亲们都来帮帮忙啊？要思路……决定我们组命运的题目。

liujingaiseng

Problem A： Predicting the Concentration of a
Virus Problem
Congratulations, Lieutenant! You've been assigned to the 43d Engineer Battalion (Combat
Heavy) in Somalia as an assistant S-3 for construction. The battalion is about to move to a new
construction site in Rwanda. Unfortunately, this region is listed with the World Health
Organization (WHO) for having persistent problems with several deadly viruses. The Battalion
S-3, MAJ Simon, needs to know what the dangers are, and how quickly the viruses spread so that
she can plan for medical attention and MEDEVAC flights.
After some research with the WHO representatives, you find that one of the viruses in
Rwanda is similar to the Hanta virus which recently killed several people in the Four Corners
region of the United States. Since that outbreak, the Hanta virus has been studied extensively, and
you decide to use the Hanta virus as a guide for determining the medical requirements for your
battalion. If just one copy of the virus enters a human body, it can start reproducing very rapidly.
In fact, the virus can double its numbers in one hour! The human immune system can be quite
effective, but this virus hides in normal cells. As a result, the immune response doesn't begin until
the virus has one million copies floating around in the body.
One of the first actions of the immune response is to raise the body temperature, which
lowers the virus replication rate to merely 150% per hour. The fever and then flu-like symptoms
are usually the first indication of illness. Some people with the virus assume that they merely have
the flu or a bad cold. This assumption leads to deadly consequences, since the immune response
alone is not enough to combat the virus. At maximum reaction, the immune system can only kill
200,000 copies of the virus per hour.
To fully combat the illness, the infected person must receive an injection and hourly doses
of a special antibiotic. The antibiotics do not affect the replication rate of the virus (the fever keeps
it at 150%), but the immune system and the antibiotics together can kill 500,000,000 copies of the
virus per hour. If these antibiotics are not started before the number of copies of the virus in the
body reaches one billion, the virus cannot be stopped. When the virus reaches one trillion copies,
the person will die.
Requirement 1: Model the initial phase of the illness for a soldier infected with one copy of the
virus. How long will it take for the immune response to begin?
Requirement 2: Model the second phase of the illness (the immune response has begun, but no
medicine has been administered). How much time do you have to get the soldier to medical
authorities?
Requirement 3:Analyze your models. What assumptions have you made? What are the strengths
and weaknesses of the models? How reliable are your results?
Requirement 4: Oh NO! It's 0200 and your body temperature just soared to 104 degrees（F）.
Thinking quickly back across your day, you realize that you started feeling hot and achy about
2000 when you returned from a recon of the construction sites in Rwanda. Belatedly recognizing
the danger signs, you immediately call for medical help. Since you're the first person with the
virus in Somalia, the medicine has to be flown in from Rwanda. While you're waiting, you can
calculate the approximate time you were infected. When was that? The doctors work as quickly as
possible, and but you don't get any medicine until 1400 the next day. Is it in time? How many
copies of the virus are in your body?
Requirement 5: Model the virus in your body during the third phase of the illness (after you
receive the medicine). What happens? How long before you are free of the virus, or in the other
case, how long before MAJ Simon has to write a sad letter to your family?
提供点好地思想啊，亲们要给力啊！

cesc4

好熟悉啊

liujingaiseng

cesc4 发表于 2011-11-16 23:10
好熟悉啊

你做过吗？  给点资料

yushour

我想求助却发不了贴？

fyx＆雪

我现在要做这个题目，给点提示呗~~