• Korean Journal of Plant Tissue Culture
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• v.22 no.2
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• pp.115-120
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• 1995

A method for cryopreservation of suspension cultured embryogenic cells derived from immature zygotic embryos of rice (Korean cultivars, Donggin-byeo and Taebaeg-byeo) was developed. The highest cell regrowth after storage in liquid nitrogen was obtained when Donggin-byeo cells were cryoprotected with a mixture of 2 M DMSO and 0.4 M sucrose and Taebaeg-byeo cells with a mixture of 0.64 M DMSO and 0.4 M sucrose at frequencies of 88% and 90%, respectively, Pretreatment in a high osmotic medium was not necessary. Upon transfer to $N_{6}$ medium suplemented with lmg/L NAA and 5 mg/L kinetin, the regenerated calli gave rise to numerous somatic embryos which subsequently underwent development into plantlets. Among approximately 100 plantlets, 25% of them were albinos.s.

• Journal of the Korea Concrete Institute
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• v.19 no.2
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• pp.233-239
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• 2007

The main objective of this study was to evaluate the effect of recycled PET fiber made from waste PET bottle on the control of plastic shrinkage cracking of cement based composites. PET is blown as a plastic material and used in a variety products such as a beverage bottle. However, waste PET bottles are thrown after the usage, raising huge problems in terms of the environment. Thus, the research on the method to recycle the PET bottles indicates important aspects in environment and economy. The method to recycle waste PET bottles as a reinforcing fiber for cement based composites is one of effective methods in terms of the recycle of waste PET bottles. In this research, the effect of recycled PET fiber geometry and length on the control of plastic shrinkage was examined through thin slab tests. A test program was carried out to understand the influence of fiber geometry, length and fiber volume fraction. Three type of recycled PET fibers including straight, twist crimped and embossed type. Three volume fraction and two fiber length were investigated for each of the three fiber geometry. Test results indicated that recycled PET fibers are effective in controlling plastic shrinkage cracking in cement based composites. In respect to effect of length of fiber, longer fiber was observed to have efficient cracking controlling with low volume fraction in same fiber geometry while shorter fiber controled plastic shrinkage cracking efficiently as addition rate increase. Also, embossed type fibers were more effective in controlling plastic shrinkage cracking than other geometry fiber at low volume fraction. But, for high volume fraction, straight type fibers were most effective in plastic shrinkage cracking controlling in cement based composites.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.232-234
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• 2009

신재생에너지 보급 확산을 위해서 정부에서는 2009년부터 2030년까지의 시평을 가진 '제3차 신재생에너지 기술개발 및 이용 보급' 기본계획을 수립하고, 이의 달성을 위하여 예산투자와 함께 기술개발 지원, 보급 보조 및 융자, 발전차액지원제도, 그린홈 100만호 보급사업 등을 다각적으로 추진하고 있다. 이러한 보급지원제도의 하위제도로써의 융자지원제도는 신재생에너지 설치자 및 생산자를 대상으로 장기저리의 융자지원을 해주는 제도이다. 이를 통해 초기 투자비를 경감, 사업적 경제성을 확보하여 신재생에너지설비 및 관련 산업을 보급, 육성하고자 하는 것이다. 융자지원을 위한 금리는 기준금리(국고채 3년물 수익률)에 연동하여 분기별로 조정되고, 시설자금, 생산자금, 운전자금으로 분류하여 태양열, 태양광, 바이오, 폐기물, 수력, 지열, LFG, 풍력, 연료전지 등의 분야에 지원한다. 따라서 본 연구에서는 융자지원제도 현황을 고찰하고, 기준금리의 변동에 따른 융자지원 금리의 변동을 함께 살펴보았다. 각 에너지원별 지원에 어떠한 영향을 주는지 알아보았다.

• The Korean Journal of Applied Statistics
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• v.15 no.1
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• pp.107-117
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• 2002

In this paper we present the optimal replacement policies following the expiration of combination warranty. We consider two types of combination warranty policies: renewing warranty and non-renewing warranty. The criterion used to determine the optimal replacement period is the expected cost rate per unit time from the user'perspective. The optimal maintenance period following the expiration of combination warranty is obtained. Some numerical examples are presented for illustrative purpose.

