subject:(multi frequency acoustics)

NSYSU

1. Wu, Chen-I. Using multi-frequency acoustic instruments to investigate the suspended sediment grain size and concentration characteristic in flume experiment and in the field.

Degree: Master, Marine Geology and chemistry, 2012, NSYSU

URL: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0726112-142244

► In the past, the suspended sediment concentration (SSC) was mainly measured by the optical backscattering device (OBS) and water sample filtration. However, there has been… (more)

▼ In the past, the suspended sediment concentration (SSC) was mainly measured by the optical backscattering device (OBS) and water sample filtration. However, there has been a new development that user is based on the acoustics backscattering (ABS) to measure the SSC in the world. The acoustic instruments have some advantages that the optical ones do not have. For example, acoustic instruments are not effected by high turbidity, biofouling and high viscosity in the water. Acoustic instruments have high spatial and temporal resolutions. And they can immediately indicate the SSC changes than the water sample filtration method. Therefore, in this study we used the multi-frequency acoustics instrument (AQUAscat-1000) to investigate the relations of the suspended sediment size and concentration to the acoustic characteristics. The results are separated into two parts: (1) The calibration process in the flume. (2) The acoustic results in the field experiment. In the first part, we examined the range of preferred bin size with respect to the different frequencies as well as the condition in the flume, and determine that conclude the 20 mm is the best range for our case. In addition, the gain should be used when the maximum SSC is less than 100 mg/l and vice versa. Therefore, in the field case around the river mouth, the signal gain should be turned off due to high concentrations. According to the sensitivity of the backscatter intensity of different frequencies to the suspended particle sizes, multiple frequencies are needed to derive the SSC when the sediment size becomes smaller. The last point in this part is the comparison of the results between the acoustics and optical instruments. When the suspended particles in the water column are transparent, the optical measurement of the SSC is underestimated, but the acoustic method is not. The result of the field experiment in 2009 showed that the AQUAscat-1000 is a better instrument to quantify SSC than the optical instruments. The SSC increase caused by the bottom sediment re-suspension was due to the wave shear. In the 2011 experiment, although the acoustic results overestimated the SSC at some points but they still had higher relation and significance with water sample data than the optical measurements. The SSC increase caused by the bottom sediment re-suspension was due to the current shear. Advisors/Committee Members: Linus Y.S Chiu (chair), James T. Liu (committee member), Yu-Huai Wang (chair), Ruey-Chang Wei (chair).

Subjects/Keywords: flume; suspended sediment; multi-frequency acoustics; optical measurement; sediment re-suspension

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Wu, C. (2012). Using multi-frequency acoustic instruments to investigate the suspended sediment grain size and concentration characteristic in flume experiment and in the field. (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0726112-142244

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Wu, Chen-I. “Using multi-frequency acoustic instruments to investigate the suspended sediment grain size and concentration characteristic in flume experiment and in the field.” 2012. Thesis, NSYSU. Accessed March 07, 2021. http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0726112-142244.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Wu, Chen-I. “Using multi-frequency acoustic instruments to investigate the suspended sediment grain size and concentration characteristic in flume experiment and in the field.” 2012. Web. 07 Mar 2021.

Vancouver:

Wu C. Using multi-frequency acoustic instruments to investigate the suspended sediment grain size and concentration characteristic in flume experiment and in the field. [Internet] [Thesis]. NSYSU; 2012. [cited 2021 Mar 07]. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0726112-142244.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Wu C. Using multi-frequency acoustic instruments to investigate the suspended sediment grain size and concentration characteristic in flume experiment and in the field. [Thesis]. NSYSU; 2012. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0726112-142244

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

2. Barbosa da Cruz Pecanha, Anderson. Evaluating the usage of multi-frequency backscatter data as an additional tool for seafloor characterization.

Degree: MS, 2016, University of New Hampshire

URL: https://scholars.unh.edu/thesis/899

► A reliable understanding of seafloor characteristics can have innumerous application in a variety of fields of knowledge, such as ocean mapping and defense. In… (more)

Subjects/Keywords: EM 2040; Frequency dependency; Multibeam backscatter; Multi-frequency backscatter; Seafloor characterization; Sonar Equation; Geology; Acoustics; Ocean engineering

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Barbosa da Cruz Pecanha, A. (2016). Evaluating the usage of multi-frequency backscatter data as an additional tool for seafloor characterization. (Thesis). University of New Hampshire. Retrieved from https://scholars.unh.edu/thesis/899

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Barbosa da Cruz Pecanha, Anderson. “Evaluating the usage of multi-frequency backscatter data as an additional tool for seafloor characterization.” 2016. Thesis, University of New Hampshire. Accessed March 07, 2021. https://scholars.unh.edu/thesis/899.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Barbosa da Cruz Pecanha, Anderson. “Evaluating the usage of multi-frequency backscatter data as an additional tool for seafloor characterization.” 2016. Web. 07 Mar 2021.

