Quantitative assessment, description

The uncertainties in human error rates may be within the stated uncertainty bounds, but such is not demonstrated from sparse experiments. Both the qualitative description of the human interaction logic and the quantitative assessment of those actions rely on the virtually untested judgment of experts. 

The term operability study should more properly be used for this type of study, though it is usually referred to as a hazard and operability study, or HAZOP study. This can cause confusion with the term hazard analysis , which is a technique for the quantitative assessment of a hazard, after it has been identified by an operability study, or similar technique. Numerous books have been written illustrating the use of HAZOP. Those by Hyatt (2003), AIChemE (2000), Taylor (2000) and Kletz (1999a) give comprehensive descriptions of the technique, with examples. 

The link between the ecological/ecotoxicological risk assessment and the risk management frameworks is demonstrated. The ecological risk assessment consists of seven interactive elements (Fig. 17). The quantitative and descriptive science used to conduct ERA (Table 5) does not answer, in a direct way, the question of what should be done to manage the risk. Science determines adversity, but the public determines acceptability (Fig. 18). But acceptable risk is a highly subjective and relative term. It is time and space-specific and depends upon definitions of quality of life and robustness of the environment. 

For those substances for which appropriate human smdies are available, the so-called average relative risk model has been used. Quantitative assessments using this model comprises four steps (1) selection of studies (2) standardized description of study results in terms of relative risk, exposure level, and duration of exposure (3) extrapolation towards zero dose and (4) application to a general (hypothetical) population. 

The originality of this present edition lies in a comprehensive presentation of the modem concepts of PolyP biochemistry, including a comparative description of PolyP metabolism in prokaryotes and eukaryotes, i.e. the role of these compounds in the cells of organisms at different stages of evolution, and offers a critical analysis of the methods of isolation and quantitative assessment of these compounds and methods of studying PolyP-dependent enzymes. The contemporary literature on these problems is presented to its maximal extent. The book may therefore serve as a manual for researchers in this field, and in particular, as a textbook. 

An essential beginning in a comprehensive and quantitative assessment of the kinetics of colloid chemical processes is the speciation at a surface that results from the reactions of solutes with surface sites. In some cases this formulation has been accomplished by a description of surface charge, but the diversity of solids and solutes in aquatic systems necessitates a broader assessment. An example is the adsorption of selenite on t lie surface of goclhite (Hayes et al., 1987) in which a... 

Yamanaka has attempted to use the relative cross-reactivities between cytochromes c of one organism and cytochrome oxidases of another to make a quantitative assessment of evolutionary similarity 440,442,44, and earlier references cited therein). If this method were successful, it would be a powerful adjunct to sequence and structure comparisons since far less material and labor are required to make an activity measurement than to carry out an amino acid sequence analysis or X-ray diffraction study. One critical requirement, of course, is that only strictly homologous proteins are compared. If noncorresponding proteins in two organisms are compared, a spurious estimate of their unrelatedness would be obtained. It is in this context that Yamanaka emphasized the need for a descriptive term for what we have called eukaryotic c. ... 

During site characterization phase, additional measurements are made to improve the preliminary assessment ofthe performance of the site, based. on the corresponding data/ knowledge gaps identified in the site selection phase. A static (descriptive) model is built and dynamic simulations are run to quantitatively assess the asset performance and the potential risks. At this stage, the aim of the characterization program is to provide enough information about subsurface properties and structure to evaluate with confidence... 

An Estimation of the Uncertainty in the Data. With regard to the data sets in the database, a specific quantitative assessment is required as to the uncertainty in the dependent and independent variables. Whenever possible, this information should be contained in the database description. 

Part 2 and its chapters presented the topic of human lead exposure in global and categorical terms, addressing the technical areas of lead intakes, uptakes (absorption), toxicokinetics, integration of toxicokinetics into in vivo disposition in a manner allowing quantitative assessments of lead exposure, etc. In contrast to these broadly descriptive aspects of human Pb exposme, the applied health discipline of quantitative risk assessment requires prescriptive approaches for site-specific, case-specific, and environmental scenario-specific lead exposure characterizations. Data from such specific exposure characterizations are combined with available data for lead dose—response relationships to arrive at some quantitative risk characterization indexed as some endpoint for human health risk. 

