Jaw Functional Orthopedics and Cranoficial Growth
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1D manipulator with vibration impact drive, based on which it is possible to create orthogonal manipulators and robots of any dimension
No full textManipulator of the investigated type may move according to a straight line. It has an advantage in the fact that by choosing geometrical parameters of the manipulator it is possible to achieve its effective operation. This is presented by using analytical and graphical methods. The performed research shows that manipulators with vibration impact drives have some positive qualities. In their structure it is not necessary to include the self-stopping mechanism. In the conservative case of the system static position of equilibrium of the impact pair can be with negative, zero or positive tightening. In the case of zero tightening eigenfrequency and period of the system does not depend on the quantity of motion of impact excitation. In the case of harmonic forced excitation resonant motions take place in the vicinity of the eigenfrequency of the conservative system with zero tightening. Analytical – numerical calculations contribute to the creation of manipulators and robots with vibration impact drives
Trajectory-based synthesis of a slider-crank mechanism for applications in inertial vibration exciters
No full textSlider-crank mechanisms are widely used in various industrial and technological machines. This paper considers a generalized diagram of a slider-crank mechanism, on the connecting rod of which an imbalanced mass can be fixed. In such a case, the slider-crank mechanism can be employed as an inertial vibration exciter. The aim of this research is to justify the geometric parameters of the mechanism to ensure a predetermined elliptical trajectory of the imbalanced mass motion. The research methodology involves the analytical derivation of the motion equations for a connecting rod point and solving the problem of synthesizing the geometric parameters of the mechanism based on the given trajectory of this point. The obtained results are presented in the form of displacements and trajectories for the connecting rod point of a specific slider-crank mechanism. The major novelty of this research lies in the further development of the theory of slider-crank mechanism synthesis for use in inertial vibration exciters. The derived analytical dependencies can be utilized by designers and engineers in the development of new types of vibration exciters for various industrial and technological vibratory equipment
Vector analysis of unmanned aircraft sea surface imaging characterization based on ISAR
No full textUtilization of airborne Inverse-Synthetic-Aperture-Radar (ISAR) for detection of moving targets on the sea surface is studied in this paper. In order to systematically analyze the characterization of radar imaging in the presence of both motion and observation uncertainty of a target, this study incorporates the Bayes-PRM multi-query algorithm for fusing ISAR multi-sensing information. The algorithm isochronously samples the physical quantities, such as UAV position, altitude, pitch angle, and velocity as a sequence of multivariate groups, and converts the time-series data of the trajectories into distributional features in graph theory. The coupled edge weights and Alternating Direction Method of Multipliers (ADMM) are introduced through the coupling framework combined with the ambient graph. With ADMM, the quadratic penalty term is used to achieve a simple linear function, and subproblems involving amplitude, linear velocity, and yaw angle can be embedded in a sequential solution scheme. The quality of the primal and dual solutions is then improved in an iterative manner to achieve vector analysis of the UAV. The potential maneuvering region of the target is fitted to a Gaussian-Wiener stochastic movement model, which in turn yields the detection expectation through point set coverage. By analyzing the tracking simulation results and diffraction theory, the experimental results are transformed into a function of the UAV multi-vector, and the angular linearization model of the multi-vector under the radar image is developed, which solves the optimal elevation angle and the optimal path for the maximum scanning radius of the airborne radar. The nominal trajectory of the UAV is effectively obtained, which confirms the improvement of the credibility of ISAR in target detecting. Through the proposed model, the results of object detection accuracy were improved
Evaluating the impact of microstructure modifications on thin film photoelectric properties
No full textMicrostructure modifications on thin photoelectrical properties refers to changes in the microscopic structure of thin films that affect their ability to convert light into electricity. This study investigates the deposition and post-treatment effects in the electric and visual qualities of GZO, IZO, and ZnO thin layers, aiming to enhance their applicability in electronic and optoelectronic devices, according to the X-raydiffraction (XRD) examination. Thin films were deposited on glass substrates using magnetic sparking at thicknesses of 300 nm and 500 nm, followed by treatments like wet aging and annealing at 220 °C. The results showed significant improvements in crystallinity and optical characteristics, with ZnO films exhibiting a preferred (003) orientation. IZO films demonstrated notable mobility at 10.96 cm2/V-sec and resistivity of 2.49×10⁻3 ohm-cm. The novelty of this research is the novel integration of wet aging and low-temperature annealing, that notably improves thin film efficiency while maintaining structural integrity. The findings indicate that post-treatment significantly enhances the properties of these thin films, suggesting their potential for various electronic applications
Processing piano audio: research on an automatic transcription model for sound signals
No full textAutomatic transcription of sound signals can convert audio to musical notes, which has significant research value. This paper extracted dual-channel constant Q transform (CQT) spectra from piano audio as features. In the design of the automatic transcription model, a CNN was employed to extract local features and then combined with a Transformer model to obtain global features. A CNN-Transformer automatic transcription model was established using a two-layer CNN and three-layer Transformers. Experiments were conducted on the MAPS and MAESTRO datasets. The results showed that dual-channel CQT outperformed short-time Fourier transform (STFT) and mono CQT in auto-transcription. Dual-channel CQT achieved the best results on frame-level transcription for the MAPS dataset, with a P value of 0.9115, an R value of 0.8055, and an F1 value of 0.8551. A sliding window with seven frames yielded the best transcription results. Compared with the deep neural network and CNN models, the CNN-Transformer model demonstrated superior performance, achieving an F1 value of 0.8551 and 0.9042 at the frame level for MAPS and MAESTRO datasets, respectively. These findings confirm the designed model's reliability for automatic piano audio transcription and highlight its practical applicability
Mathematical modeling of the possibility of creating interresonance discrete-continuous vibration technological equipment without a spring
