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Author Bia, P.; Caratelli, D.; Mescia, L.; Gielis, J.
Title (down) Electromagnetic characterization of supershaped lens antennas for high-frequency applications Type H1 Book chapter
Year 2013 Publication Abbreviated Journal
Volume Issue Pages 1679-1682 T2 - Proceedings of the 43rd European Mi
Keywords H1 Book chapter; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000330768700424 Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN 978-2-87487-031-6 Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:110954 Serial 7865
Permanent link to this record
 
 
Author Wang, L.; Ratkowsky, D.A.; Gielis, J.; Ricci, P.E.; Shi, P.
Title (down) 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
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
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.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000904525700001 Publication Date 2022-11-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2073-8994 ISBN Additional Links UA library record; WoS full record
Impact Factor 2.7 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 2.7
Call Number UA @ admin @ c:irua:191860 Serial 7301
Permanent link to this record
 
 
Author Niklas, K.J.; Shi, P.; Gielis, J.; Schrader, J.; Niinemets, U.
Title (down) Editorial: leaf functional traits : ecological and evolutionary implications Type Editorial
Year 2023 Publication Frontiers in plant science Abbreviated Journal
Volume 14 Issue Pages 1169558-5
Keywords Editorial; Sustainable Energy, Air and Water Technology (DuEL)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000964122500001 Publication Date 2023-03-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1664-462x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.6 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 5.6; 2023 IF: 4.298
Call Number UA @ admin @ c:irua:196076 Serial 7834
Permanent link to this record
 
 
Author Gielis, J.
Title (down) Double helix of phyllotaxis : analysis of the geometric model of plant morphogenesis, by Boris Rozin Type Review
Year 2021 Publication Quarterly Review Of Biology Abbreviated Journal Q Rev Biol
Volume 96 Issue 2 Pages 139-140
Keywords Review; Sustainable Energy, Air and Water Technology (DuEL)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2021-05-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0033-5770; 1539-7718 ISBN Additional Links UA library record
Impact Factor 4.25 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 4.25
Call Number UA @ admin @ c:irua:178829 Serial 7824
Permanent link to this record
 
 
Author De Tommasi, E.; Gielis, J.; Rogato, A.
Title (down) Diatom frustule morphogenesis and function : a multidisciplinary survey Type A1 Journal article
Year 2017 Publication Marine Genomics Abbreviated Journal
Volume 35 Issue Pages 1-18
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Diatoms represent the major component of phytoplankton and are responsible for about 2025% of global primary production. Hundreds of millions of years of evolution led to tens of thousands of species differing in dimensions and morphologies. In particular, diatom porous silica cell walls, the frustules, are characterized by an extraordinary, species-specific diversity. It is of great interest, among the marine biologists and geneticists community, to shed light on the origin and evolutionary advantage of this variability of dimensions, geometries and pore distributions. In the present article the main reported data related to frustule morphogenesis and functionalities with contributions from fundamental biology, genetics, mathematics, geometry and physics are reviewed.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000412957700001 Publication Date 2017-07-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1874-7787 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:144546 Serial 7807
Permanent link to this record
 
 
Author Mescia, L.; Lamacchia, C.M.; Chiapperino, M.A.; Bia, P.; Gielis, J.; Caratelli, D.
Title (down) Design of irregularly shaped lens antennas including supershaped feed Type P1 Proceeding
Year 2019 Publication Progress in Electromagnetic Research Symposium (PIERS) T2 – 2019 PhotonIcs & Electromagnetics Research Symposium – Spring (PIERS-Spring), 17-20 June, 2019, Rome, Italy Abbreviated Journal
Volume Issue Pages 169-173
Keywords P1 Proceeding; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract A new class of irregularly shaped dielectric lens antennas with a supershaped microstrip antenna feeder is presented and detailed in this work. The surface of the lens antenna and the feeder shape have been modelled by using the three and two-dimensional Gielis formula, respectively. The antenna design has been carried out by integrating an home-made software tool with the CST Microwave Studio®. The radiation properties of the whole antenna system have been evaluated using a dedicated high-frequency technique based on the tube tracing approximation. Moreover, the effects due to the multiple internal reflections have been properly modeled. The proposed model was applied to study unusual and complex lens antenna systems with the aim to design special radiation characteristics.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000550769300021 Publication Date 2020-03-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 978-1-72813-403-1; 978-1-72813-404-8; 978-1-72813-403-1 ISBN Additional Links UA library record; WoS full record
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:169169 Serial 7766
Permanent link to this record
 
