Vectorial Maps Research Articles

Rainfall erosivity variability over the United States associated with large-scale climate variations by El Niño/southern oscillation

A comprehensive investigation of the contiguous Unites States rainfall erosivity patterns in relation to the warm and cold phases of El Niño/southern Oscillation (ENSO) was described using a set of empirical and statistical analyses, such as harmonic analysis, annual cycle composites, and cross-correlation analysis. Monthly rainfall erosivity index (REI) composites for the first harmonic, covering 24-month ENSO events, are formed for all climate divisions over the United States spanning up to 29 ENSO episodes. From the harmonic vectorial maps plotted on the study area, each vector reveals both intensity and temporal phase of the ENSO-related REI teleconnection, and the corresponding candidate and core regions are determined using a machine learning technique of Gaussian Mixture Model (GMM) based on magnitude and temporal phase of climate signal, and Köppen climate classification. As a result of vectorial mapping, five core regions were designated as the northwest (NW), the north central (NC), the northeast coastal (NEC), the southeast (SE), and the southwest/middle-inland (SWM) regions. During fall (0) to spring (+) seasons, the results of this analysis show negative (positive) rainfall erosivity response to the El Niño events at the NW and NC regions (NEC, SE, and SWM regions), while the opposite patterns are detected for the cold phase of ENSO. The temporal consistency values were 0.62 to 0.86 (0.73 to 0.82), and spatial coherence values ranged from 0.93 to 0.98 (0.94 to 0.97) for the El Niño (La Niña) events. Comparative analyses of rainfall erosivity responses to both warm and cold ENSO events reveal the high significance level of the ENSO-REI correlation with an opposite tendency in monthly rainfall erosivity anomalies. Above normal rainfall erosivity anomalies during the El Niño thermal forcing are more significant than below normal rainfall erosivity departures during the La Niña events. Consequently, middle latitude rainfall erosivity responses to the El Niño and La Niña phenomena are detectable over the contiguous United States.

Teleconnection of ENSO extreme events and precipitation variability over the United States

This study describes a comprehensive investigation of the contiguous United States precipitation patterns in relation to the warm and cold phases of El Niño/southern Oscillation (ENSO) using a set of empirical and statistical analyses, such as harmonic analysis, annual cycle composites, and cross-correlation analysis. Monthly precipitation composites for the first harmonic, covering 24-month ENSO events, are formed for all climate divisions over the United States spanning up to 29 ENSO episodes. From the harmonic vectorial maps plotted on the study area, each vector reveals both intensity and temporal phase of the ENSO-related precipitation teleconnection, and the corresponding candidate and core regions are determined using a machine learning technique of Gaussian Mixture Model (GMM) based on magnitude and temporal phase of climate signal, and Köppen climate classification. As a result of vectorial mapping, five core regions were designated as North-West region (NW), South-West region (SW), Middle-Inland region (MI), South-East region (SE), and North-East region (NE). During fall (0) to spring (+) seasons, the results of this analysis show below (above) normal precipitation response to the El Niño events at the NW region (SW, MI, SE, and NE regions), while the opposite patterns are detected for the cold phase of ENSO. The temporal consistency values were 0.72 to 0.86 (0.77 to 0.82), and spatial coherence values ranged from 0.96 to 0.99 (0.94 to 0.99) for the warm (cold) events. Comparative analyses of precipitation responses to both El Niño and La Niña events reveal the high significance level of the ENSO-related precipitation signals with an opposite tendency in monthly precipitation anomalies. Positive precipitation anomalies during the El Niño thermal forcing are more significant than negative precipitation departures during the La Niña events. Consequently, middle latitude precipitation responses to the El Niño/La Niña phenomena are detectable over the contiguous United States.

On C1,α-regularity for critical points of a geometric obstacle-type problem

We consider critical points of the geometric obstacle problem on vectorial maps u:B2⊂R2→RN∫B2|∇u|2subject to u∈RN\\BN(0). Our main result is C1,α-regularity for any α<1.Technically, we split the map u=λv, where v:B2→SN−1 is the vectorial component and λ=|u| the scalar component measuring the distance to the origin. While v satisfies a weighted harmonic map equation with weight λ2, λ solves the obstacle problem for∫B2|∇λ|2+λ2|∇v|2,subject to λ≥1, where |∇v|2∈L1(B2). We then play ping-pong between the increases in the regularity of λ and v to obtain finally the C1,α-result.

