title: Damages (TV series)

text: After four seasons of manipulation and deceit that cross professional and personal lines, season five sets the stage for the final showdown between Patty and Ellen. In a storyline inspired by the vicissitudes of the whistleblower website WikiLeaks and its founder Julian Assange, Channing McClaren (Ryan Phillippe) is a computer expert and the iconoclastic founder of a website, McClarenTruth.org, devoted to government and corporate transparency. It is shown, in the premiere, that Ellen and Patty are set to go head to head in a case over the death of Ms. Walling (seen to have been attacked by two anonymous people), as Patty claims that McClaren murdered her, as well as stealing personal information and posting it on his site.


title: Damages (TV series)

text: The final season opens with Patty walking into her office to see her granddaughter sitting in at her desk drawing. Patty says to her, "Get out of mommy's chair." The girl responds, "You're not my mommy." When Patty approaches the desk, Ellen appears in place of the girl, saying, "I love you, mommy." The end of the season premiere depicts Patty being questioned by the police about Ellen's disappearance. Ellen is shown in an alley, unconscious and bleeding. While this case is occurring, Michael organizes a custody case over Catherine, with Ellen agreeing to testify against Patty after the McClaren case was over. Also, in Ellen's personal life, her mother has left her father after he threw something at her and she was scared. She lived in Ellen's apartment for a while before moving into her own apartment, only to move back in with Ellen.


title: Damages (TV series)

text: The McClaren case continues, with both Ellen and Patty being contacted by a hacker named Samurai Seven. He sold information to both of them about the involvement of Princefield in Naomi's death. However, only Patty receives this information and then Samurai Seven is found dead in a burnt-out car. In court, Ellen suspects that Patty has a personal relationship with the judge, which seems to be confirmed when Patty receives a personal call from him. However, once Ellen has raised attention to this and removed the judge from the case, Patty reveals that it was all a setup, and that she and the judge disliked each other. When Ellen finds out that Patty has received the Princefield information, she tells the new judge and Patty is forced to give Ellen the information, losing her leverage on the case.


title: Damages (TV series)

text: When questioning Naomi's daughter, Patty finds out that Naomi and McClaren possibly had a sexual relationship and so Patty goes to the media and accuses McClaren of rape. This results in both Ellen and Patty being given a gag order. Soon after, McClaren offers Naomi's daughter a settlement and she wants to take it. Ellen and Patty team up to give false evidence so that the settlement is rejected and the case continues. Ellen and Patty are both given a chance to ask questions of an expert in the data breach but have to travel to him. Once the interview is over, Ellen finds out that her flight is cancelled and Patty invites her onto her private flight, which has been delayed. While waiting in the airport, Ellen and Patty discuss the attempted murder of Ellen and the confession that Patty made. Patty says that the accusation was false and that the confession was a lie because she was at gunpoint.


title: Damages (TV series)

text: Rutger Simon is revealed to be the one who intentionally leaked Naomi Walling's personal e-mails, hoping to implicate McClaren as the leaker so he can take control of McClarentruth.org. Simon convinces Patty Hewes to become an investor in the site when he takes over in exchange for his testimony against Channing McClaren, Helmut Torben, and Bennett Herreshoff. Patty subsequently informs Ellen of her intention to call Simon as a witness for the Plaintiff. Upon getting this information, Ellen informs Torben (McClarenTruth.org's primary benefactor) of Simon's intention to testify against Channing McClaren and the possibility of Simon implicating both him and Bennett Herreshoff as part of his testimony and suggests having Simon taken out of the picture. In a meeting with Torben and Herreshoff, Simon informs them that he intends to testify against Channing McClaren but promises not to implicate either of them in his testimony. After booking an emergency flight out of the country to Dublin, Simon is killed by hitmen hired by Herreshoff and Torben. On the day of the trial, shortly before opening arguments, Patty Hewes is informed that Simon has left the country. Because Simon was Patty's only valuable witness, she drops the lawsuit. Later, Patty suggests that she intentionally gave Ellen her witness list early to see how Ellen handled the information. Patty knew Ellen would share the information with Torben, who would have Simon killed, thus proving, in Patty's eyes, that Ellen has become as manipulative as Patty.


title: Damages (TV series)

text: Attention then turns to the custody case. Ellen has the blood that was on the card she had with her the day she was attacked tested and finds out the identity of Patrick (the murderer). Ellen has her investigator track and find him. She offers Patrick immunity if he testifies against Patty. He agrees. The story has now caught up to the future shown in the premiere and Ellen is seen walking to her office through the alley. The scene then cuts to Patrick and the investigator in Ellen's office, worried that Ellen is two hours late. They call the detectives to have Patty arrested. As the two men search the roof, they discover Ellen unconscious in the alley below. As they both seem to run down to help her, only the investigator does as Patrick goes back to the office to find Michael, who has just arrived. As Ellen is being revived, a scan picture is found in her bag, revealing she is pregnant. Once awake, Ellen goes back to her office to find Michael dead, having been shot by Patrick. Patty is told about this in a mimed scene. At the end of the series finale, the final scene takes place "a few years from now" showing Patty entering a shop to find Ellen with her daughter. In her limo, Patty has a vision of Ellen coming to thank her for everything she has done. Instead, Ellen walks away, telling her daughter that she knew "that woman" back when she was a lawyer. Her daughter says Ellen is not a lawyer any more. Ellen walks with her daughter and tells her that they're going to visit her dad at the VA (the Department of Veterans Affairs) which means the child's father is Chris Sanchez. The scene ends with a closeup on Patty's face; she sits with a stoic expression on her face in silence.


title: Damages (TV series)

text: The series details the mentor-protegee relationship between high-stakes attorney Patty Hewes (Glenn Close) and newly graduated attorney Ellen Parsons (Rose Byrne). During the first three seasons Tom Shayes (Tate Donovan) acts as Patty's associate, right-hand man and later partner. Michael Nouri stars in the first two seasons as Patty's husband Phil Grey, and makes periodic guest appearances in subsequent seasons due to their characters' separation. Zachary Booth's character recurs throughout the series as Patty's damaged son, Michael Hewes.


title: Damages (TV series)

text: The first season mainly focused on a case involving Arthur Frobisher, played by Ted Danson, a man blamed for embezzlement and fraud; Željko Ivanek played his regretful attorney Ray Fiske. Noah Bean starred as David Connor, Ellen's fiancé, with Anastasia Griffith recurring prominently as Katie Connor, David's sister and the key witness in the Frobisher case (at the end of the first season Bean and Ivanek leave the main cast with the death of their characters, but still serve as occasional guest stars with their characters appearing in flashbacks). Notable recurring characters during the first season were played by Peter Facinelli, Philip Bosco, and Peter Riegert.


title: Damages (TV series)

text: The second season found Patty and her firm inadvertently thrown into a massive case against the billion dollar-worth energy corporation Ultima National Resources (UNR). William Hurt played Daniel Purcell, a mysterious man from Patty's past who initiates the case and puts it in Patty's hands. John Doman played Walter Kendrick (in a billed recurring role), the primary antagonist of the season as the CEO of UNR, while Marcia Gay Harden joined the cast as UNR's misinformed but smart and vicious lead counsel Claire Maddox. On the personal front, Anastasia Griffith returned as Ellen's friend Katie Connor, who helps her in taking down Frobisher, while Timothy Olyphant played a man in grief counseling who bonds with Ellen under ambiguous motives. Returning recurring actors in prominent roles were Ted Danson, David Costabile, Tom Aldredge, Mario van Peebles and Glenn Kessler. Notable recurring characters during the second season were played by Clarke Peters, Brett Cullen, Kevin Corrigan and Darrell Hammond.


title: Damages (TV series)

text: The third season, inspired by the Bernie Madoff scandal, tracked Patty's aggressive pursuit of bringing down the disgraced Tobin family after they were revealed to be a part of a Ponzi scheme that ripped off millions of citizens. Campbell Scott played Joe Tobin, the shamed but ultimately spoiled and selfish youngest son of the family. Martin Short played the family's longtime trusted lawyer Leonard Winstone who finds his place in this family changes as the Tobins reveal their true colors. Lily Tomlin special guest starred throughout the season as the secretive matriarch Marilyn Tobin, while Len Cariou appeared as the patriarch of the family blamed for all of the fraud and conspiracy. Returning recurring actors in prominent roles were Ted Danson, and also Timothy Olyphant in a single guest appearance. Notable recurring characters during the third season were played by Dominic Chianese, Mädchen Amick, Ben Shenkman, and Keith Carradine. Wallace Shawn also made a notable guest appearance.


title: Damages (TV series)

text: The fourth season, the first without Tate Donovan, followed a wrongful-death suit filed against a military contractor over a mysterious incident in a war zone. John Goodman played Howard Erickson, the CEO of the shadowy military contractor who becomes the defendant against Patty and Ellen over the corruption that occurred in the war zone. Dylan Baker played Jerry Boorman, a mysterious figure with secretive ties to the Middle East. Chris Messina played Chris Sanchez, an old high school friend of Ellen's and a decorated soldier suffering from posttraumatic stress disorder. Notable recurring characters during the fourth season were played by Derek Webster, Griffin Dunne, Judd Hirsch, Fisher Stevens, and Bailey Chase.


title: Damages (TV series)

text: The fifth and final season pitted Patty and Ellen against one another in court, with the case surrounding the suit of the founder of a WikiLeaks type of website, Channing McClaren, played by Ryan Phillippe. Jenna Elfman played Naomi Walling, the investment bank employee whose daughter Rachel (Alexandra Socha) sues McClaren after he releases Naomi's personal information along with the financial records she leaked to him - leading to Naomi's suicide (in reality, she was murdered and the suicide faked). Janet McTeer played Kate Franklin, an old colleague of Patty Hewes who teams up with Ellen. John Hannah played Rutger Simon, the gatekeeper of McClaren's website who is devoted to exposing fraud and corporate misconduct. Returning recurring actors in prominent roles were Judd Hirsch and Chris Messina. Notable recurring characters during the fifth season were played by Victor Garber, M. Emmet Walsh, William Sadler, Gbenga Akinnagbe and Gillian Alexy.


