Search Results (236)

Jaw in a Day (JIAD) reconstruction provides immediate restoration of mandibular form and function through a single-stage procedure that integrates fibula free flap reconstruction, virtual surgical planning (VSP), immediate dental implant placement, and delivery of a prefabricated prosthesis. Although the technique provides significant benefits in reducing rehabilitation time and improving patient outcomes, its adoption has been limited due to perceived technical complexity and unfamiliarity with dental workflow. This manuscript provides a detailed, step-by-step protocol to guide surgeons through their first JIAD case, from patient selection and data acquisition to VSP execution, intraoperative coordination, and implant positioning. Emphasis is placed on accurate osteotomy design, implant placement using guided protocols, fabrication of patient-specific hardware, and precise prosthesis pickup techniques. This guide also addresses essential OR team preparation and sterile handling of non-sterile components. By breaking down the process into actionable stages and highlighting common pitfalls and technical tips, this resource aims to lower the barrier for early adopters and enhance the success of initial JIAD cases. Full article

The growing adoption of electric buses in public transport has intensified the need for efficient scheduling algorithms. In the context of tactical planning, public transport operators must address two interdependent scheduling problems: the Single Depot Vehicle Scheduling Problem for Electric Buses (EB-SD-VSP) and the Crew Scheduling Problem for Electric Buses (EB-CSP). This study introduces a sequential approach, solving EB-SD-VSP via a Mixed-Integer Quadratic Programming (MIQP) model, and then using its solution to generate service blocks for the EB-CSP, which is then solved as a Mixed-Integer Linear Programming (MILP) model. The proposed sequential optimization approach ultimately solves the combined problem of Vehicle and Crew Scheduling for a fleet of Electric Buses (EB-SD-VCSP). Experiments on real-world bus line data from Athens, Greece demonstrate practical applicability of the approach. When compared to a baseline scenario where the services are executed with conventional buses, the proposed method can calculate efficient vehicle timetables and crew schedules for operations with electric buses. The results highlight the benefit of decomposing joint electric bus and crew planning into tractable subproblems while preserving solution quality. These findings offer a scalable tactical-level planning tool for transit agencies transitioning to electric fleets and suggest promising directions for future extensions to multi-depot and real-time scenarios. Full article

Fuel efficiency (FE) modeling under real-world conditions remains limited in Andean cities, where topographical and traffic conditions affect vehicle performance. Vehicles powered by spark-ignition engines are the most popular in Latin America, but few studies integrate dynamic conditions with geographic features. This study addresses this gap by developing an explanatory model to predict FE for light-duty vehicles (LDVs) in the Metropolitan District of Quito (DMQ), which is one of the most congested cities in Latin America. Data were collected from eight vehicles circulating under real conditions across 35 zones in the DMQ. Predictors such as vehicle speed (VSS), acceleration (A), speed per acceleration in its 95th percentile (VA[95]), road slope, and Vehicle-Specific Power (VSP) were included in the analysis. As a first attempt, linear models were tested, but the assumptions were not satisfied. Therefore, a Gamma regression model with a logarithmic link was selected. The final model achieved a Root Mean Square Error (RMSE) of 0.939, a Relative RMSE (RRMSE) of 0.155, a Mean Absolute Error (MAE) of 0.754, and an approximate coefficient of determination (${\mathrm{R}}^2$) of 0.956. This methodology combines continuous and categorical variables and offers a replicable framework for FE estimation in other urban contexts. Full article

