Search Results (431)

Humanoid robots have attracted considerable attention for their anthropomorphic structure, extended workspace, and versatile capabilities. This paper presents a novel humanoid upper-body robotic system comprising a pair of 8-degree-of-freedom (DOF) arms, a 3-DOF head, and a 3-DOF torso—yielding a 22-DOF architecture inspired by human biomechanics and implemented via standardized hollow joint modules. To overcome the critical reliance of zeroing neural network (ZNN)-based trajectory tracking on the Jacobian matrix derivative, we propose an integration-enhanced matrix derivative observer (IEMDO) that incorporates nonlinear feedback and integral correction. The observer is theoretically proven to ensure asymptotic convergence and enables accurate, real-time estimation of matrix derivatives, addressing a fundamental limitation in conventional ZNN solvers. Workspace analysis reveals that the proposed design achieves an 87.7% larger total workspace and a remarkable 3.683-fold expansion in common workspace compared to conventional dual-arm baselines. Furthermore, the observer demonstrates high estimation accuracy for high-dimensional matrices and strong robustness to noise. When integrated into the ZNN controller, the IEMDO achieves high-precision trajectory tracking in both simulation and real-world experiments. The proposed framework provides a practical and theoretically grounded approach for redundant humanoid arm control. Full article

The stability of shield tunnel segmental linings is highly sensitive to the lateral pressure coefficient, especially under weak, heterogeneous, and variable geological conditions. However, the mechanical behavior of steel plate-reinforced linings under such conditions remains insufficiently characterized. This study aims to investigate the effects of varying lateral pressures on the structural performance of reinforced tunnel linings. To achieve this, a custom-designed full-circumference loading and unloading self-balancing apparatus was developed for scaled-model testing of shield tunnels. The experimental methodology allowed for precise control of loading paths, enabling the simulation of realistic ground stress states and the assessment of internal force distribution, joint response, and load transfer mechanisms during the elastic stage of the structure. Results reveal that increased lateral pressure enhances the stiffness and bearing capacity of the reinforced lining. The presence and orientation of segment joints, as well as the bonding performance between epoxy resin and expansion bolts at the reinforcement interface, significantly influence stress redistribution in steel plate-reinforced zones. These findings not only deepen the understanding of tunnel behavior in complex geological environments but also offer practical guidance for optimizing reinforcement design and improving the durability and safety of shield tunnels. Full article

This paper investigates the problem of tracking targets with unknown but fixed 3D star-convex shapes using point cloud measurements. While existing methods typically model shape parameters as random variables evolving according to predefined prior models, this evolution process is often unknown in practice. We propose a particular approach within the Expectation Conditional Maximization (ECM) framework that circumvents this limitation by treating shape-defining quantities as parameters estimated directly via optimization. The objective is the joint estimation of target kinematics, extent, and orientation in 3D space. Specifically, the 3D shape is modeled using a radial function estimated via double Fourier series (DFS) expansion, and orientation is represented using the compact, singularity-free axis-angle method. The ECM algorithm facilitates this joint estimation: an Unscented Kalman Smoother infers kinematics in the E-step, while the M-step estimates DFS shape parameters and rotation angles by minimizing regularized cost functions, promoting robustness and smoothness. The effectiveness of the proposed algorithm is substantiated through two experimental evaluations. Full article

The varying characteristics of grid-connected energy resources necessitate a clear and effective approach for managing and scheduling generation units. Without proper control, high levels of renewable integration can pose challenges to optimal dispatch, especially as more generation sources, like wind and solar PV, are introduced. As a result, conventional power sources require an advanced management system, for instance, a virtual power plant (VPP), capable of accurately monitoring power supply and demand. This study thoroughly explores the dispatch of battery energy storage systems (BESSs) and diesel generators (DGs) through a distributionally robust joint chance-constrained optimization (DR-JCCO) framework utilizing the conditional value at risk (CVaR) and heuristic-X (H-X) algorithm, structured as a bilevel optimization problem. Furthermore, Binomial expansion (BE) is employed to linearize the model, enabling the assessment of BESS dispatch through a mathematical program with equilibrium constraints (MPECs). The findings confirm the effectiveness of the DRO-CVaR and H-X methods in dispatching grid network resources and BE under the MPEC framework. Full article

