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arXiv 2017年

作者： Bendory, Tamir Beinerty, Robert Eldarz, Yonina C. Program in Applied and Computational Mathematics Princeton University PrincetonNJ United States Institute of Mathematics and Scientific Computing University of Graz Heinrichstraße 36 Graz8010 Austria Andrew and Erna Viterbi Faculty of Electrical Engineering Technion - Israel Institute of Technology Haifa Israel

The problem of recovering a signal from its phaseless Fourier transform measurements, called Fourier phase retrieval, arises in many applications in engineering and science. Fourier phase retrieval poses fundamental theoretical and algorithmic challenges. In general, there is no unique mapping between a one-dimensional signal and its Fourier magnitude and therefore the problem is ill-posed. Additionally, while almost all multidimensional signals are uniquely mapped to their Fourier magnitude, the performance of existing algorithms is generally not well-understood. In this chapter we survey methods to guarantee uniqueness in Fourier phase retrieval. We then present different algorithmic approaches to retrieve the signal in practice. We conclude by outlining some of the main open questions in this field. Copyright © 2017, The Authors. All rights reserved.

关键词： Fourier transforms

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Mineralogical Classification of Sedimentary Rocks by Spectral Matching Techniques Based on Library and Field-Work References

Mineralogical Classification of Sedimentary Rocks by Spectra...

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Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing, WHISPERS

作者： Daniel C. Zanotta Lais V. De Souza Marcelo K. De Souza Alysson S. Ayres Vinícius F. Sales Graciela R. Racolte Delano M. Ibanez Luiz G. Silveira Maurício R. Veronez Vizlab — X-Reality and GeoInformatics Lab UNISINOS São Leopoldo RS Brazil Graduate Program in Applied Computing at Vale do Rio dos Sinos University São Leopoldo RS Brazil PETROBRAS - Petrobras Research and Development Center (CENPES) RJ Brazil

ISBN: (数字)9798331513139

ISBN: (纸本)9798331513146

Sedimentary rocks are of great importance for the oil and gas industry. Spectral matching using known references made on hyperspectral images is one of the most rapid and cost effective alternatives for the detailed analysis in these areas, since they can adequately catch the specific absorption features of the multiple minerals available. In many initiatives, scientists run the methods with standard spectral references, usually from spectral libraries or samples from other places. However, for the success of their application, they must be used along with spectral references that accurately describe the actual constituents of the surface. In this paper we scrutinize three different ways for mineralogical mapping performed by spectral matching techniques. The results showed that using reference spectra from samples collected directly on the surveyed environment can considerably improve the results, reaching high scores, pointing out that many places share common substances, but each specific material has particular differences that cannot be generalized.

关键词： Costs Systematics Signal processing Rocks Gas industry Libraries Minerals Petroleum industry Standards Hyperspectral imaging

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Indirect Calibration of Hyperspectral Images Using Rock Samples

Indirect Calibration of Hyperspectral Images Using Rock Samp...

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Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing, WHISPERS

作者： Daniel C. Zanotta Leonardo D. Araújo Marcelo K. De Souza Delano M. Ibanez Luiz G. Silveira Maurício R. Veronez Vizlab — X-Reality and GeoInformatics Lab UNISINOS São Leopoldo RS Brazil Graduate Program in Applied Computing at Vale do Rio dos Sinos University São Leopoldo RS Brazil PETROBRAS - Petrobras Research and Development Center (CENPES) RJ Brazil

ISBN: (数字)9798331513139

ISBN: (纸本)9798331513146

This paper presents a methodology for the indirect calibration of hyperspectral images using radiometric measurements from field samples. While hyperspectral imaging (HSI) is essential in remote sensing, its accuracy depends on precise calibration, which is often challenging in the field. Most approaches rely on a single standard panel used as absolute reference and the empirical line method. This often leads to mistakes and uncertainties in the analysis. In this paper we propose an alternative that utilizes radiometric data from rock samples with known spectral properties to indirectly calibrate hyperspectral images. The results show specific improvements in accuracy, particularly in the shape of the curves, compared to standard calibration method. The calibrated images offer better material differentiation and more reliable spectral signatures, which are crucial for geological mapping and mineral exploration. This approach can enhance the reliability of hyperspectral data analysis in geological and environmental studies, especially in situations where time and logistics are challenging.

