Search Results (87)

Process monitoring plays a vital role in ensuring quality stability, and, operational efficiency across fields such as manufacturing, finance, biomedical science, and environmental monitoring. Among statistical tools, control charts are widely adopted for detecting variability and abnormal patterns. Since the introduction of the basic X-bar control chart by Shewhart in the 1920s, various improved methods have emerged to address the challenge of identifying small and latent process shifts, including CUSUM, MA, EWMA, and Exp-EWMA control charts. This study introduces a novel control chart—the Moving Average–Exponentiated Exponentially Weighted Moving Average (MA-Exp-EWMA) control chart—combining the smoothing effect of MA and the adaptive weighting of Exp-EWMA. Its goal is to improve the detection of small shifts and gradual changes. Performance is evaluated using average run length (ARL), standard deviation of run length (SDRL), and median run length (MRL). Monte Carlo simulations under different distributions (normal, exponential, gamma, and Student’s t) and parameter settings assess the control chart’s sensitivity under various shift scenarios. Comparisons with existing control charts and an application to real data demonstrate the practical effectiveness of the proposed method in detecting small shifts. Full article

The dynamic contact problem describing collision of an elastic bar with a rigid obstacle, prescribed by an initial velocity, is considered in a variational formulation. The non-smooth, piecewise-linear solution is constructed analytically using partition of a 2D rectangular domain along characteristics. Challenged by the discontinuous velocity after collision, full discretization of the problem is applied that is based on a space-time finite element method. For an iterative solution of the discrete variational inequality, a primal–dual active set algorithm is used. Computer simulation of the collision problem is presented on uniform triangle grids. The active sets defined in the 2D space-time domain converge in a few iterations after re-initialization. The benchmark solution at grid points is indistinguishable from the analytical solution. The discrete energy has no dissipation, it is free of spurious oscillations, and it converges super-linearly under mesh refinement. Full article

The widespread deployment of electric vehicles (EVs) has introduced substantial challenges to electricity pricing, grid stability, and renewable energy integration. This paper proposes a real-time pricing optimization framework for large-scale EV charging networks incorporating renewable intermittency, demand elasticity, and infrastructure constraints within a high-dimensional optimization model. The core objective is to dynamically determine spatiotemporal electricity prices that simultaneously reduce system peak load, improve renewable energy utilization, and minimize user charging costs. A rigorous mathematical formulation is developed integrating over 40 system-level constraints, including power balance, transmission capacity, renewable curtailment, carbon targets, voltage regulation, demand-side flexibility, social participation, and cyber resilience. Real-time electricity prices are treated as dynamic decision variables influenced by charging station utilization, elasticity response curves, and the marginal cost of renewable and grid-supplied electricity. The problem is solved over 96 time intervals using a hybrid solution approach, with benchmark comparisons against mixed-integer programming (MILP) and deep reinforcement learning (DRL)-based baselines. A comprehensive case study is conducted on a 500-station EV charging network serving 10,000 vehicles integrated with a modified IEEE 118-bus grid model and 800 MW of variable renewable energy. Historical charging data with ±12% stochastic demand variation and real-world solar and wind profiles are used to simulate realistic operational conditions. Results demonstrate that the proposed framework achieves a 23.4% average peak load reduction per station, a 17.9% improvement in renewable energy utilization, and user cost savings of up to 30% compared to baseline flat-rate pricing. Utilization imbalances across the network are reduced, with congestion mitigation observed at over 90% of high-traffic stations. The real-time pricing model successfully aligns low-price windows with high-renewable periods and off-peak hours, achieving time-synchronized load shifting and system-wide flexibility. Visual analytics including high-resolution 3D surface plots and disaggregated bar charts reveal structured patterns in demand–price interactions, confirming the model’s ability to generate smooth, non-disruptive pricing trajectories. The results underscore the viability of advanced optimization-based pricing strategies for scalable, clean, and responsive EV charging infrastructure management in renewable-rich grid environments. Full article

