Primena rezultata naprednog razvoja prostornih struktura u oblasti 3D transformacija, konstruisanja, novih materijala - Simprolita i tehnologija

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Primena rezultata naprednog razvoja prostornih struktura u oblasti 3D transformacija, konstruisanja, novih materijala - Simprolita i tehnologija (en)
Примена резултата напредног развоја просторних структура у области 3D трансформација, конструисања, нових материјала - Симпролита и технологија (sr)
Primena rezultata naprednog razvoja prostornih struktura u oblasti 3D transformacija, konstruisanja, novih materijala - Simprolita i tehnologija (sr_RS)
Authors

Publications

Seminary Paper as an Additional Task in Teaching Descriptive Geometry

Obradović, Marija; Dimitrijević, Magdalena; Mišić, Slobodan

(Belgrade: Faculty of Architecture in Belgrade; Serbian Society for Geometry and Graphics (SUGIG), 2010)

TY  - CONF
AU  - Obradović, Marija
AU  - Dimitrijević, Magdalena
AU  - Mišić, Slobodan
PY  - 2010
UR  - https://grafar.grf.bg.ac.rs/handle/123456789/2051
AB  - As a result of introducing Bologna process in education, classes
of Descriptive geometry were reduced. In order to acquire such a
complex matter as Descriptive geometry, it was necessary to provide
an additional task as homework. After three years of experience in
practicing classic additional supplementary problems, we made an
attempt to innovate homework, following an idea to achieve
creativity in appliance of Descriptive geometry knowledge in
engineering practice. During the training classes, we recognized the
students’ problem of connecting abstract apprehensions and principles of Descriptive geometry with basic problems and tasks of engineering practice. Form of seminary paper was chosen as an appropriate one for handling the themes and method units of Descriptive geometry program. Each student, in a group of 30 students, had its own theme to elaborate in text interpretation and drawings, also recognizing (photos ...images) and presenting examples in real life (buildings or other examples in art, design or industry).
PB  - Belgrade: Faculty of Architecture in Belgrade; Serbian Society for Geometry and Graphics (SUGIG)
C3  - PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010
T1  - Seminary Paper as an Additional Task in Teaching Descriptive Geometry
EP  - 446
SP  - 435
UR  - https://hdl.handle.net/21.15107/rcub_grafar_2051
ER  - 
@conference{
author = "Obradović, Marija and Dimitrijević, Magdalena and Mišić, Slobodan",
year = "2010",
abstract = "As a result of introducing Bologna process in education, classes
of Descriptive geometry were reduced. In order to acquire such a
complex matter as Descriptive geometry, it was necessary to provide
an additional task as homework. After three years of experience in
practicing classic additional supplementary problems, we made an
attempt to innovate homework, following an idea to achieve
creativity in appliance of Descriptive geometry knowledge in
engineering practice. During the training classes, we recognized the
students’ problem of connecting abstract apprehensions and principles of Descriptive geometry with basic problems and tasks of engineering practice. Form of seminary paper was chosen as an appropriate one for handling the themes and method units of Descriptive geometry program. Each student, in a group of 30 students, had its own theme to elaborate in text interpretation and drawings, also recognizing (photos ...images) and presenting examples in real life (buildings or other examples in art, design or industry).",
publisher = "Belgrade: Faculty of Architecture in Belgrade; Serbian Society for Geometry and Graphics (SUGIG)",
journal = "PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010",
title = "Seminary Paper as an Additional Task in Teaching Descriptive Geometry",
pages = "446-435",
url = "https://hdl.handle.net/21.15107/rcub_grafar_2051"
}
Obradović, M., Dimitrijević, M.,& Mišić, S.. (2010). Seminary Paper as an Additional Task in Teaching Descriptive Geometry. in PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010
Belgrade: Faculty of Architecture in Belgrade; Serbian Society for Geometry and Graphics (SUGIG)., 435-446.
https://hdl.handle.net/21.15107/rcub_grafar_2051
Obradović M, Dimitrijević M, Mišić S. Seminary Paper as an Additional Task in Teaching Descriptive Geometry. in PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010. 2010;:435-446.
https://hdl.handle.net/21.15107/rcub_grafar_2051 .
Obradović, Marija, Dimitrijević, Magdalena, Mišić, Slobodan, "Seminary Paper as an Additional Task in Teaching Descriptive Geometry" in PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010 (2010):435-446,
https://hdl.handle.net/21.15107/rcub_grafar_2051 .

Solving the Situation of Airport Bled by Digital Terrain Modeling Using the Software Package Rinoceros

Petrović, Maja; Obradović, Marija

(Belgrade: Faculty of Architecture in Belgrade; Serbian Society for Geometry and Graphics (SUGIG), 2010)

TY  - CONF
AU  - Petrović, Maja
AU  - Obradović, Marija
PY  - 2010
UR  - https://grafar.grf.bg.ac.rs/handle/123456789/2048
AB  - In the paper, we conducted an examination of topographical
conditions of the airport Bled location, using the digital terrain
modeling. A detailed analysis of the ambience around the airport is
done in relation to natural and artificial obstacles (already built
facilities). The ambience is defined by the imaginary surfaces (the
taxiways, takeoff surface, the access surface, the internal horizontal
surface, conical surface and transitional surface of the takeoff-landing
track) through which can not or should not penetrate obstacles. Using the software package Rhinoceros, we modeled out the terrain at the foot of the mountain massif of the Savinjske Alps and the imaginary surfaces of the airport object, whereat possible obstacles were found. This method of 3D modeling gives a better visualization (display conditions on the ground) than previously applied methods of horizontal projection (2D) and methods of cross and transverse profiles
PB  - Belgrade: Faculty of Architecture in Belgrade; Serbian Society for Geometry and Graphics (SUGIG)
C3  - PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010
T1  - Solving the Situation of Airport Bled by Digital Terrain Modeling Using the Software Package Rinoceros
EP  - 564
SP  - 555
UR  - https://hdl.handle.net/21.15107/rcub_grafar_2048
ER  - 
@conference{
author = "Petrović, Maja and Obradović, Marija",
year = "2010",
abstract = "In the paper, we conducted an examination of topographical
conditions of the airport Bled location, using the digital terrain
modeling. A detailed analysis of the ambience around the airport is
done in relation to natural and artificial obstacles (already built
facilities). The ambience is defined by the imaginary surfaces (the
taxiways, takeoff surface, the access surface, the internal horizontal
surface, conical surface and transitional surface of the takeoff-landing
track) through which can not or should not penetrate obstacles. Using the software package Rhinoceros, we modeled out the terrain at the foot of the mountain massif of the Savinjske Alps and the imaginary surfaces of the airport object, whereat possible obstacles were found. This method of 3D modeling gives a better visualization (display conditions on the ground) than previously applied methods of horizontal projection (2D) and methods of cross and transverse profiles",
publisher = "Belgrade: Faculty of Architecture in Belgrade; Serbian Society for Geometry and Graphics (SUGIG)",
journal = "PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010",
title = "Solving the Situation of Airport Bled by Digital Terrain Modeling Using the Software Package Rinoceros",
pages = "564-555",
url = "https://hdl.handle.net/21.15107/rcub_grafar_2048"
}
Petrović, M.,& Obradović, M.. (2010). Solving the Situation of Airport Bled by Digital Terrain Modeling Using the Software Package Rinoceros. in PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010
Belgrade: Faculty of Architecture in Belgrade; Serbian Society for Geometry and Graphics (SUGIG)., 555-564.
https://hdl.handle.net/21.15107/rcub_grafar_2048
Petrović M, Obradović M. Solving the Situation of Airport Bled by Digital Terrain Modeling Using the Software Package Rinoceros. in PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010. 2010;:555-564.
https://hdl.handle.net/21.15107/rcub_grafar_2048 .
Petrović, Maja, Obradović, Marija, "Solving the Situation of Airport Bled by Digital Terrain Modeling Using the Software Package Rinoceros" in PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010 (2010):555-564,
https://hdl.handle.net/21.15107/rcub_grafar_2048 .

