Transaction Cost Case Studies for Six Iowa Food Producers

This document summarizes a Leopold Center Marketing Initative project (2006-M02) that looked at transaction costs incurred by Iowa-based food producers who distribute to in-state and regional markets

Case studies and benchmark transaction costs for select food products

Producer-distributors can use the information in this set of case studies to identify commercial advantages and disadvantages that can affect the success of their enterprises

How to Use Common Technologies to Minimize Perceptual Biases When Grading Essays: A Five-Step Process

Evaluation of student performance is an important component of higher education course work and a major dimension of Ignatian pedagogy. However, the process of grading essay exams (a popular assessment method in both the liberal arts and technical programs) naturally brings the threat of several perceptual biases that harm grading validity and consistency. Thus, we sought a method to collect and organize essay tests to minimize identification bias (make student authors anonymous to the grader) and randomize grading order to minimize systematic error (related to always grading the same students first or last). Specifically, in this paper, we describe a step-by-step innovative approach that uses multiple common computer technologies (NetSupport School, Word, DOS, and Excel) to prepare, administer, and grade essay examinations submitted by students. Within the Appendix, we describe the steps and how to use these common tools, but within the paper, we offer general guidelines to apply our methods using whatever software or technologies schools are currently using. The discussion section presents limitations to our described method, offers ideas of modifications that may meet the same goals, and recommends future research directions

Advanced Water Distribution Modeling and Management

Advanced Water Distribution Modeling and Management builds on Haestad Press’ Water Distribution Modeling book. Addressing the modeling process from data collection to application, Advanced Water Distribution Modeling and Management adds extensive material from an international team of experts from both academia and consulting firms and includes topics such as: In-depth coverage of optimization techniques for model calibration, system design, and pump operations. Advanced water quality modeling topics including tank mixing, water quality solution algorithms, sampling techniques, tracer studies, tank design, and maintenance of adequate disinfectant residuals. Integration of SCADA systems with water distribution modeling for estimating model demands, initial conditions, and control settings; forecasting system operations; calibrating extended-period simulation models; streamlining water quality analysis; and estimating water loss during a main break. The essentials of transient analysis including the causes and sources of transients, as well as the potential effects of transients on water distribution systems. Application of GIS technology for skeletonization, demand allocation, and pipe break analysis; discussion of the technological issues that arise when integrating GIS and water distribution modeling; and the current state of the technology. Use of models to assess water system vulnerability and security, respond to emergencies in real-time, simulate contamination events, prioritize physical security improvements, and unravel past contamination events

Sustaining star formation rates in spiral galaxies - Supernova-driven turbulent accretion disk models applied to THINGS galaxies

Gas disks of spiral galaxies can be described as clumpy accretion disks without a coupling of viscosity to the actual thermal state of the gas. The model description of a turbulent disk consisting of emerging and spreading clumps (Vollmer & Beckert 2003) contains free parameters, which can be constrained by observations of molecular gas, atomic gas and the star formation rate for individual galaxies. Radial profiles of 18 nearby spiral galaxies from THINGS, HERACLES, SINGS, and GALEX data are used to compare the observed star formation efficiency, molecular fraction, and velocity dispersion to the model. The observed radially decreasing velocity dispersion can be reproduced by the model. In the framework of this model the decrease in the inner disk is due to the stellar mass distribution which dominates the gravitational potential. Introducing a radial break in the star formation efficiency into the model improves the fits significantly. This change in star formation regime is realized by replacing the free fall time in the prescription of the star formation rate with the molecule formation timescale. Depending on the star formation prescription, the break radius is located near the transition region between the molecular-gas-dominated and atomic-gas-dominated parts of the galactic disk or closer to the optical radius. It is found that only less massive galaxies (log (M (M_solar)) <~ 10) can balance gas loss via star formation by radial gas accretion within the disk. These galaxies can thus access their gas reservoirs with large angular momentum. On the other hand, the star formation of massive galaxies is determined by the external gas mass accretion rate from a putative spherical halo of ionized gas or from satellite accretion.Comment: 26 pages, 5 figures, full figures 1 and 2 as ancillary pdf files available; accepted by A

Disjoint Hamilton cycles in transposition graphs

This paper was accepted for publication in the journal Discrete Applied Mathematics and the definitive published version is available at http://dx.doi.org/10.1016/j.dam.2016.02.007.Most network topologies that have been studied have been subgraphs of transposition graphs. Edge-disjoint Hamilton cycles are important in network topologies for improving fault-tolerance and distribution of messaging traffic over the network. Not much was known about edge-disjoint Hamilton cycles in general transposition graphs until recently Hung produced a construction of 4 edge-disjoint Hamilton cycles in the 5-dimensional transposition graph and showed how edge-disjoint Hamilton cycles in (n + 1)-dimensional transposition graphs can be constructed inductively from edge-disjoint Hamilton cycles in n-dimensional transposition graphs. In the same work it was conjectured that n-dimensional transposition graphs have n − 1 edge-disjoint Hamilton cycles for all n greater than or equal to 5. In this paper we provide an edge-labelling for transposition graphs and, by considering known Hamilton cycles in labelled star subgraphs of transposition graphs, are able to provide an extra edge-disjoint Hamilton cycle at the inductive step from dimension n to n + 1, and thereby prove the conjecture