Deformation Of Components Research Articles

Sesamoid View X-ray vs Weightbearing Computed Tomography in the Measurement of Metatarsal Pronation Angle

Category: Bunion; Midfoot/Forefoot Introduction/Purpose: First metatarsal (M1) axial rotation as measured by the metatarsal pronation angle (MPA) has increasingly become recognized as a clinically relevant component of hallux valgus deformity and methods to realign the M1 in 3 dimensions have been developed. Preoperative imaging with weightbearing computed tomography (WBCT) is considered the best way to image and measure the MPA, however WBCT is not available to many foot and ankle surgeons. The aim of this project is to investigate if the MPA measured on sesamoid view weight bearing radiographs is similar to that measured on WBCT. Methods: A retrospective analysis of patient imaging studies was performed. We identified 25 feet with both sesamoid WBR and WBCT images from a consecutive patient database. Included subjects had no trauma or foot and ankle operation between acquisition of the two scans. MPA of the WBCT for each patient was initially measured. After an appropriate washout period, the observer then measured MPA of the WBR for the cohort. Demographic statistics were calculated, a paired t-test was performed to evaluate for any significant difference in angular measurement between the two scans. Results: Patient characteristics: mean age 53 +- 16 years, mean BMI 32 +- 8 kg/m2, 13 right and 12 left feet, 19 females and 6 males. Average time between sesamoid view WBR and WBCT was 5.7 +- 9.5 months. Mean difference in MPA between WBR and WBCT = 0.6 +- 3.9 degrees (p= 0.444, t=0.777). Conclusion: Among the cohort assessed, we found no significant difference present in the measurement of the metatarsal pronation angle as evaluated on sesamoid view weightbearing radiography compared with weightbearing computed tomography (Figure 1). Routine acquisition of a sesamoid view weightbearing radiograph may be considered as an appropriate substitute for weightbearing computed tomography in the preoperative evaluation of M1 rotation in the coronal plane. These findings may benefit physicians who do not have access to weightbearing computed tomography in their clinics.

A Sparse and Locally Coherent Morphable Face Model for Dense Semantic Correspondence Across Heterogeneous 3D Faces.

The 3D Morphable Model (3DMM) is a powerful statistical tool for representing 3D face shapes. To build a 3DMM, a training set of face scans in full point-to-point correspondence is required, and its modeling capabilities directly depend on the variability contained in the training data. Thus, to increase the descriptive power of the 3DMM, establishing a dense correspondence across heterogeneous scans with sufficient diversity in terms of identities, ethnicities, or expressions becomes essential. In this manuscript, we present a fully automatic approach that leverages a 3DMM to transfer its dense semantic annotation across raw 3D faces, establishing a dense correspondence between them. We propose a novel formulation to learn a set of sparse deformation components with local support on the face that, together with an original non-rigid deformation algorithm, allow the 3DMM to precisely fit unseen faces and transfer its semantic annotation. We extensively experimented our approach, showing it can effectively generalize to highly diverse samples and accurately establish a dense correspondence even in presence of complex facial expressions. The accuracy of the dense registration is demonstrated by building a heterogeneous, large-scale 3DMM from more than 9,000 fully registered scans obtained by joining three large datasets together.

Tolerance analysis of a compliant assembly using random Non-Uniform Rational B-Spline curves and isogeometric method

Abstract Non-Uniform Rational B-Spline (NURBS) is one of the most versatile tools of computer-aided design. The concept of random NURBS curves is introduced for modeling the geometrical errors in mechanical parts and assemblies. The proposed idea is utilized to solve an example problem involving deformable components. For this purpose, profile tolerances of the parts are transformed into covariance matrices of NURBS control polygon parameters. Then, the control polygons are used as vector chains to calculate geometrical error propagation. Afterwards, isogeometric analysis (IGA) is invoked to express deformations of the parts during the assembly process as changes in the shape of the underlying control polygons. Finally, the result of the calculations is translated back into the tolerance zone of the assembly. Numerical examples are employed to examine the effect of NURBS structure (degree, knot vector, and control points) on convergence and stability of results. Outcomes of the theory are compared with direct measurements of actual assemblies and results of a Monte Carlo finite element simulation to illustrate the validity of the results. Furthermore, the developed model is used to obtain practical guidelines regarding the reduction of geometrical errors by the optimum design of the assembly.