Forming the Cupolae With Concave Polyhedral Surfaces by Corrugating a Fourfold Strip of Equilateral Triangles

Mišić, Slobodan; Obradović, Marija

(Belgrade: Faculty of Architecture in Belgrade; Serbian Society for Geometry and Graphics (SUGIG), 2010)

TY  - CONF
AU  - Mišić, Slobodan
AU  - Obradović, Marija
PY  - 2010
UR  - https://grafar.grf.bg.ac.rs/handle/123456789/2047
AB  - The cupolae with concave polyhedral surfaces consist of: two regular
polygons, n-gone and 2n-gone in parallel planes, interconnected by an
envelope constituted of series of equilateral triangles. The paper
describes cupolae which originate by corrugating of a fourfold strip of
equilateral triangles, forming thereby the envelope of a cupola. In
this manner, a non-convex polyhedron is emerged. Such a method of corrugating the envelope, allows the solutions for generating cupolae with base polygon which number of sides exceedes n=10, which was the maximal number of sides for cupole with the envelope consisted of twofold strip of equilateral triangles. By analyzing the elements of these polyhedra and by help of their paper models, we find geometric constructions and projection procedures by which it is possible to graphically display the cupolae.
PB  - Belgrade: Faculty of Architecture in Belgrade; Serbian Society for Geometry and Graphics (SUGIG)
C3  - PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010
T1  - Forming the Cupolae With Concave Polyhedral Surfaces by Corrugating a Fourfold Strip of Equilateral Triangles
EP  - 374
SP  - 363
UR  - https://hdl.handle.net/21.15107/rcub_grafar_2047
ER  - 
@conference{
author = "Mišić, Slobodan and Obradović, Marija",
year = "2010",
abstract = "The cupolae with concave polyhedral surfaces consist of: two regular
polygons, n-gone and 2n-gone in parallel planes, interconnected by an
envelope constituted of series of equilateral triangles. The paper
describes cupolae which originate by corrugating of a fourfold strip of
equilateral triangles, forming thereby the envelope of a cupola. In
this manner, a non-convex polyhedron is emerged. Such a method of corrugating the envelope, allows the solutions for generating cupolae with base polygon which number of sides exceedes n=10, which was the maximal number of sides for cupole with the envelope consisted of twofold strip of equilateral triangles. By analyzing the elements of these polyhedra and by help of their paper models, we find geometric constructions and projection procedures by which it is possible to graphically display the cupolae.",
publisher = "Belgrade: Faculty of Architecture in Belgrade; Serbian Society for Geometry and Graphics (SUGIG)",
journal = "PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010",
title = "Forming the Cupolae With Concave Polyhedral Surfaces by Corrugating a Fourfold Strip of Equilateral Triangles",
pages = "374-363",
url = "https://hdl.handle.net/21.15107/rcub_grafar_2047"
}
Mišić, S.,& Obradović, M.. (2010). Forming the Cupolae With Concave Polyhedral Surfaces by Corrugating a Fourfold Strip of Equilateral Triangles. in PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010
Belgrade: Faculty of Architecture in Belgrade; Serbian Society for Geometry and Graphics (SUGIG)., 363-374.
https://hdl.handle.net/21.15107/rcub_grafar_2047
Mišić S, Obradović M. Forming the Cupolae With Concave Polyhedral Surfaces by Corrugating a Fourfold Strip of Equilateral Triangles. in PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010. 2010;:363-374.
https://hdl.handle.net/21.15107/rcub_grafar_2047 .
Mišić, Slobodan, Obradović, Marija, "Forming the Cupolae With Concave Polyhedral Surfaces by Corrugating a Fourfold Strip of Equilateral Triangles" in PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010 (2010):363-374,
https://hdl.handle.net/21.15107/rcub_grafar_2047 .

Constructing the Egg Curves Using the Golden Ratio of Pentagon

Petrović, Maja; Obradović, Marija

(Belgrade: Faculty of Architecture in Belgrade; Serbian Society for Geometry and Graphics (SUGIG), 2010)

TY  - CONF
AU  - Petrović, Maja
AU  - Obradović, Marija
PY  - 2010
UR  - https://grafar.grf.bg.ac.rs/handle/123456789/2049
AB  - In the paper it is considered a construction of an egg curve
obtained by continual joining of the circular arcs with three different
centers. These three centers form sharp or flat triangles of the
pentagon (sharp and flat triangles are the basic building shapes of
Penrose tiling). They have many relationships with both the Fibonacci numbers and Phi. In such an egg curve, it is possible to inscribe two juxtaposed pentagons. We give also another construction which employs several, even infinite number of the pentagons. Those pentagons are forming a sequence related to Fibonacci sequence. The construction using the flat triangles will provide a curve which ratio between length of the perimeter and the sum of the length of its minor and major axes will give the coefficient Φ.
PB  - Belgrade: Faculty of Architecture in Belgrade; Serbian Society for Geometry and Graphics (SUGIG)
C3  - PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010
T1  - Constructing the Egg Curves Using the Golden Ratio of Pentagon
EP  - 541
SP  - 532
UR  - https://hdl.handle.net/21.15107/rcub_grafar_2049
ER  - 
@conference{
author = "Petrović, Maja and Obradović, Marija",
year = "2010",
abstract = "In the paper it is considered a construction of an egg curve
obtained by continual joining of the circular arcs with three different
centers. These three centers form sharp or flat triangles of the
pentagon (sharp and flat triangles are the basic building shapes of
Penrose tiling). They have many relationships with both the Fibonacci numbers and Phi. In such an egg curve, it is possible to inscribe two juxtaposed pentagons. We give also another construction which employs several, even infinite number of the pentagons. Those pentagons are forming a sequence related to Fibonacci sequence. The construction using the flat triangles will provide a curve which ratio between length of the perimeter and the sum of the length of its minor and major axes will give the coefficient Φ.",
publisher = "Belgrade: Faculty of Architecture in Belgrade; Serbian Society for Geometry and Graphics (SUGIG)",
journal = "PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010",
title = "Constructing the Egg Curves Using the Golden Ratio of Pentagon",
pages = "541-532",
url = "https://hdl.handle.net/21.15107/rcub_grafar_2049"
}
Petrović, M.,& Obradović, M.. (2010). Constructing the Egg Curves Using the Golden Ratio of Pentagon. in PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010
Belgrade: Faculty of Architecture in Belgrade; Serbian Society for Geometry and Graphics (SUGIG)., 532-541.
https://hdl.handle.net/21.15107/rcub_grafar_2049
Petrović M, Obradović M. Constructing the Egg Curves Using the Golden Ratio of Pentagon. in PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010. 2010;:532-541.
https://hdl.handle.net/21.15107/rcub_grafar_2049 .
Petrović, Maja, Obradović, Marija, "Constructing the Egg Curves Using the Golden Ratio of Pentagon" in PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010 (2010):532-541,
https://hdl.handle.net/21.15107/rcub_grafar_2049 .

