Download to View - Animated Examples
------------------------------------------------------------
Error detection uses the concept of redundancy, which means adding extra bits for detecting error at the destination.
Parity Check is one of the Error Correcting Codes.
The sender initializes the checksum to 0 and adds all data items and the checksum. However, 36 cannot be expressed in 4 bits. The extra two bits are wrapped and added with the sum to create the wrapped sum value 6. The sum is then complemented, resulting in the checksum value 9 (15 − 6 = 9).
Error Detection and correction concepts in Data communication and networksNt Arvind
single bit , burst error detection and correction in data communication networks , block coding ( hamming code , simple parity check code , Cyclic redundancy check-CRC , checksum , internet checksum etc
The sender initializes the checksum to 0 and adds all data items and the checksum. However, 36 cannot be expressed in 4 bits. The extra two bits are wrapped and added with the sum to create the wrapped sum value 6. The sum is then complemented, resulting in the checksum value 9 (15 − 6 = 9).
Error Detection and correction concepts in Data communication and networksNt Arvind
single bit , burst error detection and correction in data communication networks , block coding ( hamming code , simple parity check code , Cyclic redundancy check-CRC , checksum , internet checksum etc
Protocols And IP suite PPT
Contents are
History
TCP/IP Suite Layer
a} Network Interface
b} Internet Layer
c} Transport Layer
d} Application Layer
3.Comparison of OSI and IP
Protocols And IP suite PPT
Contents are
History
TCP/IP Suite Layer
a} Network Interface
b} Internet Layer
c} Transport Layer
d} Application Layer
3.Comparison of OSI and IP
Error detection refers to the process of identifying and detecting errors or inconsistencies in data or transmitted signals. It is an essential aspect of ensuring data integrity and reliability in various communication systems, computer networks, and storage systems.
The purpose of error detection is to determine if errors have occurred during data transmission or storage and to provide a mechanism to identify and correct these errors. Errors can occur due to various factors such as noise, interference, hardware failures, or software issues. By detecting errors, corrective measures can be taken to ensure the accuracy and integrity of the transmitted or stored data.
There are several techniques and algorithms commonly used for error detection. Here are a few notable ones:
Parity Check: Parity check is a simple and widely used error detection method. It involves adding an extra bit, called a parity bit, to a group of bits being transmitted. The parity bit is set to 1 or 0 based on whether the total number of 1s in the data is even or odd. At the receiving end, the parity bit is recalculated and compared to the received parity bit. If they do not match, an error is detected.
Checksum: Checksum is a technique that involves calculating a numerical value, often a sum or a hash, based on the data being transmitted. This value is then appended to the data. At the receiving end, the checksum is recalculated and compared to the received value. If they do not match, it indicates the presence of an error.
Cyclic Redundancy Check (CRC): CRC is a more sophisticated error detection algorithm widely used in networking protocols and storage systems. It involves generating a cyclic redundancy code based on the data being transmitted. This code is appended to the data, and at the receiving end, the code is recalculated and compared to the received code. A mismatch indicates the presence of errors.
Forward Error Correction (FEC): FEC is an error detection and correction technique that involves adding redundant information to the transmitted data. This redundancy allows the receiver to not only detect errors but also correct them without the need for retransmission. FEC is commonly used in applications where retransmission is expensive or not feasible, such as satellite communications and wireless networks.
Error detection techniques play a crucial role in ensuring data integrity and reliable communication. They provide a mechanism to detect errors and trigger appropriate actions, such as requesting retransmission or performing error correction. By implementing effective error detection mechanisms, data integrity can be maintained, and the overall quality and reliability of communication systems can be improved.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Biological screening of herbal drugs: Introduction and Need for
Phyto-Pharmacological Screening, New Strategies for evaluating
Natural Products, In vitro evaluation techniques for Antioxidants, Antimicrobial and Anticancer drugs. In vivo evaluation techniques
for Anti-inflammatory, Antiulcer, Anticancer, Wound healing, Antidiabetic, Hepatoprotective, Cardio protective, Diuretics and
Antifertility, Toxicity studies as per OECD guidelines
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
Embracing GenAI - A Strategic ImperativePeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Exploiting Artificial Intelligence for Empowering Researchers and Faculty, In...Dr. Vinod Kumar Kanvaria
Exploiting Artificial Intelligence for Empowering Researchers and Faculty,
International FDP on Fundamentals of Research in Social Sciences
at Integral University, Lucknow, 06.06.2024
By Dr. Vinod Kumar Kanvaria
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
2. Content
Why we need Error Detection?
What are the Errors?
What are the Error Detection Mechanisms?
Parity Check
Single Parity Check
Two Dimensional Parity Check
Drawbacks of Parity
2
3. Error Detection
• Data can be corrupted during transmission. Even with best prevention
methods.
• For a reliable communication, errors must be detected and corrected.
• Error detection and correction are implemented either at data link layer or
the transport layer of the OSI model.
3
4. Types of Errors
• Single bit error :-
- Only one bit in the data unit has changed.
4
0 changed to 1
Received Sent
5. Types of Errors
• Burst error :-
- It means that two or more bits in the data unit has changed.
5
Sent
Received
Bits corrupted by Burst Error
6. Error Detection Codes
• Error detecting code is to include only enough redundancy to allow the receiver to
deduce that an error occurred, but not which error, and have it request a re-
transmission.
• Used in Low Noisy Channels – Fiber Optics
• Error detection uses the concept of redundancy, which means adding extra bits
for detecting error at the destination
• To detect an error, something extra has to be added to the data/signal
• This extra is an error detection code
• 3 Techniques are there: Parity Check, Check Sum, CRC
6
7. Parity Check
• The Simplest method Available - it’s a linear, systematic block code
• 2 Parity Check Methods are there:
• Simple Parity - For Single bit Errors
• Two Dimensional - For Burst Errors
• How to use Parity Methods?
