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Global Trends of Bioethanol Science Information (바이오에탄올 학술정보 분석)

  • Kil, Sang-Cheol;Kim, Sang-Woo;Oh, Mihn-Soo
    • Economic and Environmental Geology
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    • v.45 no.5
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    • pp.589-597
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    • 2012
  • Recently, an understanding of new sources of liquid hydrocarbons such as bioethanol is economically very important. Bioethanol is actually ethyl alcohol or also referred to as ethanol, identical to drinking alcohol by its composition. There are mainly two ways of producing ethanol, namely by synthesis of hydrocarbons and from biomass. Only the second approach deserves the terminology 'bioethanol'. The present dissertation is also designed with purpose of developing the energy-saving process for the separation of bioethanol. The world population is expected to grow past 8 billion by 2030 which are almost 60% in Asia Pacific. History has shown that energy use rises much faster than population expands. World wide demand for energy will increase significantly during the next 15 years driven by population growth and the transition of emerging markets into the global economy. In developing nations, a smaller increment in GDP per capita yields a higher increment in energy consumption compared to developed countries. In this study, we analised total 2,454 dissertations for the bioethanol during the 2001~2012 periods by the programs of 'web of science' and 'recently developped program by Korea Institute of Science Technology Information'.

Geometric analysis and anti-aliasing filter for stereoscopic 3D image scaling (스테레오 3D 영상 스케일링에 대한 기하학적 분석 및 anti-aliasing 필터)

  • Kim, Wook-Joong;Hur, Nam-Ho;Kim, Jin-Woong
    • Journal of Broadcast Engineering
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    • v.14 no.5
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    • pp.638-649
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    • 2009
  • Image resizing (or scaling) is one of the most essential issues for the success of visual service because image data has to be adapted to the variety of display features. For 2D imaging, the image scaling is generally accomplished by 2D image re-sampling (i.e., up-/down-sampling). However, when it comes to stereoscopic 3D images, 2D re-sampling methods are inadequate because additional consideration on the third dimension of depth is not incorporated. Practically, stereoscopic 3D image scaling is process with left/right images, not stereoscopic 3D image itself, because the left/right Images are only tangible data. In this paper, we analyze stereoscopic 3D image scaling from two aspects: geometrical deformation and frequency-domain aliasing. A number of 3D displays are available in the market and they have various screen dimensions. As we have more varieties of the displays, efficient stereoscopic 3D image scaling is becoming more emphasized. We present the recommendations for the 3D scaling from the geometric analysis and propose a disparity-adaptive filter for anti-aliasing which could occur during the image scaling process.

Brief Review of Silicon Solar Cells (실리콘 태양전지)

  • Yi, Jun-Sin
    • Journal of the Korean Vacuum Society
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    • v.16 no.3
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    • pp.161-166
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    • 2007
  • Photovoltaic (PV) technology permits the transformation of solar light directly into electricity. For the last five years, the photovoltaic sector has experienced one of the highest growth rates worldwide (over 30% in 2006) and for the next 20 years, the average production growth rate is estimated to be between 27% and 34% annually. Currently the cost of electricity produced using photovoltaic technology is above that for traditional energy sources, but this is expected to fall with technological progress and more efficient production processes. A large scale production of solar grade silicon material of high purity could supply the world demand at a reasonably lower cost. A shift from crystalline silicon to thin film is expected in the future. The technical limit for the conversion efficiency is about 30%. It is assumed that in 2030 thin films will have a major market share (90%) and the share of crystalline cells will have decreased to 10%. Our research at Sungkyunkwan University of South Korea is confined to crystalline silicon solar cell technology. We aim to develop a technology for low cost production of high efficiency silicon solar cell. We have successfully fabricated silicon solar cells of efficiency more than 16% starting with multicrystalline wafers and that of efficiency more than 17% on single crystalline wafers with screen printing metallization. The process of transformation from the first generation to second generation solar cell should be geared up with the entry of new approaches but still silicon seems to remain as the major material for solar cells for many years to come. Local barriers to the implementation of this technology may also keep continuing up to year 2010 and by that time the cost of the solar cell generated power is expected to be 60 cent per watt. Photovoltaic source could establish itself as a clean and sustainable energy alternate to the ever depleting and polluting non-renewable energy resource.