Conic Section of a Type of Egg Curve Based Conoid

Obradović, Marija; Malešević, Branko; Petrović, Maja

(Belgrade: Faculty of Architecture in Belgrade; Serbian Society for Geometry and Graphics (SUGIG), 2010)

TY  - CONF
AU  - Obradović, Marija
AU  - Malešević, Branko
AU  - Petrović, Maja
PY  - 2010
UR  - https://grafar.grf.bg.ac.rs/handle/123456789/2052
AB  - A cubic egg curve obtained by Hügelschäffer’s construction,
can be spatially interpreted as a plane section of a type of a conoid
set through a specially chosen 4-th order intersecting curve of two
quadrics: right cylinder and cone. That implies that the apex of a
cone must lay on the axis of a cylinder in order to obtain one sheet
surface. This type of conoid will be of 4-th order, and will exclude
plane sections by conics. We consider a special case of forming an akin conoid that would include also conic sections. If the apex of the cone is set off the cylinder axis, there would appear a double conoid, as a surface set through the intersection curve of the quadrics. Its plane section will be a double egg curve obtained by generalized Hügelschäffer’s construction. In case that cylinder and cone would intersect by a degenerated 4-th degree space curve on two conics (circle and ellipse), there would emerge double egg curve, as a plane section of the double conoid. The curve degenerates onto ellipse and a quartic curve - Granville’s egg. We also gave a mathematical condition of degeneration of the base double egg curve.
PB  - Belgrade: Faculty of Architecture in Belgrade; Serbian Society for Geometry and Graphics (SUGIG)
C3  - PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010
T1  - Conic Section of a Type of Egg Curve Based Conoid
EP  - 466
SP  - 447
UR  - https://hdl.handle.net/21.15107/rcub_grafar_2052
ER  - 
@conference{
author = "Obradović, Marija and Malešević, Branko and Petrović, Maja",
year = "2010",
abstract = "A cubic egg curve obtained by Hügelschäffer’s construction,
can be spatially interpreted as a plane section of a type of a conoid
set through a specially chosen 4-th order intersecting curve of two
quadrics: right cylinder and cone. That implies that the apex of a
cone must lay on the axis of a cylinder in order to obtain one sheet
surface. This type of conoid will be of 4-th order, and will exclude
plane sections by conics. We consider a special case of forming an akin conoid that would include also conic sections. If the apex of the cone is set off the cylinder axis, there would appear a double conoid, as a surface set through the intersection curve of the quadrics. Its plane section will be a double egg curve obtained by generalized Hügelschäffer’s construction. In case that cylinder and cone would intersect by a degenerated 4-th degree space curve on two conics (circle and ellipse), there would emerge double egg curve, as a plane section of the double conoid. The curve degenerates onto ellipse and a quartic curve - Granville’s egg. We also gave a mathematical condition of degeneration of the base double egg curve.",
publisher = "Belgrade: Faculty of Architecture in Belgrade; Serbian Society for Geometry and Graphics (SUGIG)",
journal = "PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010",
title = "Conic Section of a Type of Egg Curve Based Conoid",
pages = "466-447",
url = "https://hdl.handle.net/21.15107/rcub_grafar_2052"
}
Obradović, M., Malešević, B.,& Petrović, M.. (2010). Conic Section of a Type of Egg Curve Based Conoid. in PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010
Belgrade: Faculty of Architecture in Belgrade; Serbian Society for Geometry and Graphics (SUGIG)., 447-466.
https://hdl.handle.net/21.15107/rcub_grafar_2052
Obradović M, Malešević B, Petrović M. Conic Section of a Type of Egg Curve Based Conoid. in PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010. 2010;:447-466.
https://hdl.handle.net/21.15107/rcub_grafar_2052 .
Obradović, Marija, Malešević, Branko, Petrović, Maja, "Conic Section of a Type of Egg Curve Based Conoid" in PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010 (2010):447-466,
https://hdl.handle.net/21.15107/rcub_grafar_2052 .

Developement Of Digital Model Of Terrain (Dmt) Using Autocad And Surfing Software Packages

Vujičić, Bojan; Šušić, Vladimir; Obradović, Marija

(Belgrade: Faculty of Architecture in Belgrade; Serbian Society for Geometry and Graphics (SUGIG), 2010)

TY  - CONF
AU  - Vujičić, Bojan
AU  - Šušić, Vladimir
AU  - Obradović, Marija
PY  - 2010
UR  - https://grafar.grf.bg.ac.rs/handle/123456789/2046
AB  - This paper considers a problem of developing a digital model of
topographic surface (terrain) which, as an empirical surface, requires
a specific approach in 3D modeling. The solution is found by using two
software packages: AutoCAD, used in classes of Computational
Geometry, and Surfing, used as an educational tool in several subjects at the department of Survey, on the Faculty of Civil Engineering in Belgrade. We compared these two techniques of DTM development, in order to determine the advantages and deficiencies of both. Through creating different digital models and comparing the obtained results, our goal was to contribute upgrading the techniques of processing topographic surfaces, as an important segment of planning that connects Computational Geometry and Surveying
PB  - Belgrade: Faculty of Architecture in Belgrade; Serbian Society for Geometry and Graphics (SUGIG)
C3  - PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010
T1  - Developement Of Digital Model Of Terrain (Dmt) Using Autocad And Surfing Software Packages
EP  - 705
SP  - 691
UR  - https://hdl.handle.net/21.15107/rcub_grafar_2046
ER  - 
@conference{
author = "Vujičić, Bojan and Šušić, Vladimir and Obradović, Marija",
year = "2010",
abstract = "This paper considers a problem of developing a digital model of
topographic surface (terrain) which, as an empirical surface, requires
a specific approach in 3D modeling. The solution is found by using two
software packages: AutoCAD, used in classes of Computational
Geometry, and Surfing, used as an educational tool in several subjects at the department of Survey, on the Faculty of Civil Engineering in Belgrade. We compared these two techniques of DTM development, in order to determine the advantages and deficiencies of both. Through creating different digital models and comparing the obtained results, our goal was to contribute upgrading the techniques of processing topographic surfaces, as an important segment of planning that connects Computational Geometry and Surveying",
publisher = "Belgrade: Faculty of Architecture in Belgrade; Serbian Society for Geometry and Graphics (SUGIG)",
journal = "PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010",
title = "Developement Of Digital Model Of Terrain (Dmt) Using Autocad And Surfing Software Packages",
pages = "705-691",
url = "https://hdl.handle.net/21.15107/rcub_grafar_2046"
}
Vujičić, B., Šušić, V.,& Obradović, M.. (2010). Developement Of Digital Model Of Terrain (Dmt) Using Autocad And Surfing Software Packages. in PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010
Belgrade: Faculty of Architecture in Belgrade; Serbian Society for Geometry and Graphics (SUGIG)., 691-705.
https://hdl.handle.net/21.15107/rcub_grafar_2046
Vujičić B, Šušić V, Obradović M. Developement Of Digital Model Of Terrain (Dmt) Using Autocad And Surfing Software Packages. in PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010. 2010;:691-705.
https://hdl.handle.net/21.15107/rcub_grafar_2046 .
Vujičić, Bojan, Šušić, Vladimir, Obradović, Marija, "Developement Of Digital Model Of Terrain (Dmt) Using Autocad And Surfing Software Packages" in PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010 (2010):691-705,
https://hdl.handle.net/21.15107/rcub_grafar_2046 .

The Complement of the Hugelschaffer’s Construction of the Egg Curve

Petrović, Maja; Obradović, Marija

(Belgrade: Faculty of Architecture in Belgrade; Serbian Society for Geometry and Graphics (SUGIG), 2010)

