An Object-Z formal speciication of the ODP Trader is presented which concisely captures the hierarchical context structure, the distribution of information and the communication aspects of the Trader. Particular use is made of generic classes, class inheritance and object aggregation (i.e. the instantiation of collections of similar objects) to give a structured speciication that can be readily...

An Object-Z formal speciication of the ODP Trader is presented which concisely captures the hierarchical context structure, the distribution of information and the communication aspects of the Trader. Particular use is made of generic classes, class inheritance and object aggregation (i.e. the instantiation of collections of similar objects) to give a structured speciication that can be readily...

An approximation Ansatz for the operator solution, U(z′, z), of a hyperbolic first-order pseudodifferential equation, ∂z +a(z, x, Dx) with Re(a) ≥ 0, is constructed as the composition of global Fourier integral operators with complex phases. An estimate of the operator norm in L(H, H) of these operators is provided which allows to prove a convergence result for the Ansatz to U(z′, z) in some So...

In the present paper we elaborate on the underlying Hamiltonian structure of interconnected energy-conserving physical systems. It is shown that a power-conserving interconnection of port-controlled generalized Hamiltonian systems leads to an implicit generalized Hamiltonian system, and a power-conserving partial interconnection to an implicit port-controlled Hamil-tonian system. The crucial co...

Many multicriteria problems in economics and finance require that efficient solutions be found. A recent contribution to production theory established a characterization of efficient points under closedness and free-disposability (Bonnisseau and Crettez in Econ Theory 31(2):213–223, 2007, Theorem 1). However, as will be shown using a number of examples, these results cannot be applied to simple...

We study mean-variance hedging under portfolio constraints in a general semimartingale model. The constraints are formulated via predictable correspondences, meaning that the trading strategy is restricted to lie in a closed convex set which may depend on the state and time in a predictable way. To obtain the existence of a solution, we first establish the closedness in L2 of the space of all g...

RELATIONSHIPS Relationships are critical to object modelling. It is generally agreed that associations (of several °avours), generalizations and aggregations are useful, although the exact semantics di®er between authors. It is important that we, the object-oriented community, gain a common understanding and, in that context, recent formalisms have helped to clarify the situation: the OMG-inspi...

Objectives. (1) Determine the predictive value of a school-based test of cardiovascular fitness (CVF) for insulin resistance (IR); (2) compare a "school-based" prediction of IR to a "laboratory-based" prediction, using various measures of fitness and body composition. Methods. Middle school children (n = 82) performed the Progressive Aerobic Cardiovascular Endurance Run (PACER), a school-based ...

where dA is the normalized area measure in D. The case where α = 0 is known as the (unweighted) Bergman space, often simply denoted by A2. Let φ be an analytic map from the open unit disk D into itself. The operator that takes the analytic map f to f ◦ φ is a composition operator and is denoted by Cφ . A natural generalization of a composition operator is an operator that takes f to ψ · f ◦ φ, ...