Define computer crime and its various forms.

Define computer crime and its various forms.

ans:

Alternatively referred to as cyber crime, e-crime, electronic crime, or hi-tech crime. Computer crime is an act performed by a knowledgeable computer user, sometimes referred to as a hacker that illegally browses or steals a company's or individual's private information. In some cases, this person or group of individuals may be malicious and destroy or otherwise corrupt the computer or data files.

Below is a listing of the different types of computer crimes today. Clicking on any of the links below gives further information about each crime.

Child pornography - Making or distributing child pornography.
Cyber terrorism - Hacking, threats, and blackmailing towards a business or person.
Cyberbully or Cyberstalking - Harassing others online.
Creating Malware - Writing, creating, or distributing malware (e.g. viruses and spyware.)
Denial of Service attack - Overloading a system with so many requests it cannot serve normal requests.
Espionage - Spying on a person or business.
Fraud - Manipulating data, e.g. changing banking records to transfer money to an account.
Harvesting - Collect account or other account related information on other people.

source:

http://www.computerhope.com/jargon/c/compcrim.htm

What is AI?Explain its application areas.

What is AI?Explain its application areas.

Ans:-
AI:- Artificial intelligence is a science and technology based on disciplines such as Computer Science, Biology, Psychology, Linguistics, Mathematics, and Engineering. A major thrust of AI is in the development of computer functions associated with human intelligence, such as reasoning, learning, and problem solving.
Its application areas are:

game playing

You can buy machines that can play master level chess for a few hundred dollars. There is some AI in them, but they play well against people mainly through brute force computation--looking at hundreds of thousands of positions. To beat a world champion by brute force and known reliable heuristics requires being able to look at 200 million positions per second.

speech recognition

In the 1990s, computer speech recognition reached a practical level for limited purposes. Thus United Airlines has replaced its keyboard tree for flight information by a system using speech recognition of flight numbers and city names. It is quite convenient. On the the other hand, while it is possible to instruct some computers using speech, most users have gone back to the keyboard and the mouse as still more convenient.

understanding natural language

Just getting a sequence of words into a computer is not enough. Parsing sentences is not enough either. The computer has to be provided with an understanding of the domain the text is about, and this is presently possible only for very limited domains.

computer vision

The world is composed of three-dimensional objects, but the inputs to the human eye and computers' TV cameras are two dimensional. Some useful programs can work solely in two dimensions, but full computer vision requires partial three-dimensional information that is not just a set of two-dimensional views. At present there are only limited ways of representing three-dimensional information directly, and they are not as good as what humans evidently use.

expert systems

A ``knowledge engineer'' interviews experts in a certain domain and tries to embody their knowledge in a computer program for carrying out some task. How well this works depends on whether the intellectual mechanisms required for the task are within the present state of AI. When this turned out not to be so, there were many disappointing results. One of the first expert systems was MYCIN in 1974, which diagnosed bacterial infections of the blood and suggested treatments. It did better than medical students or practicing doctors, provided its limitations were observed. Namely, its ontology included bacteria, symptoms, and treatments and did not include patients, doctors, hospitals, death, recovery, and events occurring in time. Its interactions depended on a single patient being considered. Since the experts consulted by the knowledge engineers knew about patients, doctors, death, recovery, etc., it is clear that the knowledge engineers forced what the experts told them into a predetermined framework. In the present state of AI, this has to be true. The usefulness of current expert systems depends on their users having common sense.

heuristic classification

One of the most feasible kinds of expert system given the present knowledge of AI is to put some information in one of a fixed set of categories using several sources of information. An example is advising whether to accept a proposed credit card purchase. Information is available about the owner of the credit card, his record of payment and also about the item he is buying and about the establishment from which he is buying it (e.g., about whether there have been previous credit card frauds at this establishment).

courtesy

http://www-formal.stanford.edu/jmc/whatisai/node3.html and tutorialspoint.com

What is AI? Explain its components.

q)What is AI? Explain its components.

ans:-

Artificial Intelligence (AI) is usually defined as the science of making computers do things that require intelligence when done by humans. AI has had some success in limited, or simplified, domains. However, the five decades since the inception of AI have brought only very slow progress, and early optimism concerning the attainment of human-level intelligence has given way to an appreciation of the profound difficulty of the problem.