Shape of particles may be assessed descriptively by terms such as spherical, elongated, acicular, angular, or a host of other terms. Although these are descriptive terms, if accurately used, they can convey a general idea of the particle shape. However, they reveal little about the degree to which the particles take upon a particular shape. Without a comparable quantitative measure, it may be difficult to assess the effects of particle shape on a process or product. 

The work described in this paper is preliminary. The most relevant related work seems to be the attack tree approach [5]. This approach proposes to use the classical fault tree notation in order to study security. As in our work, the attack tree contains basic events representing elementary threats. In some variants of the notation, the tree also include a description of the effect security barriers. In [7] the authors propose to use an extension of the fault-tree notation in order to deal with dynamic aspects of the threat propagation. Both of the previous works tend to focus on a quantitative assessment of security requirements whereas we have been working on qualitative requirements because this would be more consistent with the Airworthiness Safety process. Another relevant approach was proposed by the CORAS project [6], this notation aims at assisting the security risk analysis. A difference between this approach and our work is that the CORAS can be applied before the security architecture is designed whereas our approach is applied once the security architecture is established. 

Table 5.2 Exampie of numeric vaiues given to subjective, quaiitative descriptions of risk, of a typicai semi-quantitative assessment...

Since the characterization of odor is critical to the technical development of medical textile materials for odor control, it is important to have a quantitative assessment method that can offer a detailed classification of body odor. In this respect, many attempts have been made to establish qualitative description and quantitative grading of body odor. For example, six descriptive terms can be used to describe axillary sweat extracts acid, chicken broth, onion, sweat (acrid), butter, and floral. The intensity of the different types of smells can be graded on an 11-point intensity scale from 0 (none) to 10 (very strong), using which a highly trained panel of assessors can carry out a reasonably accurate assessment of body odors. 

The assessment of the contribution of a product to the fire severity and the resulting hazard to people and property combines appropriate product flammabihty data, descriptions of the building and occupants, and computer software that includes the dynamics and chemistry of fires. This type of assessment offers benefits not available from stand-alone test methods quantitative appraisal of the incremental impact on fire safety of changes in a product appraisal of the use of a given material in a number of products and appraisal of the differing impacts of a product in different buildings and occupancies. One method, HAZARD I (11), has been used to determine that several commonly used fire-retardant—polymer systems reduced the overall fire hazard compared to similar nonfire retarded formulations (12). 

The most effective specification is that which accomplishes the desired result with the fewest requirements. Properties and performance should be emphasized rather than how the objectives ate to be achieved. Excessive demonstration of emdition on the part of the writer or failure to recognize the usually considerable processing expertise held by the vendor results in a lengthy and overly detailed document that generally is counterproductive. Redundancy may lead to technical inconsistency. A requirement that cannot be assessed by a prescribed test method or quantitative inspection technique never should be included in the specifications. Wherever possible, tests should be easy to perform and highly correctable with service performance. Tests that indicate service life are especially useful. Standard test references, eg, ASTM methods, ate the most desirable, and those that ate needed should be selected carefully and the numbers of such references should be minimized. To eliminate unnecessary review activity by the would-be complier, the description of a standard test should not be paraphrased or condensed unless the original test is referenced. 

The third category of methods addressed in this chapter are error analysis and reduction methodologies. Error analysis techniques can either be applied in a proactive or retrospective mode. In the proactive mode they are used to predict possible errors when tasks are being analyzed during chemical process quantitative risk assessment and design evaluations. When applied retrospectively, they are used to identify the underlying causes of errors giving rise to accidents. Very often the distinction between task analysis and error analysis is blurred, since the process of error analysis always has to proceed from a comprehensive description of a task, usually derived from a task analysis. 

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