Free operant tasks

Error free operation and maintenance can only occur within an effective management system. At the level of the task itself, this is provided by operating instructions. However, at a more global level, separate tasks have to be organized in a systematic manner, particularly if hazardous operations are involved, and where several individuals need to coordinate to achieve an overall objective. This section illustrates some accidents due to poor organization of work or failure to carry out checks. 

There is, however, a difficulty in interpreting the outcome of these tests of free operant performance, in that it is extremely difficult to distinguish whether the recorded impairments involve an underlying deficit in the motor, sensory or motivational function (Hamilton et al., 1985 Cousins and Salamone, 1996b). Attention has therefore turned to tests in which animals are trained to make rapid movements in response to an imperative stimulus in discrete trial tasks, in which specific changes in signal detection, choice accuracy, reaction time and movement latency can potentially distinguish sensory, motor and motivational components of the deficit. 

Let us consider two partitions of the same n products. For instance, these could be the partitions of the same stimuli operated by two subjects in the course of a free sorting task. The Rand index (Rand, 1971) is defined by ... 

It allows a systematic review of the current task, and it wUl be possible to put forward recommendations for changes needed for the current task for its improvements and hazard-free operation. 

Once the tasks critical to incident-free operations are identified, standards of performance are required to establish expectations for satisfactorily executing them. Performance standards must be based on careful research in order to provide... 

Systems sueh as the EDS use a dual mieroproeessor system. As ean be seen in Figure 4-93, eritieal parameters of memory, input/output, alarm/trips, and host eomputer eommunieation are handled in the main proeessor. To maintain fast response time, this proeessor is kept free of less eritieal tasks sueh as operator interfaeing, trending, and arehiv-ing. A seeond proeessor, an administrative CPU, is used for these less eritieal yet important tasks. 

Membrane reactors can be considered passive or active according to whether the membrane plays the role of a simple physical barrier that retains the free enzyme molecules solubilized in the aqueous phase, or it acts as an immobilization matrix binding physically or chemically the enzyme molecules. Polymer- and ceramic-based micro- and ultrafiltration membranes are used, and particular attention has to be paid to the chemical compatibility between the solvent and the polymeric membranes. Careful, fine control of the transmembrane pressure during operation is also required in order to avoid phase breakthrough, a task that may sometimes prove difficult to perform, particularly when surface active materials are present or formed during biotransformahon. Sihcone-based dense-phase membranes have also been evaluated in whole-cell processes [55, 56], but... 

The class composite-operator contains procedures that transform a set of chemical species of predisposed behaviors into a set of products, provided that an optional set of prespecified conditions is satisfied. These conditions can be specified by the user or imposed by the system. They may encompass virtually any symbolically encodable concept structural character, chemical behavior, spatial orientation, reaction conditions, free-energy requirements, enthalpy considerations, toxicity, etc. An instance of the composite-operator (e.g., k) calls on the following procedures to carry out the corresponding tasks ... 

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