Home << 1 2 3 4 >>
List View
 | 
Citations
 | 
Details
   web
Records
Author Gielis, J.; Caratelli, D.; Fougerolle, Y.; Ricci, P.E.; Tavkelidze, I.; Gerats, T.
Title Universal natural shapes : from unifying shape description to simple methods for shape analysis and boundary value problems Type A1 Journal article
Year 2012 Publication PLoS ONE Abbreviated Journal
Volume 7 Issue (down) 9 Pages e29324-11
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Gielis curves and surfaces can describe a wide range of natural shapes and they have been used in various studies in biology and physics as descriptive tool. This has stimulated the generalization of widely used computational methods. Here we show that proper normalization of the Levenberg-Marquardt algorithm allows for efficient and robust reconstruction of Gielis curves, including self-intersecting and asymmetric curves, without increasing the overall complexity of the algorithm. Then, we show how complex curves of k-type can be constructed and how solutions to the Dirichlet problem for the Laplace equation on these complex domains can be derived using a semi-Fourier method. In all three methods, descriptive and computational power and efficiency is obtained in a surprisingly simple way.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000309517500001 Publication Date 2012-09-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-6203 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:102202 Serial 8711
Permanent link to this record
 
 
Author Fougerolle, Y.D.; Truchetet, F.; Demonceaux, C.; Gielis, J.
Title A robust evolutionary algorithm for the recovery of rational Gielis curves Type A1 Journal article
Year 2013 Publication Pattern recognition Abbreviated Journal
Volume 46 Issue (down) 8 Pages 2078-2091
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Gielis curves (GC) can represent a wide range of shapes and patterns ranging from star shapes to symmetric and asymmetric polygons, and even self intersecting curves. Such patterns appear in natural objects or phenomena, such as flowers, crystals, pollen structures, animals, or even wave propagation. Gielis curves and surfaces are an extension of Lamé curves and surfaces (superquadrics) which have benefited in the last two decades of extensive researches to retrieve their parameters from various data types, such as range images, 2D and 3D point clouds, etc. Unfortunately, the most efficient techniques for superquadrics recovery, based on deterministic methods, cannot directly be adapted to Gielis curves. Indeed, the different nature of their parameters forbids the use of a unified gradient descent approach, which requires initial pre-processings, such as the symmetry detection, and a reliable pose and scale estimation. Furthermore, even the most recent algorithms in the literature remain extremely sensitive to initialization and often fall into local minima in the presence of large missing data. We present a simple evolutionary algorithm which overcomes most of these issues and unifies all of the required operations into a single though efficient approach. The key ideas in this paper are the replacement of the potential fields used for the cost function (closed form) by the shortest Euclidean distance (SED, iterative approach), the construction of cost functions which minimize the shortest distance as well as the curve length using R-functions, and slight modifications of the evolutionary operators. We show that the proposed cost function based on SED and R-function offers the best compromise in terms of accuracy, robustness to noise, and missing data.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000317944800002 Publication Date 2013-01-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-3203 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:107181 Serial 8485
Permanent link to this record
 
 
Author Li, Y.; Quinn, B.K.; Niinemets, Ü.; Schrader, J.; Gielis, J.; Liu, M.; Shi, P.
Title Ellipticalness index : a simple measure of the complexity of oval leaf shape Type A1 Journal article
Year 2022 Publication Pakistan journal of botany : An official publication of pakistan botanical society Abbreviated Journal Pak J Bot
Volume 54 Issue (down) 6 Pages 1-8
Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Plants have diverse leaf shapes that have evolved to adapt to the environments they have experienced over their evolutionary history. Leaf shape and leaf size can greatly influence the growth rate, competitive ability, and productivity of plants. However, researchers have long struggled to decide how to properly quantify the complexity of leaf shape. Prior studies recommended the leaf roundness index (RI = 4πA/P2) or dissection index (DI = ), where P is leaf perimeter and A is leaf area. However, these two indices merely measure the extent of the deviation of leaf shape from a circle, which is usually invalid as leaves are seldom circular. In this study, we proposed a simple measure, named the ellipticalness index (EI), for quantifying the complexity of leaf shape based on the hypothesis that the shape of any oval leaf can be regarded as a variation from a standard ellipse. 2220 leaves from nine species of Magnoliaceae were sampled to check the validity of the EI. We also tested the validity of the Montgomery equation (ME), which assumes a proportional relationship between leaf area and the product of leaf length and width, because the EI actually comes from the proportionality coefficient of the ME. We also compared the ME with five other models of leaf area. The ME was found to be the best model for calculating leaf area based on consideration of the trade-off between model fit vs. complexity, which strongly supported the robustness of the EI for describing oval leaf shape. The new index can account for both leaf shape and size, and we conclude that it is a promising method for quantifying and comparing oval leaf shapes across species in future studies.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000814279700028 Publication Date 2022-05-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0556-3321 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.2 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 1.2
Call Number UA @ admin @ c:irua:188469 Serial 7153
Permanent link to this record
 
