Search Results - "Choi, HyungJin"

Propagating Uncertainty in Power-System DAE Models With Semidefinite Programming by Hyungjin Choi, Seiler, Peter J., Dhople, Sairaj V.

“…This paper outlines a convex-optimization-based method to estimate maximum and minimum bounds on states of differential algebraic equations (DAEs) that…”
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A Convex Data-Driven Approach for Nonlinear Control Synthesis by Choi, Hyungjin, Vaidya, Umesh, Chen, Yongxin

“…We consider a class of nonlinear control synthesis problems where the underlying mathematical models are not explicitly known. We propose a data-driven…”
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Real Power Modulation Strategies for Transient Stability Control by Elliott, Ryan T., Choi, Hyungjin, Trudnowski, Daniel J., Nguyen, Tam

“…Transient stability control of power systems is based on actions that are taken automatically following a disturbance to ensure that the system remains in…”
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Chemical Properties of Heavy Metal-Contaminated Soils from a Korean Military Shooting Range: Evaluation of Pb Sources Using Pb Isotope Ratios by Moon, Inkyeong, Kim, Honghyun, Jeong, Sangjo, Choi, Hyungjin, Park, Jungtae, Lee, Insung

“…In this study, the geochemical properties of heavy metal-contaminated soils from a Korean military shooting range were analyzed. The chemical behavior of heavy…”
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Sickness Experiences of Korean Registered Nurses at Work: A Qualitative Study on Presenteeism by Kim, Joohyun, Suh, Eunyoung E, Ju, Sejin, Choo, Hyunsim, Bae, Haejin, Choi, Hyungjin

“…Presenteeism is a relatively new concept in nursing describing the condition within which registered nurses (RNs) come to work while they are sick. The purpose…”
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Low Predictive Value of FRAX Adjusted by Trabecular Bone Score for Osteoporotic Fractures in Korean Women: A Community-Based Cohort Study by Kim, Hana, Kim, Jung Hee, Kim, Min Joo, Hong, A Ram, Choi, HyungJin, Ku, EuJeong, Lee, Ji Hyun, Shin, Chan Soo, Cho, Nam H.

“…BACKGROUNDThe value of the Fracture Risk Assessment Tool (FRAX) and the trabecular bone score (TBS) for assessing osteoporotic fracture risk has not been fully…”
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Robust power systems stability assessment with sum of squares optimization by Hyungjin Choi, Seiler, P. J., Dhople, S. V.

“…Analytic methods to quantify power systems stability margins while acknowledging uncertainty will be critical in dynamic security assessment due to the…”
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Data-driven optimal control via linear transfer operators: A convex approach by Moyalan, Joseph, Choi, Hyungjin, Chen, Yongxin, Vaidya, Umesh

“…This paper is concerned with the data-driven optimal control of nonlinear systems. We present a convex formulation of the optimal control problem with a…”
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Transient stability quantification of power systems with inverter-based resources via Koopman operator based machine learning approach by Choi, Hyungjin, Elliott, Ryan, Trudnowski, Dan, Venkat, Dhruva

“…Increased integration of inverter-based resources alters the response of large-scale power systems to contingency events. The resulting loss of control…”
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Artificial Synapse Based on Oxygen Vacancy Migration in Ferroelectric‐Like C‐Axis‐Aligned Crystalline InGaSnO Semiconductor Thin‐Film Transistors for Highly Integrated Neuromorphic Electronics by Lim, Taebin, Lee, Suhui, Lee, Jiseob, Choi, HyungJin, Jung, Byunglib, Baek, SeungHyub, Jang, Jin

“…Artificial synapses are a key component of neuromorphic computing systems. To achieve high‐performance neuromorphic computing ability, a huge number of…”
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Optimal Energy Storage Control for Transient Stability Improvement using Speed Feedback by Trudnowski, Daniel, Elliott, Ryan, Choi, Hyungjin

“…This paper presents a wide-area optimal bang-bang strategy for controlling arbitrarily-located energy storage devices to improve a power system's transient…”
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Propagating Uncertainty in Power Flow With the Alternating Direction Method of Multipliers by Choi, Hyungjin, Seiler, Peter J., Dhople, Sairaj V.

“…In this paper, we develop an optimization-based method to propagate input and parametric uncertainty to the power flow solution. The approach is based on…”
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Data-driven transient stability analysis using the Koopman operator by Matavalam, Amar Ramapuram, Hou, Boya, Choi, Hyungjin, Bose, Subhonmesh, Vaidya, Umesh

“…We present data-driven methods for power system transient stability analysis using a unit eigenfunction of the Koopman operator. We show that the Koopman…”
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A convex-optimization method to propagate uncertainty in power flow by Hyungjin Choi, Seiler, Peter J., Dhople, Sairaj V.

“…This paper presents a convex-optimization-based method to estimate maximum and minimum bounds on state variables in the power flow problem while acknowledging…”
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Pilot Structure for High Data Rate in OFDM/OQAM-IOTA System by Taewoong Yoon, Sebin Im, Sunghyun Hwang, Hyungjin Choi

“…In this paper, we introduce a novel pilot structure for OFDM/OQAM system which has high spectral efficiency by isotropic orthogonal transform algorithm (IOTA)…”
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Data-Driven Power Flow Estimation with Inverter Interfaced Energy Storage Using Dynamic Injection Shift Factor by Choi, Hyungjin, Elliott, Ryan, Byrne, Raymond

“…Dynamic injection shift factor (DISF) is the linear sensitivity factor that estimates the incremental line flows in a transmission network subject to load…”
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Inverse Uncertainty Propagation In Power Flow by Choi, Hyungjin, Elliott, Ryan, Venkat, Dhruva, Trudnowski, Dan

“…The paper presents a convex optimization approach to estimate maximum and minimum intervals on parametric/input uncertainties which satisfy constraints on…”
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Frequency versus Speed Feedback for Transient Stability Control via Energy Storage by Nguyen, Tam, Trudnowski, Daniel, Elliott, Ryan, Choi, Hyungjin

“…Transient stability is often the limiting factor in power transmission. Due to lack of inertia, high penetration of inverter-based generation may exacerbate…”
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Data-driven Battery Modeling based on Koopman Operator Approximation using Neural Network by Choi, Hyungjin, Angelis, Valerio De, Preger, Yuliya

“…Physics-based battery dynamical models are typically described by a set of highly nonlinear differential-algebraic equations or partial differential equations…”
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Robust Iterative Channel Estimation for OFDM Packet Transmission System by Se Bin Im, HyungJin Choi

“…In this paper, we propose a simple and robust iterative channel estimation algorithm in OFDM packet transmission systems. Iterative scheme with channel update…”
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