virtual Reality)-visualization, equipped with a Gough-Stewart 6-DOF (Degrees of Freedom) motion platform. Such a solution integrates a real-time tension sensor system as a source for highly realistic motion cueing control as well as the servomotor integrated into the steering system. Tension forces are measured at four points on the mock-up chassis, allowing a comprehensive analysis of rider interaction during various maneuvers. The simulator is developed to simulate realistic riding scenarios with immersive motion and visual feedback, enhanced with the simulation of external influences—headwind. This paper presents results of a validation study—pilot experiments conducted to evaluate selected riding scenarios and validate the innovative simulator setup, focusing on force distribution and system responsiveness to support further research in motorcycle HMI (Human–Machine Interaction), rider behavior, and training. Full article

This study investigates occupant kinematic and injury responses in zero-gravity seats under rear impacts at 16 km/h, 40 km/h, and 56 km/h and evaluates the protective performance of a conventional three-point seat belt system and a four-point seat belt system. First, a THUMS (Total Human Model for Safety)-based finite element assembly consisting of a regular seat model and a conventional three-point seat belt system was verified by comparing the kinematic responses and time-history curves of head acceleration, head rotation, and the T1 acceleration of PMHS (Postmortem Human Subject) tests. Then, a THUMS-based finite element assembly in a zero-gravity seat with a three-point seat belt system was created, and computational biomechanical analyses revealed that at low-to-medium impact speeds (16 and 40 km/h), the occupant exhibited backward sliding in the zero-gravity seat along the seatback with lower limb rotation and did not experience head and neck injury. However, a 56 km/h impact induced an excessive seatback rotation and caused the head to become out of position. The neck collided with the upper part of the headrest and caused a surge in the contact force between the neck and the headrest. The head injury and neck injury were comprehensively analyzed via the head injury metrics and neck injury metrics, including cervical spine injury metrics and cervical ligament injury metrics. Further, a four-point seat belt system was adopted and demonstrated better and more balanced restraining effects by reducing the relative displacement between the occupant’s head and chest in the x- and y-directions by 26% and 84%, respectively. Therefore, the occupant’s head remains in position and the collision between the neck and the headrest can be avoided. Maximum reductions in the head and neck injury metrics reached 70% and 57%, respectively. The current study illustrates the disadvantages of the traditional three-point seat belt system in restraining the occupant in a zero-gravity seat under rear impact and shows the four-point seat belt to be a better alternative. This study sheds light on seat belt system design and optimization towards future zero-gravity seats under rear impact. Full article

The purpose of this paper is to discuss the effect of earthquake (EQ) preparation on changes in meteorological parameters. The two physical quantities of temperature (T)/relative humidity (Hum) and atmospheric chemical potential (ACP) have been investigated with the use of the Japanese meteorological “open” data of AMeDAS (Automated Meteorological Data Acquisition System), which is a very dense “ground-based” network of meteorological stations with higher temporal and spatial resolutions than the satellite remote sensing open data. In order to obtain a clearer identification of any seismogenic effect, we have used the AMeDAS station data at local midnight (LT = 01 h) and our initial target EQ was chosen to be the famous 1995 Kobe EQ of 17 January 1995 (M = 7.3). Initially, we performed conventional statistical analysis with confidence bounds and it was found that the Kobe station (very close to the EQ epicenter) exhibited conspicuous anomalies in both physical parameters on 10 January 1995, just one week before the EQ, exceeding m (mean) + 3σ (standard deviation) in T/Hum and well above m + 2σ in ACP within the short-term window of one month before and two weeks after an EQ. When looking at the whole period of over one year including the day of the EQ, in the case of T/Hum only we detected three additional extreme anomalies, except in winter, but with unknown origins. On the other hand, the anomalous peak on 10 January 1995 was the largest for ACP. Further, the spatial distributions of the anomaly intensity of the two quantities have been presented using about 40 stations to provide a further support to the close relationship of this peak with the EQ. The above statistical analysis has been compared with an analysis with recent machine/deep learning methods. We have utilized a combinational use of NARX (Nonlinear Autoregressive model with eXogenous inputs) and Long Short-Term Memory (LSTM) models, which was successful in objectively re-confirming the anomalies in both parameters on the same day prior to the EQ. The combination of these analysis results elucidates that the meteorological anomalies on 10 January 1995 are considered to be a notable precursor to the EQ. Finally, we suggest a joint examination of our two meteorological quantities for their potential use in real short-term EQ prediction, as well as in the future lithosphere–atmosphere–ionosphere coupling (LAIC) studies as the information from the bottom part of LAIC. Full article

