Search Results (54)

This study develops and validates a Reduced Order Model (ROM) integrated with Digital Twin technology for real-time temperature control in the Main Control Room (MCR) of a nuclear power plant. Utilizing Computational Fluid Dynamics (CFD) simulations, we obtained detailed three-dimensional thermal flow distributions under various operating conditions. A ROM was generated using machine learning techniques based on 94 CFD cases, achieving a mean temperature error of 0.35%. The ROM was further validated against two excluded CFD cases, demonstrating high correlation coefficients (R > 0.84) and low error metrics, confirming its accuracy and reliability. Integrating the ROM with the Heating, Ventilating, and Air Conditioning (HVAC) system, we conducted a two-month simulation, showing effective maintenance of MCR temperature within predefined criteria through adaptive HVAC control. This integration significantly enhances operational efficiency and safety by enabling real-time monitoring and control while reducing computational costs and time associated with full-scale CFD analyses. Despite promising results, the study acknowledges limitations related to ROM’s dependency on training data quality and the need for more comprehensive validation under diverse and unforeseen conditions. Future research will focus on expanding the ROM’s applicability, incorporating advanced machine learning methods, and conducting pilot tests in actual nuclear plant environments to further optimize the Digital Twin-based control system. Full article

This study presents the design and validation of a numerical method based on an AI-driven ROM framework for implementing stress virtual sensing. By leveraging Reduced-Order Models (ROMs), the research aims to develop a virtual stress transducer capable of the real-time monitoring of mechanical stresses in mechanical components previously analyzed with high-resolution FEM simulations under a wide range of multiple load scenarios. The ROM is constructed through neural networks trained on Finite Element Method (FEM) outputs from multiple scenarios, resulting in a simplified yet highly accurate model that can be easily implemented digitally. The ANN model achieves a prediction error of ${\mathrm{MAE}}_{\mathrm{test}}=(0.04\pm 0.06) \mathrm{MPa}$ for the instantaneous mechanical stress predictions, evaluated over the entire range of stress values (0 to 5.32 MPa) across the component structure. The virtual sensor is capable of producing a quasi-instantaneous, detailed full stress map of the component in just 0.13 s using the ROM, for any combination of 4-load inputs, compared to the 6 min and 31 s required by the FEM. Thus, the approach significantly reduces computational complexity while maintaining a high degree of precision, enabling efficient real-time monitoring. The proposed method’s effectiveness is demonstrated through rigorous ROM validation, underscoring its potential for stress control. This precise AI-driven procedure opens new horizons for predictive maintenance strategies centered on stress cycle monitoring. Full article

Introduction: This study hypothesized that changes in the elasticity of the quadriceps and patellar tendons before and after the diagnosis of patellar tendinopathy would correlate with the range of motion (ROM) following conservative treatment. We aimed to prospectively assess post-treatment ROM using multinomial logistic regression, incorporating elasticity measurements obtained via shear wave elastography (SWE). Materials and Methods: From March 2023 to April 2024, 95 patients (86 men; aged 20–45 years, mean 25.62 ± 5.49 years) underwent SWE preoperatively and two days post-diagnosis of patellar tendinopathy. Elasticity measurements of the rectus femoris, vastus medialis, vastus lateralis, patellar tendon, and biceps tendon were obtained during full flexion and extension. Based on ROM 56 days post-treatment, patients were categorized into two groups: Group A (ROM > 120 degrees) and Group B (ROM < 120 degrees). A multinomial logistic regression algorithm was employed to classify the groups using patient information and tendon elasticity measurements both at diagnosis and 1-week post-diagnosis. Results: The predictive accuracy using only patient information was 62%, while using only elasticity measurements yielded 68% accuracy. When combining patient information with elasticity measurements taken at diagnosis and two days post-diagnosis, the algorithm achieved an accuracy of 79%, sensitivity of 92%, and specificity of 56%. Conclusions: The combination of patient information and tendon elasticity measurements obtained via SWE at pre-conservative treatment and early post-conservative treatment periods effectively predicts post-treatment ROM. This algorithm can guide rehabilitation strategies for soldiers with patellar tendinopathy. Full article