A harmonized database to follow the demographic trajectories of European cities, the TRADEVE database (Demographic Trajectories of European Cities)

TRADEVE Database provides the following information for the European Urban Morphological Zones (UMZ) of more than 10 000 inhabitants in 2011:- Name of UMZ- Name of country- Code corresponding to the vectorial maps- Population for 1961, 1971, 1981, 1991, 2001, 2011- Accompanied by vectorial maps of the UMZ perimeters for 1961, 1971, 1981, 1991 and 2001.TRADEVE database is based on Urban Morphological Zones (UMZ) (EEA, 2004). UMZ were enriched in the ESPON Database Project 2008-2014 by giving a name to UMZ and by creating a correspondence dictionary between UMZ and Local Administrative Units (LAU). A population density grid from the Joint Research Centre was originally used for attributing populations to UMZ. The integration of time comes from a retropolation of UMZ 2000 back to 1961.The Historical Population Database of European LAUs allowed to attribute population for six dates (from 1961 to 2011), in the geometry of the 2012 LAU. A data model provided evolving urban perimeters from the retropolation of UMZ 2000 back to 1961. Two criteria were used: contiguity and minimal population (2000 inhabitants) of the building blocks. The population change between 2001 and 2011 has been registered within the limits of UMZ 2000.

Quantification of coarse-graining error in Langevin and overdamped Langevin dynamics

In molecular dynamics and sampling of high dimensional Gibbs measures coarse-graining is an important technique to reduce the dimensionality of the problem. We will study and quantify the coarse-graining error between the coarse-grained dynamics and an effective dynamics. The effective dynamics is a Markov process on the coarse-grained state space obtained by a closure procedure from the coarse-grained coefficients. We obtain error estimates both in relative entropy and Wasserstein distance, for both Langevin and overdamped Langevin dynamics. The approach allows for vectorial coarse-graining maps. Hereby, the quality of the chosen coarse-graining is measured by certain functional inequalities encoding the scale separation of the Gibbs measure. The method is based on error estimates between solutions of (kinetic) Fokker–Planck equations in terms of large-deviation rate functionals.

A Web Based Geographical Information System Application: Seyyah

In the transformation process of industrial society to information society, remarkable changes especially in information technologies area are experienced. In this concept, technologies interacts with information and interdisciplinary studies gain different dimensions. One of the most noticeable typical examples of these interdisciplinary studies emerged in geography and Geographical Information Systems (GIS) spawned with the relations between the sciences, geography and informatics. GIS compiling geographical information, storing it in its database and analyzing it according to users’ needs has been recently moved to internet environment. Therefore, people introduced with Web - Based Geographical Information Systems (WebGIS). The aim of this study is to introduce Seyyah, a self- developed WebGIS application. Seyyah was designed to be used in especially elementary and high school instruction activities. High-resolution vectorial maps were used in the Seyyah, and extra features such as zooming and dragging with mouse by adding JavaScript codes to these maps were added. Then, the windows containing aimed topics over dynamic maps were opened and map keys were constructed. These information windows were directly connected to the database with the programming language, Active Server Pages.

A method for estimating the geographical distribution of the available roof surface area for large-scale photovoltaic energy-potential evaluations

A rigorously founded assessment of the potential of renewable energies is essential for the development of energy policies and regulations. Usually, a hierarchy of potentials are calculated which gradually include restrictions for the use of a specific renewable resource. This paper deals with the estimation of the technical potential of roof-integrated photovoltaic systems. The most restrictive step when estimating this potential for large-scale territories is the estimation of the roof available area in existing buildings, for which no direct data exists. The methodology proposed in this paper allows to estimate the roof area available for solar applications and also quantify the error made in this estimation. It is based on easily accessible data (such as land uses and population and building densities) and on a statistically representative stratified-sample of vectorial GIS maps of urban areas. The main point in this sampling process is that the stratification is done based on a finite set of average building typologies which comprises every urban area in the region of study. An interesting characteristic emerging from the proposed methodology is its scalability and the possibility of being used from regional to continental scales. This methodology is applied in this work to Spain and a mean available area for photovoltaic equipment on roofs of 14.0 ± 4.5 m 2 / ca . with a confidence level of 95% is obtained. Additionally, results are given for the technical limit of production of roof-integrated photovoltaic energy.

