45,024 research outputs found
Evolution of Magnetic and Superconducting Fluctuations with Doping of High-Tc Superconductors
Electronic Raman scattering from high- and low-energy excitations was studied
as a function of temperature, extent of hole doping, and energy of the incident
photons in Bi_2Sr_2CaCu_2O_{8 \pm \delta} superconductors. For underdoped
superconductors, short range antiferromagnetic (AF) correlations were found to
persist with hole doping, and doped single holes were found to be incoherent in
the AF environment. Above the superconducting (SC) transition temperature T_c,
the system exhibits a sharp Raman resonance of B_{1g} symmetry and energy of 75
meV and a pseudogap for electron-hole excitations below 75 meV, a manifestation
of a partially coherent state forming from doped incoherent quasi particles.
The occupancy of the coherent state increases with cooling until phase ordering
at T_c produces a global SC state.Comment: 6 pages, 4 color figures, PDF forma
Communication and control in an integrated manufacturing system
Typically, components in a manufacturing system are all centrally controlled. Due to possible communication bottlenecking, unreliability, and inflexibility caused by using a centralized controller, a new concept of system integration called an Integrated Multi-Robot System (IMRS) was developed. The IMRS can be viewed as a distributed real time system. Some of the current research issues being examined to extend the framework of the IMRS to meet its performance goals are presented. These issues include the use of communication coprocessors to enhance performance, the distribution of tasks and the methods of providing fault tolerance in the IMRS. An application example of real time collision detection, as it relates to the IMRS concept, is also presented and discussed
Kinetic pathways of the Nematic-Isotropic phase transition as studied by confocal microscopy on rod-like viruses
We investigate the kinetics of phase separation for a mixture of rodlike
viruses (fd) and polymer (dextran), which effectively constitutes a system of
attractive rods. This dispersion is quenched from a flow-induced fully nematic
state into the region where the nematic and the isotropic phase coexist. We
show experimental evidence that the kinetic pathway depends on the overall
concentration. When the quench is made at high concentrations, the system is
meta-stable and we observe typical nucleation-and-growth. For quenches at low
concentration the system is unstable and the system undergoes a spinodal
decomposition. At intermediate concentrations we see the transition between
both demixing processes, where we locate the spinodal point.Comment: 11 pages, 6 figures, accepted in J. Phys.: Condens. Matter as
symposium paper for the 6th Liquid Matter Conference in Utrech
Reaction-diffusion with a time-dependent reaction rate: the single-species diffusion-annihilation process
We study the single-species diffusion-annihilation process with a
time-dependent reaction rate, lambda(t)=lambda_0 t^-omega. Scaling arguments
show that there is a critical value of the decay exponent omega_c(d) separating
a reaction-limited regime for omega > omega_c from a diffusion-limited regime
for omega < omega_c. The particle density displays a mean-field,
omega-dependent, decay when the process is reaction limited whereas it behaves
as for a constant reaction rate when the process is diffusion limited. These
results are confirmed by Monte Carlo simulations. They allow us to discuss the
scaling behaviour of coupled diffusion-annihilation processes in terms of
effective time-dependent reaction rates.Comment: 11 pages, 9 figures, minor correction
Human Emotional Care Purposed Automatic Remote Portrait Drawing Generation and Display System Using Wearable Heart Rate Sensor and Smartphone Camera with Depth Perception
We propose a system that automatically generates portrait drawings for the purpose of human emotional care. Our system comprises two parts: a smartphone application and a server. The smartphone application enables the user to take photographs throughout the day while acquiring heart rates from the smartwatch worn by the user. The server collects the photographs and heart rates and displays portrait drawings automatically stylized from the photograph for the most exciting moment of the day. In the system, the user can recall the exciting and happy moment of the day through admiring the drawings and heal the emotion accordingly. To stylize photographs as portrait drawings, we employ nonphotorealistic rendering (NPR) methods, including a portrait etude stylization proposed in this paper. Finally, the effectiveness of our system is demonstrated through user studies
Crystal Interpretation of Kerov-Kirillov-Reshetikhin Bijection II. Proof for sl_n Case
In proving the Fermionic formulae, combinatorial bijection called the
Kerov--Kirillov--Reshetikhin (KKR) bijection plays the central role. It is a
bijection between the set of highest paths and the set of rigged
configurations. In this paper, we give a proof of crystal theoretic
reformulation of the KKR bijection. It is the main claim of Part I
(math.QA/0601630) written by A. Kuniba, M. Okado, T. Takagi, Y. Yamada, and the
author. The proof is given by introducing a structure of affine combinatorial
matrices on rigged configurations.Comment: 45 pages, version for publication. Introduction revised, more
explanations added to the main tex
Origins of the Isospin Violation of Dark Matter Interactions
Light dark matter (DM) with a large DM-nucleon spin-independent cross section
and furthermore proper isospin violation (ISV) may provide
a way to understand the confusing DM direct detection results. Combing with the
stringent astrophysical and collider constraints, we systematically investigate
the origin of ISV first via general operator analyses and further via
specifying three kinds of (single) mediators: A light from chiral
, an approximate spectator Higgs doublet (It can explain the
anomaly simultaneously) and color triplets. In addition, although from an
exotic mixing with generating , we can combine it with
the conventional Higgs to achieve proper ISV. As a concrete example, we propose
the model where the charged light sneutrino is the inelastic
DM, which dominantly annihilates to light dark states such as with sub-GeV
mass. This model can address the recent GoGeNT annual modulation consistent
with other DM direct detection results and free of exclusions.Comment: References added and English greatly improve
Box ball system associated with antisymmetric tensor crystals
A new box ball system associated with an antisymmetric tensor crystal of the
quantum affine algebra of type A is considered. This includes the so-called
colored box ball system with capacity 1 as the simplest case. Infinite number
of conserved quantities are constructed and the scattering rule of two olitons
are given explicitly.Comment: 15 page
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