• 한국정밀공학회지
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• 제12권12호
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• pp.72-80
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• 1995

Ultraprecision machining technology has been playing a rapidly increasing and important role in manufacturing. However, the physics of the micromachining process at very small depth of cut, which is typically 1 .mu. m or less is not well understool. Shear along the shear plane and friction at the rake face dominate in conventional machining range. But sliding along the flank face of the tool due to the elastic recovery of the workpiece material and the effects of plowing due to the large effective negative rake angle resultant from the tool edge radius may become important in micromachining range. This paper suggests an orthogonal cutting model considering the cutting edge radius and then quantifies the effect of plowing due to the large effective negative rake angle.

• 미생물학회지
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• 제39권3호
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• pp.161-165
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• 2003

Ornithobacterium rhinotracheale(OR)은 최근에 알려진 그람음성 간균으로서 가금류에서 호흡기감염을 일으킨다. OR균의 항생제 감수성과 OR에 대한 국내발생현황을 조사하기 위하여 11개 OR분리주의 8중 항생제에 대한 최소발육억제농도(MIC)와 국내 달의 OR 항체보유율을 조사하였다. 모든 분리주는 ampicillin, tetracycline 및 doxycycline에 대하여 높은 감수성을 나타내었다. MIC는 각각 0.38～2 ${\mu}g$ /ml, 0.094～3 ${\mu}g$/ml, 0.094～3 ${\mu}g$/ml으로 ciprofloxacin, norfloxacin, enrofloxacin및 ofloxacin의 MIC는 대부분 3 ${\mu}g$/ml～48 ${\mu}g$/ml로 나타났고 gentamicin에 대하여는 모든 분리주가 저항성을 나타내었다. 시판되는 OR ELISA검사 kit를 사용하여, 국내에서 사육하는 육계 및 육용종계와 산란계 188계군에 대한 항체보유율을 검사한 결과, 육계 5계군(4%),육용종계 17계군(50%),산란계 16계군(55.2%)이 OR항체 양성계군으로 나타났다. 이 결과로 보아 OR은 국내 양계장내 광범위하게 만연되어 있을 것으로 보인다.

• 한국작물학회지
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• 제34권2호
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• pp.211-219
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• 1989

담배와 인삼은 광강도에 따라 반응이 다르게 나타났다. $CO_2$ 흡수량과 RuBPCase 활성은 담배의 경우 1900 $\mu$ E m$^{-2}$ sec$^{-1}$에서 높았고 인삼은 500 $\mu$ E m$^{-2}$ sec$^{-1}$에서 높았다. 담배와 인삼의 $CO_2$ 흡수량과 RuBPCase 활성의 차이는 담배가 3.7배, 2.7배 각각 높았다. $CO_2$ 흡수량과 RuBPCase 활성과의 상관은 담배에서 고도의 정의 상관이 인정되었으나 인삼은 부의 상관이 인정되는 경향이었다. Glycolate oxidase 와 Malate dehydrogenase 활성은 담배의 경우 1,900 $\mu$ E m$^{-2}$ sec$^{-1}$에서 높았고, 인삼은 1000 $\mu$ E m$^{-2}$ sec$^{-1}$에서 높았다. 담배의 Nitrate reductase 활성은 광조건이 1900 $\mu$ E m$^{-2}$ sec$^{-1}$가 500 $\mu$ E m$^{-2}$ sec$^{-1}$보다 2배 높았으나 인삼은 광처리구 모두 Nitrate reductase 활성을 검출할 수 없었다. 단백질함량과 엽록소함량은 담배가 인삼보다 적정 광구에서 2.2배, 1.5배 각각 높았다. 엽록소 a/b의 비율은 담배의 경우 500 $\mu$ E m$^{-2}$ sec$^{-1}$에서 낮았고 인삼은 1000 $\mu$ E m$^{-2}$ sec$^{-1}$에서 낮았다. 단백질함량과 엽록소함량과의 관계는 담배에서 고도의 정상관이었고 인삼은 500 $\mu$ E m$^{-2}$ sec$^{-1}$에서 처리 후 5일에 부상관이 인정되었다. 단백질조성은 담배와 인삼이 상이하였지만 주 band의 분자량은 담배와 인삼 모두 50KD과 15KD으로 비슷하였다. 이들은 처리 후 시기가 지나면 희미해졌으며 담배는 500 $\mu$ E m$^{-2}$ sec$^{-1}$에서 인삼은 1000 $\mu$ E m$^{-2}$ sec$^{-1}$에서 47KD이었다.

