검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 186

        81.
        2014.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the present study, the effects of extracts from Korean plants on the DNA damage response in HaCaT cells exposed to ultraviolet B (UVB) were investigated. The activity of cells treated for 24 hr with ethanol extracts from Vaccinium spp. (VS), and Vitis vinifera L (VV) alone was similar to that of the non-treated control, but gradually decreased at concentrations above 200μg/mL. However, when post-incubation of UVB-exposed cells was carried out for 24 hr in medium containing VS or VV extracts, the cell activity increased in a concentration-dependent manner compared with that in the normal growth medium. The cell viability of UVB-exposed cells also increased when post-incubated in medium containing VS or VV extracts, in a concentration-dependent manner. Nuclear fragmentation analysis showed that post-incubation with VS or VV extracts decreased the UVB-induced apoptosis by about 10 and 13%, respectively, of that in cells post-incubated in growth medium. After 24 hr of post-incubation in medium containing VS or VV extracts, the level of CPD and 8-OHdG decreased in time- and concentration-dependent manners. Overall these results suggest that VS and VV extracts assist the survival of UVB-exposed cells, in accordance with the respective decrease in the levels of UVB-induced DNA damage.
        4,000원
        82.
        2014.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        전 세계적으로 기후변화와 저탄소 소비행태를 향한 움직임이 일어남에 따라 이에 대한 대처가 요구되고 있으며, 국제적인 유가상승은 그린카에 대한 소비자들의 니즈를 촉발시키고 있다. 본 논문은 그린카 산업 플랫폼 구축 정책과 기업전략을 도출하기 위한 선행 연구로서 이를 위해 정책프레임 및 실증분석, 개념적/수리적 모델링, 시스템 다이내믹스, ABM 등의 다양한 방법론을 사용하여 다각적으로 접근, 통합하여 플랫폼 관점에서의 학제적 연구 프레임워크를 제시하고자 한다. 먼저 그린카 사례 분석을 위한 산업플랫폼 분석 프레임워크를 도출하고, 필요한 구성 요소들을 제시하였으며 계량경제학 모형을 적용하여 그린 플랫폼(양면시장)에 관련된 기본 모델을 수립하였다. 또한 동태적인 관점에서의 분석을 위해 시스템 다이내믹스 모형을 그린카 환경에 접목하여, 특정 그린카 산업분석에 적용할 수 있는 시스템 다이내믹스 분석 모델을 수립하였다. 마지막으로 보다 미시적 관점에서 한국의 하이브리드 자동차 시장의 활성화 방안에 대하여 ABM을 이용하여 개별 소비자 관점에서 연구하였다. 이를 기반으로 현 한국시장에서 실행 중 혹은 실행 예정인 하이브리드 자동차 정책에 대한 분석 방안을 제시하였다.
        8,000원
        85.
        2014.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        지붕이나 여러 가지 방법과 장소에서 수집된 빗물을 처리하면 직접적 간접적으로 유익하게 사용될 수 있다. 이러한 빗물은 점점 더 높은 품질을 위해 고려되고 있고, 분리막은 이러한 빗물 처리를 위한 중요한 기술이다. 특히, 분리막은 고품질 물 생산, 높은 집적도 및 낮은 에너지 소비 등의 장점이 있다. 그럼에도 불구하고, 막오염은 수처리 및 폐수 재활용 부분과 마찬가지로 심각한 문제로 간주되고 있다. 본 연구에서는 빗물 처리에 정밀여과(MF)막을 적용하였고, 저압 자외선(LPUV)처리를 정밀여과막의 전처리로 사용하였다. 유기물에 대한 UV의 영향을 정량화하기 위해 총 유기탄소(TOC) 및 UV 흡광도(UVA)를 모두 측정하였다. 또한 UV 전처리 효과에 따른 막의 오염 정도를 조사하였다. LPUV 전처리를 하고 실험을 한 결과 조류에 의해 오염된 빗물에서 막의 오염을 제어하는데 효과적임을 알 수 있었으며, 이것은 UV 처리 후 유기물의 양이 감소하고 특성이 변화하기 때문이었다. 따라서 UV/MF 처리는 마이크로 워터 그리드 시스템과 같은 수처리를 위한 유망한 옵션이 될 수 있을 것으로 생각된다.
        4,000원
        86.
        2013.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Nanocrystalline materials have recently received significant attention in the area of advanced materials engineering due to their improved physical and mechanical properties. A solid-solution nanocrystalline powder, (Ti,Mo)C, was prepared via high-energy milling of Ti-Mo alloys with graphite. Using XRD data, the synthesis process was investigated in terms of the phase evolution. Rapid sintering of nanostuctured (Ti,Mo)C hard materials was performed using a pulsed current activated sintering process (PCAS). This process allows quick densification to near theoretical density and inhibits grain growth. A dense, nanostructured (Ti,Mo)C hard material with a relative density of up to 96 % was produced by simultaneous application of 80 MPa and a pulsed current for 2 min. The average grain size of the (Ti,Mo)C was lower than 150 nm. The hardness and fracture toughness of the dense (Ti,Mo)C produced by PCAS were also evaluated. The fracture toughness of the (Ti,Mo)C was higher than that of TiC.
