This ppt is about semiconductor diodes.You can get every basic information about PN junction diode and its working and some more information about the semiconductors.
A silicon-controlled rectifier or semiconductor-controlled rectifier is a four-layer solid-state current-controlling device. Some sources define silicon-controlled rectifiers and thyristors as synonymous,[5] other sources define silicon-controlled rectifiers as a proper subset of the set of thyristors. SCRs are mainly used in devices where the control of high power, possibly coupled with high voltage, is demanded. Their operation makes them suitable for use in medium- to high-voltage AC power control applications, such as lamp dimming, power regulators and motor control.
This ppt is about semiconductor diodes.You can get every basic information about PN junction diode and its working and some more information about the semiconductors.
A silicon-controlled rectifier or semiconductor-controlled rectifier is a four-layer solid-state current-controlling device. Some sources define silicon-controlled rectifiers and thyristors as synonymous,[5] other sources define silicon-controlled rectifiers as a proper subset of the set of thyristors. SCRs are mainly used in devices where the control of high power, possibly coupled with high voltage, is demanded. Their operation makes them suitable for use in medium- to high-voltage AC power control applications, such as lamp dimming, power regulators and motor control.
This ppt provides a brief overview on thyristors commonly known as SCRs. V- I characteristics curve, triggering methods, protection methods, series and parallel operations of SCRs, applications are discussed in this slide.
A Kelvin bridge, also called a Kelvin double bridge and in some countries a Thomson bridge, is a measuring instrument used to measure unknown electrical resistors below 1 ohm. It is specifically designed to measure resistors that are constructed as four terminal resistors.
PowerPoint Presentation on using IC 555 Timer as an Astable Multi vibrator. Working of the astable multi vibrator, advantages and disadvantages of an Astable Multi-vibrator,Input and Output Pins of 555 IC, Formulae for calculating the charge and discharge time and cycle time of the astable multi vibrator.
It’s a power electronics project. It is able to give output voltage(DC) more and less than input voltage as per requirement.
We can generate variable DC voltage which is less than input, but, the special things about this converter is, it has capability to produce variable DC voltage as high as twice the input voltage.
We have specially designed and manufactured inductor for this project.
If you want any more information about technology then follow me on Social Media:
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By this slide, I will explain about digital logic... after watching my Digital Logic Presentation you will able to gain basic idea of digital logic... also you will gain basic knowledge about number conversion, gates, k-map, and so on...
This ppt provides a brief overview on thyristors commonly known as SCRs. V- I characteristics curve, triggering methods, protection methods, series and parallel operations of SCRs, applications are discussed in this slide.
A Kelvin bridge, also called a Kelvin double bridge and in some countries a Thomson bridge, is a measuring instrument used to measure unknown electrical resistors below 1 ohm. It is specifically designed to measure resistors that are constructed as four terminal resistors.
PowerPoint Presentation on using IC 555 Timer as an Astable Multi vibrator. Working of the astable multi vibrator, advantages and disadvantages of an Astable Multi-vibrator,Input and Output Pins of 555 IC, Formulae for calculating the charge and discharge time and cycle time of the astable multi vibrator.
It’s a power electronics project. It is able to give output voltage(DC) more and less than input voltage as per requirement.
We can generate variable DC voltage which is less than input, but, the special things about this converter is, it has capability to produce variable DC voltage as high as twice the input voltage.
We have specially designed and manufactured inductor for this project.
If you want any more information about technology then follow me on Social Media:
Facebook: https://www.facebook.com/trkmahendra/
Instagram: https://www.instagram.com/trkmahendra/
Twitter: https://www.twitter.com/TRKmahendra/
TikTok: https://www.tiktok.com/trk.mahendra/
website: https://www.mahendrasingh.com.np/
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By this slide, I will explain about digital logic... after watching my Digital Logic Presentation you will able to gain basic idea of digital logic... also you will gain basic knowledge about number conversion, gates, k-map, and so on...
