Analog television or analogue television is the original television technology that uses analog signals to transmit video and audio. In an analog television broadcast, the brightness and sound are represented by rapid variations of either the amplitude, frequency or phase of the signal. Analog signals vary over a continuous range of possible values which means that electronic noise and interference becomes reproduced by the receiver, thus with analog, a moderately weak signal becomes subject to interference. In contrast, a moderately weak digital signal and a strong digital signal transmit equal picture quality. Analog television can be distributed over a cable network using cable converters. All broadcast. Motivated by the lower bandwidth requirements of compressed digital signals, since the 2000s a digital television transition is proceeding in most countries of the world, with different deadlines for cessation of analog broadcasts; the earliest systems of analog television were mechanical television systems, which used spinning disks with patterns of holes punched into the disc to scan an image.
A similar disk reconstructed the image at the receiver. Synchronization of the receiver disc rotation was handled through sync pulses broadcast with the image information; however these mechanical systems were slow, the images were dim and flickered and the image resolution low. Camera systems used similar spinning discs and required intensely bright illumination of the subject for the light detector to work. Analog television did not begin as an industry until the development of the cathode-ray tube, which uses a focused electron beam to trace lines across a phosphor coated surface; the electron beam could be swept across the screen much faster than any mechanical disc system, allowing for more spaced scan lines and much higher image resolution. Far less maintenance was required of an all-electronic system compared to a spinning disc system. All-electronic systems became popular with households after the Second World War. Broadcasters of analog television encode their signal using different systems.
The official systems of transmission are named: A, B, C, D, E, F, G, H, I, K, K1, L, M and N. These systems determine the number of scan lines, frame rate, channel width, video bandwidth, video-audio separation, so on; the colors in those systems are encoded with one of three color coding schemes: NTSC, PAL, or SECAM, use RF modulation to modulate this signal onto a high frequency or ultra high frequency carrier. Each frame of a television image is composed of lines drawn on the screen; the lines are of varying brightness. The next sequential frame is displayed; the analog television signal contains timing and synchronization information, so that the receiver can reconstruct a two-dimensional moving image from a one-dimensional time-varying signal. The first commercial television systems were black-and-white. A practical television system needs to take luminance, chrominance and audio signals, broadcast them over a radio transmission; the transmission system must include a means of television channel selection.
Analog broadcast television systems come in a variety of frame resolutions. Further differences exist in the modulation of the audio carrier; the monochrome combinations still existing in the 1950s are standardized by the International Telecommunication Union as capital letters A through N. When color television was introduced, the hue and saturation information was added to the monochrome signals in a way that black and white televisions ignore. In this way backwards compatibility was achieved; that concept is true for all analog television standards. There were three standards for the way the additional color information can be encoded and transmitted; the first was the American NTSC color television system. The European/Australian PAL and the French-former Soviet Union SECAM standard were developed and attempt to cure certain defects of the NTSC system. PAL's color encoding is similar to the NTSC systems. SECAM, uses a different modulation approach than PAL or NTSC. In principle, all three color encoding systems can be combined with any scan line/frame rate combination.
Therefore, in order to describe a given signal it's necessary to quote the color system and the broadcast standard as a capital letter. For example, the United States, Canada and South Korea use NTSC-M, Japan uses NTSC-J, the UK uses PAL-I, France uses SECAM-L, much of Western Europe and Australia use PAL-B/G, most of Eastern Europe uses SECAM-D/K or PAL-D/K and so on. However, not all of these possible combinations exist. NTSC is only used with system M though there were experiments with NTSC-A in the UK and NTSC-N in part of South America. PAL is used with a variety of 625-line standards but with the North American 525-line standard, accordin
Ni_ka is a Japanese poet, artist. She has published "AR poems" using augmented reality technology, "monitor poems" filled with emoji, other genre-crossing works to widespread acclaim. One of her AR poems, "Best 100 Cultural Energies to Generate Power in 2012 Japan!!!!!" was selected as part of the DOMMUNE Official Guidebook 2. She won M/F prize when the 3331 art fair was on show in 2014. Ni_ka took arrangement of the objects on the platform at the one-year memorial service for the 2011 Tohoku earthquake and tsunami to be an extension of concrete poetry, reacting with her "Manifesto on Updating Japanese Concrete Poetry." This inventor and practitioner "monitor poetry" and "AR poetry" states: unless I discover words, somehow absorb and aggregate within wata-shi all that hangs in suspension around words, attend these words as they emerge, this would constitute not poetry but death." In this point of view, "words" would entail a new arrangement of things, which may express the disorderly relationship between the living and the dead.
Poetry becomes an endeavor to glean this relationship from the world, rearrenging it in the same world in the form of a condensed logic. Dommune Official Guide Book 2 selected her AR poetry as one of one hundred resources for the 2012 Japanese Cultural Energy. 2011 Tōhoku earthquake and tsunami inspired her to create a new form of mourning and a trans-generic form of living in which the boundary between language and image is deconstructed. In October 2013 ni_ka attended "Shibu-karu-sai", celebrating the 40th anniversary of Shibuya Seibu Department Store's PARCO Museum. In October 2014 ni_ka collaborated with an idol unit "Kamen-Joshi" at the exhibition After 3.11 Tokyo Girl in Ginza. AR poetry is one of the original works of her that we could see a lot of pictures such as Hello Kitty, the roses, morning words, they come from Paul Celan, "Die Niemandsrose", express the mourning of 3.11, the date of the 2011 Tōhoku earthquake and tsunami. In these works, an AR rose. In Sekai Camera apprication, touching float poetry words allows the toucher to write a reply.