title: Damages (TV series)

text: Creators Todd A. Kessler, Glenn Kessler, and Daniel Zelman developed the series as centering on the relationship between a mentor and a protégée: two women in powerful positions. Although the initial story idea did not have the series set in the legal arena, the creators felt the legal world included women who commanded power and influence. The concept was inspired by the creators' interactions with their superiors and with their experiences in the entertainment industry. Todd Kessler addressed how he views gender as playing into the series' narrative saying, "I don't think we look at the story as, this is a great female story... We see the Patty-Ellen relationship as a universal one between anyone who has had a boss and goes into a job thinking that success is working hard and doing what the boss asks and realizing that it's only a small percentage of it." The setting veers away from typical legal dramas, whose storylines are often set inside courtrooms, and instead it describes the characters' lives and interactions outside the courtroom, thereby focusing on the behind-the-scenes power maneuvering and manipulation. Concerning the characters Zelman notes, "We don't look at any of the characters as good or bad or anything like that. What really motivated us to write about this world, first and foremost, was our interest in power dynamics, the dynamics of power in society."


title: Damages (TV series)

text: Each season, established lawyer Patty Hewes takes one major case. But seasons often simultaneously deal with other minor cases and later seasons focus more on Ellen's cases rather than Patty's.


title: Damages (TV series)

text: Season 1 focuses on a class action lawsuit against the fraudulent multi-billionaire CEO of a defunct company; the plot was inspired by various corporate scandals and characters involved in them, most notably the 2001 Enron scandal. Season 2 deals with the energy industry and related environmental issues; the story is influenced by recent and ongoing environmental cases in the United States in the mining industry and by the events of the 2001 California energy crisis. The writers were guided by environmental lawyer Robert F. Kennedy, Jr., who shared his experience in the field with various corporations and CEOs. Season 3 is largely based on the 2009 Bernie Madoff scandal. Season 4 describes events based on the Blackwater Security Consulting scandal.


title: Damages (TV series)

text: The series uses nonlinear narrative, employing flashforwards, foreshadowing, and red herring narration techniques. This approach has given the writers flexibility in storytelling. The narrative handles multiple plot lines and has loose ends. Zelman explains, "We know where we're going. We have tent-pole moments that we're building to all the way through to the end, and it's very clear to us where we want to end up. [However], we want to leave room for improvisation..." While the two different time-frames format was initially intended for the first season, in preparation for the second season the producers felt that the nonlinear format had become a signature of the series and decided to continue it for the second season. With the serialized format of the show decreasing the viewership, Todd Kessler contended that the second season would contain stand-alone storylines to make the show more accessible.


title: Damages (TV series)

text: When creators Kesslers and Zelman pitched the show to executives at FX, network president John Landgraf suggested they consider Glenn Close for the main character Patty Hewes. Close had earlier worked on FX's "The Shield" and had conveyed to the network officials her interest in being cast as a lead in another show, so long as the show was set in New York City. After a three-hour meeting with the creators, Close accepted the role, impressed particularly by the powerful persona of the character "as the head of her own law firm [...] in a male-dominated world". Describing her character, Close said, "Patty is a complicated character... She's not somebody who you can easily characterize. People tend to say she's manipulative and evil, which always makes me laugh, because I think women and power are still problematic, especially in this country. I take that as a compliment." In preparation for the role, Close met with several female attorneys in New York, including Mary Jo White, Lorna Schofield, and Patricia Hynes.


title: Damages (TV series)

text: The creators cast Ted Danson for the part of Arthur Frobisher, a corrupt billionaire CEO, because of his role in "The Onion Field" (1979). Danson was attracted to the project immediately after learning that Close would be playing the lead role. As part of his preparation, Danson studied the collapse of Enron by watching documentaries such as "The Smartest Guys in the Room" (2005) and meeting CEOs of various Fortune 500 corporations. The producers also suggested that Danson consult Close's acting coach Harold Guskin. Danson was initially hesitant about this suggestion, but found the consultation extremely helpful.


title: Damages (TV series)

text: Series cast members Rose Byrne and Tate Donovan, portraying Ellen Parsons and Tom Shayes respectively, secured their parts through auditions. Byrne had been unavailable when she was initially approached because she was shooting the film "28 Weeks Later" but auditioned later when the part had not yet been cast. Both Byrne and Donovan prepared for their roles by consulting lawyers and attending court trials. According to producers, the characters of Ellen's fiancé David Connor and his sister Katie were the hardest to cast.


title: Damages (TV series)

text: For the first-season cast, Noah Bean, who was cast as David, said he "gave an awful first audition" but managed to get the part when given a second chance while waiting for an elevator. When British actor Anastasia Griffith auditioned for the part of Katie Connor, the producers were hesitant to have a British actor play an American, especially since they already had an Australian (Byrne) playing an American. However, Griffith convinced the producers by speaking in an American accent throughout their follow-up meeting. At the time of casting, Griffith's role was intended only for three episodes, but it was extended after the producers realized the character's success. Željko Ivanek scored the initially very minor role of Ray Fiske through an audition, but as producers watched Ivanek's work in the dailies, they beefed up the role considerably.


title: Damages (TV series)

text: For the second-season cast, Marcia Gay Harden was, according to producer Josh Payne, a "no-brainer" for the role of Claire Maddox. They wanted an actress who could hold her own against Close. Harden's casting was also attributable, in part, to the fact that she lived in New York City where "Damages" shoots. William Hurt and Timothy Olyphant were cast late in the process. The producers debated whether they should go with one actor who created a love triangle involving Patty and Ellen, but they ultimately went with the two separate actors.


title: Damages (TV series)

text: For the third-season cast, Lily Tomlin's casting evolved out of her fandom for the show. At an art exhibit she bumped into "Damages" creator/executive producer Todd A. Kessler and interrogated him for information about upcoming twists on the show. Todd kept her in mind and later cast her as Marilyn Tobin. Dominic Chianese was also cast because of his past relationship with Kessler, as the two worked together on "The Sopranos". Martin Short was the last major actor to be cast that season; he too was a "Damages" fan. Producers were excited to work with Short, though he had very little dramatic work to refer to; he added to the "Damages" reputation of casting against-type.


title: Damages (TV series)

text: For the fourth season cast, producers initially considered actors like Edward Burns and Wentworth Miller for the role of Howard T. Erickson, because they were closer in age/physique to Erik Prince, the founder of Blackwater whom the season was based on. John Goodman stressed his availability, and the role was tailored to suit his style. Zelman saw Dylan Baker on stage years ago when Daniel was an apprentice at the Williamstown Theatre Festival in Massachusetts. His performance left an impression, and producers had thought about casting him several times before, but the timing didn't work out until Season 4, when he was cast as Jerry Boorman. Chris Messina at his first casting call, refused to play a Republican or a lawyer on the show, because he was repeatedly cast in such roles beforehand. He was awarded the role of PTSD-plagued Chris Sanchez and underwent considerable preparation for the role. He would "stay awake and not sleep...and right before action...drink two Red Bulls". He was also reluctant to join a show so late in its run. The role of Bill Herndon was, as with Ray Fiske or Katie Connor's, conceived as a very minor part but was significantly increased after Judd Hirsch made a good impression.


title: Damages (TV series)

text: For the fifth-season cast, Ryan Phillippe initially wasn't overly interested in doing "Damages", but on a phone call with producers he changed his mind after being told his character was modeled after Julian Assange, with whom Phillippe was fascinated. Jenna Elfman followed in the steps of other well-known comic actors by playing against-type on "Damages" as Naomi Walling, the victim in a lawsuit. She enthusiastically signed on for the opportunity to "play the types of scenes I haven't yet had the opportunity to play". Janet McTeer became close friends with Glenn Close while working on the film "Albert Nobbs" (2011), and Close worked with producers to offer her a key role as Kate Franklin, a recent empty nester returning to law.


title: Damages (TV series)

text: The title sequence, set to the song "When I Am Through with You" by The VLA, depicts images of New York City public sculpture, including "The Glory of Commerce" atop Grand Central Terminal, "Civic Fame" atop the Manhattan Municipal Building, and "Asia" in front of the Alexander Hamilton U.S. Custom House. The frieze of the New York County Courthouse is also shown, inscribed with a quote from George Washington, "The true administration of justice is the firmest pillar of good government".


title: Damages (TV series)

text: Due to the low ratings and high costs, it was speculated early that Season 3 might be the show's last. However, Sony reached an agreement with DirecTV to share the cost of future seasons with its Audience Network (formerly The 101 Network and originally Freeview). Other outlets were also approached about sharing the cost of a new season. However, no other network opted to pick it up, leaving Audience Network the new broadcaster. "The New York Times" reported that FX continued to hold a small stake in the show and that "[T]series offers a way for the Audience Network to define itself as a provider of niche entertainment for an educated, upper-middle-class demographic, an experiment it started by picking up the football drama "Friday Night Lights" from NBC." Glenn Close said she always thought the show was "kind of a tricky fit for FX," further stating, "I think FX was defined by "The Shield", which was a testosterone-laden show, and they continue to be a testosterone-laden network. I think we were kind of off-brand for them." "Damages" made its first premiere on DirecTV on January 5, 2011. Seasons one through three ran until the season 4 premiere on July 13, 2011.


title: Damages (TV series)

text: All five seasons have been released on DVD in regions 1, 2, and 4, while only the first season was originally released on Blu-ray. Mill Creek Entertainment released the complete series on Blu-ray and DVD on February 26, 2019.


title: Damages (TV series)

text: The first season of "Damages" received generally positive reviews from critics with the series ranking in the top ten lists of several critics, who include Robert Abele ("LA Weekly"), Robert Lloyd ("Los Angeles Times"), and Alessandra Stanley ("The New York Times"). "TV Guide" ranked the season one finale (episode #52) on its list of "TV's Top 100 Episodes of All Time".


title: Damages (TV series)

text: Season 2 was met with further critical praise, along with season 3, which Verne Gay (from "Newsday") rated A+ and termed it, "Gorgeously acted, written, paced, structured and conceived, it remains one of the best shows on TV--and maybe the most enjoyably addictive." When the series returned for its fourth season in July 2011, after it was saved by DirecTV, Maureen Ryan (of "The Huffington Post") reacted positively said "Damages knows what it's about these days. And if you want to see some prime, grade-A acting, well, you could do a lot worse". "TV Guide"s Matt Roush praised the series and stated that "Damages is worth it. And for those without access to DirecTV, worth the wait."


