Ultrafast laser-driven Rabi oscillations of a trapped atomic vapor.

Lee, Han-gyeol,Kim, Hyosub,Ahn, Jaewook Optical Society of America 2015 Optics letters Vol.40 No.4

<P>We consider the Rabi oscillation of an atom ensemble of Gaussian spatial distribution interacting with ultrafast laser pulses. Based on an analytical model calculation, we show that its dephasing dynamics is solely governed by the size ratio between the atom ensemble and the laser beam, and that every oscillation peak of the inhomogeneously broadened Rabi flopping falls on the homogeneous Rabi oscillation curve. The results are verified experimentally with a cold rubidium vapor in a magneto-optical trap. As a robust means to achieve higher-fidelity population inversion of the atom ensemble, we demonstrate a spin-echo type R(x)(π/2)R(y)(π)R(x)(π/2) composite interaction as well.</P>

Quantum dynamics of a two-state system induced by a chirped zero-area pulse

Lee, Han-gyeol,Song, Yunheung,Kim, Hyosub,Jo, Hanlae,Ahn, Jaewook American Physical Society 2016 Physical Review A Vol.93 No.2

<P>It is well known that area pulses make Rabi oscillation and chirped pulses in the adiabatic interaction regime induce complete population inversion of a two-state system. Here we show that chirped zero-area pulses could engineer an interplay between the adiabatic evolution and Rabi-like rotations. In a proof-of-principle experiment utilizing spectral chirping of femtosecond laser pulses with a resonant spectral hole, we demonstrate that the chirped zero-area pulses could induce, for example, complete population inversion and return of the cold rubidium atom two-state system. Experimental result agrees well with the theoretically considered overall dynamics, which could be approximately modeled to a Ramsey-like three-pulse interaction, where the x and z rotations are driven by the hole and the main pulse, respectively.</P>

Single-laser-pulse implementation of arbitrary ZYZ rotations of an atomic qubit

Lee, Han-gyeol,Song, Yunheung,Ahn, Jaewook American Physical Society 2017 Physical Review A Vol.96 No.1

<P>Arbitrary rotation of a qubit can be performed with a three-pulse sequence, for example, ZYZ rotations. However, this requires precise control of the relative phase and timing between the pulses, making it technically challenging in optical implementation in a short time scale. Here we show any ZYZ rotations can be implemented with a single laser pulse, that is, a chirped pulse with a temporal hole. The hole of this shaped pulse induces a nonadiabatic interaction in the middle of the adiabatic evolution of the chirped pulse, converting the central part of an otherwise simple Z rotation to a Y rotation, constructing ZYZ rotations. The result of our experiment performed with shaped femtosecond laser pulses and cold rubidium atoms shows strong agreement with the theory.</P>

The Effects of Coordinative Locomotor Training using Elastic Band on Dynamic Balance and Grip Strength in Elementary School Baseball Player

Han-Gyeol Lee 물리치료재활과학회 2021 Physical therapy rehabilitation science Vol.10 No.4

Objective: The purpose of this study was to investigate the effects of coordinative locomotor training(CLT) using elastic bands on dynamic balance and grip strength for Elementary school baseball players and to provide correct posture guidance and reference on the prevention and rehabilitation program of sports damage and injury in the future. Design: Two groups pre-post randomized controlled design. Methods: Forty-six subjects were randomly divided in two groups;1) CLT using Elastic Band group(Experimental group, n=23), 2) Routine baseball training group(Control group, n=23). The intervention was conducted total 16 times for sixty minutes a day, 2 times a week, for 8 weeks. Evaluations of dynamic balance ability and grip strength were performed with all subjects before the commencement of training and 8 weeks after training. Results: Compared to the control group after training, the dynamic balance ability and dominant handgrip strength of the experimental group were significantly more improved(p<0.05). Conclusions: We confirmed that the effects of CLT using elastic bands on dynamic balance ability and grip strength in Elementary school baseball player. This study should be used for improving the quality of the Elementary school baseball player’s training and would be contributed prevention and rehabilitation program of sports damage and injury.

