and boasting of a glorious past ie adopting the same old techniques 32

And boasting of a glorious past ie adopting the same

This preview shows page 36 - 38 out of 123 pages.

and boasting of a ―glorious past (i.e. adopting the same old techniques). 3.2 Technological Forecasting Methods The major techniques for technological forecasting may be categorized under two general headings: methods based on numeric data and judgmental methods. In the main, numeric data-based forecasting extrapolates history by generating statistical fits to historical data. A few numeric methods deal with complex interdependencies. Judgmental forecasting may also be based on projections of the past, but information sources in such models rely on the subjective judgments of experts. Again, we emphasize that technological forecasting is most appropriately applied to capabilities, not to the specific characteristics of specific devices. Numeric Data-Based Technological Forecasting Techniques: Trend Extrapolation To extrapolate is to infer the future from the past. If there has been a steady stream of technological change and improvement, it is reasonable to assume that the stream will continue to now. We can distinguish four approaches to the use of trend extrapolation. Statistical Curve Fitting This method is applicable to forecasting functional capabilities. Statistical procedures fit the past data to one or more mathematical functions such as linear, logarithmic, Fourier, or exponential. The best ht is selected by statistical test and then a forecast is extrapolated from this mathematical relationship. For example, we can forecast the fastest qualification (pole position) speeds at the Indianapolis 500 Mile Race by plotting pole position speeds against time measured in years. Beginning with the post-World War I races, the pole position speeds of Indy race cars have exponentially increased, Two technological
Image of page 36
innovations are quite easily seen in the data. One is the rear-engine car. The first such car appeared in 1961. Qualifying speeds were about 150 mph. In 1964 a rear-engine car won the pole position at slightly less than 159 mph. The growth rate of qualifying speed is significantly higher with the rear-engine technology, so different exponential functions were fitted to front- and rear-engined cars. The second easily discernible technological innovation occurred in the early 1970s. It was the use of sophisticated aerodynamic devices (wings at the rear of the car) to create down force on the cars, allowing them much higher cornering speeds-from 170 mph in 1970, to 179 mph in 1971, to 196 mph in 1973 (with the addition of wings at the front of the car). Limit Analysis Ultimately, all growth is limited, and there is an absolute limit to progress, either recognized or unrecognized. Sooner or later, projections must reflect the fact that improvements may get close to this limit but cannot exceed it. For instance, a trend of increasing energy conversion efficiency cannot eventually exceed 100%. The trend of lower and lower temperatures is limited, of course, by absolute zero. (It is interesting to note the rapid improvement in the ability to produce low temperatures that occurred around 1900)
Image of page 37
Image of page 38

You've reached the end of your free preview.

Want to read all 123 pages?

  • Winter '20
  • Process Technology and Product Technology

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture