121.
A hybrid scatter search/electromagnetism meta-heuristic for project scheduling
- Dieter Debels A; Bert De Reyck B; Roel Leus C; Mario Vanhoucke A
In the last few decades, several effective algorithms for solving the resource-constrained project scheduling problem have been proposed. However, the challenging nature of this problem, summarised in its strongly NP-hard status, restricts the effectiveness of exact optimisation to relatively small instances. In this paper, we present a new meta-heuristic for this problem, able to provide near-optimal heuristic solutions for relatively large instances. The procedure combines elements from scatter search, a generic population-based evolutionary search method, and from a recently introduced heuristic method for the optimisation of unconstrained continuous functions based on an analogy with electromagnetism theory. We present computational experiments...
122.
Electromagnetism supercharged!: Learning physics with digital simulation games
- Kurt Squire; Mike Barnett; Jamillah M. Grant; Thomas Higginbotham
Abstract: Learning scientists are increasingly turning to computer and video games as tools for learning. Simulation might not only motivate learners, but provide accessible ways for students to develop intuitive understandings of abstract physics phenomena. This study examines what learning occurs when an electromagnetism simulation game is used in a school for underserved students. Students in the experimental group performed better than students in the control group (guided discovery-based science) on measures for understanding. Game mechanics enabled students to confront weaknesses in understandings, and physics representations became tools for understanding problems. Implications for the design of educational digital media are...
123.
Weak force
- Jens Koeplinger; Hawking “euclidean Quantum Gravity; Electromagnetism Electromagnetism; Electromagnetism Electromagnetism
– Field theory / second quantization – Expectation: Operator description of 4D EQG unlikely – Suggestion for realization [2]: antide Sitter (AdS) metric ● Research problem of this talk: Find operator (first quantization) description Proposed operator description of 4D Euclidean quantum gravity
124.
Simple applications of Noether's first theorem in quantum mechanics and
electromagnetism
- Brown, Harvey R.; Holland, Peter
Internal global symmetries exist for the free non-relativistic
Schr\"{o}dinger particle, whose associated Noether charges--the space integrals
of the wavefunction and the wavefunction multiplied by the spatial
coordinate--are exhibited. Analogous symmetries in classical electromagnetism
are also demonstrated.
125.
The nature is simple in essence - on gravitation and electromagnetism
unification
- Drafta, Viorel
The proposed temporal fluctuations model attempt for a unitary vision on
gravity, electromagnetism and inertia. On obtain Newton law of gravitation and
Coulomb law by starting from simple principles. On obtain too the main results
of General Relativity Theory and Electromagnetism. One of the major points of
present work is to obtain unified potential, which allow a unitary description
of gravity and electromagnetism. As consequence, on obtain supplemental effects
responsible for conservation laws violation in certain closed systems. On
maintain the validity of conservation laws only if those systems are coupling
with vacuum. This fact can be used for energy production and/or transport. This
proposed model opening to quantum...
126.
Loop Quantization versus Fock Quantization of p-Form Electromagnetism on
Static Spacetimes
- Carrión-Álvarez, Miguel
As a warmup for studying dynamics and gravitons in loop quantum gravity,
Varadajan showed that Wilson loops give operators on the Fock space for
electromagnetism in Minkowski spacetime - but only after regularizing the loops
by smearing them with a Gaussian. Unregularized Wilson loops are too singular
to give densely defined operators. Here we present a rigorous treatment of
unsmeared Wilson loops for vacuum electromagnetism on an arbitrary globally
hyperbolic static spacetime. Our Wilson loops are not operators, but
"quasioperators": sesquilinear forms on the dense subspace of Fock space
spanned by coherent states corresponding to smooth classical solutions. To
obtain this result we begin by carefully treating electromagnetism on...
127.
On the Equivalence Principle and a Unified Description of Gravitation
and Electromagnetism
- Özer, Murat
We first investigate the form the general relativity theory would have taken
had the gravitational mass and the inertial mass of material objects been
different. We then extend this analysis to electromagnetism and postulate an
equivalence principle for the electromagnetic field. We argue that to each
particle with a different electric charge-to-mass ratio in a gravitational and
electromagnetic field there corresponds a spacetime manifold whose metric
tensor g_{\mu\nu} describes the dynamical actions of gravitation and
electromagnetism.