TY  - CONF
AU  - Petrović, Maja
AU  - Obradović, Marija
PY  - 2010
UR  - https://grafar.grf.bg.ac.rs/handle/123456789/2050
AB  - Hügelschäffer’s construction, based on the distortion of the
ellipse construction, provides an egg-shaped curve. This curve is a
mixed cubic curve, the cubic hyperbolic parabola of type A. Curve is a
three-branched and except the oval arising from mentioned construction, it contains two more branches which converge towards two asymptotes: one linear and one parabolic asymptote. Since the Hügelschäffer’s construction does not give a solution for this part of the curve, we discussed the possibility of amendments to this construction, so that the entire course of the curve could be graphically processed. We came to a solution using Cartesian hyperbole complementary to the circles from Hügelschäffer’s construction.
PB  - Belgrade: Faculty of Architecture in Belgrade; Serbian Society for Geometry and Graphics (SUGIG)
C3  - PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010
T1  - The Complement of the Hugelschaffer’s Construction of the Egg Curve
EP  - 530
SP  - 520
UR  - https://hdl.handle.net/21.15107/rcub_grafar_2050
ER  - 
@conference{
author = "Petrović, Maja and Obradović, Marija",
year = "2010",
abstract = "Hügelschäffer’s construction, based on the distortion of the
ellipse construction, provides an egg-shaped curve. This curve is a
mixed cubic curve, the cubic hyperbolic parabola of type A. Curve is a
three-branched and except the oval arising from mentioned construction, it contains two more branches which converge towards two asymptotes: one linear and one parabolic asymptote. Since the Hügelschäffer’s construction does not give a solution for this part of the curve, we discussed the possibility of amendments to this construction, so that the entire course of the curve could be graphically processed. We came to a solution using Cartesian hyperbole complementary to the circles from Hügelschäffer’s construction.",
publisher = "Belgrade: Faculty of Architecture in Belgrade; Serbian Society for Geometry and Graphics (SUGIG)",
journal = "PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010",
title = "The Complement of the Hugelschaffer’s Construction of the Egg Curve",
pages = "530-520",
url = "https://hdl.handle.net/21.15107/rcub_grafar_2050"
}
Petrović, M.,& Obradović, M.. (2010). The Complement of the Hugelschaffer’s Construction of the Egg Curve. in PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010
Belgrade: Faculty of Architecture in Belgrade; Serbian Society for Geometry and Graphics (SUGIG)., 520-530.
https://hdl.handle.net/21.15107/rcub_grafar_2050
Petrović M, Obradović M. The Complement of the Hugelschaffer’s Construction of the Egg Curve. in PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010. 2010;:520-530.
https://hdl.handle.net/21.15107/rcub_grafar_2050 .
Petrović, Maja, Obradović, Marija, "The Complement of the Hugelschaffer’s Construction of the Egg Curve" in PROCEEDINGS | BILTEN of 25th National and 2nd International Scientific Conference moNGeometrija 2010 (2010):520-530,
https://hdl.handle.net/21.15107/rcub_grafar_2050 .

About planar sections of a type of egg curve based conoid

Obradović, Marija; Petrović, Maja; Malešević, Branko

(Novi Sad: Faculty of Sciences, University of Novi Sad - Department of Mathematics and Informatics, 2009)

TY  - CONF
AU  - Obradović, Marija
AU  - Petrović, Maja
AU  - Malešević, Branko
PY  - 2009
UR  - https://grafar.grf.bg.ac.rs/handle/123456789/2026
AB  - Starting from a type of conoid which is based on a cubic egg curve obtained by Hügelschäffer’s construction, it is considered a possible occurrence of related type of conoid, which would include conic curve as a part of its plane section.  The solution is accomplished by constructively – geometrical methods, supported by Rhinoceros software package.
PB  - Novi Sad: Faculty of Sciences, University of Novi Sad - Department of Mathematics and Informatics
C3  - Book of Abstracts / XVIII Conference on Applied Mathematics PRIM 2009, Subotica, 25-27. maj, 2009
T1  - About planar sections of a type of egg curve based conoid
SP  - 14
UR  - https://hdl.handle.net/21.15107/rcub_grafar_2026
ER  - 
@conference{
author = "Obradović, Marija and Petrović, Maja and Malešević, Branko",
year = "2009",
abstract = "Starting from a type of conoid which is based on a cubic egg curve obtained by Hügelschäffer’s construction, it is considered a possible occurrence of related type of conoid, which would include conic curve as a part of its plane section.  The solution is accomplished by constructively – geometrical methods, supported by Rhinoceros software package.",
publisher = "Novi Sad: Faculty of Sciences, University of Novi Sad - Department of Mathematics and Informatics",
journal = "Book of Abstracts / XVIII Conference on Applied Mathematics PRIM 2009, Subotica, 25-27. maj, 2009",
title = "About planar sections of a type of egg curve based conoid",
pages = "14",
url = "https://hdl.handle.net/21.15107/rcub_grafar_2026"
}
Obradović, M., Petrović, M.,& Malešević, B.. (2009). About planar sections of a type of egg curve based conoid. in Book of Abstracts / XVIII Conference on Applied Mathematics PRIM 2009, Subotica, 25-27. maj, 2009
Novi Sad: Faculty of Sciences, University of Novi Sad - Department of Mathematics and Informatics., 14.
https://hdl.handle.net/21.15107/rcub_grafar_2026
Obradović M, Petrović M, Malešević B. About planar sections of a type of egg curve based conoid. in Book of Abstracts / XVIII Conference on Applied Mathematics PRIM 2009, Subotica, 25-27. maj, 2009. 2009;:14.
https://hdl.handle.net/21.15107/rcub_grafar_2026 .
Obradović, Marija, Petrović, Maja, Malešević, Branko, "About planar sections of a type of egg curve based conoid" in Book of Abstracts / XVIII Conference on Applied Mathematics PRIM 2009, Subotica, 25-27. maj, 2009 (2009):14,
https://hdl.handle.net/21.15107/rcub_grafar_2026 .

Prevođenje konkavnih kupola druge vrste u tridimenzionalne konstruktivne sisteme – prostorne rešetke

Obradović, Marija; Mišić, Slobodan

(Niš: Faculty of Architecture and Civil Engineering in Niš; Serbian Society for Geometry and Graphics (SUGIG), 2008)

