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Author |
Shi, P.; Gielis, J.; Quinn, B.K.; Niklas, K.J.; Ratkowsky, D.A.; Schrader, J.; Ruan, H.; Wang, L.; Niinemets, Ü.; Niinennets, U. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
‘biogeom’ : an R package for simulating and fitting natural shapes |
Type |
A1 Journal article |
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Year |
2022 |
Publication |
Annals of the New York Academy of Sciences |
Abbreviated Journal |
Ann Ny Acad Sci |
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Volume |
1516 |
Issue |
1 |
Pages |
123-134 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
Many natural objects exhibit radial or axial symmetry in a single plane. However, a universal tool for simulating and fitting the shapes of such objects is lacking. Herein, we present an R package called 'biogeom' that simulates and fits many shapes found in nature. The package incorporates novel universal parametric equations that generate the profiles of bird eggs, flowers, linear and lanceolate leaves, seeds, starfish, and tree-rings, and three growth-rate equations that generate the profiles of ovate leaves and the ontogenetic growth curves of animals and plants. 'biogeom' includes several empirical datasets comprising the boundary coordinates of bird eggs, fruits, lanceolate and ovate leaves, tree rings, seeds, and sea stars. The package can also be applied to other kinds of natural shapes similar to those in the datasets. In addition, the package includes sigmoid curves derived from the three growth-rate equations, which can be used to model animal and plant growth trajectories and predict the times associated with maximum growth rate. 'biogeom' can quantify the intra- or interspecific similarity of natural outlines, and it provides quantitative information of shape and ontogenetic modification of shape with important ecological and evolutionary implications for the growth and form of the living world. |
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Wos |
000829772300001 |
Publication Date |
2022-07-26 |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0077-8923; 1749-6632 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.2 |
Times cited |
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Open Access ![sorted by Open Access field, descending order (down)](img/sort_desc.gif) |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 5.2 |
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Call Number |
UA @ admin @ c:irua:189314 |
Serial |
7131 |
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Permanent link to this record |
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Author |
Shi, P.; Gielis, J.; Niklas, K.J. |
![goto web page url](http://nano.uantwerpen.be/nanorefs/img/www.gif)
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Title |
Comparison of a universal (but complex) model for avian egg shape with a simpler model |
Type |
Editorial |
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Year |
2022 |
Publication |
Annals of the New York Academy of Sciences |
Abbreviated Journal |
Ann Ny Acad Sci |
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Volume |
1514 |
Issue |
1 |
Pages |
34-42 |
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Keywords |
Editorial; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
Recently, a universal equation by Narushin, Romanov, and Griffin (hereafter, the NRGE) was proposed to describe the shape of avian eggs. While NRGE can simulate the shape of spherical, ellipsoidal, ovoidal, and pyriform eggs, its predictions were not tested against actual data. Here, we tested the validity of the NRGE by fitting actual data of egg shapes and compared this with the predictions of our simpler model for egg shape (hereafter, the SGE). The eggs of nine bird species were sampled for this purpose. NRGE was found to fit the empirical data of egg shape well, but it did not define the egg length axis (i.e., the rotational symmetric axis), which significantly affected the prediction accuracy. The egg length axis under the NRGE is defined as the maximum distance between two points on the scanned perimeter of the egg's shape. In contrast, the SGE fitted the empirical data better, and had a smaller root-mean-square error than the NRGE for each of the nine eggs. Based on its mathematical simplicity and goodness-of-fit, the SGE appears to be a reliable and useful model for describing egg shape. |
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Wos |
000803394100001 |
Publication Date |
2022-06-01 |
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ISSN |
0077-8923; 1749-6632 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.2 |
Times cited |
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Open Access ![sorted by Open Access field, descending order (down)](img/sort_desc.gif) |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 5.2 |
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Call Number |
UA @ admin @ c:irua:188470 |
Serial |
7139 |
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Permanent link to this record |
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Author |
Li, Y.; Niklas, K.J.; Gielis, J.; Niinemets, Ü.; Schrader, J.; Wang, R.; Shi, P. |
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Title |
An elliptical blade is not a true ellipse, but a superellipse : evidence from two Michelia species |
Type |
A1 Journal article |
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Year |
2022 |
Publication |
Journal of forestry research |
Abbreviated Journal |
J Forestry Res |
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Volume |
33 |
Issue |
4 |
Pages |
1341-1348 |
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Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
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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. |
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Wos |
000695118600001 |
Publication Date |
2021-09-12 |
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Edition |
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ISSN |
1007-662x; 1993-0607 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3 |
Times cited |
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Open Access ![sorted by Open Access field, descending order (down)](img/sort_desc.gif) |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 3 |
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Call Number |
UA @ admin @ c:irua:180967 |
Serial |
7152 |
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Permanent link to this record |
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Author |
Li, Y.; Quinn, B.K.; Niinemets, Ü.; Schrader, J.; Gielis, J.; Liu, M.; Shi, P. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
Ellipticalness index : a simple measure of the complexity of oval leaf shape |
Type |
A1 Journal article |
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Year |
2022 |
Publication |
Pakistan journal of botany : An official publication of pakistan botanical society |
Abbreviated Journal |
Pak J Bot |
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Volume |
54 |
Issue |
6 |
Pages |
1-8 |
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Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
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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. |
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Wos |
000814279700028 |
Publication Date |
2022-05-23 |
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Abbreviated Series Title |
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Series Volume |
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Edition |
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ISSN |
0556-3321 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.2 |
Times cited |
