Complex Dynamic Situations Research Articles

Collective learning and collective memory for coping with dynamic complexity

The need for coping with dynamic complex situations cuts through most modern life. Examples of such situations are emergency management, military command and control, traffic control (air, rail, road, water), rescue services, grid control, intensive care and industrial plant control. Consequences of failures in such situations include uncontrolled releases, injuries, poisoning and single deaths, all of which are highly desirable to prevent.Efficient performance in coping with dynamic situations is dependent on people's ability to notice, diagnose and react appropriately to the situation as well as their ability to combine and coordinate their perceptions, interpretations and actions. People are most efficient when their actions are so well trained that they can be performed automatically. People also have the ability to draw upon similar experiences and to reconfigure actions, in short, to be flexible and creative. (By creative is here meant the ability to come up with new and relevant solutions). This ability is related to their reflective actions, which are slow in comparison to the automated ones. Efficiency and creativity are both needed in complex dynamic situations. Both rely upon experience, skill and knowledge. The present workshop aims at discussing how efficiency and creativity in collaborative coping with complex dynamic situations can be learnt and trained as well as supported by information technology.This workshop was proposed by a group of European researchers, working on a project under COST 14, Cooperation Technology. We wanted to share our problems and ideas with other people, both within and outside of Europe.

Copper in indigenous and transplanted zebra mussels in relation to changing water concentrations and body weight

AbstractZebra mussels, Dreissena polymorpha, were collected monthly from a copper‐contaminated reservoir over a period of nearly 3 years. Copper concentrations in the organisms showed marked fluctuations reflecting changes in the water contamination. Bioconcentration patterns were influenced by the specific capacity of this sentinel organism to biologically integrate the continuously evolving water pollution; the sampling pattern, which inevitably introduced a certain subjectivity into monitoring results; and weight changes in the animals within the yearly cycle. Consequently, the successive monthly indications obtained with the zebra mussels provided a current biological assessment of a complex dynamic contamination situation. In a second experiment, caged mussels from three different populations were transferred for 3 months into the reservoir and sampled on six occasions. Mortality rates, attachment capacity, and a condition index revealed no substantial fitness disturbances in the transplanted organisms. Differences in dry weight throughout the experiment were attributable to the initial characteristics of each population. The influence of body mass on monitoring results was eliminated by replacing copper concentrations (μg/g dry weight) with copper burdens (μg/specimen). In terms of copper burdens, the three transplanted populations exhibited very similar metal patterns. Moderate quantitative differences between introduced and indigenous populations were interpreted as the result of physiological adaptation of the indigenous mussels to their contaminated environment. This study showed that the transfer technique with D. polymorpha is a useful tool for active biomonitoring programs.

A DISCRETIZED MODEL FOR THE DYNAMICS OF A TETHERED SATELLITE SYSTEM AND APPLICATIONS

This paper deals with a simulation of a tethered satellite system where a discretized model of the cable is considered. The characteristics of a few space discretization procedures are compared while investigating the dynamics of two physically relevant models, namely the Space Pendulum and the Space String. The study of these limit problems provides a reference line for a better understanding of other more complex dynamic situations.

Dynamic analysis of leaflet stresses and application to heart valve design

The problem is approached using an approximate and simple variational procedure. A comparison with results obtained by means of the finite element method reveals that the analytical solution is convenient from a practical engineering viewpoint. It is hoped that biomedical researchers and designers will find the present approach useful when dealing with more complex structural dynamic situations.

The representation of personal relationships: an automated system

This paper outlines the technical details of a psychological instrument called the Personal Relations Index (PRI). The instrument produces a graphical representation of any two-person relationship as seen by one member of the interaction. Several stages are involved. During a free discussion the respondent is asked to describe himself and the other person in the context of their relationship. These descriptions include attitudes, feelings or behavioural states which are referred to as elements. The elements are fed into a computer which produces a questionnaire unique to the respondent. In answering the questionnaire the respondent imposes order on his impressions by indicating how he is most likely to react to each of the other person's elements and how the other person is most likely to react to his (the respondent's) elements. A graphical representation showing the dynamic interaction between the elements and therefore the two people, is constructed by interconnecting each element with its most likely outcome(s). This graphical representation is presented to the respondents in a readily comprehensible form and enables them to understand their own problem situation and hence aids them in resolving it. Successive graphical representations of later states of affairs are also fed back to the respondents so that the improvements (in what is a complex dynamic situation) are apparent to them. The logic of the method, the syntactical structure of the questionnaire and the process of automation are described. Details of the graphs and their properties are given which emphasize the capacity of the PRI to accommodate great variability. Operational definitions and evidence of both validity and reliability are given. The penultimate section of the paper presents three examples of the use of the PRI. The paper concludes with a discussion of the feasibility of implementing the PRI in the clinical setting, details of ongoing work, and the suggestion that automated techniques provide the means of producing idiographic psychological assessments.