Number Systems — Decimal, Binary, Octal, and Hexadecimal
Base 10 (Decimal) — Represent any number using 10 digits [0–9]
Base 2 (Binary) — Represent any number using 2 digits [0–1]
Base 8 (Octal) — Represent any number using 8 digits [0–7]
Base 16(Hexadecimal) — Represent any number using 10 digits and 6 characters [0–9, A, B, C, D, E, F]
Business environment scanning market survey tools and techniques by mathankumarMathankumar S
Business Environment Scanning Market Survey Tools and Techniques (Its very clearly briefed about Entrepreneurship,
Entrepreneur, Need for Entrepreneur, Common Myths about Entrepreneurs, Benefits of Being an Entrepreneur, Innovation, Elements of Innovation, Creativity, Motivation, How should Engineer Think?, How to Identify and Motivate a Student?, Science Club, Entrepreneurship Development, Ministry of Skill Development and Entrepreneurship (MSDE), Pradhan Mantri Kaushal Vikas Yojana (PMKVY), Udyamita, Design Clinic Scheme for Design Expertise to MSME Manufacturing Sector, MSME Salient Features, MSME Schemes,
Prototype, Market Survey, MARKETING SUPPORT TO MSMEs, MARKET SURVEY FOR COMMERCIALIZATION, STARTING A NEW VENTURE, How to become a Successful Entrepreneur
Biomedical Circuits & Networks - Transient Analysis and Two Port NetworksMathankumar S
Biomedical Circuits & Networks - Transient Analysis and Two Port Networks (It includes AC and DC Response, R-L-C Circuits, time constant, Symmetrical networks, Z-Parameter, Y-Parameter ABCD Parameter and h-Parameter)
Biomedical Circuits & Networks - Network synthesis and filter designMathankumar S
Biomedical Circuits & Networks - Network synthesis and filter design (It includes cauer form, poles and zeros, Impedance function, Hurwitz polynominal, Positive real function, Types of filters, Initial value theorem, Butterworth filter, Chebyshev filter, Chebyshev approximation, Low pass filter, T and pie network, m -derived low pass filter, transfer function, selectivity parameter & discrimination parameter)
Biomedical Technical Skill Development - Questions (Multi Choice Type)Mathankumar S
Biomedical Technical Skill Development - Questions (Objective type Questions for Biomedical Engineering & Medical Electronics) - Students can able to get ideas about fundamentals
Biomedical Control Systems - BIOMEDICAL APPLICATIONS (Short Questions & Answers)Mathankumar S
Biomedical control systems - BIOMEDICAL APPLICATIONS (Short Questions & Answers) - ITS DEALS WITH Examples of Biological control Systems: Cardiovascular Control System, Endocrine Control Systems, Pupil Control System, Skeletal Muscle Servomechanism, Oculo - motor system, sugar level Control Mechanism. Temperature control, Blood pressure control.
Biomedical Control Systems - THE CONCEPT OF STABILITY & ROOT LOCUS TECHNIQUE ...Mathankumar S
Biomedical control systems - THE CONCEPT OF STABILITY & ROOT LOCUS TECHNIQUE (short Questions & Answers) - ITS DEALS WITH STABILITY OF THE SYSTEM (ROUTH HURWITZ CRITERION, ROUTH ARRAY), ROOT LOCUS TECHNIQUE, ZEROS & POLES,
Biomedical Control Systems - Time Response Analysis (Short Questions & Answers)Mathankumar S
Biomedical Control Systems - Time Response Analysis (Short Questions & Answers) - Its detailed about Standard Test Signals, Time Response Analysis of First and Second Order Systems, Steady state errors and Error constants, Effects of Adding Zero to a system, Damping System and PD & PID Controller.
Biomedical Control Systems - SYSTEM CONCEPTS (Short Questions & Answers)Mathankumar S
Biomedical Control Systems - SYSTEM CONCEPTS (Short Questions & Answers) - Its Deal with Types of systems, Open loop systems, Closed Loop systems, Effects of feedback, Mathematical Models of Physical systems: Introduction, Differential equations, Transfer functions, Block Diagram Algebra, Signal Flow Graphs.
Biological control systems - Time Response Analysis - S.Mathankumar-VMKVECMathankumar S
Biological control systems - Time Response Analysis - Step and Impulse responses of first order and second order systems, Determination of time domain specifications of first and second order systems from its output responses.
Biological control systems - System Concepts-Mathankumar.S, VMKVECMathankumar S
Biological control systems - System Concepts- Basic structure of control system - Types of systems - Open loop systems, closed loop systems, Effects of feedback, Block diagram & Signal flow graph, conversion of block diagram to signal flow graph, reduction of block diagram and signal flow graph.
