Tag Archives: IEEE Spectrum

News Clips

Do Romantic Thoughts Reduce Women’s Interest in Engineering?

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If romance reduce girls’ pursuit in engineering, probably the reverse is also true that girls choose engineering have less interest in romance as well. They should do a follow up research and survey a large sample of engineering girls, see how many of them had a boyfriend in high school.

Now, someone should come up with a research showing male engineers are not romantic, so Pat cannot complain I am not romantic.

BY Steven Cherry, IEEE Spectrum, Fri, August 26, 2011
A new study suggests thoughts of romance can reduce college women’s interest in science and engineering

In the 1960s, when women first began enrolling at universities in record numbers, many people wondered: “Why weren’t more of them studying engineering?” Fifty years later, we’re still wondering. Only one in seven U.S. engineers is a woman. The so-called “engineering gender gap” is still a chasm.

And that’s not likely to change very quickly. The average college graduate nowadays is a woman—57 percent to 43—but when it comes to the so-called STEM fields, that’s science, technology, engineering, and math, women account for only 35 percent. And most of those are for life and physical sciences, not engineering or computer science.

It’s a problem perhaps best examined by psychologists, and examining it they are. And a new series of studies argues that—as clichéd as it sounds—maybe love really does have something to do with it.

An article based on the studies, will be published next month in the peer-reviewed journal, Personality and Social Psychology Bulletin.

My guest today is the paper’s lead author. Lora Park is an assistant professor of psychology at the University of Buffalo, in New York, and principal investigator at the Self and Motivation Lab there. She joins us by phone.A new study suggests thoughts of romance can reduce college women’s interest in science and engineering

Effects of Everyday Romantic Goal Pursuit on Women’s Attitudes Toward Math and Science

Abstract:
The present research examined the impact of everyday romantic goal strivings on women’s attitudes toward science, technology,engineering, and math (STEM). It was hypothesized that women may distance themselves from STEM when the goal to be romantically desirable is activated because pursuing intelligence goals in masculine domains (i.e., STEM) conflicts with pursuing romantic goals associated with traditional romantic scripts and gender norms. Consistent with hypotheses, women, but not men, who viewed images (Study 1) or overheard conversations (Studies 2a-2b) related to romantic goals reported less positive attitudes toward STEM and less preference for majoring in math/science compared to other disciplines. On days when women pursued romantic goals, the more romantic activities they engaged in and the more desirable they felt, but the fewer math activities they engaged in. Furthermore, women’s previous day romantic goal strivings predicted feeling more desirable but being less invested in math on the following day (Study 3).

Link to the paper: http://www.buffalo.edu/news/pdf/August11/ParkRomanticAttitudes.pdf

Daily Scribble

When the Problem Is the Problem

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This is the only thing I learned from my master degree. Asking the right question is half way done to get the right answer. In fact asking the right question probably more important than getting the right answer. Once you stated the question correctly, things magically fall into place and you can outsource the work to someone else.

Finding the right problem is half the solution
By Robert W. Lucky, July 2011, IEEE Spectrum

A problem well stated is a problem half solved.
– Inventor Charles Franklin Kettering (1876–1958)

We’re all fairly good at problem solving. That’s the skill we were taught and endlessly drilled on at school. Once we have a problem, we know how to turn the crank and get a solution. Ah, but finding a problem—there’s the rub.

Everyone knows that finding a good problem is the key to research, yet no one teaches us how to do that. Engineering education is based on the presumption that there exists a predefined problem worthy of a solution. If only it were so!

After many years of managing research, I’m still not sure how to find good problems. Often I discovered that good problems were obvious only in retrospect, and even then I was sometimes proved wrong years later. Nonetheless, I did observe that there were some people who regularly found good problems, while others never seemed to be working along fruitful paths. So there must be something to be said about ways to go about this.

Internet pioneer Craig Partridge recently sent around a list of open research problems in communications and networking, as well as a set of criteria for what constitutes a good problem. He offers some sensible guidelines for choosing research problems, such as having a reasonable expectation of results, believing that someone will care about your results and that others will be able to build upon them, and ensuring that the problem is indeed open and underexplored.

All of this is easier said than done, however. Given any prospective problem, a search may reveal a plethora of previous work, but much of it will be hard to retrieve. On the other hand, if there is little or no previous work, maybe there’s a reason no one is interested in this problem. You need something in between. Moreover, even in defining the problem you need to see a way in, the germ of some solution, and a possible escape path to a lesser result, like the runaway truck ramps on steep downhill highways.

Timing is critical. If a good problem area is opened up, everyone rushes in, and soon there are diminishing returns. On unimportant problems, this same herd behavior leads to a self-approving circle of papers on a subject of little practical significance. Real progress usually comes from a succession of incremental and progressive results, as opposed to those that feature only variations on a problem’s theme.

