Pavement Network Maintenance Optimization Considering Multidimensional Condition Data

A growing body of research seeks to optimize the selection and scheduling of maintenance, repair and rehabilitation activities for networks of sections of pavement. Such research typically relies on a composite condition index, a one-dimensional and often discrete measure of the overall structural health and/or serviceability of pavement. Pavement can suffer from a large number of related but distinct distresses. Difficulties associated with unobserved heterogeneity have hampered efforts to accurately model deterioration via composite condition indices. At the same time, optimization techniques used in pavement management have been shown both to be sensitive to deterioration model specification and to become computationally intractable as condition data increase. This research describes how approximate dynamic programming can be used to manage a large network of related sections of pavement each one of which may be plagued by a number of different distresses. Approximate dynamic programming mitigates the curse of dimensionality that has haunted distinct Markov decision problem formulations of the infrastructure management problem and limited their complexity. A computational study illustrates how the proposed approach leads to more sophisticated maintenance decision rules, which can be used to ensure the suggestions of pavement management systems more closely match engineering best practice

Gaia Stellar Kinematics in the Head of the Orion A Cloud: Runaway Stellar Groups and Gravitational Infall

This work extends previous kinematic studies of young stars in the Head of the Orion A cloud (OMC-1/2/3/4/5). It is based on large samples of infrared, optical, and X-ray selected pre-main sequence stars with reliable radial velocities and Gaia-derived parallaxes and proper motions. Stellar kinematic groups are identified assuming they mimic the motion of their parental gas. Several groups are found to have peculiar kinematics: the NGC 1977 cluster and two stellar groups in the Extended Orion Nebula (EON) cavity are caught in the act of departing their birthplaces. The abnormal motion of NGC 1977 may have been caused by a global hierarchical cloud collapse, feedback by massive Ori OB1ab stars, supersonic turbulence, cloud-cloud collision, and/or slingshot effect; the former two models are favored by us. EON groups might have inherited anomalous motions of their parental cloudlets due to small-scale `rocket effects' from nearby OB stars. We also identify sparse stellar groups to the east and west of Orion A that are drifting from the central region, possibly a slowly expanding halo of the Orion Nebula Cluster. We confirm previously reported findings of varying line-of-sight distances to different parts of the cloud's Head with associated differences in gas velocity. Three-dimensional movies of star kinematics show contraction of the groups of stars in OMC-1 and global contraction of OMC-123 stars. Overall, the Head of Orion A region exhibits complex motions consistent with theoretical models involving hierarchical gravitational collapse in (possibly turbulent) clouds with OB stellar feedback.Comment: Accepted for publication in MNRAS. 26 pages, 13 figures. The two 3-D stellar kinematic movies, aimed as Supplementary Materials, can be found on YouTube at: https://youtu.be/B4GHCVvCYfo (`restricted' sample) and https://youtu.be/6fUu8sP0QFI (`full' sample

The Deceitful Artist in German Expressionist Drama

Given the strongly antibourgeois bias of Expressionist art, it is hardly surprising to find that the topos of the artist as imposter plays an important role in many early Expressionist dramas. Portrayed as an outsider, the artist is juxtaposed with a proprietary society that regards his art as a commodity. Depicting the materialistic assessment of art in capitalist society as a given, these plays explore the existential possibilities open to the artist faced with the devaluation of art in the early twentieth century. Thus, these plays reflect a concern common to literary Expressionism, i.e., criticism of bourgeois capitalism. Four plays that use this particular artist- society dialectic for social criticism are Frank Wedekind\u27s Marquis von Keith (1900), Carl Sternheim\u27s Burger Schippel (1913), Hanns Johst\u27s Der Einsame (1917), and Bertolt Brecht\u27s Baal (1918). Common to these plays is an inherent antagonism between the artist -hero and a philistine society, a society which the artist disdains yet into which he paradoxically seeks entry or upon which he is materially and/or emotionally dependent. The responses of the artist figures in the face of their ambivalence vis-a-vis a corrupt society are strikingly similar: resorting to deceit, they seek either to outwit or to coopt the bourgeoisie. The solutions offered in these plays to the particular exigencies of the artists\u27 situation establish the parameters of possible response — ranging from assimilation to total isolation — for the artist-outsider hero in bourgeois capitalist society

A Scholar\u27s Guide to Poster Power

Have you ever presented a poster at a conference? No? Want to try? It\u27s an easily implementable initial entry into conference presenting in a more intimate, low-key and low-threshold environment than it would be to start off with a formal presentation to a huge audience. Sometimes, conference fees are even waived. Regardless, the experience can bring about valuable partnerships. View this poster to learn tricks of the trade for powerful poster presentations. Remember, it\u27s really easy to make a bad poster, but not too difficult to make a great poster, especially if you follow these practical tips.https://commons.und.edu/cfl-lpp/1000/thumbnail.jp

An Overview and Discussion of Fred E. Fiedler\u27s Contingency Model of Leadership Effectiveness

A discussion of the components of Fred E. Fiedler\u27s (Professor Emeritus of Psychology at the University of Washington) Contingency Model of Leadership Effectiveness (1964), including its applicability to public libraries