1,720,988 research outputs found
The role of drift and convection–diffusion mechanisms in small energy global cosmic ray modulation: Application to the hysteresis phenomenon of proton and alpha particle satellite data
No full textThe hysteresis effect for small energies of galactic cosmic rays is due to two effects. The first is the same as for neutron monitor
energies – the delay of the interplanetary processes responsible for cosmic ray modulation with respect to the initiating solar processes,
according to the effective velocity of solar wind and shock waves propagation. Then, the observed cosmic ray intensity is
connected to the solar activity variations during many months before the time of cosmic ray measurement. The second is caused
by the time delay of small energy cosmic ray diffusion from the boundary of modulation region to the Earth's orbit. The model
describing the connection between solar activity variation and cosmic ray convection–diffusion global modulation for neutron monitor
energies is here developed by taking into account also the time-lag of the small energy particle diffusion in the Heliosphere. We
use theoretical results on drifts and analytically approximate the dependences of drifts from tilt angle, and take into account the
dependence from the sign of primary particles, and from the sign of polar magnetic field (A > 0 or A < 0). The obtained results
are applied on proton and alpha-particle satellite data. We analyze satellite 5-min data of proton fluxes with energies >1 MeV,
>2 MeV, >5 MeV, >10 MeV, >30 MeV, >50 MeV, >60 MeV, >100 MeV, and in intervals 10–30 MeV, 30–60 MeV, and 60–
100 MeV during January 1986–December 1999. We exclude periods with great cosmic ray increases caused by particle acceleration
in solar flare events. Then, we determine monthly averaged fluxes, as well as 5-month and 11-month smoothed data. We analyze also
satellite 5-min data on alpha-particle fluxes in the energy intervals 60-160 MeV, 160–260 MeV and 330–500 MeV during January
1986–May 2000. We correct observation data for drifts and then compare with what is expected according to the convection–diffusion
mechanism. We assume different dimensions of the modulation region (by the time propagation X0 of solar wind from the
Sun to the boundary of modulation region), for X0 values from 1 to 60 average months, by one-month steps. For each value of X0 we
determine the correlation coefficient between variations of expected and observed cosmic ray intensities (the estimation of cosmic ray
intensities values is given in Section 3 by Eq. (9), and the determination of correlation and regression coefficients in Section 3 by Eq.
(8)). The dimension of modulation region is determined by the value of X0 max, for which the correlation coefficient reaches the maximum
value. Then the effective radial diffusion coefficient and residual modulation in small energy region can be estimated.
© 2005 COSPAR. Published by Elsevier Ltd. All rights reserved
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Forecasting of radiation hazard: 2. On-line determination of diffusion coefficient in the interplanetary space, time of ejection and energy spectrum at the source; on-line using of neutron monitor and satellite data
No full textIn Paper 1 [Dorman, L.I., Pustil'nik, L.A., Sternlieb, A., Zukerman, I.G. Forecasting of Radiation Hazard: 1. Alerts on
Great FEP Events Beginning; Probabilities of False and Missed Alerts; on-Line Determination of Solar Energetic Particle Spectrum
by using Spectrographic Method, (Paper - COSPAR, PSW1-0022-04, This Issue, 2005) it was described the behavior of
programs ‘‘FEP-Search’’ and ‘‘FEP-Research/Spectrum’’ estimating, on the basis of on-line one-minute NM data, the beginning
of event and FEP spectrum out of the Earth's magnetosphere. We show that after these two steps it is possible to determine the
time of ejection, diffusion coefficient in the interplanetary space, and energy spectrum at the source of FEP. We consider the
following possibilities: (1) one of the above parameters is unknown; (2) two parameters are unknown; (3) all three parameters
are unknown. We show that in the first case it is necessary to determine the energy spectrum of FEP on the Earth in two
different times and automatically, from two equations, the unknown parameter can be determined (energy spectrum at the
source or diffusion coefficient, or time of ejection; the determination is done by one equation, and the other is used for control
of the model). In the second case it is necessary to determine the energy spectrum of FEP on the Earth in three different times
and from three equations two parameters can be determined automatically (for example, the energy spectrum at the source and
