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Breast phantom design for X-ray phase-contrast imaging

Research on Biomedical engineering 2019年第1期35卷 21-26页

作者： Badelli, Juliana do Carmo Ribeiro-Junior, Sebastião Antoniassi, Marcelo Conceição, Andre Luiz Coelho Graduate Program in Electrical and Computer Engineering - UTFPR Av. Sete de Setembro 3165 CuritibaParaná80230-901 Brazil Electrical Engineering Department Federal University of Paraná Rodovia BR-116 Km 98 no. 8813 Jardim das Américas CuritibaParaná81531-980 Brazil Physics Department Federal University of Technology - Paraná Av. Sete de Setembro 3165 CuritibaParaná80230-901 Brazil Deutsches Elektronen-Synchrotron DESY Notkestraße 85 Hamburg22607 Germany

Purpose: Breast cancer is one of the most diffuse diseases and its incidence rate is increasing. Mammography is the gold standard exam for screening breast cancer. Nevertheless, to provide better conditions for visualization and detection of tumors, in particular to young women, techniques exploiting the X-ray phase contrast to generate images have been studied and proposed for clinical use. As every imaging modality clinically implemented, the capabilities and limitations of an X-ray phase-contrast system dedicated to breast imaging should be evaluated by a phantom. Although for mammography, there are several commercial phantoms, for tomographic X-ray phase-contrast imaging systems dedicated to breast screening, they are absent. Therefore, this study aimed to design a breast phantom for application in phase-contrast computed tomography (PC-CT) imaging. Methods: A breast phantom dedicated to X-ray phase-contrast imaging was designed. The phantom has a cylindrical shape and is composed by PMMA, to mimic the breast of a young woman, with some inserts filled with tissue substitutes to normal and pathological breast tissues, such as ethanol and glycerol. These materials were chosen due to the similarity in the attenuation and scattering properties of normal and pathological human breast tissues. Results: A comparison between tomographic X-ray absorption imaging and tomographic X-ray phase-contrast imaging showed a significant increase in edges definition, even with materials with similar attenuation properties. Conclusion: The results of this work reinforce the need for dedicated phantoms to exploit the features of each imaging modality more realistic. In particular, the breast phantom–designed breast screening by PC-CT allows exploiting the features of this new imaging modality. © 2019, Sociedade Brasileira de Engenharia Biomedica.

关键词： Phantoms

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A PARALLEL VARIATIONAL MESH QUALITY IMPROVEMENT METHOD FOR TETRAHEDRAL MESHES 28

A PARALLEL VARIATIONAL MESH QUALITY IMPROVEMENT METHOD FOR T...

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28th International Meshing Roundtable, IMR 2019

作者： Shontz, Suzanne M. Varilla, M.A.L. Huang, Weizhang Department of Electrical Engineering and Computer Science Bioengineering Program Information and Telecommunication Technology Center University of Kansas LawrenceKS United States Husky Injection Molding Systems Ltd. Luxembourg Luxembourg Department of Mathematics University of Kansas LawrenceKS United States

ISBN: (纸本)9781733489003

There are numerous large-scale applications requiring mesh adaptivity, e.g., computational uid dynamics and weather prediction. Parallel processing is needed for simulations involving large-scale adaptive meshes. In this paper, we propose a parallel variational mesh quality improvement algorithm for use with distributed memory machines. Our method parallelizes the serial variational mesh quality improvement method by Huang and Kamenski. Their approach is based on the use of the Moving Mesh PDE method to adapt the mesh based on the minimization of an energy functional for mesh equidistribution and alignment. This leads to a system of ordinary differential equations (ODEs) to be solved which determine where to move the interior mesh nodes. An efficient solution is obtained by solving the ODEs on subregions of the mesh with overlapped communication and computation. Strong and weak scaling experiments on up to 128 cores for meshes with up to 160M elements demonstrate excellent results. © 2019 Proceedings of the 28th International Meshing Roundtable, IMR 2019. All rights reserved.

关键词： Ordinary differential equations

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Marangoni convection-driven laser fountains and waves on free surfaces of liquids

arXiv

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arXiv 2021年

作者： Lin, Feng Quraishy, Aamir Nasir Tong, Tian Li, Runjia Yang, Guang Mohebinia, Mohammadjavad Qiu, Yi Vishal, Talari Zhao, Junyi Zhang, Wei Zhong, Hong Zhang, Hang Zhou, Chaofu Tong, Xin Yu, Peng Hu, Jonathan Dong, Suchuan Liu, Dong Wang, Zhiming Schaibley, John R. Bao, Jiming Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of China ChengduSichuan610054 China Department of Electrical and Computer Engineering University of Houston HoustonTX77204 United States Department of Physics University of Arizona TucsonAZ85721 United States James C. Wyant College of Optical Sciences University of Arizona TucsonAZ85721 United States Department of Mechanical Engineering University of Houston HoustonTX77204 United States Materials Science and Engineering Program University of Houston HoustonTX77204 United States School of Science Southwest Petroleum University ChengduSichuan610500 China Department of Electrical and Systems Engineering Washington University in St. Louis St. LouisMO63130 United States Department of Electrical & Computer Engineering Baylor University WacoTX76798 United States Department of Mathematics Purdue University West LafayetteIN47907 United States Department of Physics Texas Center for Superconductivity University of Houston HoustonTX77204 United States

