Turing machine Hypothetical computing device proposed by Alan M. Turing (1936). Not actually a machine, it is an idealized mathematical model that reduces the logical structure of any computing device to its essentials. It consists of an infinitely extensible tape, a tape head that is
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Turing test ► Turkic peoples I 1951
capable of performing various operations on the tape, and a modifiable control mechanism in the head that can store instructions. As envisaged by Turing, it performs its functions in a sequence of discrete steps. His extrapolation of the essential features of information processing was instru¬ mental in the development of modern digital computers, which share his basic scheme of an input/output device (tape and tape reader), central processing unit (CPU, or control mechanism), and stored memory.
Turing test Test proposed by Alan M. Turing to determine whether a computer can be said to “think.” Turing suggested the “imitation game,” wherein a remote human interrogator, within a fixed time frame, must distinguish between a computer and a human subject based on their replies to questions posed by the interrogator. A series of such tests would mea¬ sure the computer’s success at “thinking” by the probability of its being misidentified as the human subject. The test is performed today in com¬ petitions that test the success of artificial intelligence.
Turkana, Lake See Lake Rudolf Turkana remains See Lake Turkana remains
Turkey officially Republic of Turkey Country, western Asia and southeastern Europe. Area: 299,158 sq mi (774,815 sq km), nearly all of which lies in Asia. Population (2005 est.): 72,083,000. Capitaclass="underline" Ankara.
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Ethnic groups include the Turks and Kurds.
Languages: Turkish (official), Kurdish,
Arabic. Religion: Islam (mostly Sunni).
Currency: Turkish lira. Turkey is a moun¬ tainous country with an extensive plateau covering central Anatolia. The highest peak is Mount Ararat (16,853 ft [5,137 m]). The Taurus Mountains lie in the south. Rivers include the Tigris, Euphrates, Kizil, and Menderes. Turkey is a major producer and exporter of chromite and also mines iron ore, coal, lignite, bauxite, and copper. It is the Middle East’s leading steel producer. Chief agricultural products include wheat, barley, olives, and tobacco. Tourism also is important. Turkey is a republic with one legislative house; its chief of state is the president, and the head of government is the prime minister. Turkey’s early history corresponds to that of Anatolia, the Byzantine Empire, and the Ottoman Empire. Byzantine rule emerged when Constantine the Great made Constantinople (modern Istanbul) his capital. The Ottoman Empire, begun in the 12th century, dominated for more than 600 years; it ended in 1918 after the Young Turk revolt (1908) precipitated its demise. Under the lead¬ ership of Mustafa Kemal AtatOrk, a republic was proclaimed in 1923. Tur¬ key remained neutral throughout most of World War II (1939-45), siding with the Allied powers in 1945. Since the war it has alternated between civil and military governments and has had several conflicts with Greece over Cyprus. The country has developed a strong, diversified economy,
but it has also experienced periods of political and civic turmoil between Islamists and secularists and ongoing ethnic tension with Kurdish sepa¬ ratists.
turkey Either of two species of birds in the family Meleagrididae. The North American common turkey (Meleagris gallopavo) has been domesticated since pre-Columbian times. The adult male has a feather¬ less, bright-red head, a fleshy red ornament (snood) growing over the bill, and a similar wattle on the throat. The male (gobbler or tom) may be 50 in. (1.3 m) long and may weigh over 20 lb (10 kg). Wild tur¬ keys inhabit woodlands near water, eating seeds, insects, and an occa¬ sional frog or lizard. Males assemble a harem, and each hen lays 8-15 eggs in a hollow in the ground. An excellent source of meat and easily shot, the wild turkey was practically exterminated by European settlers; conservation efforts have reestab¬ lished it in much of its former range.
The ocellated turkey {Agriocharis, or Meleagris, ocellata) of Central America has never been domesticated.
turkey vulture or turkey buzzard Species ( Cathartes aura) of long-winged, long-tailed vulture (family Cathartidae), about 30 in. (75 cm) long, with dark plumage, whitish beak and legs, bare red head covered with whitish bumps, and a 6-ft (1.8-m) wingspread. It uses its keen sense of smell to find carrion. It occurs throughout the Americas except in northern Canada; the northerly and southernmost populations are migratory.
Turkic languages Family of more than 20 Altaic languages spoken by some 135 million people from the Balkans to central Siberia. The tra¬ ditional division of Turkic is into four groups. The southeastern or Uighur group comprises Uighur, spoken mainly in Xinjiang, China; and Uzbek, spoken mainly in Uzbekistan, other Central Asian republics, and north¬ ern Afghanistan. The southwestern, or Oguz, group includes Turkish; Azer¬ baijani (Azeri), spoken in Azerbaijan and northwestern Iran; Crimean Tatar, spoken mostly in Ukraine and Uzbekistan; and Turkmen, used in Turkmenistan, northern Iran, and northern Afghanistan. The northwest¬ ern, or Kipchak, group includes Kazakh, spoken in Kazakhstan, other Central Asian republics, and western China and Mongolia; Kyrgyz, spo¬ ken in Kyrgyzstan, other Central Asian republics, and western China; Tatar; Baskhir, spoken in Bashkortostan and adjacent areas in Russia; Karachay-Balkar and Kumyk, spoken in the Russian Caucasus; and Karaim, with a few speakers in Lithuania and parts of southwestern Ukraine. The northeastern, or Altai, group comprises languages and dia¬ lects spoken in Siberia northeast of the Irtysh River and in adjacent parts of Mongolia, including Altai, Khakas, Shor, and Tuvan; and Sakha, spo¬ ken in Sakha (Yakutia) republic of Russia and adjacent areas. Distinct from all the other languages is Chuvash, spoken in Russia’s Chuvash republic and adjacent areas. The earliest attestations of Turkic are a group of 8th-century funerary inscriptions of northern Mongolia, in a distinctive writing system called runic script, or Turkic runes. With the Islamization of nearly all Turkic peoples southwest of the Irtysh beginning c. 900, Turkic languages began to adopt the Arabic alphabet. Today the Latin alpha¬ bet and Cyrillic alphabet are more extensively used.