Analysis of Hydrological Processes for Musim River Basin by Using Integrated Surface water and Groundwater Model (지표수-지하수 통합모형을 이용한 무심천 유역의 수문과정 해석)

  • Kim, Nam-Won;Chung, Il-Moon;Lee, Jeong-Woo;Won, Yoo-Seung
    • Journal of Korea Water Resources Association
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    • v.40 no.5
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    • pp.419-430
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    • 2007
  • Integrated modelling of surface water and groundwater has become important to satisfy the growing demands for sustainable water resources and improved water quality. In this study, the integrated model of the semi-distributed watershed model, SWA T and the fully-distributed groundwater flow model, MODFLOW is applied to Musirn river basin for the purpose of investigating its applicability to reproduce watershed-scale hydrological processes. This objective is accomplished by first demonstrating good agreement between the simulated discharge hydrographs with the measured hydrographs for the period of 2001 -2004 while simultaneously calibrating the calculated groundwater level distribution to observation wells. Next, the integrated model is used to evaluate the effect of different temporal precipitation averages on hydrodynamic processes of streamflow, percolation, recharge and groundwater discharge. Moreover, comprehensive simulations are performed to present the relationships between monthly precipitation and each hydrological component, and to analyze the temporal-spatial variability of recharge. The results show that the components are highly interrelated, and that the heterogeneity of watershed characteristics such as subbasin slope, land use, soil type causes a significant spatial variation of recharge. Overall it is concluded that the model is capable of reproducing the temporally and spatially varied surface and subsurface hydrological processes at the watershed scale.

Assessment of Energy Efficiency and Nutrient Balance in Organic Rice Farming Area (벼유기농업단지 에너지효율 및 양분수지 평가)

  • Gil, Geun-Hwan;Kang, Jong-Gook;Lee, Kyung-Do;Lee, Jang-Hee;Lee, Kyeong-Bo;Kim, Jae-Duk
    • Korean Journal of Environmental Agriculture
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    • v.27 no.3
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    • pp.267-273
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    • 2008
  • Energy efficiency and nutrient balance are good methods for environmental assessment of the environmentally-friendly agriculture. The objectives of this study were 1) to estimate the energy efficiency and nutrient balance of the organic rice farming, and 2) to suggest a solution to improvement the energy efficiency and nutrient balance. The set of estimation was performed at the organic rice farming area (8.9 ha) in Wanju-gun during the paddy cultivation period from 2006 to 2007. The organic farming complex consists of four weeding methods using 1) duck, 2) apple snail, 3) duck and apple snail and 4) hands and machinery. Results from this estimation should that the organic rice farming area was less efficient than conventional rice farming. The efficiency of organic farming area in 2006 was higher than in 2007. For the calculation of the nutrient balance, the N, P and K contents of input materials (cattle manure, milk vetch, mixed oilcake, rice bran, rice straw and barley straw) and output (farm products) were analysed. Annual environmental loads of N, $P_2O_5$ and $K_2O$ were estimated at 4.4 kg/10a, 13.8 kg/10a and 14.5 kg/10a, respectively. Cattle manure had the largest portion among the inputs items and nutrient concentration of cattle manure was high. Thus energy efficiency and nutrient balance depend on cattle manure input. Therefore it is necessary to control the manure input to improve the efficiency of organic rice farming.

