Redundancy physical

Protection System Independence. The protection system shall be designed to ensure that the effects of normal operations, AOEs, maintenance, testing, and DBAs on redundant channels do not result in loss of the protection function. Design techniques, such as redundancy, physical separation, functional diversity, or diversity in component design and principles of operation, shall be used to prevent loss of the protection function. The protection shall be sufficient to ensure no single failure results in loss of protection and capability exists to test channels independently to determine failures and loss of redundancy. 

Reactors are designed to be inherently safe based on physical principles, supplemented by redundant equipment and special procedures. Nuclear power benefits from the appHcation of the concept of defense in depth, ie, by using fuel form, reactor vessel, building containment, and emergency backup procedures to ensure safety. 

To reduce intensity effects, the data were normalized by reducing the area under each spectrum to a value of 1 [42]. Principal component analysis (PCA) was applied to the normalized data. This method is well suited to optimize the description of the fluorescence data sets by extracting the most useful data and rejecting the redundant ones [43]. From a data set, PCA assesses principal components and their corresponding spectral pattern. The principal components are used to draw maps that describe the physical and chemical variations observed between the samples. Software for PCA has been written by D. Bertrand (INRA Nantes) and is described elsewhere [44]. 

Filters are designed to remove unwanted information, but do not address the fact that processes involve few events monitored by many measurements. Many chemical processes are well instrumented and are capable of producing many process measurements. However, there are far fewer independent physical phenomena occurring than there are measured variables. This means that many of the process variables must be highly correlated because they are reflections of a limited number of physical events. Eliminating this redundancy in the measured variables decreases the contribution of noise and reduces the dimensionality of the data. Model robustness and predictive performance also require that the dimensionality of the data be reduced. 

An inherently safe plant1112 relies on chemistry and physics to prevent accidents rather than on control systems, interlocks, redundancy, and special operating procedures to prevent accidents. Inherently safer plants are tolerant of errors and are often the most cost effective. A process that does not require complex safety interlocks and elaborate procedures is simpler, easier to operate, and more reliable. Smaller equipment, operated at less severe temperatures and pressures, has lower capital and operating costs. 

Claims of commercial manufacturers notwithstanding, it is evident that pheromones do not function as behavioural releasers in humans in the same way as they do in other species. Instead of searching for specific reactions to purported human pheromones, it may be that these chemicals are better described as modulators (Jacob and McClintock 2000) which influence psychological states and, thereby, also influence behaviour in a variety of fashions depending on the situation in which they are experienced, or the accompanying cues. The co-occurrence of different cues can affect their interpretation (Rowe 1999). In humans, we know that odour cues provide non-redundant information about potential mates because, while both visual and olfactory cues may be used to gauge physical attractiveness, the information in each is not equivalent (Roberts, Little, Gosling, Jones, Perrett, Carter and Petrie 2005). 

The conclusions from this rather elementary survey of the symmetry constraint problem all point in the same general direction. The imposition of symmetry constraints (other than the Pauli principle) on a variationally-based model is either unnecessary or harmful. Far from being necessary to ensure the physical reality of the wave function, these constraints often lead to absurd results or numerical instabilities in the implementation. The spin eigenfunction constraint is only realistic when the electrons are in close proximity and in such cases comes out of the UHF calculation automatically. The imposition of molecular spatial symmetry on the AO basis is not necessary if that basis has been chosen carefully — i.e. is near optimum. Further, any breakdowns in the spatial symmetry of the AO basis are a useful indication that the basis has been chosen badly or is redundant. 

Furthermore, it follows from (8.2) that the money rate of profit is determined by the physical picture of the economy as represented by the technical coefficients and the real wage in the Sraffian price equation. Steedman (1977 66) argues that value magnitudes are irrelevant to the proximate determination of the profit rate and of production prices, and hence the labour theory of value is redundant. 

A traditional approach to fault diagnosis in the wider application context is based on hardware i.e. physical) redundancy methods which use multiple lines of sensors, actuators, computers and software to measure and/or control a particular variable. Typically, a voting scheme is applied to the hardware redundant system to decide if and when a fault has occurred and its likely location amongst redundant system components. The use of multiple redundancy in this way is common, for example with digital fly-by-wire flight control... 

Equations (17) and (18) allow one to link respectively (i) the dissolved CO2 concentration with the gas composition and the gas flow rate and (ii) the bicarbonate concentration with the gas composition, the gas flow rate and the pH. The estimated value can be then compared to the measured one to build a belief assignment with the same methodology and parameters than in the case of the strict physical redundancy. 

The presented approach has been applied on the process illustrated in Figure 8. In this case, several physical redundancy relations are available but the same method can be successfully applied with a standard instrumentation fulfilled by software sensors [17]. r, T2, rs, re, rr and ril are based on physical redundancy, r4 and rs on functional redundancy, rg, rg and riO are derived from dynamical modeling. As expressed in Table 2, there is not one single residual that is representative of a specific fault. A diagnosticability analysis of the signature table shows that among the 256 different states of the system ... 

The functional groups almost exclusively involved in NIRS are those involving the hydrogen atom C-H, N-H, O-H (see Figure 5.1). These groups are the overtones and combinations of their fundamental frequencies in the mid-infrared and produce absorption bands of useful intensity in the NIR. Because the absorptivi-ties of vibrational overtone and combination bands are so much weaker, in NIRS the spectra of condensed phase, physically thick samples, can be measured without sample dilution or the need to resort to difficult short-path length sampling techniques. Thus conventional sample preparation is redundant, and fortunately so, because most PAT applications require direct measurement of the sample " either in situ, or after extraction of the sample from the process in a fast loop or bypass. 

The design of most process plants relies on redundant safety features or layers of protection, such that multiple layers must fail before a serious incident occurs. Barrier analysis ) (also called Hazard-Barrier-Target Analysis, HBTA) can assist the identification of causal factors by identifying which safety feature(s) failed to function as desired and allowed the sequence of events to occur. These safety features or barriers are anything that is used to protect a system or person from a hazard including both physical and administrative layers of protection. The concepts of the hazard-barrier-target theory of incident causation are encompassed in this tool. (See Chapter 3.)... 

Two important remarks are in order here. The first is that eq. (3) does not impose any limitation on the degree of excitation of ([) , so that can be calculated whatever the composition and symmetry of Sq. In this way, even if eqs. (1), (2) and (4) assume a single reference determinant, the SDCI space that constitutes Sq can be built as a MR-SDCI and the procedure described above can be applied. The second is that care must be taken to remove the possible redundancies that could be present if Dj( i belongs to the model space Spg. In such a case, the physical effects included in each term of eq. (3) would be included twice in the diagonalization of H + A. ... 

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