• Journal of the Korean Physical Society
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• 제81권
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• pp.867-875
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• 2022

This paper explored the effect of deposition conditions on the characteristics of copper oxide (CuO_x) thin films prepared by direct current (DC) magnetron sputtering. X-ray diffraction exhibited that CuO with n-type conductivity was the main composition regardless of the DC magnetron sputtering power whereas the phase transition from n-type CuO to p-type Cu₂O was observed with decreasing the oxygen pressure (OP) from 40 to 20%. The optical band gap ranges of 1.6-1.9 eV, which are characteristic of n-type CuO, were determined for samples prepared with OPs of 30-40% while the optical band gap of 2.3 eV, which is characteristic of p-type Cu₂O, was measured for samples prepared with an OP of 20%. In addition, only Cu⁺ X-ray photoelectron spectroscopy (XPS) peak at the ~932.6 eV position exists in the films deposited with an OP of 20%, whereas only Cu²⁺ XPS peaks at ~934.2 eV and in the range of 940-945 eV are observed in the films deposited with an OP of 40%. Furthermore, as a result of XPS depth profile analysis, it was confirmed that the composition ratio of the sample prepared at an OP of 20% was Cu₂O, whereas the composition ratio of the sample prepared at an OP of 40% was CuO. These suggest that the CuO_x thin films could be constantly converted from n-type CuO to p-type Cu₂O by decreasing the oxygen partial pressure. Thin film transistors with Cu₂O deposited at 20% OP revealed p-type characteristics such as onset voltage (V_ON) of -3 V, saturated hole mobility of 8 cm²/Vs at V_GS = -28 V, subthreshold swing of 0.86 V/decade at V_GS-V_ON = -0.5 V, and on/off ratio of 1.14 × 10³.

• 전자공학회논문지SC
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• 제48권1호
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• pp.1-8
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• 2011

MR 센서에 의해 지구자기장의 세기를 측정하여 방위각을 결정하는 전자 Compass의 정밀도는 MR센서 및 OP-Amp.의 온도 Drift, DC Offset등 소자에 의한 오차, 측정주변 자성체에 의한 자기장의 왜곡, 및 Compass Tilt에 의한 오차 등의 영향을 받는다. 본 연구에서는 Set/Reset Pulse 방법에 의해 MR 센서 및 OP-Amp의 온도 Drift 및 DC Offset에 의한 오차를 해결하였고, 주변 자성체에 의한 자기장의 왜곡에 의한 오차를 Hard-Iron Calibration 루틴 수행에 의해 보상하였으며, Compass Tilt에 의한 오차를 Euler Rotational Equation에 의해 보상할 수 있는 3축 MR 센서 및 3축 Accelerometer를 기반으로 하는 전자 Compass 를 설계하였다. 특히 이와 샅이 설계한 전자 Compass를 가지고 3측 MR 센서의 서로 다른 Sensitivity와 OP-Amp.의 서로 다른 Gain등을 규준화하기 위한 Sensitivity Calibration 루틴 수행 시 Tilt의 발생으로 야기되는 오차를 정량적으로 분석하였으며, 이를 바탕으로 $1^{\circ}$정도(精度) Compass를 설계할 수 있었다.

• 한국물환경학회지
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• 제29권2호
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• pp.270-275
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• 2013

The aim of this study was to investigate the efficiency of thickness of optical panel (OP) on the growth rate of Chlorella vulgaris. The size of Chlorella vulgaris (FC-16) was $3-8{\mu}m$, having round in shape. The cells of Chlorella vulgaris was cultured in the Jaworski's Medium with deionized water at $22^{\circ}C$ for 15 days. For this experiment, three OP samples were prepared to evaluate the efficiency of thickness of OP on the growth rate of Chlorella vulgaris; 4 mm OP with LED (Light Emitting Diode) (Run 1), 6 mm OP with LED (Run 2) and 8 mm with LED (Run 3). The diffuse rate was reached 86%, 91% and 92% for Run 1, Run 2 and Run 3, respectively. Average biomass of Run 2 and Run 3 were measured 11.18% higher than that of Run 1. However, the specific growth rate for all fractions were almost same. In addition, chlorophyll content per cell and cell volume were found to be slice difference between Run 2 and Run 3. Therefore, Run 2 has more effect on growth rate of biomass for Chlorella vulgaris than Run 1 and Run 3.