With the global rise in consumer electronics, electric vehicles, and renewable energy, the demand for lithium-ion batteries (LIBs) is expected to grow. LIBs present a significant challenge for state estimations due to their complex non-linear electrochemical behavior. Currently, commercial battery management systems (BMSs) commonly use easier-to-implement and faster equivalent circuit models (ECMs) than their counterpart continuum-scale physics-based models (PBMs). However, despite processing more mathematical and computational complexity, PBMs are attractive due to their higher accuracy, higher fidelity, and ease of integration with thermal and degradation models. Various reduced-order PBM battery models and their computationally efficient numerical schemes have been proposed in the literature. However, there is limited data on the performance and feasibility of these models in practical embedded and cloud systems using standard programming languages. This study compares the computational performance of a single particle model (SPM), an enhanced single particle model (ESPM), and a reduced-order pseudo-two-dimensional (ROM-P2D) model under various battery cycles on embedded and cloud systems using Python and C++. The results show that reduced-order solvers can achieve a 100-fold reduction in solution times compared to full-order models, while ESPM with electrolyte dynamics is about 1.5 times slower than SPM. Adding thermal models and Kalman filters increases solution times by approximately 20% and 100%, respectively. C++ provides at least a 10-fold speed increase over Python, varying by cycle steps. Although embedded systems take longer than cloud and personal computers, they can still run reduced-order models effectively in Python, making them suitable for embedded applications. Full article

This article introduces a novel perspective on designing a stepping controller for bipedal robots. Typically, designing a state-feedback controller to stabilize a bipedal robot to a periodic orbit of step-to-step (S2S) dynamics based on a reduced-order model (ROM) can achieve stable walking. However, the model discrepancies between the ROM and the full-order dynamic system are often ignored. We introduce the latest results from behavioral systems theory by directly constructing a robust stepping controller using input-state data collected during flat-ground walking with a nominal controller in the simulation. The model uncertainty discrepancies are equivalently represented as bounded noise and over-approximated by bounded energy ellipsoids. We conducted extensive walking experiments in a simulation on a 22-degrees-of-freedom small humanoid robot, verifying that it demonstrates superior robustness in handling uncertain loads, various sloped terrains, and push recovery compared to the nominal S2S controller. Full article

Background: Posterior sternoclavicular joint (SCJ) dislocations are rare events that can evolve into real emergencies due to the vital structures in the mediastinum. When closed reduction maneuvers fail, open SCJ reconstruction becomes mandatory, with literature proposing several stabilization techniques that either preserve or remove the SCJ’s mobility. This study is a narrative review of the most recent literature regarding posterior trauma to the SCJ along with a single institution’s experience of this pathology, managed either conservatively or surgically, with a figure-of-eight autologous semitendinosus graft in case of closed reduction failure. Methods: This article provides an overview of posterior traumatic SCJ dislocation, and it describes five cases of patients managed for traumatic posterior SCJ dislocation treated either conservatively or surgically with a figure-of-eight semitendinosus tendon autograft reinforced with high-strength suture tape. A comparison with the most recent literature is performed, focusing on biomechanics. Results: The demographics, the mechanism of injury, the management algorithm and the surgical strategy align with the most recent literature. Despite the final treatment, at one year of follow-up, the ROM was restored with full strength throughout the range of motion of the shoulder with no neurological deficits. The reduced joint successfully healed in imaging, and patients returned to their daily lives. The surgical site wounds and donor harvest sites were perfectly healed. Conclusions: Although recent recommendations for treating posterior traumatic SCJ dislocation have advanced, no universally accepted method of stabilization exists, and the surgical strategy is generally entrusted to the surgeon’s experience. The literature still increasingly supports figure-of-eight ligament reconstruction with a biological or synthetic graft. This work further implements the literature by reporting good outcomes at follow-up. Full article

