Energetic and Dynamic Analysis of Transport of Na⁺ and K⁺ through a Cyclic Peptide Nanotube in Water and in Lipid Bilayers

Song, Yeonho,Lee, Ji Hye,Hwang, Hoon,Schatz, George C.,Hwang, Hyonseok American Chemical Society 2016 The Journal of physical chemistry B Vol.120 No.46

<P>Potential of mean force (PMF) profiles and position-dependent diffusion coefficients of Na+ and K+ are calculated to elucidate the translocation of ions through a 0.10 cyclic peptide nanotube, composed of 8 x cyclo[-(D-LeuTrp)(4)-] rings, in water and in hydrated DMPC bilayers. The PMF profiles and PMF decomposition analysis for the monovalent cations show that favorable interactions of the cations with the CPN as well as the lipid bilayer and dehydration free energy penalties are two major competing factors which determine the free energy surface for ion transport through CPNs both in water and in lipid bilayers, and that the selectivity of CPNs to cations mainly arises from favorable interaction energies of cations with CPNs and lipid bilayers that are more dominant than the dehydration penalties. Calculations of the position-dependent diffusion coefficients and dynamic friction kernels of the cations indicate that the dehydration process along with the molecular rearrangements occurring outside the channel and the coupling of the ion motions with the chain-structured water movements inside the channel lead to a decrease of the diffusion coefficients far away from the channel entrance and also reduced coefficients inside the channel. The PMF and diffusivity profiles for Na+ and K+ reveal that the energetics of ion transport through the CPN are governed by global interactions of ions with all the components in the system, while the diffusivity of ions through the channel is mostly determined by local interactions of ions with the confined water molecules inside the channel. Comparison of Na+ and K+ ion distributions based on overdamped Brownian dynamics simulations based on the PMF and diffusivity profiles with the corresponding results from molecular dynamics shows good agreement, indicating accuracy of the Bayesian inference method for determining diffusion coefficients in this application. In addition, this work shows that position-dependent diffusion coefficients of ions are required to explain the dynamics and conductance of ions through the CPN properly.</P>

내산화 코팅용 인산염계 유리의 제조 및 특성평가

송현수,최연호,윤존도,김철영 경남대학교 신소재연구소 2003 신소재연구 Vol.15 No.2

탄소/탄소 복합체의 내산화성 코팅용 인산염계 유리를 제조하였고 특성평가를 하였다. 알루미나 함량이 10, 17, 25, 28 몰%를 함유라는 인산염계 코팅막을 제조하여 기존의 인산염계 코팅막과 비교하였다. 제조된 유리에 대한 열팽창을 측정, 용해도 시험, 접합성 시험 등 특성평가를 실시하였다. 열팽창률은 17 몰%의 인산알루미늄 유리가 5.7×10^(-6)/K의 값을 갖는 것으로 나타났다. 생성된 코팅막은 모두 비정질이었으며 복합체에 대한 접합성은 좋지 않았으나 수분에 의한 환경의 영향은 없는 것으로 나타났다. The phosphate glass coating materials for oxidation resistance of carbon-carbon composite at high temperature were prepared. The coating materials consisted of phosphate and alumina with 10, 17, 25, 28 ㏖%. They were evaluated to compare the oxidation resistance with conventional phosphate coatings. Thermal expansion coefficient value of 5.7×10^(-6)/K was obtained in specimen with 25 ㏖% of Al₂0₃. Phosphate coating material prepared had amorphous phase. It did not have a good adhesion to the carbon-carbon composite substrate, but was stable under the water environment.

