scholarly journals A method of jellyfish detection based on high resolution multibeam acoustic image

2019 ◽  
Vol 283 ◽  
pp. 04008
Author(s):  
Yang Zhang ◽  
Guijuan Li ◽  
Mingwei Zhang ◽  
Yi Jiang
Keyword(s):  
High Resolution ◽  
Dynamic Characteristic ◽  
Acoustic Method ◽  
Target Strength ◽  
Characteristic Parameters ◽  
Detection Experiment ◽  
Moon Jellyfish ◽  
Acoustic Characteristics ◽  
Acoustic Image ◽  
Acoustic Images

A method based on high resolution multi-beam acoustic image was brought forward for jellyfish detection, and a moon jellyfish detection experiment was conducted on sea. In this experiment, clear acoustic images of individual moon jellyfish were obtained, acoustic method was verified available in moon jellyfish detection. Echo characteristics of individual moon jellyfish were analysed. In the echo image of individual moon jellyfish, four evident echo highlights were found, which were due to the four stomach pouches. Three acoustic characteristic parameters were proposed and estimated to describe jellyfish acoustic characteristics, which were acoustic diameter, acoustic height, and relative target strength. In addition, dynamic characteristic of moon jellyfish was also studied during its pulse motion.

scholarly journals Acoustic systems (split beam echo sounder ) to determine abundance of fish in marine fisheries

2017 ◽  
Vol 2 (1) ◽  
pp. 76 ◽  
Author(s):  
Muhammad Zainuddin Lubis ◽  
Henry M Manik
Keyword(s):  
High Resolution ◽  
Acoustic Waves ◽  
High Speed ◽  
Acoustic Method ◽  
Target Strength ◽  
Swim Bladder ◽  
Fish Stocks ◽  
Catching Up ◽  
Subsurface Ocean ◽  
Echo Sounder

Acoustic waves are transmitted into the subsurface ocean will experience scattering (scattering) caused by marine organisms, material distributed in the ocean, the structure is not homogeneous in seawater, as well as reflections from the surface and the seabed. Estimation of fish stocks in the waters wide as in Indonesia have a lot of them are using the acoustic method. The acoustic method has high speed in predicting the size of fish stocks so as to allow acquiring data in real time, accurate and high speed so as to contribute fairly high for the provision of data and information of fishery resources.  Split beam echo sounder comprises two aspects, and a transducer. The first aspect is the high-resolution color display for displaying echogram at some observations and also serves as a controller in the operation of the echo sounder. The second aspect is transceiver consisting of transmitter and receiver. The Echosounder divided beam first inserted into the ES 3800 by SIMRAD beginning of the 1980s and in 1985 was introduced to fishermen in Japan as a tool for catching up. Split beam transducer is divided into four quadrants.  Factors that contribute affect the value of Target Strength (TS) fish Strength target can generally be influenced by three factors: a target factor itself, environmental factors, and factors acoustic instrument. Factors include the size of the target, the anatomy of fish, swim bladder, the behavior of orientation.

Analisis Akustik Target Strength Penyu Hijau (Chelonia Mydas) Melalui Pengukuran Secara Terkontrol Pada Frekuensi 200 kHz

2021 ◽  
Vol 3 (2) ◽  
pp. 94-108
Author(s):  
Teddy Julyansyah ◽  
Deddy Bakhtiar ◽  
Ari Anggoro
Keyword(s):  
Green Turtle ◽  
Population Decline ◽  
Chelonia Mydas ◽  
Total Body Length ◽  
Acoustic Method ◽  
Target Strength ◽  
Acoustic Backscattering ◽  
Total Length ◽  
In Captivity ◽  
Total Body

ABSTRACT Turtles are reptiles that live in the sea and are able to migrate over long distances along the Indian Ocean, Pacific Ocean and Southeast Asia. Currently the number of turtle populations in nature has greatly decreased. This population decline is caused by natural factors and human activities that endanger the population directly or indirectly. At this time the tagging set technique (ID tag code) is a method that is often used to detect the presence of turtles by attaching tags to female turtles who are landing to lay eggs on the beach or while in captivity or the discovery of the mother turtle by fishermen. One other method that can be used to detect the presence of turtles is to use the acoustic method. The purpose of this study was to analyze the characteristics of the acoustic backscattering energy of the green turtle (Chelonia mydes) and to analyze the relationship between target strength and total body length of the green turtle (Chelonia mydas). This research was conducted in the Tapak Paderi waters pond, Bengkulu City, in August-October 2020. The average target strength (TS) value for green turtles was -48.07 dB. Based on the regression equation, the value of determination (R2) obtained is 0.78. Where this value shows that the total length of the green turtle has an effect of 78% on the average target strength (TS) value, while for 22% it is caused by other factors such as body shape, environmental factors and other factors. Based on the ANOVA test, it can be concluded that there is a relationship between the total length and the value of the target strength (TS) on the green turtle or the value of the total length has an influence on the value of the target strength (TS) on the green turtle.  

