Let S be a set of n points in the plane. We present a method where, using O(n log n) time and space, S can be pre-processed into a data structure such that given an axis-parallel query rectangle q, we can report the radius of the smallest enclosing disk of the points lying in S ∩ q in O(log n) time per query.

Given a set D of m unit disks and a set P of n points in the plane, the discrete unit disk cover problem is to select a minimum cardinality subset D′ ⊆ D to cover P. This problem is NP-hard [14] and the best ∗[email protected] †[email protected] ‡[email protected] §[email protected] ¶[email protected] ‖[email protected] ∗∗[email protected] ††[email protected]

In-memory database systems are becoming popular due to the availability and affordability of sufficiently large RAM and processors in modern high-end servers with the capacity to manage large in-memory database transactions. While fast and reliable inmemory systems are still being developed to overcome cache misses, CPU/IO bottlenecks and distributed transaction costs, disk-based data stores st...

Crop management practices (tillage, residue management, fertilization, etc.) define the soil environment to which crops are exposed and through these environmental conditions control crop growth. The purpose of this paper is to report the response of winter wheat (Triticum aestivum L.) to long-term (10 years) application of fallow tillage practices (plow, sub-till, and no-till) and N fertilizat...

This study investigates percolation and seepage through the bunds of flat and terraced paddies. Field experiments were conducted in Hsin-Pu of Hsin-Chu County, Taiwan, to measure the soil water content of various types of bund. Measurements revealed that the soil was unsaturated along the sloped surface of the terrace. Experimental results also indicated that seepage face flow did not develop e...

Fault tolerance and reliability of distributed systems is often achieved through checkpoint / restart mechanisms. Checkpointing frequency and restart delay crucially depend on data throughput and access performance of the storage medium. In this paper we discuss the opportunity to achieve subsecond checkpointing frequencies and restart delays by substituting magnetic hard disk storage with soli...

With an ever increasing amount of data to store, hierarchical storage management (HSM) systems must still use tape for tertiary storage. A disk cache is used to reduce the access time to data stored on tapes in a robot device. Due to the sequential access to tape devices, some HSM systems will transfer whole files between disk cache and tape. In this case the disk cache is forced to handle stor...

We present a polynomial time algorithm for the unit disk covering problem with an approximation factor 72, and show that this is the best possible approximation factor based on the method used. This is an improvement on the best known approximation factor of 108.

Susceptibility disks impregnated with 35 different antibiotics were assayed by the current Code of Federal Regulations method and by a new method employing an agar overlay. The new method, a simplified analytical procedure, exhibited improvement in zone definition and an increase in dose response. Assays performed by the new method were accurate and precise. The agar overlay technique appears t...

STUDY DESIGN Retrospective radiographic analysis. OBJECTIVE To determine which lumbar interbody technique is most effective for restoring lordosis, increasing disk height, and reducing spondylolisthesis. SUMMARY OF BACKGROUND DATA Lumbar interbody fusions are performed in hopes of increasing fusion potential, correcting deformity, and indirectly decompressing nerve roots. No published study...