Kinematic Attributes Research Articles

EthoWatcher OS: improving the reproducibility and quality of categorical and morphologic/kinematic data from behavioral recordings in laboratory animals.

Behavioral recordings annotated by human observers (HOs) from video recordings are a fundamental component of preclinical animal behavioral models of neurobiological diseases. These models are often criticized for their vulnerability to reproducibility issues. Here, we present the EthoWatcher-Open Source (EW-OS), with tools and procedures for the use of blind-to-condition categorical transcriptions that are simultaneous with tracking, for the assessment of HOs intra- and interobserver reliability during training and data collection, for producing video clips of samples of behavioral categories that are useful for observer training. The use of these tools can inform and optimize the performance of observers, thus favoring the reproducibility of the data obtained. Categorical and machine vision-derived outputs are presented in an open data format for increased interoperability with other applications, where behavioral categories are associated frame-by-frame with tracking, morphological and kinematic attributes of an animal's image. The center of mass (X and Y pixel coordinates), the animal's area in square millimeters, the length and width in millimeters, and the angle in degrees were recorded. It also assesses the variation in each morphological descriptor to produce kinematic descriptors. While the initial measurements are in pixels, they are later converted to millimeters using the scale calibrated by the user via the graphical user interfaces. This process enables the creation of databases suitable for machine learning processing and behavioral pharmacology studies. EW-OS is constructed for continued collaborative development, available through an open-source platform, to support initiatives toward the adoption of good scientific practices in behavioral analysis, including tools for evaluating the quality of the data that can alleviate problems associated with low reproducibility in the behavioral sciences.

Environmental Conditions Associated with Long-Track Tornadoes

Abstract Reanalysis proximity vertical profile attributes associated with long-track tornadoes [LTTs; pathlength ≥48 km (30 mi)] and short-track tornadoes [STTs; pathlengths <48 km (30 mi)] for a total of 48 212 tornadoes with pathlengths ≥0.16 km (0.1 mi) from 1979–2022 in the United States were examined. Both longer- and shorter-track tornadoes were associated with vast ranges of mixed-layer convective available potential energy, together with relatively low mixed-layer lifted condensation level heights and minimal convective inhibition. A large range of 500–9000-m wind speeds and bulk wind differences, 500–3000-m streamwise vorticities, storm-relative helicities, and storm-relative wind speeds were found for STTs. In stark contrast, LTTs only occurred when these kinematic attributes were larger in amplitude through the troposphere, supporting previously documented associations between observed longer-track tornado pathlengths and faster-propagating parent storms. A novel parameter, heavily weighted by kinematic parameters and lightly weighted by thermodynamic parameters, outperformed the significant tornado parameter in differentiating environments that were more supportive of both LTTs as well as tornadoes rated <EF5. The high correlation values R2 = 0.79 between tornado pathlength and Bunkers’ approximate tornado duration (pathlength / VBunkers) calls for improved understanding of mesocyclone periodicities, which impact tornado longevity, to improve tornado pathlength diagnoses and forecasts. Pragmatically, diagnosing LTT environments using vertical profile attributes, perhaps, is not so much a problem of determining when there might be higher expectations for LTTs, but rather a problem of when there might be lower expectations for LTTs, e.g., weaker kinematic attributes in the lower troposphere.

Influence of incorporating L-carnitine or Moringa oleifera leaves extract into semen diluent on cryosurvival and in vitro fertilization competence of buck sperm

