检索结果-内蒙古大学图书馆

arXiv 2020年

作者： Dongnam, K.O. Zuazua, Enrique Chair of Computational Mathematics Fundación Deusto University of Deusto Bilbao Basque Country48007 Spain Chair in Applied Analysis Alexander von Humboldt-Professorship Department of Mathematics Friedrich-Alexander-Universität Erlangen-Nürnberg Erlangen91058 Germany Departamento de Matemáticas Universidad Autónoma de Madrid Madrid28049 Spain

We model, simulate and control the guiding problem for a herd of evaders under the action of repulsive drivers. The problem is formulated in an optimal control framework, where the drivers (controls) aim to guide the evaders (states) to a desired region of the Euclidean space. The numerical simulation of such models quickly becomes unfeasible for a large number of interacting agents. To reduce the computational cost, we use the Random Batch Method (RBM), which provides a computationally feasible approximation of the dynamics. At each time step, the RBM randomly divides the set of particles into small subsets (batches), considering only the interactions inside each batch. Due to the averaging effect, the RBM approximation converges to the exact dynamics as the time discretization gets finer. We propose an algorithm that leads to the optimal control of a fixed RBM approximated trajectory using a classical gradient descent. The resulting control is not optimal for the original complete system, but rather for the reduced RBM model. We then adopt a Model Predictive Control (MPC) strategy to handle the error in the dynamics. While the system evolves in time, the MPC strategy consists in periodically updating the state and computing the optimal control over a long-time horizon, which is implemented recursively in a shorter time-horizon. This leads to a semi-feedback control strategy. Through numerical experiments we show that the combination of RBM and MPC leads to a significant reduction of the computational cost, preserving the capacity of controlling the overall dynamics. Copyright © 2020, The Authors. All rights reserved.

关键词： Model predictive control

来源：评论

学校读者我要写书评

暂无评论

Potential of fungal thermostable alpha amylase enzyme isolated from Hot springs of Central Anatolia(Turkey)in wheat bread quality

引用

Food Bioscience 2022年第1期45卷 214-222页

作者： Arzu Unal Asiye Seis Subasi Semra Malkoc Ijlal Ocak SElif Korcan Elif Yetilmezer Seyhun Yurdugül Hülya Yaman Turgay Sanal Alaettin Keceli Igdır University Faculty of AgricultureDepartment of Agricultural BiotechnologyI˘gdırTurkey Ministry of Agriculture and Forestry Field Crops Central Research Institute Department of Quality and TechnologyAnkaraTurkey Eskisehir Technical University Faculty of EngineeringDepartment of Environmental EngineeringEskisehirTurkey Afyon Kocatepe University Faculty of EducationDepartment of Mathematics and Science EducationDivision of Science EducationAfyonTurkey Usak University Vocational School of Health ServicesMedical Laboratory Techniques ProgramUsakTurkey Ministry of Agriculture and Forestry Field Crops Central Research Institute Department of BiotechnologyAnkaraTurkey Bolu Abant Izzet Baysal University Faculty of Arts and ScienceDepartment of BiologyBoluTurkey Bolu Abant Izzet Baysal University Vocational School of the Technical Sciences of BoluFood Technology ProgramBoluTurkey Pamukkale University School of Applied SciencesDepartment of Organic Farming Business ManagementDenizliTurkey

Many industrial processes may quickly proceed with biotechnological and enzymatic *** and production facilitator properties of enzymes have provided variable advantages for ***,enzyme utilization has become inevitable for industry and supplied financial advantages in case of the high energy requirement *** the study,the amylase enzymes were isolated from thermal spring sources,and the effect on bread quality was ***,fungal amylases were isolated from thermal spring sources(29-98◦C)in various places around *** determining the functional properties of amylase enzymes,the most active enzyme was used in bread production to examine their effect on bread *** maximum alpha-amylase activity(38.6 U/mg)has been detected in Aspergillus niger G 2-1 *** compared with the commercially available one,native alpha-amylase increased the bread volume.A significant difference(p<0.01)was found in the color properties and size of the bread between microbial produced in this study and commercially produced *** ppm alpha-amylase addition showed the optimum bread properties for dough processing.