Background: Dissection of the axillary lymph nodes during surgery for breast cancer with lymph node involvement is burdened by a complication: lymphedema. Approximately half of women undergoing axillary dissection suffer from it, with a notable impact in terms of perceived discomfort, presented quality of life, and alteration of body image. There is also no shortage of problems in the patient’s social and professional life. Methods: The present review aims to select Randomized Controlled Trials (RCTs) present in the literature regarding the effects of yoga as an alternative therapy in patients with breast cancer-related lymphedema. A search of four databases was undertaken: Cochrane, Pubmed, Scopus, and Web of Science. The searches were conducted on 19 May 2024, and updated to 30 June 2024 without date limits. RCTs without language limitations, in any context, and with any yoga variant were considered. Results: The postulated search strings highlighted a total of 69 potentially eligible studies. The study selection system consisted of two levels of screening, (1) abstract selection and (2) full-text selection, for a total of three studies included in the review. The three RCTs included involved mixed treatment sessions in an outpatient setting with a yoga teacher and at home using a DVD. In the various studies, the outcome measures concerned quality of life, ROM, spinal mobility, limb volume, and tissue induration. Conclusions: According to the analysis of the data obtained, yoga as an alternative therapy could be useful if combined with the usual care routine in women with lymphedema related to sensory cancer, in terms of improving physical, professional, and emotional quality of life and reducing symptoms such as fatigue, pain, and insomnia. Furthermore, yoga could bring about a reduction in tissue induration of the limb, greater spinal mobility evaluated in terms of improvement of the pelvic and kyphotic angle, and greater strength in shoulder abduction. Full article

Reduced-order models (ROMs) have achieved a lot of success in reducing the computational cost of traditional numerical methods across many disciplines. In fluid dynamics, ROMs have been successful in providing efficient and relatively accurate solutions for the numerical simulation of laminar flows. For convection-dominated (e.g., turbulent) flows, however, standard ROMs generally yield inaccurate results, usually affected by spurious oscillations. Thus, ROMs are usually equipped with numerical stabilization or closure models in order to account for the effect of the discarded modes. The literature on ROM closures and stabilizations is large and growing fast. In this paper, instead of reviewing all the ROM closures and stabilizations, we took a more modest step and focused on one particular type of ROM closure and stabilization that is inspired by large eddy simulation (LES), a classical strategy in computational fluid dynamics (CFD). These ROMs, which we call LES-ROMs, are extremely easy to implement, very efficient, and accurate. Indeed, LES-ROMs are modular and generally require minimal modifications to standard (“legacy”) ROM formulations. Furthermore, the computational overhead of these modifications is minimal. Finally, carefully tuned LES-ROMs can accurately capture the average physical quantities of interest in challenging convection-dominated flows in science and engineering applications. LES-ROMs are constructed by leveraging spatial filtering, which is the same principle used to build classical LES models. This ensures a modeling consistency between LES-ROMs and the approaches that generated the data used to train them. It also “bridges” two distinct research fields (LES and ROMs) that have been disconnected until now. This paper is a review of LES-ROMs, with a particular focus on the LES concepts and models that enable the construction of LES-inspired ROMs and the bridging of LES and reduced-order modeling. This paper starts with a description of a versatile LES strategy called evolve–filter–relax (EFR) that has been successfully used as a full-order method for both incompressible and compressible convection-dominated flows. We present evidence of this success. We then show how the EFR strategy, and spatial filtering in general, can be leveraged to construct LES-ROMs (e.g., EFR-ROM). Several applications of LES-ROMs to the numerical simulation of incompressible and compressible convection-dominated flows are presented. Finally, we draw conclusions and outline several research directions and open questions in LES-ROM development. While we do not claim this review to be comprehensive, we certainly hope it serves as a brief and friendly introduction to this exciting research area, which we believe has a lot of potential in the practical numerical simulation of convection-dominated flows in science, engineering, and medicine. Full article

