• 대한기계학회논문집A
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• 제32권10호
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• pp.866-872
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• 2008

Torsional oscillations of the mechanical drivetrain in electric vehicles are generated under rapid driving conditions. These lead to an uncomfortable jerking of the vehicle and to an increased stress of the mechanical components. To analyze this phenomenon, a drivetrain model is constructed with lumped parameters. The model parameters are identified by geometrical design data and experimental tests. The proposed model is validated by simulation and experimental tests in the time and the frequency domains. As a result, the torsional oscillations are observed at 7Hz of a low damped natural frequency. Also, the analysis of the effect of the parameter variations on the oscillations shows that the oscillation characteristic is mainly dependent on the rotor inertia, and the stiffness of the mounting of the drive aggregate and the driveshaft. The results will be utilized on the basis of the design of an electric drivetrain and an active control of drivetrain oscillations.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.147-152
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• 2006

This paper presents the dynamic characteristics of MR impact damper for vehicle collision system. Various types of mechanism have been proposed for reduce transmitted force to vehicle chassis and finally protect occupants from injury. In the case of frontal collision, the bumper make main role of isolation material for collision attenuation. In this study, proposed bumper system composed of MR impact damper and structures. The MR impact damper is to adopted MR fluid which has reversible properties with applied magnetic field. MR fluid operates under flow mode with Bingham flow and bellows is used for generation of fluid flow. Mathematical model of MR impact damper incorporated with MR fluid is established. Field dependent damping force is investigated with time and frequency domain. The MR impact damper is then incorporated with vehicle crash system. The governing equation of motion of vehicle model is formulated considering occupant model. Dynamic characteristics of vehicle collision system investigated with computer simulation.

• 한국콘텐츠학회논문지
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• 제15권3호
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• pp.48-56
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• 2015

1940년대 영화음악은 영화 속 장면의 상황 및 인물의 성격과 심리적 갈등을 내포하며 향후 범죄영화와 긴장감 유발 장면의 테마음악으로 표현되는 기능적 역할을 한다. 따라서 본 연구는 영화음악가 미클로스로자(Miklos Rozsa)가 참여한 영화 "이중배상"에 나오는 테마음악의 음악적 요소가 시간적 흐름에 따른 사건진행을 상징적 방법으로 구성가능하며 영상의 몰입을 위해 감성을 자극하고 상승을 유도하는 것을 입증한다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.415-418
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• 2005

To understand effects of carbon nanotubes (CNTs) dispersed in nematic liquid crystal (NLC) on electro-optic characteristic and orientation of the LC, we CNT-doped homogeneously-aligned NLC cells driven by in-plane field have been fabricated. The CNTs were aligned with a LC director from the initial state to below critical ac field, whereas the CNTs disturbed the LC director field above critical ac field. We observed motional textures in the form of vertical stripes in the local area between electrodes, which were associated with a deformation of the LC director orientation. This indicates that CNTs start vibrating three dimensionally with translational motion. Further, the hysterisis studies of voltage-dependent transmittance under dc electric field show that the amount of residual dc, which is related to image sticking problem in liquid crystal displays, is greatly reduced due to ion trapping by CNTS while keeping operating voltage and response time about the same compared to the un-doped LC cell.

• 한국보건간호학회지
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• 제19권2호
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• pp.294-304
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• 2005

Purpose: The purpose of this study was to review and analyze the trend and issues of nursing research on music therapy. This study was aimed to help direct developing better music therapy programs in the future. Method: We reviewed 57 dissertations and published articles from 1983 to Feb. 2005 that were related to music therapy in nursing. Result: Among the 57 published researches on music therapy, 47 (82.5%) were dissertations and 10 (17.5%) were published articles. Among the 57 researches, 55 (96.5%) were experiential researches and 2 (3.5%) were non-experimental researches. Surgical patients were the most popular subject for researches. The number of subject was a minimum of 7 people and maximum of 143 people. Listening to music 41 (74.5%) was the most popular program for music therapy. Among 55 researches, 33 (60.0%) had a music therapy session of 25-60 minutes and this was the most popular time duration of therapy. Among all the 108 dependent variables, 57 (52.8%) were psychological variables, 40 (37.0%) were physical variables and 11 (10.2%) were social-cognitive variables. Conclusion: There is an urgent need to develop systematic music therapy programs with different nursing interventions, as based on theories and principles while considering the physical, psychological, and social characteristic of the subjects.