Arthroscopic Treatment of Osteochondritis Dissecans of the Talus (거골 박리성 골 연골염의 관절경적 치료)

  • Choi, Chong-Hyuk;Cheon, Yong-Min
    • Journal of the Korean Arthroscopy Society
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    • v.6 no.2
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    • pp.161-170
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    • 2002
  • Purpose : To investigate arthroscopic simple excision for the treatment of osteochondritis dissecans of the talus and to examine gross change and histological evaluation of the defect through second look arthroscopy. Materials and Methods : This study included twenty-two patients who had osteochondritis dissecans of the talus that was treated with excision of arthroscopic loose body and necrotic bone tissue, leaving bleeding bed. In 7 cases, we performed second look arthroscopic examination for the evaluation of gross change of defects and histologic findings. Final results were evaluated with two clinical and functional protocols. Average follow up period was 42 months from 14 months to 8 years. Results : Ankle-hindfoot score (100 point) was improved significantly (p<0.003). Subjective and functional scores (100 points) averaged 82 points. The defect of lesion had a tendency of filling with fibrous tissue and fibrocartilage. Although the defect was filled with fibrocartilage, specific secondary lesion was not detected through second look arthroscopic examination. Conclusion : Arthroscopic debridement was an effective method for the treatment of osteochondritis dissecans of the talus without progression of secondary lesion even though the defect was filled with fibrocartilage.

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A Survey on the Critical Success Factors of Knowledge Management Using AHP (AHP 분석을 이용한 지식경영-실천요소의 중요도에 관한 실증적 연구)

  • 이영수;박준아;정광식;김진우
    • Proceedings of the Korea Inteligent Information System Society Conference
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    • 1999.03a
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    • pp.85-94
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    • 1999
  • 지식경영을 효과적으로 수행하기 위해서 기업은 지식경영을 구성하고 있는 요소를 정확히 이해할 필요가 있고, 이러한 중요 요소에 따라 투자가 이루어져야 한다. 본 연구는 지식경영의 중요 요소들을 제시함으로써, 앞으로 지식경영을 계획하고 있는 기업이 효과적으로 지식경영을 추진할 수 있는 활동 지침 및 투자 방향을 제시하고자 한다. 이를 위해, 본 연구에서는 각종 국내외 지식경영 관련 문헌에서 논의된 사항을 중심으로, 지식경영을 구성하는 30개의 중요요소를 추출하고, 분석계층도(AHP)를 이용하여 지식경영을 달성하기 위한 요소들을 위계적 구조로 정리하고, 최종단계에서 238개의 지식경영 구현의 평가기준을 마련하였다. 또한 실제로 지식경영 구현 요소들의 상대적 중요성을 파악하기 위해, 먼저 국내에서 지식경영을 추진하고 있으나 관심을 보이고 있는 48개 기업의 담당자를 대상으로 각 기업에서 추진하고 있는 지식경영의 현황 파악을 위해 지식경영 실천의 평가기준에 대한 설문을 실시하였다. 이 두 가지 설문 조사 결과를 종합해 볼 때, 기업에서는 지식경영 구현 요소 중에서 인프라 내의 프로세스와 프로세스를 구성하는 지식의 활용과 전파 등이 중요하다고 인식하고 있는 반면, 실제로는 인프라 내의 정보기술과 프로세스를 구성하는 다른 한 축인 지식의 창출과 축적 면에 투자가 이루어진 것으로 나타났다. 이 외에도 지식화, 성과와 가치의 연계 그리고 지식의 가시화 등의 요소들은 상대적 중요도 인식과는 반대로 지식경영 추진에 있어 외면당하고 있는 것으로 나타났다. 따라서 본 연구는 지식 경영의 이러한 불균형을 시정할 수 있는 방향으로 앞으로의 투자가 수행되어야 할 것을 제안하고 있다. 알 수 있다.한 것으로 연구되었다. 정상조 직에 비해 산소가 부족하여 염기성대사(anaerobic metabolism)를 많이 함으로 그 부산물인 유산 (lactic acid)이 많이 생성됨으로 정상조직보다 pH가 낮아 암 조직이 정상조직에 비해 고온온열치료에 더 잘 듣는 원인이 된다. 3) 영양이 부족한 상태의 세포는 고온온열치료에 훨씬 예민하다. 4) 암조직은 혈관상태가 정상조직에 비해 좋지 않음으로 정상조직보다 쉽게 가온이 되며, 일단 가온된 온도는 잘 식지 않음으로 정상조직에 비해 훨씬 효율적이다. 5)고 온온열치료는 4$0^{\circ}C$~43.5 $^{\circ}C$정도에서만 이 작용이 일어남으로 정상인체에서 43$^{\circ}C$이상의 가온 은 쉽지 않음으로 이 효과는 암조직에서 주고 일어나게 된다. 6)고온온열치료는 방사선치료 후에 생기는 손상의 재생을 억제함으로 방사선의 치료효과를 높인다. 7)38.5$^{\circ}C$~41.5$^{\circ}C$의 낮 은 온도에서도 암조직의 산소 상태를 호전시켜 방사선 치료효과를 증대시키는 역할을 한다.alization)가 나타난다. 그러나 무의식에 대칭화만 있는 것은 아니며, 의식의 사고양식인 비대칭도 어느 정도 나타나며, 대칭화의 정도에 따라, 대상들이 잘 구분되어 있는 단계, 의식수준의 감정단계, 집단 내에서의 대칭화 단계, 집단간에서의 대칭화 단계, 구분이 없어지는 단계로 구분하였다.systems. We believe that this taxonomy is a significant contributi

