Raymond Thornton Chandler (July 23, 1888 – March 26, 1959) was an Anglo-American novelist and screenwriter who had an immense stylistic influence upon the modern private detective story, especially in the style of the writing and the attitudes now characteristic of the genre. His protagonist, Philip Marlowe, along with Dashiell Hammett's Sam Spade, is considered synonymous with "private detective", both being played on screen by Humphrey Bogart.

Chandler was born in Chicago, Illinois, in 1888, and moved to London, United Kingdom in 1900^[1] with his Irish-born mother after they were abandoned by his father, an alcoholic civil engineer who worked for a North American railway company. His uncle, a successful lawyer, supported them.^[2] After attending a local school in Upper Norwood, Chandler was classically educated at Dulwich College, London (a public school whose alumni also include the authors P.G. Wodehouse^[2] and C. S. Forester). He did not attend university, instead spending time in Paris and Munich. In 1907, he was naturalised as a British subject in order to take the civil service examination, which he passed with the third-highest score. He then took an Admiralty job, lasting just over a year. His first poem was published during that time.^[3]

Chandler disliked the servility of the civil service and resigned, to the consternation of his family, becoming a reporter for the Daily Express and the Bristol Western Gazette newspapers. He was an unsuccessful journalist, published reviews and continued writing romantic poetry. Accounting for that time he said, "Of course in those days as now there were...clever young men who made a decent living as freelances for the numerous literary weeklies..." but "...I was distinctly not a clever young man. Nor was I at all a happy young man." ^[4]

In 1912, he borrowed money from his uncle (who expected it to be repaid with interest), and returned to North America, eventually settling in Los Angeles with his mother in 1913.^[5] He strung tennis rackets, picked fruit and endured a lonely time of scrimping and saving. Finally, he took a correspondence bookkeeping course, finished ahead of schedule, and found steady employment. In 1917, when the US entered World War I, he enlisted in the Canadian Expeditionary Force, saw combat in the trenches in France with the Gordon Highlanders, and was undergoing flight training in the fledgling Royal Air Force (RAF) in the United Kingdom at war’s end.^[2]

After the armistice, he returned to Los Angeles. He soon began a love affair with Cissy Pascal, a married woman eighteen years his senior.^[2] Cissy divorced her husband, Julian, in 1920 in an amicable separation, but Chandler's mother disapproved of the relationship and refused to sanction marriage. For four years Chandler had to support both his mother and Cissy. But when Florence Chandler died on September 26, 1923, Raymond was free to marry Cissy, and did so on February 6, 1924.^[2][6] By 1932, during his bookkeeping career, he became a highly-paid vice-president of the Dabney Oil Syndicate, but a year later, his alcoholism, absenteeism, and threatened suicide^[2] contributed to his firing.

Pulp writer

To earn a living with his creative talent, he taught himself to write pulp fiction; his first story, “Blackmailers Don't Shoot”, was published in Black Mask magazine in 1933; his first novel, The Big Sleep, was published in 1939. Literary success led to work as a Hollywood screenwriter: he and Billy Wilder co-wrote Double Indemnity (1944), based upon James M. Cain's novel of the same name. His only original screenplay was The Blue Dahlia (1946). Chandler collaborated on the screenplay of Alfred Hitchcock's Strangers on a Train (1951) - a story he thought implausible - based on Patricia Highsmith's novel. By then, the Chandlers had moved to La Jolla, California, an affluent coastal neighborhood of San Diego.

Later life and death

In 1954, Cissy Chandler died after a long illness, during which time Raymond Chandler wrote The Long Goodbye. Heartbroken and drunk, he neglected to inter Cissy's cremated remains, and they sat for 57 years in a storage locker. In a September 2010 San Diego Superior Court hearing an order was issued correcting this oversight, and on February 14, 2011, Cissy's cremains will be interred under a new grave marker with Chandler, as they wished, in Mt. Hope.^[7] After her death his subsequent loneliness worsened his natural propensity for clinical depression; he returned to drink, never quitting it for long, and the quality and quantity of his writing suffered.^[2] In 1955, he attempted suicide; literary scholars documented that suicide attempt. In The Long Embrace: Raymond Chandler and the Woman He Loved, Judith Freeman says it was “a cry for help”, given that he called the police beforehand, saying he planned to kill himself. Chandler's personal and professional life were both helped and complicated by the women to whom he was attracted — notably Helga Greene (his literary agent); Jean Fracasse (his secretary); Sonia Orwell (George Orwell's widow); and Natasha Spender (Stephen Spender's wife), the latter two of whom assumed Chandler to be a repressed homosexual.^[8]

After a respite in England (Chandler regained US citizenship in 1956^[3]), he returned to La Jolla, where in 1959 he died (according to the death certificate) in the Scripps Memorial Hospital of pneumonial peripheral vascular shock and prerenal uremia. Greene inherited the Chandler estate, after prevailing in a lawsuit vs. Fracasse.

Raymond Chandler is buried at Mount Hope Cemetery, San Diego, California, as per Frank MacShane's, The Life of Raymond Chandler. Chandler wished to be cremated and placed next to Cissy in Cypress View Mausoleum, but was buried in Mount Hope Cemetery by the County of San Diego Public Administrator's Office because he left an estate of $60,000 with no will (intestate) apparently found. The lawsuit over his estate complicated life for Helga Greene, but didn't take place until 1960.

