Top-down and Bottom-up Approaches for Synthesis of Nanoparticles

Top-down and bottom-up approaches to stable clock synthesis

In this work we present and study bottom-up, or multiplicative, clock synthesis and compare it to a proposed and alternative top-down, or divisive, methodology. The focus of the work is on the short-term stability for each approach and the implications associated with frequency multiplication and division. The analysis and simulation demonstrate that for a common application, a top-down clock s...

A Comparative Study of Effect of Bottom-up and Top-down Instructional Approaches on EFL Learners’ Vocabulary Recall and Retention

This quasi-experimental study investigated the effect of bottom-up and top-down instructional approaches on English as a foreign language (EFL) vocabulary recall and retention. To this end, 44 high school students from two intact classes were assigned to bottom-up (n = 21) and top-down (n = 23) groups. The participants were exposed to 20 hours of explicit vocabulary instruction during 10 weeks ...

Combining Top-down and Bottom-up approaches for ROBDD Construction

ROBDDs have traditionally been built in a bottom-up fashion, through the recursive use of Bryant's apply procedure [6], or the ITE [4] procedure. With these methods, the peak memory utilization is often larger than the nal ROBDD size. Though methods like Dynamic Variable Reordering [21] have been proposed to reduce the memory utilization, such schemes have an associated time penalty. In this pa...

Bottom-up, top-down

Blending Top-Down and Bottom-Up Approaches in Conceptual Design

In recent years, there has been significant attention given to improved methods and tools for engineering design. While advances for the latter stages of design have been impressive, this has not been the case for the early stages of design. In general, advances have provided for either a top-down or a bottom-up approach to design; ignoring the requirements for both abstraction and detail in a ...