968 resultados para Image of Mathematicians
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Dans cette thèse, nous décrivons les résultats d’un projet de recherche visant à mesurer et évaluer la qualité des soins obstétricaux des hôpitaux de référence au Mali et au Sénégal. Dans ces pays, la mortalité maternelle hospitalière est élevée et est liée en partie à la pratique médicale inadéquate. Cette recherche a été réalisée dans le cadre de l’étude QUARITE, un essai randomisé en grappe évaluant l’efficacité du programme GESTA International visant à réduire la mortalité maternelle hospitalière. GESTA a été mis en œuvre entre 2008 et 2010 et consistait en la formation des professionnels de santé et en la revue des cas de décès maternels. En parallèle de QUARITE, les programmes de prévention de la transmission du VIH de la mère à l’enfant (PTME) ont été mis à l’échelle à travers les pays. Ces derniers ayant également la capacité d’augmenter la qualité des soins obstétricaux, nous avons donc évalué les effets des deux programmes (GESTA et PTME) sur la qualité des soins. Dans un premier temps, à l’aide d’une recension des écrits nous avons évalué la capacité d’un audit clinique basé sur des critères à mesurer la qualité des soins obstétricaux. Cet audit vérifiait si l’offre des soins avait respecté les critères cliniques définissant la meilleure prise en charge selon l’évidence scientifique et l’avis des experts. Nous avons démontré que cet outil est largement utilisé dans les pays à faibles et moyens revenus, malgré le peu d’évidence sur sa validité (article 1). Dans un deuxième temps, nous avons développé un audit clinique basé sur des critères qui s’applique au contexte ouest-africain et qui a été approuvé par des experts-obstétriciens nationaux et internationaux. À partir des dossiers obstétricaux, les actes médicaux posés pendant le travail et l’accouchement ont été évalués à l‘aide de cet instrument. La qualité des soins a été estimée sous forme de pourcentage de critères atteints. Appliqué dans différents contextes et par différents auditeurs, nous avons démontré que notre instrument est fiable et valide (article 3). Néanmoins, l’expérience de l’audit nous a amenés à nous questionner sur le mauvais remplissage des dossiers médicaux et ses conséquences sur la qualité des soins (article 2). Dans un troisième temps, l’outil a été appliqué à large échelle pour évaluer les effets de l’intervention GESTA (article 4). Nous avons mené une révision de plus de 800 dossiers obstétricaux dans 32 hôpitaux de référence (16 bénéficiaires de l’intervention et 16 non-bénéficiaires). Grâce à cet audit clinique, nous avons démontré que le programme GESTA contribue à l’amélioration de la qualité des soins, spécifiquement l’examen clinique lors de l’admission et le suivi après l’accouchement. Dernièrement, nous avons utilisé cet instrument afin d’évaluer les effets des programmes de PTME sur la qualité des soins obstétricaux (article 5). Notre travail a documenté que seulement certaines composantes du programme de PTME améliorent la qualité des soins telles que la formation des professionnels et les services complémentaires en nutrition. En conclusion, cette recherche a identifié plusieurs pistes d’intervention pour améliorer la qualité des soins obstétricaux en Afrique de l’Ouest.
