检索结果-内蒙古大学图书馆

arXiv 2023年

作者： Frahm, Moritz Dengiz, Thomas Zwickel, Philipp Maaß, Heiko Matthes, Jörg Hagenmeyer, Veit Karlsruhe Institute of Technology Institute for Automation and Applied Informatics Eggenstein-Leopoldshafen Germany Karlsruhe Institute of Technology Institute for Industrial Production Karlsruhe Germany

In future energy systems with high shares of renewable energy sources, the electricity demand of buildings has to react to the fluctuating electricity generation in view of stability. As buildings consume one-third of global energy and almost half of this energy accounts for Heating, Ventilation, and Air Conditioning (HVAC) systems, HVAC are suitable for shifting their electricity consumption in time. To this end, intelligent control strategies are necessary as the conventional control of HVAC is not optimized for the actual demand of occupants and the current situation in the electricity grid. In this paper, we present the novel multi-zone controller Price Storage Control (PSC) that not only considers room-individual Occupants’ Thermal Satisfaction (OTS), but also the available energy storage, and energy prices. The main feature of PSC is that it does not need a building model or forecasts of future demands to derive the control actions for multiple rooms in a building. For comparison, we use an ideal, error-free Model Predictive Control (MPC), a heuristic control approach from the literature (PC), and a conventional hysteresis-based two-point control as upper and lower benchmarks. We evaluate the four controllers in a multi-zone environment for heating a building in winter and consider two different scenarios that differ in how much the permitted temperatures vary. In addition, we compare the impact of model parameters with high and low thermal capacitance. The results show that PSC strongly outperforms the conventional control approach in both scenarios and for both parameters concerning the electricity costs and OTS. For high capacitance, it leads to 22 % costs reduction while the ideal MPC achieves cost reductions of more than 39 %. Considering that PSC does not need any building model or forecast, as opposed to MPC, the results support the suitability of our developed control strategy for controlling HVAC systems in future energy systems. © 2023, CC BY.

关键词： Model predictive control

来源：评论

学校读者我要写书评

暂无评论

Distributed Control Strategy for Grid Supportive Loads in DC Microgrids

Distributed Control Strategy for Grid Supportive Loads in DC...

引用

IEEE Electronic Power Grid (eGrid)

作者： Ömer Ekin Abhishek Balakrishnan Luigi Spatafora Veit Hagenmeyer Institute for Automation and Applied Informatics (IAI) Karlsruhe Institute of Technology (KIT) Karlsruhe Germany Department of Electrical Engineering and Information Technology Karlsruhe Institute of Technology (KIT) Karlsruhe Germany

ISBN: (数字)9798331505493

ISBN: (纸本)9798331505509

The increasing penetration of inverter-connected resources, such as solar and wind, into modern power grids has made grid-supportive control strategies increasingly crucial. Particularly, power electronics-interfaced loads have recently emerged as a valuable asset for grid support. This paper presents a novel control method enabling these power electronics-interfaced loads to actively support DC bus voltage control. The proposed strategy dynamically adjusts load demand to support grid voltage control during disturbances, without significantly impacting user functionality. The method is validated through simulations of a DC Microgrid consisting of a battery, photovoltaic array, and multiple load ports. Compared to conventional proportional-integral (PI) controllers, the Grid-Supportive Load (GSL) approach shows significant improvement in voltage control, reducing voltage drops and improving overall Microgrid reliability.

关键词： Photovoltaic systems Wind PI control Decentralized control Power system control Microgrids Distributed power generation Reliability Voltage control Load modeling

来源：评论

学校读者我要写书评

暂无评论

Tuning of discrete-time angular droop controllers

Tuning of discrete-time angular droop controllers

引用

Control Technology and Applications (CCTA),

作者： Taouba Kaouther Jouini Zhiyong Sun Veit Hagenmeyer Institute of Automation and Applied Informatics (IAI) at Karlsruhe Institute of Technology Germany Department of Electrical Engineering Eindhoven University of Technology Netherlands

We study discrete-time angular-droop control in power inverter networks and leverage second-order information for the tuning. We thereby increase the rate of convergence of the closed-loop angle trajectories towards an induced steady state angle. In particular, we select the input penalty matrix, representing a tuning knob to be a sufficiently small diagonal matrix so that the closed-loop system approximately yields Newton’s method. In this way, we ensure quadratic convergence, a feat that is otherwise not achievable with a constant, sufficiently large diagonal input penalty matrix. This draws a link between second-order methods known for their quadratic rate of convergence and the tuning of inverse optimal stabilizing controllers for discrete-time integrator dynamics.