Critical reception

Critics and writers from W. H. Auden to Evelyn Waugh to Ian Fleming, greatly admired Chandler's prose.^[2] In a radio discussion with Chandler, Fleming said that the former offered “some of the finest dialogue written in any prose today.”^[9] Although his swift-moving, hardboiled style was inspired mostly by Dashiell Hammett, his sharp and lyrical similes are original: "The muzzle of the Luger looked like the mouth of the Second Street tunnel;" "He had a heart as big as one of Mae West's hips;" "Dead men are heavier than broken hearts;" "I went back to the seasteps and moved down them as cautiously as a cat on a wet floor." Chandler's writing redefined the private eye fiction genre, led to the coining of the adjective 'Chandleresque', and inevitably became the subject of parody and pastiche. Yet the detective Philip Marlowe is not a stereotypical tough guy, but a complex, sometimes sentimental man with few friends who attended university, speaks some Spanish and sometimes admires Mexicans, and is a student of chess and classical music. He will refuse a prospective client’s money if he is ethically unsatisfied with a job.

The high regard in which Chandler is generally held today is in contrast to the critical sniping that stung the author during his lifetime. In a March 1942 letter to Mrs. Blanche Knopf, published in Selected Letters of Raymond Chandler, Chandler complained, "The thing that rather gets me down is that when I write something that is tough and fast and full of mayhem and murder, I get panned for being tough and fast and full of mayhem and murder, and then when I try to tone down a bit and develop the mental and emotional side of a situation, I get panned for leaving out what I was panned for putting in the first time."

Although his work enjoys general acclaim today, Chandler has been criticised for certain aspects of his work; Washington Post reviewer Patrick Anderson once described his plots as "rambling at best and incoherent at worst", and chastised his treatment of black, female, and homosexual characters, calling him a "rather nasty man". Anderson also acknowledged Chandler's importance as a lyrical writer, and said that, despite his flaws, "he often wrote truly beautiful scenes and descriptions."

Chandler’s short stories and novels are evocatively written, conveying the time, place and ambience of Los Angeles and environs in the 1930s and 1940s.^[2] The places are real, if pseudonymous: Bay City is Santa Monica, Gray Lake is Silver Lake, and Idle Valley a synthesis of rich San Fernando Valley communities.

Raymond Chandler was also a perceptive critic of pulp fiction; his essay "The Simple Art of Murder" is the standard reference work in the field.

All but one of his novels have been cinematically adapted. Most notable was The Big Sleep (1946), by Howard Hawks, with Humphrey Bogart as Philip Marlowe. William Faulkner was a co-writer on the screenplay. Raymond Chandler's few screen writing efforts and the cinematic adaptation of his novels proved stylistically and thematically influential upon the American film noir genre.

Edward Theodore "Ed" Gein (pronounced /ˈɡiːn/; August 27, 1906 – July 26, 1984) was an American murderer and body snatcher. His crimes, which he committed around his hometown of Plainfield, Wisconsin, garnered widespread notoriety after authorities discovered Gein had exhumed corpses from local graveyards and fashioned trophies and keepsakes from their bones and skin.

After police found body parts in his house in 1957, Gein confessed to killing two women: tavern owner Mary Hogan in 1954, and a Plainfield hardware store owner, Bernice Worden, in 1957. Initially found unfit to stand trial, following confinement in a mental health facility, he was tried in 1968 for the murder of Worden and sentenced to life imprisonment, which he spent in a mental hospital. The body of Bernice Worden was found in Gein's shed; her head and the head of Mary Hogan were found inside his house. Robert H. Gollmar, the judge in the Gein case, wrote: "Due to prohibitive costs, Gein was tried for only one murder—that of Mrs. Worden."^[1]

With fewer than three murders attributed, Gein does not meet the traditional definition of a serial killer.^[2] Regardless, his real-life case influenced the creation of several fictional serial killers, including Norman Bates from Psycho, Leatherface from The Texas Chainsaw Massacre and Buffalo Bill from The Silence of the Lambs.

Gein was born in La Crosse County, Wisconsin.^[3] His parents, George and Augusta Gein, both natives of Wisconsin, had two sons: Henry George Gein, and his younger brother, Edward Theodore Gein. Despite Augusta's deep contempt for her husband, the marriage persisted because of the family's religious belief about divorce. Augusta Gein operated a small grocery store and eventually purchased a farm on the outskirts of the small town of Plainfield, Wisconsin, which then became the Gein family's permanent home.^[4]

Augusta Gein moved to this location to prevent outsiders from influencing her sons.^[4] Edward Gein left the premises only to go to school. Besides school, he spent most of his time doing chores on the farm. Augusta Gein, a fervent Lutheran, preached to her boys the innate immorality of the world, the evil of drinking, and the belief that all women (herself excluded) were prostitutes and instruments of the devil. She reserved time every afternoon to read to them from the Bible, usually selecting graphic verses from the Old Testament dealing with death, murder, and divine retribution.^[5]

With an effeminate demeanor, the younger Gein became a target for bullies. Classmates and teachers recalled off-putting mannerisms, such as seemingly random laughter, as if he were laughing at his own personal jokes. To make matters worse, his mother scolded him whenever he tried to make friends. Despite his poor social development, he did fairly well in school, particularly in reading. ^[6]

Gein tried to make his mother happy, but she was rarely pleased with her boys. She often abused them, believing that they were destined to become failures like their father. During their teens and throughout their early adulthood, the boys remained detached from people outside of their farmstead, and so had only each other for company.^[4]

