Results 251 to 260 of about 8,060,684 (303)

Spatial index technology for multi-scale and large scale spatial data

2010 18th International Conference on Geoinformatics, 2010
Large scale three-dimensional spatial data of underground and aboveground entity has features of different shapes, uneven spatial distribution and complicated spatial relationships. At present, the single spatial index structure can not satisfy the large scale three-dimensional spatial data organization and management.
Yuanyuan Liu, Gang Liu 0003, Zhenwen He
openaire   +2 more sources

Spatial scaling of microbial biodiversity

Trends in Ecology & Evolution, 2006
A central goal in ecology is to understand the spatial scaling of biodiversity. Patterns in the spatial distribution of organisms provide important clues about the underlying mechanisms that structure ecological communities and are central to setting conservation priorities. Although microorganisms comprise much of Earth's biodiversity, little is known
Jessica, Green, Brendan J M, Bohannan
openaire   +2 more sources

Spatial Scale and Saccade Programming

Perception, 1997
The global effect in eye orienting occurs when saccades land at the ‘centre of gravity’ of a target stimulus configuration. Short-latency saccades are particularly prone to this effect whereas longer-latency saccades may show more influence of fine detail.
Findlay, JM, Gilchrist, ID
openaire   +3 more sources

Spatial scale shifts in amblyopia

Vision Research, 1994
We used a masking paradigm to uncover the properties of the mechanisms engaged by the amblyopic visual system for vernier acuity and line detection. Line vernier and line detection thresholds were measured in the presence of one-dimensional noise masks varying in orientation, spatial frequency content or contrast. Our results reveal that in both normal
D M, Levi, S J, Waugh, B L, Beard
openaire   +2 more sources

The spatial scales of species coexistence

Nature Ecology & Evolution, 2017
Understanding how species diversity is maintained is a foundational problem in ecology and an essential requirement for the discipline to be effective as an applied science. Ecologists' understanding of this problem has rapidly matured, but this has exposed profound uncertainty about the spatial scales required to maintain species diversity.
Simon P. Hart, Jacob Usinowicz, Jonathan M. Levine   +2 more
openaire   +5 more sources

Spatial, Non-Spatial and Hybrid Models for Scaling

Psychometrika, 1976
In this paper, hierarchical and non-hierarchical tree structures are proposed as models of similarity data. Trees are viewed as intermediate between multidimensional scaling and simple clustering. Procedures are discussed for fitting both types of trees to data. The concept of multiple tree structures shows great promise for analyzing more complex data.
openaire   +1 more source

Finite Scale of Spatial Representation in the Hippocampus

Science, 2008
To determine how spatial scale is represented in the pyramidal cell population of the hippocampus, we recorded neural activity at multiple longitudinal levels of this brain area while rats ran back and forth on an 18-meter-long linear track. CA3 cells had well-defined place fields at all levels.
Kjelstrup, K.B., Solstad, T., Brun, V.H., Hafting, T., Leutgeb, S., Witter, M.P., Moser, E.I., Moser, M.B.   +7 more
openaire   +4 more sources

Effects of Scale in Spatial Interaction Models

Journal of Geographical Systems, 2013
We study the effects of aggregation on four different cases of nonlinear spatial gravity models. We present some theoretical results on the relationship between the mean flows at an aggregated level and the mean flow at the disaggregated level.
Arbia, Giuseppe, Petrarca, Francesca
openaire   +6 more sources

Exploring spatial scale in geography

International Journal of Geographical Information Science, 2015
This book provides a systematic and comprehensive account of the many spatial analytic methods useful for understanding the implications of spatial scale for geographical data.
openaire   +1 more source