Estimating the relationship between local, public and private investment

A discussion of whether public outlays influence private investment, modeling the timing and effectiveness of public infrastructure as a local policy instrument.Infrastructure (Economics) ; Economic development ; Municipal finance

Removing observational noise from fisheries-independent time series data using ARIMA models

Abundance indices derived from fishery-independent surveys typically exhibit much higher interannual variability than is consistent with the within-survey variance or the life history of a species. This extra variability is essentially observation noise (i.e. measurement error); it probably reflects environmentally driven factors that affect catchability over time. Unfortunately, high observation noise reduces the ability to detect important changes in the underlying population abundance. In our study, a noise-reduction technique for uncorrelated observation noise that is based on autoregressive integrated moving average (ARIMA) time series modeling is investigated. The approach is applied to 18 time series of finfish abundance, which were derived from trawl survey data from the U.S. northeast continental shelf. Although the a priori assumption of a random-walk-plus-uncorrelated-noise model generally yielded a smoothed result that is pleasing to the eye, we recommend that the most appropriate ARIMA model be identified for the observed time series if the smoothed time series will be used for further analysis of the population dynamics of a species

X-Ray Flux/Spectral Variability of the Gravitationally Lensed Blazar PKS 1830-211

From the Washington University Office of Undergraduate Research Digest (WUURD), Vol. 12, 05-01-2017. Published by the Office of Undergraduate Research. Joy Zalis Kiefer, Director of Undergraduate Research and Associate Dean in the College of Arts & Sciences; Lindsey Paunovich, Editor; Helen Human, Programs Manager and Assistant Dean in the College of Arts and Sciences Mentor: Henric Krawcynsk

The Formation of Stars: From Clouds to Cores

High resolution simulations were conducted to investigate different stages of the star formation process, from molecular cloud formation to single protostellar collapse. The simulations were performed using AstroBEAR, a state-of-the-art, multiphysics, adaptive mesh refinement code for astrophysical fluid dynamics. In each of the cases, the fluid dynamical properties of the potentially star forming gas were investigated to reveal the relative roles of gravity, magnetic fields, turbulence, and shocks. The models successfully produce many of the structural characteristics of star forming regions. While the simulations modeled isolated, or semi-isolated, phases of the star formation process, cumulatively they represent over 5 orders of magnitude change in spatial scale. Insights provided from this work will aid the development and interpretation of the next generation of simulations -- those which will model star formation through the phases using self-consistent, hierarchical frameworks

I\u27ll Love You Honey All The Time

https://digitalcommons.library.umaine.edu/mmb-vp/3201/thumbnail.jp

Now What D\u27ye Think of That

https://digitalcommons.library.umaine.edu/mmb-vp/4563/thumbnail.jp

Molecular cloud formation in high-shear, magnetized colliding flows

The colliding flows (CF) model is a well-supported mechanism for generating molecular clouds. However, to-date most CF simulations have focused on the formation of clouds in the normal-shock layer between head-on colliding flows. We performed simulations of magnetized colliding flows that instead meet at an oblique-shock layer. Oblique shocks generate shear in the post-shock environment, and this shear creates inhospitable environments for star formation. As the degree of shear increases (i.e. the obliquity of the shock increases), we find that it takes longer for sink particles to form, they form in lower numbers, and they tend to be less massive. With regard to magnetic fields, we find that even a weak field stalls gravitational collapse within forming clouds. Additionally, an initially oblique collision interface tends to reorient over time in the presence of a magnetic field, so that it becomes normal to the oncoming flows. This was demonstrated by our most oblique shock interface, which became fully normal by the end of the simulation

Lookin\u27 Out My Back Door

Portrait of Creedence Clearwater Revivalhttps://scholarsjunction.msstate.edu/cht-sheet-music/7468/thumbnail.jp