Article
Engineering, Electrical & Electronic
Jaegyeong Mun, K. K. Choi, Dong-Hun Kim
Summary: In the presence of design parameter uncertainties, a system-level robust design optimization method is proposed for a permanent magnet motor to enhance the dynamic and steady performances of the motor drive system. The influence of individual motor parameters on transient system responses is investigated through Taguchi experimental planning. The temperature-dependent material property of each motor component is examined, and the motor drive system is then optimized using the univariate dimension reduction method to ensure robustness against manufacturing tolerance and operating temperature fluctuation.
IEEE TRANSACTIONS ON MAGNETICS
(2023)
Article
Engineering, Electrical & Electronic
Jaegyeong Mun, Jongsu Lim, Yejin Kwak, Byungsu Kang, K. K. Choi, Dong-Hun Kim
Summary: A reliability-based design optimization method is proposed to ensure a given confidence level of output performances of a permanent magnet motor in the presence of operating temperature fluctuation and manufacturing tolerance. The method incorporates random material parameters and design variables due to uncertainties into a mathematical formulation, seeking optimal design with Monte Carlo simulation and a highly accurate surrogate model. The proposed method is validated using an interior-type permanent magnet synchronous motor, showing higher precision compared to conventional methods.
IEEE TRANSACTIONS ON MAGNETICS
(2021)
Article
Materials Science, Multidisciplinary
Jaegyeong Mun, K. K. Choi, Dong-Hun Kim
Summary: A robust design optimization method for a permanent magnetic motor is proposed in this paper from a system-level design perspective. It constructs a numerical model for the whole drive system by integrating a control circuit simulator into a finite element analysis tool, investigates the influence of motor parameter variations on system responses, and enhances the robustness of system performance by optimizing the motor. Finally, a comparative performance analysis is conducted to demonstrate the validity of the proposed method.
JOURNAL OF MAGNETICS
(2022)
Article
Chemistry, Multidisciplinary
Luizetta Elliott, Erika E. Salzman, Julia R. Greer
Summary: The research focuses on utilizing benzyl methacrylate-based SMPs to create 3D structures with shape transformation capabilities through two photon lithography. The structures exhibit features such as 500 nm thick petals and 2.5 µm unit cells in cubic lattices.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Optics
Vuong V. Mai, Hoon Kim
Summary: The paper introduces an adaptive beam control technique combined with beaconless PAT using a variable focus lens for addressing technical challenges in airborne free-space optical communications. Experimental demonstration shows significant improvement in the success rate of PAT and reduction in system losses by using the proposed scheme. The response time of the lens is measured to be <211 ms, and the optimum beam size at the receiver is determined by the receiver size and pointing error.
Article
Geochemistry & Geophysics
Anandaroop Ray, Yusen Ley-Cooper, Ross C. Brodie, Richard Taylor, Neil Symington, Negin F. Moghaddam
Summary: Long-range, active-source airborne electromagnetic (AEM) systems for near-surface conductivity imaging are categorized into helicopter borne and fixed-wing aircraft borne. Various factors affect the geological resolvability, and test flights over well-constrained subsurface geology are useful for resolution studies. Handling transmitter-receiver geometries in fixed-wing aircraft is challenging due to the non-linearity of the electromagnetic inverse problem. Probabilistic inversions, using information theoretic attributes, can provide a comprehensive picture of the subsurface conductivity distributions for each kind of AEM system.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Chemistry, Multidisciplinary
Yanling Wang, Liyan Zhao, Aoran Cui, Xiaojiang Wang, Qinggang He, Shikuan Yang
Summary: Microarchitectures with complex interior structures are crucial for various applications. This article introduces electrochemical sculpting processes to design the interior structure of microarchitectures through electrochemical growing and sculpting, which are intertwined under constant voltage electrodeposition mode. The thawing process of frozen electrolyte is utilized to create the desired ion concentration gradient and control the strength of sculpting and growing processes. Fully decoupling the growing and sculpting process allows for precise control over the interior structures, leading to the preparation of microarchitectures with complex interior structures.
Article
Chemistry, Analytical
Yu-Shih Chen, Ling-Yi Ke, Sung-Yang Wei, Madhu Shree Poddar, Cheng-Hsien Liu
Summary: The research successfully fabricated photopolymerized hydrogel microstructures with complex fine patterns by utilizing optofluidic thin-film lithography combined with PDMS thin-film characteristics. The design principle is based on the physical characteristics of UV light attenuation and refraction.
SENSORS AND ACTUATORS B-CHEMICAL
(2022)
Article
Computer Science, Information Systems
Mingliang Xu, Qingfeng Li, Jianwei Niu, Hao Su, Xiting Liu, Weiwei Xu, Pei Lv, Bing Zhou, Yi Yang
Summary: The article proposes a new method for generating scanning-robust aesthetic QR codes based on a module-based scanning probability estimation model. By adjusting luminance and adopting a hierarchical strategy, the method sequentially generates binary, grayscale, and color aesthetic QR codes, and can create QR codes with different visual styles by adjusting parameters. User surveys and decoding experiments show that the proposed approach has excellent performance in terms of both visual quality and scanning robustness compared to state-of-the-art algorithms.
ACM TRANSACTIONS ON MULTIMEDIA COMPUTING COMMUNICATIONS AND APPLICATIONS
(2021)
Article
Engineering, Electrical & Electronic
Fredrick Kim, Seong Eun Yang, Hyejin Ju, Seungjun Choo, Jungsoo Lee, Gyeonghun Kim, Soo-ho Jung, Suntae Kim, Chaenyung Cha, Kyung Tae Kim, Sangjoon Ahn, Han Gi Chae, Jae Sung Son
Summary: Microscale three-dimensional thermoelectric architectures can be fabricated through direct writing of particle-based thermoelectric inks, producing microthermoelectric generators with high power density.
