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A Self-adapting Pixel Antenna - Substrate Lens System for Infrared Frequencies

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Periodica Polytechnica Electrical Engineering and Computer S...

Periodica Polytechnica Electrical Engineering and Computer Science 2025年第1期69卷 14-25页

作者： Shubbar, Mustafa Rakos, Balázs Department of Automation and Applied Informatics Faculty of Electrical Engineering and Informatics Budapest University of Technology and Economics Műegyetem rkp. 3. BudapestH-1111 Hungary

In this work, we propose a concentrator lens - antenna arrangement, potentially suitable for infrared sensing and energy harvesting rectenna systems. The structure consists of a pixel antenna, self-adapting for the direction of the incident infrared radiation, and a concentrator lens, both optimized for the mid-infrared spectrum. The silicon substrate lens is situated above the pixel antenna, enabling the concentration of the incident light on the antenna;silicon was chosen due to its transparency in the IR spectrum. We examine how various parameters of the lens, in conjunction with the different states of the pixel antenna, affects the performance of the system. The simulations show that the gain of the arrangement increases considerably in correlation with the radius of the lens. The results suggest that the energy conversion efficiency of infrared rectenna systems can be enhanced by several orders of magnitude with the utilization of the proposed arrangement. © 2025 Budapest University of Technology and Economics. All rights reserved.

关键词： Rectennas

Safe switching model-free Value Iteration for general nonlinear systems

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IEEE Access 2025年

作者： Lala, Timotei University Politehnica Timisoara Faculty of Automation and Computers Departament of Automation and Applied Informatics Timisoara300223 Romania

This paper presents a solution to the well-known challenge of ensuring safety guarantees during the evaluation of controllers tuned using Value Iteration techniques on real systems. We propose an approach called Safe Switching Model-Free Value Iteration (SSMFVI), which guarantees both stability and safety of a system in closed loop with a controller optimized with Value Iteration (VI) in a model-free manner. A state dependent controlled switching rule is designed to alternate between the VI tuned controller and an initial known stabilizing admissible controller. Using the initial controller Q function and the one continuously actualized during learning, the stability of the switching mechanism in closed loop with the system is derived using the Multiple Lyapunov Functions (MLF) framework. To guarantee safety during runtime operation, the systems maximum one-step transition is estimated. Then, the switching control signal is designed to select the MFVI controller only in the region of the state space both covered by the collected transitions during the exploration phase and with the distance to the unsafe set greater than the aforementioned maximum one-step transition. This subset of the state space is determined using single-class Support Vector Machine (SVM) classification. The method includes mechanisms for early instability detection and chattering reduction near switching surfaces. The validation is conducted on a linear first order system for visualization of the results and on a real Electric Braking System circuit system, demonstrating the effectiveness of the proposed control method. © 2013 IEEE.

关键词： Optimal control systems

COMMANDER: A robust cross-machine multi-phase Advanced Persistent Threat detector via provenance analytics

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Journal of Information Security and Applications 2025年 91卷

作者： Liu, Qi Bao, Kaibin Hagenmeyer, Veit Institute for Automation and Applied Informatics Karlsruhe Institute of Technology Eggenstein-Leopoldshafen76344 Germany

Intrusion detection systems (IDS) have traditionally focused on identifying malicious behaviors caused by malware undertaking a series of suspicious activities within a short time. Facing Advanced Persistent Threat (APT) actors employing the so-called low-and-slow strategy, defenders are often blindsided by the poor performance of these IDS. Provenance-based IDS (PIDS) emerged as a promising solution for reducing false alerts, detecting true attacks, and facilitating attack investigation, by causally linking and contextualizing indicative system activities in provenance graphs. However, most existing PIDS can detect neither multi-phase nor cross-machine APT attacks, enabled by persistence and lateral movement techniques, respectively. In the present work, we propose a new PIDS called COMMANDER, which is, to our knowledge, the first system capable of detecting cross-machine multi-phase APT attacks. Further, COMMANDER targets several evasion attacks that can bypass existing PIDS, making it more robust. In addition, COMMANDER can perform whole network tracing for cross-machine multi-phase APT attacks across an industrial-sector organization, for which we additionally develop parsers for system logs of popular industrial controllers. We also develop detection rules with a reference to MITRE's knowledge base for industrial control systems. Our evaluations show that COMMANDER accurately detects attacks, outperforms existing detection systems, and delivers succinct and insightful attack graphs. © 2025

