检索结果-内蒙古大学图书馆

International Joint Conference on Neural Networks (IJCNN)

作者： Ramon Gomes da Silva Matheus Henrique Dal Molin Ribeiro Naylene Fraccanabbia Viviana Cocco Mariani Leandro dos Santos Coelho Industrial & Systems Engineering Graduate Program (PPGEPS) Pontifical Catholic University of Parana (PUCPR) Curitiba Parana Brazil Department of Mathematics Federal Technological University of Parana (UTFPR) Pato Branco Parana Brazil Mechanical Engineering Graduate Program (PPGEM) Pontifical Catholic University of Parana (PUCPR) Curitiba Parana Brazil Department of Electrical Engineering Federal University of Parana (UFPR) Curitiba Parana Brazil

ISBN: (数字)9781728169262

ISBN: (纸本)9781728169279

Bitcoin is the leading currency in the cryptocurrency market capturing attention worldwide. Forecasting the Bitcoin price as accurate as possible is essential, but due to its high volatility this task is challenging. Many researchers try, through the years, to develop efficient models for predicting the Bitcoin price using several different data-driven approaches. The objective of this paper is to develop a novel decomposition-ensemble learning model that combines Variational Mode Decomposition (VMD) and Stacking-ensemble learning (STACK) with machine learning algorithms to forecast the Bitcoin price multi-step ahead. The algorithms are k-Nearest Neighbors, Support Vector Regression with Linear kernel, Feed-forward Artificial Neural Network with single-layer perceptron, Generalized Linear Model, and Cubist. Correlation matrix (CORR), principal component analysis (PCA), and Box-Cox transformation (BOXCOX) were used as data preprocessing techniques. Estimating the performance of the proposed models (namely VMD-STACK-CORR, VMD-STACK-PCA, and VMD-STACK-BOXCOX) using relative root mean square error, symmetric mean absolute percentage error, and absolute percentage error measures, defined that for one-day-ahead forecast VMD-STAK-BOXCOX model presented the better performance, and for two and three-days-ahead forecast VMD-STACK-CORR model was chosen, compared to VMD, STACK, and machine learning algorithms models' performance. Diebold-Mariano statistical test was conducted to evaluate a reduction in forecasting errors. Therefore, the proposed models (VMD-STACK-CORR, VMD-STACK-PCA, and VMD-STACK-BOXCOX) indeed forecast accurately Bitcoin price and outperformed the compared models (VMD, STACK, and machine learning models).

关键词： Predictive models Biological system modeling Data models Bitcoin Training Machine learning algorithms

来源：评论

学校读者我要写书评

暂无评论

Spatio-temporal regularization of global ocean waves obtained from satellite and their graphical representation

arXiv

引用

arXiv 2020年

作者： Perotto, Heitor Farina, Leandro Violante-Carvalho, Nelson Institute of Geosciences Federal University of Rio Grande do Sul Porto AlegreRS Brazil Institute of Mathematics and Statistics Federal University of Rio Grande do Sul Porto AlegreRS Brazil Program of Ocean Engineering Federal University of Rio de Janeiro Rio de JaneiroRJ Brazil

An algorithm for representing irregular satellite data obtained from advanced synthetic aperture radar (ASAR) uniformly in space and time is introduced and comparison with WAVEWATCH III model (WW3) data is carried out. Swell global data for 2007 are analysed using statistical parameters such as bias and scattering index. Satellite data showed a great spatial uniformity compared with WW3 model. Results show underestimation of swell height by the model in the tropics and at specific higher latitude regions. Copyright © 2020, The Authors. All rights reserved.

关键词： Satellites

来源：评论

学校读者我要写书评

暂无评论

Simple combination method of FTIR spectroscopy and chemometrics for qualitative identification of cattle bones 3

Simple combination method of FTIR spectroscopy and chemometr...

