1,222 research outputs found
A Cosmic Ray Measurement Facility for ATLAS Muon Chambers
Monitored Drift Tube (MDT) chambers will constitute the large majority of
precision detectors in the Muon Spectrometer of the ATLAS experiment at the
Large Hadron Collider at CERN. For commissioning and calibration of MDT
chambers, a Cosmic Ray Measurement Facility is in operation at Munich
University. The objectives of this facility are to test the chambers and
on-chamber electronics, to map the positions of the anode wires within the
chambers with the precision needed for standalone muon momentum measurement in
ATLAS, and to gain experience in the operation of the chambers and on-line
calibration procedures.
Until the start of muon chamber installation in ATLAS, 88 chambers built at
the Max Planck Institute for Physics in Munich have to be commissioned and
calibrated. With a data taking period of one day individual wire positions can
be measured with an accuracy of 8.3 micrometers in the chamber plane and 27
micrometers in the direction perpendicular to that plane.Comment: 14+1 pages, 11 figures, contributed paper to the EPS2003 conference,
Aache
How People Judge the Usability of a Desktop Graphic User Interface at Different Time Points: Is there Evidence for Memory Decay, Recall Bias or Temporal Bias?
The System Usability Scale (SuS) survey is a widely respected tool for measuring usability. Generally, a SuS score is administered directly after a usability test to assess the usability and user experience of digital products. However, some researchers have used SuS as a survey as part of longitudinal ‘in the wild’ trials where SuS is often completed some period after the trial. The aim of this research was to determine if a participant’s memory of a product’s usability would change if a SuS survey was administered at different times after a test. Hence, we sought to understand if recalling the usability of a digital technology was affected by temporal bias or memory decay. This paper includes results and findings from two studies, study 1 involved evaluating a web application and study 2 involved evaluating a virtual learning environment. Collectively the two studies had 212 participants (n = 212). The findings conclude that there is no significant change of the user’s recollection of the usability of digital product as evidenced by an analysis of users who completed multiple SuS surveys over a short term period of 3 weeks or over an extended period of time of 6 months
Usability Evaluation of a Virtual Learning Environment : a University Case Study
As part of educational technology developments in Higher Education, every university has adopted a Virtual Learning Environment (VLE) that facilitates online methods of delivery by enabling the submission of course materials, course management system and computer-mediated communication. VLE is regarded as technology which is either accepted or rejected by its users such as students, academics and administrators. Perceived usefulness and ease of use play an important role in user acceptance and satisfaction. This paper provides quantitative results of usability evaluations i.e., the System Usability Scale (SUS) scores from different user groups including students (n=137), academics (n=23), administrators (n=19) and learning technologist (n=3). The qualitative element of the VLE evaluation comprised the utilization of an approach called Interactive Management (IM) (n=13). The results showed that the newly implemented VLE performed under the average usability expectation (SUS score of 58.6). Students on average evaluated the usability of the VLE higher than the staff. The usability scores of the students from different courses showed remarkable differences. The ranked and categorised feedback from the IM session highlights the importance of planning, training and communication before and during the implementation, as well as the aspect of usability and learnability of the VLE
Berry phases for 3D Hartree type equations with a quadratic potential and a uniform magnetic field
A countable set of asymptotic space -- localized solutions is constructed by
the complex germ method in the adiabatic approximation for 3D Hartree type
equations with a quadratic potential. The asymptotic parameter is 1/T, where
is the adiabatic evolution time.
A generalization of the Berry phase of the linear Schr\"odinger equation is
formulated for the Hartree type equation. For the solutions constructed, the
Berry phases are found in explicit form.Comment: 15 pages, no figure
Large violation of Bell inequalities with low entanglement
In this paper we obtain violations of general bipartite Bell inequalities of
order with inputs, outputs and
-dimensional Hilbert spaces. Moreover, we construct explicitly, up to a
random choice of signs, all the elements involved in such violations: the
coefficients of the Bell inequalities, POVMs measurements and quantum states.
Analyzing this construction we find that, even though entanglement is necessary
to obtain violation of Bell inequalities, the Entropy of entanglement of the
underlying state is essentially irrelevant in obtaining large violation. We
also indicate why the maximally entangled state is a rather poor candidate in
producing large violations with arbitrary coefficients. However, we also show
that for Bell inequalities with positive coefficients (in particular, games)
the maximally entangled state achieves the largest violation up to a
logarithmic factor.Comment: Reference [16] added. Some typos correcte
Two Planets, One Species: Does a Mission to Mars Alter the Balance in Favour of Human Enhancement?
In this chapter we examine the implications of a crewed mission to Mars, possible colonisation of the planet, and the wider implications this may have on genetic enhancement in both a terrestrial and space context. We consider the usage of both somatic and germ-line genetic engineering, and its potential impact on the evolution of Homo sapiens. We acknowledge that a mission to Mars may require the usage of such technologies if it is to be successful. Our investigation suggests that the use of such technologies might ultimately be linked with the transformation of our own species. We also consider projected timescales for the development of these genetic enhancements and the ethical questions raised by the possibility of speciation. Cooperation among spacefaring nations in this context and the development of norms for the use of such technologies is desirable
Colour reconnection in e+e- -> W+W- at sqrt(s) = 189 - 209 GeV
The effects of the final state interaction phenomenon known as colour
reconnection are investigated at centre-of-mass energies in the range sqrt(s) ~
189-209 GeV using the OPAL detector at LEP. Colour reconnection is expected to
affect observables based on charged particles in hadronic decays of W+W-.
Measurements of inclusive charged particle multiplicities, and of their angular
distribution with respect to the four jet axes of the events, are used to test
models of colour reconnection. The data are found to exclude extreme scenarios
of the Sjostrand-Khoze Type I (SK-I) model and are compatible with other
models, both with and without colour reconnection effects. In the context of
the SK-I model, the best agreement with data is obtained for a reconnection
probability of 37%. Assuming no colour reconnection, the charged particle
multiplicity in hadronically decaying W bosons is measured to be (nqqch) =
19.38+-0.05(stat.)+-0.08 (syst.).Comment: 30 pages, 9 figures, Submitted to Euro. Phys. J.
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