5,810 research outputs found
Toda brackets and cup-one squares for ring spectra
In this paper we prove the laws of Toda brackets on the homotopy groups of a
connective ring spectrum and the laws of the cup-one square in the homotopy
groups of a commutative connective ring spectrum.Comment: 22 page
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
Rotor eddy-current loss in permanent magnet brushless machines
This paper presents an analysis of the rotor eddy-current loss in modular and conventional topologies of permanent magnet brushless machine. The loss is evaluated both analytically and by time-stepped finite-element analysis, and it is shown that it can be significant in both machine topologies. It is also shown that the loss can be reduced significantly by segmenting the magnets
Reductions of the Volterra and Toda chains
The Volterra and Toda chains equations are considered. A class of special
reductions for these equations are derived.Comment: LaTeX, 6 page
On Discrete Symmetries of the Multi-Boson KP Hierarchies
We show that the multi-boson KP hierarchies possess a class of discrete
symmetries linking them to the discrete Toda systems. These discrete symmetries
are generated by the similarity transformation of the corresponding Lax
operator. This establishes a canonical nature of the discrete transformations.
The spectral equation, which defines both the lattice system and the
corresponding Lax operator, plays a key role in determining pertinent symmetry
structure. We also introduce a concept of the square-root lattice leading to a
family of new pseudo-differential operators with covariance under additional
B\"{a}cklund transformations.Comment: 11 pgs, LaTeX, IFT-P/75/93, UICHEP-TH/93-1
Frustrated quantum-spin system on a triangle coupled with lattice vibrations - Correspondence to Longuet-Higgins et al.'s Jahn-Teller model -
We investigate the quantum three spin model
of spin on a triangle, in which spins are coupled with
lattice-vibrational modes through the exchange interaction depending on
distances between spin sites. The present model corresponds to the dynamic
Jahn-Teller system proposed by Longuet-Higgins {\it et al.},
Proc.R.Soc.A.{\bf 244},1(1958). This correspondence is revealed by using the
transformation to Nakamura-Bishop's bases proposed in Phys.Rev.Lett.{\bf
54},861(1985). Furthermore, we elucidate the relationship between the behavior
of a chiral order parameter and
that of the electronic orbital angular momentum in vibronic model: The regular oscillatory behavior of the expectation value
. The increase of the additional
anharmonicity(chaoticity) is found to yield a rapidly decaying irregular
oscillation of
Optimal Lighting Conditions for Office Workers from the Perspective of Non-visual Effects
University is one of the institutions that may have to face disaster events. For two decades, there have been a number of disasters that have negatively impacted the university. Resilience is an important concept that has been developed in the field of disaster management. This concept emphasizes on building adaptive capacitythrough social development, community competences, and strong communication and information systems. Students as a community often stay in campus for their activities such as study, research, and organization activities and are therefore prone to risks and dangers. It is important for students to be prepared in facing possible disasters so as to increase the resilience in the event of a disaster in the university. This research will show the perception of students in facing disaster, and furthermore will develop comprehensive disaster mitigation at the university, not only structural resilience, but also human resource to prepare in facing disasters. The purpose of this study is to describe the preparedness and awareness of the students of the Faculty of Medicine, Faculty of Dentistry, Faculty of Nursing, and Faculty of Pharmacy of the University of Indonesia in facing disasters in an effort to increase disaster resilience in the university. This is a quantitative cross-sectional study performed on 388 respondents. Results show that generally the respondents are resilient enough in facing disasters. It showed from their answers with a percentage > 50%, there are: awareness of potentials for disaster on campus, respondents need to prepare in facing disasters, they got information from valid sources, they have been trained in disaster, appropriate answers regarding to emergency response during disaster, and knowledge regarding nearest health services. However, improvements are still needed for several variables, including disaster preparedness on campus, knowledge of early warning system in campus, ownership of catastrophe insurance, level of preparedness (which is still low at 30.9%), valid information sources, and participation in disaster response training should be increased.
Keywords: disaster, disaster management, awareness, preparedness, resilience, universit
Integrable Discretizations of Chiral Models
A construction of conservation laws for chiral models (generalized
sigma-models on a two-dimensional space-time continuum using differential forms
is extended in such a way that it also comprises corresponding discrete
versions. This is achieved via a deformation of the ordinary differential
calculus. In particular, the nonlinear Toda lattice results in this way from
the linear (continuum) wave equation. The method is applied to several further
examples. We also construct Lax pairs and B\"acklund transformations for the
class of models considered in this work.Comment: 14 pages, Late
An integrable generalization of the Toda law to the square lattice
We generalize the Toda lattice (or Toda chain) equation to the square
lattice; i.e., we construct an integrable nonlinear equation, for a scalar
field taking values on the square lattice and depending on a continuous (time)
variable, characterized by an exponential law of interaction in both discrete
directions of the square lattice. We construct the Darboux-Backlund
transformations for such lattice, and the corresponding formulas describing
their superposition. We finally use these Darboux-Backlund transformations to
generate examples of explicit solutions of exponential and rational type. The
exponential solutions describe the evolution of one and two smooth
two-dimensional shock waves on the square lattice.Comment: 14 pages, 4 figures, to appear in Phys. Rev. E http://pre.aps.org
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