引用

3rd International Conference on Natural and Environmental Sciences 2019, ICONES 2019

作者： Nadia, Y. Ramli, M. Muslem Japnur, A.F. Rusyana, A. Idroes, G.M. Suhendra, R. Muhammad Sasmita, N.R. Tallei, T.E. Idroes, R. Department of Chemistry Faculty of Mathematics and Natural Sciences Universitas Syiah Kuala Kopelma Darussalam Banda Aceh23111 Indonesia Department of Statistics Faculty of Mathematics and Natural Sciences Universitas Syiah Kuala Kopelma Darussalam Banda Aceh23111 Indonesia Department of Chemical Engineering Faculty of Engineering Universitas Syiah Kuala Kopelma Darussalam Banda Aceh23111 Indonesia Department of Informatics Faculty of Mathematics and Natural Sciences Universitas Syiah Kuala Kopelma Darussalam Banda Aceh23111 Indonesia Faculty of Teacher Training and Education Abulyatama University Lampoh Keudee Aceh Besar23372 Indonesia Epidemiology Unit Faculty of Medicine Prince of Songkla University Songkla Hat Yai90110 Thailand Department of Biology Faculty of Mathematics and Natural Sciences Sam Ratulangi University North Sulawesi Manado95115 Indonesia Department of Pharmacy Faculty of Mathematics and Natural Sciences Universitas Syiah Kuala Kopelma Darussalam Banda Aceh23111 Indonesia

This research aims to identify Aceh, Bali and Brahman cattle bones using Fourier-Transform Infrared (FTIR) spectroscopy combined with chemometrics through Principal Component Analysis (PCA). Cattle bone samples were obtained from Lambaro and Lampulo raditional market in Aceh Besar. Firstly, each bone sample was analyzed using FTIR and then followed by FTIR spectra analysis using PCA. FTIR spectra showed that inorganic samples produced from these cattle bones consisting of hydroxyl, carbonate and phosphate functional groups. Further inspection using the PCA plot, the cattle bones were separated into three groups with its difference of 90.03%. Three types of cattle bone (Aceh, Bali dan Brahman) are separated into different quadrants. Inspite of both Aceh cattle data are closed each to others and are located in the same quadrant. This experiment proved that the cattle bones of Aceh, Bali dan Brahman can be well distinguished by using the combination method of FTIR and PCA. © 2019 Published under licence by IOP Publishing Ltd.

关键词： Principal component analysis

来源：评论

学校读者我要写书评

暂无评论

Compressed diffusion

arXiv

引用

arXiv 2019年

作者： Gigante, Scott Stanley, Jay S. Vu, Ngan van Dijk, David Moon, Kevin R. Wolf, Guy Krishnaswamy, Smita Computational Biology and Bioinformatics Program Department of Computer Science Department of Genetics Yale University New HavenCT United States Department of Mathematics and Statistics Utah State University LoganUT United States Department of Mathematics and Statistics Université de Montréal MontéalQC Canada

Diffusion maps are a commonly used kernel-based method for manifold learning, which can reveal intrinsic structures in data and embed them in low dimensions. However, as with most kernel methods, its implementation requires a heavy computational load, reaching up to cubic complexity in the number of data points. This limits its usability in modern data analysis. Here, we present a new approach to computing the diffusion geometry, and related embeddings, from a compressed diffusion process between data regions rather than data points. Our construction is based on an adaptation of the previously proposed measure-based Gaussian correlation (MGC) kernel that robustly captures the local geometry around data points. We use this MGC kernel to efficiently compress diffusion relations from pointwise to data region resolution. Finally, a spectral embedding of the data regions provides coordinates that are used to interpolate and approximate the pointwise diffusion map embedding of data. We analyze theoretical connections between our construction and the original diffusion geometry of diffusion maps, and demonstrate the utility of our method in analyzing big datasets, where it outperforms competing approaches. Copyright © 2019, The Authors. All rights reserved.