At Bell Labs, the mathematician Richard Hamming used to divide his fellow researchers into two groups: those who worked behind closed doors and those whose doors were always open. The closed-door people were more focused and worked harder to produce good immediate results, but they failed in the long term.

Today I think we can take the open or closed door as a metaphor for researchers who are actively connected and those who are not. And just as there may be a right amount of networking, there may also be a right amount of reading, as opposed to writing. Hamming observed that some people spent all their time in the library but never produced any original results, while others wrote furiously but were relatively ignorant of the relevant literature.

Hamming, who shared an office with Claude Shannon and knew many famous scientists and engineers, also remarked on what he saw as a “Nobel Prize effect,” where once having achieved a famous result, a researcher felt that he or she could work only on great problems, consequently never doing great work again. From small-problem acorns, great trees of research grow.

Like a lot of things in life, it helps to be in the right place at the right time. Sometimes all the good and well-intentioned advice in the world won’t help you avoid working on a dead-end problem. I know—I’ve been there, done that

News Clips

Are Compact Fluorescent Lightbulbs Really Cheaper Over Time?

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I hate the lighting produced by CFL bulbs. I am going to switch from incandescent bulb to LED lights directly when the price of LED lights comes down. CFL is a in-between gaping technically that eventually should be phased out.

By Joseph Calamia, March 2011, IEEE Spectrum
CFLs must last long enough for their energy efficiency to make up for their higher cost

You buy a compact fluorescent lamp. The packaging says it will last for 6000 hours—about five years, if used for three hours a day. A year later, it burns out.

Last year, IEEE Spectrum reported that some Europeans opposed legislation to phase out incandescent lighting. Rather than replace their lights with compact fluorescents, consumers started hoarding traditional bulbs.

From the comments on that article, it seems that some IEEE Spectrum readers aren’t completely sold on CFLs either. We received questions about why the lights don’t always meet their long-lifetime claims, what can cause them to fail, and ultimately, how dead bulbs affect the advertised savings of switching from incandescent.

Tests of compact fluorescent lamps’ lifetime vary among countries. The majority of CFLs sold in the United States adhere to the U.S. Department of Energy and Environmental Protection Agency’s Energy Star approval program, according to the U.S. National Electrical Manufacturers Association. For these bulbs, IEEE Spectrum found some answers.

How is a compact fluorescent lamp’s lifetime calculated in the first place?

“With any given lamp that rolls off a production line, whatever the technology, they’re not all going to have the same exact lifetime,” says Alex Baker, lighting program manager for the Energy Star program. In an initial test to determine an average lifetime, he says, manufacturers leave a large sample of lamps lit. The defined average “rated life” is the time it takes for half of the lamps to go out. Baker says that this average life definition is an old lighting industry standard that applies to incandescent and compact fluorescent lamps alike.

In reality, the odds may actually be somewhat greater than 50 percent that your 6000-hour-rated bulb will still be burning bright at 6000 hours. “Currently, qualified CFLs in the market may have longer lifetimes than manufacturers are claiming,” says Jen Stutsman, of the Department of Energy’s public affairs office. “More often than not, more than 50 percent of the lamps of a sample set are burning during the final hour of the manufacturer’s chosen rated lifetime,” she says, noting that manufacturers often opt to end lifetime evaluations prematurely, to save on testing costs.

Although manufacturers usually conduct this initial rated life test in-house, the Energy Star program requires other lifetime evaluations conducted by accredited third-party laboratories. Jeremy Snyder directed one of those testing facilities, the Program for the Evaluation and Analysis of Residential Lighting (PEARL) in Troy, N.Y., which evaluated Energy Star–qualified bulbs until late 2010, when the Energy Star program started conducting these tests itself. Snyder works at the Rensselaer Polytechnic Institute’s Lighting Research Center, which conducts a variety of tests on lighting products, including CFLs and LEDs. Some Energy Star lifetime tests, he says, require 10 sample lamps for each product—five pointing toward the ceiling and five toward the floor. One “interim life test” entails leaving the lamps lit for 40 percent of their rated life. Three strikes, or burnt-out lamps, and the product risks losing its qualification.

Besides waiting for bulbs to burn out, testers also measure the light output of lamps over time, to ensure that the CFLs do not appreciably dim with use. Using a hollow “integrating sphere,” which has a white interior to reflect light in all directions, Lighting Research Center staff can take precise measurements of a lamp’s total light output in lumens. The Energy Star program requires that 10 tested lights maintain an average of 90 percent of their initial lumen output for 1000 hours of life, and 80 percent of their initial lumen output at 40 percent of their rated life.