Deaths of family members

After George Gein died of a heart attack in 1940, the Gein brothers began working at odd jobs to help with expenses. Both brothers were considered reliable and honest by residents of the community. While both worked as handymen, Ed Gein also frequently babysat for neighbors. He enjoyed babysitting, seeming to relate more easily to children than adults. Henry Gein began to reject his mother's view of the world and worried about his brother Ed's attachment to her. He spoke ill of her around his brother.^[7][8]

On May 16, 1944, a brush fire burned close to the farm, and the Gein brothers went out to extinguish it. Reportedly, the brothers were separated, and as night fell, Ed Gein lost sight of his brother. When the fire was extinguished, he reported to the police that his brother was missing. When a search party was organized, Gein led them directly to his missing brother, who lay dead on the ground. The police had concerns about the circumstances under which the body was discovered.^[7][9] The ground on which Henry Gein lay was untouched by fire, and he had bruises on his head.^[7][9] Despite this, the police dismissed the possibility of foul play and the county coroner listed asphyxiation as the cause of death. Although some investigators suspected that Ed Gein killed his brother, no charges were filed against him.^[7][9]

After his brother's death, Gein lived alone with his mother, who died on December 29, 1945, following a series of strokes, at which time Gein "lost his only friend and one true love. And he was absolutely alone in the world."^[9]

Gein remained on the farm, supporting himself with earnings from odd jobs. He boarded up rooms used by his mother, including the upstairs, downstairs parlor, and living room, leaving them untouched. He lived in a small room next to the kitchen. Gein became interested in reading death-cult magazines and adventure stories.^[7]

Arrest

On November 16, 1957, Plainfield hardware store owner Bernice Worden disappeared, and police had reason to suspect Gein. Worden's son had told investigators that Gein had been in the store the evening before the disappearance, saying he would return the following morning for a gallon of anti-freeze. A sales slip for a gallon of anti-freeze was the last receipt written by Worden on the morning she disappeared.^[10] Upon searching Gein's property, investigators discovered Worden's decapitated body in a shed, hung upside down by ropes at her wrists, with a crossbar at her ankles. The torso was "dressed out" like that of a deer.^[11] She had been shot with a .22-caliber rifle, and the mutilations performed after death.

Searching the house, authorities found:^[12]

• Four noses
• Whole human bones and fragments^[13]
• Nine masks of human skin^[14]
• Bowls made from human skulls
• Ten female heads with the tops sawed off
• Human skin covering several chair seats
• Mary Hogan's head in a paper bag^[15]
• Bernice Worden's head in a burlap sack^[16]
• Nine vulvas in a shoe box^[17]
• Skulls on his bedposts
• Organs in the refrigerator
• A pair of lips on a draw string for a windowshade
• A belt made from human female nipples
• A lampshade made from the skin from a human face

These artifacts were photographed at the crime lab and then were properly destroyed.^[18]

When questioned, Gein told investigators that between 1947 and 1952,^[19] he made as many as 40 nocturnal visits to three local graveyards to exhume recently buried bodies while he was in a "daze-like" state. On about 30 of those visits, he said he had come out of the daze while in the cemetery, left the grave in good order, and returned home empty handed.^[20] On the other occasions, he dug up the graves of recently buried middle-aged women he thought resembled his mother^[21] and took the bodies home, where he tanned their skins to make his paraphernalia. Gein admitted robbing nine graves, leading investigators to their locations. Because authorities were uncertain as to whether the slight Gein was capable of single-handedly digging up a grave in a single evening, they exhumed two of the graves and found them empty, thus corroborating Gein's confession.^[22][23]

Shortly after his mother's death, Gein had decided he wanted a sex change and began to create a "woman suit" so he could pretend to be a female.^[12] Gein's practice of donning the tanned skins of women was described as an "insane transvestite ritual".^[24] Gein denied having sex with the bodies he exhumed, explaining, "They smelled too bad."^[24] During interrogation, Gein also admitted to the shooting death of Mary Hogan, a tavern operator missing since 1954.

A 16-year-old youth whose parents were friends of Gein, and who attended ball games and movies with Gein, reported that he was aware of the shrunken heads, which Gein had described as relics from the Philippines sent by a cousin who had served in World War II.^[25] Upon investigation by the police, these were determined to be human facial skins, carefully peeled from cadavers and used as masks by Gein.

Waushara County sheriff Art Schley allegedly physically assaulted Gein during questioning by banging Gein's head and face into a brick wall, causing Gein's initial confession to be ruled inadmissible.^[9] Schley died of a heart attack in December 1968, at age 43, only a month after testifying at Gein's trial. Many who knew him said he was traumatized by the horror of Gein's crime and that this, along with the fear of having to testify (especially about assaulting Gein), led to his early death. One of his friends said "He was a victim of Ed Gein as surely as if he had butchered him."^[9]

Trial

On November 21, 1957, Gein was arraigned on one count of first degree murder in Waushara County Court, where he entered a plea of not guilty by reason of insanity.^[26] Found mentally incompetent and thus unfit to stand trial, Gein was sent to the Central State Hospital for the Criminally Insane (now the Dodge Correctional Institution), a maximum-security facility in Waupun, Wisconsin, and later transferred to the Mendota State Hospital in Madison, Wisconsin. In 1968, Gein's doctors determined he was sane enough to stand trial. The trial began on November 14, 1968, lasting one week. He was found guilty of first-degree murder by Judge Robert H. Gollmar, but because he was found to be legally insane, he spent the rest of his life in a mental hospital.^[27][28]