NO1 Uk best vashikaran specialist in delhi vashikaran baba near me online vas...Amil Baba Dawood bangali
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Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
1. DIGITAL ELECTRONICS
The term digital is derived from the Wily computers perform operations, by counting
digits. For many years, applications of digital electronics were confined to computer
systems.
Today, digital technology is applied in a wide range of areas in addition to computers.
Such applications as television, communications systems, radar, navigation and
guidance systems, military systems, medical instrumentation, industrial process control
and consumer electronics use digital techniques Over the years digital technology has
progressed from vacuum-tube circuits to discrete transistors to complex integrated
circuits, some of which contain millions of transistors.
ANALOG :
An analog quantity is one having continuous values.
Most things that can be measured quantitatively occur in nature in analog form. For
example, the air temperature changes over a continuous range of values. During a
given day, the temperature does not go from, say, 70° to 71 ° instantaneously; it takes on
all the infinite values in between. If you graphed the temperature on a typical summer
day. Other examples of analog quantities are time, pressure, distance, and sound.
DIGITAL:
A digital quantity is one having a discrete set of values.
The Digital Advantage Digital representation has certain advantages over analog
representation in electronics applications. For one thing, digital data can be processed
and transmitted more efficiently and reliably than, analog data. Also, digital data has a
great advantage when storage is necessary. For example, music when converted to
digital form can be stored more compactly and reproduced with greater accuracy and
clarity than is possible when it is in analog form. Noise (unwanted voltage fluctuations)
does not affect digital data nearly as much as it does analog signals.
ANALOG REPRESENTATION
In analog representation a quantity is represented by a voltage, current, or meter
movement that is proportional to the value of that quantity. Analog quantities such as
those cited above have an important characteristic: they can vary over a continuous
range of values.
2. DIGITAL REPRESENTATION
In digital representation the quantities are represented not by proportional quantities
but by symbols called digits. As an example, consider the digital watch, which provides
the time of day in the form of decimal digits which represent hours and minutes (and
sometimes seconds). As we know, the time of day changes continuously, but the digital
watch reading does not change continuously; rather, it changes in steps of one per
minute (or per second). In other words, this digital representation of the time of day
changes in discrete steps, as compared with the representation of time provided by an
analog watch, where the dial reading changes continuously.
The major difference between analog and digital quantities, then, can be simply stated
as follows:
Analog = continuous
Digital = discrete (step by step)
ADVANTAGES AND LIMITATIONS OF DIGITAL TECHNIQUES
Advantages:
Easier to design. Exact values of voltage or current are not important, only the
range (HIGH or LOW) in which they fall.
Information storage is easy.
Accuracy and precision are greater.
Operation can be programmed. Analog systems can also be programmed, but the
variety and complexity of the available operations is severely limited.
Digital circuits are less affected by noise. As long as the noise is not large enough
to prevent us from distinguishing a HIGH from a LOW.
More digital circuitry can be fabricated on IC chips.
Limitations:
There is really only one major drawback when using digital techniques:
The real world is mainly analog.
Most physical quantities are analog in nature, and it is these quantities that are
often the inputs and outputs that are being monitored, operated on, and
controlled by a system.
3. To take advantage of digital techniques when dealing with analog inputs and outputs,
three steps must be followed:
1. Convert the real-world analog inputs to digital form. (ADC)
2. Process (operate on) the digital information.
3. Convert the digital outputs back to real-world analog form. (DAC)
Figure: The process of converting analog sound to digital and then back to analog
Digital electronics involves circuits and systems in which there are only two possible
states. These states are represented by two different voltage levels: A HIGH and a LOW.
The two states can also be represented by Current levels, bits and bumps on a CD or
DVD, etc. In digital systems such a computers, combinations of the two states, called
codes, are used to represent numbers, symbols, alphabetic characters, and other types of
information.
4. NUMBER SYSTEMS
Introduction:
Inside today’s computers, data is represented as 1’s and 0’s. These 1’s and 0’s might be
stored magnetically on a disk, or as a state in a transistor, core, or vacuum tube. To
perform useful operations on these 1’s and 0’s had to organize them together into
patterns that make up codes. Modern digital systems do not represent numeric values
using the decimal system. Instead, they typically use a binary or two’s complement
numbering system. To understand the digital system arithmetic, one must understand
how digital systems represent numbers.
