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Inferring IGM parameters from the redshifted 21-cm Power Spectrum using Artificial Neural Networks

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arXiv 2024年

作者： Choudhury, Madhurima Ghara, Raghunath Zaroubi, Saleem Ciardi, Benedetta Koopmans, Leon V.E. Mellema, Garrelt Shaw, Abinash Kumar Acharya, Anshuman Iliev, I.T. Ma, Qing-Bo Giri, Sambit K. Astrophysics Research Centre of the Open University of Israel Ra'anana4353701 Israel Center for Fundamental Physics of the Universe Department of Physics Brown University ProvidenceRI02914 United States Department of Physics and Astronomy Haverford College 370 Lancaster Ave HaverfordPA19041 United States Center for Particle Cosmology Department of Physics and Astronomy University of Pennsylvania PhiladelphiaPA19104 United States Department of Natural Sciences The Open University of Israel 1 University Road Ra'anana4353701 Israel Kapteyn Astronomical Institute University of Groningen PO Box 800 Groningen9700AV Netherlands Max-Planck Institute for Astrophysics Karl-Schwarzschild-Straße 1 Garching85748 Germany The Oskar Klein Centre Department of Astronomy Stockholm University AlbaNova StockholmSE-10691 Sweden Department of Computer Science University of Nevada Las VegasNV89154 United States Astronomy Centre Department of Physics and Astronomy University of Sussex Pevensey II Building BrightonBN1 9QH United Kingdom School of Physics and Electronic Science Guizhou Normal University Guiyang550001 China Nordita KTH Royal Institute of Technology Stockholm University Hannes Alfvéns väg 12 StockholmSE-106 91 Sweden

The high redshift 21-cm signal promises to be a crucial probe of the state of the intergalactic medium (IGM). Understanding the connection between the observed 21-cm power spectrum and the physical quantities intricately associated with the IGM is crucial to fully understand the evolution of our Universe. In this study, we develop an emulator using artificial neural network (ANN) to predict the 21-cm power spectrum from a given set of IGM properties, namely, the bubble size distribution and the volume averaged ionization fraction. This emulator is implemented within a standard Bayesian framework to constrain the IGM parameters from a given 21-cm power spectrum. We compare the performance of the Bayesian method to an alternate method using ANN to predict the IGM parameters from a given input power spectrum, and find that both methods yield similar levels of accuracy, while the ANN is significantly faster. We also use this ANN method of parameter estimation to predict the IGM parameters from a test set contaminated with noise levels expected from the SKA-LOW instrument after 1000 hours of observation. Finally, we train a separate ANN to predict the source parameters from the IGM parameters directly, at a redshift of z = 9.1, demonstrating the possibility of a non-analytic inference of the source parameters from the IGM parameters for the first time. We achieve high accuracies, with R2-scores ranging between 0.898 − 0.978 for the ANN emulator and between 0.966 − 0.986 and 0.817 − 0.981 for the predictions of IGM parameters from 21-cm power spectrum and source parameters from IGM parameters, respectively. The predictions of the IGM parameters from the Bayesian method incorporating the ANN emulator leads to tight constraints with error bars around ±0.14 on the IGM parameters. © 2024, CC BY.

关键词： Machine learning

Slow Heat-Based Hybrid Simulated Annealing Algorithm in Vehicular Ad Hoc Network

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Computational intelligence and neuroscience 2023年第1期2023卷 9918748页

作者： Pavan Kumar Pagadala P Lalitha Surya Kumari Deepak Thakur Vivek Bhardwaj Mohammad Shahid Abdulrajak Buradi Abdul Razak Abiot Ketema Computer Science and Engineering Koneru Lakshmaiah Educational Foundation Hyderabad Telangana India. Chitkara University Institute of Engineering and Technology Chitkara University Punjab India. School of Computer Science and Engineering Lovely Professional University Jalandhar 144411 India. Department of Electrical Engineering Galgotias College of Engineering and Technology 1 Knowledge Park Phase II Noida 201306 UP India. Department of Mechanical Engineering Nitte Meenakshi Institute of Technology Bangalore India. Department of Mechanical Engineering P. A. College of Engineering (Affiliated to Visvesvaraya Technological University Belagavi) Mangaluru 574153 India. Department of Biosystems Engineering Institute of Technology Hawassa University Hawassa Ethiopia.