AI components are:

Learning

Learning is distinguished into a number of different forms. The simplest is learning by trial-and-error. For example, a simple program for solving mate-in-one chess problems might try out moves at random until one is found that achieves mate. The program remembers the successful move and next time the computer is given the same problem it is able to produce the answer immediately. The simple memorising of individual items--solutions to problems, words of vocabulary, etc.--is known as rote learning.

Reasoning

To reason is to draw inferences appropriate to the situation in hand. Inferences are classified as either deductive or inductive. An example of the former is "Fred is either in the museum or the cafŽ; he isn't in the cafŽ; so he's in the museum", and of the latter "Previous accidents just like this one have been caused by instrument failure; so probably this one was caused by instrument failure". The difference between the two is that in the deductive case, the truth of the premisses guarantees the truth of the conclusion, whereas in the inductive case, the truth of the premiss lends support to the conclusion that the accident was caused by instrument failure, but nevertheless further investigation might reveal that, despite the truth of the premiss, the conclusion is in fact false.

Problem-solving

Problems have the general form: given such-and-such data, find x. A huge variety of types of problem is addressed in AI. Some examples are: finding winning moves in board games; identifying people from their photographs; and planning series of movements that enable a robot to carry out a given task.

Perception

In perception the environment is scanned by means of various sense-organs, real or artificial, and processes internal to the perceiver analyse the scene into objects and their features and relationships. Analysis is complicated by the fact that one and the same object may present many different appearances on different occasions, depending on the angle from which it is viewed, whether or not parts of it are projecting shadows, and so forth.

Language-understanding

A language is a system of signs having meaning by convention. Traffic signs, for example, form a mini-language, it being a matter of convention that, for example, the hazard-ahead sign means hazard ahead. This meaning-by-convention that is distinctive of language is very different from what is called natural meaning, exemplified in statements like 'Those clouds mean rain' and 'The fall in pressure means the valve is malfunctioning'.

etc.

courtesy

www.alanturing.net/turing_archive/pages/reference%20articles/what%20is%20ai.html

Explain the terms : polymorphism/inheritance/class/object.

q)Explain the terms : polymorphism/inheritance/class/object.

ans:-

These all are features of object oriented programming.Lets know about them.

Object:-

An object can be considered a "thing" with some attributes and can perform a set of related activities. The set of activities that the object performs defines the object's behavior. For example, the hand can grip something or a Student(object) can give the name or address. They all have state and behavior. like ,Dogs have state (name, color, breed, hungry) and behavior (barking, fetching, wagging tail). Bicycles also have state (current gear, current pedal cadence, current speed) and behavior (changing gear, changing pedal cadence, applying brakes).

For example if “customer” and “account.” are two objects in a program, then the customer object may send a message to the account object requesting for the bank balance. Each object contains data and code to manipulate the data. Objects can interact without having to know details of each other’s data or code.

Class:-

In the real world, you'll often find many individual objects all of the same kind. There may be thousands of other bicycles in existence, all of the same make and model. Each bicycle was built from the same set of blueprints and therefore contains the same components. In object-oriented terms, we say that your bicycle is an instance of the class of objects known as bicycles. A class is the blueprint from which individual objects are created. So it can be said as collection of same type of objects.

Inheritance

Inheritance is mainly used for code reusability.In the real world there are many objects that can be specialized. In OOP, a parent class can inherit its behavior and state to children classes. Inheritance means using the Predefined Code. This is very main feature of OOP, with the advantage of Inheritance we can use any code that is previously created. This concept was developed to manage generalization and specialization in OOP. Lets say we have a class called Car and Racing Car . Then the attributes like engine no. , color of the Class car can be inherited by the class Racing Car . The class Car will be Parent class , and the class Racing Car will be the derived class or child class

The following OO terms are commonly used names given to parent and child classes in OOP:

Superclass: Parent class.

Subclass: Child class.

Base class: Parent class.

Derived class: Child class

It can have many types.

single inheritance:-one derived class inherits property from one base class

multiple “ :- one derived class inherits property from many base classes.

multi level “ :-in this many derived classes are inherited from many base classes

hierarchical “ :-under this many derived classes can be inherited from single base class

hybrid “:-it’s a combination of hierarchical and multilevel.