title: Damages (TV series)

text: The series premiere on July 24, 2007, drew 3.7 million viewers, with total of 5.1 million viewers including re-airing on the same night, becoming the most watched cable television program for the night. However, the viewership declined over the first season, partially due to the story's serialized approach, with the season finale drawing 1.4 million viewers. Regardless of its critical acclaim, "Damages" seriously suffered in its second season ratings. Season Two premiered with only 1.7 million viewers watching, even with the momentum that was built following its Golden Globe and Emmy wins. Despite the show's low ratings, FX picked up and secured the program for a third season. John Landgraf hoped the show would continue on the air following its third season; after taking into account the encore presentations and "extraordinary" DVR numbers, the ratings appeared to be quite good.


title: Damages (TV series)

text: The third-season premiere, which aired on January 25, 2010, only managed to draw in 1.483 million viewers. The third-season finale managed to pull in only 960,000 viewers.


title: Damages (TV series)

text: "Damages" won four Emmy Awards, a Golden Globe, a Casting Society of America Award, and a Satellite Award. Additionally, the series was nominated for a Producers Guild of America Award, a Writers Guild of America Award, four Screen Actors Guild Awards, and four Television Critics Association Awards, among others.


title: Damages (TV series)

text: For its first season, "Damages" was nominated for Outstanding Drama Series at the 2008 Primetime Emmy Awards, along with six other nominations. Co-creators Todd A. Kessler, Glenn Kessler, and Daniel Zelman were nominated for writing and Allen Coulter for directing the pilot episode ("Get Me a Lawyer"). Glenn Close received a nomination for Outstanding Lead Actress in a Drama Series, with co-stars Ted Danson and Željko Ivanek nominated for Outstanding Supporting Actor in a Drama Series. Close and Ivanek won in their respective categories, with the series also receiving a Creative Arts Emmy for Outstanding Casting for a Drama Series. The series earned four nominations at the 65th Golden Globe Awards, including Best Television Series – Drama, Close for Best Actress, and Rose Byrne and Ted Danson for their supporting roles. Close won the award in her category.


title: Damages (TV series)

text: For its second season, "Damages" was nominated for seven Primetime Emmy nominations at the 2009 Primetime Emmy Awards, with Glenn Close receiving her second Emmy nomination for Outstanding Lead Actress in a Drama Series. Ted Danson also received another nomination, for Outstanding Guest Actor in a Drama Series. Rose Byrne earned her first Emmy nomination for Outstanding Supporting Actress in a Drama Series and William Hurt was nominated for Outstanding Supporting Actor in a Drama Series. It was also nominated for Outstanding Directing for a Drama Series (Todd A. Kessler for "Trust Me") and received its second and final nomination for Outstanding Drama Series. On September 20, 2009, the show won its fourth Emmy Award when Glenn Close won the Emmy for Outstanding Lead Actress in a Drama Series. The series earned three nominations at the 67th Golden Globe Awards, including Close for Best Actress, and Byrne and William Hurt for their supporting roles.


title: Damages (TV series)

text: For its third season, "Damages" earned its most acting nominations at the 2010 Primetime Emmy Awards. Along with Glenn Close, Rose Byrne, and Ted Danson returning in their respective categories, featured cast additions Martin Short and Lily Tomlin as newly nominated actors. Short was nominated for Outstanding Supporting Actor in a Drama Series and Tomlin was nominated for Outstanding Guest Actress in a Drama Series. For the first time, "Damages" was unable to win a major Primetime Emmy despite their success in the nominations, as Glenn Close lost for the first time in her category, losing to Kyra Sedgwick.


title: Damages (TV series)

text: For its fourth season, "Damages" earned a Critics' Choice Television Award nomination for Dylan Baker as Best Guest Performer in a Drama Series, a Screen Actors Guild nomination for Glenn Close for Outstanding Performance by a Female Actor in a Drama Series, and a fourth consecutive Emmy nomination for Glenn Close, in the Outstanding Lead Actress in a Drama Series category.


title: Damages (TV series)

text: For its fifth and final season, Glenn Close received her third Golden Globe nomination for Best Actress – Television Series Drama, after being absent the previous two years.


title: Aliasing

text: In signal processing and related disciplines, aliasing is an effect that causes different signals to become indistinguishable (or "aliases" of one another) when sampled. It also often refers to the distortion or artifact that results when a signal reconstructed from samples is different from the original continuous signal.


title: Aliasing

text: Aliasing can occur in signals sampled in time, for instance digital audio, or the stroboscopic effect, and is referred to as temporal aliasing. It can also occur in spatially sampled signals (e.g. moiré patterns in digital images); this type of aliasing is called spatial aliasing.


title: Aliasing

text: Aliasing is generally avoided by applying low-pass filters or anti-aliasing filters (AAF) to the input signal before sampling and when converting a signal from a higher to a lower sampling rate. Suitable reconstruction filtering should then be used when restoring the sampled signal to the continuous domain or converting a signal from a lower to a higher sampling rate. For spatial anti-aliasing, the types of anti-aliasing include fast approximate anti-aliasing (FXAA), multisample anti-aliasing, and supersampling.


title: Aliasing

text: When a digital image is viewed, a reconstruction is performed by a display or printer device, and by the eyes and the brain. If the image data is processed in some way during sampling or reconstruction, the reconstructed image will differ from the original image, and an alias is seen.


title: Aliasing

text: An example of spatial aliasing is the moiré pattern observed in a poorly pixelized image of a brick wall. Spatial anti-aliasing techniques avoid such poor pixelizations. Aliasing can be caused either by the sampling stage or the reconstruction stage; these may be distinguished by calling sampling aliasing "prealiasing" and reconstruction aliasing "postaliasing."


title: Aliasing

text: Temporal aliasing is a major concern in the sampling of video and audio signals. Music, for instance, may contain high-frequency components that are inaudible to humans. If a piece of music is sampled at 32,000 samples per second (Hz), any frequency components at or above 16,000 Hz (the Nyquist frequency for this sampling rate) will cause aliasing when the music is reproduced by a digital-to-analog converter (DAC). The high frequencies in the analog signal will appear as lower frequencies (wrong alias) in the recorded digital sample and, hence, cannot be reproduced by the DAC. To prevent this, an anti-aliasing filter is used to remove components above the Nyquist frequency prior to sampling.


title: Aliasing

text: In video or cinematography, temporal aliasing results from the limited frame rate, and causes the wagon-wheel effect, whereby a spoked wheel appears to rotate too slowly or even backwards. Aliasing has changed its apparent frequency of rotation. A reversal of direction can be described as a negative frequency. Temporal aliasing frequencies in video and cinematography are determined by the frame rate of the camera, but the relative intensity of the aliased frequencies is determined by the shutter timing (exposure time) or the use of a temporal aliasing reduction filter during filming.


title: Aliasing

text: Like the video camera, most sampling schemes are periodic; that is, they have a characteristic sampling frequency in time or in space. Digital cameras provide a certain number of samples (pixels) per degree or per radian, or samples per mm in the focal plane of the camera. Audio signals are sampled (digitized) with an analog-to-digital converter, which produces a constant number of samples per second. Some of the most dramatic and subtle examples of aliasing occur when the signal being sampled also has periodic content.


title: Aliasing

text: Actual signals have a finite duration and their frequency content, as defined by the Fourier transform, has no upper bound. Some amount of aliasing always occurs when such functions are sampled. Functions whose frequency content is bounded ("bandlimited") have an infinite duration in the time domain. If sampled at a high enough rate, determined by the "bandwidth", the original function can, in theory, be perfectly reconstructed from the infinite set of samples.


title: Aliasing

text: Sometimes aliasing is used intentionally on signals with no low-frequency content, called "bandpass" signals. Undersampling, which creates low-frequency aliases, can produce the same result, with less effort, as frequency-shifting the signal to lower frequencies before sampling at the lower rate. Some digital channelizers exploit aliasing in this way for computational efficiency.


title: Aliasing

text: Sinusoids are an important type of periodic function, because realistic signals are often modeled as the summation of many sinusoids of different frequencies and different amplitudes (for example, with a Fourier series or transform). Understanding what aliasing does to the individual sinusoids is useful in understanding what happens to their sum.


title: Aliasing

text: When sampling a function at frequency (intervals ), the following functions of time yield identical sets of samples: }. A frequency spectrum of the samples produces equally strong responses at all those frequencies. Without collateral information, the frequency of the original function is ambiguous. So the functions and their frequencies are said to be "aliases" of each other. Noting the trigonometric identity:


title: Aliasing

text: we can write all the alias frequencies as positive values:  formula_2. For example, a snapshot of the lower right frame of Fig.2 shows a component at the actual frequency formula_3 and another component at alias formula_4. As formula_3 increases during the animation, formula_4 decreases. The point at which they are equal formula_7 is an axis of symmetry called the folding frequency, also known as Nyquist frequency.


title: Aliasing

text: Aliasing matters when one attempts to reconstruct the original waveform from its samples. The most common reconstruction technique produces the smallest of the formula_8 frequencies. So it is usually important that formula_9 be the unique minimum.  A necessary and sufficient condition for that is formula_10 called the Nyquist condition. The lower left frame of Fig.2 depicts the typical reconstruction result of the available samples. Until formula_3 exceeds the Nyquist frequency, the reconstruction matches the actual waveform (upper left frame). After that, it is the low frequency alias of the upper frame.


title: Aliasing

text: The figures below offer additional depictions of aliasing, due to sampling. A graph of amplitude vs frequency (not time) for a single sinusoid at frequency    and some of its aliases at      and    would look like the 4 black dots in Fig.3. The red lines depict the paths (loci) of the 4 dots if we were to adjust the frequency and amplitude of the sinusoid along the solid red segment (between    and  ).  No matter what function we choose to change the amplitude vs frequency, the graph will exhibit symmetry between 0 and    Folding is often observed in practice when viewing the frequency spectrum of real-valued samples, such as Fig.4..


title: Aliasing

text: Complex sinusoids are waveforms whose samples are complex numbers, and the concept of negative frequency is necessary to distinguish them. In that case, the frequencies of the aliases are given by just:    Therefore, as    increases from    to       also increases (from    to 0).  Consequently, complex sinusoids do not exhibit "folding".


title: Aliasing

text: When the condition    is met for the highest frequency component of the original signal, then it is met for all the frequency components, a condition called the Nyquist criterion. That is typically approximated by filtering the original signal to attenuate high frequency components before it is sampled. These attenuated high frequency components still generate low-frequency aliases, but typically at low enough amplitudes that they do not cause problems. A filter chosen in anticipation of a certain sample frequency is called an anti-aliasing filter.


