The concept and the computation of terrain representation error (ETR) are investigated and total DEM error is presented as an accuracy index for DEM evaluation at a global level. A promising method of surface modelling based on the theorem of surfaces (SMTS) has been developed. A numerical test and a real-world example are employed to comparatively analyze the simulation accuracy of SMTS and th...

Nowadays there is a wide range of systems that provide an efficient and fast data capture for the DEM generation and the spread of the computer systems has allowed the use of DEM to a high number of technicians. Unfortunately, the DEM analysis tools do not have similar development. Actually, the analyses are mainly based in the application of local scale operators that provide additional inform...

The shoot and root apical meristems (SAMs and RAMs, respectively) of higher plants are mechanistically and structurally similar. This has led previously to the suggestion that the SAM and RAM represent modifications of a fundamentally homologous plan of organization. Despite recent interest in plant development, especially in the areas of meristem regulation, genes specifically required for the...

The cumulative error at a point in a LiDAR-derived DEM consists of three components: propagated LiDAR-sensor error, propagated ground error, and interpolation error. To combine these error components so as to assess the vertical accuracy of a LiDAR-derived DEM, statistical methods based on the error propagation theory are often used. Due to the existence of systematic error, statistical methods...

The accuracy of a digital elevation model (DEM) generated from synthetic aperture radar (SAR) interferometry (InSAR) crucially depends on the length of the perpendicular baseline between SAR acquisitions. ERS-2 and Envisat cross-InSAR (CInSAR) are superior methods to create high precise DEM because the perpendicular baseline can be extended sufficiently long by compensating a slight difference ...

Interferometric synthetic aperture radar (InSAR) processing relies on phase unwrapping to convert interferometric phase to topographic height. Phase unwrapping is a di cult non-linear process that is still the subject of on-going research. Rather than processing the complete phase image to extract a digital elevation model (DEM), we use existing coarse DEMs as an integral part of the InSAR algo...

OBJECTIVE Fototest is a short simple test, applicable to illiterate subjects and not influenced by educational level. The purpose of this study is to assess its validity for cognitive impairment (CI) and dementia (DEM) under routine clinical practice conditions. MATERIAL AND METHODS A cross-sectional, multicentre and naturalistic study conducted in General Neurology clinics. The subjects were...