In the field of telecommunications, a Clos network is a kind of multistage circuit-switching network which represents a theoretical idealization of practical, multistage switching systems. It was invented by Edson Erwin in 1938 and first formalized by (French pronunciation: [ʃaʁl klo]) in 1952. By adding stages, a Clos network reduces the number of crosspoints required to compose a large crossbar switch. A Clos network topology (diagrammed below) is parameterized by three integers n, m, and r: n represents the number of sources which feed into each of r ingress stage crossbar switches; each ingress stage crossbar switch has m outlets; and there are m middle stage crossbar switches. Circuit switching arranges a dedicated communications path for a connection between endpoints for the duration of the connection. This sacrifices total bandwidth available if the dedicated connections are poorly utilized, but makes the connection and bandwidth more predictable, and only introduces control overhead when the connections are initiated, rather than with every packet handled, as in modern packet-switched networks. When the Clos network was first devised, the number of crosspoints was a good approximation of the total cost of the switching system. While this was important for electromechanical crossbars, it became less relevant with the advent of VLSI, wherein the interconnects could be implemented either directly in silicon, or within a relatively small cluster of boards. Upon the advent of complex data centers, with huge interconnect structures, each based on optical fiber links, Clos networks regained importance. A subtype of Clos network, the Beneš network, has also found recent application in machine learning. (Wikipedia).
Part of a series teaching the Clojure language. For other programming topics, visit http://codeschool.org
From playlist the Clojure language
Clojure - the Reader and Evaluator (4/4)
Part of a series teaching the Clojure language. For other programming topics, visit http://codeschool.org
From playlist the Clojure language
Clojure - the Reader and Evaluator (2/4)
Part of a series teaching the Clojure language. For other programming topics, visit http://codeschool.org
From playlist the Clojure language
This electronics video tutorial provides a basic introduction into clamper circuits which can be used to shift a waveform above or below a certain reference voltage. A clamper circuit is a type of DC restorer circuit. It converts an AC signal into a voltage varying DC signal where the av
From playlist Electronic Circuits
An intro to the core protocols of the Internet, including IPv4, TCP, UDP, and HTTP. Part of a larger series teaching programming. See codeschool.org
From playlist The Internet
Why Plenum Fiber Optic Cable, OFNP, OFNR, and LSZH Matter
Main site article: https://www.servethehome.com/what-is-plenum-fiber-optic-cable-what-is-ofnp/ STH Merch on Spring: https://the-sth-merch-shop.myteespring.co/ STH Top 5 Weekly Newsletter: https://eepurl.com/dryM09 STH Forums: https://forums.servethehome.com/ Need to know what "plenum" fib
From playlist Networking on STH
How To Network If You’re An Introvert
The Introvert's Guide To Networking Discover The 4 Emotions You Need To Make a Killer First Impression: http://bit.ly/2FZ27h5 Last week I went to a conference called ClamourCon I saw something that really surprised me. In fact it wasn’t a something, but a someone. This person, a self p
From playlist Networking
GT20.1. Sylow Theorems - Proofs
Abstract Algebra: We give proofs of the three Sylow Theorems. Techniques include the class equation and group actions on subgroups. U.Reddit course materials available at http://ureddit.com/class/23794/intro-to-group-theory Master list at http://mathdoctorbob.org/UReddit.html
From playlist Abstract Algebra
Simple Group 168 - Sylow Theory - Part 1
Abstract Algebra: Let G be a simple group of order 168. We calculate the number of Sylow subgroups, number of elements of a given order, and conjugacy class structure. In Part 1, we consider Sylow-p subgroup for p = 3, 7.
From playlist Abstract Algebra
GT20. Overview of Sylow Theory
Abstract Algebra: As an analogue of Cauchy's Theorem for subgroups, we state the three Sylow Theorems for finite groups. Examples include S3 and A4. We also note the analogue to Sylow Theory for p-groups. U.Reddit course materials available at http://ureddit.com/class/23794/intro-to-gr
From playlist Abstract Algebra
GT22. The Fundamental Theorem of Finite Abelian Groups
Edit for 5:45: Proof of FTFAG needs more steps as follows (thanks to Jack Shotton for the example in the comments): Case 3: First note, if some [xi] does not contain y, then it maps isomorphically to Z/mi in G/H. One can then show that G= [xi] x Gi, where Gi is generated by the other x
From playlist Abstract Algebra
Common polyatomic ions | Atoms, compounds, and ions | Chemistry | Khan Academy
Reviewing the common polyatomic ions, and explaining common suffixes and prefixes to help remember the formulas. Watch the next lesson: https://www.khanacademy.org/science/chemistry/chemical-reactions-stoichiome/balancing-chemical-equations/v/chemical-reactions-introduction?utm_source=YT
From playlist Atoms, compounds, and ions | Chemistry | Khan Academy
Visual Group Theory, Lecture 5.7: Finite simple groups
Visual Group Theory, Lecture 5.7: Finite simple groups A group is said to be simple if its only normal subgroups are itself and the identity. Using Sylow theorems, we can frequently conclude statemens such as "there are no simple groups of order k", for some fixed k. After we provide seve
From playlist Visual Group Theory
We're busy people who learn to code, then practice by building projects for nonprofits. Learn Full-stack JavaScript, build a portfolio, and get great references with our open source community. Join our community at https://freecodecamp.com Follow us on twitter: https://twitter.com/freecod
From playlist Networks
Refrigerators and CFCs (Intro to Solid-State Chemistry)
MIT 3.091 Introduction to Solid-State Chemistry, Fall 2018 Instructor: Jeffrey C. Grossman View the complete course: https://ocw.mit.edu/3-091F18 Course Playlist: https://www.youtube.com/playlist?list=PLUl4u3cNGP63z5HAguqleEbsICfHgDPaG Highlights Playlist: https://www.youtube.com/playlist?
From playlist “Why This Matters” Moments: Highlights from 3.091 Intro to Solid-State Chemistry
Jesus: His Life | March 25th 8/7c | HISTORY
“Jesus: His Life” explores the story of Jesus Christ through a unique lens: the people in his life who were closest to him. Each of the eight chapters is told from the perspective of different biblical figures, all of whom played a pivotal role in Jesus’ life including Joseph, John the Bap
From playlist Jesus: His Life | History
If you are interested in learning more about this topic, please visit http://www.gcflearnfree.org/ to view the entire tutorial on our website. It includes instructional text, informational graphics, examples, and even interactives for you to practice and apply what you've learned.
From playlist Networking
Ancient Aliens: Da Vinci's Secret Messages (Season 13) | History
Stay up to date on all of HISTORY's latest premieres at http://history.com/schedule According to Ancient Astronaut Theorists, Leonardo da Vinci encoded secret messages in his paintings for future generations to discover. Discover the alien knowledge that could be hidden in his work, in th
From playlist Ancient Aliens: The Alien Connection to Famous Figures | History
GT20.2 Sylow Theory for Simple 60
EDIT: At 6:50, 1, 3, 5, 7 should be 1, 3, 7, 9. At 9:35, n3 should be n2. Abstract Algebra: Using Sylow theory, we show that any simple, non-abelian group with 60 elements is isomorphic to A_5, the alternating group on 5 letters. As an application, we show that A_5 is isomorphic to t
From playlist Abstract Algebra