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Positive control, the air traffic control practice of controlling aircraft whose positions are determined by direct radar observation; Positive control in dog handling: affirmative physical or non-physical control of a dog (as in using proper leash handling technique or having successfully trained a dog with vocal commands by operant conditioning).
The positive control should give a large amount of enzyme activity, while the negative control should give very low to no activity. If the positive control does not produce the expected result, there may be something wrong with the experimental procedure, and the experiment is repeated.
Positive feedback in chemical reactions can increase the rate of reactions, and in some cases can lead to explosions. Positive feedback in mechanical design causes tipping-point, or over-centre, mechanisms to snap into position, for example in switches and locking pliers. Out of control, it can cause bridges to collapse.
The true positive in this figure is 6, and false negatives of 0 (because all positive condition is correctly predicted as positive). Therefore, the sensitivity is 100% (from 6 / (6 + 0) ). This situation is also illustrated in the previous figure where the dotted line is at position A (the left-hand side is predicted as negative by the model ...
Positive feedback occurs when the fed-back signal is in phase with the input signal. Under certain gain conditions, positive feedback reinforces the input signal to the point where the output of the device oscillates between its maximum and minimum possible states. Positive feedback may also introduce hysteresis into a circuit. This can cause ...
Such a test or clinical trial is called a placebo-controlled study, and its control is of the negative type. A study whose control is a previously tested treatment, rather than no treatment, is called a positive-control study, because its control is of the positive type. Government regulatory agencies approve new drugs only after tests ...
In addition, some gloveboxes are configured to use positive pressure, which can increase the risk of leaks. [11]: 24–28 Another non-ventilation control used in this industry is the continuous liner system, which allows the filling of product containers while enclosing the material in a polypropylene bag. This system is often used for off ...
Positive train control (PTC) is a family of automatic train protection systems deployed in the United States. [1] Most of the United States' national rail network mileage has a form of PTC. These systems are generally designed to check that trains are moving safely and to stop them when they are not.