The English mathematician George Boole (1815-1864) sought to give symbolic form to
Aristotle‘s system of logic. Boole wrote a treatise on the subject in 1854, titled an
Investigation of the Laws of Thought, on which are Founded the Mathematical Theories
of Logic and Probabilities, which codified several rules of relationship between
mathematical quantities limited to one of two possible values: true or false, 1 or 0. His
mathematical system became known as Boolean algebra.
Many number systems are in use in digital technology. The most common are the
decimal, binary, octal, and hexadecimal systems. The decimal system is clearly the most
familiar to us because it is a tool that we use every day.
In conventional arithmetic, a number system based on ten units (0 to 9) is used.
However, arithmetic and logic circuits used in computers and other digital systems
operate with only 0’s and 1’s because it is very difficult to design circuits that require
ten distinct states. The number system with the basic symbols 0 and 1 is called binary.
Although digital systems use binary numbers for their internal operations,
communication with the external world has to be done in decimal systems. In order to
simplify the communication, every decimal number may be represented by a unique
sequence of binary digits; this is known as binary encoding. In this chapter we discuss
number systems in general and the binary system in particular. In addition, we consider
the octal and hexadecimal number systems and fixed and floating-point representation
of numbers. The chapter ends with a discussion on weighted and non weighted binary
encoding of decimal digits.
Modern computers do not work with decimal numbers. Instead of, they process binary
numbers, groups of 0’s and 1’s.
5. Why binary numbers?
Because electronic devices are most reliable when designed for two – states (Binary)
operation either on or off. People do not like working with binary numbers because
they are very long. Entering binary numbers into computer becomes tedious. Therefore
octal and hexadecimal numbers are widely used to compress long strings of binary
numbers.
In general, in any number system there is an ordered set of symbols known as digits
with rules defined for performing arithmetic operations like addition, subtraction,
multiplication and division. A collection of these digits makes a number which in
general has two parts – integer and fractional, set a part by a radix point (. ), that is
Examining some of its characteristics will help us to better understand the other
systems. In the next few pages we shall introduce four numerical representation
systems that are used in the digital system. There are other systems, which we will look
at briefly.
Decimal
Binary
Octal
Hexadecimal
Decimal System
The invention of decimal number systems has been the most important factor in the
development of science and technology. The term decimal comes from the Latin word
for “ten.” The decimal number system uses positional number representation, which
means that the value of each digit is determined by its position in a number.
The base (also called radix) of a number system is the number of symbols that the
system contains. The decimal system has ten symbols: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9; in other
words it has a base of 10. Each position in the decimal system is 10 times more
significant than the previous position. The decimal system is composed of 10 numerals
or symbols. These 10 symbols are 0, 1, 2, 3, 4, 5, 6, 7, 8, 9. Using these symbols as digits
of a number, we can express any quantity. The decimal system is also called the base -
10 system because it has 10 digits.
6. People have been using the decimal (base 10) numbering system for so long that they
probably take it for granted. When one sees a number like “123”, he doesn’t think about
the value 123; rather, he generates a mental image of how many items this value
represents. In reality, however, the number 123 represents:
1*102 + 2*101 + 3*100
(Or)
100 + 20 + 3
Each digit appearing to the left of the decimal point represents a value between zero
and nine times an increasing power of ten. Digits appearing to the right of the decimal
point represent a value between zero and nine times an increasing negative power of
ten.
For example, the value 215.123 means:
2*102 + 1*101 + 5*100 + 1*10–1 + 2*10–2 + 3*10–3
(Or)
200 + 10 + 5 + 0.1 + 0.02 + 0.003
BINARY NUMBER SYSTEM
Digital computers use the binary number system, which has only two symbols: 0 and 1.
The numbers in binary system are represented as combinations of these two symbols.
The decimal system uses power of 10 and binary system uses powers of 2.
In the binary system, there are only two symbols or possible digit values, 0 and 1. This
base-2 system can be used to represent any quantity that can be represented in decimal
or other base system.
23
22
21
20
2-1
2-2
2-3
= 8 = 4 = 2 = 1 . = 0.5 = 0.25 = 0.125
Most Significant
Digit (Bit)
Binary
Point
Least Significant
Digit (Bit)
The binary numbers has a radix of 2. As r ¼ 2, only two digits are needed, and these are
0 and 1. A binary digit, 0 or 1, is called a bit. Like the decimal system, binary is a
positional system, except that each bit position corresponds to a power of 2 instead of a
power of 10.