It is well accepted that an outward Marangoni convection from a low surface tension region will make the surface depressed. Here, we report that this established perception is only valid for thin liquid films. Using surface laser heating, we show that in deep liquids a laser beam actually pulls up the fluid above the free surface generating fountains with different shapes. Whereas with decreasing liquid depth a transition from fountain to indentation with fountain-in-indentation is observed. Further, high-speed imaging reveals a transient surface process before steady elevation is formed, and this dynamic deformation is subsequently utilized to resonantly excite giant surface waves by a modulated laser beam. Computational fluid dynamics models reveal the underlying flow patterns and quantify the depth-dependent and time-resolved surface deformations. Our discoveries and techniques have upended the century-old perception and opened up a new regime of interdisciplinary research and applications of Marangoni-induced interface phenomena and optocapillary fluidic surfaces - the control of fluids with light. © 2021, CC BY.

关键词： Deformation

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Advanced phase-change materials for enhanced meta-displays

arXiv

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arXiv 2021年

作者： Hemmatyar, Omid Abdollahramezani, Sajjad Lepeshov, Sergey Krasnok, Alex Brown, Tyler Alù, Andrea Adibi, Ali School of Electrical and Computer Engineering Georgia Institute of Technology 778 Atlantic Drive NW AtlantaGA30332-0250 United States ITMO University St. Petersburg197101 Russia Photonics Initiative Advanced Science Research Center City University of New York New YorkNY10031 United States Physics Program Graduate Center City University of New York New YorkNY10016 United States

Structural colors generated due to light scattering from static all-dielectric metasurfaces have successfully enabled high-resolution, high-saturation and wide-gamut color printing applications. Despite recent advances, most demonstrations of these structure-dependent colors lack post-fabrication tunability that hinders their applicability for front-end dynamic display technologies. Phase-change materials (PCMs), with significant contrast of their optical properties between their amorphous and crystalline states, have demonstrated promising potentials in reconfigurable nanophotonics. Herein, we leverage a tunable all-dielectric reflective metasurface made of a newly emerged class of low-loss optical PCMs with superb characteristics, i.e., antimony trisulphide (Sb2S3), antimony triselenide (Sb2Se3), and binary germanium-doped selenide (GeSe3), to realize switchable, high-saturation, high-efficiency and high-resolution structural colors. Having polarization sensitive building blocks, the presented metasurface can generate two different colors when illuminated by two orthogonally polarized incident beams. Such degrees of freedom (i.e., structural state and polarization) enable a single reconfigurable metasurface with fixed geometrical parameters to generate four distinct wide-gamut colors suitable for a wide range of applications, including tunable full-color printing and displays, information encryption, and anti-counterfeiting. © 2021, CC BY.

关键词： Phase change materials

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Design and energy assessment of a new hybrid solar drying dome - Enabling Low-Cost, Independent and Smart Solar Dryer for Indonesia Agriculture 4.0

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IOP Conference Series: Earth and Environmental Science 2022年第1期998卷

作者： F E Gunawan A S Budiman B Pardamean E Djuana S Romeli N Hananda C Harito D P B Aji D N N Putri Stevanus Industrial Engineering Department BINUS Graduate Program - Master of Industrial Engineering Bina Nusantara University Jakarta Indonesia 11480 Bioinformatics and Data Science Research Center Bina Nusantara University Jakarta 11480 Indonesia Computer Science Department BINUS Graduate Program - Master of Computer Science Bina Nusantara University Jakarta Indonesia 11480 Electrical Engineering Department Faculty of Industrial Technology Universitas Trisakti Jakarta 11440 Indonesia PT. Impack Pratama Industri Jakarta Indonesia Industrial Engineering Department Faculty of Engineering Bina Nusantara University Jakarta 11480 Indonesia. Mechanical Engineering Department. Faculty of Industrial Technology Universitas Trisakti Jakarta 11440 Indonesia

