The Barycentric Coordinates Solution to the Optimal Road Junction Problem

The road junction location problems, first posited by Fermat and later generalized by Simpson, is a fundamental component of optimal network design. The barycentric resection formulas of plane surveying provide a solution of elegant simplicity to this problem. Prerequisite junction point angles for the application of the resection formulas are obtained directly from Launhardt's original analytical development of this fundamental problem in route location

Estimation of Turn Location Parameters for Cable Settings

Managers of cable yarding systems, confronted with inherently high owning and operating costs in a very competitive economic environment, need timely, inexpensive and accurate estimates of yarding production. Yarding time, and thereby production, depend on the location of the turn relative to the landing to which it must be transported. Among the important location attributes of a turn are distance and slope to the landing. For all of the turns on a setting the frequency distributions of these attributes are described by turn location parameters. Among the turn location parameters (TLPs) used by forest engineers are average yarding distance and average yarding slope. The assumptions under which a relatively new class of TLP estimators has been developed are discussed in this paper. Recognition of these assumptions and full appreciation of the limitations thereby imposed on the use of the estimators are essential to judicious application of the methodology. Formulas and procedures are given for calculation of numerical estimates and, in order to clarify and illustrate their use, an example is given

Effect of Thiamine Status on Probability of Lake Ontario Chinook Salmon Spawning in the Upper and Lower Sections of Salmon River, New York

Consumption of thiaminase-containing forage fishes reduces egg and muscle thiamine content and impairs the spawning migration of Cayuga Lake (New York) rainbow trout Oncorhynchus mykiss. Because some Chinook salmon O. tshawytscha from Lake Ontario have been shown to produce eggs low in thiamine, we examined the relationship between the migration of Chinook salmon and the thiamine content of their eggs spawned in the lower and upper sections of the Salmon River, a major tributary to Lake Ontario, in 2003–2006. Eggs from the upper section of the river were collected from 79 salmon returning to the state hatchery 25 river kilometers from the mouth. Eggs from 25 salmon in the lower section were collected from redds or females angled on redds approximately 1–3 km from the mouth. For all years combined, we found the mean thiamine concentration in eggs spawned in the lower section to be significantly lower than that for eggs spawned in the upper section; however, the annual differences in thiamine content of eggs between the upper and lower sections were significant only in 2003 and 2006. Binary logistic regression showed that the odds of spawning in the upper section was increased by 96% (95% confidence interval, 21–217%) for every nanomole of increase in the thiamine content of eggs. Therefore, the migratory achievement of Chinook salmon was significantly dependent on their thiamine status

Effect of Thiamine Status on Probability of Lake Ontario Chinook Salmon Spawning in the Upper or Lower Sections of Salmon River, New York

Consumption of thiaminase‐containing forage fishes reduces egg and muscle thiamine content and impairs the spawning migration of Cayuga Lake (New York) rainbow trout Oncorhynchus mykiss. Because some Chinook salmon O. tshawytscha from Lake Ontario have been shown to produce eggs low in thiamine, we examined the relationship between the migration of Chinook salmon and the thiamine content of their eggs spawned in the lower and upper sections of the Salmon River, a major tributary to Lake Ontario, in 2003–2006. Eggs from the upper section of the river were collected from 79 salmon returning to the state hatchery 25 river kilometers from the mouth. Eggs from 25 salmon in the lower section were collected from redds or females angled on redds approximately 1–3 km from the mouth. For all years combined, we found the mean thiamine concentration in eggs spawned in the lower section to be significantly lower than that for eggs spawned in the upper section; however, the annual differences in thiamine content of eggs between the upper and lower sections were significant only in 2003 and 2006. Binary logistic regression showed that the odds of spawning in the upper section was increased by 96% (95% confidence interval, 21–217%) for every nanomole of increase in the thiamine content of eggs. Therefore, the migratory achievement of Chinook salmon was significantly dependent on their thiamine status.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142217/1/nafm0895.pd

Road Network Design: Optimal Economic Connection of Three Horizontal control Points on Flat, Uniform Terrain

Road network design may involve selection of junction points, and a standard economic criterion can guide the initial paper location of these points. The junction point problem, in its elemental form, begins with three horizontal control points. These control points are to be linked at minimum total cost using linear road segments. Each road segment is characterized by a constant cost per unit length which may differ between segments. A mathematical optimization model has been developed for this problem. A decision algorithm for optimal network design is given and an example from the literature illustrates its application