Some of the most fundamental quantities in population ecology describe the growth and spread of populations. Population dynamics are often characterized by the annual rate of increase, λ, or the generational rate of increase, R0. Analyses involving R0 have deepened our understanding of disease dynamics and life-history complexities beyond that afforded by analysis of annual growth alone. While ...

Nearshore circulation and shoreline setup are forced through the wave radiation stress, which is a function of the frequencydirectional wave spectrum. The radiation stress components often are approximated by assuming a spectrum that is narrow-band in frequency and direction. These narrow-band approximations overestimate the true radiation stress components in 8-m water depth on the Outer Banks...

We study ideals of Borel type, including k-Borel and t-spread Veronese ideals. determine their free resolutions homological shift The multiplicity the analytic spread equigenerated squarefree principal are computed. For multiplicity, result is given under an additional assumption which always satisfied for These results used to analyze behavior height, HSj(I) as functions j, when I ideal.

An equigenerated monomial ideal $$I$$ is a Freiman if $$\mu(I^2)=\ell(I)\mu(I)-{\ell(I)\choose 2}$$ , where $$\ell(I)$$ the analytic spread of and $$\mu(I)$$ least number generators . ideals are special since there exists an exact formula computing any their powers. In this paper we give complete classification $$t$$ -spread principal Borel ideals.

Affectionately dedicated to Mel Hochster, who has been an inspiration to us for many years, on the occasion of his 65th birthday. Abstract We study the fibers of projective morphisms and rational maps. We characterize the analytic spread of a homogeneous ideal through properties of its syzygy matrix. Powers of linearly presented ideals need not be linearly presented, but we identify a weaker li...

In this paper, a low complexity long pseudo noise (PN) code acquisition scheme is proposed for spread spectrum systems including global positioning system (GPS) and code division multiple access (CDMA) system. By using a phaseshift-network, the proposed scheme has less complexity than the conventional dual correlating sequential estimation scheme. From the analytic and numerical results, it is ...

The Fisher equation, which combines di/usive motion of individuals with nonlinearities arising from their growth and competition processes, is analyzed, generalized, and applied to the dynamics of bacteria, pattern formation, and the spread of epidemics. Analytic solutions are also presented for some exactly soluble and physically relevant variants of the equation. c © 2004 Elsevier B.V. All ri...

Let R be a local, Noetherian ring and I ⊆ R an ideal. A question of Kodiyalam asks whether for fixed i > 0, the polynomial giving the ith Betti number of In has degree equal to the analytic spread of I minus one. Under mild conditions on R, we show that the answer is positive in a number of cases, including when I is divisible by m or I is an integrally closed m-primary ideal.