Centre de documentation
scientifique

Optimization of mobile radioactivity monitoring networks / Gerard B.M. Heuvelink in International journal of geographical information science IJGIS, vol 24 n°3-4 (march 2010)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 24 n°3-4 (march 2010) . - pp 365 - 382 Titre : Optimization of mobile radioactivity monitoring networks Type de document : Article/Communication Auteurs : Gerard B.M. Heuvelink, Auteur ; Zhiheng Jiang , Auteur ; S. De Bruin, Auteur ; C. Twenhöfel, Auteur Année de publication : 2010 Article en page(s) : pp 365 - 382 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale [Termes IGN] accident nucléaire [Termes IGN] algorithme du recuit simulé [Termes IGN] allocation [Termes IGN] appareil portable [Termes IGN] contamination [Termes IGN] distribution spatiale [Termes IGN] géostatistique [Termes IGN] lever mobile [Termes IGN] Pays-Bas [Termes IGN] risque technologique Résumé : (Auteur) In case of a nuclear accident, decision makers rely on high-resolution and accurate information about the spatial distribution of radioactive contamination surrounding the accident site. However, the static nuclear monitoring networks of many European countries are generally too coarse to provide the desired level of spatial accuracy. In the Netherlands, authorities are considering a strategy in which measurement density is increased during an emergency using complementary mobile measuring devices. This raises the question, where should these mobile devices be placed? This article proposes a geostatistical methodology to optimize the allocation of mobile measurement devices, such that the expected weighted sum of false-positive and false-negative areas (i.e. false classification into safe and unsafe zones) is minimized. Radioactivity concentration is modelled as the sum of a deterministic trend and a zero-mean spatially correlated stochastic residual. The trend is defined as the outcome of a physical atmospheric dispersion model, NPK-PUFF. The residual is characterized by a semivariogram of differences between the outputs of various NPK-PUFF model runs, designed to reflect the effect of uncertainty in NPK-PUFF meteorological inputs (e.g. wind speed, wind direction). Spatial simulated annealing is used to obtain the optimal monitoring design, in which accessibility of sampling sites (e.g. distance to roads) is also considered. Although the methodology is computationally demanding, results are promising and the computational load may be considerably reduced to compute optimal mobile monitoring designs in nearly real time. Copyright Taylor & Francis Numéro de notice : A2010-142 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/13658810802646687 En ligne : http://dx.doi.org/10.1080/13658810802646687 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30337 [article]

Exemplaires(2)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
079-2010022	RAB	Revue	Centre de documentation	En réserve L003	Disponible
079-2010021	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Using quadtree segmentation to support error modelling in categorical raster data / S. De Bruin in International journal of geographical information science IJGIS, vol 18 n° 2 (march 2004)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 18 n° 2 (march 2004) . - pp 151 - 168 Titre : Using quadtree segmentation to support error modelling in categorical raster data Type de document : Article/Communication Auteurs : S. De Bruin, Auteur ; A.J. de Wit, Auteur Année de publication : 2004 Article en page(s) : pp 151 - 168 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes d'information géographique [Termes IGN] arbre quadratique [Termes IGN] carte d'occupation du sol [Termes IGN] données maillées [Termes IGN] hétérogénéité [Termes IGN] modèle d'erreur [Termes IGN] précision de la classification [Termes IGN] simulation [Termes IGN] système d'information géographique [Termes IGN] variogramme Résumé : (Auteur) This paper explores the use of quadtree segmentation of a land-cover map to improve error modelling by (1) accounting for variation in classification accuracy among differently sized homogeneous map regions and (2) improving the statistical properties of map realizations generated by sequential indicator simulation (SIS). The latter was accomplished by locating the first simulation nodes -which affect many subsequent local simulations- within the largest quadtree leaves. These represent the largest homogeneous and hypothetically most accurately classified areas on the map. A case study showed that, indeed, the overall accuracy of the land-cover map increased with the quadtree leaf size, ranging from 67% for single cells in heterogeneous areas to 98% for homogeneous blocks of 256 cells. A map of the prior probability of each land-cover class was prepared on the basis of quadtree level-specific confusion matrices. Next, two unconditional SIS algorithms were used to generate sets of 50 realizations of the map, thereby accounting for spatial continuity of the residuals between indicator-transformed reference data and the priors. The proposed quadtree-guided SIS outperformed the more common multiple-steps method as judged by the reproduction of target proportions of map categories, class-specific accuracy levels and variogram reproduction. Numéro de notice : A2004-040 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : 10.1080/13658810310001629600 En ligne : https://doi.org/10.1080/13658810310001629600 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26568 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
079-04021	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Making the trade-off between decision quality and information cost / S. De Bruin in Photogrammetric Engineering & Remote Sensing, PERS, vol 69 n° 1 (January 2003)  

Public [article]  inPhotogrammetric Engineering & Remote Sensing, PERS > vol 69 n° 1 (January 2003) . - pp 91 - 98 Titre : Making the trade-off between decision quality and information cost Type de document : Article/Communication Auteurs : S. De Bruin, Auteur ; Gary J. Hunter, Auteur Année de publication : 2003 Article en page(s) : pp 91 - 98 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s) [Termes IGN] analyse coût-avantage [Termes IGN] analyse de la valeur [Termes IGN] contrôle par télédétection [Termes IGN] cultures Résumé : (Auteur) A growing problem confronting users of remotely sensed imagery is whether the use of additional or different imagery to improve decision quality is actually justified by its cost. This paper discusses how to compare these competing factors so that an acceptable trade-off may be made between them. The proposed method is based on probabilistic cost-benefit analysis. The concept of "value of information" is introduced in a practical case study using remote sensing to verify farmers' declarations for a crop subsidy program in the European Union. Application of the method requires that (1) the problem at hand can be represented by a decision tree, (2) the desirability of each decision outcome can be expressed numerically, (3) the imagery reveals information about the occurrence of events not under the decision maker's control, and (4) the probabilities of these events and the extent to which they are detectable in remotely sensed imagery can be assessed. Numéro de notice : A2003-005 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.14358/PERS.69.1.91 En ligne : https://doi.org/10.14358/PERS.69.1.91 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=22303 [article]

Assessing fitness for use: the expected value of spatial data sets / S. De Bruin in International journal of geographical information science IJGIS, vol 15 n° 5 (july 2001)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 15 n° 5 (july 2001) . - pp 457 - 471 Titre : Assessing fitness for use: the expected value of spatial data sets Type de document : Article/Communication Auteurs : S. De Bruin, Auteur ; Arnold K. Bregt, Auteur Année de publication : 2001 Article en page(s) : pp 457 - 471 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Information géographique [Termes IGN] incertitude des données [Termes IGN] jeu de données localisées [Termes IGN] modèle numérique de surface Résumé : (Auteur) This paper proposes and illustrates a decision analytical approach to compare the value of alternative spatial data sets. In contrast to other work addressing value of information, its focus is on value of control. This is a useful concept when choosing the best data set for decision making under uncertainty due to error in the reported data. Application of the concept requires probabilistic accuracy measures and a loss function representing the cost of incorrect judgement about some target property. This is illustrated by an assessment of the suitability of two digital elevation models (DEMs) for determining the volume of sand required for building a container port. To demonstrate flexibility of the approach, accuracy assessment was based on both a random and a systematic sample of error data, using designbased estimation and model-based prediction, that is geostatistics. Analysis results included the expected loss for each combination of DEM and sampling strategy. These indicated that both DEMs were equally suitable for the intended use. Operational practicability of the method is highly dependent on the willingness of database producers to give access to sample information similar to the quick looks provided to potential users of remote sensing imagery. Numéro de notice : A2001-114 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/13658810110053116 En ligne : https://doi.org/10.1080/13658810110053116 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=21814 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
079-01051	RAB	Revue	Centre de documentation	En réserve L003	Disponible