Despite their popularity, many questions about the algebraic constraints imposed by linear structural equation models remain open problems. For causal discovery, two of these problems are especially important: the enumeration of the constraints imposed by a model, and deciding whether two graphs define the same statistical model. We show how the half-trek criterion can be used to make progress ...

This paper compares a number of mathematical models for the Calvin cycle of photosynthesis and presents theorems on the existence and stability of steady states of these models. Results on five-variable models in the literature are surveyed. Next a number of larger models related to one introduced by Pettersson and Ryde-Pettersson are discussed. The mathematical nature of this model is clarifie...

Seemingly unrelated regression (SUR) models traditionally appear in econometrics but recently also emerged in likelihood factorizations of Gaussian graphical models. The literature on maximum likelihood estimation in SUR seems not to mention the possibility of a multimodallikelihood. \eVe want to increase the awareness of this phenomenon by a thorough study of a two-equation model illustrated b...

We report the measurement of reverse saturable absorption in four cubanelike transition-metal clusters with nanosecond laser pulses. We also present a five-level rate-equation model in which ionization and germinate recombination are included. A comparison between the model and the measured data shows that the population of the triplet states is generated mainly through the ionization–recombina...

in this study, the effect of environmental concern, attitudes and behaviors of the university students on the environmentally conscious purchasing behavior was investigated with the help of structural equation model (sem). sem is an effective data analysis tool that expresses the complicated causative relations between the latent variables. in this study, we collected the data from 400 univers...

platinum extraction from different secondary sources has been experimentally tested by many researchers. in this article, dissolution of platinum in aqua-regia solution from two types of spent catalysts (reforming and nitric acid production) was kinetically studied. a variety of kinetic models for heterogeneous solid-liquid reactions, including homogeneous diffusion model, shrinking core model,...

We study the slow-roll inflationary dynamics in a self-gravitating induced gravity braneworld model with bulk cosmological constant. For E ≫ M3 5 /M2 4 we find important corrections to the four-dimensional Friedmann equation which bring the standard chaotic inflationary scenario in closer agreement with recent observations. For M3 5 /M 2 P l ≪ E ≪ M3 5 /M2 4 we find five-dimensional corrections...

This paper deals with the problem of identification of photovoltaic arrays’ maximum power extraction point—information that is encrypted in the current-voltage characteristic equation. We propose a new parameterisation of the classical five parameter model of this function that, combined with the recently introduced identification technique of dynamic regressor extension and mixing, ensures a f...