Back Off Algorithm is an algorithm used for collision resolution. It works as, When this collision occurs, both the devices wait for a random amount of time before retransmitting the signal again, they keep on trying until the data is transferred successfully. This is called back off, since the nodes ‘back-off’ for a certain amount of time, before they try to re-access it again. This random amount of time is directly proportional to the number of attempts it has made to transmit the signal.AlgorithmBelow is a simple flowchart to explain the Back Off Algorithm in brief.As can be seen, that ... Read More

As we know that Cryptography comprises of two processes which are namely as encryption and decryption performed at sender and receiver end respectively. Basically Cryptography is practiced or implemented for doing secure communication between sender and receiver in the public environment in such a manner that other than these two parties no one could get or understand the message that is delivered.On the basis of type of encryption and decryption of the message we can distinguish between Classical and Quantum Cryptography as follows −Sr. No.KeyClassical CryptographyQuantum Cryptography1BasisIn Classical Cryptography encryption and decryption is done on the basis of mathematical computation.On ... Read More

EPC or Electronic Product Code is a universal identifier that are encoded on RFID (Radio Frequency Identification) tags to check identities of objects like inventory, assets and people, and track them. The second generation of this technology, as laid down by EPCglobal Tag Data Standard, is called EPC Gen 2.The architecture of EPC Gen 2, RFID network has two main components −Tags or labels − They are affixed on objects so that they can be identified or tracked.Readers or interrogators − They are the intelligent part of the system that tracks the tags.The architecture is shown as below −RFID tags ... Read More

Electronic Product Code (EPC) is a universal identifier that aims to render a unique identity to every possible physical object of the world. EPCs are mostly encoded on RFID (Radio Frequency Identification) tags that are used to check identities of objects like inventory, assets and people, and track them.EPC is the 96–bit number associated with an RFID tag for identifying a particular tag amongst other tags. It distinguishes two identical products, and also provide the product’s manufacture date, origin or batch number.The EPC structure is laid down by EPCglobal Tag Data Standard, an open standard freely defined by EPCglobal Inc.EPC ... Read More

Inverted Index and Forward Index are data structures used to search text in a document or set of documents.Inverted IndexInverted Index stores the words as index and document name(s) as mapped reference(s).Forward IndexForward Index stores the document name as index and word(s) as mapped reference(s).The following are some of the important differences between the Inverted Index and Forward Index.Sr. No.KeyInverted IndexForward Index1Mapping PatternInverted Index stores the words as index and document name(s) as mapped reference(s).Forward Index stores the document name as index and word(s) as mapped reference(s).2Index Building ProcessScan the document, prepare a list of unique words.Prepare a list of ... Read More

Steganography, or cover writing, is a method where a secret method is converted into fake looking message. This technique helps to keep a message secret. It is pretty difficult to use and understand. The structure of data remains unaltered in Steganography. It is used in text, audio, video or images. Cryptography, or secret writing, is a method where a secret method is converted in cipher text and sent to other person who then decrypt the cipher text into plain text. Cryptography can be classified as Symmetric key cryptography or Asymmetric key cryptography. Read through this article to find out more ... Read More

Suppose we have to design a data structure that supports the following two operations −addWord(word)search(word)The search(word) method can search a literal word or a regular expression string containing only letters a-z or .. A . means it can represent any one letter. So for example, if we add some words like “bad”, “dad”, “mad”, then search for search(“pad”) → false, search(“bad”) → true, search(“.ad”) → true and search(“b..”) → trueTo solve this, we will follow these steps −There are some methods, initially define insertNode(), this will take the head reference and the string s, this will work as follows −curr ... Read More

DefinitionHuffman coding provides codes to characters such that the length of the code depends on the relative frequency or weight of the corresponding character. Huffman codes are of variable-length, and without any prefix (that means no code is a prefix of any other). Any prefix-free binary code can be displayed or visualized as a binary tree with the encoded characters stored at the leaves.Huffman tree or Huffman coding tree defines as a full binary tree in which each leaf of the tree corresponds to a letter in the given alphabet.The Huffman tree is treated as the binary tree associated with ... Read More

A dictionary is defined as a general-purpose data structure for storing a group of objects. A dictionary is associated with a set of keys and each key has a single associated value. When presented with a key, the dictionary will simply return the associated value.For example, the results of a classroom test could be represented as a dictionary with student's names as keys and their scores as the values:results = {'Anik' : 75, 'Aftab' :80, 'James' : 85, 'Manisha': 77, 'Suhana' :87, 'Margaret': 82}Main operations of dictionariesDictionaries typically support so many operations −retrieve a value (based on language, attempting to ... Read More

A way to update our beliefs depended on the arrival of new, relevant pieces of evidence are provided by Bayes rule. For example, if we were trying to provide the probability that a given person has cancer, we would initially just conclude it is whatever percent of the population has cancer. However, given extra evidence such as the fact that the person is a smoker, we can update our probability, since the probability of having cancer is greater given that the person is a smoker. This allows us to utilize prior knowledge to improve our probability estimations.The rule is explained ... Read More