检索结果-内蒙古大学图书馆

arXiv 2020年

作者： Mühlpfordt, Tillmann Dai, Xinliang Engelmann, Alexander Hagenmeyer, Veit Institute for Automation and Applied Informatics Karlsruhe Institute of Technology Germany

Solving the power flow problem in a distributed fashion empowers different grid operators to compute the overall grid state without having to share grid models—this is a practical problem to which industry does not have off-the-shelf answers. In cooperation with a German transmission system operator we propose two physically consistent problem formulations (feasibility, least-squares) amenable to two solution methods from distributed optimization (the Alternating direction method of multipliers (admm), and the Augmented Lagrangian based Alternating Direction Inexact Newton method (aladin));with aladin there come convergence guarantees for the distributed power flow problem. In addition, we provide open source matlab code for rapid prototyping for distributed power flow (rapidpf), a fully matpower-compatible software that facilitates the laborious task of formulating power flow problems as distributed optimization problems;the code is available under https://github. com/KIT-IAI/rapidPF/. The approach to solving distributed power flow problems that we present is flexible, modular, consistent, and reproducible. Simulation results for systems ranging from 53 buses (with 3 regions) up to 4662 buses (with 5 regions) show that the least-squares formulation solved with aladin requires just about half a dozen coordinating steps before the power flow problem is solved. © 2020, CC-BY.

关键词： Constrained optimization

来源：评论

学校读者我要写书评

暂无评论

Hybrid multi-chip assembly of optical communication engines by in situ 3D nanolithography

引用

Light(Science & Applications) 2020年第1期9卷 1340-1350页

作者： Matthias Blaicher Muhammad Rodlin Billah Juned Kemal Tobias Hoose Pablo Marin-Palomo Andreas Hofmann Yasar Kutuvantavida Clemens Kieninger Philipp-Immanuel Dietrich Matthias Lauermann Stefan Wolf Ute Troppenz Martin Moehrle Florian Merget Sebastian Skacel Jeremy Witzens Sebastian Randel Wolfgang Freude Christian Koos Institute of Photonics and Quantum Electronics(IPQ) Karlsruhe Institute of Technology(KIT)Engesserstraße 576131 KarlsruheGermany Institute for Microstructure Technology(IMT) KITHermann-von-Helmholtz-Platz 176344 Eggenstein-LeopoldshafenGermany Institute for Automation and Applied Informatics(IAI) KITHermann-von-Helmholtz-Platz 176344 Eggenstein-LeopoldshafenGermany Vanguard Automation GmbH Gablonzer StraBe 1076185 KarlsruheGermany Fraunhofer Institute for Telecommunications Heinrich Hertz Institute(HHI)Einsteinufer 3710587 BerlinGermany Institute of Integrated Photonics(IPH) RWTH AachenSommerfeldstraße 18/2452074 AachenGermany

Three-dimensional(3D)nano-printing of freeform optical waveguides,also referred to as photonic wire bonding,allows for efficient coupling between photonic chips and can greatly simplify optical system *** a key advantage,the shape and the trajectory of photonic wire bonds can be adapted to the mode-field profiles and the positions of the chips,thereby offering an attractive alternative to conventional optical assembly techniques that rely on technically complex and costly high-precision ***,while the fundamental advantages of the photonic wire bonding concept have been shown in proof-of-concept experiments,it has so far been unclear whether the technique can also be leveraged for practically relevant use cases with stringent reproducibility and reliability *** this paper,we demonstrate optical communication engines that rely on photonic wire bonding for connecting arrays of silicon photonic modulators to InP lasers and single-mode *** a first experiment,we show an eight-channel transmitter offering an aggregate line rate of 448 Gbit/s by low-complexity intensity modulation.A second experiment is dedicated to a four-channel coherent transmitter,operating at a net data rate of 732.7 Gbit/s-a record for coherent silicon photonic transmitters with co-packaged *** dedicated test chips,we further demonstrate automated mass production of photonic wire bonds with insertion losses of(0.7±0.15)dB,and we show their resilience in environmental-stability tests and at high optical *** results might form the basis for simplified assembly of advanced photonic multi-chip systems that combine the distinct advantages of different integration platforms.

关键词： communication lithography bonding

来源：评论

学校读者我要写书评

暂无评论

Modeling Curtailment in Germany: How Spatial Resolution Impacts Line Congestion

Modeling Curtailment in Germany: How Spatial Resolution Impa...