 
Author Vermander, C.; De Wael, J.; Gielis, J.
Title De kleine boerderij : twee bijzondere tuinkamers Type A2 Journal article
Year 2019 Publication Groencontact Abbreviated Journal
Volume 45 Issue (down) 5 Pages 14-19
Keywords A2 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1374-4631 ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:164895 Serial 8142
Permanent link to this record
 
 
Author Chiapperino, M.A.; Bia, P.; Caratelli, D.; Gielis, J.; Mescia, L.; Dermol-Cerne, J.; Miklavcic, D.
Title Nonlinear dispersive model of electroporation for irregular nucleated cells Type A1 Journal article
Year 2019 Publication Bioelectromagnetics Abbreviated Journal
Volume 40 Issue (down) 5 Pages 331-342
Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract In this work, the electroporation phenomenon induced by pulsed electric field on different nucleated biological cells is studied. A nonlinear, non-local, dispersive, and space-time multiphysics model based on Maxwell's and asymptotic Smoluchowski's equations has been developed to calculate the transmembrane voltage and pore density on both plasma and nuclear membrane perimeters. The irregular cell shape has been modeled by incorporating in the numerical algorithm the analytical functions pertaining to Gielis curves. The dielectric dispersion of the cell media has been modeled considering the multi-relaxation Debye-based relationship. Two different irregular nucleated cells have been investigated and their response has been studied applying both the dispersive and non-dispersive models. By a comparison of the obtained results, differences can be highlighted confirming the need to make use of the dispersive model to effectively investigate the cell response in terms of transmembrane voltages, pore densities, and electroporation opening angle, especially when irregular cell shapes and short electric pulses are considered. Bioelectromagnetics. 2019;40:331-342. (c) 2019 Wiley Periodicals, Inc.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000472568200004 Publication Date 2019-06-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0197-8462 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:161282 Serial 8315
Permanent link to this record
 
 
Author Shi, P.; Ratkowsky, D.A.; Gielis, J.
Title The generalized Gielis geometric equation and its application Type A1 Journal article
Year 2020 Publication Symmetry-Basel Abbreviated Journal Symmetry-Basel
Volume 12 Issue (down) 4 Pages 645-10
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Many natural shapes exhibit surprising symmetry and can be described by the Gielis equation, which has several classical geometric equations (for example, the circle, ellipse and superellipse) as special cases. However, the original Gielis equation cannot reflect some diverse shapes due to limitations of its power-law hypothesis. In the present study, we propose a generalized version by introducing a link function. Thus, the original Gielis equation can be deemed to be a special case of the generalized Gielis equation (GGE) with a power-law link function. The link function can be based on the morphological features of different objects so that the GGE is more flexible in fitting the data of the shape than its original version. The GGE is shown to be valid in depicting the shapes of some starfish and plant leaves.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000540222200156 Publication Date 2020-04-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2073-8994 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.7 Times cited 4 Open Access
Notes ; This research was funded by the Jiangsu Government Scholarship for Overseas Studies (grant number: JS-2018-038). ; Approved Most recent IF: 2.7; 2020 IF: 1.457
Call Number UA @ admin @ c:irua:168141 Serial 6526
Permanent link to this record
 
