title: Diffusion radius of muonic hydrogen atoms in H-D gas

abstract:
  The diffusion radius of the 1S muonic hydrogen atoms in gaseous H_2 targets
with various deuterium admixtures has been determined for temperatures T=30 and
300 K. The Monte Carlo calculations have been performed using the partial
differential crosssections for $p\mu$ and $d\mu$ atom scattering from the
molecules H$_2$, HD and D$_2$. These cross sections include hyperfine
transitions in the muonic atoms, the muon exchange between the nuclei $p$ and
$d$, and rotational-vibrational transitions in the target molecules. The Monte
Carlo results have been used for preparing the time-projection chamber for the
high-precision measurement of the nuclear $\mu^{-}$ capture in the ground-state
$p\mu$ atom, which is now underway at the Paul Scherrer Institute.


title: The effect of AM noise on correlation phase noise measurements

abstract:
  We analyze the phase-noise measurement methods in which correlation and
averaging is used to reject the background noise of the instrument. All the
known methods make use of a mixer, used either as a saturated phase detector or
as a linear synchronous detector. Unfortunately, AM noise is taken in through
the power-to-dc-offset conversion mechanism that results from the mixer
asymmetry. The measurement of some mixers indicates that the unwanted
amplitude-to-voltage gain is of the order of 5-50 mV, which is 12-35 dB lower
than the phase-to-voltage gain of the mixer. In addition, the trick of setting
the mixer at a sweet point -- off the quadrature condition -- where the
sensitivity to AM nulls, works only with microwave mixers. The HF-VHF mixers
have not this sweet point. Moreover, we prove that if the AM noise comes from
the oscillator under test, it can not be rejected by correlation. At least not
with the schemes currently used. An example shows that at some critical
frequencies the unwanted effect of AM noise is of the same order -- if not
greater -- than the phase noise. Thus, experimental mistakes are around the
corner.


title:
Classical kinetic energy, quantum fluctuation terms and kinetic-energy
  functionals

abstract:
  We employ a recently formulated dequantization procedure to obtain an exact
expression for the kinetic energy which is applicable to all kinetic-energy
functionals. We express the kinetic energy of an N-electron system as the sum
of an N-electron classical kinetic energy and an N-electron purely quantum
kinetic energy arising from the quantum fluctuations that turn the classical
momentum into the quantum momentum. This leads to an interesting analogy with
Nelson's stochastic approach to quantum mechanics, which we use to conceptually
clarify the physical nature of part of the kinetic-energy functional in terms
of statistical fluctuations and in direct correspondence with Fisher
Information Theory. We show that the N-electron purely quantum kinetic energy
can be written as the sum of the (one-electron) Weizsacker term and an
(N-1)-electron kinetic correlation term. We further show that the Weizsacker
term results from local fluctuations while the kinetic correlation term results
from the nonlocal fluctuations. For one-electron orbitals (where kinetic
correlation is neglected) we obtain an exact (albeit impractical) expression
for the noninteracting kinetic energy as the sum of the classical kinetic
energy and the Weizsacker term. The classical kinetic energy is seen to be
explicitly dependent on the electron phase and this has implications for the
development of accurate orbital-free kinetic-energy functionals. Also, there is
a direct connection between the classical kinetic energy and the angular
momentum and, across a row of the periodic table, the classical kinetic energy
component of the noninteracting kinetic energy generally increases as Z
increases.

categories: physics.chem-ph math-ph math.MP quant-ph


title: To the Strength First Problem Full Solution: Mechanics of a Necking

abstract:
  Essentially new approach to analysis of internal forces, arising in
cylindrical rod under action of an axial tension force, has allowed to detect
the three-dimensional axisymmetric stress state. According to the new
conceptual model the axial tension force causes the tangential - hoop and
radial - stresses side by side with axial (normal) stress in the rod volume. A
completion of Lame's solution of the problem on the stress state in the
thickwalled cylinder has allowed to ascertain a mutual direct and reverse
connection of the tangential and radial stresses with the axial stress also in
the rod under action of an axial tension force. The new approach for the first
time has allowed to give the full physically adequate and mathematically
sufficiently strict description of a change of the initial cylindrical form of
a mild steel rod under action of an axial tension force on all stages of its
deforming, including the necking, the fracture process and a view of the
fracture surface. The new approach has allowed on the united methodological
base to elucidate also a number of the questions, bound with an axisymmetric
form of the soap solution film between two rings, with the breaking up of a
liquid free jet nto drops, with the causes of a buckling of the long tube under
action of internal pressure, created in it by the rested and moved fluid in it
and others.


title: Epidemic spreading on heterogeneous networks with identical infectivity

abstract:
  In this paper, we propose a modified susceptible-infected-recovered (SIR)
model, in which each node is assigned with an identical capability of active
contacts, $A$, at each time step. In contrast to the previous studies, we find
that on scale-free networks, the density of the recovered individuals in the
present model shows a threshold behavior. We obtain the analytical results
using the mean-field theory and find that the threshold value equals 1/A,
indicating that the threshold value is independent of the topology of the
underlying network. The simulations agree well with the analytic results.
Furthermore, we study the time behavior of the epidemic propagation and find a
hierarchical dynamics with three plateaus. Once the highly connected hubs are
reached, the infection pervades almost the whole network in a progressive
cascade across smaller degree classes. Then, after the previously infected hubs
are recovered, the disease can only propagate to the class of smallest degree
till the infected individuals are all recovered. The present results could be
of practical importance in the setup of dynamic control strategies.


title:
Forward Diffracted Parametric X Radiation From a Thick Tungsten Single
  Crystal at 855 MeV Electron Energy

abstract:
  Features of forward diffracted Parametric X-Radiation (PXR) were investigated
at experiments with the 855 MeV electron beam of the Mainz Microtron MAMI
employing a 410 micrometer thick tungsten single crystal. Virtual photons from
the electron field are diffracted by the (10-1) plane at a Bragg angle of 3.977
degree. Forward emitted radiation was analyzed at an energy of 40 keV with the
(111) lattice planes of a flat silicon single crystal in Bragg geometry. Clear
peak structures were observed in an angular scan of the tungsten single
crystal. The results were analyzed with a model which describes forward
diffracted PXR under real experimental conditions. The experiments show that
forward diffracted PXR may be employed to diagnose bending radii of lattice
planes in large area single crystals.


title:
The Physical Meaning of Gauge Transformations in Classical
  Electrodynamics

abstract:
  The structure of electrodynamics based on the variational principle together
with causality and space-time homogeneity is analyzed. It is proved that in
this case the 4-potential is defined uniquely. Therefore, the approach where
Maxwell equations and the Lorentz law of force are regarded as cornerstones of
the theory is not equivalent to the one described above.


title: Description of $^{4}$He tetramer bound and scattering states

abstract:
  Faddeev-Yakubovski equations are solved numerically for 4He tetramer and
trimer states using realistic helium-helium interaction models. We describe the
properties of ground and excited states, and we discuss with a special emphasis
the 4He-4He3 low energy scattering.


title: Physics in Films: An Assessment

abstract:
  Physics in Films is an alternative version of the physical science course
offered to non-science majors at the University of Central Florida. The course
uses the popularity of Hollywood films to generate interest in science and to
engage students that have traditionally been resistant to taking science
courses. Scenes that lead to teachable science moments are identified in films
and then used in class to concretize abstract physical concepts. With the wide
variety of movies available, different "flavors" of the course, each
specializing in a certain genre of film, have been created. This creates an
audience of students with a high level of interest in the teaching tool and
helps enhance their learning experience. In addition to the films, the course
uses electronic student response systems to increase class participation.
Although the course was first developed during the academic year 2002-2003, we
continue to develop and assess it. After a brief outline of the motivation for
the development of the course, we will discuss the different versions of the
course and the teaching techniques used, including the use of the student
response systems, and present data on the performance of the students in the
course. Moreover, we will present feedback on the course acquired from video
interviews with participating students.


title: Probing Non-Integer Dimensions

abstract:
  We show that two-dimensional convection-diffusion problems with a radial sink
or source at the origin may be recast as a pure diffusion problem in a
fictitious space in which the spatial dimension is continuously-tunable with
the Peclet number. This formulation allows us to probe various
diffusion-controlled processes in non-integer dimensions.


title: Air resistance

abstract:
  Most introductory physics textbooks ask students to ignore air resistance but
include no analysis of the appropriateness of that approximation. Indeed the
approximation is inappropriate in many textbook problems. This short
supplementary handout, appropriate for majors and non-majors alike, is designed
to make up for this pervasive shortcoming (see also arXiv:physics/0412107).


title: Possible Structures of Sprites

abstract:
  Upon using the hydrodynamic analog we can derive some families of stationary
Beltrami field-like solutions from the free Maxwell equations in vacuum. These
stationary electromagnetic fields are helical and/or column-like once they are
represented in a suitable frame of reference. Possible dendritic and
jelly-fish-like patterns of sprites are demonstrated.


title: Channel plasmon-polaritons: modal shape, dispersion, and losses

abstract:
  We theoretically study channel plasmon-polaritons (CPPs) with a geometry
similar to that in recent experiments at telecom wavelengths (Bozhevolnyi et
al., Nature 440, 508 (2006)). The CPP modal shape, dispersion relation, and
losses are simulated using the multiple multipole method and the finite
difference time domain technique. It is shown that, with the increase of the
wavelength, the fundamental CPP mode shifts progressively towards the groove
opening, ceasing to be guided at the groove bottom and becoming hybridized with
wedge plasmon-polaritons running along the groove edges.