• 재활용회보
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• s.1
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• pp.54-63
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• 2003

• Korean Journal of Agricultural Science
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• v.15 no.1
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• pp.15-22
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• 1988

Factors affecting the regeneration, reversion of protoplasts from mycelium of F. velutipes were investigated and the selection of auxotrophic mutants from protoplasts of F. velutipes was performed. PDP medium stabilized with 0.6M sucrose was suitable for the regeneration of protoplasts, and regeneration frequency was 0.47-1.32. The regeneration frequency of protoplasts was increased when nutrients were added to the regeneration medium. Especially, yeast extract was the most effective to regeneration of protoplasts. Regeneration pattern of protoplasts was formation of germ tubes from bud-like cells. 13-18% of monokaryotic strains was appeared from reverted protoplasts. Five of auxotrophic mutants were isolated from strains showed survival frequency of 1.9-16.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.3
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• pp.506-515
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• 2015

In this paper, we propose a group playback synchronization method using adaptive synchronization delay time by the bit rate of media to synchronize a play position of streaming media between mobile smart devices. This method consists of streaming server-side and client-side synchronization algorithms based on synchronization delay time which includes connection time, control packet transmission time, streaming data buffering time, and synchronization processing time. We implement the Android media player application with synchronization support using the proposed algorithms and present the result of performance evaluation.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.759-762
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• 2007

본 연구는 부문별 수소 및 연료전지의 수요량을 산정하고 원활한 수소공급을 위한 수소제조원의 최적믹스를 바탕으로 수소 도입 이후의 에너지믹스를 제시하는 것을 목표로 하고 있다. BaU 전망은 에너지경제연구원의 전망을 바탕으로 하였으며 기준안, 고유가안, 저유가안의 세가지 시나리오를 설정하여 각 시나리오별 분석을 수행하였다. 기준안에 따르면 수소 및 연료전지는 2015년 시장에 도입되어 2031년 5%의 시장보급률을 확보한 이후 보급률이 급격히 증가하는 것으로 나타났다. 수소 연료전지 시장중 특히 수송부문이 선도적 역할을 할 것으로 기대되며 FCV 보급대수는 2040년 1,132만대로 전체 자동차 시장의 48.4%를 차지할 전망이다. 최종에너지 중 수소의 비중은 2040년 8.7%에 이를 것으로 예측되며 수소의 도입으로 인해 1차에너지 중 신${\cdot}$재생에너지 비중이 BaU 대비 약 5.1%p 증가한 12.1%에 이를 것으로 분석되었다. 총 수소수요량은 777만톤에 이를 전망이다. 고유가안에서는 수소 및 연료전지가 2012년에 시장에 도입되는 것으로 가정하였으며 2040년 FCV 보급대수는 1,633만대에 이를 전망이다. 최종에너지 중 수소 비중은 11.5%에 이를 것으로 예상되며 1차에너지 신${\cdot}$재생에너지 비중은 11.6%로 분석되었다. 수소수요량은 1,015만톤으로 전망된다. 저유가안에서는 수소 및 연료전지가 2018년 도입되는 것으로 가정 하였다. 이 경우 2040년 FCV는 641만대가 보급되어 자동차 등록대수의 27.4%를 차지할 것으로 전망된다. 최종에너지 중 수소 비중과 1차에너지중 신${\cdot}$재생에너지 비중은 각각 5.5%, 9.1%에 이를 것으로 분석되었으며 수소수요량은 496만톤으로 전망된다.

• Journal of the Korea Concrete Institute
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• v.18 no.5 s.95
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• pp.649-656
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• 2006

In this study, powered superplasticizer(PSP) agents to improve the slump loss rate of recycled aggregate concrete were developed. To evaluate the variation of fluidity against elapsed time and the mechanical properties, twenty four specimens whose main variables had the mixing condition of aggregates, such as natural and recycled gravels, and natural and recycled fine aggregates, were tested. The concrete slump with a liquid superplasticizer greatly decreased against the elapsed time and dropped by less than 50% of initial slump after two hours. However the concrete slump with the PSP agents hardly varied until after half an hour and maintained more than 85% of initial slump even after an hour. Also the PSP agents made the compressive, splitting tensile, and flexural strength of concrete increased and the shrinkage strain decreased. Considering the properties improvement of concrete, it can be recommended that optimum mixing amount of the PSP agents should be 5% of the amount of cement.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.65.1-65.1
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• 2010

KPX(Korea Power Exchange) has been supervising FIT(Feed-in-tariff) for renewable energy power plants and supported 289MW photovoltaic power plants with Electric Power Industry Basis Fund in 2009. In this paper, we'll analyze utilization factor of these PV power plants in 2009 and for the latest 3 years and finally utilization factor of other renewable energy power plants in 2009.