 
Author Mescia, L.; Chiapperino, M.A.; Bia, P.; Lamacchia, C.M.; Gielis, J.; Caratelli, D.
Title (down) Design of electroporation process in irregularly shaped multicellular systems Type A1 Journal article
Year 2019 Publication Electronics (Basel) Abbreviated Journal
Volume 8 Issue 1 Pages 37
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Electroporation technique is widely used in biotechnology and medicine for the transport of various molecules through the membranes of biological cells. Different mathematical models of electroporation have been proposed in the literature to study pore formation in plasma and nuclear membranes. These studies are mainly based on models using a single isolated cell with a canonical shape. In this work, a spacetime (x,y,t) multiphysics model based on quasi-static Maxwells equations and nonlinear Smoluchowskis equation has been developed to investigate the electroporation phenomenon induced by pulsed electric field in multicellular systems having irregularly shape. The dielectric dispersion of the cell compartments such as nuclear and plasmatic membranes, cytoplasm, nucleoplasm and external medium have been incorporated into the numerical algorithm, too. Moreover, the irregular cell shapes have been modeled by using the Gielis transformations.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000457142800037 Publication Date 2019-01-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2079-9292 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:157203 Serial 7765
Permanent link to this record
 
 
Author Vermander, C.; De Wael, J.; Gielis, J.
Title (down) De kleine boerderij : twee bijzondere tuinkamers Type A2 Journal article
Year 2019 Publication Groencontact Abbreviated Journal
Volume 45 Issue 5 Pages 14-19
Keywords A2 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1374-4631 ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:164895 Serial 8142
Permanent link to this record
 
 
Author Van den Akker, S.; Bormans, P.; Peeters, H.; Gielis, J.; Prinsen, E.
Title (down) Cytokinin dynamics in cell suspension cultures of Bambusa balcooa Roxburgh using UPLC-ESI/MS/MS Type H3 Book chapter
Year 2012 Publication Abbreviated Journal
Volume Issue Pages 539-547 T2 - Proceedings of the 9th World Bamboo C
Keywords H3 Book chapter; Engineering sciences. Technology; Integrated Molecular Plant Physiology Research (IMPRES); Sustainable Energy, Air and Water Technology (DuEL)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:97754 Serial 7750
Permanent link to this record
 
 
Author Gielis, J.
Title (down) Conquering Mount Improbable Type P1 Proceeding
Year 2023 Publication Abbreviated Journal
Volume Issue Pages 153-173 T2 - Proceedings of the 1st International
Keywords P1 Proceeding; Economics; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Our scientific and technological worldviews are largely dominated by the concepts of entropy and complexity. Originating in 19th-century thermodynamics, the concept of entropy merged with information in the last century, leading to definitions of entropy and complexity by Kolmogorov, Shannon and others. In its simplest form, this worldview is an application of the normal rules of arithmetic. In this worldview, when tossing a coin, a million heads or tails in a row is theoretically possible, but impossible in practice and in real life. On this basis, the impossible (in the binary case, the outermost entries of Pascal's triangle xn and yn for large values of n) can be safely neglected, and one can concentrate fully on what is common and what conforms to the law of large numbers, in fields ranging from physics to sociology and everything in between. However, in recent decades it has been shown that what is most improbable tends to be the rule in nature. Indeed, if one combines the outermost entries xn and yn with the normal rules of arithmetic, either addition or multiplication, one obtains Lamé curves and power laws respectively. In this article, some of these correspondences are highlighted, leading to a double conclusion. First, Gabriel Lamé's geometric footprint in mathematics and the sciences is enormous. Second, conic sections are at the core once more. Whereas mathematics so far has been exclusively the language of patterns in the sciences, the door is opened for mathematics to also become the language of the individual. The probabilistic worldview and Lamé's footprint can be seen as dual methods. In this context, it is to be expected that the notions of information, complexity, simplicity and redundancy benefit from this different viewpoint.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2023-11-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 978-90-833839-0-3 ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:201045 Serial 9014
Permanent link to this record
 