title: Complex Spaces In Hydrodynamics: Complex Navier-Stokes Equations

abstract:
  The study is devoted to the development of new effective tools and methods of
ana-lytical hydrodynamics, including problems of existence, smoothness and
structure of laminar and turbulent flows. The main problem is complex
Navier-Stokes equations and turbulence in complex spaces. The necessity of
introducing complex spaces in hydrodynamics is deter-mined by the mechanism of
transition of a laminar flow into a turbulent flow. The author pro-poses a
non-traditional scenario of the transition: the cause of turbulence is in
destruction (cessation of existence) of a laminar flow. The article contains
the mathematical rationale for the necessity of development of the theory of
turbulence in the complex configurational space: the complex configurational
space is the natural area of existence of turbulence. Hydrody-namic flows are
regarded as flows on entropy manifolds that [flows] are supported by the two
symmetries: the symmetry of conservation of general entropy and the symmetry of
duality of impulse representation. The new symmetry has been introduced and
studied: the forminvari-ance of Helmholtz matrix of impulse density. The strict
foundation has been provided for the known fact of chaotic mechanics:
appearance of the new structure (a turbulent flow) is a result of interaction
of two entities: dissipation and vorticity. On the deep level the phenomenology
of turbulence in complex spaces is based on the transition from the mechanics
of a material point to the mechanics of an oriented material point, that
[transition] takes place in a current period of time.


title: Photonic mode density effects on single-molecule fluorescence blinking

abstract:
  We investigated the influence of the photonic mode density (PMD) on the
triplet dynamics of individual chromophores on a dielectric interface by
comparing their response in the presence and absence of a nearby gold film.
Lifetimes of the excited singlet state were evaluated in ordet to measure
directly the PMD at the molecules position. Triplet state lifetimes were
simultaneously determined by statistical analysis of the detection time of the
fluorescence photons. The observed singlet decay rates are in agreement with
the predicted PMD for molecules with different orientations. The triplet decay
rate is modified in a fashion correlated to the singlet decay rate. These
results show that PMD engineering can lead to an important suppression of the
fluorescence, introducing a novel aspect of the physical mechanism to enhance
fluorescence intensity in PMD-enhancing systems such as plasmonic devices.


title: Geometrical optics in general relativity

abstract:
  General relativity includes geometrical optics. This basic fact has relevant
consequences that concern the physical meaning of the discontinuity surfaces
propagated in the gravitational field - as it was first emphasized by
Levi-Civita.


title: Plasmon Assisted Transparency in Metal--Dielectric Microspheres

abstract:
  We present a theoretical analysis of light scattering from a layered
metal-dielectric microsphere. The system consists of two spherical resonators,
coupled through concentric embedding. Solving for the modes of this system we
find that near an avoided crossing the scattering cross section is dramatically
suppressed, exhibiting a tunable optical transparency. Similar to
electromagnetically induced transparency, this phenomenon is associated with a
large group delay, which in our system is manifest as flat azimuthal
dispersion.


title: Perturbative analysis of generally nonlocal spatial optical solitons

abstract:
  In analogy to a perturbed harmonic oscillator, we calculate the fundamental
and some other higher order soliton solutions of the nonlocal nonlinear
Schroedinger equation (NNLSE) in the second approximation in the generally
nonlocal case. Comparing with numerical simulations we show that soliton
solutions in the 2nd approximation can describe the generally nonlocal soliton
states of the NNLSE more exactly than that in the zeroth approximation. We show
that for the nonlocal case of an exponential-decay type nonlocal response the
Gaussian-function-like soliton solutions can't describe the nonlocal soliton
states exactly even in the strongly nonlocal case. The properties of such
nonlocal solitons are investigated. In the strongly nonlocal limit, the
soliton's power and phase constant are both in inverse proportion to the 4th
power of its beam width for the nonlocal case of a Gaussian function type
nonlocal response, and are both in inverse proportion to the 3th power of its
beam width for the nonlocal case of an exponential-decay type nonlocal
response.


title: Credit contagion and credit risk

abstract:
  We study a simple, solvable model that allows us to investigate effects of
credit contagion on the default probability of individual firms, in both
portfolios of firms and on an economy wide scale. While the effect of
interactions may be small in typical (most probable) scenarios they are
magnified, due to feedback, by situations of economic stress, which in turn
leads to fatter tails in loss distributions of large loan portfolios.


title:
Formation of long-lived, scarlike modes near avoided resonance crossings
  in optical microcavities

abstract:
  We study the formation of long-lived states near avoided resonance crossings
in open systems. For three different optical microcavities (rectangle, ellipse,
and semi-stadium) we provide numerical evidence that these states are localized
along periodic rays, resembling scarred states in closed systems. Our results
shed light on the morphology of long-lived states in open mesoscopic systems.


title:
Experimental study of laser detected magnetic resonance based on atomic
  alignment

abstract:
  We present an experimental study of the spectra produced by
optical/radio-frequency double resonance in which resonant linearly polarized
laser light is used in the optical pumping and detection processes. We show
that the experimental spectra obtained for cesium are in excellent agreement
with a very general theoretical model developed in our group and we investigate
the limitations of this model. Finally, the results are discussed in view of
their use in the study of relaxation processes in aligned alkali vapors.


title:
Reducing of phase retrieval errors in Fourier analysis of 2-dimensional
  digital model interferograms

abstract:
  In order to measure the radial displacements of facets on surface of a
growing spherical Cu_{2-\delta}Se crystal with sub-nanometer resolution, we
have investigated the reliability and accuracy of standard method of Fourier
analysis of fringes obtained applying digital laser interferometry method.
Guided by the realistic experimental parameters (density and orientation of
fringes), starting from 2-dimensional model interferograms and using
unconventional custom designed Gaussian filtering window and unwrapping
procedure of the retrieved phase, we have demonstrated that for considerable
portion of parameter space the non-negligible inherent phase retrieval error is
present solely due to non-integer number of fringes within the digitally
recorded image (using CCD camera). Our results indicate the range of
experimentally adjustable parameters for which the generated error is
acceptably small. We also introduce a modification of the (last part) of the
usual phase retrieval algorithm which significantly reduces the error in the
case of small fringe density.


title:
The Application Hosting Environment: Lightweight Middleware for
  Grid-Based Computational Science

abstract:
  Grid computing is distributed computing performed transparently across
multiple administrative domains. Grid middleware, which is meant to enable
access to grid resources, is currently widely seen as being too heavyweight
and, in consequence, unwieldy for general scientific use. Its heavyweight
nature, especially on the client-side, has severely restricted the uptake of
grid technology by computational scientists. In this paper, we describe the
Application Hosting Environment (AHE) which we have developed to address some
of these problems. The AHE is a lightweight, easily deployable environment
designed to allow the scientist to quickly and easily run legacy applications
on distributed grid resources. It provides a higher level abstraction of a grid
than is offered by existing grid middleware schemes such as the Globus Toolkit.
As a result the computational scientist does not need to know the details of
any particular underlying grid middleware and is isolated from any changes to
it on the distributed resources. The functionality provided by the AHE is
`application-centric': applications are exposed as web services with a
well-defined standards-compliant interface. This allows the computational
scientist to start and manage application instances on a grid in a transparent
manner, thus greatly simplifying the user experience. We describe how a range
of computational science codes have been hosted within the AHE and how the
design of the AHE allows us to implement complex workflows for deployment on
grid infrastructure.


title:
Multi-neuronal auditory coding for frequency resolution beyond the
  refractory threshold

abstract:
  We propose a new mechanism for high-pitch perception by a system of multiple
neurons capable of resolving frequencies higher than the frequency associated
with the mean refractory period up to a multiple thereof.


title:
Integrating economic and psychological insights in binary choice models
  with social interactions

abstract:
  We investigate a class of binary choice models with social interactions. We
propose a unifying perspective that integrates economic models using a utility
function and psychological models using an impact function. A general approach
for analyzing the equilibrium structure of these models within mean-field
approximation is developed. It is shown that within a mean-field approach both
the utility function and the impact function models are equivalent to threshold
models. The interplay between heterogeneity and randomness in model formulation
is discussed. A general framework is applied in a number of examples leading to
some well-known models but also showing the possibility of more complex
dynamics related to multiple equilibria. Our synthesis can provide a basis for
many practical applications extending the scope of binary choice models.


title: Charge of a particle generated by a captured pair of photons

abstract:
  The model of charge generation is based on the wave model of a particle, for
which a brief description is given. The particle is comprised of two photons,
captured in the volume of the particle, and reveals the complete relativistic
behaviour. The electromagnetic waves of the two photons are supposed to induce
an electrostatic field. The surface integral of this electrostatic field is
identified with the charge of the particle. The magnitude of the electric field
is derived from the energy density of the photons. The volume and the surface
are related to the wavelength of the photons, thus leading to a charge of the
particle, which is independent of its mass.


title: Evolving networks through deletion and duplication

abstract:
  We introduce a minimalistic model based on dynamic node deletion and node
duplication with heterodimerisation. The model is intended to capture the
essential features of the evolution of protein interaction networks. We derive
an exact two-step rate equation to describe the evolution of the degree
distribution. We present results for the case of a fixed-size network. The
results are based on the exact numerical solution to the rate equation which
are consistent with Monte Carlo simulations of the model's dynamics. Power-law
degree distributions with apparent exponents $<1$ were observed for generic
parameter choices. However, a proper finite-size scaling analysis revealed that
the actual critical exponent in such cases is equal to 1. We present a
mean-field argument to determine the asymptotic value of the average degree,
illustrating the existence of an attractive fixed point, and corroborate this
result with numerical simulations of the first moment of the degree
distribution as described by the two-step rate equation. Using the above
results, we show that the apparent exponent is determined by the
heterodimerisation probability. Our preliminary results are consistent with
empirical data for a wide range of organisms, and we believe that through
implementing some of the suggested modifications, the model could be
well-suited to other types of biological and non-biological networks.


title:
Phase sensitive detection of dipole radiation in a fiber-based high
  numerical aperture optical system

abstract:
  We theoretically study the problem of detecting dipole radiation in an
optical system of high numerical aperture in which the detector is sensitive to
\textit{field amplitude}. In particular, we model the phase sensitive detector
as a single-mode cylindrical optical fiber. We find that the maximum in
collection efficiency of the dipole radiation does not coincide with the
optimum resolution for the light gathering instrument. The calculated results
are important for analyzing fiber-based confocal microscope performance in
fluorescence and spectroscopic studies of single molecules and/or quantum dots.