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Open Access ![sorted by Open Access field, descending order (down)](img/sort_desc.gif) |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 1.2 |
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Call Number |
UA @ admin @ c:irua:188469 |
Serial |
7153 |
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Permanent link to this record |
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Author |
Li, Y.; Quinn, B.K.; Gielis, J.; Li, Y.; Shi, P. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
Evidence that supertriangles exist in nature from the vertical projections of Koelreuteria paniculata fruit |
Type |
A1 Journal article |
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Year |
2022 |
Publication |
Symmetry |
Abbreviated Journal |
Symmetry-Basel |
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Volume |
14 |
Issue |
1 |
Pages |
23 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
Many natural radial symmetrical shapes (e.g., sea stars) follow the Gielis equation (GE) or its twin equation (TGE). A supertriangle (three triangles arranged around a central polygon) represents such a shape, but no study has tested whether natural shapes can be represented as/are supertriangles or whether the GE or TGE can describe their shape. We collected 100 pieces of Koelreuteria paniculata fruit, which have a supertriangular shape, extracted the boundary coordinates for their vertical projections, and then fitted them with the GE and TGE. The adjusted root mean square errors (RMSEadj) of the two equations were always less than 0.08, and >70% were less than 0.05. For 57/100 fruit projections, the GE had a lower RMSEadj than the TGE, although overall differences in the goodness of fit were non-significant. However, the TGE produces more symmetrical shapes than the GE as the two parameters controlling the extent of symmetry in it are approximately equal. This work demonstrates that natural supertriangles exist, validates the use of the GE and TGE to model their shapes, and suggests that different complex radially symmetrical shapes can be generated by the same equation, implying that different types of biological symmetry may result from the same biophysical mechanisms. |
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Wos |
000746030100001 |
Publication Date |
2021-12-27 |
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Abbreviated Series Title |
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Series Volume |
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Edition |
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ISSN |
2073-8994 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.7 |
Times cited |
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Open Access ![sorted by Open Access field, descending order (down)](img/sort_desc.gif) |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 2.7 |
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Call Number |
UA @ admin @ c:irua:186453 |
Serial |
7158 |
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Permanent link to this record |
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Author |
Nicolau, F.; Gielis, J.; Simeone, A.L.; Simoes Lopes, D. |
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Title |
Exploring and selecting supershapes in virtual reality with line, quad, and cube shaped widgets |
Type |
P1 Proceeding |
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Year |
2022 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
21-28 |
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Keywords |
P1 Proceeding; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
Supershapes are used in Parametric Design to model, literally, thou-sands of natural and man-made shapes with a single 6 parameter formula. However, users are left to probe such a rich yet dense collection of supershapes using a set of independent 1-D sliders. Some of the formula’s parameters are non-linear in nature, making them particularly difficult to grasp with conventional 1-D sliders alone. VR appears as a promising setting for Parametric Design with supershapes since it empowers users with more natural visual inspection and shape browsing techniques, with multiple solutions being displayed at once and the possibility to design more interesting forms of slider interaction. In this work, we propose VR shape widgets that allow users to probe and select supershapes from a multitude of solutions. Our designs take leverage on thumbnails, mini-maps, haptic feedback and spatial interaction, while supporting 1-D, 2-D and 3-D supershape parameter spaces. We conducted a user study (N = 18) and found that VR shape widgets are effective, more efficient, and natural than conventional VR 1-D sliders while also usable for users without prior knowledge on supershapes. We also found that the proposed VR widgets provide a quick overview of the main supershapes, and users can easily reach the desired solution without having to perform fine-grain handle manipulations. |
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Wos |
000828657500003 |
Publication Date |
2022-04-20 |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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ISSN |
978-1-6654-9617-9 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
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Times cited |
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Open Access ![sorted by Open Access field, descending order (down)](img/sort_desc.gif) |
OpenAccess |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:188471 |
Serial |
7161 |
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Permanent link to this record |
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Author |
Wang, L.; Miao, Q.; Niinemets, Ü.; Gielis, J.; Shi, P. |
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Title |
Quantifying the variation in the geometries of the outer rims of corolla tubes of Vinca major L |
Type |
A1 Journal article |
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Year |
2022 |
Publication |
Plants |
Abbreviated Journal |
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Volume |
11 |
Issue |
15 |
Pages |
1987-12 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
Many geometries of plant organs can be described by the Gielis equation, a polar coordinate equation extended from the superellipse equation, . Here, r is the polar radius corresponding to the polar angle φ; m is a positive integer that determines the number of angles of the Gielis curve when φ ∈ [0 to 2π); and the rest of the symbols are parameters to be estimated. The pentagonal radial symmetry of calyxes and corolla tubes in top view is a common feature in the flowers of many eudicots. However, prior studies have not tested whether the Gielis equation can depict the shapes of corolla tubes. We sampled randomly 366 flowers of Vinca major L., among which 360 had five petals and pentagonal corolla tubes, and six had four petals and quadrangular corolla tubes. We extracted the planar coordinates of the outer rims of corolla tubes (in top view) (ORCTs), and then fitted the data with two simplified versions of the Gielis equation with k = 1 and m = 5: (Model 1), and (Model 2). The adjusted root mean square error (RMSEadj) was used to evaluate the goodness of fit of each model. In addition, to test whether ORCTs are radially symmetrical, we correlated the estimates of n2 and n3 in Model 1 on a log-log scale. The results validated the two simplified Gielis equations. The RMSEadj values for all corolla tubes were smaller than 0.05 for both models. The numerical values of n2 and n3 were demonstrated to be statistically equal based on the regression analysis, which suggested that the ORCTs of V. major are radially symmetrical. It suggests that Model 1 can be replaced by the simpler Model 2 for fitting the ORCT in this species. This work indicates that the pentagonal or quadrangular corolla tubes (in top view) can both be modeled by the Gielis equation and demonstrates that the pentagonal or quadrangular corolla tubes of plants tend to form radial symmetrical geometries during their development and growth. |