Study design: The advent of the Matrix Wave^TM System (Depuy-Synthes)—a bone-anchored Mandibulo-Maxillary Fixation (MMF) System—merits closer consideration because of its peculiarities. Objective: This study alludes to two preliminary stages in the evolution of the Matrix Wave^TM MMF System and details its technical and functional features. Results: The Matrix Wave^TM System (MWS) is characterized by a smoothed square-shaped Titanium rod profile with a flexible undulating geometry distinct from the flat plate framework in Erich arch bars. Single MWS segments are Omega-shaped and carry a tie-up cleat for interarch linkage to the opposite jaw. The ends at the throughs of each MWS segment are equipped with threaded screw holes to receive locking screws for attachment to underlying mandibular or maxillary bone. An MWS can be partitioned into segments of various length from single Omega-shaped elements over incremental chains of interconnected units up to a horseshoe-shaped bracing of the dental arches. The sinus wave design of each segment allows for stretch, compression and torque movements. So, the entire MWS device can conform to distinctive spatial anatomic relationships. Displaced fragments can be reduced by in-situ-bending of the screw-fixated MWS/Omega segments to obtain accurate realignment of the jaw fragments for the best possible occlusion. Conclusion: The Matrix Wave^TM MMF System is an easy-to-apply modular MMF system that can be assembled according to individual demands. Its versatility allows to address most facial fracture scenarios in adults. The option of “omnidirectional” in-situ-bending provides a distinctive feature not found in alternate MMF solutions. Full article

Testing and the estimation methods for predicting the life of crack initiation and crack growth for P92 steel using a circular sharp notched round bar specimen (CNS) under strain-controlled creep and fatigue conditions have been reported previously. A unique estimation method for the cycle-sequential characteristics of tensile and compressive peak stresses is proposed; specifically, the nominal stress range ${∆\sigma }_{net}={{(\sigma }_{max}-{\sigma }_{min})}_{net}$ and the measurement of crack length using the direct current electric potential drop (DCPD) method were adopted. This method was effective in specifying the failure life and crack initiation life by verifying the crack growth length. However, to show the universality of these results, it is important to compare the experimental results obtained under strain-controlled creep and fatigue conditions with those obtained under stress-controlled creep and fatigue conditions and with those for smooth specimens estimated based on the linear and nonlinear damage summation rule. Furthermore, it may also be important to compare these results with those of smooth specimens estimated based on the Manson–Coffin law when the failure life is fatigue-dominant. Considering these aspects, detailed experiments and analyses were systematically conducted for P92 steel in this study, and the above comparisons were conducted. The results aid in achieving a unified understanding of the law of fracture life, including those under stress- and strain-controlled creep and fatigue conditions. Full article

Rainfall simulators are essential tools in soil research, providing a controlled and repeatable approach to studying rainfall-induced erosion. However, the development of high-fidelity rainfall simulators remains a challenge. This study aimed to design, construct, and calibrate a spraying-type rainfall simulator and validate assessment criteria optimized for soil erosion research. The simulator’s design is based on a modified simulator model previously described in the literature and following the defined criteria. The calibration of the simulator was conducted in two phases, on slopes of 0° and 15°, measuring rainfall intensity, drop size, and its spatial distribution, and calculating drop falling velocity, kinetic energy, and momentum. The simulator consists of structural support, a water tank, a water-moving mechanism, a flow regulation system, and sprayers, contributing to its simplicity, cost-effectiveness, durability, rigidity, and stability, ensuring smooth simulator operation. The calibration of the rainfall simulator demonstrated that rainfall intensity increased from 1.4 mm·min⁻¹ to 4.6 mm·min⁻¹ with higher pressure in the hydraulic system (1.0 to 2.0 bar), while spatial uniformity remained within 79–91% across different nozzle configurations. The selected Rain Bird HE-VAN series nozzles proved highly effective in simulating rainfall, achieving drop diameters ranging from 0.8 mm to 1.9 mm, depending on pressure and nozzle type. The rainfall simulator successfully replicates natural rainfall characteristics, offering a controlled environment for investigating soil erosion processes. Drop velocity values varied between 2.5 and 2.9 m·s⁻¹, influencing kinetic energy, which ranged from 0.6 J·min⁻¹·m⁻² to 2.9 J·min⁻¹·m⁻², and impact momentum, which was measured between 0.005 N·s and 0.032 N·s. The simulator design suggests that it is suitable for future applications in both field and laboratory soil erosion research, ensuring repeatability and adaptability for various experimental conditions. Calibration results emphasized the significance of nozzle selection and water pressure adjustments. These factors significantly affect rainfall intensity, drop size, kinetic energy, and momentum, parameters that are critical for accurate erosion modeling. Full article