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Cette thèse pose la question du positionnement identitaire difficile qui marque la trajectoire littéraire de l’écrivaine belge Suzanne Lilar (1901-1992). Le tiraillement vécu par l’écrivaine entre sa vocation artistique et la nécessité de préserver une image de soi conforme aux normes du milieu social dans lequel elle s’inscrit se reflète dans les scénographies construites par ses œuvres littéraires, mais également dans son discours réflexif et paratextuel ainsi que dans la manière dont son œuvre est accueilli par la presse de l’époque. Le premier volet de cette analyse s’attache à circonscrire la position occupée par Suzanne Lilar sur la scène littéraire belge, dont la proximité avec le centre parisien a toujours entretenu la menace de l’assimilation, et sur la scène de l’écriture féminine. Le deuxième volet de cette thèse porte sur l’analyse des scénographies construites par les textes de fiction et les textes à tendance autobiographique de Suzanne Lilar. Les doubles scénographies que donnent à lire ces œuvres montrent que la démarche esthétique de Suzanne Lilar, sous-tendue par le besoin de légitimation de son entreprise, est basée principalement sur la multiplication des perspectives et des moyens d’expression. Le dédoublement de la scène énonciative des récits, la mise en abyme de la figure auctoriale ainsi que le travail d’autoréécriture témoignent de la nécessité de se positionner dans le champ littéraire, mais également de la méfiance de l’écrivaine envers l’écriture littéraire. Le troisième volet de cette recherche analyse l’éthos et la posture que Lilar construit à l’aide du discours réflexif et paratextuel par lequel elle assoit sa légitimité sur la scène littéraire et sociale. Enfin, la dernière partie de cette thèse capte les échos de l’œuvre de Lilar dans la presse de son temps. L’image de l’auteure construite par les médias permet de placer Lilar au sein de l’institution et du champ littéraire, mais également au sein du groupe social dans lequel elle s’inscrit. L’accueil réservé à l’écrivaine par la presse de son époque semble suivre les fluctuations de la posture construite par l’écrivaine elle-même. Cela confirme l’hypothèse selon laquelle Lilar est une auteure qui a éprouvé de la difficulté à assumer pleinement son rôle. Le positionnement en porte-à-faux – dont témoigne la figure du trompe-l’œil qui définit sa poétique – semble avoir représenté, pour Lilar, la seule manière d’assumer l’incontournable paratopie créatrice.
Landscape all'Antica and Topographical Anachronism in Roman Fresco Painting of the Sixteenth Century
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An article derived from the first chapter of the writer's doctoral thesis, “Paysage et Pouvoir. Les décors topographiques à Rome et dans le Latium au XVIe siècle.”
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La présente étude conduit les traditions fragmentées de la culture littéraire de Trieste vers les préoccupations contemporaines de la littérature mondiale à l’époque actuelle où la mondialisation est largement perçue comme le paradigme historique prédominant de la modernité. Ce que j’appelle la « littérature globalisée » renvoie à la refonte de la Weltliteratur – envisagée par Goethe et traduite comme « world literature » ou la « littérature universelle » – par des discours sur la culture mondiale et le post-nationalisme. Cependant, lorsque les études littéraires posent les questions de la « littérature globalisée », elles sont confrontées à un problème : le passage de l’idée universelle inhérente au paradigme de Goethe entre le Scylla d’un internationalisme relativiste et occidental, et le Charybde d’un mondialisme atopique et déshumanisé. Les spécialistes de la littérature mondiale qui tendent vers la première position acquièrent un fondement institutionnel en travaillant avec l’hypothèse implicite selon laquelle les nations sont fondées sur les langues nationales, ce qui souscrit à la relation entre la littérature mondiale et les littératures nationales. L’universalité de cette hypothèse implicite est réfutée par l’écriture triestine. Dans cette étude, je soutiens que l’écriture triestine du début du XXe siècle agit comme un précurseur de la réflexion sur la culture littéraire globalisée du XXIe siècle. Elle dispose de sa propre économie de sens, de sorte qu’elle n’entre pas dans les nationalismes littéraires, mais elle ne tombe pas non plus dans le mondialisme atopique. Elle n’est pas catégoriquement opposée à la littérature nationale; mais elle ne permet pas aux traditions nationales de prendre racine. Les écrivains de Triestine exprimaient le désir d’un sentiment d’unité et d’appartenance, ainsi que celui d’une conscience critique qui dissout ce désir. Ils résistaient à l’idéalisation de ces particularismes et n’ont jamais réussi à réaliser la coalescence de ses écrits dans une tradition littéraire unifiée. Par conséquent, Trieste a souvent été considérée comme un non-lieu et sa littérature comme une anti-littérature. En contournant les impératifs territoriaux de la tradition nationale italienne – comme il est illustré par le cas de Italo Svevo – l’écriture triestine a été ultérieurement incluse dans les paramètres littéraires et culturels de la Mitteleuropa, où son expression a été imaginée comme un microcosme de la pluralité supranationale de l’ancien Empire des Habsbourg. Toutefois, le macrocosme projeté de Trieste n’est pas une image unifiée, comme le serait un globe; mais il est plutôt une nébuleuse planétaire – selon l’image de Svevo – où aucune idéalisation universalisante ne peut se réaliser. Cette étude interroge l’image de la ville comme un microcosme et comme un non-lieu, comme cela se rapporte au macrocosme des atopies de la mondialisation, afin de démontrer que l’écriture de Trieste est la littérature globalisée avant la lettre. La dialectique non résolue entre faire et défaire la langue littéraire et l’identité à travers l’écriture anime la culture littéraire de Trieste, et son dynamisme contribue aux débats sur la mondialisation et les questions de la culture en découlant. Cette étude de l’écriture triestine offre des perspectives critiques sur l’état des littératures canoniques dans un monde où les frontières disparaissent et les non-lieux se multiplient. L’image de la nébuleuse planétaire devient possiblement celle d’un archétype pour le monde globalisé d’aujourd’hui.
