kinematic properties
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2022 ◽  
Vol 5 (1) ◽  
Author(s):  
Diego Gella ◽  
Daichi Yanagisawa ◽  
Rodrigo Caitano ◽  
María Victoria Ferreyra ◽  
Iker Zuriguel

AbstractPlacing an obstacle in front of a bottleneck has been proposed as a sound alternative to improve the flow of discrete materials in a wide variety of scenarios. Nevertheless, the physical reasons behind this behavior are not fully understood and the suitability of this practice has been recently challenged for pedestrian evacuations. In this work, we experimentally demonstrate that for the case of inert grains discharging from a silo, an obstacle above the exit leads to a reduction of clog formation via two different mechanisms: i) an alteration of the kinematic properties in the outlet proximities that prevents the stabilization of arches; and ii) an introduction of a clear anisotropy in the contact fabric tensor that becomes relevant when working at a quasi-static regime. Then, both mechanisms are encompassed using a single formulation that could be inspiring for other, more complex, systems.


2022 ◽  
pp. 002383092110657
Author(s):  
Chiara Celata ◽  
Chiara Meluzzi ◽  
Chiara Bertini

We investigate the temporal and kinematic properties of consonant gemination and heterosyllabic clusters as opposed to singletons and tautosyllabic clusters in Italian. The data show that the singleton versus geminate contrast is conveyed by specific kinematic properties in addition to systematic durational differences in both the consonantal and vocalic intervals; by contrast, tautosyllabic and heterosyllabic clusters differ significantly for the duration of the consonantal interval but do not vary systematically with respect to the vocalic interval and cannot be consistently differentiated at the kinematic level. We conclude that systematic variations in acoustic vowel duration and the kinematics of tongue tip gestures represent the phonetic correlates of the segmental phonological contrast between short and long consonants, rather than of syllable structure. Data are only partly consistent with the predictions of both moraic and gesture-based models of the syllable about the effects of syllable structure on speech production dynamics and call for a more gradient view of syllabification.


2021 ◽  
Vol 17 (12) ◽  
Author(s):  
Christoph J. Völter ◽  
Ludwig Huber

Contact causality is one of the fundamental principles allowing us to make sense of our physical environment. From an early age, humans perceive spatio-temporally contiguous launching events as causal. Surprisingly little is known about causal perception in non-human animals, particularly outside the primate order. Violation-of-expectation paradigms in combination with eye-tracking and pupillometry have been used to study physical expectations in human infants. In the current study, we establish this approach for dogs ( Canis familiaris ). We presented dogs with realistic three-dimensional animations of launching events with contact (regular launching event) or without contact between the involved objects. In both conditions, the objects moved with the same timing and kinematic properties. The dogs tracked the object movements closely throughout the study but their pupils were larger in the no-contact condition and they looked longer at the object initiating the launch after the no-contact event compared to the contact event. We conclude that dogs have implicit expectations about contact causality.


Author(s):  
Taisheng Yan ◽  
Jianrong Shi ◽  
Hao Tian ◽  
Wei Zhang ◽  
Bo Zhang

Abstract Based on the data release of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope survey (LAMOST DR5) and the Gaia Early Data Release 3 (Gaia EDR3), we construct a sample containing 46,109 giant (log g 3.5 dex) stars with heliocentric distance d 4 kpc, and the sample is further divided into two groups of the inner (RGC < 8.34 kpc) and outer region (RGC > 8.34 kpc). The LZ distributions of our program stars in the panels with different [Fe/H] and [α/Fe] suggest that the thick-disk consists of two distinct components with different chemical compositions and kinematic properties. For the inner region, the metal-weak thick disk (MWTD) contributes significantly when [α/Fe] > +0.2 dex and [Fe/H] < −0.8 dex, while the canonical thick-disk (TD) dominates when [Fe/H]> −0.8 dex. However, MWTD clear appears only when [α/Fe] > +0.2 dex and [Fe/H] < −1.2 dex for the outer region, and its proportion is lower than that of the inner region within the same metallicity. Similar result can be obtained from the Vφ distribution.


