• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.1605-1608
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• 2006

The contrast ratio, brightness, and uniformity of S-IPS panel, whose alignment process was employed by ion-beam-alignment (IBA) technology, were improved significantly compared with the convention rubbing's panel, because the light leakage has been reduced in dark state effectively. The IBA technology could generate a panel whose pretilt angle was stable and low after post-treatment process.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2000년도 추계학술발표논문집
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• pp.261-267
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• 2000

The purpose of this study is to analyze the effects of the auditory stimulation using pop music on EEG. The subjects in the study were eight healthy university students; five men and three women, age group of 22-28 years old. EEGs were measured for one minute at 19 channels, according to the international 10-20 system method, after both pop musics which the subject likes and not were provided with 100% and 50% volume of standard value, respectively, and the ratio of $\beta$/$\alpha$ was obtained. As a result, when the subjects heard their favorite music, the values of $\beta$/$\alpha$ ratio at the Right-Parietal.Temporal.Occipital lob(T6, O2) showed to be lower than stable state in the situation with 50% volume of standard value.

• 약학회지
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• 제31권5호
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• pp.322-329
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• 1987

A rapid and sensitive spectrophotometric method has been developed for quantitation of some phenothiazine derivatives (PTZDS). The method depends on the formation of insoluble yellow complexes between PTZDS and picric acid (PCA) in aqueous layer. These complexes are quantitatively extracted from aqueous phase into chloroform. The binding ratio of PTZDS-PCA complexes were presumed as PTZDS-1 to PCA-1 by means of mole ratio and continuous variation methods. The complexes are stable for more than 24hours in chloroform layer at room temperature. Most of compounds associated with pharmaceutical preparation of PTZDS do not interfere with this method. However, chlorpheniramine and diphenhydramine interfere with the riaethod. The binding state of PTZDS-PCA complexes were presumed by IR and $^1$H-NMR spectra as intermolecular hydrogen bonding.

• International Journal of Automotive Technology
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• 제3권4호
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• pp.165-170
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• 2002

For a vehicle Anti-lock Braking System (ABS), the control target is to maintain friction coefficients within maximum range to ensure minimum stopping distance and vehicle stability. But in order to achieve a directionally stable maneuver, tire side forces must be considered along with the braking friction. Focusing on combined braking and turning operation conditions, this paper presents a new control scheme for an ABS controller design, which calculates optimal target wheel slip ratio on-line based on vehicle dynamic states and prevailing road condition. A fuzzy logic approach is applied to maintain the optimal target slip ratio so that the best compromise between braking deceleration, stopping distance and direction stability performances can be obtained for the vehicle. The scheme is implemented using an 8-DOF nonlinear vehicle model and simulation tests were carried out in different conditions. The simulation results show that the proposed scheme is robust and effective. Compared with a fixed-slip ratio scheme, the stopping distance can be decreased with satisfactory directional control performance meanwhile.

• 한국산학기술학회논문지
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• 제8권5호
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• pp.1082-1086
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• 2007

본 연구는 국내에서 발생되는 소각재를 재활용하여 벽돌 생산을 하는 공장에서의 이원화된 작업현황을 일원화 할 수 있는 데이터 모니터링 시스템 구축을 목적으로 한다. 모니터링 시스템은 상태관리 프로세스, 위치관리 프로세스, 불량관리 프로세스, 상황관리 프로세스 등의 데이터 관리 프로세스를 이용해 데이터를 자동 관리하도록 설계하였다. 본 연구에서는 RFID 태그를 이용하여 각 공정의 상황 정보를 수집하고 수집된 정보를 가공하여 데이터 모니터링 시스템에 전송한다. 이러한 시스템을 통해 분석된 데이터는 소각재를 재활용하여 벽돌 생산을 하는 공장에서 공정자동화, 불량률 최소화, 실시간 모니터링, 적재 관리를 통해 생산 공정을 효율적으로 관리할 수 있다.

• Geomechanics and Engineering
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• 제28권5호
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• pp.463-475
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• 2022

In the mine exploitation stage; one of the critical issues is the stability assessment of post-pillars. The instability of post-pillars leads to serious safety hazards in mining operations. The focus of this study is to assess the stability of post-pillars in the 130# stope in the central ore body at Trepça hard rock mine by employing both conventional (i.e., critical span curve) and numerical methods (i.e., FLAC3D). Moreover, a new numerical based index (i.e., Pillar Yield Ratio-PYR) was proposed. The aim of PYR index is to determine a border line between stable, potentially unstable, and failure state of post-pillars at a specific mine site. The critical value of pillar width to height ratio is 2.5 for deep production stopes (e.g., > 800 m). Results showed that pillar size, mining height and mining depth significantly have affected the post-pillar stability. The reliability of numerical based index (i.e., PYR) is verified based on empirical underground pillar stability graph developed by Lunder, 1994. The proposed pillar yield ratio index and pillar stability graph can be used as a design tool in new mining areas at Trepça hard rock mine and for other situations with similar geotechnical conditions.