Aftermath

On March 20, 1958, while Gein was in detention, his house burned to the ground. Arson was suspected. When Gein learned of the incident, he shrugged and said "Just as well."^[29]

In 1958, Gein's car, which he had used to haul the bodies of his victims, was sold at a public auction for $760 ($5,773 when accounting for inflation) to carnival sideshow operator Bunny Gibbons.^[30] Gibbons later charged carnival goers 25¢ admission to see it.^[31]

On July 26, 1984, Gein died of respiratory and heart failure due to cancer in Goodland Hall at the Mendota Mental Health Institute.^[9] His grave site in the Plainfield cemetery was frequently vandalized over the years; souvenir seekers chipped off pieces of his gravestone before the bulk of it was stolen in 2000. The gravestone was recovered in June 2001 near Seattle and is now in a museum in Waushara County.^[32]

Impact on popular culture

The story of Ed Gein has had a lasting impact on popular culture as evidenced by its numerous appearances in movies, music and literature. Gein's story was adapted into a number of movies, including Deranged (1974), In the Light of the Moon (2000, later retitled Ed Gein for the U.S. market), and Ed Gein: The Butcher of Plainfield (2007). Gein influenced the nature of book and film characters, most notably such fictional serial killers as Norman Bates (Psycho), Leatherface (The Texas Chainsaw Massacre), and Buffalo Bill (The Silence of the Lambs).^[29]

At the time, the news reports of Gein's crimes spawned a subgenre of black humor.^[33] Since the 1950s, Gein has frequently been exploited in transgressive art or shock rock, often with no connection to his life or crimes beyond the shock value of his name.^[34]

A biographical musical titled "Ed Gein: the Musical" premiered on January 2, 2010 in Menasha, Wisconsin.^[35][36][37]

Overclocking é o nome que se dá ao processo de forçar um componente de um computador a rodar numa frequência, definida em hertz mais alta do que a especificada pelo fabricante. Apesar de haver diferentes razões pelas quais o overclock é realizado, a mais comum é para aumentar o desempenho do hardware. O overclocking pode resultar em superaquecimento do processador, instabilidade no sistema e às vezes pode danificar o hardware, se realizado de maneira imprópria.

A velocidade padrão de um componente está assegurada pela tensão (Volt) a que ele está definido para trabalhar. Existe uma margem ascendente (às vezes grande) de frequência que o componente tolera com essa mesma tensão até chegar a uma frequência onde é perdida a estabilidade, sendo necessário compensá-la com o incremento de tensão, aumentando consequentemente a temperatura.

O overclock pode ser aplicado basicamente a quatro componentes de hardware:

• Processador
• Placa-Mãe
• Memória
• Placa de Vídeo

Nota-se que quem procura o overclock é o gamer, entusiasta ou utilizador de software que realmente requeira grandes recursos computacionais. Se usa o PC para navegar, ouvir música, ver filmes e fazer as coisas pessoais, não tente fazer o mesmo.

A velocidade do clock num processador é definida multiplicando a velocidade da BUS pelo multiplicador, os quais estão definidos de fábrica (as vezes a velocidade da BUS pode ser designada por outros termos ou siglas, como HTT ou FSB (Front Side Bus).

O overclock está diretamente relacionado com o aumento de consumo de energia, sendo necessário ter a certeza de que a fonte de alimentação consegue alimentar (de forma estável) a potência necessária ao funcionamento do sistema em overclock. Ao consumir mais energia irá, obviamente, ter que dissipá-la por forma de calor, portanto é necessária uma boa refrigeração. Portanto, se quer iniciar no overclock, a fonte de alimentação e a refrigeração serão as primeiras etapas.

O sucesso do overclock está dependente das potencialidades de todo o hardware envolvido, onde o essencial, em primeiro lugar é a placa-mãe, depois o processador e só então a memória. Recomenda-se que seja feito a partir da BIOS mas também é possível fazê-lo por software ou alterando fisicamente os componentes.

Mas overclock não trata apenas de aumento em Mhz ou em multiplicação, nos processadores também podem ser alteradas suas diferenças de potencial para aumento de carga ou sua diminuição (underclock).

Isso pode ter certas consequências, das quais se destacam a diminuição da vida útil do hardware e o aumento de temperatura do dispositivo. Podendo até provocar a fusão dos componentes do computador. Esse aumento da temperatura é solucionado com o resfriamento do hardware.

Refrigeração

A maioria dos sistemas de refrigeração é projetada para computadores que não utilizam o overclocking, mesmo assim, hoje em dia, encontramos cada vez mais métodos eficazes para soluções de refrigeração, como ventiladores poderosos, dissipadores de calor, refrigeração a água (watercooler). Com isso aumentando a possibilidades de overclocking, Pois ao fazê-lo você estará aumentando a freqüência (velocidade) e a voltagem de operação do processador, que fará com que o processador aqueça mais do que deveria, então é necessária uma refrigeração voltada para esse processo. Quanto maior o valor do overclocking, mais será necessário refrigerá-lo.

Dissipadores de calor muitas vezes são feitos inteiramente de cobre, que possui uma alta condutividade térmica, mas o custo é elevado. Sendo assim é muito comum a utilização do alumínio, que tem uma condutividade térmica mais pobre , mas é significativamente mais barato que o cobre. Muitos dissipadores de calor combinam dois ou mais materiais para atingir um bom custo-benefício.

