3,303 research outputs found
LISA Response Function and Parameter Estimation
We investigate the response function of LISA and consider the adequacy of its
commonly used approximation in the high-frequency range of the observational
band. We concentrate on monochromatic binary systems, such as white dwarf
binaries. We find that above a few mHz the approxmation starts becoming
increasingly inaccurate. The transfer function introduces additional amplitude
and phase modulations in the measured signal that influence parameter estmation
and, if not properly accounted for, lead to losses of signal-to-noise ratio.Comment: 4 pages, 2 figures, amaldi 5 conference proceeding
The Effect of the LISA Response Function on Observations of Monochromatic Sources
The Laser Interferometer Space Antenna (LISA) is expected to provide the
largest observational sample of binary systems of faint sub-solar mass compact
objects, in particular white-dwarfs, whose radiation is monochromatic over most
of the LISA observational window. Current astrophysical estimates suggest that
the instrument will be able to resolve about 10000 such systems, with a large
fraction of them at frequencies above 3 mHz, where the wavelength of
gravitational waves becomes comparable to or shorter than the LISA arm-length.
This affects the structure of the so-called LISA transfer function which cannot
be treated as constant in this frequency range: it introduces characteristic
phase and amplitude modulations that depend on the source location in the sky
and the emission frequency. Here we investigate the effect of the LISA transfer
function on detection and parameter estimation for monochromatic sources. For
signal detection we show that filters constructed by approximating the transfer
function as a constant (long wavelength approximation) introduce a negligible
loss of signal-to-noise ratio -- the fitting factor always exceeds 0.97 -- for
f below 10mHz, therefore in a frequency range where one would actually expect
the approximation to fail. For parameter estimation, we conclude that in the
range 3mHz to 30mHz the errors associated with parameter measurements differ
from about 5% up to a factor of 10 (depending on the actual source parameters
and emission frequency) with respect to those computed using the long
wavelength approximation.Comment: replacement version with typos correcte
Miniature pressure transducer for stressed member application
Miniature pressure transducer responds to static or dynamic pressures acting against a structural surface without introducing errors caused by stresses in the structural surface. This is accomplished by a thin stainless steel pressure sensing diaphragm with an attached foil strain gage
Squamous cell carcinoma of the middle ear: Case report and literature review
A 50 year-old man with squamous cell carcinoma of the right middle ear is presented. Treatment was by surgery and radiotherapy. The literature is reviewed.
Key Words: Middle ear, carcinoma, squamous cell
Annals of African Medicine Vol.3(2) 2004: 90-9
“If You've Got Friends and Neighbours”: Constituency Voting Patterns for the UK Labour Party Leader in 2010
Most attention in British electoral studies has been paid to the pattern of voting for parties, with relatively little to that for individual candidates. In intra-party elections, however, candidates may perform better in some areas than others, illustrating V. O. Key's well-known “friends and neighbours” effect. This paper explores whether that was so at the election for the leader of the UK Labour party in 2010, expecting each of the five candidates to perform better in their own constituency and its environs and also with those constituency parties whose MPs supported their candidature. The results are in line with the expectations, especially for one of the candidates who ran an explicitly geographical campaign
When do words hurt? A multiprocess view of the effects of verbalization on visual memory
Verbal overshadowing reflects the impairment in memory performance following verbalization of nonverbal stimuli. However, it is not clear whether the same mechanisms are responsible for verbal overshadowing effects observed with different stimuli and task demands. In the present article, we propose a multiprocess view that reconciles the main theoretical explanations of verbal overshadowing deriving from the use of different paradigms. Within a single paradigm, we manipulated both the nature of verbalization at encoding (nameability of the stimuli) and postencoding (verbal descriptions), as well as the nature (image transformation or recognition) and, by implication, the demands of the final memory task (global or featural). Results from 3 experiments replicated the negative effects of encoding and postencoding verbalization in imagery and recognition tasks, respectively. However, they also showed that the demands of the final memory task can modulate or even reverse verbal overshadowing effects due to both postencoding verbalization and naming during encoding
Adolescent depression : an overview of the symptoms, causes, assessments, and treatment
Adolescence is said to be the most stressful time in a person\u27s life (Greenberg, 1989). Although the majority of adolescents adapt without much trouble, there are those who do not accept the changes as successfully as others (Greenberg, 1989). The pressures from parents, peers, school, and society can often lead to temporary periods of depression. In the 1960s, adolescent depression was unusual. However, depression in the 1990s has become the \u27common cold\u27 of mental illness (Seligman, 1995)
Long-term changes in the water quality of rainfall, cloud water and stream water for moorland, forested and clear-felled catchments at Plynlimon, mid-Wales
Long term changes in the water quality of rainfall, cloud water and stream waters draining acidic and acid sensitive moorland and forested catchments at Plynlimon, mid-Wales, are examined for the period 1983 to 2001. Atmospheric inputs of chloride and sulphate are influenced by the relative inputs of clean maritime and polluted land based air masses. There is no systematic increase or decrease over time for chloride and non-sea-salt sulphate. Rather, there is a decadal scale process possibly representative of the influence of the North Atlantic Oscillation that affects the maritime and pollution climate of the Atlantic seaboard of the UK. Over 17 years of study, there may be a small decrease in non-sea-salt sulphate of about 10 μeq l<sup>-1</sup> and a small improvement in acid neutralising capacity of about 20 to 30 μeq l<sup>-1</sup> in rainfall. There is a clear improvement in cloud water chemistry with respect to pollutant components (ammonium, nitrate, non-sea-salt sulphate) and acidity (acid neutralising capacity improved by about 300 μeq l<sup>-1</sup>) through the study period. Many of the changes in cloud water chemistry are similar to rainfall over the same period except the magnitude of change is larger for the cloud water. Within the streams, there is some evidence for reductions in acidity as reflected by acid neutralising capacity becoming less negative. For one stream, deforestation occurred during the sampling period and this led to large increases in nitrate and smaller increases in aluminium midway through the study period. However, the climate and hydrological variability largely masked out other changes. The current analysis provides only a start to identifying trends for such a complex and variable environmental system. The need for strong statistical tools is emphasised to resolve issues of: (a) hydrological induced water quality variability, (b) changing soil and groundwater "endmember" chemistry contribution to the stream and (c) the non-linear patterns of change. Nonetheless, the analysis is enhanced by examining trends in chemistry for yearly averages and yearly average low catch and high catch rainfall and cloud water events as well as low and high flow stream chemistry. This approach allows trends to be examined within the context of endmember mixing.</p> <p style='line-height: 20px;'><b>Keywords: </b>Calcium, aluminium, ammonium, pH, Gran alkalinity, ANC, nitrate, chloride, sulphate, Plynlimon, cloud, mist, rainfall, stream, acidification, North Atlantic Oscillation, trend
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