Search results for "Spatial"
showing 10 items of 2121 documents
Some contributions in disease mapping modeling
2020
Disease mapping ha recibido un gran interés durante las tres últimas décadas. Esta área de investigación persigue el estudio de la distribución geográfica de eventos relacionados con la salud, tales como la mortalidad o la incidencia de enfermedades, agregados en unidades geográficas, con el fin de identificar principalmente aquellas localizaciones que presentan un mayor riesgo. La aplicación de métodos estadísticos avanzados para llevar a cabo las estimaciones de los riesgos resulta fundamental para obtener estimaciones precisas y profundizar en el entendimiento de la distribución geográfica de las enfermedades. En esta tesis nos centramos en la aplicación y evaluación de varias propuestas…
Simulation of granular organic fertilizer application by centrifugal spreader
2021
There is no specialized equipment designed to spread granular cylindrical organic fertilizer in the soil. There are also no rational recommendations available on how to spread this type of fertilizer. Mineral fertilizer spreaders are most often used for spreading granulated organic fertilizer. However, these fertilizers are significantly different from mineral fertilizers. Due to these differences, organic granular fertilizers often are spread unevenly, and the fertilizer does not reach the required working width. Furthermore, the rate of spreading is not accurate, and the fertilizer is often crushed too much. The objective of this research is to develop a simulation model for granular orga…
Rapid learning of a spatial memory task in a lacertid lizard (Podarcis liolepis).
2018
Abstract Mammals and birds are capable of navigating to a goal using learned map-like representations of space (i.e. place learning), but research assessing this navigational strategy in reptiles has produced inconclusive results, in part due to the use of procedures that do not take account of the peculiarities of reptilian behavior and physiology. Here I present a procedure suitable for testing spatial cognition that exploits a naturally evolved, ethologically relevant ability common to many lizards (i.e. refuge seeking behavior). The procedure requires lizards to learn the location of an open refuge inside a rectangular arena containing artificial refuges in every corner, using distal ex…
Sex ratio and spatial distribution of male and female Antennaria dioica (Asteraceae) plants
2011
Sex ratio, sex spatial distribution and sexual dimorphism in reproduction and arbuscular mycorrhizal colonisation were investigated in the dioecious clonal plant Antennaria dioica (Asteraceae). Plants were monitored for five consecutive years in six study plots in Oulanka, northern Finland. Sex ratio, spatial distribution of sexes, flowering frequency, number of floral shoots and the number and weight of inflorescences were recorded. In addition, intensity of mycorrhizal fungi in the roots was assessed. Both sexes flowered each year with a similar frequency, but the overall genet sex ratio was strongly female-biased. The bivariate Ripley’s analysis of the sex distribution showed that within…
Accurate increment identification and the spatial extent of the common signal in fiveArctica islandicachronologies from the Fladen Ground, northern N…
2009
[1] The creation of networks of shell-based chronologies which can provide regionally extensive high-resolution proxies for the marine environment depends on the spatial extent of the common environmental signal preserved in the shell banding and on the reliability of the dating model. Here Arctica islandica chronologies from five neighboring sites in the North Sea are compared, and the strength of the common environmental signal across distances up to 80 km is analyzed using statistical techniques derived from dendrochronology. The signal is found to be coherent across these distances. In a linked study, chronologies based on one of the same sites but constructed by two different research …
Multi-Destination Trips and Tourism Statistics: Empirical Evidences in Sicily
2012
Abstract The knowledge of the actual magnitude and main features of tourism flows in a given destination is an essential prerequisite for the evaluation of tourism impacts and externalities. Indeed, many pleasure trips are often characterized by the visit to more than a single destination. Although the topic is well-documented in literature, the empirical results are limited to a few pioneering studies. The lack may be attributable to the failure of tourism organizations to collect data on multi-destination trip behaviour. This can be seen, for example, in the system of European statistics on tourism (according to the Council Directive 95/57 EC), where information on the average number of v…
Direct and indirect knowledge spillovers and industrial productivity
2016
AbstractThis paper analyses the importance of externalities related to the spread of innovation across sectors. Such spillover effects arise from R&D activities and input–output (IO) linkages among sectors in the country. We borrow Spatial Econometrics techniques to make consistent estimates of the impact of these systematic direct and indirect spillovers on sector’s productivity and the possibility of other types of productivity spillovers in the error term. We find that direct spillovers emanating from IO horizontal linkages determine sector’s productivity, while the indirect effects prove to be negligible. Furthermore, the technological intensity of IO linkages and the productive structu…
Improved superresolution in coherent optical systems.
2001
Objects that temporally vary slowly can be superresolved by the use of two synchronized moving masks such as pinholes or gratings. This approach to superresolution allows one to exceed Abbe’s limit of resolution. Moreover, under coherent illumination, superresolution requires a certain approximation based on the time averaging of intensity rather than of field distribution. When extensive digital postprocessing can be incorporated into the optical system, a detector array and some postprocessing algorithms can replace the grating that is responsible for information decoding. In this way, no approximation is needed and the synchronization that is necessary when two gratings are used is simpl…
Proposition of Convolutional Neural Network Based System for Skin Cancer Detection
2019
Skin cancer automated diagnosis tools play a vital role in timely screening, helping dermatologists focus on melanoma cases. Best arts on automated melanoma screening use deep learning-based approaches, especially deep convolutional neural networks (CNN) to improve performances. Because of the large number of parameters that could be involved during training in CNN many training samples are needed to avoid overfitting problem. Gabor filtering can efficiently extract spatial information including edges and textures, which may reduce the features extraction burden to CNN. In this paper, we proposed a Gabor Convolutional Network (GCN) model to improve the performance of automated diagnosis of …
Hybrid optical-digital method for local-displacement analysis by use of a phase-space representation.
2010
A method for evaluating the local deformation or displacement of an object in speckle metrology is described. The local displacements of the object in one direction are digitally coded in a one-dimensional specklegram. By optically performing the local spectrum of this pattern, one simultaneously achieves information about the local displacement and its spatial position. The good performance of this technique is demonstrated with computer-generated test signals.