• Animal cells and systems
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• 제12권4호
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• pp.211-217
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• 2008

Bax, a pro-apoptotic member of Bcl-2 family proteins, plays a central role in the mitochondria-dependent apoptosis. Apoptotic signals induce the translocation of Bax from cytosol into the mitochondria, which triggers the release of apoptogenic molecules such as cytochrome C and apoptosis-inducing factor, AIF. Bax-inhibiting peptide(BIP) is a cell permeable peptide comprised of five amino acids designed from the Bax-interaction domain of Ku70. Because BIP inhibits Bax translocation and Bax-mediated release of cytochrome C, BIP suppresses Bax-dependent apoptosis. In this study, we observed that BIP inhibited staurosporine-induced neuronal death in cultured cerebral cortex and cerebellar granule cells, but BIP failed to rescue granule cells from trophic signal deprivation-induced neuronal death, although both staurosporine-induced and trophic signal deprivation-induced neuronal death are dependent on Bax. These findings suggest that the mechanisms of the Bax activation may differ depending on the type of cell death induction, and thus BIP exhibits selective suppression of a subtype of Bax-dependent neuronal death.

• 한국소음진동공학회논문집
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• 제12권8호
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• pp.648-656
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• 2002

This paper presents the identification of temperature-dependent hysteresis of an electro-rheological (ER) fluid under various operating temperatures using the Preisach model. As a first step, polymethylaniline (PMA) particles are prepared and mixed with silicone oil to make an ER fluid. A couette type electroviscometer is then employed to obtain the field-dependent shear stress. In order to show the suitability of the Preisach model to predict a physical hysteresis phenomenon of the ER fluid, two significant properties; the minor loop property and the wiping-out property are experimentally examined under three dominant temperature conditions. Subsequently, the Preisach model for the PMA-based ER fluid is identified using experimental multiple first order descending (FOD) curves. The effectiveness of the identified hysteresis model is verified in the time domain by comparing the predicted field-dependent shear stress with the measured one under the both specified and unspecified temperatures. In addition, the hysteresis model proposed in this work is compared to Bingham model.

• 혜화의학회지
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• 제13권2호
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• pp.251-258
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• 2004

Two cases of in patients with diabetic peripheral neuropathy were reported in this clinical study. After the study, the results were as follows: 1. Diabetic peripheral neuropathy was occurred with both insulin dependent diabetic mellitus(IDDM) patients, long and short durations, and non insulin dependent diabetic mellitus(NIDDM) patients. However, the degree of subjective symptom was stronger with the former patients. 2. Non insulin dependent diabetic mellitus(NIDDM) patients on dosage of Gamisamultang (加味四物湯) showed remarkable decrease of duration of illness and pain; however, plantar causalgic pain was unremarkable. In contrast to non insulin dependent diabetic mellitus(NIDDM) patients, long duration of insulin dependent diabetic mellitus(IDDM) patients showed remarkable decrease of plantar causalgic pain: however, pain decreased unremarkably. 3. The general treatment of diabetic patients was the control of blood glucose level; however it seemed to be no effect on the degree of subjective symptom. When patients were treated with acupuncture, followed by electropucture, on Palpung(八風), Taechung(太衝:Liv3), Chok-imup(足臨泣: Gb41), Hyonjong(縣鐘 : G39), Sungsan(承山 : B57), Chok-Samni(足三里 : S36), and Yangnungchon(陽陵泉 : G34) showed a great effect on decreasing the pain.

• PNF and Movement
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• 제6권3호
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• pp.19-28
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• 2008

Purpose : The objective of this study was to determine efficacy of sleep-dependent motor learning. Methods : This is a literature study with books and internet. We searched the PubMed, Science Direct, KISS and DBpia. Key words were Sleep-dependent, motor learning, RAM and LTP. Results : Procedural memory, like declarative memory, undergoes a slow, time-dependent period of consolidation. A process has recently been described wherein performance on some procedural task improves with the mere passage of time and has been termed "enhancement". Some studies have reported that the consolidation/enhancement of perceptual and motor skill is dependent on sleep. Specially, rapid-eye-movement(REM) sleep seems to benefit procedural aspects of memory. Conclusion : Motor learning is very important for CNS injury patients. And also distribution of practice sessions is important because REM sleep is to benefit procedural aspects of memory consolidation.

• Journal of the Optical Society of Korea
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• 제20권6호
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• pp.799-806
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• 2016

We present a polarization-dependent prism array film for controlling the viewing angle distribution of liquid crystal (LC) display panels without loss of light efficiency. On a directional backlight unit, our polarization-dependent prism array film, made into a stacked bilayer with a well-aligned liquid crystalline reactive mesogen (RM) layer on the UV-imprinted prism structure, can continuously control the light refraction function of the prism array by electrically switching incident polarization states of a polarization-controlling layer prepared by a twisted nematic LC mode. The viewing angle control properties of the polarization-dependent prism array film are analyzed under different prism angle and refractive index conditions of the RM layer. A simple analytic model is also presented to describe the intermediate viewing angle distributions with continuously varying applied voltages and incident polarization states.