title: Aliasing

text: The filtered signal can subsequently be reconstructed, by interpolation algorithms, without significant additional distortion. Most sampled signals are not simply stored and reconstructed. But the fidelity of a theoretical reconstruction (via the Whittaker–Shannon interpolation formula) is a customary measure of the effectiveness of sampling.


title: Aliasing

text: Historically the term "aliasing" evolved from radio engineering because of the action of superheterodyne receivers. When the receiver shifts multiple signals down to lower frequencies, from RF to IF by heterodyning, an unwanted signal, from an RF frequency equally far from the local oscillator (LO) frequency as the desired signal, but on the wrong side of the LO, can end up at the same IF frequency as the wanted one. If it is strong enough it can interfere with reception of the desired signal. This unwanted signal is known as an "image" or "alias" of the desired signal.


title: Aliasing

text: The first use of the term ``aliasing" in this context is due to Blackman and Tukey in 1958. In their preface to the Dover reprint of this paper, they point out that the idea of aliasing had been illustrated graphically by Stumpf ten years earlier.


title: Aliasing

text: Aliasing occurs whenever the use of discrete elements to capture or produce a continuous signal causes frequency ambiguity.


title: Aliasing

text: Spatial aliasing, particular of angular frequency, can occur when reproducing a light field or sound field with discrete elements, as in 3D displays or wave field synthesis of sound.


title: Aliasing

text: This aliasing is visible in images such as posters with lenticular printing: if they have low angular resolution, then as one moves past them, say from left-to-right, the 2D image does not initially change (so it appears to move left), then as one moves to the next angular image, the image suddenly changes (so it jumps right) – and the frequency and amplitude of this side-to-side movement corresponds to the angular resolution of the image (and, for frequency, the speed of the viewer's lateral movement), which is the angular aliasing of the 4D light field.


title: Aliasing

text: The lack of parallax on viewer movement in 2D images and in 3-D film produced by stereoscopic glasses (in 3D films the effect is called "yawing", as the image appears to rotate on its axis) can similarly be seen as loss of angular resolution, all angular frequencies being aliased to 0 (constant).


title: Aliasing

text: The qualitative effects of aliasing can be heard in the following audio demonstration. Six sawtooth waves are played in succession, with the first two sawtooths having a fundamental frequency of 440 Hz (A4), the second two having fundamental frequency of 880 Hz (A5), and the final two at 1,760 Hz (A6). The sawtooths alternate between bandlimited (non-aliased) sawtooths and aliased sawtooths and the sampling rate is 22,05 kHz. The bandlimited sawtooths are synthesized from the sawtooth waveform's Fourier series such that no harmonics above the Nyquist frequency are present.


title: Aliasing

text: The aliasing distortion in the lower frequencies is increasingly obvious with higher fundamental frequencies, and while the bandlimited sawtooth is still clear at 1,760 Hz, the aliased sawtooth is degraded and harsh with a buzzing audible at frequencies lower than the fundamental.


title: Aliasing

text: A form of spatial aliasing can also occur in antenna arrays or microphone arrays used to estimate the direction of arrival of a wave signal, as in geophysical exploration by seismic waves. Waves must be sampled more densely than two points per wavelength, or the wave arrival direction becomes ambiguous.


title: Necktie

text: A necktie, or simply a tie, is a piece of cloth worn for decorative purposes around the neck, resting under the shirt collar and knotted at the throat, and often draped down the chest.


title: Necktie

text: Variants include the ascot, bow, bolo, zipper tie, cravat, and knit. The modern necktie, ascot, and bow tie are descended from the cravat. Neckties are generally unsized but may be available in a longer size. In some cultures, men and boys wear neckties as part of office attire or formal wear. Women wear them less often. Neckties can also be part of a uniform. Neckties are traditionally worn with the top shirt button fastened, and the tie knot resting between the collar points.


title: Necktie

text: The necktie that spread from Europe traces back to Croatian mercenaries serving in France during the Thirty Years' War (1618–1648). These mercenaries from the Military Frontier, wearing their traditional small, knotted neckerchiefs, aroused the interest of the Parisians. Because of the difference between the Croatian word for Croats, , and the French word, , the garment gained the name "cravat" ( in French). Louis XIV began wearing a lace cravat around 1646 when he was seven and set the fashion for French nobility. This new article of clothing started a fashion craze in Europe; both men and women wore pieces of fabric around their necks. From its introduction by the French king, men wore lace cravats, or jabots, which took a large amount of time and effort to arrange. These cravats were often tied in place by cravat strings, arranged neatly and tied in a bow.


title: Necktie

text: International Necktie Day is celebrated on October 18 in Croatia and in various cities around the world, including in Dublin, Tübingen, Como, Tokyo, Sydney and other towns.


title: Necktie

text: In 1715, another kind of neckwear, called "stocks" made its appearance. The term originally referred to a leather collar, laced at the back, worn by soldiers to promote holding the head high in a military bearing. The leather stock also afforded some protection to the major blood vessels of the neck from saber or bayonet attacks. General Sherman is seen wearing a leather stock in several American Civil War-era photographs.


title: Necktie

text: Stock ties were initially just a small piece of muslin folded into a narrow band wound a few times around the shirt collar and secured from behind with a pin. It was fashionable for men to wear their hair long, past shoulder length. The ends were tucked into a black silk bag worn at the nape of the neck. This was known as the bag-wig hairstyle, and the neckwear worn with it was the stock.


title: Necktie

text: The solitaire was a variation of the bag wig. This form had matching ribbons stitched around the bag. After the stock was in place, the ribbons would be brought forward and tied in a large bow in front of the wearer.


title: Necktie

text: Sometime in the late 18th century, cravats began to make an appearance again. This can be attributed to a group of young men called the macaronis (as mentioned in the song "Yankee Doodle"). These were young Englishmen who returned from Europe and brought with them new ideas about fashion from Italy. The French contemporaries of the macaronis were the incroyables.


title: Necktie

text: At this time, there was also much interest in the way to tie a proper cravat and this led to a series of publications. This began in 1818 with the publication of "Neckclothitania", a style manual that contained illustrated instructions on how to tie 14 different cravats. Soon after, the immense skill required to tie the cravat in certain styles quickly became a mark of a man's elegance and wealth. It was also the first book to use the word "tie" in association with neckwear.


title: Necktie

text: It was about this time that black stocks made their appearance. Their popularity eclipsed the white cravat, except for formal and evening wear. These remained popular through the 1850s. At this time, another form of neckwear worn was the scarf. This was where a neckerchief or bandana was held in place by slipping the ends through a finger or scarf ring at the neck instead of using a knot. This is the classic sailor neckwear and may have been adopted from them.


title: Necktie

text: With the industrial revolution, more people wanted neckwear that was easy to put on, was comfortable and would last an entire workday. Neckties were designed to be long, thin, and easy to knot, without accidentally coming undone. This is the necktie design still worn by millions.


title: Necktie

text: By this time, the sometimes complicated array of knots and styles of neckwear gave way to neckties and bow ties, the latter a much smaller, more convenient version of the cravat. Another type of neckwear, the ascot tie, was considered "de rigueur" for male guests at formal dinners and male spectators at races. These ascots had wide flaps that were crossed and pinned together on the chest.


title: Necktie

text: In 1922, a New York tie maker, Jesse Langsdorf, came up with a method of cutting the fabric on the bias and sewing it in three segments. This technique improved elasticity and facilitated the fabric's return to its original shape. Since that time, most men have worn the "Langsdorf" tie. Yet another development during that time was the method used to secure the lining and interlining once the tie had been folded into shape.


title: Necktie

text: After the First World War, hand-painted ties became an accepted form of decoration in the U.S. The widths of some of these ties went up to . These loud, flamboyant ties sold very well through the 1950s.


title: Necktie

text: Diagonal ("regimental or "repp") stripes are a common necktie pattern. In Britain and other Commonwealth countries, these have been used to denote association with a particular regiment, corps, or service since at least the 1920s, and are also used to represent civic and educational institutions. It is considered inappropriate for persons who are unaffiliated with a regiment, university, school, or other organization, to wear a necktie affiliated with that organization. In Commonwealth countries, necktie stripes run from the left shoulder down to the right side, but when Brooks Brothers introduced similar striped ties in the United States around the beginning of the 20th century, they had their stripes run from the right shoulder to the left side, in part to distinguish them from British regimental striped neckties. Members of the British Royal Family are frequently seen wearing regimental striped ties corresponding to the military unit in which they have served or been appointed to an honorary position such as colonel-in-chief.


title: Necktie

text: Before the Second World War ties were worn shorter than they are today; this was due, in part, to men wearing trousers at the natural waist (just above the belly button), and also due to the popularity of waistcoats, where tie length is not important as long as the tips are concealed. Around 1944, ties started to become not only wider but even wilder. This was the beginning of what was later labeled the Bold Look: ties that reflected the returning GIs' desire to break with wartime uniformity. Widths reached , and designs included Art Deco, hunting scenes, scenic "photographs", tropical themes, and even girlie prints, though more traditional designs were also available. The typical length was .


title: Necktie

text: The Bold Look lasted until about 1951 when the "Mister T" look (so termed by Esquire magazine) was introduced. The new style, characterized by tapered suits, slimmer lapels, and smaller hat brims, included thinner and not so wild ties. Tie widths slimmed to by 1953 and continued getting thinner up until the mid-1960s; length increased to about as men started wearing their trousers lower, closer to the hips. Through the 1950s, neckties remained somewhat colorful, yet more restrained than in the previous decade. Small geometric shapes were often employed against a solid background (i.e., foulards); diagonal stripes were also popular. By the early 1960s, dark, solid ties became very common, with widths slimming down to as little as .


title: Necktie

text: The 1960s brought about an influx of pop art influenced designs. The first was designed by Michael Fish when he worked at Turnbull & Asser, and was introduced in Britain in 1965; the term Kipper tie was a pun on his name, as well as a reference to the triangular shape of the front of the tie. The exuberance of the styles of the late 1960s and early 1970s gradually gave way to more restrained designs. Ties became wider, returning to their width, sometimes with garish colors and designs. The traditional designs of the 1930s and 1950s, such as those produced by Tootal, reappeared, particularly Paisley patterns. Ties began to be sold along with shirts, and designers slowly began to experiment with bolder colors.


