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Lesson Posted on 24/01/2018 Learn Basics of Computer usage
How Does Blockchain Help Fight Fraud?
Utkarsh Kumar
Skills: My ability to make Physics your favorite subject. Crash Course expert. Accomplishments: Awarded...
Lesson Posted on 23/01/2018 Learn Basics of Computer usage
Parul
A Computer is an electronic device that can be instructed to carry out an arbitrary set of arithmetic or logical operations automatically.
1. Introduction:
i. Speed: The speed of computation is very high as the signals pass at the speed of light. Thus, millions of calculations can be done in a second.
ii. Accuracy: As computers work on inbuilt software programs, there is no scope for human errors and are hence, highly accurate.
iii. Information and Storage: A computer can store a large amount of data or instructions in its memory which can be retrieved at point of time.
iv. Other characteristics include: Consistency, Automatic Operation, and Flexibility.
2. Characteristics of Computers:
i. Father of Computer: Charles Babbage
ii. Father of Modern Computer Science: Alan Tuning
iii. First Un-programmable Electronic Digital Computer: Atanasoff Berry Computer (ABC)
iv. First Purpose Electronic Digital Computer: Electronic Numerical Integrator and Calculator (ENIAC)
3. Generations of computers:
a. First Generation (1946 - 1959):
i. Used vacuum tubes & batch processing OS
ii. Machine & Assembly Languages used
iii. Examples: ENIAC, EDVAC, UNIVAC, IBM-701, IBM-650
b. Second Generation (1959 - 1965):
i. Used transistors.
ii. OS: Multi-Bag remaining, Time sharing.
iii. Memory: Magnetic cores, magnetic tapes and disks.
iv. Used assembly and high-level languages like FORTRAN, COBOL, Algol.
v. Examples: IBM 1620, IBM 7094, CDC 1604.
c. Third Generation (1965 - 1971):
i. Used ICs
ii. OS: Remote processing, Time-sharing, Real-time,
iii. Multi-programming
iv. Used High-level languages FORTRAN-II TO IV, Cobol, Pascal PL/1, Basic, Algol-68
v. Examples: IBM-360 series, Honeywell-6000 series, PDP, IBM-370/168
d. Fourth Generation (1971 - 1980):
i. VLSI Circuits Used.
ii. Memory: Semiconductor and Winchester disk.
iii. High level Languages: Fortan 77, Pascal, Cobol used.
iv. Examples: DEC 10, STAR 1000, PDP 11, Super Computers (CRAY-1, CRAY-X-MP).
e. The present generation of computers is the Fifth Generation of computers, i.e. 1980 – till date. The computers use ultra large scale integration (ULSI).
f. High level languages like C++, Java, .NET, etc. are used. Some examples are: laptop, desktop, ultrabook etc.
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Asked on 12/01/2018 Learn Basics of Computer usage
How to become home tutor in computer basis course in Imphal?
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Asked on 21/11/2017 Learn Basics of Computer usage
Answered on 09/02/2018 Learn Basics of Computer usage
Sameer
Lesson Posted on 06/11/2017 Learn Basics of Computer usage
What Are The Fundamentals Of Computer?
Dsr Krishna K
I can teach each and every topics very easily and make it stronger for the students.
First of all, a computer is initially designed to compute the data, means it has to do some mathematical and logical operations on the data according to instructions and produce the output at output devices.
Simply we can define a computer is an electronic device which takes input in the form of data from the input devices and process the data and produce output from the output devices.
i. Advantages of using computer:
1. Human effort will be reduced.
2. Time is not wasted.
3. No need of mard copy.
4. High accuracy.
ii. Components of Computer:
1. CPU: Central Processing Unit.
2. Input Devices: Keyboard, Mouse, Scanner etc.
3. Output Devices: Monitor, Printer etc.
There are lot of questions arise while reading about how input devices can communicate with cpu and how cpu displays the output to output devices.
How data is stored in computer and where processing was done?
What is RAM (Random Access Memory)?
What is ROM (Read Only Memory)?
What is Hard Disc?
In order to speak about fundamentals of computer, it's a vast subject, so learn step by step, I will mention about the topics in a simple manner to give some more detailed information about computer in the next lesson.
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Lesson Posted on 24/08/2017 Learn Basics of Computer usage
SR-IT Academy
SR - IT Academy is one of the leading tutorial point providing services like tutoring and computer training...
Lesson Posted on 23/08/2017 Learn Basics of Computer usage
SR-IT Academy
SR - IT Academy is one of the leading tutorial point providing services like tutoring and computer training...
Pattern Matching Algorithms:
There are various algorithms used to implement the pattern matching problem.
