Modeling swelling–shrinkage behavior of compacted expansive soils during wetting–drying cycles

2015 ◽  
Vol 52 (6) ◽  
pp. 783-794 ◽  
Author(s):  
Gang Wang ◽  
Xing Wei
Keyword(s):  
Deformation Behavior ◽  
Early Stage ◽  
Expansive Soils ◽  
Level Structure ◽  
Shrinkage Strain ◽  
Model Parameters ◽  
Microstructural Parameters ◽  
Phenomenological Perspective ◽  
The Difference ◽  
Reversible Component

This paper presents a straightforward approach for modelling volume change behavior of expansive soils during wetting–drying cycles. The swelling–shrinkage strain of expansive soils induced by cyclic wetting and drying was decomposed with distinctive physical background into a reversible component, which shows a synchronous change with the cyclic change of suction, and an irreversible component, which is generated mainly in the early stage of the wetting–drying process. The mechanisms of the two swelling–shrinkage strain components can be well explained through the double-level structure of expansive soils and its evolution with mechanical and hydraulic loading. The reversible component originates from the reversible deformation behavior of aggregates, and primarily depends on current suction or water content. The irreversible component is associated with the irreversible change of macrostructure, reflecting the difference in soil structures at current state and the equilibrium state. A practical constitutive model was proposed for compacted expansive clays from a global and phenomenological perspective. The model parameters can be calibrated with observed macroscopic deformation behavior without measuring microstructural parameters. The performance of the presented model was validated by simulating cyclic suction-controlled tests as well as an alternately soaked and dried test with irregular amplitudes of suctions.

scholarly journals Laws Governing Free and Actual Drying Shrinkage of 50 mm Thick Mongolian Scotch Pine Timber

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1500
Author(s):  
Xiaodong Zhu ◽  
Jingyao Zhao ◽  
Wanhui Gao ◽  
Cheng Qian ◽  
Yunjia Duan ◽  
...  
Keyword(s):  
Early Stage ◽  
Drying Shrinkage ◽  
Shrinkage Strain ◽  
Scotch Pine ◽  
Free Shrinkage ◽  
Different Temperatures ◽  
Conventional Drying ◽  
Sawn Timber ◽  
The Difference ◽  
Shrinkage Coefficient

The relationships between free shrinkage and actual shrinkage of different layers in Mongolian Scotch pine (Pinus sylvestris var. mongolica Litv.) were explored to provide basic data for the further study of drying shrinkage properties. The free shrinkage coefficients at different temperatures and the actual shrinkage strain of each layer were examined under conventional drying. The results showed high precision of free drying shrinkage of corresponding layers of thin small test strips in each layer of sawn timber. The free shrinkage increased linearly as moisture content declined. At the same temperature, the free shrinkage coefficient reached the largest values for the first layer (above 0.267), while the smallest values were recorded for the ninth layer (below 0.249). Except for the ninth layer, the free shrinkage coefficients in width directions of other representative layers decreased as temperature increased. At constant temperature, the difference in free shrinkage coefficient of test materials in the length direction of sawn timber was small for the first layer, but slightly larger and changed irregularly in the fifth and ninth layer direction. At the end of conventional drying, the plastic deformation of each layer in the early stage of drying showed a reducing trend or even reversal due to the effects of reverse stress and later damp heat. In sum, these findings look promising for future optimization of wood drying process.

scholarly journals Differences in physical symptoms between those with and without kidney disease: a comparative study across disease stages in a UK population

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Thomas J. Wilkinson ◽  
Daniel G. D. Nixon ◽  
Jared Palmer ◽  
Courtney J. Lightfoot ◽  
Alice C. Smith
Keyword(s):  
Kidney Disease ◽  
Early Stage ◽  
Symptom Burden ◽  
Final Analysis ◽  
Physical Symptoms ◽  
Disease Trajectory ◽  
High Prevalence ◽  
Comparative Group ◽  
The Difference ◽  
Disease Stages

Abstract Background Those living with kidney disease (KD) report extensive symptom burden. However, research into how symptoms change across stages is limited. The aims of this study were to 1) describe symptom burden across disease trajectory, and 2) to explore whether symptom burden is unique to KD when compared to a non-KD population. Methods Participants aged > 18 years with a known diagnosis of KD (including haemodialysis (HD) and peritoneal dialysis (PD)) and with a kidney transplant) completed the Leicester Kidney Symptom Questionnaire (KSQ). A non-KD group was recruited as a comparative group. Multinominal logistic regression modelling was used to test the difference in likelihood of those with KD reporting each symptom. Results In total, 2279 participants were included in the final analysis (age 56.0 (17.8) years, 48% male). The main findings can be summarised as: 1) the number of symptoms increases as KD severity progresses; 2) those with early stage KD have a comparable number of symptoms to those without KD; 3) apart from those receiving PD, the most frequently reported symptom across every other group, including the non-KD group, was ‘feeling tired’; and 4) being female independently increased the likelihood of reporting more symptoms. Conclusions Our findings have important implications for patients with KD. We have shown that high symptom burden is prevalent across the spectrum of disease, and present novel data on symptoms experienced in those without KD. Symptoms requiring the most immediate attention given their high prevalence may include pain and fatigue. Trial registration The study was registered prospectively as ISRCTN11596292.

