4,018 research outputs found
Lagrangian Floer potential of orbifold spheres
For each sphere with three orbifold points, we construct an algorithm to compute the open GromovāWitten potential, which serves as the quantum-corrected LandauāGinzburg mirror and is an infinite series in general. This gives the first class of general-type geometries whose full potentials can be computed. As a consequence we obtain an enumerative meaning of mirror maps for elliptic curve quotients. Furthermore, we prove that the open GromovāWitten potential is convergent, even in the general-type cases, and has an isolated singularity at the origin, which is an important ingredient of proving homological mirror symmetry.National Research Foundation of Korea; 2010-0019516; 2012R1A1A2003117; 2013R1A1A1058646 - National Research Foundation of Kore
Solvable Potentials from Supersymmetric Quantum Mechanics
A recurrence relation of Riccati-type differential equations known in
supersymmetric quantum mechanics is investigated to find exactly solvable
potentials. Taking some simple {\it ans\"atze}, we find new classes of solvable
potentials as well as reproducing the known shape-invariant ones.Comment: 14 pages, Late
Probabilistic ultimate strength analysis of submarine pressure hulls
ABSTRACTThis paper examines the application of structural reliability analysis to submarine pressure hulls to clarify the merits of probabilistic approach in respect thereof. Ultimate strength prediction methods which take the inelastic behavior of ring-stiffened cylindrical shells and hemispherical shells into account are reviewed. The modeling uncertainties in terms of bias and coefficient of variation for failure prediction methods in current design guidelines are defined by evaluating the compiled experimental data. A simple ultimate strength formulation for ring-stiffened cylinders taking into account the interaction between local and global failure modes and an ultimate strength formula for hemispherical shells which have better accuracy and reliability than current design codes are taken as basis for reliability analysis. The effects of randomness of geometrical and material properties on failure are assessed by a prelim-nary study on reference models. By evaluation of sensitivity factors important variables are determined and compare-sons are made with conclusions of previous reliability studies
Tau functions as Widom constants
We define a tau function for a generic Riemann-Hilbert problem posed on a
union of non-intersecting smooth closed curves with jump matrices analytic in
their neighborhood. The tau function depends on parameters of the jumps and is
expressed as the Fredholm determinant of an integral operator with block
integrable kernel constructed in terms of elementary parametrices. Its
logarithmic derivatives with respect to parameters are given by contour
integrals involving these parametrices and the solution of the Riemann-Hilbert
problem. In the case of one circle, the tau function coincides with Widom's
determinant arising in the asymptotics of block Toeplitz matrices. Our
construction gives the Jimbo-Miwa-Ueno tau function for Riemann-Hilbert
problems of isomonodromic origin (Painlev\'e VI, V, III, Garnier system, etc)
and the Sato-Segal-Wilson tau function for integrable hierarchies such as
Gelfand-Dickey and Drinfeld-Sokolov.Comment: 26 pages, 6 figure
Competing edge structures of Sb and Bi bilayers by trivial and nontrivial band topologies
One-dimensional (1D) edge states formed at the boundaries of 2D normal and
topological insulators have shown intriguing quantum phases such as charge
density wave and quantum spin Hall effect. Based on first-principles
density-functional theory calculations including spin-orbit coupling (SOC), we
show that the edge states of zigzag Sb(111) and Bi(111) nanoribbons drastically
change the stability of their edge structures. For zigzag Sb(111) nanoribbon,
the Peierls-distorted or reconstructed edge structure is stabilized by a
band-gap opening. However, for zigzag Bi(111) nanoribbon, such two insulating
structures are destabilized due to the presence of topologically protected
gapless edge states, resulting in the stabilization of a metallic,
shear-distorted edge structure. We also show that the edge states of the
Bi(111) nanoribbon exhibit a larger Rashba-type spin splitting at the boundary
of Brillouin zone, compared to those of the Sb(111) nanoribbon. Interestingly,
the spin textures of edge states in the Peierls-distorted Sb edge structure and
the shear-distorted Bi edge structure have all three spin components
perpendicular and parallel to the edges, due to their broken mirror-plane
symmetry. The present findings demonstrate that the topologically trivial and
nontrivial edge states play crucial roles in determining the edge structures of
normal and topological insulators.Comment: 7 pages, 8 figure
Fulminant myocarditis managed with pulsatile extracorporeal life support; use of Twin Pulse Life support (T-PLSĀ®)
Fulminant myocarditis frequently results in severe hemodynamic deterioration. High-dose vasopressors or sometimes mechanical circulatory support are required. We report on two cases of fulminant myocarditis successfully treated with pulsatile extracorporeal life support (T-PLSĀ®, Twin Pulse Life support, New heart bio.BHK, Seoul, Korea). With T-PLS, we were able to provide mechanical support to patients until they recovered completely
Energy-Efficient Probabilistic Routing Algorithm for Internet of Things
In the future network with Internet of Things (IoT), each of the things communicates with the others and acquires information by itself. In distributed networks for IoT, the energy efficiency of the nodes is a key factor in the network performance. In this paper, we propose energy-efficient probabilistic routing (EEPR) algorithm, which controls the transmission of the routing request packets stochastically in order to increase the network lifetime and decrease the packet loss under the flooding algorithm. The proposed EEPR algorithm adopts energy-efficient probabilistic control by simultaneously using the residual energy of each node and ETX metric in the context of the typical AODV protocol. In the simulations, we verify that the proposed algorithm has longer network lifetime and consumes the residual energy of each node more evenly when compared with the typical AODV protocol
Polymorphism of a COLIA1 Gene Sp1 Binding Site in Korean Women with Pelvic Organ Prolapse
PURPOSE: To evaluate the possible influence of G-->T substitution at the Sp1-binding site of the COLIA1 gene on the risk of pelvic organ prolapse (POP).
MATERIALS AND METHODS: The study group consisted of 15 women with advanced stage POP. Fifteen control subjects with uterine myomas among the postmenopausal women were matched for age and parity. DNA was obtained from peripheral blood leukocytes. The fragments of the first intron of the COLIA1 gene were amplified by real time polymerase chain reaction. The polymorphism was identified using LightCycler Technology with hybridization probes. Sequencing reactions were performed on each template using commercial primer.
RESULTS: Two groups had no significant difference in medical history, surgical, and smoking history. The homozygous peaks in two groups were noted at 57 on melting curve analysis. Sequencing reactions confirmed the G/G alleles in the 30 specimens tested. We could not find any polymorphism at the Sp1-binding site in COLIA1 gene with advanced stage POP. Statistical significance was considered to be p < .05.
CONCLUSION: The polymorphism of the Sp1-binding site in the COLIA1 gene did not contribute to the development of POP in Korea.ope
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