 
Author Yao, W.; Niinemets, Ü.; Yao, W.; Gielis, J.; Schrader, J.; Yu, K.; Shi, P.
Title (down) Comparison of two simplified versions of the Gielis equation for describing the shape of bamboo leaves Type A1 Journal article
Year 2022 Publication Plants Abbreviated Journal
Volume 11 Issue 22 Pages 3058-11
Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Bamboo is an important component in subtropical and tropical forest communities. The plant has characteristic long lanceolate leaves with parallel venation. Prior studies have shown that the leaf shapes of this plant group can be well described by a simplified version (referred to as SGE-1) of the Gielis equation, a polar coordinate equation extended from the superellipse equation. SGE-1 with only two model parameters is less complex than the original Gielis equation with six parameters. Previous studies have seldom tested whether other simplified versions of the Gielis equation are superior to SGE-1 in fitting empirical leaf shape data. In the present study, we compared a three-parameter Gielis equation (referred to as SGE-2) with the two-parameter SGE-1 using the leaf boundary coordinate data of six bamboo species within the same genus that have representative long lanceolate leaves, with >300 leaves for each species. We sampled 2000 data points at approximately equidistant locations on the boundary of each leaf, and estimated the parameters for the two models. The root–mean–square error (RMSE) between the observed and predicted radii from the polar point to data points on the boundary of each leaf was used as a measure of the model goodness of fit, and the mean percent error between the RMSEs from fitting SGE-1 and SGE-2 was used to examine whether the introduction of an additional parameter in SGE-1 remarkably improves the model’s fitting. We found that the RMSE value of SGE-2 was always smaller than that of SGE-1. The mean percent errors among the two models ranged from 7.5% to 20% across the six species. These results indicate that SGE-2 is superior to SGE-1 and should be used in fitting leaf shapes. We argue that the results of the current study can be potentially extended to other lanceolate leaf shapes.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000887783400001 Publication Date 2022-11-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2223-7747 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access OpenAccess
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:191859 Serial 7289
Permanent link to this record
 
 
Author Yao, W.; Hui, C.; Wang, L.; Wang, J.; Gielis, J.; Shi, P.
Title (down) Comparison of the performance of two polar equations in describing the geometries of elliptical fruits Type A1 Journal article
Year 2024 Publication Botany letters Abbreviated Journal
Volume Issue Pages
Keywords A1 Journal article; Antwerp engineering, PhotoElectroChemistry & Sensing (A-PECS)
Abstract In nature, the two-dimensional (2D) profiles of fruits from many plants often resemble ellipses. However, it remains unclear whether these profiles strictly adhere to the ellipse equation, as many natural shapes resembling ellipses are actually better described as superellipses. The superellipse equation, which includes an additional parameter n compared to the ellipse equation, can generate a broader range of shapes, with the ellipse being just a special case of the superellipse. To investigate whether the 2D profiles of fruits are better described by ellipses or superellipses, we collected a total of 751 mature and undamaged fruits from 31 naturally growing plants of Cucumis melo L. var. agrestis Naud. Our analysis revealed that most adjusted root-mean-square errors (> 92% of the 751 fruits) for fitting the superellipse equation to the fruit profiles were consistently less than 0.0165. Furthermore, there were 638 of the 751 fruits (ca. 85%) with the 95% confidence intervals of the estimated parameter n in the superellipse equation not including 2. These findings suggest that the profiles of C. melo var. agrestis fruits align more closely with the superellipse equation than with the ellipse equation. This study provides evidence for the existence of the superellipse in fruit profiles, which has significant implications for studying fruit geometries and estimating fruit volumes using the solid of revolution formula. Furthermore, this discovery may contribute to a deeper understanding of the mechanisms driving the evolution of fruit shapes.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001219634500001 Publication Date 2024-05-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2381-8107; 2381-8115 ISBN Additional Links UA library record; WoS full record
Impact Factor 1.5 Times cited Open Access
Notes Approved Most recent IF: 1.5; 2024 IF: NA
Call Number UA @ admin @ c:irua:205955 Serial 9140
Permanent link to this record
 
