2016 ENTRANCE EXAMINATION FOR INTERNATIONAL MASTER’S PROGRAM
Departments of Mechanical Engineering and Hydrogen Energy Systems
English (Group A, B)
[14:30~15:30]
Examinee’s number
I Explain each term within 50 words. (24 Points)
1) Tensile testing
2) Face-centered cubic structure
3) Phase transformation
4) Electromagnetism
Score
2016 ENTRANCE EXAMINATION FOR INTERNATIONAL MASTER’S PROGRAM
Departments of Mechanical Engineering and Hydrogen Energy Systems
English (Group A, B)
[14:30~15:30]
Examinee’s number
Score
II Fill out each of the numbered blanks in the following passage with one suitable word. (36 Points)
Lighter cars and airplanes could be on the horizon thanks to an advance in the manufacture of steel. Researchers
have found a way to strengthen the metal and reduce its (
) — and without (
1
2
) costs.
The advance might translate to an extra 1 mile per gallon (2 liters per kilometer) in gas mileage for a standard car,
estimates materials scientist Alan Russell of Iowa State University in Ames, who was not involved with the work. That’s not
enough to make drivers jump for joy at the gas pump, but “it’s really quite a substantial achievement,” he says.
Producing strong, lightweight materials is a delicate balancing act. Lighter materials tend to be weaker, and stronger
materials tend to be more brittle. Glass, for example, is strong but (
hands and it won’t budge, but drop it on the floor and it (
One (
5
4
3
): You can try to bend or stretch it with your
).
) of making steel lighter is to add aluminum, a less dense metal. In steel, aluminum forms an ultrastrong
compound with iron. That strength is an asset, but the compound tends to arrange into brittle bands. To disperse the
aluminum compound and make the metal (
6
) brittle, researchers led by materials scientist Hansoo Kim of Pohang
University of Science and Technology in South Korea added nickel, which caused the aluminum compound to permeate the
metal in nanometer-sized clusters instead of long bands. The clusters are too small to cause the undesirable (
but the strength and (
8
7
),
) of the aluminum remain, the researchers report online today in Nature. The researchers
examined their steel with an electron microscope to (
9
) that the aluminum clusters had formed. Then they tested the
metal by applying tension and found that it was stronger and less brittle than (
10
) steel.
The new steel is an “interesting and novel development” that stands a good chance of eventually being adopted by
industry, says metallurgist P. Chris Pistorius of Carnegie Mellon University in Pittsburgh, Pennsylvania. But it’s not a
dramatic leap forward, he says. “This is a very significant (
11
), but it does build on what we know about how steels
work.”
Where the new metal really shines is in its cost. Other lightweight, strong metals such as titanium alloys are too
(
12
) to be used in passenger vehicles. The low price of the metals used to produce the new steel means that the
price will be closer to that of standard steel, Russell says, so automakers could use it to lighten their loads without driving
up costs. “That’s the kind of thing that makes engineers salivate freely,” Russell says. “They love that kind of
improvement.”
(From “New, lightweight steel is cheap, yet strong”, Science, 2015)
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
2016 ENTRANCE EXAMINATION FOR INTERNATIONAL MASTER’S PROGRAM
Departments of Mechanical Engineering and Hydrogen Energy Systems
English (Group A, B)
[14:30~15:30]
Examinee’s number
Score
III Read the following article, and then answer the questions below it. (20 Points)
For most adults, adding small numbers requires little effort, but for some children, it can take all ten fingers and a lot of
time. Research published on 17 August in Nature Neuroscience suggests that changes in the hippocampus — a brain area
associated with memory formation — could help to explain how children eventually pick up sufficient strategies for
mathematics, and why some children learn more quickly than others. Vinod Menon, a developmental cognitive
neuroscientist at Stanford University in California, and his colleagues presented single-digit addition problems to 28 children
aged 7-9, as well as to 20 adolescents aged 14-17 and 20 young adults. Consistent with previous psychology studies, the
children relied heavily on counting out the sums, whereas adolescents and adults tended to draw on memorized information
to calculate the answers.
Committed to memory: The researchers saw this developmental change begin to unfold when they tested the same
children at two time points, about one year apart. As the children aged, they began to move away from counting on fingers
towards memory-based strategies, as measured by their own accounts and by decreased lip and finger movements during
the task. Using functional magnetic resonance imaging (fMRI) to scan the children’s brains, the team observed increased
activation of the hippocampus between the first and second time point. Neural activation decreased in parts of the prefrontal
and parietal cortices known to be involved in counting, suggesting that the same calculations had begun to engage different
neural circuits. “This paper is really a very novel contribution,” says Daniel Ansari, a developmental cognitive neuroscientist
at Western University in London, Ontario. “We’ve known for a long time that there’s this development shift in strategy, but
we’ve known very little about the fundamental underlying mechanism.” Few previous fMRI studies have followed children at
multiple time points — in part because many youngsters have trouble staying still for the duration of a brain scan.
Connections that count: Despite measuring an initial increase in hippocampal activation in children, Menon’s team
found that the strength of neural signalling was not itself the key to mathematical aptitude. In fact, addition problems
appeared to engage the hippocampus less in adolescents and adults than in children. Instead, coordination of signals in the
hippocampus with activity in the rest of the brain seemed most important, particularly with activity in the neocortex, which is
involved in long-term memory storage. Children with stronger connections between the hippocampus and neocortex were
more likely than others to answer problems with memorized maths facts. The findings provide strong empirical support for
existing theories of maths development, says Jessica Cantlon, a cognitive neuroscientist at the University of Rochester in
New York. But, she adds, “We don’t know what information is being passed between the hippocampus and the neocortex.
“One way to probe this question, she says, would be to extend the study to children with hippocampal damage or
mathematical learning impairments. Menon suggests that maturation of the hippocampus and its connections probably
underlies not only the development of memory-based maths skills in children, but also some other types of learning. “We
think this is a general principle, but obviously there is a lot more work to be done,” he says.
(From “Developing brains switch maths strategies”, Nature, 2014)
(1) What is the hippocampus? (5 points)
(2) Who has a tendency to count on fingers? Children, Adolescents, or Adults? (5 points)
(3) Explain a typical characteristic of children who answer problems with memorized maths facts. (5 points)
(4) What is the opposite word of “counting” used in this article? (5 points)
2016 ENTRANCE EXAMINATION FOR INTERNATIONAL MASTER’S PROGRAM
Departments of Mechanical Engineering and Hydrogen Energy Systems
English (Group A, B)
Examinee’s number
IV
[14:30~15:30]
Score
Robotics is one of key technologies in mechanical engineering, and many types of robots are available,
nowadays. Describe your favorite robot or a robot you want to make in the future within 200 words. (20 Points)