关键词： Computer forensics

Learning the Frequency Dynamics of the Power System Using Higher-order Dynamic Mode Decomposition

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arXiv 2025年

作者： Li, Xiao Wen, Xinyi Schäfer, Benjamin Institute for Automation and Applied Informatics Karlsruhe Institute of Technology Karlsruhe Germany

The increasing penetration of renewable energy sources, characterised by low inertia and intermittent disturbances, presents substantial challenges to power system stability. As critical indicators of system stability, frequency dynamics and associated oscillatory phenomena have attracted significant research attention. While existing studies predominantly employ linearized models, our findings demonstrate that linear approximations exhibit considerable errors when predicting frequency oscillation dynamics across multiple time scales, thus necessitating the incorporation of nonlinear characteristics. This paper proposes a data-driven approach based on higher-order dynamical mode decomposition (HODMD) for learning frequency dynamics. The proposed method offers distinct advantages over alternative nonlinear methods, including no prior knowledge required, adaptability to high-dimensional systems, and robust performance. Furthermore, HODMD demonstrates superior capability in capturing system-wide spatio-temporal modes, successfully identifying modal behaviour that remains undetectable through standard Dynamic Mode Decomposition techniques. The efficacy of the proposed methodology is validated through comprehensive case studies on both IEEE 14-bus and WECC systems. Copyright © 2025, The Authors. All rights reserved.

关键词： Dynamic mode decomposition

ECONOMY AND SUSTAINABILITY ANALYSIS WITH A NOVEL MODULAR CONFIGURABLE MULTI-MODAL WHITE-BOX BUILDING MODEL

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arXiv 2025年

作者： Cheng, Haozhen Hagenmeyer, Veit Çakmak, Hüseyin K. Institute for Automation and Applied Informatics Karlsruhe Institute of Technology Karlsruhe76131 Germany

This paper presents a novel modeling approach for building performance simulation, characterized as a white-box model with a high degree of modularity and flexibility, enabling direct integration into complex large-scale energy system co-simulations. The introduced model is described in detail, with a focus on its modular structure, and proposes various configurations that include various building insulation, heating methods, occupancy patterns, and weather data to analyze different scenarios, and the energy consumption, CO2 emissions, and heating costs are compared and analyzed across 36 introduced scenarios. The thermodynamic behavior of the model is shown to be consistent with real-world conditions, and the comparison of the scenarios concludes that the use of heat pumps for indoor heating in well-insulated buildings has significant economic and sustainability benefits, whereas the use of natural gas-fueled boilers is more cost-effective for buildings with low energy ratings. Copyright © 2025, The Authors. All rights reserved.

关键词： Sustainable building

NEW CO-SIMULATION VARIANTS FOR EMISSIONS AND COST REDUCTION OF SUSTAINABLE DISTRICT HEATING PLANNING

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arXiv 2025年

作者： Cheng, Haozhen Buccoliero, Verena Kocher, Alexander Hagenmeyer, Veit Çakmak, Hüseyin K. Institute for Automation and Applied Informatics Karlsruhe Institute of Technology Karlsruhe76131 Germany

Classical heating of residential areas is very energy-intensive, so alternatives are needed, including renewable energies and advanced heating technologies. Thus, the present paper introduces a new methodology for comprehensive variant analysis for future district heating planning, aiming at optimizing emissions and costs. For this, an extensive Modelica-based modeling study comprising models of heating center, heat grid pipelines and heating interface units to buildings are coupled in co-simulations. These enable a comparative analysis of the economic feasibility and sustainability for various technologies and energy carriers to be carried out. The new modular and highly parameterizable building model serves for validation of the introduced heat grid model. The results show that bio-methane as an energy source reduces carbon equivalent emissions by nearly 70% compared to conventional natural gas heating, and the use of hydrogen as an energy source reduces carbon equivalent emissions by 77% when equipped with a heat pump. In addition, the use of ground source heat pumps has a high economic viability when economic benefits are taken into account. The study findings highlight the importance of strategic planning and flexible design in the early stages of district development in order to achieve improved energy efficiency and a reduced carbon footprint. Copyright © 2025, The Authors. All rights reserved.

