• 가정과삶의질연구
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• 제16권3호
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• pp.111-122
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• 1998

This study analyzed the copmposition of household portfolio over the family life cycle using a survey dta of 1996 Korea Household Panel Study. The finindings showed that over th family life cycle households diversified their portfolio to meet their financial needs. In the aged stage however households were more likely to have liquidity problem than the households in th other stages due to the estate concentrated portfoplio composition.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.795-798
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• 2003

Inside of working PDP, there exist highly reactive conditions in the gap between two glass panels. MgO layer and phosphor have been investigated as a function of discharge and temperature. A drastic reduction in carbon impurity was observed on the surfaces after discharging and heat treatment. Carbon composition on the MgO and phosphor is a dominant factor for their instability

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2005년도 추계종합학술대회
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• pp.685-688
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• 2005

플라즈마 디스플레이를 위한 효율적인 서스테인 드라이버와 이를 리셋 회로와 결합시키는 유용한 결합 방법을 제시한다. 제안된 서스테인 드라이버는 외부 인덕터와 패널에 존재하는 기생 커페시터 간의 직렬공진 방식을 이용한다. 이 회로는 4개의 스위칭 소자, 인덕터, 전원공급을 목적으로 하는 외부 커패시터로 구성된다. 기존의 방식과 비교하여 입력전원전압이 두배가 되지만 스위칭 소자에 가해지는 전압스트레스는 기존의 값과 거의 동일하며, 입력 전압을 별도의 승압없이 리셋 회로의 전원으로 사용할 수 있는 장점을 가진다. 이러한 회로적 구조는 서스테인 드라이버와 리셋회로를 간단히 구성할 수 있다. 이론적 분석을 바탕으로 동작원리와 설계 예를 제시하며, 7.5인치 AC PDP 패널을 이용한 실험을 통해 타당성을 검증한다.

• 생약학회지
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• 제51권4호
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• pp.264-269
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• 2020

The study aimed to characterize chemical composition and anticancer property of the n-hexane fraction derived from Asiasari Radix et Rhizoma. The anticancer activity was evaluated on a panel of cancer cell lines including HN22, HSC2, HSC3, and HSC4 cells (human oral cancer), HCC827 and HCC827GR cells (human lung cancer), and KYSE30 and KYSE450 (human esophageal cancer) by MTS assay. As a result, The least polar subfraction from n-hexane-soluble layer displayed notable cytotoxicity on the tumor cell lines with IC50 ranging from 1.20 to 17.0 ㎍/ml. The chemical composition of constituents in the active subfraction was determined by gas chromatography-mass spectrometry (GC-MS). The essential oils comprised of sesquiterpenes including β-gurjunene (7.45%), γ-amorphene (6.61%), guaia-6,9-diene (6.40%), δ-guaiene (5.21%) and a phenylpropanoid, safrole (0.49%) were mainly identified in addition to long-chain hydrocarbons including n-heptadecane (24.60%), 7-hexadecene (4.44%) and a diterpenoid, ent-kaur-16-ene (6.57%).

• 국제지역연구
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• 제22권3호
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• pp.85-119
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• 2018

주요 상대국들과 무역에서 환율과 노동숙련도의 구성이 베트남의 무역수지에 미치는 역할 본 연구는 베트남이 주요 20개국과 무역을 할 때 환율과 노동숙련도의 구성이 무역수지에 미치는 영향을 조사하였다. 2000년부터 2016년까지의 균형패널자료 (balanced panel data)를 활용해서, 저자는 베트남의 총 무역수지와 노동기술의 정교화로 인한 무역수지를 분석하였다. 본 연구의 주요 세가지 결론은 아래와 같다: 첫째, 환율은 베트남의 무역수지에 긍정적인 영향을 미치지만 그 계수 (coefficient) 가 작아 그 효과는 제한적이라는 것을 알 수 있었다. 둘째 베트남 화폐 (VND(Vietnamese Dong))의 가치가 떨어질 경우 베트남의 고숙련노동상품과 중숙련사무직 노동생산품의 무역수지는 악화된다. 셋째, 고숙련상품과 중숙련 사무직 생산 상품의 노동 기술 숙련도를 높이고 비가격경쟁력을 향상시킴으로서 베트남의 총 무역수지를 개선할 수 있으며, 반면에 저숙련노동 및 중숙련 블루칼라 노동생산 상품은 더 이상 베트남의 총 무역수지개선에 도움이 되지 않을 것이다.

