• Journal of Photoscience
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• 제11권1호
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• pp.35-40
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• 2004

[Ru(2,2'-bipyridine)$_2$(4,4'-dicarboxy-2,2'-bipyridine)]$^{2+}$(RuBDc) is a very photostable probe that possesses favorable photophysical properties including long lifetime, high quantum yield, large Stokes' shift, and highly polarized emission. To evaluate the usefulness of this luminophore (RuBDc) for studying macromolecular dynamics, its intensity and anisotropy decays when conjugated to RNA bacteriophage MS2 were examined using frequency-domain fluorometry with a high-intensity, blue light-emitting diode (LED) as the modulated light source. The intensity decays were best fit by a sum of two exponentials, and the mean intensity decay time was 442.2 ns. The anisotropy decay data showed a single rotational correlation time (2334.9 ns), which is typical for a spherical molecule. The use of RuBDc enabled us to measure the rotational correlation time up to several microseconds. These results indicate that RuBDc can be useful for studying rotational diffusion of biological macromolecules.s.

• 한국시스템다이내믹스연구
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• 제9권2호
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• pp.27-43
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• 2008

This study investigates market barriers in increasing the market share of Alternative Fuel Vehicles (AFVs). In particular, this study first conceptualizes the AFVs market model with the aid of generic system archetypes suggested by Wolstenholme. Among four generic system archetypes suggested by Wolstenholme, the market structure of AFVs can be explained by the 'relative achievement' archetype. Starting from the generic system archetype, this study extends the model boundary step by step to take account of various model assumptions necessary to simulate the model numerically. If there is a significant network effect on vehicle operating costs, it is difficult to achieve the shift to AFVs even in the long term without a policy intervention because the car market is locked into the current structure. There are several possible policy options to break the 'locked-in' structure of the car market, such as subsidies on vehicles, subsidies on fuels, and a niche management policy.

• 한국자기공명학회논문지
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• 제6권1호
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• pp.1-11
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• 2002

Physical properties of PVB [Poly(vinyl butyral)] polymer are strongly correlated with water contents in the polymer. Thus dynamics of PVB containing 10~50(w/w) ％ of water were studied by $^{13}$ C CP/MAS/DD over the temperature range 293K -348K. From the Peak area, line width, chemical shift, and relaxation times ( $T_{1}$ $T_{1p}$) measured at 9.4 T, it was deduced that water facilitates molecular dynamics of the PVB molecules overall including conformational exchange of the racemic and meso butyaldehyde rings in the PVB. However, the influence of water was not linear to the amount of water in the PVB samples. It is suggested that water up to 30 w/w ％ of the sample is closely bound to the PVB polymer and water relatively free from the PVB polymer starts to appear when water is added more than 30 w/w ％.％.

• 한국경제지리학회지
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• 제3권2호
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• pp.23-42
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• 2000

본 연구는 경제개혁이후 중국의 지역경제성장의 불균등성에 대해 진행된 많은 연구들을 비판적으로 검토하고 시장화 전략에 의한 노동시장성장의 지리적 패턴과 그것이 갖는 지역격차 이해에 대한 함의를 검토한다. 변이할당 분석을 통해 나타난 고용성장의 지리학은 생산량에 기초한 공간경제패턴과 유사한 모습을 나타내고 있는데 이는 시장화의 심화에 따라 노동시장의 성장이 노동수요의 변화에 대응하고 있다는 점을 반증하는 것이다. 또한 생산량과 생산성의 변화가 노동시장의 성장에 대해 갖는 효과를 관찰한 결과, 비국유기업의 생산량 및 생산성의 상대적 증가가 크게 나타나고 있으며 결과적으로 지역변이효과를 통해 지역경제내 고용증대효과를 동남해안지역의 성들 중심으로 가져 온 것으로 나타났다. 반면에 국유기업은 생산량과 생산성의 상대적인 감소로 인하여 고용감소효과를 가져 왔다 결과적으로 노동시장의 성장은 생산의 증대와 함께 지역경제발전의 패턴을 결정하는 중요한 요인으로 작용하고 있다. 아울러 고용성장의 지리적 패턴에 대한 설명과 이해는 나아가 경제개혁이라는 제도적 변화와 관련시킨 연구를 통하여 보다 확대될 수 있다.

