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A radiotelephone is a communications system for transmission of speech over radio. Radiotelephone systems are rarely interconnected with the public switched telephone network, in some radio services, including GMRS, such interconnection is prohibited. "Radiotelephony" means transmission of sound by radio, in contrast to radiotelegraphy or video transmission. Where a two-way radio system is arranged for speaking and listening at a mobile station, where it can be interconnected to the public switched telephone system, the system can provide mobile telephone service; the word phone has a long precedent beginning with early US wired voice systems. The term means voice as opposed to Morse code; this would include systems fitting into the category of two-way radio or one-way voice broadcasts such as coastal maritime weather. The term is still popular in the amateur radio community and in US Federal Communications Commission regulations. A standard landline telephone allows both users to listen simultaneously.

In a radiotelephone system, this form of working, known as full-duplex, requires a radio system to transmit and receive on two separate frequencies, which both wastes bandwidth and presents some technical challenges. It is, the most comfortable method of voice communication for users, it is used in cell phones and was used in the former IMTS; the most common method of working for radiotelephones is half-duplex, which allows one person to talk and the other to listen alternately. If a single frequency is used, both parties take. Dual-frequency working or duplex splits the communication into two separate frequencies, but only one is used to transmit at a time with the other frequency dedicated to receiving; the user presses a special switch on the transmitter when they wish to talk—this is called the "press-to-talk" switch or PTT. It is fitted on the side of the microphone or other obvious position. Users may use a procedural code-word such as "over" to signal. Radiotelephones may operate at any frequency where they are licensed to do so, though they are used in the various bands between 60 and 900 MHz.

They may use simple modulation schemes such as AM or FM, or more complex techniques such as digital coding, spread spectrum, so on. Licensing terms for a given band will specify the type of modulation to be used. For example, airband radiotelephones used for air to ground communication between pilots and controllers operates in the VHF band from 118.0 to 136.975 MHz, using amplitude modulation. Radiotelephone receivers are designed to a high standard, are of the double-conversion superhet design. Transmitters are designed to avoid unwanted interference and feature power outputs from a few tens of milliwatts to 50 watts for a mobile unit, up to a couple of hundred watts for a base station. Multiple channels are provided using a frequency synthesizer. Receivers feature a squelch circuit to cut off the audio output from the receiver when there is no transmission to listen to; this is in contrast to broadcast receivers, which dispense with this. On a small network system, there are many mobile units and one main base station.

This would be typical for taxi services for example. To help direct messages to the correct recipients and avoid irrelevant traffic on the network's being a distraction to other units, a variety of means have been devised to create addressing systems; the crudest and oldest of these is called Continuous Tone-Controlled Squelch System. This consists of superimposing a precise low frequency tone on the audio signal. Only the receiver tuned to this specific tone turns the signal into audio: this receiver shuts off the audio when the tone is not present or is a different frequency. By assigning a unique frequency to each mobile, private channels can be imposed on a public network; however this is only a convenience feature—it does not guarantee privacy. A more used system is called selective calling or Selcall; this uses audio tones, but these are not restricted to sub-audio tones and are sent as a short burst in sequence. The receiver will be programmed to respond only to a unique set of tones in a precise sequence, only will it open the audio circuits for open-channel conversation with the base station.

This system is much more versatile than CTCSS, as few tones yield a far greater number of "addresses". In addition, special features can be designed in. A mobile unit can broadcast a Selcall sequence with its unique address to the base, so the user can know before the call is picked up which unit is calling. In practice many selcall systems have automatic transponding built in, which allows the base station to "interrogate" a mobile if the operator is not present; such transponding systems have a status code that the user can set to indicate what they are doing. Features like this, while simple, are one reason why they are popular with organisations that need to manage a large number of remote mobile units. Selcall is used, though is becoming superseded by much more sophisticated digital systems. Mobile radio telephone systems such as Mobile Telephone Service and Improved Mobile Telephone Service allowed a mobile unit to have a telephone number allowing access from the general telephone network, although some system


Shayde is a fictional character who appeared in the Doctor Who Magazine comic strip based on the long-running British science fiction television series Doctor Who. Shayde is an artificial being, a construct of the Gallifreyan Matrix — the massive computer network that serves as the repository of all Time Lord knowledge, he was created by the minds of the dead Time Lords that reside within the Matrix, was a servant of Rassilon. He first appeared in the story The Tides of Time, published in DWM #61-#67, written by Steve Parkhouse and drawn by Dave Gibbons. In that story, he aided the Fifth Doctor in defeating the otherdimensional demon Melanicus, at first covertly but as the Time Lords increased his power levels, he was able to manifest himself and help the Doctor directly. Among Shayde's powers are the abilities to travel through space and time unaided, fire deadly self-generated "psychic bullets" and be invisible to security systems, he can phase through solid objects and track people through time and space given enough data.

