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Simulation Winter Conference

作者： Hee Chang Yoon Seung Heon Oh Jong Hun Woo Jung-Hoon Chung Hyuk Lee Sun-Ah Jung Department of Naval Architecture and Ocean Engineering Seoul National University Seoul Republic of Korea Department of System Dynamics Mechanical Systems Safety Research Division Korea Institute of Machinery & Materials Daejeon Republic of Korea

The Sortie Generation Rate (SGR) which refers to the number of sorties that can be generated per unit time, is a key indicator for evaluating the ability of an airbase. However, an aircraft carrier has many constraints compared to a land-based airbase, such as spatial and environmental constraints, making it difficult to apply existing land-based research to analyze aircraft carrier operations. On the other hand, the Sortie Generation Process (SGP) on an aircraft carrier is similar to a logistics/production system in that sorties are generated through aircraft. Therefore, this study proposes a framework for analyzing the SGP on an aircraft carrier using discrete event simulation and defines the classes that make up the simulation. In addition, SGP analysis simulations were implemented using the proposed framework and several experiments were performed to demonstrate the feasibility of applying the proposed framework in practice.

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Drift rate analysis of the KPLO X-band center frequency 74

Drift rate analysis of the KPLO X-band center frequency

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74th International Astronautical Congress, IAC 2023

作者： Lee, Hyeon-Cheol Moon, Sangman Cho, Young Ho Kim, Dae-Kwan Heo, Haeng-Pal Satellite Payload Research & Development Division Korea Aerospace Research Institute 169-84 Gwahak-ro Yuseong-gu Daejeon34133 Korea Republic of Satellite & Space Exploration Systems Engineering and Architecture R&D Division Korea Aerospace Research Institute 169-84 Gwahak-ro Yuseong-gu Daejeon34133 Korea Republic of Future Innovation Research Center Korea Aerospace Research Institute 169-84 Gwahak-ro Yuseong-gu Daejeon34133 Korea Republic of

A Rep. of Korea's first lunar orbiter, Korea Pathfinder Lunar Orbiter (KPLO), launched on August 5, 2022, cruised along its Ballistic Lunar Transfer (BLT) orbit for 4.5 months before successfully entering the Moon trajectory on December 17, 2022. Currently, the observation mission is scheduled to be carried out by December 2022 (can be extended to one more year) as it travels around the Moon every two hours, and various data observed from six payloads are being transmitted to the Earth. In this paper, it was identified that the KPLO's X-band transmitter (XTXU) affects the receiver according to the drift and drift rate of the transmitting center frequency (Fc) when transmitting observation data to the Earth's deep space antenna, and its impact was analysed by the orbits of cruise and mission phases. As a result, the drift rate in the cruise phase was small at 13 Hz/s, so the NASA's Deep Space Network (DSN) receivers and the Korea Deep Space Antenna (KDSA) receiver contacted the KPLO easily and received it well. However, in the mission phase, the drift rate increased up to 50 Hz/s and fluctuated twice a month due to the doppler frequency, stabilized after NASA adjusted window size of the symbol rate of DSN. On the other hand, unlike DSN, the KDSA receiver automatically matched the frequency change and received it well without changing the set value. Copyright © 2023 by the International Astronautical Federation (IAF). All rights reserved.

关键词： BLT drift rate DSN KDSA KPLO XTXU

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Radar Probing Optimization for Joint Beamforming and UAV Trajectory Design in UAV-Enabled Integrated Sensing and Communication

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IEEE Transactions on Communications 2024年

作者： Liu, Yaxi Mao, Wencan He, Boxin Huangfu, Wei Huang, Tianyao Zhang, Haijun Long, Keping University Of Science And Technology Beijing Beijing Advanced Innovation Center For Materials Genome Engineering Beijing Engineering And Technology Research Center For Convergence Networks And Ubiquitous Services School Of Computer And Communication Engineering Beijing100083 China University Of Science And Technology Shunde Innovation School Beijing China National Institute Of Informatics Information Systems Architecture Science Research Division Tokyo101-8430 Japan

