scholarly journals Asymptotic waveform inversion for unbiased velocity and attenuation measurements: numerical tests and application for Vesuvius lava sample analysis

2004 ◽  
Vol 158 (1) ◽  
pp. 353-371 ◽  
Author(s):  
A. Ribodetti ◽  
S. Gaffet ◽  
S. Operto ◽  
J. Virieux ◽  
G. Saracco
Keyword(s):  
Waveform Inversion ◽  
Sample Analysis ◽  
Numerical Tests ◽  
Lava Sample

scholarly journals Extraction of the tomography mode with nonstationary smoothing for full-waveform inversion

Geophysics ◽  
2019 ◽  
Vol 84 (4) ◽  
pp. R527-R537 ◽  
Author(s):  
Gang Yao ◽  
Nuno V. da Silva ◽  
Vladimir Kazei ◽  
Di Wu ◽  
Chenhao Yang
Keyword(s):  
Time Domain ◽  
Waveform Inversion ◽  
Opening Angle ◽  
Full Waveform Inversion ◽  
Domain Modeling ◽  
Scattering Angle ◽  
Numerical Tests ◽  
Reflection Data ◽  
Full Waveform ◽  
Migration Component

Full-waveform inversion (FWI) includes migration and tomography modes. The tomographic component of the gradient from reflection data is usually much weaker than the migration component. To use the tomography mode to fix background velocity errors, it is necessary to extract the tomographic component from the gradient. Otherwise, the inversion will be dominated by the migration mode. We have developed a method based on nonstationary smoothing to extract the tomographic component from the raw gradient. By analyzing the characteristics of the scattering angle filtering, the wavenumber of the tomographic component at a given frequency is seen to be smaller than that of the migration component. Therefore, low-wavenumber-pass filtering can be applied to extract the tomographic component. The low-wavenumber-pass smoothing filters are designed with Gaussian filters that are determined by the frequency of inversion, the model velocity, and the minimum scattering angle. Thus, this filtering is nonstationary smoothing in the space domain. Because this filtering is carried out frequency by frequency, it works naturally and efficiently for FWI based on frequency-domain modeling. Furthermore, because the maximum opening angle of the reflections in a typical acquisition geometry is much smaller than the minimum scattering angle for the tomographic component, which is generally set at 160°, there is a relatively large gap between the wavenumbers of the tomographic and migration components. In other words, the nonstationary smoothing can be applied once to a group of frequencies for time-domain FWI without leaking the migration component into the tomographic component. Analyses and numerical tests indicate that two frequency groups are generally sufficient to extract the tomographic component for the typical frequency range of time-domain FWI. The numerical tests also demonstrate that the nonstationary smoothing method is effective and efficient at extracting the tomographic component for reflection waveform inversion.

Assessing Functional Language in School-Aged Children Using Language Sample Analysis

2020 ◽  
Vol 5 (3) ◽  
pp. 622-636
Author(s):  
John Heilmann ◽  
Alexander Tucci ◽  
Elena Plante ◽  
Jon F. Miller
Keyword(s):  
Computer Hardware ◽  
School Age Children ◽  
Functional Language ◽  
School Age ◽  
Clinical Use ◽  
Sample Analysis ◽  
Validity And Reliability ◽  
Language Sample Analysis ◽  
Accuracy And Repeatability ◽  
Language Sample

Purpose The goal of this clinical focus article is to illustrate how speech-language pathologists can document the functional language of school-age children using language sample analysis (LSA). Advances in computer hardware and software are detailed making LSA more accessible for clinical use. Method This clinical focus article illustrates how documenting school-age student's communicative functioning is central to comprehensive assessment and how using LSA can meet multiple needs within this assessment. LSA can document students' meaningful participation in their daily life through assessment of their language used during everyday tasks. The many advances in computerized LSA are detailed with a primary focus on the Systematic Analysis of Language Transcripts (Miller & Iglesias, 2019). The LSA process is reviewed detailing the steps necessary for computers to calculate word, morpheme, utterance, and discourse features of functional language. Conclusion These advances in computer technology and software development have made LSA clinically feasible through standardized elicitation and transcription methods that improve accuracy and repeatability. In addition to improved accuracy, validity, and reliability of LSA, databases of typical speakers to document status and automated report writing more than justify the time required. Software now provides many innovations that make LSA simpler and more accessible for clinical use. Supplemental Material https://doi.org/10.23641/asha.12456719

Issues in Language Sample Collection and Analysis With Children Using AAC

2014 ◽  
Vol 23 (2) ◽  
pp. 65-74 ◽  
Author(s):  
Gail Van Tatenhove
Keyword(s):  
Clinical Practice ◽  
Augmentative And Alternative Communication ◽  
Language Production ◽  
Expressive Language ◽  
Sample Analysis ◽  
Alternative Communication ◽  
Sample Collection ◽  
Speech Language Pathologists ◽  
Language Sample Analysis ◽  
Language Sample

Language sample analysis is considered one of the best methods of evaluating expressive language production in speaking children. However, the practice of language sample collection and analysis is complicated for speech-language pathologists working with children who use augmentative and alternative communication (AAC) devices. This article identifies six issues regarding use of language sample collection and analysis in clinical practice with children who use AAC devices. The purpose of this article is to encourage speech-language pathologists practicing in the area of AAC to utilize language sample collection and analysis as part of ongoing AAC assessment.

PEMBUATAN SURFAKTAN DARI ASAM OLEAT

2019 ◽  
Vol 1 (3) ◽  
pp. 68
Author(s):  
Puguh Setyopratomo ◽  
Edy Purwanto ◽  
H. Yefrico ◽  
H. Yefrico
Keyword(s):  
Oleic Acid ◽  
Optimum Condition ◽  
Reaction Temperature ◽  
Catalyst Concentration ◽  
Acid Number ◽  
Esterification Reaction ◽  
Number Density ◽  
Sample Analysis ◽  
Reaction Conversion ◽  
Glycerol Mono

The synthesis of glycerol mono oleic from oleic acid and glycerol is classified as an esterification reaction. This research is aimed to study the influent of reaction temperature and catalyst concentration on reaction conversion. During the experiment the temperature of reaction mixture was varied as 110 oC, 130 oC, and 150 oC, while the catalyst concentration of 1%, 3 %, and 5% was used. The batch experiment was conducted in a glass reactor equipped with termometer, agitator, and reflux condensor. The oleic acid – glycerol mol ratio of 1 : 2 was used as a mixture feed. To maintain the reaction temperature at certain level, the oil bath was used. After the temperature of reaction mixture was reached the expected value, then H2SO4 catalyst was added to the reactor.  To measure the extent of the reaction, every 30 minutes the sample was drawn out from the reactor vessel. The sample analysis include acid number, density, and viscosity measurement. From this research the optimum condition which is the temperature of reaction of 150 oC and 1% catalyst concentration was obtained. At this optimum condition the convertion reach 86% and the analysis of other physical properties of the product show the acid number of 24.12, the density of 0.922 g/cc, and the viscosity of 118.4 cp.

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