TY  - CONF
AU  - Obradović, Marija
AU  - Mišić, Slobodan
PY  - 2008
UR  - https://grafar.grf.bg.ac.rs/handle/123456789/2041
AB  - Cilj istraživanja ovog rada je bio da se iznađu geometrijska rešenja za formiranje prostornih rešetki nad pravilnim poligonalnim osnovama, tako da se postigne prostorna struktura koja ispunjava zahteve rigidnosti datog sklopa, po osnovi geometrijske stabilnosti trougla kao
ravne figure. Takođe, težnja je bila i da se nađe što jednostavnije rešenje, sa upotrebom minimalnog broja različitih štapova u samoj konfiguraciji prostorne rešetke. U tom smislu, moguće je primeniti nekoliko varijanti rasporeda štapova. Najekonomičnije od njih se svodi upravo na geometriju konkavnih kupola druge vrste, buduci da se radi o jednakoivičnim poliedrima kao osnovama za dalju nadogradnju tridimenzionalnih stuktura. Omotač konkavnih kupola druge vrste nastaje nabiranjem ravne mreže, a prevođenjem ivica ovog omotača u sistem štapova, uz dodavanje minimalnog broja različitih tipskih štapova razupirača, dobijamo strukturu kompozitnog poliedra prostorne rešetke.
AB  - The aim of this paper is to find geometric solutions for the formation of space frames over regular polygonal bases, so to achieve a spatial structure that meets the rigidity requirements of a given assembly, based on the geometric stability of a triangle as a flat figure. Also, the aim is to find the simplest possible solution, with the use of a minimum number of different struts in the configuration of the space frame. In that sense, it is possible to apply several variants of strut arrangement. The most material-efficient of them comes down to the geometry of concave cupolae of the second sort, since they are polyhedra of all the edges of the same length, as a basis for further upgrading of three-dimensional structures. The lateral surface of a concave cupola of the second sort is created by folding its triangular planar net, and by transposing the edges of this surface into a system of struts, having the minimum number of different type struts, we obtain the structure of a composite polyhedron in the role of a space frame.
PB  - Niš: Faculty of Architecture and Civil Engineering in Niš; Serbian Society for Geometry and Graphics (SUGIG)
C3  - Proccedings | Zbornik radova (24th national and 1st international scientific conference moNGeometrija 2008)
T1  - Prevođenje konkavnih kupola druge vrste u tridimenzionalne konstruktivne sisteme – prostorne rešetke
EP  - 221
SP  - 209
UR  - https://hdl.handle.net/21.15107/rcub_grafar_2041
ER  - 
@conference{
author = "Obradović, Marija and Mišić, Slobodan",
year = "2008",
abstract = "Cilj istraživanja ovog rada je bio da se iznađu geometrijska rešenja za formiranje prostornih rešetki nad pravilnim poligonalnim osnovama, tako da se postigne prostorna struktura koja ispunjava zahteve rigidnosti datog sklopa, po osnovi geometrijske stabilnosti trougla kao
ravne figure. Takođe, težnja je bila i da se nađe što jednostavnije rešenje, sa upotrebom minimalnog broja različitih štapova u samoj konfiguraciji prostorne rešetke. U tom smislu, moguće je primeniti nekoliko varijanti rasporeda štapova. Najekonomičnije od njih se svodi upravo na geometriju konkavnih kupola druge vrste, buduci da se radi o jednakoivičnim poliedrima kao osnovama za dalju nadogradnju tridimenzionalnih stuktura. Omotač konkavnih kupola druge vrste nastaje nabiranjem ravne mreže, a prevođenjem ivica ovog omotača u sistem štapova, uz dodavanje minimalnog broja različitih tipskih štapova razupirača, dobijamo strukturu kompozitnog poliedra prostorne rešetke., The aim of this paper is to find geometric solutions for the formation of space frames over regular polygonal bases, so to achieve a spatial structure that meets the rigidity requirements of a given assembly, based on the geometric stability of a triangle as a flat figure. Also, the aim is to find the simplest possible solution, with the use of a minimum number of different struts in the configuration of the space frame. In that sense, it is possible to apply several variants of strut arrangement. The most material-efficient of them comes down to the geometry of concave cupolae of the second sort, since they are polyhedra of all the edges of the same length, as a basis for further upgrading of three-dimensional structures. The lateral surface of a concave cupola of the second sort is created by folding its triangular planar net, and by transposing the edges of this surface into a system of struts, having the minimum number of different type struts, we obtain the structure of a composite polyhedron in the role of a space frame.",
publisher = "Niš: Faculty of Architecture and Civil Engineering in Niš; Serbian Society for Geometry and Graphics (SUGIG)",
journal = "Proccedings | Zbornik radova (24th national and 1st international scientific conference moNGeometrija 2008)",
title = "Prevođenje konkavnih kupola druge vrste u tridimenzionalne konstruktivne sisteme – prostorne rešetke",
pages = "221-209",
url = "https://hdl.handle.net/21.15107/rcub_grafar_2041"
}
Obradović, M.,& Mišić, S.. (2008). Prevođenje konkavnih kupola druge vrste u tridimenzionalne konstruktivne sisteme – prostorne rešetke. in Proccedings | Zbornik radova (24th national and 1st international scientific conference moNGeometrija 2008)
Niš: Faculty of Architecture and Civil Engineering in Niš; Serbian Society for Geometry and Graphics (SUGIG)., 209-221.
https://hdl.handle.net/21.15107/rcub_grafar_2041
Obradović M, Mišić S. Prevođenje konkavnih kupola druge vrste u tridimenzionalne konstruktivne sisteme – prostorne rešetke. in Proccedings | Zbornik radova (24th national and 1st international scientific conference moNGeometrija 2008). 2008;:209-221.
https://hdl.handle.net/21.15107/rcub_grafar_2041 .
Obradović, Marija, Mišić, Slobodan, "Prevođenje konkavnih kupola druge vrste u tridimenzionalne konstruktivne sisteme – prostorne rešetke" in Proccedings | Zbornik radova (24th national and 1st international scientific conference moNGeometrija 2008) (2008):209-221,
https://hdl.handle.net/21.15107/rcub_grafar_2041 .

Prostorna interpretacija Hugelschaffer-ove konstrukcije jajaste krive

Obradović, Marija; Petrović, Maja

(Niš: Faculty of Architecture and Civil Engineering in Niš; Serbian Society for Geometry and Graphics (SUGIG), 2008)

TY  - CONF
AU  - Obradović, Marija
AU  - Petrović, Maja
PY  - 2008
UR  - https://grafar.grf.bg.ac.rs/handle/123456789/2042
AB  - Konstrukcija jajaste kubne krive Hügelschäffer-ovom metodom, zasniva se na konstrukciji elipse metodom koncentričnih krugova različitih radijusa, a i b, koji odgovaraju parametrima elipse. Načinjen je pokušaj da se prostornom interpretacijom ovih krugova u bazise konusa I cilindra, objasni vrsta pravoizvodne površi koja bi kao ravan presek imala upravo ovako nastalu zatvorenu jajastu krivu. U pitanju je konoid koji kao jednu vodilju ima pravu, a kao drugu vodilju prostornu presečnu krivu ovih kvadrika.
AB  - The construction of the ovoid cubic curve by the Hügelschäffer method is based on the construction of the ellipse by the method of concentric circles of different radii, a and b, which correspond to the parameters of the ellipse. An attempt was made to explain the type of rectilinear surface by the spatial interpretation of these circles into the bases of a cone and a cylinder, which, as a plane section, will have a closed egg curve formed in this way. the rectlinear surface is a conoid that has a straight line as a directrix, and a spatial cross-sectional curve of the above quadrics as the other directrix.
PB  - Niš: Faculty of Architecture and Civil Engineering in Niš; Serbian Society for Geometry and Graphics (SUGIG)
C3  - Proccedings | Zbornik radova (24th national and 1st international scientific conference moNGeometrija 2008)
T1  - Prostorna interpretacija Hugelschaffer-ove konstrukcije jajaste krive
EP  - 232
SP  - 222
UR  - https://hdl.handle.net/21.15107/rcub_grafar_2042
ER  - 
@conference{
author = "Obradović, Marija and Petrović, Maja",
year = "2008",
abstract = "Konstrukcija jajaste kubne krive Hügelschäffer-ovom metodom, zasniva se na konstrukciji elipse metodom koncentričnih krugova različitih radijusa, a i b, koji odgovaraju parametrima elipse. Načinjen je pokušaj da se prostornom interpretacijom ovih krugova u bazise konusa I cilindra, objasni vrsta pravoizvodne površi koja bi kao ravan presek imala upravo ovako nastalu zatvorenu jajastu krivu. U pitanju je konoid koji kao jednu vodilju ima pravu, a kao drugu vodilju prostornu presečnu krivu ovih kvadrika., The construction of the ovoid cubic curve by the Hügelschäffer method is based on the construction of the ellipse by the method of concentric circles of different radii, a and b, which correspond to the parameters of the ellipse. An attempt was made to explain the type of rectilinear surface by the spatial interpretation of these circles into the bases of a cone and a cylinder, which, as a plane section, will have a closed egg curve formed in this way. the rectlinear surface is a conoid that has a straight line as a directrix, and a spatial cross-sectional curve of the above quadrics as the other directrix.",
publisher = "Niš: Faculty of Architecture and Civil Engineering in Niš; Serbian Society for Geometry and Graphics (SUGIG)",
journal = "Proccedings | Zbornik radova (24th national and 1st international scientific conference moNGeometrija 2008)",
title = "Prostorna interpretacija Hugelschaffer-ove konstrukcije jajaste krive",
pages = "232-222",
url = "https://hdl.handle.net/21.15107/rcub_grafar_2042"
}
Obradović, M.,& Petrović, M.. (2008). Prostorna interpretacija Hugelschaffer-ove konstrukcije jajaste krive. in Proccedings | Zbornik radova (24th national and 1st international scientific conference moNGeometrija 2008)
Niš: Faculty of Architecture and Civil Engineering in Niš; Serbian Society for Geometry and Graphics (SUGIG)., 222-232.
https://hdl.handle.net/21.15107/rcub_grafar_2042
Obradović M, Petrović M. Prostorna interpretacija Hugelschaffer-ove konstrukcije jajaste krive. in Proccedings | Zbornik radova (24th national and 1st international scientific conference moNGeometrija 2008). 2008;:222-232.
https://hdl.handle.net/21.15107/rcub_grafar_2042 .
Obradović, Marija, Petrović, Maja, "Prostorna interpretacija Hugelschaffer-ove konstrukcije jajaste krive" in Proccedings | Zbornik radova (24th national and 1st international scientific conference moNGeometrija 2008) (2008):222-232,
https://hdl.handle.net/21.15107/rcub_grafar_2042 .