This study aimed at scrutinizing efficiency of incorporating L-carnitine or M. oleifera leaves extract into semen diluent on improving cryopreservation capacity and in vitro fertilization ability of buck spermatozoa. Ejaculates (n=48) were collected by an artificial vagina from six adult Damascus bucks twice weekly during the breeding season (September–October). Following initial evaluation, ejaculates of each collection session from the same bucks were pooled, diluted (1:10) with glycerolized (3 % glycerol, v/v) tris-citric acid egg yolk diluent and were split into three aliquots. The first aliquot served as control, whereas the second and third aliquots were supplemented with 4 μL/mL L-carnitine and 400 μL/mL moringa leaves extract (v/v), respectively. Thereafter, all specimens were processed for cryopreservation and were stored in liquid nitrogen (-196 °C) for 12 months before post-thaw sperm criteria were analyzed by a computer-assisted sperm analysis (CASA) system. Integrity of sperm DNA post thawing was visualized in all semen groups by fluorescence imaging, and in vitro fertilization ability of spermatozoa was also determined. Inclusion of L-carnitine or moringa leaves extract into the diluent improved (P<0.05) post-thaw sperm physical, morphofunctional and kinematic attributes, whilst maintaining (P<0.05) integrity of sperm DNA throughout the freezing and thawing cycle. Consequently, both supplemented groups yielded higher (P<0.05) in vitro fertilization rates compared to control. These results accentuate the protective roles of these antioxidants on buck sperm against consequences of cryopreservation-induced oxidative stress, hence ameliorating post-thaw sperm quality and fertilization competence. This is crucial for successful application of AI and IVF in goat selective breeding programs.

Human–robot mechanics model using hip torque identification with a dual-arm nursing-care transfer robot

In response to the growing demand for robotic interventions to mitigate the profound physical strain experienced by caregivers during transfers, dual-arm robotic systems have emerged as a focal point of interest in the caregiving community due to their adaptability and versatility. However, the accuracy of existing human–robot mechanics model is insufficient, impacting the execution of transfer tasks. To enhance the model’s precision, an improved model is proposed, integrating hip torque identification. This proposed methodology involves the simplification of the human structure based on the kinematic attributes associated with the embrace of individuals by robotic arms and the subsequent computation of its inertial parameters. Accordingly, the application of D’Alembert’s principle is employed to analyze the impact of embracing motion, human posture, and the position of human–robot contact on the forces exerted on the human. This culminates in the establishment of a model. Considering the static indeterminacy predicament inherent in the model, a biomechanical data set is curated for the dual-arm transfer scenario. Leveraging this data set, a deep neural network utilizing multilayer perceptron is trained to accurately identify hip torque, thereby improving the model. Accordingly, a robotic transfer platform featuring dual arms is developed and trailed on six subjects with varying anatomical profiles. The results show that the constructed model has high accuracy. This study provides critical mechanics insights for dual-arm transfer tasks, offering potential application value in the field of nursing and rehabilitation.

Rock glacier distribution and kinematics in Shigar and Shayok basins based on radar and optical remote sensing

AbstractRecent studies have demonstrated the rock glacier destabilisation and permafrost thawing induced by warming climate represent a continuous threat to life, infrastructure and socio‐economic development in the mountainous regions of the Hindu Kush Himalaya. This study presents the first systematic rock glacier inventory for the Shigar and Shayok basins, quantifying rock glacier geomorphology and kinematics based on morphological evidence using Google Earth images and interferometric synthetic aperture radar (InSAR). The certainty index of each inventoried rock glacier is recorded, along with its geomorphological properties and kinematic attributes. The rock glacier velocity is estimated through the InSAR time series analysis of Sentinel‐1 images from 2020 to 2021, with temporal baselines at 12‐day intervals. We developed a rock glacier inventory consisting of 84 rock glaciers covering an area of 29 km2 for the Shigar Basin and 2206 rock glaciers encompassing 369 km2 for the Shayok Basin. Among these rock glaciers, 69% and 52% are categorised as active rock glaciers, respectively. Rock glaciers in both catchments are confined to elevations between 3600 and 5875 m a.s.l., with a mean area of 0.22 km2. The maximum recorded velocity for active rock glaciers in the Shigar Basin is 101 ± 9 cm year−1, with a median of 27 ± 10 cm year−1, and in the Shayok Basin 114 ± 10 cm year−1 (median of 29 ± 9 cm year−1). Temporal variations in the surface velocities of the rock glaciers reveal that they increase with rising temperatures in both catchments, highlighting the seasonality in the rock glacier surface velocity. In total, we recorded the kinematic attributes of 98% of the inventoried rock glaciers in the study area.

