BicycleA bicycle, also called a pedal cycle, bike, push-bike or cycle, is a human-powered or motor-powered assisted, pedal-driven, single-track vehicle, having two wheels attached to a frame, one behind the other. A is called a cyclist, or bicyclist. Bicycles were introduced in the 19th century in Europe. By the early 21st century there were more than 1 billion. These numbers far exceed the number of cars, both in total and ranked by the number of individual models produced. They are the principal means of transportation in many regions.
MotionIn physics, motion is the phenomenon by which an object changes its position with respect to time. Motion is mathematically described in terms of displacement, distance, velocity, acceleration, speed, and frame of reference to an observer, measuring the change in position of the body relative to that frame with a change in time. The branch of physics describing the motion of objects without reference to their cause is called kinematics, while the branch studying forces and their effect on motion is called dynamics.
Bicycle lightingBicycle lighting is illumination attached to bicycles whose purpose above all is, along with reflectors, to improve the visibility of the bicycle and its rider to other road users under circumstances of poor ambient illumination. A secondary purpose is to illuminate reflective materials such as cat's eyes and traffic signs. A third purpose may be to illuminate the roadway so that the rider can see the way ahead. Serving the latter purposes require much more luminous flux and thus more power.
Bicycle infantryBicycle infantry are infantry soldiers who maneuver on (or, more often, between) battlefields using military bicycles. The term dates from the late 19th century, when the "safety bicycle" became popular in Europe, the United States, and Australia. Historically, bicycles lessened the need for horses, fuel and vehicle maintenance. Though their use has waned over the years in many armies, they continue to be used in unconventional armies such as militias.
Bicycle touringBicycle touring is the taking of self-contained cycling trips for pleasure, adventure or autonomy rather than sport, commuting or exercise. Bicycle touring can range from single-day trips to extended travels spanning weeks or months. Tours may be planned by the participant or organized by a tourism business, local club or organization, or a charity as a fund-raising venture. Historian James McGurn speaks of bets being taken in London in the 19th century for riders of hobby-horses – machines pushed by the feet rather than pedaled – outspeeding stagecoaches.
Bicycle frameA bicycle frame is the main component of a bicycle, onto which wheels and other components are fitted. The modern and most common frame design for an upright bicycle is based on the safety bicycle, and consists of two triangles: a main triangle and a paired rear triangle. This is known as the diamond frame. Frames are required to be strong, stiff and light, which they do by combining different materials and shapes. A frameset consists of the frame and fork of a bicycle and sometimes includes the headset and seat post.
Motion estimationMotion estimation is the process of determining motion vectors that describe the transformation from one 2D image to another; usually from adjacent frames in a video sequence. It is an ill-posed problem as the motion is in three dimensions but the images are a projection of the 3D scene onto a 2D plane. The motion vectors may relate to the whole image (global motion estimation) or specific parts, such as rectangular blocks, arbitrary shaped patches or even per pixel.
Circular motionIn physics, circular motion is a movement of an object along the circumference of a circle or rotation along a circular path. It can be uniform, with a constant angular rate of rotation and constant speed, or non-uniform with a changing rate of rotation. The rotation around a fixed axis of a three-dimensional body involves the circular motion of its parts. The equations of motion describe the movement of the center of mass of a body. In circular motion, the distance between the body and a fixed point on the surface remains the same.
Newton's laws of motionNewton's laws of motion are three basic laws of classical mechanics that describe the relationship between the motion of an object and the forces acting on it. These laws can be paraphrased as follows: A body remains at rest, or in motion at a constant speed in a straight line, unless acted upon by a force. When a body is acted upon by a force, the time rate of change of its momentum equals the force. If two bodies exert forces on each other, these forces have the same magnitude but opposite directions.
Utility bicycleA utility bicycle, city bicycle, urban bicycle, European city bike (ECB), Dutch bike, classic bike or simply city-bike, is a bicycle designed for frequent very short, very slow rides through very flat urban areas. It is a form of utility bicycle commonly seen around the world, built to facilitate everyday short-distance riding (no more than 5-6 km a day) in normal clothes in cold-to-mild weather conditions.