Development and Control of an Electric Oil Pump for Automatic Transmission-Based Hybrid Electric Vehicle

Yeonho Kim,Jaesang Lee,Chihoon Jo,Yongha Kim,Minseok Song,Jonghyun Kim,Hyunsoo Kim IEEE 2011 IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY Vol.60 No.5

<P>We developed an electric oil pump (EOP) and a control algorithm for automatic transmission (AT)-based two-shaft parallel hybrid electric vehicles (HEVs). The EOP capacity was designed based on AT oil pump test results, and the torque of the EOP motor was determined by considering the flow rate and efficiency calculated according to the operating temperature of the AT fluid. A control algorithm consisting of low, high, and middle speeds according to the HEV driving mode was proposed for the operation of the designed EOP. Control logic was proposed to reduce the EOP energy requirements in the middle-speed range, in which the EOP and AT oil pump operate together. We verified that this control method could reduce electric load while supplying the required hydraulic pressure.</P>

Development of an electric oil pump control algorithm for an automatic-transmission-based hybrid electric vehicle considering the gear shift characteristics

Song, Minseok,Oh, Joseph,Kim, Jonghyun,Kim, Youngchul,Yi, Jaeshin,Kim, Yeonho,Kim, Hyunsoo SAGE Publications 2014 Proceedings of the Institution of Mechanical Engin Vol.228 No.1

<P>In this paper, an electric oil pump control algorithm for an automatic-transmission-based hybrid electric vehicle was proposed. Dynamic models of the hybrid electric vehicle powertrain and hydraulic control system, including a mechanical oil pump and an electric oil pump, were obtained, and a hybrid electric vehicle performance simulator was developed. Also, a flow consumption model of the hydraulic control system was constructed. To represent the characteristics of the hydraulic control system according to the change in the temperature of the automatic transmission fluid, a viscosity index concept was introduced. Based on the simulation and test results, a viscosity index–line pressure–electric oil pump power map was proposed to describe the power supply requirement according to the viscosity index and the required line pressure. Using the viscosity index–line pressure–electric oil pump power map, an electric oil pump control algorithm was suggested to control the electric oil pump by using multi-stage power for a given viscosity index. The mechanical oil pump speed at which the electric oil pump is turned off was obtained on the basis of the flow consumption model. The electric oil pump control algorithm was evaluated by experiments and simulations. The proposed electric oil pump control algorithm satisfied the target line pressure requirement according to the viscosity index. In addition, an electric oil pump control strategy during an automatic transmission gear shift was suggested for the situation in which the maximum line pressure required for the gear shift cannot be achieved by only the mechanical oil pump. The electric-oil-pump-assisted power was determined from the flow consumption model and the mechanical oil pump speed considering the gear shift. The simulation results confirmed that the electric oil pump control strategy satisfied the maximum line pressure during a gear shift.</P>

Motor Control of a Parallel Hybrid Electric Vehicle during Mode Change without an Integrated Starter Generator

Song, Minseok,Oh, Joseph,Choi, Seokhwan,Kim, Yeonho,Kim, Hyunsoo The Korean Institute of Electrical Engineers 2013 Journal of Electrical Engineering & Technology Vol.8 No.4

In this paper, a motor control algorithm for performing a mode change without an integrated starter generator (ISG) is suggested for the automatic transmission-based hybrid electric vehicle (HEV). Dynamic models of the HEV powertrains such as engine, motor, and mode clutch are derived for the transient state during the mode change, and the HEV performance simulator is developed. Using the HEV performance bench tester, the characteristics of the mode clutch torque are measured and the motor torque required for the mode clutch synchronization is determined. Based on the dynamic models and the mode clutch torque, a motor torque control algorithm is presented for mode changes, and motor control without the ISG is investigated and compared with the existing ISG control.

Motor Control of a Parallel Hybrid Electric Vehicle during Mode Change without an Integrated Starter Generator

Minseok Song,Joseph Oh,Seokhwan Choi,Yeonho Kim,Hyunsoo Kim 대한전기학회 2013 Journal of Electrical Engineering & Technology Vol.8 No.4

In this paper, a motor control algorithm for performing a mode change without an integrated starter generator (ISG) is suggested for the automatic transmission-based hybrid electric vehicle (HEV). Dynamic models of the HEV powertrains such as engine, motor, and mode clutch are derived for the transient state during the mode change, and the HEV performance simulator is developed. Using the HEV performance bench tester, the characteristics of the mode clutch torque are measured and the motor torque required for the mode clutch synchronization is determined. Based on the dynamic models and the mode clutch torque, a motor torque control algorithm is presented for mode changes, and motor control without the ISG is investigated and compared with the existing ISG control.