With the significant growth in the number of PHEVs, conducting in-depth research on their CO₂ emission characteristics is essential. This study used the Horiba OBS-ONE Portable Emission Measurement System (PEMS) to measure the CO₂ emissions of three Plug-in Hybrid Electric Vehicle (PHEV) types: one Series Hybrid Electric Vehicle (S-HEV), one Parallel Hybrid Electric Vehicle (P-HEV), and one Series-Parallel Hybrid Electric Vehicle (SP-HEV), during real driving conditions. The findings show a correlation between acceleration and increased CO₂ emissions for P-HEV, while acceleration has a relatively minor impact on S-HEV and SP-HEV emissions. Under urban driving conditions, the SP-HEV displays the lowest average CO₂ emission rate. However, under suburban and highway conditions, the average CO₂ emission rates follow the order S-HEV > SP-HEV > P-HEV. An analysis of CO₂ emission factors across different road types and vehicle-specific power (VSP) ranges indicates that within low VSP intervals (VSP ≤ 0 for urban, VSP ≤ 5 for suburban, and VSP ≤ 15 for highway roads), the P-HEV exhibits the best CO₂ emission control. As VSP increases, the P-HEV’s emission factors rise under all three road conditions, with its emission control capability weakening when VSP exceeds 5 in urban, 15 in suburban, and 20 on highway roads. For the SP-HEV, CO₂ emission factors increase with VSP in urban and suburban areas but remain stable on highways. The S-HEV shows minimal changes in emission factors with varying VSP. This research provides valuable insights into the CO₂ emission patterns of PHEVs, aiding vehicle optimization and policy development. Full article

The demand for high data rates and large system capacity has posed significant challenges for medium access control (MAC) methods. Successive interference cancellation (SIC) is a classical multi-user detection (MUD) method; however, it suffers from an error propagation problem. To address this deficiency, we propose a method called Virtual Signal Processing-Based Integrated Multi-User Detection (VSP-IMUD). In VSP-IMUD, the received mixed multi-user signals are treated as an equivalent signal. The channel ambiguity corresponding to each user’s signal is then examined. For channels with non-zero ambiguity values, the signal components are detected using zero-forcing (ZF) reception. Next, the detected ambiguous signal components are reconstructed and subtracted from the received mixed signal using SIC. Once all the ambiguous signals are detected, the remaining signal components with zero ambiguity values are equated to a virtual integrated signal, to which a matched filter (MF) is applied. Finally, by selecting the signal with the highest channel gain and adopting its data as the reference symbol, the remaining signals’ dataset can be determined. Our theoretical analysis and simulation results demonstrate that VSP-IMUD effectively reduces the frequency of SIC applications and mitigates its error propagation effects, thereby improving the system’s bit-error rate (BER) performance. Full article

Orthognathic surgery (OS) is a complex procedure commonly used to treat dentofacial deformities (DFDs). These conditions, related to jaw position or size and often involving malocclusion, affect approximately 15% of the population. Due to the complexity of OS, accurate planning is essential. Digital assessment using computer-aided design (CAD) and computer-aided manufacturing (CAM) tools enhances surgical predictability. However, limitations in soft tissue simulation often require surgeon input to optimize aesthetic results and minimize surgical impact. This study aimed to evaluate the accuracy of virtual surgery planning (VSP) by analyzing the relationship between planning deviations and surgical satisfaction. A single-center, retrospective study was conducted on 16 patients who underwent OS at San Pedro University Hospital of La Rioja. VSP was based on CT scans using Dolphin Imaging software (v12.0, Patterson Dental, St. Paul, MN, USA) and surgeries were guided by VSP-designed occlusal splints. Outcomes were assessed using the Orthognathic Quality of Life (OQOL) questionnaire and deviations were measured through pre- and postoperative imaging. The results showed high satisfaction scores and good overall outcomes, despite moderate deviations from the virtual plan in many cases, particularly among Class II patients. A total of 63% of patients required VSP modifications due to poor soft tissue fitting, with 72% of these being Class II DFDs. Most deviations involved less maxillary advancement than planned, while maintaining optimal occlusion. This suggests that VSP may overestimate advancement needs, especially in Class II cases. No significant differences in satisfaction were observed between patients with low (<2 mm) and high (>2 mm) deviations. These findings support the use of VSP as a valuable planning tool for OS. However, surgeon experience remains essential, especially in managing soft tissue behavior. Improvements in soft tissue prediction are needed to enhance accuracy, particularly for Class II DFDs. Full article