A refrigeração a água segue o mesmo principio de sistemas de refrigeração de motores automotivos. Este sistema veio para combater a refrigeração a ar, permitindo assim melhor resfriamento dos componentes, conseguindo-se maiores valores de overclocking nos diferentes tipos de hardware.

Existem outros métodos que podem ser utilizados em casos extremos, como o nitrogênio líquido, hélio liquido e gelo seco. Estes métodos são geralmente impraticáveis em longo prazo, por exemplo, os transistores a base de silício irão se degradar a temperaturas abaixo de -173 °C e geralmente parar de funcionar em temperaturas de -233 °C.

Vantagens

• O utilizador pode, em muitos casos, adquirir ou possuir um equipamento lento, com componentes mais baratos e fazer nele um overclock que poderá dar um ganho extra em desempenho, tornando seu equipamento com desempenho aproximado, igual ou até melhor que um mais caro.^{[carece de fontes?]}

• Maior desempenho em jogos, codificação, edição de vídeos e um adicional ganho em velocidade nas tarefas, sem nenhuma despesa adicional. No entanto, aumentará o gasto de energia. Particularmente, para entusiastas que regularmente atualizam seus hardwares, overclocking pode aumentar o tempo que um upgrade é necessário.

Desvantagens

• Muitas das desvantagens de overclocking podem ser a aliviadas ou bastante reduzidas por overclockers hábeis^{[carece de fontes?]}. Porém, durante o processo, usuários novatos podem cometer erros que poderiam ser evitados, desde um sistema instável e apresentando erros, a componentes danificados.
• Na teoria o overclock não é uma prática viável para se aumentar a velocidade de processamento. O que determinará o clock do processador é a sua capacidade de propagação de ondas eletromagnéticas sobre a superfície dos componentes aliado ao comportamento projetado (pipeline, escalabilidade). No projeto de desenvolvimento de hardware todas as especificações técnicas devem ser obedecidas para que o comportamento do processador esteja dentro do esperado. O maior exemplo de que esta prática não é viável, é a ausência de usos em aplicações comerciais e cálculos científicos (que precisariam de tempo muito grande de funcionamento sem falhas).
• O Aumento da velocidade de relógio/tensão resulta num maior consumo de energia.
• Se você usa o Windows XP, e fizer um overclock, pode ficar estável, porém se for reinstalado poderão ocorrer erros de leitura de arquivos, também poderá ocorrer erros durante a instalação de atualizações do OS.
• Em relação a temperatura, ela não irá só elevar a temperatura do processador, mas também do gabinete e consequentemente de todos os componentes internos.
• Ao fazer um overclock em algum componente, você estará perdendo automaticamente a garantia do mesmo.
• Há também um risco de incêndio, caso os componentes nao estejam devidamente arrefecidos.

George Francis Hotz (born October 2, 1989), alias geohot, million75 or simply mil is known for working with other people to unlock the iPhone, allowing the phone to be used with other wireless carriers, contrary to AT&T and Apple's intent^{[citation needed]}.^[1][2] He is also noted for jailbreaking the Playstation 3 OS^{[citation needed]}. In response to Sony disabling the "OtherOS" feature on the PlayStation 3 ^[3], he developed a method for restoring that functionality and researched several other security measures.

According to Hotz's blog, he traded his unlocked 8GB iPhone to Terry Daidone, the founder of Certicell, for a Nissan 350Z and 3 8GB iPhones.^[4] Hotz said he wanted to give the iPhones to the other members of the team who created the hack with him.^[5] Hotz's hardware based unlocking technique has largely been replaced by software unlocking that does not require dis-assembly of the iPhone.^[6]

On February 8, 2008, Hotz developed the software unlock for the iPhone's new Bootloader Version 4.6 that was previously only achievable with a "testpoint based hardware unlock".^[7]

On July 3, 2009, Hotz announced purplera1n, the first public software exploit for jailbreaking the iPhone 3GS. Details were posted on his blog.^[8]

On October 11, 2009, at 3:33AM Hotz released blackra1n, a jailbreak for all iPhones and iPod Touches. The only caveat was that the iPod touch third generation would need a "tethered jailbreak" to work.

On October 25, 2009, Hotz released Blackra1n RC2, an update to his previous blackra1n utility. This version allows MC Model iPod Touch 2G (8GB iPod Touch third generation) and new-bootrom iPhone 3GS users to jailbreak their iPod touches as well. (tethered jailbreak only)^[9]

On October 31, 2009, Hotz announced the impending release of Blackra1n RC3, this version will include blacksn0w which will allow SIM unlock of all iPhones using Blacksn0w RC1.^[10] Blacksn0w was originally scheduled for release on November 4, 2009, but due to positive test results it was moved to the 3rd. Blacksn0w was the #1 trending topic on Twitter as requested by GeoHot only moments after its release.

On March 27, 2010, Hotz established a website for his newest jailbreak software, limera1n.^[11] Limera1n was rumored to be his newest jailbreaking tool and was released, however, it was later found that Hotz registered another domain at the same time, rubyra1n.com.^[12] It is still unknown if rubyra1n will ever be released.

On June 24, 2010, Hotz wrote on Twitter that he had no plans to release a new jailbreak. He has told people looking for a jailbreak release to 'keep an eye on Spirit,^[13] the currently used program for 3.1.x jailbreaking, which lead to the belief there are plans to update the software to allow iOS 4.0 jailbreaking. This however has not had a release date confirmed.^[14]

On July 10, 2010, Hotz published that he had been able to jailbreak an iPhone 4 running iOS 4.0. As evidence, he provided a picture of the device executing Cydia. This post has since been edited and blocked from public view, in which Hotz stated that the picture was "quite obviously fake", addressing himself to "the haters".

