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Investigation of an iterative Method for Finding of Currents, Voltages and Termination Impedances of PCB Traces Based on Phase-less Near-field Data

Investigation of an Iterative Method for Finding of Currents...

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IEEE International Joint Symposium on Electromagnetic Compatibility (EMC), Signal and Power Integrity (SIPI) and EMC Europe

作者： Nowak, Robert Frei, Stephan TU Dortmund Univ On Board Syst Lab Dortmund Germany

ISBN: (纸本)9781665448888

The evaluation of near-field data can be an effective way to analyze EMI sources. In contrast to antenna measurements, near-field techniques can determine the emitted field without special requirements on the measurement environment. Moreover, critical sources can be found when current distributions can be identified. Therefore, current reconstruction methods for PCB traces were developed. With additional voltage information the termination impedances of the traces can be found. The known phase-less approaches suffers from different limitations, e.g., non-unique reconstruction results. In this paper, the necessary conditions for a unique reconstruction are discussed by investigating simulated phase-less near-field data. Based on these findings, measured near-field data of a PCB trace is evaluated, and the successful retrieval of the phase information is shown. Additionally, reconstructed voltage distributions are presented and compared to measurement data.

关键词： EMI near-field source reconstruction iterative algorithm phase retrieval current reconstruction method

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iterative algorithms for the input and state recovery from the approximate inverse of strictly proper multivariable systems

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MECHANICAL SYSTEMS AND SIGNAL PROCESSING 2018年 101卷 320-337页

作者： Chen, Liwen Xu, Qiang Lamar Univ Dan F Smith Dept Chem Engn POB 10053 Beaumont TX 77710 USA

This paper proposes new iterative algorithms for the unknown input and state recovery from the system outputs using an approximate inverse of the strictly proper linear time invariant (LTI) multivariable system. One of the unique advantages from previous system inverse algorithms is that the output differentiation is not required. The approximate system inverse is stable due to the systematic optimal design of a dummy feedthrough D matrix in the state-space model via the feedback stabilization. The optimal design procedure avoids trial and error to identify such a D matrix which saves tremendous amount of efforts. From the derived and proved convergence criteria, such an optimal D matrix also guarantees the convergence of algorithms. Illustrative examples show significant improvement of the reference input signal tracking by the algorithms and optimal D design over non-iterative counterparts on controllable or stabilizable LTI systems, respectively. Case studies of two Boeing-767 aircraft aerodynamic models further demonstrate the capability of the proposed methods. (C) 2017 Elsevier Ltd. All rights reserved.

关键词： Approximate inverse Dummy D matrix iterative algorithm Stability Strictly proper

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Numerical and Experimental correlation on Electro-Hydro Dynamic system for Small Aircraft propulsion

Numerical and Experimental correlation on Electro-Hydro Dyna...

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AIAA Propulsion and Energy Forum / IEEE Electric Aircraft Technologies Symposium (EATS)

作者： Loehrmann, Antoine Rivenc, Jean Peres, Gilles Dufour, Guillaume Rogier, Francois Kourtzanidis, Konstantinos Airbus SAS Cent Res & Technol Div 18 Rue Marius Terce FR-31025 Toulouse France Off Natl Etud & Rech Aerosp French Aerosp Lab F-31000 Toulouse France Ctr Res & Technol Hellas Chem Proc & Energy Resources Inst Thessaloniki Greece Airbus Cent R&T Toulouse France