Generalized Polarized Manifolds

We introduce and develop the notion of generalized Poisson manifolds and analyze their main properties. Several generalized Hamiltonian maps for polarized Poisson manifolds and vectorial Hamiltonian maps for systems in dimension smaller or equal than 4 are given.

An unbiased implementation of regularization mechanisms

In computer or biological vision, computation of vectorial maps of parametric quantities (e.g. feature parameters, 3D or motion cues,..) are of common use in perceptual processes. Defining them using continuous partial differential equations yields highly parallelizable regularization processes allowing to obtain well-defined estimations of these quantities. However these equations have to be sampled on real data and this step is not obvious and may introduce some bias. In order to overcome this caveat, a method, introduced by Raviat and developed by Degond and Mas-Gallic, is based on an integral approximation of the diffusion operator used in regularization mechanisms: it leads to a so-called “particle” implementation of such diffusion process. Following this formulation, the present development defines an optimal implementation of such an integral operator with the interesting property that when used on sampled data such as image pixels or 3D data voxels, it provides an unbiased implementation of the corresponding continuous operator without any other approximation. Furthermore, the method is ‘automatic’ (using symbolic computations) in the sense that given a continuous regularization mechanism, the corresponding (non-linear) discrete filter is derived automatically, as made explicit here. A step ahead, the architecture of the implementation corresponds to what is observed in cortical visual maps, leading to a certain biological plausibility. The present development is illustrated by an experiment of visual motion estimation and another experiment in image denoising.

Base maps in Belgium

After a short historical review of base cartography in Belgium, one cans observe that the new regional structures, which resulted from the constitutional reforms during the 1970s and 80s, have redrawn the landscape of base cartography production in this country. Different national and regional authorities are presently involved in base cartography. They propose solutions for basic reference cartography, either on an average scale or on a large-scale. Raster maps are often used as a temporary solution, while awaiting a vectorial version, or as a complement to the vectorial digital maps. Authorities will have to provide in the future adequate solutions for the problem of the updating of the enormous databases and for distributing and using these data.

Measurement of sound-pressure distribution in replicas of the oral cavity.

The spatial distributions of sound pressure in artificial oral cavities were measured to examine the characteristics of wave propagation in the vocal tract. The measurement was performed with plaster replicas of the oral cavity, and pure tones were used as the driving signals to obtain both amplitude and phase distributions at varied frequencies. Plane-wave propagation, which has been widely assumed for speech production models, was examined from the measured spatial distributions of sound pressure. Trajectories of media particles and vectorial maps of acoustic intensity, which can be computed from the measured pressure distributions, were also presented to visualize the acoustic field in the oral cavity. The results showed that at certain frequencies there existed points where sound pressure was absolutely zero, with the phase spatially circulating around them. Up to about 4 kHz, except at these certain frequencies, the wave front was almost one-dimensional, though an amplitude gradient was seen in the vertical direction.

A STUDY OF POLYNOMIAL MODELS FOR ASTROGRAPHIC PLATE REDUCTIONS

ABSTRACT Polynomial adjustments for the reduction of plates taken with the astrograph at the Observatorio de Campinas, Sao Paulo, Brazil, were investigated. A statistical analysis was performed on the vectorial residual maps derived from the reductions of 11 photographic plates. The results have shown the 2nd degree model to be inadequate for the reductions. A radial distortion effect in the 7 degree X 7 degree field was detected. The 5th degree radial distortion term was found to be not significant. The 2nd degree plus a term of radial distortion of the 3rd degree and the 3rd degree polynomial models give residuals of the order of 0".30, compatible with the errors of the catalogues used (Perth 70 and PPM South, preliminary version). However there are evidences that the last model gives slightly better results than the former.