Search results for "Spatial"

Spatial information transmission using orthogonal mutual coherence coding.

2005

We use the coherence of a light beam to encode spatial information. We apply this principle to obtain spatial superresolution in a limited aperture system. The method is based on shaping the mutual intensity function of the illumination beam in a set of orthogonal distributions, each one carrying the information for a different frequency bandpass or spatial region of the input object. The coherence coding is analogous to time multiplexing but with multiplexing time slots that are given by the coherence time of the illumination beam. Most images are static during times much longer than this coherence time, and thus the increase of resolution in our system is obtained without any noticeable c…

Structural problems for the renewal of planning styles: the spanish case1

2005

This article first presents a historical review of Spain's involvement in the European Spatial Development Perspective (ESDP) preparation process to determine whether ESDP guidelines are different from, contrary to or in harmony with the interests of Spanish proposals. Particular attention is paid to the priority lines and territorial objectives of the Spanish delegation and its emphasis in substantive issues related to cohesion, and linking spatial planning with European Union (EU) funding. If, as the network paradigm maintains, spatial development is not possible without new methods of governance, our work has to focus on two related questions. The first question regards the evolution and…

Running time to recognize nonregular languages by 2-way probabilistic automata

1991

R. Freivalds proved that the language {0m1m} can be recognized by 2-way probabilistic finite automata (2pfa) with arbitrarily high probability 1-ɛ. A.G.Greenberg and A.Weiss proved that no 2pfa can recognize this language in expected time \(T(n) = c^\circ{(n)}\). For arbitrary languages C.Dwork and L.Stockmeyer showed somewhat less: if a language L is recognized by a 2pfa in expected time \(T(n) = c^{n^\circ{(1)} }\), then L is regular. First, we improve this theorem replacing the expected time by the time with probability 1-ɛ. On the other hand, time bound by C.Dwork and L.Stockmeyer cannot be improved: for arbitrary k≥2 we exhibit a specific nonregular language that can be recognized by 2…

Communities, community action and planning

2014

Moment equations in a Lotka-Volterra extended system with time correlated noise

2007

A spatially extended Lotka-Volterra system of two competing species in the presence of two correlated noise sources is analyzed: (i) an external multiplicative time correlated noise, which mimics the interaction between the system and the environment; (ii) a dichotomous stochastic process, whose jump rate is a periodic function, which represents the interaction parameter between the species. The moment equations for the species densities are derived in Gaussian approximation, using a mean field approach. Within this formalism we study the effect of the external time correlated noise on the ecosystem dynamics. We find that the time behavior of the $1^{st}$ order moments are independent on th…

Modeling Spatial Data Pooled over Time: Schematic Representation and Monte Carlo Evidences

2015

The spatial autocorrelation issue is now well established, and it is almost impossible to deal with spatial data without considering this reality. In addition, recent developments have been devoted to developing methods that deal with spatial autocorrelation in panel data. However, little effort has been devoted to dealing with spatial data (cross-section) pooled over time. This paper endeavours to bridge the gap between the theoretical modeling development and the application based on spatial data pooled over time. The paper presents a schematic representation of how spatial links can be expressed, depending on the nature of the variable, when combining the spatial multidirectional relatio…

The spatial pattern of a forest ecosystem

1998

Abstract Statistical analysis of stands of trees as a whole need suitable methods of spatial statistics. Obviously, trees within a stand affect development and survival of their neighbours. They interact and therefore have to be considered as a system of dependent random variates from an unknown stochastic process. One such statistical model which considers the spatial dependence among trees in a forest and their characteristics is a marked point process. The `points', called events in spatial statistics, are the tree positions and the `marks' are tree characteristics such as crown lengths or tree species. A minimal prerequisite for any serious attempt to model an observed pattern is to tes…

Shift-and-scale-invariant pattern recognition using an elliptic coordinate-transformed phase-only filter

1992

A shift-and-scale-invariant elliptic coordinate-transformed phase-only filter in proposed. The filter is built in three steps: the complex conjugate of a basic-size target spectrum is calculated, its phase-only part is taken, and then the elliptic coordinate transformation is made. In the extreme case the scale ratio of recognizable objects equals 1:1.5, permitting good recognition of object sizes S within the range 0.83/= S/= 1.25. Discrimination abilities and relative Horner efficiencies of a few versions of the filter are calculated.

On the determination of coherent solar climates over a tropical island with a complex topography

2020

Abstract Many tropical islands aim at developing a greener self-sufficient energy production systems based on renewable energy, notably solar-generated electricity. This work explores the mean diurnal and annual solar cycles over La Reunion island (southwest Indian Ocean: 21°S, 55.5°E), and their spatial behavior, using the Solar surfAce RAdiation Heliosat – East (SARAH-E) satellite-derived data at high spatial ( 0.05 ° × 0.05 ° ) and time (hourly) resolutions over period 1999–2016. Comparisons of the SARAH-E data with ground-based measurements over the period 2011–2015 show differences of ~ 15 % for diurnal-seasonal variations. The solar resource over the island displays strong spatial var…

Attention Switching and Multimedia Learning: The Impact of Executive Resources on the Integrative Comprehension of Texts and Pictures

2014

The ability to flexibly allocate attention to goal-relevant information is pivotal for the completion of high-level cognitive processes. For instance, in comprehending illustrated texts, the reader permanently has to switch the attentional focus between the text and the corresponding picture in order to extract relevant information from both sources. Thus, the hypothesis was tested that individuals with a lower switching capacity exhibit a decreased performance in tasks that require the flexible switch of attention between two external representations. Participants read an illustrated text and answered questions that either required the extraction of information from the text alone or from …