关键词： Accuracy Uncertainty Coal Signal processing Rocks Radiometry Calibration Minerals Standards Hyperspectral imaging

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On the verification of adaptive three-dimensional multiresolution computations of the magnetohydrodynamic equations

arXiv

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arXiv 2019年

作者： Gomes, Anna Karina Fontes Domingues, Margarete Oliveira Mendes, Odim Schneider, Kai Post-graduation Program in Applied Computing National Institute for Space Research São José dos Campos Brazil Associated Laboratory for Computing and Applied Mathematics National Institute for Space Research São José dos Campos Brazil Space Geophysics Division National Institute for Space Research São José dos Campos Brazil Institut de Mathématiques de Marseille Aix-Marseille Université CNRS Centrale Marseille I2M UMR 7373

Magnetohydrodynamics is an important tool to study the dynamics of plasma Space Physics. In this context, we introduce a three-dimensional magnetohydrodynamic solver with divergence-cleaning in the adaptive multiresolution CARMEN code. The numerical scheme is based on a finite volume discretization that ensures the conservation of physical quantities. The adaptive multiresolution approach allows for automatic identification of local structures in the numerical solution and thus provides an adaptive mesh refined only in regions where the solution needs more improved resolution. We assess the three-dimensional magnetohydrodynamic CARMEN code and compare its results with the ones from the well-known FLASH code. Copyright © 2019, The Authors. All rights reserved.

关键词： Magnetohydrodynamics

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FANTOM5 CAGE profiles of human and mouse reprocessed for GRCh38 and GRCm38 genome assemblies

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Scientific Data 2017年第1期4卷 170107-170116页

作者： Abugessaisa, Imad Noguchi, Shuhei Hasegawa, Akira Harshbarger, Jayson Kondo, Atsushi Lizio, Marina Severin, Jessica Carninci, Piero Kawaji, Hideya Kasukawa, Takeya RIKEN Center for Life Science Technologies Division of Genomic Technologies 1-7-22 Suehiro-cho Tsurumi-ku Yokohama 230-0045 Japan RIKEN Omics Science Center 1-7-22 Suehiro-cho Tsurumi-ku Kanagawa 230-0045 Japan RIKEN Preventive Medicine and Diagnosis Innovation Program 2-1 Hirosawa Saitama 351-0198 Japan RIKEN Advanced Center for Computing and Communication Preventive Medicine and Applied Genomics Unit 1-7-22 Suehiro-cho Tsurumi-ku Yokohama 230-0045 Japan

The FANTOM5 consortium described the promoter-level expression atlas of human and mouse by using CAGE (Cap Analysis of Gene Expression) with single molecule sequencing. In the original publications, GRCh37/hg19 and NCBI37/mm9 assemblies were used as the reference genomes of human and mouse respectively;later, the Genome Reference Consortium released newer genome assemblies GRCh38/hg38 and GRCm38/mm10. To increase the utility of the atlas in forthcoming researches, we reprocessed the data to make them available on the recent genome assemblies. The data include observed frequencies of transcription starting sites (TSSs) based on the realignment of CAGE reads, and TSS peaks that are converted from those based on the previous reference. Annotations of the peak names were also updated based on the latest public databases. The reprocessed results enable us to examine frequencies of transcription initiations on the recent genome assemblies and to refer promoters with updated information across the genome assemblies consistently. © 2017 The Author(s).

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Exploring Drug Repurposing Success Stories Through a Network-based Approach: Insights from a Case Study

Exploring Drug Repurposing Success Stories Through a Network...

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IEEE International Conference on Bioinformatics and Biomedicine (BIBM)

作者： Elisa Pierini Ludovica Mazza Manuela Petti Paolo Tieri Data Science MSc Program Sapienza University of Rome Rome Italy DIAG Dept. Comp. Contr. Manag. Eng. Sapienza University of Rome Rome Italy IAC Institute for Applied Computing CNR National Research Council Rome Italy

ISBN: (数字)9798350386226

ISBN: (纸本)9798350386233

Drug repositioning is a promising strategy to discover new therapeutic applications for existing drugs, significantly reducing the time and costs associated with traditional drug development. This study employs a network medicine approach to analyze successful cases of drug repositioning, focusing on the exploratory hypothesis that the efficacy of repositioning may be determined by functional similarity between between diseases for which the drug was originally designed and diseases for which the same drug is reused. Network medicine tools were employed to investigate the connections between disease-associated genes, proteins, and approved drugs. Biological networks, including protein-protein interactions and functional interactions networks, as well as gene- and drug-disease association data are analyzed to identify functional similarities and possible molecular connections between diseases and treatments. Using clustering techniques and topological analysis, the results reveal a suggestive overlap of involved genes and functional interactions, emphasizing the value of computational methods in accelerating drug repositioning efforts and improving understanding of drug repositioning dynamics for more efficient therapeutic interventions.

