Transfer alignment of master and slave systems plays a key role in the inertial navigation accuracy of the marine cooperative vehicles. Accuracy enhancement of misalignment angle and orientation estimation is the main purpose of the transfer alignment. velocity and orientation matching is a well-known method for transfer alignment. However, in many applications, there are no velocity measurements of both the master and slave systems due to weight, dimensional and technological limitations of accurate speed sensors, such as Doppler velocity Loggers (DVL). angular velocity configuration is a suitable solution for transfer alignment in this situation. However, the orientation error cannot be estimated in this configuration. Taking this drawback into account, a new configuration based on using the integral of angular velocity in addition to angular velocity measurement is presented for transfer alignment in the current research. Furthermore, appropriate abilities are considered to estimate the dynamic misalignment angle, orientation error and also measurement errors of the slave gyroscope. Two linear and non-linear observation models are developed for the transfer alignment configuration. The simulation results reveal the appropriate performance of the proposed configuration for marine application, especially when there are no accurate velocity measurements. Based on the simulation results, the performance of the non-linear observation model is better than linear ones in dynamic misalignment angle estimation. Moreover, it can be inferred from the orientation error estimation that rich data in high-maneuvered motion is necessary for required estimation accuracy. Additionally, 200 runs of Monte-Carlo simulation are developed and the estimation RMSE are presented.

Background and Aim: angular cheilitis is a common condition among dental patients. However, it often responds poorly to antifungal treatment, and the use of corticosteroids can lead to lesion recurrence or medication resistance. This study aimed to assess the frequency of Staphylococcus aureus in patients who visited the Oral and Maxillofacial Medicine Department at Yazd Dental Faculty in 2017. Methods: This case- control study included 163 participants, with 65 patients diagnosed with angular cheilitis in the case group and 98 healthy individuals in the control group. Swabs were collected and inoculated on blood agar and Sabouraud dextrose agar. The cultures were then examined for the presence of Staphylococcus aureus and Candida albicans. Data were analyzed using SPSS software, employing Chi- square and t-tests, with a significance level set at  p < 0.05. Results: The study included 98 healthy individuals and 65 patients with angular cheilitis. The results indicated that Staphylococcus aureus was not detected in either the patient or control group (p < 0.9). A higher prevalence of angular cheilitis was observed among female patients. Additionally, there was a direct correlation between the presence of angular cheilitis and Candida albicans. Conclusion: The findings suggest that Staphylococcus aureus is not a contributing factor in angular cheilitis lesions. Therefore, antibiotic treatment for refractory cases should be postponed until microbial cultures confirm bacterial involvement.

Centrifuge spinning is a method that makes possible of fabrication nanofibers rapidly and at high yields.In the centrifugal spinning process, a polymer solution is delivered by the centrifugal force through small nozzle of a rapidly rotating cylindrical drum. Thereby, thinfibers are formed and collected on a collector in the form of a web. In this study, a mathematical model of the dynamics of a viscous liquid jet, which emerges from rotating drum through centrifuge spinning, was derived. The Navier-Stokes equations were solved in this system with the usual viscous free surface boundary conditions. One-dimensional equations were derived using asymptotic methods based upon a slender jet assumption and solved numerically. The effect of angular velocity upon the trajectory, radius, and tangential velocity of the jet was simulated and presented. Increasing angular velocity resulted in a decrease in the size of the liquid jet.Also, increasing angular velocity tended to increase the jet velocity which translated to increase the production rate. The jet centerline became more tightly coiled when the angular velocity increased. In addition, simulated jet diameter was compared with some results reported in our previous work.

Autonomous submarine robots are significant over the last decades. Since they can replace humans for performing dangerous underwater works. Positioning navigation is the key to guaranteeing that underwater robots can complete their task. The purpose of this paper is to control the linear and angular velocity of fish robot, to convert the robot model to unicycle model for mobile robots, which is make it possible to implement the navigation algorithm on robot. The appropriate dynamic model was simplified as a two dimensions model of robotic fish. Among different types of actuations, the tail-actuated robotic fish or BCF was considered. Also the average model of robotic fish was considered to control and its coefficient was corrected. The parameters of tail-actuating are defined as bias, amplitude and frequency. The frequency of tail-actuating was assumed to be constant but, bias, and amplitude are variable and controllable. After simulation the relations between tail-actuating parameters and rigid body linear and angular velocities was investigated. With this significance linear forward velocity and angular velocity could be controlled simultaneously and independently. This motion control applied on smooth rotation behavior with the constant speed, but it could be generalized for the others robot’s behavior. Eventually, through the amplitude, and the bias control respectively, the linear forward velocity is controlled with PI controller and 1. 67% error and angular velocity is controlled with PID controller and 2. 5% error