        4,000원
        88.
        2013.10 구독 인증기관·개인회원 무료
        양봉산업에서 말벌류에 의한 양봉농가의 피해보고가 증가 하고 있다. 또한 외래 침입종인 등검은말벌로 인해 양봉산업에서 말벌류의 관리는 더욱 어려워지고 있 는 실정이다. 양봉장을 방문하는 말벌류는 사회성 집단을 형성하며, 꿀벌을 집단적 으로 공격하는 성향을 띤다. 국내 말벌속(Genus: Vespa)은 10종으로 보고되었다. 이들 말벌류에 대한 지역별 출현 시기, 종 분포 등에 미치는 영향에 대한 생태학적 요인을 파악하는 것은 말벌류 관리에 있어 매우 중요하다. 말벌류는 봄철에는 여왕 벌이 먹이 수집활동을 통해 봉군을 형성시키며 이후 일벌을 통해 먹이 수집활동을 이어간다. 따라서 본 연구는 경북 안동대학교 양봉장 주변 야산에서 발생하는 말벌 류에 대한 연중 발생 동태를 파악하였으며, 여왕벌과 일벌의 발생을 시기를 조사하 였다. 채집된 총 개체수는 1145개체였다. 채집된 말벌류는 말벌, 좀말벌, 장수말벌, 털보말벌, 꼬마장수말벌, 등검은말벌, 검은말벌, 큰홑눈말벌으로 8종으로 이루어 져 있었다. 조사된 말벌 개체수 분포는 좀말벌:말벌:털보말벌:꼬마장수말벌:장수 말벌:검정말벌:등검은말벌이 각 36:25:12:10:10:5:2이었으며, 봄철에는 43:16:18: 6:7:8:3 이었고 여름철은 28:39:1:17:14:0:2 비율로 나타났으며, 봄철과 여름철 발 생 개체수 비율이 다르게 나타났다. 여왕벌이 월동 이후 최초 채집은 5월 1일 부터 이었고 1차 발생피크는 5월 15일~22일, 2차 발생피크는 6월 19일~26일 이었다. 채 집 개체 크기 조사를 통해 1차 피크는 여왕벌이, 2차 피크는 일벌의 발생에 의한 것 으로 판단되었다. 외부 환경적 요인에 의한 이들 발생동태 변화 추이 및 군집구조를 평가하였다.
        89.
        2013.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 129년 역사를 가지고 있는 우체국의 지속성장을 위한 핵심역량을 IPA기법으로 재평가하여 역량 강화 방안의 방향을 제시하는 것이 목적이다. 이를 위해 전국에 분포한 394명의 우체국 구성원 설문조사를 활용하여 대응표본 t-검증(paired t-test)과 IPA 매트릭스 차이(gap) 분석을 실시하였다. 분석 결과 5개 역량군과 39개 세부 역량의 중요도-수행도 차이가 있는 것으로 조사되었다. 또한 IPA매트릭스의 영역별로 유지 11개, 집중
        5,800원
        90.
        2012.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        5,800원
        92.
        2011.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We report the structural characterization of BixZn1-xO thin films grown on c-plane sapphire substrates by plasma-assisted molecular beam epitaxy. By increasing the Bi flux during the growth process, BixZn1-xO thin films with various Bi contents (x = 0~13.17 atomic %) were prepared. X-ray diffraction (XRD) measurements revealed the formation of Bi-oxide phase in (Bi)ZnO after increasing the Bi content. However, it was impossible to determine whether the formed Bi-oxide phase was the monoclinic structure α-Bi2O3 or the tetragonal structure β-Bi2O3 by means of XRD θ-2θ measurements, as the observed diffraction peaks of the 2θ value at ~28 were very close to reflection of the (012) plane for the monoclinic structure α-Bi2O3 at 28.064 and the reflection of the (201) plane for the tetragonal structure β-Bi2O3 at 27.946. By means of transmission electron microscopy (TEM) using a diffraction pattern analysis and a high-resolution lattice image, it was finally determined as the monoclinic structure α-Bi2O3 phase. To investigate the distribution of the Bi and Bi-oxide phases in BiZnO films, elemental mapping using energy dispersive spectroscopy equipped with TEM was performed. Considering both the XRD and the elemental mapping results, it was concluded that hexagonal-structure wurtzite BixZn1-xO thin films were grown at a low Bi content (x = ~2.37 atomic %) without the formation of α-Bi2O3. However, the increased Bi content (x = 4.63~13.17 atomic %) resulted in the formation of the α-Bi2O3 phase in the wurtzite (Bi)ZnO matrix.
        4,000원
        93.
        2011.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, the increasing power of distributors has given them the opportunity of introducing private brand (PB) products. Based on the game theory, this study analyzes the decision making of a distributor regarding the optimal pricing and quality strategi
        4,000원
        94.
        2011.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to investigate the effect of cytokine-induced osteoclastogenesis on tooth movement related to orthodontic force. We evaluated the cytotoxicity as well as the expression of OPG and RANKL, which influence the homeostasis of bone metabolism. Titanium particles were applied to human periodontal ligament cells and subcultured fourth generation cells. The ALP assay and the MTT assay were used to assess changes in cytotoxicity. After 48 hours, cytotoxicity increased proportionally with the concentration of titanium. With 20 mg, the cytotoxicity was the lowest. R T-PCR was u sed for assessing m R NA l evels of O PG a nd R ANKL; after 96 hours, t he m R NAs of O PG a nd R ANKL increased steeply. A western blot analysis showed that with 20 mg of titanium, the protein expression of OPG increased linearly with time, especially a fter 96 hours, while t he p rotein e xpression o f RANKL d id n ot s how significant changes with titanium processing. Given the increase in OPG expression after the initial cytotoxicity, changes in cytotoxicity with titanium may be attributable to the antagonistic effect of OPG on cytotoxicity
        4,000원
        96.
        2009.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The proliferation of the internet and electronic commerce has given the manufacturers the opportunity of direct marketing. This study analyzes the decision of manufacturers regarding whether to sell the products through independent sales company or to sel
        4,000원
        97.
        2009.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The acaricidal activities of Illicium verum fruit-derived materials against adults of Dermanyssus gallinae were examined using the direct contact application method. Based on laboratory tests, an acaricidal constituent of I. verum fruit was determined because of its potent activity. Results were compared with those of the currently used acaricides such as dichlorvos, diazinon, and carbaryl. The acaricidal principle of I. verum fruit was identified as (E)-anethole using a GC-MS. Its acaricidal activity was compared with those of 12 compounds having a similar chemical moiety. Based on the LD50 values, the acaricidal activities of (+)-or-(–)-neomenthol were the strongest (0.01 ㎎/㎠]) and (E)-anethole, (+)-or-(–)-menthol, (±)-isoborneol, (–)-menthone, and (1S)-endo-(–)-borneol showed similar results (0.02 ㎎/㎠), and (1R)-(+)-camphor and (+)-menthone also gave good activities (0.03 and 0.04 ㎎/㎠, respectively). These compounds showed more toxic acaricidal activities than diazinon and carbaryl, 0.05 and > 0.2 ㎎/㎠, respectively, but were not comparable to that of dichlorvos with 0.0002 ㎎/㎠. These results indicate that the I. verum fruit-derived materials and tested compounds descried as poultry red mites-control agents could be useful for managing field populations of D. gallinae.
        4,000원
        99.
        2008.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Repellent and acaricidal activities of eucalyptus oil, permethrin, and DEET against Leptotrombidium pallidum larvae, which are a vector transmitting tsutsugamushi disease, were evaluated under laboratory conditions using a filter paper impregnated method. The LD₅₀ values of eucalyptus oil and DEET were 0.025 and 0.018 ㎎/㎠, respectively while that of permethrin was higher than 0.2 ㎎/㎠. In the repellency test of these materials at 6.14 ㎎/㎠, eucalyptus oil gave complete repellency, and the larvae crossed the treated zone killed. But permethrin showed 60% repellency at 9.20 ㎎/㎠ and the mites croosed the zone were not killed. The percent repellency of DEET at 0.53 ㎎/㎠ was 8.3 and 2.8 times higher than that of permethrin and eucalyptus oil, respectively. The acaricidal activities of emulsifiable concentrates-pump sprayers containing the eucalyptus oil as an active ingredient were assayed. The emulsifiable concentrates containing 1% and 3% eucalyptus oil showed weak mortality at 1 hour after treatment, while all ones containing more than 6% oil produced 100% activity against L. pallidum larvae. The mortality also increased as exposure time to the concentrates increase. These results suggest that the potential of eucalyptus oil highly expected to be used as a control or repellent agent against L. pallidum larvae may be very high.
        4,000원
        100.
        2007.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Through reinvestigations of early years of King Young-Joe provincial castles, Jeonju Eupsung, this study seeks to broaden the understanding of castle construction of the later period of Chosun Dynasty. Jeonju Eupsung was established by reform-minded king and his loyalist Cho, Hyun Myung. Their new conceptual framework for reconstruction of Jeonju Eupsung was affected by Yoo, Hyung Won, a realist scholar of 17th century. It is obvious that adopted new administrative systems of financing, building and maintaining of Jeonju Eupsung were based on the his theories of castle. This study demonstrates that Jeonju Eupsung built by Cho, Hyun Myung, during the early years of King Young-Joe were based on those new concepts and systems of the new age. The study shows that the designer of this castle had in mind efficient construction design and execution and effective defense of provincial towns located on flat ground. And, the study explains how those original designer sought higher productivity through greater localization of securing resources and more detailed and improved organization of construction responsibilities. In short, this study seeks to prove that the provincial castles of the early 18th century reflected the new thinking on practicality that was spreading throughout the society of Chosun Dynasty at the time.
        5,500원
        1 2 3 4 5