title:
Weak coupling interactions of colloidal lead sulphide nanocrystals with
  silicon photonic crystal nanocavities near 1.55 microns at room temperature

abstract:
  We observe the weak coupling of lead sulphide nanocrystals to localized
defect modes of 2-dimensional silicon nanocavities. Cavity resonances
characterized with ensemble nanocrystals are verified with cold-cavity
measurements using integrated waveguides. Polarization dependence of the cavity
field modes is observed. The linewidths measured in coupling experiments are
broadened in comparison to the cold-cavity characterization, partly due to
large homogeneous linewidths of the nanocrystals. The calculated Purcell factor
for a single exciton is 75, showing promise toward applications in single
photon systems. These novel light sources operate near 1.55 micron wavelengths
at room temperature, permitting integration with current fiber communications
networks.


title: Possible Orientation Effects to Phase Diagram of Strange Matter

abstract:
  We obtain possibly valuable information about the orientation-tuning of phase
diagram of superdense nuclear matter at high fermion as well as boson number
density but low temperature, which is not accessible to relativistic heavy ion
collision experiments. Our results resemble those proposed before by Alford.
Possible observational signatures associated with the theoretically proposed
states of matter inside compact stars are discussed as well.


title:
Precise Numerical Solutions of Potential Problems Using Crank-Nicholson
  Method

abstract:
  A new numerical treatment in the Crank-Nicholson method with the imaginary
time evolution operator is presented in order to solve the Schr\"{o}dinger
equation. The original time evolution technique is extended to a new operator
that provides a systematic way to calculate not only eigenvalues of ground
state but also of excited states. This new method systematically produces
eigenvalues with accuracies of eleven digits with the Cornell potential that
covers non-perturbative regime. An absolute error estimation technique based on
a power counting rule is implemented. This method is examined with exactly
solvable problems and produces the numerical accuracy down to 10$^{-11}$.


title: Spontaneous Symmetry Breaking in Quantum Mechanics

abstract:
  We present a clear and mathematically simple procedure explaining spontaneous
symmetry breaking in quantum mechanical systems. The procedure is applicable to
a wide range of models and can be easily used to explain the existence of a
symmetry broken state in crystals, antiferromagnets and even superconductors.
It has the advantage that it automatically brings to the fore the main players
in spontaneous symmetry breaking: the symmetry breaking field, the
thermodynamic limit, and the global excitations of the thin spectrum.


title: Phase transition in Nowak-Sznajd opinion dynamics

abstract:
  The Nowak modification of the Sznajd opinion dynamics model on the square
lattice assumes that with probabilities beta and gamma the opinions flip due to
mass-media advertising from down to up, and vice versa. Besides, with
probability alpha the Sznajd rule applies that a neighbour pair agreeing in its
two opinions convinces all its six neighbours of that opinion. Our Monte Carlo
simulations and mean-field theory find sharp phase transitions in the parameter
space.


title:
Multifractal Omori Law for Earthquake Triggering: New Tests on the
  California, Japan and Worldwide Catalogs

abstract:
  The Multifractal Stress-Activated (MSA) model is a statistical model of
triggered seismicity based on mechanical and thermodynamic principles. It
predicts that, above a triggering magnitude cut-off $M_0$, the exponent $p$ of
the Omori law for the seismic decay of aftershocks is a linear increasing
function $p(M) =a M+b$ of the main shock magnitude $M$. We previously reported
empirical support for this prediction, using the Southern California SCEC
catalog. Here, we confirm this law using an updated, longer version of the same
catalog, as well as new methods to estimate $p$. One of this methods is the
newly defined Scaling Function Analysis, adapted from the wavelet transform.
This method is able to measure a singularity ($p$-value), erasing the possible
regular part of a time series. The Scaling Function Analysis also proves
particularly efficient to reveal the coexistence of several types of relaxation
laws (typical Omori sequences and short-lived swarms sequences) which can be
mixed within the same catalog. The same methods are used on data from the
worlwide Harvard CMT and show results compatible with those of Southern
California. For the Japanese JMA catalog, we still observe a linear dependence
of $p$ on $M$, yet with a smaller slope. The scaling function analysis shows
however that results for this catalog may be biased by numerous swarm
sequences, despite our efforts to remove them before the analysis.


title: Hadron locations on the rectangle

abstract:
  Hadrons are located at the orthogonal intersections of 4-branes that wrap
1-cycles of a rectangular compact space. The 4-branes are arranged in a regular
network. We reveal the conspicuous locations on the rectangle of the lightest
mesons, unflavoured and of each flavour, of the lightest meson singlet states
with hidden flavour of each kind, and of the lightest baryons of each flavour.
The Higgs field vacuum expectation value is also associated with a conspicuous
position on the rectangle, at the orthogonal intersection of 4-branes.


title: Unveiling the dynamics of the universe

abstract:
  We present two methods for describing, from a pedagogical point of view, the
solutions of Einstein's equations applied to a homogeneous and isotropic
universe. In the first method, we define an effective gravitational potential
of the universe, and the second method makes use of the fact that we can define
a dynamical system of equations. The methods are applied to different
cosmological models whose properties are discussed in turn. The ultimate
intention is to provide simple examples to be revised in a first Cosmology
course for undergraduates.


title:
The effects of solid-liquid interfacial tension on the settlement of
  sediment flocs

abstract:
  In this paper, the effects of interfacial tension between the sediment solid
particle and liquid on the settlement of sediment flocs are investigated. After
a discussion of mechanical and physical chemistry, we give a settling velocity
expression including such dynamical information of the floc growth as
interfacial tension and primary particle size \textit{etc.}. The resulting
expression indicates the average settling velocity of sediment flocs increases
with increasing solid-liquid interfacial tension in a form of power law and
deceases with the primary particle size. We report on a general method for
analyzing settling behaviors of sediment flocs under different flocculation
conditions and verify the rationality of the assumption of tension-induced
flocculation by fitting typical experimental data to the electrolyte
concentration-dependent sedimentation model which can follow from the
relationship between interfacial tension and electrolyte concentration.


title:
Crossover from Endogenous to Exogenous Activity in Open-Source Software
  Development

abstract:
  We have investigated the origin of fluctuations in the aggregated behaviour
of an open-source software community. In a recent series of papers, de Menezes
and co-workers have shown how to separate internal dynamics from external
fluctuations by capturing the simultaneous activity of many system's
components. In spite of software development being a planned activity, the
analysis of fluctuations reveals how external driving forces can be only
observed at weekly and higher time scales. Hourly and higher change frequencies
mostly relate to internal maintenance activities. There is a crossover from
endogenous to exogenous activity depending on the average number of file
changes. This new evidence suggests that software development is a
non-homogeneous design activity where stronger efforts focus in a few project
files. The crossover can be explained with a Langevin equation associated to
the cascading process, where changes to any file trigger additional changes to
its neighbours in the software network. In addition, analysis of fluctuations
enables us to detect whether a software system can be decomposed in several
subsystems with different development dynamics.


title: Impact of non-Poisson activity patterns on spreading processes

abstract:
  Halting a computer or biological virus outbreak requires a detailed
understanding of the timing of the interactions between susceptible and
infected individuals. While current spreading models assume that users interact
uniformly in time, following a Poisson process, a series of recent measurements
indicate that the inter-contact time distribution is heavy tailed,
corresponding to a temporally inhomogeneous bursty contact process. Here we
show that the non-Poisson nature of the contact dynamics results in prevalence
decay times significantly larger than predicted by the standard Poisson process
based models. Our predictions are in agreement with the detailed time resolved
prevalence data of computer viruses, which, according to virus bulletins, show
a decay time close to a year, in contrast with the one day decay predicted by
the standard Poisson process based models.

categories: physics.data-an cond-mat.stat-mech physics.bio-ph q-bio.PE


title: Equilibrium configurations of tripolar charges

abstract:
  It is shown that an ensemble of particles with tripolar (colour) charges will
necessarily cohere in a hierarchy of structures, from simple clusters and
strings to complex aggregates and cyclic molecule-like structures. The basic
combinatoric rule remains essentially the same on different levels of the
hierarchy, thus leading to a pattern of resemblance between different levels.
The number of primitive charges in each structure is determined by the symmetry
of the combined effective potential of this structure. The outlined scheme can
serve as a framework for building a model of composite fundamental fermions.


title:
Analytical Solution For Navier-Stokes Equations In Two Dimensions For
  Laminar Incompressible Flow

abstract:
  The Navier-Stokes equations describing laminar flow of an incompressible
fluid will be solved. Different group of general solutions for Navier stokes
equations governing Laminar incompressible fluids will be derived.


title:
High-precision Absolute Distance Measurement using Dual-Laser Frequency
  Scanned Interferometry Under Realistic Conditions

abstract:
  In this paper, we report on new high-precision absolute distance measurements
performed with frequency scanned interferometry using a pair of single-mode
optical fibers. Absolute distances were determined by counting the interference
fringes produced while scanning the frequencies of the two chopped lasers.
High-finesse Fabry-Perot interferometers were used to determine frequency
changes during scanning. Dual lasers with oppositely scanning directions,
combined with a multi-distance-measurement technique previously reported, were
used to cancel drift errors and to suppress vibration effects and interference
fringe uncertainties. Under realistic conditions, a precision about 0.2 microns
was achieved for a distance of 0.41 meters.


title:
Discrete Thermodynamics And Emergence Of Bifurcations In The Chemical
  Systems

abstract:
  The paper investigates emergence of pitchfork bifurcations in the chemical
systems. The systems may be split conditionally by two groups, the strong and
the weak, depending upon system complexity and its potential response to the
external impact. This work investigates birth and development of bifurcations
in the systems of both types. As a special case of a weak system with high
degree of the equilibrium transformation, emergence of bifurcations was studied
in the discrete thermodynamic model of 2-level laser.


title: On the parabolic equation method in internal wave propagation

abstract:
  A parabolic equation for the propagation of periodic internal waves over
varying bottom topography is derived using the multiple-scale perturbation
method. Some computational aspects of the numerical implementation are
discussed. The results of numerical experiments on propagation of an incident
plane wave over a circular-type shoal are presented in comparison with the
analytical result, based on Born approximation.