Motorized bicycleA motorized bicycle is a bicycle with an attached motor or engine and transmission used either to power the vehicle unassisted, or to assist with pedalling. Since it sometimes retains both pedals and a discrete connected drive for rider-powered propulsion, the motorized bicycle is in technical terms a true bicycle, albeit a power-assisted one. Typically they are incapable of speeds above , however in recent years larger motors have been built, allowing bikes to reach speeds of upwards of 72 km/h (45 mph).
Correspondence problemThe correspondence problem refers to the problem of ascertaining which parts of one image correspond to which parts of another image, where differences are due to movement of the camera, the elapse of time, and/or movement of objects in the photos.
Motion perceptionMotion perception is the process of inferring the speed and direction of elements in a scene based on visual, vestibular and proprioceptive inputs. Although this process appears straightforward to most observers, it has proven to be a difficult problem from a computational perspective, and difficult to explain in terms of neural processing. Motion perception is studied by many disciplines, including psychology (i.e. visual perception), neurology, neurophysiology, engineering, and computer science.
Motion captureMotion capture (sometimes referred as mo-cap or mocap, for short) is the process of recording the movement of objects or people. It is used in military, entertainment, sports, medical applications, and for validation of computer vision and robots. In filmmaking and video game development, it refers to recording actions of human actors and using that information to animate digital character models in 2D or 3D computer animation. When it includes face and fingers or captures subtle expressions, it is often referred to as performance capture.
Bicycle and motorcycle dynamicsBicycle and motorcycle dynamics is the science of the motion of bicycles and motorcycles and their components, due to the forces acting on them. Dynamics falls under a branch of physics known as classical mechanics. Bike motions of interest include balancing, steering, braking, accelerating, suspension activation, and vibration. The study of these motions began in the late 19th century and continues today.
Motion compensationMotion compensation in computing, is an algorithmic technique used to predict a frame in a video, given the previous and/or future frames by accounting for motion of the camera and/or objects in the video. It is employed in the encoding of video data for video compression, for example in the generation of MPEG-2 files. Motion compensation describes a picture in terms of the transformation of a reference picture to the current picture. The reference picture may be previous in time or even from the future.
Visual systemThe visual system comprises the sensory organ (the eye) and parts of the central nervous system (the retina containing photoreceptor cells, the optic nerve, the optic tract and the visual cortex) which gives organisms the sense of sight (the ability to detect and process visible light) as well as enabling the formation of several non-image photo response functions. It detects and interprets information from the optical spectrum perceptible to that species to "build a representation" of the surrounding environment.
Finding DoryFinding Dory is a 2016 American computer-animated comedy-drama adventure film produced by Pixar Animation Studios and released by Walt Disney Pictures. Directed by Andrew Stanton, produced by Lindsey Collins and written by Stanton and Victoria Strouse, the film is the sequel to Finding Nemo (2003). Ellen DeGeneres and Albert Brooks reprise their roles from the first film, with Hayden Rolence (replacing Alexander Gould), Ed O'Neill, Kaitlin Olson, Ty Burrell, Diane Keaton and Eugene Levy joining the cast.
Well-posed problemIn mathematics, a well-posed problem is one for which the following properties hold: The problem has a solution The solution is unique The solution's behavior changes continuously with the initial conditions Examples of archetypal well-posed problems include the Dirichlet problem for Laplace's equation, and the heat equation with specified initial conditions. These might be regarded as 'natural' problems in that there are physical processes modelled by these problems.
Motion controllerIn video games and entertainment systems, a motion controller is a type of game controller that uses accelerometers or other sensors to track motion and provide input. Motion controllers using accelerometers are used as controllers for video games, which was made more popular since 2006 by the Wii Remote controller for Nintendo's Wii console, which uses accelerometers to detect its approximate orientation and acceleration, and serves an image sensor, so it can be used as a pointing device.