Shayde next appeared. Having no instructions from the Time Lords, Shayde was allowed to act on his own and helped the Doctor expel the entity from the TARDIS; when the Doctor was placed on trial by the Time Lords for allowing the possession to take place and placing Gallifrey in danger, Shayde surreptitiously erased the evidence, leading to the Doctor's acquittal. It was nearly fifteen years before Shayde reappeared in the comic strip. At that time, the Doctor was in his Eighth incarnation and was dying due to the events of the previous adventure, his companions at the time and Fey had taken him back to Gallifrey where he was cured and his mind placed within the Matrix to recover. While within the Matrix, an attempt was made on the Doctor's life by a secret Time Lord sect known as the Elysians, Shayde stopped them; the assassination attempt was part of a plot by Overseer Luther, an insane Time Lord who wanted to rewrite Gallifrey's history and set himself up as a god. The Doctor managed to thwart Luther by short-circuiting his watchtower, but at the cost of his eighth body.

As Izzy and Fey watched, the Doctor regenerated into a new incarnation.. However, this was a ruse; the Doctor had realised that Fey was under external control when she had managed to pilot the TARDIS though the TARDIS manual was in Gallifreyan script, which she did not understand. Just before the Doctor prepared to sacrifice himself, Shayde offered to take his place and fake a regeneration; this way, the group, controlling Fey — the Threshold, a mercenary organisation that the Doctor had tangled with before — would seize the opportunity to bring a newly regenerated and thus weaker Doctor to them. Both disguised with personal chameleon circuits, Shayde would hold their attention while the Doctor sabotaged the Threshold's operations. In a Wild West town on an alien moon run by the Threshold, the Doctor's plans came to fruition; when Shayde and the Doctor revealed themselves to the Threshold, Shayde had to contend with the Pariah, an immensely powerful being, his predecessor. The Pariah was another construct of Rassilon, but he had tried to destroy her when she developed free will and rebelled.

Now, the Pariah wanted to take revenge, not just on Gallifrey but the whole universe. Shayde was unable to defeat the Pariah on his own, she crushed his skull. However, Fey merged with the dying Shayde and together they were able to kill the Pariah and eliminate the Threshold; the shared being, dubbed "Feyde" by the Doctor, although both of them retained their own consciousness, decided to leave and deal with what had just happened to them. Fey returned to her own time period, the 1940s, where, as an agent of the British government, she spent two years fighting the Nazis and being frustrated that Shayde would not allow her to use their powers to kill Adolf Hitler, as this would change history. In 1941, she received a sub-ether summons from the Doctor — Izzy had been kidnapped, the Doctor needed Shayde's abilities to track her whereabouts. Together, they succeeded in recovering Izzy, "Feyde" returned to World War II. Shayde is one of the few characters from the comic strip that has made the cross-over into the other spin-off media.

In a special Big Finish Productions audio play given away with DWM #326 titled No Place Like Home, Shayde helped the Fifth Doctor against another force — a mutated Gallifreyan mouse called a rovie — that had infiltrated the TARDIS and was trying to kill the Doctor and his companions. The character of Shayde was voiced by Mark Donovan

Bijective proof

In combinatorics, bijective proof is a proof technique that finds a bijective function f: A → B between two finite sets A and B, or a size-preserving bijective function between two combinatorial classes, thus proving that they have the same number of elements, |A| = |B|. One place the technique is useful is where we wish to know the size of A, but can find no direct way of counting its elements. By establishing a bijection from A to some B solves the problem if B is more countable. Another useful feature of the technique is that the nature of the bijection itself provides powerful insights into each or both of the sets; the symmetry of the binomial coefficients states that =. This means that there are as many combinations of k things in a set of size n as there are combinations of n − k things in a set of size n; the key idea of the proof may be understood from a simple example: selecting out of a group of n children which k to reward with ice cream cones has the same effect as choosing instead the n − k children to be denied them.

