In this paper, we present a new method for camera calibration using concentric circles. We demonstrate that camera calibration is possible using two views of a concentric circle with known size. A new method to determine the position of the projected center of the circle is introduced. Based on the accurate estimation of the projected circle center of two sets of 3-D concentric circles, the pro...

Extrachromosomal circular DNAs (eccDNAs) are common genetic elements in Saccharomyces cerevisiae and are reported in other eukaryotes as well. EccDNAs contribute to genetic variation among somatic cells in multicellular organisms and to evolution of unicellular eukaryotes. Sensitive methods for detecting eccDNA are needed to clarify how these elements affect genome stability and how environment...

A method of improving coating thickness measurement repeatability of the ball crater method is proposed. The improvement is realized by using image processing techniques to measure the radii of crater circles from a microscope image. While traditional methods use a limited number of operator-selected points on a circle edge to calculate the radius value, the new method measures the radius by fi...

In molecular resolution refutation, the detection of empty clauses is important. We propose a rolling circle amplification-based detection method for resolution refutation. The rolling circle amplification (RCA) technique is known to be able to distinguish and amplify circular DNA. In this paper, we describe the representation of clauses and the RCA-based detection method. Bio-lab experiments s...

The Hough transform is a powerful tool in image analysis, e.g. circle detection is a fundamental issue in image processing applications of industrial parts or tools. Because of its drawbacks, various modifications of the basic circle Hough transform (CHT) method have been suggested. This paper presents a modified method based on the basic CHT algorithm and using no trigonometric calculations in...

A numerically stable homotopy continuation method was first proposed by Enqvist for computing degree constrained rational covariance extensions. The approach was later adapted in the works of Nagamune, and Blomqvist and Nagamune, to the Nevanlinna-Pick interpolation problem and more general complexity constrained problems. Yet the method has not been developed to the fullest extent as all the p...

A nonlinear optimization based method for measuring circular control points for use with camera calibration is presented. The displacement of circle centers, caused by projection, is addressed and corrected. Camera calibration is performed taking both radial and tangential lens distortion into account. The results show some improvement with the least squares method over the classical centroid m...

A heuristic method for packing disks in a circle is constructed, and is applied to the estimation of the sizes of holes through which given sets of electric wires are to pass. In the proposed method, a sufficiently large circle is initially constructed, and it is shrunk step by step while keeping all the disks inside. For this purpose a Voronoi diagram for circles is used. Computational experim...

Background & Aims: The relationship between variations of Willis circle and some cerebrovascular diseases has been shown in previous studies. A few studies have been conducted in Iran on these variations. Methods: This study was performed on 100 recently deceased Iranians due to car accidents who had been referred to Kerman Forensic Medicine Center for autopsy. The length and diameter of cerebr...