Vancouver:

Barbosa da Cruz Pecanha A. Evaluating the usage of multi-frequency backscatter data as an additional tool for seafloor characterization. [Internet] [Thesis]. University of New Hampshire; 2016. [cited 2021 Mar 07]. Available from: https://scholars.unh.edu/thesis/899.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Barbosa da Cruz Pecanha A. Evaluating the usage of multi-frequency backscatter data as an additional tool for seafloor characterization. [Thesis]. University of New Hampshire; 2016. Available from: https://scholars.unh.edu/thesis/899

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

NSYSU

3. Chiang, Yi-hsuan. Using a multi-frequency acoustic instrument to investigate suspended sediment: case studies at the mouths of Jiulong River and Pearl River.

Degree: Master, Institute of Undersea Technology, 2018, NSYSU

URL: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0721118-103634

► In the past, the suspended sediment concentration was mainly measured by optical backscattering devices and water sample filtration method. Acoustic instruments have some advantages that… (more)

▼ In the past, the suspended sediment concentration was mainly measured by optical backscattering devices and water sample filtration method. Acoustic instruments have some advantages that the optical ones do not have. For example, acoustic instruments are not affected by high turbidity, biofouling and high viscosity in the water. It will generate reflected and backscattered signals when the sound wave hit the suspended sediment. After the signal is converted to echo intensity value, we can estimate the suspended sediment grain size and concentration by using empirical formula. Therefore, in this study we explored the use of a multi-frequency acoustic instrument (AQUAscat-1000) to investigate the difference variation in the suspended sediment grain size, bulk density and concentration and compared the results measured by an optical instrument and filtered particle data. The study sites were the coastal area south of Qinmen near Jiulong River mouth and the coastal area of the Pearl River mouth. These areas are tidal zones where river-ocean interactions are complex. Each experiment included deploying a instrumented mooring to investigate continuous river plume characteristic under the influence of tide. After measuring water temperature, salinity, chl-a and turbidity, collecting acoustic and optical data and water samples, we analyzed the suspended particle samples and compared the results. Different backscattered signals have different responses to bulk density of those three grain size groups(10-63 Î¼m, 63-153 Î¼m, >153 Î¼m). Also, whether the particles are biogenic particles or not, affects the correlation of the data sets. According to the EOF analysis and linear correlation analysis, the applicability of the multi-frequency acoustic instrument to characterize and quantify suspended particles in the river plume regime needs to be investigated further. Advisors/Committee Members: Hwa Chien (chair), Ruo-Shan Tseng (chair), James T. Liu (committee member), Linus Y.S Chiu (committee member).

Subjects/Keywords: optical backscatterance; river plume; EOF; Pearl River mouth; Jiulong River mouth; multi-frequency acoustics; suspended sediment

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Chiang, Y. (2018). Using a multi-frequency acoustic instrument to investigate suspended sediment: case studies at the mouths of Jiulong River and Pearl River. (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0721118-103634

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Chiang, Yi-hsuan. “Using a multi-frequency acoustic instrument to investigate suspended sediment: case studies at the mouths of Jiulong River and Pearl River.” 2018. Thesis, NSYSU. Accessed March 07, 2021. http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0721118-103634.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Chiang, Yi-hsuan. “Using a multi-frequency acoustic instrument to investigate suspended sediment: case studies at the mouths of Jiulong River and Pearl River.” 2018. Web. 07 Mar 2021.

Vancouver:

Chiang Y. Using a multi-frequency acoustic instrument to investigate suspended sediment: case studies at the mouths of Jiulong River and Pearl River. [Internet] [Thesis]. NSYSU; 2018. [cited 2021 Mar 07]. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0721118-103634.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Chiang Y. Using a multi-frequency acoustic instrument to investigate suspended sediment: case studies at the mouths of Jiulong River and Pearl River. [Thesis]. NSYSU; 2018. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0721118-103634

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

4. Moore, Stéphanie. Suivi des flux d'eau et de matières en suspension dans les cours d'eau par profileurs acoustiques Doppler horizontaux : Monitoring flow and fluxes of suspended sediment in rivers using side-looking acoustic Doppler current profilers.

