2,201 research outputs found
Local flow management/profile descent algorithm. Fuel-efficient, time-controlled profiles for the NASA TSRV airplane
The Local Flow Management/Profile Descent (LFM/PD) algorithm designed for the NASA Transport System Research Vehicle program is described. The algorithm provides fuel-efficient altitude and airspeed profiles consistent with ATC restrictions in a time-based metering environment over a fixed ground track. The model design constraints include accommodation of both published profile descent procedures and unpublished profile descents, incorporation of fuel efficiency as a flight profile criterion, operation within the performance capabilities of the Boeing 737-100 airplane with JT8D-7 engines, and conformity to standard air traffic navigation and control procedures. Holding and path stretching capabilities are included for long delay situations
An investigation of TNAV equipped aircraft in a simulated en route metering environment
This document presents the results of an effort to estimate how often a TNAV (Time Navigation) equipped aircraft could be given a TNAV clearance in the En Route Metering (ERM) system as a function of the percentage of arriving traffic which is TNAV equipped. A fast-time simulation of Denver Stapleton international arrival traffic in the Denver Air Route Traffic Control Center route structure, including en route metering operations, was used to develop data on estimated conflicts, clearance communications and fuel usage for traffic mixes of 25, 50, 75 and 100% TNAV equipped. This study supports an overall effort by NASA to assess the benefits and required technology for using TNAV-equipped aircraft in the ERM environment
A Qualitative Study of Pastors\u27 Kids at Cedarville University: A Pilot Study
Children of pastors (PKās) are commonly stereotyped in one of two different ways: either they are seen as the model child, or as the prodigal (Barna Group, 2013). The model child is perceived as sheltered and naĆÆve, with expectations placed on them to follow in their parentsā footsteps of faith and practice. The rebel is perhaps the more common stereotype, where children of pastors are seen as having negative feelings toward their fatherās position, and wanting to make their own mark on the world and find their own faith journey. The purpose of this study was to determine if either of these stereotypes, or other unifying factors, were present and continuing into their college years. We interviewed 15 college students at a Midwestern Christian university, whose fathers were pastors of medium sized churches (200 to 500 members). While each student interviewed commented on expectations from society in general, their personal experiences varied between the two stereotypical extremes. Apart from the acknowledgement of the stereotypes themselves, we found no major themes common to a majority of the students. This leads us to believe that the widely-held stereotypes about pastorās kids are not accurate or complete. It appears that these students are very much like their non-PK peers, varying to the same degree in their faith and life journeys, family dynamics, and social interactions
The geometric measure of entanglement for a symmetric pure state with positive amplitudes
In this paper for a class of symmetric multiparty pure states we consider a
conjecture related to the geometric measure of entanglement: 'for a symmetric
pure state, the closest product state in terms of the fidelity can be chosen as
a symmetric product state'. We show that this conjecture is true for symmetric
pure states whose amplitudes are all non-negative in a computational basis. The
more general conjecture is still open.Comment: Similar results have been obtained independently and with different
methods by T-C. Wei and S. Severini, see arXiv:0905.0012v
Bounds on Multipartite Entangled Orthogonal State Discrimination Using Local Operations and Classical Communication
We show that entanglement guarantees difficulty in the discrimination of
orthogonal multipartite states locally. The number of pure states that can be
discriminated by local operations and classical communication is bounded by the
total dimension over the average entanglement. A similar, general condition is
also shown for pure and mixed states. These results offer a rare operational
interpretation for three abstractly defined distance like measures of
multipartite entanglement.Comment: 4 pages, 1 figure. Title changed in accordance with jounral request.
Major changes to the paper. Intro rewritten to make motivation clear, and
proofs rewritten to be clearer. Picture added for clarit
Survival of entanglement in thermal states
We present a general sufficiency condition for the presence of multipartite
entanglement in thermal states stemming from the ground state entanglement. The
condition is written in terms of the ground state entanglement and the
partition function and it gives transition temperatures below which
entanglement is guaranteed to survive. It is flexible and can be easily adapted
to consider entanglement for different splittings, as well as be weakened to
allow easier calculations by approximations. Examples where the condition is
calculated are given. These examples allow us to characterize a minimum gapping
behavior for the survival of entanglement in the thermodynamic limit. Further,
the same technique can be used to find noise thresholds in the generation of
useful resource states for one-way quantum computing.Comment: 6 pages, 2 figures. Changes made in line with publication
recommendations. Motivation and concequences of result clarified, with the
addition of one more example, which applies the result to give noise
thresholds for measurement based quantum computing. New author added with new
result
Transplantation of Human Neuroblastoma Cells, Catecholaminergic and Non-Catecholaminergic: Effects on Rotational Behavoir in Parkinson's Rat Model
Cultured human catecholaminergic and noncatecholaminergic
donor cells were used in
neural transplantation experiments in a rat
model of Parkinson's disease. Using two different
human catecholaminergic neuroblastoma cell
lines, one control non-catecholaminergic neuroblastoma
cell line, and one sham control (tissue
culture medium), transplants were made into the
striatum using a modified Ungerstedt
hemiparkinsonian rat model. Significant
decreases in apomorphine-induced rotational
behavior were produced by two of three
catecholaminergic cell lines. Grafted cells staining
positively for tyrosine hydroxylase (TH) and
catecholamine fluorescence indicated viable catecholamine
activity in the two cell lines which produced
reductions in rotational behavior.
Catecholamine fluorescence was not detected in
either of the two controls. These data suggest a
link between catecholamine secretion by transplanted
cells and motor improvement using a rat
rotational behavior model
The maximally entangled symmetric state in terms of the geometric measure
The geometric measure of entanglement is investigated for permutation
symmetric pure states of multipartite qubit systems, in particular the question
of maximum entanglement. This is done with the help of the Majorana
representation, which maps an n qubit symmetric state to n points on the unit
sphere. It is shown how symmetries of the point distribution can be exploited
to simplify the calculation of entanglement and also help find the maximally
entangled symmetric state. Using a combination of analytical and numerical
results, the most entangled symmetric states for up to 12 qubits are explored
and discussed. The optimization problem on the sphere presented here is then
compared with two classical optimization problems on the S^2 sphere, namely
Toth's problem and Thomson's problem, and it is observed that, in general, they
are different problems.Comment: 18 pages, 15 figures, small corrections and additions to contents and
reference
Direct evaluation of pure graph state entanglement
We address the question of quantifying entanglement in pure graph states.
Evaluation of multipartite entanglement measures is extremely hard for most
pure quantum states. In this paper we demonstrate how solving one problem in
graph theory, namely the identification of maximum independent set, allows us
to evaluate three multipartite entanglement measures for pure graph states. We
construct the minimal linear decomposition into product states for a large
group of pure graph states, allowing us to evaluate the Schmidt measure.
Furthermore we show that computation of distance-like measures such as relative
entropy of entanglement and geometric measure becomes tractable for these
states by explicit construction of closest separable and closest product states
respectively. We show how these separable states can be described using
stabiliser formalism as well as PEPs-like construction. Finally we discuss the
way in which introducing noise to the system can optimally destroy
entanglement.Comment: 23 pages, 9 figure
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