In digital systems, the binary number system and other number systems closely related
to it are used almost exclusively. However, people are accustomed to using the decimal
number system; hence digital systems must often provide conversion between decimal
7. and binary numbers. The decimal value of a binary number can be formed by
multiplying each power of 2 by either 1 or 0, and adding the values together.
Binary Counting
The Binary counting sequence is shown in the table:
The binary digit is also referred to as Bit (the acronym for Binary Digit). A string of 4
bits is called a nibble and a string of 8 bits is called a byte. A byte is the basic unit of
data in computers.
The number 125 actually means 1* 102 + 2* 101 +5*100 . In binary system, the same
number (125) is represented as 1111101 meaning
1*26 +1* 25 +1* 24 +1*23 +1* 22 +0* 21 +1*2 0
The table (1) lists the first 20 binary numbers.
8. Table (1): First 20 Binary Numbers
To express the value of a binary number, therefore, a n-1 2n-1 + a n-2 2n-2 + ……. + a 0 is
expressed as a n-1, a n-2 ….. a 0 where ai is either 1 or 0 and n is the number of digits to
the left of the binary (radix) point.
OCTAL NUMBER SYSTEM
Digital systems operate only on binary numbers. Since binary numbers are often very
long, two shorthand notations, octal and hexadecimal, are used for representing large
binary numbers. The octal number system uses a base or radix of 8; thus it has digits
from 0 to r - 1, or 8 - 1, or 7. As in the decimal and binary systems, the positional value
of each digit in a sequence of numbers is definitely fixed. Each position in an octal
number is a power of 8, and each position is 8 times more significant than the previous
position.
The octal number system has a base of eight, meaning that it has eight possible digits:
0,1,2,3,4,5,6,7.
The octal number system has a base, or radix as 8: eight different symbols are used to
represent numbers. These are commonly 0,1,2,3,4,5,6,7. We show the first 20 octal
numbers and their decimal equivalents in the table (2).
9. Table (2) : First 20 Octal Numbers
To convert an octal number to a decimal number, we use the same sort of polynomial as
was used in the binary case, except that we now have a radix of 8 instead of 2. Therefore
1213 in octal is
=1*83+2*82+1*81+3*80
=512 + 128 + 8 + 3 =651
in decimal. Also, 1.123 in octal is 1*80+1*8-1+2*8-2+3*8-3 =1.83/512 in decimal.
HEXADECIMAL NUMBER SYSTEM
The hexadecimal system uses base 16. Thus, it has 16 possible digit symbols. It uses the
digits 0 through 9 plus the letters A, B, C, D, E, and F as the 16 digit symbols.
When the machine is handling numbers in binary but in groups of four digits, it is
convenient to have a code for representing each of these sets of four digits. Since 16
possible different numbers can be represented, the digits 0 through 9 will not suffice. So
the letters A, B, C, D, E and F are also used. Hexadecimal numbers are strings of these
digits. The numbers in decimal, binary and hexadecimal is shown in the table (3).
10. Table (3) : First 16 Hexadecimal Numbers
The base or radix of a number system is defined as the number of different digits, which
can occur in each position in the number system. The decimal number system has a
base, or radix of 10. Thus the system has 10 different digits (0,1,2, …,9), any one of
which may be used in each position in a number.
HEXADECIMAL NUMBERING SYSTEM
The hexadecimal numbering system is the most common system seen today in
representing raw computer data. This is because it is very convenient to represent
groups of 4 bits. Consequently, one byte (8 bits) can be represented by two groups of
four bits easily in hexadecimal.
11. Hexadecimal uses a base 16 numbering system. This means that we have 16 symbols to
use for digits. Consequently, we must invent new digits beyond 9. The digits used in
hex are the letters A, B, C, D, E, and F. If we start counting, we get the table below:
Data Organization
In pure mathematics a value may take an arbitrary number of bits. Digital systems, on
the other hand, generally work with some specific number of bits. Common collections
are single bits, groups of four bits (called nibbles), groups of eight bits (called bytes),
groups of 16 bits (called words), and more. The sizes are not arbitrary. There is a good
reason for these particular values.
To begin with, a single place or position in a binary number is called a bit, short for
binary digit. For example, the binary number 01102 is made up of four bits.
The rightmost bit, the one that represents the ones place, is called the Least Significant
Bit or LSB.
The leftmost bit, the one that represents the highest power of two for that number, is
called the Most Significant Bit or MSB.