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Adolescent idiopathic scoliosis (AIS) is a deformity of the spine manifested by asymmetry and deformities of the external surface of the trunk. Classification of scoliosis deformities according to curve type is used to plan management of scoliosis patients. Currently, scoliosis curve type is determined based on X-ray exam. However, cumulative exposure to X-rays radiation significantly increases the risk for certain cancer. In this paper, we propose a robust system that can classify the scoliosis curve type from non invasive acquisition of 3D trunk surface of the patients. The 3D image of the trunk is divided into patches and local geometric descriptors characterizing the surface of the back are computed from each patch and forming the features. We perform the reduction of the dimensionality by using Principal Component Analysis and 53 components were retained. In this work a multi-class classifier is built with Least-squares support vector machine (LS-SVM) which is a kernel classifier. For this study, a new kernel was designed in order to achieve a robust classifier in comparison with polynomial and Gaussian kernel. The proposed system was validated using data of 103 patients with different scoliosis curve types diagnosed and classified by an orthopedic surgeon from the X-ray images. The average rate of successful classification was 93.3% with a better rate of prediction for the major thoracic and lumbar/thoracolumbar types.
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Objective To determine scoliosis curve types using non invasive surface acquisition, without prior knowledge from X-ray data. Methods Classification of scoliosis deformities according to curve type is used in the clinical management of scoliotic patients. In this work, we propose a robust system that can determine the scoliosis curve type from non invasive acquisition of the 3D back surface of the patients. The 3D image of the surface of the trunk is divided into patches and local geometric descriptors characterizing the back surface are computed from each patch and constitute the features. We reduce the dimensionality by using principal component analysis and retain 53 components using an overlap criterion combined with the total variance in the observed variables. In this work, a multi-class classifier is built with least-squares support vector machines (LS-SVM). The original LS-SVM formulation was modified by weighting the positive and negative samples differently and a new kernel was designed in order to achieve a robust classifier. The proposed system is validated using data from 165 patients with different scoliosis curve types. The results of our non invasive classification were compared with those obtained by an expert using X-ray images. Results The average rate of successful classification was computed using a leave-one-out cross-validation procedure. The overall accuracy of the system was 95%. As for the correct classification rates per class, we obtained 96%, 84% and 97% for the thoracic, double major and lumbar/thoracolumbar curve types, respectively. Conclusion This study shows that it is possible to find a relationship between the internal deformity and the back surface deformity in scoliosis with machine learning methods. The proposed system uses non invasive surface acquisition, which is safe for the patient as it involves no radiation. Also, the design of a specific kernel improved classification performance.
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The present study focuses on the stability of the coast, exploitation of the coastal resources, human activities within the study are that extends from Fort Cochin at north to Thottappally at south, central Kerala State and hinterlands, socio-economic problems of the coastal community and the environmental issues arising in the recent past due to human activities. The objective of the study is critically analyse the coastal zone region and prevailing situation and to propose a comprehensive management plan for the sustainable development of the region under study. The thesis covers varied aspects of coastal uses like fisheries, tourism, land use, water resources etc. To critically examine the above scenarios, the ILWIS (Integrated Land and Water Information Systems) – GIS software has been used. A satellite image of the area has been used for the coastline change detection and land use patterns. The outcome of the present study will be beneficial to the various stakeholders within the coastal region and its hinterlands. To further add, this study should find better applications to similar or near-similar situations of Southeast Asia where identical scenarios are noticeable.
