Search Results (206)

Labor shortages and uneven terrain in orchards present significant challenges to autonomous navigation. This study proposes a navigation system that integrates Light Detection and Ranging (LiDAR) and Inertial Measurement Unit (IMU) data to enhance localization accuracy and map stability through Simultaneous Localization and Mapping (SLAM). To minimize distortions in LiDAR scans caused by ground irregularities, real-time tilt correction was implemented based on IMU feedback. Furthermore, the path planning module was improved by modifying the Rapidly-Exploring Random Tree (RRT) algorithm. The enhanced RRT generated smoother and more efficient trajectories with quantifiable improvements: the average shortest path length was 2.26 m, compared to 2.59 m with conventional RRT and 2.71 m with A* algorithm. Tracking performance also improved, achieving a root mean square error of 0.890 m and a maximum lateral deviation of 0.423 m. In addition, yaw stability was strengthened, as heading fluctuations decreased by approximately 7% relative to the standard RRT. Field results validated the robustness and adaptability of the proposed system under real-world agricultural conditions. These findings highlight the potential of LiDAR–IMU sensor fusion and optimized path planning to enable scalable and reliable autonomous navigation for precision agriculture. Full article

Water-soluble polymers are often used as additives to adjust the foam properties of surfactant. In this study, the effects of water-soluble polymer poly(ethylene oxide) (PEO) on foam properties of two anionic surfactants, i.e., ammonium lauryl ether sulfate (ALES) and sodium dodecyl sulfate (SDS), were investigated by experimental and molecular dynamics simulation methods. Experimental results show that the addition of PEO can reduce the foaming ability of the two surfactants, but the inhibitory effect of PEO on the foaming ability is weakened at high surfactant concentration. Compared with ALES, PEO has a more significant inhibitory effect on the foaming ability of SDS. With the increase in PEO concentration, the half-life time of foam drainage in surfactant/water-soluble polymer composite systems gradually increases. The synergistic effect between PEO and ALES is stronger than that between PEO and SDS, resulting in a longer half-life time of foam drainage in ALES/PEO composite system. Molecular dynamics simulation results indicate that the addition of PEO can decline the air–water interface thickness of bubble films and the tail tilt angle of surfactant molecules at the air–water interface. The reduction in tail tilt angle means that the surfactant molecules are more vertical to the air–water interface and the hydrophobic interaction between adjacent tail chains of surfactants is weakened, which is unfavorable to the formation of bubble films, thus decreasing the foaming ability of surfactants. Because the ALES/PEO system has larger air–water interface thickness and surfactant tail tilt angle than the SDS/PEO system, the inhibitory effect of PEO on the foaming ability of ALES is weaker than that of SDS. Adding PEO can lower the peak position of the first hydration layer of surfactant head groups, increase the number of hydrogen bonds, and reduce the diffusion coefficient of water molecules, so that the surfactant/water-soluble polymer system has longer half-life time of foam drainage than the pure surfactant system. Due to the synergistic effect between ALES and PEO, the ALES/PEO system has a higher peak value of the first hydration layer of surfactant head groups, more hydrogen bonds, and lower diffusion coefficient of water molecules than the SDS/PEO system. Therefore, the half-life time of foam drainage in the ALES/PEO system is longer than that in the SDS/PEO system. Full article