• Nuclear Engineering and Technology
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• 제15권4호
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• pp.229-235
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• 1983

원자력발전소에서 Common Mode Failures (CMFs)가 상당한 관심을 모으고 있다. 이 논문에서는 중복 시스템의 비가용도(Unavailability)에 있어서의 전체 CMFs를 잠재적 CMFs(Potential CMFs)와 의존성 인간 실수에 의한 CMFs (CMFs of dependent human error)로 나누어 이론적으로 고찰하였다. 결론적으로, 인간 실수의 의존성이 높아질수록 전체 CMFs는 의존성 인간실수에 의해서 주로 영향을 받는다고 할 수 있다. 역으로, 인간 실수의 의존성이 낮아질수록, 전체 시스템의 비가용도는 기계적 고장이나 의존성 인간실수보다 잠재적 CMFs에 의해 지배된다고 할 수 있다. 그리고, 중복 시스템의 비가용도에 있어서 전체 CMFs가 기계적 고장보다 주된 요소임도 알 수 있었다.

• 조명전기설비학회논문지
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• 제27권3호
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• pp.36-42
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• 2013

This paper deals with the frequency-dependent ground impedance of ground grids combined with the carbon ground electrodes. Ground grids are generally valid for multipurpose grounding systems as well as lightning protection systems. The carbon ground electrodes may be supplementarily used to reduce the high frequency ground impedance and to improve the transient response to surge currents. The frequency-dependent ground impedances of ground grids combined with or without the carbon ground electrodes were measured and their simulations with due regard to frequency-dependent soil resistivity were implemented by using EMTP program and Matlab modeling. As a consequence, the ground impedance of ground grids combined with the carbon ground electrodes is significantly reduced when the test current is injected at the terminal of the carbon ground electrode. The measured and simulated data for the test ground grids fairly agree with each other. It was found that the proposed method of simulating the frequency-dependent ground impedance is distinguished. The simulation techniques of predicting accurately the ground impedances without actual measurements can be used in the design of grounding systems based on ground grids and the carbon ground electrodes.

• 비파괴검사학회지
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• 제28권4호
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• pp.358-363
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• 2008

재료의 미세열화를 측정하는 비파괴검사법으로 초음파의 비선형파라미터 측정기법이 최근 주목받고 있다. 하지만 그 크기가 매우 작기 때문에 여러 측정 인자들로부터 영향을 받아 일관성 있는 측정이 어렵다. 따라서 본 연구에서는 접촉식 탐촉자를 이용한 초음파 비선형파라미터의 측정에서 측정시스템에 의존하는 인자들의 영향을 연구하였다. 그 결과 탐촉자 접촉압력과 인가전압이 충분히 클수록 시스템 비선형성의 영향을 줄일 수 있음을 알 수 있었다. 이 연구의 결과는 정확한 비선형파라미터의 측정을 위한 실험조건을 설정하는 방법으로서 유용하게 사용될 것이 기대된다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2016년도 학술발표회
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• pp.164-164
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• 2016

Radar rainfall estimates have been widely used in calculating rainfall amount approximately and predicting flood risks. The radar rainfall estimates have a number of error sources such as beam blockage and ground clutter hinder their applications to hydrological flood forecasting. Moreover, it has been reported in paper that those errors are inter-correlated spatially and temporally. Therefore, in the current study, we tested influence about spatio-temporal errors in radar rainfall estimates. Spatio-temporal errors were simulated through a stochastic simulation model, called Multivariate Autoregressive (MAR). For runoff simulation, the Nam River basin in South Korea was used with the distributed rainfall-runoff model, Vflo. The results indicated that spatio-temporal dependent errors caused much higher variations in peak discharge than spatial dependent errors. To further investigate the effect of the magnitude of time correlation among radar errors, different magnitudes of temporal correlations were employed during the rainfall-runoff simulation. The results indicated that strong correlation caused a higher variation in peak discharge. This concluded that the effects on reducing temporal and spatial correlation must be taken in addition to correcting the biases in radar rainfall estimates. Acknowledgements This research was supported by a grant from a Strategic Research Project (Development of Flood Warning and Snowfall Estimation Platform Using Hydrological Radars), which was funded by the Korea Institute of Construction Technology.

• 한국안전학회지
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• 제33권6호
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• pp.37-41
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• 2018

Process safety technology has developed from qualitative methods such as HAZOP (hazard and operability study) to semi-quantitative methods such as LOPA (layer of protection analysis), and quantitative methods are actively studied these days. Quantitative risk assessment (QRA) is often based on fault tree analysis (FTA). FTA is efficient, but difficult to apply when failure events are not independent of each other. This problem can be avoided using a Markov process (MP). MP requires definition of all possible states, and thus, generally, is more complicated than FTA. A method is proposed in this work that uses an MP model and a Weibull distribution model in order to construct a reliability model for multiple dependent failures. As a case study, a pressure safety valve (PSV) is considered, for which there are three kinds of failure, i.e. open failure, close failure, and gas tight failure. According to recently reported inspection results, open failure and close failure are dependent on each other. A reliability model for a PSV group is proposed in this work that is to reproduce these results. It is expected that the application of the proposed method can be expanded to QRA of various systems that have partially dependent multiple failure states.