Thesis (M.S. in Forestry)--University of California, Berkeley, May 1924. / Includes bibliographical references (leaves lviii).

Thesis (M.S.)--University of Wisconsin--Madison. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 146-156).

Thesis (M.S.)--Oregon State University, 1997. / Typescript (photocopy). Includes bibliographical references (leaves 38-44). Also available online.

Two theoretical formulations of logging cable system problems, the catenary model and the parabolic model are investigated and compared with the results of experiments executed on a gravity system field model. The study shows that although the shape of a free hanging cable is better described as a catenary than a parabola, both theoretical models are accurate enough to solve practical cable system problems. The few dynamic tests tried on the field model show the great importance of the dynamic forces in a logging cable system and the need for further research in this field. / Forestry, Faculty of / Graduate

Thesis (Ph. D.)--University of Idaho, 2005. / Also available online in PDF format Abstract. "May 2005." Includes bibliographical references (leaves 71-79).

The vast timber resource of the Pacific Northwest has been dwindling rapidly particularly in those areas of good accessibility close to the markets. This, together with the increased demand of a buoyant market and a rapidly expanding forest products industry,has made it necessary to recover the greatest possible amount of timber from the accessible forest acreages, and to utilize those areas previously considered inaccessible or uneconomic. In order to accomplish this, the logging industry has changed from its former role as exploiter of a large natural resource and is approaching its future role of forest manager, in which it will stress conservation and increased utilization of the available timber previously considered unmarketable. During the last decade logging operators have had to modify the traditional logging methods designed to cope with large volumes on accessible timber tracts. This has been achieved by increasing the mobility of operations, in order to cope with scattered stands of lower timber volume growing on land that is more difficult to log. Also by introducing a variety of methods for handling smaller logs, a greater wood volume per acre is being recovered. This thesis is a discussion of the planning of a modern mobile logging operation in order to take the maximum advantage of the new machines and methods of logging that have been developed. A comparison is made of the advantages and limitations of the machinery introduced recently to logging operations in order to outline the methods of operation whereby these machines may be used most effectively. The method of planning a layout is considered so that logging engineering, economics, and silvicultural considerations may be balanced in order to get the most effective utilization of the present forest crop, and to provide for the rapid regeneration and protection of the future crop. / Forestry, Faculty of / Graduate

the last few years the sawmilling industry has faced the economic pressure of increasing raw material costs, increasing conversion costs and limited product value due to competition from other products, one result of this pressure has been the development of process control systems which automate many of the cutting decisions required to convert tree-length logs into marketable products. Regardless of whether saws are positioned automatically or manually, a set of cutting instructions is essential. These instructions should, for the available log supply, provide the most economical yield consistent with market demands and mill constraints. Two critical decisions are made in converting logs into lumber. The bucking decision constrains the lumber length and hence may limit the value of the lumber. The sawing decision determines the lumber products which can be sawn from the resulting short logs. The two decisions cannot be analyzed in isolation. In order to determine the bucking strategy which yields the mix of short logs which will produce the maximum lumber value it is necessary to know the sawing pattern which will be used to convert the logs into lumber. Similarly, given a limited log supply of fixed characteristics, limited sawmill capacity and restrictions on market demand for lumber products, the optimum sawing strategy cannot be determined without information on the population of short logs which will develop from the bucking decision. Formulating the problem of determing optimum bucking-saving decisions for a limited log supply and limited sawmill capacity as a linear programming model is attractive but the large number of alternative cutting decisions make such a formulation intractable. The problem of deterring optimal bucking and saving strategies for a single log can be modelled as a dynamic programming recursion. However, the dynamic programming approach cannot efficiently handle the large number of constraints inherent in formulating an optimum bucking-sawing strateqy for a given population of tree-length logs. It was shown that the linear and dynamic programming models could be combined using Dantzig-wolfe decomposition. The linear model determines the combination of cutting strategies which optimize an objective function subject to constraints. The dynamic programming model supplies the linear model with new activities as required. The decomposition approach is attractive because it avoids the necessity of working with all possible activities in the linear programme. The L.P. calculates with the basis inverse and the dynamic programming sub-problem generates new bucking-sawing activities as required by the L. P. The efficiency of the technique was demonstrated by determing optimal bucking and sawing strategies for a population of 967 long logs. / Forestry, Faculty of / Graduate

Thesis (M.S.)--Oregon State University, 1967. / Typescript (photocopy). Includes bibliographical references (p. 49-53). Also available on the World Wide Web.

No description available.

Thesis (M.S. - Watershed Management)--University of Arizona. / Includes bibliographical references.