Background: The present study investigated the relation between dental inclination, colorimetric variation, and aesthetic perception according to the modification of incisor inclination. Smile aesthetics, shaped by morphological factors and patient perception, are vital for social attractiveness and treatment success. This study aimed to assess the effect of varying head tilt on the perceived colour of upper central incisors by simulating changes in torque of the tooth, as well as evaluate factors influencing the perception of an aesthetic smile, including morphological characteristics and gingival aesthetic parameters. Methods: The study was comprised of three stages: colour analysis, evaluation of micro- and mini-aesthetic smile features, and an image-based assessment to determine evaluator perceptions and overall smile attractiveness. A sample of 50 students with complete, lesion-free anterior dentition was analysed. To simulate the effect of orthodontic torque changes during colour analysis, subjects tilted their heads downward and upward, representing palatal and buccal crown torque, respectively. Standardized macro-intraoral photographs were captured under controlled lighting conditions using a DSLR camera stabilized on a tripod in the different positions: the neutral head position (p0), 15° upward (p + 15), and 15° downward (p − 15). Digital colour analysis was conducted in the CIELAB colour space (L*, a*, b*). In the next stage, focusing on micro- and mini-aesthetic evaluation, an additional 50 smiles were generated using artificial intelligence via the SmileCloud program—one digitally enhanced smile per subject—complementing the initial set of 50 spontaneous smiles. These 100 smile images were evaluated by 50 laypersons and 50 dentists using a visual analogue scale via an online questionnaire, in order to assess perceptions, determine smile attractiveness, and quantify gingival aesthetic parameters. Results: The statistically significant regression results are as follows: those for the L* values in all three head inclinations: downward (−15 degrees), upward (+15 degrees), and total tilting (−15 to +15 degrees), as well as for the a* values for downward tilting and the b* values for total tilting. When the head is tilted downwards, the central incisors are positioned retrusively, and the L* b* values reveal a darker and more yellowish appearance, whereas, with the head tilted upwards, the central incisors protrude, and L* a* values indicate a brighter and more greenish appear. In the evaluation stage of the smile aesthetics study, no significant differences were observed in the judgments between laypersons and dentists or between males and females. Smiles with a high or average anterior line, parallel arc, upward lip curvature, visible first/second premolars, a smile index of 5.08–5.87, and symmetry score of 1.04 were rated as more attractive. Significant asymmetries were observed between upper dental hemi-quadrants in gingival contour and interdental papilla height, highlighting subtle morphological variations relevant to smile aesthetics. Conclusions: Aesthetic assessment revealed that the findings suggest a measurable impact of head position on dental colour perception and aesthetic evaluation. Evaluator variables including profession and gender exerted negligible effects on aesthetic perception, whereas smile attractiveness features and gingival aesthetic parameters demonstrate significant clinical applicability in patient management. Full article

In precision livestock farming, synchronous and high-precision instance segmentation of multiple key body parts of sika deer serves as the core visual foundation for achieving automated health monitoring, behavior analysis, and automated antler collection. However, in real-world breeding environments, factors such as lighting changes, severe individual occlusion, pose diversity, and small targets pose severe challenges to the accuracy and robustness of existing segmentation models. To address these challenges, this study proposes an improved model, MPDF-DetSeg, based on YOLO11-seg. The model reconstructs its neck network, and designs the multipath diversion feature fusion pyramid network (MPDFPN). The multipath feature fusion and cross-scale interaction mechanism are used to solve the segmentation ambiguity problem of deer body occlusion and complex illumination. The design depth separable extended residual module (DWEResBlock) improves the ability to express details such as texture in specific parts of sika deer. Moreover, we adopt the MPDIoU loss function based on vertex geometry constraints to optimize the positioning accuracy of tilted targets. In this study, a dataset consisting of 1036 sika deer images was constructed, covering five categories, including antlers, heads (front/side views), and legs (front/rear legs), and used for method validation. Compared with the original YOLO11-seg model, the improved model made significant progress in several indicators: the mAP50 and mAP50-95 under the bounding-box metrics increased by 2.1% and 4.9% respectively; the mAP50 and mAP50-95 under the mask metrics increased by 2.4% and 5.3%, respectively. In addition, in the mIoU index of image segmentation, the model reached 70.1%, showing the superiority of this method in the accurate detection and segmentation of specific parts of sika deer, this provides an effective and robust technical solution for realizing the multidimensional intelligent perception and automated applications of sika deer. Full article

This study aimed to evaluate the feasibility of using serious games for the (tele)rehabilitation of children with disabilities affected by the Ukrainian war. Additionally, it provides requirements for technologies that can be used in war-affected areas. Structured interviews and Likert scale assessments were conducted on-site and remotely with patients of the tertiary care facility in Ukraine. All participants used the telerehabilitation platform for motor and cognitive training. Nine serious games were employed, involving trunk tilts, upper limb movements, and head control. By mid-September 2023, 186 positive user experiences were evident, with 89% expressing interest in continued engagement. The platform’s accessibility, affordability, and therapeutic benefits were highlighted. The recommendations from user feedback informed potential enhancements, showcasing the platform’s potential to provide uninterrupted rehabilitation care amid conflict-related challenges. This study suggests that serious games solutions that suit the sociopolitical and economic context offer a promising solution to rehabilitation challenges in conflict zones. The positive user experiences towards using the platform with serious games indicate its potential in emergency healthcare provision. The findings emphasize the role of technology, particularly serious gaming, in mitigating the impact of armed conflicts on children’s well-being, thereby contributing valuable insights to healthcare strategies in conflict-affected regions. Requirements for technologies tailored to the context of challenging settings were defined. Full article

