We provide a new framework for generating multiple good quality partitions (clusterings) of a single data set. Our approach decomposes this problem into two components, generating many high-quality partitions, and then grouping these partitions to obtain k representatives. The decomposition makes the approach extremely modular and allows us to optimize various criteria that control the choice o...

In [DO03] we explored partitioning regular k-gons into “circular” convex pieces. Circularity of a polygon is measured by the aspect ratio: the ratio of the diameters of the smallest circumscribing circle to the largest inscribed disk. We seek partitions with aspect ratio close to 1, ideally the optimal ratio. Although we start with regular polygons, most of the machinery developed extends to ar...

Due to dynamic and uncertain nature of many optimisation problems in real-world, the applied algorithm in this environment must be able to continuously track the changing optima over time. In this paper, we report a novel speciation-based firefly algorithm for dynamic optimisation, which improved its performance by employing prior landscape historical information. The proposed algorithm, namely...

Space partitioning techniques are a useful means of organizing geometric models into data structures. Such data structures provide easy and efficient access to a wide range of computer graphics and visualization applications like real-time rendering of large data bases, collision detection, point classification, etc. Binary Space Partitioning (BSP) trees are one of the most successful space par...

Binary Space Partition (BSP) tree and Constructive Solid Geometry (CSG) tree representations are both set-theoretic binary tree representations of solid objects used in solid modeling and computer graphics. Recently, an extension of the traditional BSP tree definition has been presented, in which surfaces used in the binary partition include curved surfaces in addition to planar surfaces. We ex...

Partitioning a digital circuit into modules before implementing on a single chip is key to balancing between test cost and test correctness of built-in current testing (BICT). Most partitioning methods use statistic analysis to find the threshold value and then to determine the size of a module. These methods are rigid and inflexible since IDDQ testing requires the measurement of an analog quan...

introduction: virtual bronchoscopy is a reliable and efficient diagnostic method for primary symptoms of lung cancer. the segmentation of airways from ct images is a critical step for numerous virtual bronchoscopy applications. materials and methods: to overcome the limitations of the fuzzy connectedness method, the proposed technique, called fuzzy connectivity - fuzzy c-mean (fc-fcm), utilized...

objective: adaptation of the pharyngeal airway space does occur after different surgical strategies of class iii patients including mandibular setback, maxillary advancement and bimaxillary surgery. the aim of this study is to conduct a detailed cephalometric evaluation of the alterations taking place in the morphology of the pharyngeal airway space after treatment of class iii skeletal deformi...

abstract acute upper airway obstruction (uao) is a life threatening complication that is well recognized after carotid endarterectomy, thyroidectomy and pharyngeal area intervention. it is not widely acknowledged that airway obstruction can occur after cervical spinal fusion surgery which was first described in 1955. there are a number of common postoperative problems which may become apparent ...