bluuebunny/crossref_metadata_2025 huggingface dataset:
A defense of statistical power analysis
Authors: Lashley Brian R.
Published: July 2002

Chow attacks statistical power analysis on theoretical
grounds. I argue that if significance testing is defensible, so is
power analysis. A number of Chow's criticisms seem to suggest
that power analysts are confused about certain fundamental issues.
I claim that few power analysts make the mistakes Chow describes.
Finally, I address Chow's claim that power analysis is irrelevant
to NHSTP because it deals with a different issue.
Default is not in the female, but in the theory
Authors: Fitch Roslyn Holly , Denenberg Victor H.
Published: July 2002

A number of commentators agree that the evidence reviewed in
the target article supports a previously unrecognized role for ovarian
hormones in feminization of the brain. Others question this view,
suggesting that the traditional model of sexual differentiation
already accounts for ovarian influence. This position is supported by
various reinterpretations of the data presented (e.g., ovarian effects
are secondary to the presence/absence of androgen, ovarian effects
are smaller than testicular effects, ovarian effects are not
organizational). We discuss these issues, and reiterate our position
that evidence of neurobehavioral ovarian effects is incompatible with
the currently accepted model of sexual differentiation. Other points
regarding species generalizations, the direct versus indirect action
of estrogen, and nonhormonal mechanisms of sexual differentiation are
also discussed. Finally, we address the controversial issue of using
ratio scores in the assessment of the human corpus callosum (where
CC scores are divided by an index of brain size). Future applications
to human research are also discussed.
The nurture of nature: Social, developmental, and environmental controls of aggression
Authors: Snowdon Charles T.
Published: July 2002

Evidence from many species suggests that social,
developmental, and cognitive variables are important influences
on aggression. Few direct activational or organizational effects of
hormones on aggression and dominance are found in nonhuman
primates. Female aggression and dominance are relatively frequent
and occur with low testosterone levels. Social, cultural, and
developmental mechanisms have more important influences on
dominance and aggression than hormones.
The myth of genetic determinism – again
Authors: Alcock John
Published: July 2002

Lifelines mounts a vigorous attack on sociobiology on
the utterly mistaken grounds that sociobiologists believe that genes
single-handedly determine social behavior. The many previously published
rebuttals to this pernicious criticism are conveniently ignored by the
author.
Reconciling discrete psychological typology with a psychobiological continuum
Authors: Le Moal Michel , Piazza Pier Vincenzo
Published: July 2002

Structure entails arrangements and interrelations of parts
that organize the whole (i.e., personality). It involves stability of
traits over time. Extraversion varies along a continuum towards
introversion. Multiple behavioral and biological variables in several
systems vary and are regulated homeostatically within the normal
range. If there is a fixed point for an individual, what inhibits
variation in the biological parameter?
The uncanny power of words
Authors: Jorion Paul J. M.
Published: July 2002

In their quality as acoustic or visual percepts, words are
linked to the emotional values of the state-of-affairs they evoke.
This allows them to engender meanings capable of operating nearly
entirely detached from percepts. Such a laying flat of meanings permits
deliberation to take place within the window of consciousness. In such
a theatre of the imagination, linguistically triggered, resides the
originality of the human psyche.
The neurobiology of knowledge retrieval
Authors: Tranel Daniel , Damasio Antonio R.
Published: July 2002

Recent investigations have explored how large-scale systems
in the brain operate in the processes of retrieving knowledge for
words and concepts. Much of the crucial evidence derives from lesion
studies, because word retrieval and concept retrieval can be clearly
dissociated in brain-damaged individuals. We discuss these findings
from the perspective of our neurobiological framework, which is cited
in Pulvermüller's target article.
The last days of discord? Evolution and culture as accounts of female–female aggression
Authors: Campbell Anne
Published: July 2002

When aggression is conceptualised in terms of a cost-benefit
ratio, sex differences are best understood by a consideration of
female costs as well as male benefits. Benefits must be extremely high
to outweigh the greater costs borne by females, and circumstances
where this occurs are discussed. Achievement of dominance is not such
a circumstance and evidence bearing upon women's egalitarian relationships is reviewed. Attempts to explain sex differences in
terms of sexual dimorphism, sex-of-target effects, social control,
and socialisation are found to be inadequate. The suggestion that
the stigmatisation of female aggreession arises not from patriarchal
imposition but from statistical rarity (resulting from evolutionary
pressures) is given serious consideration. Two hypotheses
(“internal read-out” versus social/epidemiological
representations) are described to explain the relationship between sex
differences in behaviour and corresponding lay explanations.
Perceiving abstract concepts
Authors: Wiemer-Hastings Katja , Graesser Arthur C.
Published: July 2002

The meanings of abstract concepts depend on context. Perceptual
symbol systems (PSS) provide a powerful framework for representing such
context. Whereas a few expected difficulties for simulations are
consistent with empirical findings, the theory does not clearly predict
simulations of specific abstract concepts in a testable way and does not
appear to distinguish abstract noun concepts (like truth) from
their stem concepts (such as true).
Correction to the paper ‘Entire functions of slow growth whose Julia set coincides with the plane’
Authors: BERGWEILER WALTER , EREMENKO ALEXANDRE
Published: July 2002

In our paper [1], in the proof of Proposition 1, we implicitly assume that the polynomial P is monic, although later we apply this proposition to polynomials which are not monic. The following corrections should be made in the proof of Proposition 1.
Equidistribution of parabolic fixed points in the limit set of Kleinian groups
Authors: COSENTINO SALVATORE
Published: July 2002