 
Author Tian, F.; Wang, Y.; Sandhu, H.S.; Gielis, J.; Shi, P.
Title (down) Comparison of seed morphology of two ginkgo cultivars Type A1 Journal article
Year 2020 Publication Journal Of Forestry Research Abbreviated Journal J Forestry Res
Volume 31 Issue 3 Pages 751-758
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Ginkgo biloba L. is a precious relic tree species with important economic value. Seeds, as a vital reproductive organ of plants, can be used to distinguish cultivars of the species. We chose 400 seeds from two cultivars of ginkgo (Fozhi and Maling; 200 seeds for each cultivar) as the study material and used the Gielis equation to fit the projected shape of these seeds. The coefficients of variation (CV) in root mean squared errors (RMSE) obtained from the fitted data were used to compare the level of inter-cultivar variations in seed shape. We also used the covariance analysis to compare the allometric relationships between seed weights and projected areas of these two cultivars. The Gielis equation fitted well the seed shapes of two ginkgo cultivars. The lower CV in RMSE of cultivar Fozhi than Maling indicated a less symmetrical seed shape in the latter than the former. The bootstrap percentile method showed that the seed shape differences between the two cultivars were significant. However, there was no significant difference in the exponents between the seed weights and the projected areas of these two cultivars. Overall, the significant differences in shapes between the seeds of two ginkgo cultivars were well explained by the Gielis equation; this model can be further extended to compare morphological differences in other ginkgo cultivars, and even for plant seeds or animal eggs that have similar oval shapes.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000529367600005 Publication Date 2018-07-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1007-662x ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3 Times cited 3 Open Access
Notes ; ; Approved Most recent IF: 3; 2020 IF: 0.774
Call Number UA @ admin @ c:irua:154987 Serial 6474
Permanent link to this record
 
 
Author Shi, P.-J.; Xu, Q.; Sandhu, H.S.; Gielis, J.; Ding, Y.-L.; Li, H.-R.; Dong, X.-B.
Title (down) Comparison of dwarf bamboos (Indocalamus sp.) leaf parameters to determine relationship between spatial density of plants and total leaf area per plant Type A1 Journal article
Year 2015 Publication Ecology and evolution Abbreviated Journal
Volume 5 Issue 20 Pages 4578-4589
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract The relationship between spatial density and size of plants is an important topic in plant ecology. The self-thinning rule suggests a −3/2 power between average biomass and density or a −1/2 power between stand yield and density. However, the self-thinning rule based on total leaf area per plant and density of plants has been neglected presumably because of the lack of a method that can accurately estimate the total leaf area per plant. We aimed to find the relationship between spatial density of plants and total leaf area per plant. We also attempted to provide a novel model for accurately describing the leaf shape of bamboos. We proposed a simplified Gielis equation with only two parameters to describe the leaf shape of bamboos one model parameter represented the overall ratio of leaf width to leaf length. Using this method, we compared some leaf parameters (leaf shape, number of leaves per plant, ratio of total leaf weight to aboveground weight per plant, and total leaf area per plant) of four bamboo species of genus Indocalamus Nakai (I. pedalis (Keng) P.C. Keng, I. pumilus Q.H. Dai and C.F. Keng, I. barbatus McClure, and I. victorialis P.C. Keng). We also explored the possible correlation between spatial density and total leaf area per plant using log-linear regression. We found that the simplified Gielis equation fit the leaf shape of four bamboo species very well. Although all these four species belonged to the same genus, there were still significant differences in leaf shape. Significant differences also existed in leaf area per plant, ratio of leaf weight to aboveground weight per plant, and leaf length. In addition, we found that the total leaf area per plant decreased with increased spatial density. Therefore, we directly demonstrated the self-thinning rule to improve light interception.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000363731500008 Publication Date 2015-09-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2045-7758 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:128662 Serial 7691
Permanent link to this record
 