 
Author Li, Y.; Niklas, K.J.; Gielis, J.; Niinemets, Ü.; Schrader, J.; Wang, R.; Shi, P.
Title An elliptical blade is not a true ellipse, but a superellipse : evidence from two Michelia species Type A1 Journal article
Year 2022 Publication Journal of forestry research Abbreviated Journal J Forestry Res
Volume 33 Issue (down) 4 Pages 1341-1348
Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract The shape of leaf laminae exhibits considerable diversity and complexity that reflects adaptations to environmental factors such as ambient light and precipitation as well as phyletic legacy. Many leaves appear to be elliptical which may represent a ‘default’ developmental condition. However, whether their geometry truly conforms to the ellipse equation (EE), i.e., (x/a)2 + (y/b)2 = 1, remains conjectural. One alternative is described by the superellipse equation (SE), a generalized version of EE, i.e., |x/a|n +|y/b|n = 1. To test the efficacy of EE versus SE to describe leaf geometry, the leaf shapes of two Michelia species (i.e., M. cavaleriei var. platypetala, and M. maudiae), were investigated using 60 leaves from each species. Analysis shows that the majority of leaves (118 out of 120) had adjusted root-mean-square errors of < 0.05 for the nonlinear fitting of SE to leaf geometry, i.e., the mean absolute deviation from the polar point to leaf marginal points was smaller than 5% of the radius of a hypothesized circle with its area equaling leaf area. The estimates of n for the two species were ˂ 2, indicating that all sampled leaves conformed to SE and not to EE. This study confirms the existence of SE in leaves, linking this to its potential functional advantages, particularly the possible influence of leaf shape on hydraulic conductance.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000695118600001 Publication Date 2021-09-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1007-662x; 1993-0607 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 3
Call Number UA @ admin @ c:irua:180967 Serial 7152
Permanent link to this record
 
 
Author Martínez-Dueñas, E.J.R.; de Jong van Coevorden, C.M.; Stukach, O.V.; Panokin, N.V.; Gielis, J.; Caratelli, D.
Title Electromagnetic modeling and design of a novel class of complementary split‐ring resonators Type A1 Journal article
Year 2019 Publication International journal of RF and microwave computer-aided engineering Abbreviated Journal
Volume 29 Issue (down) 4 Pages e21582
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract This research study reports the assessment of complementary split ring resonators based on Gielis transformation as basic elements for the design of high‐performance microwave components in printed technology. From the electromagnetic simulation of said structures, suitable equivalent circuit models are extracted and analyzed. Physical prototypes are fabricated and tested for design validation. The obtained results confirm that the adoption of supershaped geometries enables the synthesis of very compact scalable microwave filters.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000460308500020 Publication Date 2018-11-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1096-4290 ISBN Additional Links UA library record; WoS full record
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:155021 Serial 7867
Permanent link to this record
 
 
Author Shi, P.; Liu, M.; Ratkowsky, D.A.; Gielis, J.; Su, J.; Yu, X.; Wang, P.; Zhang, L.; Lin, Z.; Schrader, J.
Title Leaf area-length allometry and its implications in leaf shape evolution Type A1 Journal article
Year 2019 Publication Trees: structure and function Abbreviated Journal
Volume 33 Issue (down) 4 Pages 1073-1085
Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract According to Thompson’s principle of similarity, the area of an object should be proportional to its length squared. However, leaf area–length data of some plants have been demonstrated not to follow the principle of similarity. We explore the reasons why the leaf area–length allometry deviates from the principle of similarity and examine whether there is a general model describing the relationship among leaf area, width and length. We sampled more than 11,800 leaves from six classes of woody and herbaceous plants and tested the leaf area–length allometry. We compared six mathematical models based on root-mean-square error as the measure of goodness-of-fit. The best supported model described a proportional relationship between leaf area and the product of leaf width and length (i.e., the Montgomery model). We found that the extent to which the leaf area–length allometry deviates from the principle of similarity depends upon the extent of variation of the ratio of leaf width to length. Estimates of the parameter of the Montgomery model ranged between 1/2, which corresponds to a triangular leaf with leaf length as its height and leaf width as its base, and π/4, which corresponds to an elliptical leaf with leaf length as its major axis and leaf width as its minor axis, for the six classes of plants. The narrow range in practice of the Montgomery parameter implies an evolutionary stability for the leaf area of large-leaved plants despite the fact that leaf shapes of these plants are rather different.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000475992600010 Publication Date 2019-04-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0931-1890; 1432-2285 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:159970 Serial 8170
Permanent link to this record
 