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Wos |
000839115100001 |
Publication Date |
2022-08-01 |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2223-7747 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access ![sorted by Open Access field, descending order (down)](img/sort_desc.gif) |
OpenAccess |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:189315 |
Serial |
7200 |
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Permanent link to this record |
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Author |
Shi, P.; Wang, L.; Quinn, B.K.K.; Gielis, J. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
A new program to estimate the parameters of Preston's equation, a general formula for describing the egg shape of birds |
Type |
A1 Journal article |
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Year |
2023 |
Publication |
Symmetry |
Abbreviated Journal |
Symmetry-Basel |
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Volume |
15 |
Issue |
1 |
Pages |
231-10 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
Preston's equation is a general model describing the egg shape of birds. The parameters of Preston's equation are usually estimated after re-expressing it as the Todd-Smart equation and scaling the egg's actual length to two. This method assumes that the straight line through the two points on an egg's profile separated by the maximum distance (i.e., the longest axis of an egg's profile) is the mid-line. It hypothesizes that the photographed egg's profile is perfectly bilaterally symmetrical, which seldom holds true because of photographic errors and placement errors. The existing parameter estimation method for Preston's equation considers an angle of deviation for the longest axis of an egg's profile from the mid-line, which decreases prediction errors to a certain degree. Nevertheless, this method cannot provide an accurate estimate of the coordinates of the egg's center, and it leads to sub-optimal parameter estimation. Thus, it is better to account for the possible asymmetry between the two sides of an egg's profile along its mid-line when fitting egg-shape data. In this paper, we propose a method based on the optimization algorithm (optimPE) to fit egg-shape data and better estimate the parameters of Preston's equation by automatically searching for the optimal mid-line of an egg's profile and testing its validity using profiles of 59 bird eggs spanning a wide range of existing egg shapes. We further compared this method with the existing one based on multiple linear regression (lmPE). This study demonstrated the ability of the optimPE method to estimate numerical values of the parameters of Preston's equation and provide the theoretical egg length (i.e., the distance between two ends of the mid-line of an egg's profile) and the egg's maximum breadth. This provides a valuable approach for comparing egg shapes among conspecifics or across different species, or even different classes (e.g., birds and reptiles), in future investigations. |
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Wos |
000927531000001 |
Publication Date |
2023-01-13 |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2073-8994 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.7 |
Times cited |
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Open Access ![sorted by Open Access field, descending order (down)](img/sort_desc.gif) |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 2.7; 2023 IF: 1.457 |
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Call Number |
UA @ admin @ c:irua:195347 |
Serial |
7279 |
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Permanent link to this record |
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Author |
Yao, W.; Niinemets, Ü.; Yao, W.; Gielis, J.; Schrader, J.; Yu, K.; Shi, P. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
Comparison of two simplified versions of the Gielis equation for describing the shape of bamboo leaves |
Type |
A1 Journal article |
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Year |
2022 |
Publication |
Plants |
Abbreviated Journal |
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Volume |
11 |
Issue |
22 |
Pages |
3058-11 |
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Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
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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. |
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Wos |
000887783400001 |
Publication Date |
2022-11-14 |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2223-7747 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
|
Times cited |
|
Open Access ![sorted by Open Access field, descending order (down)](img/sort_desc.gif) |
OpenAccess |
|
|
Notes |
|
Approved |
Most recent IF: NA |
|
|
Call Number |
UA @ admin @ c:irua:191859 |
Serial |
7289 |
|
Permanent link to this record |
|
|
|
|
Author |
Wang, L.; Ratkowsky, D.A.; Gielis, J.; Ricci, P.E.; Shi, P. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
|
|
Title |
Effects of the numerical values of the parameters in the Gielis equation on its geometries |
Type |
A1 Journal article |
|
Year |
2022 |
Publication |
Symmetry |
Abbreviated Journal |
Symmetry-Basel |
|
|
Volume |
14 |
Issue |
12 |
Pages |
2475-12 |
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|
Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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|
Abstract |
The Lamé curve is an extension of an ellipse, the latter being a special case. Dr. Johan Gielis further extended the Lamé curve in the polar coordinate system by introducing additional parameters (n1, n2, n3; m): rφ=1Acosm4φn2+1Bsinm4φn3−1/n1, which can be applied to model natural geometries. Here, r is the polar radius corresponding to the polar angle φ; A, B, n1, n2 and n3 are parameters to be estimated; m is the positive real number that determines the number of angles of the Gielis curve. Most prior studies on the Gielis equation focused mainly on its applications. However, the Gielis equation can also generate a large number of shapes that are rotationally symmetric and axisymmetric when A = B and n2 = n3, interrelated with the parameter m, with the parameters n1 and n2 determining the shapes of the curves. In this paper, we prove the relationship between m and the rotational symmetry and axial symmetry of the Gielis curve from a theoretical point of view with the condition A = B, n2 = n3. We also set n1 and n2 to take negative real numbers rather than only taking positive real numbers, then classify the curves based on extremal properties of r(φ) at φ = 0, π/m when n1 and n2 are in different intervals, and analyze how n1, n2 precisely affect the shapes of Gielis curves. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
|
Wos |
000904525700001 |
Publication Date |
2022-11-23 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2073-8994 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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|
Impact Factor |
2.7 |
Times cited |
|
Open Access ![sorted by Open Access field, descending order (down)](img/sort_desc.gif) |
OpenAccess |
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|
Notes |
|
Approved |
Most recent IF: 2.7 |
|
|
Call Number |
UA @ admin @ c:irua:191860 |
Serial |
7301 |
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Permanent link to this record |
|
|
|
|
Author |
Shi, P.; Yu, K.; Niinemets, Ü.; Gielis, J. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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|
Title |
Can leaf shape be represented by the ratio of leaf width to length? Evidence from nine species of Magnolia and Michelia (Magnoliaceae) |
