An overview of reliability growth models and their potential use for NASA applications

An overview is provided of reliability growth literature over the past 25 years. This includes a thorough literature review of different areas of the application of reliability growth such as design, prediction, tracking/management, and demonstration. Various reliability growth models use different bases on how they characterize growth. Different models are discussed. Also, the use is addressed of reliability growth models to NASA applications. This includes the application of these models to the space shuttle main engine. For potential NASA applications, we classify growth models in two groups, which are characterized

Generalized Parton Distributions from Hadronic Observables: Zero Skewness

We propose a physically motivated parametrization for the unpolarized generalized parton distributions. At zero value of the skewness variable, $\zeta$, the parametrization is constrained by simultaneously fitting the experimental data on both the nucleon elastic form factors and the deep inelastic structure functions. A rich phenomenology can be addressed based on this parametrization. In particular, we track the behavior of the average: {\it i)} interparton distances as a function of the momentum fraction, $X$, {\it ii)} $X$ as a function of the four-momentum transfer, $t$; and {\it iii)} the intrinsic transverse momentum $k_\perp$ as a function of $X$. We discuss the extension of our parametrization to $\zeta \neq 0$ where additional constraints are provided by higher moments of the generalized parton distributions obtained from {\it ab initio} lattice QCD calculations.Comment: 42 pages, 21 figure

Technology Adoption Life Cycle and Sustainability in ERP Industry - A Data Envelopment Analysis Approach

The Technology Adoption Life Cycle (TALC) has been used in studying the sustainability of hyper-growth, high-tech markets. Recent work in this area has identified the presence of “chasm” in this lifecycle. Since most technology products ultimately derive their value from software, this study explores the effect of chasm on the sustainability issues in software industry. This paper presents an empirical study of selected ERP companies during the period 1989–2004. We investigate whether these companies experience the stages of TALC and the chasm effect as seen in other high-tech markets. Using financial data, we focus on R&D / Marketing expenses and sales revenue of companies and apply DEA to measure efficiency and investigate the sources and level of inefficiencies in these companies. The results demonstrate that efficient companies are not just investing more in R&D and Marketing, but are in fact managing the inputs better than the inefficient companies

NASAL CARRIAGE OF STAPHYLOCOCCUS AUREUS WITH SPECIAL EMPHASIS ON METHICILLINRESISTANT STAPHYLOCOCCUS AUREUS AMONG STUDENTS OF A SOUTH INDIAN MEDICAL COLLEGE - PREVALENCE AND ANTIBIOGRAM PATTERN

ABSTRACTObjective: There is paucity of information on carriage of Staphylococcus aureus and Methicillin Resistant S.aureus from developing nations includingthe medical students who could be the potential transmitters. Present study was aimed at establishing the prevalence and antibiogram pattern ofS. aureus with special emphasis on MRSA among II year MBBS students of Kasturba Medical College, Mangalore.Methods: A total of 148 students were participated in this study. Swabs taken from both anterior nares were processed, and the growth of S. aureuswas confirmed by standard procedure. Further categorization of S. aureus into MRSA was done using cefoxitin disc diffusion method, along with theantibiogram to other common drugs.Results: The number of strains of S. aureus isolated from our 148 participants was 78 with a percentage rate of 52.7. Of the 78 isolates of S. aureus,9 (11.5%) were MRSA. The overall MRSA carriage rate was 6.1%.Conclusion: The S. aureus and MRSA carriage rates recorded in this study were significantly higher when compared with other reported studies. Itwas observed that risk factors like use of antibiotics in past 6 months and snoring were found to be statistically significant in nasal carriage status ofS. aureus. Out of nine MRSA carriers, six were found to be having the parents who were busy clinicians by occupation and the close contact with themcould be the prime factor in the acquisition of MRSA carriage status.Keywords: Staphylococcus aureus, MRSA, Nasal carriage, Medical students

The length of time's arrow

An unresolved problem in physics is how the thermodynamic arrow of time arises from an underlying time reversible dynamics. We contribute to this issue by developing a measure of time-symmetry breaking, and by using the work fluctuation relations, we determine the time asymmetry of recent single molecule RNA unfolding experiments. We define time asymmetry as the Jensen-Shannon divergence between trajectory probability distributions of an experiment and its time-reversed conjugate. Among other interesting properties, the length of time's arrow bounds the average dissipation and determines the difficulty of accurately estimating free energy differences in nonequilibrium experiments

Zeroth Law compatibility of non-additive thermodynamics

Non-extensive thermodynamics was criticized among others by stating that the Zeroth Law cannot be satisfied with non-additive composition rules. In this paper we determine the general functional form of those non-additive composition rules which are compatible with the Zeroth Law of thermodynamics. We find that this general form is additive for the formal logarithms of the original quantities and the familiar relations of thermodynamics apply to these. Our result offers a possible solution to the longstanding problem about equilibrium between extensive and non-extensive systems or systems with different non-extensivity parameters.Comment: 18 pages, 1 figur