title:
Increasing Exclusion: The Pauli Exclusion Principle and Energy
  Conservation for Bound Fermions are Mutually Exclusive

abstract:
  A review of those forms of standard quantum mechanics that include the Pauli
Exclusion Principle as it is applied to atomic species, (that is versions of
quantum that are multi-electron and multi-orbital) shows they are not
consistent with energy conservation. Particular focus is given to helium in
which it is shown that energy conservation is not consistent with current
models. If the two electrons in the ground state, per current theory, are at
the same energy as the ionization energy, it is demonstrated that according to
the standard theory approximately 30 eV are lost during ionization, or
alternatively, about 30 eV of energy are created during ionization/electron
attachment. The same issue of energy loss during relaxation of energy levels
following ionization is shown to exist for all atomic species, thus
demonstrating that the Pauli Exclusion Principle (PEP) and energy conservation
are not consistent for any atomic species for current forms of distinguishable
electron forms of quantum theory. Only that form of quantum that has a single
orbital, and for which only one ionization energy can be computed (that is the
original Schrodinger form), is consistent with an energy balance. However, this
form is not consistent with common spectroscopy results, and it is argued PEP
has no meaning in this form of quantum theory. In contrast a new model,
Classical Quantum Mechanics (CQM), invented by R. Mills,, following
modification, is consistent with all spectroscopy and energy conservation for
bound electron systems. This new model is based on the validity of Maxwell s
Equations and Newton s Laws at all scales. Detailed, and remarkably simple,
computations for determining the ground state energy levels in one and two
electron systems using CQM are presented. Agreements with data are excellent.


title: MontePython: Implementing Quantum Monte Carlo using Python

abstract:
  We present a cross-language C++/Python program for simulations of quantum
mechanical systems with the use of Quantum Monte Carlo (QMC) methods. We
describe a system for which to apply QMC, the algorithms of variational Monte
Carlo and diffusion Monte Carlo and we describe how to implement theses methods
in pure C++ and C++/Python. Furthermore we check the efficiency of the
implementations in serial and parallel cases to show that the overhead using
Python can be negligible.


title: A Plausible Model for a Photon by Linear Polarization

abstract:
  A plausible photon model is presented. The model is based on the idea that
photon and particle must have the same structure. The linear polarization is
interpreted under the assumption that vibration photons interact with the
particles in the polarizer/analyzer. Slantwise flying photons are separated by
the particles of the dichroic or double-refracting material into two components
because a vibration component is absorbed and the other one is let through
inevitably. The vibrations are explained by example of the carbonate ion of
calcite.
  -----
  Es wird ein plausibles Photonenmodell vorgelegt. Das Modell basiert auf der
Vorstellung, dass Photon und Teilchen die gleiche Struktur haben muessen.
Lineare Polarisation wird gedeutet unter der Annahme, dass von den Teilchen im
Polarisator/Analysator Schwingungsphotonen aufgenommen werden. Bei schraegem
Einschuss der Photonen werden sie von den Teilchen des dichroitischen oder
doppelbrechenden Materials in zwei Komponenten getrennt, weil eine
Schwingungskomponente absorbiert wird und die andere zwangslaeufig
durchgelassen wird. Die Schwingungen werden am Beispiel des Carbonat-Ions von
Calcit erlaeutert.


title:
Quantitative two-dimensional shadowgraphic set-up for high-sensitivity
  measurement of low-density laser-plasmas

abstract:
  We present a quantitative shadowgraphic method which can measure the density
of a laser-generated plasma in air with sensitivity and resolution comparable
or better than traditional interferometric techniques. Simultaneous comparison
of both shadowgraphy and interferometry has been carried out allowing the
experimental evaluation of the reliability of the shadowgraphic method.


title:
A "black-box" re-weighting analysis can correct flawed simulation data,
  after the fact

abstract:
  There is a great need for improved statistical sampling in a range of
physical, chemical and biological systems. Even simulations based on correct
algorithms suffer from statistical error, which can be substantial or even
dominant when slow processes are involved. Further, in key biomolecular
applications, such as the determination of protein structures from NMR data,
non-Boltzmann-distributed ensembles are generated. We therefore have developed
the "black-box" strategy for re-weighting a set of configurations generated by
arbitrary means to produce an ensemble distributed according to any target
distribution. In contrast to previous algorithmic efforts, the black-box
approach exploits the configuration-space density observed in a simulation,
rather than assuming a desired distribution has been generated. Successful
implementations of the strategy, which reduce both statistical error and bias,
are developed for a one-dimensional system, and a 50-atom peptide, for which
the correct 250-to-1 population ratio is recovered from a heavily biased
ensemble.


title: Ab Initio Liquid Hydrogen Muon Cooling Simulations with ELMS in ICOOL

abstract:
  This paper presents new theoretical results on the passage of muons through
liquid hydrogen which have been confirmed in a recent experiment. These are
used to demonstrate that muon bunches may be compressed by ionisation cooling
more effectively than suggested by previous calculations.
  Muon cooling depends on the differential cross section for energy loss and
scattering of muons. We have calculated this cross section for liquid H2 from
first principles and atomic data, avoiding traditional assumptions. Thence, 2-D
probability maps of energy loss and scattering in mm-scale thicknesses are
derived by folding, and stored in a database. Large first-order correlations
between energy loss and scattering are found for H2, which are absent in other
simulations. This code is named ELMS, Energy Loss & Multiple Scattering. Single
particle trajectories may then be tracked by Monte Carlo sampling from this
database on a scale of 1 mm or less. This processor has been inserted into the
cooling code ICOOL. Significant improvements in 6-D muon cooling are predicted
compared with previous predictions based on GEANT. This is examined in various
geometries. The large correlation effect is found to have only a small effect
on cooling. The experimental scattering observed for liquid H2 in the MUSCAT
experiment has recently been reported to be in good agreement with the ELMS
prediction, but in poor agreement with GEANT simulation.


title:
Detection of radio frequency magnetic fields using nonlinear
  magneto-optical rotation

abstract:
  We describe a room-temperature alkali-metal atomic magnetometer for detection
of small, high frequency magnetic fields. The magnetometer operates by
detecting optical rotation due to the precession of an aligned ground state in
the presence of a small oscillating magnetic field. The resonance frequency of
the magnetometer can be adjusted to any desired value by tuning the bias
magnetic field. We demonstrate a sensitivity of $100\thinspace{\rm
pG/\sqrt{Hz}\thinspace(RMS)}$ in a 3.5 cm diameter, paraffin coated cell. Based
on detection at the photon shot-noise limit, we project a sensitivity of
$20\thinspace{\rm pG/\sqrt{Hz}\thinspace(RMS)}$.


title: Application of atomic magnetometry in magnetic particle detection

abstract:
  We demonstrate the detection of magnetic particles carried by water in a
continuous flow using an atomic magnetic gradiometer. Studies on three types of
magnetic particles are presented: a single cobalt particle (diameter ~150 um,
multi-domain), a suspension of superparamagnetic magnetite particles (diameter
\~1 um), and ferromagnetic cobalt nanoparticles (diameter ~10 nm, 120 kA/m
magnetization). Estimated detection limits are 20 um diameter for a single
cobalt particle at a water flow rate 30 ml/min, 5x10^3 magnetite particles at
160 ml/min, and 50 pl for the specific ferromagnetic fluid at 130 ml/min.
Possible applications of our method are discussed.


title:
Nonstationary Increments, Scaling Distributions, and Variable Diffusion
  Processes in Financial Markets

abstract:
  Arguably the most important problem in quantitative finance is to understand
the nature of stochastic processes that underlie market dynamics. One aspect of
the solution to this problem involves determining characteristics of the
distribution of fluctuations in returns. Empirical studies conducted over the
last decade have reported that they arenon-Gaussian, scale in time, and have
power-law(or fat) tails. However, because they use sliding interval methods of
analysis, these studies implicitly assume that the underlying process has
stationary increments. We explicitly show that this assumption is not valid for
the Euro-Dollar exchange rate between 1999-2004. In addition, we find that
fluctuations in returns of the exchange rate are uncorrelated and scale as
power-laws for certain time intervals during each day. This behavior is
consistent with a diffusive process with a diffusion coefficient that depends
both on the time and the price change. Within scaling regions, we find that
sliding interval methods can generate fat-tailed distributions as an artifact,
and that the type of scaling reported in many previous studies does not exist.

categories: physics.soc-ph cond-mat.stat-mech physics.data-an q-fin.ST


title:
Radiative Transfer Limits of Two-Frequency Wigner Distribution for
  Random Parabolic Waves

abstract:
  The present note establishes the self-averaging, radiative transfer limit for
the two-frequency Wigner distribution for classical waves in random media.
Depending on the ratio of the wavelength to the correlation length the limiting
equation is either a Boltzmann-like integral equation or a Fokker-Planck-like
differential equation in the phase space. The limiting equation is used to
estimate three physical parameters: the spatial spread, the coherence length
and the coherence bandwidth. In the longitudinal case, the Fokker-Planck-like
equation can be solved exactly.


title:
Self-Averaging Scaling Limits of Two-Frequency Wigner Distribution for
  Random Paraxial Waves

abstract:
  Two-frequency Wigner distribution is introduced to capture the asymptotic
behavior of the space-frequency correlation of paraxial waves in the radiative
transfer limits. The scaling limits give rises to deterministic transport-like
equations. Depending on the ratio of the wavelength to the correlation length
the limiting equation is either a Boltzmann-like integral equation or a
Fokker-Planck-like differential equation in the phase space. The solutions to
these equations have a probabilistic representation which can be simulated by
Monte Carlo method. When the medium fluctuates more rapidly in the longitudinal
direction, the corresponding Fokker-Planck-like equation can be solved exactly.


title: Performance of the PrimEx Electromagnetic Calorimeter

abstract:
  We report the design and performance of the hybrid electromagnetic
calorimeter consisting of 1152 $PbWO_4$ crystals and 576 lead glass blocks for
the PrimEx experiment at the Jefferson Laboratory. The detector was built for
high precision measurement of the neutral pion lifetime via the Primakoff
effect. Calorimeter installation and commissioning was completed with the first
physics run in fall of 2004. We present the energy and position resolution of
the calorimeter. Obtained $\pi^0$ mass resolution of $1.3 \mathrm{MeV/c^2}$ and
its production angle resolution of $0.34 \mathrm{mrad}$ demonstrate the ability
of the experiment to extract the $\pi^0$ lifetime on one percent level.