We show that the Patterson–Sullivan measure on the limit set of a geometrically finite Kleinian group with cusps can be recovered as a weak limit of sums of Dirac masses placed on an appropriate orbit of each parabolic fixed point. A corollary is a sharp asymptotic estimate for a natural counting function associated to a cuspidal subgroup. We also discuss the connection between the above counting and the Riemann hypothesis in some examples of arithmetical lattices.
Victims and victors: reflections on the
Kosovo War
Authors: FREEDMAN LAWRENCE
Published: July 2002

Both the ‘CNN effect,’ whereby images revealing large-scale suffering push governments into humanitarian interventions, and the ‘bodybags effect’, whereby images of casualties pull them away, were evident in the Kosovo War, as was the ‘bullying effect,’ whereby the use of excessive force risks draining away public support for interventions. Although Serbs deliberately tried to present themselves as victims, however, the harsh methods used to suppress Kosovar Albanian aspirations ensured that it was they who appeared as the victims. The Serb effort was also counter-productive in that it made the KLA harder, instead of easier, to defeat.
Hard X-ray generation and particle production via the
relativistic-intensity laser pulse interaction with a solid target
Authors: ANDREEV A.A. , PLATONOV K.Yu.
Published: July 2002

This paper considers various channels of electron–positron
pair, neutron, and γ-quantum generation via
the ultrashort high-power laser pulse interaction with
targets made from different materials. The positron yields
in materials with different Z are estimated for
the positron production by high-speed electrons and γ-photons.
It is shown that a picosecond 100-TW laser pulse gives
rise to formation of about 1010 positrons, possible
channels of the neutron production in light- and heavy-atom
materials being studied as well. It is ascertained that
the formation of up to 107 laser neutrons per
shot is possible when the laser intensity is ∼1021
W/cm2 on a heavy-atom target.
Solutions of the Noh problem for various equations of state
using LIE groups
Authors: AXFORD ROY A.
Published: July 2002

A method for developing invariant equations of
state (EOS) for which solutions of the Noh problem will
exist is developed. The ideal gas EOS is shown to be a
special case of the general method. Explicit solutions
of the Noh problem in planar, cylindrical, and spherical
geometry are determined for a Mie–Gruneisen and the
stiff gas equation of state.
Relativistic self-focusing of transmitted laser radiation
in plasmas
Authors: ASTHANA MEENU V. , VARSHNEY DINESH , SODHA M.S.
Published: July 2002

This paper presents an analysis of relativistic
self-focusing of a Gaussian laser beam incident normally
on a plane interface of a linear medium and a nonlinear,
nonabsorbing plasma with an intensity dependent dielectric
constant. Considering the nonlinearity to arise from the
relativistic variation of mass and the Lorentz force on
electrons. Following Wentzel–Kramers–Brillouin
(WKB) and paraxial ray approximation the phenomenon of
relativistic self-focusing of the transmitted laser radiation
has been analyzed for the arbitrary magnitude of nonlinearity.
Change in the intensity distribution along the wavefront
of the Gaussian beam, due to refraction at the interface
has also been taken into account. The variation of beamwidth
parameter with distance of propagation, self trapping condition
and critical power has been evaluated. Numerical estimates
for typical parameters of laser plasma interaction process
indicate the refraction at the interface to have a significant
effect on self-focusing.
Experimental study of picosecond laser plasma formation
in thin foils
Authors: GALIMBERTI M. , GIZZI L.A. , BARBINI A. , CHESSA P. , GIULIETTI A. , GIULIETTI D. , ROSSI A.
Published: July 2002

A high performance, fully controlled picosecond
laser system has been designed and built with the aid of
a numerical code capable of simulating the temporal behavior
of the laser system, including each active and passive
component. The laser performance was characterized with
an optical streak camera, equivalent plane monitor, and
calorimeter measurements. The laser pulse was focused on
150-nm thick foils to investigate plasma formation and
the related transmittivity of the laser light. The experimental
data are in very good agreement with the predictions of
a simple, 2D analytical model that takes into account the
actual shot-to-shot features of the laser pulse. The temporal
profile of the pulse and the intensity distribution in
the focal spot were found to play a key role in determining
the transmission properties of the laser-irradiated foil.
This work may be relevant to a wide class of laser exploded
foil plasma experiments.
X-ray diagnostics of partially transparent Fe and Al plasmas
for inverted corona targets
Authors: BESSARAB A.V. , BEL'KOV S.A. , VOINOV B.A. , GASPARYAN P.D. , ZHIDKOV N.V. , IVANOV N.V. , KUNIN A.V. , SUBBOTIN A.N. , SUSLOV N.A. , TOKAREV V.A.
Published: July 2002

Spectrum and energy measurements of X-ray radiation
emitted by partially transparent Fe and Al plasmas have
been carried out for thin-layered inverted-corona targets
on the ISKRA-5 laser facility. The targets were plastic
spherical (2-mm diam) shells of 4.6 mm thickness having
0.25 mm Fe or 0.65 mm Al thin inner coatings. The energy
radiated in Heα and Lyα resonance
lines of Fe and Al ions was measured as well. Experimental
data and results of numerical calculations are compared.
Measured laser light to X-ray conversion coefficient has
been found to be essentially low, then calculated one for
both Fe and Al coated targets. Possible reasons for this
discrepancy are discussed.
About diagnostics of Z-pinches hot points
Authors: POLITOV V.Yu. , POTAPOV A.V. , ANTONOVA L.V.
Published: July 2002