Note that the MSB represents a bit position. It doesn't mean that a '1' must exist in that
position.
12. The next four terms describe how bits might be grouped together.
• Nibble – A four bit binary number
• Byte – A unit of storage for a single character, typically an eight bit (2 nibble) binary
number (short for binary term)
• Word – Typically a sixteen bit (2 byte) binary number
• Double Word – A thirty-two bit (2 word) binary number
The following are some examples of each type of binary number.
Bit 12
Nibble 10102
Byte 101001012
Word 10100101111100002
Double Word 101001011111000011001110111011012
Bits
The smallest “unit” of data on a binary computer or digital system is a single bit. Bit, an
abbreviation for Binary Digit, can hold either a 0 or a 1. A bit is the smallest unit of
information a computer can understand. Since a single bit is capable of representing
only two different values (typically zero or one) one may get the impression that there
are a very small number of items one can represent with a single bit. That’s not true!
There are an infinite number of items one can represent with a single bit.
With a single bit, one can represent any two distinct items. Examples include zero or
one, true or false, on or off, male or female, and right or wrong. However, one are not
limited to representing binary data types (that is, those objects which have only two
distinct values). One could use a single bit to represent the numbers 321 and 1234. Or
perhaps 6251 and 2. One could also use a single bit to represent the colours green and
blue. One could even represent two unrelated objects with a single bit. For example,
one could represent the colour red and the number 3256 with a single bit. One can
represent any two different values with a single bit. However, one can represent only
two different values with a single bit.
To confuse things even more, different bits can represent different things. For example,
one bit might be used to represent the values zero and one, while an adjacent bit might
be used to represent the values true and false. How can one tell by looking at the bits?
The answer, of course, is that one can’t. But this illustrates the whole idea behind
computer data structures: data is what one define it to be. If one uses a bit to represent a
boolean (true/false) value then that bit (by definition) represents true or false. For the
bit to have any true meaning, one must be consistent. That is, if one is using a bit to
represent true or false at one point in his program, he shouldn’t use the true/false value
stored in that bit to represent green or blue later.
13. Since most items one will be trying to model require more than two different values,
single bit values aren’t the most popular data type used. However, since everything else
consists of groups of bits, bits will play an important role in programs. Of course, there
are several data types that require two distinct values, so it would seem that bits are
important by themselves. However, individual bits are difficult to manipulate, so other
data types are often used to represent boolean values.
Nibbles
A nibble is a collection of four bits. It wouldn’t be a particularly interesting data
structure except for two items: BCD (binary coded decimal) numbers and hexadecimal
numbers. It takes four bits to represent a single BCD or hexadecimal digit. With a
nibble, one can represent up to 16 distinct values. In the case of hexadecimal numbers,
the values 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, and F are represented with four bits (see
“The Hexadecimal Numbering System”). BCD uses ten different digits (0, 1, 2, 3, 4, 5, 6,
7, 8, 9) and requires four bits. In fact, any sixteen distinct values can be represented with
a nibble, but hexadecimal and BCD digits are the primary items we can represent with a
single nibble.
Bytes
Computer memory must be able to store letters, numbers, and symbols. A single bit by
itself cannot be of much use. Bits are combined to represent some meaningful data. A
group of eight bits is called a byte. It can represent a character and is the smallest
addressable datum (data item) on the most of the digital systems (e.g. 80 × 86
microprocessor). The most important data type is the byte. Main memory and
input/output addresses on the 80 × 86 are all byte addresses. This means that the
smallest item that can be individually accessed by an 80 × 86 program is an eight-bit
value. To access anything smaller requires that you read the byte containing the data
and mask out the unwanted bits. The bits in a byte are normally numbered from zero to
seven using the convention in Fig. 1.1. Bit 0 is the low order bit or least significant bit,
bit 7 is the high order bit or most significant bit of the byte. All other bits are referred by
their number.
Fig. 1.1 Bit numbering in a byte
Note: That a byte also contains exactly two nibbles (see Fig. 1.2).
Fig. 1.2 The two nibbles in a byte
14. Bits 0–3 comprise the low order nibble, bits 4–7 form the high order nibble. Since a byte
contains exactly two nibbles, byte values require two hexadecimal digits.
