scholarly journals Experimental Complex for Studying the Possibilities of Using Hydroacoustic Sensors in Underwater Vision Systems

2021 ◽  
Vol 24 (4) ◽  
pp. 54-64
Author(s):  
V.A. Shirokov ◽  
V.N. Milich
Keyword(s):  
Frequency Response ◽  
Aquatic Environment ◽  
Experimental Studies ◽  
Frequency Characteristics ◽  
Complex Object ◽  
Front Wall ◽  
Object A ◽  
Sensor Resistance ◽  
Measuring Complex ◽  
Comparison Of The Results

A description of a laboratory experimental and measuring complex is given, including a linear aquatic environment in the form of an extended cylindrical reservoir (hydro wave) and an experimental pool equipped with a system for generating test hydroacoustic signals, a set of electroacoustic and acoustoelectric transducers, and a system for amplifying and digitizing received signals. The results of experimental studies of hydroacoustic piezoelectric sensors and the features of the propagation of the waves generated by them in the described laboratory complex are presented. These results include: an assessment of the sensitivity of sensors, an assessment of the frequency characteristics of sensors, a study of the frequency response of a system of two sensors fixed at the ends of a horizontal hydro-wave guide, a comparison of the results of measurements of the frequency response of sensors in a pipe and a pool, a comparison of signal pulling over time in a pipe and a pool, a study of operation sensors in sonar mode. The most significant results illustrating the behavior of hydroacoustic signals and the potential of the measuring complex are the established possibilities for determining the resonance features of electroacoustic transducers and the detail of the characteristics of the reflection of acoustic signals from objects in an aquatic environment. The main investigated characteristics of hydroacoustic sensors are the sensitivity and frequency characteristics of the investigated sensors, the amplitude-frequency characteristics of the system from the transmitting and receiving transducers, and the features of the transducers' operation in the sonar mode. According to the research results, the characteristics of the sensitivity of the sensors and the assessment of the spread of the sensitivity indicators for representatives of the same type of different parties were obtained. The study of the frequency characteristics of the sensors was focused on the study of the dependence of the module and the phase of the sensor resistance on the frequency and on the determination of the resonance characteristics of the sensors. The presence of resonances (resistance minima) and antiresonances (resistance maxima) in several frequency regions was established. When examining the transducers in sonar mode, a glare structure of echo signals from the components of a complex object (a sphere suspended by a thread), separated by time intervals of 12.3 microseconds, was clearly observed. The delay of the signal reflected from the filament in relation to the signal reflected from the front wall of the sphere is due to the distance by two radii of the sphere, covered by the signal reflected from the filament. Carrying out research in two experimental situations (linear hydro wave and experimental pool) allows assessing the degree of adequacy of the results obtained in the sense of comparing similar experiments in different conditions.

Validation of Numerical Models Used for Designing the Composite Blade for ILX-27 Rotorcraft

2019 ◽  
Vol 2019 (4) ◽  
pp. 23-31
Author(s):  
Jakub Wilk ◽  
Radosław Guzikowski
Keyword(s):  
Epoxy Composite ◽  
Numerical Models ◽  
Experimental Studies ◽  
Strength Analysis ◽  
Laminate Glass ◽  
Composite Blade ◽  
Real Objects ◽  
Validation Procedure ◽  
Research Objects ◽  
Comparison Of The Results

Abstract The paper presents the validation procedure of the model used in the analysis of the composite blade for the rotor of the ILX-27 rotorcraft, designed and manufactured in the Institute of Aviation, by means of numerical analyses and tests of composite elements. Numerical analysis using finite element method and experimental studies of three research objects made of basic materials comprising the blade structure – carbon-epoxy laminate, glass-epoxy composite made of roving and foam filler – were carried out. The elements were in the form of four-point bent beams, and for comparison of the results the deflection arrow values in the middle of the beam and axial deformations on the upper and lower surfaces were selected. The procedure allowed to adjust the discrete model to real objects and to verify and correct the material data used in the strength analysis of the designed blade.

scholarly journals Fast frequency response of inverter-based resources and its impact on system frequency characteristics

2020 ◽  
Vol 3 (5) ◽  
pp. 475-485
Author(s):  
Lining Su ◽  
Xiaohui Qin ◽  
Shang Zhang ◽  
Yantao Zhang ◽  
Yilang Jiang ◽  
...  
Keyword(s):  
Frequency Response ◽  
Frequency Characteristics ◽  
System Frequency

THE HEAP PARTS MOVEMENT ON THE SHAREBOARD SURFACE OF THE POTATO HARVESTING MACHINE

2021 ◽  
Vol 14(63) (1) ◽  
pp. 127-140
Author(s):  
Serhii HRUSHETSKYI ◽  
Vitaly YAROPUD ◽  
Ihor KUPCHUK ◽  
Ruslana SEMENYSHENA
Keyword(s):  
Mathematical Model ◽  
Experimental Studies ◽  
Separation Process ◽  
Kinematic Parameters ◽  
Quality Performance ◽  
Machine Operation ◽  
Degree Of Damage ◽  
Total Capacity ◽  
Comparison Of The Results

