Estimation and uncertainty of reversible Markov models

Reversibility is a key concept in Markov models and Master-equation models of molecular kinetics. The analysis and interpretation of the transition matrix encoding the kinetic properties of the model relies heavily on the reversibility property. The estimation of a reversible transition matrix from simulation data is therefore crucial to the successful application of the previously developed theory. In this work we discuss methods for the maximum likelihood estimation of transition matrices from finite simulation data and present a new algorithm for the estimation if reversibility with respect to a given stationary vector is desired. We also develop new methods for the Bayesian posterior inference of reversible transition matrices with and without given stationary vector taking into account the need for a suitable prior distribution preserving the meta- stable features of the observed process during posterior inference. All algorithms here are implemented in the PyEMMA software - http://pyemma.org - as of version 2.0

Influence of tectonic inversion and salt mobility on structural styles and reservoir quality in the Norwegian Central Trough

Tectonic inversion and halokinesis are well documented as mechanisms for generating structural traps for hydrocarbons. Many sedimentary basins that contain kinematically active halite deposits have also experienced deformation related to positive tectonic inversion (contractional reactivation of pre-existing structures). In such cases, patterns of uplift are often complex and the relative role of competing deformation processes and their influence on structural style is poorly understood.The focus for this study is the Norwegian sector of the Central North Sea. A major petroleum play comprises Chalk Group reservoirs, where trap development has previously been attributed to halokinesis of the Permian Zechstein Supergroup, to Mesozoic and Cenozoic tectonic inversion events, and to a combination of both, but has never been well understood. Interpretation of high resolution 3D seismic data from a 5000 km2 area has revealed new insights into the relationship between tectonic inversion and halokinesis.Halite of the Zechstein Supergroup became mobile during the Triassic, with the creation of minibasins and adjacent salt highs. Salt movements continued until Miocene times. Tectonic inversion was driven by far-field plate margin forces and occurred during comparatively discrete intervals; the principal events are dated Maastrichtian - Danian (contemporaneous with Chalk deposition) and Eocene - Middle Miocene. The timing and extent of salt movement prior to inversion is a major control on structural style associated with that inversion; there are consistent and predictable differences between salt-free areas as opposed to salt-prone areas. Where there is no salt (or salt has been expelled) structural styles are deep-seated, more asymmetric and localized over the site of a pre-existing structural trend.Tectonic inversion and halokinesis have affected the porosity and permeability characteristics, and therefore the reservoir quality, of the Upper Cretaceous Chalk Group. Syn-depositional uplift exerted a strong influence over Chalk Group thickness distribution and depositional facies type. Sedimentological studies suggest initial (facies-related) matrix porosity variations were preserved or even enhanced during subsequent diagenesis.The physical characteristics of internal fracturing are a major control over Chalk Group reservoir quality. Historically, it has been difficult to characterize sub-seismic scale 3D heterogeneities within the Chalk Group. This study has addressed the problem of fracture development in response to fold growth through integration of theoretical considerations, subsurface data and outcrop observations, using suitably chosen structural analogues. It is probable that both inversion and halokinesis directly affected and enhanced the fracture characteristics of the reservoir

Shine On, Oh Stars! : \b Romanza

https://digitalcommons.library.umaine.edu/mmb-vp/4042/thumbnail.jp

Why Do We Teach Harmony So Badly?

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Symmetrized mean-field description of magnetic instabilities in k-(BEDT-TTF)_2Cu[N(CN)]_2 Y salts

We present a novel and convenient mean-field method, and apply it to study the metallic/antiferromagnetic interface of k-(BEDT-TTF)_2Cu[N(CN)]_2 Y organic superconductors (BEDT_TTF is bis-ethylen-dithio-tetrathiafulvalene, Y=Cl, Br). The method, which fully exploits the crystal symmetry, allows one to obtain the mean-field solution of the 2D Hubbard model for very large lattices, up to 6x10^5 sites, yielding a reliable description of the phase boundary in a wide region of the parameter space. The metal/antiferromagnet transtion appears to be second order, except for a narrow region of the parameter space, where the transition is very sharp and possibly first order. The cohexistence of metallic and antiferromagnetic properties is only observed for the transient state in the case of smooth second order transitions. The relevance of the present resaults to the complex experimental behavior of centrosymmetric k-phase BEDT-TTF salts is discussed.Comment: 9 pages in PS format, 7 figures (included in PS), 1 tabl

PROCEEDINGS OF THE 2019 CALIFORNIA WATER LAW SYMPOSIUM PANEL ORGANIZED BY GGU SCHOOL OF LAW: SGMA AND INTERCONNECTED GROUNDWATERSURFACE WATER

California’s Sustainable Groundwater Management Act (“SGMA”) has been the topic of many discussions since its enactment in 2014. The overarching goal of SGMA is to achieve sustainable groundwater basins through management plans “without causing undesirable results.” Considering the importance and magnitude of this task, it comes as no surprise that SGMA was the theme for the February 2019 California Water Law Symposium, held at the University of California (“UC”), Hastings College of Law in San Francisco. For the Symposium, Golden Gate University School of Law (“GGU”) students gathered a panel of experts to explore the relationship between groundwater plans and surface water within the context of SGMA. The GGU panel focused on issues stemming from the hydrological connections — particularly the undesirable results — between surface water and groundwater, impacts on fisheries, and the public trust doctrine

Choral March; Advance, Britannia!

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