• Journal of Labour Economics
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• v.34 no.1
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• pp.71-101
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• 2011

Using an establishment-level panel data drawn from the employment insurance administrative DB, this study investigates the relationship between elderly and youth employment in Korea. The primary focus of interest is whether or not the ageing of workforce and an increase in elderly employment have negative impacts on youth employment. In the regression using the full sample, we find the evidence that a movement in elderly employment and ageing workforce are positively related to youth employment. However, we do not find consistent evidence of the positive impact of the elderly employment on youth employment in the estimations using sub-samples divided by various criteria.

• Applied Chemistry for Engineering
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• v.20 no.4
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• pp.391-395
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• 2009

For the conversion of domestic waste-wood into energy, a fixed bed gasifier ($0.9 m{\times}2.4 m$) having the capacity of 2 ton/day was designed and constructed. The dual knife valve was used to feed waste-wood of which size was 3~5 cm and a rotary stoker system was installed in the bottom of gasifier. The pilot gasification system consisted of feeding system, fixed bed gasifier, gravity fine particle collector, heat exchanger for syngas cooling, ID fan, and cooling tower. The operation temperatures of gasifier were $700{\sim}1000^{\circ}C$ and the concentrations of syngas were CO: 25~40 vol%, $H_2$: 7~12 vol%, $CH_4$: 2~4 vol%, $CO_2$: 12~24 vol%. The calorific value of syngas was $1100{\sim}1500kcal/Nm^3$ and was enough to be applied in the industrial combustor. Also the gas engine was operated by using syngas from biomass gasifier and produced 1~4 kW of power.

• Microbiology and Biotechnology Letters
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• v.18 no.5
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• pp.525-529
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• 1990

Plant cell cultures of Lithospermum erythrorhizon were performed in stirred tank and packed-bed reactors with in situ extraction by n-hexadecane. The specific shikonin production and volumetric shikonin productivity of stirred tank reactor reached 1.5 mg shikoninlg cell and 400$\mu g$ shikonin/(L.day), respectively. In packed-bed reactor with calcium alginate-immobilized cells specific shikonin production and volumetric productivity reached 2.0 mg shikoninlg cell and 2857$\mu g$ shikonin/(L.day), which were 1.3 and 7.1 times higher than those of stirred tank reactor, respectively. The higher shikonin production and productivity of packed-bed reactor seemed to be due to high cell loading capacity of calcium alginate immobilized cells in packed-bed reactor and improved cell-cell contact.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.5
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• pp.1592-1596
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• 2010

According to the increase of the channel length with fixed width/length, characteristic curves of drain current as a function of gate bias voltage of indium gallium zinc oxide (IGZO) thin-film transistors moved to a positive direction of gate voltage, and field-effect mobility decreased. In case of fixed length and width of channel, field-effect mobility was lower and subthreshold slope was larger when drain bias voltage was higher. Due to large work function of IGZO, band bending at the junction region between IGZO channel and source/drain electrodes was expected to be in opposite direction to that between silicon and metal electrodes; this could explain the above results.

• Proceedings of the Korean Society for Quality Management Conference
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• 1998.11a
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• pp.647-658
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• 1998

