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The index array approach and the dual tiled similarity algorithm for UAS hyper-spatial image processing / Lihong Su in Geoinformatica, vol 20 n° 4 (October - December 2016)  

Public [article]  inGeoinformatica > vol 20 n° 4 (October - December 2016) . - pp 859 - 878 Titre : The index array approach and the dual tiled similarity algorithm for UAS hyper-spatial image processing Type de document : Article/Communication Auteurs : Lihong Su, Auteur ; Y. Huang, Auteur ; James Gibeaut, Auteur ; Longzhuang Li, Auteur Année de publication : 2016 Article en page(s) : pp 859 - 878 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique [Termes IGN] distorsion d'image [Termes IGN] géoréférencement [Termes IGN] processeur graphique Résumé : (Auteur) Unmanned aerial systems (UAS) have been used as a robust tool for agricultural and environmental applications in recent years. Remote sensing systems based on UAS typically acquire massive hyper-spatial images in its short turnaround. This paper takes advantage of graphics processing unit (GPU) massive parallel computation in order to process the huge data timely and efficiently. More specifically, this paper presents an index array approach for lens distortion correction and geo-referencing. They are the two essential components in UAS hyper-spatial image processing. The index array approach is also capable of parallelizing image file I/O and the orthoimage generation. In addition, this paper presents the dual tiled similarity algorithm for the image co-registration. The index array approach and the dual tiled similarity algorithm were evaluated using two UAS remote sensing datasets of South Padre island shorelines. The results show that this index array approach was able to speed up at least 10 times the lens distortion correction and the geo-referencing relative to the central processing unit (CPU) computation. This dual tiled algorithm could provide 12 times speedup compared with the CPU similarity computation. Numéro de notice : A2016-817 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1007/s10707-016-0253-2 En ligne : http://dx.doi.org/10.1007/s10707-016-0253-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=82621 [article]

Efficient evaluation of continuous spatio-temporal queries on moving objects whith uncertain velocity / Y. Huang in Geoinformatica, vol 14 n° 2 (April 2010)  

Public [article]  inGeoinformatica > vol 14 n° 2 (April 2010) . - pp 163 - 200 Titre : Efficient evaluation of continuous spatio-temporal queries on moving objects whith uncertain velocity Type de document : Article/Communication Auteurs : Y. Huang, Auteur ; C. Lee, Auteur Année de publication : 2010 Article en page(s) : pp 163 - 200 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Bases de données localisées [Termes IGN] classification barycentrique [Termes IGN] distance euclidienne [Termes IGN] objet mobile [Termes IGN] requête continue [Termes IGN] requête spatiotemporelle [Termes IGN] vitesse Résumé : (Auteur) Continuous Range (CR) query and Continuous K-Nearest Neighbor (CKNN) query are two important types of spatio-temporal queries. Given a time interval [ts , te ] and a moving query object q, a CR query is to find the moving objects whose Euclidean distances to q are within a user-given distance at each time instant within [ts , te ]. A CKNN query is to retrieve the K-Nearest Neighbors (KNNs) of this query object q at each time instant within [ts , te ]. In this paper, we investigate how to process these spatio-temporal queries efficiently under the situation that the velocity of each object is not fixed. This uncertainty on the velocity of object inevitably results in high complexity in processing spatio-temporal queries. We will discuss the complications incurred by this uncertainty and propose two algorithms, namely the Possibility-based possible within objects searching algorithm and the Possibility-based possible KNN searching algorithm, for the CR query and the CKNN query, respectively. A Possibility-based model is designed accordingly to quantify the possibility of each object being the result of a CR query or a CKNN query. Comprehensive experiments are performed to demonstrate the effectiveness and the efficiency of the proposed approaches. Copyright Springer Numéro de notice : A2010-064 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : 10.1007/s10707-009-0081-8 Date de publication en ligne : 23/04/2009 En ligne : https://doi.org/10.1007/s10707-009-0081-8 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30260 [article]

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057-2010021	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Cloaking locations for anonymous location based services: a hybrid approach / C. Zhang in Geoinformatica, vol 13 n° 2 (June 2009)  