We present the results of X-ray diagnostics of Z-pinch
hot points, formed during fast electrical discharges through exploding
Al wires. Experimental data include the pinhole images and X-ray time
integrated radiation spectra. These spectra were obtained with high
spectral resolution in the range 1.5–2.2 keV, contained the
most intensive resonance lines of Al H- and He-like ions. Comparison
of the recorded lines width and peak intensities with the corresponding
modeled values, enables us to estimate the main hydrodynamical parameters
of hot point, such as average temperature and density, being achieved at
a moment of its maximum compression. Additionally, on the base of
theoretical analysis of the spectral intensities distribution in
well-resolved Lyα satellites, the gradient of compression
velocities field is concluded. Some features of the investigated
lines spectra forming are discussed.
Correlated stopping of relativistic electrons in supercompressed
DT fuel
Authors: DEUTSCH C. , FROMY P.
Published: July 2002

The electromagnetic stopping of intense and relativistic
electron beams (REB) arising from femtosecond lasers interacting
with a precompressed deuterium–tritium (DT) fuel is
investigated within the Bohr–Fermi formalism with a large
impact parameter. Dynamical intrabeam correlations in the target
are shown to be quantitatively significant for various arrangements
of projectile electrons and the overall REB penetration in the DT fuel.
Formation of a hot plasma filament during the focusing of
imploding cylindrical corona
Authors: ASKAR'YAN G.A. , BULANOV S.V. , SOKOLOV I.V.
Published: July 2002

We present the results of the theoretical studies
of the plasma heating in the flows which converge toward
the axis of cylindrical cavity. We show that as a result
of the shock wave reflection from the axis, the narrow
hot filament is formed. This phenomenon is important for
the interpretation of the dynamic processes in the electric
discharges used for X-ray generation. We notice that the
plasma parameters which can be of interest for inertial
confinement fusion (ICF) can be reached in such the processes.
Effects of magnetic fields on wave propagation in dense
laser-produced plasmas
Authors: CAIRNS R.A. , RAU B.
Published: July 2002

Simulations of the interaction of very intense short
pulse lasers with solid density plasmas have indicated
that there may be very high magnetic fields and electron
temperatures in the vicinity of the focal spot. We investigate
the propagation of an incident electromagnetic wave under
these conditions, both analytically and by means of a particle
code, and show that the evanescence length of the wave
field in a highly overdense plasma may be much greater
than is usually supposed. This effect could be important
in understanding the penetration of energy into the overdense
region and the particle heating and acceleration which
takes place there.
Laser absorption and fast electron transport in deformed targets
Authors: MACCHI A. , RUHL H. , CORNOLTI F.
Published: July 2002

The effect of surface deformations on laser absorption
and transport in overdense plasma targets is investigated
with 2D Vlasov simulations. Fractional absorption increases
strongly with the deformation depth and scales weakly with
density or intensity. Fast electrons generated in the skin
layer have high tangential velocity directed toward the
deformation center. In the case of a single, smooth
deformation, they may be collimated by magnetic fields
into a single jet which penetrates deeply into the plasma.
Small-scale surface corrugations are able to destroy the
collimation of a single jet leading to multiple jets or
diffuse electron sprays.
Short pulse interaction experiments for fast ignitor applications
Authors: BORGHESI M. , MACKINNON A.J. , GAILLARD R. , MALKA G. , VICKERS C. , WILLI O. , OFFENBERGER A.A. , CANAUD B. , MIQUEL J.L. , BLANCHOT N. , DAVIES J.R. , PUKHOV A. , MEYER-TER-VEHN J.
Published: July 2002

A detailed investigation of many aspects of the physics
of laser–plasma interaction at very high laser
intensities is required in order to assess the feasibility
and the promise of the fast ignitor scheme for inertial
confinement fusion. Relevant results, obtained in a series
of experiments carried out at the Rutherford Appleton Laboratory,
Chilton (UK) and at the Centre d'Etudes Atomique,
Limeil Valenton (France), are presented and discussed here.
In particular, the formation of plasma channels was observed
following the propagation of relativistically intense,
ps laser pulses through underdense plasmas. The channels
persist long after the interaction, and their expansion
has been measured. Efficient guiding of ultraintense laser
pulses, both through preformed density channels and through
solid guides, has been demonstrated. Finally, indication
of collimated fast electron propagation through solid targets
has been obtained from the observation of filamentary ionization
tracks in laser irradiated solid targets.
Relativistic interaction of rippled laser beams with plasmas
Authors: ASTHANA M.V. , GIULIETTI A. , GIULIETTI D. , GIZZI L.A. , SODHA M.S.
Published: July 2002