Deepwater fold-thrust belt contraction driven by mixed deformation components

The formation of fold-thrust belts is driven by compressive stresses caused by crustal tectonics, gravity, or a combination of both. The formation mechanism of a single compressive stress component has been thoroughly investigated by laboratory experiments and field observations. It is yet less well established how fold-thrust systems deform under multiple compressional stresses. The formation of the deepwater fold-thrust belt on the northwest Borneo margin has been previously explained by compressive gravity-driven stresses in the south and crustal-driven tectonics in the north. This study focuses on the transition zone between the gravity-driven south and crustal-driven north, and investigates the structural diversity around this transition using 3D seismic-reflection data. Structural interpretation results reveal two structural provinces distinct in deformation styles and structural kinematics within the deepwater fold-thrust belt. Folds and thrusts in each structural province reflect deformation stresses that occurred at different times with different orientation. Structural features in each structural province developed independently and were preserved largely without mixing in the fold-thrust belt, except for an interference zone of ca. 15 km in width. The fold-thrust belt can be interpreted to have formed by a multi-directional compressive stress system and exhibits greater structural heterogeneity than deformation caused by a single-component compressive stress system. Particular deformation characteristics and fault activity in the interference zone reflect a complex disparate compressive stress relationship.

Can Below-Knee Casts be Effective for Clubfoot Management in Walking-Age Children? A Prospective Cohort Study.

Above-knee casts pose a major challenge in the day-to-day activities among walking age clubfoot patients due to complete restriction of knee movement. This current study investigates the effectiveness of below-knee casts compared to above-knee casts for managing walking age clubfoot deformity. After approval from the institutional ethical committee, we enrolled walking age clubfoot patients for deformity correction through corrective manipulation and casting through below-knee casts over 2years. The corrective manipulation was performed using the Ponseti technique. The patients were followed for a minimum of 2years period. To compare the effectiveness of below-knee casts over above-knee casts, we enrolled equal numbers of walking age clubfeet matched for age and gender. We compared the two groups in terms of initial and post-correction Dimeglio scores, individual deformities corrections (maximum ankle dorsiflexion, heel varus correction, foot abduction), failure rates, relapses, and complication rates. 56 patients with 80 clubfeet with a mean follow-up of 39.98monthswere considered for the final analysis. There were 29 patients in the below-knee cast group and 27 in the above-knee cast group, with 40 clubfeet each. The patients in the above-knee casting group had significantly better post-correction Dimeglio scores and individual deformity components corrections than the below-knee cast group. There were nil failures in the above-knee casting group and 7.5% in the below-knee cast group. The relapse rate was 15% in both groups, with none requiring any extensive soft tissue procedure. We did not encounter any major complications during the treatment and follow-up. The deformity correction and maintenance are suboptimal with the below-knee casts. Therefore, above-knee casts should be the preferred management modality for correction of walking age clubfoot deformities.

Contribution to Lateral Torsional Buckling of Girders with Rotational Restraints

AbstractThe instability case of lateral torsional buckling (LTB) under bending load My is known to be of decisive importance in the design of beams with open cross‐sections. This instability case is expressed by a lateral displacement and simultaneous torsion (or twisting) of the member axis. The restraint of one or both of these deformation components represents an effective and practice oriented method to stabilize beams against LTB. In practice, therefore, use is made of regulations from the current version of EN 1993‐1‐1:2010, Annex BB, which allow for the consideration of the stabilizing effect of continuous and planar components directly connected to the compression chords of the beams. This paper presents the results of a study that investigated the effects of the innovations introduced in the draft standard for the 2nd generation of EN 1993‐1‐1 for the LTB verification of beams with I and H cross‐sections on the regulations for the calculation of the minimum stiffness of a rotational restraint to avoid LTB. In the first part of the paper, the background of the existing and new regulations is discussed together with previous proposals for adapting the definition of the minimum rotation restraint. In addition, a comparison is made with current specifications for the minimum rotational stiffness contained in the National Annex of DIN EN 1993‐1‐1. Subsequently, the regulations of the minimum rotational stiffness in prEN1993‐1‐1, Annex D are assessed.