Analysis of pedestrians’ head and lower limb injuries at the tissue level is lacking in studies of tram–pedestrian collisions. The purpose of this paper therefore to investigate the impact response process and severity of pedestrians’ injuries in tram–pedestrian collisions, using the Total Human Model for Safety (THUMS) pedestrian human body model together with the tram FE model. Two full-scale tram–pedestrian dummy crash tests were performed to validate the FE model, and the total correlation and analysis (CORA) score of head acceleration yielded values of 0.840 and 0.734, confirming a strong agreement between the FE-simulated head responses and the experimental head kinematics. The effects of different tram speeds and impact angles on pedestrians’ impact response injuries and the differences were further analyzed. The results indicate that direct impact of the lower limb with the tram’s obstacle deflector leads to lower limb bone shaft fractures and knee tissue damage. Neck fling contributed to worsened head injury. Coup contusions were the predominant type of brain contusion, surpassing contrecoup contusions, while diffuse axonal injury was mainly concentrated in the collision-side region of the brain. Pedestrians’ injuries are influenced by tram velocity and impact angle: higher tram velocities increase the risk of lower limb and head injuries. The risk of head injury for pedestrians is higher when the impact angle is negative, while lower limb injuries are more significant when the impact angle is 0°. This study provides practical guidance for enhancing tram safety and protecting pedestrians. Full article

Triticum urartu Thum. ex Gandil. is a wild diploid wheat species (2n = 2x = 14) that is an A^u genome donor of modern polyploid cultivars of durum and bread wheat. In the last decade, this relict species has attracted breeders as donors of various agronomically important characteristics to broaden the genetic diversity of cultivated wheat. In addition, T. urartu can be considered as a model species for studying the evolution, biology and genomics of wheat without the cross-influence of homologous sub-genomes. Various genetic engineering technologies, including transgenesis and genome editing, may be applied to facilitate the functional characterization of genes located in A chromosomes. Such biotechnological techniques are still required for the efficient tissue culture systems to allow easy plant regeneration. The objective of our study was to assess the abilities of in vitro plant regeneration from zygotic immature embryo-derived tissues of spring and winter types of T. urartu. Three synthetic auxins, 2,4-D, Dicamba and Picloram, at four concentrations were studied to stimulate morphogenic responses in spring T. urartu. The induction medium supplemented with 4 mg·L⁻¹ Dicamba stimulated the highest frequency of regenerable callus production (65.8%), promoting the generation of 5.7 plants. Although the presence of 2 mg·L⁻¹ 2,4-D was less effective in stimulating regenerable callus formation (53.2%) than Dicamba, it allowed the regeneration of more plants from one regenerable callus (9.3 plants). These two treatments also successfully initiated morphogenesis in winter assertions; however, their regenerative capacity was generally lower. The frequency of regenerable callus production was accession-dependent and fluctuated within 31.3 to 49.2%, with a formation of an average 2.2–5.8 plants per callus. The relatively simple and fast regeneration system described in this study could be further used as the basis for regenerating transgenic plants of T. urartu. Full article

Nowadays, riding comfort is more significant than before for evaluating the quality of high–speed railways and sitting is the most common posture for its passengers. This study aimed to analyze and optimize the pressure distribution and sitting comfort of second–class seats with different design parameters. Firstly, 21 pressure features were calculated after the field sitting tests conducted on a CRH Train. The subjective comfort was quantified as a linear combination of 6 pressure features in 21, which were selected using stepwise regression analysis (R² = 0.684). A seat-human finite element model was established using THUMS for a human body and MAT_57 for the seat foam. Finally, this study analyzed the effects of foam and seat angles on interface pressure distribution and comfort ratings. The set of design parameters with the highest comfort was selected from 12 free combinations. The results show that the seat foam with less stiffness may not improve sitting comfort due to the asymmetry of the seat frame. Moreover, appropriately increasing the stiffness of the cushion and backrest will not lead to a decrease in subjective feelings and the pressure distribution becomes more reasonable as the inclination angle increases within 10 degrees. The final optimization increases the computational comfort of the seat-human model by 6.5 in a −50 to 50 scale. Full article

In comparison with vehicle-to-pedestrian collision, pedestrian-to-ground contact usually results in more unpredictable injuries (e.g., intracranial, neck, and abdominal injuries). Although there are many studies for different applications of such methods, this paper conducts an in-depth analysis of urban traffic pedestrian accidents. The effects of pedestrian rotation angle (PRA) and pedestrian facing orientation (PFO) on head and neck injury risk in a ground contact are investigated by the finite element numerical models and different probabilistic analyses. It goes without saying that this study provides a theoretical basis for the prediction and protection study of pedestrian ground contact injury risk. In our experiments, 24 pedestrian-to-ground simulations are carried out by the THUMS v4.0.2 model considering eight PRAs (0°, 45°, 90°, 135°, 180°, 225°, 270°, 315°, 360°) and three PFOs (x+, x−, y+). Each test was simulated with loading the average linear and rotational velocities that obtained from real-world pedestrian accidents at the pedestrian’s center of gravity. The results show that both PRAs and PFOs have significant impacts on head and neck injuries. Head HIC value caused by PRA 0–135° is much higher than that caused by PRA 180–315°. Neck injury risk caused by PRA 180° is the greatest one in comparison with other PRAs. The PRAs 90° and 270° usually induce a relatively lower neck injury risk. For PFO, the risk of head and neck injury was lower than PFOy+ and PFOx+ or PFOx−, which means PFOy+ was a safer landing orientation for both head and neck. The potential risk of head and neck injuries caused by the ground contact was strongly associated with the symmetry/asymmetric features of human anatomy. Full article

A combination of airbag, seatbelt, and other restraint systems greatly reduces injury to drivers in small offset collisions. However, the airbag causes accidental injury to the driver in the deployment process. To maximize the protection effect of the restraint system on the driver, this study proposes a pre-tensioned force-limiting seatbelt. A small offset collision accident with video information was simulated by using a Neon sedan and the THUMS (v.4.0.2) finite element model. The effectiveness of the accident model and the matching use of a pre-tensioned force-limiting seatbelt and airbag for driver protection were verified. To obtain the best parameter matching of protection effect, first, the seatbelt force-limiting A, pre-tensioned force B, pre-tensioned time C, airbag ignition time D, and mass flow coefficient E were selected as influencing factors, and orthogonal tests with different factor levels were designed. Then, the direct analysis method was applied to analyze the influence laws of each factor on driver dynamic response and injury. In addition, the radial basis function surrogate model was constructed by synthesizing each kind of critical injury value to the human body. Combined with NSGA-II multi-objective genetic algorithm, the structural performance parameters of the restraint system were optimized and matched. Results showed that the optimal protection matching parameters of the restraint system were 4933.5 N−2499.9 N−16 ms−15.3 ms−0.5 (A−B−C−D−E). Finally, the best matching parameters were input into the accident model for verification. After optimization, the WIC and $N_{ij}$ of drivers were reduced by 37.9% and 45.3%, respectively. The results show that the optimized restraint system can protect the driver the most. Full article