More abstractly and the two quantities asserted to be equal count the subsets of size k and n − k of any n-element set S. Let A be the set of all k-element subsets of S, the set A has size. Let B be the set of all n−k subsets of S, the set B has size. There is a simple bijection between the two sets A and B: it associates every k-element subset with its complement, which contains the remaining n − k elements of S, hence is a member of B. More formally, this can be written using functional notation as, f: A → B defined by f = Xc for X any k-element subset of S and the complement taken in S. To show that f is a bijection, first assume that f = f, to say, X1c = X2c. Take the complements of each side, using the fact that the complement of a complement of a set is the original set, to obtain X1 = X2; this shows. Now take any n−k-element subset of S in B, say Y, its complement in S, Yc, is a k-element subset, so, an element of A. Since f = c = Y, f is onto and thus a bijection; the result now follows since the existence of a bijection between these finite sets shows that they have the same size, that is, =.

Problems that admit bijective proofs are not limited to binomial coefficient identities. As the complexity of the problem increases, a bijective proof can become sophisticated; this technique is useful in areas of discrete mathematics such as combinatorics, graph theory, number theory. The most classical examples of bijective proofs in combinatorics include: Prüfer sequence, giving a proof of Cayley's formula for the number of labeled trees. Robinson-Schensted algorithm, giving a proof of Burnside's formula for the symmetric group. Conjugation of Young diagrams, giving a proof of a classical result on the number of certain integer partitions. Bijective proofs of the pentagonal number theorem. Bijective proofs of the formula for the Catalan numbers. Binomial theorem Schröder–Bernstein theorem Double counting Combinatorial principles Combinatorial proof Categorification Loehr, Nicholas A.. Bijective Combinatorics. CRC Press. ISBN 143984884X, ISBN 978-1439848845. "Division by three" – by Doyle and Conway.

"A direct bijective proof of the hook-length formula" – by Novelli and Stoyanovsky. "Bijective census and random generation of Eulerian planar maps with prescribed vertex degrees" – by Gilles Schaeffer. "Kathy O'Hara's Constructive Proof of the Unimodality of the Gaussian Polynomials" – by Doron Zeilberger. "Partition Bijections, a Survey" – by Igor Pak. Garsia-Milne Involution Principle – from MathWorld

Robert Choulet

Robert Choulet is a French aerodynamics engineer influential in race car dynamics. A disciple of aerodynamics pioneer Charles Deutsch, Choulet worked for Deutsch's Société d'Études et de Réalisations Automobiles from 1963 to 1967. During this period, he worked on the aerodynamics of the CD cars, he joined Matra in 1968. One of his first projects was the Matra M640 Le Mans 24 Hours car. Following that, he returned to SERA-CD and was involved in designing the famous Porsche 917 the LH version, the Can-Am cars that followed, he was influential in designing the Alfa Romeo 33TT12. From 1976 to 1980, Choulet worked with the Ligier Formula One team, being involved in the design of the JS5, JS7, JS9, JS11 and JS11/15 models. SERA and Choulet worked with the Alfa Romeo sports car team in 1977 and on Alfa's Formula One car in 1979. Choulet created the Aérodyne company in 1983 working on such different cars as Formula Ford Rondeau and Audi Quattro for rally racing, he worked for many years for Peugeot. He was influential in the Group C Peugeot 905 programme as well as for Jordan Formula One team and the rally cars Peugeot 206 and Citroën Xsara WRC.

In the 2000s, he became involved with Panasonic Toyota Racing and has been a consultant for Toyota Motorsport GmbH in Cologne since 2011. Lycée du Parc Ecole centrale Paris in 1959 IFP School - Ecole Nationale Supérieure du Pétrole et des Moteurs in 1960. Joseph Béthenod Prize Society of Automotive Engineers: Massion Award Membership: SIA Auto Hebdo n° 229, 21 August 1980 Robert Choulet profile at Robert Choulet profile at ChicaneF1 S. I. A. Journal Société des ingénieurs de l'automobile, September 1984 issue: Rappel des conclusions sur le comportement des véhicules freinés à grande vitesse Auto Technologies Congress, Monte-Carlo, January 1985: La stabilité de plate-forme des véhicules futurs SERA

Amanda Seales

Amanda Ingrid Seales known by the stage name Amanda Diva, is an American comedian, disc jockey, recording artist, television personality, author. Aside from her solo career, she was a touring member of the musical group Floetry. Since 2017, she has starred in the HBO comedy series Insecure. Seales is one of the co-hosts of the syndicated daytime talk show The Real alongside Loni Love, Tamera Mowry, Adrienne Bailon, Jeannie Mai. Amanda Seales was born in Inglewood, CA at Daniel Freeman Hospital on July 1, 1981, her mother was raised in Mt. Moritz, Grenada, her father is African-American. As a result, both she and her mother are dual citizens of the United States of Grenada, she moved to Orlando, Florida in 1989, where she attended Dr. Phillips High School, she graduated from SUNY-Purchase acquired a master's degree in African-American studies with a concentration in Hip hop from Columbia University. Seales's first film was a minor role as Katy in a Half; the next year Seales was Me as Deonne Wilburn.