Experimental study on the seismic behavior of ECE corroded reinforced concrete short pier columns

• ECE tests conducted on RC short pier columns. • Experimental investigations on seismic behavior of corroded RC short pier columns. • An investigation in the influence of corrosion and axial load on bending, shear, and slip deformation components. • The prediction equations for the shear strength of corroded short piers were derived. This paper experimentally investigates the effects of corrosion and axial load on the seismic performance of reinforced concrete (RC) short pier columns. In this study, five RC columns were designed and fabricated, and the electrochemical chloride erosion (ECE) technique was used to simulate the corrosion process. The damage process, hysteresis behavior, stiffness degradation, energy dissipation capacity, and shear deformation were all considered while analyzing the seismic behavior of the test specimens. The experiments found showed that the axial load has a substantial impact on the deformation capacity of corroded RC short pier columns. With increasing corrosion level and axial load level, the energy dissipation capacity after the peak point decreases significantly, demonstrating the adverse coupling impact of corrosion damage and axial loads. Furthermore, the corrosion damage can weaken the shear capacity of the RC column and can increase the proportion of shear deformation to the total deformation. Based on the experimental results, a formula for determining the shear strength of the RC short pier column was suggested, accounting for corrosion damage and axial load level.

Measuring Land Surface Deformation over Soft Clay Area Based on an FIPR SAR Interferometry Algorithm—A Case Study of Beijing Capital International Airport (China)

Long-term settlement monitoring of infrastructure built in soft clay areas is of great importance. When using InSAR technology for soft clay settlement monitoring, deformation modeling is a key process. In most InSAR deformation modeling, each component of the total deformation is expressed directly with a fixed functional model in phase functions and assumed to occupy an equal weight. This causes equal weight assumption uncertainty and ignores the actual certain contribution of each phase component related to certain deformational factors. Moreover, the commonly used mathematical empirical models in traditional InSAR are not suitable for describing the nonlinear characteristics of the temporal settlement evolution for soft clay. To address these limitations, we propose an SAR interferometry algorithm, namely, FIPR (FastICA Poisson-curve reciprocal accumulation method), which separates the original InSAR signal based on FastICA to extract each deformation component, and then the models can each extract deformation components and estimate the unknown parameters based on a reciprocal accumulation method. Each independent component and the obtained deformation parameters are used to generate the final deformation time series. Both simulated and real data experiments were designed. The simulated experimental results indicated that the sICA (spatial independent component analysis) separated results were much closer to the original signals than those of the tICA (temporal independent component analysis), with their RMSE lower than 2 mm, and the sICA is thus more highly recommended. Beijing Capital International Airport in China was selected as the study area in the real data experiment. Using 24 high-resolution TerraSAR-X radar satellite images from January 2012 to February 2015, the time-series deformation was obtained, with the maximum cumulative subsidence of 126 mm. The modeling accuracy for the proposed model was estimated as ±2.6 mm, with an improvement of 36.6% compared to the EWA-LM (linear model with equal weight accumulation) algorithm and 16.1% compared to the EWA-PC (Poisson curve with equal weight accumulation) algorithm. The RMSE with external leveling measurements was estimated as ±1.0 mm, with 69.7% improvement compared to EWA-LM and 50% to EWA-PC. This indicated that FIPR can reduce the uncertainty of artificial assumptions in deformation modeling and improve the accuracy of deformation analysis for highways in soft clay areas, providing a reference for road maintenance and management.