 
Author Gielis, J.; Ricci, P.E.; Tavkhelidze, I.
Title The Möbius phenomenon in Generalized Möbius-Listing surfaces and bodies, and Arnold's Cat phenomenon Type A1 Journal article
Year 2021 Publication Advanced Studies : Euro-Tbilisi Mathematical Journal Abbreviated Journal
Volume 14 Issue (down) 4 Pages 17-35
Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Möbius bands have been studied extensively, mainly in topology. Generalized Möbius-Listing surfaces and bodies providing a full geometrical generalization, is a quite new field, motivated originally by solutions of boundary value problems. Analogous to cutting of the original Möbius band, for this class of surfaces and bodies, results have been obtained when cutting such bodies or surfaces. In general, cutting leads to interlinked and intertwined different surfaces or bodies, resulting in very complex systems. However, under certain conditions, the result of cutting can be a single surface or body, which reduces complexity considerably. Our research is motivated by this reduction of complexity. In the study of cutting Generalized Möbius-Listing bodies with polygons as cross section, the conditions under which a single body results, displaying the Möbius phenomenon of a one-sided body, have been determined for even and odd polygons. These conditions are based on congruence and rotational symmetry of the resulting cross sections after cutting, and on the knife cutting the origin. The Möbius phenomenon is important, since the process of cutting (or separation of zones in a GML body in general) then results in a single body, not in different, intertwined domains. In all previous works it was assumed that the cross section of the GML bodies is constant, but the main result of this paper is that it is sufficient that only one cross section on the whole GML structure meets the conditions for the Möbius phenomenon to occur. Several examples are given to illustrate this.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000774655100002 Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links UA library record; WoS full record
Impact Factor Times cited Open Access OpenAccess
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:183081 Serial 8258
Permanent link to this record
 
 
Author Caratelli, D.; Gielis, J.; Ricci, P.E.; Tavkhelidze, I.
Title Some properties of “bulky” links, generated by Generalized Möbius Listing's bodies GML4n Type A2 Journal article
Year 2016 Publication Journal of mathematical sciences Abbreviated Journal
Volume 216 Issue (down) 4 Pages 509-518
Keywords A2 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract In the present paper, we consider the bulky knots and bulky links that appear after cutting of generalized MöbiusListing GML 4 n bodies (with corresponding radial cross sections square) along different generalized MöbiusListing surfaces GML 2 n situated in it. The aim of this article is to examine the number and geometric structure of independent objects that appear after such a cutting process of GML 4 n bodies. In most cases, we are able to count the indices of the resulting mathematical objects according to the known tabulation for knots and links of small complexity.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2016-06-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1072-3374; 1573-8795 ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:133948 Serial 8554
Permanent link to this record
 
 
Author Tian, F.; Wang, Y.; Sandhu, H.S.; Gielis, J.; Shi, P.
Title Comparison of seed morphology of two ginkgo cultivars Type A1 Journal article
Year 2020 Publication Journal Of Forestry Research Abbreviated Journal J Forestry Res
Volume 31 Issue (down) 3 Pages 751-758
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Ginkgo biloba L. is a precious relic tree species with important economic value. Seeds, as a vital reproductive organ of plants, can be used to distinguish cultivars of the species. We chose 400 seeds from two cultivars of ginkgo (Fozhi and Maling; 200 seeds for each cultivar) as the study material and used the Gielis equation to fit the projected shape of these seeds. The coefficients of variation (CV) in root mean squared errors (RMSE) obtained from the fitted data were used to compare the level of inter-cultivar variations in seed shape. We also used the covariance analysis to compare the allometric relationships between seed weights and projected areas of these two cultivars. The Gielis equation fitted well the seed shapes of two ginkgo cultivars. The lower CV in RMSE of cultivar Fozhi than Maling indicated a less symmetrical seed shape in the latter than the former. The bootstrap percentile method showed that the seed shape differences between the two cultivars were significant. However, there was no significant difference in the exponents between the seed weights and the projected areas of these two cultivars. Overall, the significant differences in shapes between the seeds of two ginkgo cultivars were well explained by the Gielis equation; this model can be further extended to compare morphological differences in other ginkgo cultivars, and even for plant seeds or animal eggs that have similar oval shapes.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000529367600005 Publication Date 2018-07-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1007-662x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3 Times cited 3 Open Access
Notes ; ; Approved Most recent IF: 3; 2020 IF: 0.774
Call Number UA @ admin @ c:irua:154987 Serial 6474
Permanent link to this record
 
 
Author Gielis, J.; Tavkhelidze, I.; Ricci, P.E.
Title About “bulky” links generated by generalized Möbius-Listing bodies GML2n Type A2 Journal article
Year 2013 Publication Journal of mathematical sciences Abbreviated Journal
Volume 193 Issue (down) 3 Pages 449-460
Keywords A2 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract In this paper, we consider the bulky knots and bulky links, which appear after cutting of a Generalized MöbiusListing GMLn2 body (with the radial cross section a convex plane 2-symmetric figure with two vertices) along a different Generalized MöbiusListing surfaces GMLn2 situated in it. The aim of this report is to investigate the number and geometric structure of the independent objects that appear after such a cutting process of GMLn2 bodies. In most cases we are able to count the indices of the resulting mathematical objects according to the known classification for the standard knots and links.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2013-08-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1072-3374; 1573-8795 ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:110953 Serial 7404
Permanent link to this record
 
