The effect of additional observations on a previous least squares estimate

Additional observations effect on previous least squares estimat

Dollarizing Qualitative Discriminators Used in Best Value Source Selections

With the decreasing budget that gets allocated to the Department of Defense each year, the government needs to be able to acquire more with less. This has a direct impact on how source selections are conducted. This research proposes a method using four different levels of cost that will provide the government with the best overall value in the conduction of source selections. This differs from previous source selections, because source selection teams, in general, only considered proposal price in their evaluation

Candidate genes colocalized to linkage regions in inflammatory bowel disease

Background and Aims: The genes encoding for tumor necrosis factor-alpha (TNF-alpha), epidermal growth factor receptor (EGFR) and the vitamin D receptor (VDR) are colocalized to inflammatory bowel disease-associated linkage regions on chromosomes 6, 7 and 12. An association study of these gene polymorphisms with ulcerative colitis or Crohn's disease and a stratification according to disease phenotypes was performed in order to identify gentically homogenous subgroups. Patients and Methods: 119 healthy, unrelated controls, 95 patients with Crohn's disease and 93 patients with ulcerative colitis were genotyped for the (G to A) -308 TNF-alpha promoter polymorphism on chromosome 6, the codon 497 EGFR polymorphism on chromosome 7 and the Taql polymorphism of the VDR gene on chromosome 12. After genotyping, patients were stratified according to the respective disease phenotype. Results: A disequilibrium in the distribution of the VDR genotypes was found in patients with ulcerative colitis compared to controls (p = 0.024). In fistulizing and fibrostenotic Crohn's disease the `TT' genotype was significantly reduced compared with other phenotypes (p = 0.006), whereas the `tt' genotype was found more frequently (p = 0.04). The frequency of the WT allele of the EGFR gene was significantly higher in ulcerative colitis (p = 0.04) than in controls. Further significant differences, concerning the associations of the different polymorphisms and disease susceptibility or clinical phenotypes, were not observed. Conclusions: Regardless of the disease phenotype, the associations between the polymorphisms and inflammatory bowel disease investigated herein are modest, even after stratification for the disease phenotypes. Hence, these polymorphisms are unlikely to confer the reported linkage between inflammatory bowel disease and chromosomes 6, 7 and 12. Copyright (C) 2002 S. Karger AG, Basel

Charged sectors, spin and statistics in quantum field theory on curved spacetimes

The first part of this paper extends the Doplicher-Haag-Roberts theory of superselection sectors to quantum field theory on arbitrary globally hyperbolic spacetimes. The statistics of a superselection sector may be defined as in flat spacetime and each charge has a conjugate charge when the spacetime possesses non-compact Cauchy surfaces. In this case, the field net and the gauge group can be constructed as in Minkowski spacetime. The second part of this paper derives spin-statistics theorems on spacetimes with appropriate symmetries. Two situations are considered: First, if the spacetime has a bifurcate Killing horizon, as is the case in the presence of black holes, then restricting the observables to the Killing horizon together with "modular covariance" for the Killing flow yields a conformally covariant quantum field theory on the circle and a conformal spin-statistics theorem for charged sectors localizable on the Killing horizon. Secondly, if the spacetime has a rotation and PT symmetry like the Schwarzschild-Kruskal black holes, "geometric modular action" of the rotational symmetry leads to a spin-statistics theorem for charged covariant sectors where the spin is defined via the SU(2)-covering of the spatial rotation group SO(3).Comment: latex2e, 73 page

Twin Texts and Technology: Enhancing Algebra Instruction for Elementary Teachers

Introduction: Algebra is often thought of as a course taken in high school, not a part of mathematics instruction in the elementary grades. In reality, algebra is the study of mathematics concerning structure, relations, and quantity and justifying those relationships (Blanton, 2008)

Set Membership Parameter Estimation and Design of Experiments Using Homothety

In this note we address the problems of obtaining guaranteed and as good as possible estimates of system parameters for linear discrete–time systems subject to bounded disturbances. Some existing results relevant for the set–membership parameter identification and outer–bounding are first reviewed. Then, a novel method for characterizing the consistent parameter set based on homothety is offered; the proposed method allows for the utilization of general compact and convex sets for outer–bounding. Based on these results, we consider the one–step input design and identifiability problems in set–membership setting. We provide a guaranteed approach for the one–step input design problem, by selecting optimal inputs for the purpose of parameter estimation. As optimality criterion, the dimension and the outer– bounding volume of the “anticipated ” consistent parameter set is considered. We furthermore derive a sufficient criterion for (one–step) parameter identifiability, i.e. when a point estimate for a parameter can be guaranteed for all possible measurements

Introducing New Methodologies for Identifying Design Patterns for Internationalization and Localization

This paper describes a new methodology for deriving interaction design patterns from an analysis of ethnographic data. It suggests using inductive and deductive analysis processes to identify and articulate patterns that address the needs of culturally diverse users of interactive, collaborative systems. This might inform the internationalization and localization process of computer supported collaboration systems

Long term trend of selected halogenated hydrocarbons

The so-called 'Library of Background Air' at the Oregon Graduate Institute was used to determine the trend in volume mixing ratios of selected halogenated hydrocarbons in the time period 1977-1989. This library consists of background air samples most of them taken at Cape Meares (Oregon). For storage stainless steel containers are used. Tests have shown the gases under consideration to be stable in these containers. Analyses using a GC/MS-system were performed for the CFCs 11, 12, 12B1 (HALON 1211, CBrClF2), 22, 113, 114 and CH3Cl, CH3Br, CH3CCl3, CCl4. The advantage of this unique investigation: different aged air samples are analyzed at the same time with the same instrument. No calibrations or intercalibrations are needed. All data are presented in normalized mixing ratios versus time. We discuss the results, derive rate constants and present a formula to describe the nonlinear increases