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2025 International Technical Meeting of The Institute of Navigation, ITM 2025

作者： Kang, Minjae Jeong, Hojoon Park, Jaeuk Kee, Changdon Interdisciplinary Program in Space Systems Seoul National University Korea Republic of Department of Aerospace Engineering and SNU-IAMD Seoul National University Korea Republic of

ISBN: (纸本)9780936406404

This study presents the design of a lunar navigation satellite constellation to provide global Positioning, Navigation, and Timing (PNT) services, beginning with coverage at the lunar South Pole and gradually expanding to the entire Moon. Building upon an initial Phase 1 constellation that ensures reliable PNT at the South Pole, Phase 2 extends this coverage globally, addressing the challenges of providing continuous navigation services across the lunar surface. The proposed Hybrid Frozen Constellation combines Elliptical Lunar Frozen Orbits (ELFOs) and Circular Frozen Orbits to offer a cost-effective and efficient solution, leveraging the stable South Pole-oriented orbits while minimizing the number of satellites required. The study explores various satellite configurations to achieve best Position Dilution of Precision (PDOP) across the entire lunar surface. By carefully analyzing the geometry and phasing of the orbits, the design aims to maximize navigation performance while reducing the satellite volume. Simulation results confirm that the full constellation achieves over 98% PDOP availability, ensuring PDOP values remain below 6, meeting the GPS standards for reliable navigation. This performance guarantees accurate positioning, even in challenging regions of the lunar surface, and supports both robotic and crewed exploration missions. © 2025 Proceedings of the International Technical Meeting of The Institute of Navigation, ITM. All rights reserved.

关键词： Lunar missions

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Producing the best for aerospace and defense: systems architecting and engineering program at the University of Southern California

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Astropolitics 2011年第2-3期9卷 165-172页

作者： Madni, Azad M. Systems Architecting and Engineering Program University of Southern California Los Angelos CA 90089-0193 3715 McClintock Avenue GER 240 United States

The systems Architecting and engineering Graduate program at the University of Southern California began as a graduate educational program primarily focused on aerospace and defense. Founded by Eberhardt Rechtin in 1987, the program today is a science, technology, engineering, and math success story in terms of its growth, teaching approach, and contributions to the engineering workforce in aerospace and defense. systems Architecting and engineering is a multidisciplinary field that cuts across science, technology, engineering, and math, and draws on concepts from psychology, sociology, biology, and economics. This paper presents the genesis of this program, its teaching philosophy, its evolution in response to the demands of the marketplace, and its vision for the future. © Taylor & Francis Group, LLC.

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A Multi-String Photovoltaic Current-Voltage (I-V) Curve Tracer 1

A Multi-String Photovoltaic Current-Voltage (I-V) Curve Trac...

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1st engineering and Science International Conference 2024, ESIC 2024

作者： Rivai, A. Erixno, O. Rahim, N.A. Elias, M.F.M. Jamaludin, J. Ramadhani, F. Universiti Malaya Kuala Lumpur Malaysia Energy systems engineering program School of Electrical Engineering Telkom University Bandung Indonesia Centre of Excellent Sustainable Energy and Climate Change Telkom university Bandung Indonesia

This paper presents the design and the development of multi-string I-V curve tracer for photovoltaic (PV) strings. It uses a capacitive load and double pole relay to measure the I-V characteristics of a multiple PV strings simultaneously. The prototype is developed using a PIC18F4550 micro-controller and a graphical user interface GUI designed using Microsoft's Visual Studio software. The I-V characteristics of the PV string are displayed on LCD (Liquid Crystal Display) and computer. The performance and functionality of the proposed I-V curve tracer have been tested using four PV strings. The experimental test shows that the proposed I-V tracer can measure and display the I-V characteristic of each PV string smoothly in the normal and shading conditions. © 2025 Institute of Physics Publishing. All rights reserved.