title: Necktie

text: In the 1980s, narrower ties, some as narrow as but more typically wide, became popular again. Into the 1990s, as ties got wider again, increasingly unusual designs became common. Novelty (or joke) ties or deliberately kitschy ties designed to make a statement gained a certain popularity in the 1980s and 1990s. These included ties featuring cartoon characters, commercial products, or pop culture icons, and those made of unusual materials, such as plastic or wood. During this period, with men wearing their trousers at their hips, ties lengthened to .


title: Necktie

text: At the start of the 21st century, ties widened to wide, with a broad range of patterns available, from traditional stripes, foulards, and club ties (ties with a crest or design signifying a club, organization, or order) to abstract, themed, and humorous ones. The standard length remains , though other lengths vary from 117 cm to 152 cm. While ties as wide as inches are still available, ties under wide also became popular, particularly with younger men and the fashion-conscious. In 2008 and 2009 the world of fashion saw a return to narrower ties.


title: Necktie

text: In 1660, in celebration of its hard-fought victory over the Ottoman Empire, a crack regiment from Croatia visited Paris. There, the soldiers were presented as glorious heroes to Louis XIV, a monarch well known for his eye for personal adornment. It so happened that the officers of this regiment were wearing brightly colored handkerchiefs fashioned of silk around their necks. These neckcloths struck the fancy of the king, and he soon made them an insignia of royalty as he created a regiment of Royal Cravattes. The word "cravat" is derived from the "à la croate"—in the style of the Croats.


title: Necktie

text: The four-in-hand necktie (as distinct from the four-in-hand knot) was fashionable in Great Britain in the 1850s. Early neckties were simple, rectangular cloth strips cut on the square, with square ends. The term "four-in-hand" originally described a carriage with four horses and a driver; later, it also was the name of a London gentlemen's club, The Four-in-Hand Driving Company founded in 1856. Some etymologic reports are that carriage drivers knotted their reins with a four-in-hand knot (see below), whilst others claim the carriage drivers wore their scarves knotted 'four-in-hand', but, most likely, members of the club began wearing their neckties so knotted, thus making it fashionable. In the latter half of the 19th century, the four-in-hand knot and the four-in-hand necktie were synonymous. As fashion changed from stiff shirt collars to soft, turned-down collars, the four-in-hand necktie knot gained popularity; its sartorial dominance rendered the term "four-in-hand" redundant usage, shortened "long tie" and "tie".


title: Necktie

text: In 1926, Jesse Langsdorf from New York City introduced ties cut on the bias (US) or cross-grain (UK), allowing the tie to evenly fall from the knot without twisting; this also caused any woven pattern such as stripes to appear diagonally across the tie.


title: Necktie

text: Today, four-in-hand ties are part of men's dress clothing in both Western and non-Western societies, particularly for business.


title: Necktie

text: Four-in-hand ties are generally made from silk or polyester and occasionally with cotton. Another material used is wool, usually knitted, common before World War II but not as popular nowadays. More recently, microfiber ties have also appeared; in the 1950s and 1960s, other manmade fabrics, such as Dacron and rayon, were also used, but have fallen into disfavor. Modern ties appear in a wide variety of colors and patterns, notably striped (usually diagonally); club ties (with a small motif repeated regularly all over the tie); foulards (with small geometric shapes on a solid background); paisleys; and solids. Novelty ties featuring icons from popular culture (such as cartoons, actors, or holiday images), sometimes with flashing lights, have enjoyed some popularity since the 1980s.


title: Necktie

text: A seven-fold tie is an unlined construction variant of the four-in-hand necktie which pre-existed the use of interlining. Its creation at the end of the 19th century is attributed to the Parisian shirtmaker Washington Tremlett for an American customer. A seven-fold tie is constructed completely out of silk. A six-fold tie is a modern alteration of the seven-fold tie. This construction method is more symmetrical than the true seven-fold. It has an interlining which gives it a little more weight and is self-tipped.


title: Necktie

text: A skinny tie is a necktie that is narrower than the standard tie and often all-black. Skinny ties have widths of around at their widest, compared to usually for regular ties. Skinny ties were first popularized in the late 1950s and early 1960s by British bands such as the Beatles and the Kinks, alongside the subculture that embraced such bands, the mods. This is because clothes of the time evolved to become more form-fitting and tailored. They were later repopularized in the late 1970s and early 1980s by new wave and power pop bands such as the Knack, Blondie and Duran Duran.


title: Necktie

text: The "pre-tied" necktie, or more commonly, the clip-on necktie, is a permanently knotted four-in-hand or bow tie affixed by a clip or hook. The clip-on tie sees used with children, and in occupations where a traditional necktie might pose a safety hazard to mechanical equipment operators, etc. (see below).


title: Necktie

text: The perceived utility of this development in the history of the style is evidenced by the series of patents issued for various forms of these ties, beginning in the late 19th century, and by the businesses filing these applications and fulfilling a market need for them. For instance, a patent filed by Joseph W. Less of the "One-In-Hand Tie Company" of Clinton, Iowa for "Pre-tied neckties and methods for making the same" noted that:


title: Necktie

text: The Inventor proceeded to claim for the invention—the latest version of the 1930s–1950s product line from former concert violinist Joseph Less, Iowan brothers Walter and Louis, and son-in-law W. Emmett Thiessen evolved to be identifiable as the modern clip-on—"a novel method for making up the tie ... [eliminating] the neckband of the tie, which is useless and uncomfortable in warm weather ... [and providing] means of attachment which is effective and provides no discomfort to the wearer", and in doing so achieves "accurate simulation of the Windsor knot, and extremely low material and labor costs". Notably, the company made use of ordinary ties purchased from the New York garment industry and was a significant employer of women in the pre-war and World War II years.


title: Necktie

text: Although he did not invent it, the Windsor knot is named after the Duke of Windsor. The Duke did favor a voluminous knot; however, he achieved this by having neckties specially made of thicker cloths.


title: Necktie

text: In the late 1990s, two researchers, Thomas Fink and Yong Mao of Cambridge's Cavendish Laboratory, used mathematical modeling to discover that 85 knots are possible with a conventional tie (limiting the number "moves" used to tie the knot to nine; longer sequences of moves result in too large a knot or leave the hanging ends of the tie too short). The models were published in academic journals, while the results and the 85 knots were published in layman's terms in a book entitled "The 85 Ways to Tie a Tie". Of the 85 knots, Fink and Mao selected 13 knots as "aesthetic" knots, using the qualities of symmetry and balance. Based on these mathematical principles, the researchers came up with not only the four necktie knots in common use, but nine more, some of which had seen limited use, and some that are believed to have been codified for the first time.


title: Necktie

text: The use of coloured and patterned neckties indicating the wearer's membership in a club, military regiment, school, professional association (Royal Colleges, Inns of Courts) et cetera, dates only from the late-19th century England. The immediate forerunners of today's college neckties were in 1880 the oarsmen of Exeter College, Oxford, who tied the bands of their straw hats around their necks.


title: Necktie

text: In the United Kingdom and many Commonwealth countries, neckties are commonly an essential component of a school uniform and are either worn daily, seasonally or on special occasions with the school blazer. In Hong Kong, Australia and New Zealand, neckties are worn as the everyday uniform, usually as part of the winter uniform. In countries with no winter such as Sri Lanka, Singapore, Malaysia, and many African countries, the necktie is usually worn as part of the formal uniform on special occasions or functions. Neckties may also denote membership in a house or a leadership role (i.e. school prefect, house captain, etc.).


title: Necktie

text: The most common pattern for such ties in the UK and most of Europe consists of diagonal stripes of alternating colors running down the tie from the wearer's left. Since neckties are cut on the bias (diagonally), the stripes on the cloth are parallel or perpendicular to the selvage, not diagonal. The colors themselves may be particularly significant. The dark blue and red regimental tie of the Household Division is said to represent the blue blood (i.e. nobility) of the Royal Family, and the red blood of the Guards.


title: Necktie

text: In the United States, diagonally striped ties are commonly worn with no connotation of a group membership. Typically, American striped ties have the stripes running downward from the wearer's right (the opposite of the European style). (However, when Americans wear striped ties as a sign of membership, the European stripe style may be used.) In some cases, American "repp stripe" ties may simply be reverse images of British regimental ties. Striped ties are strongly associated with the Ivy League and preppy style of dress.


title: Necktie

text: An alternative membership tie pattern to diagonal stripes is either a single emblem or a crest centered and placed where a tie pin normally would be, or a repeated pattern of such motifs. Sometimes, both types are used by an organization, either simply to offer a choice or to indicate a distinction among levels of membership. Occasionally, a hybrid design is used, in which alternating stripes of color are overlaid with repeated motif patterns.


title: Necktie

text: Neckties are sometimes part of uniforms worn by women, which nowadays might be required in professions such as in the restaurant industry or in police forces. In many countries, girls are nowadays required to wear ties as part of primary and secondary school uniforms.


title: Necktie

text: Ties may also be used by women as a fashion statement. During the late 1970s and 1980s, it was not uncommon for young women in the United States to wear ties as part of a casual outfit. This trend was popularized by Diane Keaton who wore a tie as the titular character in "Annie Hall" in 1977.


title: Necktie

text: In 1993, neckties reappeared as prominent fashion accessories for women in both Europe and the U.S. Canadian recording artist Avril Lavigne wore neckties with tank tops early in her career.


title: Necktie

text: Traditionally, ties are a staple of office attire, especially for professionals. Proponents of the tie's place in the office assert that ties neatly demarcate work and leisure time.


title: Necktie

text: The theory is that the physical presence of something around your neck serves as a reminder to knuckle down and focus on the job at hand. Conversely, loosening the tie after work signals that one can relax.


title: Necktie

text: Outside of these environments, ties are usually worn especially when attending traditionally formal or professional events, including weddings, important religious ceremonies, funerals, job interviews, court appearances, and fine dining.


title: Necktie

text: The debate between proponents and opponents of the necktie center on social conformity, plainness, professional expectation, and personal, sartorial expression. Quoting architect Louis Sullivan, Frank Lloyd Wright said: "Form follows function". Applied sartorially, the necktie's decorative function is so criticized.


title: Necktie

text: Among many Christian denominations teaching the doctrine of plain dress, long neckties are not worn by men; this includes many Anabaptist communities (such as the Conservative Mennonite churches), traditional Quakers (who view neckties as contravening their testimony of simplicity), and some Holiness Methodists (such as the Reformed Free Methodists who view neckties as conflicting with the belief in outward holiness).


