What is "blocking"

Block \Block\ (bl[o^]k), v. t. [imp. & p. p. Blocked (bl[o^]kt); p. pr. & vb. n. Blocking.] [Cf. F. bloquer, fr. bloc block. See Block, n.]

1. To obstruct so as to prevent passage or progress; to prevent passage from, through, or into, by obstructing the way; -- used both of persons and things; -- often followed by up; as, to block up a road or harbor; to block an entrance.

   With moles . . . would block the port.
   --Rowe.

   A city . . . besieged and blocked about.
   --Milton.

2. To secure or support by means of blocks; to secure, as two boards at their angles of intersection, by pieces of wood glued to each.

3. To shape on, or stamp with, a block; as, to block a hat.

4. to cause (any activity) to halt by creating an obstruction; as, to block a nerve impulse; to block a biochemical reaction with a drug.

   To block out, to begin to reduce to shape; to mark out roughly; to lay out; to outline; as, to block out a plan.

Blocking \Block"ing\, n.

1. The act of obstructing, supporting, shaping, or stamping with a block or blocks.

2. Blocks used to support (a building, etc.) temporarily.

1630s, verbal noun from present participle of block (v.). By 1891 in U.S. football; by 1961 in theater.

n. 1 The act by which something is blocked; an obstruction. 2 (context theater English) The precise movement and positioning of actors on a stage in order to facilitate the performance of a play, ballet, film or opera (originally planned using miniature blocks). 3 Blocks used to support (a building, etc.) temporarily. vb. (present participle of block English)

n. (American football) the act of obstructing someone's path with your body; "he threw a rolling block into the line backer" [syn: block, interference]

Blocking may refer to:

In martial arts, blocking is the act of stopping or deflecting an opponent's attack for the purpose of preventing injurious contact with the body. A block usually consists of placing a limb across the line of the attack.

In theatre, blocking is the precise staging of actors in order to facilitate the performance of a play, ballet, film or opera. The term derives from the practice of 19th-century theatre directors such as Sir W. S. Gilbert who worked out the staging of a scene on a miniature stage using blocks to represent each of the actors. (Gilbert's practice is depicted in Mike Leigh's 1999 film Topsy-Turvy.)

In contemporary theater, the director usually determines blocking during rehearsal, telling actors where they should move for the proper dramatic effect, ensure sight lines for the audience and work with the lighting design of the scene.

Each scene in a play is usually "blocked" as a unit, after which the director will move on to the next scene. The positioning of actors on stage in one scene will usually affect the possibilities for subsequent positioning unless the stage is cleared between scenes. During the blocking rehearsal, the assistant director, stage manager or director take notes about where actors are positioned and their movements on stage. It is especially important for the stage manager to note the actors' positions, as a director is not usually present for each performance, and it becomes the stage manager's job to ensure that actors follow the assigned blocking from night to night.

In film, the term is sometimes used to speak of the arrangement of actors in the frame. In this context, there is also a need to consider the movement of the camera as part of the blocking process (see Cinematography).

In the statistical theory of the design of experiments, blocking is the arranging of experimental units in groups (blocks) that are similar to one another.

In American football, blocking or interference (or running interference) is a legal move occurring when one player obstructs another player's path with his body. The purpose of blocking is to prevent defensive players tackling the ball carrier, or to protect the quarterback while attempting to pass or hand-off the ball. Offensive linemen and fullbacks tend to do the most blocking, although wide receivers are often asked to help block on running plays and halfbacks may be asked to help block on passing plays, while tight ends performs pass block and run block if they are not running routes to receive catches. As a general rule blocking is a push; one is not allowed to grasp someone or do any sort of pulling, and the hands must not be outside the line of each armpit, otherwise a holding penalty will be levied. Blocking is also not permitted beyond five yards from the line of scrimmage until the quarterback has handed-off the ball to a runner, or a receiver has touched the ball after it has been passed.

Outside sport, "running interference" is a metaphor that refers to a person's helping someone in the performance of a task without directly assisting in the task. Often this is done by attracting attention to oneself (so as to deflect attention from the other person) or throwing oneself into harm's way.

Blocking is a general, American English term for the use of short pieces (blocks) of dimensional lumber in wood framed construction. Uses include filling, spacing, joining, or reinforcing members. Blocking is typically made from short off-cuts or defective, warped pieces of lumber. Blocking is also sometimes used by people in construction with the sense of a shim or spacer. Names for similar materials in other forms of English include dwang, nog, noggin, and nogging.

