A problem inherent to the performance of disk systems is the data placement in cyinders in such a way that the seek time is minimized. If successive searchers are independent, then the optimal placement for conventional one-headed disk systems is the organ-pipe arrangement. According to this arrangement the most frequent cylinder is placed in the central location, while the less frequent cylind...

Given a simple polygon P with m vertices and a set S of n points in the plane, we consider the problem of finding a rigid motion placement of P that contains the maximum number of points in S. We present two solutions to this problem that represent time versus space tradeoffs. The first algorithm runs in O(n3m3) expected time using O(n2m2) space. The second algorithm runs in O(n3m3 log(nm)) det...

Dynamic data redistribution is a key technique for maintaining data locality and workload balance in data-parallel languages like HPF. On the other hand, redistributions can be very expensive and signiicantly degrade a program's performance. In this article, we present a novel and aggressive approach for avoiding unnecessary remappings by eliminating partially dead and partially redundant distr...

We model a market, such as an online software market, in which an intermediary connects sellers and buyers by displaying sellers' products. With two vertically-differentiated products, an intermediary can place either: (1) one product, not necessarily the better one, on the first page, and the other hidden on the second page; or (2) both products on the first page. We show that it can be optima...

In recent years, size of VLSI circuits is dramatically grown and layout generation of current circuits has become a dominant task in design flow. Standard cell placement is an effective stage of physical design and quality of placement affects directly on the performance, power consumption and signal immunity of design. Placement can be performed analytically or heuristically. Analytical placer...

In this paper, optimal placement of Phasor Measurement Unit (PMU) using Global Positioning System (GPS) is discussed. Ant Colony Optimization (ACO), Simulated Annealing (SA), Particle Swarm Optimization (PSO) and Genetic Algorithm (GA) are used for this problem. Pheromone evaporation coefficient and the probability of moving from state x to state y by ant are introduced into the ACO. The modifi...