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Simulation Sickness
Simulator sickness is a subset of motion sickness that is typically experienced while playing video games from first-person perspective. It was discovered in the context of aircraft pilots who undergo training for extended periods of time in flight simulators. Due to the spatial limitations imposed on these simulators, perceived discrepancies between the motion of the simulator and that of the vehicle can occur and lead to simulator sickness. It is similar to motion sickness in many ways, but occurs in simulated environments and can be induced without actual motion. Symptoms of simulator sickness include discomfort, apathy, drowsiness, disorientation, fatigue, and nausea. These symptoms can reduce the effectiveness of simulators in flight training and result in systematic consequences such as decreased simulator use, compromised training, ground safety, and flight safety. Pilots are less likely to want to repeat the experience in a simulator if they have suffered from simulator sick ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motion Sickness
Motion sickness occurs due to a difference between actual and expected motion. Symptoms commonly include nausea, vomiting, cold sweat, headache, dizziness, tiredness, loss of appetite, and increased salivation. Complications may rarely include dehydration, electrolyte problems, or a lower esophageal tear. The cause of motion sickness is either real or perceived motion. This may include car travel, air travel, sea travel, space travel, or reality simulation. Risk factors include pregnancy, migraines, and Ménière's disease. The diagnosis is based on symptoms. Treatment may include behavioral measures or medications. Behavioral measures include keeping the head still and focusing on the horizon. Three types of medications are useful: antimuscarinics such as scopolamine, H1 antihistamines such as dimenhydrinate, and amphetamines such as dexamphetamine. Side effects, however, may limit the use of medications. A number of medications used for nausea such as ondansetro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semicircular Canal
The semicircular canals are three semicircular interconnected tubes located in the innermost part of each ear, the inner ear. The three canals are the lateral, anterior and posterior semicircular canals. They are the part of the bony labyrinth, a periosteum-lined cavity on the petrous part of the temporal bone filled with perilymph. Each semicircular canal contains its respective semicircular duct, i.e. the lateral, anterior and posterior semicircular ducts, which provide the sensation of angular acceleration and are part of the membranous labyrinth—therefore filled with endolymph. Structure The semicircular canals are a component of the bony labyrinth that are at right angles from each other and contain their respective semicircular duct. At one end of each of the semicircular ducts is a dilated sac called a membranous ampulla, which is more than twice the diameter of the ducts. Each ampulla contains an ampullary crest, the crista ampullaris which consists of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salivation
Saliva (commonly referred as spit or drool) is an extracellular fluid produced and secreted by salivary glands in the mouth. In humans, saliva is around 99% water, plus electrolytes, mucus, white blood cells, epithelial cells (from which DNA can be extracted), enzymes (such as lingual lipase and amylase), and antimicrobial agents (such as secretory IgA, and lysozymes). The enzymes found in saliva are essential in beginning the process of digestion of dietary starches and fats. These enzymes also play a role in breaking down food particles entrapped within dental crevices, thus protecting teeth from bacterial decay. Saliva also performs a lubricating function, wetting food and permitting the initiation of swallowing, and protecting the oral mucosa from drying out. Saliva has specialized purposes for a variety of animal species beyond predigestion. Certain swifts construct nests with their sticky saliva. The foundation of bird's nest soup is an aerodramus nest. Venomous sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nausea
Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. It can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the throat. Over 30 definitions of nausea were proposed in a 2011 book on the topic. Nausea is a non-specific symptom, which means that it has many possible causes. Some common causes of nausea are gastroenteritis and other gastrointestinal disorders, food poisoning, motion sickness, dizziness, migraine, fainting, low blood sugar, anxiety, hyperthermia, dehydration and lack of sleep. Nausea is a side effect of many medications including chemotherapy, or morning sickness in early pregnancy. Nausea may also be caused by disgust and depression. Medications taken to prevent and treat nausea and vomiting are called antiemetics. The most commonly prescribed antiemetics in the US are promethazine, metoclopramide, and the newer ondansetron. The word na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Six Degrees Of Freedom
Six degrees of freedom (6DOF), or sometimes six degrees of movement, refers to the six mechanical degrees of freedom of movement of a rigid body in three-dimensional space. Specifically, the body is free to change position as forward/backward (surge), up/down (heave), left/right (sway) translation in three perpendicular axes, combined with changes in orientation through rotation about three perpendicular axes, often termed yaw (normal axis), pitch (transverse axis), and roll (longitudinal axis). Three degrees of freedom (3DOF), a term often used in the context of virtual reality, typically refers to tracking of rotational motion only: pitch, yaw, and roll. Robotics Serial and parallel manipulator systems are generally designed to position an end-effector with six degrees of freedom, consisting of three in translation and three in orientation. This provides a direct relationship between actuator positions and the configuration of the manipulator defined by its forwa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotary-wing Aircraft
A rotary-wing aircraft, rotorwing aircraft or rotorcraft is a heavier-than-air aircraft with rotary wings that spin around a vertical mast to generate lift. Part 1 (Definitions and Abbreviations) of Subchapter A of Chapter I of Title 14 of the U. S. Code of Federal Regulations states that rotorcraft "means a heavier-than-air aircraft that depends principally for its support in flight on the lift generated by one or more rotors." The assembly of several rotor blades mounted on a single mast is referred to as a rotor. The International Civil Aviation Organization (ICAO) defines a rotorcraft as "supported in flight by the reactions of the air on one or more rotors". Rotorcraft generally include aircraft where one or more rotors provide lift throughout the entire flight, such as helicopters, gyroplanes, autogyros, and gyrodynes Compound rotorcraft augment the rotor with additional thrust engines, propellers, or static lifting surfaces. Some types, such as helicopters, are capable ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fixed-wing Aircraft
