In order to incorporate the skyline operator into the data stream engine, we need to address the problem of skyline cardinality estimation, which is very important for extending the query optimizer’s cost model to accommodate skyline queries. In this paper, we propose robust approaches for estimating the skyline cardinality over sliding windows in the stream environment. We first design an appr...

We describe a method for recovering the camera position and orientation parameters from a single mountain image. It is based on the alignment of the mountain skyline with a synthetic skyline generated from a digital elevation map. Image plane alignment of three image skyline feature points with three model feature points is rst hypothesized and the position and orientation parameters for the hy...

Growing interests in multi-criteria decision support applications have resulted in a flurry of efficient skyline algorithms. In practice, real-world decision support applications require to access data from disparate sources. Existing techniques define the skyline operation to work on a single set, and therefore, treat skylines as an “add-on" on top of a traditional Select-Project-Join query pl...

The Wireless GIS technology is progressing rapidly in the area of mobile communications. Location-based spatial queries are becoming an integral part of many new mobile applications. The Skyline queries are latest apps under Location-based services. In this paper we introduce Goal Directed Relative Skyline queries on Time dependent (GD-RST) road networks. The algorithm uses travel time as a met...

Skyline queries are a class of preference queries that compute the pareto-optimal tuples from a set of tuples and are valuable for multi-criteria decision making scenarios. While this problem has received significant attention in the context of single relational table, skyline queries over joins of multiple tables that are typical of storage models for RDF data has received much less attention....

With the growing adoption of web services on the Internet, service selection becomes an important issue of service-oriented computing (SOC). Appropriate services selection algorithm is the fundamental guarantee to compose complex services from singlefunction components effectively. The quality of selected component services is crucial for the performance of the service composition. Therefore, i...

We advocate the extension of relational database systems to support preference queries. Many database applications today— from e-commerce to queries over scientific data-sets—are essentially best-match searches. Relational queries are ill-suited for these. Supporting preference criteria in the query language can extend its expresssiveness to cover best-match queries in a natural way. We study s...

In many decision-making applications, the skyline query is frequently used to find a set of dominating data points (called skyline points) in a multidimensional dataset. In a high-dimensional space skyline points no longer offer any interesting insights as there are too many of them. In this paper, we introduce a novel metric, called skyline frequency that compares and ranks the interestingness...

There has been interest recently in skyline queries, also called Pareto queries, on relational databases. Relational query languages do not support search for “best” tuples, beyond the order by statement. The proposed skyline operator allows one to query for best tuples with respect to any number of attributes as preferences. In this work, we explore what the skyline means, and why skyline quer...

By definition, objects that are skyline points cannot be compared with each other. Yet, thanks to the probabilistic skyline model, skyline points with repeated observations can now be compared. In this model, each object will be assigned a value to denote for its probability of being a skyline point. When we are using this model, some questions will naturally be asked: (1) Which of the objects ...