Jaw Functional Orthopedics and Cranoficial Growth
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Sector orifice with a correlation-based analysis
No full textIn single and multiphase flows, an orifice is a vital flow-measuring and flow-controlling device that operates on Bernoulli’s theorem on the determination of the pressure drop (∆p). Laboratory, petroleum, energy, nuclear, mining, chemical, processing, and food industries all depend on flow monitoring and flow regulations. A sector or segmental orifice meter is a much simpler device used for drainage and sediment-laden type non-homogeneous flow. Sector orifice meter analysis is the rate of flow, pressure and velocity profile concerning input parameters to find out the ∆p and coefficient of discharge (Cd) of an orifice meter. The present study varies with different sector angles (θ), Reynolds number (Re) and space ratio (s/d) of the sector orifice for the flow analysis with the use of CFD (Ansys. Inc) based study. The numerical simulation range considered for θ (30°-180°), Re (10000-100000), and s/d (0.1-0.9). To compute the flow rate, ∆p and Cd by using air as a working fluid to present a flow problem through high viscous flow. The simulation also presents the pressure and velocity profiles along the flow on the variant of Re, θ and s/d. Based on the numerical data a correlation developed which will help the measurement through sector orifice for wide range of future application. With the comparison of the existing literature, this will give a good contribution to sector orifice for accurate flow measurement for high viscous flow
Researching low frequency vibration of automobile-robot
No full textAutomobile-robot (self-driving automobile) is being researched and developed vigorously. When the automobile-robot is moving on the road surface, the low frequency vibration excitation not only influences the ride comfort of the automobile-robot but also strongly affects the durability of the vehicle’s structures. To research the automobile-robot’s vibration in the low frequency region, a dynamic model of the vehicle is established to calculate the vibration equations in the time region. Based on the theory of the Laplace transfer function, the automobile-robot’s vibration equations in the time region are transformed and converted to the vibration equations in the frequency region. Then, the effect of the design parameters and operation parameters on the characteristic of the automobile-robot’s acceleration-frequency is simulated and analyzed to evaluate the ride comfort as well as the durability of the automobile-robot’s structures in the frequency region. The research results show that the design parameters of the stiffness, mass, and road wavelength remarkably affect the characteristic of the automobile-robot’s acceleration-frequency. To reduce the resonant amplitude of the acceleration-frequency in the vertical and pitching direction of the automobile-robot, the stiffness parameters of the automobile-robot's and tires should be reduced while the mass of the automobile-robot’s body should be increased. Additionally, the road’s roughness also needs to be decreased or the road’s quality needs to be enhanced to reduce the resonant amplitude of the automobile-robot’s acceleration-frequency
Logo recognition of vehicles based on deep convolutional generative adversarial networks
No full textVehicle logo recognition plays a critical role in enhancing the efficiency of intelligent transportation systems by enabling accurate vehicle identification and tracking. Despite advancements in image recognition technologies, accurately detecting and classifying vehicle logos in diverse and dynamically changing environments remains a significant challenge. This research introduces an innovative approach utilizing a Deep Convolutional Generative Adversarial Network (DCGAN) framework, tailored specifically for the complex task of vehicle logo recognition. Unlike traditional methods, which heavily rely on manual feature extraction and pre-defined image processing techniques, our method employs a novel DCGAN architecture. This architecture automatically learns the distinctive features of vehicle logos directly from data, enabling more robust and accurate recognition across various conditions. Furthermore, we propose a refined training strategy for both the generator and discriminator components of our DCGAN, optimized through extensive experimentation, to enhance the model’s ability to generate high-fidelity vehicle logo images for improved training efficacy. The technical core of our approach lies in the strategic integration of transfer learning techniques. These techniques significantly boost classification accuracy by leveraging pre-learned features from vast image datasets, thereby addressing the challenge of limited labeled data in the vehicle logo domain. Our experimental results demonstrate a substantial improvement in logo detection and classification accuracy, achieving an Intersection over Union (IoU) ratio of 42.67 % and a classification accuracy of 99.78 %, which markedly surpasses the performance of existing methods. This research not only advances the field of vehicle logo recognition but also contributes to the broader domain of measurement science and technology, offering a technically sound and logically coherent solution to a complex problem