An investigation of the growth of a radially symmetrical
ripple, superimposed on a Gaussian laser beam in a plasma
is presented. Based on WKB and paraxial ray approximation
the phenomenon of relativistic self-focusing (RSF) is analytically
investigated. The differential equation for beamwidth parameter
of rippled laser beam is evaluated. The ripple gets focused
when the initial power of the ripple is greater than the
critical power for focusing. The focusing is found to be
considerably affected by the power of the main beam and
the phase angle between the electric vectors of the main
beam and the ripple. At higher intensities the saturation
effects of nonlinearity become predominant, making the
nonlinear refractive index in the paraxial region have
slower radial dependence, and thus the ripple extract relatively
less energy from its neighborhood. The case of magnetized
plasmas is also preliminarily discussed.
Frequency doubling multi-terawatt sub-picosecond pulses
for plasma interactions
Authors: NEELY D. , ALLOTT R.M. , CLARKE R.J. , COLLIER J.L. , DANSON C.N. , EDWARDS C.B. , HERNANDEZ-GOMEZ C. , HUTCHINSON M.H.R. , NOTLEY M. , PEPLER D.A. , RANDERSON M. , ROSS I.N. , SPRINGALL J. , STUBBS M. , WINSTONE T. , DANGOR A.E.
Published: July 2002

Frequency doubling a 140 × 110 mm 40 J sub-ps
1054 nm beam for laser matter interaction studies was investigated
at the Central Laser Facility, with efficiencies greater
than 60% being achieved. The conversion characteristics
(efficiency, beam quality, focusability, and pulse length)
for two large 157 mm diameter aperture high quality KDP
crystals of thickness 2 mm and 4 mm were studied. Using
a fundamental drive beam of two times diffraction limited
quality, focal spots of four times the diffraction limit
in the frequency doubled beam were achieved and beam degradation
effects shown to be minimal.
Ab initio, nonperturbative calculations of laser-induced
continuum structure in helium
Authors: PASPALAKIS E. , KYLSTRA N.J. , KNIGHT P.L.
Published: July 2002

We present the results of ab initio, nonperturbative,
R-Matrix Floquet calculations of laser-induced continuum structures
in helium. We compare our results with recent experimental data and
good agreement is found.
A simple model of high harmonic generation in a plasma
Authors: NUZZO S. , ZARCONE M. , FERRANTE G. , BASILE S.
Published: July 2002

We apply the average electron model to describe high
harmonic generation in a collisional plasma in a laser
field. The model is based on the coupled kinetic equations
for electron velocity and electron temperature. The harmonic
intensities are obtained from the Fourier coefficients
of the nonlinear part of the electron velocity. Numerical
calculations are reported for both strongly and weakly
ionized plasmas in the nonstationary regime. We show the
role of collisions frequencies as well as of quiver and
thermal velocities in the harmonic generation efficiency.
Highly charged ions from rare gas and metal clusters in
intense laser fields
Authors: VIALLON J. , BORDAS C. , CHEVALEYRE J. , LEBAULT M.-A. , ELLERT CH. , DOBOSZ S. , LEZIUS M. , NORMAND D. , SUBLEMONTIER O. , SCHMIDT M. , GUET C. , HUBER B.A.
Published: July 2002

Rare gas or lead clusters of several hundreds to many thousands
of atoms per cluster were irradiated by intense laser pulses
producing peak intensities up to 1017W/cm2.
Fast, highly charged fragment ions were observed by means of
standard TOF mass spectrometry as well as a magnetic deflection
TOF device (MDTOF). Charge states of up to Xe30+
or Pb18+ were detected with maximum kinetic energies
reaching far beyond 100 keV for Xe. A strong dependence of the
charging and heating process on the laser pulse duration was
found. While the resulting ionic fragment spectra are qualitatively
similar for rare gas and lead clusters, the kinetic energies for the
metal clusters seem to be significantly lower.
Quantum kinetic theory of plasmas in strong laser fields
Authors: BORNATH TH. , SCHLANGES M. , HILSE P. , KREMP D. , BONITZ M.
Published: July 2002

A kinetic theory for quantum many-particle systems in
time-dependent electromagnetic fields is developed based
on a gauge-invariant formulation. The resulting kinetic
equation generalizes previous results to quantum systems
and includes many-body effects. It is, in particular, applicable
to the interaction of strong laser fields with dense correlated
plasmas. Numerical results are obtained for the cycle-averaged
electron–ion collision frequency in a high-frequency field.
Diagnosis of peak laser intensity from high-energy ion measurements
during intense laser interactions with underdense plasmas
Authors: KRUSHELNICK K. , CLARK E. , NAJMUDIN Z. , SALVATI M. , SANTALA M.I.K. , TATARAKIS M. , DANGOR A.E. , MALKA V. , NEELY D. , ALLOTT R. , DANSON C.
Published: July 2002

Experiments were performed using high-power laser pulses
(greater than 50 TW) focused into underdense helium, neon,
or deuterium plasmas (ne
≤ 5 × 1019 cm−3).
Ions having energies greater than 300 keV were measured
to be produced primarily at 90° to the axis of laser
propagation. Ion energies greater than 6 MeV were recorded
from interactions with neon. Spatially resolved pinhole
images of the ion emission were also obtained and were
used to estimate the intensity of the focused radiation
in the interaction region.
Self-magnetic field calculations in ray-tracing codes
Authors: HUMPHRIES STANLEY , PETILLO JOHN
Published: July 2002

Beam-generated magnetic fields strongly influence the
behavior of relativistic electron guns. Existing methods
used in ray-tracing codes have limited accuracy and may
not correctly represent nonlaminar beams. We describe a
technique for the magnetic field calculation in a
two-dimensional code based on the assignment of particle
currents to the faces of elements in the mesh used for
the electrostatic calculation. The balanced calculation
of electric and magnetic forces in the same iteration
cycle reduces the possibility of numerical filamentation
instabilities. With simple rules of assignment on boundary
faces, the method also handles field contributions of
electrode currents. Several benchmark calculations
performed on conformal meshes illustrate the versatility
of the technique.
Electron beam-excited Xe excilamp's optimal characteristics
Authors: BOICHENKO A.M. , YAKOVLENKO S.I. , TARASENKO V.F.
Published: July 2002

