A genetic algorithm based knowledge discovery system for the design of fluid dispensing processes for electronic packaging

In the semiconductor manufacturing industry, fluid dispensing is a very common process used for die-bonding and microchip encapsulation in electronics packaging. Understanding the process behaviour is important as it aids in determining appropriate settings of the process parameters for a high-yield, low cost and robust operation. In this paper, a genetic algorithm (GA) based knowledge discovery system is proposed to discover knowledge about the fluid dispensing process. This knowledge is expressed in the form of rules derived from experimental data sets. As a result, appropriate parameters can be set which will be more effective with respect to the required quality of encapsulation. Rules generated by the GA based knowledge discovery system have been validated using a computational system for process optimization of fluid dispensing. The results indicate that the rules generated are useful and promising in aiding optimization of the fluid dispensing process in terms of better optimization results and shorter computational time

Extended Tree Augmented Naive Classifier

Abstract. This work proposes an extended version of the well-known tree-augmented naive Bayes (TAN) classifier where the structure learning step is performed without requiring features to be connected to the class. Based on a modification of Edmonds ’ algorithm, our structure learning procedure explores a superset of the structures that are considered by TAN, yet achieves global optimality of the learning score function in a very efficient way (quadratic in the number of features, the same com-plexity as learning TANs). A range of experiments show that we obtain models with better accuracy than TAN and comparable to the accuracy of the state-of-the-art classifier averaged one-dependence estimator.

Antarctic Bacteria as Astrobiological Models

Antarctica contains many different types of habitat that would traditionally be considered harsh from a human perspective; it can be extremely cold, have low levels of liquid water, low humidity, low nutrient availability, high levels of salinity and high levels of non-ionizing radiation. Yet a wide variety of bacteria have been found living there, despite these harsh conditions; some of them are believed to be unique to the continent, others more cosmopolitan in distribution. When we compare aspects of these Antarctic habitats to conditions known to occur on Mars, or to what is known of the icy moons of Jupiter and Saturn, we find notable similarities even though, clearly, significant differences remain. It is therefore unsurprising that scientists have used bacteria isolated from the Antarctic as astrobiological models. The extent to which this has been done to date, however, is perhaps surprisingly limited despite the enormous potential in this approach. In this chapter, we examine the differences and similarities between specific habitats in Antarctica and those which they might mimic on Mars, Europa and Enceladus. It considers the nature of the microbiological adaptions found in these Antarctic habitats and the experiments carried out to date on bacteria isolated from them. The chapter concludes by discussing the future potential of Antarctic bacterial species as well as the lessons learnt in understanding the limits of life here on Earth and the possibility of finding evidence of microbial life elsewhere in the solar system