Investigation of robust ship course control based on auxiliary loop method

A novel robust control law is investigated on the problem of ship stabilization on the trajectory, which allows one to compensate perturbations in the parameters of the mathematical model of ship dynamics in cases of their changes caused by external conditions, namely: sea waves, currents, wind gusts, etc. To implement the proposed control law, only measured adjustable values are required such as the yaw angle and the control action that is the angle of the rudder of the ship. The synthesized ship course control system was investigated in MATLAB. The law of controlling the ship’s course with unknown parameters and external disturbances in the power supply is proposed. The design of the control law is based on a robust auxiliary loop algorithm and Khalil observers. The simulations illustrate the efficiency of the proposed control law.

Method for stabilization of the microwave modulation index in order to suppress the light shift of the coherent population trapping resonances

For the resonance of coherent population trapping (CPT), we show that in the case of a spatially inhomogeneous light shift (for example, due to the Gaussian transversal profile of the light beam intensity), the zero position of the error signal, formed by the use of phase-jump technique, depends on the integration time of the spectroscopic signal. Basing on this effect, we propose two-loop method to stabilize the microwave power at the point where the light shift vanishes.

Effect of position of radial air injection plane on control of thermo-acoustic instability using active closed-loop method

Thermo-acoustic instability occurs when self-excited oscillations are generated due to the coupling between unsteady heat release and acoustics. This phenomenon can result in an increased rate of vibration, structural damage, and produces unwanted emissions. Thermo-acoustic instability occurs in rocket engines, gas turbines, combustors, and furnaces. When thermo-acoustic instability occurs, many modes are developed naturally at a specific point. Some waves are unstable and some are stable. So, to study this phenomenon the most unstable waves are considered and a technique is developed to suppress these unstable waves. A radial air injector as a closed-loop active control method is used for breaking the coupling between the heat waves and acoustics inside the 1D combustion chamber. The distance between the burner and the air injector is varied for the fixed position of the burner with respect to the Rijke tube, that is, x/L = 0.01125, 0.0075, and 0.00375. This closed-loop method works based on the feedback acquired from a microphone. The control method is built using DAQ and Arduino with the LabVIEW as interface for Arduino (LIFA). An air flow rate controller setup is developed to control and measure air required for suppressing the thermo-acoustic instability. Thermo-acoustic instability is effectively suppressed with the help of radial injection in the form of micro-jets at the downstream of the burner as the closed-loop controlling method. It is concluded that when the radial micro-jet air injection plane is closer to the burner head, the thermo-acoustic instability gets suppressed in a short time and with a lesser quantity of air.

Unsatisfying mitral valve repair? The “Loop method”: a lifebelt to grab

Intra-operative mitral valve repair failure is a common condition in patients with complex myxomatous disease requiring aortic re-clamping and application of a fast and easy surgical technique to correct the residual imperfection. Herein we describe a reproducible method of artificial chord reconstruction which preserves the previous accomplished acts and allows for accurate chordal length measurement basing on the annuloplasty as the reference level.

On Intermedia Animation By Transition Indexing Methods In Pseudocode

On understanding the intermedia animation with image-loop method using transition indexing approach. Image-Looping on photo-image, graphics object or graph figure creates a motion picture of still images with delayed seconds in between each frame. <div><br></div>

On Intermedia Animation By Transition Indexing Methods In Pseudocode

On understanding the intermedia animation with image-loop method using transition indexing approach. Image-Looping on photo-image, graphics object or graph figure creates a motion picture of still images with delayed seconds in between each frame. <div><br></div>

Determination of Yield and Botanical Composition of the Meadow and Grassland in Çolpan Village at the Shores of Lake Van

This study was carried out at the meadows and pastures in Çolpan village of Van province in 2020. In the study, matter yield, botanical composition, plant covered area, rate of decreaser/increaser/invader species were determined. The Loop method was used to determine the botanical composition. In grassland area were identified 69 species belonging to 17 families. In meadow area were identified 20 species belonging to 6 families. The amount of Poaceae, Fabaceae and other families found in the grassland area were determined as 18.66%, 15.65%, and 65.69%, respectively. In the meadow area, the amount of Poaceae, Fabaceae and other families were determined as 67.50%, 15.0%, and 17.50%, respectively. Artemisia spicigera (4.74%) Taeniatherum caput-medusae (5.0%) Arenaria serpyllifolia (5.0%) Medicago monantha (5.92%) species were the most common species found in the grassland area. Hordeum brevisubulatum (25.5%), Bromus scoparius (16.75%), and Taraxacum androssovii (9.25%) species were the most common species found in the meadow area. According to the ratio of good plants, pasture was classified as poor pasture and meadow was in the moderate meadow class. Grassland and meadow matter yields were found to be 91.4 kg/da and 385.2 kg/da, respectively. In the grassland of Çolpan village, invader species were found to be dense. It was concluded that grassland area should be improved.