 
Author Shi, P.; Gielis, J.; Niklas, K.J.
Title (down) Comparison of a universal (but complex) model for avian egg shape with a simpler model Type Editorial
Year 2022 Publication Annals of the New York Academy of Sciences Abbreviated Journal Ann Ny Acad Sci
Volume 1514 Issue 1 Pages 34-42
Keywords Editorial; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
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.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000803394100001 Publication Date 2022-06-01
Series Editor Series Title Abbreviated Series Title
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 OpenAccess
Notes Approved Most recent IF: 5.2
Call Number UA @ admin @ c:irua:188470 Serial 7139
Permanent link to this record
 
 
Author Düking, R.; Gielis, J.; Liese, W.
Title (down) Carbon flux and carbon stock in a bamboo stand and their relevance for mitigating climate change Type A3 Journal article
Year 2011 Publication Bamboo Science & Culture Abbreviated Journal
Volume 24 Issue 1 Pages 1-6
Keywords A3 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract In this report we describe the basics of biological carbon fixation in bamboo forests. Confusing carbon stock with carbon flux has led to false expectations on the significance of bamboo forests as carbon sinks. Furthermore, misunderstandings about the growth of bamboo culms can lead to highly exaggerated expectations on the productivity of bamboo.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1535-7635 ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:91091 Serial 7578
Permanent link to this record
 
 
Author Shi, P.; Yu, K.; Niinemets, Ü.; Gielis, J.
Title (down) 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)
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.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000611074700001 Publication Date 2020-12-31
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1999-4907 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.951 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 1.951
Call Number UA @ admin @ c:irua:174473 Serial 7572
Permanent link to this record
 
 
Author Gielis, J.; Caratelli, D.; Tavkelidze, I.; Fougerolle, Y.; Ricci, P.E.; Gerats, T.
Title (down) Bulky knots and links generated by cutting generalized Mobius-Listing bodies and applications in the natural sciences Type H2 Book chapter
Year 2013 Publication Abbreviated Journal
Volume Issue Pages 167-183 T2 - Math Art Summit : Koninklijke Vlaamse
Keywords H2 Book chapter; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN 978-90-6569-119-4 Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:110955 Serial 7569
Permanent link to this record
 
 
Author de Jong van Coevorden, C.M.; Gielis, J.; Caratelli, D.
Title (down) Application of Gielis transformation to the design of metamaterial structures Type A1 Journal article
Year 2018 Publication Journal of physics : conference series Abbreviated Journal
Volume 963 Issue Pages Unsp 012008
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract In this communication, the use of Gielis transformation to design more compact metamaterial unit cells is explored. For this purpose, transformed complementary split ring resonators and spiral resonators are coupled to micro-strip lines and theirbehaviour is investigated. The obtained results confirm that the useof the considered class of supershaped geometries enables the synthesis of very compact scalable microwave components.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000435022800008 Publication Date 2018-02-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1742-6588; 1742-6596 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:150947 Serial 7475
Permanent link to this record
 
