Statistical modelA statistical model is a mathematical model that embodies a set of statistical assumptions concerning the generation of sample data (and similar data from a larger population). A statistical model represents, often in considerably idealized form, the data-generating process. When referring specifically to probabilities, the corresponding term is probabilistic model. A statistical model is usually specified as a mathematical relationship between one or more random variables and other non-random variables.
Hot WheelsHot Wheels is an American brand of scale model cars invented by Elliot Handler and introduced by his company Mattel on May 18, 1968. It was the primary competitor of Matchbox until Mattel bought Matchbox owner Tyco Toys in 1997. Many automobile manufacturers have since licensed Hot Wheels to make scale models of their cars, allowing the use of original design blueprints and detailing. Although Hot Wheels were originally intended to be for children and young adults, they have become popular with adult collectors, for whom limited edition models are now made available.
Solar vehicleA solar vehicle or solar electric vehicle is an electric vehicle powered completely or significantly by direct solar energy. Usually, photovoltaic (PV) cells contained in solar panels convert the sun's energy directly into electric energy. The term "solar vehicle" usually implies that solar energy is used to power all or part of a vehicle's propulsion. Solar power may also be used to provide power for communications or controls or other auxiliary functions.
Off-road vehicleAn off-road vehicle (ORV), sometimes referred to as an off-highway vehicle (OHV), overland vehicle, or adventure vehicle, is considered to be any type of vehicle which is capable of driving off paved or gravel surfaces, such as trails and forest roads that have rough and low traction surfaces. These vehicles are generally characterized by having large tyres with deep, open treads, a flexible suspension, or even caterpillar tracks. Because of their versatility, several types of motorsports involve racing off-road vehicles.
Dual gaugeIn railway engineering, "gauge" is the transverse distance between the inner surfaces of the heads of two rails, which for the vast majority of railway lines is the number of rails in place. However, it is sometimes necessary for track to carry railway vehicles with wheels matched to two different gauges. Such track is described as dual gauge – achieved either by addition of a third rail, if it will fit, or by two additional rails. Dual-gauge tracks are more expensive to configure with signals and sidings, and to maintain, than two separate single-gauge tracks.
FrictionFriction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. There are several types of friction: Dry friction is a force that opposes the relative lateral motion of two solid surfaces in contact. Dry friction is subdivided into static friction ("stiction") between non-moving surfaces, and kinetic friction between moving surfaces. With the exception of atomic or molecular friction, dry friction generally arises from the interaction of surface features, known as asperities (see Figure 1).
Amphibious vehicleAn amphibious vehicle (or simply amphibian), is a vehicle that is a means of transport viable on land as well as on or under water. Amphibious vehicles include amphibious bicycles, ATVs, cars, buses, trucks, railway vehicles, combat vehicles and hovercraft. Classic landing craft are not amphibious vehicles as they do not offer any real land transportation at all, although they are part of amphibious warfare. Ground effect vehicles, such as ekranoplans, will likely crash on any but the flattest of landmasses so are also not considered to be amphibious vehicles.
Nonlinear systemIn mathematics and science, a nonlinear system (or a non-linear system) is a system in which the change of the output is not proportional to the change of the input. Nonlinear problems are of interest to engineers, biologists, physicists, mathematicians, and many other scientists since most systems are inherently nonlinear in nature. Nonlinear dynamical systems, describing changes in variables over time, may appear chaotic, unpredictable, or counterintuitive, contrasting with much simpler linear systems.
Glossary of rail transport termsRail terminology is a form of technical terminology. The difference between the American term railroad and the international term railway (used by the International Union of Railways and English-speaking countries outside the United States) is the most significant difference in rail terminology. These and other terms have often originated from the parallel development of rail transport systems in different parts of the world. In English-speaking countries outside the United Kingdom, a mixture of US and UK terms may exist.
Tsunami earthquakeIn seismology, a tsunami earthquake is an earthquake which triggers a tsunami of significantly greater magnitude, as measured by shorter-period seismic waves. The term was introduced by Japanese seismologist Hiroo Kanamori in 1972. Such events are a result of relatively slow rupture velocities. They are particularly dangerous as a large tsunami may arrive at a coastline with little or no warning. The distinguishing feature for a tsunami earthquake is that the release of seismic energy occurs at long periods (low frequencies) relative to typical tsunamigenic earthquakes.
