Computer Science, Website Design, Enhanced Business Technology

Write three paragraphs (4-7 sentences each) with three website references (i.e. quotes from websites) on Ajax technology and/or its business implications.

Let A and B be two stations attempting to transmit on an Ethernet. Each has a steady queue of frames ready to send; A’s frames will be numbered ?1, ?2 and so on, and B’s similarly. Let ? = 51.2 ???? be the exponential backoff base unit. Suppose A and B simultaneously attempt to send frame 1, collide, and happen to choose backoff times of 0 × ? and 1 × ?, respectively. As a result, Station A transmits ?1 while Station B waits. At the end of this transmission, B will attempt to retransmit ?1 while A will attempt to transmit ?2. These first attempts will collide, but now A backs off for either 0 × ? or 1 × ? (with equal probability), while B backs off for time equal to one of 0 × ?, 1 × ?, 2 × ? and 3× ? (with equal probability). (a) Give the probability that A wins this second backoff race immediately after his first collision. (b) Suppose A wins this second backoff race. A transmits ?2 and when it is finished, A and B collide again as A tries to transmit ?3 and B tries once more to transmit ?1. Give the probability that A wins this third backoff race immediately after the first collision. (c) What is the probability that A wins all the ? backoff races. (? is a given constant) (d) Assume that there are 3 stations sharing the Ethernet. Will the chance for A to win all the backoff races decrease or increase? Why?

C++ PROGRAMMING.

S-DES: The purpose of this assignment is to implement algorithm for encryption with the simplified DES-type algorithm.

· Item #1. Write a C++ program that performs one round of the simplified DES-type algorithm. Test your code with a plaintext = 011100100110 and K = 010011001.

Java Programing

Write a program called reverseProg.  

This program will do the following

1. Asks the user to input a string, it reads the string and does the followings
   1. Prints the string in reverse order.
   2. Displays the characters that are in position 7^th, 8^th and 9^th of this string
   3. Displays the length of the string
   4. Displays the string in all UPPER CASE

Sample output example:

Enter a string: Wilmington University

String Entered is: Wilmington University

Wilmington University spelled backward is: ytsirevinU notgnimliW

The 7^th character in the string is: T

The 8^th character in the string is: O

The 9^th character in the string is: N

Length of the string is: 21

What python codes should I use to solve this question below?

Use input() function once to retrieve an input and assign that input value to a variable. Check if the input contains the string “an”. If so, use input() function one more time to retrieve an input and assign the new input value to a different variable. Now, replace “an” characters in the first variable with the first two characters of the second variable if only the second variable has at least two characters

Java Program

The program must prompt for an integer divisor in the range 10-20 and will print all numbers 1-1000 that are divisible by that divisor. You MUST use a while loop for this. Use printf to display the numbers in right-aligned columns, 10 to a line. For example, “%5d” would be the format String to allow a field width of 5 to display the number. If the number entered by the user is out of range just print an error message.

1. What is the DUAL table?

2. Explain the USER function.

3. Explain the ROWNUM pseudocolumn.

4. What is a sequence?

5. Answer the following in reference to sequences

   a. Show the SQL code to create a sequence per the following:

   Sequence Name: testsequence

   Starts with: 100

   Increments by: 2

   b. Show the SQL command to display the next available sequence value (1st value).

   c. Show the SQL command to display the next available sequence value (2nd value).

   d. Show the SQL command to display the current sequence value.

   e. Show the SQL code to delete the sequence

The todo section in java please

LinkedStack class (provided as a skeleton) is to implement TextbookStackInterface using chain of nodes to manage the data (see the textbook implementation).

The instance variable topNode is defined as chain head reference. The empty stack should have this variable set to null.

Skeleton of LinkedStack class is provided. Please note that in addition to all the methods defined in the TextbookStackInterface there are two methods: displayStack and remove that you also need to implement:

• displayStack method should display all the entries on the stack without destroying it
• remove(n) method should remove the topmost n entries from the stack; in case the stack contains less than n entries, the method should remove as many as possible.

The class includes main with test cases to test your methods. The output of your program must match the sample run below:

SAMPLE RUN

*** Create a stack ***

--> Pushing A B C D E on the stack

Done adding 5 elements.

The content of the stack:

E

D

C

B

A

--> Testing peek, pop, isEmpty:

E is at the top of the stack.

E is removed from the stack.

D is at the top of the stack.

D is removed from the stack.

C is at the top of the stack.

C is removed from the stack.

B is at the top of the stack.

B is removed from the stack.

A is at the top of the stack.

A is removed from the stack.

--> The stack should be empty:

isEmpty() returns true

CORRECT - exception has been thrown: cannot complete peek() - stack is empty

CORRECT - exception has been thrown: cannot complete pop() - stack is empty

The stack is empty

--> Testing clear:

--> Pushing A B C D E F G on the stack

Done adding 7 elements.

The content of the stack:

G

F

E

D

C

B

A

--> Calling clear()

The stack is empty

--> Testing remove:

--> Calling remove(4) on empty stack

0 elements have been removed.

The stack is empty

--> Pushing A B C D E F G H I J on the stack

Done adding 10 elements.