12-Gb/s Over Four Balanced Lines Utilizing NRZ Braid Clock Signaling With No Data Overhead and Spread Transition Scheme for 8K UHD Intra-Panel Interfaces

Lee, Yeonho,Choi, Yoonjae,Song, Junyoung,Hwang, Sewook,Bae, Sang-Geun,Jun, Jaehun,Kim, Chulwoo IEEE 2019 IEEE journal of solid-state circuits Vol.54 No.2

<P>This paper presents a new pin/energy-efficient data and clock signaling scheme, named braid clock signaling (BCS). This signaling scheme efficiently embeds clock information into the data stream without data overhead, unnecessary pins, and channels for clock. To remove the data overhead, the clock information is embedded in every other data period. This high transition density (TD) leads to the enhanced jitter tracking performance of a receiver and increased stability. Furthermore, a spread transition scheme (STS) removes the additional power consumption for the embedded clock with little electromagnetic interference (EMI). As non-return-to-zero (NRZ) signaling uses only two voltage levels, the NRZ BCS secures a large input voltage margin at the receiver side, unlike other pin-efficient multi-level signaling schemes. An analysis of the secured voltage margin shows improved energy efficiency over conventional pin-efficient multi-level signaling schemes, even without consideration of their clocking power dissipation. The prototype transceiver is fabricated in a 28-nm CMOS process with a 12-Gb/s delay-locked loop (DLL)-based receiver over four lines.</P>

양극성장애 환자용 한국어판 기분 기록 스마트폰 어플리케이션의 개발 및 임상적 적용

송가영(Kayoung Song),이세정(Saejeong Lee),윤 운(Woon Yoon),김창윤(Changyoon Kim),주연호(Yeonho Joo),이중선(Jungsun Lee),전명욱(Myong-Wuk Chon) 대한신경정신의학회 2018 신경정신의학 Vol.57 No.3

Objectives The aim of this study was to develop a Korean version of a mood chart application on an Android platform. Methods This application is based on the traditional mood chart. Eighteen adults with DSM-5 bipolar disorder were enrolled from November 2016 to March 2017. They were asked to rate their daily mood scores and severity of irritability and impulsivity for six months. Their clinicians rated their symptom severity monthly using the Clinical Global Impression-7 (CGI-7) scale. After six months, the participants completed an anonymous questionnaire regarding their satisfaction with the application. Results Of the 18 patients, one withdrew their consent from this study and six were males (35.3%) ; their mean age was 31.71±8.56 years. The mean follow-up duration was 159.12±49.45 days and the period of application use was 143.65±52.11 days. The mean total response rate was 59.45% and the mean response rate on the same day was 43.06%. The adherence to using the application decreased significantly declined over the duration since enrollment [odds ratio (OR)=1.008, p=0.008] but tended to increase according to age (OR=0.958, p=0.002). The application mood scores were correlated significantly with the manic (β=0.307, p=0.004) and depressive (β=-0.701, p<0.001) subscale, and the total (β=1.026, p=0.002) of the CGI-7 (linear mixed models). The majority of subjects agreed that the application helped them manage their symptoms (92.86%), stating that the application was easy to use (78.57%). Conclusion This application could be a valid and useful tool to monitor the mood symptoms of patients with bipolar disorder in Korea.