关键词： Carbon capture and utilization

A Review on Novel District Concepts in Urban Energy Systems

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SSRN

SSRN 2025年

作者： Galenzowski, Johannes Waczowicz, Simon Çakmak, Hüseyin K. Tajalli-Ardekani, Erfan Beichter, Sebastian Ekin, Ömer Mikut, Ralf Hagenmeyer, Veit Karlsruhe Institute of Technology Kaiserstraße 12 Karlsruhe76131 Germany Institute for Automation and Applied Informatics Germany

Recently, there has been a surge of interest in novel concepts for jointly operating devices in urban areas in clusters, motivated by their potential to support decarbonization, enhance power system flexibility, and promote energy justice. Such clusters encompass multiple devices or buildings but operate on a smaller scale than cities. Examples include Renewable Energy Communities and Positive Energy Districts. These Novel District Concepts (NDCs) integrate interdisciplinary urban planning and social sciences terminology into the energy domain. However, these concept’s precise definitions and practical implementation lack consistency, leading to conceptual ambiguities in the literature. ... (see comment to the editor) © 2025, The Authors. All rights reserved.

关键词： Clean energy

Optimum settings for PID control of nonlinear systems

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arXiv 2025年

作者： Vrabel, R. Slovak University of Technology in Bratislava Institute of Applied Informatics Automation and Mechatronics Bottova 25 Trnava917 01 Slovakia

This paper investigates the application of piecewise linear approximation for the control of nonlinear systems, particularly focusing on the effective linearization of systems modeled by the differential equation y(n) + f(y, y', . . . , y(n-1)) = u(t). We explore the use of PID controllers in conjunction with piecewise linearization, tackling the challenges of nonlinear dynamics by dividing the function f into smaller regions or simplices over a predefined compact set D ⊂ Rn. The parameter h determines the number of linear pieces and influences the approximation accuracy. By increasing h, the system's behavior increasingly mirrors that of the original nonlinear system, leading to enhanced performance of the control system. The paper further discusses the optimization of PID controller parameters through the Particle Swarm Optimization method, with a focus on minimizing the ITAE and ISO criteria. Numerical simulations demonstrate the efficacy of the approach, highlighting the trade-off between computational complexity and approximation accuracy in the context of control system *** Codes 93C10 © 2025, CC BY.

关键词： Three term control systems

A simulation Approach to Improve the Performance of a Sub-assembly Zone in Automotive Industry

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A simulation Approach to Improve the Performance of a Sub-as...

Cybernetics & informatics (K&I)

作者： Monika Herchlová Pavel Važan Fedor Burčiar Martin Juhás Bohuslava Juhásová Dominik Čambál Institue of Applied Informatics Automation and Mechatronics Faculty of Materials Science and Technology in Trnava Slovak University of Technology in Bratislava Trnava Slovakia

ISBN: (数字)9798331541811

ISBN: (纸本)9798331541828

This research summarises how the creation of a virtual model and experimentation in a virtual environment provided valuable support in bottleneck identification and offered actionable insights for value adjustments to process performance within a sub-assembly *** research extends on the current knowledge of how modelling and simulation have become indispensable in optimizing industrial processes. Presented in the paper is a subassembly zone with a planned change in automated guided vehicle (AGV) track length and the layout of the zone. After the verified and validated model was experimented with, it provided satisfactory values to modify the parameters of a manufacturing sub-assembly zone, positively affecting its *** proposed method for finding the required measures to meet the expectations was to conduct a simulation study before the sub-assembly zone’s parameters were to be changed. A model of the system was developed and digitalized into the simulator environment, providing a comprehensive visual representation of performance indicators of the system dynamics. Its conception and operation unveiled the bottlenecks as regards vehicle speed and program and posts’ processing times. Afterwards, experiments were conducted with the goal of finding the appropriate value adjustments under given conditions from the stakeholders. The contribution of this work is reduction in operator count and post’s cycle times with approximation of cycle time to the rate of the shop floor cadence, the increase in the overall throughput of the zone by 1.29 %, identification of a shortcoming in the AGV program and appropriate speed adjustments.

关键词： Measurement Visualization Remotely guided vehicles System dynamics Layout Virtual environments Throughput Manufacturing Stakeholders Optimization