a b s t r a c tComputerized grading of hardwood lumber according to NHLA rules would permit fast assessment of sawn lumber and the evaluation of potential edging and trimming operations to improve lumber value. More importantly, to enable optimization of the hardwood lumber sawing process, a fast means of evaluating the potential value of boards before they are sawn is necessary. As log and lumber scanning systems become prevalent and common, these needs become more pressing. From an automation perspective, the NHLA lumber grades are difficult to implement efficiently in a computer program. Exhaustive approaches that examine every potential cutting size and combination to determine the grade give accurate grading solutions, at the cost of computation time. Other approaches have examined heuristic methods that implement key parts of the grading rules, or used artificial neural network methods, both with the loss of accuracy. Here, a different approach to computerized grading is examined that takes a hybridized approach using projected yield from cut-up simulation and neural network methods. This new hybrid approach has the advantage of both accuracy and high-processing speed. Such an approach lends itself to log sawing optimization with respect to NHLA grades and market values when internal log defect information is known.Published by Elsevier B.V.

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Paste fill formulations focus on use of treated mine/mill waste materials and a variety of additives to reduce the impact/costs of surface waste disposal and improve pertinent underground mining parameters, in the main cost, reserves recovery and local and regional ground stability. Cost of such additives must be optimised. Mix and/or delivery mismanagement can result in costly pipeline and/or borehole blockages. Delays to production are the main cost impacts. Actual costs of pipeline/borehole clearance are of secondary importance. This paper first describes paste fill preparation and delivery mechanisms and then various performance failure modes including disaggregation, in-void dilution and inappropriate slurry rheology. Topics considered include fill delivery reliability, adherence to specifications, mix formulation cost effectiveness and commercially available additives.