2,871 research outputs found
Conceptual design and analysis of shadow shield systems for thermal protection of cryogenic propellants Interim report
Conceptual design and analysis of shadow shield systems for thermal protection of cryogenic propellant
Thermal testing by internal IR heating of the FEP module
A spacecraft module, to be integrated with the FLTSATCOM spacecraft, was tested in a simulated orbit environment separate from the host spacecraft. Thermal vacuum testing of the module was accomplished using internal IR heating rather than conventional external heat sources. For this configuration, the technique produced boundary conditions expected for flight to enable verification of system performance and thermal design details
Testing for a pure state with local operations and classical communication
We examine the problem of using local operations and classical communication
(LOCC) to distinguish a known pure state from an unknown (possibly mixed)
state, bounding the error probability from above and below. We study the
asymptotic rate of detecting multiple copies of the pure state and show that,
if the overlap of the two states is great enough, then they can be
distinguished asymptotically as well with LOCC as with global measurements;
otherwise, the maximal Schmidt coefficient of the pure state is sufficient to
determine the asymptotic error rate.Comment: 11 pages, 2 figures. Published version with small revisions and
expanded title
Performance prediction and analysis of the lunar heat flow probes
This report describes the mathematical modeling of the thermal behavior of the heat flow probes and surrounding medium. The computer models developed simulate the thermal performance of the conductivity experiments and will aid in the interpretation of lunar data.Under Subcontract No. 8 of Prime Contract No. NAS 9-6037 with Columbia Universityby D. Nathanson and R. Merriam.Introduction -- Brief review of Heat Flow Experiment -- Description of thermal models -- Evaluation of computer mathematical models -- Predicted performance in the lunar environment -- Conclusions and recommendations -- Appendice
Complexity for Modules Over the Classical Lie Superalgebra gl(m|n)
Let be a
classical Lie superalgebra and be the category of finite
dimensional -supermodules which are completely reducible over the
reductive Lie algebra . In an earlier paper the authors
demonstrated that for any module in the rate of growth of the
minimal projective resolution (i.e., the complexity of ) is bounded by the
dimension of . In this paper we compute the complexity
of the simple modules and the Kac modules for the Lie superalgebra
. In both cases we show that the complexity is related to
the atypicality of the block containing the module.Comment: 32 page
Utility of Parental Mediation Model on Youth’s Problematic Online Gaming
The Parental Mediation Model PMM) was initially designed to regulate children’s attitudes towards the traditional media. In the present era, because of prevalent online media there is a need for similar regulative measures. Spending long hours on social media and playing online games increase the risks of exposure to the negative outcomes of online gaming. This paper initially applied the PMM developed by European Kids Online to (i) test the reliability and validity of this model and (ii) identify the effectiveness of this model in controlling problematic online gaming (POG). The data were collected from 592 participants comprising 296 parents and 296 students of four foreign universities, aged 16 to 22 years in Kuala Lumpur (Malaysia). The study found that the modified model of the five-factor PMM (Technical mediation, Monitoring mediation, Restrictive mediation, Active Mediation of Internet Safety, and Active mediation of Internet Use) functions as a predictor for mitigating POG. The findings suggest the existence of a positive relation between ‘monitoring’ and ‘restrictive’ mediation strategies and exposure to POG while Active Mediation of Internet Safety and Active mediation of Internet use were insignificant predictors. Results showed a higher utility of ‘technical’ strategies by the parents led to less POG. The findings of this study do not support the literature suggesting active mediation is more effective for reducing youth’s risky behaviour. Instead, parents need to apply more technical mediations with their children and adolescents’ Internet use to minimize the negative effects of online gaming
SIC-POVMs and the Extended Clifford Group
We describe the structure of the extended Clifford Group (defined to be the
group consisting of all operators, unitary and anti-unitary, which normalize
the generalized Pauli group (or Weyl-Heisenberg group as it is often called)).
We also obtain a number of results concerning the structure of the Clifford
Group proper (i.e. the group consisting just of the unitary operators which
normalize the generalized Pauli group). We then investigate the action of the
extended Clifford group operators on symmetric informationally complete POVMs
(or SIC-POVMs) covariant relative to the action of the generalized Pauli group.
We show that each of the fiducial vectors which has been constructed so far
(including all the vectors constructed numerically by Renes et al) is an
eigenvector of one of a special class of order 3 Clifford unitaries. This
suggests a strengthening of a conjuecture of Zauner's. We give a complete
characterization of the orbits and stability groups in dimensions 2-7. Finally,
we show that the problem of constructing fiducial vectors may be expected to
simplify in the infinite sequence of dimensions 7, 13, 19, 21, 31,... . We
illustrate this point by constructing exact expressions for fiducial vectors in
dimensions 7 and 19.Comment: 27 pages. Version 2 contains some additional discussion of Zauner's
original conjecture, and an alternative, possibly stronger version of the
conjecture in version 1 of this paper; also a few other minor improvement
Interpretations of Presburger Arithmetic in Itself
Presburger arithmetic PrA is the true theory of natural numbers with
addition. We study interpretations of PrA in itself. We prove that all
one-dimensional self-interpretations are definably isomorphic to the identity
self-interpretation. In order to prove the results we show that all linear
orders that are interpretable in (N,+) are scattered orders with the finite
Hausdorff rank and that the ranks are bounded in terms of the dimension of the
respective interpretations. From our result about self-interpretations of PrA
it follows that PrA isn't one-dimensionally interpretable in any of its finite
subtheories. We note that the latter was conjectured by A. Visser.Comment: Published in proceedings of LFCS 201
High-Throughput and Cost-Effective Characterization of Induced Pluripotent Stem Cells.
Reprogramming somatic cells to induced pluripotent stem cells (iPSCs) offers the possibility of studying the molecular mechanisms underlying human diseases in cell types difficult to extract from living patients, such as neurons and cardiomyocytes. To date, studies have been published that use small panels of iPSC-derived cell lines to study monogenic diseases. However, to study complex diseases, where the genetic variation underlying the disorder is unknown, a sizable number of patient-specific iPSC lines and controls need to be generated. Currently the methods for deriving and characterizing iPSCs are time consuming, expensive, and, in some cases, descriptive but not quantitative. Here we set out to develop a set of simple methods that reduce cost and increase throughput in the characterization of iPSC lines. Specifically, we outline methods for high-throughput quantification of surface markers, gene expression analysis of in vitro differentiation potential, and evaluation of karyotype with markedly reduced cost
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