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A base class is a class from which other classes are derived. The class that inherits is called derived class. The inheriting class is called the derived class.

The principle of duality states that starting with a Boolean relation, another relation can be derived by

1. Changing each OR sing (+) to an AND sign (.).
2. Changing each AND sing (.) to an OR sign (+).
3. Replacing each 0 by 1 and each 1 by 0.
4. All variables are complemented.

For example, (X + Y’) dual is (X’. Y)

This law states that the double complement of a variable gives the same variable.

The name of a web browser is Google Chrome.

A bus topology consists of a central cable with a terminator at each end. All nodes (file server, workstations, and peripherals) are connected to the linear cable.

Uniform Resource Locator.

A database is a collection of large amount of related data. In other words, It is a collection of database tables.

The advantage of pointer is memory can be allocated or deallocated dynamically.

• Used in mathematical problems like matrices etc.
• They are used in the implementation of other data structures like linked lists etc.
• Database records are usually implemented as arrays.
• Used in lookup tables by computer.

The operator :: known as scope resolution operator helps in defining member function outside the class.

A class is a structured data type in C++ which is a collection of variables and functions.

The examples for non-linear data structures are trees and graphs.

The examples for linear data structures are stack, queues and linked lists.

Industry Standard Architecture

The two antivirus software are Norton Antivirus and Kaspersky Antivirus.

It is an electronic circuit having one or more than one input and only one output.

A stack is an ordered collection of items in which data items may be inserted and deleted at one end. This end is referred as “top”. The opposite to top is known as “base”. The most recently added item in the stack is removed first. This working principle is sometimes called LIFO (Last In First Out). Newer inserted elements will be near the top and elements that are inserted at the beginning are near the base.

The applications of stack:

• Arithmetic Expression evaluation
• Arithmetic Expression conversion
• Recursive function .
• Backtracking (game playing, finding paths, exhaustive searching)
• Memory management, run-time environment for nested language features.

The operation on stack is

• stack() creates a new empty stack,
• push(item) insert new item at the top of stack,
• pop() removes the top element from the stack,
• peek() returns the top item of the stack,
• Empty() checks the stack is empty or not and
• size() returns number of items present in the stack

LHS: = (X+Y) (X+Z)
= XX + XZ + XY + YZ
= X + XZ + XY + YZ
= X + (1 + Z +Y) YZ
= X + YZ
= RHS

• A minterm is a special product of literals, in which each input variable appears exactly once.
• A maxterm is a sum of literals, in which each input variable appears exactly once.

The motherboard is a large printed circuit board and every physical unit is connected to it. It is the main circuit board of computer system.

Step 1: if FRONT = -1 then
Print “Queue is Underflow”
Exit
End of if
Step 2: ITEM = QUEUE [FRONT]
Step 3: if FRONT = REAR then
FRONT = 0 REAR = 0
Else
FRONT = FRONT+1
Step 4: return

Step 1: ifFRONT = -1 then 

Print “Queue is Underflow” 

Exit 

End of if 

Step 2: ITEM QUEUE [FRONT] 

Step 3: if FRONT = REAR then 

FRONT = 0 

REAR = 0 

Else 

FRONT = FRONT + 1 

Step 4: return

1. Network Interface Cards:
The network interface card (NIC) provides the physical connection between the network and the computer workstation. Network interface cards are a major factor in determining the speed and performance of a network. The most common network interface connections are Ethernet cards.

2. Switches:
A switch is a hardware device that provides a central connection point for cables from workstations, servers, and peripherals. Switch forwards data only to the port on which the destination system is connected.

3. Repeaters:
Since a signal loses strength as it passes along a cable, it is often necessary to boost the signal with a device called a repeater. The repeater electrically amplifies the signal it receives and rebroadcasts it.

4. Routers:
Routers are network devices that route data around the network. By examining data as it arrives, the router can determine the destination address for the data; then, by using tables of defined routes, the router decides the best way for the data to reach destination. The router can direct traffic to prevent crash.

5. Hubs:
A network hub contains multiple ports. When a packet arrives at one port, it is copied to all ports of the hub for transmission.

The two types of hubs are active or passive hubs. Active hubs regenerate signal before forwarding it to all the ports and requires a power supply. Passive hubs, do not need power and they don’t regenerate the data signal.

6. Gateways:
It is a device that connects dissimilar networks. The term gateway is applied to any device, system, or software application that can perform the function of translating data from one format to another. The key feature of a gateway is that it converts the format of the data, not the data itself.

The conversion from one data format to another takes time, and so the flow of data through a gateway is always slower than the flow of data without one.

7. Modems:
Modem is a short form of the terms modulator and demodulator. Modems translate digital signals from a computer into analog signals that can travel across phone lines. The modem modulates the signal at the sending end and demodulates at the receiving end.

