In this paper, we present a clustering-based color indexing scheme for effective amd efficient image retrieval, which is essentially an exploration on the application of clustering technique to image retrieval. In our approach, the color features are clustered automatically using a color clustering algorithm twice (called two-level clustering processing) and two color feature summarizations are...

We prove an acylindrical accessibility theorem for finitely generated groups acting on R-trees. Namely, we show that if G is a freely indecomposable non-cyclic k-generated group acting minimally and D-acylindrically on an R-tree X then there is a finite subtree Tε ⊆ X of measure at most 2D(k − 1) + ε such that GTε = X. This generalizes theorems of Z. Sela and T. Delzant about actions on simplic...

Article history: Received 12 March 2015 Accepted 28 June 2015 Available online 22 July 2015

In this paper we address the problem of indexing spatial data, in particular two dimensional rectangles. We propose an approach which uses two B +-trees, each of them indexing the projected sides of the given rectangles. The approach, which we name 2dMAP21, can also be easily parallelized. We focus on queries of the type \\nd all rectangles included within another (reference) rectangle". We com...

Deep convolutional neural networks (CNNs) have had a major impact in most areas of image understanding, including object category detection. In object detection, methods such as R-CNN have obtained excellent results by integrating CNNs with region proposal generation algorithms such as selective search. In this paper, we investigate the role of proposal generation in CNN-based detectors in orde...

The development of a spatiotemporal access method suitable for objects moving on fixed networks is a very attractive challenge due to the great number of real-world spatiotemporal database applications and fleet management systems dealing with this type of objects. In this work, a new indexing technique, named Fixed Network R-Tree (FNR-Tree), is proposed for objects constrained to move on fixed...

We prove an acylindrical accessibility theorem for finitely generated groups acting on R-trees. Namely, we show that if G is a freely indecomposable non-cyclic k-generated group acting minimally and M-acylindrically on an R-tree X then for any ǫ > 0 there is a finite subtree Yǫ ⊆ X of measure at most 2M (k − 1) + ǫ such that GYǫ = X. This generalizes theorems of Z.Sela and T.Delzant about actio...

Several applications require management of data which is spatially dynamic, e.g., tracking of battle ships or moving cells in a blood sample. The capability of handling the temporal aspect, i.e., the history of such type of data, is also important. This paper presents and evaluates three temporal extensions of the R-tree, the 3D R-tree, the 2+3 R-tree and the HR-tree, which are capable of index...

Driven by many real applications, in this paper we study the problem of similarity search with implicit object features; that is, the features of each object are not pre-computed/evaluated. As the existing similarity search techniques are not applicable, a novel and efficient algorithm is developed in this paper to approach the problem. The R-tree based algorithm consists of two steps: feature ...

The construction of an efficient tree structure should take into account parameters which can be optimised. Coverage of a node, "dead area" of a node and overlap between nodes are examples of such parameters. Taking these parameters under account is important since minimization of a node coverage leads to more precise searching within the tree, minimization of a node "dead area" reduces the num...