 
Author Caratelli, D.; Gielis, J.; Natalini, P.; Ricci, P.E.; Tavkhelidze, I.
Title The Robin problem for the Helmholtz equation in a starlike planar domain Type A1 Journal article
Year 2011 Publication Georgian mathematical journal Abbreviated Journal
Volume 18 Issue (down) 3 Pages 465-479
Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract The interior and exterior Robin problems for the Helmholtz equation in starlike planar domains are addressed by using a suitable Fourier-like technique. Attention is in particular focused on normal-polar domains whose boundaries are defined by the so-called superformula introduced by J. Gielis. A dedicated numerical procedure based on the computer algebra system Mathematica© is developed in order to validate the proposed approach. In this way, highly accurate approximations of the solution, featuring properties similar to the classical ones, are obtained. The computed results are found to be in good agreement with the theoretical findings on Fourier series expansion presented by L. Carleson.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000296166100004 Publication Date 2021-02-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1072-947x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:91086 Serial 8658
Permanent link to this record
 
 
Author Gielis, J.
Title Fred Van Oystaeyen : Time hybrids: a new generic theory of reality Type Review
Year 2023 Publication Symmetry, Culture and Science Abbreviated Journal
Volume 34 Issue (down) 3 Pages 347-351
Keywords Review; Sustainable Energy, Air and Water Technology (DuEL)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links UA library record
Impact Factor Times cited Open Access OpenAccess
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:199538 Serial 8871
Permanent link to this record
 
 
Author Yao, W.; Niinemets, Ü.; Yao, W.; Gielis, J.; Schrader, J.; Yu, K.; Shi, P.
Title Comparison of two simplified versions of the Gielis equation for describing the shape of bamboo leaves Type A1 Journal article
Year 2022 Publication Plants Abbreviated Journal
Volume 11 Issue (down) 22 Pages 3058-11
Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Bamboo is an important component in subtropical and tropical forest communities. The plant has characteristic long lanceolate leaves with parallel venation. Prior studies have shown that the leaf shapes of this plant group can be well described by a simplified version (referred to as SGE-1) of the Gielis equation, a polar coordinate equation extended from the superellipse equation. SGE-1 with only two model parameters is less complex than the original Gielis equation with six parameters. Previous studies have seldom tested whether other simplified versions of the Gielis equation are superior to SGE-1 in fitting empirical leaf shape data. In the present study, we compared a three-parameter Gielis equation (referred to as SGE-2) with the two-parameter SGE-1 using the leaf boundary coordinate data of six bamboo species within the same genus that have representative long lanceolate leaves, with >300 leaves for each species. We sampled 2000 data points at approximately equidistant locations on the boundary of each leaf, and estimated the parameters for the two models. The root–mean–square error (RMSE) between the observed and predicted radii from the polar point to data points on the boundary of each leaf was used as a measure of the model goodness of fit, and the mean percent error between the RMSEs from fitting SGE-1 and SGE-2 was used to examine whether the introduction of an additional parameter in SGE-1 remarkably improves the model’s fitting. We found that the RMSE value of SGE-2 was always smaller than that of SGE-1. The mean percent errors among the two models ranged from 7.5% to 20% across the six species. These results indicate that SGE-2 is superior to SGE-1 and should be used in fitting leaf shapes. We argue that the results of the current study can be potentially extended to other lanceolate leaf shapes.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000887783400001 Publication Date 2022-11-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2223-7747 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access OpenAccess
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:191859 Serial 7289
Permanent link to this record
 
 
Author Gao, J.; Huang, W.; Gielis, J.; Shi, P.
Title Plant morphology and function, geometric morphometrics, and modelling : decoding the mathematical secrets of plants Type Editorial
Year 2023 Publication Plants Abbreviated Journal
Volume 12 Issue (down) 21 Pages 3724-2
Keywords Editorial; Sustainable Energy, Air and Water Technology (DuEL)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001103336500001 Publication Date 2023-10-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2223-7747 ISBN Additional Links UA library record; WoS full record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:201173 Serial 9072
Permanent link to this record
 