The Estimation of Long-Range Internal Stress Fields by Spectral-Acoustic Method

2014 ◽  
Vol 1013 ◽  
pp. 121-126 ◽  
Author(s):  
Aleksandr Smirnov ◽  
Nikolai Ababkov ◽  
Aleksandra Glinka
Keyword(s):  
Conceptual Model ◽  
Physical And Mechanical Properties ◽  
Acoustic Method ◽  
Electron Microscopic ◽  
Limiting State ◽  
Acoustic Characteristics ◽  
Complex Criterion ◽  
Microscopic Studies ◽  
Hazardous Production

A conceptual model consisting of diagrams, text and terminology dictionary, made in a formalized way and representations of functions, each of which reflects the real state of the long-running metal at all stages of the life cycle. Based on the developed conceptual model, analysis of the results of electron microscopic studies measuring the acoustic characteristics and determination of physical and mechanical properties of the complex criterion limiting state long working metal technical devices hazardous production facilities.

scholarly journals New broadband methods for resonance classification and high-resolution imagery of fish with swimbladders using a modified commercial broadband echosounder

2010 ◽  
Vol 67 (2) ◽  
pp. 365-378 ◽  
Author(s):  
Timothy K. Stanton ◽  
Dezhang Chu ◽  
J. Michael Jech ◽  
James D. Irish
Keyword(s):  
High Resolution ◽  
Pulse Compression ◽  
Target Strength ◽  
Compression Technique ◽  
Range Resolution ◽  
High Resolution Imagery ◽  
Broadband Signal ◽  
Scattering Strength ◽  
Broadband Signal Processing ◽  
Lower Frequencies

Abstract Stanton, T. K., Chu, D., Jech, J. M., and Irish, J. D. 2010. New broadband methods for resonance classification and high-resolution imagery of fish with swimbladders using a modified commercial broadband echosounder. – ICES Journal of Marine Science, 67: 365–378. A commercial acoustic system, originally designed for seafloor applications, has been adapted for studying fish with swimbladders. The towed system contains broadband acoustic channels collectively spanning the frequency range 1.7–100 kHz, with some gaps. Using a pulse-compression technique, the range resolution of the echoes is ∼20 and 3 cm in the lower and upper ranges of the frequencies, respectively, allowing high-resolution imaging of patches and resolving fish near the seafloor. Measuring the swimbladder resonance at the lower frequencies eliminates major ambiguities normally associated with the interpretation of fish echo data: (i) the resonance frequency can be used to estimate the volume of the swimbladder (inferring the size of fish), and (ii) signals at the lower frequencies do not depend strongly on the orientation of the fish. At-sea studies of Atlantic herring demonstrate the potential for routine measurements of fish size and density, with significant improvements in accuracy over traditional high-frequency narrowband echosounders. The system also detected patches of scatterers, presumably zooplankton, at the higher frequencies. New techniques for quantitative use of broadband systems are presented, including broadband calibration and relating target strength and volume-scattering strength to quantities associated with broadband signal processing.

High‐resolution target strength measurements in deep water

1999 ◽  
Vol 105 (2) ◽  
pp. 1049-1049 ◽  
Author(s):  
Egil Ona ◽  
Ingvald Svellingen
Keyword(s):  
High Resolution ◽  
Deep Water ◽  
Target Strength

Effect of Clamped Toolholders on Dynamic Characteristics of Spindle System of Machining Center

2012 ◽  
Vol 6 (2) ◽  
pp. 168-174 ◽  
Author(s):  
Haruhisa Sakamoto ◽  
◽  
Taiga Matsuda ◽  
Shinji Shimizu ◽  
Keyword(s):  
Dynamic Characteristic ◽  
Dynamic Characteristics ◽  
Dynamic Stiffness ◽  
Physical Parameters ◽  
Characteristic Parameters ◽  
Spindle System ◽  
Press Fit ◽  
Equivalent Damping Coefficient ◽  
Response Method ◽  
Tooling System

In this study, dynamic characteristics are determined based on the impulse response method, the correction of discretization errors and the identification of equivalent physical parameters, as found in the vibration model having one degree of freedom. In the experiments, the test tool is cylindrical bar shaped and made from solid tungsten carbide, and four toolholders with chucking mechanisms, including the shrinkfit type, collet type, hydraulic type, and press-fit type, are used. Since it had been previously confirmed that one of the tool preparation jigs had dynamic characteristics similar to those of an actual machine tool’s spindle, the dynamic characteristics of the jig could be measured the way the spindle system is measured in this study. From the experimental examinations, the following were clarified. (1) Chucking of the tooling system enhances the first mode vibration of the spindle system markedly. (2) The type of tool chuck used changes the dynamic characteristics of the spindle system. The trend in the dynamic stiffness corresponds well with that in the equivalent damping coefficient but is opposite to that in the equivalent stiffness. (3) The magnitude order of the dynamic characteristic parameters of the spindle system corresponds well with the inherent values of the dynamic characteristic parameters of the toolholders themselves; that is, the inherent dynamic characteristics of the tooling system can be used as the criteria to estimate the effect on the dynamic characteristics of the spindle system.

Influence of Bolted Joint on Dynamic Characteristics of Combined Three-Section Crossbeam

2010 ◽  
Vol 37-38 ◽  
pp. 534-539
Author(s):  
Tie Neng Guo ◽  
Dong Liang Guo ◽  
Li Gang Cai ◽  
Bin Song ◽  
Jing Nan Zhao
Keyword(s):  
Machine Tool ◽  
Dynamic Analysis ◽  
Dynamic Characteristic ◽  
Dynamic Characteristics ◽  
Bolted Joints ◽  
Experimental Result ◽  
Bolted Joint ◽  
Cnc Milling ◽  
Characteristic Parameters

The combined three-section crossbeam is an important component in the heavy gantry CNC milling-lathing machine tool and the dynamic characteristics are key precision factors for the machine tool. Three sections of the combined crossbeam are bolted by large industrial bolts and the influence of bolted joints should be evaluated in the dynamic analysis of the combined crossbeam. The dynamic characteristics of the combined three-section crossbeam were extracted by the modal experiment. The FEM of the monolithic crossbeam was modeled to analyze the dynamic characteristic parameters. The comparison of the analysis result and experimental result were shown. The experimental result matched well with the FEM of the monolithic crossbeam without bolted joints. As a result, the influence of the bolted joints could be ignorable in dynamic characteristic for the combined three-section crossbeam.

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