Accumulation of irreversible deformation of soils as a result of repeated loading

Objective. The purpose of the study is to establish the patterns of accumulation of irreversible soil deformations from repeated loading.Method. When loading soils, the balance between external and internal forces is established gradually over a more or less long time. Therefore, with a single application of a cyclic load, such an equilibrium can be achieved only in a relatively long time.Result. An approximate method is proposed for calculating the magnitude of the deformation developed as a result of the action of a cyclic load. The cases are determined when it is necessary to take into account the viscous component of deformation and when the latter can be neglected. It has been established that when determining the deformation of soils that has developed during a single application of such cyclic loads that are characteristic of the process of their compaction by machines, in all cases, except for rolling them with rollers on pneumatic tires, the viscous component of deformation can be ignored.Conclusion. In a relatively short time of the load, the state of equilibrium can be achieved only in the process of soil deformation by repeated loading. With an increase in the number of loading repetitions, the soil gradually hardens, and the deformation decreases. This occurs both due to the irreversible and reversible parts of the deformation. Consequently, the soil deformation modulus increases from cycle to cycle.

ESTUDIO NUMÉRICO DE LUBRICACIÓN VISCOELASTOHIDRODINÁMICA EN PRÓTESIS DE RODILLA CON FLUIDO NO NEWTONIANO

In this work, a computational model of thin film lubrication applied to a knee prosthesis was designed in order to make a comparison between three constitutive models, i.e. a power law, the Carreau-Yasuda model and the Cross model. The equivalent model of the knee prosthesis was modeled as a rigid cylinder on a deformable plane. The mechanical behavior of the deformable component representing the tibial base was assumed as a viscoelastic Standard Linear Solid(SLS). The governing equations were solved simultaneously with the determination of a free-moving boundary by implementing it in COMSOL Multiphysics software. The results obtained showed that the Cross model presents the highest shear rate value, the lowest film thickness and the dynamic viscosity with less variation along the lubrication channel, reaching a minimum viscosity value of 0.02 Pa.s. The Carreau-Yasuda model presents the highest value of friction coefficient, being 21.5 % higher than for the Power Law model and 3.67 % higher than the Cross model.

A new cyclic model for FRP‐confined rubberized concrete

AbstractThis article proposes a new constitutive model for the cyclic behavior of rubberized concrete confined with fiber‐reinforced polymer (FRP) sheets. The model is calibrated with experimental results from 18 confined rubberized concrete (CRuC) cylinders tested in cyclic compression. The cylinders had 60% total aggregate volume replacement with recycled tyre rubber. Parameters investigated include the type of confining material (Carbon or Aramid FRP) and number of layers (two, three, or four). The results indicate that using FRP confinement leads to a strong (up to 100 MPa) and highly deformable (axial strains up to 7%) rubberized concrete that can be used in structural applications. The proposed constitutive model predicts accurately the material response under cyclic loading and can thus be used for design/analysis of highly deformable components made of FRP CRuC. This article contributes toward the development of advanced constitutive models for FRP CRuC, thus promoting the wider use of recycled materials in construction industry.

Effect of polymer amount on the mechanical behavior of polymer-infiltrated zirconia-ceramic composite at different pre-sintering temperatures

Polymer-infiltrated zirconia-ceramic composite (PIZC) comprises a pre-sintered zirconia-ceramic matrix and a polymer. In this work, pre-sintered zirconia-ceramic was infiltrated with varied amounts of methacrylate-based polymer. Therefore, this paper reports the effect of polymer amount on the mechanical behavior of PIZC at 1100 °C–1300 °C pre-sintering temperatures. Conventional mechanical tests were performed to obtain the elastic modulus and fracture toughness while Vickers micro-indentations were employed to extract the Vickers hardness. Advanced mechanical behaviour analysis was characterized by plastic deformation resistance, elastic and plastic deformation components and brittleness index. Increasing the amount of polymer from 0 to 42% led to the corresponding decrease in elastic modulus, hardness and fracture toughness by at least 78, 85 and 75%, respectively. As the temperature was increased, both elastic modulus and hardness increased while the fracture toughness initially increased but decreased at higher temperature. Mechanical properties and polymer amount were well modelled by connected-grain models which usefully explained the densification process occurring at higher temperatures. Plastic deformation resistance and component and brittleness index confirmed better plastic properties for PIZC at higher polymer amounts and lower temperature. Therefore, in order to utilize the plastic properties of PIZC during the CAD/CAM process, these findings recommended the processing of PIZC at not-lower-than 26% polymer amount and 1100 °C, which could greatly facilitate its precision ductile machining mode realization. Finally, the results provide a technical guidance for the selection of appropriate polymer amount when fabricating dental restorations from this novel ceramic-composite.