Type |
A1 Journal article |
|
Year |
2021 |
Publication |
Forests |
Abbreviated Journal |
Forests |
|
|
Volume |
12 |
Issue |
1 |
Pages |
41 |
|
|
Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
Leaf shape is closely related to economics of leaf support and leaf functions, including light interception, water use, and CO2 uptake, so correct quantification of leaf shape is helpful for studies of leaf structure/function relationships. There are some extant indices for quantifying leaf shape, including the leaf width/length ratio (W/L), leaf shape fractal dimension (FD), leaf dissection index, leaf roundness index, standardized bilateral symmetrical index, etc. W/L ratio is the simplest to calculate, and recent studies have shown the importance of the W/L ratio in explaining the scaling exponent of leaf dry mass vs. leaf surface area and that of leaf surface area vs. leaf length. Nevertheless, whether the W/L ratio could reflect sufficient geometrical information of leaf shape has been not tested. The FD might be the most accurate measure for the complexity of leaf shape because it can characterize the extent of the self-similarity and other planar geometrical features of leaf shape. However, it is unknown how strongly different indices of leaf shape complexity correlate with each other, especially whether W/L ratio and FD are highly correlated. In this study, the leaves of nine Magnoliaceae species (>140 leaves for each species) were chosen for the study. We calculated the FD value for each leaf using the box-counting approach, and measured leaf fresh mass, surface area, perimeter, length, and width. We found that FD is significantly correlated to the W/L ratio and leaf length. However, the correlation between FD and the W/L ratio was far stronger than that between FD and leaf length for each of the nine species. There were no strong correlations between FD and other leaf characteristics, including leaf area, ratio of leaf perimeter to area, fresh mass, ratio of leaf fresh mass to area, and leaf roundness index. Given the strong correlation between FD and W/L, we suggest that the simpler index, W/L ratio, can provide sufficient information of leaf shape for similarly-shaped leaves. Future studies are needed to characterize the relationships among FD and W/L in leaves with strongly varying shape, e.g., in highly dissected leaves. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000611074700001 |
Publication Date |
2020-12-31 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
1999-4907 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.951 |
Times cited |
|
Open Access ![sorted by Open Access field, descending order (down)](img/sort_desc.gif) |
OpenAccess |
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Notes |
|
Approved |
Most recent IF: 1.951 |
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Call Number |
UA @ admin @ c:irua:174473 |
Serial |
7572 |
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Permanent link to this record |
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Author |
Niklas, K.J.; Shi, P.; Gielis, J.; Schrader, J.; Niinemets, U. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
Editorial: leaf functional traits : ecological and evolutionary implications |
Type |
Editorial |
|
Year |
2023 |
Publication |
Frontiers in plant science |
Abbreviated Journal |
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Volume |
14 |
Issue |
|
Pages |
1169558-5 |
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Keywords |
Editorial; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
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Editor |
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Language |
|
Wos |
000964122500001 |
Publication Date |
2023-03-21 |
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Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
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ISSN |
1664-462x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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|
Impact Factor |
5.6 |
Times cited |
|
Open Access ![sorted by Open Access field, descending order (down)](img/sort_desc.gif) |
OpenAccess |
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Notes |
|
Approved |
Most recent IF: 5.6; 2023 IF: 4.298 |
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|
Call Number |
UA @ admin @ c:irua:196076 |
Serial |
7834 |
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Permanent link to this record |
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Author |
Gielis, J.; Ricci, P.E.; Tavkhelidze, I. |
![goto web page url](http://nano.uantwerpen.be/nanorefs/img/www.gif)
![find record details (via OpenURL) openurl](img/xref.gif)
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Title |
The Möbius phenomenon in Generalized Möbius-Listing surfaces and bodies, and Arnold's Cat phenomenon |
Type |
A1 Journal article |
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Year |
2021 |
Publication |
Advanced Studies : Euro-Tbilisi Mathematical Journal |
Abbreviated Journal |
|
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Volume |
14 |
Issue |
4 |
Pages |
17-35 |
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Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
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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. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000774655100002 |
Publication Date |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
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ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
|
Times cited |
|
Open Access ![sorted by Open Access field, descending order (down)](img/sort_desc.gif) |
OpenAccess |
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Notes |
|
Approved |
Most recent IF: NA |
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|
Call Number |
UA @ admin @ c:irua:183081 |
Serial |
8258 |
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Permanent link to this record |
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Author |
Gielis, J. |
![goto web page url](http://nano.uantwerpen.be/nanorefs/img/www.gif)
![find record details (via OpenURL) openurl](img/xref.gif)
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Title |
Phi-bonacci in Ancient Greece |
Type |
A1 Journal article |
|
Year |
2021 |
Publication |
Symmetry : culture and science |
Abbreviated Journal |
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Volume |
32 |
Issue |
1 |
Pages |
25-40 |
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Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
Fibonacci numbers are a very popular subject in mathematics, culture and science. A major open question is why the ancient Greeks overlooked this series, while they were very familiar with the golden mean and division in extreme and mean ratio. Furthermore, they could compute the square root of five to a high degree of precision using Theon 's ladder. This fact is based on tables built with side and diagonal numbers, and it is a simple and incredibly efficient method to compute roots of integers, though it is little known even now among most of the experts. The biologist D 'Arcy Wentworth Thompson showed that the same method could be used to generate the Fibonacci series using a simple shift in the computation of the tables. He argues, quite convincingly, that the ancient Greeks could not have overlooked this. Actually, the same method can be used to generate all possible regular phyllotaxis patterns. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000643822700002 |
Publication Date |
2021-03-30 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
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ISSN |
0865-4824 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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Impact Factor |