Some of them are:
Brute Force:
The elements of the array come from a set _ called the alphabet; the elements themselves are called characters. Common examples are ASCII text, where each character is an seven-bit integer1, strands of DNA, where the alphabet is the set of nucleotides {A,C, G, T}, or proteins, where the alphabet is the set of 22 amino acids.
The problem we want to solve is the following. Given two strings, a text T[1 .. n] and a pattern P[1 ..m], find the first substring of the text that is the same as the pattern. (It would be easy to extend our algorithms to find all matching substrings, but we will resist.) A substring is just a contiguous subarray. For any shift s, let Ts denote the substring T[s .. s +m− 1]. So more formally, we want to find the smallest shift s such that Ts = P, or report that there is no match.
For example,if the text is the string ‘AMANAPLANACATACANALPANAMA’2 and the pattern is ‘CAN’, then the output should be 15. If the pattern is ‘SPAM’, then the answer should be ‘none’. In most cases the pattern is much smaller than the text; to make this concrete, I’ll assume that m < n/2. Here’s the ‘obvious’ brute force algorithm, but with one immediate improvement. The inner while loop compares the substring Ts with P. If the two strings are not equal, this loop stops at the first character mismatch.
ALGORITHM: Brute_Force(T[1 .. n], P[1 ..m]):
For s
equal
i
while equal and i <= m
if T[s + i − 1] != P[i]
equal
else
i
if equal
return s
return ‘none’
Boyer-Moore algorithm:
The Boyer-Moore algorithm (Boyer & Moore 1977) is considered one of the most efficient algorithms for general pattern matching applications. It is able to recognize and skip certain areas in the text where no match would be possible.
The pattern is shifted from left to right across the text, as in brute-force pattern matching, but comparison is performed from right to left on the pattern. As soon as a mismatch is detected, the pattern is shifted to the right according to one of two key heuristics: the extended bad character rule and the good suffix rule.
To illustrate the operation of these heuristics, suppose that the pattern, P, is aligned at position k of T, and that a mismatch has been detected between the character at position i of the pattern that is, P[i] 6= T[k + i − 1]. Then let c = T[k + i − 1], the mismatched character of the text, and t = P[i + 1: : :m], the suffix of the pattern which matches the corresponding portion of the text.
The extended bad character rule proposes that if there is an occurrence of c in P to the left of i, hat the pattern be shifted so that the two occurrences of c are aligned. If no such shift is possible, the pattern is shifted completely past the c in the text.
The good suffix rule attempts to align the matched suffix, t, with a previous occurrence of t in the pattern (for example, in the pattern reduced, the suffixed occurs twice). If there are no other occurrences of t in the pattern, then the pattern is e shifted so that the a prefix of the pattern matches a suffix of t in the text, or, if this is not possible, shifted completely past t.
The Boyer-Moore algorithm checks both of these heuristics at each stage of the matching process; if both shifts are possible, then the maximum is chosen. In this way, Boyer-Moore achieves so-called `sub-linear' performance for most texts.
To apply the Boyer-Moore algorithm to the permuted output of the Burrows-Wheeler transform, we de_ne an array Hr to relate the characters in T with their position in F, such that 8i : 1 _ i _ n; T[i] = F[Hr[i]]
The Hr array can be computed e_ciently with the following procedure:
Compute-Hr-Array(W; id)
1. i id
2. for j 1 to n do
3. i W[i]
4. Hr[j] i
5. end for
where id is the index of the _rst character in L, obtained from the BWT output.
The Hr array introduces the possibility of accessing random characters in the permuted string. Using this technique, we have implemented a Boyer-Moore algorithm for BWT by adapting a standard Boyer-Moore routine to access character i at F[Hr[i]] instead of at T[i]. The asymptotic complexity is the same for this approach as for Boyer-Moore on uncompressed text, although in practice it is a little slower, due to the time taken to construct Hr, and an extra dereference each time a character is needed.
KMP String Matching Algorithm: Plan
KMP Iteration:
Case 1: 0 · r − ` < p
– We’ve matched another symbol; increment r
– Our current match is the empty string and the next symbol does not
match p[0]; increment ` and r
– Our current match is a nonempty proper prefix of p and the next
symbol does not extend this match
Case 2: r − ` = p
Lesson Posted on 19/08/2017 Learn Basics of Computer usage
Himansu Sekhar
Worked as soft skill trainer and Delivery Analyst . Worked with MNC( IBM) on Advanced computer knowledge training .
Basic Concepts Of Computer:
1.1 Introduction:
A computer is a programmable machine designed to perform arithmetic and logical operations automatically and sequentially on the input given by the user and gives the desired output after processing. Computer components are
divided into two major categories namely hardware and software. Hardware is the machine itself and its connected devices such as monitor, keyboard, mouse etc. Software are the set of programs that make use of hardware for performingvarious functions.
