1,160 research outputs found
Dynamical Gauge Boson and Strong-Weak Reciprocity
It is proposed that asymptotically nonfree gauge theories are consistently
interpreted as theories of composite gauge bosons. It is argued that when
hidden local symmetry is introduced, masslessness and coupling universality of
dynamically generated gauge boson are ensured. To illustrate these ideas we
take a four dimensional Grassmannian sigma model as an example and show that
the model should be regarded as a cut-off theory and there is a critical
coupling at which the hidden local symmetry is restored. Propagator and vertex
functions of the gauge field are calculated explicitly and existence of the
massless pole is shown. The beta function determined from the factor of
the dynamically generated gauge boson coincides with that of an asymptotic
nonfree elementary gauge theory. Using these theoretical machinery we construct
a model in which asymptotic free and nonfree gauge bosons coexist and their
running couplings are related by the reciprocally proportional relation.Comment: 19 pages, latex, 6 eps figures, a numbers of corrections are made in
the tex
Solvable Optimal Velocity Models and Asymptotic Trajectory
In the Optimal Velocity Model proposed as a new version of Car Following
Model, it has been found that a congested flow is generated spontaneously from
a homogeneous flow for a certain range of the traffic density. A
well-established congested flow obtained in a numerical simulation shows a
remarkable repetitive property such that the velocity of a vehicle evolves
exactly in the same way as that of its preceding one except a time delay .
This leads to a global pattern formation in time development of vehicles'
motion, and gives rise to a closed trajectory on -
(headway-velocity) plane connecting congested and free flow points. To obtain
the closed trajectory analytically, we propose a new approach to the pattern
formation, which makes it possible to reduce the coupled car following
equations to a single difference-differential equation (Rondo equation). To
demonstrate our approach, we employ a class of linear models which are exactly
solvable. We also introduce the concept of ``asymptotic trajectory'' to
determine and (the backward velocity of the pattern), the global
parameters associated with vehicles' collective motion in a congested flow, in
terms of parameters such as the sensitivity , which appeared in the original
coupled equations.Comment: 25 pages, 15 eps figures, LaTe
Presence of Many Stable Nonhomogeneous States in an Inertial Car-Following Model
A new single lane car following model of traffic flow is presented. The model
is inertial and free of collisions. It demonstrates experimentally observed
features of traffic flow such as the existence of three regimes: free,
fluctuative (synchronized) and congested (jammed) flow; bistability of free and
fluctuative states in a certain range of densities, which causes the hysteresis
in transitions between these states; jumps in the density-flux plane in the
fluctuative regime and gradual spatial transition from synchronized to free
flow. Our model suggests that in the fluctuative regime there exist many stable
states with different wavelengths, and that the velocity fluctuations in the
congested flow regime decay approximately according to a power law in time.Comment: 4 pages, 4 figure
Energy Dissipation Burst on the Traffic Congestion
We introduce an energy dissipation model for traffic flow based on the
optimal velocity model (OV model). In this model, vehicles are defined as
moving under the rule of the OV model, and energy dissipation rate is defined
as the product of the velocity of a vehicle and resistant force which works to
it.Comment: 15 pages, 19 Postscript figures. Reason for replacing: This is the
submitted for
Toda Lattice Solutions of Differential-Difference Equations for Dissipative Systems
In a certain class of differential-difference equations for dissipative
systems, we show that hyperbolic tangent model is the only the nonlinear system
of equations which can admit some particular solutions of the Toda lattice. We
give one parameter family of exact solutions, which include as special cases
the Toda lattice solutions as well as the Whitham's solutions in the Newell's
model. Our solutions can be used to describe temporal-spatial density patterns
observed in the optimal velocity model for traffic flow.Comment: Latex, 13 pages, 1 figur
Fate of Vector Dominance in the Effective Field Theory
We reveal the full phase structure of the effective field theory for QCD,
based on the hidden local symmetry (HLS) through the one-loop renormalization
group equation including quadratic divergences. We then show that vector
dominance (VD) is not a sacred discipline of the effective field theory but
rather an accidental phenomenon peculiar to three-flavored QCD. In particular,
the chiral symmetry restoration in HLS model takes place in a wide phase
boundary surface, on which the VD is realized nowhere. This suggests that VD
may not be valid for chiral symmetry restoration in hot and/or dense QCD.Comment: 4 pages, 3 figures. One reference added. Minor modification to
shorten the manuscript. This is the version to appear in Physical Review
Letter
High sensitivity and multifunctional micro-Hall sensors fabricated using InAlSb/InAsSb/InAlSb heterostructures
Further diversification of Hall sensor technology requires development of materials with high electron mobility and an ultrathin conducting layer very close to the material's surface. Here, we describe the magnetoresistive properties of micro-Hall devices fabricated using InAlSb/InAsSb/InAlSb heterostructures where electrical conduction was confined to a 30 nm-InAsSb two-dimensional electron gas layer. The 300 K electron mobility and sheet carrier concentration were 36 500 cm(2) V-1 s(-1) and 2.5 x 10(11) cm(-2), respectively. The maximum current-related sensitivity was 2 750 V A(-1) T-1, which was about an order of magnitude greater than AlGaAs/InGaAs pseudomorphic heterostructures devices. Photolithography was used to fabricate 1 mu m x 1 mu m Hall probes, which were installed into a scanning Hall probe microscope and used to image the surface of a hard disk
Early improvement of HbA1c, weight and low-density lipoprotein (LDL) for Type 2 diabetes (T2D) patient by Rybelsus (oral semaglutide)
Background: Latest topic for Type 2 diabetes (T2D) would be oral semaglutide (Rybelsus).
Case presentation: Patient is 74-year-old female with T2D. She showed 65.5 kg (BMI 28.7 kg/m2) and HbA1c 7.4% in Feb 2022.
Results: She started Rybelsus 3-7mg/day, and then she had clinical effects as 58kg and 6.0% in June 2022, respectively.
Discussion: Rybelsus is characteristic for its clinical efficacy of improvement for glucose variability and body weight. Various data were from Semaglutide Treatment Effect in People with Obesity (STEP) and Peptide Innovation for Early diabetes treatment (PIONEER) studies. This report becomes hopefully useful reference for diabetic research
Detail Analysis of Peripheral Artery Disease (PAD) Using SYNAPSE VINCENT Technology
Background: Information and communication technology (ICT) has been developed remarkably with artificial intelligence (AI) and three-dimensional reconstruction image analysis.
Patient and Method: The patient is an 84-year-old male with type 2 diabetes (T2D). The computed tomography (CT) data were analyzed by the application of SYNAPSE VINCENT system.
Results: His ankle brachial index (ABI) showed 1.16/0.65 (right/left) with large difference as peripheral artery disease (PAD). He showed calcification of aorta calcification, the occlusions of left superficial femoral artery (SFA) and right tibial artery.
Discussion: This technique can provide detail images, which contribute much for patients with arteriosclerotic cardiovascular disease (ASCVD)
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