386 research outputs found
Globe tourism
This is a journal article.For many years the Globe has been often derided and occasionally praised as a tourist
destination. Why? And does it matter? Dennis Kennedy and Gabriel Egan dispute the
issue
Globe tourism
For many years the Globe has been often derided and occasionally praised as a tourist
destination. Why? And does it matter? Dennis Kennedy and Gabriel Egan dispute the
issue
Sea Control in the Arctic: A Soviet Perspective
In the Punic Wars, Hannibal surprised and strategically dislocated the Roman legions by attacking them with his war elephants as he made his way across what had been considered to be an insurmountable geographical barrier, the Alps. In a similar fashion, recent developments in Soviet Arctic mobility and logistics give the Soviets the capability to inflict strategic surprise on the West. Although there is no evidence that the Soviets intend to implement the strategic plans or concepts of operations discussed here, they do possess substantial capabilities in the Arctic which could threaten the United States and Canada. U.S. and Canadian strategists must consider these capabilities in determining our territorial defense plans and our Arctic defense forces
An evaluation of the quality of training and usability of the Fleet Management System-Real Time (FMS-RT)
This thesis recommends ways to improve the content of the
training curriculum and software usability of the Fleet Management
System-Real Time (FMS-RT). The premise of this thesis is that the
Navy should increase its performance during major overhauls and
availabilities. According to experts, the current FMS-RT training program
could be improved with the addition of three curriculum areas:
project management training, advanced project management estimating
techniques, and the more specific assignment of responsibilities in
the implementation of the program. In addition, many problems and
possible enhancements to the FMS-RT software were identified by our
usability survey. Incorporating these changes to the training curriculum
and software should allow the navy to increase ships force performance
during overhauls.http://archive.org/details/evaluationofqual00mansLieutenant, United States NavyApproved for public release; distribution is unlimited
Equivalence classes of functions of finite Markov chains
A matrical representation of a Markov chain consists of the initial vector and transition matrix of the chain, along with matrices that specify which observable response occurs for each state. The likelihood function based on a Markov model can be stated in a general way using the components of the model's matrical representation. It follows directly from that statement that two models are equivalent in likelihood if they are related through matrix operations that constitute a change of basis of the matrical representation. Two necessary properties of a change matrix associating two Markov models that are members of the same equivalence class with respect to likelihood are derived. Examples are provided, involving use of the results in analyzing identifiability of Markov models, including a useful application of diagonalization that provides a connection between the problem of identifiability and the eigenvalue problem.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22239/1/0000675.pd
ESTimating plant phylogeny: lessons from partitioning
BACKGROUND: While Expressed Sequence Tags (ESTs) have proven a viable and efficient way to sample genomes, particularly those for which whole-genome sequencing is impractical, phylogenetic analysis using ESTs remains difficult. Sequencing errors and orthology determination are the major problems when using ESTs as a source of characters for systematics. Here we develop methods to incorporate EST sequence information in a simultaneous analysis framework to address controversial phylogenetic questions regarding the relationships among the major groups of seed plants. We use an automated, phylogenetically derived approach to orthology determination called OrthologID generate a phylogeny based on 43 process partitions, many of which are derived from ESTs, and examine several measures of support to assess the utility of EST data for phylogenies. RESULTS: A maximum parsimony (MP) analysis resulted in a single tree with relatively high support at all nodes in the tree despite rampant conflict among trees generated from the separate analysis of individual partitions. In a comparison of broader-scale groupings based on cellular compartment (ie: chloroplast, mitochondrial or nuclear) or function, only the nuclear partition tree (based largely on EST data) was found to be topologically identical to the tree based on the simultaneous analysis of all data. Despite topological conflict among the broader-scale groupings examined, only the tree based on morphological data showed statistically significant differences. CONCLUSION: Based on the amount of character support contributed by EST data which make up a majority of the nuclear data set, and the lack of conflict of the nuclear data set with the simultaneous analysis tree, we conclude that the inclusion of EST data does provide a viable and efficient approach to address phylogenetic questions within a parsimony framework on a genomic scale, if problems of orthology determination and potential sequencing errors can be overcome. In addition, approaches that examine conflict and support in a simultaneous analysis framework allow for a more precise understanding of the evolutionary history of individual process partitions and may be a novel way to understand functional aspects of different kinds of cellular classes of gene products
The Hydrogen Epoch of Reionization Array Dish II: Characterization of Spectral Structure with Electromagnetic Simulations and its science Implications
We use time-domain electromagnetic simulations to determine the spectral
characteristics of the Hydrogen Epoch of Reionization Arrays (HERA) antenna.