전기 히트 펌프 시스템의 센서 고장 감지 및 진단 기술을 위한 온도 센서 예측모델 개발

이한결(Lee, Han-Gyeol),김효준(Kim, Hyo-Jun),조영흠(Cho, Young-Hum) 대한건축학회 2022 대한건축학회 학술발표대회 논문집 Vol.42 No.1

별 불가사리(Asterina pectinifera) 바이오차의 수용액 내 중금속(Pb, Cu, Zn, Cd) 흡착특성 및 적용성 평가

전한결(Han Gyeol Jeon),정경훈(Kyung Hoon Cheong),이재욱(Jae-Wook Lee),이정수(Jung-Soo Lee),문덕현(Deok Hyun Moon) 대한환경공학회 2020 대한환경공학회지 Vol.42 No.5

목적 : 중금속은 수계에 유출 시 다양한 생물체에 영향을 미치며 최종적으로 인체 내에 축적되어 지속적인 건강손상을 초래한다. 이에 많은 중금속 처리법이 개발되었으나 처리비용 및 비환경적 문제에 따라 이를 보완하는 연구가 필요한 실정이다. 따라서 본 연구는 국내에 서식하는 불가사리(Asterina pectinifera, SF)를 이용해 바이오차를 제조한 후 분석 장비를 이용한 정성, 정량적 특성평가 및 Batch-Test를 통해 수용액 내 중금속의 처리 적용성을 판단하였다. 방법 : 불가사리를 무산소 조건에서 7℃/min로 승온온도를 조절하여 300℃로 2시간 유지시켜 바이오차(NACSF)를 제조한 후 특성평가를 위해 XRD, XRF, FT-IR, SEM-EDX, 원소분석기 등을 사용했으며, NACSF의 중금속별 Batch-Test 후 용액을 ICP-OES로 농도분석을 통하여 처리 특성을 평가하였다. 결과 및 토의 : SF와 NACSF의 특성평가 결과 탄소와 CaCO₃가 주성분임을 확인하였으며 Pb, Cu, Zn, Cd 각각 10mg/L의 중금속 폐수를 제조하여 NACSF를 적용한 결과 흡착량은 Pb ≫Cu > Zn ≥Cd 순을 따르는 것으로 확인되었으며, 흡착등온식은 Langmuir 모델에 적합하였다. 또한 CaCO₃에 의한 알칼리도 상승으로 모든 실험구에서 pH는 7~8 로 측정되었다. 결론 : NACSF는 Pb으로 오염된 수용액에 가장 적합한 것으로 보였으며 알칼리도로 인한 pH중화 효과로 흡착과 침전이 상호적으로 일어난 것으로 판단된다. 따라서 NACSF는 경제적이며 친환경적으로 다양한 영역에서 활용될 것으로 예상된다. Objectives : Heavy metals caused by industrialization have affected human society for several decades. Because of their toxicity for humans, lots of heavy metal treatments have been developed. However, many of those treatments have economic considerations and environmental disadvantages. This work explored an experimental assessment of adsorption of heavy metals using starfish (SF) biochar through quantitative and qualitative characterization and batch-tests. Methods : Biochar (NACSF) was produced at 300℃ for 2 h in anaerobic conditions. The NACSF was characterized with XRD, XRF, FT-IR, SEM-EDX and elemental analyses. Moreover, batch-tests for each heavy metal using NACSF were conducted with ICP-OES analyses in order to evaluate the adsorption characteristics. Results and Discussion : Based on the characterization results, the NACSF consisted of carbon and CaCO₃ mainly. The adsorption rates of Pb, Cu, Zn and Cd decreased in the following order: Pb ≫Cu > Zn ≥Cd. Moreover, the Langmuir equation fit all adsorption data better than the Freundlich equation. Also, due to the alkalinity of NACSF, the measured pH values of all experimental groups were approximately 7~8. Conclusions : The NACSF treatment was the most effective for Pb removal and it was determined that precipitation and surface adsorption were the most likely mechanisms for Pb removal. Thus, NACSF derived from starfish could be an cost-effective and eco-friendly treatment for heavy metal contaminated wastewater.

