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Invasion
An invasion is a military offensive in which large numbers of combatants of one geopolitical entity aggressively enter territory owned by another such entity, generally with the objective of either: conquering; liberating or re-establishing control or authority over a territory; forcing the partition of a country; altering the established government or gaining concessions from said government; or a combination thereof. An invasion can be the cause of a war, be a part of a larger strategy to end a war, or it can constitute an entire war in itself. Due to the large scale of the operations associated with invasions, they are usually strategic in planning and execution. History Archaeological evidence indicates that invasions have been frequent occurrences since prehistory. In antiquity, before radio communications and fast transportation, the only way for a military to ensure adequate reinforcements was to move armies as one massive force. This, by its very nature, led to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancient World
Ancient history is a time period from the beginning of writing and recorded human history to as far as late antiquity. The span of recorded history is roughly 5,000 years, beginning with the Sumerian cuneiform script. Ancient history covers all continents inhabited by humans in the period 3000 BCAD 500. The three-age system periodizes ancient history into the Stone Age, the Bronze Age, and the Iron Age, with recorded history generally considered to begin with the Bronze Age. The start and end of the three ages varies between world regions. In many regions the Bronze Age is generally considered to begin a few centuries prior to 3000 BC, while the end of the Iron Age varies from the early first millennium BC in some regions to the late first millennium AD in others. During the time period of ancient history, the world population was already exponentially increasing due to the Neolithic Revolution, which was in full progress. While in 10,000 BC, the world population stood ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minefield
A land mine is an explosive device concealed under or on the ground and designed to destroy or disable enemy targets, ranging from combatants to vehicles and tanks, as they pass over or near it. Such a device is typically detonated automatically by way of pressure when a target steps on it or drives over it, although other detonation mechanisms are also sometimes used. A land mine may cause damage by direct blast effect, by fragments that are thrown by the blast, or by both. Landmines are typically laid throughout an area, creating a ''minefield'' which is dangerous to cross. The use of land mines is controversial because of their potential as indiscriminate weapons. They can remain dangerous many years after a conflict has ended, harming civilians and the economy. Seventy-eight countries are contaminated with land mines and 15,000–20,000 people are killed every year while many more are injured. Approximately 80% of land mine casualties are civilians, with children as the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Territory (country Subdivision)
A territory is an area of land, sea, or space, particularly belonging or connected to a country, person, or animal. In international politics, a territory is usually either the total area from which a state may extract power resources or an administrative division is usually an area that is under the jurisdiction of a sovereign state. As a subdivision a territory is in most countries an organized division of an area that is controlled by a country but is not formally developed into, or incorporated into, a political unit of the country that is of equal status to other political units that may often be referred to by words such as "provinces" or "regions" or "states". In its narrower sense, it is "a geographic region, such as a colonial possession, that is dependent on an external government." Etymology The origins of the word "territory" begin with the Proto-Indo-European root ''ters'' ('to dry'). From this emerged the Latin word ''terra'' ('earth, land') and later the L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trench Warfare
Trench warfare is a type of land warfare using occupied lines largely comprising Trench#Military engineering, military trenches, in which troops are well-protected from the enemy's small arms fire and are substantially sheltered from artillery. Trench warfare became archetypically associated with World War I (1914–1918), when the Race to the Sea rapidly expanded trench use on the Western Front (World War I), Western Front starting in September 1914.. Trench warfare proliferated when a Weapons of World War I, revolution in firepower was not matched by similar advances in mobility (military), mobility, resulting in a grueling form of warfare in which the defender held the advantage. On the Western Front in 1914–1918, both sides constructed elaborate trench, underground, and dugout systems opposing each other along a front (military), front, protected from assault by barbed wire. The area between opposing trench lines (known as "no man's land") was fully exposed to artillery ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tourism
Tourism is travel for pleasure or business; also the theory and practice of touring, the business of attracting, accommodating, and entertaining tourists, and the business of operating tours. The World Tourism Organization defines tourism more generally, in terms which go "beyond the common perception of tourism as being limited to holiday activity only", as people "travelling to and staying in places outside their usual environment for not more than one consecutive year for leisure and not less than 24 hours, business and other purposes". Tourism can be domestic (within the traveller's own country) or international, and international tourism has both incoming and outgoing implications on a country's balance of payments. Tourism numbers declined as a result of a strong economic slowdown (the late-2000s recession) between the second half of 2008 and the end of 2009, and in consequence of the outbreak of the 2009 H1N1 influenza virus, but slowly recovered until the COV ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motion Detection