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Vibrio are important during hatchery rearing. aquaculture phase and post-harvest quality of shrimps. Vibrio spp are of concern to shrimp farmers and hatchery operators because certain species can cause Vibriosis. Vibrio species are of concern to humans because certain species cause serious diseases.With the progress in aquaculture, intensive systems used for shrimp aquaculture create an artificial environment that increases bacterial growth. To maintain the productivity of such an intensive aquaculture, high inputs of fish protein have to be employed for feeding together with high levels of water exchange and the massive use of antibiotics/ probiotics / chemicals. It seems that the combination of these conditions favours the proliferation of vibrios and enhances their virulence and disease prevalence. The risk of a microbial infection is high, mainly at larval stages. The effect and severity are related to Vibrio species and dose, water, feed, shrimp quality and aquaculture management.Consumption of seafood can occasionally result in food-bome illnesses due to the proliferation of indigenous pathogens like Vibrio.Of the l2 pathogenic Vibrio species, 8 species are known to be directly food associated. Strict quality guidelines have been laid by the importing nations, for the food products that enter their markets. The microbiological quality requirement for export of frozen shrimp products is that V.cholerae, V.parahaemolyticus and V. vulnificus should be absent in 25g of the processed shrimp (Export Inspection Council of India, 1995). The mere presence of these pathogenic Vibrios is sufficient for the rejection of the exported product.The export rejections cause serious economic loss to the shrimp industry and might harm the brand image of the shrimp products from the countiy.There is a need for an independent study on the incidence of different pathogenic vibrios in shrimp aquaculture and investigate their biochemical characteristics to have a better understanding about the growth and survival of these organisms in the shrimp aquaculture niche. PCR based methods (conventional PCR, duplex PCR, multiplex-PCR and Real Time PCR) for the detection of the pathogenic Vibrios is important for rapid post-harvest quality assessment. Studies on the genetic heterogeneity among the specific pathogenic vibrio species isolated from shrimp aquaculture system provide; valuable information on the extent of genetic diversity of the pathogenic vibrios, the shrimp aquaculture system.So the present study was undertaken to study the incidence of pathogenic Vibrio spp. in Penaeus monodon shrimp hatcheries and aquaculture farms, to carry out biochemical investigations of the pathogenic Vibrio spp isolated from P. monodon hatchery and. aquaculture environments, to assess the effect of salt (NaCl) on the growth and enzymatic activities of pathogenic Vibrio spp., to study the effect of preservatives, and chemicals on the growth of pathogenic Vibrio spp. and to employ polymerase chain reaction (PCR) methods for the detection of pathogenic V ibrio spp.Samples of water (n=7) and post-larvae (n=7) were obtained from seven Penaeus monodon hatcheries and samples of water (n=5), sediment (n=5) and shrimp (n=5) were obtained from five P. monodon aquaculture farms located on the East Coast of lndia. The microbiological examination of water, sediment, post-larvae and shrimp samples was carried out employing standard methods and by using standard media.The higher bacterial loads were obtained in pond sediments which can be attributed to the accumulation of organic matter at the pond bottom which stimulated bacterial growth.Shrimp head. (4.78 x 105 +/- 3.0 x 104 cfu/g) had relatively higher bacterial load when compared to shrimp muscle 2.7 x 105 +/- 1.95 x 104 cfu/g). ln shrimp hatchery samples, the post-larvae (2.2 x 106 +/- 1.9 x 106 cfu/g) had higher bacterial load than water (5.6 x 103 +/- 3890 cfu/ml).The mean E.coli counts were higher in aquaculture pond sediment (204+/-13 cfu/g) and pond water (124+/-88 cfu/ml). Relatively lower Escherichia coli counts were obtained from shrimp samples (12+/-11 to 16+/-16.7 cfu/g). The presence of E.coli in aquaculture environment might have been from the source water. E.coli was not detected in hatchery waters and post-larvae.