ISBN: (数字)9781624106118

ISBN: (纸本)9781624106118

In this study, we explored numerical and experimental tools, in order to study phenomena linked toEHD (Electro Hydro Dynamics), for the purpose of thrust applications for MAV (Micro Air Vehicles). A canonical case was considered, namely a wire of 50µm radius with a DC positive voltage, in front of a NACA 2412 profile at ground *** numerical approach consisted of self-consistently solving the ionization and drift phases, by combining a Poisson solver, for the electric field computation, and a plasma-fluid solver in an iterative process, until steady state was reached. The code COPAIER, developed by ONERA, was used for this *** discharge current was computed for several voltages between the electrodes, and the EHD force was injected into a CFD solver, in order to retrieve the ionic wind characteristics. An experimental study was also performed, by measuring the current-voltage characteristics. The latter was compared to numerical results. A deviation of less than 20% was obtained, as long as the discharge remained in the corona regime. Given the complexity of the studied phenomena, this result was better than our expectation. The corona to streamer transition was not studied, but could be taken into account by COPAIER. At last, the effect of pressure was experimentally studied, in the range between atmospheric pressure and 700mbars. The derating factor was evaluated between these two conditions: in our case, it was necessary, either to reduce the voltage by 10%, or to increase the electrodes gap by 30%.

关键词： Micro Air Vehicle NACA 2412 Aircraft Propulsion Electro Hydro Dynamics Numerical Modeling Poisson's Equation Finite Element Formulation Velocity Profiles Dielectric Barrier Discharge iterative algorithm

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An iterative model-free feature screening procedure: Forward recursive selection

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KNOWLEDGE-BASED SYSTEMS 2022年 246卷

作者： Xia, Siwei Yang, Yuehan Civil Aviat Flight Univ China Sch Sci Deyang Peoples R China Cent Univ Finance & Econ Sch Stat & Math Beijing Peoples R China

Many researchers have studied the combinations of machine learning techniques and traditional statistical strategies, and proposed effective procedures for complicated data sets. Yet, there is still some lack of running time and prediction accuracy. In this paper, we propose an iterative feature screening procedure, named forward recursive selection. We combine the random forest and forward selection to address the model-based limitations and the related requirements. We also use the forward strategy with a limited number of iterations to improve the computational efficiency. To provide the theoretical guarantees of this method, we calculate functions of the permutation importance of this algorithm in different models and data with group structures. Numerical comparisons and empirical analysis support our results, and the proposed procedure works well. (c) 2022 Elsevier B.V. All rights reserved.

关键词： Random forest Forward selection iterative algorithm Statistical modeling

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UAV-Assisted Data Rate Maximization Under 3-D Channel Model 93

UAV-Assisted Data Rate Maximization Under 3-D Channel Model

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IEEE 93rd Vehicular Technology Conference (VTC-Spring)

作者： Lin, Jianzhen Pan, Cunhua He, Chunlong Wang, Kezhi Shenzhen Univ Guangdong Key Lab Intelligent Informat Proc Shenzhen Peoples R China Queen Mary Univ London Sch Elect Engn & Comp Sci London England Northumbria Univ Dept Comp & Informat Sci Newcastle Upon Tyne Tyne & Wear England

ISBN: (纸本)9781728189642

This paper investigates a UAV-enabled wireless downlink system, where a UAV-enabled base station flies above a group of Internet of things devices (IoTDs) and transmits data to them. In order to ensure the fairness among all IoTDs, we jointly optimize scheduling association and UAV trajectory to maximize the minimal throughput of all IoTDs under the 3-dimensional (3-D) channel model. Meanwhile, to ensure the stability of communication, we aim to guarantee a high probability of line-of-sight (LoS) links between the UAV and all IoTDs. The optimization problem is non-convex and we propose an iterative algorithm based on the block coordinate descent and successive convex approximation to solve it. Furthermore, we show the convergence of the algorithm through simulations. It is shown that the proposed algorithm achieves higher data rate than the traditional scheme without guaranteeing the LoS probability.

关键词： UAV communication trajectory iterative algorithm

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Pumping energy consumption minimization through simulation-optimization modelling

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JOURNAL OF HYDROLOGY 2022年第PartA期612卷

作者： Mallios, Zisis Siarkos, Ilias Karagiannopoulos, Panagiotis Tsiarapas, Athanasios Aristotle Univ Thessaloniki Sch Civil Engn Thessaloniki Greece

