Geometric constraint solving has applications in a wide variety of elds, such as mechanical engineering, chemical molecular conformation, geometric theorem proving, and surveying. The problem consists of a given set of geometric elements and a description of geometric constraints between the elements. The goal is to nd all placements of the geometric entities which satisfy the given constraints...

refractor ambiguities are big problem in seismic refraction method especially in seismic engineering. there can be hidden subsurface geological phenomena such as hidden faults and shear zones which are not simply predicted by the travel-time graph or some geophysical methods. head wave amplitudes are used to show the resolution of refractor ambiguities and the existence of anisotropy in complex...

In algebraic approaches to geometric computing, the general procedure is as follows [11]: first, the geometric configuration, including both the hypotheses and the conclusion, is translated into an algebraic formulation in a prerequisite algebraic language; second, algebraic computations are carried out to the conclusion by utilizing the computational rules of the algebra and the given hypothes...

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...

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 study, first energy absorption of axial and bending loading is considered. next, thin walled structures under oblique loading are investigated using abaqus computer simulation, where 180 different cases are simulated. simulation results of the thin walled structures under oblique loading were compared with the experimental results of nagel, and good agreement was perceived. simulation r...

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...