Vehicular ad hoc networks (VANETs) using reliable protocols of routing have become crucial in identifying the changes to topology on a continuous basis for a large collection of vehicles. For this purpose, it becomes important to identify an optimal configuration of these protocols. There are several possible configurations that have been preventing the configuration of efficient protocols that do not make use of automatic and intelligent design tools. It can further motivate using the techniques of metaheuristics like the tools, which are well-suited to be able to solve these problems. The glowworm swarm optimization (GSO), simulated annealing (SA), and slow heat-based SA-GSO algorithms have been proposed in this work. The SA is a method of optimization, which imitates the manner in which the thermal system has been frozen down to its lowest state of energy. In the GSO, there is guidance to the rules of feasibility, where the swarm converges to its feasible regions very fast. Additionally, for overcoming any premature convergence, there is a local search strategy that is based on the SA and is used for making a search that is near to its true optimum solutions. Finally, this sluggish temperature-based SA-GSO algorithm will be employed to solve routing problems and problems of heat transfer. There is a hybrid slow heat SA-GSO algorithm with a faster speed of convergence and higher precision of computation that is more effective in solving problems of constrained engineering.

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A CNN-based Approach for three-class classification of motor imagery EEG data including 'rest state' in hybrid multi-user BCI

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A CNN-based Approach for three-class classification of motor...

IEEE International Conference on Bioinformatics and Biomedicine

作者： Jianhai Zhang Li Zhu Chongwei Su Gaochao Cui Dariusz Zapala Wanzeng Kong School of Computer Science and Techonology Hangzhou Dianzi University Cognitive Science Department Xiamen University National Institute of Advanced Industrial Science and Technology Institute of Psychology John Paul II Catholic University of Lubin School of Computer Science and Technology Hangzhou Dianzi University

ISBN: (纸本)9781728118680

Multi-user BCI (brain computer interface) refers to a kind of BCI in which there are several users participating in one task. Differently from P300 and SSVEP (steady-state visual evoked potential), MI (motor imagery)-BCI does not rely on external stimulus, which is more widely used in the assistance of disabled people. The main problem of MI-BCI is to achieve asynchronous control, which needs to improve the rest state recognition accuracy. We proposed a CNN-based approach for three-class classification of motor imagery EEG data including rest state in hybrid multi-user BCI. Firstly, we designed a two-user hybrid MI-BCI experimental paradigm and moreover proposed a CNN-based processing framework method which contains several strategies for inter-brain phase locked value (PLV) features fusion. Results show that the alpha band shows the significantly better performance than other bands and the classification performance of multi-user MI is better than single-user MI. Multi-user BCI is a potential way to enhance the performance of asynchronous MI-BCI.

关键词： EEG motor imagery CNN inter-brain PLV resting state Phyla Electroencephalography multi-user Asynchronous control Imagery (Psychotherapy) images Motor

Revealing the Invisible: Visual Analytics and Explanatory Storytelling for Advanced Team Sport Analysis

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Revealing the Invisible: Visual Analytics and Explanatory St...

2018 International Symposium on Big Data Visual and Immersive Analytics, BDVA 2018

作者： Stein, Manuel Breitkreutz, Thorsten Haussler, Johannes Seebacher, Daniel Niederberger, Christoph Schreck, Tobias Grossniklaus, Michael Keim, Daniel Janetzko, Halldor Department of Computer and Information Science University of Konstanz Germany VIZRT Switzerland Institute for Computer Graphics and Knowledge Visualization Graz University of Technology Austria Department of Geography University of Zurich Switzerland

ISBN: (纸本)9781538691946

The analysis of invasive team sports often concentrates on cooperative and competitive aspects of collective movement behavior. A main goal is the identification and explanation of strategies, and eventually the development of new strategies. In visual sports analytics, a range of different visual-interactive analysis techniques have been proposed, e.g., based on visualization using for example trajectories, graphs, heatmaps, and animations. Identifying suitable visualizations for a specific situation is key to a successful analysis. Existing systems enable the interactive selection of different visualization facets to support the analysis process. However, an interactive selection of appropriate visualizations is a difficult, complex, and time-consuming task. In this paper, we propose a four-step analytics conceptual workflow for an automatic selection of appropriate views for key situations in soccer games. Our concept covers classification, specification, explanation, and alteration of match situations, effectively enabling the analysts to focus on important game situations and the determination of alternative moves. Combining abstract visualizations with real world video recordings by Immersive Visual Analytics and descriptive storylines, we support domain experts in understanding key situations. We demonstrate the usefulness of our proposed conceptual workflow via two proofs of concept and evaluate our system by comparing our results to manual video annotations by domain experts. Initial expert feedback shows that our proposed concept improves the understanding of competitive sports and leads to a more efficient data analysis. © 2018 IEEE.

关键词： Visualization

EMCCD-SPAD Camera data fusion for high spatial resolution time-of-flight imaging.

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EMCCD-SPAD Camera data fusion for high spatial resolution ti...

