Let P be a set of n points in ~d (where d is a small fixed positive integer), and let F be a collection of subsets of ~d, each of which is defined by a constant number of bounded degree polynomial inequalities. We consider the following F-range searching problem: Given P, build a data structure for efficient answering of queries of the form, "Given a 7 ~ F, count (or report) the points of P lyi...

Given an array A of size n, we consider the problem of answering range majority queries: given a query range [i..j] where 1 ≤ i ≤ j ≤ n, return the majority element of the subarray A[i..j] if it exists. We describe a linear space data structure that answers range majority queries in constant time. We further generalize this problem by defining range α-majority queries: given a query range [i..j...

The volume and complexity of the data produced in the field of environmental sciences has dramatically increased in the past few years. Traditional data management infrastructures cannot deal with this complexity. Enabling discovery, access and management of this data in a federated manner is the role of the new generation of data grids. We have designed OpEnDaG (Open Environmental Data Grid), ...

Given a set of n objects each characterized by d attributes speci ed at m xed time instances we are interested in the problem of designing space e cient indexing structures such that arbitrary temporal range search queries can be handled e ciently When m our problem reduces to the d dimensional orthogonal search problem We establish e cient data structures to handle several classes of the gener...

We study a longstanding problem in computational geometry: 2-d dynamic orthogonal range reporting. We present a new data structure achieving O ( logn log logn + k ) optimal query time and O ( log2/3+o(1) n ) update time (amortized) in the word RAM model, where n is the number of data points and k is the output size. This is the first improvement in over 10 years of Mortensen’s previous result [...

For the submillimeter band observations, we have been routinely adopting the calibration cycle time of 20–30 minutes, which is the same as any typical centimeter and millimeter band observations. This cycle time, largely corrects only the instrumental phase fluctuations and there exists residual phase fluctuations, which are attributed to temporal and spatial atmospheric phase fluctuations. Hen...

A range query applies an aggregation operation over all selected cells of an OLAP data cube where selection is specified by the range of contiguous values for each dimension. Many works have focused on efficiently computing range sum or range max queries. Most of these algorithms use a uniformly partitioning scheme for the data cube. In this paper, we improve on query costs of some of these exi...

Sensor networks and the data they collect have become increasingly prevalent and large. Sensor networks are frequently employed to observe objects in motion and are used to record traffic data, observe wildlife migration patterns, and observe motion from many other settings. In order to perform accurate statistical analyses of this data over arbitrary periods of time, the data must be faithfull...

In this dissertation, we present a number of new techniques and tools for proving lower bounds on the operational time of data structures. These techniques provide new lines of attack for proving lower bounds in both the cell probe model, the group model, the pointer machine model and the I/O-model. In all cases, we push the frontiers further by proving lower bounds higher than what could possi...

independence of observations is a fundamental assumption in designing an x chart for individual observations. but unfortunately, the assumption of existence of independent data is not even approximately satisfied. in fact, there is one kind of autocorrelation in the data. this paper demonstrates, through simulating an ar(1) process, that the autocorrelation in the data has deep effect on x char...