关键词：

来源：评论

学校读者我要写书评

暂无评论

TreeSwap: Data Augmentation for Machine Translation via Dependency Subtree Swapping

arXiv

引用

arXiv 2023年

作者： Nagy, Attila Lakatos, Dorina Barta, Botond Ács, Judit Department of Automation and Applied Informatics Budapest University of Technology and Economics Hungary Institute for Computer Science and Control Hungary

Data augmentation methods for neural machine translation are particularly useful when limited amount of training data is available, which is often the case when dealing with low-resource languages. We introduce a novel augmentation method, which generates new sentences by swapping objects and subjects across bisentences. This is performed simultaneously based on the dependency parse trees of the source and target sentences. We name this method TreeSwap. Our results show that TreeSwap achieves consistent improvements over baseline models in 4 language pairs in both directions on resource-constrained datasets. We also explore domain-specific corpora, but find that our method does not make significant improvements on law, medical and IT data. We report the scores of similar augmentation methods and find that TreeSwap performs comparably. We also analyze the generated sentences qualitatively and find that the augmentation produces a correct translation in most cases. Our code is available on Github. © 2023, CC BY.

关键词： Neural machine translation

来源：评论

学校读者我要写书评

暂无评论

Verifiable Certificateless Signcryption Scheme for Smart Grids

Verifiable Certificateless Signcryption Scheme for Smart Gri...

引用

International Conference on System Reliability and Science (ICSRS)

作者： Mohammed Ramadan Ghada Elbez Veit Hagenmeyer KASTEL Security Research Labs Institute of Automation and Applied Informatics (IAI) Karlsruhe Institute of Technology (KIT) Eggenstein-Leopoldshafen Germany

Smart Grids (SG) are potential replacements for older power grids, capable of adapting and distributing energy based on demand. The recent technological advances and the increased dependence on electrical energy are all factors in the increased need for reliable and efficient energy systems. The complexity of the smart grid arises from using various components and the high requirements for real-time reliable two-way communication. Accordingly, this represents additional security and privacy challenges. In this paper, we proposed a security and efficient certificateless signcryption scheme with flexible verifiability properties using equality test techniques for Advanced Metering Infrastructure (AMI) within the SG; abbreviated CL-SG. The proposed scheme provides privacy-preserving, confidentiality, data integrity, verifiability, and reduces the level of trust in the third party (e.g., central unit, substation, data concentrator, etc.). The performance evaluation regarding security and complexity analysis shows that the proposed scheme is secure and efficient with good functionality to be fully adopted and implemented within SG. Also, an extended future work is presented to add more flexibility and security properties and features to the current proposed model.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Inverse Methods: How Feasible are Spatially Low-Resolved Capacity Expansion Modeling Results When Disaggregated at High Resolution?

SSRN

引用

SSRN 2023年

作者： Frysztacki, Martha Maria Hagenmeyer, Veit Brown, Tom Institute for Automation and Applied Informatics Karlsruhe Institute of Technology Eggenstein-Leopoldshafen76344 Germany Department of Digital Transformation in Energy Systems

Spatially highly-resolved capacity expansion models are often simplified to a lower spatial resolution because they are computationally ***, the simplification mixes sites with different renewable features while removing transmission lines that can cause *** a consequence, the results may represent an infeasible system when the capacities are fed back into higher spatial *** far there has been no detailed investigation of how to disaggregate results and whether the spatially highly-resolved disaggregated model is *** is challenging since there is no unique way to invert the *** proceed in two stages. First, we propose three methods to disaggregate spatially low-resolved results: (a) uniformly distribute the regional result across its original regions, (b) re-optimising each region separately (c) a novel approach that minimises the ``excess electricity''.Second, we investigate the resulting highly-resolved models' feasibility by running an operational dispatch. While re-optimising yields the best results, our custom inverse-method provides comparable results for less computational ***-wise, our results strengthen that modeling every country by a single region is *** that, we find that results obtained from state-of-the-art reduced models with 100-200 regions for Europe still yield 3-7% of loadshedding, depending on model resolution and inverse method. © 2023, The Authors. All rights reserved.

关键词： Inverse problems

来源：评论

学校读者我要写书评

暂无评论

TSO-DSO Interaction: Privacy-Preserving Optimal Power Flow with Distributed Generators Using a Machine Learning-Based Approach

TSO-DSO Interaction: Privacy-Preserving Optimal Power Flow w...

引用

IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC)

作者： Burak Dindar Can Berk Saner Hüseyin Kemal Çakmak Veit Hagenmeyer Institute for Automation and Applied Informatics Karlsruhe Institute of Technology Germany Department of Electrical and Computer Engineering National University of Singapore Singapore

ISBN: (数字)9798350318098

ISBN: (纸本)9798350318104

The integration of distributed generators (DGs) into the electrical grid has introduced new dimensions in power system management: Enhancing efficiency and operational flexibility of the grid requires taking into account the DGs located at the distribution level in dispatch decisions, while also considering the operational constraints of both distribution and transmission levels. However, the centralization of cooperation between transmission system operators (TSOs) and distribution system operators (DSOs) is troublesome due to privacy concerns of both parties. In present paper, we introduce a Machine Learning-Based Privacy-Preserving Optimal Power Flow (MLB-PP-OPF) framework. This method enables the seamless inclusion of DGs at the distribution level in optimal power flow calculations, all while adhering to the operational limits of both systems and maintaining data privacy. The proposed approach leverages three machine learning models to map the distribution system variables to active and reactive power flows at the point of common coupling, and to determine the feasible operating region of the distribution system in a privacy-preserving manner. Comparative case studies, performed on the coupled IEEE 30-bus transmission and 33-bus distribution test systems, demonstrate that the results achieved using MLB-PP-OPF align almost perfectly with those obtained through classical OPF, while maintaining data privacy.