title: Necktie

text: Other Holiness Methodist denominations, such as the Evangelical Wesleyan Church, allow a long necktie that is black. While Reformed Mennonites, among some other Anabaptist communities, reject the long necktie, the wearing of the bow tie is customary.


title: Necktie

text: In the early 20th century, the number of office workers began increasing. Many such men and women were required to wear neckties because it was perceived as improving work attitudes, morale, and sales.


title: Necktie

text: Removing the necktie as a social and sartorial business requirement (and sometimes forbidding it) is a modern trend often attributed to the rise of popular culture. Although it was common as everyday wear as late as 1966, over the years 1967–69, the necktie fell out of fashion almost everywhere, except where required. There was a resurgence in the 1980s, but in the 1990s, ties again fell out of favor, with many technology-based companies having casual dress requirements, including Apple, Amazon, eBay, Genentech, Microsoft, Monsanto, and Google.


title: Necktie

text: In western business culture, a phenomenon known as Casual Friday has arisen, in which employees are not required to wear ties on Fridays, and then—increasingly—on other, announced, special days. Some businesses have extended casual dress days to Thursday, and even Wednesday; others require neckties only on Monday (to start the workweek). At the furniture company IKEA, neckties are not allowed.


title: Necktie

text: An example of anti-necktie sentiment is found in Iran, where the government of the Islamic Republic considers neckties to be "decadent, un-Islamic and viewed as "symbols of the Cross" and the oppressive West." To date, most Iranian men in Iran have retained the Western-style long-sleeved collared shirt and three-piece suit, while excluding the necktie. While ties are viewed as "highly politicised clothing" in Iran, some Iranian men continue to wear them, as do many Westerners who visit the country.


title: Necktie

text: Neckties are viewed by various sub- and counter-culture movements as being a symbol of submission and slavery (i.e., having a symbolic chain around one's neck) to the corrupt elite of society, as a "wage slave".


title: Necktie

text: For 60 years, designers and manufacturers of neckties in the United States were members of the Men's Dress Furnishings Association but the trade group shut down in 2008 as a result of declining membership due to the declining numbers of men wearing neckties.


title: Necktie

text: In 2019, US presidential candidate Andrew Yang drew attention when he appeared on televised presidential debates without a tie. Yang dismissed media questions about it, saying that voters should be focused on more important issues.


title: Necktie

text: New Zealand Member of Parliament Rawiri Waititi has been vocal in his opposition to neckties, calling them a "colonial noose". In February 2021, he was ejected from Parliament for refusing to wear a tie, drawing attention and parliamentary debate, which ultimately resulted in the requirement being dropped from NZ parliament's "appropriate business attire" requirements for males.


title: Necktie

text: Tyrone Blade, the marketing department manager of Henry Bucks, a men's clothing store in Australia, said that neckties continue to be a well-sold item at his store, but stated that the reason men were buying them has changed. He described the necktie as "more of a 'want' item instead of a 'need' item".


title: Necktie

text: Necktie wearing presents some risks for entanglement, infection, and vasoconstriction. A 2018 study published in the medical journal "Neuroradiology" found that a Windsor knot tightened to the point of "slight discomfort" could interrupt as much as 7.5 percent of cerebral blood flow. A 2013 study published in the "British Journal of Ophthalmology" found increased intraocular pressure in such cases, which can aggravate the condition of people with weakened retinas. There may be additional risks for people with glaucoma.


title: Necktie

text: Entanglement is a risk when working with machinery or in dangerous, possibly violent, jobs such as police officers and prison guards, and certain medical fields.


title: Necktie

text: Paramedics performing life support remove an injured man's necktie as a first step to ensure it does not block his airway. Neckties might also be a health risk for persons other than the wearer. They are believed to be vectors of disease transmission in hospitals. Notwithstanding such fears, many doctors and dentists wear neckties for a professional image. Hospitals take seriously the cross-infection of patients by doctors wearing infected neckties, because neckties are less frequently cleaned than most other clothes. On September 17, 2007, British hospitals published rules banning neckties. In such a context, some instead prefer to use bow ties due to their short length and relative lack of hindrance.


title: Necktie

text: Police officers, traffic wardens, and security guards in the UK wear clip-on ties which instantly unclip when pulled to prevent any chance of strangulation during a confrontation. They are part of the National Framework Contract for the police uniform.


title: Yad Vashem

text: Yad Vashem (; literally, "a memorial and a name") is Israel's official memorial to the victims of the Holocaust. It is dedicated to preserving the memory of the Jews who were murdered; honoring Jews who fought against their Nazi oppressors and Gentiles who selflessly aided Jews in need; and researching the phenomenon of the Holocaust in particular and genocide in general, with the aim of avoiding such events in the future.


title: Yad Vashem

text: Established in 1953, Yad Vashem is located on the western slope of Mount Herzl, also known as the Mount of Remembrance, a height in western Jerusalem, above sea level and adjacent to the Jerusalem Forest. The memorial consists of a complex containing two types of facilities: some dedicated to the scientific study of the Holocaust and genocide in general, and memorials and museums catering to the needs of the larger public. Among the former there are a research institute with archives, a library, a publishing house, and an educational center, and the International School for Holocaust Studies; among the latter, the Holocaust History Museum, memorial sites such as the Children's Memorial and the Hall of Remembrance, the Museum of Holocaust Art, sculptures, outdoor commemorative sites such as the Valley of the Communities, and a synagogue.


title: Yad Vashem

text: A core goal of Yad Vashem's founders was to recognize non-Jews who, at personal risk and without a financial or evangelistic motive, chose to save Jews from the ongoing genocide during the Holocaust. Those recognized by Israel as Righteous Among the Nations are honored in a section of Yad Vashem known as the Garden of the Righteous Among the Nations.


title: Yad Vashem

text: Yad Vashem is the second-most-visited Israeli tourist site, after the Western Wall, with approximately one million visitors each year. It charges no admission fee.


title: Yad Vashem

text: "[To] them will I give in my house and within my walls a [memorial] and a [name], better than sons and daughters; I will give them an everlasting [name], that shall not be cut off [from memory]."


title: Yad Vashem

text: The desire to establish a memorial in the historical Jewish homeland for Jewish victims of the Nazi Holocaust originated during World War II, in response to emerging accounts of the mass murder of Jews in Nazi-occupied countries. Yad Vashem was first proposed in September 1942, at a board meeting of the Jewish National Fund, by Mordecai Shenhavi, a member of Kibbutz Mishmar Ha'emek. In August 1945, the plan was discussed in greater detail at a Zionist meeting in London. A provisional board of Zionist leaders was established that included David Remez as chairman, Shlomo Zalman Shragai, Baruch Zuckerman, and Shenhavi. In February 1946, Yad Vashem opened an office in Jerusalem and a branch office in Tel Aviv, and in June that year convened its first plenary session. In July 1947, the First Conference on Holocaust Research was held at the Hebrew University of Jerusalem. However, the outbreak of the 1947–1949 Palestine war brought operations to a standstill for two years.


title: Yad Vashem

text: On 19 August 1953, the Knesset, Israel's Parliament, unanimously passed the Yad Vashem Law, establishing the Holocaust Martyrs' and Heroes' Remembrance Authority, the aim of which was "the commemoration in the Homeland of all those members of the Jewish people who gave their lives, or rose up and fought the Nazi enemy and its collaborators," and to set up "a memorial to them, and to the communities, organizations and institutions that were destroyed because they belonged to the Jewish people."


title: Yad Vashem

text: On 29 July 1954, the cornerstone for the Yad Vashem building was laid on a hill in western Jerusalem, to be known as the Mount of Remembrance (); the organization had already begun projects to collect the names of individuals killed in the Holocaust; acquire Holocaust documentation and personal testimonies of survivors for the Archives and Library; and develop research and publications. The memorial and museum opened to the public in 1957.


title: Yad Vashem

text: The location of Yad Vashem on the western side of Mount Herzl, an area devoid of weighty historical associations, was chosen to convey a symbolic message of "rebirth" after destruction, distinct from the Chamber of the Holocaust, founded in 1948 on Mount Zion. Thus, the latter museum, whose walls are lined with plaques memorializing over 2,000 Jewish communities destroyed during the Holocaust, portrays the Holocaust as a continuation of the "death and destruction" that plagued Jewish communities throughout Jewish history.


title: Yad Vashem

text: In 1982, Yad Vashem sponsored the International Conference on Holocaust and Genocide, which included six presentations on the Armenian genocide. It later withdrew from the conference after threats by the Turkish government that Jewish lives would be put in danger if the conference went ahead.


title: Yad Vashem

text: On 15 March 2005, a new Museum complex four times larger than the old one opened at Yad Vashem. It included the Holocaust History Museum with a new Hall of Names, a Museum of Holocaust Art, an Exhibitions Pavilion, a Learning Center and a Visual Center. The new Yad Vashem museum was designed by Israeli-Canadian architect Moshe Safdie, replacing the previous 30-year-old exhibition. It was the culmination of a $100 million decade-long expansion project.


title: Yad Vashem

text: In November 2008, rabbi Yisrael Meir Lau was appointed chairman of Yad Vashem's council, replacing Tommy Lapid. The vice chairmen of the council are Yitzhak Arad and Moshe Kantor. Elie Wiesel was vice chairman of the council until his death on 2 July 2016.


title: Yad Vashem

text: Yitzhak Arad served as the chairman of the directorate from 1972 to 1993. He was succeeded by Avner Shalev, who served as chairman until February 2021. Shalev was succeeded as chairman by Dani Dayan in August 2021.


title: Yad Vashem

text: The members of the Yad Vashem directorate are Yossi Ahimeir, Daniel Atar, Michal Cohen, Matityahu Drobles, Avraham Duvdevani, Boleslaw (Bolek) Goldman, Vera H. Golovensky, Moshe Ha-Elion, Shlomit Kasirer, Yossi Katribas, Yehiel Leket, Baruch Shub, Dalit Stauber, Zehava Tanne, Shoshana Weinshall, and Dudi Zilbershlag.


title: Yad Vashem

text: The director-general is Dorit Novak. The head of the International Institute for Holocaust Research is John Najmann. The chair for Holocaust studies is Dan Michman. The chief historian is Dina Porat. The academic advisor is Yehuda Bauer.


