The Class A pan coefficient (Kp) has been used to convert pan evaporation (ECA) to grass-reference evapotranspiration (ETo), an important component in water management of irrigated crops. There are several methods to determine Kp values, using wind speed, relative humidity and fetch length and conditions. This paper analyses the following methods to estimate Kp values: Doorenbos & Pruitt (1977)...

The choice of a finitely supported distribution is viewed as a degenerate bilinear form on the polynomials in the spectral parameter z and the matrix representing multiplication by z in terms of an orthogonal basis is constructed. It is then shown that the same induced time dependence for finitely supported distributions which gives the ith KP flow under the dual isomorphism induces the ith flo...

Analytic-bilinear approach for construction and study of integrable hierarchies, in particular, the KP hierarchy is discussed. It is based on the generalized Hirota identity. This approach allows to represent generalized hierarchies of integrable equations in a condensed form of finite functional equations. Resolution of these functional equations leads to the τ-function and addition formulae t...

We present a Lagrangian for the bilinear discrete KP (or HirotaMiwa) equation. Furthermore, we show that this Lagrangian can be extended to a Lagrangian 3-form when embedded in a higher dimensional lattice, obeying a closure relation. Thus we establish the multiform structure as proposed in [8] in a higher dimensional case.

Starting from a self-dual SU(∞) Yang-Mills theory in (2 + 2) dimensions, the Plebanski second heavenly equation is obtained after a suitable dimensional reduction. The self-dual gravitational background is the cotangent space of the internal two-dimensional Riemannian surface required in the formulation of SU(∞) Yang-Mills theory. A subsequent dimensional reduction leads to the KP equation in (...

A wave function of the N -component KP Hierarchy with continuous flows determined by an invertible matrix H is constructed from the choice of an MN -dimensional space of finitely-supported vector distributions. This wave function is shown to be an eigenfunction for a ring of matrix differential operators in x having eigenvalues that are matrix functions of the spectral parameter z. If the space...

Presence-only data present challenges for selecting thresholds to transform species distribution modeling results into binary outputs. In this article, we compare two recently published threshold selection methods (maxSSS and maxF pb) and examine the effectiveness of the threshold-based prevalence estimation approach. Six virtual species with varying prevalence were simulated within a real land...

Bases are exhibited for Kn, Kp,q, and Qd, and it is shown how each cycle of the various graphs can be built as a hierarchical ordered sum in which all of the partial sums are (simple) cycles with each cycle from either the basis or one of the hierarchically constructed cycle-sets meeting the partial sum of its predecessors in a nontrivial path. A property that holds for this “connected sum” of ...

This paper is a brief review of the program initiated some years ago in [JMP]. The main goal of this program is to understand the formation and the propagation properties of surface states in regions with corrugated boundaries. The history of this problem and its physical aspects are discussed in [JMP, KP]. The results described in this review are obtained in collaborations with Yoram Last and ...

In 70’s there was discovered a construction how to attach to some algebraicgeometric data an infinite-dimensional subspace in the space k((z)) of the Laurent power series. The construction was successfully used in the theory of integrable systems, particularly, for the KP and KdV equations [10, 19]. There were also found some applications to the moduli of algebraic curves [2, 3]. Now it is know...