This case study shows how a student’s strategies and associated conceptions emerged and changed over the course of a 6-session tutoring curriculum designed to develop conceptual knowledge of linear functions. Using microgenetic and sequential analyses, we identify the student’s strategies and conceptions and describe how these changed. We show how the student did not erase his original concepti...

A methodology is presented for the design synthesis of metamaterials that act as thin multifrequency artificial magnetic conductors. These structures are realized by placing a frequency-selective surface above a conventional prefect electric conductor, separated by a thin dielectric layer. The frequency-selective surface design is optimized using a microgenetic algorithm to operate at multiple,...

Variability in strategy selection is an important characteristic of learning new skills such as mathematical skills. Strategies gradually come and go during this development. In 1996, Siegler described this phenomenon as "overlapping waves." In the current microgenetic study, we attempted to model these overlapping waves statistically. In addition, we investigated whether development in strateg...

In four experiments, participants had to detect symmetries or repetitions distributed over two depth planes, under presentation times of 200-1000 ms. Structurally corresponding elements were placed in different planes (Experiments 1a and 1b) or in the same plane (Experiments 2a and 2b). Results suggest (a) an ongoing interaction between regularity cues and depth cues, and (b) that efficient det...

Primed matching was used to examine the microgenesis of perceptual organization for line configurations that vary in the connectedness between their four line components, and for hierarchical patterns composed of four outline closed figures. The results for the line configurations showed that the configural organization of the disconnected line segments was available for priming very early, and...

An important family of blind equalization algorithms identify a communication channel model based on fitting higher order cumulants, which poses a nonlinear optimization problem. Since higher order cumulant-based criteria are multimodal, conventional gradient search techniques require a good initial estimate to avoid converging to local minima. We present a novel scheme which uses genetic algor...

We have developed a powerful parallel genetic algorithm design tool for photonic crystal and waveguide structures. The tool employs a small-population-size genetic algorithm (microgenetic algorithm) for global optimization and a two-dimensional finite-difference time-domain method to rigorously design and optimize the performance of photonic devices. We discuss the implementation and performanc...

We created a socially assistive robotic learning companion to support English-speaking children’s acquisition of a new language (Spanish). In a two-month microgenetic study, 34 preschool children will play an interactive game with a fully autonomous robot and the robot’s virtual sidekick, a Toucan shown on a tablet screen. Two aspects of the interaction were personalized to each child: (1) the ...

Determination of optimal cutting parameters is one of the most important elements in any process planning of metal parts. This paper presents a multi-objective optimization technique, based on genetic algorithms, to optimize the cutting parameters in turning processes: cutting depth, feed and speed. Two conflicting objectives, tool life and operation time, are simultaneously optimized. The prop...

We report on a case of a French-speaking patient whose performance on reading aloud single words was characteristically deep dyslexic (in spite of preserved ability to identify letters), and whose comprehension on silent sentence reading was agrammatic and strikingly poorer than on oral reading. The first part of the study is mainly informative as regards (i) the relationship between letter ide...