This paper focuses on the formidable challenges that underwater robots encounter in complex marine environments. To address these issues, inspired by the cownose ray, an innovative scheme is proposed, utilizing four six-bar mechanisms to mimic its pectoral fin movement. Subsequently, the paper elaborates on the design, computation, and simulation of the bionic pectoral fin mechanism. A Watt-type six-bar mechanism is adopted, and by axially overlaying two scaled-identical mechanisms and setting a phase difference, the pectoral fin waving of the cownose rays is simulated. SolidWorks and ADAMS are employed for precise modeling and simulation. Following this, an experimental prototype is constructed, with the rod assembly produced by subtractive machining. Motion capture and six-dimensional force experiments are then conducted to evaluate its motion dynamics and propulsion efficacy. The experimental results demonstrate that when the two pectoral fins on either side flap synchronously or inversely, the robot can generate varying thrust, lift, and lateral forces, enabling smooth advancement and turning. These findings validate the feasibility and efficacy of bionic design, offering innovative concepts and methodologies for underwater robot development. Full article

The widespread deployment of electric vehicles (EVs) has introduced substantial challenges to electricity pricing, grid stability, and renewable energy integration. This paper presents the first real-time quantum-enhanced electricity pricing framework for large-scale EV charging networks, marking a significant departure from existing approaches based on mixed-integer programming (MILP) and deep reinforcement learning (DRL). The proposed framework incorporates renewable intermittency, demand elasticity, and infrastructure constraints within a high-dimensional optimization model. The objective is to dynamically determine spatiotemporal electricity prices that reduce system peak load, improve renewable utilization, and minimize user charging costs. A rigorous mathematical formulation is developed, integrating over 40 system-level constraints, including power balance, transmission limits, renewable curtailment, carbon targets, voltage regulation, demand-side flexibility, social participation, and cyber-resilience. Real-time electricity prices are treated as dynamic decision variables influenced by station utilization, elasticity response curves, and the marginal cost of renewable and grid electricity. The model is solved across 96 time intervals using a quantum-classical hybrid method, with benchmark comparisons against MILP and DRL baselines. A comprehensive case study is conducted on a 500-station EV network serving 10,000 vehicles, coupled with a modified IEEE 118-bus grid and 800 MW of variable renewable energy. Historical charging data with ±12% stochastic demand variation and real-world solar/wind profiles are used to simulate realistic conditions. Results show that the proposed framework achieves a 23.4% average peak load reduction per station, a 17.9% gain in renewable utilization, and up to 30% user cost savings compared to flat-rate pricing. Network congestion is mitigated at over 90% of high-traffic stations. Pricing trajectories align low-price windows with high-renewable periods and off-peak hours, enabling synchronized load shifting and enhanced flexibility. Visual analytics using 3D surface plots and disaggregated bar charts confirm structured demand-price interactions and smooth, stable price evolution. These findings validate the potential of quantum-enhanced optimization for scalable, clean, and adaptive EV charging coordination in renewable-rich grid environments. Full article

