2,639 research outputs found
Passive MIMO Radar Detection
Passive multiple-input multiple-output (MIMO) radar is a sensor network comprised of multiple distributed receivers that detects and localizes targets using the emissions from multiple non-cooperative radio frequency transmitters. This dissertation advances the theory of centralized passive MIMO radar (PMR) detection by proposing two novel generalized likelihood ratio test (GLRT) detectors. The first addresses detection in PMR networks without direct-path signals. The second addresses detection in PMR networks with direct-path signals. The probability distributions of both test statistics are investigated using recent results from random matrix theory. Equivalence is established between PMR networks without direct-path signals and passive source localization (PSL) networks. Comparison of both detectors with a centralized GLRT for active MIMO radar (AMR) detection reveals that PMR may be interpreted as the link between AMR and PSL sensor networks. In particular, under high direct-path-to-noise ratio (DNR) conditions, PMR sensitivity and ambiguity approaches that of AMR. Under low-DNR conditions, PMR sensitivity and ambiguity approaches that of PSL. At intermediate DNRs, PMR sensitivity and ambiguity smoothly varies between that of AMR and PSL. In this way, PMR unifies PSL and AMR within a common theoretical framework. This result provides insight into the fundamental natures of active and passive distributed sensing
Effects of Clinical Competency in Nursing Students following the Implementation of Student-Led Learning
Research and supporting evidence represent a gap identified in didactic learning between students and faculty. This gap shows emotional factors of the nursing curriculum that may suggest negative impacts on nursing students, but also improvements that can be made to increase students’ clinical competency levels. By adhering to strict definitions of student-led learning theory and clinical competency, we were able to create concrete evidence with measurable data that can contribute to the elimination of this gap in learning. Upon inspection of past text, we identified a need for further research on this topic to bring awareness and encourage this method to be implemented in more nursing programs. Past research played a key role in assisting our team to identify factors that contribute to students\u27 emotional impacts of nursing school and aided us in seeing how similar learning methods impacted students who participated.
Our findings were gathered through the qualitative analysis of anonymous Google surveys in participants of our student-led skills labs. The survey allowed us to determine that each participant had a substantial improvement in skill level on the topics discussed, as well as an improvement in comfort level. These improvements in clinical competency and emotional influence help create a well-rounded nursing student. This program can be adjusted to encourage further skills practice and improvement in clinical judgment. Factors such as retention of skill and comfort level are continued to be studied and will be analyzed in December of 2023.
We recommend there be a leading role as the program grows, ensuring the integrity and advancement of the program. We can say with confidence that our research contributed to past research, further supporting the implementation of student-led learning in the nursing curriculum at Murray State University
Fabrication and evaluation of low fiber content alumina fiber/aluminum composites
The mechanical fabrication of low volume percent fiber, polycrystalline alumina fiber reinforced aluminum composites was accomplished. Wire preform material was prepared by liquid-metal infiltration of alumina fiber bundles. The wires were subsequently encapsulated with aluminum foil and fabricated into bulk composite material by hot-drawing. Extensive mechanical, thermal and chemical testing was conducted on preform and bulk material to develop a process and material data base. In addition, a preliminary investigation of mechanical forming of bulk alumina fiber reinforced aluminum composite material was conducted
Dating Deborah Hall: A Portrait Reconsidered
The elaborate, full-length portrait of Deborah Hall (1766, Brooklyn Museum) is one of the landmarks of Colonial portraiture, having earned its place in the canon for the pictorial innovations displayed by its creator, the enigmatic William Williams (1727-1791). The dominant narrative holds that Hall, the fifteen-year-old daughter of the Philadelphia printer David hall, tends her roses in an imaginary Garden of Love, surroundings Williams adapted from symbols of beauty and chastity found in emblem books of the period. The scholarly assumption is that the painting served to promote Deborah\u27s marital suitability to potential suitors visiting the Hall residence. The current research unravels and disproves this interpretation by revealing an error that has existed since the painting was purchased from descendants of the family in 1942. In addition, the essay reveals the original print source for the painting, suspected to exist but undiscovered until now. Also examined for the first time are the circumstances of Deborah\u27s early death in 1770 at the age of sixteen, as well as new research on her siblings, William Hall and David Hall, Jr. (also painted by Williams). These revelations offer a refreshing opportunity to view Deborah Hall--the person as well as the painting--in a completely new light