Solar dryer is typically used for agricultural purposes in Indonesia. There are many economically important crops requiring storage or drying under particular environmental conditions such as temperature and humidity. High temperatures inside solar dryer prevents the growth of microorganism, and quickly reduce moisture content from the substance. A hybrid solar dryer is generally considered to provide the most optimum solution, however solar panels may be expensive and they still only provide heat or energy in the daytime. Hence, we propose here a new kind of hybrid solar dryer for 24/7 optimum conditions for crops - enabled by recent advances in energy technologies as well as Industry 4.0. This study aims to create an efficient, affordable and a self-sufficient intelligent energy system that will be applied to agriculture for storage or drying purposes by measuring the energy needs for the optimal drying system. Therefore, it is crucial to estimate and assess the critical energy needs for such new systems in order to optimize and design such smart solar dryer (SSD) system especially for Indonesia's agricultural needs. We use design experience of our industry partner (PT Impack Pratama Industri, Indonesia) who has been working extensively on such solar dryer dome (SDD) based on polycarbonate material (only solar irradiation, no other technologies) and theoretical framework based on first principles in thermodynamics to estimate and assess critical energy needs for such dome with all the smart technologies. The calculation was performed based on Mollier diagram and the result still a rough estimation of energy required.

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Publisher Correction: Battery-free wireless imaging of underwater environments

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Nature communications 2022年第1期13卷 6011页

作者： Sayed Saad Afzal Waleed Akbar Osvy Rodriguez Mario Doumet Unsoo Ha Reza Ghaffarivardavagh Fadel Adib Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology Cambridge MA 02139 USA. MIT Media Lab Massachusetts Institute of Technology Cambridge MA 02139 USA. Program in Media Arts and Sciences Massachusetts Institute of Technology Cambridge MA 02139 USA. Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology Cambridge MA 02139 USA. fadel@mit.edu. MIT Media Lab Massachusetts Institute of Technology Cambridge MA 02139 USA. fadel@mit.edu. Program in Media Arts and Sciences Massachusetts Institute of Technology Cambridge MA 02139 USA. fadel@mit.edu. MIT Sea Grant Massachusetts Institute of Technology Cambridge MA 02139 USA. fadel@mit.edu.

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Localization transition in three-dimensional stealthy hyperuniform disordered systems

arXiv

引用

arXiv 2021年

作者： Sgrignuoli, F. Torquato, S. Dal Negro, L. Department of Electrical and Computer Engineering & Photonics Center Boston University 8 Saint Mary’s Street BostonMA02215 United States Department of Chemistry Department of Physics Princeton Institute for the Science and Technology of Materials Program in Applied and Computational Mathematics Princeton University PrincetonNJ08540 United States Division of Material Science and Engineering Boston University 15 Saint Mary’s Street BrooklineMA02446 United States Department of Physics Boston University 590 Commonwealth Avenue BostonMA02215 United States

The purpose of this work is to understand the fundamental connection between structural correlations and light localization in three-dimensional (3D) open scattering systems of finite size. We numerically investigate the transport of vector electromagnetic waves scattered by resonant electric dipoles spatially arranged in 3D space by stealthy hyperuniform disordered point patterns. Three-dimensional stealthy hyperuniform disordered systems (3D-SHDS) are engineered with different structural correlation properties determined by their degree of stealthiness χ. Such fine control of exotic states of amorphous matter enables the systematic design of optical media that interpolate in a tunable fashion between uncorrelated random structures and crystalline materials. By solving the electromagnetic multiple scattering problem using Green’s matrix spectral method, we establish a transport phase diagram that demonstrates a clear delocalization-localization transition beyond a critical scattering density that depends on χ. The transition is characterized by studying the Thouless number and the spectral statistics of the scattering resonances. In particular, by tuning the χ parameter, we demonstrate large spectral gaps and suppressed sub-radiant proximity resonances, facilitating light localization. Moreover, consistently with previous studies, our results show a region of the transport phase diagram where the investigated scattering systems become transparent. Our work provides a systematic description of the transport and localization properties of light in stealthy hyperuniform structures and motivates the engineering of novel photonic systems with enhanced light-matter interactions for applications to both classical and quantum devices. Copyright © 2021, The Authors. All rights reserved.