• 가정과삶의질연구
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• 제29권5호
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• pp.121-140
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• 2011

The purpose of this study is to understand how the economic conditions and needs of single-parent families are different between single-mother and single-father families, and also how they are dependent on household composition. The data for this study were drawn from the 1st Korea Welfare Panel Study and analyzed by frequencies, means, ${\chi}^2$, t-test, F-test, and logistic regression with the STATA 9.1 program. The major findings are as follows: (1) Single-parent families are more likely to live in a three-generation household than married couple families. (2) The composition of a three-generation household of single-parent families is affected by sex, age, education, type of marital disruption, the type of employment of single parents and the age of the last-born child. (3) The income-to-needs ratio is not significantly different depending on the sex of the single parents and their household composition. However, material hardship is significantly low in three-generation household single-parent families. (4) There are differences between three-generation single-parent families and independent single-parent families in income sources: The ratio of public transfer to total incomes is higher in three-generation households than independent households, while the ratio of private transfer to total incomes is higher in independent households.

• 한국산학기술학회논문지
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• 제6권6호
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• pp.497-501
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• 2005

Dry film 공정에 의해 PDP(Plasma Display Panel)용 무연 투명유전체를 제조하였다. 여러 슬러리 조성으로부터 고밀도 green sheet를 제조하는데 최적의 조성을 선정하였다. 한편, 슬러리는 양질의 green sheet를 제작하는데 적합한 shear thinning 특성을 나타냈다. 제조한 투명유전체의 열팽창계수는 유리기판인 PD-200과 유사한 $97{\times}10^{-7}/^{\circ}C$로 측정되었다. PD-200에 접합된 투명유전체의 단면 주사현미경 관찰로부터 두 층은 갭이 없이 매우 견실히 접합되어 있음을 확인할 수 있었다.

• 유통과학연구
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• 제15권4호
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• pp.25-32
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• 2017

Purpose - The introduction and expansion of the railway network since the 19th century brought revolutionary changes in economic activities, performance, and structure. The purpose of this study is estimating the impact of railroads on the local agricultural and manufacturing structures in the 19th century USA. Research design, data, and methodology - To identify the impact of railroads on local economic structure, county-level panel data from the U.S. census were analyzed using a panel fixed-effect differences-in-differences regression. The empirical investigation focuses on whether railroads changed the overall volume and sectoral composition of the local agricultural sector, and whether they contributed to the growth of the local manufacturing industry and its productivity. Results - The railroad introduction led to the relative decline of the agricultural sector, while encouraging the growth of market-oriented gardening. As such, manufacturing productivity increased by the introduction of railroads, although manufacturing inputs and home manufactures were unaffected. Conclusions - The findings imply that railroads contributed to the growth of market-oriented farming in rural areas, and the rise of productivity in the local manufacturing sector. Meanwhile, evidence of railroad-driven growth for the entire agricultural sector or a massive reallocation of resources from agriculture to manufacturing were not found.

• 열처리공학회지
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• 제23권6호
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• pp.301-308
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• 2010

A steel with chemical composition, 0.22% C, 0.25% Si, 1.26% Mn, 0.22% Cr, 0.04% Ti, 0.0042% B, and a microstructure of ferrite and spheroidized cementite has been press-formed to automotive center pillar followed by local-hardening heat-treatment. Hardness, tensile properties, fractography, microstructure and surface roughness of local-hardening heat-treated automotive center pillar have been examined. The directly heated and quenched area had fully martensitic structure with Vickers hardenss in the range of 500 to 510. The heat affected area close to the directly heated area showed dual-phase structure of ferrite and martensite. The width of the heat-treated and heat-affected areas after the local-hardening heat treatment was ranging from 32 mm to 50 mm. The surface of the local-hardening heat-treated center pillar revealed some temper color as a consequence of the oxidation during the heat treatment, but the surface roughness was not affected by the local-hardening heat treatment.

• Journal of the Korean Wood Science and Technology
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• 제23권4호
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• pp.74-84
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• 1995

Eight types of thin composite panels were manufactured by press-lam and mat-forming process applied to optimum manufacturing condition, studied in former first research by author (1995). They were tested and compared with control boards on dimensional stability, internal bond strength, tensile strength, Screw withdrawal strength, and bending properties. These thin composite panels manufactured by mat-forming process were generally superior to those by press-lam in dimensional stability and mechanical properties. In the dimensional stability and mechanical properties of thin composite panels manufactured by mat-forming process, the thin composite panels (A and E type) composed of particle or sawdust core and veneer face with polyethylene film, were as good as those of common plywood (control board). Internal bond strength showed highest value in the thin composite panel(D type) which composed of particle core and polypropylene screen face with polyethylene film. The thin composite panels(G and H type) composed of sawdust or particle core and polypropylene screen face with polyethylene film by press-lam and mat-forming process, showed most highest value in dimensional stability and water absorption.