MOTIVATION The problem of early-stage protein folding is critical for protein structure prediction. The model presented introduces a common definition of protein structures which may be treated as the possible in silico early-stage form of the polypeptide chain. Limitation of the conformational space to the ellipse path on the Ramachandran map was tested as a possible sub-space to represent the...

We study the local geometry of testing a mean vector within a high-dimensional ellipse against a compound alternative. Given samples of a Gaussian random vector, the goal is to distinguish whether the mean is equal to a known vector within an ellipse, or equal to some other unknown vector in the ellipse. Such ellipse testing problems lie at the heart of several applications, including non-param...

In this paper, a 2 DOF haptic yawing joystick for use as the navigation input device in virtual environments is introduced. The haptic yawing joystick can perform a 360°_range yawing motion and ±100°_range pitching motion. The device can support weights of up to 26N along the x axis and 10N along the y axis with 10kHz of sampling rate. For the haptic yawing joystick, an ellipse navigation algor...

For fitting an ellipse to a point sequence, ML (maximum likelihood) has been regarded as having the highest accuracy. In this paper, we demonstrate the existence of a “hyperaccurate” method which outperforms ML. This is made possible by error analysis of ML followed by subtraction of high-order bias terms. Since ML nearly achieves the theoretical accuracy bound (the KCR lower bound), the result...

-In this paper, we present a fast and robust ellipse extraction method. The proposed method can extract ellipses with high accuracy and speed from images with complicated backgrounds. It consists of two parts. First, we extract arc segments from an ellipse approximated by short straight lines that are extracted by a fast line extraction algorithm. Second, the arc segments are used to calculate ...

In this work we propose an efficient and original method for ellipse detection which relies on a recent contour representation based on arcs and line segments [1]. The first step of such a detection is to locate ellipse candidate with a grouping process exploiting geometric properties of adjacent arcs and lines. Then, for each ellipse candidate we extract a compact and significant representatio...

We propose a new method that always fits an ellipse to a point sequence extracted from images. The currently known best ellipse fitting method is hyper-renormalization of Kanatani et al., but it may return a hyperbola when the noise in the data is very large. Our proposed method returns an ellipse close to the point sequence by random sampling of data points. Doing simulation, we show that our ...

Direct numerical simulation of the wake flow around and behind a planar ellipse using a random vortex method is presented. Fluid is considered incompressible and the aspect ratios of ellipse and the angles of attacks are varied. This geometry can be a logical prelude to the more complex geometries, but less time dependent experimental measurements are available to validate the numerical results...

When conic sections are introduced to mathematics classes, certain real-world examples are often cited. Favorites include lamp-shade shadows for hyperbolas, paths of baseballs for parabolas, and planetary orbits for ellipses. There is, however, another outstanding example of an ellipse. Known simply as the Ellipse, it is a gathering place for thousands of Americans every year, and it is probabl...

In this paper, we introduce a new method for ellipse detection. This method takes the advantages of major axis of an ellipse to find ellipse parameter fast and efficiently. It only needs an one-dimensional accumulator array to accumulate the length information for minor axis of the ellipse. This method does not require the evaluation of the tangents or curvatures of the edge contours, which are...