Calculations of optimal parameters for the e-beam excited
Xe spontaneous radiation source (excilamp) at λ ∼
172 nm have been done. There have been defined optimal
values of gas density and specific excitation power. Gas
temperature dependence of radiation conversion efficiency
related to the injected media energy have been also computed.
It has been shown that there is an optimum in excitation
pulse duration at frequency operation mode.
A Guide to Experiments in Quantum Optics,
Hans-Albert Bachor. 1998. John Wiley & Sons, Inc.
(New York). 378 pp. $95.00. ISBN 3-527-29298-5.
Authors: Sergienko Alexander
Published: July 2002

This book succeeds in providing an experimentalist's
view of quantum optics, complementing the many standard
texts which take a theoretical point of view (see, e.g.,
M.O. Scully and M.S. Zubairy Quantum Optics, Cambridge
University Press, 1997). As the title indicates, the book
focuses mainly on experimental efforts and the realistic
conditions of experimental tests. The choice of topics
was clearly the result of the author's experience
in the field of experimental quantum optics and a solid
understanding of the pedagogical requirements of the material.
Guest Editor's Preface
Authors: Caruso Angelo
Published: July 2002

This issue of Laser and Particle Beams
(LPB) includes only a portion of the more than
200 papers presented to the XXV European Conference on
Laser Interaction with Matter (ECLIM), organized by the
Frascati ICF Physics and Technology Laboratory of the Associazione
EURATOM-ENEA, in Formia (Italy), on May 4-8, 1999.
Space charge electrostatic fields and focusing of a sheet
electron beam with diffused edges
Authors: PANICKER JAYASHREE , CHOYAL Y. , MAHESHWARI K.P. , SHARMA U.
Published: July 2002

An analytical and numerical study of the stability
of sheet electron beams in periodically cusped magnetic
fields (PCM) is made. The beam has been considered as having
edges with a prescribed density variation. In estimating
the electrostatic fields, we have considered the density
variation of both the edges along the width and thickness
of the sheet beam. The conditions for beam focusing and
beam matching are discussed.
Figure of merit for nonlinear materials in second-order
cascaded nonstationary processes
Authors: TOCI GUIDO , VANNINI MATTEO , SALIMBENI RENZO
Published: July 2002

In this paper, we present and discuss an extension
and an improvement of the Figure of Merit (FoM) that we
introduced in a previous paper. The FoM describes the effectiveness
of the frequency doubling materials for ultrashort light
pulse modulators via second-order cascaded effects.
In the present work, as an input pulse we use a temporal
Gaussian pulse so that our perturbative method allows an
analytical expression even for the output pulse field after
the second pass inside the crystal. For the first time
together with the completely analytical expression for
the second pass, we report also the exact numerical coefficients
for the peak phase modulation. With the FoM it is possible
to choose the more appropriate nonlinear material and the
use of the cascaded interaction process. Finally, we present
for the first time the FoM dependence from the wavelength
in the interval 0.5–1 μm, and to a table already
shown we added more nonlinear materials.
Improved use of big laser systems for inertial fusion energy
Authors: HORA HEINRICH , AYDIN MERAL
Published: July 2002

The big lasers for inertial fusion (NIF or LMJ)
may be used with 2 to 3 times larger pulse energy if instead
of the third harmonics, the fundamental wavelength is applied.
A necessary condition especially for direct drive is then
to suppress the stochastic (15 ps) pulsation of the interaction
as the basic obstacle of anomalous interaction. The experiments
by Maddever and the numerical analysis using the genuine
two-fluid model resulted in the knowledge that appropriate
application of smoothing is necessary to suppress primarily
the pulsation and, to a lesser extent, the self-focusing
and filamentation. With these larger laser pulses, fusion
gains of 35 and above can be reached suing the very uncomplicated
and robust volume ignition.
Anomalous burning through of thin foils at high brightness
laser radiation heating
Authors: KOUTSENKO A.V. , LEBO I.G. , MATZVEIKO A.A. , MIKHAILOV Yu.A. , ROZANOV V.B. , SKLIZKOV G.V. , STARODUB A.N.
Published: July 2002

The results of the experiments at the installation
“PICO,” with thin foils heating by laser radiation
pulses of nanosecond duration are reported. The Al foils
with thickness in the range from 3 μ up to 40 μ
were used as targets. The flux density was varied from
1013 W/cm2 to 1014 W/cm2.
The sharp dependence of the portion of laser energy that
passed through the target on foil thickness was observed.
This phenomena was accompanied by a relatively small decrease
of the passed radiation pulse duration. The anomalously
high speed burning through of thin foil was observed in
these experiments and the conclusion on the possible mechanism
of this phenomena has been done on the base of comparison
of experimental data with theoretical calculations. The
observed phenomena can be interpreted with a conjecture
about the local burning through of a target, in the small
areas of the target surface, with many more values of flux
density than the average one following laser radiation
self-focusing and formation of “hot spots.”
Study of high-aspect ratio capsule in indirect-drive experiments
at the ISKRA-5 facility
Authors: BEL'KOV S.A. , ABZAEV F.M. , BESSARAB A.V. , BONDARENKO S.V. , BUSHUEV V.S. , GAIDACH V.A. , GARANIN S.G. , DOLGOLEVA G.V. , DOROGOTOVTSEV V.M. , ZHIDKOV N.V. , IZGORODIN V.M. , KIRILLOV G.A. , KOCHEMASOV G.G. , LITVIN D.N. , MARTYNENKO S.P. , MERKULIEV Yu.A. , MURUGOV V.M. , MKHITARIAN L.S. , PETROV S.I. , PINEGIN A.V. , SENIK A.V. , SUSLOV N.A.
Published: July 2002

