Papers by Hyung Keun Choi
Physical Review Letters, Jan 9, 2007
Investigating the scaling behavior of annealed Ga1−xMnxAs anomalous Hall coefficients, we note a ... more Investigating the scaling behavior of annealed Ga1−xMnxAs anomalous Hall coefficients, we note a universal crossover regime where the scaling behavior changes from quadratic to linear, attributed to the anomalous Hall Effect intrinsic and extrinsic origins, respectively. Furthermore, measured anomalous Hall conductivities when properly scaled by carrier concentration remain constant, equal to theoretically predicated values, spanning nearly a decade in conductivity as well as over 100 K in TC. Both the qualitative and quantitative agreement confirms the validity of new equations of motion including the Berry phase contributions as well as tunablility of the intrinsic anomalous Hall Effect.
한국분석과학회 학술대회, May 1, 2012
Daehan macwi'gwa haghoeji, 2008
Background: The purpose of this study is to determine the optimal dose of remifentanil and propof... more Background: The purpose of this study is to determine the optimal dose of remifentanil and propofol for minimizing the cardiovascular changes to tracheal intubation during total intravenous anesthesia (TIVA) using propofol target controlled infusion (TCI). Methods: One hundred thirty five patients, aged 20-60 years, were randomly divided into three groups. Anesthesia was induced with remifentanil, propofol and rocuronium 1 mg/kg for intubation. Group I received remifentanil 0.1μg/kg/min and a propofol target concentration 4μg/ml. Group II received remifentanil 0.2μg/kg/min and propofol 4μg/ml. Group III received remifentanil 0.2μg/kg/min and propofol 3μg/ml. Remifentanil was infused continuously, and 2 minutes after remifentanil infusion, propofol was infused continuously. Mean arterial blood pressure (MAP) and heart rate (HR) were measured at pre-induction, 1 minute after remifentanil infusion, before propofol TCI, immediately before and after intubation and 1, 2, 3 minutes after intubation, respectively. Results: Compared with pre-induction values, MAP at immediately after intubation was significantly increased in group I, but decreased in group II, with no change in group III. The HR immediately after intubation was significantly increased after intubation in all groups compared to the pre-induction values, but the rate of increase of HR in groups II, III were significantly lower than those of group I (p ＜ 0.05). Hypotension was observed in 6 patients in group II and 3 in group III. Conclusions: Remifentanil 0.2μg/kg/min and the propofol target concentration 3μg/ml are optimal doses for minimizing cardiovascular changes and side effects to tracheal intubation during TIVA.
Physical Review Letters, Jan 9, 2007
Investigating the scaling behavior of annealed Ga1−xMnxAs anomalous Hall coefficients, we note a ... more Investigating the scaling behavior of annealed Ga1−xMnxAs anomalous Hall coefficients, we note a universal crossover regime where the scaling behavior changes from quadratic to linear, attributed to the anomalous Hall Effect intrinsic and extrinsic origins, respectively. Furthermore, measured anomalous Hall conductivities when properly scaled by carrier concentration remain constant, equal to theoretically predicated values, spanning nearly a decade in conductivity as well as over 100 K in TC. Both the qualitative and quantitative agreement confirms the validity of new equations of motion including the Berry phase contributions as well as tunablility of the intrinsic anomalous Hall Effect.
한국분석과학회 학술대회, May 1, 2012
Daehan macwi'gwa haghoeji, 2008
Background: The purpose of this study is to determine the optimal dose of remifentanil and propof... more Background: The purpose of this study is to determine the optimal dose of remifentanil and propofol for minimizing the cardiovascular changes to tracheal intubation during total intravenous anesthesia (TIVA) using propofol target controlled infusion (TCI). Methods: One hundred thirty five patients, aged 20-60 years, were randomly divided into three groups. Anesthesia was induced with remifentanil, propofol and rocuronium 1 mg/kg for intubation. Group I received remifentanil 0.1μg/kg/min and a propofol target concentration 4μg/ml. Group II received remifentanil 0.2μg/kg/min and propofol 4μg/ml. Group III received remifentanil 0.2μg/kg/min and propofol 3μg/ml. Remifentanil was infused continuously, and 2 minutes after remifentanil infusion, propofol was infused continuously. Mean arterial blood pressure (MAP) and heart rate (HR) were measured at pre-induction, 1 minute after remifentanil infusion, before propofol TCI, immediately before and after intubation and 1, 2, 3 minutes after intubation, respectively. Results: Compared with pre-induction values, MAP at immediately after intubation was significantly increased in group I, but decreased in group II, with no change in group III. The HR immediately after intubation was significantly increased after intubation in all groups compared to the pre-induction values, but the rate of increase of HR in groups II, III were significantly lower than those of group I (p ＜ 0.05). Hypotension was observed in 6 patients in group II and 3 in group III. Conclusions: Remifentanil 0.2μg/kg/min and the propofol target concentration 3μg/ml are optimal doses for minimizing cardiovascular changes and side effects to tracheal intubation during TIVA.
Jounal of The Korea Society of Information Technology Policy & Management, 2021
Jounal of The Korea Society of Information Technology Policy & Management, 2020
Jounal of The Korea Society of Information Technology Policy & Management, 2021
Jounal of The Korea Society of Information Technology Policy & Management, 2020
Jounal of The Korea Society of Information Technology Policy & Management, Apr 1, 2020
Jounal of The Korea Society of Information Technology Policy & Management, 2020
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Papers by Hyung Keun Choi