CEE
597

Risk Analysis and Management
Final Exam
Wed. May 7,1998; 3 noon to 5:30 pm.
Test is open book and open notes. You have 150 minutes for this 150 point exam.
Write clearly and
Show
important steps.
Again
my
apology: I hope you hmedmore
thn
this simp& test addresses.
1.
(8
points) Different peopk indulge themselves
in
different ways.
Some
peopk smoke,
some
enjoy
motorcycle riding, and others go rock climbing. Define
3 different quantitative criteria that can be
applied to and used to describe health risks associated with all three activities. Indicate for each
criteria why it is important, what dimension of risk it emphasizes, and what it neglects.
2.
(8 points) Of all the case studies (except TMI) we discussed or in the reading (Bhopal, Titianic, DC
10, Challenger, different short studies
...),
which one was your favorite?
What did
it teach about the character of system failures? (23 paragraphs)
3. (15 points) Three college friends Amy, Joe, and Lasandra decide after slope day to go camping. They
grab their sleeping bags and related camping gear, a few cans of food, and a box of pots and assorted
items. At dinner time the question arises: Do they have some tool for opening the canned food?
A manual
can opener might be in the box (p
=
0.6), Amy and Joe might have brought their pocket knives
which have a can opener (p
=
0.30 for each knife). Lasandra thinks she brought her portable can
opener
(p
=
0.75) that uses Dsize batteries, but she completely forgot to bring batteries (p
=
0). Amy and Joe
might have D batteries in their flashlights (p
=
0.20 each).
a) Describe this problem by an event tree (lay out the events,
unnecessary branches).
b) Draw a fault tree to describe this situation.
C)
Use your fault tree to compute the probability they can open the cans for dinner.
4
(12 points) Consider the system described by the
netwwk
below.
a)
What are all the minimal cut sets?
b)
If all elements have a 5% failure rate, except A which is 99% reliable,
what approximately is the probability that the system fails?
E)
Draw a fault tree for the system.
d)
If you could upgrade any component in the original network to 99% reliability,
which would most improve system reliability?
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View Full Document5. (12 points) Close calls (violations of safe distance regulations) occur at an airport
on average at a rate of 0.04 per day.
a) What is the mean and variance of the number that occur per year.
b) What is the probability that there is at least one close call in a 30 day period?
C)
What are the mean and variance of the time until the 5th close call.
d) Is a Poisson process a good model of the arrival of such events? Why or why not.
6. (20 points) Consider the 3 marketing strategies (illustrated below) advocated by Susan, Matt and
Anna. Assume that outcomes
1 and 2 and 3 are all equally likely.
Susan
Matt
Anna
Markets poor
Steady economy
Hot market
In answering the qarestzons
balm
ya
my
use, but are not restricted to:
Average Gain
Stand. Deviation
Maximum possible
Median
a) What criteria would be helpful to quantify the relative attractiveness of these three proposals?
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 Spring '07
 Stedinger
 pts, Matt Anna

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