|
Times cited |
|
Open Access ![sorted by Open Access field, descending order (down)](img/sort_desc.gif) |
OpenAccess |
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Notes |
|
Approved |
Most recent IF: NA |
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|
Call Number |
UA @ admin @ c:irua:178322 |
Serial |
8376 |
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Permanent link to this record |
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Author |
Shi, P.; Chen, L.; Quinn, B.K.; Yu, K.; Miao, Q.; Guo, X.; Lian, M.; Gielis, J.; Niklas, K.J. |
![goto web page url](http://nano.uantwerpen.be/nanorefs/img/www.gif)
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Title |
A simple way to calculate the volume and surface area of avian eggs |
Type |
A1 Journal article |
|
Year |
2023 |
Publication |
Annals of the New York Academy of Sciences |
Abbreviated Journal |
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Volume |
1524 |
Issue |
1 |
Pages |
118-131 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
Egg geometry can be described using Preston's equation, which has seldom been used to calculate egg volume (V) and surface area (S) to explore S versus V scaling relationships. Herein, we provide an explicit re-expression of Preston's equation (designated as EPE) to calculate V and S, assuming that an egg is a solid of revolution. The side (longitudinal) profiles of 2221 eggs of six avian species were digitized, and the EPE was used to describe each egg profile. The volumes of 486 eggs from two avian species predicted by the EPE were compared with those obtained using water displacement in graduated cylinders. There was no significant difference in V using the two methods, which verified the utility of the EPE and the hypothesis that eggs are solids of revolution. The data also indicated that V is proportional to the product of egg length (L) and maximum width (W) squared. A 2/3-power scaling relationship between S and V for each species was observed, that is, S is proportional to (LW2)(2/3). These results can be extended to describe the shapes of the eggs of other species to study the evolution of avian (and perhaps reptilian) eggs. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
|
Wos |
000975679400001 |
Publication Date |
2023-04-28 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0077-8923; 1749-6632 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
5.2 |
Times cited |
|
Open Access ![sorted by Open Access field, descending order (down)](img/sort_desc.gif) |
OpenAccess |
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Notes |
|
Approved |
Most recent IF: 5.2; 2023 IF: 4.706 |
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Call Number |
UA @ admin @ c:irua:196724 |
Serial |
8827 |
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Permanent link to this record |
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Author |
Gielis, J. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
Fred Van Oystaeyen : Time hybrids: a new generic theory of reality |
Type |
Review |
|
Year |
2023 |
Publication |
Symmetry, Culture and Science |
Abbreviated Journal |
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Volume |
34 |
Issue |
3 |
Pages |
347-351 |
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Keywords |
Review; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
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Publication Date |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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Series Volume |
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Series Issue |
|
Edition |
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ISSN |
|
ISBN |
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Additional Links |
UA library record |
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Impact Factor |
|
Times cited |
|
Open Access ![sorted by Open Access field, descending order (down)](img/sort_desc.gif) |
OpenAccess |
|
|
Notes |
|
Approved |
Most recent IF: NA |
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|
Call Number |
UA @ admin @ c:irua:199538 |
Serial |
8871 |
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Permanent link to this record |
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Author |
Huang, L.; Ratkowsky, D.A.; Hui, C.; Gielis, J.; Lian, M.; Shi, P. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
Inequality measure of leaf area distribution for a drought-tolerant landscape plant |
Type |
A1 Journal article |
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Year |
2023 |
Publication |
Plants |
Abbreviated Journal |
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Volume |
12 |
Issue |
17 |
Pages |
3143-11 |
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Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
Measuring the inequality of leaf area distribution per plant (ILAD) can provide a useful tool for quantifying the influences of intra- and interspecific competition, foraging behavior of herbivores, and environmental stress on plants’ above-ground architectural structures and survival strategies. Despite its importance, there has been limited research on this issue. This paper aims to fill this gap by comparing four inequality indices to measure ILAD, using indices for quantifying household income that are commonly used in economics, including the Gini index (which is based on the Lorenz curve), the coefficient of variation, the Theil index, and the mean log deviation index. We measured the area of all leaves for 240 individual plants of the species Shibataea chinensis Nakai, a drought-tolerant landscape plant found in southern China. A three-parameter performance equation was fitted to observations of the cumulative proportion of leaf area vs. the cumulative proportion of leaves per plant to calculate the Gini index for each individual specimen of S. chinensis. The performance equation was demonstrated to be valid in describing the rotated and right shifted Lorenz curve, given that >96% of root-mean-square error values were smaller than 0.004 for 240 individual plants. By examining the correlation between any of the six possible pairs of indices among the Gini index, the coefficient of variation, the Theil index, and the mean log deviation index, the data show that these indices are closely related and can be used interchangeably to quantify ILAD. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
001065193100001 |
Publication Date |
2023-08-31 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2223-7747 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
|
Times cited |
|
Open Access ![sorted by Open Access field, descending order (down)](img/sort_desc.gif) |
OpenAccess |
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Notes |
|
Approved |
Most recent IF: NA |
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|
Call Number |
UA @ admin @ c:irua:199564 |
Serial |
8886 |
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Permanent link to this record |
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Author |
Shi, P.; Gielis, J.; Niklas, K.J.; Niinemets, Ü.; Schrader, J. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
Leaf functional traits : ecological and evolutionary implications |
Type |
ME3 Book as editor |
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Year |
2023 |
Publication |
|
Abbreviated Journal |
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Volume |
|
Issue |
|
Pages |
185 p. |
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Keywords |
ME3 Book as editor; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
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Publication Date |
2023-04-14 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
|
ISBN |
978-2-8325-2086-4; 1664-8714 |
Additional Links |
UA library record |
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|
Impact Factor |