The article is devoted to the problem of the reduction of tubers mechanical damages while providing qualitative indicators of the potato heap separation process. Theoretical and experimental dependences of the influence of design and kinematic parameters of the machine operation on the quality performance are obtained. Within the field of experimental studies, a field installation was made to investigate the potato harvester as a whole on the efficiency of separation, the degree of damage, the magnitude of losses and the total capacity for aggregation. Comparison of the results of theoretical and experimental studies showed that the developed mathematical model of the process of separation of potato heap is adequate.

scholarly journals An Approach to Risk Assessment and Threat Prediction for Complex Object Security Based on a Predicative Self-Configuring Neural System

Symmetry ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 102
Author(s):  
Nikolai Vladimirovich Korneev ◽  
Julia Vasilievna Korneeva ◽  
Stasis Petrasovich Yurkevichyus ◽  
Gennady Ivanovich Bakhturin
Keyword(s):  
Neural Network ◽  
Risk Assessment ◽  
Fundamental Problem ◽  
Experimental Studies ◽  
Neural System ◽  
Assessment System ◽  
Classification Model ◽  
Complex Object ◽  
Assessment Problems ◽  
First Time

We identified a set of methods for solving risk assessment problems by forecasting an incident of complex object security based on incident monitoring. The solving problem approach includes the following steps: building and training a classification model using the C4.5 algorithm, a decision tree creation, risk assessment system development, and incident prediction. The last system is a predicative self-configuring neural system that includes a SCNN (self-configuring neural network), an RNN (recurrent neural network), and a predicative model that allows for determining the risk and forecasting the probability of an incident for an object. We proposed and developed: a mathematical model of a neural system; a SCNN architecture, where, for the first time, the fundamental problem of teaching a perceptron SCNN was solved without a teacher by adapting thresholds of activation functions of RNN neurons and a special learning algorithm; and a predicative model that includes a fuzzy output system with a membership function of current incidents of the considered object, which belongs to three fuzzy sets, namely “low risk”, “medium risk”, and “high risk”. For the first time, we gave the definition of the base class of an object’s prediction and SCNN, and the fundamental problem of teaching a perceptron SCNN was solved without a teacher. We propose an approach to neural system implementation for multiple incidents of complex object security. The results of experimental studies of the forecasting error at the level of 2.41% were obtained.

Information-Measuring Complex for Registration High Frequency Gravitational Waves

2020 ◽  
pp. 42-51
Author(s):  
I. S. Golyak ◽  
A. N. Morozov ◽  
A. L. Nazolin ◽  
S. E. Tabalin
Keyword(s):  
Solid State ◽  
Active Region ◽  
Gravitational Waves ◽  
Spectral Range ◽  
High Frequency ◽  
Experimental Studies ◽  
Yag Laser ◽  
Information Measuring ◽  
Measuring Complex ◽  
Fabry Perot

The information-measuring complex designed to register high-frequency fluctuations of the space-time metric and its main elements are described in paper. The complex is based on a Fabry-Perot interferometer with highly reflective mirrors and a two-meter resonator. A solid-state Nd: YAG laser with a wavelength λ = 1064 nm is used for pumping. To read the signal, an InGaAs receiver DET10N2, with a working spectral range of 500-1700 nm and an active region of 0.8 mm2, is applied. Using the developed complex, experimental studies of signal registration at readout frequencies of 1 MHz and 20 MHz were carried out. The graphs of signal fluctuations in time and the spectra constructed from them are given.

Free Convection, Forced Convection, and Acoustic Vibrations in a Constant Temperature Vertical Tube

1959 ◽  
Vol 81 (1) ◽  
pp. 68-74 ◽  
Author(s):  
T. W. Jackson ◽  
W. B. Harrison ◽  
W. C. Boteler
Keyword(s):  
Heat Transfer ◽  
Free Convection ◽  
Sound Pressure ◽  
Experimental Studies ◽  
Experimental System ◽  
Vertical Tube ◽  
Acoustic Vibrations ◽  
Average Temperature ◽  
Comparison Of The Results ◽  
The Heat Transfer Coefficient

Experimental studies of heat transfer to air with superposed forced and free convection were reported in a previous paper [1]. In studies reported in this paper, the same experimental system was employed, but a complication was added in the form of acoustic vibrations in the flow field. By comparison of the results with and without acoustic vibrations under conditions which were otherwise the same, an effort has been made to determine the effect of acoustic vibrations on heat transfer. The Nusselt modulus, based on the log mean temperature difference, ranged from 17.2 to 50.6; the Graetz modulus, based on the bulk or average temperature of the air, ranged from 40.2 to 1633; and the Grashof-Prandtl D/L modulus, based on properties of air at the wall temperature, ranged from 0.967 × 105 to 1.26 × 106. The results indicated that sound pressure levels below approximately 118 decibels had little effect on the heat-transfer coefficient. Below 118 decibels free convection forces were evident. Above 118 decibels free convection forces were apparently negligible and the effect of sound appeared to be considerable.

