This dataset includes the finite element models (FEMs) used for the MS Thesis entitled: Influence of Uncertainties in Terrestrial Laser Scanning on Structural Reliability and Bridge Load Rating by Carly K. Loving. These FEMs were created in SAP 2000
and contain models from both thesis manuscripts. The following lists summarizes...
In this dissertation we consider two application specific flow and transport models in porous media at multiple scales: 1) methane gas transport models for hydrate formation and dissociation in the subsurface under two-phase conditions, and 2) coupled flow and biomass-nutrient model for biofilm growth in complex geometries with biofilm, and...
This dataset contains data layers used and produced by a fuzzy logic model for biomass loss risk under projected climate change in Oregon and Washington west of the Cascade Mountains crest.
A long running problem in mathematical biology is the prediction of extinction events, a specialized case of the larger global stability problem found in differential equations and dynamical systems theory. A central technical question is how to introduce the randomness observed in real ecological systems not accounted for in deterministic...
An understanding of natural coastal hazards is essential for improving resilience of coastal communities. Effective management of coastal hazards relies on prediction tools and mitigation structures that have been designed to handle the dynamic coastal system. This dissertation is a collection of manuscripts that cover a diverse range of fundamental...
The bacteria Myxococcus xanthus clusters into fruiting bodies in the absence of food. The movement of M. xanthus has three aspects: self-propulsion (run), change of direction due to collision (tumble), and Brownian fluctuations in movement. We propose a minimalist PDE model for the concentrations of left and right moving agents...
This paper describes the analysis of data from a three-year gross time study of skyline, balloon, and helicopter yarding systems operating in Western Oregon. Data collection activities were designed and supervised by the Pacific Northwest Forest and Range Experiment Station, U.S.D.A. Forest Service. The specific logging systems studied were running...
A computer program package to estimate cable yarding
payload capability was made. The package was intended to
expand applicability of existing packages and to be user
friendly. It has six system options: live skyline, standing
skyline, running skyline, slackline, multispan and highlead.
In the standing skyline and multispan analyses, load...
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...
Large woody debris recruitment to streams from adjacent riparian forests influences stream
channel morphology, sediment routing, and fish habitat. A mathematical model was developed
to 1) determine whether the trees in a stand adjacent to a stream, upon falling, would provide
large woody debris of a specified size to the...
There is much interest in the State of Vermont in cable harvesting. Since there are no time studies available for cable harvesting with various machines in Vermont, it is necessary to arrive at production and cost levels by a different method.
The method chosen for this paper is made up...
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...
The objective of this paper is to develop a methodology for determining running skyline yarder performance based on the mechanical characteristics of the yarder and its interaction with the load and the terrain. A code for implementing this procedure on the HP-9020 will be prepared .
This paper discusses the development of a computer simulation program for the operation of a log landing for the proposed Helistat airship. The first part of the paper describes the time study used to develop production rates for the chasers, buckers, front-end loaders, and skidders to be used on the...
An analysis of forces on two tree intermediate supports is presented. The analysis is in two parts:
The maximum force that the support jack will experience. The movement and forces created in the two tree support by the skyline and carriage. The maximum force on the support jack occurs when...
Potentially large savings can be realized within the forest industry by improved machine scheduling, labour scheduling, machine investment, inventory management, and the maximization of wood value. Forecasting must change within the forest industry from Ttguesstimatesll to more efficient production forecasting models. Much work needs to be done with data collection...
This paper describes the analysis of data from a three-year gross time study of skyline, balloon, and helicopter yarding systems operating in Western Oregon. Data collection activities were designed and supervised by the Pacific Northwest Forest and Range Experiment Station, U.S.D.A. Forest Service. The specific logging systems studied were running...
A semi-empirical mobility model is presented which predicts tracked vehicle performance in timber harvesting applications. The interactions between the log load and the
terrain, the log load and the vehicle, and the vehicle and the terrain cause resistances for the vehicle. The mobility
model calculates these resistances, comparing them to...
LOCCOST is an interactive computer program that
predicts stump to mill logging costs, stumpage and net
present value of a harvest based on stand data, pond value
and logging parameters, entered by the user. The program is
intended for use by foresters to evaluate the economics of
different stand management...
The principles of mobility are applied to the forest setting to
simulate the movement of logs with a rubber tired-skidder. A computer
program was written to perform the analysis . Vehicle-terrain and logterrain
interactions are the resistances which must be overcome by
the available vehicle power. The rate at which...