• 대한심미치과학회지
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• 제23권1호
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• pp.4-15
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• 2014

붕괴된 교합평면을 보철적으로 재구성하는 과정에 있어 face-bow와 교합기는 필수적으로 필요한 기구로 사용되어왔다. 일반적으로 Ear rod를 사용하는 face bow는 상악 정중선의 오차와 교합평면의 canting이 발생할 가능성이 있는데 이런 문제점을 해결하기위해 환자의 안면 정중선을 기준으로 하는 face bow가 개발되어왔다. Ear-bow를 이용한 mounting에서 종종 발생하는 오류를 보완하는 방법으로 환자 안면의 중심과 교합기의 중심을 일치시키려는 개념의 mounting technique이 시도되고 있으며 이를 esthetic mounting이라 한다. 이들 중 하나인OP finder 1(OP1)을 사용한 증례를 보고하고자 한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 하계학술대회 논문집
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• pp.521-524
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• 1990

There is an increasing interest in high-speed signal processing in modern telecommunication and consumer electronics applications. HDTV, ISDN. A limiting factor in Op-Amp based analog integrated circuits is the limited useful frequency range. This research program will develop a new CMOS Op-Amp architecture with improved gainband width product. The new design CMOS Op-Amp will achieve up to 100MHz unity gainband width with a 1.5-micron design rule.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.561-565
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• 1999

We measured the optical properties in Ag/chalcogenide films with the exposure of 325nm-Held laser In addition we have investigated the Ag doping mechanism as considering the changes of Ag-concentration distribution and optical energy gap ( $E_{op}$ ) with Photon-dose. The "windows" characteristics of Ag thin film occur around the wavelength of 325 nm and the Ag is evaluated to be transparent, without an absorption, in the region. While the $E_{op}$ of S $b_2$ $S_3$ thin film was changed largely by an exposure of HeNe laser(632.8 nm) an exposure of HeCd laser resulted in relatively small variation of $E_{op}$ . Therefore it is thought that photon absorption at the metal layer plays an important role in Ag photodoping.on at the metal layer plays an important role in Ag photodoping.

• 대한임상독성학회지
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• 제6권1호
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• pp.25-31
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• 2008

Purpose: Acute organophosphate (OP) poisoning may be monitored by measuring the acetylcholinesterase (AChE). It is important to assess severity and establish prognostic tests in the early stage of OP poisoning. The aim of this study was to look at the relationship between various clinical aspects of the OP poisoning, prognostic indicators of OP poisoning including Simplified Acute Physiology Score (SAPS) 3, and the associated changes in AChE levels. Methods: Clinical data and initial AChE levels from thirty-seven patients with OP poisoning were prospectively reviewed from 12 teaching hospitals in South Korea from August 2005 to July 2006. Clinical manifestations at the time of arrival such as miosis, respiratory abnormality, salivation, urinary incontinence, GCS score, AVPU scale, need for intubation, and mechanical ventilation requirements were recorded. SAPS 3 was calculated using clinical data and laboratory results. Results: The median level of AChE was 9.8 (1.3-53.6) U/gHb. There was no significant difference in AChE levels between the groups with and without cholinergic symptoms. The median level of AChE of the patients who required intubation and those who did not were 3.5 U/gHb and it 19.7 U/gHb respectively (Mann-Whitney test; p<0.001). The AChE levels were also significantly different (p=0.007) in patients who needed mechanical ventilation compared to those who did not with AChE levels found to be 3.1 U/gHb and it was 14.8 U/gHb, respectively. Level of consciousness assessed using the AVPU scale was correlated with AChE levels (Kruskal-Wallis test; p=0.013). GCS score were correlated with AChE levels (p=0.007, Spearman's rho = 0.454). In addition, the lower the level of initial AChE, the longer the ICU stay (p=0.029, Spearman's rho=-0.380). SAPS 3 was inversely correlated with the initial AChE (p<0.001, Spearman's rho=-0.633). Conclusion: In the acute OP poisoning, low AChE levels appear to help indicate the severity of poisoning. The initial AChE level may be a useful prognostic parameter for acute OP poisoning.