• Bulletin of the Korean Chemical Society
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• 제27권11호
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• pp.1825-1831
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• 2006

The influence of solvent viscosity on conformational dynamics of the heme-pocket, a small vacant site near the binding site of myoglobin (Mb) and hemoglobin (Hb), and playing a functionally important role by serving as a station in ligand binding and escape, was studied by probing time-resolved vibrational spectra of CO photodissociated from MbCO and HbCO in $D_2O$, 75 wt% glycerol/$D_2O$, and trehalose at 283 K. Two absorption bands ($B_1$ and $B_2$) of the sample in viscous solvents, arising from CO in the heme pocket, are very similar to those in $D_2O$. Two bands in Mb and Hb under all three solvents exhibit very similar nonexponential spectral evolution ($B_1$ band; blue shifting and broadening, $B_2$ band; narrowing with a negligible shifting), suggesting that in the present experimental time window of 100 ps, the extents of the spectral shift and narrowing is much influenced neither by the viscosity of solvent nor by the quaternary contact of Hb. Spectral evolution can be described by a biexponential function with a fast universal time constant of 0.52 ps and a slow time constant ranging from 13 to 32 ps. For both proteins in all three solvents majority of spectral evolution occurs with the fast universal time constant. The magnitude of the slow rate in the spectral shift of B1 band decreases with increasing solvent viscosity, indicating that it is influenced by global conformational change which is retarded in viscous solvent, thereby serve as a reporter of global conformational change of heme proteins after deligation.

• 한국시스템다이내믹스학회:학술대회논문집
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• 한국시스템다이내믹스학회 2002년도 추계학술대회발표논문집
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• pp.59-100
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• 2002

본 연구는 공여 된 신지가 기업회생에 어떠한 영향을 미치고 어떠한 역할을 하는지 시스템 다이내믹스 모형 개발과 시뮬레이션을 통해서 검증한다. 국내 기업회생 사례연구를 통해서 어떻게 조직시스템이 공여 된 신지에 반응을 하는지를 알아보고 공여 된 신뢰와 기업회생에 관한 관계를 수리적으로 모형 화한다. 그리고 공여 된 신지가 어떻게 조직시스템을 위기의 상황에서 다시 회생하도록 움직이는지 알아보기 위해서 시스템 다이내믹스 모형을 개발한다. 모형은 '문제의 발생-해결' 의 관점에서 구축하였고, 공여 된 신뢰에 대한 선행이론으로 귀인이론, 위지 커뮤니케이션을 통한 위기공유를 도출하였다. 본 연구는 시뮬레이션 결과를 통해 공여 된 신지가 기업회생의 새로운 조건이라는 사실을 검증함으로써 기업회생의 동태적 과정에 대한 이론적 통찰과 실무적 시사점을 제공한다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.332.1-332.1
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• 2016

Application of magnetic fields is important to characterize the carrier dynamics in semiconductor quantum structures. We performed photoluminescence (PL) measurements from an InGaP-AlInGaP single quantum well under pulsed magnetic fields to 50 T. The zero field interband PL transition energy matches well with the self-consistent Poisson-Schr?dinger equation. We attempted to analyze the dimensionality of the quantum well by using the diamagnetic shift of the magnetoexciton. The real quantum well has finite thickness that causes the quasi-two-dimensional behavior of the exciton diamagnetic shift. The PL intensity diminishes with increasing magnetic field because of the exciton motion in the presence of magnetic field.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.482-485
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• 1996

We design a homing guidance law based on the proportional navigation for the fast-rolling, single-axis control missiles and analyse the misdistance of the designed guidance system. The guidance law includes a compensation scheme which compensates for the phase-shift between the commanded and achieved acceleration which is peculiar to the fast rolling airframe with single-axis control. In the error analysis of the guidance system, we calculate the misdistance with respect to the target maneuver on the 3-dimensional space via direct simulations. Also, we conduct adjoint simulation on the 2-dimensional plane in case that phase-shift is perfectly compensated. Finally we approximate the linear time-varying dynamics of the missile with autopilot to a linear time-invarient system, and as a result we can find the misdistance as a closed-form.

• 유공압시스템학회논문집
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• 제6권1호
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• pp.25-31
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• 2009

This study presents an analytical model of hydraulic clutch system of a power shift transmission to analyze pressure modulation characteristics. A typical hydraulic clutch system was modeled by using AMESim in which the parameters of major components were measured for simulation. Test apparatus was established using the components of power shift and power shuttle clutches with instrumental equipment. The results of simulation and experiment were so close that the proposed analytical model in this study was validated. However the cylinder model analogized clutch dynamics need to be improved in future study. The effects of parameters of orifice diameter, accumulator stroke and oil temperature on pressure modulation were analyzed respectively. The results of parameter sensitivity analysis show that modulation time and set pressure can be easily adjusted by changing parameter values. It is also found that the hydraulic clutch system used in this study is so susceptible to oil temperature that cooling equipment is necessary.

• 한국자기공명학회논문지
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• 제22권4호
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• pp.76-81
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• 2018

Investigation of the protein-protein interaction mode at atomic resolution is essential for understanding on the underlying functional mechanisms of proteins as well as for discovering druggable compounds blocking deleteriou interprotein interactions. Solution NMR spectroscopy provides accurate and precise information on intermolecular interactions even for weak and transient interactions, and it is also markedly useful for examining the change in the conformation and dynamics of target proteins upon binding events. In this mini-review, we comprehensively describe three unique and powerful methods of solution NMR spectroscopy, paramagnetic relaxation enhancement (PRE), pseudo-contact shift (PCS), and residual dipolar coupling (RDC), for the study on protein-protein interactions.