关键词： Graphical user interfaces

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Ecology, Spatial Structure, and Selection Pressure Induce Strong Signatures in Phylogenetic Structure

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Artificial life 2025年第2期31卷 129-152页

作者： Moreno, Matthew Andres Rodriguez-Papa, Santiago Dolson, Emily University of Michigan Department of Ecology and Evolutionary Biology Center for the Study of Complex Systems Michigan Institute for Data and AI in Society Michigan State University Department of Computer Science and Engineering Michigan State University Department of Computer Science and Engineering Program in Ecology Evolution Behavior

Evolutionary dynamics are shaped by a variety of fundamental, generic drivers, including spatial structure, ecology, and selection pressure. These drivers impact the trajectory of evolution and have been hypothesized to influence phylogenetic structure. For instance, they can help explain natural history, steer behavior of contemporary evolving populations, and influence the efficacy of application-oriented evolutionary optimization. Likewise, in inquiry-oriented Artificial Life systems, these drivers constitute key building blocks for open-ended evolution. Here we set out to assess (a) if spatial structure, ecology, and selection pressure leave detectable signatures in phylogenetic structure;(b) the extent, in particular, to which ecology can be detected and discerned in the presence of spatial structure;and (c) the extent to which these phylogenetic signatures generalize across evolutionary systems. To this end, we analyze phylogenies generated by manipulating spatial structure, ecology, and selection pressure within three computational models of varied scope and sophistication. We find that selection pressure, spatial structure, and ecology have characteristic effects on phylogenetic metrics, although these effects are complex and not always intuitive. Signatures have some consistency across systems when using equivalent taxonomic unit definitions (e.g., individual, genotype, species). Furthermore, we find that sufficiently strong ecology can be detected in the presence of spatial structure. We also find that, while low-resolution phylogenetic reconstructions can bias some phylogenetic metrics, high-resolution reconstructions recapitulate them faithfully. Although our results suggest a potential for evolutionary inference of spatial structure, ecology, and selection pressure through phylogenetic analysis, further methods development is needed to distinguish these drivers' phylometric signatures from each other and to appropriately normalize phylogenetic metrics.

关键词： agent-based simulation Artificial Life Ecology evolution evolutionary dynamics phylogenetic analysis phylogeny metrics

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Development of a hanging pendulum thrust stand for pulsed plasma thrusters

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Acta Astronautica 2025年 234卷 368-386页

作者： Li, Yueh-Heng Lien, Wai-Cheng Liu, Sheng-Wen Institute of Space Systems Engineering National Cheng Kung University Tainan70101 Taiwan Department of Aeronautics and Astronautics National Cheng Kung University Tainan70101 Taiwan International Doctoral Degree Program on Energy Engineering National Cheng Kung University Tainan70101 Taiwan

Thrust stands are essential tools for evaluating the performance of propulsion systems, including Hall effect thrusters, ion thrusters, and pulsed plasma thrusters (PPTs). Our thrust stand supports a prototype weighing up to 0.8 kg and measures impulses from 150 to 550 μN s. It generates voltage oscillations with peaks between 5 mV and 35 mV, which, combined with NI voltage modules, minimizes weight constraints on the propulsion system while maintaining accurate measurements under low thrust-to-weight conditions. This design introduces a novel approach compared to conventional torsional thrust stands. By aligning the propulsion system's center of mass with the pendulum arm, we eliminate the need for spring torque. Instead, gravitational torque provides the necessary equivalent spring constant for damping. The eddy-current damper, featuring a copper plate, doubles as both a damping mechanism and a counterweight, allowing adjustments for different propulsion system weights. Unlike elastic pivots, this design avoids performance degradation from material fatigue or thermal effects. Challenges in the current system include non-linear spring and damping coefficients caused by PPT power cables and pulse-width errors during calibration. Future improvements will consist of cable feed-throughs to isolate vibrations without introducing unwanted coefficients. Additionally, the improvement aims to optimize the impulse generator's power supply to eliminate calibration errors caused by high-voltage pulse-width fluctuations. © 2025 The Authors

关键词： Ion propulsion

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Using the Guide to the systems engineering Body of Knowledge (SEBoK version 0.5) for Undergraduate System engineering program Assessment

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INCOSE International Symposium 2012年第1期22卷 2208-2220页

作者： Parnell, Gregory S. McCarthy, Daniel J. Hardman, Nicholas Yale, Gary E. United States Air Force Academy CO United States Military Academy West Point NY United States Department of Systems Engineering United States Military Academy West Point NY United States United States Air Force Academy CO United States Systems Engineering Program United States Air Force Academy CO United States

The draft of the Guide to the systems engineering Body of Knowledge (SEBoK version 0.5) was released in a wiki format on September 19, 2011. This paper uses SEBoK to assess the undergraduate systems engineering programs at the United States Military Academy at West Point and the United States Air Force Academy. Both ABET accredited engineering programs educate cadets in to be future leaders of character in their respective military services. We first review the rationale for undergraduate SE programs at the academies. Next, we compare the two programs including their program objectives, student outcomes, curricula, enrolments, and graduate assignments for each program. Then, we compare each of the SE programs to the SEBoK knowledge areas. We conclude with ideas on how undergraduate SE programs can use the SEBoK in planning and execution of their academic programs. © 2012 The Authors.