Investigating 56 High Galactic Latitude Open Cluster Candidates in Gaia DR3

Using Gaia DR3 data, we revisit 56 high Galactic latitude (∣b∣ ≥ 30°) open cluster (OC) candidates with poor shapes of color–magnitude diagrams (CMDs), including unclear and paired main sequences (MSs). We aim to confirm their physical reality and explore whether the special MS morphology is intrinsic to genuine OCs. Initially, we redetermine cluster memberships by integrating five outlier detection algorithms into pyUPMASK. However, this work fails to reproduce the 56 clusters. Instead, we find an alternative set of 56 clusters, six of which are non-duplicates. To ascertain whether the six clusters are real OCs, we build synthetic CMDs to derive reliable cluster properties, including fundamental parameters, binary fraction, and mass of the cluster. Subsequently, we investigate the structural parameters and the age–mass and mass–radius relations of the six candidate OCs. Finally, we utilize a multidimensional approach, incorporating cluster properties, spatial structure, kinematic attributes, and CMD verification, to assess their physical reality as genuine OCs further. Our results suggest that the six candidates should be physical OCs, exhibiting well-defined CMD characteristics. Moreover, we discover two of the six OCs as potential binary clusters.

Rock Glacier Inventory of the Southwestern Pamirs Supported by InSAR Kinematics

Although rock glaciers (RGs) are prevalent in the southwestern Pamirs, systematic studies on them are scarce. This article introduces the first inventory of RGs in the southwestern Pamirs, situated at the western edge of the High Mountain Asia region. The inventory, established through a combination of Google Earth optical imagery and Interferometric Synthetic Aperture Radar (InSAR) techniques, encompasses details on the locations, geomorphological parameters, and kinematic attributes of RGs. A total of 275 RGs were cataloged in an area of 55.52 km2 from 3620 to 5210 m in altitude. Our inventory shows that most RGs in this region are talus-connected (213 landforms), with the highest frequency facing northeast (23%). The distribution of RGs thins from west to east and is more abundant in higher altitudes. The Shakhdara range to the south hosts a denser and more active population of RGs than the Shughnon range to the north, highlighting the influence of topography and precipitation. Overall, RGs in the southwestern Pamirs exhibit high activity levels, with active RGs predominating (58%). A comparison between active and transitional RGs showed no significant differences in elevation, temperature, and slope. Glacier-connected and glacier forefield-connected RGs demonstrated higher line-of-sight (LOS) velocities than talus-connected and debris-mantled slope-connected RGs, underscoring the significant impact of precipitation and meltwater on their activity.

The New Zealand Community Fault Model – version 1.0: an improved geological foundation for seismic hazard modelling

ABSTRACT The New Zealand Community Fault Model (NZ CFM) is a publicly available representation of New Zealand fault zones that have the potential to produce damaging earthquakes. Compiled through collaborative engagement between New Zealand earthquake-science experts, this first edition (version 1.0) of the NZ CFM builds upon previous compilations of earthquake-source active fault models with the addition of new and modified information. Developed primarily to support an update of the New Zealand National Seismic Hazard Model, the NZ CFM comprises two principal components. The first dataset is a two-dimensional map representation of the surface traces of 880 generalised fault zones. Each fault zone is assigned specific geometric and kinematic attributes, including uncertainties, supplemented with a subjective quality ranking focused primarily on the confidence in assigned slip rates. The second component is a three-dimensional representation of the fault zones as triangulated mesh surfaces that are projected down-dip from the two-dimensional mapped traces to a geophysically-defined maximum fault rupture depth. This article summarises the compilation and parameterisation of the NZ CFM, along with background on its relation to predecessor datasets, and forward applications to probabilistic seismic hazard assessment and physics-based earthquake models currently being developed for Aotearoa New Zealand.