Degree: Docteur es, Sciences de la terre et de l'univers, et de l'environnement, 2011, Université de Grenoble

URL: http://www.theses.fr/2011GRENU043

►

Cette thèse est une étude de l'applicabilité des profileurs acoustiques Doppler horizontaux (H-ADCP) pour le suivi des flux d'eau et de matières en suspension (MES)… (more)

▼

Cette thèse est une étude de l'applicabilité des profileurs acoustiques Doppler horizontaux (H-ADCP) pour le suivi des flux d'eau et de matières en suspension (MES) dans les rivières. Plus d'un an de données acquises avec des H-ADCP de 300, 600 et 1200 kHz sur quatre sites, sur le Rhône, l'Isère et la Saône, avec des géométries et des conditions de forçage contrastées sont analysées. Les résultats montrent qu'une profondeur de section limitée peut poser problème en raison de la diffusion d'une partie de l'énergie acoustique par la surface libre. De plus, quand l'intensité rétrodiffusée par les particules est trop faible, les mesures de vitesse sont sous-estimées ou plus dispersées par rapport aux mesures de référence. Des relations de vitesse indice sont toutefois établies en fonction de l'intensité et de la concentration afin de corriger les vitesses. La concentration en MES est déterminée à partir de l'atténuation acoustique qui est importante pour des suspensions concentrées de limons (> ~100 mg/L). Les constantes d'atténuation sont obtenues par calage sur des mesures de turbidité~; elles sont proches des valeurs théoriques calculées pour les distributions granulométriques des particules primaires. Les mesures acoustiques de concentration sont en bon accord avec les mesures de référence et reproduisent finement la dynamique temporelle. En outre, l'évolution de la granulométrie est étudiée à partir des mesures multi-fréquences d'atténuation sous l'hypothèse que les distributions granulométriques sont lognormales. Cette étude montre qu'une fois que les conditions limites pour des mesures fiables sont bien établies, le H-ADCP est un outil performant pour le suivi des flux d'eau et de MES dans les rivières, surtout pendant des périodes de fortes concentrations telles que des crues.

The work investigates the feasibility of using horizontal acoustic Doppler current profilers (H-ADCPs) to monitor fluxes of water and suspended sediment in rivers. Year-long data sets acquired with H-ADCPs operating at 300, 600 and 1200 kHz at four sites with varying geometries and flow forcing conditions on the Rhône, Saône and Isère rivers are analyzed. Findings show that limited depth can pose a problem due to scattering of a fraction of the acoustic energy from the air-water interface. A second problem arises when the backscattered intensity from the suspended sediment is too weak; this leads to underestimation or higher variability of the velocity estimates compared to reference values. Nevertheless, index-velocity relationships are established as a function of concentration and intensity in order to correct the velocity measurements. Concentrations of suspended sediment can be determined from the acoustic attenuation, which is substantial for silt-sized particles at concentrations > ~100 mg/L. Attenuation constants obtained by comparison with turbidity data are in good agreement with the theoretical values calculated for the measured grain size distributions of the primary particles. The acoustic measurements of concentration are…

Advisors/Committee Members: Hurther, David (thesis director), Le Coz, Jérôme (thesis director).

Subjects/Keywords: Mesures acoustiques multi-fréquences; Flux de sédiments en suspension; ADCP horizontaux; Atténuation acoustique; Multi-frequency acoustics; Suspended sediment fluxes; Horizontal ADCPs; Acoustic attenuation; 550

…156 7.6 Four examples of the multi-frequency size estimation method based on the acoustic… …determined from multi-frequency attenuation data by assuming lognormal size distributions. The… …determine whether multi-frequency attenuation data can provide accurate measurements of grain size… …Variation of the sediment absorption ratios with particle radius for the three frequency… …at Romans-sur-Isère. (b) The median grain radius obtained using the multi…

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Moore, S. (2011). Suivi des flux d'eau et de matières en suspension dans les cours d'eau par profileurs acoustiques Doppler horizontaux : Monitoring flow and fluxes of suspended sediment in rivers using side-looking acoustic Doppler current profilers. (Doctoral Dissertation). Université de Grenoble. Retrieved from http://www.theses.fr/2011GRENU043

Chicago Manual of Style (16^th Edition):

Moore, Stéphanie. “Suivi des flux d'eau et de matières en suspension dans les cours d'eau par profileurs acoustiques Doppler horizontaux : Monitoring flow and fluxes of suspended sediment in rivers using side-looking acoustic Doppler current profilers.” 2011. Doctoral Dissertation, Université de Grenoble. Accessed March 07, 2021. http://www.theses.fr/2011GRENU043.

MLA Handbook (7^th Edition):

Moore, Stéphanie. “Suivi des flux d'eau et de matières en suspension dans les cours d'eau par profileurs acoustiques Doppler horizontaux : Monitoring flow and fluxes of suspended sediment in rivers using side-looking acoustic Doppler current profilers.” 2011. Web. 07 Mar 2021.