Unmanned aerial vehicle (UAV)-enabled massive multiple-input-multiple-output (MIMO) integrated sensing and communication (ISAC) is an emerging platform to perform communication and sensing efficiently and flexibly. However, the existing works barely consider the radar probing tasks and neglect the benefits of the dedicated sensing signal. In this paper, we focus on joint optimizations in radar probing tasks, and a novel indicator is introduced, namely radar probing error. Two optimizations in radar probing tasks are established: i) joint transmit beamforming design for large-scale regional radar probing and communication task;ii) joint transmit beamforming and UAV trajectory design for communication enhancement and radar probing task. For the former task, we adopt both communication and novel sensing precoders to further support the MIMO radar. A semidefinite relaxation is utilized to relax the original non-convex problem, which is proven to be tight. For the latter task, we adopt block coordinate descent to alternately optimize the precoders and UAV trajectory where the fractional programming approach and successive convex approximation are further adopted. Experiment results testify the validation of the proposed methods for radar probing tasks in UAV-enabled MIMO ISAC. Moreover, results show the fundamental trade-off between the dual functions and reveal the effectiveness of the introduced sensing precoder. © 1972-2012 IEEE.

关键词： Unmanned aerial vehicles (UAV)

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The Effect of Surface Pit Treatment on Fretting Fatigue Crack Initiation

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Computers, Materials & Continua 2021年第1期66卷 659-673页

作者： Qingming Deng Xiaochun Yin Magd Abdel Wahab Department of Mechanics and Engineering Science Nanjing University of Science and TechnologyNanjing210094China Soete Laboratory Department of Electrical EnergyMetalsMechanical Constructions and SystemsFaculty of Engineering and ArchitectureGhent UniversityZwijnaarde9052Belgium Division of Computational Mechanics Ton Duc Thang UniversityHo Chi Minh CityVietnam Faculty of Civil Engineering Ton Duc Thang UniversityHo Chi Minh CityVietnam

This paper analyses the effect of surface treatment on fretting fatigue specimen by numerical simulations using Finite Element *** processed specimen refers to artificially adding a cylindrical pit to its contact ***,the contact radius between the pad and the specimen is controlled by adjusting the radius of the *** stress distribution and slip amplitude of the contact surface under different contact geometries are *** critical plane approach is used to predict the crack initiation life and to evaluate the effect of processed specimen on its fretting fatigue *** crack initiation life and angle can be predicted by the critical plane *** parameter is used to consider the effect of contact *** is shown that the crack initial position is dependent on the tensile *** same type of model,three kinds of critical plane parameters and Ruiz method provide very similar position of crack ***,the improved sample is much safer than the flat-specimen.

关键词： Finite element analysis surface pit stress distribution fretting fatigue critical plane approach

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Plugging Effect of Fine Pore Water in Opc and LC3 Paste During Accelerated Carbonation Monitored Via Single-Sided Nuclear Magnetic Resonance Spectroscopy

SSRN

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SSRN 2024年

作者： Cheng, Luge Kurihara, Ryo Ohkubo, Takahiro Kitagaki, Ryoma Suda, Yuya Teramoto, Atsushi Maruyama, Ippei Department of Architecture Graduate School of Engineering The University of Tokyo Tokyo113-8656 Japan Department of Applied Chemistry and Biotechnology Graduate School of Engineering Chiba University Chiba263-8522 Japan Division of Human Environmental Systems Graduate School of Engineering Hokkaido University Sapporo060-8628 Japan Department of Architecture Graduate School of Advanced Science and Engineering Hiroshima University Hiroshima739-8527 Japan Civil Engineering Program Faculty of Engineering University of the Ryukyus Okinawa903-0213 Japan Nagoya University Japan

This study focuses on the investigation of the influence of CO2 concentration on the carbonation process in cementitious paste using ordinary Portlandite cement and limestone-calcined clay cement, specifically on the water content distribution. Employing single-sided nuclear magnetic resonance spectroscopy for water profiling, we revealed that the water content of fine pores (interlayer space and gel pores) was consistent at the carbonation front under accelerated carbonation processes with CO2 concentrations of 5% and 1%, demonstrating the plugging effect where fine pore water governs the carbonation progress. This effect was absent under natural carbonation conditions because of the carbonation process was slower than drying. It was confirmed that the rate-determining mechanisms of natural and accelerated carbonation with CO2 concentrations greater than 1% were different. © 2024, The Authors. All rights reserved.

关键词： Carbonation

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Blockchain based Public Auditing Outsourcing for Cloud Storage 27

Blockchain based Public Auditing Outsourcing for Cloud Stora...

