Comparison of several methods for calculation of reference evapotranspiration

Abstract The knowledge of the evapotranspiration of natural ecosystems and plant populations is of fundamental importance in several branches of science, research and practical uses. Nevertheless, the harmonisation of the large number of methods and user needs often causes problems. The objective of the analyses was to explore the output range and sensitivity of models of different physical approaches under local conditions. We performed descriptive statistical and sensitivity analysis of 10 commonly used estimation models - one of them with two variants. Correlation between modelled and measured evapotranspiration data series was assessed. The magnitude of the model outputs, their variability and responses to the changes of selected atmospheric parameters were evaluated. Priestley-Taylor, Penman-Monteith-FAO-56, Shuttleworth-Wallace (parameterized with alternative radiation balance), Szász and Makkink proved to be the most sensitive methods. As regards the systematic error, Makkink and Shuttleworth-Wallace showed the best agreement with pan evaporation, while Shuttleworth-Wallace, Blaney-Criddle and Makkink models were found to be the closest to the Penman-Monteith-FAO-56 method as a reference value. </jats:p

Instant Object Detection in Lidar Point Clouds

In this paper we present a new approach for object classification in continuously streamed Lidar point clouds collected from urban areas. The input of our framework is raw 3-D point cloud sequences captured by a Velodyne HDL-64 Lidar, and we aim to extract all vehicles and pedestrians in the neighborhood of the moving sensor. We propose a complete pipeline developed especially for distinguishing outdoor 3-D urban objects. Firstly, we segment the point cloud into regions of ground, short objects (i.e. low foreground) and tall objects (high foreground). Then using our novel two-layer grid structure, we perform efficient connected component analysis on the foreground regions, for producing distinct groups of points which represent different urban objects. Next, we create depth-images from the object candidates, and apply an appearance based preliminary classification by a Convolutional Neural Network (CNN). Finally we refine the classification with contextual features considering the possible expected scene topologies. We tested our algorithm in real Lidar measurements, containing 1159 objects captured from different urban scenarios

Fast 3-D Urban Object Detection on Streaming Point Clouds

Efficient and fast object detection from continuously streamed 3-D point clouds has a major impact in many related research tasks, such as autonomous driving, self localization and mapping and understanding large scale environment. This paper presents a LIDAR-based framework, which provides fast detection of 3-D urban objects from point cloud sequences of a Velodyne HDL-64E terrestrial LIDAR scanner installed on a moving platform. The pipeline of our framework receives raw streams of 3-D data, and produces distinct groups of points which belong to different urban objects. In the proposed framework we present a simple, yet efficient hierarchical grid data structure and corresponding algorithms that significantly improve the processing speed of the object detection task. Furthermore, we show that this approach confidently handles streaming data, and provides a speedup of two orders of magnitude, with increased detection accuracy compared to a baseline connected component analysis algorithm

ON THE OXIMINE COMPLEXES OF TRANSITION METALS. PART CXVIII. STUDY ON THE PROTOLYTIC EQUILIBRIA IN THE SOLUTIONS OF MIXED CHELATES OF THE TYPE [Co(Diox.H)2AB]n WITH ALICYCLIC &#945;-DIOXIMES1

16 new chelate compounds of the type [Co(Diox.H)2AB]n (Diox.H2-alicyclic &#945;-dioxime with C5..C8 in the hydroaromatic ring, A, B monodentate ligands: NCO-, NO2-, S2O32-, NH3, pyridine, aromatic amine) were obtained by air oxidation of the components and by various substitution reactions, respectively. The complexes were characterized by FTIR spectra. The complicated protolytic equilibria with the participation of the intramolecular O-H..O hydrogen bridges of the Co(Diox.H)2 moieties were studied by spectrophotometric and potentiometric measurements