Stress performance-influencing factors

At the next organizational level are factors directly causing error 1) job characteristics such o Complexity, time stress, noise, lighting, environment, or mental requirements, and 2) individual factors such as personality, and team performance. These, collectively, are called performance-influencing factors, or PIFs. 

Figure 9. Stressing factors, influencing factors, and weathering ejfects that contribute to wood-finish performance.

HMI specifications and applied solutions as Piping and Instrumentation Diagrams (P ID), data formats, types of data obtained, ergonomics of control room and organizational factors directly influencing on operator performance and should be incorporated into HRA analysis. Under consideration should also be taken the performance shaping factors (PSFs), such as stress, estabUshed procedures affecting human operator performance, etc. 

Physical Activity (Work) and Other External Influence Factors. Usually a distinction is made between pulse rate at rest and pulse rate under physical (work) stress. The work pulse frequency depends on the time and level of work stress as well as the degree of fitness of the person performing the work. Pulse frequency for permanent work is that which at a prolonged uniform level of work will remain fairly constant. Up to that state of equilibrium (steady state) there is almost a linear relationship between pulse frequency and oxygen intake. Beyond the steady state, pulse frequency will increase until complete exhaustion sets in (Figure 6.12). The permanent performance limit for physical work is reached at that point in time when, at a maximum work load, the pulse frequency does not rise any further. 

With high-performance plastics, dynamic loads such as creep, fatigue, and impact and related issues are important considerations in many designs (see ASTM D 4092). These materials behaviors are influenced by many factors, including in particular temperature, time, previous stress history, and the ambient conditions. In order for these influencing factors to be examined separately from one another, test methods have been developed to permit this separation of individual factors. 

Design limitations. The adhesive joint must be carefully designed for optimal performance. Design factors must include the type of stress, environmental influences, and production methods that will be used. The strength of the adhesive joint is dependent on the type and direction of stress. Generally, adhesives perform better when stressed in shear or tension than when exposed to cleavage or peel forces. 

The variability of human performance is reflected by individual differences of skill, experience, motivation, and other personal characteristics of work force. There can be a wide range of specific environmental situations and other physical aspects of the tasks to be performed. Only some of this variation regarding the performance-shaping factors is accounted for in HEP s by provision of different estimates of HEP s for different sets of influencing factors such as experience of the operator, level of stress, and ergonomic layout. 

The two steps in the removal of a particle from the Hquid phase by the filter medium are the transport of the suspended particle to the surface of the medium and interaction with the surface to form a bond strong enough to withstand the hydraulic stresses imposed on it by the passage of water over the surface. The transport step is influenced by such physical factors as concentration of the suspension, medium particle size, medium particle-size distribution, temperature, flow rate, and flow time. These parameters have been considered in various empirical relationships that help predict filter performance based on physical factors only (8,9). Attention has also been placed on the interaction between the particles and the filter surface. The mechanisms postulated are based on adsorption (qv) or specific chemical interactions (10). 

As tree fruit species are perennial crops, year-to-year influences are often detected. For example, factors in the previous year(s) (e.g. water or nutrient deficiency, hail storm damage, shoot deformation caused by aphids, too high or too low crop load) strongly influence the tree s performance in the next year (Tromp and Wertheim, 2005). Thus, a major objective of agronomic practices used is to buffer the orchard from stress and to keep trees in a balance/equilibrium between vegetative and generative activity. 

Actually there are defined no minimum requirements for the stability or the dynamics of the hydrophobicity of silicone elastomers. The presently existing knowledge has been achieved from long-time field and laboratory tests. Because of the complexity of the stress factors, the results are not always comparable. Thus, systematic laboratory experiments have to be performed to be able to validate the influence of different material parameters. This paper deals with experiments on the influence of single stress parameters on the hydrophobicity. The results are compared with the electrical behavior of droplet layers on the silicone mbber surfaces. 

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