Kinematic Investigations of a Novel Flapping Actuation Design with Mutually Perpendicular 3 Cylindrical Joint Approach for FW-Drones

The transmission mechanism of artificial flapping-wing drones generally needs low weight and the fewest interconnecting components, making their development challenging. The four-bar Linkage mechanism for flapping actuation has generally been used till now with complex and heavy connecting designs, but our proposed novel perpendicularly organized 3-cylindrical joint mechanism is designed to be unique and lighter weight with smooth functioning performance. The proposed prototype transforms the rotary motion of the motor into a specific angle of flapping movement, where the dimensions and specifications of the design components are proportional to the obtained flapping angle. Power consumption and flapping actuation can be monitored by adjusting the motor's rotational speed to control the individual wing in this mechanism. The proposed mechanism consists of a crank with three slightly slidable cylindrical joints perpendicularly arranged to each other with a specified distance in a well-organized pattern to produce a flapping movement at the other end. In order to examine the kinematic attributes, a mathematical process approach is formulated, and kinematic simulations are performed using SIMSCAPE multibody MATLAB, PYTHON programming and COMPMECH GIM software. The proposed invention's real-time test bench prototype model is designed, tested and analyzed for flapping validation.

Incorporating InSAR kinematics into rock glacier inventories: insights from 11 regions worldwide

Abstract. Rock glaciers are landforms related to permafrost creep that are sensitive to climate variability and change. Their spatial distribution and kinematic behaviour can be critical for managing water resources and geohazards in periglacial areas. Rock glaciers have been inventoried for decades worldwide, often without assessment of their kinematics. The availability of remote sensing data however makes the inclusion of kinematic information potentially feasible, but requires a common methodology in order to create homogeneous inventories. In this context, the International Permafrost Association (IPA) Action Group on rock glacier inventories and kinematics (2018–2023), with the support of the European Space Agency (ESA) Permafrost Climate Change Initiative (CCI) project, is defining standard guidelines for the inclusion of kinematic information within inventories. Here, we demonstrate the feasibility of applying common rules proposed by the Action Group in 11 regions worldwide. Spaceborne interferometric synthetic aperture radar (InSAR) was used to characterise identifiable moving areas related to rock glaciers, applying a manual and a semi-automated approach. Subsequently, these areas were used to assign kinematic information to rock glaciers in existing or newly compiled inventories. More than 5000 moving areas and more than 3600 rock glaciers were classified according to their kinematics. The method and the preliminary results were analysed. We identified drawbacks related to the intrinsic limitations of InSAR and to various applied strategies regarding the integration of non-moving rock glaciers in some investigated regions. This is the first internationally coordinated work that incorporates kinematic attributes within rock glacier inventories at a global scale. The results show the value of designing standardised inventorying procedures for periglacial geomorphology.

Collapsed mitochondrial cristae in goat spermatozoa due to mercury result in lethality and compromised motility along with altered kinematic patterns

Earlier we have reported mercury-induced alterations in functional dynamics of buck spermatozoa through free radicals-mediated oxidative stress and spontaneous acrosome reaction. Based on our earlier findings, we aimed to investigate the effect of mercury exposure on motility, kinematic patterns, DNA damage, apoptosis and ultra-structural alterations in goat spermatozoa following in vitro exposure to different concentrations (0.031–1.25 µg/ml) of mercuric chloride for 15 min and 3 h. Following exposure of sperm cells to 0.031 µg/ml of mercuric chloride for 3 h, livability and motility of sperms was significantly reduced along with altered kinematic patterns, significant increase in per cent necrotic sperm cells and number of cells showing DNA damage; and this effect was dose- and time-dependent. Contrary to up-regulation of Bax gene after 3 h in control group, there was significant increase in expression of Bcl-2 in mercury-treated groups. Transmission electron microscopy studies revealed rifts and nicks in plasma and acrosomal membrane, mitochondrial sheath, and collapsed mitochondria with loss of helical organization of mitochondria in the middle piece of spermatozoa. Our findings evidently suggest that mercury induces necrosis instead of apoptosis and targets the membrane, acrosome, mid piece of sperms; and the damage to mitochondria seems to be responsible for alterations in functional and kinematic attributes of spermatozoa.

The influence of temporal predictability on express visuomotor responses.