title:
Test of the one-way speed of light and the first-order experiment of
  Special Relativity using phase-conjugate interferometers

abstract:
  With a Michelson interferometer using a phase-conjugate mirror (PCM) that
reverses the uniform phase shift in a light path, we can conduct a first-order
experiment of Special Relativity. Utilization of the PCM changes the basic
concepts of an interference experiment. Placing a conventional partially
reflecting mirror just in front of the PCM at the end of a light path, we can
test the isotropy of the one-way speed of light in a system moving uniformly in
a straight line and conduct the one-way Sagnac experiment. According to the
reported phase-conjugate Sagnac experiment using a segment light path, we can
expect that the phase shift is phi = 4pivL/clambda in the one-way Sagnac
experiment with path length L and speed v, even with an increasingly larger
radius of the rotation. Based on these and the experimental fact of the
generalized Sagnac effect, it is very important to examine whether there is the
same phase shift for the test of the one-way speed of light and the first-order
experiment using the PCM in a system in straight-line uniform motion. The
sensitivities of these experiments are very high.


title: Exploring the phase space of the quantum delta kicked accelerator

abstract:
  We experimentally explore the underlying pseudo-classical phase space
structure of the quantum delta kicked accelerator. This was achieved by
exposing a Bose-Einstein condensate to the spatially corrugated potential
created by pulses of an off-resonant standing light wave. For the first time
quantum accelerator modes were realized in such a system. By utilizing the
narrow momentum distribution of the condensate we were able to observe the
discrete momentum state structure of a quantum accelerator mode and also to
directly measure the size of the structures in the phase space.


title:
Maxwell demon in Granular gas: a new kind of bifurcation? The
  hypercritical bifurcation

abstract:
  This paper starts with the investigation of the behaviour of a set of two
subsystems which are able to exchange some internal quantity according to a
given flux function. It is found that this sytem exhibit a bifurcation when the
flux passes through a maximum and that its kind (super-critical/sub-critical)
depends on the dissymmetry of the flux function near the maximum. It is also
found a new kind of bifurcation when the flux function is symmetric: we call it
hypercritical bifurcation because it generates much stronger fluctuations than
the super-critical one. The effect of a white noise is then investigated. We
show that an experimental set-up, leading to the Maxwell demon in granular gas,
displays all these kinds of bifurcation, just by changing the parameters of
excitation. It means that this system is much less simple as it was thought.


title:
Performance Of A Liquid Argon Time Projection Chamber Exposed To The
  WANF Neutrino Beam

abstract:
  We present the results of the first exposure of a Liquid Argon TPC to a
multi-GeV neutrino beam. The data have been collected with a 50 liters
ICARUS-like chamber located between the CHORUS and NOMAD experiments at the
CERN West Area Neutrino Facility (WANF). We discuss both the instrumental
performance of the detector and its capability to identify and reconstruct low
multiplicity neutrino interactions.


title: Stochastic Time

abstract:
  We present a simple dynamical model to address the question of introducing a
stochastic nature in a time variable. This model includes noise in the time
variable but not in the "space" variable, which is opposite to the normal
description of stochastic dynamics. The notable feature is that these models
can induce a "resonance" with varying noise strength in the time variable.
Thus, they provide a different mechanism for stochastic resonance, which has
been discussed within the normal context of stochastic dynamics.


title: A unifying approach to left handed material design

abstract:
  In this letter we show that equivalent circuits offer a qualitative and even
quantitative simple explanation for the behavior of various types of
left-handed (or negative index) meta-materials. This allows us to optimize
design features and parameters, while avoiding trial and error simulations or
fabrications. In particular we apply this unifying circuit approach in
accounting for the features and in optimizing the structure employing parallel
metallic bars on the two sides of a dielectric film.


title:
Effect of transient pinning on stability of drops sitting on an inclined
  plane

abstract:
  We report on new instabilities of the quasi-static equilibrium of water drops
pinned by a hydrophobic inclined substrate. The contact line of a statically
pinned drop exhibits three transitions of partial depinning: depinning of the
advancing and receding parts of the contact line and depinning of the entire
contact line leading to the drop's translational motion. We find a region of
parameters where the classical Macdougall-Ockrent-Frenkel approach fails to
estimate the critical volume of the statically pinned inclined drop.


title: Boltzmann Distribution and Temperature of Stock Markets

abstract:
  The minute fluctuations of of S&P 500 and NASDAQ 100 indices display
Boltzmann statistics over a wide range of positive as well as negative returns,
thus allowing us to define a {\em market temperature} for either sign. With
increasing time the sharp Boltzmann peak broadens into a Gaussian whose
volatility $ \sigma $ measured in $1/ \sqrt{{\rm min}}$ is related to the
temperature $T$ by $T= \sigma / \sqrt{2}$. Plots over the years 1990--2006 show
that the arrival of the 2000 crash was preceded by an increase in market
temperature, suggesting that this increase can be used as a warning signal for
crashes. A plot of the Dow Jones temperature over 78 years reveals a remarkable
stability through many historical turmoils, interrupted only by short heat
bursts near the crashes.


title:
Scale invariant multiplier and multifractality of absolute returns in
  stock markets

abstract:
  The statistical properties of the multipliers of the absolute returns are
investigated using one-minute high-frequency data of financial time series. The
multiplier distribution is found to be independent of the box size $s$ when $s$
is larger than some crossover scale, providing direct evidence of the existence
of scale invariance in financial data. The multipliers with base $a=2$ are well
approximated by a normal distribution and the most probable multiplier scales
as a power law in respect to the base $a$. We unravel that the volatility
multipliers possess multifractal nature which is independent of construction of
the multipliers, that is, the values of $s$ and $a$.


title:
Fast random number generation using 128 bit multimedia extension
  registers on Pentium class machines

abstract:
  In this work it is shown how 128 bit SSE2 multimedia extension registers,
present in Pentium IV class 32 bit processors, may be used to generate random
numbers at several times greater speed then when regular general purpose
registers are used. In particular, a 128 bit algorithm is presented for the
Marsaglia MWC1616 generator from the DIEHARD battery of random number generator
tests, and its performance is compared to that of the conventional approach.


title: Stereography using a single lens

abstract:
  In this paper we have put forth an innovative method of obtaining a
stereographic image on a single frame using a single lens. This method has been
verified experimentally. A preliminary prototype of the same is built with an
optimized use of the material available in the laboratory. The prospective
applications of this technique are also explored in brief. This method once
commercialized, will reduce the expenses incurred in the stereo videography. We
also propose a simplified method of obtaining anaglyph.


title: Homophily, Cultural Drift and the Co-Evolution of Cultural Groups

abstract:
  In studies of cultural differentiation, the joint mechanisms of homophily and
influence have been able to explain how distinct cultural groups can form.
While these mechanisms normally lead to cultural convergence, increased levels
of heterogeneity can allow them to produce global diversity. However, this
emergent cultural diversity has proven to be unstable in the face of "cultural
drift"- small errors or innovations that allow cultures to change from within.
We develop a model of cultural differentiation that combines the traditional
mechanisms of homophily and influence with a third mechanism of 2network
homophily", in which network structure co-evolves with cultural interaction. We
show that if social ties are allowed to change with cultural influence, a
complex relationship between heterogeneity and cultural diversity is revealed,
in which increased heterogeneity can reduce cultural group formation while
simultaneously increasing social connectedness. Our results show that in
certain regions of the parameter space these co-evolutionary dynamics can lead
to patterns of cultural diversity that are stable in the presence of cultural
drift.


title: Verification of crystal collimation model in experiment

abstract:
  The studies of crystal collimation in the experiments at Relativistic Heavy
Ion Collider and Tevatron and in computer simulations reveal strong coherent
effects observed in a very broad angular range. Our theory explains the effects
by coherent scattering on the potential of bent crystal atomic planes, which
amplifies beam diffusion in accelerator by orders of magnitude. This coherent
scattering in bent crystal is being studied in a CERN SPS experiment. We
present Monte Carlo predictions for the SPS and Tevatron experiments, and show
the implications of the coherent scattering effect for crystal collimation in
the Large Hadron Collider.


title: Interactive computer simulations of electrokinetic physics phenomena

abstract:
  In our days, the necessity of laboratory apparatus accustoming by building up
specific software objects for studying the virtual evolution of physical
phenomena is a major request. In this respect, the aim of the present paper is
to present a developed set of electricity interactive simulation computer
applica-tions. By following an Object Oriented Programming technology, the
necessary software objects are described. Finally, specific examples are
extensively presented as well as some screen-shots of the applications
interface.


title:
A class of traveling-envelope solutions of free Schr\"odinger equation
  generated by Lorentz transformation

abstract:
  We develop a class of traveling-envelope solutions of Schr\"odinger equation
for a free particle whose amplitude is moving with constant group velocity
while keeping its shape undistorted. We show that solution with arbitrary
finite group velocity is obtained by Lorentz boosting the solution with
vanishing group velocity, if the quantum average energy $E$ and momentum $p$
are related to the rest-mass $m$ of the particle by Einstein formula
$E^2/c^2-p^2=m^2c^2$. The wave function is spatially localized with finite-size
support which is decreasing as the rest-mass and/or group velocity are
increased. For a particle with vanishing rest-mass yet finite momentum, we show
that the group and phase velocities are equal to the velocity of light and the
wavelength is given by Einstein another formula $\lambda_P=h/p$.


