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Automatic link establishment

Automatic Link Establishment known as ALE, is the worldwide de facto standard for digitally initiating and sustaining HF radio communications. ALE is a feature in an HF communications radio transceiver system that enables the radio station to make contact, or initiate a circuit, between itself and another HF radio station or network of stations; the purpose is to provide a reliable rapid method of calling and connecting during changing HF ionospheric propagation, reception interference, shared spectrum use of busy or congested HF channels. A standalone ALE radio combines an HF SSB radio transceiver with an internal microprocessor and MFSK modem, it is programmed with a unique ALE address, similar to a phone number. When not in contact with another station, the HF SSB transceiver scans through a list of HF frequencies called channels, listening for any ALE signals transmitted by other radio stations, it decodes calls and soundings sent by other stations and uses the bit error rate to store a quality score for that frequency and sender-address.

To reach a specific station, the caller enters the ALE Address. On many ALE radios this is similar to dialing a phone number; the ALE controller selects the best available idle channel for that destination address. After confirming the channel is indeed idle, it sends a brief selective calling signal identifying the intended recipient; when the distant scanning station detects ALE activity, it stops scanning and stays on that channel until it can confirm whether or not the call is for it. The two stations' ALE controllers automatically handshake to confirm that a link of sufficient quality has been established notify the operators that the link is up. If the callee fails to respond or the handshaking fails, the originating ALE node selects another frequency either at random or by making a guess of varying sophistication. Upon successful linking, the receiving station emits an audible alarm and shows a visual alert to the operator, thus indicating the incoming call, it indicates the callsign or other identifying information of the linked station, similar to Caller ID.

The operator un-mutes the radio and answers the call can talk in a regular conversation or negotiates a data link using voice or the ALE built-in short text message format. Alternatively, digital data can be exchanged via a built-in or external modem depending on needs and availability; the ALE built-in text messaging facility can be used to transfer short text messages as an "orderwire" to allow operators to coordinate external equipment such as phone patches or non-embedded digital links, or for short tactical messages. Due to the vagaries of ionospheric communications, HF radio as used by large governmental organizations in the mid-20th century was traditionally the domain of skilled and trained radio operators. One of the new characteristics that embedded microprocessors and computers brought to HF radio via ALE, was alleviation of the need for the radio operator to monitor and change the radio frequency manually to compensate for ionospheric conditions or interference. For the average user of ALE, after learning how to work the basic functions of the HF transceiver, it became similar to operating a cellular mobile phone.

For more advanced functions and programming of ALE controllers and networks, it became similar to the use of menu-enabled consumer equipment or the optional features encountered in software. In a professional or military organization, this does not eliminate the need for skilled and trained communicators to coordinate the per-unit authorized frequency lists and node addresses – it allows the deployment of unskilled technicians as "field communicators" and end-users of the existing coordinated architecture. An ALE radio system enables connection for voice conversation, data exchange, instant messaging, file transfer, geo-position tracking, or telemetry. With a radio operator initiating a call, the process takes a few minutes for the ALE to pick an HF frequency, optimum for both sides of the communication link, it signals the operators audibly and visually on both ends, so they can begin communicating with each other immediately. In this respect, the longstanding need in HF radio for repetitive calling on pre-determined time schedules or tedious monitoring static is eliminated.

It is useful as a tool for finding optimum channels to communicate between stations in real-time. In modern HF communications, ALE has replaced HF prediction charts, propagation beacons, chirp sounders, propagation prediction software, traditional radio operator educated guesswork. ALE is most used for hooking up operators for voice contacts on SSB, HF internet connectivity for email, SMS phone texting or text messaging, real-time chat via HF text, Geo Position Reporting, file transfer. High Frequency Internet Protocol or HFIP may be used with ALE for internet access via HF; the essence of ALE techniques is the use of automatic channel selection, scanning receivers, selective calling and robust burst modems. An ALE node decodes, it uses the fact. By noting how much error-correction occurred in each received and decoded message, an ALE node can detect the "quality" of the path between the sending station and itself; this information is coupled with the ALE address of the sending node and the channel the message was received on, stored in the node's Link Quality Analysis memory.