Measuring 3D face deformations from RGB images of expression rehabilitation exercises

BackgroundThe accurate (quantitative) analysis of 3D face deformation is a problem of increasing interest in many applications. In particular, defining a 3D model of the face deformation into a 2D target image to capture local and asymmetric deformations remains a challenge in existing literature. A measure of such local deformations may be a relevant index for monitoring the rehabilitation exercises of patients suffering from Parkinson’s or Alzheimer’s disease or those recovering from a stroke. MethodsIn this paper, a complete framework that allows the construction of a 3D morphable shape model (3DMM) of the face is presented for fitting to a target RGB image. The model has the specific characteristic of being based on localized components of deformation. The fitting transformation is performed from 3D to 2D and guided by the correspondence between landmarks detected in the target image and those manually annotated on the average 3DMM. The fitting also has the distinction of being performed in two steps to disentangle face deformations related to the identity of the target subject from those induced by facial actions. ResultsThe method was experimentally validated using the MICC-3D dataset, which includes 11 subjects. Each subject was imaged in one neutral pose and while performing 18 facial actions that deform the face in localized and asymmetric ways. For each acquisition, 3DMM was fit to an RGB frame whereby, from the apex facial action and the neutral frame, the extent of the deformation was computed. The results indicate that the proposed approach can accurately capture face deformation, even localized and asymmetric deformations. ConclusionThe proposed framework demonstrated that it is possible to measure deformations of a reconstructed 3D face model to monitor facial actions performed in response to a set of targets. Interestingly, these results were obtained using only RGB targets, without the need for 3D scans captured with costly devices. This paves the way for the use of the proposed tool in remote medical rehabilitation monitoring.

The Role of the Plantaris in Intramuscular Gastrocnemius Equinus Correction

Equinus deformity is a common cause of foot and ankle pathology. The purpose of our study was to evaluate the role of the plantaris in equinus. Secondary aims were to describe the role of the plantaris in intramuscular gastrocnemius recession and to determine the prevalence of the plantaris in our patient population. We measured ankle dorsiflexion during the steps of a Baumann-type intramuscular gastrocnemius recession. Eighty-nine patients were enrolled in our study. Fourteen of 89 (15.7%) patients did not have a plantaris. A mean dorsiflexion of 9 (interquartile range 6-12)° was obtained after transection of the plantaris tendon and an additional mean 8 (interquartile range 5-10)° was obtained after recession of the gastrocnemius aponeurosis. There was a strong positive correlation (rs = 0.842) of dorsiflexion increase after plantaris transection and dorsiflexion increase after gastrocnemius recession (p < .00). Linear regression showed that for every one-degree of dorsiflexion increase with plantaris transection, there was a predicted dorsiflexion increase of 0.69° with gastrocnemius recession. These results indicate that the plantaris is a component of equinus deformity.