Global population growth and rapid economic development, along with modern goals for creating sustainable communities, render it necessary to focus on fundamental, finite resources such as water and energy. The interdependencies between water and energy are well known, while recently the interest of the scientific and policy communities on their dependency relationship has grown noticeably. On the one hand, water is used throughout the energy industry, while, on the other hand, the water system needs energy for collecting, pumping, supplying and treating water. Considering the latter case, great importance should be given when specifically referring to groundwater resources for the abstraction of which a large amount of energy is generally required. Therefore, minimizing the energy consumed for pumping groundwater is extremely important, and, for this reason, a large number of studies have been conducted in order to address this certain issue. However, most of the studies dealing with pumping cost minimization problems ignore the effect of friction losses on the total energy consumed for pumping and transporting groundwater. Under this perspective, the present paper attempts to highlight the importance of including friction losses in such type of problems by combining a simulation model and an optimization algorithm. Through the formulation of different setups of the same problem, that is the energy cost minimization for pumping groundwater from a system of wells and transporting it through transmission lines, it was found that only when including friction losses in the optimization problem, all managed wells are being used for pumping water, thus resulting in more reasonable and workable solutions.

关键词： Water-energy nexus Groundwater management Pumping energy minimization Friction losses iterative algorithm Combined simulation-optimization

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Field and Numerical Investigations of Wave Effects on Groundwater Flow and Salt Transport in a Sandy Beach

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WATER RESOURCES RESEARCH 2022年第11期58卷 e2022WR032077-e2022WR032077页

作者： Yu, Shengchao Wang, Chaoyue Li, Hailong Zhang, Xiaolang Wang, Xuejing Qu, Wenjing Southern Univ Sci & Technol Sch Environm Sci & Engn State Environm Protect Key Lab Integrated Surface Shenzhen Peoples R China Univ Hong Kong Dept Earth Sci Hong Kong Peoples R China Hebei GEO Univ Hebei Ctr Ecol & Environm Geol Res Sch Water Resources & Environm Shijiazhuang Hebei Peoples R China

Coastal dynamic forces, such as waves and tides, altogether drive groundwater circulation and salt transport in the intertidal zone. However, few numerical studies have ever considered the combined effects of waves and tides. In this study, the fluctuations of wave height are integrated with tidal level together using an iterative least squares fitting method, in which the wave height can be acquired from measured sea level in the surf zone, and this fitted wave height is further verified by wind speed. Groundwater flow and salt transport were then simulated using the MARUN code to evaluate the impacts after considering wave effect. The simulated equivalent freshwater head and salinity of the model with wave effect presented less difference with the measured data compared with the simulated results of the model without wave effect. After incorporating the wave effect in a model, submarine groundwater discharge (SGD) was increased, among which recirculated SGD grew more rapidly than the fresh, leading to the proportion of the fresh SGD accounting for a small proportion (1.1%). The water influx and efflux rates increased greatly especially during the period of high wave height. Most of the influx occurred in the intertidal zone, while a considerable amount of efflux occurred in the subtidal zone. The iterative algorithm to separate the wave height from the mixed field data can be employed to identify and quantify the respective effects of tides and the combined effects of waves and tides on the density-dependent beach groundwater flow.

关键词： coastal beach iterative algorithm tidal level wave height wave setup

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iterative synthesis of binary inline Fresnel holograms for high-quality reconstruction in divergent beams with DMD

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OPTICS AND LASERS IN ENGINEERING 2022年 150卷 106859-106859页

作者： Cheremkhin, Pavel A. Evtikhiev, Nikolay N. Krasnov, Vitaly V. Starikov, Rostislav S. Zlokazov, Evgenii Yu Natl Res Nucl Univ MEPhI Moscow Engn Phys Inst Kashirskoe Shosse 31 Moscow Russia

Aim of this paper is formation of single focused diffraction order using binary amplitude modulation for digital micromirror device (DMD) applications. This can be achieved by using inline binary Fresnel holograms with divergent incident beam. However, extremely low reconstruction quality and diffraction efficiency of such holograms, synthesized by conventional means, prevent it. Here, we present new iterative method of synthesis of binary inline Fresnel holograms with much higher image reconstruction quality and diffraction efficiency compared to standard technique of hologram direct calculation. Synthesis procedure was carried out in two stages. The first stage of the new technique is based on Gerchberg-Saxton algorithm with two principal differences. First one is that synthesized diffractive optical element (DOE) is not a phase one, but an inline binary amplitude hologram. And second difference is that incident wavefront is spherical instead of a plane one. The second stage includes an application of the direct search with random trajectory method which greatly improves hologram characteristics by consequent processing of every pixel in it. The resulting binary inline Fresnel holograms in comparison to ones, synthesized using direct calculation method, have up to 11 times lower reconstruction error and up to 4 times higher diffraction efficiency. Results of optical reconstruction using DMD also demonstrate superiority of the new approach.