The influence of the rolling maneuver on the free vibration of swept wings is studied in this article. Non-Classical effects like warping inhibition and transverse shear flexibility are included in the structural model. Within the model developed herein, both static and dynamic instabilities are simultaneously addressed. The governing equations and boundary conditions are determined via Hamilton's Variational Principle, include coupling between the angular velocity of the maneuver and the elastic degrees of freedom. The result partial differential equations are transformed into a set of eigenvalue/boundary value equations through the extended Galerkin approach and solved by numerical integration. Finally, the results of the numerical simulation and the effects of the rolling angular velocity on the natural frequencies are presented for classic and shear deformable wings. Furthermore, validations of selected results against the previous publications are supplied. Results are indicative of the significant influence of the rolling maneuver on the natural frequencies and the static instability.

This paper presents two different kinds of regulating control strategies for the angular velocity of a rigid body model with two torque actuators. The first strategy presents piece-wise constant, states dependent feedback control laws. The method is based on the construction of a cost function V (not a Lyapunov function), which is sum of two semi-positive definite functions 1 V and 2 V. The semipositive definite function 1 V is dependent on the first m state variables which can be steered along the given vector fields and 2 V is dependent on the remaining m n - state variables which can be steered along the missing Lie brackets. The values of the functions 1 V and 2 V allow in determining a desired direction of system motion and permit to construct a sequence of controls such that the sum of these functions decreases in an average sense. The second strategy presents a time-varying feedback law based on the model reference approach, where the trajectory of the extended system is chosen as the model reference trajectory. The controllers are designed in such a way that after each time period T, the trajectory of the rigid body model intersects the trajectory of the model reference which can be made asymptotically stable. The proposed feedback law is as a composition of a standard stabilizing feedback control for a Lie bracket extension of the original system and a periodic continuation of a specific solution to an open loop control problem stated for an abstract equation on a Lie group.

The Planetary gears are widely used in the Power trains of the tractors and the heavy duty machinery such as automatic transmissions, final drive systems, and high-low speed units of the modem tractors.For designing the systems in which the Planetary gears are used, we need the formulas which can show the relationship between the angular velocity of the gears in different situations.Up to now, the definite formulas for the Planetary gears, have not been presented by any one, and the special tables are used instead of the formulas, which are complex and time wasting.In this survey, fourteen formulas have been determined which show the revolution relationship between the gears of the system in different situations and are usable .in the simple Planetary systems.

In this paper, damping mode of a satellite attitude control is designed and implemented using magnetic actuators in software /hardware-in-the-loop testbed. To this end, the equivalent of Earth’ s magnetic field is designed using Helmholtz coil, frictionless is made by air-bearing, and algorithms are developed on designed control board. By measuring the Earth’ s magnetic field, actuator commands are generated by the damping algorithm then braking torque is produced. Some applied restrictions and special requirements such as non-simultaneous operation between magnetic sensor and magnetic actuators, air-bearing friction, initial angular velocity are considered. By identifying the air-bearing frictional model, the results are compared in software/hardware-in-the-loop. The compared results show that the ability of the designed system to perform damping mode.

The traditional method for studying non-stationary signals is spectrogram based on the short-time Fourier transform (STFT). The well known limitation of the STFT is the inherent trade-off between time and frequency resolution. The Wigner-Ville (WV) distribution has the best time-frequency resolution, but its draw back is generating cross-terms. The matching pursuit (MP) distribution based on using the Gaussian atom is always positive, does not include crossterm, and has convenient resolution. In this paper, we have shown in addition to the known properties, the MP distribution can also remove the additive noise inherently. On the other words, we are able to remove the noise just by limiting the algorithm iterations and without paying any additional cost. Although the MP distribution based on using the Gaussian atoms is always positive and it has convenient resolution, according to the MP the time marginal and the frequency marginal will not be obtained accurately. In this paper, it has been shown that by implementing the minimum cross entropy (MCE) technique according to the MP distribution as a priory positive distribution, the new extracted distribution has the most similarity to the MP distribution and it also satisfies the correct time and frequency marginal.