On July 13, 2010, Hotz announced his retirement from iDevices hacking, saying that it's not fun as it used to be, and people were taking too serious something he used to do just as a distraction.^[15]

On October 8, 2010, Hotz confirmed he was releasing a Jailbreak on 10/11/10; one day after the release of GreenPois0n. He also posted a picture of limera1n running on an iPhone 3G S, iPod Touch fourth generation, iPhone 4 and on the iPad.

On October 9, 2010, Hotz released limera1n Beta 1 - without support for the 3GS (due to a problem with the bootrom). Additionally, the exploit has been found to be moderately buggy, even on supported devices.^[16] This suspended the release of the SHAtter exploit in the form of greenpois0n, due for release the next day. On the limera1n website, he claims this was to make the Chronic Dev team "do the right thing" - presumably implying that they should save their jailbreak exploit for fifth generation devices.^[17] He later went on to release three more betas, containing support for iPhone 3GS models, along with various bug fixes and other stability enhancements.

On October 11, 2010, Hotz released what appears to be the final version of his ^[16] jailbreak (RC1b). Hotz also put on his website that the Mac version of this jailbreak is "coming in 7 years".

Hacking the PlayStation 3

In the end of 2009, Hotz announced his efforts to hack the Sony PlayStation 3,^[18] a console widely regarded as being the only fully locked and secure system of the seventh generation era. Hotz opened a blog to document his progress, and five weeks later, on January 22, 2010, he announced that he had successfully hacked the machine by enabling himself read and write access to the machine's system memory and having hypervisor level access to the machine's processor.^[19][20] Hotz also detailed the many things his work could allow, such as homebrew and PlayStation 2 emulation (a feature removed by Sony in newer revisions of the console to tackle production costs).^[21]

On January 26, 2010, Hotz released the exploit to the public. It requires the OtherOS function of the machine, and consists of a Linux kernel module and gaining control of the machine's hypervisor via bus glitching.^[22] Hotz wrote that "Sony may have difficulty patching the exploit". On March 28, 2010, Sony has responded by announcing to release a PlayStation 3 firmware update that removes the OtherOS feature,^[23] a feature that was already absent on the newer Slim revisions of the machine. This generated an uproar by the PlayStation 3 community. Hotz had then announced plans of a custom firmware, similar to the custom firmware for the PlayStation Portable, to enable Linux and OtherOS support, while still retaining the features of newer firmwares.

As of April 7, 2010, Hotz had posted a video on the internet detailing his supposed progress with custom firmware on the machine, and showing a PlayStation 3 running and having the OtherOS feature enabled on firmware 3.21. He had named his custom firmware as 3.21OO, and said it may work on newer Slim models of the console, as the feature was removed altogether with the launch of the newer revision. However, he had never announced a release date for the alleged firmware nor had he mentioned whether he was working on the same hack for the latest firmware version of 3.41.^[24]

On July 13, 2010, Hotz posted a message on his Twitter account stating that he was giving up trying to crack the PS3 any further.^[25]

On January 6, 2011, he shows a demo of running homebrew applications on PS3 firmware 3.55 without using any jailbreak usb dongles, based on the discovery of the security exploit by the fail0verflow team.^[26]

On January 7, 2011, he showed off a demo video running homebrew applications on PlayStation 3 custom firmware 3.55.^[27]

On January 11, 2011, Sony filed a temporary restraining order (TRO) against Mr. Hotz in the US District Court of Northern California.^[28]

Sony lawsuit

On January 12 , 2011, Sony sued Mr. Hotz on 8 counts for violation of the DMCA.^[29] In response, Carnegie Mellon University professor David S. Touretzky mirrored Hotz' writings and issued a statement confirming that Hotz' publication is within his right to free speech.^[30]

Other accomplishments and recognition

Hotz was a finalist at the 2004 ISEF competition in Portland OR with his project "Mapping Robot". Recognition included interviews on the Today Show and Larry King.^[31] Hotz was a finalist at the 2005 ISEF competition, with his project "The Googler".^[32] Continuing with robots, Hotz competed in his school's highly successful Titanium Knights battlebots team. George also worked on his project, "Neuropilot," in which he was able to read EEG signals off his head with hardware from the OpenEEG project.

Hotz competed in the 2007 Intel International Science and Engineering Fair, a science competition for high school students, where his project, entitled "I want a Holodeck", received awards and prizes in several categories.^[33] Hotz has received considerable attention in mainstream media, including interviews on the Today Show, Fox, CNN, NBC, CBS, G4, ABC^[34] CNBC,^[35] and articles in several magazines, newspapers, and websites, including Forbes,^[36] and BBC.^[37]

The Forbes article said Hotz hopes to go into neuroscience: "hacking the brain," he called it. In March 2008, PC World magazine listed George as one of the top 10 Overachievers under 21.^[38]

He entered the Rochester Institute of Technology in 2007, quickly after gaining notoriety for hacking the iPhone, but quickly flunked out and withdrew from the school. In December 2007, Hotz travelled to Sweden to attend the Stockholm International Youth Science Seminar and talk about his 3D imaging invention (called Project Holodeck) that netted him a $20,000 Intel prize earlier that year.^[39]

Personal life

Hotz grew up in Glen Rock, New Jersey, where he attended the Bergen County Academies, a magnet public high school. He was in AEDT (Academy for Engineering and Design Technology). ^[40]

Um algoritmo é uma sequência finita de instruções bem definidas e não ambíguas, cada uma das quais pode ser executada mecanicamente num período de tempo finito e com uma quantidade de esforço finita.