Effective real-time control systems require fast and accurate models. The thermal profile models of the rolls presented in this paper are proposed for a real-time control system for the design of the rolling schedule. The thermal profile of the roll defines the shape of the roll surface, its convexity, and, finally, the shape of the final product of the flat rolling, its convexity, and flatness. This paper presents accurate semi-analytical and finite element (FE) models, which serve to obtain an accurate solution of the joint thermal and mechanical problem, that is, heat transfer and thermal expansion. The results of the FE simulation are used for training the developed thermal model based on the neural network (NN) and for the creation of a dynamic reduced order model (ROM) of the roll surface profile. The pre-trained NN model gives accurate results and is faster than the FE model, but the model is not very useful for fast calculations in a real-time control system, mainly because the temperature distribution inside the rolls is not explicitly used in further calculations. In contrast, the ROM is fast and accurate and provides surface-shaped results that can be immediately used by other models of the real-time control system. The results of the simulation of the real process are also shown. Calculations of the roll campaign (more than 9 h) by the FEM model last several hours, while by the ROM less than 20 s. Full article

Background: Adhesive capsulitis (AC) causes a global limitation of both active and passive range of motion (ROM) in the shoulder, with or without pain, and no specific radiographic findings. Its course is self-limiting and progresses through three or four stages. The diagnosis is primarily clinical, since imaging tests are nonspecific. Treatment options include physical therapy (PT), intra-articular corticosteroid injections, suprascapular nerve block (SSNB), and hydrodilatation (HD). The latter is useful for expanding and reducing inflammation of the joint capsule through the insufflation of saline solution, anesthetics, and corticosteroids. Objectives: To compare whether patients with AC, stratified by phase 1 and 2, who receive high-volume HD as treatment achieve better outcomes in terms of shoulder pain and function compared to patients who receive low-volume HD. To compare whether there are differences in PT times and to determine mean axillary recess (AR) values. Methods: A randomized, parallel-block, triple-blind clinical trial will be conducted in 64 patients with AC in phases 1 and 2, aged 30 to 70 years, with limited active and passive ROM in two planes, and shoulder pain lasting more than 3 months. HD will be administered with volumes of 20 mL or 40 mL, followed by a conventional rehabilitation program. Outcomes will be reviewed at the 1st, 3rd, and 6th months of HD. Variables collected will include Shoulder Pain and Disability Index (SPADI), Visual Analog Scale (VAS), Range of motion (ROM), Lattinen index (LI), AR size, and time to completion of PT. Results: HD has been gaining clinical relevance in interventional rehabilitation as a treatment for AC, although its medium- and long-term efficacy remains a matter of debate. The variability in the volumes used for capsular expansion, with studies ranging from 18 mL to 47 mL, is compounded by the fact that most of these studies do not differentiate between AC stages. This could influence treatment effectiveness. Furthermore, diagnosis remains a challenge since valid and specific diagnostic parameters are lacking. Conclusions: Understanding the differences between HD techniques, considering the influence of certain factors such as the volume used or the stages of AC, as well as improving diagnosis and the coordination of scientific work. This could facilitate the development of protocols for the use of HD in AC. Full article

