Grouping genetic operators for the delineation of functional areas based on spatial interaction

The delineation of functional economic areas, or market areas, is a problem of high practical relevance, since the delineation of functional sets such as economic areas in the US, Travel-to-Work Areas in the United Kingdom, and their counterparts in other OECD countries are the basis of many statistical operations and policy making decisions at local level. This is a combinatorial optimisation problem defined as the partition of a given set of indivisible spatial units (covering a territory) into regions characterised by being (a) self-contained and (b) cohesive, in terms of spatial interaction data (flows, relationships). Usually, each region must reach a minimum size and self-containment level, and must be continuous. Although these optimisation problems have been typically solved through greedy methods, a recent strand of the literature in this field has been concerned with the use of evolutionary algorithms with ad hoc operators. Although these algorithms have proved to be successful in improving the results of some of the more widely applied official procedures, they are so time consuming that cannot be applied directly to solve real-world problems. In this paper we propose a new set of group-based mutation operators, featuring general operations over disjoint groups, tailored to ensure that all the constraints are respected during the operation to improve efficiency. A comparative analysis of our results with those from previous approaches shows that the proposed algorithm systematically improves them in terms of both quality and processing time, something of crucial relevance since it allows dealing with most large, real-world problems in reasonable time.

Weighted composition operators on the predual and dual Banach spaces of Beurling algebras on Z

Let vv be a weight sequence on ZZ and let ψ,φψ,φ be complex-valued functions on ZZ such that φ(Z)⊂Zφ(Z)⊂Z. In this paper we study the boundedness, compactness and weak compactness of weighted composition operators Cψ,φCψ,φ on predual Banach spaces c0(Z,1/v)c0(Z,1/v) and dual Banach spaces ℓ∞(Z,1/v)ℓ∞(Z,1/v) of Beurling algebras ℓ1(Z,v)ℓ1(Z,v).

Geometry of Dirac Operators

Thesis (Master, Mathematics & Statistics) -- Queen's University, 2016-07-04 20:27:20.386

Off-farm Labour Decision of Italian Farm Operators. Factor Markets Working Document No. 61, August 2013

This paper analyses the factors affecting off-farm labour decisions of Italian farm operators. Using micro-level data from the Farm Business Survey (REA) over the pre- and post-2003 CAP reform periods, we investigated the impact that operator, family, farm and market characteristics exert on these choices. Among other things, the paper focuses also on the differential impact of those variables for operators of smaller and larger holdings. The main results suggest that operator and family characteristics have a significant impact on the decision to participate in off-farm work more for smaller than for bigger farms. By contrast, farm characteristics are more relevant variables for bigger farms. In particular, decoupled farm payments, by increasing the marginal productivity of farm labour, lower the probability of working off the farm only in bigger farms, while coupled subsidies in pre-reform years do not have a significant impact on labour decisions. Finally, we show that, after accounting for the standard covariates, local and territorial labour market characteristics generally have a low effect on off-farm work operators’ choices.

Production expenses of farm operators, by states 1949-58.

Cover title.

Outline for training of powered industrial truck operators.

Mode of access: Internet.

A chapter in the theory of linear operators in Hilbert space,

Mode of access: Internet.

Material development for training for operators of speed measuring devices. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

A directory of rural and specialized transit operators. Volume 1: eastern U.S. systems.

Urban Mass Transportation Administration, Washington, D.C.

A directory of rural and specialized transit operators. Volume 2: central U.S. systems.

Urban Mass Transportation Administration, Washington, D.C.

A directory of rural and specialized transit operators. Volume 3: western U.S. systems.

Urban Mass Transportation Administration, Washington, D.C.

Modern methods of testing milk and milk products; a handbook prepared for the use of dairy students, butter-makers, cheese-makers, producers of milk, operators in condenseries, managers of milk-shipping stations, milk-inspectors, physicians, etc.,

Mode of access: Internet.

Alleged coercive and discriminatory practices against retail gasoline operators by oil company suppliers : interim report of Subcommittee No. 5 on Distribution Problems to the Select Committee on Small Business, House of Representatives, Eighty-fourth Congress, first session, pursuant to H. Res. 114, a resolution creating a Select Committee to Conduct a Study and Investigation of the Problems of Small Business.

Mode of access: Internet.