5,151 research outputs found
Scheduling Algorithm for Mission Planning and Logistics Evaluation (SAMPLE). Volume 2: Mission payloads subsystem description
The scheduling algorithm for mission planning and logistics evaluation (SAMPLE) is presented. Two major subsystems are included: The mission payloads program; and the set covering program. Formats and parameter definitions for the payload data set (payload model), feasible combination file, and traffic model are documented
Scheduling Algorithm for Mission Planning and Logistics Evaluation (SAMPLE). Volume 1: User's guide
An interactive computer program for automatically generating traffic models for the Space Transportation System (STS) is presented. Information concerning run stream construction, input data, and output data is provided. The flow of the interactive data stream is described. Error messages are specified, along with suggestions for remedial action. In addition, formats and parameter definitions for the payload data set (payload model), feasible combination file, and traffic model are documented
A Computational Procedure to Detect a New Type of High Dimensional Chaotic Saddle and its Application to the 3-D Hill's Problem
A computational procedure that allows the detection of a new type of
high-dimensional chaotic saddle in Hamiltonian systems with three degrees of
freedom is presented. The chaotic saddle is associated with a so-called
normally hyperbolic invariant manifold (NHIM). The procedure allows to compute
appropriate homoclinic orbits to the NHIM from which we can infer the existence
a chaotic saddle. NHIMs control the phase space transport across an equilibrium
point of saddle-centre-...-centre stability type, which is a fundamental
mechanism for chemical reactions, capture and escape, scattering, and, more
generally, ``transformation'' in many different areas of physics. Consequently,
the presented methods and results are of broad interest. The procedure is
illustrated for the spatial Hill's problem which is a well known model in
celestial mechanics and which gained much interest e.g. in the study of the
formation of binaries in the Kuiper belt.Comment: 12 pages, 6 figures, pdflatex, submitted to JPhys
A Cross-cohort Description of Young People’s Housing Experience in Britain over 30 Years: An Application of Sequence Analysis
Methods. Sequence Analysis supported by Event History Analysis. Key Findings. Despite only 12 years separating both cohorts, the younger 1970 cohort exhibited very different patterns of housing including a slower progression out of the parental home and into stable tenure, and an increased reliance on privately rented housing. Returns to the parental home occurred across the twenties and into the thirties in both cohorts, although occurred more frequently and were more concentrated among certain groups in the 1970 cohort compared to the 1958 cohort. Although fewer cohort members in the 1970 cohort experienced social housing, and did so at a later age, social housing was also associated with greater tenure immobility in this younger cohort. Conclusions. The housing experiences of the younger cohort became associated with more unstable tenure (privately rented housing) for the majority. Leaving the parental home was observed to be a process, as opposed to a one-off event, and several returns to the parental home were documented, more so for the 1970 cohort. These findings are not unrelated, and in the current environment of rising house prices, collapses in the (youth) labour market and rising costs of higher education, are likely to increase in prevalence across subsequent cohorts
Normalizers of Irreducible Subfactors
We consider normalizers of an irreducible inclusion of
factors. In the infinite index setting an inclusion
can be strict, forcing us to also investigate the semigroup
of one-sided normalizers. We relate these normalizers of in to
projections in the basic construction and show that every trace one projection
in the relative commutant is of the form for some
unitary with . This enables us to identify the
normalizers and the algebras they generate in several situations. In particular
each normalizer of a tensor product of irreducible subfactors is a tensor
product of normalizers modulo a unitary. We also examine normalizers of
irreducible subfactors arising from subgroup--group inclusions .
Here the normalizers are the normalizing group elements modulo a unitary from
. We are also able to identify the finite trace -bimodules in
as double cosets which are also finite unions of left cosets.Comment: 33 Page
Elastohydrodynamic study of actin filaments using fluorescence microscopy
We probed the bending of actin subject to external forcing and viscous drag.
Single actin filaments were moved perpendicular to their long axis in an
oscillatory way by means of an optically tweezed latex bead attached to one end
of the filaments. Shapes of these polymers were observed by epifluorescence
microscopy. They were found to be in agreement with predictions of semiflexible
polymer theory and slender-body hydrodynamics. A persistence length of m could be extracted.Comment: RevTex, 4 pages, 5 eps figs, submitted to PR
A Study to Determine the Effectiveness Audio-Visuals Have on Teaching Computer Aided Drafting
The following hypothesis was applied to this study: 1. There is a difference in the performance of basic drafting students who are taught computer aided drafting using audio-visuals and basic drafting students who are taught computer aided drafting using the teacher-lecture method
Subtypes of Toddlers with Autism Spectrum Disorders: Implications for Early and Future Diagnosis
Autism spectrum disorders (ASDs) are a group of disorders that affect social, communication, and behavioral development. Identification of clinically distinct subtypes of ASDs, especially in the developmental period when delays or deficits are first recognized (i.e., in the first few years of life), can lend clues to etiology and trajectory and enhance current knowledge on early manifestations of the disorders. Moreover, identification of clinically distinct subtypes of ASDs may inform early identification efforts. Past research suggests that social relations, verbal abilities, nonverbal abilities, and the presence of certain stereotyped interests and behaviors (SIB) may be important factors in delineating subtypes of ASDs in toddlers. Yet there is no published study that examines empirically derived subtypes in a sample of such young children. Therefore, the purpose of this study was to determine whether clinically distinct subtypes can be derived from a sample of toddlers who fail an autism screen and are subsequently diagnosed with developmental concerns, including an ASD. Results found that subtypes delineated by social-communicative maturity were found in both of the aforementioned samples of children. Furthermore, the ASD only sample was also distinguished by rate and intensity of certain types of SIB. Implications for autism theory, early identification, and early intervention are discussed
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