The European Health Technology Assessment (HTA) regulation (HTAR) came into effect in January 2025 and impacts the HTA process in all European Member States. Member States must give due consideration to the joint clinical assessment (JCA) report. This may require adaptations at the national level. This paper describes the anticipated changes to the Dutch national HTA process and how the Dutch National Health Care Institute (Zorginstituut Nederland, ZIN) prepared for this, because sharing experience between Member States can be of general interest for future expansion of the EU HTAR. ZIN’s implementation activities were facilitated by a project-governance structure and by a continuous gap analysis of the current national assessment and appraisal process of medicinal products, resulting in a concrete action plan. The implementation of the HTAR has two major implications for ZIN’s HTA process, namely that the scoping phase starts much earlier and that the JCA report is the starting point for the national assessment. Gaps, challenges and issues were identified in the categories: information and knowledge, IT and template, communication and stakeholder engagement, capacity and resources, and financial aspects. Based on a thorough and well-defined implementation plan, ZIN is ready to implement the HTAR in national HTA processes and to take on (co-)assessor roles for JCA of medicinal products in 2025. Full article

Obesity, characterized by excessive or abnormal accumulation of body fat, is associated with a range of metabolic and inflammatory diseases, including osteoarthritis (OA). In obese individuals, adipose tissue expansion—via adipocyte hypertrophy or hyperplasia—is accompanied by altered secretion of adipokines such as leptin and adiponectin, which play significant roles in immune modulation, metabolism, and skeletal homeostasis. Leptin, acting through the hypothalamus, regulates the sympathetic nervous system and modulates hormonal axes, influencing bone metabolism and cartilage integrity. Elevated leptin concentrations in the synovial fluid, and the presence of its receptors on cartilage surfaces, suggest its direct role in cartilage degradation and OA progression. Conversely, adiponectin exerts anti-inflammatory effects, modulates osteoblast and macrophage activity, and appears to have a protective function in joint metabolism. These findings underscore the complex interplay between the adipose tissue, adipokines, and the osteochondral unit, highlighting the importance of their balance in maintaining joint health. Full article

The swift expansion of China’s automotive manufacturing industry has spurred a constant rise in the demand for automotive parts production and distribution, making the optimization of distribution routes in complex environments a crucial research topic. Efficiently optimizing these routes not only boosts production efficiency and cuts costs for automotive manufacturers but also enhances supply chain management and advances sustainable development. This study focuses on the optimization of automotive parts distribution routes under a multi-manufacturer collaboration framework. An optimization model is proposed to minimize the total operational costs within a joint distribution system, incorporating an improved Ant Colony Optimization (ACO) algorithm to formulate an effective solution approach. The model considers complex factors such as dynamic demand, time-window constraints, and periodic distribution. A PIVNS algorithm integrating a virtual distribution center with an enhanced variable neighborhood search is designed to efficiently address the problem. The efficacy of the proposed model and algorithm is substantiated through extensive experiments grounded in real-world case studies. The results confirm the high computational efficiency of the proposed approach in solving large-scale problems, which significantly reduces distribution costs while improving overall supply chain performance. Specifically, the PIVNS algorithm achieves an average travel distance of 2020.85 km, an average runtime of 112.25 s, a total transportation cost of CNY 12,497.99, and a loading rate of 86.775%. These findings collectively highlight the advantages of the proposed method in enhancing efficiency, reducing costs, and optimizing resource utilization. Overall, this study provides valuable insights for logistics optimization in automotive manufacturing and offers a significant reference for future research and practical applications in the field. Full article

