scholarly journals A qualitative representation of evolving spatial entities in two-dimensional topological spaces

1998 ◽  
pp. 150-164
Keyword(s):  
Topological Spaces ◽  
Two Dimensional ◽  
Qualitative Representation ◽  
Spatial Entities

Modeling Spatial Evolution

2018 ◽  
pp. 235-259 ◽  
Author(s):  
G. Jayanthi ◽  
V. Uma
Keyword(s):  
Temporal Relations ◽  
Spatial Evolution ◽  
Two Dimensional ◽  
Formal Representation ◽  
Effect Analysis ◽  
Spatial Features ◽  
Spatio Temporal ◽  
Point Line ◽  
Spatial Entities ◽  
Interval Logic

Geographic features in the real world are represented by spatial entities such as point, line, and area in two-dimensional surfaces. These features tend to evolve in time, thereby characterizing change in their physical identity, evolution into new species, thus describing geomorphological change of geographic features. These phenomena can be formalized using spatio-temporal relations. Formal representation of changing geographic (spatial) features is the interest of this chapter. Formal methods for representing the event and process that causes geomorphological change are presented. The formalization of geographic entities that are temporally and spatially related in a two-dimensional plane using the interval logic and spatial logic would facilitate the understanding of how modeling of space-time using spatio-temporal relations represents spatial evolution over time. Representation of temporal dynamism can be accomplished using various models. Modeling using spatio-temporal graph is more apt as it contributes to the cause-effect analysis.

THE QUALITATIVE TREATMENT OF SPATIAL DATA

2007 ◽  
Vol 16 (04) ◽  
pp. 661-682 ◽  
Author(s):  
KAZUKO TAKAHASHI ◽  
TAKAO SUMITOMO
Keyword(s):  
Data Structure ◽  
Spatial Data ◽  
Spatial Reasoning ◽  
Symbolic Representation ◽  
Two Dimensional ◽  
Efficient Treatment ◽  
Dimensional Plane ◽  
Topological Reasoning ◽  
Qualitative Representation ◽  
New Framework

This paper aims at an efficient treatment of spatial data using qualitative representation. We propose a new framework called PLCA, which provides a symbolic representation for the figure in a two-dimensional plane, focusing on the connections between regions. It is based on four simple objects: points(P), lines(L), circuits(C) and areas(A). The entire figure is represented as a combination of these objects. Pairs of areas, circuits or lines never cross. The simple, clear data structure based on objects makes the system feasible and easy to implement. A PLCA expression can be subject to topological reasoning such as judging the connection patterns of areas. We define the operations of area integration and area division on a PLCA expression. These operations preserve the consistency of the expression, and correspond to real actions on the figures. We can add attributes to each object, such as the properties that hold on an area or that an object represents, and make an attributed PLCA. The operations of area integration/division on an attributed PLCA correspond to the alteration of the classification level of objects, and semantic spatial reasoning can be performed on an attributed PLCA.

On Embedding a Qualitative Representation in a Two-Dimensional Plane

2008 ◽  
Vol 8 (1-2) ◽  
pp. 4-26 ◽  
Author(s):  
Kazuko Takahashi ◽  
Takao Sumitomo ◽  
Izumi Takeuti
Keyword(s):  
Two Dimensional ◽  
Dimensional Plane ◽  
Qualitative Representation

Sedimentation in long sea outfalls

1995 ◽  
Vol 32 (2) ◽  
pp. 123-132
Author(s):  
K. H. M. Ali ◽  
R. Burrows ◽  
A. E. Wose
Keyword(s):  
Finite Difference ◽  
Experimental Investigations ◽  
Two Dimensional ◽  
Bed Morphology ◽  
Qualitative Representation ◽  
Sea Outfalls ◽  
Finite Difference Approach

This paper presents results of analytical and experimental investigations of sediment motion and bed morphology in circular outfalls. Behaviour of prototype and model sediments were studied in detail. A two-dimensional finite difference approach has been shown to provide qualitative representation of the experimental observations.

Spectrophotometric measurements of objective-prism spectra

1966 ◽  
Vol 24 ◽  
pp. 118-119
Author(s):  
Th. Schmidt-Kaler
Keyword(s):  
Progress Report ◽  
Two Dimensional ◽  
Objective Prism ◽  
Made In

I should like to give you a very condensed progress report on some spectrophotometric measurements of objective-prism spectra made in collaboration with H. Leicher at Bonn. The procedure used is almost completely automatic. The measurements are made with the help of a semi-automatic fully digitized registering microphotometer constructed by Hög-Hamburg. The reductions are carried out with the aid of a number of interconnected programmes written for the computer IBM 7090, beginning with the output of the photometer in the form of punched cards and ending with the printing-out of the final two-dimensional classifications.

Introductory paper

1966 ◽  
Vol 24 ◽  
pp. 3-5
Author(s):  
W. W. Morgan
Keyword(s):  
Line Intensity ◽  
Classification Scheme ◽  
Two Dimensional ◽  
Spectral Classification ◽  
Dimensional Array ◽  
Rr Lyrae ◽  
Metallic Line ◽  
Introductory Paper ◽  
Parameter Varying ◽  
Definition Of

1. The definition of “normal” stars in spectral classification changes with time; at the time of the publication of theYerkes Spectral Atlasthe term “normal” was applied to stars whose spectra could be fitted smoothly into a two-dimensional array. Thus, at that time, weak-lined spectra (RR Lyrae and HD 140283) would have been considered peculiar. At the present time we would tend to classify such spectra as “normal”—in a more complicated classification scheme which would have a parameter varying with metallic-line intensity within a specific spectral subdivision.

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