Humans are able to generate target-directed visuomotor responses in less than 100 ms after stimulus onset. These "express" responses have been termed stimulus-locked responses (SLRs) and are proposed to be modulated by visuomotor transformations performed subcortically via the superior colliculus. Unfortunately, these responses have proven difficult to detect consistently across individuals. The recent report of an effective paradigm for generating SLRs in 100% of participants appears to change this. The task required the interception of a target moving at a constant velocity that emerged from behind a barrier. Here, we aimed to reproduce the efficacy of this paradigm for eliciting SLRs and to test the hypothesis that its effectiveness derives from the predictability of target onset time as opposed to target motion per se. In one experiment, we recorded surface electromyogram (EMG) from shoulder muscles as participants made reaches to intercept temporally predictable or unpredictable targets. Consistent with our hypothesis, predictably timed targets produced more frequent and stronger SLRs than unpredictably timed targets. In a second experiment, we compared different temporally predictable stimuli and observed that transiently presented targets produced larger and earlier SLRs than sustained moving targets. Our results suggest that target motion is not critical for facilitating the SLR expression and that timing predictability does not rely on extrapolation of a physically plausible motion trajectory. These findings provide support for a mechanism whereby an internal timer, probably located in cerebral cortex, primes the processing of both visual input and motor output within the superior colliculus to produce SLRs.NEW & NOTEWORTHY Express stimulus-driven responses in humans have been proposed to be originated subcortically via the superior colliculus. These short-latency responses are facilitated by the presentation of dynamic visual stimuli. Here, we show that this facilitation is related to the predictable target timing, regardless of its kinematic attributes. We propose that the superior colliculus can be primed to generate express stimulus-driven motor responses via cortical top-down projection.

Consistent seismic event location and subsurface parameters inversion through slope tomography: a variable-projection approach

SUMMARY We revisit the hypocentre–velocity problem, which is of interest in different fields as for example microseismics and seismology. We develop a formulation based on kinematic migration of two picked kinematic attributes in the 2-D case, the traveltime and the slope (horizontal component of the slowness vector), from which we are able to retrieve the location and subsequently the origin time correction and the subsurface parameters mainly velocity. We show how, through a variable projection, the optimization problem boils down to a physically consistent and parsimonious form where the location estimation is projected into the subsurface parameter problem. We present in this study a proof of concept validated by a toy test in two dimensions and a synthetic case study on the Marmousi model. The method presented in this study is extendible to three dimensions by incorporating the crossline slope or the backazimuth as a supplementary attribute.

Time-migration velocity estimation using Fréchet derivatives based on nonlinear kinematic migration/demigration solvers

Advanced seismic imaging and inversion are dependent on a velocity model that is sufficiently accurate to render reliable and meaningful results. For that reason, methods for extracting such velocity models from seismic data are always in high demand and are topics of active investigation. Velocity models can be obtained from both the time and depth domains. Relying on the former, time migration is an inexpensive, quick and robust process. In spite of its limitations, especially in the case of complex geologies, time migration can, in many instances (e.g. simple to moderate geological structures), produce image results compatible to the those required for the project at hand. An accurate time-velocity model can be of great use in the construction of an initial depth-velocity model, from which a high-quality depth image can be produced. Based on available explicit and analytical expressions that relate the kinematic attributes (namely, traveltimes and local slopes) of local events in the recording (demigration) and migrated domains, we revisit tomographic methodologies for velocity-model building, with a specific focus on the time domain, and on those that makes use of local slopes, as well as traveltimes, as key attributes for imaging. We also adopt the strategy of estimating local inclinations in the time-migrated domain (where we have less noise and better focus) and use demigration to estimate those inclinations in the recording domain. On the theoretical side, the main contributions of this work are twofold: 1) we base the velocity model estimation on kinematic migration/demigration techniques that are nonlinear (and therefore more accurate than simplistic linear approaches) and 2) the corresponding Frechet derivatives take into account that the velocity model is laterally heterogeneous. In addition to providing the comprehensive mathematical algorithms involved, three proof-of-concept numerical examples are demonstrated, which confirm the potential of our methodology.