O conceito de algoritmo é frequentemente ilustrado pelo exemplo de uma receita, embora muitos algoritmos sejam mais complexos. Eles podem repetir passos (fazer iterações) ou necessitar de decisões (tais como comparações ou lógica) até que a tarefa seja completada. Um algoritmo corretamente executado não irá resolver um problema se estiver implementado incorretamente ou se não for apropriado ao problema.

Um algoritmo não representa, necessariamente, um programa de computador, e sim os passos necessários para realizar uma tarefa. Sua implementação pode ser feita por um computador, por outro tipo de autômato ou mesmo por um ser humano. Diferentes algoritmos podem realizar a mesma tarefa usando um conjunto diferenciado de instruções em mais ou menos tempo, espaço ou esforço do que outros. Tal diferença pode ser reflexo da complexidade computacional aplicada, que depende de estruturas de dados adequadas ao algoritmo. Por exemplo, um algoritmo para se vestir pode especificar que você vista primeiro as meias e os sapatos antes de vestir a calça enquanto outro algoritmo especifica que você deve primeiro vestir a calça e depois as meias e os sapatos. Fica claro que o primeiro algoritmo é mais difícil de executar que o segundo apesar de ambos levarem ao mesmo resultado.

O conceito de um algoritmo foi formalizado em 1936 pela Máquina de Turing de Alan Turing e pelo cálculo lambda de Alonzo Church, que formaram as primeiras fundações da Ciência da computação.

Etimologia

A palavra algoritmo tem origem no sobrenome, Al-Khwarizmi, do matemático persa do século IX Mohamed ben Musa, cujas obras foram traduzidas no ocidente cristão no século XII, tendo uma delas recebido o nome Algorithmi de numero indorum, sobre os algoritmos usando o sistema de numeração decimal (indiano). Outros autores, entretanto, defendem a origem da palavra em Al-goreten (raiz - conceito que se pode aplicar aos cálculos).^[1]

Formalismo

Fluxograma, um exemplo de algoritmo imperativo. O estado em vermelho indica a entrada do algoritmo enquanto os estados em verde indicam as possíveis saídas.

Um programa de computador é essencialmente um algoritmo que diz ao computador os passos específicos e em que ordem eles devem ser executados, como por exemplo, os passos a serem tomados para calcular as notas que serão impressas nos boletins dos alunos de uma escola. Logo, o algoritmo pode ser considerado uma sequência de operações que podem ser simuladas por uma máquina de Turing completa.

Quando os procedimentos de um algoritmo envolvem o processamento de dados, a informação é lida de uma fonte de entrada, processada e retornada sob novo valor após processamento, o que geralmente é realizado com o auxílio de uma ou mais estrutura de dados.

Para qualquer processo computacional, o algoritmo precisa estar rigorosamente definido, especificando a maneira que ele se comportará em todas as circunstâncias. A corretude do algoritmo pode ser provada matematicamente, bem como a quantidade assintótica de tempo e espaço (complexidade) necessários para a sua execução. Estes aspectos dos algoritmos são alvo da análise de algoritmos.

A maneira mais simples de se pensar um algoritmo é por uma lista de procedimentos bem definida, na qual as instruções são executadas passo a passo a partir do começo da lista, uma idéia que pode ser facilmente visualizada através de um fluxograma. Tal formalização adota as premissas da programação imperativa, que é uma forma mecânica para visualizar e desenvolver um algoritmo. Concepções alternativas para algoritmos variam em programação funcional e programação lógica.

Término do algoritmo

Alguns autores restringem a definição de algoritmo para procedimentos que eventualmente terminam. Marvin Minsky constatou que se o tamanho de um procedimento não é conhecido de antemão, tentar descobri-lo é um problema indecidível, já que o procedimento pode ser executado infinitamente, de forma que nunca se terá a resposta. Alan Turing provou em 1936 que não existe máquina de Turing para realizar tal análise para todos os casos, logo não há algoritmo para realizar tal tarefa para todos os casos. Tal condição é conhecida atualmente como problema da parada.

Para algoritmos intermináveis o sucesso não pode ser determinado pela interpretação da resposta e sim por condições impostas pelo próprio desenvolvedor do algoritmo durante sua execução.

Implementação

A maioria dos algoritmos é desenvolvida para ser implementada em um programa de computador. Apesar disso eles também podem ser implementados por outros modos tais como uma rede neural biológica (tal como no cérebro quando efetuamos operações aritméticas) em circuitos elétricos ou até mesmo em dispositivos mecânicos.

Para programas de computador existe uma grande variedade de linguagens de programação, cada uma com características específicas que podem facilitar a implementação de determinados algoritmos ou atender a propósitos mais gerais.

Análise de algoritmos

Ver artigo principal: Análise de algoritmos

A análise de algoritmos é um ramo da ciência da computação que estuda as técnicas de projeto de algoritmos e os algoritmos de forma abstrata, sem estarem implementados em uma linguagem de programação em particular ou implementadas de algum outro modo. Ela preocupa-se com os recursos necessários para a execução do algoritmo tais como o tempo de execução e o espaço de armazenamento de dados. Deve-se perceber que para um dado algoritmo pode-se ter diferentes quantidades de recursos alocados de acordo com os parâmetros passados na entrada. Por exemplo, se definirmos que o fatorial de um número natural é igual ao fatorial de seu antecessor multiplicado pelo próprio número, fica claro que a execução de fatorial(10) consome mais tempo que a execução de fatorial(5).