title: Stochastic Model for Power Grid Dynamics

abstract:
  We introduce a stochastic model that describes the quasi-static dynamics of
an electric transmission network under perturbations introduced by random load
fluctuations, random removing of system components from service, random repair
times for the failed components, and random response times to implement optimal
system corrections for removing line overloads in a damaged or stressed
transmission network. We use a linear approximation to the network flow
equations and apply linear programming techniques that optimize the dispatching
of generators and loads in order to eliminate the network overloads associated
with a damaged system. We also provide a simple model for the operator's
response to various contingency events that is not always optimal due to either
failure of the state estimation system or due to the incorrect subjective
assessment of the severity associated with these events. This further allows us
to use a game theoretic framework for casting the optimization of the
operator's response into the choice of the optimal strategy which minimizes the
operating cost. We use a simple strategy space which is the degree of tolerance
to line overloads and which is an automatic control (optimization) parameter
that can be adjusted to trade off automatic load shed without propagating
cascades versus reduced load shed and an increased risk of propagating
cascades. The tolerance parameter is chosen to describes a smooth transition
from a risk averse to a risk taken strategy...

categories: physics.soc-ph cond-mat.dis-nn cond-mat.other cs.OH


title: The Role of Weight on Community Structure of Networks

abstract:
  The role of weight on the weighted networks is investigated by studying the
effect of weight on community structures. We use weighted modularity $Q^w$ to
evaluate the partitions and Weighted Extremal Optimization algorithm to detect
communities. Starting from idealized and empirical weighted networks, the
distribution or matching between weights and edges are disturbed. Using
dissimilarity function $D$ to distinguish the difference between community
structures, it is found that the redistribution of weights does strongly affect
the community structure especially in dense networks. This indicates that the
community structure in networks is a suitable property to reflect the role of
weight.


title:
Two falling-chain demonstrations based on Einstein's equivalence
  principle

abstract:
  Simple demonstrations based on the equivalence principle are given of how a
folded chain and a horizontal flat chain fall down when one chain end is fixed
to a rigid support.


title:
Experimental verification of minima in excited long-range Rydberg states
  of Rb_2

abstract:
  Recent theoretical studies with alkali atoms A$^{\ast}$ excited to high
Rydberg states predicted the existence of ultra long-range molecular bound
states. Such excited dimers have large electric dipole moments which, in
combination with their long radiative lifetimes, make them excellent candidates
for manipulation in applications. This letter reports on experimental
investigations of the self-broadening of Rb principal series lines, which
revealed multiple satellites in the line wings. The positions of the satellites
agree quantitatively with theoretically-predicted minima in the excited
long-range Rydberg states of Rb$_2$.


title:
Plausible Explanation Attempts against the Supraluminal Propagation of
  Light

abstract:
  The supposed supraluminal velocities of light are caused above all by
interaction of matter with electromagnetic radiation from the sender and/or the
own environment. Anti-Stokes frequencies which result in the consequence that
the refractive index becomes less than 1 or negative during strong optical
laser stimulation even are emitted in a increased manner under suitable
conditions. The light propagation is retarded simultaneously by interaction
within the matter. The velocity of light remains a limiting speed which can not
be exceeded. The refractive index is defined in a new manner and a simple
collision theory presented for impacts between photon and corpuscle.
  -----
  Die vermeintlichen Ueberlichtgeschwindigkeiten werden vor allem durch
Wechselwirkung der Materie mit der elektromagnetischen Strahlung aus dem Sender
bzw. aus der eigenen Umgebung verursacht. Es werden unter geeigneten
Bedingungen vermehrt anti-Stokessche Frequenzen emittiert, die zur Folge haben,
dass die Brechzahl kleiner als 1 oder bei starker Laseranregung sogar negativ
wird. Gleichzeitig wird durch die Wechselwirkung innerhalb der Materie die
Lichtausbreitung gebremst. Die Lichtgeschwindigkeit bleibt eine
Grenzgeschwindigkeit, die nicht ueberschritten werden kann. Die Brechzahl wird
neu definiert und eine einfache Stosstheorie fuer Stoesse zwischen Photon und
Teilchen vorgestellt.


title:
Modified Sagnac experiment for measuring travel-time difference between
  counter-propagating light beams in a uniformly moving fiber

abstract:
  A fiber optic conveyor has been developed for investigating the travel-time
difference between two counter-propagating light beams in uniformly moving
fiber. Our finding is that there is a travel-time difference
Deltat=2vDeltal/c^2 in a fiber segment of length Deltal moving with the source
and detector at a speed v, whether the segment is moving uniformly or
circularly.


title: The boundary layer problem in Bayesian adaptive quadrature

abstract:
  The boundary layer of a finite domain [a, b] covers mesoscopic lateral
neighbourhoods, inside [a, b], of the endpoints a and b. The correct diagnostic
of the integrand behaviour at a and b, based on its sampling inside the
boundary layer, is the first from a set of hierarchically ordered criteria
allowing a priori Bayesian inference on efficient mesh generation in automatic
adaptive quadrature.


title:
Extinction theorem and propagation of electromagnetic waves between two
  semi-infinite anisotropic magnetoelectric materials

abstract:
  Based on molecular optics we investigate the reflection and refraction of an
electromagnetic wave between two semi-infinite anisotropic magnetoelectric
materials. In terms of Hertz vectors and the principle of superposition, we
generalize the extinction theorem and derive the propagation characteristics of
wave. Using these results we can easily explain the physical origin of Brewster
effect. Our results extend the extinction theorem to the propagation of wave
between two arbitrary anisotropic materials and the methods used can be applied
to other problems of wave propagation in materials, such as scattering of
light.


title: A study of resistance forces

abstract:
  In this paper we present an example of a simple study of velocity
proportional resistance force. Some experimental determinations are presented.


title: Plausible Suggestion for a Deterministic Wave Function

abstract:
  A deterministic axial vector model for photons is presented which is suitable
also for particles. During a rotation around an axis the deterministic wave
function a has the following form a = ws r exp(+-i wb t). ws is either the
axial or scalar spin rotation frequency (the latter is proportional to the
mass), r radius of the orbit (also amplitude of a vibration arising later from
the interaction by fusing of two oppositely circling photons), wb orbital
angular frequency (proportional to the velocity) and t time. "+" before the
imaginary i means a right-handed and "-" a left-handed rotation. An interaction
happens if particles (including the photons) meet themselves through collision
and melt together.
  -----
  Es wird ein deterministisches Drehvektor-Modell fuer Photonen vorgestellt,
das auch fuer Teilchen geeignet ist. Bei einer Kreisbewegung um eine Achse hat
die deterministische Wellenfunktion a die folgende Form a = ws r exp(+-i wb t).
Dabei bedeuten ws entweder die axiale oder die skalare Spin-Kreisfrequenz
(letztere ist proportional der Masse), r Radius der Kreisbahn (auch Amplitude
einer sich spaeter durch Wechselwirkung ergebenden Schwingung aus zwei
entgegengesetzt kreisenden verschmolzenen Photonen), wb Kreisbahn-Frequenz (ein
Mass fuer die Bahngeschwindigkeit) und t Zeit. Das "+" vor dem imaginaeren i
bedeutet eine rechtshaendige und das "-" eine linkshaendige Rotation. Eine
Wechselwirkung tritt ein, wenn sich Teilchen einschliesslich der Photonen durch
Stossprozesse begegnen und dabei verschmelzen.


title: Dynamics of allosteric action in multisite protein modification

abstract:
  Protein functions in cells may be activated or modified by the attachment of
several kinds of chemical groups. While protein phosphorylation, i.e. the
attachment of a phosphoryl (PO$_3^-$) group, is the most studied form of
protein modification, and is known to regulate the functions of many proteins,
protein behavior can also be modified by nitrosylation, acetylation,
methylation, etc. A protein can have multiple modification sites, and display
some form of transition only when enough sites are modified. In a previous
paper we have modeled the generic equilibrium properties of multisite protein
modification (R.Chignola, C. Dalla Pellegrina, A. Del Fabbro, E.Milotti,
Physica A {\bf 371}, 463 (2006)) and we have shown that it can account both for
sharp, robust thresholds and for information transfer between processes with
widely separated timescales. Here we use the same concepts to expand that
analysis starting from a dynamical description of multisite modification: we
give analytical results for the basic dynamics and numerical results in an
example where the modification chain is cascaded with a Michaelis-Menten step.
We modify the dynamics and analyze an example with realistic
phosphorylation/dephosphorylation steps, and give numerical evidence of the
independence of the allosteric effect from the details of the
attachment-detachment processes. We conclude that multisite protein
modification is dynamically equivalent to the classic allosteric effect.


title:
Seismic motion in urban sites consisting of blocks in welded contact
  with a soft layer overlying a hard half space: I. Finite set of blocks

abstract:
  We address the problem of the response to a seismic wave of an urban site
consisting of $N$ non-identical, non-equispaced blocks overlying a soft layer
underlain by a hard substratum. The results of a theoretical analysis,
appealing to a space-frequency mode-matching (MM) technique, are compared to
those obtained by a space-time finite element (FE) technique. The two methods
are shown to give rise to the same prediction of the seismic response for N=1
and N=2 blocks. The mechanism of the interaction between blocks and the ground,
as well as that of the mutual interaction between blocks, are studied. It is
shown that the presence of a small number of blocks modifies the seismic
disturbance in a manner which evokes qualitatively, but not quantitatively,
what was observed during the 1985 Michoacan earthquake in Mexico City.
Disturbances at a much greater level, induced by a large number of blocks (in
fact, a periodic set) are studied in the companion paper.


title: The Social Network of Contemporary Popular Musicians

abstract:
  In this paper we analyze two social network datasets of contemporary
musicians constructed from allmusic.com (AMG), a music and artists' information
database: one is the collaboration network in which two musicians are connected
if they have performed in or produced an album together, and the other is the
similarity network in which they are connected if they where musically similar
according to music experts. We find that, while both networks exhibit typical
features of social networks such as high transitivity, several key network
features, such as degree as well as betweenness distributions suggest
fundamental differences in music collaborations and music similarity networks
are created.


title: Cascades of Dynamical Transitions in an Adaptive Population

abstract:
  In an adaptive population which models financial markets and distributed
control, we consider how the dynamics depends on the diversity of the agents'
initial preferences of strategies. When the diversity decreases, more agents
tend to adapt their strategies together. This change in the environment results
in dynamical transitions from vanishing to non-vanishing step sizes. When the
diversity decreases further, we find a cascade of dynamical transitions for the
different signal dimensions, supported by good agreement between simulations
and theory. Besides, the signal of the largest step size at the steady state is
likely to be the initial signal.


