We introduce a novel dynamic model for discrete time-series data, in which the temporal sampling may be nonuniform. The model is specified by constructing a hierarchy of Poisson factor analysis blocks, one for the transitions between latent states and the other for the emissions between latent states and observations. Latent variables are binary and linked to Poisson factor analysis via Bernoul...

A new class of space-time models derived from standard dynamic factor models is proposed. The temporal dependence is modeled by latent factors while the spatial dependence is modeled by the factor loadings. Factor analytic arguments are used to help identify temporal components that summarize most of the spatial variation of a given region. The temporal evolution of the factors is described in ...

Introduction: In this study the automatic separation of oral and salivary gland activity and spontaneous secretion by means of factor analysis for quantitative salivary gland scintigraphy is introduced. Methods: After intravenous administration of 99mTc sodium pertechnetate, dynamic scintigraphy was performed. 20 minutes after tracer application 2 ml of lemon juice was delivered to stimulate t...

in this paper, the main factors in the analysis of the railway concrete sleepers areinvestigated and new recommendations are made in order to improve the accuracy of the currentpractices in analysis of the railway track system. first, a comprehensive literature survey isconducted, then, fem models for a railway track system are developed and used to discuss andevaluate the assumptions commonly ...

progressive collapse is a chain reaction of failures propagating throughout a portion of the structure disproportionate to the original local failure occurring when a sudden loss of a critical load‐bearing element initiates a structural element failure, eventually resulting in partial or full collapse of the structure. both general services administration (gsa) and united states department of d...

we studied litterfall dynamic of tree plantations in dez river floodplain, at 14 to 15 years old. the plantations consist of populus euphratica oliv., eucalyptus camaldulensis dehnh., e. microtheca f. muell, acacia farnesiana (l.) willd., a. salicina lindl., a. saligna (labill.) h. wendl., a. stenophylla benth. and dalbergia sissoo roxb. litterfall was different between the tree species, and le...

response modification factor (r factor) is one of the seismic design parameters to be considered in evaluating the performance of buildings during strong motions. this paper has tried to evaluate the response modification factor of concrete coupled shear wall structures with various length/depth ratios of spandrel beams. the effect of diagonal reinforcement of spandrel beam was also evaluated o...

the problem of several finite moving cracks in a functionally graded material is solved by dislocation technique under the condition of anti-plane deformation. by using the fourier transform the stress fields are obtained for a functionallygraded strip containing a screw dislocation. the stress components reveal the familiar cauchy singularity at thelocation of dislocation. the solution is empl...

ports are the most important economic, political and military bottlenecks. this puts shoreline structures (port) in the class of important structures and they have a crucial role in the countries’ life. pile and deck wharf and their access bridges and offshore deck (jetties), are one of the parts which are supplier of coupling between the land and the waterfront. correct and exact estimation of...