scholarly journals Effect of water medium upon the process of ore disintegration in wet self-grinding mills

2019 ◽  
Vol 109 ◽  
pp. 00058
Author(s):  
Vitalii Monastyrskyi ◽  
Serhii Monastyrskyi ◽  
Borys Mostovyi
Keyword(s):  
Aquatic Environment ◽  
Experimental Studies ◽  
The Body ◽  
Angle Of Repose ◽  
Hydrodynamic Resistance ◽  
Uniform Structure ◽  
Water Medium ◽  
Large Piece ◽  
Grinding Mills ◽  
Expansion Force

This article presents the results of theoretical and experimental studies on the processes of destruction ore in wet self-grinding mills under the influence of the aquatic environment on it. The equivalent circuit for determining the stress-strain state of a large piece (ball) exposed to the load at an angle of repose of the material in motion are justified. A uniformly distributed pressure acts on the body of arbitrary shape, depending on the hydrostatic pressure of the pulp inside the drum and the force of hydrodynamic resistance). It is assumed that a large piece has the shape of a sphere with a uniform structure, but in some of its parts there are cavities filled with an incompressible fluid. Under the action of these forces inside the cavity wedging effects of water occur, the effect of which on the strength ores depends on the expansion force and the angle of the micro crack. The experimental researches are done under laboratory and industrial conditions. It was established that the disintegration of kimberlitic ore in MMC is significantly influenced by the characteristics of the aquatic environment pH and Eh, the values of which vary from 3.2 to 7.0 and from -500 to +1020 mV.

Subject or object: a product’s scent congruent perspectives

2017 ◽  
Vol 30 (3) ◽  
pp. 402-416
Author(s):  
Ana M. Arboleda ◽  
Carlos Arce-Lopera ◽  
Samuel González
Keyword(s):  
Design Methodology ◽  
Experimental Studies ◽  
Quality Attributes ◽  
Marketing Strategies ◽  
Content Type ◽  
Object A ◽  
Reference Quality ◽  
The Subject ◽  
The Individual ◽  
Practical Implications

Purpose The purpose of this paper is evaluate to what extent consumers can recognise a scent within a context that is congruent either with the product or with the user, respectively, objects’ quality or subjects’ involvement. Design/methodology/approach This paper consists of two experimental studies. The first study assesses people’s capacity to recognise three scents: leather, synthetic leather, and fabric. The second study assesses the way in which a frame of reference (quality or involvement) affects people’s capacity for scent recognition (leather and fabric). Findings Results confirm the difficulty of scent recognition revealing, in the first study, a low level of consistency in subjects’ responses. The second study shows an interaction between the type of scent and consumers’ framework: subjects who are primed to think about product quality present more accurate scent recognition when they smell leather, whereas subjects who are primed to think about themselves present more accurate scent recognition when they smell fabric. Practical implications These results can be used in brand communication. A scent, such as that of leather, should highlight quality attributes in its communication. If the product is unscented, communication should highlight the subject who uses the product. Originality/value Previous studies show the importance of the consistency between scent and product marketing strategies. This study complements these findings by differentiating the context where a scent is presented considering either the product (the object’s quality attributes) or the individual who uses that product (subject’s involvement).

Numerical and Experimental Studies on Frequency Characteristics of $\hbox{TE}_{11}$-Mode Enhanced Coaxial Vircator

2011 ◽  
Vol 39 (9) ◽  
pp. 1762-1767 ◽  
Author(s):  
Yongpeng Zhang ◽  
Guozhi Liu ◽  
Hao Shao ◽  
Tiezhu Liang ◽  
Ligang Zhang ◽  
...  
Keyword(s):  
Experimental Studies ◽  
Frequency Characteristics

A novel analysis method for fault diagnosis of hydro-turbine governing system

2017 ◽  
Vol 231 (2) ◽  
pp. 164-171 ◽  
Author(s):  
Xin Xia ◽  
Wei Ni ◽  
Yingjun Sang
Keyword(s):  
Fault Diagnosis ◽  
Frequency Response ◽  
Experimental Studies ◽  
Response Functions ◽  
Output Frequency ◽  
Frequency Response Functions ◽  
Hydro Turbine ◽  
Identification Method ◽  
Governing System ◽  
Diagnosis Method

The fault diagnosis of hydro-turbine governing system is important to the operation of the hydropower station and the stability of the power grid. In order to improve the diagnostic accuracy and efficiency, a novel fault diagnosis method based on nonlinear output frequency response functions and a novel identification method of nonlinear output frequency response functions have been proposed and applied to the problem of hydro-turbine governing system fault diagnostics. First, the nonlinear model of hydro-turbine governing system is built. And the fault diagnosis principles based on nonlinear output frequency response functions are also introduced. Then, the disadvantages of the traditional identification method are discussed, and a novel identification method is proposed for nonlinear output frequency response functions according to the operation characteristic of hydro-turbine governing system. Finally, simulation verification and experimental studies have been presented to demonstrate the accuracy and efficiency of the proposed fault diagnosis method. The results indicate that the proposed method is simple and practical for fault diagnosis of hydro-turbine governing system.

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