Representation Of Spatial Objects Research Articles

Spatial representations of objects used away and towards the body: The effect of near and far space.

An action with an object can be accomplished only if we encode the position of the object with respect to our body (i.e., egocentrically) and/or to another element in the environment (i.e., allocentrically). However, some actions with the objects are directed towards our body, such as brushing our teeth, and others away from the body, such as writing. Objects can be near the body, that is within arm reaching, or far from the body, that is outside arm reaching. The aim of this study was to verify if the direction of use of the objects influences the way we represent their position in both near and far space. Objects typically used towards (TB) or away from the body (AB) were presented in near or far space and participants had to judge whether an object was closer to them (i.e., egocentric judgement) or closer to another object (i.e., allocentric judgement). Results showed that egocentric judgements on TB objects were more accurate in near than in far space. Moreover, allocentric judgements on AB objects were less accurate than egocentric judgements in near space but not in far space. These results are discussed with respect to the different roles that visuo-motor and visuo-spatial mechanisms play in near space and far space, respectively.

An Aggregated Shape Similarity Index: A Case Study of Comparing the Footprints of OpenStreetMap and INSPIRE Buildings

The mutual identification of spatial objects is a fundamental issue when updating geographic data with other data sets. Representations of spatial objects in different sources may not have the same identifiers, which would unambiguously assign them to each other. Intersections of spatial objects can be used for this purpose, but this does not allow for the detection of possible changes and their quantification. The aim of this paper is to propose a simple, applicable procedure for calculating the shape similarity measure, which should be able to efficiently identify different representations of spatial objects in two data sources, even though they may be changed or generalised. The main result is the aggregated index of shape similarity and instructions for its calculation and implementation. The shape similarity index is based on the calculation of the set similarity, the distance of the boundaries, and the differences in the area, perimeter, and number of the vertices of areal spatial objects. In the case study, the footprints of the building complexes in Dúbravka (part of the city of Bratislava, the capital of Slovakia) are compared using data from OpenStreetMap and INSPIRE (Infrastructure for Spatial Information in Europe) Buildings. A contribution to the quality check of the OpenStreetMap data is then a secondary result. The proposed method can be effectively used in the semi-automatic integration of heterogeneous data sources, updating the data source with other spatial data, or in their quality control.

Representation of spatial objects by shift-equivariant similarity-preserving hypervectors

Representation of spatial objects by shift-equivariant similarity-preserving hypervectors

Shrinking of spatial hand representation but not of objects across the lifespan

Perception and action are based on cerebral spatial representations of the body and the external world. However, spatial representations differ from the physical characteristics of body and external space (e.g., objects). It remains unclear whether these discrepancies are related to functional requirements of action and are shared between different spatial representations, indicating common brain processes. We hypothesized that distortions of spatial hand representation would be affected by age, sensorimotor practice and external space representation. We assessed hand representations using tactile and verbal localization tasks and quantified object representation in three age groups (20–79 yrs, total n = 60). Our results show significant shrinking of spatial hand representations (hand width) with age, unrelated to sensorimotor functions. No such shrinking occurred in spatial object representations despite some common characteristics with hand representations. Therefore, spatial properties of body representation partially share characteristics of object representation but also evolve independently across the lifespan.

Representing spatial objects in data warehouses: a logical solution

Spatial data warehouse logical design involves mainly extending the techniques used in relational logical data warehouse design for the support of spatial objects, i.e., geometric objects in space. Spatial objects can have different geometric granularities and can be found at different hierarchical levels of a dimension in the logical model of a data warehouse. This paper addresses data warehouse logical design considerations for a consolidated representation of spatial and non-spatial data. The novelty of the model presented in this paper is the representation of spatial objects in a logical and semantically effective manner. With this approach, complex spatial objects can be modelled in a generic and user-friendly format. The model also includes ROLAP operations supporting the navigation across different dimensions' levels and the execution of queries. The functionality of the model is also provided by a number of example queries.

Fuzzy Similarity and Fuzzy Inclusion Measures in Polyline Matching: A Case Study of Potential Streams Identification for Archaeological Modelling in GIS

Abstract When combining spatial data from various sources, it is often important to determine similarity or identity of spatial objects. Besides the differences in geometry, representations of spatial objects are inevitably more or less uncertain. Fuzzy set theory can be used to address both modelling of the spatial objects uncertainty and determining the identity, similarity, and inclusion of two sets as fuzzy identity, fuzzy similarity, and fuzzy inclusion. In this paper, we propose to use fuzzy measures to determine the similarity or identity of two uncertain spatial object representations in geographic information systems. Labelling the spatial objects by the degree of their similarity or inclusion measure makes the process of their identification more efficient. It reduces the need for a manual control. This leads to a more simple process of spatial datasets update from external data sources. We use this approach to get an accurate and correct representation of historical streams, which is derived from contemporary digital elevation model, i.e. we identify the segments that are similar to the streams depicted on historical maps.

Integrating Multiple Geometric Representations within Spatial Data Warehouse Structures for Enhanced Collaborative Decision-Making Processes

Abstract Spatial Decision Support Systems (SDSSs) have been successfully used to help decision-makers in several application domains. When it comes to enabling the collaboration of all these decision-makers with one common SDSS, a Spatial Data Warehouse (SDW) is commonly considered as an efficient option, particularly when large volumes of data are available. This SDW has to accommodate all the decision-makers, anywhere and anytime, with the right geo-referenced data at the right time while respecting the characteristics of their displaying devices. Since this aim is still unachievable due to the complexity of spatial processing, we propose to shorten the processing time by leveraging the use of multiple representations of spatial objects in SDWs. For the sake of illustration and unlike any existing solution, we focus in this paper on the integration of multiple geometric representations in SDW and we propose new definitions to reflect the impact of this integration. We also highlight the importance of this integration via the implementation of a collaborative scenario related to the management of industrial accidents in Algeria.