Photogrammetry protocol in babies with congenital torticollis: part 1 – inter-arch intraoral assessment
No full textTorticollis is defined as an imbalance of the sternocleidomastoid muscle (SCM), with less extension of the neck, resulting in a preference to turn the head more from one side to the other. The characteristics frequently found are: ear contralateral to the torticollis displaced forward, facial asymmetry, and contralateral occipital flattening, as well as a smaller ipsilateral eye, causing misalignment of the eyes. This condition can also cause mandibular inclination (MI), in the frontal plane, with a difference in opening between the maxilla and mandible from one side or the other. The diagnosis and treatment of torticollis are routinely carried out by the physiotherapist and the diagnosis of this mandibular inclination is traditionally through visual examination. This assessment of mandibular inclination, carried out by the dentist, in an objective manner, can contribute to the diagnosis and also to the monitoring of proposed treatments that should reduce mandibular asymmetries. The objective of this study was to create a protocol for objective measurement of the distance between the maxilla and mandible, on the right and left sides, using photogrammetry, to detect whether mandibular inclination can be observed by the shorter inter-arch distance on the side corresponding to the torticollis. Case reports of two babies (1 baby aged 9 months and another aged 1 year and 1 month), diagnosed with congenital torticollis. Photogrammetry was carried out: the babies were positioned on a dental stretcher and photographed in maximum opening, intermediate, and closing positions. Using the photos and the IMAGE J program, measurements between the maxilla and mandible were taken (see photogrammetry description). Results: The measurement protocol used in both babies confirmed the greater mandibular inclination by approaching the hemi-arch corresponding to the side of the torticollis, compared to the opposite side. Objective measurement of mandibular inclination can be part of the timely diagnosis for congenital torticollis. Studies with an adequate sample size and methodology are necessary to confirm this diagnostic tool
Open-source hand prosthesis: evaluation of mechanical feasibility and additive manufacturing potential
No full textThis study delves into the risks associated with 3D-printed hand prostheses lacking mechanical feasibility studies. Such unvalidated prostheses may exhibit various issues like durability shortcomings, anatomical incompatibility, functional safety concerns, manufacturing quality deficiencies, and health risks due to inappropriate materials. These issues can lead to damage or premature failure during use, discomfort, skin irritation, injuries, inability to withstand functional loads, and health hazards from toxic or allergenic substances. Therefore, ensuring the safety, quality, and effectiveness of these prostheses is crucial. The study focuses on a mechanical feasibility study conducted through Finite Element Analysis (FEA) simulations on an open-source hand prosthesis model. It evaluates mechanical properties, stress concentration areas, and displacement on the prosthesis surface. The methodology comprises three key steps: acquiring the virtual model, conducting computational simulations, and selecting the 3D printing material. The simulations assess the prosthesis’s ability to withstand compressive forces and identify stress concentration areas. Results from the study indicate that using PETG as the constituent material demonstrates mechanical viability and satisfactory performance under static force conditions. This finding underscores the importance of rigorous testing and adherence to standards in developing 3D-printed hand prostheses. Such studies contribute significantly to enhancing these devices’ safety and effectiveness, facilitating their broader adoption in healthcare settings. In summary, this study highlights the critical need for mechanical feasibility studies in the development of 3D-printed hand prostheses. It emphasizes the significance of following strict standards and regulations to ensure these devices’ safety, quality, and functionality. By doing so, it paves the way for the widespread use of these prostheses in healthcare, benefiting users and advancing the field of prosthetic technology
Design and analysis of tracking differentiator based on SO(3)
No full textMotivated by the issue of insufficient dynamic performance and tracking accuracy in SO(3)-based attitude tracking differentiators during large-angle maneuvers and complex trajectory tracking, a novel design approach for a three-degree-of-freedom attitude tracking differentiator within the SO(3) framework is proposed by incorporating second-order system theory and Lie group theory and improving the classical tracking differentiator. The kinematics model and error dynamics model of a rigid body on SO(3) are derived, and a reasonable virtual control input on SO(3) is constructed subsequently in order to achieve better dynamic response and tracking performance. Simulation and experimental results validate that the designed tracking differentiator could realize rapid and smooth convergence during large-angle maneuvers, and the initial large tracking error rapidly drops to near zero in a short period of time; additionally, it can also track expected time-varying curves well in complex trajectory tracking, with initial errors rapidly decreasing and maintaining at normal levels, demonstrating excellent tracking and control capabilities. There are strong application prospects for this new approach in addition to its theoretical significance