The structural analysis of shelterbelts forms the foundation of their planning and management, yet the scientific and effective quantification of shelterbelt structures requires further investigation. This study developed an innovative heterogeneous analytical framework, integrating three key methodologies: the LeWoS algorithm for wood–leaf separation, TreeQSM for structural reconstruction, and 3D alpha-shape spatial quantification, using terrestrial laser scanning (TLS) technology. This framework was applied to three typical farmland shelterbelts in the Ulan Buh Desert oasis, enabling the first precise quantitative characterization of structural components during the leaf-on stage. The results showed the following to be true: (1) The combined three-algorithm method achieved ≥90.774% relative accuracy in extracting structural parameters for all measured traits except leaf surface area. (2) Branch length, diameter, surface area, and volume decreased progressively from first- to fourth-order branches, while branch angles increased with ascending branch order. (3) The trunk, branch, and leaf components exhibited distinct vertical stratification. Trunk volume and surface area decreased linearly with height, while branch and leaf volumes and surface areas followed an inverted U-shaped distribution. (4) Horizontally, both surface area density (Scd) and volume density (Vcd) in each cube unit exhibited pronounced edge effects. Specifically, the Scd and Vcd were greatest between 0.33 and 0.60 times the shelterbelt’s height (H, i.e., mid-canopy). In contrast, the optical porosity (Op) was at a minimum of 0.43 H to 0.67 H, while the volumetric porosity (Vp) was at a minimum at 0.25 H to 0.50 H. (5) The proposed volumetric stratified porosity (Vsp) metric provides a scientific basis for regional farmland shelterbelt management strategies. This three-dimensional structural analytical framework enables precision silviculture, with particular relevance to strengthening ecological barrier efficacy in arid regions. Full article

To analyze the hydrodynamic performance of the Voith–Schneider Propeller (VSP) under high eccentricity (e = 0.9), open-water performance numerical calculations were conducted for the VSP at different eccentricities. The results were compared with experimental data, revealing significant discrepancies at high eccentricity. Analysis identified that during the experiment, the VSP blades did not strictly move according to the prescribed “normal intersection principle” when passing near the eccentric point, which was the primary cause of the errors between the calculation and experiment. Further research demonstrated that when the blades pass near the eccentric point, both the individual blade and the overall propeller exhibit strong unsteady pulsation phenomena. The characteristics of these unsteady forces become more pronounced with increasing eccentricity. For the VSP under high eccentricity (e = 0.9), different Blade Steering Curves near the eccentric point were designed using a parametric method. The hydrodynamic performance of the VSP under these different curves was compared. The study demonstrates that rationally optimizing the motion of blades is a key approach to improving their hydrodynamic performance. At J = 2.4, the adoption of Opt-5 enables a 4.67% increase in thrust, a 25.19% reduction in thrust pulsation, a 12.74% reduction in torque, an 81.94% reduction in torque pulsation, and a 19.95% improvement in efficiency for the VSP. Full article

Background and Objectives: Orbital floor fractures are challenging to treat, due to the complex orbital anatomy and limited surgical access. Emerging technologies—such as virtual surgical planning (VSP), 3D printing, patient-specific implants (PSIs), and intraoperative navigation—offer promising advancements to improve the surgical precision and clinical outcomes. This review systematically evaluates and synthesizes current technological modalities with respect to their accuracy, operative duration, cost-effectiveness, and postoperative functional outcomes. Materials and Methods: A systematic review was conducted according to the PRISMA 2020 guidelines. The PubMed, Scopus, and PRIMO databases were searched for clinical studies published between 2019 and September 2024. Out of 229 articles identified, 9 met the inclusion criteria and were analyzed using the PICO framework. Results: VSP and 3D printing enhanced diagnostics and presurgical planning, offering improved accuracy and reduced planning time. Pre-bent PSIs shaped on 3D models showed superior accuracy, lower operative times, and better cost efficiency compared to intraoperative mesh shaping. Custom-designed PSIs offered high precision and clinical benefit but required a longer production time. Intraoperative navigation improved implant positioning and reduced the complication rates, though a detailed cost analysis remains limited. Conclusions: VSP, 3D printing, and intraoperative navigation significantly improve surgical planning and outcomes in orbital floor reconstruction. Pre-bent PSIs provide a time- and cost-effective solution with strong clinical performance. While customized PSIs offer accuracy, they are less practical in time-sensitive settings. Navigation systems are promising tools that enhance outcomes and may serve as an alternative to custom implants when time or resources are limited. Full article