关键词： Embeddings

来源：评论

学校读者我要写书评

暂无评论

The Diffuse Ionized Gas of the Large Magellanic Cloud

arXiv

引用

arXiv 2023年

作者： Smart, B.M. Haffner, L.M. Barger, K.A. Ciampa, D.A. Hill, A.S. Krishnarao, D. Madsen, G.J. Department of Astronomy University of Washington SeattleWA98195 United States Department of Physics Astronomy and Mathematics University of Hertfordshire HatfieldAL10 9AB United Kingdom Department of Astronomy University of Wisconsin-Madison MadisonWI53706 United States Department of Physical Sciences Embry-Riddle Aeronautical University Daytona BeachFL32114-3900 United States Department of Physics & Astronomy Texas Christian University Fort WorthTX76129 United States Department of Computer Science Math Physics and Statistics University of British Columbia Okanagan Campus KelownaBCV1V 1V7 Canada Space Science Institute BoulderCO80301 United States Dominion Radio Astrophysical Observatory Herzberg Program in Astronomy and Astrophysics National Research Council Canada PentictonBC Canada NSF Astronomy and Astrophysics Postdoctoral Fellow Johns Hopkins University BaltimoreMD21218 United States Department of Physics Colorado College Colorado SpringsCO United States Space Telescope Science Institute BaltimoreMD21218 United States Institute of Astronomy University of Cambridge Madingley Road CambridgeCB3 0HA United Kingdom

The Large Magellanic Cloud (LMC) has an extensive Hα emission halo that traces an extended, warm ionized component of its interstellar medium. Using the Wisconsin Hα Mapper (WHAM) telescope, we present the first kinematic Hα survey of an extensive region around the LMC, from ( b) = (264◦. 5, −45◦. 5) to (295◦. 5, −19◦. 5), covering +150 ≤ vLSR ≤ +390 km s−1. We find that ionized hydrogen exists throughout the galaxy and extends several degrees beyond detected neutral hydrogen emission (log (NH i/cm−2 ) ≈ 18.3) as traced by 21-cm in current surveys. Using the column density structure of the neutral gas and stellar line-of-sight depths as a guide, we estimate the upper limit mass of the ionized component of the LMC to be roughly Mionized ≈ (0.6−1.8)×109 M☉, which is comparable to the total neutral atomic gas mass in the same region (Mneutral ≈ 0.75 − 0.85 × 109 M☉). Considering only the atomic phases, we find Mionized/Mionized+neutral, to be 46%–68% throughout the LMC and its extended halo. Additionally, we find an ionized gas cloud that extends off of the LMC at ( b) ≈ (285◦, −28◦) into a region previously identified as the Leading Arm complex. This gas is moving at a similar line-of-sight velocity as the LMC and has Mionized/Mionized+neutral = 13%–51%. This study, combined with previous studies of the SMC and extended structures of the Magellanic Clouds, continues to suggest that warm, ionized gas is as massive and dynamically-important as the neutral gas in the Magellanic System. © 2023, CC BY.

关键词： Galaxies

来源：评论

学校读者我要写书评

暂无评论

Models for plasma kinetics during simultaneous therapeutic plasma exchange and extracorporeal membrane oxygenation

arXiv

引用

arXiv 2020年

作者： Puelz, Charles Danial, Zach Marinaro, Jon Raval, Jay Griffith, Boyce E. Peskin, Charles S. Courant Institute of Mathematical Sciences New York University Department of Emergency Medicine University of New Mexico Department of Pathology University of New Mexico Departments of Mathematics Applied Physical Sciences and Biomedical Engineering University of North Carolina Carolina Center for Interdisciplinary Applied Mathematics University of North Carolina Computational Medicine Program University of North Carolina McAllister Heart Institute University of North Carolina

This paper focuses on the derivation and simulation of mathematical models describing new plasma fraction in blood for patients undergoing simultaneous extracorporeal membrane oxygenation and therapeutic plasma exchange. Models for plasma exchange with either veno–arterial or veno–venous extracorporeal membrane oxygenation are considered. Two classes of models are derived for each case, one in the form of an algebraic delay equation and another in the form of a system of delay differential equations. In special cases, our models reduce to single compartment ones for plasma exchange that have been validated with experimental data [15]. We also show that the algebraic delay equations are forward Euler discretizations of the delay differential equations, with timesteps equal to transit times through model compartments. Numerical simulations are performed to compare different model types, to investigate the impact of plasma device port switching on the efficiency of the exchange process, and to study the sensitivity of the models to their parameters. Copyright © 2020, The Authors. All rights reserved.

