28,170 research outputs found
Geometric aspects of nonholonomic field theories
A geometric model for nonholonomic Lagrangian field theory is studied. The
multisymplectic approach to such a theory as well as the corresponding Cauchy
formalism are discussed. It is shown that in both formulations, the relevant
equations for the constrained system can be recovered by a suitable projection
of the equations for the underlying free (i.e. unconstrained) Lagrangian
system.Comment: 29 pages; typos remove
Hamilton-Jacobi Theory in k-Symplectic Field Theories
In this paper we extend the geometric formalism of Hamilton-Jacobi theory for
Mechanics to the case of classical field theories in the k-symplectic
framework
The Bank of Canada's Management of Foreign Currency Reserves
This article describes the Bank's management of the liquid foreign currency portion of the government's official reserves. It broadly outlines the operations of the Exchange Fund Account (EFA), the main account in which Canada's reserves are held. It then briefly reviews the evolution of the objectives and management of the EFA over the past 25 years, particularly in light of the changing level of reserves and developments in financial markets. The EFA is funded by Canada's foreign currency borrowings in capital markets. The article focuses on the comprehensive portfolio framework used to manage the Account, which matches assets and liabilities. Under this framework, funds are invested in assets that match, as closely as possible, the characteristics of foreign currency liabilities issued, helping to immunize the portfolio against currency and interest rate risks.
The limits of open acess as a regulatory yardstick in the regulation of utilities in Latin America
This paper contends that the identification of a pro-competitive agenda in the process of regulatory reform undertaken in many developing countries, particularly in the field of utilities regulation, ultimately rests on the vision held by the authority about the sources of market failures. Conventional Industrial Organization theory assumes that the exercise of market power by incumbent firms limits the access of potential competitive entrants, and therefore, government regulation should curb such power. However, the existence of market “power” is an inference from conventional “equilibrium” thinking on markets and competition, where such power is associated with the static conditions of markets, away from the efficient equilibrium epitomized by the Perfect Competition model. By logical inference, an alternative “market process” view that regards markets as entities subject to constant disequilibrium should lead to alternative normative conclusions. Under this alternative view, exploring the role of rules and institutions is essential for the analysis of “efficient” market outcomes. Such efficiency is related to the capacity of market participants to coordinate their productive activities, and complementary entrepreneurial synergies. This paper outlines an alternative network competition perspective, focused on the integration of complementary capabilities, as a regulatory yardstick. This view balances the rights of incumbent firms to exploit their rights, and the possibilities of third parties to integrate into the network concerned on a non-discriminatory basis, thereby preserving the investments of incumbents on a more equitable basis. It also explores the experience of selected Latin American countries in the development of this network competition approach.
Unified formalism for higher-order non-autonomous dynamical systems
This work is devoted to giving a geometric framework for describing
higher-order non-autonomous mechanical systems. The starting point is to extend
the Lagrangian-Hamiltonian unified formalism of Skinner and Rusk for these
kinds of systems, generalizing previous developments for higher-order
autonomous mechanical systems and first-order non-autonomous mechanical
systems. Then, we use this unified formulation to derive the standard
Lagrangian and Hamiltonian formalisms, including the Legendre-Ostrogradsky map
and the Euler-Lagrange and the Hamilton equations, both for regular and
singular systems. As applications of our model, two examples of regular and
singular physical systems are studied.Comment: 43 pp. We have corrected and clarified the statement of Propositions
2 and 3. A remark is added after Proposition
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