Modern electronic devices such as smartphones, wearable devices, and robots typically integrate three-dimensional sensors to track the device’s movement in the 3D space. However, sensor measurements in three-dimensional vectors are highly sensitive to device orientation since a slight change in the device’s tilt or heading can change the vector values. To avoid complications, applications using these sensors often use only the magnitude of the vector, as in geomagnetic-based indoor positioning, or assume fixed device holding postures such as holding a smartphone in portrait mode only. However, using only the magnitude of the vector loses the directional information, while ad hoc posture assumptions work under controlled laboratory conditions but often fail in real-world scenarios. To resolve these problems, we propose a universal vector calibration algorithm that enables consistent three-dimensional vector measurements for the same physical activity, regardless of device orientation. The algorithm works in two stages. First, it transforms vector values in local coordinates to those in global coordinates by calibrating device tilting using pitch and roll angles computed from the initial vector values. Second, it additionally transforms vector values from the global coordinate to a reference coordinate when the target coordinate is different from the global coordinate by correcting yaw rotation to align with application-specific reference coordinate systems. We evaluated our algorithm on geomagnetic field-based indoor positioning and bidirectional step detection. For indoor positioning, our vector calibration achieved an 83.6% reduction in mismatches between sampled magnetic vectors and magnetic field map vectors and reduced the LSTM-based positioning error from 31.14 m to 0.66 m. For bidirectional step detection, the proposed algorithm with vector calibration improved step detection accuracy from 67.63% to 99.25% and forward/backward classification from 65.54% to 100% across various device orientations. Full article

This study investigates how three technical factors—steering wheel tilt, torque, and cabin vibration frequency—affect driver posture. Heavy-truck drivers often suffer from musculoskeletal disorders (MSDs), mainly due to poor cabin ergonomics and prolonged postures during work. In countries like Ecuador, making major structural changes to cabin design is not feasible. These factors were identified through video analysis and surveys from drivers at two Ecuadorian trucking companies. An experimental system was developed using a simplified cabin to control these variables, while posture and muscle activity were recorded in 16 participants using motion capture, inertial sensors, and electromyography (EMG) on the upper trapezius, middle trapezius, triceps brachii, quadriceps muscle, and gastrocnemius muscle. The test protocol simulated key truck-driving tasks. Data were analyzed using ANOVA (${\displaystyle p<0.05}$), with technical factors and mass index as independent variables, and posture metrics as dependent variables. Results showed that head mass index significantly affected head abduction–adduction (${\displaystyle -}$8.12 to ${\displaystyle -}$2.18°), and spine mass index influenced spine flexion–extension (${\displaystyle -}$0.38 to 6.99°). Among technical factors, steering wheel tilt impacted trunk flexion–extension (${\displaystyle -}$13.56 to 16.99°) and arm rotation (${\displaystyle -}$31.1 to 19.7°). Steering wheel torque affected arm rotation (${\displaystyle -}$30.49 to ${\displaystyle -}$6.77°), while vibration frequency influenced forearm flexion–extension (3.76 to 16.51°). EMG signals showed little variation between muscles, likely due to the protocol’s short duration. These findings offer quantitative support for improving cabin ergonomics in low-resource settings through targeted, cost-effective design changes. Full article

Background/Objectives: Proper nasal irrigation techniques are essential for treating nasal and sinus conditions, influencing drug delivery efficiency and patient comfort. This study evaluates how different head positions—upright, right-tilted, and left-tilted—affect the distribution of saline solution in the nasal cavity and maxillary sinus using computational fluid dynamics (CFD). Methods: CFD simulations were conducted on a CT-based model of a healthy adult. A 4 mL saline solution was administered into the right nostril over three seconds. Fluid distribution and percentage of nasal mucosa coverage was analyzed in the inferior, middle, and superior thirds of the nasal cavity and the right maxillary sinus. Results: In the upright position, fluid primarily accumulated in the inferior (0.075 mL) and middle (0.015 mL) nasal regions, with minimal sinus penetration (0.002 mL). Right-tilting improved maxillary sinus coverage (0.028 mL) and increased irrigation of the inferior region (0.086 mL), while left-tilting enhanced central nasal coverage with only slight sinus penetration improvement. Irrigation patterns exhibited a rapid initial wetting phase followed by a slower, steady increase. Conclusions: Head position significantly influences the distribution achieved by nasal irrigation. These findings can guide clinical recommendations for specific conditions or postoperative care. Full article