引用

International Conference on European Electricity Market, EEM

作者： Martha Frysztacki Tom Brown Karlsruhe Institute of Technology Institute for Automation and Applied Informatics Germany

ISBN: (数字)9781728169194

ISBN: (纸本)9781728169200

This paper investigates the effects of network constraints in energy system models at transmission level on renewable energy generation and curtailment as the network is being spatially aggregated. We seek to reproduce historically measured curtailment in Germany for the years 2013-2018 using an open model of the transmission system, PyPSA-Eur. Our simulations include spatial and temporal considerations, including congestion per line as well as curtailment per control zone and *** indicate that curtailment at high network resolution is significantly overestimated due to inaccurate allocation of electricity demand and renewable capacities to overloaded sites. However, high congestion rates of the transmission network decrease as the network is clustered to a smaller number of nodes, thus reducing curtailment. A measure to capture errors in the assignment of electricity demand and power plants is defined and hints towards a preferable spatial resolution. Thus, we are able to balance the effects of accurate node assignment and network congestion revealing that a reduced model can capture curtailment from recent historical data. This shows that it is possible to reduce the network to improve computation times and capture the most important effects of network constraints on variable renewable energy feed-in at the same time.

关键词：

来源：评论

学校读者我要写书评

暂无评论

3Dprinted highly compact varifocal optics

3Dprinted highly compact varifocal optics

引用

Imaging Systems and Applications, ISA 2020 - Part of Imaging and applied Optics Congress 2020

作者： Sieber, Ingo Thelen, Richard Gengenbach, Ulrich Karlsruhe Institute of Technology Institute for Automation and Applied Informatics Hermann-von-Helmholtz-Platz 1 Eggenstein-Leopoldshafen76344 Germany Karlsruhe Institute of Technology Institute of Microstructure Technology - KNMF Hermann-von-Helmholtz-Platz 1 Eggenstein-Leopoldshafen76344 Germany

Surface measurements of a high-resolution 3Dprinted rotation optics are compared to nominal shape to deduce improvements of process parameters. Feeding back the data into the model allows for usage as digital twin for... 详细信息

ISBN: (纸本)9781557528209

关键词： Optimization

来源：评论

学校读者我要写书评

暂无评论

Microscopic fluctuations in power-grid frequency recordings at the sub-second scale

arXiv

引用

arXiv 2022年

作者： Schäfer, Benjamin Gorjão, Leonardo Rydin Cigdem, G. Yalcin Förstner, Ellen Jumar, Richard Maass, Heiko Kühnapfel, Uwe Hagenmeyer, Veit Institute for Automation and Applied Informatics Karlsruhe Institute of Technology Eggenstein-Leopoldshafen76344 Germany Department of Computer Science OsloMet - Oslo Metropolitan University OsloN-0130 Norway Jülich52428 Germany Department of Physics Istanbul University Vezneciler 34134 Turkey

Complex systems, such as the power grid, are essential for our daily lives. Many complex systems display (multi-)fractal behavior, correlated fluctuations and power laws. Whether the power-grid frequency, an indicator about the balance on supply and demand in the electricity grid, also displays such complexity remains a mostly open question. Within the present article, we utilize highly resolved measurements to quantify the properties of the power-grid frequency. We show that below 1 second, the dynamics may fundamentally change, including a suddenly increasing power spectral density, emergence of multifractality and a change of correlation behavior. We provide a simplified stochastic model involving positively correlated noise to reproduce the observed dynamics, possibly linked to frequency dependent loads. Finally, we stress the need for high-quality measurements and discuss how we obtained the data analyzed here. © 2022, CC BY.

关键词： Stochastic models

来源：评论

学校读者我要写书评

暂无评论

Evaluation of semi-supervised learning using sparse labeling to segment cell nuclei

引用

Current Directions in Biomedical Engineering 2020年第3期6卷

作者： Bruch, Roman Rudolf, Rüdiger Mikut, Ralf Reischl, Markus Institute of Molecular and Cell Biology Mannheim University of Applied Sciences Mannheim Germany Institute for Automation and Applied Informatics Karlsruhe Institute of Technology Karlsruhe Germany

The analysis of microscopic images from cell cultures plays an important role in the development of drugs. The segmentation of such images is a basic step to extract the viable information on which further evaluation steps are build. Classical image processing pipelines often fail under heterogeneous conditions. In the recent years deep neuronal networks gained attention due to their great potentials in image segmentation. One main pitfall of deep learning is often seen in the amount of labeled data required for training such models. Especially for 3D images the process to generate such data is tedious and time consuming and thus seen as a possible reason for the lack of establishment of deep learning models for 3D data. Efforts have been made to minimize the time needed to create labeled training data or to reduce the amount of labels needed for training. In this paper we present a new semisupervised training method for image segmentation of microscopic cell recordings based on an iterative approach utilizing unlabeled data during training. This method helps to further reduce the amount of labels required to effectively train deep learning models for image segmentation. By labeling less than one percent of the training data, a performance of 90% compared to a full annotation with 342 nuclei can be achieved. © 2020 by Walter de Gruyter Berlin/Boston 2020.