128.
Boundary value problems and the validity of the Post constraint in
modern electromagnetism
- Lakhtakia, Akhlesh
When a (frequency-domain) boundary value problem involving a homogeneous
linear material is solved to assess the validity of the Post constraint, a
conflict arises between the fundamental differential equations of
electromagnetism in the chosen material and a naive application of the usual
boundary conditions. It is shown here that the conflict vanishes when the
boundary conditions are properly derived from the fundamental equations, and
the validity of the Post constraint in modern macroscopic electromagnetism is
thereby reaffirmed.
129.
Gravito-electromagnetism versus electromagnetism
- Tartaglia, Angelo; Ruggiero, Matteo Luca
The paper contains a discussion of the properties of the gravito-magnetic
interaction in non stationary conditions. A direct deduction of the equivalent
of Faraday-Henry law is given. A comparison is made between the
gravito-magnetic and the electro-magnetic induction, and it is shown that there
is no Meissner-like effect for superfluids in the field of massive spinning
bodies. The impossibility of stationary motions in directions not along the
lines of the gravito-magnetic field is found. Finally the results are discussed
in relation with the behavior of superconductors.
130.
On the Relationship of Quantum Mechanics to Classical Electromagnetism
and Classical Relativistic Mechanics
- Field, J. H.
Some connections between quantum mechanics and classical physics are
explored. The Planck-Einstein and De Broglie relations, the wavefunction and
its probabilistic interpretation, the Canonical Commutation Relations and the
Maxwell--Lorentz Equation may be understood in a simple way by comparing
classical electromagnetism and the photonic description of light provided by
classical relativistic kinematics. The method used may be described as `inverse
correspondence' since quantum phenomena become apparent on considering the low
photon number density limit of classical electromagnetism. Generalisation to
massive particles leads to the Klein--Gordon and Schr\"{o}dinger Equations. The
difference between the quantum wavefunction of the photon and a classical
electromagnetic wave is discussed in some detail.
131.
On the physical meaning of the gauge conditions of Classical
Electromagnetism : the hydrodynamics analogue viewpoint
- Rousseaux, Germain
Based on an analogy between Fluid Mechanics and Electromagnetism, we claim
that the gauge conditions of Classical Electromagnetism are not equivalent
contrary to the common belief. These "gauges" are usually considered as
mathematical conditions that one must specify in order to solve any
electromagnetic problem. Here, the author shows that these conditions are
physical constraints which can be interpreted as electromagnetic continuity
equations. As a consequence, light cannot be considered as a pure transverse
wave in vacuum from the point of view of the potentials. We discuss the (lack
of) meaning of gauge transformations.
132.
On the coupling of fluid dynamics and electromagnetism at the top of the earth's core
- Benton, E. R.
A kinematic approach to short-term geomagnetism has recently been based upon pre-Maxwell frozen-flux electromagnetism. A complete dynamic theory requires coupling fluid dynamics to electromagnetism. A geophysically plausible simplifying assumption for the vertical vorticity balance, namely that the vertical Lorentz torque is negligible, is introduced and its consequences are developed. The simplified coupled magnetohydrodynamic system is shown to conserve a variety of magnetic and vorticity flux integrals. These provide constraints on eligible models for the geomagnetic main field, its secular variation, and the horizontal fluid motions at the top of the core, and so permit a number of tests of the...
133.
Analogy electromagnetism-acoustics: Validation and application to local
impedance active control for sound absorption
- Nicolas, Laurent; Furstoss, M.; Galland, Marie-Annick
An analogy between electromagnetism and acoustics is presented in 2D. The
propagation of sound in presence of absorbing material is modeled using an open
boundary microwave package. Validation is performed through analytical and
experimental results. Application to local impedance active control for free
field sound absorption is finally described.
134.
The invariance of classical electromagnetism under Charge-conjugation, Parity and Time-reversal (CPT) transformations
- Norbury, John W.