Is there any way to accelerate these lifetime tests?

“There are techniques for accelerated testing of incandescent lamps, but there’s no accepted accelerated testing for other types,” says Michael L. Grather, the primary lighting performance engineer at Luminaire Testing Laboratory and Underwriters’ Laboratories in Allentown, Penn For incandescent bulbs, one common method is to run more electric current through the filament than the lamp might experience in normal use. But Grather says a similar test for CFLs wouldn’t give consumers an accurate prediction of the bulb’s life: “You’re not fairly indicating what’s going to happen as a function of time. You’re just stressing different components—the electronics but not the entire lamp.”

Perhaps the closest such evaluation for CFLs is the Energy Star “rapid cycle test.” For this evaluation, testers divide the total rated life of the lamp, measured in hours, by two and switch the compact fluorescent on for five minutes and off for five minutes that number of times. For example, a CFL with a 6000-hour rated life must undergo 3000 such rapid cycles. At least five out of a sample of six lamps must survive for the product to keep its Energy Star approval.

In real scenarios, what causes CFLs to fall short of their rated life?

As anyone who frequently replaces CFLs in closets or hallways has likely discovered, rapid cycling can prematurely kill a CFL. Repeatedly starting the lamp shortens its life, Snyder explains, because high voltage at start-up sends the lamp’s mercury ions hurtling toward the starting electrode, which can destroy the electrode’s coating over time. Snyder suggests consumers keep this in mind when deciding where to use a compact fluorescent. The Lighting Research Center has published a worksheet [PDF] for consumers to better understand how frequent switching reduces a lamp’s lifetime. The sheet provides a series of multipliers so that consumers can better predict a bulb’s longevity. The multipliers range from 1.5 (for bulbs left on for at least 12 hours) to 0.4 (for bulbs turned off after 15 minutes). Despite any lifetime reduction, Snyder says consumers should still turn off lights not needed for more than a few minutes.

Another CFL slayer is temperature. “Incandescents thrive on heat,” Baker says. “The hotter they get, the more light you get out of them. But a CFL is very temperature sensitive.” He notes that “recessed cans”—insulated lighting fixtures—prove a particularly nasty compact fluorescent death trap, especially when attached to dimmers, which can also shorten the electronic ballast’s life. He says consumers often install CFLs meant for table or floor lamps inside these fixtures, instead of lamps specially designed for higher temperatures, as indicated on their packages. Among other things, these high temperatures can destroy the lamps’ electrolytic capacitors—the main reason, he says, that CFLs fail when overheated.

How do shorter-than-expected lifetimes affect the payback equation?

Actually predicting the savings of switching from an incandescent must account for both the cost of the lamp and its energy savings over time. Although the initial price of a compact fluorescent (which can range [PDF] from US $0.50 in a multipack to over $9) is usually more than that of an incandescent (usually less than a U.S. dollar), a CFL can use a fraction of the energy an incandescent requires. Over its lifetime, the compact fluorescent should make up for its higher initial cost in savings—if it lives long enough. It should also offset the estimated 4 milligrams of mercury it contains. You might think of mercury vapor as the CFL’s equivalent of an incandescent’s filament. The electrodes in the CFL excite this vapor, which in turn radiates and excites the lamp’s phosphor coating, giving off light. Given that coal-burning power plants also release mercury into the air, an amount that the Energy Star program estimates at around 0.012 milligrams per kilowatt-hour, if the CFL can save enough energy it should offset this environmental cost, too.

Exactly how long a CFL must live to make up for its higher costs depends on the price of the lamp, the price of electric power, and how much energy the compact fluorescent requires to produce the same amount of light as its incandescent counterpart. Many manufacturers claim that consumers can take an incandescent wattage and divide it by four, and sometimes five, to find an equivalent CFL in terms of light output, says Russ Leslie, associate director at the Lighting Research Center. But he believes that’s “a little bit too greedy.” Instead, he recommends dividing by three. “You’ll still save a lot of energy, but you’re more likely to be happy with the light output,” he says.

To estimate your particular savings, the Energy Star program has published a spreadsheet where you can enter the price you’re paying for electricity, the average number of hours your household uses the lamp each day, the price you paid for the bulb, and its wattage. The sheet also includes the assumptions used to calculate the comparison between compact fluorescent and incandescent bulbs. Playing with the default assumptions given in the sheet, we reduced the CFL’s lifetime by 60 percent to account for frequent switching, doubled the initial price to make up for dead bulbs, deleted the assumed labor costs for changing bulbs, and increased the CFL’s wattage to give us a bit more light. The compact fluorescent won. We invite you to try the same, with your own lighting and energy costs, and let us know your results.