Transposing an Octogonal Cupola of Second Sort Into a Bionic Polyspherical Form

Obradović, Marija; Jović, Biljana

(Dresden: Technische Universität Dresden; International Society for Geometry and Graphics (ISGG), 2008)

TY  - CONF
AU  - Obradović, Marija
AU  - Jović, Biljana
PY  - 2008
UR  - https://grafar.grf.bg.ac.rs/handle/123456789/2043
AB  - In the paper there is presented a method of transposing a polyhedral structure, composed of two
regular polygons: octagon and hexadecagon as the bases, and the envelope formed of equilateral triangular strip, which is named octagonal concave cupola of second sort, into a bionic form of curved surfaces. Cupola is term taken from Johnson’s solids (J3, J4, J5), but in extended sense, for the lack of subsistent name, though its geometry is closest to the geometry of those Johnson’s solids. Geometry of octagonal concave cupola of second sort has subserved as a model for congenial geometrical form, which includes spherical segments instead of equilateral triangles and base polygons, by ablation of which we obtain a close spatial form. The methods of Constructive geometry are applied in the paper. Since the coordinates of the points and the parameters of octagonal concave cupola of second sort are known, they have been used for defining the spherical radii, which segments form a spatial structure, whereat the new polispherical shape, with its new qualities would be obtained, instead of polyhedral. Four different spherical segments, would substitute a spatial hexahedral layout, consisted of six equilateral triangles, and the fifth would link them into a convergent ensemble, while the base polygon would be replaced with new spherical polygonal calotte. This form preserves altitudes, distances and symmetries of original polyhedron, by which transposing it is obtained. Although the majority of geometrical parameters are invariant to the original geometrical matrix, the new geometrical configurations are found, similar to the ones from nature, as the result of such a substitution of surfaces. They bring additional aesthetic, applicable and static properties, interesting for further researches. This shows that in the future implementation in constructive systems, the plane panels of equilateral triangles can be replaced by spherical shells. There would exist two variants of such a transposing of polyhedral surface to a polyspherical, whereat in the first case the spherical shells would be concave, and in second they would be convex, which refer to two variants of forming the envelope of concave cupola of second sort. The structure derived in this manner, can find its application in architecture, civil engineering, landscape architecture and design.
PB  - Dresden: Technische Universität Dresden; International Society for Geometry and Graphics (ISGG)
C3  - Proceedings of the 13th International Conference on Geometry and Graphic - ICGG 2008
T1  - Transposing an Octogonal Cupola of Second Sort Into a Bionic Polyspherical Form
EP  - 9
SP  - 1
SP  - 114 (in Program book)
UR  - https://hdl.handle.net/21.15107/rcub_grafar_2043
ER  - 
@conference{
author = "Obradović, Marija and Jović, Biljana",
year = "2008",
abstract = "In the paper there is presented a method of transposing a polyhedral structure, composed of two
regular polygons: octagon and hexadecagon as the bases, and the envelope formed of equilateral triangular strip, which is named octagonal concave cupola of second sort, into a bionic form of curved surfaces. Cupola is term taken from Johnson’s solids (J3, J4, J5), but in extended sense, for the lack of subsistent name, though its geometry is closest to the geometry of those Johnson’s solids. Geometry of octagonal concave cupola of second sort has subserved as a model for congenial geometrical form, which includes spherical segments instead of equilateral triangles and base polygons, by ablation of which we obtain a close spatial form. The methods of Constructive geometry are applied in the paper. Since the coordinates of the points and the parameters of octagonal concave cupola of second sort are known, they have been used for defining the spherical radii, which segments form a spatial structure, whereat the new polispherical shape, with its new qualities would be obtained, instead of polyhedral. Four different spherical segments, would substitute a spatial hexahedral layout, consisted of six equilateral triangles, and the fifth would link them into a convergent ensemble, while the base polygon would be replaced with new spherical polygonal calotte. This form preserves altitudes, distances and symmetries of original polyhedron, by which transposing it is obtained. Although the majority of geometrical parameters are invariant to the original geometrical matrix, the new geometrical configurations are found, similar to the ones from nature, as the result of such a substitution of surfaces. They bring additional aesthetic, applicable and static properties, interesting for further researches. This shows that in the future implementation in constructive systems, the plane panels of equilateral triangles can be replaced by spherical shells. There would exist two variants of such a transposing of polyhedral surface to a polyspherical, whereat in the first case the spherical shells would be concave, and in second they would be convex, which refer to two variants of forming the envelope of concave cupola of second sort. The structure derived in this manner, can find its application in architecture, civil engineering, landscape architecture and design.",
publisher = "Dresden: Technische Universität Dresden; International Society for Geometry and Graphics (ISGG)",
journal = "Proceedings of the 13th International Conference on Geometry and Graphic - ICGG 2008",
title = "Transposing an Octogonal Cupola of Second Sort Into a Bionic Polyspherical Form",
pages = "9-1-114 (in Program book)",
url = "https://hdl.handle.net/21.15107/rcub_grafar_2043"
}
Obradović, M.,& Jović, B.. (2008). Transposing an Octogonal Cupola of Second Sort Into a Bionic Polyspherical Form. in Proceedings of the 13th International Conference on Geometry and Graphic - ICGG 2008
Dresden: Technische Universität Dresden; International Society for Geometry and Graphics (ISGG)., 1-9.
https://hdl.handle.net/21.15107/rcub_grafar_2043
Obradović M, Jović B. Transposing an Octogonal Cupola of Second Sort Into a Bionic Polyspherical Form. in Proceedings of the 13th International Conference on Geometry and Graphic - ICGG 2008. 2008;:1-9.
https://hdl.handle.net/21.15107/rcub_grafar_2043 .
Obradović, Marija, Jović, Biljana, "Transposing an Octogonal Cupola of Second Sort Into a Bionic Polyspherical Form" in Proceedings of the 13th International Conference on Geometry and Graphic - ICGG 2008 (2008):1-9,
https://hdl.handle.net/21.15107/rcub_grafar_2043 .

Concave Regular Faced Cupolae of Second Sort

Obradović, Marija; Mišić, Slobodan

(Dresden: Technische Universität Dresden; International Society for Geometry and Graphics (ISGG), 2008)

