9,258 research outputs found
Mutual insurance of transport infrastructure construction risks as an inherent part of competitive environment
In this article we introduce mutual insurance as an inherent part of competitive environment in the field of insurance of the transport infrastructure construction risks.
The competitive environment makes a great impact on the market behavior of the actors. The monopolization creates the environment, which does not prevent the negative steps of the firm in different directions.
The article shows, that mutual insurance is a significant factor which can prevent the monopolization of the insurance market. This is a specific factor that is inherent only to this kind of the market.
The competitive advantages of the mutual insurance organizations, their attractiveness to the clients (the insured) are conditioned with the specific relations between the insured and the insurance organization, such as the decision of the main questions of the financial activity of the insurer on the meeting of all the insured or their representatives, the possibility to insure the risks, which the commercial insurers do not insure and some others.peer-reviewe
Fermionic and Bosonic Stabilizing Effects for Type I and Type II Dimension Bubbles
We consider two types of "dimension bubbles", which are viewed as 4d
nontopological solitons that emerge from a 5d theory with a compact extra
dimension. The size of the extra dimension varies rapidly within the domain
wall of the soliton. We consider the cases of type I (II) bubbles where the
size of the extra dimension inside the bubble is much larger (smaller) than
outside. Type I bubbles with thin domain walls can be stabilized by the
entrapment of various particle modes whose masses become much smaller inside
than outside the bubble. This is demonstrated here for the cases of scalar
bosons, fermions, and massive vector bosons, including both Kaluza-Klein zero
modes and Kaluza-Klein excitation modes. Type II bubbles expel massive particle
modes but both types can be stabilized by photons. Plasma filled bubbles
containing a variety of massless or nearly massless radiation modes may exist
as long-lived metastable states. Furthermore, in contrast to the case with a
"gravitational bag", the metric for a fluid-filled dimension bubble does not
exhibit a naked singularity at the bubble's center.Comment: 17 pages, no figs; to appear in Phys.Rev.
Onsager coefficients of a Brownian Carnot cycle
We study a Brownian Carnot cycle introduced by T. Schmiedl and U. Seifert
[Europhys. Lett. \textbf{81}, 20003 (2008)] from a viewpoint of the linear
irreversible thermodynamics. By considering the entropy production rate of this
cycle, we can determine thermodynamic forces and fluxes of the cycle and
calculate the Onsager coefficients for general protocols, that is, arbitrary
schedules to change the potential confining the Brownian particle. We show that
these Onsager coefficients contain the information of the protocol shape and
they satisfy the tight-coupling condition irrespective of whatever protocol
shape we choose. These properties may give an explanation why the
Curzon-Ahlborn efficiency often appears in the finite-time heat engines
Gravity with extra dimensions and dark matter interpretation: Phenomenological example via Miyamoto-Nagai galaxy
A configuration whose density profile coincides with the Newtonian potential
for spiral galaxies is constructed from a 4D isotropic metric plus extra
dimensional components. A Miyamoto-Nagai ansatz is used to solve Einstein
equations. The stable rotation curves of such system are computed and, without
fitting techniques, we recover with accuracy the observational data for flat or
not asymptotically flat galaxy rotation curves. The density profiles are
reconstructed and compared to that obtained from the Newtonian potential.Comment: 10 pages, 10 figures, submitted to Brazilian Journal of Physic
The European fruit lecanium, Lecanium tiliae (L.) (Homoptera: Coccidae), in southwestern British Columbia
Lecanium tiliae normally has one annual generation in southwestern British Columbia. There was a partial second in a year following a mild winter. The heaviest infestations were on horse chestnut, Japanese plum, hawthorn, and maple, in that order. Hawthorn was damaged. The proportion of males tended to be higher in high than in low populations, and to decrease with increasing altitude. Severe winter cold caused marked population decreases and cold weather in June noticeable decreases. Natural enemies found in 1969-72 are listed
A Sequence of Declining Outbursts from GX339-4
The flux and spectrum of the black hole candidate GX339-4 has been monitored
by the Burst and Transient Source Experiment (BATSE) on the Compton Gamma-ray
Observatory (CGRO) since the observatory became operational in May 1991.
Between the summer of 1991 and the fall of 1996, eight outbursts from GX339-4
were observed. The history of these outbursts is one of declining fluence or
total energy release, as well as a shortening of the time between outbursts. A
rough linear correlation exists between the fluence emitted during an outburst
and the time elapsed between the end of the previous outburst and the beginning
of the current one. The peak flux is also roughly linearly correlated with
outburst fluence. The lightcurves of the earlier, more intense, outbursts
(except for the second one) can be modeled by a fast exponential (time constant
~ 10 days) followed by a slower exponential (~ 100 days) on the rise and a fast
exponential decay (~ 5 days) on the fall. The later, weaker, outbursts are
modeled with a single rising time constant (~ 20 days) and a longer decay on
the fall (~ 50 days). An exponential model gives a marginally better fit than a
power law to the rise/decay profiles. GX339-4 is a unique source in having more
frequent outbursts than other low mass x-ray binary black hole candidates.
These observations can be used to constrain models of the behavior of the
accretion disk surrounding the compact object.Comment: Accepted for Publication in the Astrophysical Journal Letters, AASTE
Two-Photon Entanglement and EPR Experiments Using Type-2 Spontaneous Parametric Down Conversion
Simultaneous entanglement in spin and space-time of a two-photon quantum state generated in type-2 spontaneous parametric down-conversion is demonstrated by the observation of quantum interference with 98% visibility in a simple beam-splitter (Hanburry Brown-Twiss) anticorrelation experiment. The nonlocal cancellation of two-photon probability amplitudes as a result of this double entanglement allows us to demonstrate two different types of Bell's inequality violations in one experimental setup
Demonstration of Non-Deterministic Quantum Logic Operations using Linear Optical Elements
Knill, Laflamme, and Milburn recently showed that non-deterministic quantum
logic operations could be performed using linear optical elements, additional
photons (ancilla), and post-selection based on the output of single-photon
detectors [Nature 409, 46 (2001)]. Here we report the experimental
demonstration of two logic devices of this kind, a destructive controlled-NOT
(CNOT) gate and a quantum parity check. These two devices can be combined with
a pair of entangled photons to implement a conventional (non-destructive) CNOT
that succeeds with a probability of 1/4.Comment: 4 pages, 5 figures; Minor change
Separate Universes Do Not Constrain Primordial Black Hole Formation
Carr and Hawking showed that the proper size of a spherical overdense region
surrounded by a flat FRW universe cannot be arbitrarily large as otherwise the
region would close up on itself and become a separate universe. From this
result they derived a condition connecting size and density of the overdense
region ensuring that it is part of our universe. Carr used this condition to
obtain an upper bound for the density fluctuation amplitude with the property
that for smaller amplitudes the formation of a primordial black hole is
possible, while larger ones indicate a separate universe. In contrast, we find
that the appearance of a maximum is not a consequence of avoiding separate
universes but arises naturally from the geometry of the chosen slicing. Using
instead of density a volume fluctuation variable reveals that a fluctuation is
a separate universe iff this variable diverges on superhorizon scales. Hence
Carr's and Hawking's condition does not pose a physical constraint on density
fluctuations. The dynamics of primordial black hole formation with an initial
curvature fluctuation amplitude larger than the one corresponding to the
maximum density fluctuation amplitude was previously not considered in detail
and so we compare it to the well-known case where the amplitude is smaller by
presenting embedding and conformal diagrams of both types in dust spacetimes.Comment: Updated version corresponds to the published version
10.1103/PhysRevD.83.124025, 22 pages, 22 figure
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