Computational Optical Sensing and Imaging, COSI 2019

作者： Callenberg, Clara Lyons, Ashley den Brok, Dennis Henderson, Robert Hullin, Matthias B. Faccio, Daniele Institute of Computer Science II University of Bonn Bonn53115 Germany School of Physics and Astronomy University of Glasgow GlasgowG12 8QQ United Kingdom Institute for Micro and Nano Systems University of Edinburgh EdinburghEH8 9YL United Kingdom

High temporal resolution SPAD imagers are currently limited by their pixel count. Here we show that data can be combined with a higher spatial resolution EMCCD camera to achieve the advantages of both. © OSA 2019... 详细信息

ISBN: (纸本)9781943580637

关键词： Cameras

Experimental realization of phonon demultiplexing in three-dimensions

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arXiv 2020年

作者： Bilal, Osama R. Yee, Chern Hwee Rys, Jan Schumacher, Christian Daraio, Chiara Department of Mechanical engineering University of Connecticut Storrs United States Department of Mechanical and Process Engineering ETH Zürich Zürich8092 Switzerland Computer Graphics Laboratory ETH Zürich Zürich8092 Switzerland Division of Engineering and Applied Science California Institute of Technology PasadenaCA91125 United States

Phononic metamaterials enabled the realization of many acoustic components analogous to their electronic counterparts, such as transistors, logic gates and calculators. A key component among these is the demultiplexer, a device that receives multiple signals and sorts them based on their frequencies into separate channels. Previous experimental realizations of acoustic and elastic multiplexers have employed plates with pillars or holes to demultiplex frequencies. However, existing realizations are confined to two-dimensions, which can limit potential acoustic or elastic circuit design. Here we show the first experimental realization of a three-dimensional, four channel phononic demultiplexer. Our design methodology is based on bundles of pass-bands within a large band gap that can easily be tuned for multi-channel frequency demultiplexing. The proposed design can be utilized in acoustic and elastic information processing, nondestructive evaluation and communication applications among others. Copyright © 2020, The Authors. All rights reserved.

关键词： Demultiplexing

Spontaneous Chirality Flipping in an Orthogonal Spin-Charge Ordered Topological Magnet

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arXiv 2023年

作者： Miao, H. Bouaziz, J. Fabbris, G. Meier, W.R. Yang, F.Z. Li, H.X. Nelson, C. Vescovo, E. Zhang, S. Christianson, A. Lee, H.N. Zhang, Y. Batista, C.D. Blügel, S. Materials Science and Technology Division Oak Ridge National Laboratory Oak RidgeTN37831 United States Peter Grünberg Institut Institute for Advanced Simulation Forschungszentrum Jülich &JARA JülichD-52425 Germany Advanced Photon Source Argonne National Laboratory ArgonneIL60439 United States Department of Physics and Astronomy The University of Tennessee KnoxvilleTN37996 United States Guangzhou China National Synchrotron Light Source II Brookhaven National Laboratory UptonNY11973 United States Max-Planck-Institut fur Physik komplexer Systeme Nothnitzer Straße 38 Dresden01187 Germany Min H. Kao Department of Electrical Engineering and Computer Science University of Tennessee KnoxvilleTN37996 United States Quantum Condensed Matter Division Shull-Wollan Center Oak Ridge National Laboratory Oak RidgeTN37831 United States

The asymmetric distribution of chiral objects with opposite chirality is of great fundamental interests ranging from molecular biology to particle physics1. In quantum materials, chiral states can build on inversion-symmetry-breaking lattice structures or emerge from spontaneous magnetic ordering induced by competing interactions. Although the handedness of a chiral state can be changed through external fields2,3, a spontaneous chirality flipping has yet to be discovered. In this letter, we present experimental evidence of chirality flipping via changing temperature in a topological magnet EuAl4, which features orthogonal spin and charge density waves (SDW/CDW). Using circular dichroism of Bragg peaks in the resonant magnetic x-ray scattering, we find that the chirality of the helical SDW flips through a first order phase transition with modified SDW wavelength. Intriguingly, we observe that the CDW couples strongly with the SDW and displays a rare commensurate-to-incommensurate transition at the chirality flipping temperature. Combining with first principles calculations and angle resolved photoemission spectroscopy, our results support a Fermi surface origin of the helical SDW with intertwined spin, charge, and lattice degrees of freedom in EuAl4. Our results reveal an unprecedented spontaneous chirality flipping and lays the groundwork for a new functional manipulation of chirality through momentum dependent spin-charge-lattice interactions. © 2023, CC BY.