• 전자공학회논문지A
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• 제33A권6호
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• pp.239-247
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• 1996

The accuracy of sample-and-hold amplifiers (SHA's) empolying a CMOS process in limited by nonideal factors such as linearity errors of an op amp and feedthrough errors of switches. In this work, after some linearity improvement techniques for an op amp are discussed, three different SHA's for video signal processing are designed, simulated, and compared. The CMOS SHA design techniques with a 12-bit level accuracy are proposed by minimizing cirucit errors based on the simulated results.

• 재활치료과학
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• 제10권2호
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• pp.141-150
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• 2021

목적 : 본 연구는 뇌졸중 환자에게 Cognitive Orientation to daily Occupational Performance(CO-OP) 중재법을 적용하여 작업수행의 질, 상지기능 및 실행기능에 영향을 주는지 확인하고자 하였다. 연구방법 : 연구대상은 재활치료를 받고 있는 입원, 외래 환자 중 발병한지 3개월 이상된 뇌졸중 환자 5명이었다. 연구는 단일집단 사전-사후 평가로 설계되었다. 중재는 1일 1회 30분간 주 5회로 총 20회기를 적용하였다. 중재활동은 환자가 선정한 중요도는 높지만 만족도와 수행도는 낮은 활동을 선정하여 진행하였다. 평가도구로는 수행의 질을 평가하는 Performance Quality Rating Scale(PQRS)과 Canadian Occupational Performance Measure(COPM), 실행기능을 알아보기 위한 Executive Function Performance Test for Koreans(EFPT-K), 상지기능을 알아보기 위한 Motor Activity Log(MAL)를 사용하였다. 중재 전·후를 비교할 수 있는 통계방법으로는 비모수 검정인 Wilcoxon's signed rank test를 사용하였다. 통계학적 유의수준은 p<0.05로 하였다. 결과 : 상지기능은 모든 항목에서 유의미한 변화를 나타냈으며 실행기능은 시작하기 항목을 제외한 준비하기, 순서정하기, 판단과 안전, 종결하기 전 항목에서 유의미한 변화를 나타냈다. 또한, 작업수행도 유의미한 차이를 보였다. 결론 : 만성 뇌졸중 환자를 중심으로 20회기의 CO-OP 중재를 통해 상지기능, 실행기능, 작업수행을 향상시켰다. 뇌졸중 환자의 작업수행뿐 아니라 세부적인 작업 요소 향상에 긍정적인 영향을 도출하였다.

• 대한약리학회지
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• 제17권2호
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• pp.31-36
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• 1981

Heavy metals which are present as trace elements in human body have been known to modify various enzymatic reaction. These metals can be essential or non-essential. Zinc, copper and calcium are essential in maintaining some biological processes, whereas non-essential metals such as cadmium, lead and mercury produce accumulatve toxic effect. Cadmium accumulated in pancreas can cause toxicity and damage of pancreatic cells, thereby influencing CHO metabolism. Lead compounds are known to produce toxic effects on the kidney, digestive system and brain fellowed by inhibition of activity of ${\rho}-aminolevulinic$ acid and biosynthesis of hemoproteins and cytochrome. Evidence has been accumulated that zinc not only acts as a cofactor in enzyme reaction but also prevents toxic effect induced by heavy metal such as copper and cadmium. To demonstrate the effect of heavy metals on pancreatic secretion, part of uncinate pancreas was taken and incubated in Krebs-Ringer bicarbonate buffer with heavy metals used. Additional treatment with CCK-OP was performed when needed. After incubation during different period of time, medium was analyzed for amylase activity using Bernfeld's method. The present study was attempted in order to elucidate the effect of several kinds of heavy metal on exocrine pancreatic secretion in vitro. The results obtained are as follows: 1) CCK-OP stimulated significantly amylase release from pancreatic fragments in vitro. 2) CCK-OP response of amylase release from pancreatic fragments was inhibited by treatmant with cadmium, especially high doses of cadmium. 3) CCK-OP response of amylase release from pancreatic fragments was inhibited when pretreated with $10^{-4}M$ copper chloride. 4) Lead chloride at the concentration of $10^{-3}M\;and\;10^{4}M$ stimulated the basal amylase release in vitro but CCK-OP response did not augment by lead chloride. 5) Zine chloride did not affect amylase release from pancreatic fragment in vitro. From the results mentioned above, it is suggested that CCK-OP response was inhibited it the amylase release from pancreatic fragments pretreated with cadmium and copper chloride.