Two shells with the diameter of 0.8–0.9 mm
and a wall thickness of ≅1 μm were produced at
the Lebedev Physics Institute for the experiments conducted
at the ISKRA-5 facility. The results of two experiments
with the aforementioned shells conducted at the ISKRA-5
facility with the use of an indirect-drive set up. In one
of the experiments, the diameter of the golden hohlraum
was D = 2 mm while in the other it was D =
4 mm. In these experiments it was observed to be ≅4
times the difference of the average laser intensity on the
hohlraum surface. The results of computational analysis of the
experiments are also presented here.
Research on the development of a method of spatially temporary
smoothing of a high-power laser beam
Authors: DERKACH V.N. , BONDARENKO S.V. , GARANIN S.G. , GROMOV A.I. , GUS'KOV S.J. , KIRILLOV G.A. , KIR'YANOV J.F. , KOCHEMASOV G.G. , KRAVCHENKO A.G. , LYBUNSKAYA T.E. , MERKUL'EV J.A. , OKUTIN G.P. , PETROV S.I. , RUKAVISHNIKOV N.N. , SUSLOV N.A. , SUKHAREV S.A.
Published: July 2002

The investigations of the influence of various
types of wavefront distortions, varying in time, on the
intensity distribution on the surface of a target are carried
out. It is shown that distortions of a wavefront, equivalent
to transverse displacement in time of a beam in far field
at an angle of approximately 10 diffraction angles, results
in practically full smoothing of a specl-structure of intensity
distribution. Creation of phase distortions of a beam assigned
as running in a cross section wave with an amplitude of
more than 3 radian and with a spatial size exceeding 20–30
times the size of the kinoform phase plate element, permits
us to reduce the depth of modulation in distribution of
intensity in far field also. The capability of application
is considered as a smoothing device of the dynamic plasma
layer, based on the volume-structured medium. The model
of energy transport process in such media is developed.
Matching of calculation and experimental results is conducted.
Plasma frequency and harmonic emission from fs-laser plasmas
Authors: TEUBNER U. , GIBBON P. , ALTENBERND D. , OBERSCHMIDT D. , FÖRSTER E. , MYSYROWICZ A. , AUDEBERT P. , GEINDRE J.-P. , GAUTHIER J.C.
Published: July 2002

Electromagnetic emission at the plasma frequency
ωp and its harmonics
nωp has been
studied. Although such emission is well known from very
low density plasmas (electron density of the order of
ne ≈ 108
cm−3) now, for the first time it has
also been observed from a high density plasma (electron
density of the order of ne ≈
1023 cm−3) produced by a
high-intensity femtosecond laser pulse. This radiation is
strongly connected to jets of high energy electrons produced
in such steep gradient plasmas by collective mechanisms, and
probably to nonlinear Langmuir waves in the overdense plasma
region. Theoretical investigations using particle-in-cell
simulations have been made to pinpoint the physical origin
and properties of the emission. Preliminary results show a
very weak scaling of the ωp and
2ωp emission with intensity, which
should provide clues for future theoretical analyses. Although
not the main subject of the present work, also harmonics up
to the 20th of the laser fundamental may have been
observed close to the ωp and
2ωp line emission in the present
experiment (PACS numbers: 52.40.Nk, 42.65.ky, 52.65.-y,
33.20.Ni, 52.25.Qt).
Turbulent mixing investigations at the ISKRA-4 facility
Authors: GARANIN S.G.
Published: July 2002

Results of turbulent mixing research of thin Al
and Au layers under laser acceleration of the three-laser
targets Si/Al/Au are presented. Analyses of experimental
data under the program SND-TUR, where the Nikiforov model
is used for turbulent mixing description, testify to the
essential impact of hot spots on the examined processes
in distribution of laser radiation intensity on the surface
of the target. Experimental setup on the laser beams'
smoothing by the “foam” coated on the target,
has been considered. The results of the first experiments
are presented.
Phase measurements without interferometry: 2D transverse
phase detection by numerical beam intensity analysis
Authors: CHESSA P. , GALIMBERTI M. , BARBINI A. , DANSON C.N. , GIULIETTI A. , GIULIETTI D. , GIZZI L.
Published: July 2002

A whole family of laser-plasma interaction experiments
is based on the phase analysis of the laser pulse after
the propagation in a plasma. Typically, this phase is obtained
by means of interferometry. As pulsed interferometry is
a much more difficult task than taking simple images of
the beam, we developed a numerical code for extracting
phase information from images. The technique, based on
the algorithm of Gerchberg–Saxton, showed to be very
effective in retrieving 2D phase distributions of simulated
as well as real beams. The convergence of the algorithm
is fast (some minutes on a personal computer). The electronic
noise in real images is intrinsically discarded by the
algorithm.
Dynamic modeling and analysis of a two d.o.f. mobile manipulator
Authors: Naderi D. , Meghdari A. , Durali M.
Published: July 2002