关键词： Respiratory therapy

来源：评论

学校读者我要写书评

暂无评论

Finding shortest and nearly shortest path nodes in large substantially incomplete networks

arXiv

引用

arXiv 2022年

作者： Kitsak, Maksim Ganin, Alexander Elmokashfi, Ahmed Cui, Hongzhu Eisenberg, Daniel A. Alderson, David L. Korkin, Dmitry Linkov, Igor Faculty of Electrical Engineering Mathematics and Computer Science Delft University of Technology Delft Netherlands Network Science Institute Northeastern University BostonMA02115 United States Department of Systems and Information Engineering University of Virginia CharlottesvilleVA22904 United States U.S. Army Engineer Research and Development Center Contractor Concord MA01742 United States Simula Metropolitan Center for Digital Engineering Oslo Norway Bioinformatics and Computational Biology Program Worcester Polytechnic Institute WorcesterMA01609 United States Institute for Genomic Medicine Columbia University Medical Center New YorkNY United States Operations Research Department Naval Postgraduate School MontereyCA93943 United States Data Science Program Worcester Polytechnic Institute WorcesterMA01609 United States Computer Science Department Worcester Polytechnic Institute WorcesterMA01609 United States U.S. Army Engineer Research and Development Center Environmental Laboratory Concord MA01742 United States

Dynamic processes on networks, be it information transfer in the Internet, contagious spreading in a social network, or neural signaling, take place along shortest or nearly shortest paths. Unfortunately, our maps of most large networks are substantially incomplete due to either the highly dynamic nature of networks, or high cost of network measurements, or both, rendering traditional path finding methods inefficient. We find that shortest paths in large real networks, such as the network of protein-protein interactions (PPI) and the Internet at the autonomous system (AS) level, are not random but are organized according to latent-geometric rules. If nodes of these networks are mapped to points in latent hyperbolic spaces, shortest paths in them align along geodesic curves connecting endpoint nodes. We find that this alignment is sufficiently strong to allow for the identification of shortest path nodes even in the case of substantially incomplete networks. We demonstrate the utility of latent-geometric path finding in problems of cellular pathway reconstruction and communication security. Copyright © 2022, The Authors. All rights reserved.

关键词： Proteins

来源：评论

学校读者我要写书评

暂无评论

The effect of lard concentration and ozonation on changes in polarization angle of olive oil

引用

Journal of Physics: Conference Series 2021年第1期1943卷

作者： F A Saputra M Azam F Arianto K F Sofjan H Sugito I Alkian Department of Physics Faculty of Science and Mathematics Diponegoro University Semarang Indonesia 50275 Study Program of Automation Engineering Technology Vocational School Diponegoro University

This research aims to analyze the effect of ozone exposure time and lard mixture on the polarization angle of transmission of olive oil. The study uses a transmission polarization method with a laser (λ = 532 nm) as a light source. The research sample in the form of olive oil mixed with lard at a concentration of 10, 20, 40, and 80%, with an ozone exposure time of 0-30 minutes. The sample is subjected to external electric fields with variations from 0-4.5 x 102 kV/m to increase the change's polarization angle. The results showed that the change in polarization angle would change linearly with the increase in lard concentration with olive oil. Olive oil with a low concentration of lard (10%) experienced an increase in the change in polarization angle with a value of 0.31 ° due to the effect of 90 minutes of ozone exposure. In general, the results of the study showed that increased concentrations of lard, ozone exposure time, electric field strengths caused an increase in changes in the polarization angle in a mixture of olive oil and lard.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Many-core algorithms for high-dimensional gradients on phylogenetic trees

