4,637 research outputs found
Indeterminacy of Holographic Quantum Geometry
An effective theory based on wave optics is used to describe indeterminacy of
position in holographic spacetime with a UV cutoff at the Planck scale.
Wavefunctions describing spacetime positions are modeled as complex
disturbances of quasi-monochromatic radiation. It is shown that the product of
standard deviations of two position wavefunctions in the plane of a holographic
light sheet is equal to the product of their normal separation and the Planck
length. For macroscopically separated positions the transverse uncertainty is
much larger than the Planck length, and is predicted to be observable as a
"holographic noise" in relative position with a distinctive shear spatial
character, and an absolutely normalized frequency spectrum with no parameters
once the fundamental wavelength is fixed from the theory of gravitational
thermodynamics. The spectrum of holographic noise is estimated for the GEO600
interferometric gravitational-wave detector, and is shown to approximately
account for currently unexplained noise between about 300 and 1400Hz. In a
holographic world, this result directly and precisely measures the fundamental
minimum interval of time.Comment: 4 pages, LaTeX. Considerably shortened from earlier version.
Conclusions are unchanged. Submitted to PR
Exploring Elder Consumers Interactions With Information Technology
Advances in health care are enabling the population of the United States to live longer.  Use of information technology can improve the quality of life for the elderly, yet many older consumers have limited interactions with information technology and so may be denied its potential benefits for enhancing quality of life.  This study explores older peoples’ current interactions with information technology, details personal and technological factors which may impact engagement, and discusses the resulting sociological and commercial implications for encouraging the elderly to embrace information technology toward enhancing quality of life
Comparison of consensus profiles obtained at the end of product-specific training with profiles obtained by individual measurements and statistical analysis
In many occasions descriptive analysis consists of product-specific training where the samples to be measured are used during the training. Towards the end of the training period it is common practice to present these samples and reach a consensus on their profiles, which we have called Training Consensus Profiles (TCP). Following the TCP, the samples are scored by each assessor and the results are statistically analysed to obtain statistical profiles. The objective of the present work was to compare the TCP with the statistical profiles in samples from three different food categories: fernet (an herb-based alcoholic drink), mayonnaise, and spaghetti. General Procrustes analysis showed that the TCP and statistical profiles were similar. A case is made, that if this type of training and measurement are to be followed, the statistical measuring stage could be left aside, directly reporting the results obtained from the TCP. Advantages and limitations on reporting these TCP profiles are discussed
A model for the shape of the Fourier amplitude spectrum of acceleration at high frequencies
At high frequencies f the spectrum of S-wave accelerations is characterized by a trend of exponential decay, e^(−πkf). In our study, the spectral decay parameter k shows little variation at a single station for multiple earthquakes at the same distances, but it increases gradually as the epicentral distance increases. For multiple recordings of the San Fernando earthquake, k increases slowly with distance, and k is systematically smaller for sites on rock than for sites on alluvium. Under the assumption that the Fourier spectrum of acceleration at the source is constant above the corner frequency (an ω^(−2) source model), the exponential decay is consistent with an attenuation model in which Q increases rapidly with depth in the shallow crustal layers
Crisis Planning: Increasing Effectiveness, Decreasing Discomfort
Although the percentage of businesses involved in crisis planning increased after September 11, 2001, it is still alarmingly low. Some managers believe crisis planning unnecessary, while others become overwhelmed when attempting to plan for all potential crises. Even those managers who develop plans may find them overly-simplistic or ineffective when crises occur. This work discusses the importance of crisis planning and presents a five-step process to simplify planning efforts while increasing their effectiveness. Effective crisis preparedness can be achieved by forming a crisis team, analyzing vulnerabilities, creating strategies, working the plans, and assessing plan performance. 
The Role Of Guatemalan Crisis Management Attitudes In Foreign Direct Investment Initiatives
Improvements in communication, transportation, and technology continue to drive business globalization. Foreign Direct Investment (FDI) is one way in which firms can globalize. Although firms seeking FDI opportunities may investigate the commercial, economic, political, and natural resource environment of the potential host country, cultural issues including crisis management attitudes are sometimes overlooked. This study reviews crisis management considerations, investigates attitudes of indifference displayed by Guatemalan businesses with respect to crisis management, and discusses the implications for firms seeking FDI opportunities in Guatemala
Alignment procedure for the VIRGO Interferometer: experimental results from the Frascati prototype
A small fixed-mirror Michelson interferometer has been built in Frascati to
experimentally study the alignment method that has been suggested for VIRGO.
The experimental results fully confirm the adequacy of the method. The minimum
angular misalignment that can be detected in the present set-up is 10
nrad/sqrt{Hz}Comment: 10 pages, LaTex2e, 4 figures, 5 tables. Submitted to Phys. Lett.
Field tests of a portable MEMS gravimeter
Gravimeters are used to measure density anomalies under the ground. They are applied in
many different fields from volcanology to oil and gas exploration, but present commercial systems
are costly and massive. A new type of gravity sensor has been developed that utilises the same
fabrication methods as those used to make mobile phone accelerometers. In this study, we describe
the first results of a field-portable microelectromechanical system (MEMS) gravimeter. The stability
of the gravimeter is demonstrated through undertaking a multi-day measurement with a standard
deviation of 5.58 × 10−6 ms−2
. It is then demonstrated that a change in gravitational acceleration of
4.5 × 10−5 ms−2
can be measured as the device is moved between the top and the bottom of a 20.7 m
lift shaft with a signal-to-noise ratio (SNR) of 14.25. Finally, the device is demonstrated to be stable in
a more harsh environment: a 4.5 × 10−4 ms−2 gravity variation is measured between the top and
bottom of a 275-m hill with an SNR of 15.88. These initial field-tests are an important step towards
a chip-sized gravity senso
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