Snake robots can contact their environments along their whole bodies. This distributed contact makes them versatile and robust locomotors, but also makes controlling them a challenging problem involving high-dimensional configuration spaces, with no direct way to break their motion down into “driving” and “steering” actions. In this paper, we use concepts from geometric mechanics—e.g., expanded...

Environment size has been shown to influence the reliance on local and global geometric cues during reorientation. Unless changes in environment size are produced by manipulating length and width proportionally, changes in environment size are confounded by the amount of the environment that is visible from a single vantage point. Yet, the influence of the amount of the environment that is visi...

Some interesting aspects of motion and control such as those found in biological and robotic locomotion, and attitude control of spacecraft, involve geometric concepts. When an animal or a robot moves its joints in a periodic fashion, it can rotate or move forward. This observation leads to the general idea that when one variable in a system moves in a periodic fashion, motion of the whole obje...

In this paper we discuss the variety of planar spiral segments and their applications in objects in both the real and artificial world. The discussed curves with monotonic curvature function are well-known in geometric modelling and computer aided geometric design as fair curves, and they are very significant in aesthetic shape modelling. Fair curve segments are used for two-point G1 and G2 Her...

Let S be a set of n points in the plane, let E be the complete Euclidean graph whose point-set is S, and let G be the Delaunay triangulation of S. We present a very simple local algorithm that, given G, constructs a subgraph of G of degree at most 11 that is a geometric spanner of G with stretch factor 2.86, and hence a geometric spanner of E with stretch factor < 7. This algorithm gives an O(n...

‎In this paper first we define the morphism between geometric spaces in two different types‎. ‎We construct two categories of $uu$ and $l$ from geometric spaces then investigate some properties of the two categories‎, ‎for instance $uu$ is topological‎. ‎The relation between hypergroups and geometric spaces is studied‎. ‎By constructing the category $qh$ of $H_{v}$-groups we answer the question...

statement of problem: digital subtraction radiography (dsr) needs reproducible alignment between the x-ray source, the object, and the film for obtaining identical projections of the same anatomic region. purpose: the aim of this study was to evaluate the effect of bite registrations (placed on individual bite blocks) on the reproducibility of parallel periapical radiographs, obtained every 2 m...

geometric morphometric method was used to examine body shape variations among all the seven valid species of the genus alburnus in iran. in total 409 specimens of a. chalcoides, a. filippii, a. atropatenae, a. caeruleus, a. mossulensis, a. hohenackeri and a. zagrosensis were collected from babolrud, baleqlu-chai, miriseh, sarabeleh, gamasiyab, mahabad-chai rivers and the gandoman lagoon, respec...

landmark based geometric morphometrics and comparison of meristic characters was used to understand potential differences between populations of waspi in mashkil and mokran basins. 97 specimens of waspies were caught (64 from mashkil river and 33 from sarbaz river). 14 landmarks were digitized on pictures taken from left side of specimens and meristic characters were counted. data were analyzed...

In this paper we propose an novel algorithm for detecting changes in street scenes when the vehicle revisits sections of the street at different times. The proposed algorithm detects structural geometric changes, changes due to dynamically moving objects and as well as changes in the street appearance (e.g. posters put up) between two traversal times. We exploit geometric, appearance and semant...