 
Author Bia, P.; Caratelli, D.; Mescia, L.; Gielis, J.
Title (down) Analysis and synthesis of supershaped dielectric lens antennas Type A1 Journal article
Year 2015 Publication IET microwaves, antennas and propagation Abbreviated Journal
Volume 9 Issue 14 Pages 1497-1504
Keywords A1 Journal article; Engineering sciences. Technology; Mass communications; Sustainable Energy, Air and Water Technology (DuEL)
Abstract A novel class of supershaped dielectric lens antennas, whose geometry is described by the three-dimensional (3D) Gielis formula, is introduced and analysed. To this end, a hybrid modelling approach based on geometrical and physical optics is adopted in order to efficiently analyse the multiple wave reflections occurring within the lens and to evaluate the relevant impact on the radiation properties of the antenna under analysis. The developed modelling procedure has been validated by comparison with numerical results already reported in the literature and, afterwards, applied to the electromagnetic characterisation of Gielis dielectric lens antennas with shaped radiation pattern. Furthermore, a dedicated optimisation algorithm based on quantum particle swarm optimisation has been developed for the synthesis of 3D supershaped lens antennas with single feed, as well as with beamforming capabilities.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000364491200002 Publication Date 2015-08-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1751-8725 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:128659 Serial 7441
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Author Li, Y.; Niklas, K.J.; Gielis, J.; Niinemets, Ü.; Schrader, J.; Wang, R.; Shi, P.
Title (down) An elliptical blade is not a true ellipse, but a superellipse : evidence from two Michelia species Type A1 Journal article
Year 2022 Publication Journal of forestry research Abbreviated Journal J Forestry Res
Volume 33 Issue 4 Pages 1341-1348
Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract The shape of leaf laminae exhibits considerable diversity and complexity that reflects adaptations to environmental factors such as ambient light and precipitation as well as phyletic legacy. Many leaves appear to be elliptical which may represent a ‘default’ developmental condition. However, whether their geometry truly conforms to the ellipse equation (EE), i.e., (x/a)2 + (y/b)2 = 1, remains conjectural. One alternative is described by the superellipse equation (SE), a generalized version of EE, i.e., |x/a|n +|y/b|n = 1. To test the efficacy of EE versus SE to describe leaf geometry, the leaf shapes of two Michelia species (i.e., M. cavaleriei var. platypetala, and M. maudiae), were investigated using 60 leaves from each species. Analysis shows that the majority of leaves (118 out of 120) had adjusted root-mean-square errors of < 0.05 for the nonlinear fitting of SE to leaf geometry, i.e., the mean absolute deviation from the polar point to leaf marginal points was smaller than 5% of the radius of a hypothesized circle with its area equaling leaf area. The estimates of n for the two species were ˂ 2, indicating that all sampled leaves conformed to SE and not to EE. This study confirms the existence of SE in leaves, linking this to its potential functional advantages, particularly the possible influence of leaf shape on hydraulic conductance.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000695118600001 Publication Date 2021-09-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1007-662x; 1993-0607 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 3
Call Number UA @ admin @ c:irua:180967 Serial 7152
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Author Mescia, L.; Bia, P.; Gielis, J.; Caratelli, D.
Title (down) Advanced particle swarm optimization methods for electromagnetics Type P1 Proceeding
Year 2023 Publication Abbreviated Journal
Volume Issue Pages 109-122 T2 - Proceedings of the 1st International
Keywords P1 Proceeding; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Electromagnetic design problems involve optimizing multiple parameters that are nonlinearly related to objective functions. Traditional optimization techniques require significant computational resources that grow exponentially as the problem size increases. Therefore, a method that can produce good results with moderate memory and computational resources is desirable. Bioinspired optimization methods, such as particle swarm optimization (PSO), are known for their computational efficiency and are commonly used in various scientific and technological fields. In this article we explore the potential of advanced PSO-based algorithms to tackle challenging electromagnetic design and analysis problems faced in real-life applications. It provides a detailed comparison between conventional PSO and its quantum-inspired version regarding accuracy and computational costs. Additionally, theoretical insights on convergence issues and sensitivity analysis on parameters influencing the stochastic process are reported. The utilization of a novel quantum PSO-based algorithm in advanced scenarios, such as reconfigurable and shaped lens antenna synthesis, is illustrated. The hybrid modeling approach, based on the unified geometrical description enabled by the Gielis Transformation, is applied in combination with a suitable quantum PSO-based algorithm, along with a geometrical tube tracing and physical optics technique for solving the inverse problem aimed at identifying the geometrical parameters that yield optimal antenna performance.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2023-11-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 978-90-833839-0-3 ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:201048 Serial 9002
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Author Tavkhelidze, I.; Gielis, J.; Pinelas, S.
Title (down) About some methods of analytic representation and classification of a wide set of geometric figures with “complex” configuration Type A3 Journal article
Year 2020 Publication Sn – 1512-0066 Abbreviated Journal
Volume 34 Issue Pages 81-84
Keywords A3 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:174475 Serial 7406
Permanent link to this record
 