Author(s):  
Daria Leiber ◽  
David Eickholt ◽  
Anh-Tu Vuong ◽  
Gunther Reinhart

AbstractThis article presents a novel approach for the automated 3D-layout planning of multi-station assembly lines. The planning method is based on a comprehensive model of the used production resources, including their geometry, kinematic properties, and general characteristics. Different resource types can be included in the planning system. A genetic algorithm generates and optimizes possible layouts for a line. The optimization aims to minimize the line’s area and the costs for assembling the line while simultaneously optimizing the resources’ positioning to perform their tasks. The line’s cycle time is considered as a boundary condition. For the evaluation of different layout alternatives, a multi-body simulation is performed. A parameter study is used to set the algorithm’s parameters. Afterward, the algorithm is applied to three increasingly complex examples to validate and evaluate its functionality. The approach is promising for industrial applications as it allows the integration of various resource types and individualization of the optimization function.


Author(s):  
R. Raddi ◽  
S. Torres ◽  
A. Rebassa-Mansergas ◽  
J. Maldonado ◽  
M. E. Camisassa ◽  
...  

Geophysics ◽  
2021 ◽  
pp. 1-56
Author(s):  
Shibo Xu ◽  
Alexey Stovas

Understanding the kinematics of horizontally-layered reservoir rocks is important to their proper characterization and to accomplish this it is necessary to specify the explicit model for these kinematic properties. The accurate approximations for traveltime and relative geometrical spreading in an elastic homogeneous orthorhombic (ORT) have been investigated with different forms: Shifted Hyperbola Form (SHF), Taylor Series (TS) and the Rational Form (RF). This paper extends these approximations to the multi-layered ORT model by adopting composite coefficients and effective model parameters. The multi-layered model is characterized without and with the azimuthal variation among layers. There is an overdetermined problem when the azimuthal variation exists; and to address that case, the Least Squares Method (LSM) is adopted. To check the feasibility of the expansion, we select the SHF (Shifted Hyperbola Form) approximation specified in the homogeneous elastic ORT model for the calculation in the numerical example. Four groups of examples are analyzed to investigate the influence on the accuracy of the approximation with the change in rotation angle, degree of anisotropy, and the direction of the orientation. The results indicate that, for the multi-layer, the accuracy of the approximation is proportional to the degree of anisotropy and the value of the angle of rotation. The relative errors in travel time and relative geometrical spreading in this multi-layered extension are very small and can be implemented in practical applications


Author(s):  
Jesse van de Sande ◽  
Scott M Croom ◽  
Joss Bland-Hawthorn ◽  
Luca Cortese ◽  
Nicholas Scott ◽  
...  

Abstract The kinematic morphology-density relation of galaxies is normally attributed to a changing distribution of galaxy stellar masses with the local environment. However, earlier studies were largely focused on slow rotators; the dynamical properties of the overall population in relation to environment have received less attention. We use the SAMI Galaxy Survey to investigate the dynamical properties of ∼1800 early and late-type galaxies with log (M⋆/M⊙) &gt; 9.5 as a function of mean environmental overdensity (Σ5) and their rank within a group or cluster. By classifying galaxies into fast and slow rotators, at fixed stellar mass above log (M⋆/M⊙) &gt; 10.5, we detect a higher fraction (∼3.4σ) of slow rotators for group and cluster centrals and satellites as compared to isolated-central galaxies. We find similar results when using Σ5 as a tracer for environment. Focusing on the fast-rotator population, we also detect a significant correlation between galaxy kinematics and their stellar mass as well as the environment they are in. Specifically, by using inclination-corrected or intrinsic $\lambda _{R_{\rm {e}}}$ values, we find that, at fixed mass, satellite galaxies on average have the lowest $\lambda _{\, R_{\rm {e}},\rm {intr}}$, isolated-central galaxies have the highest $\lambda _{\, R_{\rm {e}},\rm {intr}}$, and group and cluster centrals lie in between. Similarly, galaxies in high-density environments have lower mean $\lambda _{\, R_{\rm {e}},\rm {intr}}$ values as compared to galaxies at low environmental density. However, at fixed Σ5, the mean $\lambda _{\, R_{\rm {e}},\rm {intr}}$ differences for low and high-mass galaxies are of similar magnitude as when varying Σ5 ($\Delta \lambda _{\, R_{\rm {e}},\rm {intr}} \sim 0.05$, with σrandom = 0.025, and σsyst &lt; 0.03). Our results demonstrate that after stellar mass, environment plays a significant role in the creation of slow rotators, while for fast rotators we also detect an independent, albeit smaller, impact of mass and environment on their kinematic properties.


2021 ◽  
Vol 162 (3) ◽  
pp. 100
Author(s):  
Di-Chang Chen ◽  
Jia-Yi Yang ◽  
Ji-Wei Xie ◽  
Ji-Lin Zhou ◽  
Subo Dong ◽  
...  

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