scholarly journals Roost sites of chimney swift ( Chaetura pelagica ) form large‐scale spatial networks

2021 ◽  
Author(s):  
Courtney E. le Roux ◽  
Joseph J. Nocera
Keyword(s):  
Large Scale ◽  
Spatial Networks ◽  
Chaetura Pelagica

scholarly journals Identification of Critical Nodes in Large-Scale Spatial Networks

2019 ◽  
Vol 6 (2) ◽  
pp. 842-851 ◽  
Author(s):  
Vishaal Krishnan ◽  
Sonia Martinez
Keyword(s):  
Large Scale ◽  
Spatial Networks ◽  
Critical Nodes

scholarly journals Clustering and Visualizing Functionally Similar Regions in Large-Scale Spatial Networks

2017 ◽  
Vol 25 (0) ◽  
pp. 398-406
Author(s):  
Takayasu Fushimi ◽  
Kazumi Saito ◽  
Tetsuo Ikeda ◽  
Kazuhiro Kazama
Keyword(s):  
Large Scale ◽  
Spatial Networks

scholarly journals Macro and micro scale modelling of multi-modal transportation spatial networks in the city-state of Doha, Qatar

2020 ◽  
Author(s):  
Mark David Major ◽  
◽  
Heba O. Tannous ◽  
Sarah Al-Thani ◽  
Mahnoor Hasan ◽  
...  
Keyword(s):  
Large Scale ◽  
Space Syntax ◽  
Transportation Systems ◽  
Spatial Networks ◽  
Micro Scale ◽  
Geographical Regions ◽  
The Usa ◽  
National Boundaries ◽  
City State ◽  
The City

Researchers and practitioners have been modeling the street networks of metropolitan and geographical regions using space syntax or configurational analysis since the late 1990s and early 2000s. Some models even extend to a national scale. A few examples include the island of Great Britain, within the national boundaries of England, over half of the Combined Statistical Area of Metropolitan Chicago and the entirety of Chatham County, Georgia and the City of Savannah in the USA, and the Chiang-rai Special Economic Zone in northern Thailand bordering Myanmar and Laos. Researchers at Qatar University constructed a space syntax model of Metropolitan Doha in 2018. It covered a land area of 650 km2 , encompassing over 24,000 streets, and approximately eighty-five percent (~85%) of the total population (~2.8 million) in Qatar. In a short time, this model led to a deeper understanding of spatial structure at the metropolitan and neighborhood level in Doha compared to other cities of the world, especially in the Gulf Cooperation Council region. The paper presents the initial results of expanding this model to the State of Qatar, which provides ideal conditions for this type of large-scale modeling using space syntax. It occupies the Qatari Peninsula on the Arabian Peninsula adjacent to the Arabian/Persian Gulf, offering natural boundaries on three sides. Qatar also shares only a single border with another country to the southwest, which Saudi Arabia closed due to the current diplomatic blockade. The expanded model includes all settlements and outlying regions such as Al Ruwais and Fuwayriţ in the far north, Al Khor and the Industrial City of Ras Laffan in the northeast, and Durkan and Zekreet in the west. Space syntax is serving as the analytical basis for research into the effect of the newly opened rail transportation systems on Doha's urban street network. Researchers are also utilizing space syntax to study micro-scale spatial networks for pedestrians in Souq Waqif, Souq Wakra, and other Doha neighborhoods. The paper gives a brief overview of this research's current state with an emphasis on urban studies.

scholarly journals Identification of critical node clusters for consensus in large-scale spatial networks

2017 ◽  
Vol 50 (1) ◽  
pp. 14156-14161 ◽  
Author(s):  
Vishaal Krishnan ◽  
Sonia Martínez
Keyword(s):  
Large Scale ◽  
Spatial Networks ◽  
Critical Node

An Efficient Approach for Tackling Large Real World Qualitative Spatial Networks

2016 ◽  
Vol 25 (02) ◽  
pp. 1550031 ◽  
Author(s):  
Michael Sioutis ◽  
Jean-François Condotta ◽  
Manolis Koubarakis
Keyword(s):  
Large Scale ◽  
State Of The Art ◽  
Preferential Attachment ◽  
Hash Table ◽  
The State ◽  
Spatial Networks ◽  
Scale Free ◽  
Web Of Data ◽  
Attachment Mechanism ◽  
Random Scale

We improve the state-of-the-art method for checking the consistency of large qualitative spatial networks that appear in the Web of Data by exploiting the scale-free-like structure observed in their constraint graphs. We propose an implementation scheme that triangulates the constraint graphs of the input networks and uses a hash table based adjacency list to efficiently represent and reason with them. We generate random scale-free-like qualitative spatial networks using the Barabási-Albert (BA) model with a preferential attachment mechanism. We test our approach on the already existing random datasets that have been extensively used in the literature for evaluating the performance of qualitative spatial reasoners, our own generated random scale-free-like spatial networks, and real spatial datasets that have been made available as Linked Data. The analysis and experimental evaluation of our method presents significant improvements over the state-of-the-art approach, and establishes our implementation as the only possible solution to date to reason with large scale-free-like qualitative spatial networks efficiently.

Some comments about observations and image processing of comet 29P/Schwassmann-Wachmann 1

1999 ◽  
Vol 173 ◽  
pp. 243-248
Author(s):  
D. Kubáček ◽  
A. Galád ◽  
A. Pravda
Keyword(s):  
Image Processing ◽  
Large Scale ◽  
Harvard College ◽  
Oak Ridge ◽  
Large Scale Structures ◽  
Short Period Comet ◽  
Short Period ◽  
Scale Structures ◽  
Harvard College Observatory ◽  
Period Comet

AbstractUnusual short-period comet 29P/Schwassmann-Wachmann 1 inspired many observers to explain its unpredictable outbursts. In this paper large scale structures and features from the inner part of the coma in time periods around outbursts are studied. CCD images were taken at Whipple Observatory, Mt. Hopkins, in 1989 and at Astronomical Observatory, Modra, from 1995 to 1998. Photographic plates of the comet were taken at Harvard College Observatory, Oak Ridge, from 1974 to 1982. The latter were digitized at first to apply the same techniques of image processing for optimizing the visibility of features in the coma during outbursts. Outbursts and coma structures show various shapes.

Evolution of Large-Scale Coronal Structures

1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Large Scale ◽  
Coronal Magnetic Field ◽  
Source Surface ◽  
Solar Cycles ◽  
Characteristic Relationship ◽  
The Magnetic Field ◽  
Coronal Structures

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.

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