关键词： Topology

3088 – SUBCLONAL ARCHITECTURE AND DIFFERENTIATION TRAJECTORIES OF LEUKEMIA-INITIATING CELLS IN ADULT ACUTE LYMPHOBLASTIC LEUKEMIA

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Experimental Hematology 2022年 111卷 S88-S89页

作者： Alec Geßner Tjeerd Sijmonsma Yu WeiJia Khalil Abou-El-Ardat Manuel Kaulich Stefan Günther Fabian Lang Florian Büttner Michael Rieger Hematology/Oncology Goethe University Hospital Frankfurt Frankfurt Germany Hematology/Oncology Goethe University Frankfurt Frankfurt Germany Institute of Biochemistry II Goethe University Frankfurt Frankfurt Germany Max-Planck-Institute for Heart and Lung Research Bad Nauheim Germany Departments of Medicine and Computer Science Goethe University Frankfurt Frankfurt Germany

While remission rates in adult B-cell precursor acute lymphoblastic leukemia (BCP-ALL) are >90% after first-line therapy, the prognosis after relapse is dismal with survival rates under 10%. Relapse may arise from remaining therapy-resistant leukemia-initiating cells (LICs), thus identifying molecular resistance mechanisms of LICs is of high medical need. To investigate subclonal architecture, clonal interference and differentiation trajectories of LICs in BCP-ALL, we developed sophisticated genetic barcoding systems at genomic and transcriptomic level to track individual LICs and their progeny. Thereby, we can detect the single-cell barcode together with cellular mRNAs and 100 surface markers using single-cell CITE-Seq. We stably transduced established patient-derived B-ALLs (PDLTCs) with lentiviral barcoding constructs and performed single-cell RNA sequencing of leukemic cells at different organ locations after in vivo leukemogenesis. We showed that while the majority of freshly transduced PDLTCs homed and engrafted in bone marrow and spleen seven days after transplantation, the LIC frequency of various PDLTCs was only at 1% at full-blown leukemia. Dominant subclones demonstrated a strong local expansion accounting for most of the tumor mass, whereas hundreds of small clones persisted throughout the disease without expansion. Importantly, only 20% of subclones were in various organs within one recipient, while 60% of subclones expanded locally restricted. The clonal composition was highly variable between recipient mice, suggesting a high selective pressure by the local microenvironment. Molecular profiling at single-cell level will delineate whether individual subclones follow similar differentiation trajectories and elucidate the molecular composition (targets, surface markers) of LICs, also after therapy pressure, to identify vulnerabilities to break resistance.

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Developing future human-centered smart cities: Critical analysis of smart city security, data management, and ethical challenges

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arXiv 2020年

作者： Ahmad, Kashif Maabreh, Majdi Ghaly, Mohamed Khan, Khalil Qadir, Junaid Al-Fuqaha, Ala Hamad Bin Khalifa University Doha Qatar Department of Computer Information Systems Faculty of Prince Al-Hussein Bin Abdullah Ii for Information Technology The Hashemite University Zarqa13133 Jordan Research Center for Islamic Legislation & Ethics College of Islamic Studies Hamad Bin Khalifa University Doha Qatar Department of Information Technology and Computer Science Pak-Austria Fachhochschule: Institute of Applied Sciences and Technology KPK Haripur Pakistan Department of Computer Science and Engineering Faculty of Engineering Qatar University Doha Qatar Department of Electrical Engineering Information Technology University Lahore Pakistan

As the globally increasing population drives rapid urbanisation in various parts of the world, there is a great need to deliberate on the future of the cities worth living. In particular, as modern smart cities embrace more and more data-driven artificial intelligence services, it is worth remembering that (1) technology can facilitate prosperity, wellbeing, urban livability, or social justice, but only when it has the right analog complements (such as well-thought out policies, mature institutions, responsible governance);and (2) the ultimate objective of these smart cities is to facilitate and enhance human welfare and social flourishing. Researchers have shown that various technological business models and features can in fact contribute to social problems such as extremism, polarization, misinformation, and Internet addiction. In the light of these observations, addressing the philosophical and ethical questions involved in ensuring the security, safety, and interpretability of such AI algorithms that will form the technological bedrock of future cities assumes paramount importance. Globally there are calls for technology to be made more humane and human-centered. In this paper, we analyze and explore key challenges including security, robustness, interpretability, and ethical (data and algorithmic) challenges to a successful deployment of AI in human-centric applications, with a particular emphasis on the convergence of these concepts/challenges. We provide a detailed review of existing literature on these key challenges and analyze how one of these challenges may lead to others or help in solving other challenges. The paper also advises on the current limitations, pitfalls, and future directions of research in these domains, and how it can fill the current gaps and lead to better solutions. We believe such rigorous analysis will provide a baseline for future research in the domain. © 2020, CC BY.

关键词： Information management