Uncontrolled inputs

Altered release. Tetanus is an infectious disease caused by the bacterium Clostridium tetani. This bacterium produces a neurotoxin active on inhibitory synapses in the spinal cord. Motor neurons, which supply skeletal muscle and cause contraction, have cell bodies that lie in the spinal cord. Under normal circumstances, these motor neurons receive excitatory and inhibitory inputs from various sources. The balance of these inputs results in the appropriate degree of muscle tone or muscle contraction. Tetanus toxin prevents the release of gamma amino butyric acid (GABA), an important neurotransmitter active at these inhibitory synapses. Eliminating inhibitory inputs results in unchecked or unmodulated excitatory input to the motor neurons. The resulting uncontrolled muscle spasms initially occur in the muscles of the jaw, giving rise to the expression lockjaw. The muscle spasms eventually... 

PCP intoxication is unpredictable, and talk-down therapy is not recommended. Sensory input should be minimized. Antianxiety and/or antipsychotic drug therapy may be necessary if behavior is uncontrollable. 

The occurrence of an abnormal energy input that is sufficient to initiate an uncontrolled self-reaction... 

A fault is understood as an unpermitted deviation of at least one characteristic property or parameter of the system from the acceptable, usual or standard condition. A fault can stem from several origins as depicted by the Figure 1. It can be caused by an unexpected perturbation i.e., a major deviation from one input acting on the system) or by a disturbance i.e., the action of an unknown and uncontrolled input on the system). Another fault origin can be an error of any sensor or actuator, which is a deviation between the measured and the true or specified value. 

In most research and development projects it is important that as many factors as possible be known. Unknown factors can be the witches and goblins of many projects - unknown factors are often uncontrolled, and as a result such systems appear to behave excessively randomly and erratically. Because of this, the initial phase of many research and development projects consists of screening a large number of input variables to see if they are factors of the system that is, to see if they have an effect on the system. 

To simplify the presentation of this chapter, we will look only at variation in the level of measured system outputs, but the same approach can also be applied to variation in the level of measured system inputs. We will assume that all controllable inputs (known and unknown) are fixed at some specified level (see Figure 3.1). Any variation in the output from the system will be assumed to be caused by variation in the uncontrolled inputs (known and unknown) or by small, unavoidable variations about the set levels of the controlled inputs [Davies (1956)]. 

A factor is defined as one of the variables contributing to a particular result or situation. It is an input variable that has (or may have) an influence upon the system. Factors can be controlled or uncontrolled by the experimenter. Controlled factors are identified experimental conditions... 

In dry climates such as South European countries, the low and infrequent precipitations hamper the wash-out and the moistening of road surface, favouring road dust resuspension by traffic-induced turbulence. Moreover additional inputs of dust come from the urban soil resuspension due to the little vegetal covering and from sporadic intensive deposition of Saharan dust outbreaks or uncontrolled construction/demolition activities. 

Input variables are controllable, uncontrollable and disturbance variables. Controllable variables or factors X1 X2,..., X are variables, that can be directed or that can affect the research subject in order to change the response. They can be numerical (example temperature) or categorical (example raw material supplier). Uncontrollable variables Z1 Z2,..., Zp are measured and controlled during the experiment but they cannot be changed at our wish. They can be a major cause for variability in the responses. Other sources of variability are deviations around the set points of the controllable factors, plus sampling and measurement error. Furthermore, the system itself may be composed of parts that also exhibit variability. Disturbance, non controlled variables Wi, W2,..., Wq are immeasurable and their values are randomly changed in time. 

The referral form also includes check boxes for the physician to mark the appropriate ICD-9-CM codes. For diabetes education, he includes the common ICD-9 codes 250.00 (i.e., uncomplicated type 2 diabetes, controlled), 250.02 (i.e., uncomplicated type 2 diabetes, uncontrolled), and an Other field with room for the physician to add a more specific code (Buck and Lockyear, 2007). For the hyperlipidemia component, he has also included the common codes used to describe these conditions. Within the referral form is the statement of medical necessity and contact information for the physician and patients to reach the pharmacy to make appointments. Although Dr. Brouchard likes the form that he has created, he plans on revising the form based on his experience and input from the physicians office after a few months of use. He wants to make sure that the referral form is as easy to use as possible and that it contains most of the information he needs to submit claims successfully. 

The detailed analysis of the different sub-processes of the boiler, as summarized in Figure 3, shows that the two largest dissipations are due to the uncontrolled kinetics of combustion (26.2% of the total exergy input), and heat transfer (34.5%) as heat passes from hot products at a high average (1 - Tq/T) to liquid and gaseous H2O with a relative low average (1 - Tq/T). 

Care should also be taken to ensure that GxP data are not being extracted from the application manipulated in an uncontrolled manner by another application, and then input back into the original application. Situations such as this destroy the data traceability necessary to meet regulatory requirements. They often arise because users have developed a local workaround to a system problem rather than reporting the issue and getting it resolved and fixed properly by the nominated support team. 

Assuming that the effect of control in steady state is defined by a set of controller setpoints and fixed values for a subset of uncontrolled inputs, it is appropriate to use a worst-case design formulation in which a single choice of p is required to accommodate all possible values of the uncertain parameters. In other words, the only steady-state adaptation to uncertainty is that implicit in the choice of controller setpoints. This is potentially conservative however, it is a fair approximation to industrial practice, where minimizing the need for... 

The procedure identify-nondissipative-pathways constructs the set of enabling conditions that lead to a top-level event. It takes as its input the variable-influence pathways, which it obtains from the procedure, construct-variable-influence-pathways. TLE variables are then identified, and each variable contained in the set is traced to identify potentially feasible roots for causing the TLE. When an achievable root is identified (i.e., an input disturbance, controlled or uncontrolled, which can enable the top-level event), it is collected into root causes and returned. The algorithm used by this procedure is shown below ... 

PCP intoxication is more unpredictable and more difficult to treat than other psychosis-producing drugs. Most clinicians suggest that sensory input be minimized to the extent possible thus talk-down therapy is not recommended and may in fact make the patient worse. If PCP intoxication is suspected, patients should be left alone in a quiet, dimly lit room. If behavior is uncontrollable, antianxiety and/or antipsychotic drug therapy may be necessary. 

With these conditions and c [uestions in mind, why is P more often limiting in lakes than on land, at least in the temperate zone P limits lake productivity because (a) unlike C and N, there are no mechanisms that can increase inputs of P when it is in short supply, as discussed above (b) P is relatively immobile within and through terrestrial ecosystems, so inputs of P to lakes are small and (c) lakes have an uncontrollable loss of P, in the sinking of particulate organic matter out of the euphotic zone. 

---