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Low grade and High grade Gliomas are tumors that originate in the glial cells. The main challenge in brain tumor diagnosis is whether a tumor is benign or malignant, primary or metastatic and low or high grade. Based on the patient's MRI, a radiologist could not differentiate whether it is a low grade Glioma or a high grade Glioma. Because both of these are almost visually similar, autopsy confirms the diagnosis of low grade with high-grade and infiltrative features. In this paper, textural description of Grade I and grade III Glioma are extracted using First order statistics and Gray Level Co-occurance Matrix Method (GLCM). Textural features are extracted from 16X16 sub image of the segmented Region of Interest(ROI) .In the proposed method, first order statistical features such as contrast, Intensity , Entropy, Kurtosis and spectral energy and GLCM features extracted were showed promising results. The ranges of these first order statistics and GLCM based features extracted are highly discriminant between grade I and Grade III. In this study which gives statistical textural information of grade I and grade III Glioma which is very useful for further classification and analysis and thus assisting Radiologist in greater extent.
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In this paper the effectiveness of a novel method of computer assisted pedicle screw insertion was studied using testing of hypothesis procedure with a sample size of 48. Pattern recognition based on geometric features of markers on the drill has been performed on real time optical video obtained from orthogonally placed CCD cameras. The study reveals the exactness of the calculated position of the drill using navigation based on CT image of the vertebra and real time optical video of the drill. The significance value is 0.424 at 95% confidence level which indicates good precision with a standard mean error of only 0.00724. The virtual vision method is less hazardous to both patient and the surgeon
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We describe a technique for finding pixelwise correspondences between two images by using models of objects of the same class to guide the search. The object models are 'learned' from example images (also called prototypes) of an object class. The models consist of a linear combination ofsprototypes. The flow fields giving pixelwise correspondences between a base prototype and each of the other prototypes must be given. A novel image of an object of the same class is matched to a model by minimizing an error between the novel image and the current guess for the closest modelsimage. Currently, the algorithm applies to line drawings of objects. An extension to real grey level images is discussed.
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The capability of estimating the walking direction of people would be useful in many applications such as those involving autonomous cars and robots. We introduce an approach for estimating the walking direction of people from images, based on learning the correct classification of a still image by using SVMs. We find that the performance of the system can be improved by classifying each image of a walking sequence and combining the outputs of the classifier. Experiments were performed to evaluate our system and estimate the trade-off between number of images in walking sequences and performance.
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Con base en las preocupaciones de la época sobre la susceptibilidad al romance y acoso sexual de la trabajadora de oficina, este artículo propone explorar la representación de secretarias y taquígrafas en TheType-Writer Girl (1897), de Grant Allan, y en North of Fifty-Three (1914), de Bertrand Sinclair. Se mirará la presión para adquirir la independencia económica y autonomía personal a través del trabajo en oficina. También, la necesidad de ajustarse a ideologías presentes en la sociedad, que abogaban un destino predeterminado de matrimonio e hijos para la mujer. Se pregunta si el género de literatura workinggirl de esos tiempos abogaba la imagende la mujer independiente, trabajadora y emocionalmente realizada, o si el trabajo de oficina era interpretado como un paso natural hacia una evolución de niñas a madres. Este artículo también cuestiona si la oficina ficcional fue presentada como una ubicación de autonomía y potencial femeninos, o si fue vista como un espacio hostil y peligroso del que debería escapar lo más pronto posible para mantener la seguridad del hogar.
