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Analog Computers
An analog computer or analogue computer is a type of computation machine (computer) that uses physical phenomena such as Electrical network, electrical, Mechanics, mechanical, or Hydraulics, hydraulic quantities behaving according to the mathematical principles in question (''analog signals'') to Scientific modelling, model the problem being solved. In contrast, digital computers represent varying quantities symbolically and by discrete values of both time and amplitude (digital signals). Analog computers can have a very wide range of complexity. Slide rules and nomograms are the simplest, while naval gunfire control computers and large hybrid digital/analog computers were among the most complicated. Complex mechanisms for process control and protective relays used analog computation to perform control and protective functions. Analog computers were widely used in scientific and industrial applications even after the advent of digital computers, because at the time they were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Control System
A control system manages, commands, directs, or regulates the behavior of other devices or systems using control loops. It can range from a single home heating controller using a thermostat controlling a domestic boiler to large industrial control systems which are used for controlling processes or machines. The control systems are designed via control engineering process. For continuously modulated control, a feedback controller is used to automatically control a process or operation. The control system compares the value or status of the process variable (PV) being controlled with the desired value or setpoint (SP), and applies the difference as a control signal to bring the process variable output of the plant to the same value as the setpoint. For sequential and combinational logic, software logic, such as in a programmable logic controller, is used. Open-loop and closed-loop control Feedback control systems Logic control Logic control systems for indus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hellenistic Period
In classical antiquity, the Hellenistic period covers the time in Greek history after Classical Greece, between the death of Alexander the Great in 323 BC and the death of Cleopatra VII in 30 BC, which was followed by the ascendancy of the Roman Empire, as signified by the Battle of Actium in 31 BC and the Roman conquest of Ptolemaic Egypt the following year, which eliminated the last major Hellenistic kingdom. Its name stems from the Ancient Greek word ''Hellas'' (, ''Hellás''), which was gradually recognized as the name for Greece, from which the modern historiographical term ''Hellenistic'' was derived. The term "Hellenistic" is to be distinguished from "Hellenic" in that the latter refers to Greece itself, while the former encompasses all the ancient territories of the period that had come under significant Greek influence, particularly the Hellenized Middle East, after the conquests of Alexander the Great. After the Macedonian conquest of the Achaemenid Empire in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crete
Crete ( ; , Modern Greek, Modern: , Ancient Greek, Ancient: ) is the largest and most populous of the Greek islands, the List of islands by area, 88th largest island in the world and the List of islands in the Mediterranean#By area, fifth largest island in the Mediterranean Sea, after Sicily, Sardinia, Cyprus, and Corsica. Crete is located about south of the Peloponnese, and about southwest of Anatolia. Crete has an area of and a coastline of 1,046 km (650 mi). It bounds the southern border of the Aegean Sea, with the Sea of Crete (or North Cretan Sea) to the north and the Libyan Sea (or South Cretan Sea) to the south. Crete covers 260 km from west to east but is narrow from north to south, spanning three longitudes but only half a latitude. Crete and a number of islands and islets that surround it constitute the Region of Crete (), which is the southernmost of the 13 Modern regions of Greece, top-level administrative units of Greece, and the fifth most popu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kythera
Kythira ( ; ), also transliterated as Cythera, Kythera and Kithira, is an Greek islands, island in Greece lying opposite the south-eastern tip of the Peloponnese peninsula. It is traditionally listed as one of the seven main Ionian Islands, although it is distant from the main group. Administratively, it belongs to the Islands (regional unit), Islands regional unit, which is part of the Attica (region), Attica region, despite its distance from the Saronic Islands, around which the rest of Attica is centered. As a municipality, it includes the island of Antikythera to the south. The island is strategically located between the Greek mainland and Crete, and from ancient times until the mid-19th century was a crossroads of merchants, sailors, and conquerors. As such, it has had a long and varied history and has been influenced by many civilizations and cultures. This is reflected in its architecture (a blend of traditional, Aegean Sea, Aegean and Venice, Venetian elements), as well as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antikythera
Antikythera ( , ; , ) or Anticythera, known in antiquity as Aigilia (), is a Greek island lying on the edge of the Aegean Sea, between Crete and Peloponnese. Since the 2011 local government reform, it is part of the municipality of Kythira island. Antikythera may also refer to the Kythira Strait, Kythira-Antikythira Strait, through which Mediterranean water enters the Sea of Crete. Its land area is , and it lies south-east of Kythira. It is the most distant part of the Attica (region), Attica region from its heart in the Athens metropolitan area. It is Lozenge (shape), lozenge-shaped, NNW to SSE by ENE to WSW. It is notable for being the location of the discovery of the Antikythera mechanism and for the historical Roman-era Antikythera wreck. Its main settlement and port is Potamós (pop. 34 inhabitants in the 2011 census). The only other settlements are Galanianá (pop. 15), and Charchalianá (pop. 19). Antikythera is periodically visited by the Ablemon Nautical Company f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antikythera Wreck
The Antikythera wreck () is a Roman-era shipwreck dating from the second quarter of the first century BC."''The Antikythera Shipwreck. The Ship, The Treasures, The Mechanism. National Archaeological Museum, April 2012 – April 2013''". Hellenic Ministry of Culture and Tourism; National Archaeological Museum. Editors Nikolaos Kaltsas & Elena Vlachogianni & Polyxeni Bouyia. Athens: Kapon, 2012, . It was discovered by sponge diving, sponge divers off Point Glyphadia on the Greece, Greek island of Antikythera in 1900. The wreck yielded numerous statues, coins, and other artifacts dating back to the fourth century BC, as well as the severely corroded remnants of a device many regard as the world's oldest known analog computer, the Antikythera mechanism. These ancient artifacts, works of art, and elements of the ship are now on display at the National Archaeological Museum, Athens, National Archaeological Museum of Athens. Discovery Around Easter 1900, Captain Dimitrios Kondos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