Motion detection is the process of detecting a change in the position of an object relative to its surroundings or a change in the surroundings relative to an object. It can be achieved by either mechanical or electronic methods. When it is done by natural organisms, it is called motion perception. Methods Motion can be detected by monitoring changes in: *Infrared light (passive and active sensors) *Visible light (video and camera systems) *Radio frequency energy (radar, microwave and tomographic motion detection) *Sound (microphones, other acoustic sensors) *Kinetic energy ( triboelectric, seismic, and inertia-switch sensors) *Magnetism (magnetic sensors, magnetometers) *Wi-Fi Signals ( WiFi Sensing) Mechanical The most basic forms of mechanical motion detection utilize a switch or trigger. For example, the keys of a typewriter use a mechanical method of detecting motion, where each key is a switch that is either off or on, and each letter that appears is a result of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Closed-circuit Television
Closed-circuit television (CCTV), also known as video surveillance, is the use of video cameras to transmit a signal to a specific place, on a limited set of monitors. It differs from broadcast television in that the signal is not openly transmitted, though it may employ point-to-point (P2P), point-to-multipoint (P2MP), or Mesh networking, mesh wired or Wireless, wireless links. Even though almost all video cameras fit this definition, the term is most often applied to those used for surveillance in areas that require additional security or ongoing monitoring (Videotelephony is seldom called "CCTV"). Surveillance of the public using CCTV is common in many areas around the world. In recent years, the use of body worn video cameras has been introduced as a new form of surveillance, often used in law enforcement, with cameras located on a police officer's chest or head. Video surveillance has generated significant debate about balancing its use with individuals' right to privac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Danewerk
The Danevirke or Danework (modern Danish spelling: ''Dannevirke''; in Old Norse; ''Danavirki'', in German; ''Danewerk'', literally meaning '' earthwork of the Danes'') is a system of Danish fortifications in Schleswig-Holstein, Germany. This historically important linear defensive earthwork across the neck of the Cimbrian peninsula was initiated by the Danes in the Nordic Iron Age about AD 650. It was later expanded multiple times during Denmark's Viking Age and High Middle Ages. The Danevirke was last used for military purposes in 1864 during the Second War of Schleswig. The Danevirke consists of several walls, trenches and the Schlei Barrier. The walls stretch for 30 km, from the former Viking trade centre of Hedeby near Schleswig on the Baltic Sea coast in the east to the extensive marshlands in the west of the peninsula. One of the walls (named ''Østervolden''), between the Schlei and Eckernförde inlets, defended the Schwansen peninsula. According to written sour ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hadrian's Wall
Hadrian's Wall ( la, Vallum Aelium), also known as the Roman Wall, Picts' Wall, or ''Vallum Hadriani'' in Latin, is a former defensive fortification of the Roman province of Britannia, begun in AD 122 in the reign of the Emperor Hadrian. Running from Wallsend on the River Tyne in the east to Bowness-on-Solway in the west of what is now northern England, it was a stone wall with large ditches in front of it and behind it that crossed the whole width of the island. Soldiers were garrisoned along the line of the wall in large forts, smaller milecastles and intervening turrets. In addition to the wall's defensive military role, its gates may have been customs posts. A significant portion of the wall still stands and can be followed on foot along the adjoining Hadrian's Wall Path. The largest Roman archaeological feature in Britain, it runs a total of in northern England. Regarded as a British cultural icon, Hadrian's Wall is one of Britain's major ancient tourist attra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Wall Of China
The Great Wall of China (, literally "ten thousand ''li'' wall") is a series of fortifications that were built across the historical northern borders of ancient Chinese states and Imperial China as protection against various nomadic groups from the Eurasian Steppe. Several walls were built from as early as the 7th century BC, with selective stretches later joined by Qin Shi Huang (220–206 BC), the first emperor of China. Little of the Qin wall remains. Later on, many successive dynasties built and maintained multiple stretches of border walls. The best-known sections of the wall were built by the Ming dynasty (1368–1644). Apart from defense, other purposes of the Great Wall have included border controls, allowing the imposition of duties on goods transported along the Silk Road, regulation or encouragement of trade and the control of immigration and emigration. Furthermore, the defensive characteristics of the Great Wall were enhanced by the construction of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fortification
A fortification is a military construction or building designed for the defense of territories in warfare, and is also used to establish rule in a region during peacetime. The term is derived from Latin ''fortis'' ("strong") and ''facere'' ("to make"). From very early history to modern times, defensive walls have often been necessary for cities to survive in an ever-changing world of invasion and conquest. Some settlements in the Indus Valley civilization were the first small cities to be fortified. In ancient Greece, large stone walls had been built in Mycenaean Greece, such as the ancient site of Mycenae (famous for the huge stone blocks of its ' cyclopean' walls). A Greek '' phrourion'' was a fortified collection of buildings used as a military garrison, and is the equivalent of the Roman castellum or English fortress. These constructions mainly served the purpose of a watch tower, to guard certain roads, passes, and borders. Though smaller than a real fortress, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terrain
Terrain or relief (also topographical relief) involves the vertical and horizontal dimensions of land surface. The term bathymetry is used to describe underwater relief, while hypsometry studies terrain relative to sea level. The Latin word (the root of ''terrain'') means "earth." In physical geography, terrain is the lay of the land. This is usually expressed in terms of the elevation, slope, and orientation of terrain features. Terrain affects surface water flow and distribution. Over a large area, it can affect weather and climate patterns. Importance The understanding of terrain is critical for many reasons: * The terrain of a region largely determines its suitability for human settlement: flatter alluvial plains tend to have better farming soils than steeper, rockier uplands. * In terms of environmental quality, agriculture, hydrology and other interdisciplinary sciences; understanding the terrain of an area assists the understanding of watershed boundaries, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