|
Times cited |
|
Open Access ![sorted by Open Access field, descending order (down)](img/sort_desc.gif) |
OpenAccess |
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Notes |
|
Approved |
Most recent IF: NA |
|
|
Call Number |
UA @ admin @ c:irua:198002 |
Serial |
8894 |
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Permanent link to this record |
|
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Author |
Lian, M.; Shi, P.; Zhang, L.; Yao, W.; Gielis, J.; Niklas, K.J. |
![goto web page url](http://nano.uantwerpen.be/nanorefs/img/www.gif)
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Title |
A generalized performance equation and its application in measuring the Gini index of leaf size inequality |
Type |
A1 Journal article |
|
Year |
2023 |
Publication |
Trees: structure and function |
Abbreviated Journal |
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Volume |
37 |
Issue |
|
Pages |
1555-1565 |
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Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
The goal of this study is to provide a rigorous tool to quantify the inequality of the leaf size distribution of an individual plant, thereby serving as a reference trait for quantifying plant adaptations to local environmental conditions. The tool to be presented and tested employs three components: (1) a performance equation (PE), which can produce flexible asymmetrical and symmetrical bell-shaped curves, (2) the Lorenz curve (i.e., the cumulative proportion of leaf size vs. the cumulative proportion of number of leaves), which is the basis for calculating, and (3) the Gini index, which measures the inequality of leaf size distribution. We sampled 12 individual plants of a dwarf bamboo and measured the area and dry mass of each leaf of each plant. We then developed a generalized performance equation (GPE) of which the PE is a special case and fitted the Lorenz curve to leaf size distribution using the GPE and PE. The GPE performed better than the PE in fitting the Lorenz curve. We compared the Gini index of leaf area distribution with that of leaf dry mass distribution and found that there was a significant difference between the two indices that might emerge from the scaling relationship between leaf dry mass and area. Nevertheless, there was a strong correlation between the two Gini indices (r2 = 0.9846). This study provides a promising tool based on the GPE for quantifying the inequality of leaf size distributions across individual plants and can be used to quantify plant adaptations to local environmental conditions. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
|
Wos |
001069570200001 |
Publication Date |
2023-08-26 |
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Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0931-1890; 1432-2285 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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|
Impact Factor |
2.3 |
Times cited |
|
Open Access ![sorted by Open Access field, descending order (down)](img/sort_desc.gif) |
Not_Open_Access: Available from 26.02.2024 |
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Notes |
|
Approved |
Most recent IF: 2.3; 2023 IF: 1.842 |
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Call Number |
UA @ admin @ c:irua:199562 |
Serial |
8874 |
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Permanent link to this record |
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Author |
Wang, L.; Shi, P.; Chen, L.; Gielis, J.; Niklas, K.J. |
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Title |
Evidence that Chinese white olive (Canarium album(Lour.) DC.) fruits are solids of revolution |
Type |
A1 Journal article |
|
Year |
2023 |
Publication |
Botany letters |
Abbreviated Journal |
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Volume |
|
Issue |
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Pages |
1-7 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
Although many fruit geometries resemble a solid of revolution, this assumption has rarely been rigorously examined. To test this assumption, 574 fruits of Canarium album (Lour.) DC. which appear to have an ellipsoidal shape, were examined to determine the validity of a general avian-based egg-shape equation, referred to as the explicit Preston equation (EPE). The assumption that the C. album fruit geometry is a solid of revolution is tested by applying the volume formula for a solid of revolution using the EPE. The goodness of fit of the EPE was assessed using the adjusted root-mean-square error (RMSEadj). The relationship between the observed volume (Vobs) of each fruit, as measured by water displacement in a graduated cylinder, and the predicted volumes (Vpre) based on the EPE was also evaluated using the equation Vpre = slope * Vobs. All the RMSEadj values were smaller than 0.05, which demonstrated the validity of the EPE based on C. album fruit profiles. The 95% confidence interval of the slope of Vpre vs. Vobs included 1.0, indicating that there was no significant difference between Vpre and Vobs. The data confirm that C. album fruits are solids of revolution. This study provides a new approach for calculating the volume and surface area of geometrically similar fruits, which can be extended to other species with similar fruit geometries to further explore the ontogeny and evolution of angiosperm reproductive organs. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Wos |
001033135400001 |
Publication Date |
2023-07-25 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2381-8107; 2381-8115 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.5 |
Times cited |
|
Open Access ![sorted by Open Access field, descending order (down)](img/sort_desc.gif) |
Not_Open_Access: Available from 24.01.2024 |
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Notes |
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Approved |
Most recent IF: 1.5; 2023 IF: NA |
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Call Number |
UA @ admin @ c:irua:198001 |
Serial |
8864 |
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Permanent link to this record |
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Author |
Li, Q.; Niklas, K.J.J.; Niinemets, U.; Zhang, L.; Yu, K.; Gielis, J.; Gao, J.; Shi, P. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
Stomatal shape described by a superellipse in four Magnoliaceae species |
Type |
A1 Journal article |
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Year |
2023 |
Publication |
Botany letters |
Abbreviated Journal |
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Volume |
|
Issue |
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Pages |
1-9 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
Stomata are essential for the exchange of water vapour and atmospheric gases between vascular plants and their external environments. The stomatal geometries of many plants appear to be elliptical. However, prior studies have not tested whether this is a mathematical reality, particularly since many natural shapes that appear to be ellipses are superellipses with greater or smaller edge curvature than predicted for an ellipse. Compared with the ellipse equation, the superellipse equation includes an additional parameter that allows generation of a larger range of shapes. We randomly selected 240 stomata from each of four Magnoliaceae species to test whether the stomatal geometries are superellipses or ellipses. The stomatal geometries for most stomata (943/960) were found to be described better using the superellipse equation. The traditional “elliptical stomata hypothesis” resulted in an underestimation of the area of stomata, whereas the superellipse equation accurately predicted stomatal area. This finding has important implications for the estimation of stomatal area in studies looking at stomatal shape, geometry, and function. |