关键词： Phase diagrams

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Field-driven metamorphoses of isolated skyrmions within the conical state of cubic helimagnets

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Physical Review B 2021年第6期104卷 064432-064432页

作者： Andrey O. Leonov C. Pappas Ivan I. Smalyukh Department of Chemistry Faculty of Science Hiroshima University Kagamiyama Higashi Hiroshima Hiroshima 739-8526 Japan Chirality Research Center Hiroshima University Higashi Hiroshima Hiroshima 739-8526 Japan IFW Dresden Postfach 270016 D-01171 Dresden Germany Faculty of Applied Sciences Delft University of Technology Mekelweg 15 2629JB Delft The Netherlands Soft Materials Research Center and Materials Science and Engineering Program University of Colorado Boulder Colorado 80309 USA Department of Physics and Department of Electrical Computer and Energy Engineering University of Colorado Boulder Colorado 80309 USA Renewable and Sustainable Energy Institute National Renewable Energy Laboratory and University of Colorado Boulder Colorado 80309 USA

Topologically stable field configurations appear in many fields of physics, from elementary particles to condensed matter and cosmology. Deep physical relations and common physical features of a large variety of very different solitonic states in these systems arise from the mathematical similarity of phenomenological equations. During the last decade, chiral liquid crystals and chiral magnets took on the role of model objects for the experimental investigation of topological solitons and the understanding of their nonsingular field configurations. This is directly related to the discovery of particle-like chiral skyrmions, which are also considered as promising ingredients for technological applications. Here we introduce a paradigm of facile skyrmionic networks with mutually orthogonal orientations of constituent isolated skyrmions. On the one hand, such networks are envisioned as a novel concept of spintronic devices based, e.g., on gapless skyrmion motion along each other, and are presumably responsible for precursor phenomena near the ordering temperatures of bulk cubic helimagnets. In particular, we demonstrate an interconversion between mutually orthogonal skyrmions: horizontal skyrmions may swirl into an intermediate spring-like state and subsequently squeeze into vertical skyrmions with both polarities. On the other hand, skyrmion tubes are considered as building blocks for particle-like states with more involved internal structure. A family of target-skyrmions, which includes a so far overlooked type with a multiple topological charge, is formed owing to the tendency to minimize the interaction energy between vertical and horizontal skyrmions. The conical phase serves as a suitable background for considered skyrmion evolution. It substantializes the attracting skyrmion-skyrmion interaction in the skyrmionic networks, shapes their internal structure, and guides the nucleation processes. Alternatively, intricate textural changes of isolated skyrmions result

关键词： Skyrmions Chiral magnets Cholesteric liquid crystals Helimagnets

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Simultaneous localization and mapping of a mobile robot with surveillance and flying cameras

Simultaneous localization and mapping of a mobile robot with...

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2018 SICE International Symposium on Control Systems, SICE ISCS 2018

作者： Chang, Wen-Chung Wu, Chia-Hung Huang, Yang-Cheng Andini, Dianthika Puteri Department of Electrical Engineering National Taipei University of Technology Taipei106 Taiwan International Graduate Program in Electrical Engineering and Computer Science National Taipei University of Technology Taipei106 Taiwan

ISBN: (纸本)9784907764586

Localization and exploration of robotic systems has been a highly active research area in recent years. In order to explore unknown environments with better precision, a robotic system employing surveillance and flying cameras is proposed in this paper. Specifically, a mobile robot equipped with an onboard monocular camera performs visual simultaneous localization and mapping with extended Kalman filtering (EKF-VSLAM) and moves from indoor to outdoor environments. To correct the estimation errors of the system during the task, a least squares-based correction approach is proposed. The proposed robotic system employs surveillance cameras in indoor environment and a flying camera in outdoor environment to correct estimation error from the onboard monocular camera. The proposed correction approach, integrated with the conventional EKF-VSLAM, has been validated by experiments demonstrating better precision. © 2018 The Society of Instrument and Control Engineers - SICE.

关键词： Mobile robots

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An Implementation of Reinforcement Learning in Assembly Path Planning based on 3D Point Clouds

An Implementation of Reinforcement Learning in Assembly Path...

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2018 International Automatic Control Conference, CACS 2018

作者： Chang, Wen-Chung Andini, Dianthika Puteri Pham, Van-Toan Department of Electrical Engineering National Taipei University of Technology Taipei106 Taiwan International Graduate Program in Electrical Engineering and Computer Science National Taipei University of Technology Taipei106 Taiwan

ISBN: (纸本)9781538662786

3D point clouds consisting of a lot of informatively geometric data have been playing critical roles in many applications such as 3D segmentation, polyline annotation for lane tracking, and especially in manufacturing industry. In particular, this paper proposes to apply Reinforcement Learning (RL) to resolve an automated assembly task based on 3D point cloud data. To address this task, the proposed structure is separated into 2 stages including registration stage and assembly path planning stage. Firstly, in the registration stage, one of the objects is matched to an assembled model to determine the transformation between two 3D point clouds by using RANdom Sample Consensus (RANSAC) and Iterative Closet Point (ICP). Secondly, we employ Q-learning method to train a model to make optimal decisions in assemble path planning task. The entire optimized assembly path planning task has been successfully accomplished for typical objects. Finally, the performance of the approach developed in this paper has been validated by experiments. © 2018 IEEE.

关键词： Reinforcement learning

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