TY  - CONF
AU  - Obradović, Marija
AU  - Mišić, Slobodan
PY  - 2008
UR  - https://grafar.grf.bg.ac.rs/handle/123456789/2044
AB  - Cupola is a polyhedron which is consisted of two regular polygons: n-gon and 2n-gon in parallel planes, connected by alternating sequence of squares and equilateral triangles, i.e. Johnson’s solids J3, J4 and J5. However, it is possible to form a polyhedron with the analogously chosen regular n-gon and 2n-gon in parallel planes, in that manner to have a base polygon with n ≥
6, and whose envelope would be formed of series of equilateral triangles, creating a concave
polyhedron, similar to the Johnson’s cupolae, and furthermore to the Johnson’s rotundae. In a lack of an adequate name, we deemed to engender the meaning of the term cupola to a concave
polyhedron that includes regular faces polygons in its geometry, whereat two of them are n-gon and 2n-gon in parallel planes. The method of forming such a cupola is based on wrinkling the net of equilateral triangles, which produce a twofold strip, by folding of which we obtain a deltahedral
envelope surface. Such manner of creating a polyhedron, gives a solution to a problem of creating a regular faced solid which includes even ‘unconstructable’ polygons, as heptagon and nonagon. In this paper, there are described concave regular faced cupolae originated by wrinkling the envelope net consisted of two rows [(2x3+1)n] of equilateral triangles; therefore they are named: the cupolae of second sort. The cupolae originated by using envelope net made of tree rows of equilateral triangles would thus be named: concave regular faced cupolae of third sort, and so on. Concave regular faced cupolae of second sort can have the starting bases from n=4 to n=10. Hendecagon can not be used for the start base polygon (n-gon), because the distance from its double sided counterpart polygon in the parallel plane, would exceed the double value of equilateral triangle’s altitude, the width of the envelope strip. The main parameters of these solids can be found by determining the trajectory of the envelope strip’s elementary cell’s vertices, consisted of six equilateral triangles, which will move around the edge of 2n-gon, behaving as mechanism. The shape of trajectory would show the curve of higher order, therefore there would be two ways to assemble the envelope, so there would exist two possible altitudes of such obtained polyhedrons. There are fourteen solids that would be classified as the concave regular faced cupolae of second sort.
PB  - Dresden: Technische Universität Dresden; International Society for Geometry and Graphics (ISGG)
C3  - Proceedings of the 13th International Conference on Geometry and Graphic - ICGG 2008
T1  - Concave Regular Faced Cupolae of Second Sort
EP  - 10
SP  - 1
SP  - 164 (in Program book)
UR  - https://hdl.handle.net/21.15107/rcub_grafar_2044
ER  - 
@conference{
author = "Obradović, Marija and Mišić, Slobodan",
year = "2008",
abstract = "Cupola is a polyhedron which is consisted of two regular polygons: n-gon and 2n-gon in parallel planes, connected by alternating sequence of squares and equilateral triangles, i.e. Johnson’s solids J3, J4 and J5. However, it is possible to form a polyhedron with the analogously chosen regular n-gon and 2n-gon in parallel planes, in that manner to have a base polygon with n ≥
6, and whose envelope would be formed of series of equilateral triangles, creating a concave
polyhedron, similar to the Johnson’s cupolae, and furthermore to the Johnson’s rotundae. In a lack of an adequate name, we deemed to engender the meaning of the term cupola to a concave
polyhedron that includes regular faces polygons in its geometry, whereat two of them are n-gon and 2n-gon in parallel planes. The method of forming such a cupola is based on wrinkling the net of equilateral triangles, which produce a twofold strip, by folding of which we obtain a deltahedral
envelope surface. Such manner of creating a polyhedron, gives a solution to a problem of creating a regular faced solid which includes even ‘unconstructable’ polygons, as heptagon and nonagon. In this paper, there are described concave regular faced cupolae originated by wrinkling the envelope net consisted of two rows [(2x3+1)n] of equilateral triangles; therefore they are named: the cupolae of second sort. The cupolae originated by using envelope net made of tree rows of equilateral triangles would thus be named: concave regular faced cupolae of third sort, and so on. Concave regular faced cupolae of second sort can have the starting bases from n=4 to n=10. Hendecagon can not be used for the start base polygon (n-gon), because the distance from its double sided counterpart polygon in the parallel plane, would exceed the double value of equilateral triangle’s altitude, the width of the envelope strip. The main parameters of these solids can be found by determining the trajectory of the envelope strip’s elementary cell’s vertices, consisted of six equilateral triangles, which will move around the edge of 2n-gon, behaving as mechanism. The shape of trajectory would show the curve of higher order, therefore there would be two ways to assemble the envelope, so there would exist two possible altitudes of such obtained polyhedrons. There are fourteen solids that would be classified as the concave regular faced cupolae of second sort.",
publisher = "Dresden: Technische Universität Dresden; International Society for Geometry and Graphics (ISGG)",
journal = "Proceedings of the 13th International Conference on Geometry and Graphic - ICGG 2008",
title = "Concave Regular Faced Cupolae of Second Sort",
pages = "10-1-164 (in Program book)",
url = "https://hdl.handle.net/21.15107/rcub_grafar_2044"
}
Obradović, M.,& Mišić, S.. (2008). Concave Regular Faced Cupolae of Second Sort. in Proceedings of the 13th International Conference on Geometry and Graphic - ICGG 2008
Dresden: Technische Universität Dresden; International Society for Geometry and Graphics (ISGG)., 1-10.
https://hdl.handle.net/21.15107/rcub_grafar_2044
Obradović M, Mišić S. Concave Regular Faced Cupolae of Second Sort. in Proceedings of the 13th International Conference on Geometry and Graphic - ICGG 2008. 2008;:1-10.
https://hdl.handle.net/21.15107/rcub_grafar_2044 .
Obradović, Marija, Mišić, Slobodan, "Concave Regular Faced Cupolae of Second Sort" in Proceedings of the 13th International Conference on Geometry and Graphic - ICGG 2008 (2008):1-10,
https://hdl.handle.net/21.15107/rcub_grafar_2044 .

Pseudosymmetry of General Collinear Planes

Obradović, Marija

(Dresden: Technische Universität Dresden; International Society for Geometry and Graphics (ISGG), 2008)

TY  - CONF
AU  - Obradović, Marija
PY  - 2008
UR  - https://grafar.grf.bg.ac.rs/handle/123456789/2045
AB  - The paper is considering a special case of general collinear planes, which creates an
illusion of axial symmetry of the corresponding figures, for the specially chosen method of mapping. Comparing the original figure in one plane with the associated figure in another plane, without showing the constructive method of mapping, the observer would be misled to a conclusion that the type of correlation of the planes comports with the case of affine association of points, more precisely - the axial symmetry. However, correspondent points do not assort to axial symmetry, moreover, there is neither definite nor infinite collineation center in which the linker-lines would intersect. This is, actually, the case of general collinear planes, which infinitely distant points are mapped to vanishing points on a vanishing line of corresponding plane. The kind of general collinear planes that would provide such a case of pseudosymmetrical plane figures, polygons or curves, imply the vanishing lines to form the same angles with the double straight line – the line of the planes that is mapped to itself. It is important, besides, that the axes of the mapped curves must be overlapped with the main perpendiculars of the planes. These perpendiculars are radical axes of the mapped absolute involution from the infinitely distant straight line of one plane, to a vanishing line of another. In the same manner, a circle could be mapped to an identical circle, a square to an identical square, even regular polygons can be mapped to identical and apparently symmetrical figures, as well as parallelograms and rectangles, nevertheless the planes are not affine. This result can be accomplished thanks to the special choice of the particular points, which provides the anticipated solution.
PB  - Dresden: Technische Universität Dresden; International Society for Geometry and Graphics (ISGG)
C3  - Proceedings of the 13th International Conference on Geometry and Graphic - ICGG 2008
T1  - Pseudosymmetry of General Collinear Planes
EP  - 7
SP  - 1
SP  - 173 (in Program book)
UR  - https://hdl.handle.net/21.15107/rcub_grafar_2045
ER  - 
@conference{
author = "Obradović, Marija",
year = "2008",
abstract = "The paper is considering a special case of general collinear planes, which creates an
illusion of axial symmetry of the corresponding figures, for the specially chosen method of mapping. Comparing the original figure in one plane with the associated figure in another plane, without showing the constructive method of mapping, the observer would be misled to a conclusion that the type of correlation of the planes comports with the case of affine association of points, more precisely - the axial symmetry. However, correspondent points do not assort to axial symmetry, moreover, there is neither definite nor infinite collineation center in which the linker-lines would intersect. This is, actually, the case of general collinear planes, which infinitely distant points are mapped to vanishing points on a vanishing line of corresponding plane. The kind of general collinear planes that would provide such a case of pseudosymmetrical plane figures, polygons or curves, imply the vanishing lines to form the same angles with the double straight line – the line of the planes that is mapped to itself. It is important, besides, that the axes of the mapped curves must be overlapped with the main perpendiculars of the planes. These perpendiculars are radical axes of the mapped absolute involution from the infinitely distant straight line of one plane, to a vanishing line of another. In the same manner, a circle could be mapped to an identical circle, a square to an identical square, even regular polygons can be mapped to identical and apparently symmetrical figures, as well as parallelograms and rectangles, nevertheless the planes are not affine. This result can be accomplished thanks to the special choice of the particular points, which provides the anticipated solution.",
publisher = "Dresden: Technische Universität Dresden; International Society for Geometry and Graphics (ISGG)",
journal = "Proceedings of the 13th International Conference on Geometry and Graphic - ICGG 2008",
title = "Pseudosymmetry of General Collinear Planes",
pages = "7-1-173 (in Program book)",
url = "https://hdl.handle.net/21.15107/rcub_grafar_2045"
}
Obradović, M.. (2008). Pseudosymmetry of General Collinear Planes. in Proceedings of the 13th International Conference on Geometry and Graphic - ICGG 2008
Dresden: Technische Universität Dresden; International Society for Geometry and Graphics (ISGG)., 1-7.
https://hdl.handle.net/21.15107/rcub_grafar_2045
Obradović M. Pseudosymmetry of General Collinear Planes. in Proceedings of the 13th International Conference on Geometry and Graphic - ICGG 2008. 2008;:1-7.
https://hdl.handle.net/21.15107/rcub_grafar_2045 .
Obradović, Marija, "Pseudosymmetry of General Collinear Planes" in Proceedings of the 13th International Conference on Geometry and Graphic - ICGG 2008 (2008):1-7,
https://hdl.handle.net/21.15107/rcub_grafar_2045 .