Pipeline steel is highly susceptible to hydrogen embrittlement (HE) in hydrogen environments, which compromises its structural integrity and operational safety. Existing studies have primarily focused on the degradation trends of mechanical properties in hydrogen environments, but there remains a lack of quantitative failure prediction models. To investigate the failure behavior of X65 pipeline steel under hydrogen environments, this paper utilized notched round bar specimens with three different radii and smooth round bar specimens to examine the effects of pre-charging time, the coupled influence of stress triaxiality and hydrogen concentration, and the coupled influence of strain rate and hydrogen concentration on the HE sensitivity of X65 pipeline steel. Fracture surface morphologies were characterized using scanning electron microscopy (SEM), revealing that hydrogen-enhanced localized plasticity (HELP) dominates failure mechanisms at low hydrogen concentrations, while hydrogen-enhanced decohesion (HEDE) becomes dominant at high hydrogen concentrations. The results demonstrate that increasing stress triaxiality or decreasing strain rate significantly intensifies the HE sensitivity of X65 pipeline steel. Based on the experimental findings, failure prediction models for X65 pipeline steel were developed under the coupled effects of hydrogen concentration and stress triaxiality as well as hydrogen concentration and strain rate, providing theoretical support and mathematical models for the engineering application of X65 pipeline steel in hydrogen environments. Full article

To investigate the micromechanical fracture behavior of high-strength steel, an integrated experimental and numerical study was conducted on Q460C steel and its welded joints, with specimens extracted from the base metal, weld metal, and the heat-affected zone (HAZ). Eighteen smooth round bars were tested under monotonic and cyclic loading to analyze mechanical performance and stress–strain curves. A constitutive model was developed based on the experimental results and numerical simulations. Additionally, eighteen notched round bars with three different notch sizes and three different zones were tested under monotonic loading, and thirty-six notched round bars with three different notch sizes, three different zones, and two loading protocols were tested under cyclic loading. The stress-modified critical strain model (SMCS) and void growth model (VGM) were calibrated and validated using the test results. The study reveals that the HAZ is more susceptible to cracking under cyclic loading. A positive correlation between toughness parameters and plasticity was discovered. The validated VGM and SMCS provide a reliable tool for predicting ductile fracture in Q460C steel and its welds, offering significant insights for the design and safety assessment of high-strength steel structures. Full article

This paper presents experimental results on the influence of the spiral anchor system on the flexural behavior of concrete beams reinforced with glass fiber-reinforced plastic (GFRP) bars. The experimental program consisted of eight beams with the spiral anchor system and two control fiber-reinforced concrete beams without any spiral anchor system. All specimens were tested under bending load. Rough and smooth surface textures of GFRP bars were considered. The test parameters were the diameter of spiral anchor and the condition of the GFRP reinforcement bars as either bonded or unbonded to the surrounding grout. The experimental results indicate that beams reinforced with a rough GFRP bar with an anchor system under flexural load had higher ultimate flexural strength, first crack strength, and stiffness as compared to the beams without an end anchor system. The success of the anchor system is attributed to the confining effect of the steel spiral in anchoring the reinforcement ends. This confining effect enhances the anchorage capacity of the anchor system and subsequently improves the overall flexural performance of the reinforced concrete beams. Full article

X80 steel pipelines are widely used in oil and gas transportation, and the quality and fracture behavior of the girth weld have an important influence on the safety and performance of the pipeline. This study presents a comprehensive investigation into the microstructure, mechanical properties, and fracture characteristics of X80 steel welded joints. Through microstructure analysis and mechanical testing, the hardness, impact, and tensile properties of the base metal, heat-affected zone, and weld zone are evaluated. Digital Image Correlation (DIC) technology is employed to scrutinize the strain behavior under quasi-static tensile tests for both smooth and notched round bar specimens, providing a detailed strain distribution analysis. The findings indicate that, while X80 welded joints are well-formed without significant defects, the hardness and impact properties vary across different zones, with the base metal exhibiting the highest impact toughness and the weld zone the lowest. Notched tensile tests reveal that the presence and geometry of notches significantly alter the stress state and deformation characteristics, influencing the fracture mode. The DIC analysis further elucidates the strain concentration and localization behavior in the weld zone, highlighting the importance of notch size in determining the load-bearing capacity and ductility of the welded joints. This study contributes to a deeper understanding of the fracture mechanics in X80 pipeline girth welds and offers valuable insights for the optimization of welding practices and the assessment of pipeline integrity. Full article

