Star tracker constraint violations digital capability description and analysis results. Mission planning, mission analysis, and software formulation

Results of star tracker constraint violation analyses performed with the digital computer program Shuttle Attitude and Pointing Time Line Processor (SAPT) are presented. Results are typical of those utilized to provide the information required to update Baseline Reference Mission Attitude and Pointing Time Lines. Descriptions of SAPT modifications implemented to perform these analyses are also presented

Patterns of Asexuality in the United States

In this paper we use data from the 2002 National Survey of Family Growth (NSFG) to ascertain and analyze patterns of asexuality in the United States. We endeavor to extend the earlier work of Bogaert (2004) on this topic, which focused on patterns of asexuality in Great Britain. Using a social constructionist perspective to study asexuality, we conceptualize and measure the phenomenon in several ways, according to behavior, desire, and self-identification. We use the NSFG respondent sampling weights to produce several sets of unbiased estimates of the percentages of persons in the U.S. population, aged 15-44, who are asexual; each set is based on one or more of the various definitions of asexuality. Finally, we describe some of the characteristics of the asexual population using multinomial logistic regression.self-identification, sexual behavior

Deaths Exceed Births in Most of Europe, But Not in the United States

In this brief, authors Kenneth Johnson, Layton Fields, and Dudley Poston, Jr. present important new findings about the diminishing number of births compared to deaths in Europe and the United States from their recent article in Population and Development Review. Their research focuses on the prevalence and dynamics of natural decrease in subareas of Europe and the United States in the first decade of the twenty-first century using counties (United States) or county-equivalents (Europe). The authors report that 58 percent of the 1,391 counties of Europe had more deaths than births during that period compared to just 28 percent of the 3,137 U.S. counties. Natural decrease is more widespread in Europe because its population is older, fertility rates are lower, and there are fewer women of child-bearing age. Natural decrease is a major policy concern because it drains the demographic resilience from a region, diminishing its economic viability and competitiveness. The implications of the recent European immigrant surge for natural decrease are uncertain, but the authors’ analysis suggests that natural decrease is likely to remain widespread in Europe for the foreseeable future

The Statistical Modeling Of The Fertility Of Chinese Women

This article is concerned with the statistical modeling of children ever born (CEB) fertility data. It is shown that in a low fertility population, such as China, the use of linear regression approaches to model CEB is statistically inappropriate because the distribution of the CEB variable is often heavily skewed with a long right tail. For five sub-groups of Chinese women, their fertility is modeled using Poisson, negative binomial, and ordinary least squares (OLS) regression models. It is shown that in almost all instances there would have been major errors of statistical inference had the interpretations of the results been based only on the results of the linear regression models

Technology assessment of portable energy RDT and P

Results are presented of a workshop conducted to assess portable energy technology. The results were evaluated and areas for future research were considered. Several research categories were studied: increasing presently available fuel supplies, developing new fuel sources, utilization of new transportation fuels, improving conservation practices, and equitable distribution of fuel supplies. Several research projects were proposed, and work statements were constructed for those considered suitable

Using Zero-inflated Count Regression Models To Estimate The Fertility Of U. S. Women

In the modeling of count variables there is sometimes a preponderance of zero counts. This article concerns the estimation of Poisson regression models (PRM) and negative binomial regression models (NBRM) to predict the average number of children ever born (CEB) to women in the U.S. The PRM and NBRM will often under-predict zeros because they do not consider zero counts of women who are not trying to have children. The fertility of U.S. white and Mexican-origin women show that zero-inflated Poisson (ZIP) and zero-inflated negative binomial (ZINB) models perform better in many respects than the Poisson and negative binomial models. Zero-inflated Poisson and negative binomial regression models are statistically appropriate for the modeling of fertility in low fertility populations, especially when there is a preponderance of women in the society with no children

The Multinomial Regression Modeling of the Cause-of-Death Mortality of the Oldest Old in the U.S.

The statistical modeling of the causes of death of the oldest old (persons aged 80 and over) in the U.S. in 2001 was conducted in this article. Data were analyzed using a multinomial logistic regression model (MNLM) because multiple causes of death are coded on death certificates and the codes are nominal. The percentage distribution of the 10 major causes of death among the oldest old was first examined; we next estimated a multinomial logistic regression equation to predict the likelihood of elders dying of one of the causes of death compared to dying of an “other cause.” The independent variables used in the equation were age, sex, race, Hispanic origin, marital status, education, and metropolitan/non-metropolitan residence. Our analysis provides insights into the cause of death structure and dynamics of the oldest old in the U.S., demonstrates that MNLM is an appropriate statistical model when the dependent variable has nominal outcomes, and shows the statistical interpretation for complex results provided by MNLM

Changchun Children Data Set

The Changchun Children Data-set consists of data on 1,461 children in Changchun schools. The survey was conducted in the urban and rural areas of Changchun, a city in Jilin Province in northeastern China in June and July of 1987. Dudley Poston (Texas A&M University) and Toni Falbo (University of Texas) conducted the survey in collaboration with Liu Yunde, Gu Zhongqing, Wang Shengjin, and Yin Hao, all of them (at the time) demographers at the Population research Institute of Jilin University. The survey contained four parts, with the children's teachers and parents (usually the mothers) each completing two parts. The data-set contains 33 variables for each of the children in the survey. For a detailed statement about the survey see D. Poston and T. Falbo, "Academic performance and personality traits of Chinese Children: 'Onlies' versus Others," American Journal of Sociology 96 (September, 1990), esp. pp. 437-441. The data-set is formatted in Stata, Version 8, accompanied by a codebook

Poverty in the Texas borderland and lower Mississippi Delta: A comparative analysis of differences by family type

We provide a comparative analysis of county-level poverty in the two poorest regions of the United States - the Texas Borderland and the Lower Mississippi Delta - with a special focus on differences by family type. Our results reveal important regional variation in both the prevalence of poverty and the composition of the poor population across major family types. Using OLS regression models of family type-specific poverty we demonstrate three key findings: 1) There are no significant regional differences in poverty levels by family type between the Borderland and the Delta, net of important structural factors that characterize the regions; 2) with the exception of the employment rate, the structural factors associated with poverty among married couple and single female-headed families are quite different; and 3) paradoxically, areas in the Borderland with high in-migration are especially likely to suffer from high married-couple family poverty. Our results suggest the need for regionally targeted and demographically tailored anti-poverty policies.family structure, Mississippi Delta, persistent poverty, poverty, regional poverty, Texas Borderland