When a call is initiated, the LQA

Brauer's theorem on induced characters

Brauer's theorem on induced characters known as Brauer's induction theorem, named after Richard Brauer, is a basic result in the branch of mathematics known as character theory, which is, in turn, part of the representation theory of a finite group. Let G be a finite group and let Char denote the subring of the ring of complex-valued class functions of G consisting of integer combinations of irreducible characters. Char is known as the character ring of G, its elements are known as virtual characters, it is a ring by virtue of the fact that the product of characters of G is again a character of G. Its multiplication is given by the elementwise product of class functions. Brauer's induction theorem shows that the character ring can be generated by induced characters of the form λ H G, where H ranges over subgroups of G and λ ranges over linear characters of H. In fact, Brauer showed that the subgroups H could be chosen from a restricted collection, now called Brauer elementary subgroups; these are direct products of cyclic groups whose order is a power of a prime.

Using Frobenius reciprocity, Brauer's induction theorem leads to his fundamental characterization of characters, which asserts that a complex-valued class function of G is a virtual character if and only if its restriction to each Brauer elementary subgroup of G is a virtual character. This result, together with the fact that a virtual character θ is an irreducible character if and only if θ > 0 and ⟨ θ, θ ⟩ = 1 gives a means of constructing irreducible characters without explicitly constructing the associated representations. An initial motivation for Brauer's induction theorem was application to Artin L-functions, it shows that those are built up from or more general Hecke L-functions. Significant for that application is whether each character of G is a non-negative integer combination of characters induced from linear characters of subgroups. In general, this is not the case. In fact, by a theorem of Taketa, if all characters of G are so expressible G must be a solvable group. An ingredient of the proof of Brauer's induction theorem is that when G is a finite nilpotent group, every complex irreducible character of G is induced from a linear character of some subgroup.

A precursor to Brauer's induction theorem was Artin's induction theorem, which states that |G| times the trivial character of G is an integer combination of characters which are each induced from trivial characters of cyclic subgroups of G. Brauer's theorem removes the factor |G|, but at the expense of expanding the collection of subgroups used; some years after the proof of Brauer's theorem appeared, J. A. Green showed that no such induction theorem could be proved with a collection of subgroups smaller than the Brauer elementary subgroups; the proof of Brauer's induction theorem exploits the ring structure of Char. The set of integer combinations of characters induced from linear characters of Brauer elementary subgroups is an ideal I of Char, so the proof reduces to showing that the trivial character is in I. Several proofs of the theorem, beginning with a proof due to Brauer and John Tate, show that the trivial character is in the analogously defined ideal I* of Char* by concentrating attention on one prime p at a time, constructing integer-valued elements of I* which differ from the trivial character by a sufficiently high power of p.

Once this is achieved for every prime divisor of |G|, some manipulations with congruences and algebraic integers, again exploiting the fact that I* is an ideal of Ch*, place the trivial character in I. An auxiliary result here is that a Z -valued class function lies in the ideal I* if its values are all divisible by |G|. Brauer's induction theorem was proved in 1946, there are now many alternative proofs. In 1986, Victor Snaith gave a proof by a radically different approach, topological in nature. There has been related recent work on the question of finding natural and explicit forms of Brauer's theorem, notably by Robert Boltje. Isaacs, I. M.. Character Theory of Finite Groups. Dover. ISBN 0-486-68014-2. Zbl 0849.20004. Corrected reprint of the 1976 original, published by Academic Press. Zbl 0337.20005 Snaith, V. P.. Explicit Brauer Induction: With Applications to Algebra and Number Theory. Cambridge Studies in Advanced Mathematics. 40. Cambridge University Press. ISBN 0-521-46015-8. Zbl 0991.20005

