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Classification of information systems research revisited: A keyword analysis approach
A number of studies have previously been conducted on keyword analysis in order to provide a comprehensive scheme to classify information systems (IS) research. However, these studies appeared prior to 1994, and IS research has clearly developed substantially since then with the emergence of areas such as electronic commerce, electronic government, electronic health and numerous others. Furthermore, the majority of European IS outlets - such as the European Journal of Information Systems and Information Systems Journal - were founded in the early 1990s, and keywords from these journals were not included in any previous work. Given that a number of studies have raised the issue of differences in European and North American IS research topics and approaches, it is arguable that any such analysis must consider sources from both locations to provide a representative and balanced view of IS classification. Moreover, it has also been argued that there is a need for further work in order to create a comprehensive keyword classification scheme reflecting the current state of the art. Consequently, the aim of this paper is to present the results of a keyword analysis utilizing keywords appearing in major peer-reviewed IS publications after the year 1990 through to 2007. This aim is realized by means of the two following objectives: (1) collect all keywords appearing in 24 peer reviewed IS journals after 1990; and (2) identify keywords not included in the previous IS keyword classification scheme. This paper also describes further research required in order to place new keywords in appropriate IS research categories. The paper makes an incremental contribution toward a contemporary means of classifying IS research. This work is important and useful for researchers in understanding the area and evolution of the IS field and also has implications for improving information search and retrieval activities
The Intensities of Cosmic Ray H and He Nuclei at ~250 MeV/nuc Measured by Voyagers 1 and 2 - Using these Intensities to Determine the Solar Modulation Parameter in the Inner Heliosphere and the Heliosheath Over a 40 Year Time Period
We have determined the solar modulation potential, phi, vs. time that is
observed at Voyager 1 and 2 from measurements of the H and He nuclei
intensities at a common energy of 250 MeVnuc. The H nuclei have a rigidity 0.7
GV, the He nuclei 1.4 GV. These measurements cover a 40 year time period, which
includes almost 4 cycles of solar 11 year sunspot variations, throughout the
inner heliosphere out to the HTS at distances of 95 AU and 85 AU, respectively
at V1 and V2, and then beyond in the heliosheath. Inside the HTS the modulation
potential vs. time curves at V1 and V2 show a very similar temporal structure
to those observed at the Earth. During a later period of maximum solar
modulation from 2000.0 to 2005.0 when V1 and V2 are in the outer heliosphere
between 60-94 AU, the main temporal features of the modulation potential curves
at all 3 locations match up with appropriate time delays at V1 and V2 if it is
assumed that spatially coherent structures are moving outward past V1 and V2,
with outward speeds of up to 700 Kms negative 1. After 2004.0 V1 and V2 are at
latitudes of positive 35 and negative 30 respectively, placing lower limits on
the latitude extent of these structures. Beyond the HTS in the heliosheath the
modulation potential slowly decreases at both spacecraft with only a weak
evidence of the unusual modulation minimum observed at the Earth in 2009, for
example. A sudden decrease of the modulation potential 50 MV for both H and He
nuclei occurs at V1 just before the heliopause crossing at about 122 AU. This
decrease has not yet been observed at V2, which is now at 113 AU and still
observing a modulation potential 60 MV.Comment: 28 pages, 9 Figure
The use of orbitals and full spectra to identify misalignment
In this paper, a SpectraQuest demonstrator is used to introduce misalignment in a rotating set-up. The vibrations caused by misalignment is measured with both accelerometers on the bearings and eddy current probes on the shaft itself. A comparison is made between the classical spectral analysis, orbitals and full spectra. Orbitals are used to explain the physical interpretation of the vibration caused by misalignment. Full spectra allow to distinguish unbalance from misalignment by looking at the forward and reversed phenomena. This analysis is done for different kinds of misalignment, couplings, excitation forces and combined machinery faults
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