检索结果-内蒙古大学图书馆

arXiv 2022年

作者： Sandoval, Ilya Orson Petsagkourakis, Panagiotis del Rio-Chanona, Ehecatl Antonio Centre for Process Systems Engineering Imperial College London London United Kingdom

Neural ordinary differential equations (Neural ODEs) define continuous time dynamical systems with neural networks. The interest in their application for modelling has sparked recently, spanning hybrid system identification problems and time series analysis. In this work we propose the use of a neural control policy capable of satisfying state and control constraints to solve nonlinear optimal control problems. The control policy optimization is posed as a Neural ODE problem to efficiently exploit the availability of a dynamical system model. We showcase the efficacy of this type of deterministic neural policies in two constrained systems: the controlled Van der Pol system and a bioreactor control problem. This approach represents a practical approximation to the intractable closed-loop solution of nonlinear control problems. Copyright © 2022, The Authors. All rights reserved.

关键词： Reinforcement learning

来源：评论

学校读者我要写书评

暂无评论

Effect of droplet superficial velocity on mixing efficiency in a microchannel

引用

Journal of Zhejiang University-Science A(Applied Physics & engineering) 2022年第10期23卷 783-794页

作者： Jin-yuan QIAN Lei ZHAO Xiao-juan LI Wen-qing LI Zhi-jiang JIN Institute of Process Equipment College of Energy EngineeringZhejiang UniversityHangzhou 310027China State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310027China

In this study, droplet characteristics including droplet length and formation time, and mixing efficiency in droplets were investigated via the volume of fluid(VOF) method coupled with a user defined scalar(UDS) model. A cross-shaped junction with a square cross-section was designed and used for droplet formation. An initial arrangement which differed from that of a conventional operation was adopted. Results show that when the droplet superficial velocity is constant, the exchange between the dispersed phase velocity and the continuous phase velocity has a marginal effect on the droplet formation ***, the exchange has a great effect on droplet length. These findings provide a valuable guide for future operation of droplet formation. In addition, the results show that the mixing efficiency in the droplet forming stage can be classified into time-dominated and length-dominated regimes according to the droplet superficial velocity. When a droplet flows in a microchannel,a higher droplet superficial velocity increases mixing efficiency due to the faster inner circulation and shorter droplet length.

关键词： Droplet characteristics Mixing efficiency Inner circulation Droplet superficial velocity

来源：评论

学校读者我要写书评

暂无评论

Detecting Generative Artificial Intelligence Essays using Large Language Models: Machine and Deep Learning Approaches

Detecting Generative Artificial Intelligence Essays using La...

引用

2024 International Conference on engineering and Computing, ICECT 2024

作者： Tariq, Rasikh Casillas-Munoz, F. Ashraf, Waqar Muhammad Ramirez-Montoya, Maria Soledad University College London The Sargent Centre for Process Systems Engineering Department of Chemical Engineering LondonWC1E 7JE United Kingdom Institute for the Future of Education Tecnologico de Monterrey N.L. Monterrey64849 Mexico EGADE Business School Tecnologico de Monterrey N.L. Monterrey64849 Mexico

ISBN: (纸本)9798350349719

The study focuses on discerning between human and AI-generated essays, highlighting the ethical implications of AI in academia. It employs various algorithms like logistic regression, Support Vector Machine (SVM), decision trees, random forests, KNN, and LSTM to develop models for essay classification. The TF-IDF technique (Term Frequency-Inverse Document Frequency) is applied to assess document word importance, with rigorous parameter tuning ensuring model accuracy. Findings revealed SVM's exceptional precision and recall, highlighting its robustness in accurately classifying essays, while decision trees offer simplicity but increased misclassification risk. KNN strikes a balance and random forests as well. LSTM excels in contextual understanding, albeit with higher computational demands. The research emphasizes the significance of algorithm selection in maintaining academic integrity and fostering genuine student creativity. SVM emerges as a robust and accurate choice for essay classification, ensuring fair assessment and upholding academic honesty. © 2024 IEEE.

关键词： Long short-term memory

来源：评论

学校读者我要写书评

暂无评论

EMMS-based modeling of gas-solid generalized fluidization:Towards a unified phase diagram

引用

Chinese Journal of Chemical engineering 2021年第1期34卷 27-34页

作者： Juanbo Liu Xinhua Liu Wei Ge State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China Dalian National Laboratory for Clean Energy Dalian 116023China

Hydrodynamic features of gas-solid generalized fluidization can be well expressed in the form of phase diagrams,which are important for engineering *** structure presents almost universally in generalized fluidization and should be considered in such phase ***,current phase diagrams were mainly proposed for cocurrent upward flow according to experimental data or empirical correlations with homogeneous *** energy-minimization multiscale(EMMS)model has shown the capability of capturing mesoscale structure in generalized fluidization,so EMMS-based phase diagrams of generalized fluidization were proposed in this article,which describe more reasonable global hydrodynamics over all regimes including the important engineering phenomena of choking and *** characteristics were also found in discrete particle simulation under various *** wider range of application,the typical hydrodynamic parameters of the phase diagrams were correlated to non-dimensional numbers reflecting the effects of material properties and operation *** study thus shows a possible route to develop a unified phase diagram in the future.

