Pressure Bias

Pressure bias is a confluence of external influences that exerts pressure on the decision makers to discount the fidelity of information that, in the absence of that pressure, may cause them to make different decisions than those chosen. These pressures may originate from several sources ... 

In addition, bias played a role in the systemic management deficiencies desaibed in the ensuing investigative reports, hearings, and press conferences. These deficiencies contributed to the safety breakdown that caused this event. Specifically, feedback bias and pressure bias were clearly present. 

The Shuttle Challenger disaster represents a real-world example in which an organization, NASA, allowed the bridge between systems engineering and safety that had existed throughout NASA s history, from Mercury to Gemini to Apollo and on to the early development of the shuttle, to collapse. The Safety Breakdown Theory in this case was the result of several biases that contributed to the failure. As described in Chapter 6, The Glismann Effect—in the form of Pressure bias. Feedback bias, and Availability bias—was obviously present ... 

Uncontrolled Variables and Randomization. A number of further variables, such as ambient conditions (temperature, pressure, etc), can be identified but not controlled, or are only ha2ily identified or not identified at all but affect the results of the experiment. To ensure that such uncontrolled variables do not bias the results, randomisation is introduced in various ways into the experiment to the extent that this is practical. 

Mathematical Consistency Requirements. Theoretical equations provide a method by which a data set s internal consistency can be tested or missing data can be derived from known values of related properties. The abiUty of data to fit a proven model may also provide insight into whether that data behaves correctiy and follows expected trends. For example, poor fit of vapor pressure versus temperature data to a generally accepted correlating equation could indicate systematic data error or bias. A simple sermlogarithmic form, (eg, the Antoine equation, eq. 8), has been shown to apply to most organic Hquids, so substantial deviation from this model might indicate a problem. Many other simple thermodynamics relations can provide useful data tests (1—5,18,21). 

A master controller is necessary to control a single steam header pressure from multiple parallel boilers. The boilers are increased or decreased in load together. There is a bias station at each boiler if uneven response is desired. The boiler master, a widely used device, can... 

By being independent of the audited activities, the auditor is unaware of the pressures, the excuses, the informal instructions handed down and can examine operations objectively without bias and without fear of reprisals. It is for this reason that it was considered appropriate for the auditor to have no direct responsibility for the work being audited i.e. audits carried out by a manager, supervisor, or foreman of his/her own department or section do not qualify as internal quality audits in ISO 9001 1994. However, they will qualify under ISO 9000 2000. 

Figure 12-2C. Dry vacuum pump cyiinder for very iow absoiute suction pressures. Vaives in heads for iow ciearance and high voiumetric efficiency. (Used by permission Bui. L-679-BiA, 1957. Dresser-Rand Company.)...

This concept is demonstrated schematically in Figure 1.11. It can be seen that the initial bias in a system of proteins containing two conformations (square and spherical) lies far toward the square conformation. When a ligand (filled circles) enters the system and selectively binds to the circular conformations, this binding process removes the circles driving the backward reaction from circles back to squares. In the absence of this backward pressure, more square conformations flow into the circular state to fill the gap. Overall, there is an enrichment of the circular conformations when unbound and ligand-bound circular conformations are totaled. 

Figure 1(a) shows the etch rates of niobium oxide pillar and Si film, and the etch selectivity of Si to niobium oxide as a function of CI2 concentration. The etch condition was fixed at coil rf power of 500 W, dc-bias to substrate to 300 V and gas pressure of 5 mTorr. As the CI2 concentration increased, the etch rate of niobium oxide pillar gradually decreased while Si etch rate increased. It indicates that the etch mechanism of niobium oxide in Cl2/Ar gas is mainly physical sputtering. As a result, the etch selectivity of Si film to niobium oxide monotonously increased. The effect of coil rf power on the etch rate and etch selectivity was examined as shown in Fig. 1(b). As the coil rf power increased, the etch rates of niobium oxide and Si increased but the etch rate of niobium oxide showed greater increase than that of Si. It is attributed to the increase of ion density with increasing coil rf power. Figure 1 (c)... 

Fig. 2. FESEM images of (a) niobium oxide arrays before etching, and of Si nanodot arrays etched for (b) 20 s and (c) 30 s at 20% CI2, 500 W coil rf power, 300 V dc-bias voltage and 5 mTorr gas pressure...

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