关键词： Alpha-amylase Thermal spring Quality of bread Commercial enzymes

来源：评论

学校读者我要写书评

暂无评论

Manifestations of metastable criticality in the long-range structure of model water glasses

arXiv

引用

arXiv 2021年

作者： Gartner, Thomas E. Torquato, Salvatore Car, Roberto Debenedetti, Pablo G. Department of Chemistry Princeton University PrincetonNJ United States Department of Physics Princeton University PrincetonNJ United States Program in Applied and Computational Mathematics Princeton University PrincetonNJ United States Princeton Institute for the Science and Technology of Materials Princeton University PrincetonNJ United States Department of Chemical and Biological Engineering Princeton University PrincetonNJ United States

Much attention has been devoted to water’s metastable phase behavior, including polyamorphism (multiple amorphous solid phases), and the hypothesized liquid-liquid transition and associated critical point. However, the possible relationship between these phenomena remains incompletely understood. Using molecular dynamics simulations of the realistic TIP4P/2005 model, we found a striking signature of the liquid-liquid critical point in the structure of water glasses, manifested as a pronounced increase in long-range density fluctuations at pressures proximate to the critical pressure. By contrast, these signatures were absent in glasses of two model systems that lack a critical point. We also characterized the departure from equilibrium upon vitrification via the non-equilibrium index;water-like systems exhibited a strong pressure dependence in this metric, whereas simple liquids did not. These results reflect a surprising relationship between the metastable equilibrium phenomenon of liquid-liquid criticality and the non-equilibrium structure of glassy water, with implications for our understanding of water phase behavior and glass physics. Our calculations suggest a possible experimental route to probing the existence of the liquid-liquid transition in water and other fluids. © 2021, CC BY.

关键词： Criticality (nuclear fission)

来源：评论

学校读者我要写书评

暂无评论

Stochastic enzyme kinetics and the quasi-steady-state reductions: Application of the slow scale linear noise approximation à la Fenichel

arXiv

引用

arXiv 2021年

作者： Eilertsen, Justin Srivastava, Kashvi Schnell, Santiago Mathematical Reviews American Mathematical Society 416 4th Street Ann ArborMI48103 United States Department of Mathematics University of Michigan Ann ArborMI48109 United States Department of Biological Sciences University of Notre Dame Notre DameIN46556 United States Department of Applied and Computational Mathematics and Statistics University of Notre Dame Notre DameIN46556 United States

The linear noise approximation models the random fluctuations from the mean-field model of a chemical reaction that unfolds near the thermodynamic limit. Specifically, the fluctuations obey a linear Langevin equation up to order Ω−1/2, where Ω is the size of the chemical system (usually the volume). In the presence of disparate timescales, the linear noise approximation admits a quasi-steady-state reduction referred to as the slow scale linear noise approximation (ssLNA). Curiously, the ssLNAs reported in the literature are slightly different. The differences in the reported ssLNAs lie at the mathematical heart of the derivation. In this work, we derive the ssLNA directly from geometric singular perturbation theory and explain the origin of the different ssLNAs in the literature. Moreover, we discuss the loss of normal hyperbolicity and we extend the ssLNA derived from geometric singular perturbation theory to a non-classical singularly perturbed problem. In so doing, we disprove a commonly-accepted qualifier for the validity of stochastic quasi-steady-state approximation of the Michaelis-Menten reaction *** Codes 37M10 (Primary), 92E20, 60J22, 60H10, 60H35, 82-10 (Secondary) © 2021, CC BY.