No full textIn the article is implemented interresonance mechanical oscillating system vibrational technological equipment, which provides using two continuous of connected area successively to working body vibrational machines. Disturbance of the structure is carried out by applying a variable-sign power supply voltage to the reactive continuous section, where in interaction with the magnetic field from the permanent magnets, a variable-sign disturbance force occurs. Inertial forces from the reactive continuous section are transferred to the intermediate continuous section, which resonates with the working body. In fact, an interresonance discrete-continuous oscillating system is obtained in which there are no springs. The function of springs is performed by bodies with distributed parameters that have elastic properties. Based on the Krylov-Duncan functions, a system of equations was formed that establishes the amplitude of oscillations of the working body. The amplitude-frequency characteristic of the discrete-continuous system was studied, which confirms the possibility of creating interresonance oscillating systems of vibrating technological equipment without springs
Development of gear fault identification of wind turbine’s transmission system based on VMD and FNN
No full textIn order to improve the safety of wind turbine, this paper takes the high-speed spur gear on output shaft in the transmission system of the wind turbine as the study object. The original signals of the gear in different fault states which obtained from the experimental platform decompose by the empirical mode decomposition method (EMD) and the variational mode decomposition method (VMD), respectively. Then the different gear fault types’ eigenvectors were built. Fuzzy neural network (FNN) is adopted to learn the fault types and eigenvector samples of gears, and then the fault types of gears are identified. It is found that the fault features decomposed by VMD method have reached a high accurate recognition rate point to the fact that VMD has good applicability in the fault recognition of gear in wind turbine
Method of experimental determination of the effective area of a pneumatic spring of high-speed rolling stock
No full textThe object of research is a pneumatic spring of high-speed rolling stock of the railway. The method of experimental static testing of a pneumatic spring of high-speed rolling stock is presented. Based on experimental tests, the “force-strain” dependences of a pneumatic spring are obtained when the pressure gauge in the pneumatic spring changes from 2.5 atm up to 5.0 atm. Using a thermodynamic model, a quadratic equation is found to determine the effective area of a pneumatic spring. It is established that when the pressure gauge in the pneumatic spring changes from 2.5 atm up to 5.0 atm the effective area of the pneumatic spring varies from 0.231 m2 to 0.306 m2. The scientific novelty lies in the fact that for the first time, on the basis of static experiments, the change in the effective area of the pneumatic spring of high-speed rolling stock depending on the value of the gauge pressure in the spring was established. This will make it possible to determine the forces acting on the pneumatic spring in different operating conditions, ensuring the required level of safety of rolling stock
Welcoming pregnant women as a strategy for adherence to dental prenatal care and health promotion in early childhood
No full textThis research deals with implementing Dental Prenatal Care as a public policy in the Brazilian Unified Health System (SUS) to care for pregnant women and their future babies. The legal framework that assures pregnant women's rights of priority in accessing services is usually not enough to guarantee the health promotion coverage goals for this population group, who frequently have low adherence to dental care. Brazilian Unified Healthcare System (SUS) recommends monitoring pregnant women through eight mensal consultations during healthy pregnancy. Oral health is usually not monitored to the same extent, and many pregnant women still go through pregnancy without any dental consultation. This study was proposed to improve dental prenatal care and program adherence by mothers and children in the Basic Healthcare Unit Amaro José de Souza, in the municipality of Barueri, through the increased participation of the dental surgeon in the pregnant women welcoming team. A cross-sectional cohort study was designed to identify and meet the demands of low-risk pregnant women. For six months, all the women attending prenatal care at BHU Amaro José de Souza in Barueri were invited to participate and receive personal guidance from the multi-professional team. Information on dental health was investigated through questions targeting previous knowledge about the recommended moments for the first dental appointment of a child, the importance of exclusive nasal respiration, the identification of craniofacial asymmetries at birth, and general baby care. Attitudes and self-care were also investigated, including prenatal program adherence. Answers were collected in a Google Form platform and analyzed to characterize the group's literacy about prenatal care and breastfeeding and identify information needs about dental health care during pregnancy. At the same time, a welcoming expanded listening, educational, and preventive health action was developed: conversation and sharing experience groups were promoted monthly for pregnant women, breastfeeding mothers, and their families. 90 pregnant women out of the 104 attending the BHU in the six months of the research were invited, and 83 agreed to participate. All the participants declared at least one previous appointment with the healthcare team, 92.8 % of them, with a gynecologist. The nursing team was involved in 53.0 % of the appointments, but only 6.0 % were reported to have been conducted exclusively by a nurse. A dental surgeon appointment was mentioned by 30.1 % of the research participants. The dental health literacy investigation revealed that 57.8 % believed they should only take their babies to a dental appointment after teething, and 27.7 % were aware of the child's craniofacial asymmetries at birth. Only 28.9 % had previous knowledge about the importance of exclusive nasal respiration. Despite only 34.9 % having their first pregnancy, 78.3 % declared they would appreciate receiving information about pregnancy. After the guidance, 72.0 % of the pregnant women had undergone dental prenatal care. Workshops for pregnant women and breastfeeding mothers provided a convenient welcoming space, to listen and provide guidance to pregnant women and their families, in addition to demystifying the fear of dental care during pregnancy and breastfeeding. The intervention to guide pregnant women to perceive the BHU as an educational and health promotion space, not just a curative intervention, effectively increased adherence to dental prenatal care. The contact with the Specialist in Functional Jaw Orthopedics in this first phase of life facilitated dental health education and access to more complex cases. The prenatal program adherence, the pregnant woman’s self-care, and the care of the baby were favored by the welcoming, expanded listening, and personalized service
