Helicopter yarding systems have become a popular tool in
removing timber from steep slopes, sensitive soils, limited access
areas, and environmentally sensitive stands. Little is known about
the system's dynamics. This study is part of a research project to
explore "advanced" logging systems as to their economic efficiency
Heuristics based on Monte-Carlo Integer Programming (MCIP) and Tabu Search
(TS) techniques were developed for generating easily implementable bucking rules that are
applicable to entire stands (as opposed to individual stem classes), and for selecting the
rule-set that provides the best feasible solution (given log prices and market constraints).
A log breakdown model, SAW3D, was developed to
optimize lumber recovery from logs of any shape in 3-
dimensional space. The program uses a polygonal cross
section representation of logs; three nested dynamic
programming (DP) algorithms to optimize log breakdown,
flitch and cant edging, and trimming operations; and a
An extension of the sensitivity analysis of linear programming, called parametric programming is used in determining optimal sawtimber logging system mix. The five logging systems under study are manual log-length, system, log-length processor and harvester systems, manual tree-length system and tree-length harvester system. In conditions where it is not exactly...
In certain cases in system modeling, parameter search problems
are complicated by the availability of scanty and corrupt physical
system data and a large number of model parameters. An algorithm
using man-machine interaction is presented to attack this type
of parameter search problem with the objective of efficiency in the...
Biomechanical models have been used in designing human work
environments to evaluate potential risks to workers before a work environment is
constructed. In order for work environments to be modeled correctly, most
biomechanical models require as input, an accurate body posture of the worker.
This information can be obtained by,...
This dissertation consists of three papers on land use economics and policies.
The first two papers focus primarily on local land use policies and urban development.
The third paper addresses the question how environmental amenities affect
households' residential choices in a metropolitan area.
In the first paper, an option value...
Many engineering devices and propulsion systems suffer from undesirable effects of cavitation; such as degradation in the efficiency of pumps and turbines, generation of noise and vibration on ship propeller, increased drag and erosion of propeller blade, etc.
In spite of decades of research on this problem, detailed study of...
We investigate the optimal harvesting strategies for McKendrick type population models. Models of this type endow the population with a continuous age structure. They consist of a partial differential equation with a boundary condition which involves an integral of the solution. We study two problems, the first concerns the yield...
A model is presented which predicts the net present
value of a stand level multi-entry harvest plan. The model
accounts for potential volume losses due to harvest-related soil compaction. The goal of this project was to answer five economic questions about the issue of soil compaction in forestry. The five...