This
paper presents the kinematic and dynamic modeling of a two
degrees of freedom manipulator attached to a vehicle with a
two degrees of freedom suspension system. The vehicle is considered
to move with a constant linear speed over an irregular
ground-surface while the end-effector tracks a desired trajectory in a
fixed reference frame. In addition, the effects of highly coupled
dynamic interaction between the manipulator and vehicle (including the suspension
system's effects) have been studied. Finally, simulation results for the
end-effector's straight-line trajectory are presented to illustrate these effects.
Modeling and control of biped robot dynamics
Authors: Caux S. , Zapata R.
Published: July 2002

This paper addresses the problem of modeling biped dynamics and the use of such models for the control of walking, running and jumping robots. We describe two approaches to dynamic modeling: the basic Lagrange approach and the non-regular dynamic approach. The new non-regular dynamic approach takes into account discontinuities due to rigid contact between punctual feet and the ground without computing the exact impact time. The contact is close to the physical situation given by non-linear laws (impenetrability, non-smooth contact and real friction cone). Contact dynamics can be well managed with an accurate dynamic model that respects energy consistency during all the phases encountered during

a step (0, 1 or 2 contacts). With this model, we can first study the equilibrum of a biped standing on one foot by a linearisation method. In the second stage, the unified modelized equation is used to establish a general control frame based on non-regular dynamical decoupling. A comparison is made and some simulation results are given with a two degree of freedom planar biped robot.
Introduction
Authors: Salichs M.A. , Balaguer C.
Published: July 2002

Mobile robotics is a very attractive research field. There are two main reasons for this. The first is the high number of applications and sectors where these machines could be
introduced in the future: transport, agriculture, military, aerospace, etc. The second reason is that mobile robots are excellent test-beds to develop and integrate the results of many other research areas: control, computer vision, electronics, mechanics, artificial intelligence, etc. The third IFAC Symposium on Intelligent Autonomous Vehicles was an opportunity to present some of the latest developments in the area. Authors presented not only new methods and technologies to solve the classical problems related to intelligent autonomous vehicles, which include path planning, localization, environment modeling, path following, etc., but also new approaches to their design, such as new architectures, new navigation procedures, self-learning systems, etc. In addition, many different applications and vehicles were considered: from autonomous ocean vehicles to planetary rovers. This special issue of Robotica comprises some revised and updated selected papers of the Symposium. The variety of selected papers includes surveys, applications and design and development aspects of intelligent autonomous vehicles.
Overcoming the red-feeling: the development of confidence to teach music in primary school amongst student teachers
Authors: Hennessy Sarah
Published: July 2002

The music curriculum, along with the other arts in primary education in England, is under pressure from an increasing governmental focus on ‘core’ subjects. Recruits to the profession are particularly important to the long-term health of music in schools. As part of a longitudinal study to evaluate the efficacy of the university-based arts courses in preparing student teachers, the author looked at the factors affecting music. In so doing it emerged that feelings of confidence were a significant feature in the profile of successful students. The findings from this longitudinal study contribute to our understanding of how students perceive their development as teachers of music and the other arts in primary schools. The subjects of this study were students following a four-year Bachelor of Arts in Education BA(Ed.) course that prepared them to teach the full range of school curriculum subjects as generalists. The analysis of a series of semi-structured interviews reveals a complex interaction between prior experience and beliefs, and the quality of school experience.
AN ECONOMIC FRAMEWORK FOR EVALUATING A MULTILEAF COLLIMATOR
Authors: Dunscombe Peter , Roberts Gisele
Published: July 2002

Objectives: As health care budgets continue to face close
scrutiny, any new acquisition must be evaluated for both costs and outcomes.
This study was undertaken to demonstrate the application of an economic
framework for the evaluation of a multileaf collimator as an example of a new
technology that can have both quantifiable and nonquantifiable benefits for
patients, staff, and cancer care institutions.

Methods: Using financial data from the Northeastern Ontario
Regional Cancer Centre (NEORCC) and a recognized staffing model, a commercial
spreadsheet, developed to economically characterize the principal radiotherapy
processes has been used to determine the net incremental annual cost of a
multileaf collimator (MLC).

Results: The incremental annual cost of purchasing an MLC is
estimated at approximately $85,000 (1997 CDN $). Without increasing patient
throughput, this increases the average cost of a course of radiotherapy by
approximately CDN $200. Savings can be accrued by decreasing mold room
activity, increasing the hourly patient capacity on each treatment machine,
and decreasing sick time due to strain injuries.

Conclusions: Although the clinical outcome of techniques
facilitated by MLCs, such as intensity-modulated radiation therapy, are
unknown at this time, an economic context within which to objectively evaluate
this technology is presented. The framework presented suggests a method of
quantifying outcome-justified expenditures, such as improved patient outcome
and greater treatment flexibility, which, when offset against the incremental
annual equipment cost, may be used to help justify the acquisition of
multileaf technology.
ASYMPTOTIC EFFICIENCY OF THE TWO STAGE ESTIMATOR IN I
(2) SYSTEMS
Authors: Paruolo Paolo
Published: July 2002

