Learning plateau

Figure 3.4 presents a fast learner who achieves the final performance level earlier than on average (dotted, highest curve), a so-called slow starter who needs more time and who shows an intermediate learning plateau (continuous, middle curve), and a learner who never achieves the required level and probably fails (striped, lowest curve). Ideally, the assessment system should optimally reflect the kind of learning curves depicted here, but our assessment system cannot produce these learning curves in the same way. 

The dotted, highest learning curve represents a trainee who constantly performs above standards, the eontinuous middle curve reflects a trainee with a temporary learning plateau around tl and t2 ( slow started ), and the striped lowest curve refers to a trainee who eonstantly performs below standard and fails. Straight lines coimect the points of measurement to obtain a certain learning curve, but these lines do not necessarily represent the real learning processes in-between. In Figure 3.6 the three trainees are assessed at the same four moments to illustrate possible variations, but in reality trainees are not assessed simultaneously and the intervals differ. 

Plateau slope is usually a function of metallurgical segregation that sometimes occurs during the production of a hydriding alloy(2, 3, 4). in some applications a sloped plateau is desired, but in most cases a reasonably flat plateau is preferred. We have learned to vary (or largely eliminate, if desired) the plateau slope by heat treatment techniques ( 2,4 ). ... 

Having described the structural elements of foams approaching the dry-foam limit (O —> 1), it is still a daunting task to describe the structure and properties of the system as a whole. The task is even more difficult for systems in which O Q is exceeded, but the polyhedral regime has not yet been reached. In this case, the drops have exceedingly complex shapes, and linear and tetrahedral Plateau borders, as defined above, are not present. Much can be learned about the qualitative behavior by considering 2-D model systems, in which the drops do not start out as spheres but as parallel circular cylinders, and tetrahedral Plateau borders do not arise. We shall first consider the particularly simple monodisperse case, with a subsequent gradual increase in complexity. 

Former residents of McMurdo Station will also recall the windstorms that suddenly reduce visibility to less than 100 ft (30.48 m), with wind speeds in excess of 55 knots (101.9 km/h), and wind-chill temperatures that drop below -100°F (-73.3°C). Under these conditions, all personnel in McMurdo are required to remain in-doors (Condition 1) and all travel is suspended for the duration of the storm that may last several days. The classification of weather conditions detailed in Table 2.3 is the responsibility of the McMurdo Weather Office (Mac Weather). Condition 1 storms can occur anywhere within the Transantarctic Mountains during the austral spring and fall especially on major outlet glaciers, such as the Reedy Glacier in Fig. 2.11, that channel the katabatic winds from the polar plateau to the Ross Ice Shelf or to the Ross Sea. Field parties that experience such storms learn first-hand that weather still rules in Antarctica. 

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