NATURE ELECTRONICS
(2021)
Article
Automation & Control Systems
Insoon Yang
Summary: This article investigates the problem of control policy robustness and proposes a dynamic programming solution based on Wasserstein distribution. The study shows that the contraction property of Bellman operators can extend single-stage performance guarantees to multistage guarantees.
IEEE TRANSACTIONS ON AUTOMATIC CONTROL
(2021)
Article
Management
Taozeng Zhu, Jingui Xie, Melvyn Sim
Summary: The study introduces a joint estimation and robustness optimization framework to address the impact of estimation uncertainty in optimization problems. By incorporating both the parameter estimation process and the optimization problem seamlessly, the framework aims to obtain solutions that are immune to parameter perturbations. The size of the uncertainty set, based on the accuracy of parameter estimation from data using specific procedures, is maximized to achieve this goal.
MANAGEMENT SCIENCE
(2022)
Article
Computer Science, Information Systems
Liang Zeng, Jintai Li, Jianxin Liu, Rongwen Guo, Hang Chen, Rong Liu
Summary: This paper applies a particle swarm algorithm to optimize the spacing and shift in Hankel integration, avoiding traditional grid search algorithms. Comparing with other filters, the proposed 201-point filter shows good numerical performance and high accuracy.
Article
Mechanics
Nishant K. Shakya, Srikant S. Padhee
Summary: This paper discusses the necessary conditions to eliminate the hygrothermal instabilities in asymmetric laminate composites and proposes a generalized stacking sequence that satisfies all the stability conditions. The optimization of the proposed stacking sequence is conducted analytically and numerically, and the results are verified through sensitivity analysis. The proposed approach is shown to be more efficient and equally sensitive to errors in the optimized sequence.
COMPOSITE STRUCTURES
(2023)
Article
Geochemistry & Geophysics
Burke J. Minsley, Nathan Leon Foks, Paul A. Bedrosian
Summary: The article introduces an open-source Bayesian algorithm GeoBIPy for robust uncertainty analysis of AEM data. The algorithm provides a robust assessment of geophysical parameter uncertainty using a trans-dimensional approach and allows users to solve for parameters such as data errors and corrections to measured instrument height. Probability distributions for a user-specified number of lithologic classes are developed through posterior clustering of McMC-derived resistivity models.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Engineering, Electrical & Electronic
Byungsu Kang, K. K. Choi, Dong-Hun Kim
IEEE TRANSACTIONS ON MAGNETICS
(2018)
Article
Engineering, Electrical & Electronic
Byungsu Kang, Chang-Eob Kim, Hyunkyoo Cho, K. K. Choi, Dong-Hun Kim
IEEE TRANSACTIONS ON MAGNETICS
(2018)
Article
Thermodynamics
Mike Augspurger, K. K. Choi, H. S. Udaykumar
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2018)
Article
Mechanics
Pratik Das, Oishik Sen, K. K. Choi, Gustaaf Jacobs, H. S. Udaykumar
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2018)
Article
Computer Science, Interdisciplinary Applications
Oishik Sen, Nicholas J. Gaul, K. K. Choi, Gustaaf Jacobs, H. S. Udaykumar
JOURNAL OF COMPUTATIONAL PHYSICS
(2018)
Article
Mechanics
O. Sen, N. J. Gaul, S. Davis, K. K. Choi, G. Jacobs, H. S. Udaykumar
Article
Engineering, Mechanical
Min-Yeong Moon, K. K. Choi, Nicholas Gaul, David Lamb
JOURNAL OF MECHANICAL DESIGN
(2019)
Article
Physics, Applied
Sangyup Lee, Oishik Sen, Nirmal Kumar Rai, Nicholas J. Gaul, K. K. Choi, H. S. Udaykumar
JOURNAL OF APPLIED PHYSICS
(2019)
Article
Materials Science, Multidisciplinary
Byungsu Kang, Jaegyeong Mun, Jongsu Lim, K. K. Choi, Dong-Hun Kim
JOURNAL OF MAGNETICS
(2019)
Article
Computer Science, Interdisciplinary Applications
Min-Yeong Moon, K. K. Choi, David Lamb
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2019)
Article
Materials Science, Multidisciplinary
Byungsu Kang, Jaegyeong Mun, Jongsu Lim, K. K. Choi, Dong-Hun Kim
JOURNAL OF MAGNETICS
(2019)
Article
Engineering, Mechanical
Hyunkyoo Cho, Kyung K. Choi, Jaekwan Shin
JOURNAL OF MECHANICAL DESIGN
(2020)
Article
Computer Science, Interdisciplinary Applications
Min-Yeong Moon, Hyun-Seok Kim, Kangsu Lee, Byoungjae Park, K. K. Choi
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2020)
Article
Engineering, Electrical & Electronic
Jaegyeong Mun, Jongsu Lim, Yejin Kwak, Byungsu Kang, K. K. Choi, Dong-Hun Kim
Summary: A reliability-based design optimization method is proposed to ensure a given confidence level of output performances of a permanent magnet motor in the presence of operating temperature fluctuation and manufacturing tolerance. The method incorporates random material parameters and design variables due to uncertainties into a mathematical formulation, seeking optimal design with Monte Carlo simulation and a highly accurate surrogate model. The proposed method is validated using an interior-type permanent magnet synchronous motor, showing higher precision compared to conventional methods.
IEEE TRANSACTIONS ON MAGNETICS
(2021)
Article
Engineering, Mechanical
K. K. Choi, Paramsothy Jayakumar, Matthew Funk, Nicholas Gaul, Tamer M. Wasfy
JOURNAL OF COMPUTATIONAL AND NONLINEAR DYNAMICS
(2019)