关键词： Drugs Proteins Obesity Costs Knowledge based systems Focusing Machine learning Biology Diabetes Diseases

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Exploring Diversity in Engineering and Technology for Knowledge and Innovation 1

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丛书名： Advanced Structured Materials

1000年

作者： Azman Ismail Fatin Nur Zulkipli Ahmad Fitriadhy Sayyid Zainal Abidin Syed Ahmad Andreas Öchsner

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Surrogate approximation of the grad-shafranov free boundary problem via stochastic collocation on sparse grids

arXiv

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arXiv 2021年

作者： Elman, Howard C. Liang, Jiaxing Sánchez-Vizuet, Tonatiuh Department of Computer Science Institute for Advanced Computer Studies University of Maryland College Park United States Applied Mathematics & Statistics and Scientific Computing Program University of Maryland College Park United States Courant Institute of Mathematical Sciences New York University Department of Mathematics The University of Arizona

In magnetic confinement fusion devices, the equilibrium configuration of a plasma is determined by the balance between the hydrostatic pressure in the fluid and the magnetic forces generated by an array of external coils and the plasma itself. The location of the plasma is not known a priori and must be obtained as the solution to a free boundary problem. The partial differential equation that determines the behavior of the combined magnetic field depends on a set of physical parameters (location of the coils, intensity of the electric currents going through them, magnetic permeability, etc.) that are subject to uncertainty and variability. The confinement region is in turn a function of these stochastic parameters as well. In this work, we consider variations on the current intensities running through the external coils as the dominant source of uncertainty. This leads to a parameter space of dimension equal to the number of coils in the reactor. With the aid of a surrogate function built on a sparse grid in parameter space, a Monte Carlo strategy is used to explore the effect that stochasticity in the parameters has on important features of the plasma boundary such as the location of the x-point, the strike points, and shaping attributes such as triangularity and elongation. The use of the surrogate function reduces the time required for the Monte Carlo simulations by factors that range between 7 and over *** Codes 65C30, 65C05, 65N35, 65N99, 65Z05 Copyright © 2021, The Authors. All rights reserved.

关键词： Monte Carlo methods

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Analysis of Positional and Geometric Accuracy of Objects in Survey with Unmanned Aerial Vehicle (UAV)

Analysis of Positional and Geometric Accuracy of Objects in ...

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IEEE International Symposium on Geoscience and Remote Sensing (IGARSS)

作者： Gabriel Soares Leonardo Campos Inocencio Maurício Roberto Veronez Luiz Gonzaga da Silveira Fabiane Bordin Fernando Pinho Marson UNISINOS Advanced Visualization & Geoinformatics Laboratory São Leopoldo RS Brazil Graduate Program on Applied Computing - UNISINOS São Leopoldo RS Brazil São Leopoldo RS Brazil Universidade do Vale do Rio dos Sinos Sao Leopoldo RS BR

This study aimed the analysis of the positional and geometric accuracy of objects in orthomosaics obtained through different unmanned aerial vehicle (UAV) data processing software covering an area located within Universidade do Vale do Rio dos Sinos - UNISINOS in São Leopoldo, RS. A total of nine ground control points (GCP) and twenty checkpoints were surveyed in order register and classify the processed orthomosaics according to the cartographic accuracy standard - Padrão de Exatidão Cartográfica (PEC). Four software was employed to process the UAV data: Pix4D mapper, Agisoft PhotoScan, Menci APS and Bentley Context Capture. The results obtained from each software were compared and identified the smallest distortions when processing with and without ground control points. The flight was executed at a height of 90m with 60% sidelap and 80% overlap using an ST800 UAV equipped with a Sony NEX-7 small format non-metric camera with 24 megapixels resolution. The software GeoPEC was used to classify the orthomosaics according to PEC. For data processed with ground control points all orthomosaics were classified “Class A” in 1/500 scale, however, only Menci APS did not present a trend line via t-student test. On the other hand, Menci APS presented the worst results without the ground control points. In processing with GCP, all orthomosaics obtained optimum results with an approximated error of 2,5 m 2 , about 0.03% of the area.

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Tunable Source of Quantum-Correlated Photons with Integrated Pump Rejection in a Silicon CMOS Platform

Tunable Source of Quantum-Correlated Photons with Integrated...

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Frontiers in Optics + Laser Science 2021, FiO+LS 2021 - Part of Frontiers in Optics, FiO 2021

作者： Fargas Cabanillas, Josep M. Kramnik, Danielius Ramesh, Anirudh Gentry, Cale M. Stojanović, Vladimir Kumar, Prem Popović, Miloš A. Department of Electrical and Computer Engineering Photonics Center Boston University BostonMA02215 United States Department of Electrical Engineering and Computer Science UC Berkeley BerkeleyCA94720 United States Graduate Program in Applied Physics Northwestern University EvanstonIL60208 United States Department of Electrical Computer and Energy Engineering University of Colorado BoulderCO80309 United States Center for Photonic Communication and Computing Dept. of Electrical and Computer Eng. Northwestern University EvanstonIL60208 United States

ISBN: (纸本)9781557528209

A wavelength-tunable, silicon photon-pair source based on spontaneous four-wave mixing, integrated with a pump rejection filter in a single, flip-chip packaged CMOS chip, is demonstrated with a coincidence-to-accidentals ratio of 9.1 with no off-chip pump filtering. Frontiers in Optics / Laser Science © Optica Publishing Group 2021.

关键词： CMOS integrated circuits

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