关键词： Deep learning

来源：评论

学校读者我要写书评

暂无评论

Uncertainty Quantification for Optimal Power Flow Problems

Uncertainty Quantification for Optimal Power Flow Problems

引用

90th Annual Meeting of the International Association of applied Mathematics and Mechanics, GAMM 2019

作者： Mühlpfordt, Tillmann Hagenmeyer, Veit Faulwasser, Timm Institute for Automation and Applied Informatics Karlsruhe Institute of Technology Karlsruhe Germany

The need to de-carbonize the current energy infrastructure, and the increasing integration of renewables pose a number of difficult control and optimization problems. Among those, the optimal power flow (OPF) problem—i.e., the task to minimize power system operation costs while maintaining technical and network limitations—is key for operational planning of power systems. The influx of inherently volatile renewable energy sources calls for methods that allow to consider stochasticity directly in the OPF problem. Here, we present recent results on uncertainty quantification for OPF problems. Modeling uncertainties as second-order continuous random variables, we will show that the OPF problem subject to stochastic uncertainties can be posed as an infinite-dimensional L2-problem. A tractable reformulation thereof can be obtained using polynomial chaos expansion (PCE), under mild assumptions. We will show advantageous features of PCE for OPF subject to stochastic uncertainties. For example, multivariate non-Gaussian uncertainties can be considered easily. Finally, we comment on recent progress on a Julia package for PCE. © 2019 The Authors Proceedings in applied Mathematics & Mechanics published by Wiley-VCH Verlag GmbH & Co. KGaA Weinheim.

关键词： Uncertainty analysis

来源：评论

学校读者我要写书评

暂无评论

On Optimal Control of Flat Hybrid Automata

引用

IFAC-PapersOnLine 2020年第2期53卷 6800-6805页

作者： Frederik Zahn Tobias Kleinert Veit Hagenmeyer Institute for Automation and Applied Informatics Karlsruhe Institute of Technology Karlsruhe Germany Chair of Process Control Engineering RWTH Aachen University Aachen Germany

Recently, Flat Hybrid Automata (FHA) were introduced as a new model class of hybrid systems. In order to answer the evident question of an optimal operation of the new class of FHA, a well-posed optimization problem definition for FHA is presented. This problem formulation also includes costs on discrete–state transitions and switching actions. We present a solution for a reduced problem: FHA with autonomous switching. For these, a new algorithm is introduced which solves the optimal control problem. The application of this optimization algorithm is shown with an electrical network example.

关键词： Flat hybrid automata differential flatness hybrid switched systems modeling optimal control of hybrid systems

来源：评论

学校读者我要写书评

暂无评论

Approaches for Solution-Processed Encapsulation of Printed Medical Wearable Devices

引用

Current Directions in Biomedical Engineering 2020年第3期6卷

作者： Chen, Zehua Gengenbach, Ulrich Koker, Liane Mansour, Maher Institute of Automation and Applied Informatics (IAI) Karlsruhe Institute of Technology (KIT) Karlsruhe Germany German-Jordanian University Amman Jordan

Wearable medical devices offer a great opportunity to monitor human vital signs to improve healthcare. The use of printing technologies is a promising approach to fabricate the wearables. An encapsulation must be applied to achieve longterm stability and reliability of the printed wearables. In this paper, we discuss the encapsulation requirements of printed wearable medical devices. Different encapsulation approaches are illustrated by means of various examples. Thereby, the focus lies upon solution-processed encapsulation, including the compatible materials and printing technologies. © 2020 by Walter de Gruyter Berlin/Boston.

关键词： Medical applications

来源：评论

学校读者我要写书评

暂无评论

CAD2Real: Deep learning with domain randomization of CAD data for 3D pose estimation of electronic control unit housings

arXiv

引用

arXiv 2020年

作者： Bäuerle, Simon Barth, Jonas de Menezes, Elton Tavares Steimer, Andreas Mikut, Ralf Institute for Automation and Applied Informatics Karlsruhe Institute of Technology Karlsruhe Germany Robert Bosch GmbH Germany

Electronic control units (ECUs) are essential for many automobile components, e.g. engine, anti-lock braking system (ABS), steering and airbags. For some products, the 3D pose of each single ECU needs to be determined during series production. Deep learning approaches can not easily be applied to this problem, because labeled training data is not available in sufficient numbers. Thus, we train state-of-the-art artificial neural networks (ANNs) on purely synthetic training data, which is automatically created from a single CAD file. By randomizing parameters during rendering of training images, we enable inference on RGB images of a real sample part. In contrast to classic image processing approaches, this data-driven approach poses only few requirements regarding the measurement setup and transfers to related use cases with little development effort. Copyright © 2020, The Authors. All rights reserved.

关键词： Control systems

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：