Ni_ka's works are a kind of conceptual art which showed dynamic activity in Smartphone and monitor, but the concept is that come from the movement of Japanese concrete poetry called VOU, ASA. She created "monitor poetry". Monitor poetry is used in emoji and decomoji, influenced by Seiichi Niikuni, Katsue Kitasono, Gozo Yoshimasu and Stéphane Mallarmé. In January 2015, her work named "WEB h a l l e l u j a h 「a」－blood／arch" translated by Andrew Campana, was uploaded on the web magazine CURA. Website
The US 75 mm gun was the standard American gun mounted to a mobile platform during World War II. They were mounted on tanks but were mounted on the B-25 Mitchell medium bomber aircraft. There were four variants used during the war: M2, M3, M5, M6, they were considered the standard American tank guns. The M2 and M3 were used on the Lee tank, the M3 was used on the Sherman tank, the M6 was used on the Chaffee light tank; the M3 was used on a prototype medium tank. The M5 variant was fitted on the US B-25 Mitchell medium bomber aircraft; the 75 mm tank gun has its origins in the famous French Canon de 75 modèle 1897 field gun of World War I fame, adopted by the United States and used well into World War II as the 75 mm M1897 field gun. The tank and field guns fired the same range of 75x350R ammunition; the primary round was the 6.76 kg M48 high explosive round, which travelled at 625 m/s and contained 1.5 pounds of TNT filling and a choice of two fuzes, the super quick and the delay, which had delays of 0.05 and 0.15 seconds respectively.
SQ was the standard setting, with PD used against structures, gun positions or protected vehicles. The field gun origins of the ordnance and ammunition ensured that the M2/3/6 series HE round was effective for its caliber; the M48 was available in two versions and supercharge, which had an increased propellent charge for greater muzzle velocity and range. Other rounds fired by the 75 mm tank guns included the T30 canister shot for use against troops in the open at short range. This, a giant shotgun shell full of large numbers of steel balls, was used in the Pacific. There was the M89 base-ejecting hexachloroethane smoke round and the M64 white phosphorus round, which proved effective in the bocage fighting around Normandy. There were two different armor-piercing rounds; the first armor-piercing round was the 6.32 kg M72 AP-T, a plain uncapped armor-piercing round whose performance dropped off as range increased due to poor aerodynamics. The M72 was replaced by the 6.63 kg M61 armor-piercing capped ballistic capped high explosive with tracer shell.
The blunt armor-piercing cap, made of a softer metal, helped to prevent shell shatter at higher velocities and against sloped and face-hardened armor. The aerodynamic ballistic cap acted as a windscreen and improved ballistic performance, maintained velocity, hence increased penetration at longer ranges. Once the projectile had penetrated the target, a small explosive charge contained in a cavity at the base of the shell would detonate, shattering the shell and increasing damage inside the enemy vehicle; the tracer helped in the aiming of a second shot. In practice, the majority of M61 rounds were shipped without the explosive filler; the M61A1 used an improved method of attaching the ballistic cap to the shell. The M61 had a muzzle velocity of 617 m/s and was credited with the ability to penetrate 81 millimetres of rolled homogeneous armor plate at 0° from vertical at 500 yards range, a quite acceptable performance by the standards of 1942; this ammunition type proved lethal to the Panzer III and IV, as these tanks were protected by a maximum of 50 mm of face-hardened armor with little slope, which the 75 mm M3 with M61 was capable of penetrating from at least 1,500 m.
However, in March 1942, the Germans introduced the Ausf. G verson of the Panzer IV, armed with the 48-caliber long KwK 40 gun, had frontal hull armour increased to 80 mm - however, its turret and gun mantlet retained their 50 mm thickness; this was somewhat compensated by the M4 Sherman's improved armor over the earlier M3 Lee making up for the 75mm M3's diminishing battlefield dominance. British tanks in the early years of World War II relied on high-velocity, smaller-calibre anti-tank guns, such as the 40 mm calibre Ordnance QF 2 pounder and 57 mm calibre Ordnance QF 6 pounder, for their primary armament; as tank guns, these had the great disadvantage of either not having a effective HE round or not having an HE round at all. After experiencing the effectiveness of the American 75 mm tank guns in the infantry support role, the British opted to adopt the American caliber and ammunition by the expedient of boring-out the 6 pounder tank gun to make the Ordnance QF 75 mm. By 1944, this had become the standard British tank gun, equipping the Cromwell tank and Churchill tank for the campaigns in northwest Europe.
T6 Experimental anti-aircraft gun based on the M1897 field gun. The barrel was shortened from 36 to 31 calibers, the Nordenfelt screw breech replaced with the sliding block breech. T7 / M2 Adaptation of the T6 for tank gun role. Used on the early M3 Lee. Barrel length: 31 calibers Muzzle velocity: 588 m/s with M72 AP shellT8 / M3 Longer derivative of the M2. Equipped American and British vehicles such as the M4 Sherman, the models of the M3 Lee and the Churchill III/IV; the US Army experimented with mounting the M3 on various wheeled carriages for use as anti-tank gun, but the program was cancelled due to a lack of requirement. Barrel length: 40 calibers Muzzle velocity: 619 m/s with M72 AP shellM4 The 75 mm aircraft gun M4 is a modification of the M3 gun found in medium tanks, it differs from the M3 gun, only in having a seat for the spline