Strong bond rearrangement and hydrogen-pair emission in linear geometry following water ionization by electron impact

SynopsisThe H0 + O+ + H0 fragmentation of water by electron impact is studied using the delayed extraction time-of-flight technique to uncover kinematic attributes of suprathermal O+ ions. It is found that the H0 pair ejections occur under a large angular rearrangement, in an approximate linear geometry, and leaving the O+ near at rest, with ∼50% of the O+ produced in water fragmentation by swift electrons presenting this feature. It is shown that this behavior is closely associated to the excitation of satellites one-electron-two-vacancies states near the 2a1 orbital.

Comparative Evaluation of Motility and Kinematics of Fresh Versus Frozen-Thawed Spermatozoa of Cattle and Buffalo Bull by CASA

A study was undertaken on semen of three mature bulls each of Gir, Surti and Murrah breed to evaluate the comparative motion characteristics and kinematics of their fresh and frozen-thawed spermatozoa by Biovis CASA. The ejaculates (n= 24/breed) having &gt;75% initial motility were diluted @ 80 million sperm/ml using TFYG extender and were assessed. Amongst motility traits, the total motile, rapid progressive motile and slow progressive motile spermatozoa percentage decreased significantly by 23.08 - 30.09, 43.57 - 55.18, 9.12 - 22.75 %, respectively, plessthan0.01), while non-progressive motile sperm (4.78 - 21.48%) and immotile sperm (164.38 - 178.38 %) percentage increased significantly ( plessthan0.01) in frozen-thawed semen compared to that of fresh semen. The post-thaw quality of semen of all three breeds was in acceptable range. The mean values of sperm velocity/kinematic parameters observed in frozen-thawed semen of Gir, Surti and Murrah bulls, based on total motile sperms, viz., average path velocity, curvilinear velocity, straight line velocity, linearity, straightness, beat-cross frequency, amplitude of lateral head displacement, dancing frequency and dancing mean decreased significantly by 13.70 - 17.79; 9.76 - 12.95; 13.28 - 21.90; 7.28 - 9.68; 4.36 - 7.79; 15.56 - 25.15; 8.78 - 10.50; 6.16 - 18.67 and 12.98 - 15.96 %, respectively, as compared to that of their fresh semen samples. However, wobbling index remained almost same for both fresh and frozen semen. All motility traits differed but none of kinematics/velocity traits differed significantly between breeds/species. The values of all velocity parameters for progressive motile sperms were higher than total motile sperms in all three breeds. The effect of freezing-thawing on velocity and kinematic attributes was much less compared to absolute sperm motility, and both the fresh and frozen-thawed sperms behaved identically with respect to their velocity and kinematics. The rapid progressive motile sperm in both fresh (r=0.41 to 0.92) and frozen-thawed (r=044 to 0.88) semen had significant correlations with most of their velocity traits, and the later were significantly and positively or negatively inter-related among each other in semen of all three breeds. It was therefore concluded that cryopreservation process significantly reduces the motility and kinematics attributes of bovine spermatozoa and, CASA analysis of fresh semen for motility and velocity traits could predict the post-thawed sperm motility and velocity/ kinematics of spermatozoa.

3D mapping of kinematic attributes in anisotropic media

Based on the rotation of a slowness surface in anisotropic media, we have derived a set of mapping operators that establishes a point-to-point correspondence for the traveltime and relative-geometric-spreading surfaces between these calculated in nonrotated and rotated media. The mapping approach allows one to efficiently obtain the aforementioned surfaces in a rotated anisotropic medium from precomputed surfaces in the nonrotated medium. The process consists of two steps: calculation of a necessary kinematic attribute in a nonrotated, e.g., orthorhombic (ORT), medium, and subsequent mapping of the obtained values to a transformed, e.g., rotated ORT, medium. The operators we obtained are applicable to anisotropic media of any type; they are 3D and are expressed through a general form of the transformation matrix. The mapping equations can be used to develop moveout and relative-geometric-spreading approximations in rotated anisotropic media from existing approximations in nonrotated media. Although our operators are derived in case of a homogeneous medium and for a one-way propagation only, we discuss their extension to vertically heterogeneous media and to reflected (and converted) waves.

