1 Establishing a standard work sampling method for mastication ...

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delay and productive categories were further divided to assess how often the machine engages in the elements within these categories (Figure 2). Figure 2. Using Systematic Random Sampling, the masticator’s activities were divided into productive and delay categories as well as separating the research delay. Productive time was divided into its elements: traveling, masticating standing material and masticating downed material. Delay time was also divided into its elements: operational delay, personal delay and mechanical delay. This machine used an integrated (front-end attached) horizontal drum type masticator, review of existing literature shows similar percentages for similar machines but vastly different percentages for boom-mounted rotary type masticators. Bolding (2006) showed that these machine types differ significantly (p
of the mastication treatment operation (Figure 3). The cost for this machine appears to be more sensitive to changes in production rate and robust against changes in the utilization rate, especially at higher production rates. Figure 3. Effect of various production rates and utilization rates on the overall cost of the mastication treatment. The methods described should serve as a guide for land managers to approximate treatment costs. These estimates were developed from the treatment of areas that were dominated by relatively light fuel loading primarily comprised of shrub species. Extrapolating these figures to areas dominated by heavier fuel loading and different vegetation is not advisable as the variables that affect cost in those situations may be different. That said, the costs observed in this study were within the range of mastication costs ($100-1395/ac) and comparable to those found by other studies (Vitorelo 2009). The lower production rate of small machines is offset by low initial purchase price, yielding costs similar to that of the larger machines. For example, Bolding (2006) reported the cost for a similar machine type of $27.74/ton, and $24.97/ton for a boommounted machine. Conclusions This study of an integrated horizontal drum type masticator in northwestern California yielded useful results. The evaluation of the three work sampling methods established systematic random sampling as the preferred method for mastication operations analysis based on ease of implementation as the lack of difference in accuracy among the three different methods. Work sampling allows calculation of productivity rate which is crucial as productivity was shown to 9
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Page 3 and 4: Table 1. Site characteristics of ni
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Page 7: Table 3. The results for the three
Page 11 and 12: Halbrook, J., H-S. Han, R. Graham,

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