scholarly journals Use of functional cluster analysis of CPTU data for assessment of a subsoil rigidity

2018 ◽  
Vol 40 (2) ◽  
pp. 117-124 ◽  
Author(s):  
Zb. Młynarek ◽  
J. Wierzbicki ◽  
W. Wołyński
Keyword(s):  
Cluster Analysis ◽  
Data Analysis ◽  
Functional Data Analysis ◽  
Functional Data ◽  
Penetration Test ◽  
Empirical Relationships ◽  
Piezocone Penetration Test ◽  
Cone Tip Resistance ◽  
Constrained Modulus ◽  
Tip Resistance

AbstractThis paper shows an example of the grouping of piezocone penetration test (CPTU) characteristics using functional data analysis, together with the results of clustering, in the form of a subsoil rigidity model. The subsoil rigidity model was constructed based on layer separation using the proposed method, as well as the k-means method. In the construction of the subsoil rigidity model, the constrained modulus M was applied. These moduli were determined from empirical relationships for overconsolidated and normally consolidated soils from Poland based on cone tip resistance.

Reliability of Piezocone Penetration Test Methods for Estimating the Coefficient of Consolidation of Cohesive Soils

2005 ◽  
Vol 1913 (1) ◽  
pp. 62-76 ◽  
Author(s):  
Murad Y. Abu-Farsakh ◽  
Munir D. Nazzal
Keyword(s):  
Test Methods ◽  
Cohesive Soils ◽  
Penetration Test ◽  
Coefficient Of Consolidation ◽  
Piezocone Penetration Test ◽  
Cone Tip Resistance ◽  
Tip Resistance ◽  
Penetration Depths ◽  
Better Than

The current piezocone penetration test (PCPT) interpretation methods were evaluated for their capability to estimate the vertical coefficient of consolidation (c v) of cohesive soils reasonably by using the piezocone dissipation tests. Seven PCPT methods were evaluated. Six sites in Louisiana were selected for this study. At each site, in situ PCPT tests were performed, and soundings of cone tip resistance, sleeve friction, and pore pressures at different locations were recorded. Piezocone dissipation tests also were conducted at different penetration depths. High-quality Shelby tube samples were collected close to the PCPT tests and were used to carry out a comprehensive laboratory testing program. The (c v) values predicted by the different interpretation methods were compared with the reference values determined from the oedometer laboratory tests. The results of this study showed that two methods can estimate cv better than the other prediction methods.

scholarly journals Estimating Hydraulic Conductivity of Overconsolidated Soils Based on Piezocone Penetration Test (PCPT)

2021 ◽  
Vol 6 (3) ◽  
pp. 32
Author(s):  
Binyam M. Bekele ◽  
Chung R. Song ◽  
Gyunam Jin ◽  
Mark Lindemann
Keyword(s):  
Hydraulic Conductivity ◽  
Pore Pressure ◽  
Correction Factor ◽  
Soil Mechanics ◽  
Data Sets ◽  
Penetration Test ◽  
Piezocone Penetration Test ◽  
Cone Tip Resistance ◽  
Tip Resistance ◽  
Overconsolidated Soils

Overconsolidated (OC) soils may develop a low or negative pore pressure during PCPT. Thus, it is challenging to develop an “on-the-fly” estimation of hydraulic conductivity from PCPT results. This study presents a method to estimate the hydraulic conductivity of OC soils from PCPT results based on a previously developed method for normally consolidated (NC) soils. To apply the existing method, PCPT pore pressure in OC soils is adjusted by using a correction factor. An equation for the correction factor is derived based on the concepts of critical state soil mechanics, cavity expansion, and consolidation theories. Then, it was reformulated so that traditional cone indices could be used as input parameters. It is shown that the correction factor is mainly influenced by the cone tip resistance, pore pressure, and the rigidity index. The comparison of predicted, which is based on corrected pore pressure and measured hydraulic conductivity showed a good match for four well documented data sets. With the findings of the study, it is expected that an “on-the-fly” estimation of hydraulic conductivity of overconsolidated soils is possible.

scholarly journals Basis Expansions for Functional Snippets

Biometrika ◽  
2020 ◽  
Author(s):  
Zhenhua Lin ◽  
Jane-Ling Wang ◽  
Qixian Zhong
Keyword(s):  
Data Analysis ◽  
Convergence Rate ◽  
Functional Data Analysis ◽  
Functional Data ◽  
Covariance Function ◽  
Covariance Estimation ◽  
Simulation Studies ◽  
Finite Sample ◽  
Covariance Functions ◽  
The Mean

Summary Estimation of mean and covariance functions is fundamental for functional data analysis. While this topic has been studied extensively in the literature, a key assumption is that there are enough data in the domain of interest to estimate both the mean and covariance functions. In this paper, we investigate mean and covariance estimation for functional snippets in which observations from a subject are available only in an interval of length strictly (and often much) shorter than the length of the whole interval of interest. For such a sampling plan, no data is available for direct estimation of the off-diagonal region of the covariance function. We tackle this challenge via a basis representation of the covariance function. The proposed estimator enjoys a convergence rate that is adaptive to the smoothness of the underlying covariance function, and has superior finite-sample performance in simulation studies.

scholarly journals Novel Analytic Approaches to Investigate Minute-Level Actigraphy and Associations With Physical Function

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 194-195
Author(s):  
Kaiyuan Hua ◽  
Sheng Luo ◽  
Katherine Hall ◽  
Miriam Morey ◽  
Harvey Cohen
Keyword(s):  
Physical Activity ◽  
Data Analysis ◽  
Physical Function ◽  
Functional Data Analysis ◽  
Functional Data ◽  
Gait Speed ◽  
Community Dwelling ◽  
Accelerometer Data ◽  
Single Leg Stance ◽  
Minute Walk

Abstract Background. Functional decline in conjunction with low levels of physical activity has implications for health risks in older adults. Previous studies have examined the associations between accelerometry-derived activity and physical function, but most of these studies reduced these data into average means of total daily physical activity (e.g., daily step counts). A new method of analysis “functional data analysis” provides more in-depth capability using minute-level accelerometer data. Methods. A secondary analysis of community-dwelling adults ages 30 to 90+ residing in southwest region of North Carolina from the Physical Performance across the Lifespan (PALS) study. PALS assessments were completed in-person at baseline and one-week of accelerometry. Final analysis includes 669 observations at baseline with minute-level accelerometer data from 7:00 to 23:00, after removing non-wear time. A novel scalar-on-function regression analysis was used to explore the associations between baseline physical activity features (minute-by-minute vector magnitude generated from accelerometer) and baseline physical function (gait speed, single leg stance, chair stands, and 6-minute walk test) with control for baseline age, sex, race and body mass index. Results. The functional regressions were significant for specific times of day indicating increased physical activity associated with increased physical function around 8:00, 9:30 and 15:30-17:00 for rapid gait speed; 9:00-10:30 and 15:00-16:30 for normal gait speed; 9:00-10:30 for single leg stance; 9:30-11:30 and 15:00-18:00 for chair stands; 9:00-11:30 and 15:00-18:30 for 6-minute walk. Conclusion. This method of functional data analysis provides news insights into the relationship between minute-by-minute daily activity and health.

A kNN procedure in semiparametric functional data analysis

2021 ◽  
pp. 109028
Author(s):  
Silvia Novo ◽  
Germán Aneiros ◽  
Philippe Vieu
Keyword(s):  
Data Analysis ◽  
Functional Data Analysis ◽  
Functional Data
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