关键词： Couplings Data privacy Reactive power Privacy Machine learning Generators Data models

来源：评论

学校读者我要写书评

暂无评论

ciscNet - A Single-Branch Cell Instance Segmentation and Classification Network

arXiv

引用

arXiv 2022年

作者： Böhland, Moritz Neumann, Oliver Schilling, Marcel P. Reischl, Markus Mikut, Ralf Löffler, Katharina Scherr, Tim Institute for Automation and Applied Informatics Karlsruhe Institute of Technology Eggenstein-Leopoldshafen Germany

Automated cell nucleus segmentation and classification are required to assist pathologists in their decision making. The Colon Nuclei Identification and Counting Challenge 2022 (CoNIC Challenge 2022) supports the development and comparability of segmentation and classification methods for histopathological images. In this contribution, we describe our CoNIC Challenge 2022 method ciscNet to segment, classify and count cell nuclei, and report preliminary evaluation results. Our code is available at https://***/ciscnet/ciscnet-conic-2022. Copyright © 2022, 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

What ODE-Approximation Schemes of Time-Delay Systems Reveal about Lyapunov-Krasovskii Functionals

arXiv

引用

arXiv 2022年

作者： Scholl, Tessina H. Hagenmeyer, Veit Gröll, Lutz Institute for Automation and Applied Informatics Karlsruhe Institute of Technology Karlsruhe76021 Germany

The article proposes an approach to complete-type and related Lyapunov-Krasovskii functionals that neither requires knowledge of the delay-Lyapunov matrix function nor does it involve linear matrix inequalities. The approach is based on ordinary differential equations (ODEs) that approximate the time-delay system. The ODEs are derived via spectral methods, e.g., the Chebyshev collocation method (also called pseudospectral discretization) or the Legendre tau method. A core insight is that the Lyapunov-Krasovskii theorem resembles a theorem for Lyapunov-Rumyantsev partial stability in ODEs. For the linear approximating ODE, only a Lyapunov equation has to be solved to obtain a partial Lyapunov function. The latter approximates the Lyapunov-Krasovskii functional. Results are validated by applying Clenshaw-Curtis and Gauss quadrature to a semi-analytical result of the functional, yielding a comparable finite-dimensional approximation. In particular, the article provides a formula for a tight quadratic lower bound, which is important in applications. Examples confirm that this new bound is significantly less conservative than known results. Copyright © 2022, The Authors. All rights reserved.

关键词： Ordinary differential equations

来源：评论

学校读者我要写书评

暂无评论

Classification of Bundle Branch Blocks with QRS Templates Extracted from 12-lead ECGs

引用

Current Directions in Biomedical Engineering 2021年第2期7卷 582-585页

作者： Welle, Hannes Nagel, Claudia Loewe, Axel Mikut, Ralf Dössel, Olaf Institute of Biomedical Engineering KIT Fritz-Haber-Weg 1 Karlsruhe Germany Institute for Automation and Applied Informatics KIT Hermann-von-Helmholtz-Platz 1 Eggenstein-Leopoldshafen Germany

Being non-invasive, cheap and widely available, the 12-lead electrocardiogram (ECG) is a standard method to assess cardiac function. Still, its reliable interpretation requires specialized knowledge and experience, rendering a second opinion valuable. We evaluated the performance of machine learning based classification of 11,705 healthy and bundle branch block 12-lead ECGs from 3 open databases. For each lead of the ECG signal, a representative QRS-complex template was extracted automatically. Principal component analysis (PCA) was applied to the concatenated, normalized and rescaled QRS signals to reduce their dimensionality. Multilayer perceptron and support-vector machine classifiers were trained using the principal components of weighted and non-weighted QRS template signals as input data. Classifiers achieved F1 scores between 0.92 and 0.96 on the test set for different input configurations. Anomaly based weighting slightly improved the performance of the classifiers. Neither class-wise PCA for feature extraction nor adding information on sex, gender and electrical heart axis to the input data yielded considerable improvement of the F1 scores. The achieved classification accuracy is similar to deep learning classifier performances and should generalize robustly to other ECG datasets. Our results suggest that this simple and well interpretable approach based on morphological signal characteristics is suitable for automatically and non-invasively identifying bundle branch block pathologies in clinical or smart electronics contexts. © 2021 by Walter de Gruyter Berlin/Boston.

关键词： Electrocardiograms

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：