title:
Minimal energy configurations for charged particles on a thin conducting
  disc: the perimeter particles

abstract:
  The lowest energy configurations for N equal charged particles confined to a
thin conducting disc have been investigated in detail up to N=160 and in
outline for further values up to N=500. For all values of N up to 160 the
particle configurations can be described in terms of concentric shells. The
number of perimeter particles p appears to be simply related to N and to the
mean radius of the outermost internal shell. Justification for these relations
is obtained from a simple model based on the well-known distribution of
continuous charge on a conducting disc.


title: Fourier Diffusion and Special Relativity in Nanotechnology

abstract:
  In this paper the transport phenomena in On-Chip-Transmission Line are
investigated . The transport equation are developed and solved. The near light
speed phenomena in OCTL are investigated Key words: On-chip transmission line,
transport phenomena, near light speed phenomena


title: Practical Formula for Laser Intensity at Beam Spray Onset

abstract:
  A practical formula for calculating laser intensity at the onset of beam
spray is presented with application to inertial confinement fusion at the
National Ignition Facility.

categories: physics.plasm-ph nlin.CD nlin.PS physics.optics


title:
Comment on "Negative Refractive Index in Artificial Metamaterials" [A.
  N. Grigorenko, Opt. Lett., 31, 2483 (2006)]

abstract:
  A key optical parameter characterizing the existence of negative refraction
in a thin layer of a composite material is the effective refractive index of an
equivalent, homogenized layer with the same physical thickness as the initial
inhomogeneous composite. Measuring the complex transmission and reflection
coefficients is one of the most rigorous ways to obtain this parameter. We
dispute Grigorenko's statement (Optics Letters 31, 2483 (2006)) that measuring
only the reflection intensity spectrum is sufficient for determining the
effective refractive index. We discuss fundamental drawbacks of Grigorenko's
technique of using a best-fit approximation with an a priori prescribed
dispersive behavior for a given metamaterial and an 'effective optical
thickness' that is smaller than the actual thickness of the sample. Our
simulations do not confirm the Grigorenko paper conclusions regarding the
negative refractive index and the negative permeability of the nanopillar
sample in the visible spectral range.


title: Generalized Sagnac Effect

abstract:
  Experiments were conducted to study light propagation in a light waveguide
loop consisting of linearly and circularly moving segments. We found that any
segment of the loop contributes to the total phase difference between two
counterpropagating light beams in the loop. The contribution is proportional to
a product of the moving velocity v and the projection of the segment length
Deltal on the moving direction, Deltaphi=4pivDeltal/clambda. It is independent
of the type of motion and the refractive index of waveguides. The finding
includes the Sagnac effect of rotation as a special case and suggests a new
fiber optic sensor for measuring linear motion with nanoscale sensitivity.


title: General problems of the internal gravity waves linear theory

abstract:
  The internal gravity waves are the oscillations present in the gravitational
field of the stratified medium, that is the mediums which density raises with
the depth change. If the equilibrium state of the component volume of this
medium is disturbed, for example, upward, then it will become more heavy, than
the medium surrounding it, and Archimedian forces will cause its motion back to
its equilibrium position . The main parameter of any oscillation system is the
oscillation frequency, and it is determined by the ratio of two factors - the
restoring forces seeking to return the disturbed system to its equilibrium
position and the inertial forces. For the internal waves the restoring forces
are proportional to the vertical gradient of density of the liquid, and the
inertial forces are proportional to the density itself. The oscillating
frequency typical for the internal gravitational waves is the value
N(z)=({-g/ro(z)}* {d{ro(z)}/d{z}})^{-1/2} called the buoyancy frequency or
Brunt-Vaisala frequency. Here ro(z) - the density as the function of the depth
z, g - the acceleration of the gravity, the sign "-" originates due to the
fact, that the density raises with the increasing depth and consequently
{d{ro}/dz}<0. The paper has considered the planar internal gravitational waves
in the exponentially stratified medium, that is in the medium with the constant
distribution of Brunt-Vaisala frequency in depth, analyzed the problem of the
waves reflection from the planar boundaries, defined the Green's function for
the equation of the internal gravity waves in the exponentially stratified
medium of the of the endless depth, and also outlined the information on the
main properties of the internal gravity waves in the stratified layer of the
terminated depth and in the stratified mediums with average shift streams.


title: Balanced vehicular traffic at a bottleneck

abstract:
  The balanced vehicular traffic model is a macroscopic model for vehicular
traffic flow. We use this model to study the traffic dynamics at highway
bottlenecks either caused by the restriction of the number of lanes or by
on-ramps or off-ramps. The coupling conditions for the Riemann problem of the
system are applied in order to treat the interface between different road
sections consistently. Our numerical simulations show the appearance of
synchronized flow at highway bottlenecks.


title:
White Organic Light-Emitting Diodes with fine chromaticity tuning via
  ultrathin layer position shifting

abstract:
  Non-doped white organic light-emitting diodes using an ultrathin
yellow-emitting layer of rubrene (5,6,11,12-tetraphenylnaphtacene) inserted on
either side of the interface between a hole-transporting NPB
(4,4'-bis[N-(1-naphtyl)-N-phenylamino]biphenyl) layer and a blue-emitting DPVBi
(4,4'-bis(2,2'-diphenylvinyl)-1,1'-biphenyl) layer are described. Both the
thickness and the position of the rubrene layer allow fine chromaticity tuning
from deep-blue to pure-yellow via bright-white with CIE coordinates (x= 0.33,
y= 0.32), a external quantum efficiency of 1.9%, and a color rendering index of
70. Such a structure also provides an accurate sensing tool to measure the
exciton diffusion length in both DPVBi and NPB (8.7 and 4.9 nm respectively).


title: Prisoner's Dilemma on community networks

abstract:
  We introduce a community network model which exhibits scale-free property and
study the evolutionary Prisoner's Dilemma game (PDG) on this network model. It
is found that the frequency of cooperators decreases with the increment of the
average degree $\bar{k}$ from the simulation results. And reducing
inter-community links can promote cooperation when we keep the total links
(including inner-community and inter-community links) unchanged. It is also
shown that the heterogeneity of networks does not always enhance cooperation
and the pattern of links among all the vertices under a given
degree-distribution plays a crucial role in the dominance of cooperation in the
network model.


title:
An expansion based on Reynolds number powers for the velocity field of
  elementary analytical flows

abstract:
  The paper describes a possible physical characterization for the definition
of elementary fluid flow. As consequence, an analytical expansion based on
Reynolds number powers for the velocity field is shown in the weakly turbulent
case.

categories: physics.flu-dyn math-ph math.MP nlin.CD nlin.CG physics.comp-ph


title:
Optimal Paths in Complex Networks with Correlated Weights: The
  World-wide Airport Network

abstract:
  We study complex networks with weights, $w_{ij}$, associated with each link
connecting node $i$ and $j$. The weights are chosen to be correlated with the
network topology in the form found in two real world examples, (a) the
world-wide airport network, and (b) the {\it E. Coli} metabolic network. Here
$w_{ij} \sim x_{ij} (k_i k_j)^\alpha$, where $k_i$ and $k_j$ are the degrees of
nodes $i$ and $j$, $x_{ij}$ is a random number and $\alpha$ represents the
strength of the correlations. The case $\alpha > 0$ represents correlation
between weights and degree, while $\alpha < 0$ represents anti-correlation and
the case $\alpha = 0$ reduces to the case of no correlations. We study the
scaling of the lengths of the optimal paths, $\ell_{\rm opt}$, with the system
size $N$ in strong disorder for scale-free networks for different $\alpha$. We
calculate the robustness of correlated scale-free networks with different
$\alpha$, and find the networks with $\alpha < 0$ to be the most robust
networks when compared to the other values of $\alpha$. We propose an
analytical method to study percolation phenomena on networks with this kind of
correlation. We compare our simulation results with the real world-wide airport
network, and we find good agreement.

categories: physics.soc-ph cond-mat.stat-mech physics.comp-ph physics.data-an


title:
Attosecond streaking experiments on atoms: quantum theory versus simple
  model

abstract:
  A new theoretical approach to the description of the attosecond streaking
measurements of atomic photoionization is presented. It is a fully quantum
mechanical description based on numerical solving of the time-dependent
Schroedinger equation which includes the atomic field as well as the fields of
the XUV and IR pulses. Also a simple semiempirical description based on sudden
approximation is suggested which agrees very well with the exact solution.


title: The use of diffractive screens for electronic imaging

abstract:
  Diffractive screens are high-resolution elements with capability for
generating holographic-like images from a sequence of planes where TV frames
are seen oblique to it. If we project a sequence of contour lines of an object
it could be seen in continuous horizontal parallax to a size of 1m3.


title: Electrophoresis of a polyelectrolyte through a nanopore

abstract:
  A hydrodynamic model for determining the electrophoretic speed of a
polyelectrolyte through a nanopore is presented. It is assumed that the speed
is determined by a balance of electrical and viscous forces arising from within
the pore and that classical continuum electrostatics and hydrodynamics may be
considered applicable. An explicit formula for the translocation speed as a
function of the pore geometry and other physical parameters is obtained and is
shown to be consistent with experimental measurements on DNA translocation
through nanopores in silicon membranes. Experiments also show a weak dependence
of the translocation speed on polymer length that is not accounted for by the
present model. It is hypothesized that this is due to secondary effects that
are neglected here.


title: Quantum Econophysics

abstract:
  The relationships between game theory and quantum mechanics let us propose
certain quantization relationships through which we could describe and
understand not only quantum but also classical, evolutionary and the biological
systems that were described before through the replicator dynamics. Quantum
mechanics could be used to explain more correctly biological and economical
processes and even it could encloses theories like games and evolutionary
dynamics. This could make quantum mechanics a more general theory that we had
thought. Although both systems analyzed are described through two apparently
different theories (quantum mechanics and game theory) it is shown that both
systems are analogous and thus exactly equivalents. So, we can take some
concepts and definitions from quantum mechanics and physics for the best
understanding of the behavior of economics and biology. Also, we could maybe
understand nature like a game in where its players compete for a common welfare
and the equilibrium of the system that they are members.