Since a byte contains eight bits, it can represent 28, or 256, different values. Generally,
a byte is used to represent numeric values in the range 0.255, signed numbers in the
range –128.. + 127 (refer “Signed binary representation”). Many data types have fewer
than 256 items so eight bits is usually sufficient. For a byte addressable machine, it turns
out to be more efficient to manipulate a whole byte than an individual bit or nibble. For
this reason, most programmers use a whole byte to represent data types that require no
more than 256 items, even if fewer than eight bits would suffice. For example, we’ll
often represent the boolean values true and false by 000000012 and 000000002
(respectively).
Probably the most important use for a byte is holding a character code. Characters
typed at the keyboard, displayed on the screen, and printed on the printer all have
numeric values.
Words
A word is a group of 16 bits. Bits in a word are numbered starting from zero on up to
fifteen. The bit numbering appears in Fig. 1.3.
Fig. 1.3 Bit numbers in a word
Like the byte, bit 0 is the low order bit and bit 15 is the high order bit. When referencing
the other bits in a word use their bit position number.
Notice that a word contains exactly two bytes. Bits 0 through 7 form the low order byte,
bits 8 through 15 form the high order byte (see Fig. 1.4).
Fig. 1.4 The two bytes in a word
15. Naturally, a word may be further broken down into four nibbles as shown in Fig. 1.5.
Fig. 1.5 Nibbles in a word
Nibble zero is the low order nibble in the word and nibble three is the high order nibble
of the word. The other two nibbles are “nibble one” and “nibble two”.
With 16 bits, 216 (65,536) different values can be represented. These could be the values
in the range 0 to 65,535 (or –32,768 to +32,767) or any other data type with no more than
65,536 values.
Words can represent integer values in the range 0 to 65,535 or –32,768 to 32,767.
Unsigned numeric values are represented by the binary value corresponding to the bits
in the word. Signed numeric values use the two’s complement form for numeric values
(refer “Signed binary representation”).
Double Words
A double word is exactly what its name implies, a pair of words. Therefore, a double
word quantity is 32 bits long.
16. CONVERSIONS
Code Conversion
Converting from one code form to another code form is called code conversion, like
converting from binary to decimal or converting from hexadecimal to decimal.
Binary-To-Decimal Conversion
Any binary number can be converted to its decimal equivalent simply by summing
together the weights of the various positions in the binary number which contain a 1.
and
You should have noticed that the method is to find the weights (i.e., powers of 2) for
each bit position that contains a 1, and then to add them up.
There are 2 methods:
Reverse of Binary-To-Decimal Method
Repeat Division
Reverse of Binary-To-Decimal Method
Repeat Division-Convert decimal to binary
This method uses repeated division by 2. Convert 2510 to binary
17. DECIMAL NUMBER TO BINARY NUMBER
To convert a decimal number into binary number it requires successive division by 2
writing down each quotient and its remainder. The remainders are taken in the reverse
order, which is the binary equivalent of the decimal number. For example, let it is
required to convert the decimal number 25 to its binary equivalent.
The binary equivalent for 2510 =110012
To convert decimal fractions into equivalent binary fractions repeatedly double the
decimal fraction. The number (0 or 1) that appears on the left is written separately. The
bits that are written in this manner are read from top to bottom with a decimal point on
the left. For example if the given number is 0.0625, conversion is done in the following
manner.
The Multiplication cannot be continued further, as the fractional part in the previous
step has already become zero. Therefore, 0.062510 = .00012
DECIMAL NUMBER TO OCTAL NUMBER
Conversion from decimal to octal can be performed by repeatedly dividing the decimal
number by 8 and using each remainder as a digit in the octal number being formed. For
instance, to convert decimal number 200 to an octal representation, we divide as
follows.
Therefore (200)10 = (310)8
18. DECIMAL NUMBER TO HEXADECIMAL NUMBER
One way to convert decimal to Hexadecimal is the hex dabbles. The idea is as divide
successively by 16, writing down the remainders. Here is a sample of how it is done. To
convert decimal 2429 to hexadecimal,
Therefore (2429)10 = (9AF)16
BINARY NUMBER TO DECIMAL NUMBER
For converting the value of Binary numbers to decimal equivalent we have to find its
quantity, which is found by multiplying a digit by its place value. The following
example illustrates the conversion of binary numbers to decimal system.