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Flow Analysis and an Experimental Study on Formation of Slurry Ice in the Reversing Flow Layer (역전 유동층 내의 유동해석 및 슬러리아이스 생성에 관한 연구)

  • Oh, Cheol;Choi, Young-Gyu
    • Journal of Advanced Marine Engineering and Technology
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    • v.35 no.4
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    • pp.421-428
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    • 2011
  • Thermal energy storage(TES) cooling system using cheaper electricity of off-peak time has been applied to relieve a significant portion of the peak demand of electricity during the daytime in summer. Slurry ice type thermal energy storage cooling system is one kind of more efficient ice-thermal energy storage cooling system than Ice-on-Coil type or Encapsulated type TES cooling system, even though, which are more popular TES system. This experimental study was carried out to observe flow pattern and formation of slurry ice in reversing flow layer to improve efficiency of heat transfer between fluid and freezing tube and to disturb ice adhesion on tube surface. The reversing flow layer was made by using reversing materials in heat exchanger section(test section) to disturb ice adhesion. At this experiment, styrofoam balls and poly propylene balls were used as reversing materials, and a 20wt% solution of ethylene glycol was used as reversing flow layer. The experimental apparatus was constructed of the test section for making/storing slurry ice, the brine tank, pumps for circulating of a 20wt% solution of ethylene glycol and brine, a flow-meter, a data logger for measuring the temperature. The experiments were carried out under various conditions, with volumetric flow rate, ball filling rate and air filling rate.

Induction of Embryogenic Callus and Plant Regeneration by Mature Embryo Culture of Onion (Allium cepa L.) (양파의 성숙배 배양을 통한 체세포배발생 캘러스 유기 및 식물체 재분화)

  • Cho Kwang-Soo;Hur Eun-Joo;Hong Su-Young;Moon Ji-Young
    • Journal of Plant Biotechnology
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    • v.32 no.1
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    • pp.31-35
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    • 2005
  • To obtain regeneration system of onion, we analyzed the effects of 2,4-D and BA concentration on the embryogenic callus induction from mature embryos. The highest embryogenic callus induction ratio was shown on MS medium (Murashie and Skoog 1962) containing $2.5\;\cal{mg/L}\;or\;5\;\cal{mg/L}$ picloram after mature embryos were placed on medium. When induced callus were cultured on half strength of MS medium containing $1\;\cal{mg/L}$ Kinetin, the highest shoot formation ratio was observed on MS medium containing $1\;{mg/L}$ 2,4-D and $1\;{mg/L}$ BA. Embryogenic callus were cultured in MS liquid medium containing $1\;\ccal{mg/L}$ of 2,4-D and $1\;\cal{mg/L}$ BA. The suspension cultured cell clumps could be mass propagated. Embryogenic callus were friable, but non-embryogenic callus included a lot of moisture, hence the identification between embryogenic and non-embryogenic callus as easily achieved. When embryogenic callus as cultured on half strength of MS medium containing $1\;\cal{mg/L}$ Kinetin, shoots were induced. The whole plantlet was obtained on rooting medium containing $0.5\;\cal{mg/}$ of NAA.