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Corporate Author |
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Place of Publication |
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Editor |
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Language |
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Wos |
001024190300001 |
Publication Date |
2023-07-12 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2381-8107; 2381-8115 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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Impact Factor |
1.5 |
Times cited |
|
Open Access ![sorted by Open Access field, descending order (down)](img/sort_desc.gif) |
Not_Open_Access: Available from 12.01.2024 |
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Notes |
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Approved |
Most recent IF: 1.5; 2023 IF: NA |
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Call Number |
UA @ admin @ c:irua:197847 |
Serial |
8935 |
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Permanent link to this record |
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Author |
Gielis, J. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
Simon Stevin as a central figure in the development of abstract algebra and generic programming |
Type |
A1 Journal article |
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Year |
2023 |
Publication |
Symmetry : culture and science |
Abbreviated Journal |
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Volume |
34 |
Issue |
2 |
Pages |
155-168 |
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Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
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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. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
001068714100003 |
Publication Date |
2023-07-11 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
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Edition |
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ISSN |
0865-4824 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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Impact Factor |
|
Times cited |
|
Open Access ![sorted by Open Access field, descending order (down)](img/sort_desc.gif) |
Not_Open_Access: Available from 08.02.2024 |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:198000 |
Serial |
8929 |
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Permanent link to this record |
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Author |
Ricci, P.E.; Gielis, J. |
![find book details (via ISBN) isbn](img/isbn.gif)
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Title |
From Pythagoras to Fourier and from geometry to nature |
Type |
MA3 Book as author |
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Year |
2022 |
Publication |
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Abbreviated Journal |
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Volume |
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Issue |
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Pages |
146 p. |
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Keywords |
MA3 Book as author; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
|
Publication Date |
2022-03-23 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
|
ISBN |
978-90-832323-0-0; 978-90-832323-1-7 |
Additional Links |
UA library record |
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Impact Factor |
|
Times cited |
|
Open Access ![sorted by Open Access field, descending order (down)](img/sort_desc.gif) |
Not_Open_Access |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:186730 |
Serial |
7166 |
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Permanent link to this record |
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Author |
Gielis, J. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
Double helix of phyllotaxis : analysis of the geometric model of plant morphogenesis, by Boris Rozin |
Type |
Review |
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Year |
2021 |
Publication |
Quarterly Review Of Biology |
Abbreviated Journal |
Q Rev Biol |
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Volume |
96 |
Issue |
2 |
Pages |
139-140 |
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Keywords |
Review; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
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Publication Date |
2021-05-19 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0033-5770; 1539-7718 |
ISBN |
|
Additional Links |
UA library record |
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Impact Factor |
4.25 |
Times cited |
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Open Access ![sorted by Open Access field, descending order (down)](img/sort_desc.gif) |
Not_Open_Access |
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Notes |
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Approved |
Most recent IF: 4.25 |
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Call Number |
UA @ admin @ c:irua:178829 |
Serial |
7824 |
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Permanent link to this record |
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Author |
Chapman, D.; Gielis, J. |
![find record details (via OpenURL) openurl](img/xref.gif)
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Title |
Gielis transformations for the audiovisual geometry database |
Type |
A1 Journal article |
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Year |
2021 |
Publication |
Symmetry : culture and science |
Abbreviated Journal |
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Volume |
32 |
Issue |
2 |
Pages |
177-180 |
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Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
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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. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
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Publication Date |
2021-07-02 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0865-4824 |
ISBN |
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Additional Links |
UA library record |
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Impact Factor |
|
Times cited |
|
Open Access ![sorted by Open Access field, descending order (down)](img/sort_desc.gif) |
Not_Open_Access |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:180965 |
Serial |
8004 |
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Permanent link to this record |
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Author |
Gielis, J.; Brasili, S. |
![find record details (via OpenURL) openurl](img/xref.gif)
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Title |
The apeirogon and dual numbers |
Type |
A1 Journal article |
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Year |
2021 |
Publication |
Symmetry : culture and science |
Abbreviated Journal |
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Volume |
32 |
Issue |
2 |
Pages |
157-160 |
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Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
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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. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000670122100011 |
Publication Date |
2021-07-02 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0865-4824 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
|
Times cited |
|
Open Access ![sorted by Open Access field, descending order (down)](img/sort_desc.gif) |
Not_Open_Access |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:179759 |
Serial |
8652 |
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Permanent link to this record |
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Author |
Zhang, L.; Quinn, B.K.; Hui, C.; Lian, M.; Gielis, J.; Gao, J.; Shi, P. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
