• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.1132-1136
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• 2004

In this paper, we intend to make FFS mode cell with LC alignment used non-rubbing method, ion beam alignment method on the a-C:H thin film, to analyze electro-optical characteristics in this cell. We studied on the suitable inorganic thin film for FFS-LCD and the aligning capabilities of nematic liquid crystal (NLC) using the new alignment material of a-C:H thin film as working gas at rf bias condition. A high pretilt angle of about 5$^{\circ}$ by ion beam(IB) exposure on the a-C:H thin film surface was measured. An excellent voltage-transmittance (V-T) and response time curve of the ion-beam-aligned FFS-LCD was observed with oblique ion beam exposure on the DLC thin films.

• Toxicological Research
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• 제6권1호
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• pp.89-97
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• 1990

Neural regulation of phenylethanolamine N-meth-yltransferase (PNMT) was studied with reserpine as a neuronal agent in rat adrenal medulla. The enzyme activity assay and northern blot analysis were performed to determine whether the induction of PNMT activity after reserpine treatment was associated with elevation of mRNA coding for PNMT. The i.p. administration of reserpine (2.5 mg/kg) on alternate days fot 4 injections to rats brought about 30% increase of adrenal medullary PNMT activity and approximately 60% stimulation of the PNMT mRNA level in rat adrenal gland. A dose of 10 mg/kg of reserpine was chosen to perform optimum induction of PNMT activity in the rat adrenal gland based on the results of dose response curve of reserpine. Time course reserpine (10 mg/kg) effects on the rat adrenal medullary PNMT were as follows: 1. Peripheral PNMT activity reached maximum level after 7 days of drug treatment on alternate days. 2. Trans-synaptic stimulation by reserpine increased pretranslational activity of rat adrenal PNMT, but not translational activity. 3. Immunotitration of PNMT molecule after reserpine treatment indicated that reserpine produced an enzyme with greater antibody affinity than endogenous molecule in the rat adrenal gland.

• 대한전자공학회논문지
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• 제18권4호
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• pp.12-20
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• 1981

본 연구에서는 랜덤신호로서 Gaussian 랜덤 신호와 PRBS(pseudo random binary sequence) 신호를 시험신호로 선정하였다. 실제로 인간을 실험대상으로 하여 E.O.G.(electro-oculography)로서 안구운동을 측정하고 통계통신이론에 바탕을 둔 랜덤신호 해석법으로 신호처리를 하여 동안계의 동 특성을 추정하였다. 본 연구에서 얻어진 주요결과를 요약하면 다음과 같다. 1. 주파수 응답의 결과 이득 특성은 0.7∼0.9Hz및 1.8∼2Hz에서 잠정적인 2번의 상승이 나타났으며, 이는 추적도중 발생한 saccade에 원인이 있었다. 2. Gaussian 랜덤입력에 대한 파워스펙트럼 밀도와 상호스펙트럼 밀도의 데이터로부터 단위시 간당 동안계의 정보전달비를 구한 결과 1.24 bits/sec를 나타냈다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(1)
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• pp.299-303
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• 2003

This paper deals with the frequency sensing methods at HVDC system. The objects of frequency information in HVDC system areto fire a valve and to control a frequency of AC network. Conventionally, there are two methods to measure a frequency of AC network. The first method is to draw out from the synchronous machine and the second method is from AC network. Two methods have advantages and disadvantage each other. For the extreme case of a receiving system of zero inertia (no generation), synchronous machine is essential. In this situation, the frequency information received from the synchronous machine shaft. However, the speed of synchronous machine is oscillated when a disturbance in AC network occurs, and HVDC may be oscillated due to an oscillation speed. To solve this drawback, in this paper, new frequency sensing method is proposed. A proposed method that is use a modified curve-fitting algorithm, has a robust characteristics against a harmonics and unbalanced faults. Consequently, A proposed method is verified by PSCAD/EMTDC Program and experimental test.

• 한국환경과학회지
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• 제18권8호
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• pp.867-876
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• 2009

Although renewable power is regarded a way to active response to climate change, the stability of whole power system could be a serious problem in the future due to its uncertainties such as indispatchableness and intermittency. From this perspective, the peak time impact of stochastic wind power generation is estimated using simulation method up to year 2030 based on the 3rd master plan for the promotion of new and renewable energy on peak time. Result shows that the highest probability of wind power impact on peak time power supply could be up to 4.41% in 2030. The impact of wind power generation on overall power mix is also analyzed up to 2030 using SCM model. The impact seems smaller than expectation, however, the estimated investment cost to make up such lack of power generation in terms of LNG power generation facilities is shown to be a significant burden to existing power companies.

