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27 Results Found

  • Article
  • Open Access
6 Citations
5,404 Views
30 Pages

Minkowski Dimension and Explicit Tube Formulas for p-Adic Fractal Strings

  • Michel L. Lapidus,
  • Hùng Lũ’ and
  • Machiel Van Frankenhuijsen

The theory of complex dimensions describes the oscillations in the geometry (spectra and dynamics) of fractal strings. Such geometric oscillations can be seen most clearly in the explicit volume formula for the tubular neighborhoods of a p-adic fract...

  • Article
  • Open Access
1,211 Views
21 Pages

Performance Evaluation of a High-Gain Axisymmetric Minkowski Fractal Reflectarray for Ku-Band Satellite Internet Communication

  • Prabhat Kumar Patnaik,
  • Harish Chandra Mohanta,
  • Dhruba Charan Panda,
  • Ribhu Abhusan Panda,
  • Malijeddi Murali and
  • Heba G. Mohamed

In this article, a high-gain axisymmetric Minkowski fractal reflectarray is designed and fabricated for Ku-Band satellite internet communications. High gain is achieved here by carefully optimising the number of unit cells, their shape modifier, foca...

  • Article
  • Open Access
5 Citations
2,824 Views
20 Pages

In this article, a second-order iterated Circular Minkowski fractal antenna (CMFA) tailored for ultra-wideband (UWB) applications is designed and developed. Leveraging the power of Minkowski fractal geometry, this antenna design achieves a high gain...

  • Article
  • Open Access
16 Citations
3,640 Views
18 Pages

Minkowski–Sierpinski Fractal Structure-Inspired 2 × 2 Antenna Array for Use in Next-Generation Wireless Systems

  • Arshad Karimbu Vallappil,
  • Bilal A. Khawaja,
  • Mohamad Kamal A. Rahim,
  • Muhammad Uzair,
  • Mohsin Jamil and
  • Qasim Awais

In this paper, the design, simulation, fabrication, and characterization study of a low-cost and directional hybrid four-element (2 × 2 configuration) Minkowski–Sierpinski fractal antenna array (MSFAA) for the high-efficiency IEEE 802.11a...

  • Article
  • Open Access
728 Views
12 Pages

Design of High-Gain Linear Polarized Fabry–Perot Antenna Based on Minkowski Fractal Structure

  • Wei Hu,
  • Liangfu Peng,
  • Tao Tang,
  • Maged A. Aldhaeebi and
  • Thamer S. Almoneef

High-gain linear polarized antennas are widely used in wireless communications. However, the insertion loss of the feed network increases, limiting the potential for enhancing antenna gain. In this paper, a high-gain linear polarized Fabry–Pero...

  • Article
  • Open Access
12 Citations
4,087 Views
16 Pages

Minkowski’s Loop Fractal Antenna Dedicated to Sixth Generation (6G) Communication

  • Maria-Alexandra Paun,
  • Mihai-Virgil Nichita,
  • Vladimir-Alexandru Paun and
  • Viorel-Puiu Paun

In this study, we will discuss the engineering construction of a special sixth generation (6G) antenna, based on the fractal called Minkowski’s loop. The antenna has the shape of this known fractal, set at four iterations, to obtain maximum per...

  • Article
  • Open Access
8 Citations
2,745 Views
14 Pages

In light of the predicament concerning the small gain and narrow frequency range of miniature antennas, this paper employs the implementation of a fractal repeating array structure and a double-layer folding antenna structure. Through these measures,...

  • Article
  • Open Access
3 Citations
1,718 Views
11 Pages

28 November 2024

A substrate-integrated waveguide (SIW) bandpass filter (BPF) with extraordinary selectivity and an adequate upper stopband for C-band Satellite Communication (SATCOM) applications is proposed in this paper. The design comprises comb-shaped slots engr...

  • Article
  • Open Access
2 Citations
2,264 Views
23 Pages

The intersection of fractals, non-Euclidean geometry, spatial autocorrelation, and urban structure offers valuable theoretical and practical application insights, which echoes the overarching goal of this paper. Its research question asks about conne...

  • Article
  • Open Access
18 Citations
3,849 Views
15 Pages

Nanoscale 3D Spatial Analysis of Zirconia Disc Surfaces Subjected to Different Laser Treatments

  • Erveton Pinheiro Pinto,
  • Robert S. Matos,
  • Marcelo A. Pires,
  • Lucas dos Santos Lima,
  • Ştefan Ţălu,
  • Henrique Duarte da Fonseca Filho,
  • Shikhgasan Ramazanov,
  • Shahram Solaymani and
  • Claudio Larosa

We propose the application of morphological, fractal and multifractal analysis to differentiate surface patterns on zirconia-based ceramics after laser treatments. Furthermore, we introduce two new approaches for ceramic surfaces: the Moran correlogr...

  • Article
  • Open Access
3 Citations
2,318 Views
13 Pages

13 October 2022

The direct wave between the transceiver antenna negatively affects the dynamic range and imaging quality of ground penetrating radar (GPR). Suppressing this direct wave is a vital problem in enhancing the performance of the whole GPR system. In this...

  • Article
  • Open Access
29 Citations
6,294 Views
9 Pages

Minkowski Island and Crossbar Fractal Microstrip Antennas for Broadband Applications

  • Roman Kubacki,
  • Mirosław Czyżewski and
  • Dariusz Laskowski

27 February 2018

The paper presents microstrip patch antennas, which are based on the fractal antenna concept, and use planar periodic geometries, providing improved characteristics. The properties of the fractal structure were used in a single-fractal layer design a...