101 =1*23-1 +0*23-2+1*23-3
= 1*22 +0*21+1*20
= 4 + 0 +1
= 5
1001 =1*24-1 +0*24-2+0*24-3 + 1*24-4
= 1*23 + 0*22 + 0*21 + 1*20
= 8+1
= 9
11.011 =1*22-1 +1*22-2+0*22-3 +1*22-4+1*22-5
=1*21 +1*20+0*2-1 +1*2-2+1*2-3
= 2+1+1/4+1/8
=3 3/8
BINARY NUMBER TO OCTAL NUMBER
There is a simple trick for converting a binary number to an octal number. Simply
group the binary digits into groups of 3, starting at the octal point, and read each set of
three binary digits.
Octal to Decimal, Decimal to Octal Conversion
Converting octal to decimal is just like converting binary to decimal, except instead of
powers of 2, we use powers of 8. That is, the LSB is 80, the next is 81, then 82, etc.
To convert 172 in octal to decimal:
1 7 2
82 81 80
Weight = 1*82 + 7*81 + 2*80
= 1*64 + 7*8 + 2*1
= 12210
19. Converting decimal to octal is just like converting decimal to binary, except instead of
dividing by 2, we divide by 8. To convert 122 to octal:
122/8 = 15 remainder 2
15/8 = 1 remainder 7
1/8 = 0 remainder 1
= 1728
If using a calculator to perform the divisions, the result will include a decimal fraction
instead of a remainder. The remainder can be obtained by multiplying the decimal
fraction by 8. For example, 122/8 = 15.25. Then multiply 0.25 * 8 to get a remainder of 2.
Octal to Binary, Binary to Octal Conversion
Octal becomes very useful in converting to binary, because it is quite simple. The
conversion can be done by looking at 3 bit combinations, and then concatenating them
together. Here is the equivalent for each individual octal digit and binary
representation:
each octal digit with the corresponding three binary digits.
For example, 372 in octal becomes 010 111 010 or 010111010 in binary.
777 in octal becomes 111 111 111 or 111111111 in binary.
The same applies in the other direction:
100111010 in binary becomes 100 111 010 or 472 in octal.
Since it is so easy to convert back and forth between octal and binary, octal is sometimes
used to represent binary codes. Octal is most useful if the binary code happens to be a
multiple of 3 bits long. Sometimes it is quicker to convert decimal to binary by first
converting decimal to octal, and then octal to binary.
20. Hex to Decimal and Decimal to Hex Conversion
Converting hex to decimal is just like converting binary to decimal, except instead of
powers of 2, we use powers of 16. That is, the LSB is 160, the next is 161, then 162, etc.
To convert 15E in hex to decimal:
1 5 E
162 161 160
Weight = 1*162 + 5*161 + 14*160
= 1*256 + 5*16 + 14*1
= 35010
Converting decimal to hex is just like converting decimal to binary, except instead of
dividing by 2, we divide by 16. To convert 350 to hex:
350/16 = 21 remainder 14 = E
21/16 = 1 remainder 5
1/16 = 0 remainder 1
So we get 15E for 350.
Again, note that if a calculator is being used, you may multiple the fraction remainder
by 16 to produce the remainder. 350/16 = 21.875.
Then to get the remainder, 0.875 * 16 = 14.
Hex to Binary and Binary to Hex Conversion
Going from hex to binary is similar to the process of converting from octal to binary.
One must simply look up or compute the binary pattern of 4 bits for each hex code, and
concatenate the codes together.
To convert AE to binary:
A = 1010
E = 1110
So AE in binary is 1010 1110
The same process applies in reverse by grouping together 4 bits at a time and then look
up the hex digit for each group.
Binary 11000100101 broken up into groups of 4:
0110 0010 0101 (note the 0 added as padding on the MSB to get up to 4 bits)
6 2 5
= 62516
21. Hex to Octal and Octal to Hex Conversion
Convert Octal (Hexadecimal) to Binary first.
• Regroup the binary number by three bits per group starting from LSB if Octal is
required.
• Regroup the binary number by four bits per group starting from LSB if Hexadecimal
is required.
These conversions are done through the binary conversion. Recall that, a group of 4-bits
represent a hexadecimal digit and a group of 3-bits represent an octal digit.
Hex to Octal Conversion
1. Convert the given hexadecimal number into binary.
2. Starting from right make groups of 3-bits and designate each group an octal digit.
Octal to Hex Conversion
1. Convert the given octal number into binary.
2. Starting from right make groups of 4-bits and designate each group as a Hexadecimal
digit.