The content of the stack:

J

I

H

G

F

E

D

C

B

A

--> Calling remove(4)

removing J

removing I

removing H

removing G

4 elements have been removed.

The content of the stack:

F

E

D

C

B

A

--> Calling remove(10)

removing F

removing E

removing D

removing C

removing B

removing A

6 elements have been removed.

The stack is empty

*** Done ***

Process finished with exit code 0

public final class LinkedStack<T> implements TextbookStackInterface<T>
{
    private Node<T> topNode; // references the first node in the chain

    public LinkedStack()
    {
        // TODO PROJECT #3
    } // end default constructor

    public void push(T newEntry)
    {
        // TODO PROJECT #3
    } // end push

    public T peek() throws InsufficientNumberOfElementsOnStackException
    {
        // TODO PROJECT #3
        return null; // THIS IS A STUB
    } // end peek

    public T peek2() throws InsufficientNumberOfElementsOnStackException
    {
        // TODO PROJECT #3
        return null; // THIS IS A STUB
    } // end peek2

    public T pop() throws InsufficientNumberOfElementsOnStackException
    {
        // TODO PROJECT #3
        return null; // THIS IS A STUB
    } // end pop

    public boolean isEmpty()
    {
        // TODO PROJECT #3
        return false;  // THIS IS A STUB
    } // end isEmpty

    public void clear()
    {
        // TODO PROJECT #3

    } // end clear

    public int remove(int numberOfElements)
    {

        // TODO PROJECT #3
        return 0; // THIS IS A STUB
    } // end remove

    public void displayStack()
    {
        // TODO PROJECT #3
    } // end displayStack

public interface TextbookStackInterface<T>
{
   /** Adds a new entry to the top of this stack.
       @param newEntry  An object to be added to the stack. */
   public void push(T newEntry);
  
   /** Removes and returns this stack's top entry.
       @return  The object at the top of the stack. 
       throws  appropriate exception if the stack is empty before the operation. */
   public T pop();
  
   /** Retrieves this stack's top entry.
       @return  The object at the top of the stack.
       throws  appropriate exception if the stack is empty. */
   public T peek();
  
   /** Detects whether this stack is empty.
       @return  True if the stack is empty. */
   public boolean isEmpty();
  
   /** Removes all entries from this stack. */
   public void clear();
} // end StackInterface

To understand the value of counting loops:

1. Write a java program that implements matrix multiplication using counting loop constructs.
2. Then write the same program using only logical loops—for example, while loops.
3. Write 2 classes for each program

Sample Result is shown below:

Enter the number of rows of matrix A: 2

Enter the number of columns of matrix A: 3

Enter the number of columns of matrix B: 3

Enter the number of columns of matrix B: 4

Enter matrix A;

1 2 3

4 5 6

Enter matrix B:

7 8 9 10

11 12 13 14

15 16 17 18

Matrix A:

1 2 3

4 5 6

Matrix B:

7    8    9 10

11    12 13 14

15 16 17    18

Product of matrix A and Matrix B ( A x B) :

74 80 86 92

173 188 203    218   

In java please create a class with a method to be able to add ints into a linked List and to be able to print out all the values at the end.

public class Node {

int data;

Node next;

1. Now write a query that shows first and last name of probation officers. Include the field prob_id but rename prob_id to probation officer ID.

2. Write a query that will show crime id, and the total charges for each crime ID. Include an alias for the total charges column called Total Charges.

3. Write a query that will concat the last and first names of criminals into one column. Add a space and comma between the last and first name of criminals. Give the column the alias Criminal Name.

4. List the last name and first name of all authors in only 1 column. Add a comma to separate the two names.

5. Run a query that will return the order#, item#, isbn, quantity, paideach. Include in the query a arithmetic operation that will total quantity and paideach. Alias the virtual column so it is labeled Item Total

Write a program that prompts the user to enter three sets of five double numbers each. (You may assume the user responds correctly and doesn’t enter non-numeric data.)

The program should accomplish all of the following:

a. Store the information in a 3×5 array.

b. Compute the average of each set of five values.

c. Compute the average of all the values.

d. Determine the largest value of the 15 values.

e. Report the results.

Each major task should be handled by a separate function using the traditional C approach to handling arrays.

Accomplish task “b” by using a function that computes and returns the average of a one-dimensional array; use a loop to call this function three times.

The other tasks should take the entire array as an argument, and the functions performing tasks “c” and “d” should return the answer to the calling program.

Must be done in C for DEV C++

This exercise will test your ability to use the basic instance methods of String. The exercise is to create a program that compares two Strings ignoring the case and returns the offset between the first two distinct characters in the two Strings from left to right.

All the input strings have five characters.

For this exercise, compareToIgnoreCase() and compareTo() methods are not allowed.

Example 1, "London" and "Lately" will return the offset between 'o' and 'a', which is 14

Example 2, "London" and "lately" will return the offset between 'o' and 'a', which is 14

Example 3, "LONDON" and "lately" will return the offset between 'o' and 'a', which is 14

Example 4, "LONDON" and "Loathe" will return the offset between 'n' and 'a', which is 13

Example 4, "LONDON" and "london" will return 0

The class name should be: Lab14_CustomizedStringComparison

What kind of problems attributes make in entropy-based decision trees. How can we solve them?