• 한국조경학회지
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• 제46권4호
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• pp.61-75
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• 2018

본 연구의 목적은 도시계획시설로 조성되는 완충녹지가 $PM_{2.5}$(초미세먼지) 저감에 효과가 있는지를 규명하고, 도로변 완충녹지의 구조, 녹량(녹지용적), 식재유형에 따른 초미세먼지 변화량을 분석하여 초미세먼지 저감을 위한 완충녹지 조성 시 활용할 수 있는 요소들을 도출하는 것이었다. 연구대상지는 송파구를 선정하였고, 양재대로, 송파대로에 인접한 5개의 완충녹지에서 16개 조사구를 선정해 현장조사를 실시하였다. $PM_{2.5}$ 농도 측정결과, 조사구별 평균농도는 계절 상관없이 보도 $46.6{\mu}g/m^3$, 녹지 $45.5{\mu}g/m^3$, 주거지 $42.9{\mu}g/m^3$로 모두 도로($53.2{\mu}g/m^3$)보다 낮았으며, 주거지 농도 값이 가장 낮았다. 완충녹지의 농도 저감효과 확인을 위해 완충녹지의 녹량과 초미세먼지 상대비율간의 상관관계 분석결과, 교목과 관목 전체 녹량이 높은 그룹의 상대비율이 낮은 것으로 확인되어 완충녹지 녹량의 영향력을 증명했으며, 관목 부족형이 교목 부족형보다 농도상대비율이 더 높은 것으로 확인되어 관목의 영향이 더 큰 것으로 판단되었다. 교목과 관목의 식재구조에 따른 녹피율과 녹지용적계수가 복합적으로 $PM_{2.5}$ 농도 저감에 영향을 미치고 있었으며, 교목의 열수와 관목의 층위구조가 $PM_{2.5}$ 농도 저감에 중요한 영향요인으로 판단되었다. 특히, 초미세먼지 농도가 높은 겨울철 완충녹지의 $PM_{2.5}$ 농도저감 특성 분석결과, 관목의 녹피율이 중요한 요인이었다.

• 대한수의학회지
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• 제33권4호
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• pp.735-746
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• 1993

Electrocardiographic parameters of amplitude and the shape of waves on the unipolar precordial chest leads in the normal Korean native cattles have been measured with a 3 channel electrocardiograph built in a computed and analysis. The study was conducted on 98 heads of mean age of 17.6 months. The wave forms of P, T and QRS complex wave in all leads showed various types. The parameters of the amplitude in the wave types showed the most frequency in each lead that were analyzed as follow : 1. In P wave, amplitudes of positive type showed a frequency of 92.9% and 93.9% in leads $CV_6LU$ and $CV_6LL$ that were $83.8{\pm}31.0{\mu}V$ and $76.0{\pm}30.7{\mu}V$, and negative type showed a frequency of 97.9% in lead V 10 that were $-80.2{\pm}29.4{\mu}V$, respectively. But the plate type in leads $CV_6RU$ and $CV_6RL$ showed frequency of 48% and 58.3%, respectively. 2. Average amplitude of the QRS complex were in a range of $277.0{\pm}154.0{\mu}V$ to $648.2{\pm}146.2{\mu}V$(mean of $418.8{\pm}139.4{\mu}V$) in all leads that were manifested the Low-Voltage QRS complex(below 1 mV in unipolar precordial leads). Average amplitudes of each wave type in the QRS complex were $-250.0{\pm}139.8{\mu}V$ and $-399.2{\pm}226.8{\mu}V$ in the QS group types that showed a frequency of 50.0% and 82.5% in the leads $CV_6LU$ and $CV_6LL$, respectively. And average amplitudes of the R group types showed a frequency of 85.6%, 56.1% and 75.8% in the $CV_6RU$, $CV_6RL$ and $V_{10}$ that were $321.5{\pm}142.1{\mu}V$, $271.6{\pm}139.9{\mu}V$ and $552.4{\pm}132.7{\mu}V$, respectively. 3. In T waves, Amplitudes of the positive type showed a frequency of 60.2%, 46.9% and 83.7% in leads of $CV_6LL$, $CV_6RU$ and $CV_6RL$ that were respectively $184.7{\pm}93.7{\mu}V$ $103.7{\pm}64.43{\mu}V$ and $111.8{\pm}39.3{\mu}V$, the negative type showed a frequency of 62.2% and 93.7% in leads $CV_6LU$ and $V_{10}$ that were $142.2{\pm}82.1{\mu}V$ and $-280.3{\pm}107.2{\mu}V$, respectively. 4. Average amplitude of ST segment were $3.7{\pm}33.1{\mu}V$, $0.9{\pm}23.1{\mu}V$, $10.9{\pm}28.6{\mu}V$, $5.8{\pm}28.3{\mu}V$ and $-34.7{\pm}48.4{\mu}V$ in leads $CV_6LL$, $CV_6RU$, $CV_6RL$, $CV_6LU$ and $V_{10}$ respectively.