In radio, and wireless communications in general, blocking is a condition in a receiver in which an off-frequency signal (generally further off-frequency than the immediately adjacent channel) causes the signal of interest to be suppressed.

Blocking rejection is the ability of a receiver to tolerate an off-frequency signal and avoid blocking. A good automatic gain control design is part of achieving good blocking rejection.

In knitting, crochet and other textile arts, blocking is a final stage of handmade textile production that adjusts the shape of the finished piece. Not all pieces need blocking; however, blocking is standard for lace work and is not uncommon in sweaters, socks, and other solid projects. Through heat and moisture, blocking sets the stitches and standardizes the final dimensions, and may enhance the drape. Hand manufacture places natural stresses on fabrics that may result in deviations from its intended shape and size. Blocking is only effective on natural fibres but a technique called "killing" may be used on synthetic fibres to achieve an effect similar to blocking.

The degree of malleability is determined by the type of yarn used, with wool providing the most flexibility. For projects that are produced in sections, blocking is normally done prior to final assembly.

Blocking is an animation technique in which key poses are created to establish timing and placement of characters and props in a given scene or shot. This technique is most commonly used in 3D computer animation.

Blocking is often the first step in the pose-to-pose style of animating, as opposed to the straight-ahead style of animation (though it sometimes plays a role in straight-ahead as well). Blocking poses are not necessarily exclusively keyframes. Blocked-in poses may also include important in-betweens, extremes, and breakdowns necessary to establishing the flow and timing of a particular shot.

In 3D, the animation curves of a blocked shot are often created using "stepped" or "square" tangencies, which provides no interpolation between animation poses. This allows the animator to see the poses of the animation without any strange and/or unintentional automatic interpolation. While this is sometimes problematic due to gimbal lock, seeing the poses in this way allows the animator to adjust the timing of an animation quickly, without the distraction of the software's automatic interpolation.

Category:Animation techniques

In computing, a process is an instance of a computer program that is being executed. A process always exists in exactly one process state. A process that is blocked is one that is waiting for some event, such as a resource becoming available or the completion of an I/O operation.

In a multitasking computer system, individual tasks, or threads of execution, must share the resources of the system. These resources might be:

• the CPU
• network
• memory
• disk

When one task is using a resource, it is generally not possible, or desirable, for another task to access it. The techniques of mutual exclusion are used to prevent this concurrent use. When the other task is blocked, it is unable to execute until the first task has finished using the shared resource.

Programming languages and scheduling algorithms are designed to minimize the over-all effect blocking. A process that blocks may prevent local work-tasks from progressing. In this case "blocking" often is seen as not wanted. However, such work-tasks may instead have been assigned to independent processes, where halting one has no or little effect on the others, since scheduling will continue. An example is "blocking on a channel" where passively waiting for the other part (no polling or spin loop) is part of the semantics of channels. Correctly engineered any of these may be used to implement reactive systems.

Deadlock means that processes pathologically wait for each other in a circle. As such it is not directly associated with blocking.

Once the event occurs for which the process is waiting ("is blocked on"), the process is advanced from blocked state to an imminent one, such as runnable.

In public transport, blocking is the practice of dividing the parts of a scheduled route among vehicles and drivers. It follows the process of dividing the route into trips. In blocking, these trips are pieced together into blocks that are relatively contiguous in space and time. The goal of blocking is to optimize the schedule such that:

• Drivers can start and end their shift in the same place.
• Off-route travel costs are minimized.
• Layover time is minimized, while allowing drivers adequate time for breaks.
• Vehicles are not switching routes too frequently, which can confuse passengers.

Category:Scheduling (transportation) Category:Public transport

In linguistics, blocking refers to the morphological phenomenon in which a possible form for a word cannot surface because it is "blocked" by another form whose features are the most appropriate to the surface form's environment. More basically, it may also be construed as the "non-occurrence of one form due to the simple existence of another."

Word formation employs processes such as the plural marker in English s or es (e.g. dog and dogs or wish and wishes). This plural marker is not, however, acceptable on the word child (as in *childs), because it is "blocked" by the presence of the competing form children, which in this case inherits features from an older morphological process.

One promising approach to blocking effects is that of distributed morphology, which asserts that semantic and syntactic features create slots or cells in which items can appear. Blocking happens when one cell is engaged by one form as opposed to another. Blocking has been explained along two primary dimensions: the size of the blocking object, and the existence of ungrammatical forms.