압력센서와 가속도센서를 활용한 직장인들을 위한 스마트 벨트

김한결(Han-Gyeol Kim),김지연(Ji-Yeon Kim),이승태(Seung-Tae Lee),이희연(Hee-youn Lee),장현국(Hyun-kook Jang) 한국정보과학회 2018 한국정보과학회 학술발표논문집 Vol.2018 No.6

여성의 호르몬 변화가 운동능력에 미치는 영향

이한결(Han-Gyeol Lee),윤영제(Young-Jeoi Yoon) 한국엔터테인먼트산업학회 2016 한국엔터테인먼트산업학회 학술대회 논문집 Vol.2016 No.5

본 연구는 여성호르몬의 변화가 운동능력에 미치는 영향을 알아보았다. 31명의 여자 대학생을 대상으로 여포기 후기와 황체기 중기에 심장허파능력, 들숨능력, 여성호르몬, 혈액인자를 검사하였다. 연구결과, 심장허파능력은 여포기 후기에 비해 황체기 중기에 최대산소섭취량, MET, 최대에너지소비량이 유의하게 감소하였다. 들숨능력은 여포기 후기에 비해 황체기 중기에 최대들숨압, 평균들숨압, 최대들숨유속, 평균들숨유속이 유의하게 감소하였고, 최대들숨량은 유의하게 증가하였다. 여성호르몬은 여포기 후기에 비해 황체기 중기에 에스트로겐이 유의하게 감소하였고, 프로게스테론은 유의하게 증가하였다. 혈액인자는 여포기 후기에 비해 황체기 중기에 적혈구, 헤모글로빈, 적혈구용적률이 유의하게 감소하였다. 본 연구결과를 통해 여성호르몬의 변화가 운동능력에 미치는 영향을 미친다는 것을 알 수 있었다. 따라서 여성의 생리주기에 따른 운동능력의 변화를 고려한 운동프로그램 처방이 이루어져야 할 것이다. This study aimed to investigate the effect of variation of female sex hormones on exercise ability. The subjects of this research were 31 female students. To achieve this purpose, their cardiopulmonary ability and inspiratory ability were measured at late-follicular and mid-luteal phases, and boold sample were assayed for sex hormone and blood factor at late-follicular and mid-luteal phases. Maximal oxygen uptake, MET, and maximal energy consumption which are sub-factors of Cardiopulmonary ability were significantly decreased at mid-luteal phase than late-follicular phase. Maximal inspiratory pressure, average inspiratory pressure, maximal inspiratory flow, average inspiratory flow which are sub-factors of Inspiratory ability were significantly decreased at mid-luteal phase than late-follicular phase, but maximal inspiratory volume was significantly decreased at late-follicular phase than mid-luteal phase. Estrogen which is sub-factor of female sex hormones was decreased at mid-luteal phase than late-follicular phase. progesterone which is sub-factor of female sex hormones war increased at mid-luteal phase than late-follicular phase. Red blood cell, hemoglobin, hematocrit which are sub-factors of blood factors were significantly decreased at mid-luteal phase than late-follicular phase. According to the research results, variation of female sex hormones affect exercise ability. when prescribing an exercise program for women, variation of exercise ability according to the menstrual cycle is considered.

CNN 기반 D-STLC 송신 안테나 선택 성능 실험

이한결(Han-Gyeol Lee),정진곤(Jingon Joung) 한국통신학회 2019 한국통신학회 학술대회논문집 Vol.2019 No.11

냉동사이클을 활용한 공기 열원 히트펌프 성능예측모델 개발

이한결(Lee, Han-Gyeol),김효준(Kim, Hyo-Jun),조영흠(Cho, Young-Hum) 대한건축학회 2022 대한건축학회 학술발표대회 논문집 Vol.42 No.2