Konkavna kupola nad hendekagonalnom osnovom

Mišić, Slobodan; Obradović, Marija

(Niš: Faculty of Architecture and Civil Engineering in Niš; Serbian Society for Geometry and Graphics (SUGIG), 2008)

TY  - CONF
AU  - Mišić, Slobodan
AU  - Obradović, Marija
PY  - 2008
UR  - https://grafar.grf.bg.ac.rs/handle/123456789/2040
AB  - Predmet istraživanja je konstruktivno geometrijska geneza novih geometrijskih tela, kupola sa konkavnim poliedarskim površima, koje bi korišćenjem pravilnih n-tougaonika u svojoj mreži, obrazovale zatvorene prostorne celine. Ove poliedarske forme – kupole, za polazne ntougaonike imaju jedanaestougaonik i dvadesetdvougaonik u paralelnim horizontalnim ravnima. Način formiranja ovakve kupole zasniva se na nabiranju mreže koja obrazuje traku, a presavijanjem iste dobija se deltaedarski omotač koji čine nizovi pravilnih poligona – jednakostraničnih trouglova. Za geometrijsko određivanje osnovnih parametara tela korišćeni su preseci pramenova lopti sa centrima u karakterističnim tačkama prostornog sedmostranika ABCDEFG kao osnovne ćelije kupole nad hendekagonalnom osnovom. Objašnjene su geometrijske konstrukcije i projekcioni postupci pomoću kojih je moguće prikazati kupolu nad hendekagonalnom osnovom, kroz pronalaženje međusobnih relacija parametara, dimenzija i elemenata samog tela.
AB  - The subject of the research is the constructive geometric genesis of new geometric solids, domes with concave polyhedral surfaces, which, by using regular n-gons in their net, would form closed spatial units. These polyhedral forms - cupolae, for the starting n-gons have a hendecagon (eleven sided polygon) and doicosagon (twenty two sided polygon) in parallel horizontal planes. The way of forming such a cupola is based on the folding the planar triangular net that forms the strip, so that a delta-shaped shell is obtained. It consists of rows of regular polygons - equilateral triangles. To geometrically determine the basic parameters of the solid, the cross sections of spheres with centers at the characteristic points of the spatial heptagon ABCDEFG were used as the basic cells of the cupola with the hendecagonal base. Geometric constructions and projection procedures are explained, by means of which it is possible to obtain the cupola over the hendecagonal base, through finding the mutual relations of parameters, dimensions and elements of the solid itself.
PB  - Niš: Faculty of Architecture and Civil Engineering in Niš; Serbian Society for Geometry and Graphics (SUGIG)
C3  - Proccedings | Zbornik radova (24th national and 1st international scientific conference moNGeometrija 2008)
T1  - Konkavna kupola nad hendekagonalnom osnovom
EP  - 178
SP  - 169
UR  - https://hdl.handle.net/21.15107/rcub_grafar_2040
ER  - 
@conference{
author = "Mišić, Slobodan and Obradović, Marija",
year = "2008",
abstract = "Predmet istraživanja je konstruktivno geometrijska geneza novih geometrijskih tela, kupola sa konkavnim poliedarskim površima, koje bi korišćenjem pravilnih n-tougaonika u svojoj mreži, obrazovale zatvorene prostorne celine. Ove poliedarske forme – kupole, za polazne ntougaonike imaju jedanaestougaonik i dvadesetdvougaonik u paralelnim horizontalnim ravnima. Način formiranja ovakve kupole zasniva se na nabiranju mreže koja obrazuje traku, a presavijanjem iste dobija se deltaedarski omotač koji čine nizovi pravilnih poligona – jednakostraničnih trouglova. Za geometrijsko određivanje osnovnih parametara tela korišćeni su preseci pramenova lopti sa centrima u karakterističnim tačkama prostornog sedmostranika ABCDEFG kao osnovne ćelije kupole nad hendekagonalnom osnovom. Objašnjene su geometrijske konstrukcije i projekcioni postupci pomoću kojih je moguće prikazati kupolu nad hendekagonalnom osnovom, kroz pronalaženje međusobnih relacija parametara, dimenzija i elemenata samog tela., The subject of the research is the constructive geometric genesis of new geometric solids, domes with concave polyhedral surfaces, which, by using regular n-gons in their net, would form closed spatial units. These polyhedral forms - cupolae, for the starting n-gons have a hendecagon (eleven sided polygon) and doicosagon (twenty two sided polygon) in parallel horizontal planes. The way of forming such a cupola is based on the folding the planar triangular net that forms the strip, so that a delta-shaped shell is obtained. It consists of rows of regular polygons - equilateral triangles. To geometrically determine the basic parameters of the solid, the cross sections of spheres with centers at the characteristic points of the spatial heptagon ABCDEFG were used as the basic cells of the cupola with the hendecagonal base. Geometric constructions and projection procedures are explained, by means of which it is possible to obtain the cupola over the hendecagonal base, through finding the mutual relations of parameters, dimensions and elements of the solid itself.",
publisher = "Niš: Faculty of Architecture and Civil Engineering in Niš; Serbian Society for Geometry and Graphics (SUGIG)",
journal = "Proccedings | Zbornik radova (24th national and 1st international scientific conference moNGeometrija 2008)",
title = "Konkavna kupola nad hendekagonalnom osnovom",
pages = "178-169",
url = "https://hdl.handle.net/21.15107/rcub_grafar_2040"
}
Mišić, S.,& Obradović, M.. (2008). Konkavna kupola nad hendekagonalnom osnovom. in Proccedings | Zbornik radova (24th national and 1st international scientific conference moNGeometrija 2008)
Niš: Faculty of Architecture and Civil Engineering in Niš; Serbian Society for Geometry and Graphics (SUGIG)., 169-178.
https://hdl.handle.net/21.15107/rcub_grafar_2040
Mišić S, Obradović M. Konkavna kupola nad hendekagonalnom osnovom. in Proccedings | Zbornik radova (24th national and 1st international scientific conference moNGeometrija 2008). 2008;:169-178.
https://hdl.handle.net/21.15107/rcub_grafar_2040 .
Mišić, Slobodan, Obradović, Marija, "Konkavna kupola nad hendekagonalnom osnovom" in Proccedings | Zbornik radova (24th national and 1st international scientific conference moNGeometrija 2008) (2008):169-178,
https://hdl.handle.net/21.15107/rcub_grafar_2040 .