arXiv

引用

arXiv 2023年

作者： Gangavarapu, Karthik Ji, Xiang Baele, Guy Fourment, Mathieu Lemey, Philippe Matsen, Frederick A. Suchard, Marc A. Department of Biomathematics David Geffen School of Medicine at UCLA University of California Los Angeles United States Department of Mathematics School of Science & Engineering Tulane University New Orleans United States Department of Microbiology Immunology and Transplantation Rega Institute KU Leuven Leuven Belgium Australian Institute for Microbiology and Infection University of Technology Sydney UltimoNSW Australia Public Health Sciences Division Fred Hutchinson Cancer Research Center SeattleWA United States Department of Statistics University of Washington Seattle United States Department of Genome Sciences University of Washington Seattle United States Howard Hughes Medical Institute Fred Hutchinson Cancer Research Center SeattleWA United States Department of Biostatistics Jonathan and Karin Fielding School of Public Health University of California Los Angeles United States Department of Human Genetics David Geffen School of Medicine at UCLA University of California Los Angeles United States Departments of Biostatistics Biomathematics and Human Genetics University of California Los Angeles 695 Charles E. Young Dr. South Los AngelesCA90095-7088 United States

Advancements in high-throughput genomic sequencing are delivering genomic pathogen data at an unprecedented rate, positioning statistical phylogenetics as a critical tool to monitor infectious diseases globally. This rapid growth spurs the need for efficient inference techniques, such as Hamiltonian Monte Carlo (HMC) in a Bayesian framework, to estimate parameters of these phylogenetic models where the dimensions of the parameters increase with the number of sequences N. HMC requires repeated calculation of the gradient of the data log-likelihood with respect to (wrt) all branch-length-specific (BLS) parameters that traditionally takes O(N2) operations using the standard pruning algorithm. A recent study proposes an approach to calculate this gradient in O(N), enabling researchers to take advantage of gradient-based samplers such as HMC. The CPU implementation of this approach makes the calculation of the gradient computationally tractable for nucleotide-based models but falls short in performance for larger state-space size models, such as Markov-modulated and codon models. Here, we describe novel massively parallel algorithms to calculate the gradient of the log-likelihood wrt all BLS parameters that take advantage of graphics processing units (GPUs) and result in many fold higher speedups over previous CPU implementations. We benchmark these GPU algorithms on three computing systems using three evolutionary inference examples exploring complete genomes from 997 dengue viruses, 62 carnivore mitochondria and 49 yeasts, and observe a greater than 128-fold speedup over the CPU implementation for codon-based models and greater than 8-fold speedup for nucleotide-based models. As a practical demonstration, we also estimate the timing of the first introduction of West Nile virus into the continental Unites States under a codon model with a relaxed molecular clock from 104 full viral genomes, an inference task previously intractable. We provide an implementation of our GP

关键词： Phylogenetic

来源：评论

学校读者我要写书评

暂无评论

CLASSIFICATION OF RANK TWO WEAK FANO BUNDLES ON DEL PEZZO THREEFOLDS OF DEGREE FOUR

arXiv

引用

arXiv 2020年

作者： Fukuoka, Takeru Hara, Wahei Ishikawa, Daizo Graduate School of Mathematical Sciences The University of Tokyo 3-8-1 Komaba Meguro-ku Tokyo153-8914 Japan The Mathematics and Statistics Building University of Glasgow University Place GlasgowG12 8QQ United Kingdom Department of Mathematics School of Science and Engineering Waseda University Ohkubo 3-4-1 Shinjuku Tokyo169-8555 Japan

We classify rank two vector bundles on a given del Pezzo threefold of degree four whose projectivizations are weak Fano into seven cases. We also give an example for each of these seven *** Codes 14J30, 14J45, 14J60 C... 详细信息

关键词： Classification (of information)

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：