Software Engineering Answers

a) The stack class has been created as follows:

class Stack { 

int maxSize; 

double stackÄrray[ ] 

int top;

i) Write the constructer method to initiate Stack class properties.  

ii) Write the pop() method to remove a value from the Stack.

public double pop ( )

b) Assume S is stack developed using a linked list. 

Show the final contents of the Stack after executing the following code.

for (int k=1; k<=7;k++)

   s. push (k) ; 

for (int k=1; k<=7;k++)   

s . push (s.pop ( ) ) ;

c) The Queue class has been created as follows, to store integer values.

class Queue {

LinkedList queueList; 

int n Items;

i)Write the constructor to initiate the Queue class properties.

ii)Write a method to insert a value to the Queue.

public void insert (int i)

iii)Write a method to delete a value from a Queue.

public Link delete()

iv)What is the major limitation of Linear queues?

Write a paper summarizing recent advances in one of the leading edge software application areas.

Potential choices include: advanced Web-based applications, virtual reality, artificial neural networks,

advanced human interfaces, intelligent agents.

Consider the following relational database schema which records suppliers and items supplied by suppliers. Supplier supply many items and an item is supplied by many suppliers for different prices. item (itemNo: varchar (10), description: varchar(30), QuantityInHand: Integer) supply (sno: varchar (10), itemNo: varchar (10), UnitPrice: float, quantity: integer) supplier (sno: varchar(10), name: varchar(50), address: varchar(30)) Supplier table has attributes supplier number (sno), name and address. Supply table consists of supplier number, item number, price and quantity supplied. Item table has attributes, item number (itemNo), description and Quantity in hand. Write relational SQL statements to answer the following questions. a) List all items which are supplied by ‘Swan suppliers’ with more than 20 quantities. List item number, description, supplied quantity and unit price of an item. b) List suppliers that do not supply the item ‘Manuscript Books’. List the supplier number and name.

Consider the following query:

Query 2:

SELECT c.RegNo, c.model, c.year, o.NIC

FROM cars c, owner o

WHERE c.RegNo=o.RegNo and year =2017 and price <6000000

1. Assume there are no indexes available on either table. If the join algorithm used is block nested loops join, draw the extended query plan for Query 2.

2. Calculate the cost of executing Query 2 using the plan designed in question 2. Show the steps in the calculation.

3. If the join algorithm used is Index nested loops join, what are indexes needed in order to have an optimal plan for Query 2?

4. Draw the extended query plan for Query 2 using identified indexes in question 4.

5. Calculate the cost of executing Query 2 using the plan designed in question 5. Show the steps in the calculation

a) Briefly explain RAID technique. What is the purpose of RAID?

b) Consider a disk with a sector size of 512 bytes, block size of 2048 bytes, 1000 tracks per surface, 100 sectors per track and 3 single-sided platters. Average seek time is 2 msec. The disk is spinning at a speed of 2400 rpm. You need to store an Employee file which contains 2000 records which are in fixed-length format. An employee record is 1024 bytes. No record spans multiple blocks.

(i). How many Employee records can be stored in a block of the above disk?

(ii). How many Employee records can be stored in a single track?

(iii). How many cylinders are needed to store the entire Employee file?

(iv). What is the total time required to transfer a track of data from the above disk? Consider average seek time and average rotational delay.

(v). Assuming that the data in the above disk are stored using the Next Block concept, what would be the time taken to read the entire stock file from the disk.

Where do you stand on the controversial encryption issue? Should governments like the United States be allowed to have an escrowed key to all encrypted communications? Is unfettered encryption a good thing for cyberspace?

During software design, four things must be considered: Algorithm Design, Data Design, UI Design and Architecture Design. Briefly explain each of these and give TWO (2) example of documentation that might be produced. 

Design a circuit that accepts a three bit binary number as input, and produces a three bit output that is double the input value. Ignore the most significant bit for results of eight or more, since you are delivering a three bit output. In other words, your circuit output is the three least significant bits of the result. Examples: An input of 011 (3 in decimal) should produce an output of 110 (6). An input of 110 (6 in decimal) should produce an output of 100 (4 in decimal). Why is that? While the proper arithmetic result should be 1100 (12 in decimal), your circuit can deliver only three bits as output, therefore the leading one is lost. That leading one represents a value of 8, correct? So losing the 8 leaves a remainder of 4. The same thing happens in registers when a result exceeds the bit capacity of the register. Your solution must include a truth table and K-Maps for the three output functions. You do not need to draw a logic diagram.

3.It has been suggested that one of the problems of having a user closely involved with a software development team is that they “go native”. That is, they adopt the outlook of the development team and lose sight of the needs of their user colleagues. Suggest three ways how you might avoid this problem and discuss the advantages and disadvantages of each approach.

1.A banking system provides users with several services:

a) to check their accounts to see recent transactions and balances;

b) to pay bills online;

c)to buy and sell investments

All of these services require a secure log-in. If the system crashes or the network connection fails during a transaction, all the financial data must be left in a consistent state.

a)    Draw use case diagrams for these requirements. (Use standard symbol and shapes. MS Office Visio or Figma are optional tools)

Give th