An inconsistency measure of spatial data sets with respect to topological constraints

An inconsistency measure can be used to compare the quality of different data sets and to quantify the cost of data cleaning. In traditional relational databases, inconsistency is defined in terms of constraints that use comparison operators between attributes. Inconsistency measures for traditional databases cannot be applied to spatial data sets because spatial objects are complex and the constraints are typically defined using spatial relations. This paper proposes an inconsistency measure to evaluate how dirty a spatial data set is with respect to a set of integrity constraints that define the topological relations that should hold between objects in the data set. The paper starts by reviewing different approaches to quantify the degree of inconsistency and showing that they are not suitable for the problem. Then, the inconsistency measure of a data set is defined in terms of the degree in which each spatial object in the data set violates topological constraints, and the possible representations of spatial objects are points, curves, and surfaces. Finally, an experimental evaluation demonstrates the applicability of the proposed inconsistency measure and compares it with previously existing approaches.

Beyond Retinotopic Mapping: The Spatial Representation of Objects in the Human Lateral Occipital Complex

The spatial representation in the human ventral object-related areas (i.e., the lateral occipital complex [LOC]) is currently unknown. It seems plausible, however, that it would diverge from the strict retinotopic mapping (characteristic of V1) to a more invariant coordinate frame, thereby allowing for reliable object recognition in the face of eye, head, or body movement. To study this, we compared the fMRI activation in LOC when object displacement was limited to either the retina or the screen by manipulating eye position and object locations. We found clear adaptation in LOC when the object's screen position was fixed, regardless of the object's retinal position. Furthermore, we found significantly greater activation in LOC in the hemisphere contralateral to the object's screen position, although the visual task was constructed in a way that the objects were present equally often on each of the 2 retinal hemifields. Together, these results indicate that a sizeable fraction of the neurons in LOC may have head-based receptive fields. Such an extraretinal representation may be useful for maintenance of object coherence across saccadic eye movements, which are an integral part of natural vision.

A design and application of a multi-agent system for simulation of multi-actor spatial planning

Multi-agent Systems (MAS) offer a conceptual approach to include multi-actor decision making into models of land use change. The main goal is to explore the use of MAS to simulate spatial scenarios based on modelling multi-actor decision-making within a spatial planning process. We demonstrate MAS that consists of agents representing organizations and interest groups involved in an urban allocation problem during a land use planning process. The multi-actor based decision-making is modelled by generating beliefs and preferences of actors about the location of and relation between spatial objects. This allows each agent to confront these beliefs and preferences with it's own desires and with that of other agents. The MAS loosely resembles belief, desire and intentions architecture. Based on a case study for a hypothetical land use planning situation in a study area in the Netherlands we discuss the potential and limitations of the MAS to build models that enable spatial planners to include the ‘actor factor’ in their analysis and design of spatial scenarios. In addition, our experiments revealed the need for further research on the representation of spatial objects and reasoning, learning and communication about allocation problems using MAS.

Point representation of spatial objects and query window extension: a new technique for spatial access methods

The use of Spatial Access Methods (SAMs) in spatial database systems, such as Geographical Information Systems, is necessary to achieve efficient retrieval of data items according to their spatial properties. Existing SAMs organizing minimum bounding rectangle (MBR) approximations of spatial objects can be classified into four groups. Each group is characterized by the special technique adopted for managing MBRs: (a) Ordering, (b) Transformation, (c) Clipping, and (d) Overlapping. This paper introduces a new technique. The basic idea of this technique is to represent all spatial objects by their MBRs and further reduce them into points of the same dimensionality, so that any multidimensional Point Access Method (PAM) may be used to support access. Essential for the functionality of the new method is the query window extension. The results of both analytical and experimental work show that SAMs using the new technique clearly outperform popular SAMs, such as the R- and R*-trees for data sets consisting of equal-sized MBRs. As for data sets of varying MBR sizes a competitive performance can be obtained.

Using Neoclassical Consumer-Choice Theory to Produce a Market Map From Purchase Data

This article presents a new model for estimating the spatial representation of objects and preference vectors from actual choice behavior of individuals or households. It is based on neoclassical economic theory of consumer choice. The model integrates both decisions of which good(s) to buy and the quantity of purchase. Overall preference is decomposed into price effects and intrinsic preference for the good. A maximum likelihood method for estimating the model parameters is described and illustrated using choice data of ketchup brands collected by the use of electronic supermarket scanners.

Spatial representation of objects in the young blind child

Four experiments investigated the young blind child's ability to discover, construct and transform representation of objects, in particular those that preserve the spatial relationships among object parts. Experiment 1 showed that three 18–36-month-old blind children systematically explored novel objects using distinctive haptic manipulations linked to novel shape versus texture. Experiments 2, 3 and 4 pursued a single blind child's ability to represent and transform the spatial configurations of objects. By 2 1 12 years, this child was able to rapidly recognize and identify familiar geometric figures following brief exploration (Experiment 2). By 3 years, she was able to recognize novel objects under 180° rotations when their configurations differed from distractors only in the spatial relationships holding among object parts (Experiment 3). At this age, she was also able to infer the locations corresponding to spatial parts of novel objects (the top, bottom, front, back and side) when the objects were upright or rotated, defined only by the location of a single “anchor” term that established their orientation (Experiment 4). In all cases, the blind child's performance was quite similar to that of sighted controls. The results indicate that visual experience is not necessary for the early natural emergence of the capacity to represent and transform spatial descriptions of objects.