 
Author Shi, P.-J.; Xu, Q.; Sandhu, H.S.; Gielis, J.; Ding, Y.-L.; Li, H.-R.; Dong, X.-B.
Title Comparison of dwarf bamboos (Indocalamus sp.) leaf parameters to determine relationship between spatial density of plants and total leaf area per plant Type A1 Journal article
Year 2015 Publication Ecology and evolution Abbreviated Journal
Volume 5 Issue (down) 20 Pages 4578-4589
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract The relationship between spatial density and size of plants is an important topic in plant ecology. The self-thinning rule suggests a −3/2 power between average biomass and density or a −1/2 power between stand yield and density. However, the self-thinning rule based on total leaf area per plant and density of plants has been neglected presumably because of the lack of a method that can accurately estimate the total leaf area per plant. We aimed to find the relationship between spatial density of plants and total leaf area per plant. We also attempted to provide a novel model for accurately describing the leaf shape of bamboos. We proposed a simplified Gielis equation with only two parameters to describe the leaf shape of bamboos one model parameter represented the overall ratio of leaf width to leaf length. Using this method, we compared some leaf parameters (leaf shape, number of leaves per plant, ratio of total leaf weight to aboveground weight per plant, and total leaf area per plant) of four bamboo species of genus Indocalamus Nakai (I. pedalis (Keng) P.C. Keng, I. pumilus Q.H. Dai and C.F. Keng, I. barbatus McClure, and I. victorialis P.C. Keng). We also explored the possible correlation between spatial density and total leaf area per plant using log-linear regression. We found that the simplified Gielis equation fit the leaf shape of four bamboo species very well. Although all these four species belonged to the same genus, there were still significant differences in leaf shape. Significant differences also existed in leaf area per plant, ratio of leaf weight to aboveground weight per plant, and leaf length. In addition, we found that the total leaf area per plant decreased with increased spatial density. Therefore, we directly demonstrated the self-thinning rule to improve light interception.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000363731500008 Publication Date 2015-09-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2045-7758 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:128662 Serial 7691
Permanent link to this record
 
 
Author Dattoli, G.; Di Palma, E.; Gielis, J.; Licciardi, S.
Title Parabolic trigonometry Type A1 Journal article
Year 2020 Publication International journal of applied and computational mathematics Abbreviated Journal
Volume 6 Issue (down) 2 Pages 37
Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2020-03-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2349-5103 ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:167049 Serial 6578
Permanent link to this record
 
 
Author Gielis, J.
Title Double helix of phyllotaxis : analysis of the geometric model of plant morphogenesis, by Boris Rozin Type Review
Year 2021 Publication Quarterly Review Of Biology Abbreviated Journal Q Rev Biol
Volume 96 Issue (down) 2 Pages 139-140
Keywords Review; Sustainable Energy, Air and Water Technology (DuEL)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2021-05-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0033-5770; 1539-7718 ISBN Additional Links UA library record
Impact Factor 4.25 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 4.25
Call Number UA @ admin @ c:irua:178829 Serial 7824
Permanent link to this record
 
 
Author Caratelli, D.; Gielis, J.; Ricci, P.E.
Title Fourier-like solution of the Dirichlet problem for the Laplace Equation in k-type Gielis domains Type A1 Journal article
Year 2011 Publication Journal of pure and applied mathematics : advances and applications Abbreviated Journal
Volume 5 Issue (down) 2 Pages 99-111
Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract The interior and exterior Dirichlet problems for the Laplace equation in k-type Gielis domains are analytically addressed by using a suitable Fourier-like technique. A dedicated numerical procedure based on the computer-aided algebra tool Mathematica© is developed in order to validate the proposed approach. In this way, highly accurate approximations of the solution, featuring properties similar to the classical ones, are obtained. Computed results are found to be in good agreement with theoretical findings on Fourier series expansion presented by Carleson.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:91090 Serial 7982
Permanent link to this record
 
 
Author Chapman, D.; Gielis, J.
Title Gielis transformations for the audiovisual geometry database Type A1 Journal article
Year 2021 Publication Symmetry : culture and science Abbreviated Journal
Volume 32 Issue (down) 2 Pages 177-180
Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract This publication introduces the audiovisual geometry database with Gielis transformations as initial records for a prototype of the database. A concise overview is given of the rationale behind the database and studying wave phenomena with Gielis transformations. First results on a form of timbral polyphony observed in Gielis curves and future work are briefly discussed.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2021-07-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0865-4824 ISBN Additional Links UA library record
Impact Factor Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:180965 Serial 8004
Permanent link to this record
 