Um meio de exibir um algoritmo a fim de analisá-lo é através da implementação por pseudocódigo em português estruturado. O exemplo a seguir é um algoritmo em português estruturado que retorna (valor de saída) a soma de dois valores (também conhecidos como parâmetros ou argumentos, valores de entrada) que são introduzidos na chamada da função:

Algoritmo "SomaDeDoisValores";

variável:

SOMA,A,B: inteiro;

inicio

Escreva("Digite um numero");

Leia(A);

escreva("digite outro numero");

leia(B);

Soma ← A + B;

escreva(SOMA);

fim.

Classificação

Classificação por implementação

Pode-se classificar algoritmos pela maneira pelo qual foram implementados.

• Recursivo ou iterativo - um algoritmo recursivo possui a característica de invocar a si mesmo repetidamente até que certa condição seja satisfeita e ele é terminado, que é um método comum em programação funcional. Algoritmos iterativos usam estruturas de repetição tais como laços, ou ainda estruturas de dados adicionais tais como pilhas, para resolver problemas. Cada algoritmo recursivo possui um algoritmo iterativo equivalente e vice-versa, mas que pode ter mais ou menos complexidade em sua construção.
• Lógico - um algoritmo pode ser visto como uma dedução lógica controlada. O componente lógico expressa os axiomas usados na computação e o componente de controle determina a maneira como a dedução é aplicada aos axiomas. Tal conceito é base para a programação lógica.
• Serial ou paralelo - algoritmos são geralmente assumidos por serem executados instrução a instrução individualmente, como uma lista de execução, o que constitui um algoritmo serial. Tal conceito é base para a programação imperativa. Por outro lado existem algoritmos executados paralelamente, que levam em conta as arquiteturas de computadores com mais de um processador para executar mais de uma instrução ao mesmo tempo. Tais algoritmos dividem os problemas em subproblemas e o delegam a quantos processadores estiverem disponíveis, agrupando no final o resultado dos subproblemas em um resultado final ao algoritmo. Tal conceito é base para a programação paralela. De forma geral, algoritmos iterativos são paralelizáveis; por outro lado existem algoritmos que não são paralelizáveis, chamados então problemas inerentemente seriais.
• Determinístico ou não-determinístico - algoritmos determinísticos resolvem o problema com uma decisão exata a cada passo enquanto algoritmos não-determinísticos resolvem o problema ao deduzir os melhores passos através de estimativas sob forma de heurísticas.
• Exato ou aproximado - enquanto alguns algoritmos encontram uma resposta exata, algoritmos de aproximação procuram uma resposta próxima a verdadeira solução, seja através de estratégia determinística ou aleatória. Possuem aplicações práticas sobretudo para problemas muito complexos, do qual uma resposta correta é inviável devido à sua complexidade computacional.

Classificação por paradigma

Pode-se classificar algoritmos pela metodologia ou paradigma de seu desenvolvimento, tais como:

• Divisão e conquista - algoritmos de divisão e conquista reduzem repetidamente o problema em sub-problemas, geralmente de forma recursiva, até que o sub-problema é pequeno o suficiente para ser resolvido. Um exemplo prático é o algoritmo de ordenação merge sort. Uma variante dessa metodologia é o decremento e conquista, que resolve um sub-problema e utilização a solução para resolver um problema maior. Um exemplo prático é o algoritmo para pesquisa binária.
• Programação dinâmica - pode-se utilizar a programação dinâmica para evitar o re-cálculo de solução já resolvidas anteriormente.
• Algoritmo ganancioso - um algoritmo ganancioso é similar à programação dinâmica, mas difere na medida em que as soluções dos sub-problemas não precisam ser conhecidas a cada passo, uma escolha gananciosa pode ser feita a cada momento com o que até então parece ser mais adequado.
• Programação linear
• Redução - a redução resolve o problema ao transformá-lo em outro problema. É chamado também transformação e conquista.
• Busca e enumeração - vários problemas podem ser modelados através de grafos. Um algoritmo de exploração de grafo pode ser usado para caminhar pela estrutura e retornam informações úteis para a resolução do problema. Esta categoria inclui algoritmos de busca e backtracking.
• Paradigma heurístico e probabilístico - algoritmos probabilísticos realizam escolhas aleatoriamente. Algoritmos genéticos tentam encontrar a solução através de ciclos de mutações evolucionárias entre gerações de passos, tendendo para a solução exata do problema. Algoritmos heurísticos encontram uma solução aproximada para o problema.

Classificação por campo de estudo

Cada campo da ciência possui seus próprios problemas e respectivos algoritmos adequados para resolvê-los. Exemplos clássicos são algoritmos de busca, de ordenação, de análise numérica, de teoria de grafos, de manipulação de cadeias de texto, de geometria computacional, de análise combinatória, de aprendizagem de máquina, de criptografia, de compressão de dados e de interpretação de texto.

Classificação por complexidade

Ver artigo principal: Complexidade computacional

Alguns algoritmos são executados em tempo linear, de acordo com a entrada, enquanto outros são executados em tempo exponencial ou até mesmo nunca terminam de serem executados. Alguns problemas possuem múltiplos algoritmos enquanto outros não possuem algoritmos para resolução.