diffusion coefficient in the interplanetary space). In the third case, by using data for four different times all three unknown
parameters can be determined (time of ejection, diffusion coefficient in the interplanetary space and energy spectrum at the
source of FEP), and one equation can be used for control of the model. We describe in detail the algorithms of the programs
‘‘FEP-Research/Time of Ejection’’, ‘‘FEP-Research/Source’’ and ‘‘FEP-Research/Diffusion’’. We show the behavior of these
programs on some historical great FEP events. On the basis of these on-line programs the time of ejection, diffusion coefficient
in the interplanetary space and energy spectrum at the source of FEP can be determined. To extend the obtained information
to the region of very small energies, we use, together with NM data, also the available satellite one-minute data. On the basis
of these results it is shown the forecasting feasibility of expected radiation hazard for computers, electronics, solar batteries,
and technology in space at different distances from the Sun and at different helio-latitudes. We show that the same procedure
can be done for satellites on different orbits in the magnetosphere, by taking into account the change of cut-off rigidities along
the orbits (for human health, solar batteries, computers, electronics, technology). By the method of coupling functions fordifferent altitudes in the atmosphere we describe some principles of on-line radiation hazard forecasting for air-planes on regular
and non-regular lines in dependence of altitude and cut-off rigidity, and estimation of shielding will be made The on-line
on-ground forecasting of radiation hazard for people health and technology will be done in dependence of cut-off rigidity and
atmospheric pressure. If for some cases the expected radiation hazard will be higher than some definite dangerous level, on-line
special Alerts will be send. These programs are tested on some examples of historical great FEP events.
© 2005 COSPAR. Published by Elsevier Ltd. All rights reserved
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Effective non-vertical and apparent cutoff rigidities for a cosmic ray latitude survey from Antarctica to Italy in minimum of solar activity
No full textIn this paper we will report the results of the computation of cutoff rigidities of vertical and non-vertical incident cosmic ray particles.
Non-vertical effective cutoff rigidities have been computed by tracing particle trajectories through the ‘‘real’’ geomagnetic magnetic field
comprising the International Geomagnetic Reference Field model (IGRF95, IAGA Division 5 Working Group 8, 1996: Sabaka, T.J.,
Langel, R.A., Baldwin, R.T., Conrad, J.A. The geomagnetic field, 1900–1995, including the large scale fields from magnetospheric
sources and NASA candidate models for the 1995 IGRF revision. J. Geomag. Geoelect. 49, 157–206, 1997.) and the Tsyganenko [Tsyganenko,
N.A. A magnetospheric magnetic field model with a warped tail current sheet. Planet. Space Sci. 37, 5–20, 1989.] magnetosphere
model. The computation have been done for the backward route (from Antarctica to Italy) of the Italian Antarctic ship
survey 1996–1997, for geographic points corresponding to the daily average coordinates of the ship; for zenith angles 15°, 30°, 45°
and 60°, and azimuth angles from 0° to 360° in steps of 45°. By means of the obtained non-vertical cutoffs the apparent cutoff rigidities
have been calculated. The information on integral multiplicities of secondary neutrons detected by the neutron monitor in dependence of
the zenith angle of incoming primary cosmic ray particles have also been used. This information is based on the theoretical calculations
of meson-nuclear cascades of primary protons with different rigidities arriving to the Earth’s atmosphere at the zenith angles of 0°, 15°,
30°, 45°, 60° and 75°. The difference between the computed apparent and vertical cutoff rigidities reaches ~1 GV at rigidities >7–8 GV.
At rigidities of 10–16 GV, the difference between the apparent and vertical cutoff rigidities is larger than that obtained earlier by Clem
et al. [Clem, J.M., Bieber, J.W., Duldig, M., Evenson, P., Hall, D., Humble, J.E. Contribution of obliquely incident particles to neutron
monitor counting rate. J. Geophys. Res. 102, 26919–26926, 1997.] and Dorman et al. [Dorman, L.I., Villoresi, G., Iucci, N., Parisi, M.,
Tyasto, M.I., Danilova, O.A., Ptitsyna, N.G. Cosmic ray survey to Antarctica and coupling functions for neutron component near solar
minimum (1996–1997), 3. Geomagnetic effects and coupling functions. J. Geophys. Res. 105, 21047–21056, 2000.].
© 2007 COSPAR. Published by Elsevier Ltd. All rights reserved
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
- …
