scholarly journals Non-Local SAR Tomography for Large-Scale Urban Mapping

2019 ◽  
Author(s):  
Yilei Shi ◽  
Yuanyuan Wang ◽  
Xiao Xiang Zhu ◽  
Richard Bamler
Keyword(s):  
Large Scale ◽  
Non Local ◽  
Urban Mapping ◽  
Local Sar

The Uncertainty Principle Derived by The Finite Transmission Speed of Light and Information

2014 ◽  
Vol 3 (3) ◽  
pp. 257-266 ◽  
Author(s):  
Piero Chiarelli
Keyword(s):  
Uncertainty Principle ◽  
Large Scale ◽  
Uncertainty Relations ◽  
Speed Of Light ◽  
Energy Fluctuation ◽  
Hydrodynamic Analogy ◽  
Non Local ◽  
Minimum Uncertainty ◽  
Quantum Hydrodynamic ◽  
Transmission Speed

This work shows that in the frame of the stochastic generalization of the quantum hydrodynamic analogy (QHA) the uncertainty principle is fully compatible with the postulate of finite transmission speed of light and information. The theory shows that the measurement process performed in the large scale classical limit in presence of background noise, cannot have a duration smaller than the time need to the light to travel the distance up to which the quantum non-local interaction extend itself. The product of the minimum measuring time multiplied by the variance of energy fluctuation due to presence of stochastic noise shows to lead to the minimum uncertainty principle. The paper also shows that the uncertainty relations can be also derived if applied to the indetermination of position and momentum of a particle of mass m in a quantum fluctuating environment.

scholarly journals Sliding Contacts in Planetary Magnetospheres

Symmetry ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 283
Author(s):  
Elena Belenkaya ◽  
Igor Alexeev
Keyword(s):  
Large Scale ◽  
Strong Field ◽  
Magnetized Plasma ◽  
Sliding Contacts ◽  
Radio Emissions ◽  
Planetary Magnetospheres ◽  
Current Task ◽  
Surrounding Space ◽  
Non Local ◽  
A Current

In the planetary magnetospheres there are specific places connected with velocity breakdown, reconnection, and dynamo processes. Here we pay attention to sliding layers. Sliding layers are formed in the ionosphere, on separatrix surfaces, at the magnetopauses and boundaries of stellar astrospheres, and at the Alfvén radius in the equatorial magnetosphere of rapidly rotating strongly magnetized giant planets. Although sliding contacts usually occur in thin local layers, their influence on the global structure of the surrounding space is very great. Therefore, they are associated with non-local processes that play a key role on a large scale. There can be an exchange between different forms of energy, a generation of strong field-aligned currents and emissions, and an amplification of magnetic fields. Depending on the conditions in the magnetosphere of the planet/exoplanet and in the flow of magnetized plasma passing it, different numbers of sliding layers with different configurations appear. Some are associated with regions of auroras and possible radio emissions. The search for planetary radio emissions is a current task in the detection of exoplanets.

scholarly journals Introducing Twitter Daily Estimates of Residents and Non-Residents at the County Level

2021 ◽  
Vol 10 (6) ◽  
pp. 227
Author(s):  
Yago Martín ◽  
Zhenlong Li ◽  
Yue Ge ◽  
Xiao Huang
Keyword(s):  
Large Scale ◽  
Local Population ◽  
External Validation ◽  
Population Estimates ◽  
County Level ◽  
Internal Validation ◽  
Population Movements ◽  
Dynamic Component ◽  
Home Location ◽  
Non Local

The study of migrations and mobility has historically been severely limited by the absence of reliable data or the temporal sparsity of available data. Using geospatial digital trace data, the study of population movements can be much more precisely and dynamically measured. Our research seeks to develop a near real-time (one-day lag) Twitter census that gives a more temporally granular picture of local and non-local population at the county level. Internal validation reveals over 80% accuracy when compared with users’ self-reported home location. External validation results suggest these stocks correlate with available statistics of residents/non-residents at the county level and can accurately reflect regular (seasonal tourism) and non-regular events such as the Great American Solar Eclipse of 2017. The findings demonstrate that Twitter holds the potential to introduce the dynamic component often lacking in population estimates. This study could potentially benefit various fields such as demography, tourism, emergency management, and public health and create new opportunities for large-scale mobility analyses.