scholarly journals A Bayesian ensemble data assimilation to constrain model parameters and land-use carbon emissions

2018 ◽  
Vol 15 (9) ◽  
pp. 2909-2930 ◽  
Author(s):  
Sebastian Lienert ◽  
Fortunat Joos
Keyword(s):  
Land Use ◽  
Carbon Emissions ◽  
Latin Hypercube Sampling ◽  
Historical Period ◽  
Model Parameters ◽  
Dynamic Global Vegetation Model ◽  
Order Of Magnitude ◽  
The Difference ◽  
Wood Harvest ◽  
Global Vegetation

Abstract. A dynamic global vegetation model (DGVM) is applied in a probabilistic framework and benchmarking system to constrain uncertain model parameters by observations and to quantify carbon emissions from land-use and land-cover change (LULCC). Processes featured in DGVMs include parameters which are prone to substantial uncertainty. To cope with these uncertainties Latin hypercube sampling (LHS) is used to create a 1000-member perturbed parameter ensemble, which is then evaluated with a diverse set of global and spatiotemporally resolved observational constraints. We discuss the performance of the constrained ensemble and use it to formulate a new best-guess version of the model (LPX-Bern v1.4). The observationally constrained ensemble is used to investigate historical emissions due to LULCC (ELUC) and their sensitivity to model parametrization. We find a global ELUC estimate of 158 (108, 211) PgC (median and 90 % confidence interval) between 1800 and 2016. We compare ELUC to other estimates both globally and regionally. Spatial patterns are investigated and estimates of ELUC of the 10 countries with the largest contribution to the flux over the historical period are reported. We consider model versions with and without additional land-use processes (shifting cultivation and wood harvest) and find that the difference in global ELUC is on the same order of magnitude as parameter-induced uncertainty and in some cases could potentially even be offset with appropriate parameter choice.

scholarly journals P300 and Decision Making under Risk and Ambiguity

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Lei Wang ◽  
Jiehui Zheng ◽  
Shenwei Huang ◽  
Haoye Sun
Keyword(s):  
Decision Making ◽  
Early Stage ◽  
Event Related Potentials ◽  
Underlying Mechanism ◽  
P300 Amplitude ◽  
Early Assessment ◽  
Decision Making Under Risk ◽  
Related Potentials ◽  
The Difference ◽  
Ambiguous Condition

Our study aims to contrast the neural temporal features of early stage of decision making in the context of risk and ambiguity. In monetary gambles under ambiguous or risky conditions, 12 participants were asked to make a decision to bet or not, with the event-related potentials (ERPs) recorded meantime. The proportion of choosing to bet in ambiguous condition was significantly lower than that in risky condition. An ERP component identified as P300 was found. The P300 amplitude elicited in risky condition was significantly larger than that in ambiguous condition. The lower bet rate in ambiguous condition and the smaller P300 amplitude elicited by ambiguous stimuli revealed that people showed much more aversion in the ambiguous condition than in the risky condition. The ERP results may suggest that decision making under ambiguity occupies higher working memory and recalls more past experience while decision making under risk mainly mobilizes attentional resources to calculate current information. These findings extended the current understanding of underlying mechanism for early assessment stage of decision making and explored the difference between the decision making under risk and ambiguity.

scholarly journals Serum CYR61 As A Potential Biomarker for The Diagnosis of Esophagogastric Junction Tumor

2021 ◽  
Author(s):  
Ling-Yu Chu ◽  
Jian-Yuan Zhou ◽  
Yi-Xuan Zhao ◽  
Yan-Ting Ou ◽  
Tian Yang ◽  
...  
Keyword(s):  
Early Stage ◽  
Area Under The Curve ◽  
Serum Levels ◽  
Enzyme Linked Immunosorbent Assay ◽  
Operating Characteristics ◽  
Tumor Patients ◽  
Chi Square ◽  
Potential Biomarker ◽  
The Difference ◽  
Normal Controls

