In 1847, Domenico Ragona-Scinà (1820-1892) published a method of optically superimposing images using an angled piece of colored glass. He showed that if one looks at a black, filled circle through the colored glass and superimposes on it the reflection from the glass of something white, the filled circle looks tinted with the complementary color of the background: simultaneous color contrast o...

In an earlier paper [l] the writer showed the development of a variational method for starlike functions and applied this method to a general class of extremal problems connected with the coefficients of the function. It is the purpose of this paper to study the classes of extremal problems to which this variational method can be applied and to make some remarks as to its utility. The class S* ...

This paper concentrates on the InCircle predicate which is used for the computation of the Voronoi diagram of smooth closed curves. The predicate decides the position of a query object relative to the Voronoi circle of three given ones. We focus on (nonintersecting) ellipses but our method extends to arbitrary closed smooth curves, given in parametric representation. We describe an efficient al...

Formation control is an important sub-problem in multi-agent robotics and a number of decentralized control strategies have been developed to solve the formation control problem, e.g., [1], [2], [3]. However, there is still no underlying theory that governs the selection of a particular formation. In other words, if an agent has a choice between two formations, which one should it choose? In th...

Detection of circular objects in digital images is an important problem in several vision applications. Circle detection using randomized sampling has been developed in recent years to reduce the computational intensity. Randomized sampling, however, is sensitive to noise that can lead to reduced accuracy and false-positive candidates. This paper presents a new circle detection method based upo...

This paper describes an approved algorithm for the problems of unequal circle packing – the quasi-physical quasihuman algorithm. First, the quasi-physical approach for the general packing problems is described in solving the pure problems of unequal circle packing. The method is an analogy to the physical model in which a number of smooth cylinders are packed inside a container. A quasi-human s...

In industrial computed tomography (CT), the mismatch between the X-ray energy and the effective thickness makes it difficult to ensure the integrity of projection data using the traditional scanning model, because of the limitations of the object's complex structure. So, we have developed a CT imaging method that is based on a spherical trajectory. Considering an unrestrained trajectory for ite...

Hough transform (HT) has been the most common method for circle detection, exhibiting robustness, but adversely demanding considerable computational effort and large memory requirements. Alternative approaches include heuristic methods that employ iterative optimization procedures for detecting multiple circles. Since only one circle can be marked at each optimization cycle, multiple executions...