Middle Preclassic Maya Shell Ornament Production

2018 ◽  
Author(s):  
Bobbi Hohmann ◽  
Terry G. Powis ◽  
Paul F. Healy
Keyword(s):  
Large Scale ◽  
Scale Production ◽  
Large Scale Production ◽  
Belize River Valley ◽  
Preclassic Maya ◽  
Preclassic Period ◽  
Non Local ◽  
Degree Of Control ◽  
Middle Preclassic ◽  
Marine Shell

Extensive archaeological investigations at the site of Pacbitun, a medium-sized Maya center located in west-central Belize, have revealed the large-scale production of marine shell ornaments during Middle Preclassic period (900-300 B.C.). Non-local marine shell and the restricted nature of its distribution indicate that some degree of control may have been exerted over the production and/or distribution of marine shell or the finished shell products. The sheer quantities of shell working debris in the site core of Pacbitun suggest that these ornaments were intended for intra- or extra-community exchange. Two different scenarios are presented to account for the quantity and spatial distribution of Middle Preclassic shell and shell working materials at Pacbitun and in the Belize River valley.

Families, Funerals and Facebook: Reimag(in)ing and ‘Curating’ Toraja Kin in Trans-local Times

2015 ◽  
Vol 3 (2) ◽  
pp. 239-266 ◽  
Author(s):  
Kathleen M. Adams
Keyword(s):  
Social Media ◽  
Large Scale ◽  
Local Times ◽  
Funeral Rites ◽  
Familial Relationships ◽  
Familial Bonds ◽  
Non Local ◽  
In Trans ◽  
Anthropological Literature

AbstractThe Sa'dan Toraja of upland Sulawesi, Indonesia have long been celebrated in the anthropological literature for their elaborate procession-filled mortuary rituals, which draw vast networks of kith and kin to mourn, memorialise, and reaffirm familial bonds and obligations. Whether residing in the homeland or abroad, most Torajans underscore funeral rites as the most vital expression of Toraja familial and cultural identity. Although some estimates suggest that more Torajans now reside off-island and overseas than remain in the homeland, extended familial funerals in the homeland continue to have a centripetal physical, economic and emotional pull. While various scholars have documented the ways in which remittances from Toraja migrants or the presence of international tourists have transformed Toraja funerals in recent decades, this article focusses on the role of social media in navigating global familial relationships and rituals. Indonesia has the largest number of Facebook subscribers in the world, and this study offers the first exploration of the ways in which Facebook interweaves far-flung familial relationships. This study also examines house-society orientations in the Toraja highlands and addresses the use of Facebook by Torajans in the homeland to cultivate continued allegiances to ancestral houses (around which extended Toraja families are oriented). Finally, this article also examines a large-scale 2012 Toraja funeral in order to spotlight the contours of the Toraja family in the current era of neoliberalism and cyber-technologies. The article offers insights into the ways in which various Torajans navigate social media and non-local corporations to image, reimagine and negotiate familial identities for various audiences (local, national and transnational).

scholarly journals Mapping Urban Areas Using a Combination of Remote Sensing and Geolocation Data

2019 ◽  
Vol 11 (12) ◽  
pp. 1470 ◽  
Author(s):  
Nan Xia ◽  
Liang Cheng ◽  
ManChun Li
Keyword(s):  
Remote Sensing ◽  
Land Surface ◽  
Urban Areas ◽  
Large Scale ◽  
High Spatial Resolution ◽  
Human Life ◽  
Human Movement ◽  
Night Time ◽  
Urban Mapping ◽  
The City

