NASA TLA workload analysis support. Volume 1: Detailed task scenarios for general aviation and metering and spacing studies

The techniques required to produce and validate six detailed task timeline scenarios for crew workload studies are described. Specific emphasis is given to: general aviation single pilot instrument flight rules operations in a high density traffic area; fixed path metering and spacing operations; and comparative workload operation between the forward and aft-flight decks of the NASA terminal control vehicle. The validation efforts also provide a cursory examination of the resultant demand workload based on the operating procedures depicted in the detailed task scenarios

A survey and analysis of the certification requirement preferences of New Hampshire elementary school principals

Thesis (Ed.M.)--Boston Universit

State promotion of local public goods: The case of public libraries, 1880-1929

The public library movement of the late nineteenth and early twentieth centuries led to a significant expansion of library services across the United States. We study the impact of state-level institutional development on the creation of local public goods. State library commissions were modestly funded state entities charged with helping localities establish libraries. State library associations were voluntary organizations with a similar mission, having as members the librarians of existing public libraries. Library-enabling legislation clarified the legality and taxation possibilities for local government entities such as towns, municipalities and counties to support libraries. Employing panel data drawn from a series of detailed reports on public libraries conducted by the U.S. Bureau of Education, we use a difference-in-differences methodology to identify the impact of commissions, associations, and enabling legislation on library development in matched pairs of counties that straddle state borders. Our results suggest that state-level institutions and legislation had a statistically and economically significant effect on public library development. The finding has implications for future interpretations of the history of the United States as a “nation of joiners”; local civic engagement and associational life was importantly influenced by larger scale civic and political action. JEL classifications: H40, H75, N31, N32, N41, N4

Public libraries and political participation, 1870-1940

The public library movement of the late 19th and early 20th centuries fostered a rapid increase in the number and quality of public libraries in cities and towns across the United States. One important argument for libraries was that they would enhance American democracy by promoting virtues of citizenship and enabling access to information. This paper examines how voter turnout was affected, in the short-term, by the establishment of public libraries, using a county-by-election year panel. Our empirical strategy exploits the founding dates of public libraries as discrete events that should have influenced subsequent voting behavior. Over the wide range of specifications considered, the vast majority of regression results suggest that libraries had no significant short term impact on voter turnout. We discuss potential reasons for this finding, and compare it with recent work finding a positive impact of newspapers on political participation. JEL classifications: H40, H75, N31, N32, N41, N4

Stewardship Contracting in the Siuslaw National Forest

(no abstract

The Decline and Rise of Interstate Migration in the United States: Evidence from the IPUMS, 1850-1990

We examine evidence on trends in interstate migration over the past 150 years, using data from the Integrated Public Use Microdata Series of the U.S. Census (IPUMS). Two measures of migration are calculated. The first considers an individual to have moved if she is residing in a state different from her state of birth. The second considers a family to have moved if it is residing in a state different from the state of birth of one of its young children. The latter measure allows us estimate the timing of moves more accurately. Our results suggest that overall migration propensities have followed a U-shaped trend since 1850, falling until around 1900 and then rising until around 1970. We examine variation in the propensity to make an interstate move by age, sex, race, nativity, region of origin, family structure, and education. Counterfactuals based on probit estimates of the propensity to migrate suggest that the rise in migration of families since 1900 is largely attributable to increased educational attainment. The decline of interstate migration in the late nineteenth century remains to be explained.

On-line diagnosis of unrestricted faults

A formal model for the study of on-line diagnosis is introduced and used to investigate the diagnosis of unrestricted faults. A fault of a system S is considered to be a transformation of S into another system S' at some time tau. The resulting faulty system is taken to be the system which looks like S up to time tau, and like S' thereafter. Notions of fault tolerance error are defined in terms of the resulting system being able to mimic some desired behavior as specified by a system similar to S. A notion of on-line diagnosis is formulated which involves an external detector and a maximum time delay within which every error caused by a fault in a prescribed set must be detected. It is shown that if a system is on-line diagnosable for the unrestricted set of faults then the detector is at least as complex, in terms of state set size, as the specification. The use of inverse systems for the diagnosis of unrestricted faults is considered. A partial characterization of those inverses which can be used for unrestricted fault diagnosis is obtained

A case of the Rodriguez Villegas conjecture

Let L be a number field and let E be any subgroup of the units O_L^* of L. If rank(E) = 1, Lehmer's conjecture predicts that the height of any non-torsion element of E is bounded below by an absolute positive constant. If rank(E) = rank(O_L^*), Zimmert proved a lower bound on the regulator of E which grows exponentially with [L:Q]. Fernando Rodriguez Villegas made a conjecture in 2002 that "interpolates" between these two extremes of rank. Here we prove a high-rank case of this conjecture. Namely, it holds if L contains a subfield K for which [L:K] >> [K:Q] and E contains the kernel of the norm map from O_L^* to O_K^*

Constructing and Writing Mathematical Proofs: A Guide for Mathematics Students

This little book is not intended to be a textbook for a course dealing with an introduction to constructing and writing mathematical proofs. It is intended to be a reference book for students who need to construct and write proofs in their upper division mathematics courses. So it is assumed that students who use this as a reference have already taken an “introduction to proofs” course. With the exception of Chapter 1, each chapter in the book has a description of a proof technique along with some justification as to why it is a valid proof method. There are then one or two completed proofs written according to the writing guidelines for mathematical proofs in Appendix A. The intent is to illustrate a well-written proof for that particular proof method. Each chapter then ends with three to five practice problems, most of which deal with mathematical proofs. Completed proofs (or solutions) for the practice problems are contained in Appendix B. So, students can check their work or see other examples of well-written proofs. Chapter 1 contains most of the definitions used in the first six chapters of this book and a short summary of some logic that is pertinent to constructing mathematical proofs. The proofs in this book primarily use the concepts of even and odd integers, the concept of one integer dividing another, and the concept of congruence in the integers. Most of this book is based on material in chapter 3 of the book Mathematical Reasoning: Writing and Proof, Version 2.1 by Ted Sundstrom, which is a textbook for an “introduction to proofs” course. It is free to download as a pdf file at https://scholarworks.gvsu.edu/books/9/. A printed version of this book is also available on amazon.com for $22 at http://gvsu.edu/s/16z. Finally, there is a website for Mathematical Reasoning: Writing and Proof, Version 2.1. Please visit www.tedsundstrom.com and click on the TEXTBOOKS button in the upper right corner. This website contains useful resources for an introduction to mathematical proofs course, and some of these resources could be useful for students in upper division mathematics courses.https://scholarworks.gvsu.edu/books/1023/thumbnail.jp