Due to the long operation period of Beijing Metro Line 2 and the complex surrounding building environment, this paper comprehensively studied the mechanical properties of new tunnels using close-fitting undercrossing based on pre-support technology. To control structural deformation caused by the expansion project, methods such as laboratory tests, numerical simulation, and field tests were adopted to systematically analyze the tunnel mechanics during the undercrossing of existing metro lines. First, field tests were carried out on the existing Line 2 and Line 3 tunnels during the construction period. It was found that the close-fitting construction based on pre-support technology caused small deformation displacement in the subway tunnels, with little impact on the smoothness of the existing subway rail surface. The fluctuation range was −1 to 1 mm, ensuring the safety of existing subway operations. Then, a refined finite difference model for the close-fitting undercrossing construction process based on pre-support technology was established, and a series of field and laboratory tests were conducted to obtain calculation parameters. The reliability of the numerical model was verified by comparing the monitored deformation of existing structures with the simulated structural forces and deformations. The influence of construction methods on the settlement changes of existing line tracks, structures, and deformation joints was discussed. The research results show that this construction method effectively controls the settlement deformation of existing lines. The settlement deformation of existing lines is controlled within 1~3 cm. The deformation stress of the existing lines is within the concrete strength range of the existing structure, and the tensile stress is less than 3 MPa. The maximum settlement and maximum tensile stress of the station in the pre-support jacking scheme are −5.27 mm and 2.29 MPa. The construction scheme with pre-support can more significantly control structural deformation, reduce stress variations in existing line structures, and minimize damage to concrete structures. Based on the monitoring data and simulation results, some optimization measures were proposed. Full article

Aluminum alloy, due to its low melting point and high thermal conductivity, deforms and contracts significantly during welding. To mitigate this and achieve full penetration in a single pass, this study uses GTAW (Gas Tungsten Arc Welding) additive manufacturing and optimizes welding groove parameters via the Box-Behnken Response Surface Methodology. The focus is on improving tensile strength and penetration depth by analyzing the effects of groove angle, root face width, and root gap. The results show that groove angle most significantly affects tensile strength and penetration depth. Hardness profiles exhibit a W-shape, with base material hardness decreasing and weld zone hardness increasing as groove angle rises. Root face width reduces hardness fluctuation in the weld zone, and an appropriate root gap compensates for thermal expansion, enhancing joint performance. The interaction between root face width and root gap most impacts tensile strength, while groove angle and root face width interaction most affects penetration depth. The optimal welding parameters for 7xxx aluminum alloy GTAW are a groove angle of 70.8°, root face width of 1.38 mm, and root gap of 0 mm. This results in a tensile strength of 297.95 MPa and penetration depth of 5 mm, a 90.38% increase in tensile strength compared to the RSM experimental worst group. Microstructural analysis reveals the presence of β-Mg₂Si and η-MgZn₂ strengthening phases, which contribute to the material’s enhanced mechanical properties. Fracture surface examination exhibits characteristic ductile fracture features, including dimples and shear lips, confirming the material’s high ductility. The coexistence of these strengthening phases and ductile fracture behavior indicates excellent overall mechanical performance, balancing strength and plasticity. Full article

The development of thermoelectric modules based on skutterudite materials requires stable, low-resistance interfaces between segments operating at different temperature ranges. This study investigates the microstructure, thermoelectric performance, and thermal stability of the following two joints: In_0.4Co₄Sb₁₂/Co₄Sb_10.8Te_0.6Se_0.6 (n-type) and CeFe₃Co_0.5Ni_0.5Sb₁₂/In_0.25Co₃FeSb₁₂ (p-type), fabricated by pulse plasma sintering (PPS). Scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) analyses confirmed the formation of well-bonded interfaces without pores or cracks. Aging at 773 K for 168 h did not result in morphological or chemical degradation, and phase composition remained unchanged according to X-ray diffraction (XRD). Surface Seebeck coefficient mapping and contact resistance measurements showed negligible changes after annealing, confirming electrical stability. To provide context for potential applications, theoretical energy conversion efficiencies were estimated based on measured thermoelectric properties, yielding 13.2% and 10.1% for the n- and p-type segmented legs, respectively. Additionally, measured coefficients of thermal expansion (CTE) indicated low mismatch between jointed materials, supporting good mechanical compatibility. The results demonstrate that the selected material combinations are thermally, chemically, and electrically stable and can be effectively used in segmented thermoelectric legs for intermediate-temperature applications. Full article

