• 제목/요약/키워드: g-continuous

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LoG Scale-Space를 이용한 라인의 중심축 검출 (Medial Axis Detection of Stripes Using LoG Scale-Space)

  • 변기원;남기곤;주재흠
    • 융합신호처리학회논문지
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    • 제11권3호
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    • pp.183-188
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    • 2010
  • 본 논문에서는 LoG scale-space를 이용한 그레이스케일 영상에서 연속패턴 라인 중심축 검출 기법을 제안한다. 제안된 기법은 LoG의 스케일 크기를 적응적으로 가변하여 라인 중심축을 검출하는 방법이다. 작은 스케일의 LoG 연산자는 라인의 에지점에서 영교차 특성이 나타나며, 영교차점을 중심으로 좌우에 +/- 극성을 가진 극점이 존재하게 된다. 즉 일정한 폭을 가지는 라인은 양쪽 가장자리에서 2개의 +극점을 가지게 된다. LoG의 확산동작을 반복함에 따라 스케일을 증가시키면 +극점은 라인 양쪽 에지영역에서 중심영역으로 이동하여 점진적으로 가까워져서 최종적으로 하나의 극점으로 중첩되어진다. 연속패턴 라인 중심축은 2개의 +극점이 중심영역에서 중첩되는 점이다. 제안하는 방법은 기존의 이진영상에서 적용되는 세선화 방법보다 강인하게 연속패턴 라인 중심축을 검출함을 확인하였다.

에탄올 발효방법에 따른 음식물류 폐기물의 바이오에탄올 생산성 비교 (Comparison of Bio-ethanol Productivity Using Food Wastes by Various Culture Modes)

  • 강희정;리홍선;김용진;김성준
    • KSBB Journal
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    • 제25권5호
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    • pp.471-477
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    • 2010
  • In order to improve bio-ethanol productivity by various cultivation methods in this paper, the culture modes using food wastes, such as batch culture, high-cell-density fermentation, SSF (simultaneous saccharification and fermentation) by fill & draw, continuous culture by fill & draw were performed and their productivities were compared. SSFs by fill & draw were performed by continuous decompression using 1 L evaporator system, and by 10 L bioreactor without decompression. In addition, the continuous cultures by fill & draw mode using SFW (saccharafied food wastes) medium were performed by changes of 40% culture broth with intervals of 12 h (0.03 $h^{-1}$), 6 h (0.07 $h^{-1}$), 3 h (0.13 $h^{-1}$). Consequently, productivities of bio-ethanol were 2.52 g/L-h and 1.30 g/L-h in batch culture and high- cell-density fermentation, respectively. The productivities of SSF by fill & draw showed 2.24 g/L-h and 2.03 g/L-h in continuous decompression with 1 L evaporator and 10 L bioreactor without decompression, respectively. Also, the productivities in continuous culture by fill & draw modes showed 2.02 g/L-h, 4.07 g/L-h and 6.25 g/L-h by medium change with intervals of 12 h, 6 h, and 3 h, respectively. In conclusion, the highest ethanol productivity was obtained in the continuous culture mode by fill & draw with dilution rate of 0.13 $h^{-1}$.

Continuous Propionic Acid Production from Cheese Whey Using In Situ Spin Filter

  • Gupta, Achin;Srivastava, Ashok K.
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제6권1호
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    • pp.1-5
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    • 2001
  • The potential use of spin filter device to retain Propionibacterium acidipropionici in the bioreactor under continuous mode of fermentation, and improve acid productivity, was examined. The yield of propionic acid based on lactose concentration was 51% in batch and 54% in continuous (dilution rate = 0.05 h(sup)-1) operation. The yield in continuous fermentation with cell retention using spin filter of 10 micron size (dilution rate = 0.05 h(sup)-1) was even higher at 70% (w/w). The volumetric productivity under batch and continuous mode of operation were 0.312g L(sup)-1 h(sup)-1 and 0.718g L(sup)-1 h(sup)-1 respectively. Continuous fermentation with cell retention demonstrated even higher volumetric productivities at 0.98g L(sup)-1 h(sup)-1 with out clogging problems. It could be used for utilization of cheese whey to produce propionic acid at higher yield and productivities.