Modems provide a relatively slow method of communication. Modems are available as internal devices that plug into expansion slots in a system; external devices that plug into serial or USB ports;

Step 1: ifFRONT = -1 then
Print “Queue is Underflow”
Exit
End of if
Step 2: ITEM QUEUE [FRONT]
Step 3: if FRONT = REAR then
FRONT = 0
REAR = 0
Else
FRONT = FRONT + 1
Step 4: return

The built-in functions associated with GROUP functions in SQL are

1. COUNT function:
returns the count of records that satisfies the condition for each group of records.
Example:
SELECT department, COUNT(*)FROM employees WHERE salary > 25000 GROUP BY department;

2. MAX function:
returns the maximum values from the column for each group of records.
Example:
SELECT department, MAX(salary) FROM employees GROUP BY department;

3. MIN function:
returns the lowest values from the column for each group of records.
Example:

SELECT department, MIN(salary) FROM employees GROUP BY department;

4. AVG function:
returns the average values from the column for each group of records.
Example:
SELECT AVG(cost) FROM products WHERE category = ‘Clothing’;

5. SUM function:
returns the total values from the column for each group of records.
Example:
SELECT department, SUM(sales)FROM order_details GROUP BY department;

6. DISTINCT function:
returns the once occurrence of many repeated values from the column for each group of records.
Example:

SELECT DISTINCT department from Employees;

The advantages of OOPs are:

1. OOP provides a clear modular structure for programs. Large problems can be reduced to
smaller and more manageable problems.

2. In OOP, data can be made private to a class such that only member functions of the class can access the data. This principle of data hiding helps the programmer to build a secure program.

3. Implementation details are hidden from other modules and other modules has a clearly defined interface.

4. It is easy to maintain and modify existing code as new objects can be created with small differences to existing ones.

5. With the help of polymorphism, the same function or same operator can be used for different purposes. This helps to manage software complexity easily.

6. In OOP, programmer not only defines data types but also deals with operations applied for data structures.

Network security refers to any activities designed to protect network and related activities. It protects the usability, reliability, integrity, and safety of network and data. Good network security identifies a variety of threats and stops them from entering or spreading on network.

The network security concerns with allowing only legal or authorized users and programs to gain access to information resources like databases. It also ensures that properly authenticated users get access only to those resources that they are supposed to use. Many network security threats today are spread over the Internet. The most common include:

• Viruses, worms, and Trojan horses
• Spyware and adware
• Zero-day attacks also called zero-hour attacks
• Hacker attacks Denial of service attacks
• Data interception and theft
• Identity theft

A network security system usually consists of many components. Ideally, all components work together, which minimizes maintenance and improves security. Network security components include:

• Anti-virus and anti-spyware.
• Firewall, to block unauthorized access to your network.
• Intrusion prevention systems (IPS), to identify fast-spreading threats, such as zero-day or zero-hour attacks.
• Virtual Private Networks (VPNs), to provide secure remote access.

The network security makes use of a variety of resources like user name, password, encrypted smart cards, biometrics, and firewalls to protect resources.

A data warehouse (DW) is a database used for reporting. The data is offloaded from the operational systems for reporting. The components of data warehouse are data sources, data transformation, reporting, metadata, operations, and operational components.

In short, data is moved from databases used in operational systems into a data warehouse staging area, then into a data warehouse and finally into a set of conformed data marts. Data is copied from one database to another using a technology called ETL (Extract, Transform, Load).

Sourcing, Acquisition, Cleanup and Transformation Tools:
The functionality includes:

• Removing unwanted data from operational databases
• Converting to common data names and definitions
• Establishing defaults for missing data
• Accommodating source data definition changes

Meta data:
Meta data is data about data that describes the data warehouse. It is used for building, maintaining, managing and using the data warehouse.

Object-oriented programming is a programming methodology based on objects, instead of just functions and procedures. These objects are organized into classes, which allow individual objects to be group together.

Limitations:

1. Size:
Object-Oriented programs are much larger than other programs. In the early days of computing, space on hard drives, floppy drives and in memory was at a premium. Today we do not have these restrictions.

2. Effort:
Object-Oriented programs require a lot of work to create. Specifically, a great deal of planning goes into an object-oriented program well before a single piece of code is ever written. Initially, this early effort was felt by many to be a waste of time. In addition, because the programs were larger (see above) coders spent more time actually writing the program.

3. Speed:
Object-Oriented programs are slower than other programs, partially because of their size. Other aspects of Object-Oriented Programs also demand more system resources, thus slowing the program down.

4. Not suitable for all types of problems:
There are problems that lend themselves well to functional-programming style, logic -programming style, or procedure-based programming style, and applying object-oriented programming in those situations will not result inefficient programs.

5. Not all programs can be modeled accurately by the objects model. If you just want to read in some data, do something simple to.it and write it back out, you have no need to define classes and objects. However, in some OOP languages, you may have to perform this extra step.

6. The objects often require extensive documentation.

In object-oriented programming, inheritance is a way to form new classes using classes that have already been defined.
1. Single inheritance:
A derived class with only one base class is called single inheritance. For example, If A is base class then class B derive from base class A.

2. Multilevel inheritance:
A class can be derived from another derived class which is known as multilevel inheritance. For example, The derived class C inherit B class whereas B is derived from class A.