In 2002 she appeared on Russell Simmons' Def Poetry Jam. Seales became publicly known as "VJ Amanda Diva" on MTV2 Sucker Free Countdown on Sundays. In 2016 she appeared as Tiffany DuBois. In 2016, Seales began hosting her own show on truTV called Greatest Ever. On January 26, 2019, HBO debuted her first stand-up comedy special I Be Knowin'. Bring the Funny is a comedy competition series that premiered on July 9, 2019 on NBC. Seales hosts, alongside judges Kenan Thompson, Chrissy Teigen, Jeff Foxworthy. On January 6, 2020, Seales was announced as a permanent co-host of the syndicated daytime talk show The Real, alongside Loni Love, Tamera Mowry, Adrienne Bailon, Jeannie Mai. In 2007, Seales replaced Natalie Stewart of the musical duo Floetry on tour with Marsha Ambrosius, in December of that same year Seales released her first extended play Life Experience. In 2008, she was featured on the song "Manwomanboogie" on Q-Tip's Grammy-nominated album The Renaissance. On March 3, 2009, Seales released Rhymes & Soul.

Seales hosts a weekly podcast titled Small Doses. In 2010, Seales teamed up with Truth. In 2019, Amanda Seales was involved in a controversy where many people mistakenly reported that she had accused former NFL player and neurosurgeon resident Myron Rolle of sexually harassing several women, she did not make these accusations herself, but was sharing that she had heard those allegations from other women. Multiple people who were spreading that story have since admitted that Seales did not make those allegations herself. Although she vehemently furthered the narrative, classifying Myron Rolle a sexual predator via YouTube

Patriarch Pimen I of Moscow

Patriarch Pimen, was the 14th Patriarch of Moscow and the head of the Russian Orthodox Church from 1970 to 1990. He was born to a pious family in 1910 in the village of Kobylino, Kaluga Governorate, in the town of Bogorodsk near Moscow. On December 5, 1925, he became a monk at Sretensky Monastery in Moscow, he spent years in various Russian monasteries and cathedrals, in Murom and Pskov. In 1954 Pimen became namestnik of Troitse-Sergiyeva Lavra. On November 17, 1957, in Odessa, he was consecrated bishop of vicar of the Diocese of Odessa. Beginning December 26, 1957, he was bishop of vicar of the Moscow diocese. From July 1960 to November 14, 1961, he was Chancellor of the Moscow Patriarchate. On November 23, 1960, he was elevated to the rank of archbishop. On March 16, 1961, he became archbishop of Belyov. On November 14, 1961, he was appointed Metropolitan of Ladoga. After the death of Patriarch Alexius I in 1970, Metropolitan Pimen was chosen Patriarchal Locum Tenens a temporary replacement; because 1970 was the centennial of Lenin's birth, Soviet authorities did not want a church council to select a new Patriarch during that year.

A Local Council was opened May 30, 1971. On June 2, 1971, the final day of the Council, Metropolitan Pimen was elected Patriarch of Moscow and All Russia, he was enthroned on June 3 of that year. Pimen's task was to lead a Christian church in a state ruled by an atheist Communist party. In his post, he worked with the Communist authorities, participating in numerous "peace movement" conferences sponsored by the government. Pimen was awarded the Soviet Peace Fund Medal and, in 1970, the Gold Medal "Борцу за мир" by the'Soviet Committee for the Defence of Peace'. Pimen was a member of the World Peace Council from 1963 onwards. In 1961, Pimen was awarded the Order of the Red Banner of Labour, one of the highest awards of the time. Near the end of his difficult term as head of the Russian Orthodox Church, he organized the celebration of the 1000th anniversary of the Christianization of Rus' in 1988; this event coincided with political reforms that ended much of the Communist party's anti-religious activity, the church celebration was seen as marking the end of the persecution of Orthodox Christianity in the Soviet Union.

When Patriarch Pimen died in 1990, the government made no effort to influence the choice of his successor. Pimen