다구찌 기법으로 더 알려진 품질공학은 아직도 우리 나라 현장에선 어려운 것으로 인식되어 잘 사용되지 않고 있다. 일본에서는 품질공학을 다방면에 적용하고 있다. 제공공정이나 화학공정에 사용되는 것은 당연하나, 양복 디자이너, 의사의 진단에도 적용한 것이 보고되고 있다. 품질공학을 고정된 기법으로 보는 것이 아니라, 모든 현실의 문제를 해결하는 방법으로 적용을 넓혀가고, 새로운 연구를 거듭하고 있다. 그럼에도 불구하고, 일본 JUSE나, 전문가들은 품질공학 확산을 위해 다방면으로 노력하고 있다. 현재 일본에선 품질공학을 ISO화하자는 주장이 있다. 의무적으로 모든 공장에 적용 시키자는 것이다. 일본 전문가들은 일본 기업 운영 시스템이 경직되었음을 경고하면서, 일본의 경영자 층과 관리자 층이 환경변화에 적응하지 못하고, 구태의연한 모습을 많이 지적한다. 기술자들도 수동적이고, 새로운 시도를 하지 않는 무사안일 주의가 팽배했음도 지적하고 있다. 구미의 엔지니어들은 좋은 기법이라면, 스스로 먼저 공부하여 적용하는 데 비하여, 한국이나 일본에서는 좋은 기법의 활용도 경영층의 이해가 선행되야 한다. 경영층이 품질공학을 이해하지 못하면 도리어 품질공학 도입을 반대하게 된다. 경영층을 이해 시키는 방법으론, 현재의 상태가 위기임을 강조하고, 새로운 방법으로 품질공학을 소개한다. 그 다음 품질공학의 사례를 들어 확신을 심어주는 것이 한 방법이다.

• Journal of the Earthquake Engineering Society of Korea
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• v.5 no.1
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• pp.37-44
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• 2001

면진기술은 주로 저층 구조물의 내진설계에서 적용되는 방법으로 건물과 기초사이에 면진장치를 설치하여 상부로 전달되는 지진하중을 효과적으로 감소시킨다. 그러나 이 방법은 중.고층 구조물에 그대로 적용하기에는 여러 가지 기술적 문제가 따르므로, 구보물의 중간층 일부를 분리시켜 상부로 전달되는 지진력을 감소시킬 수 있을 것이다. 본 노문에서는 저층 뿐만 아니라, 중.고층 정형구조물의 주상복합건물과 같은 비정형 구조물에 대하여 구조물의 중간층 일부를 비선형 면진장치로 면진시키고 그 효과를 분석하였다. 이러한 중간층 면진 구조물의 경우, 고정기초 구조물에 비하여 적은 층간변위나 층전단력이 발생하였으며, 특히 주상복합건물에서 상당한 효과를 볼 수 있었다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.1
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• pp.132-141
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• 1992

The critical condition for onset of Benard convection with variable viscosity .nu.=.nu.$_{0}$exp(-CT) has been obtained using a linear stability theory. The bottom wall is rigid while the upper surface may be either free or rigid. The two boundaries are subject to convective heat transfer. The critical Rayleigh numbers are presented up to maximum viscosity ratio of 3000. It is greater for smaller upper and/or lower surface Biot numbers. Its dependence on the viscosity ratio is complicated. However, a simple sublayer theory is found to be applicable for extremely large viscosity ratio. In such cases, the critical Rayleigh number and the critical wave number are functions of viscosity ratio and lower surface Biot number.r.

• Journal of the Korean Magnetics Society
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• v.27 no.3
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• pp.82-86
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• 2017

The IrMn based GMR-SV films with three different buffer layers were prepared on Corning glass by using ion beam deposition and DC magnetron sputtering method. The major and minor magnetoresistance curves for three different buffer layers beneath the structure of NiFe(15 nm)/CoFe(5 nm)/Cu(2.5 nm)/CoFe(5 nm)/NiFe(7 nm)/IrMn(10 nm)/Ta(5 nm) at room temperature have shown different magnetoresistance properties. When the samples were annealed at $250^{\circ}C$ in vacuum, the magnetoresistance ratio, the coercivity of pinned ferromagnetic layer, and the interlayer coupling field of free ferromagnetic layer were enhanced while the exchange bias coupling field did not show noticeable changes.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.406-409
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• 2001

The production of fumaric acid in a novel fixed-layer fermenter using Rhizopus oryzae KCTC 6946 was studied. When yeast extract and corn steep liquor were used as nitrogen sources, fumaric acid produced was 6.4 g/L and 6.8 g/L, respectively. Compared with the flask cultivation, fumaric acid concentration was about 200% when yeast extract was used as a nitrogen source, but reached to 93% when corn steep liquor was used.

• 한국가스학회:학술대회논문집
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• 2005.10a
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• pp.135-140
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• 2005