Polymorphism:-

Its an important OOPs concept , Polymorphism means taking more than one forms .Polymorphism gives us the ultimate flexibility in extensibility. The ability to define more than one function with the same name is called Polymorphism.Polymorphism allows the programmer to treat derived class members just like their parent class’s members. More precisely, Polymorphism in object-oriented programming is the ability of objects belonging to different data types to respond to calls of methods of the same name .If a Dog is commanded to speak(), this may elicit a bark(). However, if a Pig is commanded to speak(), this may elicit an oink(). Each subclass overrides the speak() method inherited from the parent class Animal.

example is

Simple example of Polymorphism, look at an Account (it may be checking or saving assuming each attract different dividends) you walk in a bank and ask a teller what is my balance? or dividends? you don't need to specify what kind of an account you're having he will internally figure out looking at his books and provide you the details.

Differentiate between POP and OOPs.

Differentiate between POP and OOPs.
ans:
Here.we are going to understand about structured programming /also called procedure oriented programming and object oriented programming with the help of following description.

Concept of POP (procedural oriented programming):- Conventional programming using high level languages such as COBOL,FORTRAN and C, is commonly known as procedure oriented programming(POP).

Procedure oriented programming basically consists of writing a list of instructions(or actions) for the computer to follow, and organizing these instructions into groups known as functions.While we concentrate on the development , very little attention is given to the data that are being used by various functions.

Diagrammatically we can show POP as

Some characteristics (features) of Procedure Oriented Programming are :-

1) Emphasis is on doing things(algorithms).

2) Large programs are divided into smaller programs known as functions.

3) Most of the functions share global data.

4) Data more openly around the system from function to function.

5) Functions transform data from one form to another.

6) Employs top-down approach in program design.

OOP (Object Oriented Programming)concepts:-

The major motivating factor in the invention of object oriented is to remove some of the flaws encountered in the procedural oriented approach. Object oriented programming uses concept of “Object” and treats data as a critical element in the program development and does not allow it to flow freely around the system. It ties data more closely to the functions that operate on it, and protects it from accidental modifications from outside functions.

Some characteristics (features) of Object Oriented Programming are :-

1) Emphasis is on data rather than procedures or algorithms.

2) Programs are divided into what are known as objects.

3) Data structures are designed such that characterize the objects.

4) Functions that operate on the data are tied together in the data structure.

5) Data is hidden and cannot be accessed by external functions.

6) Objects may communicate with each other through functions.

7) New data and functions can be easily added whenever necessary.

8) Follows bottom-up approach in program design.

Explain about OSI model of networking.

Explain about OSI model of networking.
ans:-

OSI model:-

The OSI, or Open System Interconnection, model defines a networking framework for implementing protocols in seven layers. Control is passed from one layer to the next, starting at the application layer in one station, and proceeding to the bottom layer, over the channel to the next station and back up the hierarchy.

image courtesy:

https://www.lifewire.com/layers-of-the-osi-model-illustrated-818017

---------------------->Application (Layer 7)

This layer supports application and end-user processes.
Communication partners are identified, quality of service is identified, user authentication and privacy are considered, and any constraints on data syntax are identified.

----------------------->Presentation layer (layer 6):-

This layer provides independence from differences in data representation (encryption) by translating from application to network format, and vice versa.
The presentation layer works to transform data into the form that the application layer can accept.

------------------------>Session (Layer 5)

This layer establishes, manages and terminates connections between applications.

----------------------->Transport (Layer 4)

This layer provides transparent transfer of data between end systems, or hosts, and is responsible for end-to-end error recovery and flow control.
It ensures complete data transfer.

------------------------->Network (Layer 3)

This layer provides switching and routing technologies, creating logical paths, known as virtual circuits, for transmitting data from node to node

------------------------>Data Link (Layer 2)

At this layer, data packets are encoded and decoded into bits.
It furnishes transmission protocol knowledge and management and handles errors in the physical layer, flow control and frame synchronization

------------------------->Physical (Layer 1)

This layer conveys the bit stream - electrical impulse, light or radio signal -- through the network at the electrical and mechanical level.
It provides the hardware means of sending and receiving data on a carrier, including defining cables, cards and physical aspects

Explain about client-server and peer-to-peer networking

Explain about client-server and peer-to-peer networking.