title: Twin Families of Bisolitons in Dispersion Managed Systems

abstract:
  We calculate bisoliton solutions using a slowly varying stroboscopic
equation. The system is characterized in terms of a single dimensionless
parameter. We find two branches of solutions and describe the structure of the
tails for the lower branch solutions.


title:
Photoionization in negative streamers: fast computations and two
  propagation modes

abstract:
  Streamer discharges play a central role in electric breakdown of matter in
pulsed electric fields, both in nature and in technology. Reliable and fast
computations of the minimal model for negative streamers in simple gases like
nitrogen have recently been developed. However, photoionization was not
included; it is important in air and poses a major numerical challenge. We here
introduce a fast and reliable method to include photoionization into our
numerical scheme with adaptice grids, and we discuss its importance for
negative streamers. In particular, we identify different propagation regimes
where photoionization does or does not play a role.


title: Design of an interaction region with head-on collisions for the ILC

abstract:
  An interaction region (IR) with head-on collisions is considered as an
alternative to the baseline configuration of the International Linear Collider
(ILC) which includes two IRs with finite crossing-angles (2 and 20 mrad).
Although more challenging for the beam extraction, the head-on scheme is
favoured by the experiments because it allows a more convenient detector
configuration, particularly in the forward region. The optics of the head-on
extraction is revisited by separating the e+ and e- beams horizontally, first
by electrostatic separators operated at their LEP nominal field and then using
a defocusing quadrupole of the final focus beam line. In this way the septum
magnet is protected from the beamstrahlung power. Newly optimized final focus
and extraction optics are presented, including a first look at post-collision
diagnostics. The influence of parasitic collisions is shown to lead to a region
of stable collision parameters. Disrupted beam and beamstrahlung photon losses
are calculated along the extraction elements.


title:
Theoretical studies of the atomic transitions in boron-like ions: Mg
  VIII, Si X and S XII

abstract:
  In this paper, we have carried out the calculations of the weighted
oscillator strengths and the transition probabilities for a few low-lying
transitions of boron-like ions: Mg VIII, Si X and S XII which are
astrophysically important, particularly, in the atmospheres of the solar
corona. We have employed an all-order relativistic many-body theory called the
relativistic coupled-cluster theory to calculate very precisely these atomic
quantities of astrophysical interest. We have reported for the first time the
transition probabilities for some forbidden transitions which are unavailable
in the literature; either theoretically or experimentally. We also discuss the
physical effects associated with these transitions. Our data can be used for
the identification of spectral lines arising from the coronal atmospheres of
Sun and Sun-like stars having an extended corona.


title: On data analysis and variable selection: the minimum entropy analysis

abstract:
  In this work, we present a minimum entropy analysis scheme for variable
selection and preliminary data analysis. The variable selection can be achieved
by the increasing preference of variables. We show such a preference to has a
unqiue form, which is given by the entropy of models associated with variables.
Evaluating the entropy provides a complete ranking scheme of variables. This
scheme not only indicates preferred variables but also may reveal the system's
nature and properties. We illustrate the proposed scheme to analyze a set of
geological data for three carbonate rock units in Texas and Oklahoma, and
compare to the discriminant function analysis. The result suggests this scheme
to provide a quick and robust analysis, and the use in data analysis is
promising.


title: Collisional broadening of alkali doublets by helium perturbers

abstract:
  We report results for the Lorentzian profiles of the Li I, Na I and K I
doublets and the Na I subordinate doublet broadened by helium perturbers for
temperatures up to 3000 K They have been obtained from a fully
quantum-mechanical close-coupling description of the colliding atoms, the
Baranger theory of line shapes and new ab initio potentials for the
alkali-helium interaction. For all lines except the 769.9 nm K I line, the
temperature dependence of the widths over the range 70 < T < 3000 K is
accurately represented by the power law form w=aT^b with 0.37 < b < 0.43. The
769.9 K I line has this form for 500 < T < 3000 K with b = 0.49. Although the
shifts have a more complex temperature dependence, they all have the general
feature of increasing with temperature above T=500 K apart from the 769.9 K I
line whose shift decreases with temperature.


title:
Variable selection based on entropic criterion and its application to
  the debris-flow triggering

abstract:
  We propose a new data analyzing scheme, the method of minimum entropy
analysis (MEA), in this paper. New MEA provides a quantitative criterion to
select relevant variables for modeling the physical system interested. Such
method can be easily extended to various geophysical/geological data analysis,
where many relevant or irrelevant available measurements may obscure the
understanding of the highly complicated physical system like the triggering of
debris-flows. After demonstrating and testing the MEA method, we apply this
method to a dataset of debris-flow occurrences in Taiwan and successfully find
out three relevant variables, i.e. the hydrological form factor, numbers and
areas of landslides, to the triggering of observed debris-flow events due to
the 1996 Typhoon Herb.


title: Long-term power-law fluctuation in Internet traffic

abstract:
  Power-law fluctuation in observed Internet packet flow are discussed. The
data is obtained by a multi router traffic grapher (MRTG) system for 9 months.
The internet packet flow is analyzed using the detrended fluctuation analysis.
By extracting the average daily trend, the data shows clear power-law
fluctuations. The exponents of the fluctuation for the incoming and outgoing
flow are almost unity. Internet traffic can be understood as a daily periodic
flow with power-law fluctuations.


title: The origin of mass,spin and interaction

abstract:
  We argue that a non commutative geometry at the Compton scale is at the root
of mass, Quantum Mechanical spin and QCD and electromagnetic interactions. It
also leads to a reconciliation of linearized General Relativity and Quantum
Theory.


title:
Passively Q-switched diode-pumped Cr4+:YAG/Nd3+:GdVO4 monolithic
  microchip laser

abstract:
  the realization of high repetition rate passively Q-switched monolithic
microlaser is a challenge since a decade. To achieve this goal, we report here
on the first passively Q-switched diode-pumped microchip laser based on the
association of a Nd:GdVO4 crystal and a Cr4+:YAG saturable absorber. The
monolithic design consists of 1 mm long 1% doped Nd:GdVO4 optically contacted
on a 0.4 mm long Cr4+:YAG leading to a plano-plano cavity. A repetition rate as
high as 85 kHz is achieved. The average output power is approximately 400 mW
for 2.2 W of absorbed pump power and the pulse length is 1.1 ns.


title: A novel internal waves generator

abstract:
  We present a new kind of generator of internal waves which has been designed
for three purposes. First, the oscillating boundary conditions force the fluid
particles to travel in the preferred direction of the wave ray, hence reducing
the mixing due to forcing. Secondly, only one ray tube is produced so that all
of the energy is in the beam of interest. Thirdly, temporal and spatial
frequency studies emphasize the high quality for temporal and spatial
monochromaticity of the emitted beam. The greatest strength of this technique
is therefore the ability to produce a large monochromatic and unidirectional
beam.


title: High power spatial single-mode quantum cascade lasers at 8.9 $\mu$m

abstract:
  High performance of InP-based quantum cascade lasers emitting at $\lambda$ ~
9$\mu$m are reported. Thick electroplated gold layer was deposited on top of
the laser to improve heat dissipation. With one facet high reflection coated,
the devices produce a maximum output power of 175mW at 40% duty cycle at room
temperature and continuous-wave operation up to 278K.


title: Bubbles and Filaments: Stirring a Cahn-Hilliard Fluid

abstract:
  The advective Cahn-Hilliard equation describes the competing processes of
stirring and separation in a two-phase fluid. Intuition suggests that bubbles
will form on a certain scale, and previous studies of Cahn-Hilliard dynamics
seem to suggest the presence of one dominant length scale. However, the
Cahn-Hilliard phase-separation mechanism contains a hyperdiffusion term and we
show that, by stirring the mixture at a sufficiently large amplitude, we excite
the diffusion and overwhelm the segregation to create a homogeneous liquid. At
intermediate amplitudes we see regions of bubbles coexisting with regions of
hyperdiffusive filaments. Thus, the problem possesses two dominant length
scales, associated with the bubbles and filaments. For simplicity, we use use a
chaotic flow that mimics turbulent stirring at large Prandtl number. We compare
our results with the case of variable mobility, in which growth of bubble size
is dominated by interfacial rather than bulk effects, and find qualitatively
similar results.


title: 2D pattern evolution constrained by complex network dynamics

abstract:
  Complex networks have established themselves along the last years as being
particularly suitable and flexible for representing and modeling several
complex natural and human-made systems. At the same time in which the
structural intricacies of such networks are being revealed and understood,
efforts have also been directed at investigating how such connectivity
properties define and constrain the dynamics of systems unfolding on such
structures. However, lesser attention has been focused on hybrid systems,
\textit{i.e.} involving more than one type of network and/or dynamics. Because
several real systems present such an organization (\textit{e.g.} the dynamics
of a disease coexisting with the dynamics of the immune system), it becomes
important to address such hybrid systems. The current paper investigates a
specific system involving a diffusive (linear and non-linear) dynamics taking
place in a regular network while interacting with a complex network of
defensive agents following Erd\"os-R\'enyi and Barab\'asi-Albert graph models,
whose nodes can be displaced spatially. More specifically, the complex network
is expected to control, and if possible to extinguish, the diffusion of some
given unwanted process (\textit{e.g.} fire, oil spilling, pest dissemination,
and virus or bacteria reproduction during an infection). Two types of pattern
evolution are considered: Fick and Gray-Scott. The nodes of the defensive
network then interact with the diffusing patterns and communicate between
themselves in order to control the spreading. The main findings include the
identification of higher efficiency for the Barab\'asi-Albert control networks.


title: Programmable Trigger Logic Unit Based on FPGA Technology

abstract:
  A programmable trigger logic module (TRILOMO) was implemented successfully in
an FPGA using their internal look-up tables to save Boolean functions. Up to 16
trigger input signals can be combined logically for a fast trigger decision.
The new feature is that the trigger decision is VME register based. The changes
are made without modifying the FPGA code. Additionally the module has an
excellent signal delay adjustment.