Topic
Tangential angle
About: Tangential angle is a research topic. Over the lifetime, 154 publications have been published within this topic receiving 1457 citations.
Papers published on a yearly basis
Papers
TL;DR: In this article, the authors proposed a new method to carry out phase division and explore tangential angular features of the displacement-time curve of creep slopes as well as the acceleration characteristics in the process of slope deformation and the pre-warning criteria for critical failure.
Abstract: The forecasting of the failure time of a slope remains a worldwide problem because of many different possibilities of geological conditions in combination with many varying external factors such as climate and vegetation, and not well-defined or unknown time effects in deformation and failure models. The aim of this paper is to suggest a new method to carry out the phase division and to explore tangential angular features of the displacement-time curve of creep slopes as well as the acceleration characteristics in the process of slope deformation and the pre-warning criteria for critical failure. An imminent failure is pro-ceeded with usually three basic deformation phases, namely primary creep (“decelerated”), secondary creep (“steady-state”) and tertiary creep (“accelerated”). Mostly, only during the accelerated phase the imminence of a possible slope failure is rec-ognized. The analysis of displacement data from a series of landslides allowed to recognize different evolutionary patterns of displacement. A quantitative approach was proposed to describe the tangential angle of the displacement-time curve and a new criterion based on the angle was put forward to divide the accelerated phase into three sub-phases: initial acceleration, medium acceleration, and the critical failure. A pre-warning criterion for critical failure is also proposed consequently. Changes of acceleration showed completely different characteristics from those of cumulative displacement and displacement in the process of slope deformation. The values of acceleration usually oscillate around 0 prior to the critical failure phase, whereas the acceleration increases abruptly when the deformation moves into the critical failure phase. This allows, therefore, for a method to forecast the time of the failure. So it is possible to define different alert acceleration threshold values to be used for emergency management.
125 citations
TL;DR: This paper analyzes the so-called intrinsic heat equation governing the motion of plane curves obeying a geometric equation and shows how the presence of a nontrivial tangential velocity can prevent numerical solutions from forming various instabilities.
Abstract: In this paper we study evolution of plane curves satisfying a geometric equation $v= \beta(k,
u)$, where v is the normal velocity and k and $
u$ are the curvature and tangential angle of a plane curve $\Gamma$. We follow the direct approach and we analyze the so-called intrinsic heat equation governing the motion of plane curves obeying such a geometric equation. The intrinsic heat equation is modified to include an appropriate nontrivial tangential velocity functional $\alpha$. We show how the presence of a nontrivial tangential velocity can prevent numerical solutions from forming various instabilities. From an analytical point of view we present some new results on short time existence of a regular family of evolving curves in the degenerate case when $\beta(k,
u)=\gamma(
u) k^m$, $0 < m\le 2$, and the governing system of equations includes a nontrivial tangential velocity functional.
110 citations
Patent•
6 Apr 1992TL;DR: In this article, a set of associated rectangles representing the document image, identifying a column edge associated with the set of aligned rectangles, comparing rectangles from the set to identify those that are in the same column and suitably far apart, calculating a tangential angle between the rectangles identified and identifying the most common tangential angles as the skew angle.
Abstract: In a character recognition system, a method and apparatus for correcting the skew of a document image. Skew correction is typically performed during segmentation of the document image into text and non-text parts. Skew correction generally involves skew angle determination and correction of the document image based on the skew angle. A skew angle is determined through the steps of: providing a set of associated rectangles representing the document image, identifying a column edge associated with the set of associated rectangles, comparing rectangles from the set of associated rectangles to identify those that are in the same column and suitably far apart, calculating a tangential angle between the rectangles identified and identifying the most common tangential angle as the skew angle. Once the skew angle is determined, correction of the document image is made by constructing real skewed rectangles from corresponding extracted rectangles and rotating each of the real skewed rectangles around an origin coordinate for a distance based on the skew angle.
91 citations
77 citations
TL;DR: In this paper, a general method that solves for tangential contacts between two surfaces or between two curves is described, which is general in that this solution is not a collection of special case algorithms adapted to a restricted set of surface or curve types.
Abstract: A general method that solves for tangential contacts between two surfaces or between two curves is described. It is general in that this solution is not a collection of special case algorithms adapted to a restricted set of surface or curve types. A vector field on the parameter space of one of the surfaces is defined and it is seen that the tangential contact points are zeros of this vector field. The only requirements for the proposed method are that curves and surfaces be parametrically defined, C2, and that the tangential contact be order one. The method has been used in the CIMPLEX system from Automation Technology Products since July 1987 and has proved to be reliable, efficient and accurate.
50 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 5 |
| 2020 | 4 |
| 2019 | 3 |
| 2018 | 1 |
| 2017 | 4 |
| 2016 | 5 |