Publications [#236018] of Robert Calderbank

Papers Published

1. Calderbank, AR; Coffman, EG; Flatto, L, Optimal directory placement on disk storage devices, Journal of the ACM (JACM), vol. 35 no. 2 (April, 1988), pp. 433-446, Association for Computing Machinery (ACM) [doi]
   (last updated on 2025/02/21)

   Abstract:
   Two mathematical models dealing with optimal placement of directories on disk devices are analyzed. Storage addresses on the disk are approximated by points in the interval [0, 1]. Requests for information on the disk are represented by a sequence of file names. To process a request, a read-write head is first moved to a directory kept on the disk that specifies the address of the file, and then a head is moved to the specified address. The addresses are assumed to be independent and uniform on [0,1].In the first model we consider a system of two heads separated by a fixed distance d and a directory situated at 0 ≤ x ≤ 1. In the second model we consider a system consisting of one head and n ≥ 2 directories at 0 ≤ x1 < x2 < … < xn ≤ 1. For both models we study the problem of finding those values of the parameters that minimize the expected head motion to process a request in statistical equilibrium. © 1988, ACM. All rights reserved.