Systems Tasks

The widespread use of multiscale modeling necessitates the concomitant development of system-level tasks (see Fig. 1) for designing suitable experiments, 

---

Whenever ID WIN-NMR or 2D WIN-NMR start, the appropriate application window appears on screen (see Figs. 2.5 and 2.6). This window may be minimized, maximized and resized using the standard MS-WINDOWS techniques. Access to the MS-WINDOWS system task menu is by clicking the button positioned to the left of the title bar. This menu may be used to switch to other running programs or to close one of the WIN-NMR sessions. Refer to the MS-WINDOWS manual for a detailed explanation of the individual window elements and for specific window manipulation techniques. As an example the ID WIN-NMR application window is shown. It consists of several menus, buttons and subwindows (Fig. 4.2). 

Most large networked systems embody human beings as, in effect, system components , alongside the hardware and software components, though as indicated above such humans may become actively involved only when things go wrong with the computers and their communication. In other cases, there may be a deliberate decision to sub-divide some overall system task into activities that can be readily automated, and those that are best left to human beings to carry out. Systems that incorporate human components in either of these ways are termed here computer-based systems. 

A hierarchy of models can often be derived from a more detailed model under certain assumptions. This approach was discussed above in the case of deterministic, continuum models (see Fig. 3a). Such hierarchical models can be valuable in multiscale modeling. Let us just mention two cases. First, one could use different models from a hierarchy of models for different situations or length scales. This approach plays a key role in hybrid multiscale simulation discussed extensively below. Second, one could easily apply systems tasks to a simpler model to obtain an approximate solution that is then refined by employing a more sophisticated, accurate, and expensive model from the hierarchy. 

J. L. Richard G. A. Payne, Eds. Mycotoxins Risks in Plant, Animal, and Human Systems. Task Force Report No. 139 Council for Agricultural Science and Technoplogy Ames, IA, USA, 2003. 

The metrics system will require informed practitioners to reliably complete the system tasks. There are many examples where poorly trained personnel collected data that was misunderstood or just wrong. This wastes resources by collecting improper and potentially useless data and may lead to erroneous conclusions about performance. A false sense of confidence could result fl-om improper data that indicates the process safety system is operating more reliably than is true. On the other hand, invalid data may lead to a conclusion that action is needed when, in fact, the process safety system is meeting expectations. 

CP/M is an acronym for Control Program for Microcomputers. In essence, CP/M is merely an operating system, primarily for controlling disk access. An operating system is the base software for a computer. It takes care of routine system tasks and provides a link between the computer and any other software you may be running. 

System Variables These are set for all users on the machine. System variables are used to provide information needed by the system when running applications or performing system tasks. 

C. It has to do with the pre-determined times certain system tasks are performed, such as disk defragmenting, virus checking, and so on. 

In moving toward a system design, once tasks have been aneilyzed rmd associated mental models characterized, designers ceui use this knowledge to address the relationship between the human and the interactive system. Task tillocation is a process of assigning the various tasks identified via the... 

Testing - whereby representative users are observed working through selected system tasks whilst an assessor records how well the user interface actually performs. 

Kondraske, G.V. 2000. A working model for human system-task interfaces. In J.D. Bronzino (Ed.), Handbook of Biomedical Engineering, 2nd ed. Boca Raton, FL, CRC Press. 

To provide a common conceptual basis for the analysis of any task in a manner that facilitates system-task interface assessments and decision-making... 

A succinct statement of GSPT designed to emphasize key constructs is presented below in a step-like format. The order of steps is intended to suggest how one might approach any system or system-task interface situation to apply GSPT. While somewhat terse and to-the-point, it is nonetheless an essential prerequisite for a reasonably complete understanding of the ERM ... 

The above statement is intended to reflect the true complexity that exists in systems, tasks, and their interfaces when viewed primarily from the perspective of performance. This provides a basis for the judicious decision making required to realize the best practical implementation in a given situation where many engineering trade-offs must be considered. While a two-level approach is described... 

In modern human-machine systems, task assignments maybe adaptive or blended rather than strictly allocated. The information-processing capabilities of modem machines often includes some form of task knowledge and reasoning capabilities that provide for an adaptive task allocation that shifts the task demands on the basis of contextual variables. Also, in many cases human performance is augmented by (blended with) machine performance to accomplish a given task. 

---