We revisit classical geometric search problems under the assumption of rational coordinates. Our main result is a tight bound for point separation, ie, to determine whether n given points lie on one side of a query line. We show that with polynomial storage the query time is Θ(log b/ log log b), where b is the bit length of the rationals used in specifying the line and the points. The lower bou...

We develop a number of space-efficient tools including an approach to simulate divide-and-conquer space-efficiently, stably selecting and unselecting a subset from a sorted set, and computing the kth smallest element in one dimension from a multi-dimensional set that is sorted in another dimension. We then apply these tools to solve several geometric problems that have solutions using some form...

The successful implementation of mass storage archives require careful attention to performance optimizations, to ensure that the system can handle the ooered load. However, performance optimizations require an understanding of user access patterns. Since on-line archives and digital libraries are so new, little information is available. has run an on-line mass storage archive of space data, th...

I present deep spectroscopy of four H II regions in the inner, metal-rich zone of the spiral galaxy M101 obtained with the LRIS spectrograph at the Keck telescope. From the analysis of the collisionally excited lines in two of the target H II regions, H1013 and H493, I have obtained oxygen abundances 12 + log(O/H) = 8.52 and 12 + log(O/H) = 8.74, respectively. These measurements extend the dete...

The successful implementation of mass storage archives require careful attention to performance optimizations, to ensure that the system can handle the ooered load. However, performance optimizations require an understanding of user access patterns. Since on-line archives and digital libraries are so new, little information is available. has run an on-line mass storage archive of space data, th...

We present a new static dictionary that is very fast and compact, while also extremely easy to implement. A combination of properties make this algorithm very attractive for applications requiring large static dictionaries: 1. High performance, with membership queries taking O(1)-time with a near-optimal constant. 2. Continued high performance in external memory, with queries requiring only 1-2...