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27th IEEE International Conference on Parallel and Distributed systems, ICPADS 2021

作者： Lin, Yangfei Li, Jie Kimura, Shigetomo Zhang, Yongbing Ji, Yusheng Yang, Yang Graduate School of Systems and Information Engineering University of Tsukuba Ibaraki Tsukuba Japan Shanghai Jiao Tong University Department of Computer Science and Engineering Shanghai China University of Tsukuba Faculty of Engineering Information and Systems Ibaraki Tsukuba Japan National Institute of Informatics Information Systems Architecture Research Division Tokyo Japan School of Mathematics and Computer Science Fuzhou University Fuzhou China

ISBN: (纸本)9781665408783

Cloud storage services offer flexible, convenient solutions for business and personal users to store data. Traditionally, Third Party Auditors (TPAs) are introduced to ensure data integrity for public auditing. However, TPAs may also be untrusted for forging the auditing results or colluding with cloud storage servers to deceive users. In this paper, we propose a novel Blockchain-based Public Auditing Outsourcing system without TPAs (BPAO), in which the computationally expensive operations in public auditing are outsourced through blockchain to the cloud servers without risking users' privacy. Our security analysis indicates that BPAO achieves soundness and robustness. The experimental results show that BPAO is computationally efficient for cloud storage user. © 2021 IEEE.

关键词： Smart contract

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A Routing Protocol for UAV-Assisted Vehicular Delay Tolerant Networks

IEEE Open Journal of the Computer Society

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IEEE Open Journal of the Computer Society 2021年第1期2卷 85-98页

作者： Du, Zhaoyang Wu, Celimuge Yoshinaga, Tsutomu Chen, Xianfu Wang, Xiaoyan Yau, Kok-Lim Alvin Ji, Yusheng Graduate School of Informatics and Engineering The University of Electro-Communications Tokyo182-8585 Japan Vtt Technical Research Centre of Finland Oulu90570 Finland Graduate School of Science and Engineering Ibaraki University Ibaraki310-8512 Japan School of Engineering and Technology Sunway University Sunway47500 Malaysia Information Systems Architecture Research Division National Institute of Informatics Tokyo101-8430 Japan

Vehicular delay tolerant networks (VDTNs) enable information sharing among mobile nodes in scenarios where cellular base stations are unavailable and the connections between the mobile nodes are intermittent. While unmanned aerial vehicles (UAVs) have shown to improve the performance of VDTNs, existing routing protocols, such as PRoPHET, consider the encounter probability between mobile nodes only, which does not fully address the characteristics of UAVs in route selection. In this paper, we propose a routing protocol, which considers both the encounter probability and the persistent connection time between mobile nodes for each encounter, in UAV-assisted VDTNs. By introducing the persistent connection time in route selection, the proposed protocol is able to evaluate the stability of a communication link more accurately in the UAV-assisted VDTN environment. The proposed protocol is evaluated using realistic simulations by comparing it with existing baselines. The simulation results verify that the proposed protocol can improve the reliability of message forwarding while reducing network overhead and end-to-end delay. © 2020 IEEE.

关键词： Delay tolerant networks

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Evaluating slam 2d and 3d mappings of indoor structures 37

Evaluating slam 2d and 3d mappings of indoor structures

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37th International Symposium on Automation and Robotics in Construction: From Demonstration to Practical Use - To New Stage of Construction Robot, ISARC 2020

作者： Nitta, Y. Bogale, D.Y. Kuba, Y. Tian, Z. Division of Architecture and Civil Engineering Ashikaga University Japan Department of Civil Engineering Debre Berhan University Ethiopia Division of Systems and Information Engineering Ashikaga University Japan

ISBN: (纸本)9789529436347

This paper introduces a navigation algorithm of mobile indoor unmanned ground vehicle (UGV). The navigation methodology with AR markers is presented and demonstrated in detail. In the navigation algorithm, the mobile indoor UGV can make 2D or 3D map inside the structure. From the driving test, it has seen that the navigation algorithm with AR marker is essential to control the attitude of the UGV and drive autonomously. The proposed navigation algorithm is very important to drive UGV autonomously inside building. Lastly, for investigating the capability of Simultaneous Localization and Mapping (SLAM) data, the 2D and 3D maps are evaluated by comparing to traditional survey and structure from motion (SfM). In conducting the map, slowing the speed of UGV affects the 2D map negatively, while it has positive impact in 3D mapping. Using visual SLAM with LiDAR makes 3D map very easily and rapidly as compared to SfM. From these results, the proposed navigation algorithm and manufactured prototype UGV with the mapping device for 2D and 3D are useful for studying the inside buildings even in the developing countries. © 2020 Proceedings of the 37th International Symposium on Automation and Robotics in Construction, ISARC 2020: From Demonstration to Practical Use - To New Stage of Construction Robot. All rights reserved.