Background：Esophagogastric junction tumor (EGJ) is a rare but fatal disease with a rapid rising incidence worldwide in the late 20 years, and it lacks a convenient and safe method for diagnosis. This study aimed to evaluate the potential of serum CYR61 as a biomarker for the diagnosis of EGJ tumor. Methods: Enzyme-linked immunosorbent assay (ELISA) was used to estimate CYR61 levels in sera of 152 EGJ tumor patients and 137 normal controls. Receiver operating characteristics (ROC) was carried out to evaluate the diagnostic accuracy. The Mann–Whitney’s U test was used to compare the difference of serum levels of CYR61 between groups. And chi-square tests were employed to estimate the correlation of the positive rate of serum CYR61 between/among subgroups. Results: Serum CYR61 levels were statistically lower in EGJ tumor and early-stage EGJ tumor patients than those in normal controls (P<0.0001). The sensitivity, specificity, and the area under the curve (AUC) of this biomarker in EGJ tumor were 88.2%, 43.8% and 0.691, respectively, and those for early stage of EGJ tumor were 80.0%, 66.4% and 0.722, respectively. Analyses showed that there was no correlation between the clinical data and the levels of CYR61 (P>0.05). Conclusion: This study showed that CYR61 might be a potential biomarker to assist the diagnosis of EGJ tumor.

scholarly journals Distilling Deep Structural Facial Relationships for FAU Intensity Estimation

2021 ◽  
Author(s):  
Yingruo Fan ◽  
Jacqueline CK Lam ◽  
Victor On Kwok Li
Keyword(s):  
Structural Characteristics ◽  
Model Performance ◽  
Training Model ◽  
Model Parameters ◽  
Intensity Estimation ◽  
Structural Relationships ◽  
Proposed Model ◽  
Comparable Performance ◽  
Knowledge Distillation ◽  
The Difference

<div> <div> <div> <p>Facial emotions are expressed through a combination of facial muscle movements, namely, the Facial Action Units (FAUs). FAU intensity estimation aims to estimate the intensity of a set of structurally dependent FAUs. Contrary to the existing works that focus on improving FAU intensity estimation, this study investigates how knowledge distillation (KD) incorporated into a training model can improve FAU intensity estimation efficiency while achieving the same level of performance. Given the intrinsic structural characteristics of FAU, it is desirable to distill deep structural relationships, namely, DSR-FAU, using heatmap regression. Our methodology is as follows: First, a feature map-level distillation loss was applied to ensure that the student network and the teacher network share similar feature distributions. Second, the region-wise and channel-wise relationship distillation loss functions were introduced to penalize the difference in structural relationships. Specifically, the region-wise relationship can be represented by the structural correlations across the facial features, whereas the channel-wise relationship is represented by the implicit FAU co-occurrence dependencies. Third, we compared the model performance of DSR-FAU with the state-of-the-art models, based on two benchmarking datasets. Our proposed model achieves comparable performance with other baseline models, though requiring a lower number of model parameters and lower computation complexities. </p> </div> </div> </div>

scholarly journals Summertime canopy albedo is sensitive to forest thinning

2013 ◽  
Vol 10 (9) ◽  
pp. 15373-15414 ◽  
Author(s):  
J. Otto ◽  
D. Berveiller ◽  
F.-M. Bréon ◽  
N. Delpierre ◽  
G. Geppert ◽  
...  
Keyword(s):  
Forest Management ◽  
Tree Species ◽  
Structural Changes ◽  
Near Infrared ◽  
Canopy Structure ◽  
Model Parameters ◽  
Transfer Model ◽  
Forest Thinning ◽  
Crown Volume ◽  
The Difference

Abstract. Despite an emerging body of literature linking canopy albedo to forest management, understanding of the process is still fragmented. We combined a stand-level forest gap model with a canopy radiation transfer model and satellite-derived model parameters to quantify the effects of forest thinning, that is removing trees at a certain time during the forest rotation, on summertime canopy albedo. The effects of different forest species (pine, beech, oak) and four thinning strategies (light to intense thinning regimes) were examined. During stand establishment, summertime canopy albedo is driven by tree species. In the later stages of stand development, the effect of tree species on summertime canopy albedo decreases in favour of an increasing influence of forest thinning on summertime canopy albedo. These trends continue until the end of the rotation where thinning explains up to 50% of the variance in near-infrared canopy albedo and up to 70% of the variance in visible canopy albedo. More intense thinning lowers the summertime shortwave albedo in the canopy by as much as 0.02 compared to unthinned forest. The structural changes associated with forest thinning can be described by the change in LAI in combination with crown volume. However, forests with identical canopy structure can have different summertime albedo values due to their location: the further north a forest is situated, the more the solar zenith angle increases and thus the higher is the summertime canopy albedo, independent of the wavelength. Despite the increase of absolute summertime canopy albedo values with latitude, the difference in canopy albedo between managed and unmanaged forest decreases with increasing latitude. Forest management thus strongly altered summertime forest albedo.