New indices to balance α-diversity against tree size inequality |
Type |
A1 Journal article |
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Year |
2024 |
Publication |
Journal of forestry research |
Abbreviated Journal |
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Volume |
35 |
Issue |
1 |
Pages |
31-39 |
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Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
The number and composition of species in a community can be quantified with alpha-diversity indices, including species richness (R), Simpson's index (D), and the Shannon-Wiener index (HGREEK TONOS). In forest communities, there are large variations in tree size among species and individuals of the same species, which result in differences in ecological processes and ecosystem functions. However, tree size inequality (TSI) has been largely neglected in studies using the available diversity indices. The TSI in the diameter at breast height (DBH) data for each of 999 20 m x 20 m forest census quadrats was quantified using the Gini index (GI), a measure of the inequality of size distribution. The generalized performance equation was used to describe the rotated and right-shifted Lorenz curve of the cumulative proportion of DBH and the cumulative proportion of number of trees per quadrat. We also examined the relationships of alpha-diversity indices with the GI using correlation tests. The generalized performance equation effectively described the rotated and right-shifted Lorenz curve of DBH distributions, with most root-mean-square errors (990 out of 999 quadrats) being < 0.0030. There were significant positive correlations between each of three alpha-diversity indices (i.e., R, D, and H') and the GI. Nevertheless, the total abundance of trees in each quadrat did not significantly influence the GI. This means that the TSI increased with increasing species diversity. Thus, two new indices are proposed that can balance alpha-diversity against the extent of TSI in the community: (1 – GI) x D, and (1 – GI) x H'. These new indices were significantly correlated with the original D and HGREEK TONOS, and did not increase the extent of variation within each group of indices. This study presents a useful tool for quantifying both species diversity and the variation in tree sizes in forest communities, especially in the face of cumulative species loss under global climate change. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
001131698000001 |
Publication Date |
2023-12-28 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
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ISSN |
1007-662x; 1993-0607 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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Impact Factor |
3 |
Times cited |
|
Open Access ![sorted by Open Access field, descending order (down)](img/sort_desc.gif) |
Not_Open_Access |
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Notes |
|
Approved |
Most recent IF: 3; 2024 IF: 0.774 |
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Call Number |
UA @ admin @ c:irua:201972 |
Serial |
9061 |
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Permanent link to this record |
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Author |
Tian, F.; Wang, Y.; Sandhu, H.S.; Gielis, J.; Shi, P. |
![goto web page url](http://nano.uantwerpen.be/nanorefs/img/www.gif)
![find record details (via OpenURL) openurl](img/xref.gif)
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Title |
Comparison of seed morphology of two ginkgo cultivars |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Journal Of Forestry Research |
Abbreviated Journal |
J Forestry Res |
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Volume |
31 |
Issue |
3 |
Pages |
751-758 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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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. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000529367600005 |
Publication Date |
2018-07-28 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1007-662x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3 |
Times cited |
3 |
Open Access ![sorted by Open Access field, descending order (down)](img/sort_desc.gif) |
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Notes |
; ; |
Approved |
Most recent IF: 3; 2020 IF: 0.774 |
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Call Number |
UA @ admin @ c:irua:154987 |
Serial |
6474 |
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Permanent link to this record |
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Author |
Shi, P.; Ratkowsky, D.A.; Gielis, J. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
The generalized Gielis geometric equation and its application |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Symmetry-Basel |
Abbreviated Journal |
Symmetry-Basel |
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Volume |
12 |
Issue |
4 |
Pages |
645-10 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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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. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000540222200156 |
Publication Date |
2020-04-21 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
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Edition |
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ISSN |
2073-8994 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.7 |
Times cited |
4 |
Open Access ![sorted by Open Access field, descending order (down)](img/sort_desc.gif) |
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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 |
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Call Number |
UA @ admin @ c:irua:168141 |
Serial |
6526 |
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Permanent link to this record |
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Author |
Gielis, J.; Caratelli, D.; Shi, P.; Ricci, P.E. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
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Title |
A note on spirals and curvature |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Growth and form |
Abbreviated Journal |
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Volume |
1 |
Issue |
1 |
Pages |
1-8 |
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Keywords |
A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
Starting from logarithmic, sinusoidal and power spirals, it is shown how these spirals are connected directly with Chebyshev polynomials, Lamé curves, with allometry and Antonelli-metrics in Finsler geometry. Curvature is a crucial concept in geometry both for closed curves and equiangular spirals, and allowed Dillen to give a general definition of spirals. Many natural shapes can be described as a combination of one of two basic shapes in nature—circle and spiral—with Gielis transformations. Using this idea, shape description itself is used to develop a novel approach to anisotropic curvature in nature. Various examples are discussed, including fusion in flowers and its connection to the recently described pseudo-Chebyshev functions. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
|
Wos |
|
Publication Date |
2020-02-23 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
|
ISBN |
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Additional Links |
UA library record |
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Impact Factor |
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Times cited |
|
Open Access ![sorted by Open Access field, descending order (down)](img/sort_desc.gif) |
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Notes |
|
Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:167061 |
Serial |
6569 |
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Permanent link to this record |