Construction of Local Shape Adjustable Surfaces Using Quintic Trigonometric Bézier Curve

Based on quintic trigonometric Bézier like basis functions, the biquintic Bézier surfaces are modeled with four shape parameters that not only possess the key properties of the traditional Bézier surface but also have exceptional shape adjustment. In order to construct Bézier like curves with shape parameters, we present a class of quintic trigonometric Bézier like basis functions, which is an extension of a traditional Bernstein basis. Then, according to these basis functions, we construct three different types of shape adjustable surfaces such as general surface, swept surface and swung surface. In addition to the application of the proposed method, we also discuss the shape adjustment of surfaces showing with curvature nephogram (with and without fixing the boundaries). However, the modeling examples shows that the suggested approach is efficient and easy to implement.

Automation of the inner design of the aircraft

The task of forming the wind-swept surface according to the results of the aircraft’s inner design is described. The approach of the integration of natural and virtual prototyping in the design of equipment compartments is substantiated. Such approaches open up new possibilities for creating intelligent composition algorithms that eliminate the "blind search". For the practical implementation of these approaches, it is necessary to link the appropriate software to standard geometric modeling systems in the form of additional computational modules. Preparing the aircraft for design automation complicates the mathematical description of geometric models of placed objects, increases the complexity of their visualization in modern computer graphics systems and the need to create an additional interface between new geometric models and common CAD systems (SolidWorks, AutoCAD, COMPAS, etc.).

Reproductive biology of NW Mediterranean tonguefish Symphurus nigrescens and Symphurus ligulatus

The population structure and reproductive biology of deep-water continental margin Cynoglossidae is poorly known. Here, we focused on two highly abundant species of the upper slope of the NW Mediterranean Sea, Symphurus nigrescens and S. ligulatus. Megafaunal sampling of 37 hauls was conducted between April 2003 and May 2004 in the Blanes canyon and the adjacent open slope between 300–1500 m depth. The differential bathymetric distribution between the two species was surveyed by standardizing catch data per unit of swept surface and by pooling resulting densities by 100 m depth interval. Females of both species were classified into a five-stage maturity scale according to their external appearance and their gonads dissected for histological analysis. The analysis of the species' bathymetric distribution revealed a differential and only partial overlap. In both species, an increase in size with depth was observed coinciding with the dominance of females in deeper depth strata. The shallower species, S. nigrescens showed a marked spawning period with a peak in summer. In contrast, the deeper-living species, S. ligulatus, presented a longer spawning period ranging from spring to autumn. Moreover, histological examination demonstrated that the ovaries of both species had an asynchronous organization. Present results on spatial-temporal size frequency distribution, spawning temporality and oocyte size are discussed assuming interspecific competition and the different environmental conditions related to their bathymetric distribution.