Vancouver:

Moore S. Suivi des flux d'eau et de matières en suspension dans les cours d'eau par profileurs acoustiques Doppler horizontaux : Monitoring flow and fluxes of suspended sediment in rivers using side-looking acoustic Doppler current profilers. [Internet] [Doctoral dissertation]. Université de Grenoble; 2011. [cited 2021 Mar 07]. Available from: http://www.theses.fr/2011GRENU043.

Council of Science Editors:

Moore S. Suivi des flux d'eau et de matières en suspension dans les cours d'eau par profileurs acoustiques Doppler horizontaux : Monitoring flow and fluxes of suspended sediment in rivers using side-looking acoustic Doppler current profilers. [Doctoral Dissertation]. Université de Grenoble; 2011. Available from: http://www.theses.fr/2011GRENU043

5. Sommer, Andrew Patrick. VIBRATION-BASED HEALTH MONITORING OF MULTIPLE-STAGE GEAR TRAIN AND DIFFERENTIAL PLANETARY TRANSMISSION INVOLVING TEETH DAMAGE AND BACKLASH NONLINEARITY.

Degree: MS, Mechanical Engineering, 2011, Cal Poly

URL: https://digitalcommons.calpoly.edu/theses/631 ; 10.15368/theses.2011.186

► The objective of this thesis is to develop vibration-based fault detection strategies for on-line condition monitoring of gear transmission systems. The study divides the… (more)

Subjects/Keywords: vibration health monitoring; malfunction diagnostics; multi-body kinematic model; epicyclic transmission; backlash; joint time-frequency analysis; Acoustics, Dynamics, and Controls; Applied Mechanics; Computer-Aided Engineering and Design; Dynamics and Dynamical Systems; Electro-Mechanical Systems; Engineering Mechanics; Mechanics of Materials; Propulsion and Power; Signal Processing

…29 25. A comparison of frequency domain components of force magnitude in Stage 1 and Stage… …31 26. Frequency domain components of force magnitude in Stage 2 with an eccentric gear… …44 x 40. Time and frequency domain representations of force in the planetary and fixed… …linear multi-body dynamics software model. Double sided tooth impacts and associated loading… …The frequency domain analysis reveals that an eccentric tooth on a gear installed on the…

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Sommer, A. P. (2011). VIBRATION-BASED HEALTH MONITORING OF MULTIPLE-STAGE GEAR TRAIN AND DIFFERENTIAL PLANETARY TRANSMISSION INVOLVING TEETH DAMAGE AND BACKLASH NONLINEARITY. (Masters Thesis). Cal Poly. Retrieved from https://digitalcommons.calpoly.edu/theses/631 ; 10.15368/theses.2011.186

Chicago Manual of Style (16^th Edition):

Sommer, Andrew Patrick. “VIBRATION-BASED HEALTH MONITORING OF MULTIPLE-STAGE GEAR TRAIN AND DIFFERENTIAL PLANETARY TRANSMISSION INVOLVING TEETH DAMAGE AND BACKLASH NONLINEARITY.” 2011. Masters Thesis, Cal Poly. Accessed March 07, 2021. https://digitalcommons.calpoly.edu/theses/631 ; 10.15368/theses.2011.186.

MLA Handbook (7^th Edition):

Sommer, Andrew Patrick. “VIBRATION-BASED HEALTH MONITORING OF MULTIPLE-STAGE GEAR TRAIN AND DIFFERENTIAL PLANETARY TRANSMISSION INVOLVING TEETH DAMAGE AND BACKLASH NONLINEARITY.” 2011. Web. 07 Mar 2021.

Vancouver:

Sommer AP. VIBRATION-BASED HEALTH MONITORING OF MULTIPLE-STAGE GEAR TRAIN AND DIFFERENTIAL PLANETARY TRANSMISSION INVOLVING TEETH DAMAGE AND BACKLASH NONLINEARITY. [Internet] [Masters thesis]. Cal Poly; 2011. [cited 2021 Mar 07]. Available from: https://digitalcommons.calpoly.edu/theses/631 ; 10.15368/theses.2011.186.

Council of Science Editors:

Sommer AP. VIBRATION-BASED HEALTH MONITORING OF MULTIPLE-STAGE GEAR TRAIN AND DIFFERENTIAL PLANETARY TRANSMISSION INVOLVING TEETH DAMAGE AND BACKLASH NONLINEARITY. [Masters Thesis]. Cal Poly; 2011. Available from: https://digitalcommons.calpoly.edu/theses/631 ; 10.15368/theses.2011.186

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