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Effects of aeration and centrifugation conditions on omega-3 fatty acid production by the mixotrophic dinoflagellate Gymnodinium smaydae in a semi-continuous cultivation system on a pilot scale

  • Ji Hyun You;Hae Jin Jeong;Sang Ah Park;Se Hee Eom;Hee Chang Kang;Jin Hee Ok
    • ALGAE
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    • 제39권2호
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    • pp.109-127
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    • 2024
  • High production and efficient harvesting of microalgae containing high omega-3 levels are critical concerns for industrial use. Aeration can elevate production of some microalgae by providing CO2 and O2. However, it may lower the production of others by generating shear stress, causing severe cell damage. The mixotrophic dinoflagellate Gymnodinium smaydae is a new, promising microalga for omega-3 fatty acid production owing to its high docosahexaenoic acid content, and determining optimal conditions and methods for high omega-3 fatty acid production and efficient harvest using G. smaydae is crucial for its commercial utilization. Therefore, to determine whether continuous aeration is required, we measured densities of G. smaydae and the dinoflagellate prey Heterocapsa rotundata in a 100-L semi-continuous cultivation system under no aeration and continuous aeration conditions daily for 9 days. Furthermore, to determine the optimal conditions for harvesting through centrifugation, different rotational speeds of the continuous centrifuge and different flow rates of the pump injecting G. smaydae + H. rotundata cells into the centrifuge were tested. Under continuous aeration, G. smaydae production gradually decreased; however, without aeration, the production remained stable. Harvesting efficiency and the dry weights of omega-3 fatty acids of G. smaydae + H. rotundata cells at a rotational speed of 16,000 rpm were significantly higher than those at 2,000-8,000 rpm. However, these parameters did not significantly differ at injection pump flow rates of 1.0-4.0 L min-1. The results of the present study provide a basis for optimized production and harvest conditions for G. smaydae and other microalgae.

탑형 발효기에 의한 에탄올 연속 생산 (Continuous Ethanol Production by Tower Fermentor)

  • 서근학;송승구김재형
    • KSBB Journal
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    • 제9권2호
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    • pp.104-107
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    • 1994
  • Cone 형태 탑형발효기에서 연속발효실험을 수행 결과 발효조 최대 효모 농도는 37.5-39.5g/l이었고 최대 에탄올 생산성은 희석율 0.32 $hr^{-1}$에서 16.3gEtOH/L.hr 이었다. 평균 에탄올 수율은 0.48 g/EtOH/g glucose로서 이는 이론적 수율의 94%였다. Cone형태 탑형발효기는 에탄올 연속생신시 효과적인 발효기로 생각되었다.

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$\alpha$-아밀레이즈와 고정화된 글루코아밀레이즈를 이용한 전분의 액화 및 당화 (Liquefaction and Saccharification of Starch Using $\alpha$-Amylase and Immobilized Glucoamylase)

  • 안대희;장호남
    • 한국미생물·생명공학회지
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    • 제19권5호
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    • pp.497-503
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    • 1991
  • Packed bed column과 continuous stirred tank reactor에서 고정화된 glucoamylase의 catalytic activity를 비교하였다. Settling chamber를 이용한 연속애화, 당화 공정을 사용하여 액화된 전분으로부터 포도당을 연속적으로 생산하였다. . Chitin에 고정화된 glucoamylase에 의한 당화실험에 있어서는 dextrin의 농도가 100g/l일 때, 체류시간 20분 동안 20의 당화수율을 나타냈다.

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Production of Lactococcal Bacteriocin using Repeated-Batch and Continuous Cultures

  • Yoo, Jin-Young
    • Journal of Microbiology and Biotechnology
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    • 제2권4호
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    • pp.284-287
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    • 1992
  • Repeated-batch and continuous cultures of Lactococcus sp. 1112-1 were carried out for bacteriocin production using a glucose-casein medium. Repeated-batch culture did not efficiently enhanced the bacteriocin production. Continuous production was possible at the dilution rate of 0.4 $h^{-1}$. Maximum specific production rate ($Q^p$), bacteriocin production and biomass at the dilution rate were 347, 136 IU/g/h, 2, 121 IU/ml and 2.45 g/L, respectively.

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THE OPERATORS 𝜋G OF BEST APPROXIMATIONS AND CONTINUOUS METRIC PROJECTIONS

  • RHEE, HYANG JOO
    • Journal of applied mathematics & informatics
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    • 제40권3_4호
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    • pp.669-674
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    • 2022
  • In this paper, we shall consider some properties of the metric projection as a set valued mapping. For a set G in a metric space E, the mapping 𝜋G; x → 𝜋G(x) of E into 2G is called set valued metric projection of E onto G. We investigated the properties related to the projection PS(·)(·) and 𝜋S(·)(·) as one-sided best simultaneous approximations.