Background/Objectives: Rapidly progressive osteoarthritis of the hip (RPOH) has unique diagnostic and surgical challenges due to rapid joint degeneration and acetabular structural alterations. This study aimed to investigate correlations between preoperative spinopelvic geometry and anterior acetabular wall bone stock deficiency in RPOH patients and introduce an advanced imaging measurement techniques for cases with amputated femoral heads. Methods: A prospective observational study was conducted that enrolled 85 patients, comprising 40 with unilateral RPOH (Zazgyva Grade II or III) and 45 controls with primary osteoarthritis (OA). Preoperative spino-pelvic parameters (pelvic tilt—PT, sacral slope—SS, lumbar lordosis—LL, and T1 pelvic angle) and acetabular anterior wall characteristics (anterior center edge angle—ACEA, anterior wall index—AWI, and anterior acetabular surface area—AASA) were measured using standardized radiographic and CT imaging protocols, including a new methodology for acetabular center estimation in femoral head-amputated cases. Results: Significant differences were identified between RPOH and primary OA patients in the PT (22.5° vs. 18.9°, p = 0.032), SS (37.8° vs. 41.1°, p = 0.041), T1 pelvic angle (14.3° vs. 11.8°, p = 0.018), and anterior center edge angle (25.3° vs. 29.7°, p = 0.035). RPOH patients exhibited pronounced spinopelvic misalignment and anterior acetabular deficiencies. Conclusions: RPOH is associated with spinopelvic misalignment and anterior acetabular wall deficiency. Accurate preoperative diagnosis imaging and personalized surgical approaches specifically addressing acetabular bone stock deficiencies are mandatory in these cases. Full article

The aerodynamic loading of four as well as of six tilted flat plates-panels arranged in tandem and in close proximity to the ground is examined through force and pressure measurements. In the four-plate set up, conducted in an open-circuit wind tunnel, a movable floor is used to vary the ground clearance, and a one-component force balance is employed to measure the drag coefficient Cd of each plate for tilt angles 10° to 90° and for two head-on wind directions, 0° and 180°. An increase in the ground clearance from 20% to 60% of the plates’ chord length, results in a Cd increase of over 40% in the downstream plates, and up to 20% in the leading one. For tilt angles below 40°, the drag on the first plate is up to 25% higher under the 180° wind direction compared to the opposite direction. Pressure distributions are also presented on a series of six much larger plates, examined in a closed-circuit wind tunnel at tilt angles ±30°. While the windward surfaces exhibit relatively uniform pressure distributions, regions of low pressure develop on their suction side, near the plates’ tips leading edge, tending to become uniform streamwise. Full article

Historically, the field of discourse marker research has moved from relying on intuition to more and more ecological data, with written, spoken, and now multimodal corpora available to study these pervasive pragmatic devices. For some topics, video is necessary to capture the complexity of interactive phenomena, such as feedback in dialogue. Feedback is the process of communicating engagement, alignment, and affiliation (or lack thereof) to the other speaker, and has attracted a lot of attention recently, from fields such as psycholinguistics, conversation analysis, or second language acquisition. Feedback can be expressed by a variety of verbal/vocal and visual/gestural devices, from questions to head nods and, crucially, discourse or pragmatic markers such as “okay, alright, yeah”. Verbal-vocal and visual-gestural forms often co-occur, which calls for more investigation of their combinations. In this study, we analyze multimodal pragmatic markers of feedback in a corpus of French dialogues, where all feedback devices have previously been categorized into either “alignment” (expression of mutual understanding) or “affiliation” (expression of shared stance). After describing the distribution and forms within each modality taken separately, we will focus on interesting multimodal combinations, such as [negative oui ‘yes’ + head tilt] or [mais oui ‘but yes’ + forward head move], thus showing how the visual modality can affect the semantics of verbal markers. In doing so, we will contribute to defining multimodal pragmatic markers, a status which has so far been restricted to verbal markers and manual gestures, at the expense of other devices in the visual modality. Full article

