• 제목/요약/키워드: Effective medium

검색결과 2,515건 처리시간 0.03초

브러그만 유효 굴절 박막에서의 표면 플라즈몬 공명 센서 설계 (Design of Surface Plasmon Resonance Sensor with Bruggeman Effective Medium Layers)

  • 배영규;이승열
    • 센서학회지
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    • 제29권2호
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    • pp.118-122
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    • 2020
  • This paper proposes a specific sensor-design strategy and the possibility of improving the sensing performance, which can be obtained by replacing part of the existing plasmonic sensor based on the Kretschmann configuration method with an effective refractive-index layer. By replacing the metal layer with an effective refractive-index layer composed of gold and the material to be sensed, an improvement in the detection performance, accompanied by an increase in the sensed incident angle, is observed, and the gold-composition ratio that demonstrates the best result is presented. Subsequently, an increase in the sensed incident angle generated in the previous step can be suppressed by randomly etching a portion of the prism adjacent to the metal layer in a sub-wavelength scale. Finally, this study analyzes the optimization of the metal-layer thickness in a given sensor structure. An effective refractive thin-film surface plasmon resonance sensor design that can achieve optimal sensing performance is then proposed.

농촌유역에서의 초기강우손실 특성분석과 계수 산정식 개발 - 금강.삽교천 중소유역을 중심으로- (Characteristic Analysis of the Coefficient of Initial Abstraction and Development of its Formular in the Rural Watersheds - for the Small-Medium Watersheds in the Geum and Sapkyo River -)

  • 김태철;이정선
    • 한국농공학회논문집
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    • 제50권6호
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    • pp.3-12
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    • 2008
  • It is important to estimate accurate effective rainfall to analyse flood flow and long-term runoff for the rational planning, design, and management of water resource. The initial abstraction is also important to estimate effective rainfall. The Soil Conservation Service (SCS) has developed a procedure and it has been most commonly applied to estimate effective rainfall. But the SCS method still has weak points, because of unnatural assumptions such as antecedent moisture conditions and initial abstraction. The coefficient of initial abstraction(K) is depending on the soil moisture condition and antecedent rainfall. The maximum storage capacity of Umax which is calibrated by stream flow data in the proposed watershed was derived from the DAWAST(DAily WAtershed STreamflow) model. The values of K obtained from 69 storm events at the five watersheds are ranging from 0.133 to 0.365 and its mean value is 0.207. Effective rainfall could be estimated more reasonably by introducing new concept of initial abstraction. The equation of $K=0.076Sa^{0.255}$ was recommended instead of 0.2 and it could be applicable to the small-medium rural watersheds.

어성초(魚腥草)의 줄기배양에 의한 식물체(植物體) 재분화(再分化) (Plant Regeneration by the Stem Culture in Houttuynia cordata Thunberg)

  • 추병길;류점호;두홍수;권태호
    • 한국약용작물학회지
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    • 제4권2호
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    • pp.126-131
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    • 1996
  • 약용식물(藥用植物)로써 이용 가능성 큰 어성초(魚腥草)의 이차(二次) 대사산물(代謝産物)의 생산에 기초가 되는 조직배양체계(組織培養體系)를 확립하고자 어성초(魚腥草)의 절간(節間), 절(節) 및 엽(葉)의 절편체(切片體)를 이용(利用)하여 캘러스를 형성(形成)시키고, 형성(形成)된 캘러스로부터 식물체(植物體) 재분화(再分化)를 시도하였다. 1. Embryogenic 캘러스 형성(形成)은 모든 절편체(切片體)에서 2, 4-D 1 mg/L와 kinetin 0. 5 mg/L을 첨가(添加)하였을 때 가장 효과적이었다. 2. 절간(節間)에서의 캘러스 형성(形成)이 엽(葉)보다 더 효과적이었다. 3. 어성초(魚腥草)의 절간(節間)으로부터 embryogenic 캘러스 형성(形成)은 ${\frac{1}{2}}\;MS$ 배지(培地)가 효과적이었다. 4. 배지내(培地內)에 1%의 활성탄(活性炭)을 첨가(添加)하였을 경우 캘러스를 형성(形成)시키지 않고 배양(培養)된 절(節)로 부터 직접 식물체(植物體)가 분화(分化)되었다. 5. Embryogenic 캘러스로부터 식물체(植物體) 재분화(再分化)는 0. 2 mg/L NAA와 1 mg/L BA를 첨가(添加)한 배지(培地)가 다른 조합(組合)의 배지(培地)보다 분화율(分化率)이 높았다.

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생물반응기를 이용한 Lilium longiflorum ′Geogil′의 대량번식 (Micropropagation of Lilium longiflorum 'Geogia' by Using Bioreactor.)

