559 research outputs found
On the structure of subsets of an orderable group with some small doubling properties
The aim of this paper is to present a complete description of the structure
of subsets S of an orderable group G satisfying |S^2| = 3|S|-2 and is
non-abelian
Quantum effects in the radial thermal expansion of bundles of single-walled carbon nanotubes doped with 4He
The radial thermal expansion (ar) of bundles of single-walled carbon
nanotubes saturated with 4He impurities to the molar concentration 9.4% has
been investigated in the interval 2.5-9.5 K using the dilatometric method. In
the interval 2.1-3.7 K (ar) is negative and is several times higher than the
negative (ar) for pure nanotube bundles. This most likely points to 4He atom
tunneling between different positions in the nanotube bundle system. The excess
expansion was reduced with decreasing 4He concentration.Comment: 4 pages, 1 figure, will be published in Fiz.Nizk Temp. #7, 201
The Lagrange and Markov spectra from the dynamical point of view
This text grew out of my lecture notes for a 4-hours minicourse delivered on
October 17 \& 19, 2016 during the research school "Applications of Ergodic
Theory in Number Theory" -- an activity related to the Jean-Molet Chair project
of Mariusz Lema\'nczyk and S\'ebastien Ferenczi -- realized at CIRM, Marseille,
France. The subject of this text is the same of my minicourse, namely, the
structure of the so-called Lagrange and Markov spectra (with an special
emphasis on a recent theorem of C. G. Moreira).Comment: 27 pages, 6 figures. Survey articl
A Meinardus theorem with multiple singularities
Meinardus proved a general theorem about the asymptotics of the number of
weighted partitions, when the Dirichlet generating function for weights has a
single pole on the positive real axis. Continuing \cite{GSE}, we derive
asymptotics for the numbers of three basic types of decomposable combinatorial
structures (or, equivalently, ideal gas models in statistical mechanics) of
size , when their Dirichlet generating functions have multiple simple poles
on the positive real axis. Examples to which our theorem applies include ones
related to vector partitions and quantum field theory. Our asymptotic formula
for the number of weighted partitions disproves the belief accepted in the
physics literature that the main term in the asymptotics is determined by the
rightmost pole.Comment: 26 pages. This version incorporates the following two changes implied
by referee's remarks: (i) We made changes in the proof of Proposition 1; (ii)
We provided an explanation to the argument for the local limit theorem. The
paper is tentatively accepted by "Communications in Mathematical Physics"
journa
Poisson's ratio in cryocrystals under pressure
We present results of lattice dynamics calculations of Poisson's ratio (PR)
for solid hydrogen and rare gas solids (He, Ne, Ar, Kr and Xe) under pressure.
Using two complementary approaches - the semi-empirical many-body calculations
and the first-principle density-functional theory calculations we found three
different types of pressure dependencies of PR. While for solid helium PR
monotonically decreases with rising pressure, for Ar, Kr, and Xe it
monotonically increases with pressure. For solid hydrogen and Ne the pressure
dependencies of PR are non-monotonic displaying rather deep minimums. The role
of the intermolecular potentials in this diversity of patterns is discussed.Comment: Fizika Nizkikh Temperatur 41, 571 (2015
Inverse Additive Problems for Minkowski Sumsets II
The Brunn-Minkowski Theorem asserts that for convex bodies , where
denotes the -dimensional Lebesgue measure. It is well-known that
equality holds if and only if and are homothetic, but few
characterizations of equality in other related bounds are known. Let be a
hyperplane. Bonnesen later strengthened this bound by showing where
and
. Standard
compression arguments show that the above bound also holds when
and , where denotes a
projection of onto , which gives an alternative generalization
of the Brunn-Minkowski bound. In this paper, we characterize the cases of
equality in this later bound, showing that equality holds if and only if
and are obtained from a pair of homothetic convex bodies by `stretching'
along the direction of the projection, which is made formal in the paper. When
, we characterize the case of equality in the former bound as well
The Impact of the Functional Layer Composition of Glucose Test-Strips on the Stability of Electrochemical Response
Herein, the impact of the chemical stability of RedOx mediator ferricyanide, K3
[Fe(CN)6
]
(FC), a type of buffer solution used for bioreceptor preparation, gel composition (carboxymethylcellulose, CMC, Aerosile, AS, and alginate, ALG) on the long term stability of glucose test-strips and
their analytical performance was examined. By simple addition of ALG to the functional gel aiming
to improve its viscosity, we managed to enhance the sensitivity of conventional CMC-containing
amperometric glucose test-strips from 3.3 µA/mM to 3.9 µA/mM and extend their shelf life from
8 months to 1.7 years. Moreover, during the course of investigations, it was revealed that the activity
of enzyme in dependence with the used buffer did not linearly correlate with its activity in a dried
functional layer, and the entire long-term electrochemical signal of glucose test-strips was determined
by RedOx mediator FC chemical stability. The most stable and sensitive test-strips were obtained by
the screen-printing approach from a gel containing 24 mg/mL GOx prepared in citrate buffer with
pH 6, 200 mg/mL of FC and 10 mg/mL of CMC supplemented with 25 mg/mL of ALG
Rule-Based Ventral Cavity Multi-organ Automatic Segmentation in CT Scans
We describe a newmethod for the automatic segmentation of multiple organs of the ventral cavity in CT scans. The methodisbasedonasetofrulesthatdeterminetheorderin which theorgansare isolatedand segmented, from the sim- plestonetothemostdifficultone. First,thebodyisisolated from the background. Second, the trachea and the left and right lungsare segmentedbasedon theirair content.Third, thespleenandthekidneys–theorganswithhighbloodcon- tent–aresegmented. Finally,thekidneyissegmentedbased onthesurroundingorganssegmentation. Eachorganisindi- vidually segmentedwitha four-stepprocedure that consists of: 1) definition of an inclusive region of interest; 2) identi- fication of the largest axial cross-section slice; 3) Semoval of background structuresbymorphologicaloperations,and; 4) 3D region growing segmentation. Ourmethod is unique in that ituses the same generic segmentation approach for all organsand in that it relieson the segmentationdifficultyof organs toguide the segmentationprocess. Experimental re- sultson15CTscansoftheVISCERALAnatomy2Challenge trainingdatasetsyieldaDicevolumeoverlapsimilarityscore of 79.1 for the trachea, 97.4 and 97.6 for the left and right lungs, 89.2 for the spleen, and 92.8 for the left kidney. For the5CT scans testdatasets, theDice scoresare97.9,97.0, 85.6, 93.4 and 90.2, respectively. Our method achieved an overallDICE score of 92.8 andwas ranked first among the fivemethodsthatparticipated inthechallenge. Copyright c © by the paper’s authors. Copying permitted only for private and academic purposes
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