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181 points EndXA | 1 comments | | HN request time: 0s | source
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PinguTS ◴[] No.40728639[source]
I know, this is an old paper, but I don't follow the this assumption:

> The terms jerk and snap mean very little to most people, including physicists and engineers.

Almost 20 years ago we defined jerk into our standards for lift applications. I know jerk is an important parameter for any modern rotating machine that includes gears.

While in lift applications it is known as the roller coaster effect, people in different parts of the world have a different taste on when they want to use a lift. I know I over simplify when I say, that American people want to have the gut feeling when riding a lift, especially an express lift in those high buildings. In difference in Asian countries the lift ride must be smooth as possible. They don't like to have the feeling of riding a lift at all. In Europe it is something in between. Lift manufacturers have to respect those (end) costumers otherwise the are not chosen.

The same in any rotating machine with some sort of gears. Because jerk and those higher orders contribute to the wear and tear of gears. As you want to have longer lasting gears many modern machine manufacturers limit those parameters to reduce wear and tear. So, with a little software change I can demand a higher price because service and maintenance can be reduced.

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account42 ◴[] No.40728717[source]
> American people want to have the gut feeling when riding a lift, especially an express lift in those high buildings. In difference in Asian countries the lift ride must be smooth as possible. They don't like to have the feeling of riding a lift at all. In Europe it is something in between

How representative are these stated preferences actually of the population. I'd imagine that the individual preferences vary greatly from person to person and also change with age.

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matsemann ◴[] No.40729400[source]
It might not be a strict "preference", more of an expectation how things should be based on previous experience. Like, if you're used to an elevator with a bit of a jerk, an elevator taking you there just as fast but smoother might feel not as fast.
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fbdab103 ◴[] No.40729930[source]
Yet it is a captive market. If I am in a building, I only have access to a singular type of elevator. Why not always give the smoothest ride possible unless it is $0.12 cheaper for the installer, so everyone has to suffer forever.
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1. failbuffer ◴[] No.40732920[source]
You could just as well ask "why not give the fastest ride possible so everyone saves time?"