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This thesis proposes a solution to the problem of estimating the motion of an Unmanned Underwater Vehicle (UUV). Our approach is based on the integration of the incremental measurements which are provided by a vision system. When the vehicle is close to the underwater terrain, it constructs a visual map (so called "mosaic") of the area where the mission takes place while, at the same time, it localizes itself on this map, following the Concurrent Mapping and Localization strategy. The proposed methodology to achieve this goal is based on a feature-based mosaicking algorithm. A down-looking camera is attached to the underwater vehicle. As the vehicle moves, a sequence of images of the sea-floor is acquired by the camera. For every image of the sequence, a set of characteristic features is detected by means of a corner detector. Then, their correspondences are found in the next image of the sequence. Solving the correspondence problem in an accurate and reliable way is a difficult task in computer vision. We consider different alternatives to solve this problem by introducing a detailed analysis of the textural characteristics of the image. This is done in two phases: first comparing different texture operators individually, and next selecting those that best characterize the point/matching pair and using them together to obtain a more robust characterization. Various alternatives are also studied to merge the information provided by the individual texture operators. Finally, the best approach in terms of robustness and efficiency is proposed. After the correspondences have been solved, for every pair of consecutive images we obtain a list of image features in the first image and their matchings in the next frame. Our aim is now to recover the apparent motion of the camera from these features. Although an accurate texture analysis is devoted to the matching pro-cedure, some false matches (known as outliers) could still appear among the right correspon-dences. For this reason, a robust estimation technique is used to estimate the planar transformation (homography) which explains the dominant motion of the image. Next, this homography is used to warp the processed image to the common mosaic frame, constructing a composite image formed by every frame of the sequence. With the aim of estimating the position of the vehicle as the mosaic is being constructed, the 3D motion of the vehicle can be computed from the measurements obtained by a sonar altimeter and the incremental motion computed from the homography. Unfortunately, as the mosaic increases in size, image local alignment errors increase the inaccuracies associated to the position of the vehicle. Occasionally, the trajectory described by the vehicle may cross over itself. In this situation new information is available, and the system can readjust the position estimates. Our proposal consists not only in localizing the vehicle, but also in readjusting the trajectory described by the vehicle when crossover information is obtained. This is achieved by implementing an Augmented State Kalman Filter (ASKF). Kalman filtering appears as an adequate framework to deal with position estimates and their associated covariances. Finally, some experimental results are shown. A laboratory setup has been used to analyze and evaluate the accuracy of the mosaicking system. This setup enables a quantitative measurement of the accumulated errors of the mosaics created in the lab. Then, the results obtained from real sea trials using the URIS underwater vehicle are shown.
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A traditional method of validating the performance of a flood model when remotely sensed data of the flood extent are available is to compare the predicted flood extent to that observed. The performance measure employed often uses areal pattern-matching to assess the degree to which the two extents overlap. Recently, remote sensing of flood extents using synthetic aperture radar (SAR) and airborne scanning laser altimetry (LIDAR) has made more straightforward the synoptic measurement of water surface elevations along flood waterlines, and this has emphasised the possibility of using alternative performance measures based on height. This paper considers the advantages that can accrue from using a performance measure based on waterline elevations rather than one based on areal patterns of wet and dry pixels. The two measures were compared for their ability to estimate flood inundation uncertainty maps from a set of model runs carried out to span the acceptable model parameter range in a GLUE-based analysis. A 1 in 5-year flood on the Thames in 1992 was used as a test event. As is typical for UK floods, only a single SAR image of observed flood extent was available for model calibration and validation. A simple implementation of a two-dimensional flood model (LISFLOOD-FP) was used to generate model flood extents for comparison with that observed. The performance measure based on height differences of corresponding points along the observed and modelled waterlines was found to be significantly more sensitive to the channel friction parameter than the measure based on areal patterns of flood extent. The former was able to restrict the parameter range of acceptable model runs and hence reduce the number of runs necessary to generate an inundation uncertainty map. A result of this was that there was less uncertainty in the final flood risk map. The uncertainty analysis included the effects of uncertainties in the observed flood extent as well as in model parameters. The height-based measure was found to be more sensitive when increased heighting accuracy was achieved by requiring that observed waterline heights varied slowly along the reach. The technique allows for the decomposition of the reach into sections, with different effective channel friction parameters used in different sections, which in this case resulted in lower r.m.s. height differences between observed and modelled waterlines than those achieved by runs using a single friction parameter for the whole reach. However, a validation of the modelled inundation uncertainty using the calibration event showed a significant difference between the uncertainty map and the observed flood extent. While this was true for both measures, the difference was especially significant for the height-based one. This is likely to be due to the conceptually simple flood inundation model and the coarse application resolution employed in this case. The increased sensitivity of the height-based measure may lead to an increased onus being placed on the model developer in the production of a valid model