Updated Understanding of the Ripley Landslide Kinematics Using Satellite InSAR

The Thompson River valley hosts 14 landslides along a 10 km section, which threaten the two major railroads connecting the Port of Vancouver and the interior provinces in Canada. The Ripley landslide is one of the active landslides in this section of the valley. Previous research at this site included an analysis of landslide deformations using satellite radar interferometry focusing on deformations measured in the line of sight between the satellite and the slopes, and average downslope displacement (deformations projected in the average downslope direction). Since then, further stratigraphic interpretation has provided an enhanced understanding of the Ripley landslide. In this update, the new stratigraphic interpretation is supplemented with satellite InSAR data from May 2015 to May 2017 to enhance the current understanding of the landslide kinematics. The results indicate that the Ripley landslide has been moving at a rate between 2 and 82 mm per year, corresponding to a very slow to slow landslide. It is also observed that the movements tend to be near-horizontal on areas closer to the toe of the landslide, while the vertical component of deformation increases near the scarp of the landslide. This, together with the interpreted stratigraphy, indicates the kinematics corresponds to a compound landslide. This is consistent with interpreted landslide kinematics of older, more mature landslides in the area that have shown episodes of retrogression and suggests the possibility of a similar future behaviour of the Ripley landslide.

What Do Patients Report Regarding Their Real-World Function Following Triplane Metatarsophalangeal Joint Arthrodesis for Hallux Valgus?

First metatarsalphalangeal (MTP) joint arthrodesis has been employed for decades for pain related to arthritis and other associated abnormalities. Despite the commonality of the procedure there continues to be questions regarding functional expectations following the procedure especially when employed for correction of hallux valgus deformity. We surveyed 60 patients who had a triplane MTP joint arthrodesis at mean 28.4 months (median 27.8) regarding their activities of daily living and sports activity through a direct conversation. Secondary endpoints assessed were return to activity, deformity correction and arthrodesis healing rate based on chart review and weightbearing radiographs. The primary outcomes showed robust return to all activities of daily living with 97% able to walk without restrictions and or pain, 98% were able to walk at a normal pace and 95% responded that loss of motion of their big toe did not affect their daily function. Regarding return to sports all patients that participated in sports before surgery resumed participation after with a trend toward increased sports activity. Early return to walking in a fracture boot was noted in this cohort at mean 4.1 days, return to athletic shoe at mean 6.3 weeks and full unrestricted activity at mean 13.3 weeks with no non-unions identified on radiographic or clinical exam. Deformity correction of the typical components of hallux valgus deformity was similar to previously published studies. This data set supports the hypothesis that patients undergoing first MTP joint arthrodesis can expect rapid and full return to activities of daily living and sports with a low complication rate.

Formation of en-échelon pull-apart arrays in pure-shear dominated transpression

We report on a series of small-scale, en-échelon faults in limestone (Les Matelles, France) that result in the formation of a series of linked pull-aparts (en-échelon pull-apart arrays) that have been infilled with calcite. The formation of stylolite seams and isolated veins occurs adjacent to these fault zones, which constrain the direction of minimum infinitesimal stretching axis (commonly interpreted as maximum compressional stress). We observe that en-échelon pull-apart arrays occur when the maximum infinitesimal shortening direction is at 55° or greater to the enveloping surfaces of the en-échelon fault arrays. This situation differs from en-échelon vein arrays, in which the maximum horizontal infinitesimal shortening direction occurs at 55° or less to the enveloping surfaces. We interpret these features with respect to transpressional strain modeling, which distinguishes between wrench (simple shear) dominated transpression and pure shear dominated transpression. Pure shear dominated transpression occurs if the maximum infinitesimal shortening direction is at 55° or greater to the enveloping surfaces, and results in a maximum infinitesimal stretching direction that is vertical. The formation of en-échelon vein arrays with vertical enveloping surfaces require a horizontal infinitesimal stretching direction, which is incompatible with pure shear dominated transpression. Rather, en-échelon pull-apart arrays form to accommodate the wrench component of deformation in pure-shear dominated transpression.