  • Review
  • Open Access
86 Citations
16,699 Views
26 Pages

Fractal Antennas: An Historical Perspective

  • Jaume Anguera,
  • Aurora Andújar,
  • Jeevani Jayasinghe,
  • V. V. S. S. Sameer Chakravarthy,
  • P. S. R. Chowdary,
  • Joan L. Pijoan,
  • Tanweer Ali and
  • Carlo Cattani

Fractal geometry has been proven to be useful in several disciplines. In the field of antenna engineering, fractal geometry is useful to design small and multiband antenna and arrays, and high-directive elements. A historic overview of the most signi...

  • Article
  • Open Access
8 Citations
2,474 Views
11 Pages

24 November 2022

A compact and wide-stop band half mode substrate integrated waveguide (HMSIW) filter, incorporated with a hybrid fractal on the upper plane and a complementary split ring resonator (CSRR), along with a defected ground structure (DGS) etched on the bo...

  • Article
  • Open Access
14 Citations
3,004 Views
13 Pages

Evaluating the Topological Surface Properties of Cu/Cr Thin Films Using 3D Atomic Force Microscopy Topographical Maps

  • Mohammad Sadeghi,
  • Amir Zelati,
  • Sahar Rezaee,
  • Carlos Luna,
  • Robert Saraiva Matos,
  • Marcelo Amanajás Pires,
  • Nilson S. Ferreira,
  • Henrique Duarte da Fonseca Filho,
  • Azin Ahmadpourian and
  • Ştefan Ţălu

19 September 2022

In the present work, Cu/Cr thin films were deposited on substrates of a different nature (Si, Glass, Bk7, and ITO) through a thermal evaporation deposition method. Non-contact atomic force microscopy (AFM) was used to obtain 3D AFM topographical maps...

  • Article
  • Open Access
1,728 Views
13 Pages

This paper presents a circularly polarized hybrid cylindrical dielectric resonator antenna (HCDRA) over a modified Minkowski unit-cell-based metasurface for 5G n79 band (4.4–5 GHz) and IEEE 802.11n WLAN (5 GHz) applications. The location of the...

  • Article
  • Open Access
11 Citations
1,826 Views
9 Pages

Counting-Based Effective Dimension and Discrete Regularizations

  • Ivan Horváth,
  • Peter Markoš and
  • Robert Mendris

10 March 2023

Fractal-like structures of varying complexity are common in nature, and measure-based dimensions (Minkowski, Hausdorff) supply their basic geometric characterization. However, at the level of fundamental dynamics, which is quantum, structure does not...

  • Article
  • Open Access
21 Citations
5,554 Views
16 Pages

Modern expansion and three-dimensional growth are rapidly altering the morphological features of traditional cities. This morphological phenomenon fully reflects the internal organization mode and composition rules of modern cities. This study draws...

  • Brief Report
  • Open Access
10 Citations
6,674 Views
9 Pages

Julia and Mandelbrot Sets for Dynamics over the Hyperbolic Numbers

  • Vance Blankers,
  • Tristan Rendfrey,
  • Aaron Shukert and
  • Patrick D. Shipman

Julia and Mandelbrot sets, which characterize bounded orbits in dynamical systems over the complex numbers, are classic examples of fractal sets. We investigate the analogs of these sets for dynamical systems over the hyperbolic numbers. Hyperbolic n...

  • Article
  • Open Access
4 Citations
3,374 Views
11 Pages

21 October 2021

The specific advantage of fractal geometry to realize compact antenna features is exploited in this work for the design of a miniaturized Planar Inverted-F Antenna configuration with a large bandwidth. The conventional quadrilateral radiating element...

  • Article
  • Open Access
1,418 Views
20 Pages

This paper presents a systematic methodology for identifying optimal scaling regions in segment-based box-counting fractal dimension calculations through a three-phase algorithmic framework combining grid offset optimization, boundary artifact detect...

  • Article
  • Open Access
25 Citations
3,319 Views
16 Pages

1 January 2023

A frequency-selective surface (FSS) optimization method combining a curve-fitting technique and an improved bacterial foraging optimization (IBFO) algorithm is proposed. In the method, novel Koch curve-like FSS and Minkowski fractal islands FSS were...

  • Data Descriptor
  • Open Access
5 Citations
5,253 Views
8 Pages

UAV-Based 3D Point Clouds of Freshwater Fish Habitats, Xingu River Basin, Brazil

  • Margaret Kalacska,
  • Oliver Lucanus,
  • Leandro Sousa,
  • Thiago Vieira and
  • Juan Pablo Arroyo-Mora

10 January 2019

Dense 3D point clouds were generated from Structure-from-Motion Multiview Stereo (SFM-MVS) photogrammetry for five representative freshwater fish habitats in the Xingu river basin, Brazil. The models were constructed from Unmanned Aerial Vehicle (UAV...

  • Article
  • Open Access
3 Citations
2,910 Views
22 Pages

Morphological Analysis of a Collapsing Cavitation Bubble near a Solid Wall with Complex Geometry

  • Minglei Shan,
  • Fangyong Shu,
  • Yu Yang,
  • Yu Shang,
  • Cheng Yin and
  • Qingbang Han

31 January 2023

The interaction mechanism between the cavitation bubble and a solid wall is a basic problem in bubble collapse prevention and application. In particular, when bubble collapse occurs near solid walls with arbitrarily complex geometries, it is difficul...

  • Article
  • Open Access
21 Citations
3,088 Views
17 Pages

Study of Texture Indicators Applied to Pavement Wear Analysis Based on 3D Image Technology

  • Yutao Li,
  • Yuanhan Qin,
  • Hui Wang,
  • Shaodong Xu and
  • Shenglin Li

30 June 2022

Pavement texture characteristics can reflect early performance decay, skid resistance, and other information. However, most statistical texture indicators cannot express this difference. This study adopts 3D image camera equipment to collect texture...