title: Yad Vashem

text: The aims of Yad Vashem are education, research and documentation, and commemoration. Yad Vashem organizes professional development courses for educators both in Israel and throughout the world; develops age-appropriate study programs, curricula, and educational materials for Israeli and foreign schools in order to teach students of all ages about the Holocaust; holds exhibitions about the Holocaust; collects the names of Holocaust victims; collects photos, documents, and personal artifacts; and collects Pages of Testimony memorializing victims of the Holocaust. Yad Vashem seeks to preserve the memory and names of the six million Jews murdered during the Holocaust, and the numerous Jewish communities destroyed during that time. It holds ceremonies of remembrance and commemoration; supports Holocaust research projects; develops and coordinates symposia, workshops, and international conferences; and publishes research, memoirs, documents, albums, and diaries related to the Holocaust. Yad Vashem also honors non-Jews who risked their lives to save Jews during the Holocaust.


title: Yad Vashem

text: The International Institute for Holocaust Studies at Yad Vashem, founded in 1993, offers guides and seminars for students, teachers, and educators, and develops pedagogic tools for use in the classroom. Yad Vashem trains 10,000 domestic and foreign teachers every year. The organization operates a web site in several languages, including German, Hebrew, Persian, and Arabic. In 2013 Yad Vashem launched an online campaign in Arabic, promoting Yad Vashem's website. The campaign reached over 2.4 million Arabic speakers from around the globe, and the traffic to Yad Vashem's website was tripled.


title: Yad Vashem

text: The institution's policy is that the Holocaust "cannot be compared to any other event". In 2009 Yad Vashem fired a docent for comparing the trauma Jews suffered in the Holocaust to the trauma Palestinians suffered during 1947–1949 Palestine war, including the Deir Yassin massacre.


title: Yad Vashem

text: "Yad Vashem Studies" is a peer-reviewed semi-annual scholarly journal on the Holocaust. Published since 1957, it appears in both English and Hebrew editions.


title: Yad Vashem

text: Yad Vashem opened to the public in 1957. Its exhibits focused on Jewish resistance in the Warsaw ghetto, the uprisings in Sobibor and Treblinka death camps, and the struggle of survivors to reach Israel.


title: Yad Vashem

text: In 1993, planning began for a larger, more technologically advanced museum to replace the old one. The new building, designed by Canadian-Israeli architect Moshe Safdie, consists of a long corridor connected to 10 exhibition halls, each dedicated to a different chapter of the Holocaust. The museum combines the personal stories of 90 Holocaust victims and survivors and presents approximately 2,500 personal items including artwork and letters donated by survivors and others. The old historical displays revolving around anti-Semitism and the rise of Nazism have been replaced by exhibits that focus on the personal stories of Jews killed in the Holocaust. According to Avner Shalev, the museum's curator and chairman, a visit to the new museum revolves around "looking into the eyes of the individuals. There weren't six million victims, there were six million individual murders."


title: Yad Vashem

text: The new museum was dedicated on 15 March 2005 in the presence of leaders from 40 states and then Secretary General of the UN Kofi Annan. President of Israel Moshe Katzav said that Yad Vashem serves as "an important signpost to all of humankind, a signpost that warns how short the distance is between hatred and murder, between racism and genocide".


title: Yad Vashem

text: In April 2019, Yad Vashem will break ground on a new subterranean center to house and conserve millions of artifacts from the Holocaust.


title: Yad Vashem

text: The first architect involved in the design of Yad Vashem was Munio Weinraub, who worked on the project from 1943 till the 1960s, together with his architectural partner Al Mansfield. He was approached for this purpose by Mordechai Shenhavi, the initiator and first director of the institution. Weinraub's plans were not realised as a whole, but some of his ideas are visible in Yad Vashem today.


title: Yad Vashem

text: The new Holocaust History Museum, designed by Moshe Safdie, is shaped like a triangular concrete prism that cuts through the landscape, illuminated by a skylight. Visitors follow a preset route that takes them through underground galleries that branch off from the main hall. Safdie is also the architect behind the Children's Memorial and the Deportees (cattle-car) Memorial.


title: Yad Vashem

text: The Hall of Names is a memorial to the six million Jews who were murdered in the Holocaust. The main hall is composed of two cones: one ten meters high, with a reciprocal well-like cone excavated into the underground rock, its base filled with water. On the upper cone is a display featuring 600 photographs of Holocaust victims and fragments of Pages of Testimony. These are reflected in the water at the bottom of the lower cone, commemorating those victims whose names remain unknown. Surrounding the platform is the circular repository, housing the approximately 2.2 million Pages of Testimony collected to date, with empty spaces for those yet to be submitted.


title: Yad Vashem

text: Since the 1950s, Yad Vashem has collected approximately 110,000 audio, video, and written testimonies by Holocaust survivors. As the survivors age, the program has expanded to visiting survivors in their homes, to tape interviews. Adjoining the hall is a study area with a computerized data bank where visitors can do online searches for the names of Holocaust victims.


title: Yad Vashem

text: The Archive is the oldest department of Yad Vashem. Before presenting an exhibition, Yad Vashem collects items. The best known of these are the historical photographs, as well as the Pages of Testimonies collected from survivors. The latter is a database of personal information about those who survived and those who were murdered in the Holocaust. Yad Vashem has also acquired access to the database of the International Tracing Service of Bad Arolsen of the International Committee of the Red Cross, and these two databases complement each other for research purposes.


title: Yad Vashem

text: One of Yad Vashem's tasks is to honor non-Jews who risked their lives, liberty, or positions to save Jews during the Holocaust. To this end, a special independent commission, headed by a retired Supreme Court justice, was established. The commission members, including historians, public figures, lawyers, and Holocaust survivors, examine and evaluate each case according to a well-defined set of criteria and regulations. The Righteous receive a certificate of honor and a medal, and their names are commemorated in the Garden of the Righteous Among the Nations, on the Mount of Remembrance, Yad Vashem. This is an ongoing project that will continue for as long as there are valid requests, substantiated by testimonies or documentation. Five hundred and fifty-five individuals were recognized during 2011, and , more than 27,921 individuals have been recognized as Righteous Among the Nations.


title: Yad Vashem

text: Yad Vashem's declared policy is not to provide meaningful recognition, even in a possible new category, to Jews who rescued Jews, regardless of the number of people their activism saved. The stated reason is that Jews had an obligation to save fellow Jews and do not deserve recognition.


title: Yad Vashem

text: Yad Vashem houses the world's largest collection of artwork produced by Jews and other victims of Nazi occupation in 1933–1945. The Yad Vashem Art Department supervises a 10,000-piece collection, adding 300 pieces a year, most of them donated by survivors' families or discovered in attics. Included in the collection are works by Alexander Bogen, Alice Lok Cahana, Samuel Bak, and Felix Nussbaum.


title: Agyness Deyn

text: Agyness Deyn (; born Laura Michelle Hollins; 16 February 1983) is an English model and actress. She is best known for her successful modelling career in the 2000s, and has been called one of the decade's top models. Since her retirement from modelling in the 2010s, she has pursued acting and design, among other ventures.


title: Agyness Deyn

text: Born Laura Michelle Hollins, Deyn is from Littleborough, near Rochdale in Greater Manchester. Deyn later moved to Failsworth near Oldham. The second of three children, she moved to Rossendale, Lancashire, and attended All Saints Roman Catholic High School, as well as Bacup and Rawtenstall Grammar School and Sixth Form, Waterfoot.


title: Agyness Deyn

text: Deyn's name was apparently coined to further her modelling career after she consulted her mother's friend, a numerology expert, who advised her of the most 'fortuitous' way to spell the name 'Agnes'. It was reported that her mother Lorraine (a nurse), and her sister Emily both changed their surname to Deyn, while Lorraine has changed the I in her first name to Y.


title: Agyness Deyn

text: Deyn's working life started at a fish and chip shop in Stubbins, Rossendale, where she was a part-time server at the age of 13. Even at an early age she had an eye for style and by 17 she had already had her head shaved. "I've had short hair since I was 13, and when I was 17, I had a skinhead." In 1999, she won the "Rossendale Free Press" "Face of '99" competition, aged just 16.


title: Agyness Deyn

text: Deyn's biography claims that she was "spotted" while shopping with fashion designer Henry Holland in Kentish Town, London. She then signed with SELECT Model Management.


title: Agyness Deyn

text: In May 2007, she was featured on the cover of American "Vogue", alongside Doutzen Kroes, Caroline Trentini, Raquel Zimmermann, Sasha Pivovarova, Jessica Stam, Coco Rocha, Hilary Rhoda, Chanel Iman and Lily Donaldson as "The World's Next Top Models." She has also been featured on the covers of: UK "Vogue", the "Observer Woman" supplement, "The Sunday Times Style", "Pop", "Grazia", "Time", "Style & Life", "Vogue Italia" and numerous other international publications.


title: Agyness Deyn

text: She has walked the runways for Chanel, Dolce & Gabbana, Burberry, Hermés, Dior, Lanvin, DKNY, Karl Lagerfeld, Moschino, Versace, Michael Kors, Zac Posen, Celine, Roberto Cavalli, Bottega Veneta, Proenza Schouler, Tommy Hilfiger, Stella McCartney, Viktor & Rolf, Max Mara, Oscar De La Renta, Ralph Lauren, Giles Deacon, Alexander Wang, Jean Paul Gaultier, Alberta Ferretti, Carolina Herrera, and Yves Saint Laurent.


title: Agyness Deyn

text: Deyn has appeared in advertisements for Dior, Burberry, Emporio Armani, Calvin Klein, Moncler, Anna Sui, Giorgio Armani, John Galliano, Gianfranco Ferré, Blumarine, Vivienne Westwood, Cacharel, Doc Martens, Shiseido, Mulberry, Paul Smith, Adidas, and Reebok.


title: Agyness Deyn

text: She has been the face of fragrance "The Beat" by Burberry, "Gold by Giles Deacon" at New Look replacing Drew Barrymore, Jean Paul Gaultier's fragrance "Ma Dame", "Shiseido" (replacing Angelina Jolie), "Rock Me!" by Anna Sui, and childhood friend Henry Holland's label "House of Holland". In 2009, Deyn landed a Uniqlo campaign and appeared in a commercial with Gabriel Aubry.


title: Agyness Deyn

text: In May 2008, Deyn was guest editor of "i-D" magazine. The issue was devoted to her and includes articles written by and about Deyn, as well as interviews she conducted with fashion designers such as Vivienne Westwood. Deyn's was on one of the fourteen covers of "V magazine" autumn issue. Each cover employs a head shot of a famous model, either from new models or established supermodels; it was photographed by Inez van Lamsweerde and Vinoodh Matadin.


