Fusiform Rust Trends in East Texas

Four surveys of pine plantations in East Texas between 1969 and 1984 indicate that fusiform rust (Cronartium quercuum (Berk.) Miyabe ex Shirai f. sp. fusiforme) infection rates are increasing on slash pine (Pinus elliottii Engelm. var. elliottii) and either decreasing or about constant on loblolly pine (Pinus taeda L.). Currently, stem infections occur on about 1 in 2 slash pines and 1 in 14 loblolly pines. South. J. Appl. For. 10:215-216, Nov. 1986

Establishment of permanent growth and yield plots in loblolly and slash pine plantations

Permanent plots have been established in 178 loblolly and 78 slash pine plantations throughout East Texas to study the development of stand structure over time. Analysis of the data will provide methods of estimating growth and yield, mortality, and site productivity to assist managers of these plantations

Site Index Equations for Loblolly and Slash Pine Plantations on Non-Old Fields in East Texas

Equations to estimate site index (index age 25 years) for plantations of loblolly pine (Pinus taeda L.) and slash pine (Pinus elliottii Engelm.) on non-old fields in East Texas have been developed. The height-prediction curves were based on the Richards’ growth function and track well within the range of the data (1-17 years). South. J. Appl. For. 10:109-112, May 1986

Research Report No. 1, Fusiform Rust Occurrence

Fusiform rust ( Cronartium quercuum (Berk.) Miyabe ex Shirai f. sp. fusiforme) infection occurs on 57% of planted slash pine ( Pinus elliottii Engelm. ) and on 11 % of planted loblolly pine ( Pinus laeda l.) trees on non-old-fields in East Texas. Future utilization of these planted pines may be affected by the rust infection rates

Solving inverse problems of identification type by optimal control methods

Inverse problems of identification type for nonlinear equations are considered within the framework of optimal control theory. The rigorous solution of any particular problem depends on the functional setting, type of equation, and unknown quantity (or quantities) to be determined. Here the authors present only the general articulations of the formalism. Compared to classical regularization methods (e.g. Tikhonov coupled with optimization schemes), their approach presents several advantages, namely: (i) a systematic procedure to solve inverse problems of identification type; (ii) an explicit expression for the approximations of the solution; and (iii) a convenient numerical solution of these approximations

Research Report No. 2, Tree Quality

One of two planted loblolly pine trees (Pinus taeda L.) and over one of three (36%) planted slash pine trees (Pinus elliottii Engelm.) on non-old-fields in East Texas have a poor quality stem. For both species, o poor quality stem is three times more likely to occur on trees with crowns in the upper canopy then in the lower canopy

Control mechanisms for a nonlinear model of international relations

Some issues of control in complex dynamical systems are considered. The authors discuss two control mechanisms, namely: a short range, reactive control based on the chaos control idea and a long-term strategic control based on an optimal control algorithm. They apply these control ideas to simple examples in a discrete nonlinear model of a multi-nation arms race

Planar Octilinear Drawings with One Bend Per Edge

In octilinear drawings of planar graphs, every edge is drawn as an alternating sequence of horizontal, vertical and diagonal ($45^\circ$) line-segments. In this paper, we study octilinear drawings of low edge complexity, i.e., with few bends per edge. A $k$-planar graph is a planar graph in which each vertex has degree less or equal to $k$. In particular, we prove that every 4-planar graph admits a planar octilinear drawing with at most one bend per edge on an integer grid of size $O(n^2) \times O(n)$. For 5-planar graphs, we prove that one bend per edge still suffices in order to construct planar octilinear drawings, but in super-polynomial area. However, for 6-planar graphs we give a class of graphs whose planar octilinear drawings require at least two bends per edge

Reframing Optimal Control Problems for Infectious Disease Management in Low-Income Countries

Optimal control theory can be a useful tool to identify the best strategies for the management of infectious diseases. In most of the applications to disease control with ordinary differential equations, the objective functional to be optimized is formulated in monetary terms as the sum of intervention costs and the cost associated with the burden of disease. We present alternate formulations that express epidemiological outcomes via health metrics and reframe the problem to include features such as budget constraints and epidemiological targets. These alternate formulations are illustrated with a compartmental cholera model. The alternate formulations permit us to better explore the sensitivity of the optimal control solutions to changes in available budget or the desired epidemiological target. We also discuss some limitations of comprehensive cost assessment in epidemiology

Homogenization of weakly coupled systems of Hamilton--Jacobi equations with fast switching rates

We consider homogenization for weakly coupled systems of Hamilton--Jacobi equations with fast switching rates. The fast switching rate terms force the solutions converge to the same limit, which is a solution of the effective equation. We discover the appearance of the initial layers, which appear naturally when we consider the systems with different initial data and analyze them rigorously. In particular, we obtain matched asymptotic solutions of the systems and rate of convergence. We also investigate properties of the effective Hamiltonian of weakly coupled systems and show some examples which do not appear in the context of single equations.Comment: final version, to appear in Arch. Ration. Mech. Ana