Commix

Commix is a drum and bass project now composed of George Levings from Cambridge, UK. Based in Cambridge, Commix comprised George Levings, Guy Brewer and Conrad Whittle; as a DJ/production team, they began working together in 2002 and the trio released a series of 12-inch singles on the Aquasonic, Tangent Recordings, Good Looking Records, Creative Source and Brand.nu labels, with notable tracks including 2003's "Feel Something", 2004's "Herbie" and "Surround". After Whittle's departure, Commix was signed to Goldie's label Metalheadz in 2005; the trio met. Commix's signature track, "Satellite Song", was featured on the Metalheadz compilation Winter of Content, while two other club favourites were paired up on a 12-inch single, their debut album, Call To Mind, was released in summer 2007, to positive reviews. Call To Mind was the second release of an artist album on Metalheadz, after Goldie's Rufige Kru alter-ego's Malice in Wonderland; the duo has notably remixed tracks by artists including Bebel Gilberto, Adam F and DJ Die.

Brewer left the group in March 2012. In 2016, new material appeared on Commix' SoundCloud page which pays more tribute to sound design rather than on samples. Additionally, the second studio album was announced for release on Metalheadz; the sampler "Generation 1" was released in April 2016. Commix's sound has been influenced by many different musical genres, their sound features elements of liquid funk, techno and house. Levings played saxophone and piano, before venturing into the hip hop and electronic music scenes. Brewer had a wide-ranging interest in music before being introduced to drum and bass. Levings as a solo artist introduced a style less reliant on samples but rather on sound design; the SoundCloud page states that Commix will prospectively appear "with a renewed sense of purpose". Call To Mind Dusted The Future Sound of Cambridge The Future Sound of Cambridge 3 FabricLive.44 Metalheadz "Re:Call to Mind" "Feel Something / Soul Rebels" "Give You Everything / I'll Take You There" "Something Better / All You Need" "I Want To Know / Hold On Be Strong" "You'll See / Trojan" "Herbie / Variations" "Take You Higher / Gets Me Higher" "Together" "Brass Eye / Solitude" "Surround / Deep Joy" "Black Queen / Five Reasons "Satellite Song" "Urban Legend / If I Should Fall" "Midas Touch" "Five Reasons" "Providence / Hot Flush" "How You Gonna Feel" "The Perfect Blue" "Be True / Satellite Type 2" "Faceless / Solvent" "Talk To Frank / Electric" "Envious / Justified" "Double Double" "Generation 1" "Generation 2" "Old School String / Kosmos 2251 / Shine Bright" "Dispatch Dubplate 12" "Generation 3" "Loves Cruel Game" "Spaces" "Whatever You Want" "Identify" "Backchat / Games" DJ FreshWhen The Sun Goes Down Bebel Gilberto – Aganjú DJ Die – Autumn Suv – Suenos Different Vice Versa – Luck of the Draw Tactile – Aldabra Brooklyn – Stages DJ Trax – Tomorrows New Dawn Rufige Kru – Is This Real The Nextmen – Dig No Wrong Origin Unknown – Lunar Bass Alex Reece – Basic Principles Avalanches – Tonight SpectraSoul – Away With Me DJ Suv - Suenos Different I Wannabe - Dreams Commix discography at Discogs Commix on SoundCloud

Sri Lankan cricket team in South Africa in 2018–19

The Sri Lanka cricket team toured South Africa in February and March 2019 to play two Tests, five One Day Internationals and three Twenty20 International matches. The ODI fixtures were part of both teams' preparation for the 2019 Cricket World Cup. In February 2019, Sri Lanka named Dimuth Karunaratne as the captain of their Test side, after Dinesh Chandimal was dropped due to poor form. Chandimal was omitted from Sri Lanka's ODI squad for the tour. Sri Lanka won the Test series their first Test series win in South Africa, it was the first time that a team from Asia had won a Test series in South Africa. South Africa won the ODI series 5–0, it was the fourth time in less than two years that Sri Lanka had been whitewashed in a five-match ODI series. For the T20I series, Faf du Plessis was named as South Africa's captain for the first match, with JP Duminy named as captain for the remaining two fixtures. South Africa completed a whitewash in the T20I series, winning 3–0. Ahead of the last two ODIs, Aiden Markram, Hashim Amla and JP Duminy were added to South Africa's squad, with Reeza Hendricks and Wiaan Mulder being dropped.