• Parity Generate – Sender’s Side
• Parity Detect – Receiver’s Side
7
8. Single Parity Check(VRC)
Vertical Redundancy Check
• In Single parity check, a parity bit is added to every data unit so that the total
number of 1s is even or odd.
11010011 1
• Therefore, the total number of bits transmitted would be 9 bits.
( 8 bits of information + 1 bit parity = n data bits into n+1 bits)
8
Information(1 byte – 8 bits)
Additional Bit added(PARITY BIT)
9. Single Parity check(Cont.)
Parity Generation
• There are two ways to generate a Single parity bit.
• One is called Even parity and the other is Odd parity.
• What is even parity?
• the total number of 1’s transmitted must be even.
• What is odd parity?
• the total number of 1’s transmitted must be odd
9
10. Parity Generation-VRC
• Parity bit is chosen so that the number of 1 bits in the code-word
is even (or odd)
• computing the (even) parity bit as the modulo 2 sum or XOR of
the data bits.
• use XOR and XNOR logic gates in circuits to generate parity bits
in practically (in devices).
10
11. How is the even parity bit generated?
Total number of ‘1’s should be even.
If the byte that we want to transmit is:
• Step 1: count the number of 1’s in the byte.
• Answer: 5
• Step 2: compute the parity value.
• Since the total number of 1’s is 5, the even parity bit will have a value of 1.
• If the number of bits are already even, the parity bit will be ‘0’.
11
1 0 1 0 1 1 0 1
1 0 1 0 1 1 0 1 1
12. How is the odd parity bit generated?
Total number of ‘1’s should be odd.
If the byte that we want to transmit is:
• Step 1: count the number of 1’s in the byte.
• Answer: 4
• Step 2: compute the parity value.
• Since the total number of 1’s is 4, the odd parity bit will have a value of 1.
• If the number of bits are already odd, the parity bit will be ‘0’.
12
1 0 1 0 1 1 0 0
1 0 1 0 1 1 0 0 1
13. Single Parity check(Cont.)
Parity Detection
13
Drop Redundant Bit
and
Accept Data
Reject DataEven
Count Number of ‘1’ s in Received Data
Yes
No
Request Re -Transmission
Odd
• In Even parity Concept• In Odd parity Concept
14. 1 1 0 0 1 0 0 0 11 0 1 0 1 1 0 1 1
Drawbacks of Single Parity Check
• Only can detect single bit errors ; Single bit errors are rare.
• Can not detect errors, if 2 bits are interchanged.
14
1 0 1 0 1 1 0 1 1 1 1 1 0 1 0 0 1 1
5+1=6 5+1=6
5+1=6 3+1=4
15. Two Dimensional Parity Check(LRC)
Longitudinal Redundancy Check
• In two-dimensional parity check, a block of bits is divided into rows and a
redundant row of bits is added to the whole block.
• Even Parity Concept
15
16. Two Dimensional Parity check(Cont.)
Parity Generation
• A block of bits is organized in a table (rows & columns) a parity bit is
calculated for each row and column.
• Compute (m + n + 1) parity bits and send (mn + m + n + 1) bits
1) Adds a parity bit to each character then adds a row of parity bits after a block of
characters
2) The row of parity bits is actually a parity bit for each “column” of characters
3) The row of parity bits plus the column parity bits add a great amount of
redundancy to a block of characters
• Lets see this with an example:
16
17. Two Dimensional Parity Generation
Even Parity Concept
17
1100111 1011101 0111001 0101001
1 1 0 0 1 1 1
1 0 1 1 1 0 1
0 1 1 1 0 0 1
0 1 0 1 0 0 1
Original Data
1100111 1011101 0111001 0101001
Row Parity
No ‘1’s : 5
No ‘1’s : 5
No ‘1’s : 4
No ‘1’s : 3
No ‘1’s : 3
1
1
1
0
1
1 0 1
0 1 0 1 0 1 0 1
10101010
Column Parity
This will Send
18. Drawbacks of 2D Parity Check
• 4- and more bit errors can be detected in some cases
• 1 affect 2 , 2 affect 3, 3 affect 4, 4 affect 4 – so Can not detect in this case
• Disadvantage: too many check bits !!!
• Can not detect errors, if 2 bits in one data unit are changed and 2 bits in exactly
the same position in another data unit is changed.
18
19. Drawbacks
• Both simple parity and 2D parity do not catch all the errors.
• Simple parity only catches odd numbers of bit errors, and can not
catch if 2 bits interchanged.
• 2D parity is better at catching errors, but requires too many check
bits added to a block of data.
• Can not use in 4 bit errors and more bit errors in some cases.
19
20. Summary
• Parity checking is a means of checking if the communication of a sequence of bits
has been correctly received.
• Parity bit is an extra bit that is attached to the data bits/Signal that is being
transferred from one location to another.
• The two types of most commonly used parity checking are:
Single Parity Check 2D Parity Check
• odd parity
• even parity
• Single Parity bit checking can detect single error only, double errors will not be
detected. Even the 2D parity is not efficient and can not use in some cases.
20
When you receive a parcel from a friend, how would you know that the contents are what your friend has send to you?
One way is to call your friend up and confirm with him what he has sent to you.
Another way is for your friend to include a packing list detailing what is in the parcel, and you can tally the items in the parcel with the packing list.
In the same way when your computer/ printer receives a message, how would your computer/printer know that the received message is correct?
One way is for the computer to double check with the sending computer what he has received, just like you calling up your friend to check the contents of the parcel.
Another way is for the sending computer to include some information in the message, so that by examining the information you are able to know whether the received message is correct. (Like the packing list).