关键词： Fluidization Phase diagram Dimensionless correlation Mesoscale Mathematical modeling EMMS

来源：评论

学校读者我要写书评

暂无评论

Classifier Surrogates to Ensure Phase Stability in Optimisation-Based Design of Solvent Mixtures

SSRN

引用

SSRN 2024年

作者： Karia, Tanuj Chaparro, Gustavo Chachuat, Benoît Adjiman, Claire S. Department of Chemical Engineering The Sargent Centre for Process Systems Engineering Institute for Molecular Science and Engineering Imperial College London LondonSW7 2AZ United Kingdom

The ability to guarantee a single and homogeneous liquid phase is a key consideration in computer-aided mixture/blend design (CAMbD). In this article, we investigate the use of a classifier surrogate of the phase stability condition within a CAMbD optimisation model for designing solvent mixtures with guaranteed phase stability properties. We show how to develop such classifiers for describing multiple candidate mixtures over a range of compositions and temperatures based on the generation of reliable phase stability data using thermodynamic models such as UNIFAC. We test the approach on two solvent design case studies and illustrate its effectiveness in enabling the in silico design of stable mixtures, simultaneously providing a probability of phase stability as an interpretable metric. © 2024, The Authors. All rights reserved.

关键词： Neural networks

来源：评论

学校读者我要写书评

暂无评论

Long-short term memory autoencoder using delta with beta bands of EEG enables highly accurate prediction of seizure outcome in Infantile Epileptic Spasms Syndrome of unknown etiology

Long-short term memory autoencoder using delta with beta ban...

引用

Annual International Conference of the IEEE engineering in Medicine and Biology Society (EMBC)

作者： Ryosuke Suzui Jun Natsume Tatsuki Saito Koichi Fujiwara Department of Pediatrics Nagoya University Graduate School of Medicine Nagoya Japan Department of Human and Process Systems Nagoya University Graduate School of Engineering Nagoya Japan

ISBN: (数字)9798350371499

ISBN: (纸本)9798350371505

[Background] Infantile epileptic spasms syndrome (IESS) is a developmental epileptic encephalopathy in infants, which is often difficult to be predicted long-term seizure outcomes at the time of onsets. The aim of this study is to predict its long-term outcome by analyzing EEG data at the onset of IESS of unknown etiology. [Methods] The study included eighteen patients with IESS of unknown etiology. Thirteen patients in whom seizures disappeared after initial treatments were categorized into a good outcome group, and five patients with continuation or relapse of seizures were into a poor outcome group. We trained a machine learning (ML) model from clinical EEG data of patients in the good outcome group only utilizing an anomaly detection framework. The delta and the beta bands, constructing basis of hypsarrhythmia were extracted from scalp EEG data during sleep by bandpass filtering, and the phase of each band was used as features of the ML model. Long-short term memory autoencoder (LSTM-AE), which copes with anomaly detection with time series data, was adopted as the ML model. We tested its performance of long-term outcome prediction. This trial was repeated ten times randomly exchanging training, validation, and test datasets for precise performance evaluation. [Results] The trained LSTM-AE model achieved a sensitivity, specificity, and accuracy of 0.82 ± 0.08, 0.80 ± 0.10, and 0.81 ± 0.10, respectively, when patients the poor outcome group were detected, which may contribute to clinical decision. [Conclusion] The developed ML model enabled highly accurate prediction of seizure outcomes of IESS of unknown etiology from the EEG data at its onset.

关键词： Pediatrics Accuracy Sensitivity Biological system modeling Predictive models Brain modeling Feature extraction Data models Electroencephalography Anomaly detection

来源：评论

学校读者我要写书评

暂无评论

Modification to solution-diffusion model for performance prediction of nanofiltration of long-alkyl-chain ionic liquids aqueous solutions based on ion cluster

引用

Green Energy & Environment 2020年第1期5卷 105-113页

作者： Jianguo Qian Ruiyi Yan Xiaomin Liu Chunshan Li Xiangping Zhang Key Laboratory of Green Process and Engineering Beijing Key Laboratory of Ionic Liquids Clean ProcessState Key Laboratory of Multiphase Complex SystemsInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China College of Chemistry and Chemical Engineering University of Chinese Academy of SciencesBeijing100049China