关键词： Students

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Phasor-FSTM:a new paradigm for multicolor super-resolution imaging of living cells based on fluorescence modulation and lifetime multiplexing

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Light(Science & Applications) 2025年第1期14卷 258-270页

作者： Luwei Wang Yue Chen Jiaqing Guo Xiaoyu Weng Wei Yan Jun Song Tong Ye Junle Qu Center for Biomedical Optics and Photonics&College of Physics and Optoelectronic Engineering Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong ProvinceShenzhen UniversityShenzhen518060China The Photonics Center of Shenzhen University Shenzhen UniversityShenzhen518060China Department of Bioengineering CU-MUSC Bioengineering ProgramClemson UniversityCharlestonSouth Carolina29634USA

Multicolor microscopy and super-resolution optical microscopy are two widely used techniques that greatly enhance the ability to distinguish and resolve structures in cellular *** methods have individually transformed cellular imaging by allowing detailed visualization of cellular and subcellular structures,as well as organelle ***,integrating multicolor and super-resolution microscopy into a single method remains challenging due to issues like spectral overlap,crosstalk,photobleaching,phototoxicity,and technical *** challenges arise from the conflicting requirements of using different fluorophores for multicolor labeling and fluorophores with specific properties for super-resolution *** propose a novel multicolor super-resolution imaging method called phasor-based fluorescence spatiotemporal modulation(Phasor-FSTM).This method uses time-resolved detection to acquire spatiotemporal data from encoded photons,employs phasor analysis to simultaneously separate multiple components,and applies fluorescence modulation to create super-resolution ***-FSTM enables the identification of multiple structural components with greater spatial accuracy on an enhanced laser scanning confocal microscope using a single-wavelength *** demonstrate the capabilities of Phasor-FSTM,we performed two-color to four-color super-resolution imaging at a resolution of~λ/5 and observed the interactions of organelles in live cells during continuous imaging for a duration of over 20 *** method stands out for its simplicity and adaptability,seamlessly fitting into existing laser scanning microscopes without requiring multiple laser lines for excitation,which also provides a new avenue for other super-resolution imaging technologies based on different principles to build multi-color imaging systems with the requirement of a lower budget.

关键词： resolution lifetime simplicity

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Numerical analysis of Ga gradient effects in ACIGS absorbers for high-efficiency tandem solar cells

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Optical and Quantum Electronics 2025年第3期57卷 1-19页

作者： Boukortt, Nour El I. Loureiro, Antonio Garcia Almutairi, Ohood A. Centro Singular de Investigación en Tecnoloxías Intelixentes University of Santiago de Compostela Santiago de Compostela Spain Department of Electronics and Information Systems Ghent University Technology Park 126 Zwijnaarde Belgium Department of Electronic and Electrical Engineering University College London LondonWC1E 6BT United Kingdom Energy Systems Program College of Engineering & Energy Abdullah Al Salem University Khaldiya Kuwait

Ag-alloyed Cu(In,Ga)Se₂ (ACIGS) is a promising material for the bottom subcell in tandem solar cell structures, offering a tunable bandgap that spans the optimal range for maximum efficiency;however, the bandgap widening of ACIGS thin films poses a significant challenge in enhancing their photocurrent. This paper investigates the impact of different grading profiles, specifically focusing on the 'hockey stick'/V-like Ga gradient–induced (GGI) profiles, on the performance of thin-film ACIGS cells. To enhance the physical understanding of these grading profiles we have used Silvaco TCAD tools to analyze how these profiles' depths, notch position, and slope affect the power conversion efficiency (PCE). The optimized ACIGS cell achieves a PCE of 25.80%, compared to 23.60% for the reference device. For the tandem configuration, we pair the optimized ACIGS bottom cell (double grading profile) with a perovskite top cell (band gap ~ 1.66 eV), achieving an overall efficiency of 30.26% under AM1.5G illumination. The obtained results highlight the critical role of Ga gradient profiles in enhancing the bottom cell's performance and stability. Additionally, we compare our results with existing studies to evaluate the broader impact of Ga compositional optimization on ACIGS-based solar cells. This work provides valuable insights into advanced grading strategies and helps us understand the physical behaviour of these high-performance tandem solar cells. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2025.

