Search results for "second-order"
showing 10 items of 38 documents
Comparing local structures of spatio-temporal point processes on linear networks
2022
We employ the Local Indicators of Spatio-Temporal Association (LISTA) functions on linear networks to build a statistical test for local second-order structure. This allows to identify differences in the spatio-temporal clustering behaviour of two point patterns, a point pattern of interest and a background one, both occurring on the same linear network. We illustrate the proposed methodology analysing a traffic-related problem.
Some extensions in space-time LGCP: application to earthquake data
2017
In this paper we aim at studying some extensions of complex space-time models, useful for the description of earthquake data. In particular we want to focus on the Log-Gaussian Cox Process (LGCP, [1]) model estimation approach, with some results on global informal diagnostics. Indeed, in our opinion the use of Cox processes that are natural models for point process phenomena that are environmentally driven could be a new approach for the description of seismic events. These models can be useful in estimating the intensity surface of a spatio-temporal point process, in constructing spatially continuous maps of earthquake risk from spatially discrete data, and in real-time seismic activity su…
Some properties and applications of local second-order characteristics for spatio-temporal point processes on networks
2021
Point processes on linear networks are increasingly being considered to analyse events occurring on particular network-based structures. In this work, we extend Local Indicators of Spatio-Temporal Association (LISTA) functions to the non-Euclidean space of linear networks, allowing to obtain information on how events relate to nearby events. In particular, we propose the local version of two inhomogeneous second-order statistics for spatio-temporal point processes on linear networks, the K- and the pair correlation functions. We also show that these LISTA functions are useful for diagnostics of models specified on the networks, and can be helpful to assess the goodness-of-fit of different s…
The reflexivity of human languaging and Nigel Love's two orders of language
2017
Abstract Nigel Love's distinction between first-order language and second-order language exposes the fallacy of the code view of linguistic communication. Persons do not ‘use’ the forms that are said to constitute a pre-existing language system; they adapt and shape their bodily behaviour, including their vocalizing, in accordance with community-level norms and practices that have historical continuity and thus define the cultural-historical traditions of a community. Individuals normatively orient to these continuities and self-reflexively engage in forms of situated appropriation of them as they flexibly adapt them to the requirements of situations in the pursuance of their goals. Love ha…
Qualitative investigations of boundary value problem for self‐similar second order system which arises from modeling of surface chemical reactions
1997
„Qualitative investigations of boundary value problem for self‐similar second order system which arises from modeling of surface chemical reactions" Mathematical Modelling Analysis, 2(1), p. 41-47 First Published Online: 14 Oct 2010
Locally weighted minimum contrast estimation for spatio-temporal log-Gaussian Cox processes
2023
A local version of spatio-temporal log-Gaussian Cox processes is proposed by using Local Indicators of Spatio-Temporal Association (LISTA) functions plugged into the minimum contrast procedure, to obtain space as well as time-varying parameters. The new procedure resorts to the joint minimum contrast fitting method to estimate the set of second-order parameters. This approach has the advantage of being suitable in both separable and non-separable parametric specifications of the correlation function of the underlying Gaussian Random Field. Simulation studies to assess the performance of the proposed fitting procedure are presented, and an application to seismic spatio-temporal point pattern…
Infinitely many periodic solutions for a second-order nonautonomous system
2003
The existence of infinitely many solutions for a second-order nonautonoumous system was investigated. Some multiplicity results for problem (P) under very different assumptions on the potential G were established. It was shown that infinitely many solutions follow from a variational principle by B. Ricceri.
Diagnostics for nonparametric estimation in space-time seismic processes
2010
In this paper we propose a nonparametric method, based on locally variable bandwidths kernel estimators, to describe the space-time variation of seismic activity of a region of Southern California. The flexible estimation approach is introduced together with a diagnostic method for space-time point process, based on the interpretation of some second-order statistics, to analyze the dependence structure of observed data and suggest directions for fit improvement. In this paper we review a diagnostic method for space-time point processes based on the interpretation of the transformed version of some second-order statistics. The method is useful to analyze dependence structures of observed dat…
Politiskās komunikācijas lomas analīze Eiropas Parlamenta vēlēšanās.
2016
Šis pētījums sniedz secinājumus, kas ir balstīti uz politiskās komunikācijas argumentācijas analīzi, par to, kā pašreizējā analītiskā pieeja politiskajā zinātnē var tikt pārveidota attiecībā uz Eiropas Parlamenta (EP) vēlēšanu analīzi. Šis darbs koncentrējas uz politiskās komunikācijas raksturu EP vēlēšanu laikā Zviedrijā 2014.gadā, lai izpētītu to, vai politiskā komunikācija bija vairāk svarīga ES vai nacionālā līmeņa jautājumiem. Šī darba sākumpunkts ir mūsdienu kritika par otrās šķiras vēlēšanu teoriju un tās analītisko modeli, kuru 1980.gadā attīstīja pētnieki Reifs un Šmits. Saskaņā ar Reifu un Šmitu EP vēlēšanas tiek uzskatītas par otrās šķiras svarīguma vēlēšanu procesu un, kur polit…
An existence result for a Neumann problem
2015
The main result of this paper deals with the existence of at least one positive solution for a second order Neumann boundary value problem. Such a result is obtained by using an abstract coincidence point theorem that allows to get our conclusion under non standard conditions on the nonlinearity.