 
Author Mescia, L.; Chiapperino, M.A.; Bia, P.; Gielis, J.; Caratelli, D.
Title Modeling of electroporation induced by pulsed electric fields in irregularly shaped cells Type A1 Journal article
Year 2018 Publication IEEE transactions on biomedical engineering Abbreviated Journal
Volume 65 Issue (down) 2 Pages 414-423
Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract During the past decades, the poration of cell membrane induced by pulsed electric fields has been widely investigated. Since the basic mechanisms of this process have not yet been fully clarified, many research activities are focused on the development of suitable theoretical and numerical models. To this end, a nonlinear, nonlocal, dispersive, and space-time numerical algorithm has been developed and adopted to evaluate the transmembrane voltage and pore density along the perimeter of realistic irregularly shaped cells. The presented model is based on the Maxwell's equations and the asymptotic Smoluchowski's equation describing the pore dynamics. The dielectric dispersion of the media forming the cell has been modeled by using a general multirelaxation Debye-based formulation. The irregular shape of the cell is described by using the Gielis' superformula. Different test cases pertaining to red blood cells, muscular cells, cell in mitosis phase, and cancer-like cell have been investigated. For each type of cell, the influence of the relevant shape, the dielectric properties, and the external electric pulse characteristics on the electroporation process has been analyzed. The numerical results demonstrate that the proposed model is an efficient numerical tool to study the electroporation problem in arbitrary-shaped cells.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000422914700018 Publication Date 2017-11-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0018-9294 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:148417 Serial 8264
Permanent link to this record
 
 
Author Shi, P.; Liu, M.; Yu, X.; Gielis, J.; Ratkowsky, D.A.
Title Proportional relationship between leaf area and the product of leaf length and width of four types of special leaf shapes Type A1 Journal article
Year 2019 Publication Forests (19994907) Abbreviated Journal
Volume 10 Issue (down) 2 Pages 178
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract The leaf area, as an important leaf functional trait, is thought to be related to leaf length and width. Our recent study showed that the Montgomery equation, which assumes that leaf area is proportional to the product of leaf length and width, applied to different leaf shapes, and the coefficient of proportionality (namely the Montgomery parameter) range from 1/2 to π/4. However, no relevant geometrical evidence has previously been provided to support the above findings. Here, four types of representative leaf shapes (the elliptical, sectorial, linear, and triangular shapes) were studied. We derived the range of the estimate of the Montgomery parameter for every type. For the elliptical and triangular leaf shapes, the estimates are π/4 and 1/2, respectively; for the linear leaf shape, especially for the plants of Poaceae that can be described by the simplified Gielis equation, the estimate ranges from 0.6795 to π/4; for the sectorial leaf shape, the estimate ranges from 1/2 to π/4. The estimates based on the observations of actual leaves support the above theoretical results. The results obtained here show that the coefficient of proportionality of leaf area versus the product of leaf length and width only varies in a small range, maintaining the allometric relationship for leaf area and thereby suggesting that the proportional relationship between leaf area and the product of leaf length and width broadly remains stable during leaf evolution.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000460744000102 Publication Date 2019-02-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1999-4907 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:157200 Serial 8427
Permanent link to this record
 
 
Author Gielis, J.; Brasili, S.
Title The apeirogon and dual numbers Type A1 Journal article
Year 2021 Publication Symmetry : culture and science Abbreviated Journal
Volume 32 Issue (down) 2 Pages 157-160
Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract The richness, diversity, connection, depth and pleasure of studying symmetry continue to open doors. Here we report a connection between Coxeter's Apeirogon and the geometry associated with pictorial space, parabolic rotation and dual numbers.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000670122100011 Publication Date 2021-07-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0865-4824 ISBN Additional Links UA library record; WoS full record
Impact Factor Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:179759 Serial 8652
Permanent link to this record
 
 
Author Gielis, J.
Title Simon Stevin as a central figure in the development of abstract algebra and generic programming Type A1 Journal article
Year 2023 Publication Symmetry : culture and science Abbreviated Journal
Volume 34 Issue (down) 2 Pages 155-168
Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Simon Stevin (1548-1620) is mainly known for the decimal system and his Clootkrans proof. His influence is also profound in infinitesimal calculus, mechanics, and even in abstract algebra and today’s conception of polynomials, algorithms, and generic programming. Here we review his influence as assessed in generic programming. According to Dr. Stepanov, one of the most influential researchers in generic programming, Stevin’s work on polynomials can be regarded as the essence of generic programming: an algorithm from one domain can be applied in another similar domain.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001068714100003 Publication Date 2023-07-11
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0865-4824 ISBN Additional Links UA library record; WoS full record
Impact Factor Times cited Open Access Not_Open_Access: Available from 08.02.2024
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:198000 Serial 8929
Permanent link to this record
 