Urban areas are essential to daily human life; however, the urbanization process also brings about problems, especially in China. Urban mapping at large scales relies heavily on remote sensing (RS) data, which cannot capture socioeconomic features well. Geolocation datasets contain patterns of human movement, which are closely related to the extent of urbanization. However, the integration of RS and geolocation data for urban mapping is performed mostly at the city level or finer scales due to the limitations of geolocation datasets. Tencent provides a large-scale location request density (LRD) dataset with a finer temporal resolution, and makes large-scale urban mapping possible. The objective of this study is to combine multi-source features from RS and geolocation datasets to extract information on urban areas at large scales, including night-time lights, vegetation cover, land surface temperature, population density, LRD, accessibility, and road networks. The random forest (RF) classifier is introduced to deal with these high-dimension features on a 0.01 degree grid. High spatial resolution land cover (LC) products and the normalized difference built-up index from Landsat are used to label all of the samples. The RF prediction results are evaluated using validation samples and compared with LC products for four typical cities. The results show that night-time lights and LRD features contributed the most to the urban prediction results. A total of 176,266 km2 of urban areas in China were extracted using the RF classifier, with an overall accuracy of 90.79% and a kappa coefficient of 0.790. Compared with existing LC products, our results are more consistent with the manually interpreted urban boundaries in the four selected cities. Our results reveal the potential of Tencent LRD data for the extraction of large-scale urban areas, and the reliability of the RF classifier based on a combination of RS and geolocation data.

scholarly journals Graph CNNs with Motif and Variable Temporal Block for Skeleton-Based Action Recognition

2019 ◽  
Vol 33 ◽  
pp. 8989-8996 ◽  
Author(s):  
Yu-Hui Wen ◽  
Lin Gao ◽  
Hongbo Fu ◽  
Fang-Lue Zhang ◽  
Shihong Xia
Keyword(s):  
Spatial Structure ◽  
Action Recognition ◽  
Large Scale ◽  
Human Skeleton ◽  
Semantic Roles ◽  
Temporal Domain ◽  
Non Local ◽  
Novel Model ◽  
Local Block ◽  
Skeleton Structure

Hierarchical structure and different semantic roles of joints in human skeleton convey important information for action recognition. Conventional graph convolution methods for modeling skeleton structure consider only physically connected neighbors of each joint, and the joints of the same type, thus failing to capture highorder information. In this work, we propose a novel model with motif-based graph convolution to encode hierarchical spatial structure, and a variable temporal dense block to exploit local temporal information over different ranges of human skeleton sequences. Moreover, we employ a non-local block to capture global dependencies of temporal domain in an attention mechanism. Our model achieves improvements over the stateof-the-art methods on two large-scale datasets.

scholarly journals Non-local dispersion and the reassessment of Richardson's t3-scaling law

2021 ◽  
Vol 932 ◽  
Author(s):  
G.E. Elsinga ◽  
T. Ishihara ◽  
J.C.R. Hunt
Keyword(s):  
Large Scale ◽  
Scaling Law ◽  
Taylor Dispersion ◽  
Small Time ◽  
Inertial Range ◽  
Small Scale ◽  
Mean Square ◽  
Dispersion Regime ◽  
Non Local ◽  
Scale Properties

The Richardson-scaling law states that the mean square separation of a fluid particle pair grows according to t3 within the inertial range and at intermediate times. The theories predicting this scaling regime assume that the pair separation is within the inertial range and that the dispersion is local, which means that only eddies at the scale of the separation contribute. These assumptions ignore the structural organization of the turbulent flow into large-scale shear layers, where the intense small-scale motions are bounded by the large-scale energetic motions. Therefore, the large scales contribute to the velocity difference across the small-scale structures. It is shown that, indeed, the pair dispersion inside these layers is highly non-local and approaches Taylor dispersion in a way that is fundamentally different from the Richardson-scaling law. Also, the layer's contribution to the overall mean square separation remains significant as the Reynolds number increases. This calls into question the validity of the theoretical assumptions. Moreover, a literature survey reveals that, so far, t3 scaling is not observed for initial separations within the inertial range. We propose that the intermediate pair dispersion regime is a transition region that connects the initial Batchelor- with the final Taylor-dispersion regime. Such a simple interpretation is shown to be consistent with observations and is able to explain why t3 scaling is found only for one specific initial separation outside the inertial range. Moreover, the model incorporates the observed non-local contribution to the dispersion, because it requires only small-time-scale properties and large-scale properties.

scholarly journals Non-local SAR Image Despeckling Based on Similar Pixels Selected

2012 ◽  
Vol 1 (2) ◽  
pp. 171-181
Author(s):  
Guang-ting Li ◽  
Ping-ping Huang ◽  
Wei-dong Yu
Keyword(s):  
Sar Image ◽  
Non Local ◽  
Image Despeckling ◽  
Local Sar
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