Parsimonious slope tomography based on eikonal solvers and the adjoint-state method

Velocity macromodel building is an essential step of the seismic imaging workflow. Indeed, obtaining acceptable results through migration or full waveform inversion is highly dependent on the kinematic accuracy of the background/initial velocity model. Two decades ago, stereotomography was proposed as an alternative to reflection traveltime tomography, the first relying on semi-automatic picking of locally coherent events associated with small reflection or diffraction segments tied to scatterers in depth by a pair of rays, while the latter on interpretive picking of laterally continuous reflections. The flexibility of stereotomography paved the way for many developments that have shown the efficiency of the method whilst emphasizing on the complementary information carried out by traveltimes and slopes of locally coherent events. A recent formulation recast stereotomography under a matrix-free formulation based on eikonal solvers and the adjoint-state method. In the latter, like in the previous works, the scatterer positions and the velocity field are updated jointly to tackle the ill-famed velocity–position coupling in reflection tomography. Following on from this adjoint-state formulation, we propose a new parsimonious formulation of slope tomography that offers the chance to restrain the problem to minimizing the residuals of a single data class being a slope, in search of a sole parameter class being the subsurface velocity field. This parsimonious formulation results from a variable projection, which is implemented by enforcing a consistency between the scatterer coordinates and the velocity macromodel through migration of kinematic attributes. We explain why the resulting reduced-parametrization inversion is more suitable for tomographic problems than the most common joint inversion strategy. We benchmark our method against the complex Marmousi model along with a validation through time domain full waveform inversion and then present the results of a field data case study.

Simulation of straw movement by discrete element modelling of straw-sweep-soil interaction

Understanding residue and soil behaviour under the impact of tillage tools is critical for designing tools for conservation tillage. A soil-tool-residue interaction model was developed for a sweep and oat straw using the discrete element method. Soil, sweep, and straw were modelled using spherical particles, walls, and clumps respectively. A virtual field consisting of two layers including a soil layer and a top straw layer was constructed. Dynamic attributes including soil moving area, straw moving area, residue cover, kinetic energy, straw velocity, acceleration, displacement, and moving trajectory were monitored. Comparing the simulated values of soil and straw moving areas with those calculated from analytical models in literature, the calibrated model parameters of ball stiffness and clump stiffness were 8730 and 332 N m−1 respectively. The model had an overall relative error of 7.3% as comparing predicted straw displacements and residue cover with those measured in a soil bin test and extracted from previous experimental data in the literature. Increasing the travel speed of the sweep increased the residue cover reduction and straw displacements. The kinematic attributes clearly demonstrated three stages of the straw movement: forced, projectile, and overturning movements. The results demonstrated that it is feasible to obtain dynamic attributes of bulk materials and individual particles of a straw-sweep-soil interaction system using the discrete element model.

Global optimization strategies for implementing 3D common-reflection-surface stack using the very fast simulated annealing algorithm: Application to real land data

The 3D common-reflection-surface (CRS) stack operator depends on eight kinematic wavefield attributes that must be extracted from the prestack data. These attributes are obtained by an efficient optimization strategy based on the maximization of the coherence measure of the seismic reflection events included by the CRS stacking operator. The main application of these kinematic attributes is to simulate zero-offset stacked data; however, they can also be used for regularization of the prestack data, prestack migration, and velocity model determination. The initial implementations of the 3D CRS stack used grid-search techniques to determine the attributes in several steps with the drawback that accumulated errors can deteriorate the final result. In this work, the global optimization very fast simulated annealing algorithm is used to search for the kinematic attributes by applying three optimization strategies for implementing CRS stacking: (1) simultaneous global search of five kinematic attributes of the 3D common-diffraction-surface stacking operator, (2) two-step global optimization strategy to first search for three attributes and then five attributes of the CRS stacking operator, and (3) simultaneous global search of eight kinematic attributes of the CRS operator. The proposed CRS stacking algorithms are applied to land data of the Potiguar Basin, Brazil. It is demonstrated that the one-step optimization strategy of the eight parameters produces the best results, however, with a higher computational cost.