2,483 research outputs found
A travel guide to the canonical bundle formula
We survey known results on the canonical bundle formula and its applications
in algebraic geometry.Comment: 17 pages, to appear in the Proceedings of the conference Birational
Geometry and Moduli Space
Convection Patterns in Liquid Oxide Films on ZrB 2 –SiC Composites Oxidized at a High Temperature
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66000/1/j.1551-2916.2007.01784.x.pd
Parameter Mismatches and Perfect Anticipating Synchronization in bi-directionally coupled external cavity laser diodes
We study perfect chaos synchronization between two bi-directionally coupled
external cavity semiconductor lasers and demonstrate for the first time that
mismatches in laser photon decay rates can explain the experimentally observed
anticipating time in synchronization.Comment: Latex 4 page
Parallelization of BiCGMisR method with cache-cache elements preconditioning
We consider Krylov subspace methods for solving a linear system of equations on parallel computer with distributed memory. For speed-up of parallel computation, it is necessary to shorten the communication time among processors. However, in paral- lelized Krylov subspace methods, global synchronization points for inner products cause increment of communication time. Thus, we created the strategy for reduction of synchro- nization points of parallel Krylov subspace methods. We transform the computation of parameter βk to reduce the number of synchronization points of various Krylov subspace methods per one iteration. In this paper, we apply this strategy to three-term recurrence and propose parallel BiCGMisR method as the effective solver suited to parallel computer with distributed memory. Furthermore, through several numerical experiments, we make clear that parallel BiCGMisR method outperforms other methods from the viewpoints of both elapsed time and speed-up on parallel computer with distributed memory
Inverse Anticipating Synchronization
We report a new type of chaos synchronization:inverse anticipating
synchronization, where a time delay chaotic system can drive another system in
such a way that the driven system anticipates the driver by synchronizing with
its inverse future state. We extend the concept of inverse anticipating chaos
synchronization to cascaded systems. We propose means for the experimental
observation of inverse anticipating chaos synchronization in external cavity
lasers.Comment: LaTex 6 pages, resubmitted to PR
Asymmetric Patterns of Visual Field Defect in Primary Open-Angle and Primary Angle-Closure Glaucoma
Purpose: To compare the hemifield asymmetry of visual field (VF) loss in primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG) across all severity levels.
Methods: A total of 522 eyes of 327 patients with POAG (mean age ± SD, 54.1 ± 12.4 years) and 375 eyes of 204 patients with PACG (67.3 ± 8.9 years) were included. Subjects meeting the definitions of POAG or PACG were included. Means of the total deviation (TD) values (Humphrey 24-2 VF) in the Glaucoma Hemifield Test (GHT) regions were calculated in early (≥ −6 dB), moderate (< −6 dB and ≥ −12 dB), and advanced (< −12 dB) stages of POAG and PACG eyes. Then the differences of the TD values between superior and inferior hemifield GHT regions of POAG and PACG eyes were calculated. Also, the relationship between the values of pattern SD (PSD) and mean TD (mTD) was compared between POAG and PACG.
Results: In POAG eyes in the early stage, three regions (central, paracentral, and peripheral) in the superior hemifield had greater loss than their inferior counterparts; in moderate and advanced stages, all GHT regions in the superior hemifield had greater loss than their inferior counterparts. In PACG eyes, siginificantly fewer regions in the superior hemifield were significantly worse than their inferior counterpart, compared with POAG: one region (central) in early stage, two regions (central and peripheral) in moderate stage, and one region (central) in advanced stage. POAG eyes had greater PSD values than PACG eyes for given mean of TD values.
Conclusions: In both POAG and PACG eyes, VF damage was more pronounced in superior hemifield than inferior hemifield; however, this tendency was more obvious in POAG eyes than in PACG eyes
Coexistence of Ferroelectric Triclinic Phases and Origin of Large Piezoelectric Responses in Highly Strained BiFeO3 films
The structural evolution of the strain-driven morphotropic phase boundary
(MPB) in BiFeO3 films has been investigated using synchrotron x-ray
diffractometry in conjunction with scanning probe microscopy. Our results
demonstrate the existence of mixed-phase regions that are mainly made up of two
heavily tilted ferroelectric triclinic phases. Analysis of first-principles
computations suggests that these two triclinic phases originate from a phase
separation of a single monoclinic state accompanied by elastic matching between
the phase-separated states. These first-principle calculations further reveal
that the intrinsic piezoelectric response of these two low-symmetry triclinic
phases is not significantly large, which thus implies that the ease of phase
transition between these two energetically close triclinic phases is likely
responsible for the large piezoelectric response found in the BiFeO3 films near
its MPB. These findings not only enrich the understandings of the lattice and
domain structure of epitaxial BiFeO3 films but may also shed some light on the
origin of enhanced piezoelectric response near MPB.Comment: 19 pages, 3 figures and 1 tabl
Lag time and parameter mismatches in synchronization of unidirectionally coupled chaotic external cavity semiconductor lasers
We report an analysis of synchronization between two unidirectionally coupled
chaotic external cavity master/slave semiconductor lasers with two
characteristic delay times, where the delay time in the coupling is different
from the delay time in the coupled systems themselves. We demonstrate for the
first time that parameter mismatches in photon decay rates for the master and
slave lasers can explain the experimental observation that the lag time is
equal to the coupling delay time.Comment: LaTex, 5 pages, submitted to PRE(R
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