A neural network simulator for educational purposes
No full textArtificial neural networks are inspired by biologic processes. Artificial neural networks are important because they can be used to deduct a function from observations, in other words artificial neural networks can learn from experience. Artificial neural network simulator to fulfill a need into the growing interest of neural network education is introduced in this study. NeuroQuick Laboratory simulator is implemented using object-oriented programming by Delphi programming and these classes can be used to create a standalone application with artificial neural networks. The NeuroQuick Laboratory Simulator is designed for a broad range of users, including beginning graduate/advanced undergraduate students, engineers, and scientists. It is particularly well-suited for use in individual student projects or as a simulation tool in one- or two-semester neural network-related courses at universities
Influence of the rough surface and speed of crankpin bearing on the power of the engine
No full textTo fully evaluate the influence of the rough surface (σ) and speed (ω) of the crankpin bearing on the engine power, a combination model of the slider crank mechanism and crankpin bearing’s lubrication is established to calculate the mathematical equations for the simulation. Three indexes of the bearing-capacity (W), friction-force (F), and friction-coeficient (μ) are used to evaluate the influence of the change of the crankpin bearing’s speed and rough surface on the engine’s power. The study shows that increasing ω not only effectively reduces the load capacity of the crankpin bearing but also increases the F and μ in the engine’s crankpin bearing, thereby directly reducing the engine’s power. Besides, the reduction of ω also reduces the bearing-capacity of the crankpin bearing. To optimize the engine’s power, the engine’s speed should be maintained at 2000 r/min to improve the engine’s power. In addition, under the effect of the rough surface of the crankpin bearing, the W of the crankpin bearing is insignificantly affected by the change of the rough surface while both the F and μ are greatly affected. In particular, the maximum F at σ = 8 μm and σ = 10 μm is increased by 68.3 % and 77.7 % in comparison with the maximum F at minimum value of σ = 2 μm, respectively. Therefore, in the design of the engine, the rough surface of the crankpin bearing should be reduced to improve the engine’s power. Additionally, the design parameters of the crankpin bearings should also be optimized to further improve the engine’s power
Exciters of vibrations with two pairs of impacting surfaces
No full textExciters of vibrations of the type when one vibrating mass performs impacts into two immovable supports, which are located on the opposite sides with respect to the mass, are investigated. Here because of the connection of the vibrating mass with the supports the system may have the point of equilibrium located at equal or different distances from the impacting surfaces. Also, because of the difference of coefficients of restitution of impacts the system may have symmetric or non-symmetric laws of motions of the vibrating mass. Such systems are important in pipe robots and other engineering devices. Typical results of investigation of dynamics of such systems are obtained. The presented results can be used in the process of design of systems with vibrators having two impacting pairs. Investigations are performed by using analytical as well as numerical methods (calculations are performed by C++ Builder Community Edition, Newmark constant average acceleration method is used for numerical integration of equations of motion). The obtained typical graphical relationships show symmetric as well as unsymmetric regimes of motion and enable to perform their comparison. The basic novelty of this paper is the investigation of unsymmetric regimes of motion
Use of fibre optic systems for detection of small leaks on trunk pipelines
No full textThis paper is devoted to the issue of efficiency of application of fibre optic leak detection systems for identification of small leaks on trunk pipelines. The main methods of leak detection currently in use have been considered, and parametric and fibre optic LDS have been selected for comparative analysis. In the course of the research a model of product leakage from an underground oil pipeline equipped with a fibre-optic LDS was built in the COMSOL Multiphysics software package. The result of the simulation was the estimated time of leak identification by the fibre-optic system, which turned out to be much shorter than that of the parametric LDS. Compensable environmental damage for each type of system was then calculated, confirming the effectiveness of fibre optic LDS for detecting small leaks on trunk pipelines due to the significant reduction in compensable damage