A fixed-wing aircraft is a heavier-than-air aircraft, such as an airplane, which is capable of flight using aerodynamic lift. Fixed-wing aircraft are distinct from rotary-wing aircraft (in which a rotor mounted on a spinning shaft generates lift), and ornithopters (in which the wings oscillate to generate lift). The wings of a fixed-wing aircraft are not necessarily rigid; kites, hang gliders, variable-sweep wing aircraft, and airplanes that use wing morphing are all classified as fixed wing. Gliding fixed-wing aircraft, including free-flying gliders and tethered kites, can use moving air to gain altitude. Powered fixed-wing aircraft (airplanes) that gain forward thrust from an engine include powered paragliders, powered hang gliders and ground effect vehicles. Most fixed-wing aircraft are operated by a pilot, but some are unmanned or controlled remotely or are completely autonomous (no remote pilot). History Kites Kites were used approximately 2,800 years ago ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Psyche (psychology)
The psyche is currently used to describe the totality of the human mind, conscious and unconscious. Especially in older texts, the English word soul is sometimes used synonymously. ''Psychology'' is the scientific or objective study of the psyche. The word has a long history of use in psychology and philosophy, dating back to ancient times, and represents one of the fundamental concepts for understanding human nature from a scientific point of view. Etymology The basic meaning of the Greek word ψυχή (''psyche'') was 'life'. Although unsupported, some have claimed it is derived from the verb ψύχω (''psycho'', 'to blow'). Derived meanings included 'spirit', 'soul', 'ghost', and ultimately 'self' in the sense of 'conscious personality' or 'psyche'. Ancient psychology The idea of the psyche is central to the philosophy of Plato. Scholars translate the Platonic conceptualization of the term as "soul" in the sense that he believed that it is immortal. In his Phaedo, Pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UH-60 Blackhawk
The Sikorsky UH-60 Black Hawk is a four-blade, twin-engine, medium-lift military utility helicopter manufactured by Sikorsky Aircraft. Sikorsky submitted a design for the United States Army's Utility Tactical Transport Aircraft System (UTTAS) competition in 1972. The Army designated the prototype as the ''YUH-60A'' and selected the Black Hawk as the winner of the program in 1976, after a fly-off competition with the Boeing Vertol YUH-61. Named after the Native American war leader Black Hawk, the UH-60A entered service with the U.S. Army in 1979, to replace the Bell UH-1 Iroquois as the Army's tactical transport helicopter. This was followed by the fielding of electronic warfare and special operations variants of the Black Hawk. Improved UH-60L and UH-60M utility variants have also been developed. Major variants include the Navy's SH-60 Seahawk, the Air Force's HH-60 Pave Hawk, the Coast Guard's MH-60 Jayhawk and the civilian S-70. In addition to use by U.S. armed forc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
US Army
The United States Army (USA) is the primary land service branch of the United States Department of Defense. It is designated as the Army of the United States in the United States Constitution.Article II, section 2, clause 1 of the United States Constitution (1789).See alsTitle 10, Subtitle B, Chapter 301, Section 3001 It operates under the authority, direction, and control of the United States secretary of defense. It is one of the six armed forces and one of the eight uniformed services of the United States. The Army is the most senior branch in order of precedence amongst the armed services. It has its roots in the Continental Army, formed on 14 June 1775 to fight against the British for independence during the American Revolutionary War (1775–1783). After the Revolutionary War, the Congress of the Confederation created the United States Army on 3 June 1784 to replace the disbanded Continental Army.Library of CongressJournals of the Continental Congress, Volume 27/ref> Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
US Coast Guard
The United States Coast Guard (USCG) is the maritime security, search and rescue, and law enforcement service branch of the armed forces of the United States. It is one of the country's eight uniformed services. The service is a maritime, military, multi-mission service unique among the United States military branches for having a maritime law enforcement mission with jurisdiction in both domestic and international waters and a federal regulatory agency mission as part of its duties. It is the largest coast guard in the world, rivaling the capabilities and size of most navies. The U.S. Coast Guard protects the United States' borders and economic and security interests abroad; and defends its sovereignty by safeguarding sea lines of communication and commerce across U.S. territorial waters and its Exclusive Economic Zone. Due to ever-expanding risk imposed by transnational threats through the maritime and cyber domains, the U.S. Coast Guard is at any given time deployed to a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
US Navy
The United States Navy (USN) is the naval warfare, maritime military branch, service branch of the United States Department of Defense. It is the world's most powerful navy with the largest Displacement (ship), displacement, at 4.5 million tons in 2021. It has the world's largest aircraft carrier fleet, with List of aircraft carriers in service, eleven in service, one undergoing trials, two new carriers under construction, and six other carriers planned as of 2024. With 336,978 personnel on active duty and 101,583 in the Ready Reserve, the U.S. Navy is the third largest of the United States military service branches in terms of personnel. It has 299 deployable combat vessels and about 4,012 operational aircraft as of 18 July 2023. The U.S. Navy is one of six United States Armed Forces, armed forces of the United States and one of eight uniformed services of the United States. The United States Navy traces its origins to the Continental Navy, which was established during ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