• Natural Product Sciences
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• 제16권4호
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• pp.239-244
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• 2010

Protein tyrosine phosphatase 1B (PTP1B), a negative regulator of insulin signaling, has served as a potential drug target for the treatment of type 2 diabetes. The MeOH extracts of twenty-nine medicinal plants, traditionally used in Vietnam as anti-diabetes agents, were investigated for PTP1B inhibitory activity in vitro. The results indicated that, most materials showed moderate to strong inhibitory activity with $IC_{50}$ values ranging from $3.4\;{\mu}g/mL$ to $35.1\;{\mu}g/mL$; meanwhile, eleven extracts (37.9%) could demonstrate PTP1B activity with $IC_{50}$ values less than $15.5\;{\mu}g/mL$; sixteen extracts (55.2%) could demonstrate PTP1B activity with $IC_{50}$ values ranging from $15.5\;{\mu}g/mL$ to $35.1\;{\mu}g/mL$. The study may provide a proof, at least in a part, for the ethno-medical use in diabetes disease of these plants.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1632-1633
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• 2011

In IEC 62305-1 standard, the simple circuit consisting of RLC is used in order to form the fast rise time of 0.25/100 ${\mu}s$. But this circuit is very expensive system because the system is needed very high charging voltage up to 3.5 MV. In this paper, we suggest the generator which generates the current up to 10 kA by using the low charging voltage of the dozen kV. Therefore the generator was installed then we compared measure results with calculated results.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(2)
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• pp.145-148
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• 2002

In this paper, a voltage controlled oscillator (VCO) with automatic amplitude control is designed using a 0.35${\mu}{\textrm}{m}$ CMOS process. A cross-coupled PMOS pair is used for a negative resistance to compensate for the losses in the LC resonator, and an automatic\ulcorner amplitude control function is adapted to provide constant output power independent of the Q-factor of the LC resonator. The designed VCO operates in the 200MHz to 550MHz frequency range using different external resonators. The simulated phase noise is -128 dBc/Hz at 100KHz offset from the carrier frequency of 260MHz. It dissipates 0.㎽ from a 3V power supply. The area is 300${\mu}{\textrm}{m}$ x1201${\mu}{\textrm}{m}$.

• Advances in Traditional Medicine
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• 제7권4호
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• pp.385-389
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• 2007

We undertook the present study to evaluate different pharmacological as antioxidant, antibacterial and cytotoxic activities of the crude ethanolic extract of Momordica charantia (Family: Cucurbitaceae) leaves. The antioxidant property of the extract was assessed by 1, 1-diphenyl-2-picryl hydrazyl free radical scavenging assay. The extract showed antioxidant activity where $IC_{50}$ was about ${\sim}500{\mu}g/ml\;and\;IC_{50}$ was about ${\sim}10{\mu}g/ml$ for standard drug ascorbic acid. The extract showed a broad spectrum of antibacterial activity against all the tested gram positive and gram-negative bacteria where Staphylococcus epidermidis, Staphylococcus aureus, Salmonella typhi and Shigella dysenteriae were prominent. And the zones of inhibition were ranging from 8-15 mm for all the tested bacteria. Its cytotoxic property was evaluated by brine shrimp lethality bioassay. The extract showed significant lethality and the $LC_{50}$ value was $20{\mu}g/ml$.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 A
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• pp.141-143
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• 1994

In this paper, an electrostatic micro-actuator is fabricated using flat p+ diaphragm. To avoid the buckling of the flat p+ diaphragm, the processes are designed appropriately. The fabrication processes of the actuator are the anisotropic etching with EPW, the boron diffusion process, Al deposition and the silicon to glass bonding using the negative photoresist. The distance between the p+ and Al electrodes is $10{\mu}m$, and the thickness of the p+ diaphragm is $2{\mu}m$. The measurement of the characteristic of the actuator is performed at 50V. The center displacement of the diaphragm is $1.5{\mu}m$ at 10Hz. In comparison with the experimental data of the actuator with corrugated diaphragm, it is confirmed that the actuator with flat diaphragm is more effective than that with corrugated one in the small deflection region.