关键词： Random processes

来源：评论

学校读者我要写书评

暂无评论

Solving determinantal systems using homotopy techniques

arXiv

引用

arXiv 2018年

作者： Hauenstein, J.D. Safey El Din, M. Schost, É. Vu, T.X. Department of Applied and Computational Mathematics and Statistics University of Notre Dame United States Sorbonne Université CNRS INRIA Laboratoire d'Informatique de Paris 6 PolSys Paris France David Cheriton School of Computer Science University of Waterloo ON Canada

Let K be a field of characteristic zero and K be an algebraic closure of K. Consider a sequence of polynomials G = (g1,..., gs) in K[X1,..., Xn], a polynomial matrix F = [fi,j] ∈ K[X1,..., Xn]p×q, with p ≤ q, and the algebraic set Vp(F, G) of points in K at which all polynomials in G and all p-minors of F vanish. Such polynomial systems appear naturally in e.g. polynomial optimization, computational geometry. We provide bounds on the number of isolated points in Vp(F, G) depending on the maxima of the degrees in rows (resp. columns) of F. Next, we design homotopy algorithms for computing those points. These algorithms take advantage of the determinantal structure of the system defining Vp(F, G). In particular, the algorithms run in time that is polynomial in the bound on the number of isolated points. Copyright © 2018, The Authors. All rights reserved.

关键词： Polynomials

来源：评论

学校读者我要写书评

暂无评论

Rapidly Rotating Wall-Mode Convection

arXiv

引用

arXiv 2024年

作者： Vasil, Geoffrey M. Burns, Keaton J. Lecoanet, Daniel Oishi, Jeffrey S. Brown, Benjamin P. Julien, Keith School of Mathematics The Maxwell Institute for Mathematical Sciences University of Edinburgh EH9 3FD United Kingdom Department of Mathematics Massachusetts Institute of Technology CambridgeMA02139 United States Center for Computational Astrophysics Flatiron Institute New YorkNY10010 United States Department of Engineering Sciences and Applied Mathematics Northwestern University EvanstonIL60208 United States CIERA Northwestern University EvanstonIL60201 United States Department of Mechanical Engineering University of New Hampshire DurhamNH03824 United States Department of Astrophysical & Planetary Sciences University of Colorado Boulder BoulderCO80309 United States Department of Applied Mathematics University of Colorado Boulder BoulderCO80309 United States

In the rapidly rotating limit, we derive a balanced set of reduced equations governing the strongly nonlinear development of the convective wall-mode instability in the interior of a general container. The model illustrates that wall-mode convection is a multiscale phenomenon where the dynamics of the bulk interior diagnostically determine the small-scale dynamics within Stewartson boundary layers at the sidewalls. The sidewall boundary layers feedback on the interior via a nonlinear lateral heat-flux boundary condition, providing a closed system. Outside the asymptotically thin boundary layer, the convective modes connect to a dynamical interior that maintains scales set by the domain geometry. In many ways, the final system of equations resembles boundary-forced planetary geostrophic baroclinic dynamics coupled with barotropic quasi-geostrophic vorticity. The reduced system contains the results from previous linear instability theory but captured in an elementary fashion, providing a new avenue for investigating wall-mode convection in the strongly nonlinear regime. We also derive the dominant Ekman-flux correction to the onset Rayleigh number for large Taylor number, Ra ∼ 31.8 Ta1/2 − 4.43 Ta5/12 for no-slip boundaries. However, we find that the linear onset in a finite cylinder differs noticeably compared to a Cartesian channel. We demonstrate some of the reduced model’s nonlinear dynamics with numerical simulations in a cylindrical container. © 2024, CC BY.

关键词： Cylinders (containers)

来源：评论

学校读者我要写书评

暂无评论

Quantum error correction using hypergraph States

arXiv

引用

arXiv 2017年

作者： Balakuntala, Shashanka Paul, Goutam Department of Applied Mathematics and Computational Sciences PSG College of Technology Coimbatore641 004 India Cryptology and Security Research Unit R. C. Bose Centre for Cryptology and Security Indian Statistical Institute Kolkata700 108 India

Graph states have been used for quantum error correction by Schlingemann et al. [Physical Review A 65.1 (2001): 012308]. Hypergraph states [Physical Review A 87.2 (2013): 022311] are generalizations of graph states and they have been used in quantum algorithms. We for the first time demonstrate how hypergraph states can be used for quantum error correction. We also point out that they are more efficient than graph states in the sense that to correct equal number of errors on the same graph topology, suitably defined hypergraph states require less number of gate operations than the corresponding graph states. Copyright © 2017, The Authors. All rights reserved.