title: Agyness Deyn

text: In June 2009, the "Daily Mirror" reported that Deyn had quit modeling to spend more time with her then boyfriend, singer-songwriter Miles Kane. The newspaper quoted a source as saying that modeling had started to bore Deyn and that she had hired an acting agent to pursue an acting career in British independent films.


title: Agyness Deyn

text: In October 2012, Deyn once again announced that she has retired from modeling in an interview with "The Independent". She stated, "I suppose I have stopped modeling officially. I've not done any for a good long while now. I think it was about four years ago when my feelings were changing towards the industry. I didn't hate it, but I was yearning to do something different. I was on a gradient. It was a gradual thing." She intends to focus on her acting career.


title: Agyness Deyn

text: Deyn provides vocals for the single "Who" by Five O'Clock Heroes as well as featuring in the video. The single was poorly received by "NME", who gave it only a 2/10. The single charted at No. 109 in the UK. Until recently she was a member of the now defunct group Lucky Knitwear. Deyn's voice can be heard at the beginning of Rihanna's music video for "We Found Love".


title: Agyness Deyn

text: In the 2010 film "Clash of the Titans", Deyn played Aphrodite, Greek goddess of beauty, love, and sex.


title: Agyness Deyn

text: In 2012, Deyn starred opposite Richard Coyle in "Pusher", an English language remake of Nicolas Winding Refn's Danish film of the same name, where she played Flo, a strong-minded stripper.


title: Agyness Deyn

text: On 28 February 2012, Deyn played her first role on the West End stage, as Paula in François Archambault's comedy, "The Leisure Society". After receiving excellent reviews for her role in that play, Deyn was cast to play the main female role, Chris Guthrie, in a film adaptation of the Scottish-set novel "Sunset Song".


title: Agyness Deyn

text: In 2013, Deyn played the lead role in "Electricity", a film adaptation of the novel by Ray Robinson, about the journey of a young woman with epilepsy.


title: Agyness Deyn

text: In 2017, Deyn began filming "Hard Sun", a pre-apocalyptic crime drama for the BBC at Hanstead Park in Bricket Wood, Hertfordshire.


title: Agyness Deyn

text: In 2019, Deyn starred in Alex Ross Perry's "Her Smell" as Marielle Hell, bassist for the fictional band Something She.


title: Agyness Deyn

text: In 2010, Deyn collaborated with her younger sister Emily to create a line of T-shirts and tank tops for high street chain Uniqlo.


title: Agyness Deyn

text: In 2012, Deyn began a design partnership with Dr. Martens called Agyness Deyn for Dr. Martens, a line of accessories, shoes, and clothing. In spring of 2014, she planned to release a third collaboration with the brand.


title: Agyness Deyn

text: She currently works with the agencies Elite New York City, Why Not Model Agency in Milan, and Oui Management in Paris.


title: Agyness Deyn

text: Deyn was married to American actor Giovanni Ribisi from 2012 to 2015. In August 2016, Deyn married hedge fund manager Joel McAndrew in New York. In the 2000s, she dated musicians Albert Hammond Jr. of the Strokes, Alex Greenwald of Phantom Planet, and Miles Kane of the Last Shadow Puppets.


title: Proof of work

text: Proof of work (PoW) is a form of cryptographic proof in which one party (the "prover") proves to others (the "verifiers") that a certain amount of a specific computational effort has been expended. Verifiers can subsequently confirm this expenditure with minimal effort on their part. The concept was invented by Moni Naor and Cynthia Dwork in 1993 as a way to deter denial-of-service attacks and other service abuses such as spam on a network by requiring some work from a service requester, usually meaning processing time by a computer. The term "proof of work" was first coined and formalized in a 1999 paper by Markus Jakobsson and Ari Juels.


title: Proof of work

text: Proof of work was later popularized by Bitcoin as a foundation for consensus in a permissionless decentralized network, in which miners compete to append blocks and mint new currency, each miner experiencing a success probability proportional to the computational effort expended. PoW and PoS (proof of stake) remain the two best known Sybil deterrence mechanisms. In the context of cryptocurrencies they are the most common mechanisms.


title: Proof of work

text: A key feature of proof-of-work schemes is their asymmetry: the "work" – the computation – must be moderately hard (yet feasible) on the prover or requester side but easy to check for the verifier or service provider. This idea is also known as a CPU cost function, client puzzle, computational puzzle, or CPU pricing function. Another common feature is built-in incentive-structures that reward allocating computational capacity to the network with value in the form of money.


title: Proof of work

text: The purpose of proof-of-work algorithms is not proving that certain work was carried out or that a computational puzzle was "solved", but deterring manipulation of data by establishing large energy and hardware-control requirements to be able to do so. Proof-of-work systems have been criticized by environmentalists for their energy consumption.


title: Proof of work

text: One popular system, used in Hashcash, uses partial hash inversions to prove that computation was done, as a goodwill token to send an e-mail. For instance, the following header represents about 2 hash computations to send a message to codice_1 on January 19, 2038:


title: Proof of work

text: It is verified with a single computation by checking that the SHA-1 hash of the stamp (omit the header name codice_2 including the colon and any amount of whitespace following it up to the digit '1') begins with 52 binary zeros, that is 13 hexadecimal zeros:


title: Proof of work

text: Whether PoW systems can actually solve a particular denial-of-service issue such as the spam problem is subject to debate;


title: Proof of work

text: the system must make sending spam emails obtrusively unproductive for the spammer, but should also not prevent legitimate users from sending their messages. In other words, a genuine user should not encounter any difficulties when sending an email, but an email spammer would have to expend a considerable amount of computing power to send out many emails at once. Proof-of-work systems are being used by other, more complex cryptographic systems such as bitcoin, which uses a system similar to Hashcash.


title: Proof of work

text: Known-solution protocols tend to have slightly lower variance than unbounded probabilistic protocols because the variance of a rectangular distribution is lower than the variance of a Poisson distribution (with the same mean). A generic technique for reducing variance is to use multiple independent sub-challenges, as the average of multiple samples will have a lower variance.


title: Proof of work

text: Finally, some PoW systems offer shortcut computations that allow participants who know a secret, typically a private key, to generate cheap PoWs. The rationale is that mailing-list holders may generate stamps for every recipient without incurring a high cost. Whether such a feature is desirable depends on the usage scenario.


title: Proof of work

text: Computer scientist Hal Finney built on the proof-of-work idea, yielding a system that exploited reusable proof of work (RPoW).


title: Proof of work

text: The idea of making proofs of work reusable for some practical purpose had already been established in 1999. Finney's purpose for RPoW was as token money. Just as a gold coin's value is linked to gold mining cost, the value of an RPoW token is guaranteed by the value of the real-world resources required to 'mint' a PoW token. In Finney's version of RPoW, the PoW token is a piece of Hashcash.


title: Proof of work

text: A website can demand a PoW token in exchange for service. Requiring a PoW token from users would inhibit frivolous or excessive use of the service, sparing the service's underlying resources, such as bandwidth to the Internet, computation, disk space, electricity, and administrative overhead.


title: Proof of work

text: Finney's RPoW system differed from a PoW system in permitting the random exchange of tokens without repeating the work required to generate them. After someone had "spent" a PoW token at a website, the website's operator could exchange that "spent" PoW token for a new, unspent RPoW token, which could then be spent at some third-party website similarly equipped to accept RPoW tokens. This would save the resources otherwise needed to 'mint' a PoW token. The anti-counterfeit property of the RPoW token was guaranteed by remote attestation. The RPoW server that exchanges a used PoW or RPoW token for a new one of equal value uses remote attestation to allow any interested party to verify what software is running on the RPoW server. Since the source code for Finney's RPoW software was published (under a BSD-like license), any sufficiently knowledgeable programmer could, by inspecting the code, verify that the software (and, by extension, the RPoW server) never issued a new token except in exchange for a spent token of equal value.


title: Proof of work

text: Until 2009, Finney's system was the only RPoW system to have been implemented; it never saw economically significant use.


title: Proof of work

text: RPoW is protected by private keys. Those keys are stored in the trusted platform module (TPM) hardware and by manufacturers holding TPM private keys. Stealing a TPM manufacturer's key or obtaining the key by examining the TPM chip itself would subvert that assurance.


title: Proof of work

text: At the IACR conference Crypto 2022 researchers presented a paper describing Ofelimos, a blockchain protocol with a consensus mechanism based on "proof of useful work" (PoUW). Rather than miners consuming energy in solving complex, but essentially useless, puzzles to validate transactions, Ofelimos achieves consensus while simultaneously providing a decentralized optimization problem solver. The protocol is built around Doubly Parallel Local Search (DPLS), a local search algorithm that is used as the PoUW component. The paper gives an example that implements a variant of WalkSAT, a local search algorithm to solve Boolean problems.


title: Proof of work

text: In 2009, the Bitcoin network went online. Bitcoin is a proof-of-work digital currency that, like Finney's RPoW, is also based on the Hashcash PoW. But in Bitcoin, double-spend protection is provided by a decentralized P2P protocol for tracking transfers of coins, rather than the hardware trusted computing function used by RPoW. Bitcoin has better trustworthiness because it is protected by computation. Bitcoins are "mined" using the Hashcash proof-of-work function by individual miners and verified by the decentralized nodes in the P2P bitcoin network.


title: Proof of work

text: Since the creation of Bitcoin, proof-of-work has been the predominant design of peer-to-peer cryptocurrency. Studies have estimated the total energy consumption of cryptocurrency mining. The PoW mechanism requires a vast amount of computing resources, which consume a significant amount of electricity. 2018 estimates from the University of Cambridge put Bitcoin’s energy consumption as equal to that of Switzerland.


title: Proof of work

text: Each block that is added to the blockchain, starting with the block containing a given transaction, is called a confirmation of that transaction. Ideally, merchants and services that receive payment in the cryptocurrency should wait for at least one confirmation to be distributed over the network, before assuming that the payment was done. The more confirmations that the merchant waits for, the more difficult it is for an attacker to successfully reverse the transaction in a blockchain—unless the attacker controls more than half the total network power, in which case it is called a 51% attack.


title: Proof of work

text: Within the Bitcoin community there are groups working together in mining pools. Some miners use application-specific integrated circuits (ASICs) for PoW. This trend toward mining pools and specialized ASICs has made mining some cryptocurrencies economically infeasible for most players without access to the latest ASICs, nearby sources of inexpensive energy, or other special advantages.