This study delves into the construction of reduced-order models (ROMs) of a flow field over a NACA 0012 airfoil at a moderate Reynolds number and an angle of attack of $8^{\circ }$. Numerical simulations were computed through the finite-volume solver OpenFOAM. The analysis considers two different reduction techniques: the standard Galerkin projection method, which involves projecting the governing equations onto proper orthogonal decomposition modes (POD−ROMs), and the cluster-based network model (CNM), a fully data-driven nonlinear approach. An analysis of the topology of the dominant POD modes was conducted, uncovering a traveling wave pattern in the wake dynamics. We compared the performances of both ROM techniques regarding their prediction of flow field behavior and integral quantities. The ROM framework facilitates the practical actuation of control strategies with significantly reduced computational demands compared to the full-order approach. Full article

This cross-sectional observational study aims to determine isokinetic normality data at different speeds, and isometric data of ankle and knee joints, in healthy basketball players aged 15–16 years old. The participants were recruited through non-probabilistic convenience sampling. Sociodemographic, anthropometric, and biomechanical variables were collected. The study involved 42 participants. Right-leg dominance was higher in women (85.7%) than in men (78.6%). Men had a higher weight, height, and body mass index compared to women. Statistically significant differences were observed between sex and height (p < 0.001). Significant differences were found between sexes in knee flexor and extensor strength at different isokinetic speeds (30°, 120°, and 180°/s), except for the maximum peak strength knee flexion at 180°/s in the right leg. In the ankle, the variables inversion, eversion, and work strength values at different isokinetic speeds and full RoM, by sex, were not significantly different, except for the right (p = 0.004) and the left (p = 0.035) ankle full RoM. The study found lower knee extensor strength in women, indicating the need to improve knee flexor/extensor strength in women to match that of men, as seen in other joints. The results can guide the development of preventive and therapeutic interventions for lower limb injuries in basketball players. Full article

(1) Background: Chronic non-bacterial osteomyelitis (CNO), also known as sclerosing osteomyelitis of Garrè, is a rare inflammatory bone disease with a specific clinical picture, uncertain pathogenesis, and no consensus on an effective treatment. Most frequently affecting other long bones, CNO may rarely involve the clavicle. The aim of this study was to present the results of a series of patients affected by CNO of the clavicle treated with total and partial clavicula resection. In addition, a literature review of different types of treatment of CNO was performed. (2) Methods: We retrospectively reviewed three patients with Sclerosing Osteomyelitis of Garre’ of the clavicle treated with partial resection of the clavicle (one) and with total clavicular resection (two). (3) Results: Patients (two female and one male) were an average age of 35.7 years at the time of the operation. At the 4-year follow-up, the mean active ROM was: 143° forward flexion, 133° abduction, 42° external rotation with an internal rotation of two patients at the interscapular level and one patient at the lumbosacral junction. The mean ASES score was 92/100 (range 87–100). In the literature review, after screening the abstracts and full texts for eligibility, 34 studies met the inclusion criteria. Conclusions: Partial or total clavicular resection resulted an effective treatment of CNO of the clavicle. The procedure seems to be particularly indicated after the failure of more conservative treatments. Full article

Background: It is not clear whether rehabilitation after surgery for trigger finger is effective. The aim of this study was to reveal its effectiveness for trigger finger. Methods: This study was a randomized, controlled trial that included patients who underwent operations for trigger fingers. The patients in the rehabilitation group had postoperative occupational therapy (OT) for 3 months, while the patients in the control group were not referred for rehabilitation but received advice for a range of motion exercises. We evaluated the severity of trigger finger, Disability of Arm-Shoulder-Hand (DASH) score, pain-visual analogue scale (VAS), grip strength, whether they gained a full range of motion (ROM), and complications before and after surgery. Results: Finally, 29 and 28 patients were included in the control and rehabilitation groups, respectively. At final follow-up, the DASH score, grip strength, and ROM were significantly improved in the rehabilitation group compared to that preoperatively. At final follow-up, pain was significantly improved in both groups from that preoperatively. There were no significant differences in the results, including the DASH score, grip strength, ROM and pain-VAS between the control and rehabilitation groups at the final follow-up. Subgroup analysis showed that there is a significant difference in the DASH score of patients doing housework or light work and those with a duration of symptoms >12 months between the control and rehabilitation groups at the final follow-up. Full article