• KSBB Journal
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• 제11권2호
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• pp.140-150
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• 1996

가정용 혈중 cholesterol 측정시스템을 개발하고자, 그 성능을 조절할 수 었는 벤수들의 최적화가 수 행되었다. 시스템의 주요 구성성분은 분석에 요구되는 효소들 (cholesterol esterase, cholesterol oxidase, 그리고 horseradish peroxidase) 이 부동화된 nitrocellulose membrane strip과 비 이온세척제 (Tri­t ton X-1OO) 및 발색물질 (3,3'-diaminobenzidine) 이 포함된 시료운반용액이다. 시료와 운반용액이 훈 합된 수용액을 membrane의 하단으로부터 흡수시키 면 모세관현상에 의해 시료는 부통화된 효소층으로 전달되어 연속효소반응이 일어난다. 마지막 효소반 응에서 발색물질은 산화되고 그에 따라 cholesterol 농도에 비례한 특정색이 신호로써 발생된다. 그 신호세기에 대해 효소들의 부동화조건과 운반용액의 화학조성이 최적화되었다. 최적조건 하에서 구성된 측정시스템의 농도응탑곡선은 혈중 cholesterol 농도를 측정하기에 충분히 높은 민감도를 나타내었다.

• ALGAE
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• 제32권2호
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• pp.131-137
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• 2017

Although green algae of the genus Closterium are considered ideal models for testing toxicity in aquatic ecosystems, little data about the effects of toxicity on these algal species is currently available. Here, Closterium ehrenbergii was used to assess the acute toxicity of copper (Cu). The median effective concentration ($EC_{50}$) of copper sulfate based on a dose response curve was $0.202mg\;L^{-1}$, and reductions in photosynthetic efficiency ($F_v/F_m$ ratio) of cells were observed in cultures exposed to Cu for 6 h, with efficiency significantly reduced after 48 h (p < 0.01). In addition, production of reactive oxygen species significantly increased over time (p < 0.01), leading to damage to intracellular organelles. Our results indicate that Cu induces oxidative stress in cellular metabolic processes and causes severe physiological damage within C. ehrenbergii cells, and even cell death; moreover, they clearly suggest that C. ehrenbergii represents a potentially powerful test model for use in aquatic toxicity assessments.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.409-412
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• 2005

Just as the vibration modes of a beam are dependent on its end constraints or boundary conditions. Vibration modes of a tire are dependent on its patch and spindle constraints. This dependence is key to understanding the dynamic properties of a tire and is apparent in various analytical and experimental investigations in the literature. One of the main task in a modal analysis is the measurement of the Frequency Response Function (FRFs). Because all the subsequent analysis is based on these FRFs, their quality is critically important in obtaining accurate modal parameter estimates. In rotating systems, FRFs are frequently contaminated by harmonic peaks related to such factors as imbalance, misalignment. This harmonic peaks appear in the FRFs as sharp spikes, which can be erroneously treated in modal curve-fitting procedures as structural modes. The harmonic peaks removal method is demonstrated by application to modal analysis on rotating tires. The results show substantial improvement in FRF quality.

• 한국소음진동공학회논문집
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• 제24권8호
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• pp.613-620
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• 2014

A few Humidifier have vibration problems caused by velocity of flow, piping vibration and karman vortex. The crack is generated on pipe wall and humidifier are damaged. Vibration analysis is conducted to prevent pipe damage during the design. But the other problem are caused after analysis of vibration. Therefore in this paper, the vibration and static analysis have been measured and analyzed for pipes and curve. Also modal test is conducted for analysis of natural frequency.

• 한국정밀공학회지
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• 제25권10호
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• pp.48-57
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• 2008

MR Fluid, one of functional fluids, is developed for the application to automobile products. MR CDC damper using MR fluid has following principles. When ar electric current is applied to the solenoid, apparent viscosity of MR fluid passing through the annular gap which acts as magnetic circuits varies directly as the intensity of the current. These devices have a simple structure and excellent lime response characteristics, emerging as the alternatives of the conventional semi-active suspension systems. In this study, a design procedure of the magnetic circuit through the solenoid fore and the flux ring functioning as a magnetic path is investigated so as to optimize the design and performance of MR CDC dampers for the vehicles. In addition, an operating point on the B-H curve, the magnetization according to the variation in the annular gap, the pole piece width and the density of MR fluid are studied to design the optimal piston head within the restrained dimension range.