  • 한봉희;서은정;예병우;유희주
    • Journal of Plant Biotechnology
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    • 제31권3호
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    • pp.197-201
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    • 2004
  • 자구를 형성 및 비대시키기 위하여 BA 0.5 mg/L와 IAA 0.5 mg/L가 첨가된 MS 배지에서 Lilium longiflorum 'Geogia'의 신초를 증식하였다. 증식된 신초 cluster를 5 L air lift 생물반응기에 배양하였다. 자구비대는 sucrose 60 g/L 및 1∼2배 사이의 MS 배지 염류농도에서 효과적이었다. 재료 투입량은 100 g을 투입하는 것이 자구형성 및 자구비대에 적절하였다. 배양방법은 air-lift 방법이 자구의 형성 및 비대를 촉진하였으며, 주입공기량은 200∼300 mL$.$$min^{-1}$을 주입하는 것이 자구비대에 효과적이었다.

On the direct strength and effective yield strength method design of medium and high strength steel welded square section columns with slender plate elements

  • Shen, Hong-Xia
    • Steel and Composite Structures
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    • 제17권4호
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    • pp.497-516
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    • 2014
  • The ultimate carrying capacity of axially loaded welded square box section members made of medium and high strength steels (nominal yield stresses varying from 345 MPa to 460 MPa), with large width-to-thickness ratios ranging from 35 to 70, is analyzed by finite element method (FEM). At the same time, the numerical results are compared with the predicted results using Direct Strength Method (DSM), modified DSM and Effective Yield Strength Method (EYSM). It shows that curve a, rather than curve b recommended in Code for design of steel structures GB50017-2003, should be used to check the local-overall interaction buckling strength of welded square section columns fabricated from medium and high strength steels when using DSM, modified DSM and EYSM. Despite all this, EYSM is conservative. Compared to EYSM and modified DSM, DSM provides a better prediction of the ultimate capacities of welded square box compression members with large width-thickness ratios over a wide range of width-thickness ratios, slenderness ratios and steel grades. However, for high strength steels (nominal yield strength greater than 460 MPa), the numerical and existent experimental results indicate that DSM overestimates the load-carrying capacities of the columns with width-thickness ratio smaller than 45 and slenderness ratio less than 80. Further, for the purpose of making it suitable for a wider scope, DSM has been modified (called proposed modified DSM). The proposed modified DSM is in excellent agreement with the numerical and existing experimental results.

공급자 부품품질 향상을 위한 품질보증시스템 개선방안 (Enhancement of Quality Assurance System for Improving the Quality of Suppliers' Product)

  • 한성재;함동한
    • 대한안전경영과학회지
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    • 제16권3호
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    • pp.351-362
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    • 2014
  • A prerequisite for improving the quality of a product is to enhance the quality of its parts supplied from outsourced enterprises. An enterprise certified by ISO 9001 Quality Management System is expected to develop their effective quality assurance system and maintain it through continuous control and improvement, thereby ensuring the good quality of products that they produce. However, it is reported that small and medium-sized enterprises certified by ISO 9001 have difficulty establishing an effective quality assurance system. This study aims to propose a new method of improving a quality assurance system that can be more effective in small and medium-sized enterprises. This study collectively considered requirements specified in several international standards on quality system and the results of expert group brainstorming to identify evaluation areas and items for assessing a quality assurance system. Based on these evaluation areas and items, a set of checklists for diagnosing and improving a quality assurance system was developed. In order to demonstrate the usefulness of the proposed method, this study applied it to ten small and medium-sized enterprises and could identify four approaches for improving their current quality assurance system. The presented improvement method, which consists of establishment of quality goals and quality innovation plan, defective products corrective activities, 4M and design change process, improvement of customer quality information management, is expected to be utilized as a useful tool for the enhancement of the quality assurance system of small and medium-sized enterprises.

한국잔디류에서 포복경 배양을 통한 캘러스 유기와 재분화에 관한 연구 (Callus Induction and Plant Regeneration from Stolon in Zoysiagrass)

  • 김종보;박순정;김두환
    • 아시안잔디학회지
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    • 제11권4호
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    • pp.311-320
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    • 1997
  • This study was carried out to induce and maintain callus from 59 zoysiagrass lines, to know the effective disinfestation method for zoysiagrass stolon as explant and the difference in the response of callus induction among 59 lines, and to investigate the effect of medium, growth regulators, light, temperature, stolon part and internode position on callus induction and emhryogenic callus(E.C.) formation. The treatment of 0.lmg/L $HgCl_2$for 15 min resulted in no contamination and the highest callus induction(46.6%). Callus was induced from the 59 zoysiagrass lines. The callus growth of Z. japonica and Z. sinica was generally better than Z. matrella Ten cell lines whose callus and stolon grow fast in culture and in field, respectively were selected to he used for breeding. Callus induction was the most effective at 2.0mg /L of both 2, 4-D and picloram in MS medium. MS medium was the best for callus induction and growth while LS medium was the best for embryogenic callus and shoot formation. Callus induction and growth was better at 28, 31$^{\circ}C$. than 25$^{\circ}C$. and dark condition was better than light condition in MS me-dium containing 2mg/L 2,4-D. While callus induction was better with node part as explant than with internode part, callus growth and embryogenic callus formation was better with internode part. In 'Japonica 1', the first internode was the most effective in callus induction, but third internode was the best in '$M_2$ X $S_2$'.

