The bow shape is the most critical factor to determine icebreaking performance of an icebreaker. Mechanism study on process for different types necessary initial design icebreaker hull form. This paper proposed ice-ship interaction model based meshfree method, Peridynamics, in which geometric mathematics concept embedded detect contact between material points and ship hull. Furthermore, a fast ...

the objective of this study was to evaluate different pistachio hullers and determine the proper harvest time of pistachio nuts for hulling. three pistachio hulling machines (helical drum, helical- blade drum, rubber drum) at three harvest times and 15 days interval were evaluated. the hulling efficiency, percentage of damaged nuts, faulty hulled nuts and unhulled nuts were measured at each tim...

Fourier descriptors are powerful features for the recognition of two-dimensional connected shapes. In this article, we propose a method to define Fourier descriptors even for broken shapes, i.e. shapes that can have more than one contour. The method is based on the convex hull of the shape and the distance to the closest actual contour point along the convex hull. We define different invariant ...

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau...

We present a numerical algorithm for nonnegative matrix factorization (NMF) problems under noisy separability. An NMF problem under separability can be stated as one of finding all vertices of the convex hull of data points. The research interest of this paper is to find the vectors as close to the vertices as possible in a situation in which noise is added to the data points. Our algorithm is ...

Article history: Received 21 February 2008 Accepted 24 February 2009 Available online 24 March 2009 Communicated by T. Asano

A concavity tree is a data structure for hierarchically representing the shape of two-dimensional silhouettes using convex polygons. In this paper, we present a new algorithm for concavity tree extraction. The algorithm is fast, works directly on the pixel grid of the shape, and uses exact convex hull computations. We compare our method to the morphological approach to concavity tree extraction...