ENGS4 2004 Midterm Exam

1
ENGS 4

• Midterm Takehome Examination
• Time 1.5 hours
• Conditions You cannot discuss the content of
  this exam with anyone. All work submitted must
  be your own. Please show your work clearly.
• Submission Electronic answers must be mailed to
  gvc_at_dartmouth.edu by midnight Feb 6. Paper
  answers must be put into George Cybenkos
  Cummings Hall mailbox before the receptionist
  leaves Feb 6 (about 430PM).

2

• The Google and CNN logo images are located at
• http//www.google.com/images/logo.gif
• and
• http//i.a.cnn.net/cnn/.element/img/1.1/logo/logo.
  gif
• respectively.
• Write an HTML command that will generate a table
  with two rows and two columns. The first row
  contains Google and CNN in the two cells and
  the second row contains the corresponding logos
  in such a way that the logos are links to the
  Google and CNN home pages respectively. Sizing
  is not important.
• A packet switched network connects two offices
  one in New York and one in London. There are 5
  routers between the two offices and each router
  introduces a delay of 0.001 seconds due to
  routing overhead. The total length of the wires
  on the route between the two offices is 5000
  kms. The packets travel at a rate of 100000 kms
  per second through the wires. What is the total
  latency along that path Show your work.

3

• Here are three possible approaches to the email
  SPAM problem
• Classify a message as SPAM if it contains any of
  the words viagra discount cheap
  deals.
• Classify a message as SPAM if over 80 of the
  messages from the same sender have been deleted
  in the past.
• Classify a message as SPAM if the previous
  message from the same sender was deleted without
  reading and as non-SPAM if the message was read.
• Which of these approaches is rule-based
  state-based Markovian Explain your answer as
  well as possible.
• The next page shows a network with nodes and
  latencies between them. Show the execution of
  the Bellman-Ford Routing algorithm on this
  network step by step.

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Network for Problem 4
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