This paper presents a genetic algorithm to solve the orienteering problem, which is concerned with finding a path between a given set of control points, among which a start and an end point are specified, so as to maximize the total score collected subject to a prescribed distance constraint. Employing several sets of test problems from the literature, the performance of the genetic algorithm i...

In an earlier paper [Journal of Mathematical Economics, 37 (2002) 17–38], we proved that if a preference relation on a commodity space is non-representable by a real-valued function then that chain is necessarily a long chain, a planar chain, an Aronszajn-like chain or a Souslin chain. In this paper, we study the class of planar chains, the simplest example of which is the Debreu chain (R2, <l)...

Social networks can be embedded in an n-dimensional space, where the dimensions may reveal or denote underlying properties of interest. When the pertaining actors occupy niches of resources in this space, e.g., organizational niches of affiliates, we show there exists a non-monotonic effect of dimensionality change. Depending on niche width, relatively narrow or wide, dimensionality change has ...

The Federal Reserve adjusts the federal funds target rate discretely, causing discontinuity in short-term interest rates. Unlike Poisson jumps, these adjustments are well anticipated by the market. We propose a term structure model that incorporates an anticipated jump component with known arrival times but random jump size. We find that doing so improves the model performance in capturing the ...

The 1H nuclear spin-lattice relaxation time (T1) of H2 and H2@C60 in organic solvents varies with solvent, and it varies proportionally for H2 and for H2@C60. Since intermolecular magnetic interactions are ruled out, the solvent must influence the modulating processes of the relaxation mechanisms of H2 both in the solvent cage and inside C60. The temperature dependence of T1 also is very simila...

This paper characterizes properties of chance attitudes (nonadditive measures). It does so for decision under uncertainty (unknown probabilities), where it assumes Choquet expected utility, and for decision under risk (known probabilities), where it assumes rank-dependent utility. It analyzes chance attitude independently from utility. All preference conditions concern simple violations of the ...

Saddlepath learning occurs when agents know the form but not the coefficients of the saddlepath relationship defining rational expectations equilibrium. Under saddlepath learning, we obtain a completely general relationship between determinacy and e-stability, and generalise Minimum State Variable results previously derived only under full information. When the system is determinate, we show th...

An ordering of multidimensional alternatives is separable on a set of dimensions if fixing values on the complementary dimensions always produces the same induced ordering. Most often, studies of separability assume continuous alternative spaces; as we show, separability has different properties when alternative spaces are discrete. For instance, two well-known theorems of Gorman—that common se...

To a considerable extent, risk aversion as it is commonly observed is caused by loss aversion. Several indexes of loss aversion have been proposed in the literature. The one proposed in this paper leads to a clear decomposition of risk attitude into three distinct components: basic utility, probability weighting, and loss aversion. The index is independent of the unit of payment. The main theor...

For a market with an atomless continuum of assets, we formulate the intuitive idea of a ‘‘well-diversified’’ portfolio, and present a notion of ‘‘exact arbitrage’’, strictly weaker than the more conventional notion of ‘‘asymptotic arbitrage’’, and necessary and sufficient for the validity of an APT pricing formula. Our formula involves ‘‘essential’’ risk, one based on a specific index portfolio...