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[n° ou bulletin]
est un bulletin de Geomatica / Canadian institute of geomatics = Association canadienne des sciences géomatiques (Canada) (1993 -) ![]()
[n° ou bulletin]
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Dépouillements
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Aggregate keyword nearest neighbor queries on road networks / Pengfei Zhang in Geoinformatica, vol 22 n° 2 (April 2018)
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[article]
Titre : Aggregate keyword nearest neighbor queries on road networks Type de document : Article/Communication Auteurs : Pengfei Zhang, Auteur ; Huaizhong Lin, Auteur ; Yunjun Gao, Auteur ; Dongming Lu, Auteur Année de publication : 2018 Article en page(s) : pp 237 - 268 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes d'information géographique
[Termes IGN] langage naturel (informatique)
[Termes IGN] plus proche voisin, algorithme du
[Termes IGN] point d'intérêt
[Termes IGN] requête spatiale
[Termes IGN] réseau routier
[Termes IGN] système d'information géographiqueRésumé : (Auteur) Given a group Q of query points and a set P of points of interest (POIs), aggregate nearest neighbor (ANN) queries find a POI p from P that achieves the smallest aggregate distance. Specifically, the aggregate distance is defined over the set of distances between p and all query points in Q$\mathcal {Q}$. Existing studies on ANN query mainly consider the spatial proximity, whereas the textual similarity has received considerable attention recently. In this work, we utilize user-specified query keywords to capture textual similarity. We study the aggregate keyword nearest neighbor (AKNN) queries, finding the POI that has the smallest aggregate distance and covers all query keywords. Nevertheless, existing methods on ANN query are either inapplicable or inefficient when applied to the AKNN query. To answer our query efficiently, we first develop a dual-granularity (DG) indexing schema. It preserves abstracts of the road network by a tree structure, and preserves detailed network information by an extended adjacency list. Then, we propose a minimal first search (MFS) algorithm. It traverses the tree and explores the node with the minimal aggregate distance iteratively. This method suffers from false hits arising from keyword tests. Thus, we propose the collaborative filtering technique, which performs keywords test by multiple keyword bitmaps collectively rather than by only one. Extensive experiments on both real and synthetic datasets demonstrate the superiority of our algorithms and optimizing strategies. Numéro de notice : A2018-364 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10707-017-0315-0 Date de publication en ligne : 29/12/2017 En ligne : https://doi.org/10.1007/s10707-017-0315-0 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90726
in Geoinformatica > vol 22 n° 2 (April 2018) . - pp 237 - 268[article]A novel computational knowledge-base framework for visualization and quantification of geospatial metadata in spatial data infrastructures / Gangothri Rajaram in Geoinformatica, vol 22 n° 2 (April 2018)
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[article]
Titre : A novel computational knowledge-base framework for visualization and quantification of geospatial metadata in spatial data infrastructures Type de document : Article/Communication Auteurs : Gangothri Rajaram, Auteur ; Harish Chandra Karnatak, Auteur ; Swaminathan Venkatraman, Auteur ; et al., Auteur Année de publication : 2018 Article en page(s) : pp 269 - 305 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Infrastructure de données
[Termes IGN] cadre conceptuel
[Termes IGN] métadonnées
[Termes IGN] métadonnées géographiques
[Termes IGN] pondération
[Termes IGN] qualité des metadonnées
[Termes IGN] service webRésumé : (Auteur) Advances in Metadata research have been instrumental in predictions and `fitness-of-use evaluation' for the effective Decision-making process. For the past two decades, the model has been developed to provide visual assistance for assessing the quality information in metadata and quantifying the degree of metadata population. Still, there is a need to develop a framework that can be generic to adopt all the standards available for Geospatial Metadata. The computational analysis of metadata for specific applications remains uncharted for investigations and studies. This work proposes a computational framework for Geospatial Metadata by integrating TopicMaps and Hypergraphs (HXTM) based on the elements and their dependency relationships. A purpose-built dataset extracted from schemas of various standardisation organisations and existing knowledge in the discipline is utilised to model the framework and thereby evaluate ranking strategies. Hypergraph-Helly Property based Weight-Assignment Algorithm (HHWA) have been proposed for HXTM framework to calculate Stable weights for Metadata Elements. Recursive use of Helly-property ensures predominant elements, while Rank Order Centroid (ROC) method is used to compute standard weights. A real corpus using case studies from FGDC's Standard for Geospatial Metadata, INSPIRE Metadata Standards, and ISRO Metadata Content Standard (NSDI 2.0) is used to validate the proposed framework. The observations show that the Information Gain (Entropy) of the proposed model along with the algorithm proves to be computationally smart for quantification purposes and visualises the strength of Metadata Elements for all applications. A prototype tool, `MetDEVViz- MetaData Editor, Validator &Visualization' is designed to exploit the benefits of the proposed algorithm for the case studies that acts as a web service to provide a user interface for editing, validating and visualizing metadata elements. Numéro de notice : A2018-365 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10707-018-0317-6 Date de publication en ligne : 28/02/2018 En ligne : https://doi.org/10.1007/s10707-018-0317-6 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90730
in Geoinformatica > vol 22 n° 2 (April 2018) . - pp 269 - 305[article]The national geographic characteristics of online public opinion propagation in China based on WeChat network / Chuan Ai in Geoinformatica, vol 22 n° 2 (April 2018)
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[article]
Titre : The national geographic characteristics of online public opinion propagation in China based on WeChat network Type de document : Article/Communication Auteurs : Chuan Ai, Auteur ; Bin Chen, Auteur ; Lingnan He, Auteur ; et al., Auteur Année de publication : 2018 Article en page(s) : pp 311 - 334 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale
[Termes IGN] caractérisation
[Termes IGN] Chine
[Termes IGN] interaction spatiale
[Termes IGN] réseau social
[Termes IGN] villeRésumé : (Auteur) Offline networks have been the subject of intense academic scrutiny for many decades, but we still know little about the nationwide spatial interaction patterns and its application for public opinion management of online social networks. With the aim of uncovering the geographic interaction characteristics of online public opinion propagation, we analyze a large dataset obtained from WeChat, the most popular social media application in China, and construct the spatial interaction network G, which contains 359 city-nodes. It is found that the communities in the network and the administrative division corresponded well with each other, and cities with high betweenness and degree also develop well in the economy. Public opinion propagation depends on the state of online interaction. The findings indicate that public opinion should be managed separately by regions divided according to the community division, and different regions should adopt different management methods according to their economic, historical and political characteristics. In our work, the possibility and opportunity is presented to study the spatial interaction patterns of online public opinion propagation with the massive behavioral data and the methods of complex network. Numéro de notice : A2018-366 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10707-017-0311-4 En ligne : https://doi.org/10.1007/s10707-017-0311-4 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90731
in Geoinformatica > vol 22 n° 2 (April 2018) . - pp 311 - 334[article]Efficient task assignment in spatial crowdsourcing with worker and task privacy protection / An Liu in Geoinformatica, vol 22 n° 2 (April 2018)
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[article]
Titre : Efficient task assignment in spatial crowdsourcing with worker and task privacy protection Type de document : Article/Communication Auteurs : An Liu, Auteur ; Weiqi Wang, Auteur ; Shuo Shang, Auteur ; Qing Li, Auteur ; Xiangliang Zhang, Auteur Année de publication : 2018 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique
[Termes IGN] cryptage
[Termes IGN] données localisées des bénévoles
[Termes IGN] géolocalisation
[Termes IGN] production participative
[Termes IGN] protection de la vie privéeRésumé : (Auteur) Spatial crowdsourcing (SC) outsources tasks to a set of workers who are required to physically move to specified locations and accomplish tasks. Recently, it is emerging as a promising tool for emergency management, as it enables efficient and cost-effective collection of critical information in emergency such as earthquakes, when search and rescue survivors in potential ares are required. However in current SC systems, task locations and worker locations are all exposed in public without any privacy protection. SC systems if attacked thus have penitential risk of privacy leakage. In this paper, we propose a protocol for protecting the privacy for both workers and task requesters while maintaining the functionality of SC systems. The proposed protocol is built on partially homomorphic encryption schemes, and can efficiently realize complex operations required during task assignment over encrypted data through a well-designed computation strategy. We prove that the proposed protocol is privacy-preserving against semi-honest adversaries. Simulation on two real-world datasets shows that the proposed protocol is more effective than existing solutions and can achieve mutual privacy-preserving with acceptable computation and communication cost. Numéro de notice : A2018-367 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10707-017-0305-2 En ligne : https://doi.org/10.1007/s10707-017-0305-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90732
in Geoinformatica > vol 22 n° 2 (April 2018)[article]A spatio-temporal scenario model for emergency decision / Cheng Liu in Geoinformatica, vol 22 n° 2 (April 2018)
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[article]
Titre : A spatio-temporal scenario model for emergency decision Type de document : Article/Communication Auteurs : Cheng Liu, Auteur ; Jing Qian, Auteur ; Danhuai Guo, Auteur ; Yi Liu, Auteur Année de publication : 2018 Article en page(s) : pp 411 - 433 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique
[Termes IGN] cadre conceptuel
[Termes IGN] catastrophe naturelle
[Termes IGN] dommage matériel
[Termes IGN] données spatiotemporelles
[Termes IGN] modèle conceptuel de données
[Termes IGN] outil d'aide à la décision
[Termes IGN] relation topologique
[Termes IGN] représentation
[Termes IGN] secours d'urgenceRésumé : (Auteur) A structural and quantitative representation of disaster status contributes to efficient emergency decision-making, for this purpose, a representation model for disaster status is developed in this paper, called spatio-temporal scenario model (short for STSM model). Concept of the term `scenario' is discussed at first. Then, based on the concept, STSM model is proposed and introduced in detail. It contains two components: developing scenario connotation and developing spatio-temporal framework. Scenario connotation is to develop representation of disaster status of each object, consisting of object representation and damage representation. Spatio-temporal framework is to develop representation of evolution of disaster status, consisting of representation of spatial relation, temporal relation, natural environment and emergency response. Finally, an example is provided to show the effectiveness of STSM model. Advantages of the developed model lie in four aspects: flexibility in describing dynamic disaster status; universal representation of disaster status contributing to similarity assessment; helping in evaluating emergency severity with the quantitative representation of disaster status. Moreover, it helps decision-makers obtain a more comprehensive representation for disaster evolution in a certain time space. Numéro de notice : A2018-368 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10707-017-0313-2 Date de publication en ligne : 20/12/2017 En ligne : https://doi.org/10.1007/s10707-017-0313-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90733
in Geoinformatica > vol 22 n° 2 (April 2018) . - pp 411 - 433[article]