关键词： Optical radar

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A comparative analysis for different finite element types in strain-gradient elasticity simulations performed on Firedrake and FEniCS

arXiv

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arXiv 2024年

作者： Sarar, B. Cagri Yildizdag, M. Erden Fabbrocino, Francesco Abali, B. Emek International Research Center on Mathematics and Mechanics of Complex Systems University of L'Aquila L'Aquila Italy Department of Architecture Design and Urban Planning University of Sassari Alghero07041 Italy Faculty of Naval Architecture and Ocean Engineering Istanbul Technical University Istanbul34469 Turkey Department of Engineering Telematic University Pegaso Napoli80143 Italy Department of Materials Science and Engineering Division of Applied Mechanics Uppsala University Box 35 Uppsala751 03 Sweden

The layer-upon-layer approach in additive manufacturing, open or closed cells in polymeric or metallic foams involve an intrinsic microstructure tailored to the underlying applications. Homogenization of such architectured materials creates metamaterials modeled by higher-gradient models, specifically when the microstructure's characteristic length is comparable to the length scale of the structure. In this study, we conduct a comparative analysis of various finite elements methods for solving problems in strain-gradient elasticity. We employ open-source packages from Firedrake and FEniCS. Different finite element formulations are tested: we implement Lagrange, Argyris, Hermite elements, a Hu-Washizu type (mixed) formulation, as well as isogeometric analysis with Non-Uniform Rational B-Splines (NURBS). For the numerical study, we investigate one- and twodimensional problems discussed in the literature of strain-gradient modeling. All developed codes are open-access to encourage research in Finite Element Method (FEM) based computation of generalized continua. Copyright © 2024, The Authors. All rights reserved.

关键词： Microstructure

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A Multi-Player Potential Game Approach for Sensor Network Localization with Noisy Measurements

arXiv

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arXiv 2024年

作者： Xu, Gehui Chen, Guanpu Fidan, Baris Hong, Yiguang Qi, Hongsheng Parisini, Thomas Johansson, Karl H. The Key Laboratory of Systems and Control Academy of Mathematics and Systems Science Beijing China The Division of Decision and Control Systems School of Electrical Engineering and Computer Science KTH Royal Institute of Technology Stockholm100 44 Sweden The Division of Decision and Control Systems School of Electrical Engineering and Computer Science KTH Royal Institute of Technology Stockholm100 44 Sweden The Department of Mechanical and Mechatronics Engineering University of Waterloo WaterlooONN2L 3G1 Canada Department of Control Science and Engineering Tongji University Shanghai201804 China Shanghai Research Institute for Intelligent Autonomous Systems Shanghai201210 China Key Laboratory of Systems and Control Academy of Mathematics and Systems Science Beijing China School of Mathematical Sciences University of Chinese Academy of Sciences Beijing China The Department of Electrical and Electronic Engineering Imperial College London LondonSW7 2AZ United Kingdom The Department of Engineering and Architecture University of Trieste Trieste34127 Italy

Sensor network localization (SNL) is a challenging problem due to its inherent non-convexity and the effects of noise in inter-node ranging measurements and anchor node position. We formulate a non-convex SNL problem as a multi-player non-convex potential game and investigate the existence and uniqueness of a Nash equilibrium (NE) in both the ideal setting without measurement noise and the practical setting with measurement noise. We first show that the NE exists and is unique in the noiseless case, and corresponds to the precise network localization. Then, we study the SNL for the case with errors affecting the anchor node position and the inter-node distance measurements. Specifically, we establish that in case these errors are sufficiently small, the NE exists and is unique. It is shown that the NE is an approximate solution to the SNL problem, and that the position errors can be quantified accordingly. Based on these findings, we apply the results to case studies involving only inter-node distance measurement errors and only anchor position information inaccuracies. Copyright © 2024, The Authors. All rights reserved.

关键词： Sensor nodes

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