 
Author Gielis, J.; Tavkhelidze, I.; Ricci, P.E.
Title Generalized Möbius-Listing bodies and the heart Type A3 Journal article
Year 2023 Publication Sn – 2247-689x Abbreviated Journal
Volume 13 Issue (down) 2 Pages 58-70
Keywords A3 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Generalized Möbius-Listing surfaces and bodies generalize Möbius bands, and this research was motivated originally by solutions of boundary value problems. Analogous to cutting of the original Möbius band, for this class of surfaces and bodies, results have been obtained when cutting such bodies or surfaces. The results can be applied in a wide range of fields in the natural science, and here we propose how they can serve as a model for the heart and the circulatory system.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos http://rjm-cs.ro/2023v13i2_7.pdf#page=1 Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links UA library record; http://rjm-cs.ro/2023v13i2_7.pdf#page=1
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:200773 Serial 9043
Permanent link to this record
 
 
Author Caratelli, D.; Gielis, J.; Tavkhelidze, I.; Ricci, P.E.
Title Spherical harmonic solution of the Robin problem for the Helmholtz equation in a supershaped shell Type A1 Journal article
Year 2013 Publication Applied mathematics Abbreviated Journal
Volume 4 Issue (down) 1a Pages 263-270
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract The Robin problem for the Helmholtz equation in normal-polar shells is addressed by using a suitable spherical harmonic expansion technique. Attention is in particular focused on the wide class of domains whose boundaries are defined by a generalized version of the so-called superformula introduced by Gielis. A dedicated numerical procedure based on the computer algebra system Mathematica? is developed in order to validate the proposed methodology. In this way, highly accurate approximations of the solution, featuring properties similar to the classical ones, are obtained.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2013-01-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2152-7385 ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:107177 Serial 8576
Permanent link to this record
 
 
Author Lin, S.; Zhang, L.; Reddy, G.V.P.; Hui, C.; Gielis, J.; Ding, Y.; Shi, P.
Title A geometrical model for testing bilateral symmetry of bamboo leaf with a simplified Gielis equation Type A1 Journal article
Year 2016 Publication Ecology and evolution Abbreviated Journal
Volume 6 Issue (down) 19 Pages 6798-6806
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract The size and shape of plant leaves change with growth, and an accurate description of leaf shape is crucial for describing plant morphogenesis and development. Bilateral symmetry, which has been widely observed but poorly examined, occurs in both dicot and monocot leaves, including all nominated bamboo species (approximately 1,300 species), of which at least 500 are found in China. Although there are apparent differences in leaf size among bamboo species due to genetic and environmental profiles, bamboo leaves have bilateral symmetry with parallel venation and appear similar across species. Here, we investigate whether the shape of bamboo leaves can be accurately described by a simplified Gielis equation, which consists of only two parameters (leaf length and shape) and produces a perfect bilateral shape. To test the applicability of this equation and the occurrence of bilateral symmetry, we first measured the leaf length of 42 bamboo species, examining >500 leaves per species. We then scanned 30 leaves per species that had approximately the same length as the median leaf length for that species. The leaf-shape data from scanned profiles were fitted to the simplified Gielis equation. Results confirmed that the equation fits the leaf-shape data extremely well, with the coefficients of determination being 0.995 on average. We further demonstrated the bilateral symmetry of bamboo leaves, with a clearly defined leaf-shape parameter of all 42 bamboo species investigated ranging from 0.02 to 0.1. This results in a simple and reliable tool for precise determination of bamboo species, with applications in forestry, ecology, and taxonomy.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000385626100003 Publication Date 2016-09-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2045-7758 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:144547 Serial 7998
Permanent link to this record
 
 
Author Gielis, J.
Title Er bestaan geen absurde, irrationele, onregelmatige of onderling niet-onmeetbare meetkundige getallen Type A2 Journal article
Year 2021 Publication Wiskunde en onderwijs Abbreviated Journal
Volume 47 Issue (down) 188 Pages 23-33
Keywords A2 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2032-0485 ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:183083 Serial 7934
Permanent link to this record