Computer Sciences Corporation

About: Computer Sciences Corporation is a based out in . It is known for research contribution in the topics: Spacecraft & Software development. The organization has 1916 authors who have published 2389 publications receiving 62729 citations. The organization is also known as: CSC.

Prevalence of Down Syndrome Among Children and Adolescents in 10 Regions of the United States

Abstract: OBJECTIVE: We aimed to estimate the prevalence of Down syndrome (DS) among children and adolescents aged 0 to 19 years in 10 regions of the United States. METHODS: This study was a cross-sectional analysis of live-born infants with DS during 1979–2003 from 10 population-based birth defects registries in the United States. We estimated the prevalence of DS at birth and among children aged 0 to 19 years in each region and in all regions pooled. The prevalence of DS among children and adolescents was calculated overall and according to age group, race/ethnicity, infant gender, and presence of a major heart defect. RESULTS: From 1979 through 2003, the prevalence of DS at birth increased by 31.1%, from 9.0 to 11.8 per 10000 live births in 10 US regions. In 2002, the prevalence among children and adolescents (0–19 years old) was 10.3 per 10000. The prevalence of DS among children in a given age group consistently increased over time but decreased with age within a given birth cohort. The pooled prevalence of DS among children and adolescents was lower among non-Hispanic black individuals and other racial/ethnic groups compared with non-Hispanic white individuals; it was also lower among females than males. CONCLUSIONS: This study provides prevalence estimates of DS among children and adolescents from 10 US regions. These estimates varied according to region, race/ethnicity, and gender, suggesting possible variation in prevalence at birth or in survival rates on the basis of these characteristics.

Some Experiments in Local Microcode Compaction for Horizontal Machines

Abstract: Microcode compaction is an essential tool for the compilation of high-level language microprograms into microinstructions with parallel microoperations. The purpose of the research reported in this paper is to compare four microcode compaction methods reported in the literature: first-come first-served, critical path, branch and bound, and list scheduling. In order to do this a complete, machine independent method of representing the microoperations of real machines had to be developed; and the compaction algorithms had to be recast to use this representation. The compaction algorithms were then implemented and tested on microcode produced by a compiler for a high-level microprogramming language. The results of these experiments were that for all cases examined the first-come first-served and list scheduling algorithms produced microcode compacted into a minimal number of microinstructions in time that was a polynomial function of order two of the number of input microoperations.

A field information-based system for estimating fish temperature tolerances

Abstract: In 1979, Biesinger et al. described a technique for spatial and temporal matching of records of stream temperatures and fish sampling events to obtain estimates of yearly temperature regimes for freshwater fishes of the United States. This article describes the state of this Fish and Temperature Database Matching System (FTDMS), its usage to estimate thermal requirements for fishes, some proposed maximum temperature tolerances for several freshwater fish species, and the way these FTDMS-derived values relate to various laboratory test results. Although applicable to all species for which collection records exist, initial development and refinement of FTDMS has focused on estimating the maximum weekly mean temperature tolerance for 30 common fishes of the United States. The method involves extensive use of automated data processing during data incorporation, quality assurance checks, data matching, and endpoint calculation. Maximum weekly mean temperatures derived from FTDMS were always less than ...

The correlation of peak ground acceleration amplitude with seismic intensity and other physical parameters

Abstract: An analysis of acceleration/intensity correlations has been carried out using a new, worldwide data sample compiled for this study from data measured from nearly 1500 strong-motion accelerograms. This new data sample has been extensively analyzed using a variety of statistical models. It has been found that the correlation equation relating peak horizontal ground acceleration (a H ) to Modified Mercalli intensity ( I MM ) which best describes the trends in the subset of this new sample consisting of the nearly 900 observations for which a H ≧ 10 cm/sec2 is log a H = 0.25 I M M + 0.25 for a H given in cm/sec2. Analyses of the dependence of this correlation on other variables such as local earthquake magnitude (M) , epicentral distance (R) and the geographical region in which the earthquakes are occuring suggest that over the range of these variables encompassed by the available data, the correlation equation which best fits the data is log a H = 0.14 I M M + 0.24 M − 0.68 log R + β k where R is given in kilometers and β Western United States = 0.60 β Japan = 0.69 β Southern Europe = 0.88. Thus, the Southern European data indicate peak horizontal accelerations at fixed values of intensity, magnitude and epicentral distance which are about a factor of two higher than the corresponding values for the Western United States and Japan. Sufficient data are not yet available to determine whether this difference is due to a consistent measurement bias associated with the assignment of intensities in Southern Europe or to variations in the regional tectonic environment in which the earthquakes are occurring.