6속 AT 기반 하이브리드 자동차의 모드변환 시 전동식 오일펌프 제어로직 개발

송민석(Minseok Song),김종현(Jonghyun Kim),김연호(Yeonho Kim),이학성(Haksung Lee),김현수(Hyunsoo Kim) 한국자동차공학회 2010 한국자동차공학회 학술대회 및 전시회 Vol.2010 No.11

In this study, an electric oil pump(EOP) control algorithm was proposed during mode change for a automatic transmission(AT) based parallel hybrid electric vehicle(HEV). From the experiment, it was observed that the engine clutch pressure drops during the mode change and at the steady state because additional flow rate should be supplied for the engagement of the engine clutch. In order to minimize the pressure drop during the mode change and maintain the demanded line pressure after the mode change, a 3 stage EOP control algorithm was suggested and its performance was evaluated by the experiments. It was found that the EOP control algorithm is able to reduce the pressure drop and maintain the target line pressure. In addition, the EOP speed at each stage is determined based on the automatic transmission fluid temperature

Conformational Effects in the Transport of Glucose through a Cyclic Peptide Nanotube: A Molecular Dynamics Simulation Study

Seo, Yongil,Song, Yeonho,Schatz, George C.,Hwang, Hyonseok American Chemical Society 2018 The Journal of physical chemistry B Vol.122 No.34

<P>The transport behavior of glucose through a cyclic peptide nanotube (CPN), composed of 8 × cyclo[-(Trp-<SMALL>D</SMALL>-Leu)<SUB>4</SUB>-Gln-<SMALL>D</SMALL>-Leu-] rings embedded in DMPC lipid bilayers was examined using all-atom molecular dynamics (AAMD) simulations. Two conformational isomers of β-<SMALL>D</SMALL>-glucose, equatorial (<SUP>4</SUP>C<SUB>1</SUB>) and axial (<SUP>1</SUP>C<SUB>4</SUB>) chair conformers, were used to examine conformational effects on the hydrogen bond network, energetics, and diffusivity of glucose transport through the CPN. Calculations of the number of hydrogen bonds of the two glucose conformers with water molecules and with the CPN illustrate that the total number of hydrogen bonds of the conformers decreases inside the channel compared to bulk water due to the confinement characteristics of the interior of the CPNs although new hydrogen bonds between the hydroxyl and hydroxymethyl hydrogens of glucose and the carbonyl oxygens in the CPN backbone are formed. Despite the decrease of the number of hydrogen bonds inside the CPN, intramolecular hydrogen bonds of <SUP>1</SUP>C<SUB>4</SUB> are maintained during permeation of <SUP>1</SUP>C<SUB>4</SUB> through the CPN. The retention of intramolecular hydrogen bonds and the spherical shape of <SUP>1</SUP>C<SUB>4</SUB> give rise to considerably weaker orientational preferences and higher diffusion coefficients for <SUP>1</SUP>C<SUB>4</SUB> than those of <SUP>4</SUP>C<SUB>1</SUB> inside and outside the CPN. Due to larger dipole moments induced by the alignment of hydroxyl and hydroxymethyl groups, <SUP>1</SUP>C<SUB>4</SUB> has more favorable interactions with the CPN backbone at the channel entrances and inside the channel than <SUP>4</SUP>C<SUB>1</SUB>. In the middle of the CPN channel, entropic gains originating from higher orientational and translational degrees of freedom of <SUP>1</SUP>C<SUB>4</SUB> than those of <SUP>4</SUP>C<SUB>1</SUB> also contribute to lower free energy wells for <SUP>1</SUP>C<SUB>4</SUB> inside the CPN. This work reveals that the conformational variation and intramolecular hydrogen bond formation of β-<SMALL>D</SMALL>-glucose can have important effects on the energetics and dynamics of glucose transport through CPNs, providing insight into the translocation mechanism of <SMALL>D</SMALL>-glucose into the cell through glucose transporters (GLUTs) and the dynamics of glucose confined in silica nanochannels. It is also demonstrated that CPNs can indeed facilitate the permeation of small hydrophilic molecules such as glucose and can be utilized as a novel carrier system for hydrophilic drug compounds into the cell.</P> [FIG OMISSION]</BR>