Public [article]  inGeoinformatica > vol 13 n° 2 (June 2009) . - pp 159 - 182 Titre : Cloaking locations for anonymous location based services: a hybrid approach Type de document : Article/Communication Auteurs : C. Zhang, Auteur ; Y. Huang, Auteur Année de publication : 2009 Article en page(s) : pp 159 - 182 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement [Termes IGN] service fondé sur la position [Termes IGN] téléphonie mobile [Termes IGN] utilisateur nomade Résumé : (Auteur) An important privacy issue in Location Based Services is to hide a user’s identity while still provide quality location based services. Previous work has addressed the problem of locational $\mathcal{K}$-anonymity either based on centralized or decentralized schemes. However, a centralized scheme relies on an anonymizing server (AS) for location cloaking, which may become the performance bottleneck when there are large number of clients. More importantly, holding information in a centralized place is more vulnerable to malicious attacks. A decentralized scheme depends on peer communication to cloak locations and is more scalable. However, it may pose too much computation and communication overhead to the clients. The service fulfillment rate may also be unsatisfied especially when there are not enough peers nearby. This paper proposes a new hybrid framework called HiSC that balances the load between the AS and mobile clients. HiSC partitions the space into base cells and a mobile client claims a surrounding area consisting of base cells. The number of mobile clients in the surrounding cells is kept and updated at both client and AS sides. A mobile client can either request cloaking service from the centralized AS or use a peer-to-peer approach for spatial cloaking based on personalized privacy, response time, and service quality requirements. HiSC can elegantly distribute the work load between the AS and the mobile clients by tuning one system parameter base cell size and two client parameters - surrounding cell size and tolerance count. By integrating salient features of two schemes, HiSC successfully preserves query anonymity and provides more scalable and consistent service. Both the AS and the clients can enjoy much less work load. Additionally, we propose a simple yet effective random range shifting algorithm to prevent possible privacy leakage that would exist in the original P2P approach. Our experiments show that HiSC can elegantly balance the work load based on privacy requirements and client distribution. HiSC provides close to optimal service quality. Meanwhile, it reduces the response time by more than an order of magnitude from both the P2P scheme and the centralized scheme when anonymity level(value of $\mathcal{K}$) or number of clients is large. It also reduces the update message cost of the AS by nearly 6 times and the peer searching message cost of the clients by more than an order of magnitude. Copyright Springer Numéro de notice : A2009-074 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10707-008-0047-2 En ligne : https://doi.org/10.1007/s10707-008-0047-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29704 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
057-09021	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Continuous K-nearest neighbor query for moving objects with uncertain velocity / Y. Huang in Geoinformatica, vol 13 n° 1 (March 2009)  

Public [article]  inGeoinformatica > vol 13 n° 1 (March 2009) . - pp 1 - 25 Titre : Continuous K-nearest neighbor query for moving objects with uncertain velocity Type de document : Article/Communication Auteurs : Y. Huang, Auteur ; C.C. Chen, Auteur ; C. Lee, Auteur Année de publication : 2009 Article en page(s) : pp 1 - 25 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Bases de données localisées [Termes IGN] base de données spatiotemporelles [Termes IGN] classification barycentrique [Termes IGN] objet mobile [Termes IGN] requête spatiale [Termes IGN] requête spatiotemporelle [Termes IGN] vitesse Résumé : (Auteur) One of the most important queries in spatio-temporal databases that aim at managing moving objects efficiently is the continuous K-nearest neighbor (CKNN) query. A CKNN query is to retrieve the K-nearest neighbors (KNNs) of a moving user at each time instant within a user-given time interval [t s , t e ]. In this paper, we investigate how to process a CKNN query efficiently. Different from the previous related works, our work relieves the past assumption, that an object moves with a fixed velocity, by allowing that the velocity of the object can vary within a known range. Due to the introduction of this uncertainty on the velocity of each object, processing a CKNN query becomes much more complicated. We will discuss the complications incurred by this uncertainty and propose a cost-effective P2 KNN algorithm to find the objects that could be the KNNs at each time instant within the given query time interval. Besides, a probability-based model is designed to quantify the possibility of each object being one of the KNNs. Comprehensive experiments demonstrate the efficiency and the effectiveness of the proposed approach. Copyright Springer Numéro de notice : A2009-003 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : 10.1007/s10707-007-0041-0 En ligne : https://doi.org/10.1007/s10707-007-0041-0 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29633 [article]

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057-09011	RAB	Revue	Centre de documentation	En réserve L003	Disponible

A digital photogrammetry system for industrial monitoring / Y. Huang (1997)

Public Titre : A digital photogrammetry system for industrial monitoring Type de document : Monographie Auteurs : Y. Huang, Auteur Editeur : Kensington [Australie] : University of New South Wales Année de publication : 1997 Collection : Reports from School of Geomatic Engineering num. S-47 Importance : 150 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-0-85839-072-0 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique [Termes IGN] chambre métrique [Termes IGN] détection d'objet [Termes IGN] métrologie dimensionelle [Termes IGN] orientation du capteur [Termes IGN] photogrammétrie numérique [Termes IGN] reconstruction 3D [Termes IGN] station de travail de photogrammétrie numérique Index. décimale : 33.30 Photogrammétrie numérique Résumé : (Auteur) The purpose of this research is to study methods used in digital photogrammetry and machine vision, and develop them into a measuring system for industrial monitoring. The digital photgrammetry system includes steps of camera orientation, feature extraction, 3D object construction and the application of the recognition of regular objects. Numéro de notice : 67483 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Monographie Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=61784

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67483-01	33.30	Livre	Centre de documentation	Photogrammétrie - Lasergrammétrie	Disponible