• 한국전기전자재료학회논문지
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• 제17권2호
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• pp.201-206
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• 2004

We have performed computer simulation and experiment to obtain electro-optic characteristics of reflective hybrid aligned nematic (R-HAN) cell driven by fringe field, in which the cell consists of polarizer, optical compensation film, LC layer and reflector. Conventional R-HAN cell driven by fringe field using only the LC layer shows high wavelength dispersion at dark-state and thus viewing angle characteristic is strongly wavelength-dependent. In order to improve this demerit, we added one optical compensation film to conventional R-HAN cell. The display with optimized cell parameters shows low wavelength dispersion at dark-state and exhibits a wide viewing angle without the occurrence of grey scale inversion over a wide range of viewing angles and the contrast ratio greater than 5 over exists about 120$^{\circ}$ in vortical direction and 160$^{\circ}$in horizontal direction. Experimental results show good agreements with theoretical results and fast response time.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1038-1040
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• 2005

This paper describes the optimal design, construction and performance evaluation of voltage divider used in high power testing laboratory for voltage measuring system. These dividers, which are of R, C, R&C type voltage dividers, the voltage to be measured range from voltage to several ten kilovolts, the frequency of the signals has a bandwidth from DC to megaHertz Measuring transient voltage and currents in the high voltage power laboratory is generally accompanied by electromagnetic interface and induced noise. above all, the measuring capabilities of voltage measuring system are dependent upon short response time and it must be as free as possible of inductive effects. In this paper presents both characteristic of voltage divider and design of voltage measuring system.

• 한국재료학회지
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• 제19권6호
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• pp.319-324
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• 2009

The deposition behavior and structural and magnetic properties of electroless Co-B and Co-Fe-B deposits, as well as the amorphous ribbon substrates, were investigated. These Co-based alloy deposits exhibited characteristic polycrystalline structures and surface morphology and magnetic properties that were dependent on the type of amorphous substrates. The catalytic activity sequence of the amorphous ribbon electrodes for anodic oxidation of DMAB was estimated from the current density-potential curve in the anodic partial electrolytic bath that did not contain the metal ions. Both the deposition rate and potential in the initial region were obtained in order of the catalytic activity, depending on the alloy compositions of the substrates. The deposition rate linearly varied against the deposition time. The initial deposition potential may have also determined the structural and magnetic properties of the deposit based on the thickness of ${\mu}m$ order. Furthermore, a basic study of the electroless deposition processes on an amorphous ribbon substrate has been carried out in connection with the structural and magnetic properties of the deposits.

• Animal cells and systems
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• 제11권1호
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• pp.17-22
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• 2007

The effects of antimetabolite 6-AN (6-amino-nicotinamide) on viability and morphology of L6 myoblast cells have been investigated. 6-AN ($100{\mu}M$) induced a time-dependent decrease in cell viability with respect to the untreated control cells. Following 6-AN administration the viability rate started to decline sharply, reaching about 23% of the untreated control cells at 48 h. Inverted phase-contrast microscopy revealed that 6-AN caused characteristic morphological changes such as irregularly elongated and stellate shape of cells, round-shaped nucleus, cytoplasmic vacuolization, irregular cell arrangements and formation of large spaces among cell clusters. The concentrations of ATP and $NAD^{+}$ in the 6-AN treated cells were significantly lower (p < 0.01) than those of the untreated control cells. In contrast, the concentration of AMP was significantly increased by the 6-AN treatment. Activities of catalase, superoxide dismutase and glutathione peroxidase in 6-AN treated cells were significantly higher (p < 0.01) than those of the untreated control cells. The activities of glyceraldehyde-3-phosphate dehydrogenase in 6-AN treated cells were significantly lower (p < 0.01) than those of the untreated control cells. The results suggest that 6-AN caused marked reduction of cell viability and alterations of some important metabolites and enzymes.

• Nuclear Engineering and Technology
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• 제53권8호
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• pp.2646-2651
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• 2021

A rectangular-shaped PET system with an adjustable gantry (AGPET) has been developed for imaging small animals. The AGPET system employs a new depth of interaction (DOI) method using a depth dependent reflector patterns and a new digital time pickoff method based on the pulse reconstruction method. To evaluate the performance of the AGPET, timing resolution, intrinsic spatial resolution and point source images were acquired. The timing resolution and intrinsic spatial resolution were measured using two detector modules and Na-22 gamma source. The PET images were acquired in two field of view (FOV) sizes, 30 mm and 90 mm, to demonstrate the characteristic of the AGPET. As a result of in the experiment results, the timing resolution was 0.9 ns using the pulse reconstruction method based on the bi-exponential model. The intrinsic spatial resolution was an average of 1.7 mm and the spatial resolution of PET images after DOI correction was 2.08 mm and 2.25 mm at the centers of 30 mm and 90 mm FOV, respectively. The results show that the proposed AGPET system provided higher sensitivity and resolution for small animal imaging.