关键词： Silver alloys

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Effect of Sn addition on electrochemical activity of ribbons of Mg-Al-Ca anode material for rechargeable magnesium batteries fabricated by rapid solidification

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Keikinzoku/Journal of Japan Institute of Light Metals 2025年第1期75卷 9-13页

作者： Fukuta, Yoshitaka Kikura, Kensei Tsukeda, Tadayoshi Aida, Tetsuo Tabata, Hironobu Kurihara, Hideki Suzuki, Mayumi Program of Materials Science and Engineering Studies in Science and Engineering Graduate School of Science and Engineering University of Toyama 3190 Gofuku Toyama-shi Toyama930-8555 Japan Graduate School of Science and Engineering University of Toyama Toyama-shi Toyama Japan Faculty of Sustainable Design Academic Assembly University of Toyama Toyama-shi Toyama Japan CHUETSU METAL WORKS CO. LTD. Nakaniikawagun Toyama Japan Saitama Industrial technology Center Kawaguchi-shi Saitama Japan Department of Mechanical Systems Engineering Faculty of Engineering Toyama Prefectural University Imizu-shi Toyama Japan

Magnesium-based batteries are potential candidates for next-generation rechargeable batteries due to the divalent nature of magnesium cations and the natural abundance of magnesium resources. In this study, the electrochemical activity of Mg-6mass%Al-3mass%Ca anodes combined with Sn was investigated. Thin ribbons of the anode specimens were prepared by a single-roll rapid solidification method. The results showed that the electrochemical activity increased upon adding 1 mass% Sn, while it decreased for 3 mass% Sn. Based on the results of an X-ray diffraction analysis, the addition of Sn led to the formation of Mg2Sn and Ca2Sn phases, which increased the lattice distortion. Scanning electron microscopy observations indicated that these secondary phases were homogeneously distributed for 1 mass% Sn addition, while they were coarsely distributed for 3 mass% Sn. © 2025 The Japan Institute of Light Metals.

关键词： X ray diffraction analysis

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Large Pre-Trained Models and Few-Shot FineTuning for Virtual Metrology: A Framework for Uncertainty-Driven Adaptive Process Control in Semiconductor Manufacturing

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IEEE Transactions on Automation Science and engineering 2025年 22卷 15351-15370页

作者： Lin, Chin-Yi Tseng, Tzu-Liang Emon, Solayman Hossain Tsai, Tsung-Han University of Texas at EL Paso Department of Industrial Manufacturing and Systems Engineering Texas El PasoTX79968 United States Computational Science Program University of Texas at EL Paso Texas El PasoTX79968 United States National Taipei University of Business Institute of Information and Decision Sciences Taipei10051 Taiwan

High-precision wafer metrology poses significant cost and throughput challenges in modern semiconductor manufacturing, where frequent process changes and recipe variations demand highly adaptive and scalable solutions. In this paper, we present a Generative-FewShot-Active Virtual Metrology (GFA-VM) framework that unifies large-scale generative modeling, few-shot fine-tuning, and uncertainty-driven active sampling into a single, data-centric system. A foundational generative model, built on a hybrid architecture of Transformer networks and Variational Autoencoders (VAEs), learns diverse sensor characteristics in an offline stage without relying on extensive labeled data. During online inference, the model produces both wafer quality predictions and predictive uncertainties;samples exceeding a dynamic uncertainty threshold are selected for physical measurement and few-shot model recalibration. This selective sampling both reduces measurement costs and adapts rapidly to new process conditions (e.g., novel recipes or equipment upgrades), requiring only a handful of freshly labeled wafers. The paper further addresses the long-term stability of the system through a self-updating mechanism that adjusts the uncertainty threshold when distributional shifts occur. Empirical evaluations confirm that our GFA-VM approach achieves state-of-the-art accuracy while significantly reducing metrology overhead compared to conventional virtual metrology methods. Additionally, rigorous theoretical analyses—including proofs of convergence and label cost bounds—demonstrate the reliability of using a generative foundation plus meta-learning technique. By fostering on-demand adaptation within a closedloop framework, GFA-VM offers a comprehensive, scalable strategy for next-generation semiconductor process control. © 2004-2012 IEEE.

关键词： Semiconductor device measurement Metrology Semiconductor device modeling Semiconductor process modeling Uncertainty Adaptation models Accuracy Data models Predictive models Manufacturing

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