These simulations are part of a multi-faceted campaign to determine the
effectiveness of the dish's design for obtaining a detection of redshifted 21
cm emission from the epoch of reionization. Our simulations show the existence
of reflections between HERA's suspended feed and its parabolic dish reflector
that fall below -40 dB at 150 ns and, for reasonable impedance matches, have a
negligible impact on HERA's ability to constrain EoR parameters. It follows
that despite the reflections they introduce, dishes are effective for
increasing the sensitivity of EoR experiments at relatively low cost. We find
that electromagnetic resonances in the HERA feed's cylindrical skirt, which is
intended to reduce cross coupling and beam ellipticity, introduces significant
power at large delays ( dB at 200 ns) which can lead to some loss of
measurable Fourier modes and a modest reduction in sensitivity. Even in the
presence of this structure, we find that the spectral response of the antenna
is sufficiently smooth for delay filtering to contain foreground emission at
line-of-sight wave numbers below Mpc, in
the region where the current PAPER experiment operates. Incorporating these
results into a Fisher Matrix analysis, we find that the spectral structure
observed in our simulations has only a small effect on the tight constraints
HERA can achieve on parameters associated with the astrophysics of
reionization.Comment: Accepted to ApJ, 18 pages, 17 Figures. Replacement matches accepted
manuscrip
Willingness to Get Vaccinated and Attitude Toward COVID-19 among Humanities and Social Sciences Students
Divergent viewpoints about COVID-19 health guidelines continue to impact the collective effort to reduce COVID-19 transmission. Thus, this descriptive-correlational study was conducted to determine if there is a significant relationship between the level of willingness to get vaccinated against COVID-19 and the attitude toward COVID-19 among sixty randomly selected Grade 12 Humanities and Social Sciences students of the University of San Carlos - South Campus in Cebu City, Philippines. Online data collection was done through two adapted and reliable Likert-type survey questionnaires. The findings indicated that the degree of willingness to be vaccinated was high (x = 3.79, SD = .98), while the level of attitude toward COVID-19 was very high (x = 4.36, SD = .75). Moreover, the correlation between the two variables was found to be significant, r(58) = 0.48, p = .000104, p < .05 at = .05. Therefore, the null hypothesis of no significant relationship was rejected, and the researchers found that there is a weakly positive correlation (r =.48) between the levels of willingness to be vaccinated and the students' attitude regarding COVID-19. This result indicates that their attitude toward COVID-19 improves in proportion to their vaccination willingness. This also suggests that adolescents who understand authorized COVID-19 vaccination guidelines are more eager to get the COVID-19 vaccine. The researchers recommend that more initiatives be developed to boost the public's desire and attitude toward COVID-19 immunization, and that additional research be conducted to validate results and examine trends in other communities
The Hydrogen Epoch of Reionization Array Dish I: Beam Pattern Measurements and Science Implications
The Hydrogen Epoch of Reionization Array (HERA) is a radio interferometer
aiming to detect the power spectrum of 21 cm fluctuations from neutral hydrogen
from the Epoch of Reionization (EOR). Drawing on lessons from the Murchison
Widefield Array (MWA) and the Precision Array for Probing the Epoch of
Reionization (PAPER), HERA is a hexagonal array of large (14 m diameter) dishes
with suspended dipole feeds. Not only does the dish determine overall
sensitivity, it affects the observed frequency structure of foregrounds in the
interferometer. This is the first of a series of four papers characterizing the
frequency and angular response of the dish with simulations and measurements.
We focus in this paper on the angular response (i.e., power pattern), which
sets the relative weighting between sky regions of high and low delay, and
thus, apparent source frequency structure. We measure the angular response at
137 MHz using the ORBCOMM beam mapping system of Neben et al. We measure a
collecting area of 93 m^2 in the optimal dish/feed configuration, implying
HERA-320 should detect the EOR power spectrum at z~9 with a signal-to-noise
ratio of 12.7 using a foreground avoidance approach with a single season of
observations, and 74.3 using a foreground subtraction approach. Lastly we study
the impact of these beam measurements on the distribution of foregrounds in
Fourier space.Comment: 13 pages, 9 figures. Replaced to match accepted ApJ versio
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