The invariance of classical electromagnetism under charge-conjugation, parity, and time-reversal (CPT) is studied by considering the motion of a charged particle in electric and magnetic fields. Upon applying CPT transformations to various physical quantities and noting that the motion still behaves physically demonstrates invariance.
135.
Geometric Interpretation of Electromagnetism in a Gravitational Theory
with Space--Time Torsion
- Horie, Kenichi
A complete geometric unification of gravity and electromagnetism is proposed
by considering two aspects of torsion: its relation to spin established in
Einstein--Cartan theory and the possible interpretation of the torsion trace as
the electromagnetic potential. Starting with a Lagrangian built of Dirac
spinors, orthonormal tetrads, and a complex rather than a real linear
connection we define an extended spinor derivative by which we obtain not only
a very natural unification, but can also fully clarify the nontrivial
underlying fibre bundle structure. Thereby a new type of contact interaction
between spinors emerges, which differs from the usual one in Einstein--Cartan
theory. The splitting of the linear connection into a...
136.
AN ELECTROMAGNETISM ALGORITHM OF NEURAL NETWORK ANALYSIS- AN APPLICATION TO TEXTILE RETAIL OPERATION
- Peitsang Wu; Wen-hung Yang; Nai-chieh Wei
This paper applies a heuristic algorithm, called the “Electromagnetism Algorithm ” (EM) [3], for neural network training. We develop a meta-model of the relationships between key inputs and performance measures of an apparel retail operations using neural network technology. This method simulates the electromagnetism theory of physics by considering each weight connection in a neural network as an electrical charge. Through the attraction and repulsion of the charges, weights move toward the optimality without being trapped into local optima like other algorithms such as genetic algorithm and gradient descent method. The computation results show that the EM algorithm not only...
137.
The Unification of Electromagnetism and Gravitation in the Context of
Quantized Fractal Space Time
- Sidharth, B. G.
The attempts to unify electromagnetism and gravitation have included the
formulations of Herman Weyl and the Kaluza Klein theory with the fifth
dimension. More recently there have been fruitful attempts in the domain of
Quantum Superstrings and the author's formulation in terms of Quantum
Mechanical Kerr-Newman Black Holes. Though all these appear to be widely
divergent approaches, they are shown to have a unified underpinning in the
context of quantized fractal space time.
138.
A Conjugation Symmetry in Linear Electromagnetism, in Extension of
Materials with Negative Real Permittivity and Permeability Scalars
- Lakhtakia, A.
If all space is occupied by a linear bianisotropic material--whether
homogeneous or not--then the concurrent replacements of the permittivity and
the impermeability tensors by the negatives of their respective complex
conjugates and of the magnetoelectric tensors by their respective complex
conjugates (in the Boys-Post representation) imply the conjugation of both E
and H, in the absence of externally impressed sources. This conjugation
symmetry in linear electromagnetism has observable consequences when the linear
bianisotropic material occupies a bounded region.
139.
Unification of Gravitation and Electromagnetism in a Relativistic Version of Finslerian Geometry
- Baki, P.; ;
A theory of gravitation is considered in a relativistic version of Finslerian geometry. It is found that both the geodesic equations and the Finslerian analogue of the Einstein's field equations have terms that involve the electromagnetic field tensor, thereby pointing out to the geometrization of electrodynamics and hence to a unification of gravitation and electromagnetism. A possibility of a non-gravitational electromagnetic redshift is explored. Mical antiozonant were incorporated.
(Af. J. of Science and Technology: 2002 3(2): 101-106)
140.
Metric Unification of Gravitation and Electromagnetism Solves the
Cosmological Constant Problem
- Özer, Murat
We first review the cosmological constant problem, and then mention a
conjecture of Feynman according to which the general relativistic theory of
gravity should be reformulated in such a way that energy does not couple to
gravity. We point out that our recent unification of gravitation and
electromagnetism through a symmetric tensor has the property that the free
electromagnetic energy and the vacuum energy do not contribute explicitly to
the curvature of spacetime just like the free gravitational energy. Therefore
in this formulation of general relativity, the vacuum energy density has its
very large value today as in the early universe, while the cosmological
constant does not exist at...