This paper derives the distribution of the two stage estimator
of cointegrating parameters in I(2) systems, abbreviated
2SI2, under several assumptions regarding the drift of the process.
The asymptotic distribution is compared with that of the maximum
likelihood (ML) estimator derived in Johansen (1997, Scandinavian
Journal of Statistics 24, 433–462). It is found that the
two asymptotic distributions are the same, thus showing that the 2SI2
estimator is asymptotically as efficient as ML.
Density and diversity of lianas along a chronosequence in a central Panamanian lowland forest
Authors: Dewalt Saara J. , Schnitzer Stefan A. , Denslow Julie S.
Published: July 2002

The abundance and diversity of lianas were examined along a tropical forest chronosequence at the Barro Colorado Nature Monument, Panama. Lianas ≥0.5 cm diameter were sampled along transects in two replicated stands in secondary (20, 40, 70 and 100 y after abandonment) and old-growth (>500 y) forests. Ordination of stands based on relative abundance, but not presence-absence, showed a significant separation of stands by age. Lianas were significantly more abundant and diverse (Fisher's α) in younger forests (20 and 40 y) than in older forests (70 and 100 y, and old-growth). The decline in liana abundance with stand age was offset by increased mean basal area per individual, resulting in a relatively constant total basal area and estimated biomass across stand age. The proportions of tendril climbers decreased and stem twiners increased over stand age. Decline in liana abundance and changes in liana composition may be related to changes in support and light availability. Although lianas are recognized as playing an important role in the early secondary sucession of many tropical forests, these results have shown that their important contribution to total basal area and biomass can continue as the forest matures, even as the numbers of established lianas declines.
Termite assemblages in two distinct montane forest types at 1000 m elevation in the Maliau Basin, Sabah
Authors: Jones David T.
Published: July 2002

Termites were surveyed at an altitude of 1000 m in Maliau Basin, Sabah (Borneo), in two primary forest habitats: lower montane forest and stunted facies of upper montane forest. Soil, wood, litter, termite nests, and arboreal microhabitats up to a height of 2 m above ground were sampled using a belt transect protocol. Two transects were run in each forest type. The upper montane forest transects collected 11 and 13 species, compared with 15 and 19 in the lower montane forest transects. With the addition of species records from casual sampling (conducted with roughly equal effort in each forest type), totals of 18 species were found in the upper montane forest, and 34 species in the lower montane forest. Similar species richness and relative abundance of wood-feeding termites were found in both forest types. However, the lower montane forest had greater richness and relative abundance of species that feed on soil and extremely decayed soil-like wood. This difference is attributed mainly to (i) the well developed, organic-rich soils of the lower montane forest being more suitable for soil-dwelling and mound-building termites compared with the upper montane forest which has sandy soils with a thick covering of peat, and (ii) the low-stature and open canopy of the upper montane forest creates microclimatic conditions which are adverse for soil-feeding termites compared with the high, closed canopy in the lower montane forest. As expected, comparisons with similar studies in lowland forests in Southeast Asia confirmed that the upland forests are relatively depauperate.
Ecology of two species of echimyid rodents (Hoplomys gymnurus and Proechimys semispinosus) in central Panamá
Authors: Adler Gregory H. , Tomblin David C. , Lambert Thomas D.
Published: July 2002

The family Echimyidae is one of the most widely distributed rodent families in the Neotropics. Virtually every tropical lowland forest contains at least one echimyid species, and many areas contain half a dozen or more species. The commonest terrestrial representatives of the family are within the genus Proechimys, and several species such as Proechimys semispinosus (Central American spiny rat) have been the subject of intensive ecological studies (e.g. Adler 1994, 1996; Adler & Beatty 1997, Alberico & Gonzalez 1993, Fleming 1971, Gliwicz 1984, Gonzalez-M. & Alberico 1993). P. semispinosus is often the most abundant rodent throughout its geographic range in Central America and northwestern South America, and its ecology is now fairly well-known.
Architectures and applications of intelligent agents: A survey
Authors: MÜLLER JÖRG P.
Published: July 2002

The objective of this paper is twofold. In its first part, we survey the state of the art in research on agent architectures. The architecture of an agent describes its modules and capabilities, and how these operate together. We structure the field by investigating three important research threads, i.e. architectures for reactive agents, deliberative agents and interacting agents. Then we describe various hybrid approaches that reconcile these three threads, aiming at a combination of different features like reactivity, deliberation and the ability to interact with other agents. These approaches are contrasted with architectural issues of recent agent-based work, including software agents, softbots, believable agents, as well as commercial agent-based systems. The second part of the paper addresses software engineers and system designers who are interested in applying agent technology to their problem domains. The objective of this part is to assist these readers in deciding which agent architecture to choose for a specific application. We characterise the most important domains to which the different approaches described in the first part have been applied, propose an application-related taxonomy of agents, and give a set of guidelines to select the right agent (architecture) for a given application.
DEPENDENCE AMONG SPACINGS
Authors: Khaledi Baha-Eldin , Kochar Subhash
Published: July 2002

In this paper, we study the dependence properties of spacings.
It is proved that if X1,...,
Xn are exchangeable random variables
which are TP2 in pairs and their joint density is
log-convex in each argument, then the spacings are MTP2
dependent. Next, we consider the case of independent but
nonhomogeneous exponential random variables. It is shown
that in this case, in general, the spacings are not MTP2
dependent. However, in the case of a single outlier when
all except one parameters are equal, the spacings are shown
to be MTP2 dependent and, hence, they are associated.
A consequence of this result is that in this case, the
variances of the order statistics are increasing. It is
also proved that in the case of the multiple-outliers model,
all consecutive pairs of spacings are TP2 dependent.