Acrossocheilus Oshima, 1919, a cyprinid genus of Cyprinidae in southern China and currently comprises 26 valid species. In this study, we describe Acrossocheilus dabieensis sp. nov. from the Dabie Mountains, China. This new species differs from its congeners by the following combination of characters: The second primary vertical bar (PB2) is situated beneath the anterior origin of the dorsal fin in females and subadult males. Vertical bars extend to the end of the ventral abdomen in juveniles, and they gradually recede above the lateral line in adult females, whereas they are absent in adult males. The last unbranched dorsal-fin ray is slender with a smooth posterior margin. Phylogenetic analyses based on the mitochondrial DNA sequences indicate that A. dabieensis sp. nov. is a monophyletic group, and it forms a sister group with A. kreyenbergii, reinforcing the status of the new species. A key to the barred species of Acrossocheilus is also provided. Full article

Scheduling is essential in managing projects. ‘Schedula Anima’ is a new software designed to provide a comprehensive view of schedules between early and late dates for construction project managers. Capturing the dynamic nature of projects, it offers improved visualization through an animation process that creates incremental frames of bar charts and the corresponding resource graphs. As activity delays are simulated, it is observed that delays earlier in the schedule have more significant effects on project completion. A new prioritization method is introduced to evaluate the ease of rescheduling activities. A metric for monitoring resource usage float is presented, and the search space for resource utilization is delineated. As resource smoothing is studied in the resource usage graph and the time domain, a correlation is discovered between resource smoothness and the float consumption rate. It is shown that the schedule and resource usage graph comprises five sub-areas representing different risk exposures. Animation also improves communication in project teams and is beneficial in education. Finally, it is discovered that the permutations of activities in the simulation form a group. Enhancing our perception of resource utilization and the management of delays, ‘Schedula Anima’ brings a renewed perspective to project scheduling. Full article

Objectives: Hybrid implants commonly exhibit decreased corrosion resistance and fatigue due to differences in compressive residual stresses between the smooth and rough surfaces. The main objective of this study was to investigate the influence of an annealing heat treatment to reduce the residual stresses in hybrid implants. Methodology: Commercially pure titanium (CpTi) bars were heat-treated at 800 °C and different annealing times. Optical microscopy was used to analyze the resulting grain growth kinetics. Diffractometry was used to measure residual stress after heat treatment, corrosion resistance by open circuit potential (E_OCP), corrosion potentials (E_CORR), and corrosion currents (I_CORR) of heat-treated samples, as well as fatigue behavior by creep testing. The von Mises distribution and the resulting microstrains in heat-treated hybrid implants and in cortical and trabecular bone were assessed by finite element analysis. The results of treated hybrid implants were compared to those of untreated hybrid implants and hybrid implants with a rough surface (shot-blasted). Results: The proposed heat treatment (800 °C for 30 min, followed by quenching in water at 20 °C) could successfully homogenize the residual stress difference between the two surfaces of the hybrid implant (−20.2 MPa). It provides better fatigue behavior and corrosion resistance (p ˂ 0.05, ANOVA). Stress distribution was significantly improved in the trabecular bone. Heat-treated hybrid implants performed worse than implants with a rough surface. Clinical significance: Annealing heat treatment can be used to improve the mechanical properties and corrosion resistance of hybrid surface implants by homogenizing residual stresses. Full article