1.2 Objectives:
1.3 Characteristics of computers:
The characteristics of computers that have made them so powerful and universally useful are speed, accuracy, diligence, versatility and storage capacity. Let us discuss them briefly.
i. Speed:
Computers work at an incredible speed. A powerful computer is capable of performing about 3-4 million simple instructions per second.
ii. Accuracy:
In addition to being fast, computers are also accurate. Errors that may occur can almost always be attributed to human
error (inaccurate data, poorly designed system or faulty instructions/programs written by the programmer)
iii. Diligence:
Unlike human beings, computers are highly consistent. They do not suffer from human traits of boredom and tiredness
resulting in lack of concentration. Computers, therefore, are better than human beings in performing voluminous and
repetitive jobs.
iv. Versatility:
Computers are versatile machines and are capable of performing any task as long as it can be broken down into a
series of logical steps. The presence of computers can be seen in almost every sphere – Railway/Air reservation, Banks, Hotels, Weather forecasting and many more.
v. Storage Capacity:
Today’s computers can store large volumes of data. A piece of information once recorded (or stored) in the computer,
can never be forgotten and can be retrieved almost instantaneously.
1.4 Computer Organization:
A computer system consists of mainly four basic units; namely input unit, storage unit, central processing
unit and output unit. Central Processing unit further includes Arithmetic logic unit and control unit, as shown in
computer performs five major operations or functions irrespective of its size and make. These are:
1.4.1 Functional Units:
a. Input Unit: This unit is used for entering data and programs into the computer system by the user for
processing.
b. Storage Unit: The storage unit is used for storing data and instructions before and after processing.
c. Output Unit: The output unit is used for storing the result as output produced by the computer after processing.
d. Processing: The task of performing operations like arithmetic and logical operations is called processing. The Central Processing Unit (CPU) takes data and instructions from the storage unit and makes all sorts of calculations based on the instructions given and the type of data provided. It is then sent back to the storage unit. CPU includes Arithmetic logic unit (ALU) and control unit (CU).
e. Arithmetic Logic Unit: All calculations and comparisons, based on the instructions provided, are carried out within the ALU. It performs arithmetic functions like addition, subtraction, multiplication, division and also logical operations like greater than, less than and equal to etc.
f. Control Unit: Controlling of all operations like input, processing and output are performed by control unit. It takes care of step by step processing of all operations inside the computer.
1.4.2 Memory:
Computer’s memory can be classified into two types; primary memory and secondary memory
a. Primary Memory can be further classified as RAM and ROM.
b. Secondary Memory:
RAM is volatile memory having a limited storage capacity. Secondary/auxiliary memory is storage other than the RAM. These include devices that are peripheral and are connected and controlled by the computer to enable permanent storage of programs and data. Secondary storage devices are of two types; magnetic and optical. Magnetic devices include hard disks and optical storage devices are CDs, DVDs, Pen drive, Zip drive etc.
1.4.3 Input / Output Devices:
These devices are used to enter information and instructions into a computer for storage or processing and to deliver the processed data to a user. Input/Output devices are required for users to communicate with the computer. In simple terms, input devices bring information INTO the computer and output devices bring information OUT of a computer system. These input/output devices are also known as peripherals since they surround the CPU and memory of a computer system.
a) Input Devices:
An input device is any device that provides input to a computer. There are many input devices, but the two most common ones are a keyboard and mouse. Every key you press on the keyboard and every movement or
click you make with the mouse sends a specific input signal to the computer.
1.5 Computer Software:
Computer software is the set of programs that makes the hardware perform a set of tasks in particular order. Hardware and software are complimentary to each other. Both have to work together to produce meaningful results. Computer software is classified into two broad categories; system software and application software.
1.5.1 System Software:
System software consists of a group of programs that control the operations of a computer equipment including functions like managing memory, managing peripherals, loading, storing, and is an interface between the application programs and the computer. MS DOS (Microsoft’s Disk Operating System), UNIX are examples of system software.
1.5.2 Application software:
Software that can perform a specific task for the user, such as word processing, accounting, budgeting or payroll, fall
under the category of application software. Word processors, spreadsheets, database management systems are all
examples of general purpose application software. Types of application software are:
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Lesson Posted on 08/07/2017 Learn Basics of Computer usage
Computer Worksheet For Grade I/II
Preethi Vinitha W.
I have done my MBA & B.tech in IT and I have four years experience in teaching. Both as tutor and Teacher.
Chapters: How Does a Computer Work And Starting Up And Shutting Down:
1. Write T for True and F for False:
2. Fill in the blanks:
3. Rearrange the steps in correct order to show how a computer is shut down:
4. Answer the following:
_______________________________________________________________________________________________________________________________________________________________________________________________________________________________________
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