Badminton, a dynamic racquet sport demanding agility and power, features the overhead forehand smash as a pivotal offensive shot. Utilizing 3D motion analysis, this research delves into the intricate biomechanical facets underpinning this pivotal shot, with a dual focus on both novice and proficient players. Through a comparative analysis of these two player cohorts, the investigation aims to elucidate the fundamental factors influencing the quality of the forehand smash. Our findings reveal that skilled players exhibit significant improvements in smash quality, including a 60.2% increase in shuttlecock speed, reduced clearance height, and flight angle at release. These enhancements are associated with specific determinants, such as consistent positioning, racket angle at impact, and range of motion (ROM) in various joints. More crucially, full-body tension-arc formation and a four-segment whip-like smash contribute to these improvements. Unique to the whip-like smash is the rapid trunk and shoulder rotations in early whip-like control inducing passive elbow flexion and wrist over-extension, enhancing the stretch-shortening cycle (SSC) effect of muscles for a more powerful smash. Emphasizing this uniqueness and the determinants simplify smash learning, potentially boosting training effectiveness. This research contributes to a deeper understanding of badminton’s biomechanics and offers practical implications for coaches and players to enhance their forehand smashes, especially among beginners. Full article

Purpose: This study quantifies the gait characteristics of patients with degenerative lumbar scoliosis (DLS) and patients with simple lumbar spinal stenosis (LSS) by means of a three-dimensional gait analysis system, aiming to determine the image of spinal deformity on gait and the correlation between spinal–pelvic parameters and gait characteristics in patients with DLS to assist clinical work. Methods: From June 2020 to December 2021, a total of 50 subjects were enrolled in this study, of whom 20 patients with DLS served as the case group and 30 middle-aged and elderly patients with LSS were selected as the control group according to the general conditions (sex, age, and BMI) of the case group. Spinal–pelvic parameters were measured by full-length frontal and lateral spine films one week before surgery, and kinematics were recorded on the same day using a gait analysis system. Results: Compared to the control group, DLS patients exhibited significantly reduced velocity and cadence; gait variability and symmetry of both lower limbs were notably better in the LSS group than in the DLS group; joint ROM (range of motion) across multiple dimensions was also lower in the DLS group; and correlation analysis revealed that patients with a larger Cobb angle, T1PA, and higher CSVA tended to walk more slowly, and those with a larger PI, PT, and LL usually had smaller stride lengths. The greater the PI-SS mismatch, the longer the patient stayed in the support phase. Furthermore, a larger Cobb angle correlated with worse coronal hip mobility. Conclusions: DLS patients demonstrate distinctive gait abnormalities and reduced hip mobility compared to LSS patients. Significant correlations between crucial spinopelvic parameters and these gait changes underline their potential influence on gait disturbances in DLS. Our study identifies a Cobb angle cut-off of 16.1 as a key predictor for gait abnormalities. These insights can guide personalized treatment and intervention strategies, ultimately improving the quality of life for DLS patients. Full article

This study aimed to evaluate the reliability of the RSQ Motion sensor and its validity against the Propriometer and electronic goniometer in measuring the active range of motion (ROM) of the shoulder. The study included 15 volunteers (mean age 24.73 ± 3.31) without any clinical symptoms with no history of trauma, disease, or surgery to the upper limb. Four movements were tested: flexion, abduction, external and internal rotation. Validation was assessed in the full range of active shoulder motion. Reliability was revised in full active ROM, a fixed angle of 90 degrees for flexion and abduction, and 45 degrees for internal and external rotation. Each participant was assessed three times: on the first day by both testers and on the second day only by one of the testers. Goniometer and RSQ Motion sensors showed moderate to excellent correlation for all tested movements (ICC 0.61–0.97, LOA < 23 degrees). Analysis of inter-rater reliability showed good to excellent agreement between both testers (ICC 0.74–0.97, LOA 13–35 degrees). Analysis of intra-rater reliability showed moderate to a good agreement (ICC 0.7–0.88, LOA 22–37 degrees). The shoulder internal and external rotation measurement with RSQ Motion sensors is valid and reliable. There is a high level of inter-rater and intra-rater reliability for the RSQ Motion sensors and Propriometer. Full article