Deepening inside the homonyms of 'Wildbacher' by means of SSR markers
Sixteen accessions of the grapevine cultivar 'Wildbacher' coming from different European repositories and from Styrian and Italian private vineyards were analysed by genetic fingerprinting with SSR markers. Five different molecular profiles were found, confirming that the name 'Wildbacher' is commonly used as a homonym. Several new genotypes could be linked to the previous list of the 'Wildbacher' family. In particular, in Italian commercial vineyards two main 'Wildbacher' varieties defined by A and B genetic profiles were found. They correspond to the two reference genotypes from Styria, 'Wildbacher Blau' ('Blauer Wildbacher)' and 'Wildbacher Spätblau'. In both countries 'Wildbacher Blau' represents the most spread and better performing type and it is earlier ripening compared to 'Wildbacher Spätblau'. They were morphologically and genetically very similar to each other and they shared at least one allele at each of the 11 SSR loci analyzed for cultivar identification. Three different other 'Wildbacher' genotypes from a German collection were identified as individual cultivars. While 'Rotblättriger' (genotype C) and 'Frühblau' from Germany (genotype D) showed some genetic similarity with A and B genotypes, E 'Wildbacher', coming from Hungary, proved to have a distinct genetic profile. Close relationship to the key variety (for the development of European diversity) 'Heunisch' is indicated by sharing one allele at all loci investigated so far. There exist some indications that the second parent is an extinct wild vine. Evaluation of morphological parameters resulted in some differences among all five genotypes.
Email is Evil! Behavioural Responses towards Permission-based Direct Email Marketing and Gender Differences
Purpose
This study aims to assess consumers’ beliefs in three Middle Eastern Arab countries regarding attitudinal and behavioural responses towards permission-based direct email marketing (hereafter DEM) and the moderating role of gender in the hypothesised path model.
Design/methodology/approach
Structural equation modelling was used to test the hypothesised path model by using data collected from 829 respondents.
Findings
The findings show that attitude was found to fully mediate the relationship between beliefs and behavioural responses towards permission-based DEM. Gender moderates the relationship between beliefs and attitudes and responses to permission-based DEM. Notably, female respondents were found to react more actively when exposed to permission-based DEM.
Research limitations/implications
Further qualitative research is needed to learn more about how and why individuals develop behavioural intentions in certain ways towards opt-in DEM. In addition, neuropsychology approaches such as eye-tracking are endorsed for future research to gain more insights and conquer biases associated with self-reporting procedures in countries where such technologies are deemed as legal and ethical to be used with human subjects.
Practical implications
Advertisers promoting products and services in the Middle Eastern Arab context should take further steps to enhance the quality of information (including cultural sensitiveness) and the perceived entertainment value that could be delivered to consumers through permission-based DEM, especially for female internet users. Additionally, this study highly recommends the double opt-in approach to permission-based DEM.
Originality/value
To the best of the authors’ knowledge, this is the first attempt to address the gender role as a moderator of the path depicting the effectiveness of permission-based DEM approach in the Middle East (Arab counties) from beliefs to behavioural responses via attitudes
HV 11423: The Coolest Supergiant in the SMC
We call attention to the fact that one of the brightest red supergiants in
the SMC has recently changed its spectral type from K0-1 I (December 2004) to
M4 I (December 2005) and back to K0-1 I (September 2006). An archival spectrum
from the Very Large Telescope reveals that the star was even cooler (M4.5-M5 I)
in December 2001. By contrast, the star was observed to be an M0 I in both
October 1978 and October 1979. The M4-5 I spectral types is by far the latest
type seen for an SMC supergiant, and its temperature in that state places it
well beyond the Hayashi limit into a region of the H-R diagram where the star
should not be in hydrostatic equilibrium. The star is variable by nearly 2 mag
in V, but essentially constant in K. Our modeling of its spectral energy
distribution shows that the visual extinction has varied during this time, but
that the star has remained essentially constant in bolometric luminosity. We
suggest that the star is currently undergoing a period of intense instability,
with its effective temperature changing from 4300 K to 3300 K on the time-scale
of months. It has one of the highest 12-micron fluxes of any RSG in the SMC,
and we suggest that the variability at V is due primarily to changes in
effective temperature, and secondly, due to changes in the local extinction due
to creation and dissipation of circumstellar dust. We speculate that the star
may be nearing the end of its life.Comment: Accepted by the Astrophysical Journa
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