This study presents a data-driven methodology to optimize the operational efficiency of a tugboat equipped with a Voith-Schneider Propeller (VSP) based on full-scale fuel consumption and vessel performance data. The objective is to identify optimal combinations of engine RPM and propeller pitch to reduce fuel consumption during low-demand phases without compromising maneuverability. Sea trials were conducted under controlled conditions using a dual flowmeter system and onboard speed measurements. The data enabled the construction of performance curves, efficiency ratios, and interpolated maps of fuel consumption. Optimal configurations were identified across defined speed ranges, and continuous efficiency zones were visualized through iso-consumption and contour plots. The results reveal a nonlinear relationship between propeller pitch, speed, and fuel demand, with maximum efficiency occurring at medium-to-high pitch values and speeds between 3 and 6 knots. This methodology provides a replicable tool for energy management in port operations and supports informed decisions during accompanying operations and standby periods. Efficiency differences over 300% between RPM–pitch settings were found, highlighting the operational impact of informed configuration choices. Moreover, the structured dataset and visual analysis framework lay the groundwork for future digital twin models aimed at enhancing operational efficiency in VSP-powered tugboats. Full article

Wear, fatigue, and corrosion are just a few of the issues that mechanical components in engineering experience, leading to surface deterioration. Enhancing the surface characteristics of engineering components is therefore essential. The surface properties of engineering objects can be improved by applying different surface treatments. One of these processes is shot peening (SP). Process parameters are crucial for SP. This necessitates the optimization of SP process parameters. In this study, we applied SP and vibratory shot peening (VSP) processes to different steel materials (AISI 8620, AISI 5140, AISI 4140, and AISI 1020) using different process parameters, aiming to determine the effects of these parameters on hardness, residual stress, and surface roughness. The highest compressive residual stress (CRS) and hardness values for shot-peened samples were obtained at the 24–26 A intensity for all steels. For all steel-group VSP samples, the highest CRS and hardness values were obtained at the 60 s −4 mm parameter. This paper aims to predict Almen intensity values using CRS, surface roughness, and hardness values from various steels. The supplied experimental data was utilized to estimate the SP Almen intensity value using a number of machine learning (ML) methods, eliminating the need for costly and time-consuming experimentation. With an RMSE of 0.0731, R2 of 0.9665, and MAE of 0.0613, the deep neural network (DNN) surpassed the other models in terms of prediction accuracy. The results indicate that artificial intelligence technology could be utilized to accurately evaluate Almen intensity. Full article

This study presents a phenomenological model for predicting the thermomechanical behaviour of spring-type actuators made of shape memory alloys (SMAs). The model incorporates the kinetics of martensite–austenite phase transitions as a function of temperature and applied stress. The primary innovation is the inclusion of a scalar internal variable that represents the evolution of the phase transformation within a phenomenological macroscopic model. This approach enables the deformation–force–temperature behaviour of SMA-based spring elements under cyclic loading to be accurately described. A set of constitutive equations was derived to describe reversible and residual strains, along with transformation start and finish conditions. Model parameters were calibrated using experimental data from VSP-1 and TN-1K SMA springs that were subjected to thermal cycling. The validation results show a high correlation between the theoretical predictions and the experimental data, with deviation margins of less than 6.5%. The model was then applied to designing and analysing thermosensitive actuator mechanisms for temperature control systems. This yielded accurate deformation–force characteristics, demonstrating low inertia and high repeatability. This approach enables the efficient prediction and improvement of the performance of SMA-based spring elements in actuators, making it relevant for adaptive systems in marine and aerospace applications. Full article