关键词： Error correction

来源：评论

学校读者我要写书评

暂无评论

Electron-Hydrogen Atom Scattering with Screened Coulomb Potential

Electron-Hydrogen Atom Scattering with Screened Coulomb Pote...

引用

第三届全国计算原子与分子物理学术会议

作者： Song Bin Zhang Jian Guo Wang R.K Janev Xiang Jun Chen Department of Modern Physics University of Science and Technology of China Hefei 230026 China Institute of Applied Physics and Computational Mathematics Beijing 100088 China Macedonian Academy of Sciences and Arts P. O. Box 428 1000 Skopje Macedonia

来源：评论

学校读者我要写书评

暂无评论

Butterfly-Accelerated Solution of Coupled Volume Integral and Hydrodynamic Equations

Butterfly-Accelerated Solution of Coupled Volume Integral an...

引用

USNC-URSI Radio Science Meeting (Joint with AP-S Symposium)

作者： Doolos Aibek Uulu Yang Liu Abdulkadir C. Yucel Hakan Bagci Department of Mathematics and Natural Sciences University of Central Asia (UCA) Naryn Kyrgyzstan Applied Mathematics & Computational Research Division Lawrence Berkeley National Laboratory Berkeley USA School of Electrical and Electronic Engineering Nanyang Technological University (NTU) Singapore Computer Electrical and Mathematical Science and Engineering Division King Abdullah University of Science and Technology (KAUST) Thuwal Saudi Arabia

ISBN: (数字)9789463968119

ISBN: (纸本)9798350359497

In recent years, advancements in plasmonic devices have enabled the localization of electromagnetic fields at subwavelength scales, contributing to breakthroughs in various scientific and engineering fields (J. C. Ndukaife, et al., ACS Nano, 2014,8,9,9035-9043). These structures are often made of metals and their electric properties are typically represented by the classical Drude model (S. A. Maier, 2007, Springer, New York). As the size of the plasmonic structures approaches the nanoscale, the classical Drude model falls short in explaining the collective movement of free electrons in metals. The interaction between moving charges and the electromagnetic fields can be described by a coupled system of the Maxwell and hydrodynamic equations (X. Zheng, et al., IEEE Trans. Antennas Propag., 2018,66,9, 4759-4771).

关键词： Location awareness Conferences Integral equations Metals Plasmons Hydrodynamics Mathematical models

来源：评论

学校读者我要写书评

暂无评论

PROOFS OF MODULO 11 AND 13 CYLINDRIC KANADE-RUSSELL CONJECTURES FOR A2 ROGERS-RAMANUJAN TYPE IDENTITIES

arXiv

引用

arXiv 2023年

作者： Uncu, Ali Kemal Johann Radon Institute for Computational and Applied Mathematics Austrian Academy of Science Altenbergerstraße 69 LinzA-4040 Austria University of Bath Faculty of Science Department of Computer Science BathBA2 7AY United Kingdom

We present proofs of two new families of sum-product identities arising from the cylindric parti tions paradigm. Most of the presented expressions, the related sum-product identities, and the ingredients for the proofs were first conjectured by Kanade-Russell in the spirit of Andrews-Schilling-Warnaar identities o the A2 Rogers-Ramanujan type. We follow the footsteps of Kanade-Russell while we alter the computations heavily to accomplish our *** Codes 05A15, 05A17, 05A19, 11B65, 11P84, 17B65, 68R05 Copyright © 2023, The Authors. All rights reserved.

关键词：

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：