Physical Property of Hemp/Tencel Eco-Friendly Blend Spun Yarns (Hemp/Tencel 혼합 친환경 방적사의 물성)

  • Kim, Seung-Jin;Woo, Ji-Yun;Jang, Hong-Won;Kang, Ji-Man;Jang, Jae-Sik
    • Proceedings of the Korean Society of Dyers and Finishers Conference
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    • 2012.03a
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    • pp.62-62
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    • 2012
  • 지구온난화 및 환경오염의 영향으로 선진국을 중심으로한 환경규제가 심해지면서, 홈 텍스타일 분야에서는 세계 패션 트렌드 및 소비자 선호에 부응한 친환경 섬유소재 개발, 웰빙 시대에 적합한 기능성 및 고감성 제품개발을 통한 차별화가 요구되고 있다. 최근의 섬유산업의 동향도 인체에 무해한 천연적인 섬유소재에 많은 관심이 증대됨에 따라 개인의 건강 뿐만 아니라 환경을 생각하는 생활패턴인 친환경섬유의 개발이 새로운 트렌드로 떠오르고 있는 실정이다. 헴프는 일년생 식물로서 학명은 Cannabis sativa L.이다. 헴프섬유의 장점으로 내구성 및 내수성, 항균성 등이 우수한 것으로 보고되고 있으나 양질의 원료 확보, 세섬도 추출 기술 및 combing 기술 등의 부족으로 100% 헴프 세 번수 방적사의 제조가 어려워 주로 면섬유와의 혼합소재로 제조되어 왔다. 최근 들어, 친환경 소재로서 박테리아 성장 억제 기능을 가진 재생섬유인 Tencel 소재를 이용하여 stiff한 Hemp의 성질에 유연성을 추가하여 촉감을 개선함과 동시에, Tencel과 Hemp를 혼용함으로써 soft touch부터 harsh touch까지 혼용율에 의한 다양한 감성을 느끼게 함으로써 용도의 다양화 추구가 시도되어 왔다. Hemp의 거친 느낌을 완화시키고 Tencel의 박테리아 억제 기능과 Hemp의 항균기능, 방충, 탈취기능이 상호 보완되어 친환경적이고 위생적인 다용도 홈 인테리어 및 가구용 직물 등의 제품으로 Hemp/Tencel 복합사가 많이 사용되고 있다. 본 연구는 Hemp와 Tencel의 혼용율의 변화에 따른 복합사의 물리적 특성을 확인하기 위하여 천연복합 태번수 방적사 최적 사설계 이론을 적용하여 Hemp 섬유 혼용율에 따른 사의 물성분석을 함으로써 Hemp/Tencel 방적사 최적 공정 조건을 결정하기 위한 사설계 이론 결과와 실험결과를 비교 분석하고자 한다. 최적 천연 Hemp복합방적사 사설계의 이론화 및 사 물성 DB화 그리고 태번수 Hemp사의 물성분석 및 이들을 DB화 함으로써 가구용 직물로 많이 사용되는 친환경 Hemp 소재사의 방적성 향상을 꾀하고자 한다. 이를 위해서 제조한 방적사의 Dry heat shrinkage와 Wet heat shrinkage를 측정하여 확인하였고 인장시험기를 이용하여 Tenacity, Initial Modulus, breaking strain을 측정 분석하였다. 방적사의 표면 특성은 영상 현미경 시스템을 사용하여 ${\times}40$ 배율로 측정하여 확인하였다.

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