Background/Objectives: Virtual surgical planning (VSP) has become the gold standard in mandibular reconstructions with autografts. While commercial services are available, efforts are under way to address their shortcomings, which may include inefficiency, inconvenience, and susceptibility to error. We developed a novel approach to calculate knowledge-based reconstruction proposals. The objective of our work is to implement software for automated VSP and to evaluate it on retrospective clinical cases. Methods: We developed software, which incorporates registration of a naturally shaped mandible, tumor resection planning, knowledge-based calculation of reconstruction proposals, and manual refinement of proposals. Three surgeons planned 21 retrospective clinical cases utilizing our software. They rated its usability via the System Usability Scale (SUS) and rated the quality of the proposed reconstructions and the final surgical plan via a five-point Likert scale (1: totally disagree–5: totally agree). Results: Surgeons rated the usability with an average SUS score of 76.7. Times for VSP were consistently less than 20 min. The surgeons agreed with the proposals with a mean value of 4.7 ± 0.4. In 15 cases they made minor refinements. Finally, they agreed with the final surgical plan in twenty cases (score of 5) and with minor discrepancies in one case (score of 4). Conclusions: We developed an easy-to-use software for the automated VSP of mandibular reconstructions with autografts. The results demonstrate that reconstruction proposals can be calculated efficiently based on standardized rules. Our system allows surgeons to autonomously derive, compare, and rapidly refine high-quality reconstruction proposals based on key decisions. Full article

Single-phase short-circuit faults are severe asymmetrical fault modes in high renewable energy power systems. They can easily cause large-scale renewable energy to enter the low-voltage ride-through (LVRT) state. When such symmetrical or asymmetrical faults occur in the transmission channels of high-proportion wind power clusters, they may trigger the tripping of thermal power units and a transient voltage drop in most wind turbines in the high-proportion wind power area. This causes an instantaneous active power deficiency and poses a low-frequency oscillation risk. To address the deficiencies of wind turbine units in fault ride-through (FRT) and active frequency regulation capabilities, a power emergency support scheme for wind power clusters based on doubly fed variable-speed pumped storage dynamic excitation is proposed. A dual-channel energy control model for variable-speed pumped storage units is established via AC excitation control. This model provides inertia support and FRT energy simultaneously through AC excitation control of variable-speed pumped storage units. Considering the transient stability of the power network in the wind power cluster transmission system, this scheme prioritizes offering dynamic reactive power to support voltage recovery and suppresses power oscillations caused by power deficiency during LVRT. The electromagnetic torque completed the power regulation within 0.4 s. Finally, the effectiveness of the proposed strategy is verified through modeling and analysis based on the actual power network of a certain region in Northeast China. Full article

Background/Objectives: Orthognathic surgery has evolved with digital advancements, improving precision and predictability. Traditional free-hand techniques rely on surgeon expertise, often leading to variable outcomes. Fully guided approaches integrate computer-assisted surgery, including virtual surgical planning (VSP), CAD/CAM, and dynamic navigation, enhancing accuracy and efficiency. This review compares these approaches, assessing their impact on surgical accuracy, efficiency, and patient outcomes. Methods: A scoping review was conducted across PubMed, MEDLINE, Scopus, Cochrane Library, and Embase databases, focusing on clinical trials and cohort studies. Key parameters analyzed include surgical precision, operative efficiency, complication rates, and functional/aesthetic results. Results: Fully guided techniques achieve sub-millimetric accuracy with mean length deviations ranging from 1.3 mm to 2.4 mm and mean angular deviations between 2.29° and 3.51°. Moreover, these approaches markedly reduce operative time, averaging between 34 min and 1.7 h, and postoperative complications. Digital tools streamline workflow, improving reproducibility and aesthetic outcomes. Free-hand methods remain cost-effective but require greater surgical expertise, often resulting in longer recovery periods and higher variability. Conclusions: Computer-assisted orthognathic surgery enhances precision and efficiency, outperforming free-hand techniques in accuracy and predictability. While free-hand methods remain viable for simpler cases, fully guided approaches optimize surgical execution. Future research should explore hybrid strategies combining digital precision with manual adaptability to further refine surgical techniques. Full article