2015 - 2016
Comprehensive Examination (Regular) 

Question) Indicate True or False for following statements with a justification within 30 words. No credit is given for answers with no justification.  

a. For successful design, you must practice diversification followed by convergence.
Answer)TRUE
b. Appraisal cost is likely to be the most expensive element of cost of quality.
Answer)TRUE
c. Before an architectural pattern is chosen for use in a particular system it must have a code implementation to expedite its reuse.
Answer)FALSE
d.Quantitative methods for evaluating the quality of proposed architectural designs are freely available.
Answer) FALSE
e. In component-based software engineering, the team searches for available components at the outset of the project.
Answer)FALSE
f. With thorough testing it is possible to remove all defects from a program prior to delivery to the customer.
Answer)FALSE
g. Many software metrics can only be measured indirectly.
Answer)TRUE
h. Software testing is deemed complete at end of budgeted duration for testing.
 Answer)FALSE
i. Design patterns are not applicable to the design of object-oriented software.
Answer)FALSE

Question) Differentiate the following: 
a. Analysis vs. design

Question:
Assume that there are two algorithms A and B for a given problem P. The time complexity functions of algorithms A and B are 5n and log2n    respectively. Which algorithm should be selected assuming that all other conditions remain the same for both the algorithms?

Solution:
Assuming that all conditions remain the same for both algorithms, the best algorithm takes less time when the input is changed to a larger value. Results obtained employing different values of n are shown below:

QUESTION 1.For each of the following applications,  determine whether  TCP or UDP is used as the transport layer protocol  and explain the reason(s) for your choice [5 x 2 = 10]
a)File Transfer
b)Watching a real time streamed video
c)Web browsing
d)A Voice over IP (VoIP) telephone conversation

Solution
a)File transfer :This should be TCP The reason is that you want a file to be transmitted in its entirety without any errors, therefore the error detection and correction properties of TCP are needed.
b)Watching a real time streamed video :This should be UDP. The reason is that when watching a movie, delay is critical and therefore there simply isn't any time to seek the retransmission of any errors. The simplicity of UDP is therefore required.
c)Web browsing :This should be TCP The reason is that web pages need to be delivered without error so that all content is properly formatted and presented. Therefore the error detection and correction properties of TCP are needed.
d)A Voice over IP (VoIP) telephone conversation :This should be UDP. The reason is that a telephone conversation has strict timing requirements for the transfer of data and seeking the retransmission of any errors would introduce too much delay. Therefore the simplicity of UDP is needed.

Section – A (7 x 8 marks = 56 marks)

Question 1.The co-ordinates of only one eighth of the total pixels lying on circumference of a circle are computed. Why? The Bresenhem’s circle drawing algorithm can be adapted for computing the coordinates of other pixels, explain?

Solution Scheme: 
Circle is symmetric about its axis. So, if point (x,y) is on the circle, then we can trivially compute (450 segment) seven other points (y,x),(y,-x),(x,-y),(-x,-y),(-y,-x),(-y,x),(-x,y) using the symmetry.(2 marks)
Bresenhem’s circle drawing algorithm (6 marks)

Question 2.Cohen-Sutherland line clipping technique uses the concept of region codes (or outcodes) in order to clip lines. Suppose a rectangular clip window ABCD is defined such that the lower left hand corner is at A(1,2) and upper right hand corner is at C (9,8). Clip the following line segments using Cohen Sutherland technique
  Line 1 from P(-1,7) to Q(11,1)
  Line 2 from R(3,7) to S(3,10)
  Line 3 from U(2,3) to V(8,4).

QUESTION 1(10 Marks)
Q1a.Explain the following methods of ContentProvider class [5]
(Note: Full marks is awarded if methods parameters and return type is explained.)

Answer)
i.canonicalize(Uri url):

• A canonical URI is one that can be transported across devices, backup/restore, and other contexts, and still be able to refer to the same data item. Typically this is implemented by adding query params to the URI allowing the content provider to verify that an incoming canonical URI references the same data as it was originally intended for and, if it doesn't, to find that data (if it exists) in the current environment.
• Parameters Url: uri: the Uri to canonicalize. this value must never be null
• Returns : URI Return the canonical representation of url, or null if canonicalization of that Uri is not supported.