DOUBLE MEANING

To the Editor: I read the “Mechatronics Clarifications” letter in the October issue, as well as the article “Who Owns Mechatronics” in the June issue, with some interest. After reading, I can feel that the confusion is largely caused by the phenomenon of the same word having two different meanings. In the case of “mechatronics,” the invention of this word is a combination of “mechanism” and “electronics,” while the word was interpreted by the editorial of IEEE/ASME Transactions on Mechatronics in 1996 as a combination of “mechanics” and “electronics.”

As explained by the author of the letter, the first meaning of “mechatronics” when this word was invented was not a combination of two disciplines. Instead, a mechanism is a system. According to the standard terminology of the International Federation for the Promotion of Mechanism and Machine Science, a “mechanism” is a “system of bodies designed to convert motions of, and forces on, one or several bodies into constrained motions of, and forces on, other bodies.” Whereas quite clearly, the interpretation of mechatronics in 1996 is that mechatronics is a combination of two disciplines or two primary disciplines—i.e., mechanics and electronics.

Thus, to this reader, the word “mechatronics” should obviously be credited to Tetsuro Mori, but not for the meaning as we know it today—i.e., mechatronics as an interdiscipline with two primary founding disciplines—that is, mechanics and electronics. I believe that this interpretation must have been in the academic world before 1996. When this reader was on the faculty of the Department of Manufacturing Engineering at City University of Hong Kong in 1994, the department already had a mechatronics specialization that was developed before 1994 (perhaps in 1990) with the understanding that mechatronics is an interdiscipline.

In conclusion, who owns the interpretation of mechatronics as an interdiscipline, especially a combination of mechanics and electronics, is indeed unknown; yet it is fortunate that today there is a consensus that mechatronics is an interdiscipline.

W.J. ZHANG, P.E.
SASKATOON, SASK.

SPACE ALLOCATION

To the Editor: Regarding Mechanical Engineering December 2008:

“Tech Focus” (page 21, column 1, paragraph 4) “...heating up to 50°C for only...” and “Tar on Tap” (page 31, paragraph 7) “...and heated to 80°C...” should read “50 °C” and “80 °C” with a space between the amount and the unit (see IEEE/ASTM SI 10-2002 Section 3.5.1.d, “... a space shall be left between...”).

Also with “Tar on Tap” page 33 column 1 paragraph 6 “...to reach about 450°F...”. “Tar on Tap” was written with metric dominance. Degrees Celsius should have been at least included in this line.

Thank you for your time and attention.

MATTHEW ZOTTER, P.E.
BROOMFIELD, COLO.

SAFE MASS

To the Editor: A degree in engineering is not required to understand the concept that vehicle mass = vehicle safety (Editorial, February). The relationship is well documented in texts and papers on traffic safety. Would you prefer your wife and kids to be in a Prius or a Suburban when the inattentive driver of a loaded eighteen-wheel truck plows into the rear of their vehicle at a relative speed of 25 mph? Americans are not misguided in their predisposition to buy and operate the safest cars that their budgets will allow.

Let’s say that ASME’s encouragement of the Obama administration results in expedited implementation of CAFÉ mandates on U.S. automobile manufacturers. The outcome of cutting off the supply of the large, heavy, and affordable vehicles that Americans desire will be a marked increase in roadway fatalities. Is ASME ready to shoulder its share of the responsibility for this increase in the number of highway deaths?

If our government reduced the risk of high-speed accidents between passenger vehicles and heavy commercial trucks and buses on U.S. highways by building separate roads for the commercial traffic, I would consider trading in my GMC Yukon for something smaller and more fuel efficient. I am not pleased by ASME’s position that my personal safety while traveling by car is less important than saving energy.

G. FRED LIEBKEMANN IV, P.E.
SLIDELL, LA.

HIGH-PRICED ALTERNATIVE

To the Editor: If President Obama and the Energy Department statisticians were metric, perhaps he and his advisors would have been able to make sense of the energy data in the U.S., and, using simple math, avoid falling into a trap.

I like Mr. Obama, but I have doubts about his presidency when I hear him saying: We will “double the amount of energy that comes from renewable sources by the end of my first term.” He should know that that’s not possible. But instead, during his State of the Union speech, he proclaimed that we’ll reach that goal in three years, not four.

Presented with the government’s numbers in unified units, he would realize that the majority of the renewable power in the U.S. comes from hydro and from biological sources. Trying to increase those yields we would have to ask: Where shall we find the extra rivers to dam? And where do we look for the extra land to double the wood and corn production?

Understanding those limitations, Mr. Obama apparently relies on direct solar, wind, and geothermal energy growth. All three sources are presently producing less than 1 percent of national capacity. To reach the stated goal, we would have to build nine times more windmills, solar plants, and geothermal stations than we installed in the previous decades, and do it in three years.

While the cost would be prohibitive, is the deadline at all realistic under any cost?

Jimmy Carter committed the U.S. to derive 20 percent of its energy from renewable sources by the year 2000. In 1978, Ralph Nader said, “Everything will be solar in 30 years.” The 30 years just passed.

Three, even four years is too short a time to forget about a commitment. Obama’s retreating from his goal now, before funds for this extraordinary spending are cast into the concrete foundations of windmills, would seem a prudent, presidential gesture.

STAN JAKUBA
WEST HARTFORD, CONN.

MATH AND MECHANICS

To the Editor: I am amazed that anyone would presume to cite the “research” (“Signs of Future Engineers,” News & Notes, December) that finds high scores in math at school an indicator of future success as a scientist or engineer. What it shows is that people who like doing math at school continue to do math in later life and tend to get into professions where writing and publishing mathematical papers is the sign of achievement.

One of the problems in engineering today is the tendency in both schools and colleges to identify students suitable for a career in engineering on the basis of their skills in math and physics, whilst showing unconcealed contempt for either recognizing or—perish the thought—encouraging the one skill that engineering is all about: making things.

In my experience on the faculty of a Big Ten school, I found the most promising students were the farm boys, people who knew before they came to college how many sides there are on a hex nut. It is always easier to teach math to someone with a mechanical aptitude than to teach mechanical aptitude to a mathematician. And having done work associated with the nuclear industry for several decades, I say, Lord preserve us from physicists doing engineering design.

DOUGLAS L. MARRIOTT
SOUTH LEBANON, OHIO