Benign paroxysmal torticollis (BPT) is a condition characterized by episodes of alternating head tilt in infants. Mild cases may be mistaken for Congenital Muscular Torticollis, potentially leading to unnecessary treatment. This case report describes an infant with suspected mild BPT who exhibited alternating head tilt and colic but demonstrated normal motor development. The head tilt resolved spontaneously without intervention. Physical therapists should be aware of mild benign paroxysmal torticollis and monitor such cases carefully to differentiate it from other forms of torticollis and to provide reassurance to parents. Full article

To rectify significant heading calculation errors in polarized light navigation for unmanned aerial vehicles (UAVs) under tilted states, this paper proposes a method for compensating horizontal attitude angles based on horizon detection. First, a defogging enhancement algorithm that integrates Retinex theory with dark channel prior is adopted to improve image quality in low-illumination and hazy environments. Second, a dynamic threshold segmentation method in the HSV color space (Hue, Saturation, and Value) is proposed for robust horizon region extraction, combined with an improved adaptive bilateral filtering Canny operator for edge detection, aimed at balancing detail preservation and noise suppression. Then, the progressive probabilistic Hough transform is used to efficiently extract parameters of the horizon line. The calculated horizontal attitude angles are utilized to convert the body frame to the navigation frame, achieving compensation for polarization orientation errors. Onboard experiments demonstrate that the horizontal attitude angle estimation error remains within 0.3°, and the heading accuracy after compensation is improved by approximately 77.4% relative to uncompensated heading accuracy, thereby validating the effectiveness of the proposed algorithm. Full article

Background: Foreign body airway obstruction is a sudden emergency that can occur unexpectedly in healthy people, leading to severe consequences if immediate first aid is not provided. Unlike the Heimlich maneuver for adults, the first aid for infant choking is less widely known and more complex, making it difficult to explain verbally. This study aimed to assess the efficiency of using an animated graphics interchange format (GIF) to teach first aid for infant choking due to foreign bodies. Methods: Eighty adults who had not received recent training in choking first aid within the last two years were randomly assigned to either the auditory (n = 40) or audiovisual (n = 40) groups. The participants were asked to perform first aid on an infant manikin under the guidance of a researcher using a smartphone in a separate room. The auditory group received verbal instructions only, while the audiovisual group received animated GIFs on their smartphones along with verbal instructions simultaneously. The entire process was recorded with two cameras, and two emergency physicians reviewed the videos to assess the adequacy of the first aid administered. Results: The “infant position”, “supporting arm posture”, and “head tilt” were more adequate in the audiovisual group. The Instruction Performance scores were higher in the audiovisual group. There was no significant difference in the time required to administer first aid between the two groups. Conclusions: Audiovisual guidance using animated GIFs has been shown to effectively enhance the adequacy of first-aid performance for infant airway obstruction caused by foreign bodies. Full article

The ovine respiratory complex significantly affects lamb welfare and production efficiency, necessitating accurate diagnostic methods for pulmonary lesions. This study explores the relationship between clinical scoring, auscultation, ultrasonography, and macroscopic post-mortem evaluation to assess respiratory disease in 111 lambs. A standardized clinical scoring system, adapted from bovine models, evaluated ocular and nasal discharge, head tilt, cough, and rectal temperature. Auscultation categorized pulmonary sounds, while ultrasonography identified lung abnormalities, including B-lines, consolidations, pleural effusion, and abscesses. Macroscopic post-mortem examinations confirmed lesion extent. Kendall–Tau-B correlation coefficient analysis revealed significant associations between the methods (p < 0.01), with a high correlation between auscultation and clinical scoring τ of 0.634 (95% CI: 0.489 to 0.765), auscultation and ultrasonography τ of 0.611 (95% CI: 0.500 to 0.710), and ultrasonography and post-mortem findings τ 0.608 (95% CI: 0.460 to 0.731). While auscultation and clinical scoring provided useful insights, ultrasonography exhibited superior sensitivity in detecting subclinical and early-stage lesions, aligning closely with post-mortem evaluations. These findings emphasize ultrasonography as an effective tool for diagnosing respiratory disease in lambs, improving diagnostic accuracy and enabling timely interventions to mitigate disease impact and reduce antimicrobial use. Full article