Markov Influence Diagrams.

Markov influence diagrams (MIDs) are a new type of probabilistic graphical model that extends influence diagrams in the same way that Markov decision trees extend decision trees. They have been designed to build state-transition models, mainly in medicine, and perform cost-effectiveness analyses. Using a causal graph that may contain several variables per cycle, MIDs can model various patient characteristics without multiplying the number of states; in particular, they can represent the history of the patient without using tunnel states. OpenMarkov, an open-source tool, allows the decision analyst to build and evaluate MIDs-including cost-effectiveness analysis and several types of deterministic and probabilistic sensitivity analysis-with a graphical user interface, without writing any code. This way, MIDs can be used to easily build and evaluate complex models whose implementation as spreadsheets or decision trees would be cumbersome or unfeasible in practice. Furthermore, many problems that previously required discrete event simulation can be solved with MIDs; i.e., within the paradigm of state-transition models, in which many health economists feel more comfortable

Influence diagrams for complex litigation

Effective advocacy depends critically on the ability of attorneys to formulate, analyze, and compare rival courses of action. Whereas attorneys have been doing these things for centuries using little more than their gut instincts and experiences, sophisticated decision aids are now available that can improve the way attorneys assess the value of their cases and the strategic decisions that they make. These aids are proving valuable in medicine and business, but they have not impacted legal practice. This Article seeks to correct this oversight by showing how easy-to-use graphical models provide guidance for strategic legal decisions. Beginning with a paradigmatic example of a plain- tiff who must choose between proceeding to trial or settling out of court, the Article shows how decision aids handle the uncertainties and interdependencies that arise when real-world considerations are introduced. In particular, the Article makes the case that influence diagrams, a relative newcomer in the field of decision analysis, should be the decision aid of choice in complex litigation matters

Determination of micellar system behavior in the presence of salt and water-soluble polymers using the phase diagram technique

The application of micellar systems has been growing during the last years because of their importance in various practical situations. Continued development of their application is necessary. If the principal economic interest of microemulsions is for some time enhanced oil recovery, the following also have significant applications such as pharmaceutical preparations, painting, and products for engine lubrication. The effect of variation in composition of anionic surfactants (α oleifin sulfonates) and the presence of a water-soluble charged polymer (Xanthan gum) and an uncharged polymer [poly (ethylene glycol)] on the phase behaviour of pseudo- ternary systems of water–oil surfactants was investigated. Several domains were observed when the composition of surfactants and cosurfactants (e.g., pentanol) in a mixture is varied. The appearance of these domains in the phase diagram has been attributed to the formation of different Winsor systems