Mathematical modeling for nanofiltration of ionic liquids(ILs) solutions could assist to understand transfer mechanism and predict experimental values. In this work, modeling by solution-diffusion model for nanofiltration of long-alkyl-chain ILs aqueous solutions was proposed. Molecular simulations were performed to validate the existence of ion cluster in long-alkyl-chain ILs aqueous solution. Based on the results of simulations, parameters used in the solution-diffusion model were modified, such as concentration of ILs and diameter of ion *** modeling process was developed for three long-alkyl-chain ILs aqueous solutions with different concentrations(1-alkyl-3-methylimidazolium chloride: [C6 mim]Cl, [C8 mim]Cl, [C10 mim]Cl). The calculated values obtained from modified solution-diffusion model could well match the experimental values.

关键词： Solution-diffusion model Nanofiltration Long-alkyl-chain ionic liquid Molecular dynamic simulation Ion cluster

来源：评论

学校读者我要写书评

暂无评论

Operability-economics trade-offs in adsorption-based CO2 capture processes

arXiv

引用

arXiv 2023年

作者： Sachio, Steven Ward, Adam Pini, Ronny Papathanasiou, Maria M. Department of Chemical Engineering Imperial College London United Kingdom Sargent Centre for Process Systems Engineering Imperial College London United Kingdom

Low-carbon dispatchable power underpins a sustainable energy system, providing load balancing complementing wide-scale deployment of intermittent renewable power. In this new context, fossil fuel-fired power plants must be coupled with a post-combustion carbon capture (PCC) process capable of highly transient operation. To tackle design and operational challenges simultaneously, we have developed a computational framework that integrates process design with techno-economic assessment. The backbone of this is a high-fidelity PCC mathematical model of a pressure-vacuum swing adsorption process. We demonstrate that the cost-optimal design has limited process flexibility, challenging reactiveness to disturbances, such as those in the flue gas feed conditions. The results illustrate that flexibility can be introduced by relaxing the CO2 recovery constraint on the operation, albeit at the expense of the capture efficiency of the process. We discover that adsorption-based processes can accommodate for significant flexibility and improved performance with respect to the operational constraints on CO2 recovery and purity. The results herein demonstrate a trade-off between process economics and process operability, which must be effectively rationalised to integrate CO2 capture units in the design of low-carbon energy systems. © 2023, CC BY.

关键词： Carbon dioxide

来源：评论

学校读者我要写书评

暂无评论

Towards Production Wide Optimisation for Upstream Field Recovery

Towards Production Wide Optimisation for Upstream Field Reco...

引用

2021 AIChE Annual Meeting

作者： Ramjanee, Shakeel Centre for Process Systems Engineering Imperial College LondonSW7 2AZ United Kingdom

ISBN: (纸本)9781713852834

Current integrated modelling systems employed in the upstream hydrocarbon industry are computationally intensive, restrictive in their ability to apply multi objective optimisation and not directly fit for purpose for day to day usage for optimising production on a short term decision horizon. © 2021 American Institute of Chemical Engineers. All rights reserved.

关键词： Multiobjective optimization

来源：评论

学校读者我要写书评

暂无评论

Internal pricing in integrated energy system design

引用

Frontiers in Energy Research 2025年 13卷

作者： Granacher, Julia Schnidrig, Jonas Chuat, Arthur Lepour, Dorsan Terrier, Cédric Castro-Amoedo, Rafael Marechal, Francois M. A. Industrial Process and Energy Systems Engineering group École Polytechnique Fédérale de Lausanne Sion Switzerland CIRAIG Institue of Energy and Environment University of Applied Sciences Western Switzerland Sion Switzerland

Environmentally sustainable and economically viable process and energy systems are imperative to a successful energy transition. Often, design configurations are derived from a global perspective, in which the individual needs and interests of actors within the system are overlooked. This work proposes an approach for designing a system considering its entire scope and acknowledging the individual actors within the system. System solutions are generated from the perspective of a universal decision-maker who is aware of the whole system, and the obtained solution space is analyzed regarding implications for the individual actors. Thereby, prices of internal exchanges between actors that would allow for the realization of the optimal integrated system solution while granting each actor their economic objectives are derived. The approach is demonstrated in three distinct case studies varying in size: a bio-based industrial site, a renewable energy community, and a national energy system. All case studies yield system configurations allowing the actors to profit from economic benefits emerging from synergies from internal cooperation. Further research must delve into diverse system settings and actor paradigms to enhance the robustness and applicability of the derived insights. Copyright © 2025 Granacher, Schnidrig, Chuat, Lepour, Terrier, Castro-Amoedo and Maréchal.

关键词： Integrated circuit design

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：