Time Series Multi-Sensors of Interferometry Synthetic Aperture Radar for Monitoring Ground Deformation

A stack of images is a prerequisite for the multi-temporal interferometric synthetic aperture radar (MT-InSAR) due to the wrapped nature of the interferometric phase. Although the SBAS technique can relieve the requirement of the amount of SAR data, dozens of SAR acquisitions could be regarded as the minimum requirement. However, due to the limitation of the imaging capability of the spaceborne SAR system, the amount of available SAR data acquired from only one SAR sensor is often not enough to satisfy the requirement for phase unwrapping based on the Nyquist sampling assumption. Fortunately, there sometimes may be more than one SAR stack, that is, stacks of SAR data acquired from different SAR systems. In this study, we propose a methodology to detect ground deformation by combining multiple SAR images acquired from different satellite systems for MT-InSAR analysis. First, the low-pass deformation is estimated based on time series SAR acquisitions with low spatial resolution and long wavelengths such as ENVISAT ASAR (ASAR). This information is then incorporated into the processing of time series of SAR acquisitions with high spatial resolution and short wavelength, such as TerraSAR-X (TSX). Specifically, the low-pass deformation will be subtracted from each differential interferogram generated from short-wavelength SAR images, and the rest of the MT-InSAR analysis will be based on the double-differentiation interferograms. Then, the residual deformation will be calculated from these double-differentiation interferograms and together with the low-pass deformation forms the full deformation. As the principal component of deformation has already been subtracted, the phase gradient of those double-differentiated interferograms will be smooth enough to facilitate the phase unwrapping. Between January 2009 and September 2010, 14 ASAR images and 11 TSX images acquired from Tianjin, China are selected as the test data. A root means square error (RMSE) of 9.1 mm/year is achieved from 11 TSX images, while a root means square error of 3.7 mm/year is achieved from 14 ASAR images. However, an RMSE of 1.6 mm/year is achieved when integrating 11 TSX images and 14 ASAR images for MT-InSAR analysis. The experiments show that the proposed method can effectively detect ground deformation.

Mapping the Recent Vertical Crustal Deformation of the Weihe Basin (China) Using Sentinel-1 and ALOS-2 ScanSAR Imagery

The Weihe Basin, located in central China, is a Cenozoic rift basin that is characterized by a complicated geological background, with intense tectonic movement and relatively significant seismic activity. The faulting behaviors, slip rates, geometrical structures, and possible surface traces of the active faults in the Weihe Basin are still not well known. The goal of this work is to provide a more complete picture of recent vertical ground deformation of the basin and to identify active faults. We derived two basin-wide average InSAR deformation maps during 2015–2019 using C-band Sentinel-1A/B and L-band ALOS PALSAR2 ScanSAR imagery. The basin-wide vertical and east–west deformation components decomposed from ascending and descending InSAR measurements show that vertical movement dominates the deformation of the Weihe Basin. Subsidence and uplift maxima both occurred over the Xi’an region at rates of about −146 and 20 mm/y, respectively. A subsidence of ~38 mm/y was found at Sanyuan, Fuping, Weinan, Lantian, Qianxian, and Xingping while an uplift of ~11 mm/y was found at Fufeng, Huxian, Jingyang, Fuping, Pucheng, and Huaxian. The significant vertical deformation in these regions is spatially linked to previously identified or unmapped faults. A slip rate of ~13.7 mm/y on faults F20, F6, F10, and F7 explained the observed uplift of up to 5 mm/y in the Fufeng and Wugong areas. Furthermore, surface fault traces were clearly identified for faults F7-1, F8-1, F20, F25, and F26 based on discontinuities in the InSAR-derived vertical deformation measurements. Our results provide an accurate and economical way to delineate the surface deformation and fault movement and the associated geohazards over the Weihe Basin, and offer independent unprecedented data for further geological and geophysical interpretation.

Multiple Spatial Spectral Components of Static Skin Deformation for Predicting Macroscopic Roughness Perception.

A previous study suggested a relationship between the spatial spectrum of finger pad skin deformation and perception of macroscopic roughness features. This study tested a new hypothesis that macroscopic roughness perception is the result of a weighted linear combination of multiple spatial spectral components of skin deformation. Experiments were conducted by capturing close-up images of finger pad deformation while the pads were pushed onto specimens with macroscopic features. Additionally, the roughness perceptions of these specimens were collected using a magnitude estimation method. The combination of spectral components predicted the roughness perception more accurately than any single spectral component. This suggests that roughness perception is mediated by multiple Gabor filter-like neural systems with different spatial periods, such as visual perception.