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Quality circle: |
A
small group of people who normally work as a unit
and meet frequently for the purpose of uncovering
and solving problems with the quality of the items
produced, process capability or process control. |
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Quarter-decay ratio: |
Often considered to be the ultimate underdamped
response, quarter-decay ratios occur when the
amplitude of the subsequent period is one quarter of
that of the current period. |
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Ramp change: |
A
forcing function introduced on a system or process
input variable in which the level of the variable
changes according to a continuous slope. Although
not often used for testwork purposes, sometimes a
trend in an uncontrollable variable can be extracted
to represent a ramp change. |
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Rapid prototyping: |
A
series of approaches to obtaining an initial or
prototype of a part or assembly quickly. See, for
example, stereolithography. |
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Reaction curve: |
An
open loop test on a process in which the control
variable is allowed to change according to a step
change and the reaction of the process is measured.
Reaction curves provide information about delay
time, process time constant, and process gain. |
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Real time: |
Refers to tasks or functions executed so rapidly
that feedback is used to guide task completion. The
performance of computations concerning a physical
process such that the results are used to control
the process. |
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Re-engineering: |
The redefinition of a company's internal processes. |
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Reverse engineering: |
The process of dissecting how a product is
manufactured by taking it apart. |
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Regulator control: |
Method to study a control system response to a
change in load. |
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Response time: |
The length of time required for a system to arrive
at and remain within a set deviation (±X %) of the
final steady state value in a transient analysis. |
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Rise time: |
The length of time required for a system to first
arrive at the final steady state value in a
transient analysis. |
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Robotics: |
The study of the design and use of robots,
particularly for their use in manufacturing and
related processes. |
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Robustness: |
The ability of a system to remain stable over a
large range if changes in system inputs (loads and
set points). |
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Rule-based expert system: |
A
functional system in which knowledge is stored in
the form of simple if-then or condition-action
rules. |
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Sensor: |
A
transducer whose input is a physical phenomenon and
whose output is a quantitative measure of the
phenomenon. |
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Sequence control: |
The control of a series of machine movements, with
the completion of one movement initiating the next.
The extent of movements is typically not specified
by numerical input data. |
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Servo control: |
Method to study a control system response to a set
point change. |
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Servomechanism: |
An
automatic device for controlling large amounts of
power by means of small amounts of power. |
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Servomotor: |
A
power-driven mechanism supplementing a primary
control system operated by a comparatively feeble
force. |
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Set point: |
Input to a control system that is the desired level
of the output. |
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Simulation: |
(1) A device, system or computer program that
represents certain features of the behavior of a
physical or abstract system. Vendors of planning and
scheduling, forecasting and demand management, and
other types of decision support systems make growing
use of simulation to compare the consequences of
alternative courses of action. (2) A CAD/CAM program
that simulates the effect of structural, thermal or
kinematic conditions on a part under design. (3) The
use of a mathematical model to test various design
configurations. |
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Sine change: |
A
forcing function introduced on a system or process
input variable in which the level of the variable
changes by oscillating according to a sine wave.
This is done at a variety of frequencies to
determine the steady-state or frequency response
analysis. |
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Software: |
The entire set of programs, procedures and related
documentation associated with a computer. |
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Solid modelling: |
Three-dimensional modelling in which solid
characteristics of an object are built into the
database so that complex internal structures can be
realistically represented. |
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Stability: |
A
characteristic of a system in which the response
arrives at a steady state value with no further
oscillation in the case of a step input change or in
which the amplitude ratio of the frequency response
over the entire range of frequencies is less than
1.0. |
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Standardization: |
The promotion of conformity by means of a standard;
the establishment of criteria for uniform practices. |
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Statistical process control (SPC): |
A
quality control method to continuous monitor a
process rather than inspection of a finished
product, with the intent to achieve control of the
process and eliminate defective product. |
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Statistical quality control (SQC): |
A
procedure that applies the laws of probability and
statistical techniques to observed characteristics
of a product or process. |
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Step change: |
A
forcing function introduced on a system or process
input variable in which the level of the variable
changes instantaneously to a new steady state value.
This is done to determine the transient response of
a system. |
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Supervisory control: |
The use of microcomputers and workstations to
accomplish operator interface, data acquisition,
process monitoring and some degree of production
control. |
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Supervisory control and data acquisition (SCADA):
|
A
procedure accomplished in an industrial setting by
means of a microcomputer in which a data highway (or
DCS) provides set-point control through a
multi-variable software system. |
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Supply chain management: |
Use of information technology to endow automated
intelligence to an ever-growing network of cash
registers, delivery vehicles, distribution centres,
factories and raw material suppliers. In Australia,
the mining industry has set up a web site to manage
the purchasing and acquisition of supplies,
services, and materials across the industry. |
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System integration: |
Ability of computers, instrumentation and/or
equipment to share data or applications with other
system components. |
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System response: |
A
measure of how a system responds to a particular
input change. It may be a transient response to a
step or impulse change or a steady state response to
a ramp or sine wave change. |
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System transfer function: |
A
mathematical function that transforms an input
variable into the system output variable. |
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Throughput: |
(1) The rate at which work or production proceeds
through a manufacturing factory or processing plant.
(2) The rate at which information is processed
through a computer. |
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Time-based competition: |
The belief that the first producer and vendor of a
product has a significant market advantage, leading
companies to adapt their organization in a way to
minimize the time it takes to develop a product to
exploit this advantage. |
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Total quality management: |
A
holistic approach to quality control that stresses
the building of manufacturing processes that force
their users to confront quality problems, rather
than passing them on. |
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Transducer: |
A
device that converts signals from one form to
another. |
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Transient response: |
The response curve over time of a control system or
process reacting to a step change in the set point
or process load. |
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Transportation planning: |
A
computer program that optimizes assignments from
plants to distribution centres, and from
distribution centres to stores, by combining systems
to ensure the most economical means are employed on
a scale that no human planner could match. |
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Under-damped system: |
A
control system in which the transient response
oscillates around the final steady state value
before stabilizing. |
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Warehouse management systems: |
Software that integrates activities performed
mechanically and by humans with an information
system to effectively manage inventory processes and
direct warehouse activities. |
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Zeigler-Nichols rules: |
A
set of rules established in the 1940s to calculate
controller settings, proportional gain, integral
time constant, and derivative time constant, from
knowledge about system transient response variables
- dead time, process time constant, and process
gain. |