Objective: Inflammatory arthritis (IA) has been linked to a number of adverse pregnancy outcomes (APOs), but the mechanisms linking IA-related immune dysregulation to compromised reproductive success remain poorly understood. This project will examine how IA affects pregnancy outcomes and alters the associated immune microenvironment using SKG (ZAP70^W163C) mice, a mouse model that suffers from arthritis resembling human IA. Methods: IA was induced in SKG mice on a C57BL/6J background via mannan exposure. Wild-type C57BL/6 mice served as controls. Pregnancy rates, conception time, embryo resorption rates, and immune parameters (cytokine levels and splenic/lymph node/placental immune cell subsets) were analyzed. Joint pathology was evaluated via histology (HE is staining) and anti-CCP antibody levels. Flow cytometry was used to analyze immune populations within the spleen along with the associated lymphatic nodes. Results: Synovial hyperplasia, elevated anti-CCP, and systemic inflammation were all observed in IA mice. Compared to controls, IA mice demonstrated a reduced mating success rate, prolonged conception time, decreased pregnancy rates, and increased embryo resorption. IA mice showed elevated Th1/Th17 cytokines-IFN-γ, TNF-α, and IL-17, and an expansion of pro-inflammatory immune cells, including NK cells, CD11b+ myeloid cells, neutrophils, M1 macrophages, and Tc1, in the spleen/lymph nodes. Placental immune dysregulation featured increased NKT, NK, and CD4+ cell infiltration. Conversely, anti-inflammatory subsets, such as M2 macrophages and dendritic cells, were reduced. Conclusions: IA increased APOs and skewed the immune microenvironment toward a pro-inflammatory state dominated by Th1/Th17/Tc1 responses and cytotoxic cell activation. These findings highlight immune dysregulation as a key driver of IA-associated pregnancy complications, providing mechanistic insights for therapeutic intervention. Full article

In recent years, forest education has become a critical element in global environmental governance. This study employed the CiteSpace tool to systematically analyze 2917 titles of the forest education literature from the Web of Science Core Collection. The goal was to explore the spatial and temporal trends, thematic evolution, and emerging research directions in this field. The research shows that in recent years, the annual number of published papers on forest education has been on a continuous upward trend, and the attention to the subject has increased significantly. The research field mainly takes the United States in North America as the core center, with the joint participation of scholars from Europe and Asia. The development trajectory of the discipline shows a trend of gradual expansion toward multidisciplinary intersections and multidisciplinary integration based on traditional forestry and environmental sciences. Research hotspots mainly focus on core issues such as forest management, climate change, ecosystem services, and biodiversity. In recent years, they have expanded to include willingness to pay, prevalence, and student groups. It is expected that the research focus in the coming years will be on the cross-cutting issues of integrating forests with the economy, social public health, environmental protection, and sustainable development. Full article

The unprecedented expansion of wireless networks has resulted in spectrum sharing between numerous connected devices, demanding advanced interference management and higher energy consumption, which exacerbates the carbon footprint. Near-field communication emerges as a promising solution to these challenges as it enables precise signal focusing which reduces power consumption by providing higher spatial multiplexing gains. This review explores how near-field (NF) multiple-input multiple-output (MIMO) beamforming can enhance energy efficiency by optimizing beamfocusing and minimizing unnecessary energy expenditure. We discuss the latest advancements in near-field beamforming, emphasizing energy-efficient strategies and sustainable practices. Recognizing which practical channel models are better suited for near-field communication, we delve into the integration of Electromagnetic Information Theory (EIT) as a joint model for realistic applications. We also discuss the channel models for near-field beamforming, incorporating EIT to provide a comprehensive overview of current methodologies. We further analyze the strengths and limitations of existing channel models and discuss the state-of-the-art models which address existing gaps. We also explore opportunities for the practical deployment of energy-efficient near-field beamforming systems. By summarizing future research directions, this review aims to advance the understanding and application of sustainable energy practices in near-field communication technologies. Full article