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계대세포를 이용한 소 수정란의 체외배양 체계에 관한 연구 (Effects of established cell lines on bovine embryo development during in vitro culture)

  • 주석천;이병천;이원유;최윤석;황우석
    • 대한수의학회지
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    • 제37권3호
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    • pp.647-659
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    • 1997
  • To overcome the difficulties of collecting and culture of primary cell from genital tract on embryonic development, the present study was carried out to investigate the critical effect of cell lines, such as BRL and Vero cell and its conditioned medium on the development of early Korean native cattle embryos in vitro. Oocytes collected from slaughterhouse ovaries were matured in TCM199 containing FSH, estradiol-$17{\beta}$ and FBS with granulosa cell monolayer for 24 hours and then fertilized in vitro using frozen-thawed, heparin-treated spermatozoa in TALP for 30 hours. And then early embryos (1-2cell) were cultured in TCM199 containing 10% FBS with BOEC, Granulosa, BRL, Vera cell monolayers and conditioned medium for 2~3 days. Development to morulae and blastocysts were recorded, also examined the number of blastomeres presented a valuable parameter for the evaluation of embryonic development. The early cleavage rates of in vitro fertilized embryos co-cultured, there was no differences between primary cell and cell lines(p<0.05). The rate of development to the later stage, coculture of BRL cell was significantly higher than that of the primary cell(p<0.05). The rates of development to morula and blastocyst were significantly higher in vero cell than BRL, Granulosa, Oviduct epithelial cell conditioned medium. In the result of effect of serum on development of early bovine embryos, the use of media containing serum were significantly higher than the use of not containing one on development of early and later stage of embryos. The result of number of blastomeres in blastocysts, there is no differences between primary cell and cell lines. The blastocysts from coculture were higher than from conditioned medium in blastomere cells. In summary, these experments have proved that the culture system in TCM199 with BRL, Vero cell monolayers is effective on in vitro development of early bovine embryos, In addition, it is effective to development of bovine embryos that containing serum in conditioned medium, or in co-culture rather than in conditioned medium alone. The use of cell lines opponent to primary cells is effective in bovine embryo culture.

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Mass Propagation of Sundew, Drosera rotundifolia L. through Shoot Culture

  • Jang, Gi-Won;Park, Ro-Dong
    • Journal of Plant Biotechnology
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    • 제1권2호
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    • pp.97-100
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    • 1999
  • In order to establish in vitro propagation method of sundew, Drosera rotundifolia L., the effects of MS medium concentration, cytokinin type and concentration, pH, and auxin type and concentration on shoot proliferation and root formation were investigated using shoots at 3 month after seed germination. The highest shoot production was obtained with the half strength of MS ($\frac{1}{2}$ MS) medium than with any other strength of MS medium tested. Addition of kinetin or BA in $\frac{1}{2}$ MS medium was strongly suppressed shoot proliferation. The suppression of shoot proliferation was more effective in BA-supplemented $\frac{1}{2}$ MS medium than kinetin-supplemented. The optimum pH of the media for shoot proliferation was pH 5.7-6.7. Shoots were subcultured in $\frac{1}{2}$ MS medium supplemented with 0.5mg/L 2,4-D for rooting every 8 weeks. All subcultured shoots produced extensive root systems after 5 to 6 week culture. Plantlets after root development were planted in plastic pots filled with moss. The survival rate of plantlets was almost 100%. On subculturing every 8 weeks, hundreds of the plants were propagated from a single plant within a year.

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중소기업을 위한 지식서비스 수요 조사 모형 개발 (The development of knowledge service needs assessment model for small and medium-sized businesses)

  • 맹윤호;유선희;서진이
    • 지식경영연구
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    • 제16권4호
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    • pp.169-190
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    • 2015
  • The status of small and medium-sized enterprises has been changed into more independent business entities rather than simply subcontractor so that the utilization of specialized knowledge has been much more necessary for the survival in the market. However, small and medium-sized enterprises, it is difficult to sufficient investment in knowledge services due to limited resources relative to large enterprises and demand for knowledge services business of government support is growing. For this reason, it is important to measure accurately the demand for knowledge services of small and medium-sized enterprises in knowledge management for effective utilization of knowledge service. In this study, we analyzed previous studies on small and medium-sized enterprises knowledge services that can be utilized in a comprehensive way. As a result, we developed knowledge service needs assessment model based on five critical success factors for continual growth and 12 types of knowledge service. This model has been modified and supplemented through expert meeting using delphi research method and topic modeling analysis using secondary data. This study is attempted to appropriately measure necessary knowledge services for small and medium-sized enterprises so that generated the evaluation model of knowledge service demands, comprehensively dealing with core knowledge services for many kinds of business entities. It is expected that the developed model will be a useful tool to understand and evaluate knowledge services demands of enterprises.