GEOMETRICAL STRUCTURES AND THEIR APPLICATION IN TECHNICS
Main researcher
: ŠČURIĆ, VLASTA (46205) Assistants
BABIĆ, IVANKA (70564)
SLIEPČEVIĆ, ANA (43680)
SZIROVICZA, VLASTA (45794)
GORJANC, SONJA (176314)
KUČINIĆ, BRANKO (24350)
BEBAN-BRKIĆ, JELKA (93450)
Type of research: basic Duration from: 10/07/91. to 12/31/95. Papers on project (total): 27
Institution name: Geodetski fakultet, Zagreb (7) Department/Institute: Institute for Higher Geodesy Address: Ulica fra Andrije Kačića Miošića 26 City: 10000 - Zagreb, Croatia
Communication
Phone: 385 (0)1 4561-222
Fax: 385 (0)1 445-410
Summary: The pencils of the cone section types IV, VI, and VII in
isotropic plane have been completely classified. The equations of these
pencils have been given in their normal form, as well as the
interpretation of all geometric invariants. The diagrams are presented by
means of computer and plotter. It has been proved that the special
hyperbola of the isotropic plane is isotropically analogous to the
equilateral hyperbola of Euclidean plane. The classification of the
quadrics in the flag space has also been given, as well as some metric
relations. With the quadrics bundle arranged in quadrics pencils, the rays
of Niče's oriented complex have been determined. The ray congruences of
this complex have been researched, as well as the surfaces made by the
points adjecent to these rays. M-model of the hyperbolic space in
Moebius plane has been made. The graphic projecting in the hyperbolic
space has been given. The Monges method of projections in H3-space is
interpreted in M-model. The round surfaces in construction engineering
have been applied at the level of the projects. By means of isogonal
transformation the focal curve of the range of conics has been brought
into the connection with the polar curve of the stretchable four-bar
linkage in the cinematics. The transformation of the projective space,
called quartic inversion, has been defined and its properties researched.
Quartic inversion was connected with pedal deducing of surfaces, and pedal
surfaces of some (1,2) congruences was constructed by computer. The
library of classes (object-oriented programming) corresponding with the
basic geometric elements and transformations has been formed.
Keywords: two- and three dimensional space: real projective, affine, isotropic, Euclidean, hyperbolic; flag space, Moebius plane, surface, curve, pencil and bundle of surfaces of second order, pencil of conic sections, classification, normal form, curve of the centers, curve of isotropic focal points, transformation, ray complex, ray congruence, design, theory of mechanisms, object-oriented programming
Research goals: The goal of the project is to classify still
unresearched conesection pencils in the isotropic plane, as the basis for
the additional research of quadrics pencils in the isotropic spaces; to
research as many isotropic spaces analogous with those in Euclidean space,
as well as among the isotropic spaces themselves, as possible. To
establish the hyperbolic perspective and there presentation of technical
objcts with an aim to achieve the posibility of having the methods of
macro-projecting at disposal in the future (big dimensions, high speeds).
To prepare focal properties of higher circular curves and surfaces in
the real projective space for the processing by meansof computer graphics,
which makes it possible to expect the wider usage of round surfaces in the
construction engineering. To derive pedal curves of cone sections in
the isotropic plane. To show the connection between the pedal derivation
and square inversion through polar reciprocal curve, and to examine the
properties of the derived curves of 4th order. To derive the pedal
surfaces of the (1,2) congruence by means of quartic inversion.
Linear programming of the material for teaching geometrical subjects and
for making models.
COOPERATION - INSTITUTIONS
Name of institution
: Montanuniversitaet, Institut fuer
Mathematic und angewandte Geometrie Type of institution: University/Faculty Type of cooperation: Joint publishing of scientific papers City: Leoben, Austrija Other information about the project.