Results 161 to 170 of about 667,394 (343)

Approximating multidimensionality with asymmetric unidimensional IRT models

open access: yesBritish Journal of Mathematical and Statistical Psychology, EarlyView.
Abstract Unidimensional item response theory (IRT) models are widely used even in settings where assessment data exhibit subtle forms of multidimensionality. Recent empirical evidence suggests that when item difficulty is associated with dimensionality, asymmetric item characteristic curves (ICCs) emerge in the unidimensional approximation.
Xiangyi Liao   +5 more
wiley   +1 more source

Efficient Estimation of Copula-based Semiparametric Markov Models [PDF]

open access: yes
This paper considers efficient estimation of copula-based semiparametric strictly stationary Markov models. These models are characterized by nonparametric invariant (one-dimensional marginal) distributions and parametric bivariate copula functions ...
Yanping Yi, Xiaohong Chen, Wei Biao Wu
core  

Late Holocene moisture variability in Arctic Alaska from chitin δ18O

open access: yesBoreas, EarlyView.
Amplified warming in the Arctic has resulted in reduced sea‐ice extent, which can impact regional climate dynamics. Elucidating past moisture variability in response to changing temperatures and sea‐ice conditions can offer insight into how anthropogenic climate change may impact Arctic areas such as the Alaskan North Slope in the future. We contribute
Briana A. Edgerton, Melissa L. Chipman
wiley   +1 more source

Towards an ‘absolute’ timing of biostratigraphic and environmental phases from the Saalian late glacial to the Weichselian pleniglacial in central Europe—Insights from a lacustrine succession in Lichtenberg, northern Germany

open access: yesBoreas, EarlyView.
Palynological records are central to the biostratigraphic subdivision of the Late Pleistocene in central Europe. Yet many interglacial and interstadial phases—such as the Eemian, Brörup and Odderade—remain only poorly constrained in time due to limited numerical dating.
Michael Hein   +19 more
wiley   +1 more source

A Generalized ARFIMA Process with Markov-Switching Fractional Differencing Parameter [PDF]

open access: yes
We propose a general class of Markov-switching-ARFIMA processes in order to combine strands of long memory and Markov-switching literature. Although the coverage of this class of models is broad, we show that these models can be easily estimated with the
Wolfgang Härdle, Wen-Jen Tsay
core  

Advancing Global Oral Health Research Through Community and Academic Partnerships: An Overview of the CORE Programme

open access: yesCommunity Dentistry and Oral Epidemiology, EarlyView.
ABSTRACT Background The increasing burden of oral diseases in low‐ and middle‐income countries (LMICs) and limited access to and affordability of oral care disproportionately impact disadvantaged groups. Oral health research has been dominated by professional academic perspectives with limited contribution from the communities involved. The aim of this
Carol C. Guarnizo‐Herreño   +9 more
wiley   +1 more source

Association in time of a finite semi-Markov process

open access: yes
We derive three equivalent sufficient conditions for association in time of a finite state semi-Markov process in terms of transition probabilities and crude hazard rates.
Dharmadhikari, Avinash, Kuber, Madhuri
core  

A Survey of Methods for Constructing 3D Urban Models From Point Clouds

open access: yesComputer Graphics Forum, EarlyView.
The survey outlines a general process for constructing 3D models from point clouds and categorizes the methods based on their use of templates, basic surface primitives, hybrid approaches, or linear primitives. Additionally, the survey reviews the datasets and benchmarks that are essential for testing and training the developed methods.
Chiara Romanengo   +5 more
wiley   +1 more source

Home - About - Disclaimer - Privacy