Recreational trip timing and duration prediction: A research note

This paper presents models that predict two recreational fishing trip parameters: the length of a trip and the timing of a trip within a year. A discrete choice (logit) model linking the choice of trip timing to calendar events, the demographic characteristics of anglers as well as the nature of the trip is econometrically estimated. A Tobit model is used to evaluate the relationship between fishing trip length and personal and trip characteristics. The results indicate that timing choice and trip length can be explained well in terms of observable personal and trip variables. Knowledge of these relationships is a useful input to tourism/recreational fishing management as well as to the development of tourism/fishing activity simulation models.recreational fishing, trip timing, length of recreational trips, tourism simulation, environmental impact management, Environmental Economics and Policy,

Hamiltonian and Phase-Space Representation of Spatial Solitons

We use Hamiltonian ray tracing and phase-space representation to describe the propagation of a single spatial soliton and soliton collisions in a Kerr nonlinear medium. Hamiltonian ray tracing is applied using the iterative nonlinear beam propagation method, which allows taking both wave effects and Kerr nonlinearity into consideration. Energy evolution within a single spatial soliton and the exchange of energy when two solitons collide are interpreted intuitively by ray trajectories and geometrical shearing of the Wigner distribution functions.Comment: 12 pages, 5 figure

Broadband Epsilon-Near-Zero Metamaterials with Step-Like Metal-Dielectric Multilayer Structures

The concept of the broadband epsilon-near-zero meta-atom consisting of layered stacks with specified metallic filling ratio and thickness is proposed based on the Bergman spectral representation of the effective permittivity. The step-like metal-dielectric multilayer structures are designed to achieve realistic broadband epsilon-near-zero meta-atoms in optical frequency range. These meta-atoms can be integrated as building blocks for unconventional optical components with exotic electromagnetic properties over a wide frequency range, such as the demonstrated broadband directional emission and phase front shaping.Comment: 18 pages, 7 figure

Realizing broadband electromagnetic transparency with a graded-permittivity sphere

Broadband electromagnetic transparency phenomenon is realized with a well-designed graded-permittivity sphere, which has an extremely low scattering cross section over a wide frequency range, based on the generalized Mie scattering theory and numerical simulation in full-wave condition. The dynamic polarization cancellation is revealed by studying the variation of the polarization with respect to the frequency. Furthermore, a properly-designed multi-shell sphere is also proposed and examined in order to reduce the rigorous conditions for realizing the broadband transparency in experiments.Comment: 15 pages, 4 figure