However, the day after Amla was added to South Africa's ODI squad, he took compassionate leave, missing the last two matches, with Hendricks recalled. Kusal Perera was ruled out of Sri Lanka's ODI squad for the final two ODIs, after suffering a hamstring injury in the third ODI. Lungi Ngidi and Anrich Nortje were ruled out of South Africa's T20I squad for the final two T20Is due to injury. Junior Dala was added to South Africa's squad for the third T20I. Series home at ESPN Cricinfo

Andy Needham

Andrew Paul Needham is an English former professional footballer who scored 30 goals from 103 appearances in the Football League playing for Birmingham City, Blackburn Rovers and Aldershot. He played as a forward. Needham was born in Lancashire; when he left school in 1971, he joined Birmingham City as an apprentice, turned professional two years later. He made his debut in the First Division on 20 March 1976, deputising for Peter Withe in a 1–1 draw at home to Coventry City, came on as substitute to score in the next game, started the next; those were the only first-team appearances. He signed for Second Division club Blackburn Rovers in the 1976 close season, but after only five league appearances he moved on again in March 1977, this time to Aldershot of the Fourth Division. At Aldershot he formed a good partnership with fellow new arrival John Dungworth. Dungworth was a prolific goalscorer – 58 league goals from 105 games, compared with Needham's 29 from 95 – but Needham's contribution was described by teammate Alex McGregor thus:I know John Dungworth was the star, but Needham was such a great partner for him because he used to run and take players away from John to score the goals.

Andy never got the credit he deserved because he was a wonderful lad as well. A hip injury forced Needham's retirement from League football in 1980 at the age of 24, he became a taxi driver

.45 Winchester Magnum

The.45 Winchester Magnum is a.45 caliber rimless cartridge intended for use in semi-automatic pistols. The cartridge is externally a lengthened.45 ACP with a thicker web to withstand higher operating pressures. The 45 Win Mag is nearly identical in dimensions and loading to the.45 NAACO developed by the North American Arms Corporation for their Brigadier pistol, developed to supply to the Canadian Army after World War II. The army did not adopt the pistol and its non-NATO standard ammunition; the cartridge has been used by hunters and metallic silhouette shooters. Although the.45 Winchester Magnum may be based on the.45 ACP and have the same Rim and Base dimensions, the.45 Winchester Magnum has no parent case. The.45 Winchester Magnum case is redrawn with longer case. The thicker wall dimensions of the.45 Winchester Magnum are designed to accommodate a higher internal pressure than that of the.45 ACP. The.45 Winchester Magnum had been on the drawing board for two years before its introduction, in 1979, by Winchester.

The cartridge did not gain much popularity due to the intermittent availability of the Wildey and LAR Grizzly pistols. The cartridge was chambered in the Thompson-Center Contender single shot pistols; the cartridge was chambered for the Freedom Arms Model 83 single-action revolver via an available optional cylinder. The.45 Winchester Magnum gained a following among IHMSA competitors as it provided the power and performance necessary to knock down targets at an extended range. The cartridge has been used by handgun hunters and is among the few semi-automatic pistol cartridges which have been adopted for this sport. Table of handgun and rifle cartridges List of handgun cartridges.45 Super.45 ACP.44 Magnum.45 GAP.475 Wildey Magnum 10 mm caliber 11 mm caliber