Prof., Doctor of sciences Volkov V.Ya.,
Ph.D. Ilyasova O.B.,
Ph.D. Kaygorodtseva N.V.
Siberian State Automobile and Road Academy, Russian
Federation
Improvement of the geometrical
graphic preparation of graduates of engineering specialties of technical universities
Now in a number of leading technical
universities in Europe and America, as an alternative to the traditional courses of descriptive
geometry and engineering graphics, a course of engineering graphics and
computer modeling, with some elements of descriptive geometry is proposed; it
greatly simplifies the content of these courses, reducing them to elementary
geometrical graphic information. We
believe it will essentially lower level of geometric, design and creative training of future engineers and
further it will affect the level of development and geometric CAD system device
of graphic editors.
We think that as a new paradigm of the
traditional course of descriptive geometry, it is necessary to do this course
more mathematical, introducing the theory of geometric parameterization not
only objects but also the geometrical conditions, to formalize the solutions of
geometric problems, using an analysis of their conditions and to
do the processes of designing of
surfaces and different manifolds in a form of the algorithm. At the same time
are of interest the generalizations of geometric apparatus on space of
different dimensions and structural characteristics. Such an approach, in our
opinion, will significantly improve the training of engineering specialists, by
developing not only spatial, but also logical thinking; it will also create a
geometric apparatus which can be used as a basis for CAD system and engineering
software products.
To determine the dimension of the space
of images and preimages formulas of counting the dimension of the linear and
curvilinear objects from the theory of parametrisation are applied.
As a basic calculation equation for
determining the dimension (parametric number) linear object the formula of Hermann Grassmann [7], which
is contained in a number of references [5,6] is used:
, (1)
where n - dimension of the space, in
which the Grassmann manifold is considered,
m - dimension of the plane (element),
which forms the Grassmann manifold.
Besides linear elements in the space
E3, there are nonlinear, that is, curvilinear elements: algebraic curves and
surfaces. Calculation of
dimensions of these elements in a space can be done according to the formula of
parametric numbers [2]:
,
(2)
where m - the order
of an algebraic curve, n - the dimension of space.
To determine the dimension of linear
combinations of sets of objects the
formula is used[2]:
(3)
where ri - the
number of basic objects - the dimension of the Grassmann manifold mi - the main
objects belonging to the planes (spaces), p - the number of different basic
objects.
The dimension of Shuberts’ manifolds of
m-planes by the formula [2] is calculated:
(4)
To define the dimension of combinations
of Shuberts’ manifolds the formula [2]
is used:
(5)
To determine the dimension of sets of
linear combinations and curved objects the formula [1] is used:
, (6)
where n - dimension
of the ambient space, m - the dimension of the required main object , p - the
order of curves and surfaces.
Now, at the time of the digital,
information and software technology, when all the information (images, sound,
etc.) are encoded in the symbols and signs, particularly relevant method
proposed by Schubert [8] which is currently being developed by Professor V. Ya.
Volkov [3] .
The method consists in the formal
representation of the generalized condition of incidence of special symbols,
and the possibility of using special algebraic operations to calculate its
dimension.
It is proposed by scientists’ geometry
to use the letter e (pronounced "eshka") in order to describe the
conditions of incidence and in order to identify appropriate sets, then the
generalized condition of incidence will be represented in symbolic form [3]:
(7)
In the following
notation the number of upper and lower indices are equal, and the quantities m,
m-1, ..., 1, 0; am, am-1, ..., a1, a0 - take the values of
natural numbers, including "zero" (0, 1 , 2, 3, 4, ...), ie values
of the numbers which are used to denote the number of objects. The
values of the upper indices m, m-1, ..., 1, 0, define the
dimension of the required linear
manifold (the very meaning of m) and
the dimensions of all its linear subsets up to the point. The lower indices
define the dimension of space or subspace, to which belongs the required
element.
A generalized condition of incidence, as well
as geometric objects of the space, which are characterized by the dimension,
which is determined by the formula [2]:
, (8)
where n - dimension
of the space in which the incidence is considered, m - dimension of the space
(element), that satisfies the generalized condition of incidence, ai – the
lower indices in symbolic interpretations of condition (2).
After calculating the degree of
parallelism the dimension of the conditions of parallelism can be determined according
to the formula [3]:
, (9)
where p / / - value
of the degree of parallelism, n - dimension of the space, in which the condition of parallelism is regarded, m
and q - the dimension of parallel elements, and besides .
Before the direct process of graphical
modeling the properties of the simulated set can be determined by the
properties of prototypes - the model and the specified display, that is, to do an
analysis of baseline data and with some calculations, to predict the number of
responses and their dimension. But
first of all, it is necessary to make sure in the adequacy of the modeled space
and in particular in the adequacy of the constructed model.
Here the notion of "adequacy
model" is taken as the conventional concept of fit of the model which is modeled
as an object or process. In this case we mean adequacy not generally, but
according to the properties of models that are considered essential for the
study [4].
Three axioms [2] are accepted for an
adequate required model:
Axiom 1. The dimension of the space of the images and
preimages are identical.
Axiom 2. Structural characteristics of the space of
images and preimages are equivalent.
Axiom 3. Space of images and preimages are defined
relative to the same class of geometric problems.
On the basis of three axioms, simple
graphical models, which can solve the problem of projective, affine and metric
spaces, are presented.
The model of
the 3-dimensional space:
The projective space
Fig 1. The model of intersecting lines Fig.2 The intersection of the line
and
The
plane
The
affine space: The metric space:
Fig.3 Positional
and affine problems Flg.4 Positional,
affine and metric
problems (Mongers’ draft)
Innovation transformed descriptive
geometry mustn’t be the discipline which serves the engineering graphics and
plays the role of the theoretical bases for the construction drawings. It can and should become a
mathematical discipline with the evidence base and get right for further
development because a solving of the problems of a constructive, analytical and
axiomatic modeling in constructing the displays are still actual today and will
remain so tomorrow.
References:
1. A. Volkov V.Ya.
Graphics optimization models of multivariate processes: a monograph / V.Ya.
Volkov, M.A. Chizhik – Omsk, Omsk State Service University, 2009. - 101 p.
2. Volkov, V. Ya. Multivariate
enumerative geometry: a monograph / V.Ya. Volkov, V. Yu Yurkov. – Omsk, Omsk
State Pedagogical University, 2008. - 244 p.
3. Volkov V.Ya. The theory of parameterization
and modeling of geometric objects of multidimensional spaces and its applications:
Abstract. Thesis of Doctor of
engineering science / VY Volkov. - Moscow Aviation Institute, 1983. - 27 p.
4. Lopatnikov L.I.
Economics and Mathematics Dictionary: Dictionary of modern economics / L.I.
Lopatnikov. - 5th ed., Revised. and add. - Moscow: Delo, 2003. - 520.
5. Rosenfeld B.A.
Multidimensional Space / B.A. Rosenfeld. - Moscow: Nauka, 1966. - 647 p.
6. Chetverukhin N.F.
Parameterization and its applications in geometry / N.F. Chetverukhin, L.
Jackiewicz / / Mathematics in School, 1963. - ¹ 5. - S. 15-23.
7.Grassmann H. Die lineare Ausdehnungslehre ein neuer Zaweig der Mathematik / H.
Grassmann. – Leipzig, 1844. – 279 s.
8.Schubert H. Kalkul der
abzahlenden Geometrie / H. Schubert. – Berlin, heidelberg, New-York: Springer
Verlag, 1979. – 349 s.