 
Author Tavkhelidze, I.; Gielis, J.; Pinelas, S.
Title (down) About some methods of analytic representation and classification of a wide set of geometric figures with “complex” configuration Type H1 Book chapter
Year 2020 Publication Abbreviated Journal
Volume Issue Pages 347-359 T2 - Differential and difference equations
Keywords H1 Book chapter; Sustainable Energy, Air and Water Technology (DuEL)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2020-10-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN 978-3-030-56322-6 Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:174479 Serial 7407
Permanent link to this record
 
 
Author Gielis, J.; Tavkelidze, I.; Ricci, P.E.
Title (down) About “bulky” links, generated by generalized Möbius-Listing bodies Type H3 Book chapter
Year 2011 Publication Abbreviated Journal
Volume Issue Pages 115-128 T2 - Proceedings of the International Conf
Keywords H3 Book chapter; Sustainable Energy, Air and Water Technology (DuEL)
Abstract
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN 978-9941-0-3727-6 Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:97753 Serial 7403
Permanent link to this record
 
 
Author Tavkhelidze, I.; Cassisa, C.; Gielis, J.; Ricci, P.E.
Title (down) About “bulky” links, generated by generalized Möbius Listing's bodies GML3n Type A1 Journal article
Year 2013 Publication Matematica e applicazioni : atti della Accademia nazionale dei Lincei Abbreviated Journal
Volume 24 Issue 1 Pages 11-38
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract In the present paper we consider the “bulky knots'' and ”bulky links'', which appear after cutting a Generalized Möbius Listing's GMLn3 body (whose radial cross section is a plane 3-symmetric figure with three vertices) along different Generalized Möbius Listing's surfaces GMLn2 situated in it. This article is aimed to investigate the number and geometric structure of the independent objects appearing after such a cutting process of GMLn3 bodies. In most cases we are able to count the indices of the resulting mathematical objects according to the known tabulation for Knots and Links of small complexity.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000316567700002 Publication Date 2013-03-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1120-6357 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:107174 Serial 7405
Permanent link to this record
 
 
Author Gielis, J.; Tavkhelidze, I.; Ricci, P.E.
Title (down) About “bulky” links generated by generalized Möbius-Listing bodies GML2n Type A2 Journal article
Year 2013 Publication Journal of mathematical sciences Abbreviated Journal
Volume 193 Issue 3 Pages 449-460
Keywords A2 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
Abstract In this paper, we consider the bulky knots and bulky links, which appear after cutting of a Generalized MöbiusListing GMLn2 body (with the radial cross section a convex plane 2-symmetric figure with two vertices) along a different Generalized MöbiusListing surfaces GMLn2 situated in it. The aim of this report is to investigate the number and geometric structure of the independent objects that appear after such a cutting process of GMLn2 bodies. In most cases we are able to count the indices of the resulting mathematical objects according to the known classification for the standard knots and links.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2013-08-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1072-3374; 1573-8795 ISBN Additional Links UA library record
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:110953 Serial 7404
Permanent link to this record
 
