Jerk (physics)In physics, jerk or jolt is the rate at which an object's acceleration changes with respect to time. It is a vector quantity (having both magnitude and direction). Jerk is most commonly denoted by the symbol j and expressed in m/s3 (SI units) or standard gravities per second (g0/s). As a vector, jerk j can be expressed as the first time derivative of acceleration, second time derivative of velocity, and third time derivative of position: Where: a is acceleration v is velocity r is position t is time Third-order differential equations of the form are sometimes called jerk equations.
Intersection numberIn mathematics, and especially in algebraic geometry, the intersection number generalizes the intuitive notion of counting the number of times two curves intersect to higher dimensions, multiple (more than 2) curves, and accounting properly for tangency. One needs a definition of intersection number in order to state results like Bézout's theorem. The intersection number is obvious in certain cases, such as the intersection of the x- and y-axes in a plane, which should be one.
Priority inversionIn computer science, priority inversion is a scenario in scheduling in which a high priority task is indirectly superseded by a lower priority task effectively inverting the assigned priorities of the tasks. This violates the priority model that high-priority tasks can only be prevented from running by higher-priority tasks. Inversion occurs when there is a resource contention with a low-priority task that is then preempted by a medium-priority task.
High-occupancy vehicle laneA high-occupancy vehicle lane (also known as an HOV lane, carpool lane, diamond lane, 2+ lane, and transit lane or T2 or T3 lanes) is a restricted traffic lane reserved for the exclusive use of vehicles with a driver and two or more passengers, including carpools, vanpools, and transit buses. These restrictions may be only imposed during peak travel times or may apply at all times. There are different types of lanes: temporary or permanent lanes with concrete barriers, two-directional or reversible lanes, and exclusive, concurrent, or contraflow lanes working in peak periods.
FlywheelA flywheel is a mechanical device which uses the conservation of angular momentum to store rotational energy; a form of kinetic energy proportional to the product of its moment of inertia and the square of its rotational speed. In particular, assuming the flywheel's moment of inertia is constant (i.e., a flywheel with fixed mass and second moment of area revolving about some fixed axis) then the stored (rotational) energy is directly associated with the square of its rotational speed.