关键词： Amplitude DOE Divergent beams DOE synthesis iterative algorithm Digital micromirror device Binarization

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Separable Synchronous Multi-Innovation Gradient-Based iterative Signal Modeling From On-Line Measurements

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IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT 2022年 71卷

作者： Xu, Ling Ding, Feng Zhu, Quanmin Jiangnan Univ Sch Internet Things Engn Minist Educ Key Lab Adv Proc Control Light Ind Wuxi 214122 Jiangsu Peoples R China Wuxi Vocat Inst Commerce Sch Internet Things Technol Wuxi 214153 Jiangsu Peoples R China Univ West England Dept Engn Design & Math Bristol BS16 1QY Avon England

This article is aimed to study the modeling problems of combinational signals or periodic signals. To overcome the computation complexity of modeling the signals with plenty of characteristic parameters, a parameter separation scheme is developed based on the different characteristic of the signals to be modeled. For the purpose of achieving high-accuracy performance and reducing complexity, two multi-innovation gradient-based iterative (MIGI) subalgorithms are presented by means of gradient search. In terms of the phenomenon that the coupling parameters lead to the inability of algorithms, a separable synchronous (SS) interactive estimation method is proposed to eliminate the coupling parameters and perform the signal modeling algorithm in accordance with the hierarchical principle. By means of simulation experiments, the proposed SS iterative signal modeling algorithm based on the moving batch data is used for estimating a power signal with three sine waves and a periodic square wave signal. The results demonstrate the effectiveness of the proposed method for modeling the combinational signals with multiple frequencies and other periodic signals. Since the proposed method combines real-time data sampling and iterative estimation, it can be used for on-line identification.

关键词： Computational modeling Estimation Data models Technological innovation Frequency estimation Real-time systems iterative algorithms Gradient search hierarchical identification iterative algorithm multi-innovation identification parameter estimation signal modeling

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Complex Variable Multi-phase Distribution System State Estimation Using Vectorized Code

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Journal of Modern Power Systems and Clean Energy 2020年第4期8卷 679-688页

作者： Izudin Džafić Rabih A.Jabr Tarik Hrnjić IEEE Faculty of Electrical Engineering University of SarajevoZmaja od Bosne bb 71000 SarajevoBosnia and Herzegovina Department of Electrical&Computer Engineering American University of BeirutP.O.Box 11-0236Riad El-Solh/Beirut 11072020Lebanon

With the advent of advanced energy management systems in distribution systems,there is a growing interest in rapid and reliable code for distribution system state estimation(DSSE)in large-scale *** DSSE methods employed in the industry are based on load scaling as they are well suited to the abundance of *** to the paucity of real-time measurements in DSSE,phasor measurement units(PMUs)have been proposed as a potential solution to increase the estimation ***,load scaling methodologies are not extendable for exploiting *** paper proposes a high-performance DSSE method that can handle the PMUs together with all common measurement types in industrial *** using Wirtinger calculus,the method operates entirely in complex variables and employs the latest version of advanced vector extensions(AVX-2)to reap the maximum potential of computer processing *** paper highlights the derivation of complex DSSE in matrix form,from which one can infer the implications on code reliability and *** results are reported on large-scale multi-phase distribution systems,and they are contrasted with a publicly available code for DSSE in real *** simulation results show that loop unrolling in AVX-2 contributes about a two-fold increase in the solving speed.

关键词： iterative algorithm least squares approximation optimization method distribution system state estimation

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