This study was conducted to examine the coefficient of drag resistance (µ) between a log and bare forest soil during partial
suspension yarding. Drag resistance in this study was defined as the resistance due to friction between the soil and the log plus the resistance due to the plowing action...
This study compares the production rates and yarding costs of prebunching
with a low investment skyline yarder and swinging with a larger
skyline yarder to full-cycle thinning with the larger yarder The study
analyzes two slackpulling techniques (manual and haulback assisted) and
two carriages (a multi-span carriage and a clamping...
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
and environmental...
Cable logging systems are being applied frequently in thinning young-growth forests, but the dynamics of these systems are relatively unknown. This study is part of a research project to develop aerial logging systems for thinning and to analyze them for economic, silvicultural, and environmental implications. The objectives of my study...
Intensive forest management requires efficient logging techniques
to remain economical. Commercial thinnings and shorter
rotations increase piece count inversely to piece size. Continued
research aimed toward effective log handling processes is essential.
The purpose of this study was to evaluate one case of a self-loading
log truck (integral loader and...
The necessity for the evaluation of training methods on a between
methods basis is suggested. Current methods of training evaluations
are considered, and found to be generally deficient for their
lack of between technique comparisons. The necessity for an outline
of planned comparative analysis of training methods is indicated and...
A computer simulation was developed as a technique for
studying the effects of the process dynamics on the operator's
sampling and control behavior. This methodology was
used to study the effects of the process input memory
variation in the presence of different observation noise
levels. It was concluded that the...
With increasing frequency man is required to operate as a
controller of complex processes. Although his ability to operate
quickly varying processes has been extensively studied, his ability
to control slowly varying processes has been largely neglected.
Often his performance in such tasks is dependent upon his ability
to forecast...
There are a nearly unlimited number of situations in which the
status of time-varying processes must be updated. The monitoring of
these processes usually occurs at periodic intervals. Whether the
monitoring is performed by man or machine, a decision must be made
regarding the frequency of these activities, that is,...
It is a widely accepted premise of industrial management that an
interruption in the performance of a task will be accompanied by a
decrease in operator skill level upon resuming performance of the
task. Moreover, it has been generally assumed that this loss of
skill is related to several factors...
Productivity gains in the manufacturing sector have generally been
credited to investments in production facilities that supplemented or
replaced manual labor. Insertion of circuit boards is a key activity in
the electronics industry. Improvements in productivity of circuit board
manufacture may be achieved by replacing manual component insertion with
automatic...
A simulation study of end-of-aisle order picking AS/R systems
is made with special emphasis on improving the system throughput by
introducing a zone near the home (Input/Output) location on each side
of the aisle, for storing partially picked pallets. The study considered
class-based-turnover assignment policies, one with a zone and...
A heuristic is developed to plan loads for containerized cargo ships. It is designed to serve a port which uses gantry cranes (transtainers) and trucks to handle containers. The model recognizes constraints on ship stability, placing containers in a bay with the proper length, placing refrigerated cargo near electrical outlets,...
A dynamic approach to the Bayesian theory of sampling inspection
by attributes for the single sampling case is presented. A model is
developed which assumes a sequence of lots of equal known size and
lots generated by a process operating in a random manner. The model
also assumes constant associated...
ANSI/ASQC Z1.4 is a widely used attributes
acceptance sampling system. A necessary aspect of a
scheme, from both a theoretical and psychological
viewpoint, is the switching between normal, tightened,
and reduced inspection as a function of quality
history. In the latest revision of the standard the
switching rules were altered...
This paper addresses the order-picking problem in a warehouse
and establishes some criteria for the planning, design, and improvement
of a warehouse layout to increase the order-picking efficiency.
A simulation model has been developed to study the effect of
warehouse layout on the order-picking throughput. Three major design
elements of...
The principal objective of this study was to compare the results of a proposed method based upon the response surface model to the Taguchi method. To modify the
Taguchi method, the proposed model was developed to encompass the following
objectives. The first, with the exception of the Taguchi inner array,...
The goal of this study is to test the accuracy of
various mutual fund timing and selectivity models under a
range of portfolio managerial skills and varying market
conditions. Portfolio returns in a variety of skill
environments are generated using a simulation procedure. The
generated portfolio returns are based on...