scholarly journals Quantification of uncertainties in OCO-2 measurements of XCO<sub>2</sub>: simulations and linear error analysis

2016 ◽  
Vol 9 (10) ◽  
pp. 5227-5238 ◽  
Author(s):  
Brian Connor ◽  
Hartmut Bösch ◽  
James McDuffie ◽  
Tommy Taylor ◽  
Dejian Fu ◽  
...  
Keyword(s):  
Bias Correction ◽  
Total Error ◽  
Important Variable ◽  
Model Parameters ◽  
Error Sources ◽  
Variable Error ◽  
Operational Algorithm ◽  
The Difference ◽  
Variable Errors ◽  
Types Of Error

Abstract. We present an analysis of uncertainties in global measurements of the column averaged dry-air mole fraction of CO2 (XCO2) by the NASA Orbiting Carbon Observatory-2 (OCO-2). The analysis is based on our best estimates for uncertainties in the OCO-2 operational algorithm and its inputs, and uses simulated spectra calculated for the actual flight and sounding geometry, with measured atmospheric analyses. The simulations are calculated for land nadir and ocean glint observations. We include errors in measurement, smoothing, interference, and forward model parameters. All types of error are combined to estimate the uncertainty in XCO2 from single soundings, before any attempt at bias correction has been made. From these results we also estimate the "variable error" which differs between soundings, to infer the error in the difference of XCO2 between any two soundings. The most important error sources are aerosol interference, spectroscopy, and instrument calibration. Aerosol is the largest source of variable error. Spectroscopy and calibration, although they are themselves fixed error sources, also produce important variable errors in XCO2. Net variable errors are usually < 1 ppm over ocean and ∼ 0.5–2.0 ppm over land. The total error due to all sources is ∼ 1.5–3.5 ppm over land and ∼ 1.5–2.5 ppm over ocean.

scholarly journals The Robust Consensus of a Noisy Deffuant-Weisbuch Model

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Jiangbo Zhang ◽  
Yiyi Zhao
Keyword(s):  
Discrete Time ◽  
Model Parameters ◽  
Positive Probability ◽  
Noise Strength ◽  
Opinion Formation ◽  
Time Step ◽  
Absolute Value ◽  
The Difference ◽  
Robust Consensus

We construct a new opinion formation of the Deffuant-Weisbuch model with the interference of the outer noise, where there are finite n agents and the evolution is discrete-time. The opinion interaction occurs by one randomly chosen pair at each time step. The difference to the original Deffuant-Weisbuch model is that communications of any selected pairs will be affected by noises. The aim of this paper is to study the robust consensus of this noisy Deffuant-Weisbuch model. We first define the noise strength as the maximum noise absolute value. We will then show that when the noise strength is less than a certain threshold, this noisy model will achieve T-robust consensus when t is sufficiently large; next we prove that the noisy model achieves robust consensus with a positive probability; finally, we demonstrate these results and provide numerical relations among the noise strength and some model parameters.

scholarly journals Fluorescence-Labeled Amyloid Beta Monomer: A Molecular Dynamical Study

Molecules ◽  
2020 ◽  
Vol 25 (15) ◽  
pp. 3524
Author(s):  
János Gera ◽  
Gábor Paragi
Keyword(s):  
Single Molecule ◽  
Early Stage ◽  
Conformational Space ◽  
Dynamic Simulations ◽  
Dynamical Study ◽  
Fluorescence Dye ◽  
Aβ Aggregation ◽  
The Difference ◽  
Open Question ◽  
The Impact

The aggregation process of the Amyloidβ (Aβ) peptide is one of the central questions in Alzheimers’s research. Fluorescence-labeled single-molecule detection is a novel technique concerning the early stage investigation of Aβ aggregation, where the labeling dyes are covalently bound to the Aβ monomer. As the influence of the dye on the conformational space of the Aβ monomer can be significant, its effect on the seeding process is an open question. The applied fluorescent molecule continuously switches between an active (ON) and an inactive (OFF) state, where the latter supports an extra rotational restriction at many commercially available dyes. However, only a few theoretical studies simulated the Aβ monomer in the presence of a dye and none of them considered the difference between the ON and the OFF states. Therefore, we examined the impact of a selected fluorescence dye (Alexa 568) on the conformational space of the monomeric Aβ(1–42) peptide in its ON and OFF state by replica exchange molecular dynamic simulations. Investigations on secondary structure elements as well as dye-peptide contact analysis for the monomers are presented. Experimental and theoretical NMR shifts were contrasted to qualify the calculation protocol and theoretical values of the labeled and the non-labeled peptide were also compared. We found that the first five residues have higher helical propensity in the presence of the dye, and electrostatic properties could strongly affect the connection between the dye and the peptide parts.

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