Alarms adaptation

Brizzi, R., Delfino, G. and Pellegrini, R. (2002) Specialized mucous glands and their possible adaptive role in the males of some species of Rana (Amphibia, Anura). J. Morph. 254, 328-341. Chen, C. and Osuch, M. V. (1969) Biosynthesis of bufadienolides - 3Bhydroxycholonates as precursors in Bufo marinus bufadienolides synthesis. Biochem. Pharmacol. 18, 1797-1802. Chivers, D. P. and Smith, R. J. F. (1998) Chemical alarm signalling in aquatic predator-prey systems a review and prospectus. Ecosci. 5, 338-352. 

Under certain circumstances, anxiety is an appropriate emotional response. We expect a person to feel sad after a signihcant loss such as the death of a loved one, and it is eqnally reasonable for a person to feel fearful and anxious when faced with a frightening situation such as a painful or risky medical procedure. Indeed, in the context of the fight or flight reaction readily witnessed in nature when a predator is lurking near its intended prey, the physical and mental symptoms of anxiety can indeed be adaptive. This anxiety clearly serves as an appropriate alarm that potential danger is nearby and readies the individnal for a self-protective response. 

The immediate response to stress in a normotensive person may be considered to fall in the alarm reaction stage of what Selye (145,147) has elected to call a general adaptation syndrome, whose manifestations are essentially independent of the specific nature of the stress. The development of clinically sustained hypertension has been considered by him to fall into a second stage of resistance to a prolonged exposure to stress. Similarly, Wolf et al. (166) have presented recently an interesting discussion of hypertension as a reaction pattern to stress. The very readable article by White (164) also stresses the importance of the neurogenic aspects of early hypertension as a major factor that must be dealt with in the management of this disease. 

This has essential consequences for the design of emergency measures. A technical measure to prevent a runaway could be a temperature alarm set at, for example, 10 K above the process temperature. This works well with nth-order reactions, where the alarm is activated at approximately half of the TMRld. However, autocatalytic reactions are not only accelerated by temperature, but also by time. This can lead to a sharp temperature increase. In the case shown in Figure 12.2, a temperature alarm is not effective, because there is no time left to take measures in the example given, only a few minutes are left before runaway. Therefore, it is important to know if a decomposition reaction is of autocatalytic nature or not that is, the safety measures must be adapted to this type of reaction. 

With the plethora of electronic timers and alarm watches on the market one would think it would be a simple task to adapt these units as demolition timers. Most of these devices do not put out sufficient energy to their alarm buzzers to reliably detonate an electric blasting cap. But it is not extremely difficult to modify them by using a Silicon-Controlled Rectifier (SCR) switching circuit. The PLO is known to have used timers adapted from a cheap digital alarm watch and a SCR in Lebanon. 

Stage 1 Adaptation begins with alarm or awareness that exposure causes symptoms. 

Williams (1964, 1992), however, argued that there are considerable problems in explaining the evolution of an alarm pheromone. It was assumed that individuals produced alarm substance to warn their school or species of danger, but schools of fish are not composed of closely related individuals (Naish et al. 1993). Magurran et al. (1996) further demonstrated that fright responses in fish were elicited in a context-dependent manner. The alarm responses were likely exaggerated in the laboratory condition where the opportunities for escape were largely reduced. In the natural environment, alarm substances did not produce adaptive behaviors. In crustaceans, behaviors similar to the alarm response in fish can be elicited by the reception of injured conspecifics (Hazlett, Chap. 18). 

Crustaceans and fishes share similar habitats but have evolved different chemical communication systems that are adaptive to their life styles. Some fish and crustacean species use alarm substances to avoid predators some use migratory... 

Since that time, little progress has been made in the area of psychophysiologically based adaptive systems. To date, there are only a few examples of such systems. Yamamoto and Isshiki (1992) described one system that uses skin conductance responses (SCR) to maintain alertness. In their system, skin conductance is measured continuously for spontaneous changes. If 3 minutes elapse without a change, an auditory alarm sounds. The subjects in their study were expected to expend effort at the sound of the alarm and therefore change their SCR, which in turn would shut off the alarm. The system described by Yamamoto and Isshiki functions as a simple alertness monitor and therefore does not truly represent an application of adaptive automation. Recently, however, a prototype of an adaptive system for moderating operator workload that is driven by changes in EEG has been described. 

In order to enhance the anti-interference capability of the system, the optical isolators 6 N137 module is adapted between the transceiver and controller of the CAN bus.. The CC2420 module is the RF transceiver between the coordinator and the router node or the end node. First the RF transceiver CC2420 receives the information and transmit to the 80C51 microprocessor, then the information is transmitted to the host computer by the CAN bus. The keyboard module, the LCD display module and the alarm module are designed on... 

Process optimization, process management, trend analysis, alarm processing, control-system design, and adaptive control... 

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