 
Author Huang, W.; Li, Y.; Niklas, K.J.; Gielis, J.; Ding, Y.; Cao, L.; Shi, P.
Title (down) A superellipse with deformation and its application in describing the cross-sectional shapes of a square bamboo Type A1 Journal article
Year 2020 Publication Symmetry-Basel Abbreviated Journal Symmetry-Basel
Volume 12 Issue 12 Pages 2073
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Many cross-sectional shapes of plants have been found to approximate a superellipse rather than an ellipse. Square bamboos, belonging to the genus Chimonobambusa (Poaceae), are a group of plants with round-edged square-like culm cross sections. The initial application of superellipses to model these culm cross sections has focused on Chimonobambusa quadrangularis (Franceschi) Makino. However, there is a need for large scale empirical data to confirm this hypothesis. In this study, approximately 750 cross sections from 30 culms of C. utilis were scanned to obtain cross-sectional boundary coordinates. A superellipse exhibits a centrosymmetry, but in nature the cross sections of culms usually deviate from a standard circle, ellipse, or superellipse because of the influences of the environment and terrain, resulting in different bending and torsion forces during growth. Thus, more natural cross-sectional shapes appear to have the form of a deformed superellipse. The superellipse equation with a deformation parameter (SEDP) was used to fit boundary data. We find that the cross-sectional shapes (including outer and inner rings) of C. utilis can be well described by SEDP. The adjusted root-mean-square error of SEDP is smaller than that of the superellipse equation without a deformation parameter. A major finding is that the cross-sectional shapes can be divided into two types of superellipse curves: hyperellipses and hypoellipses, even for cross sections from the same culm. There are two proportional relationships between ring area and the product of ring length and width for both the outer and inner rings. The proportionality coefficients are significantly different, as a consequence of the two different superellipse types (i.e., hyperellipses and hypoellipses). The difference in the proportionality coefficients between hyperellipses and hypoellipses for outer rings is greater than that for inner rings. This work informs our understanding and quantifying of the longitudinal deformation of plant stems for future studies to assess the influences of the environment on stem development. This work is also informative for understanding the deviation of natural shapes from a strict rotational symmetry.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000602546300001 Publication Date 2020-12-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2073-8994 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.7 Times cited Open Access
Notes Approved Most recent IF: 2.7; 2020 IF: 1.457
Call Number UA @ admin @ c:irua:174472 Serial 8622
Permanent link to this record
 
 
Author Shi, P.; Chen, L.; Quinn, B.K.; Yu, K.; Miao, Q.; Guo, X.; Lian, M.; Gielis, J.; Niklas, K.J.
Title (down) 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
Volume 1524 Issue 1 Pages 118-131
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
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.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000975679400001 Publication Date 2023-04-28
Series Editor Series Title Abbreviated Series Title
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 OpenAccess
Notes Approved Most recent IF: 5.2; 2023 IF: 4.706
Call Number UA @ admin @ c:irua:196724 Serial 8827
Permanent link to this record
 
 
Author Fougerolle, Y.D.; Truchetet, F.; Demonceaux, C.; Gielis, J.
Title (down) A robust evolutionary algorithm for the recovery of rational Gielis curves Type A1 Journal article
Year 2013 Publication Pattern recognition Abbreviated Journal
Volume 46 Issue 8 Pages 2078-2091
Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
Abstract Gielis curves (GC) can represent a wide range of shapes and patterns ranging from star shapes to symmetric and asymmetric polygons, and even self intersecting curves. Such patterns appear in natural objects or phenomena, such as flowers, crystals, pollen structures, animals, or even wave propagation. Gielis curves and surfaces are an extension of Lamé curves and surfaces (superquadrics) which have benefited in the last two decades of extensive researches to retrieve their parameters from various data types, such as range images, 2D and 3D point clouds, etc. Unfortunately, the most efficient techniques for superquadrics recovery, based on deterministic methods, cannot directly be adapted to Gielis curves. Indeed, the different nature of their parameters forbids the use of a unified gradient descent approach, which requires initial pre-processings, such as the symmetry detection, and a reliable pose and scale estimation. Furthermore, even the most recent algorithms in the literature remain extremely sensitive to initialization and often fall into local minima in the presence of large missing data. We present a simple evolutionary algorithm which overcomes most of these issues and unifies all of the required operations into a single though efficient approach. The key ideas in this paper are the replacement of the potential fields used for the cost function (closed form) by the shortest Euclidean distance (SED, iterative approach), the construction of cost functions which minimize the shortest distance as well as the curve length using R-functions, and slight modifications of the evolutionary operators. We show that the proposed cost function based on SED and R-function offers the best compromise in terms of accuracy, robustness to noise, and missing data.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000317944800002 Publication Date 2013-01-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-3203 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:107181 Serial 8485
Permanent link to this record