• Journal of information and communication convergence engineering
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• 제3권4호
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• pp.179-183
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• 2005

A photodiode capable of obtaining a sufficient photo/ dark current ratio at both forward bias state and reverse bias state is proposed. The photodiode includes a glass substrate, an aluminum film formed as a lower electrode over the glass substrate, an alumina film formed as an insulator barrier over the aluminum film, a hydrogenated amorphous silicon film formed as a photo conduction layer over a portion of the alumina film, and a transparent conduction film formed as an upper electrode over the hydro-generated amorphous silicon film. A good quality alumina $(Al_2O_3)$ film is formed by oxidation of aluminum film using electrolyte solution of succinic acid. Alumina is used as a potential barrier between amorphous silicon and aluminum. It controls dark-current restriction. In case of photodiodes made by changing the formation condition of alumina, we can obtain a stable dark current $(\~10^{-12}A)$ in alumina thickness below $1000{\AA}$. At the reverse bias state of the negative voltage in ITO (Indium Tin Oxide), the photo current has substantially constant value of $5{\times}10^{-9}$ A at light scan of 100 1x. On the other hand, the photo/dark current ratios become higher at smaller thicknesses of the alumina film. Therefore, the alumina film is used as a thin insulator barrier, which is distinct from the conventional concept of forming the insulator barrier layer near the transparent conduction film. Also, the structure with the insulator thin barrier layer formed near the lower electrode, opposed to the ITO film, solves the interface problem of the ITO film because it provides an improved photo current/dark current ratio.

• 한국재난정보학회 논문집
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• 제19권4호
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• pp.851-858
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• 2023

연구목적: 종래의 PSC 거더에 비해 단면 효율이 개선된 양각 거더교의 구조적 안전성을 확보하기 위한 연구를 수행하였다. 이를 위해 거더 길이, 높이, 폭과 같은 단면의 제원을 정하고 강연선의 배치를 설계하여 정적 및 동적 하중에 의한 양각 거더의 실질적인 성능을 검증하였다. 연구방법: 정적 성능 실험은 1차 및 2차 정적 하중에 대한 처짐, 균열 등의 거동 응답을 측정하여 사용성 한계상태를 검토하였다. 또한, 동적 하중 재하 실험은 시간에 따른 가속도, 변위 거동 응답을 측정하여 고유진동수 및 감쇠비를 산정하여 사용성 한계상태를 검토하였다. 연구결과: 정적 성능 실험 결과 최대 재하하중 기준 처짐값은 안정적인 거동을 나타났고, 최대 재하하중 수준에서 측정된 균열폭은 매우 작아서 사용성 한계상태를 만족하는 것으로 나타났다. 또한, 동적 하중 재하 실험 설계 시 산정된 고유진동수를 상회하는 고유진동수가 나타났으며, 현행 규정에 만족하는 감쇠비를 확보하는 것으로 나타났다.

• 대한의용생체공학회:의공학회지
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• 제45권2호
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• pp.101-107
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• 2024

Steady-state visual evoked potential-based brain-computer interface (SSVEP-BCI) is one of the promising systems that can serve as an alternative input device due to its stable and fast performance. However, one of the major bottlenecks is that some individuals exhibit no or very low SSVEP responses to flickering stimulation, known as SSVEP illiteracy, resulting in low performance on SSVEP-BCIs. However, a lengthy duration is required to enhance multiple SSVEP responses using traditional single-frequency transcranial alternating current stimulation (tACS). This research proposes a novel approach using dual-frequency tACS (df-tACS) to potentially enhance SSVEP by targeting the two frequencies with the lowest signal-to-noise ratio (SNR) for each participant. Seven participants (five males, average age: 24.42) were exposed to flickering checkerboard stimuli at six frequencies to determine the weakest SNR frequencies. These frequencies were then simultaneously stimulated using df-tACS for 20 minutes, and the experiment was repeated to evaluate changes in SSVEP responses. The results showed that df-tACS effectively enhances the SNR at each targeted frequency, suggesting it can selectively improve target frequency responses. The study supports df-tACS as a more efficient solution for SSVEP illiteracy, proposing further exploration into multi-frequency tACS that could stimulate more than two frequencies, thereby expanding the potential of SSVEP-BCIs.

• 상하수도학회지
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• 제22권5호
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• pp.581-587
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• 2008

In this study, we investigated the buffering effect with different COD, $NH_4{^+}-N$ and TP shock loads on the performance of lab-scale Sequencing Batch Reactor(SBR) using synthetic wastewater. This study was operated under the following conditions : HRT, 12 hrs : MLSS, 2,000 mg/L : F/M ratio, $0.2kgCOD/kgMLSS{\cdot}d$ : SRT, 20days, and was increased by a factor, COD : ranging from 200-2000 mg/L, $NH_4{^+}-N$ : ranging from 30-300 mg/L, T-P : ranging from 5-50 mg/L in the reactor. As results, COD removal rate at different shock loads was decreased until 42.1%(stable state : 95%) and concentration with effluent was higher than 695 mg/L(at Run 6). In case of $NH_4{^+}-N$ removal rate was decreased until 35.8% from 97.0% and also T-P removal rate was decreased until 5.0%. Effluent concentrations of COD, $NH_4{^+}-N$ and T-P were rapidly increased according to shock loads and needed 3, 4 and 6 additional cycle times for recovering the stable condition.