• 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.

• 한국정밀공학회지
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• 제11권4호
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• pp.38-46
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• 1994

The vibration amplitude of boring bar is generally large at the tool tip, because it has the high length-diameter(L/D) ratio. A new dynamic cutting force model is presented by considering the change of shear angle under dynamic cutting. The boring bar is modelled as a cantilever with dynamic force acting at the tool end point. Based on this realistic continuous system model, the equation of motion of borring bar is solved by numerical computations. A good agreement is found between the proposed model and the experimental results.

• The Korean Journal of Pain
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• 제7권2호
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• pp.193-198
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• 1994

The analgesic efficacy and side-effects of combined continuous epidural infusion of bupivacaine and morphine, in comparison with intramuscular (IM) administration of narcotics, for postoperative pain relief after cesarean section and hysterectomy were evaluated. We divided 60 patients into 4 groups randomly. IM (meperidine) group after cesarean section (Group 1, n = 20); Continuous epidural group after cesarean section (Group 2, n=20); IM (meperidine) group after hysterectomy (Group 3, n=10); Continuous epidural group after hysterectomy (Group 4, n=10). Following each operation, the epidural groups had an epidural catheter placed ($L_{2{\sim}3}$ or $L_{3{\sim}4}$), and a bolus of 1.5mg of morphine was injected, and followed by continuous infusion of 0.3% bupivacaine 2ml/hour and morphine 2.5mg/day for 48 hours. The IM groups had received meperidine 50mg IM injection every 4 hours as needed. We evaluated analgesic efficacy with VAS (visual analogue scale) at 1, 2, 24, 48, and 72 hours after operation. The side-effects (nausea &, vomiting, respiratory depression, pruritus and urinary retention) were evaluated with 4 points scale at day 1, 2, and 3 after operation. The results were as follows 1) The continuous epidural (bupivacaine+morphine) groups were superior to the IM (meperidine) groups with respect to postoperative analgesia at 1, 2, and 24 hours after cesarean section, and at 1, 2, 24, and 48 hours after hysterectomy. 2) Vomiting were more frequent in the epidural groups 2 days after cesarean section. 3) Pruritus was more frequent in the epidural groups 1 and 2 days after cesarean section.

• 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.

• 대한수학회지
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• 제33권1호
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• pp.155-167
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• 1996

Let X be a compact Hausdorff space, C(X) denote the set of all continuous real valued functions on X and $\ell \in N$ be any natural number.

• East Asian mathematical journal
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• 제28권3호
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• pp.287-292
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• 2012

In this paper, we establish the strong convergence for the Mann iterative scheme associated with uniformly continuous pseudocontractive mappings in real Banach spaces. Moreover, our technique of proofs is of independent interest.

• 한국미생물·생명공학회지
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• 제23권3호
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• pp.346-351
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• 1995

To produce ethanol from Jerusalem artichoke powder efficiently, Kluyveromyces marxianus F043 cells were encapsulated in 2% sodium alginate and were cultured in a countinuous reactor to investigate the fermentation properties. Immobilized K. marxianus F043 cells were activated for 48 hours in a fermentor for continuous ethanol production. The culture in a CSTR using a Jerusalem artichoke substrate treated with 2% cellulase showed a decrease in ethanol concentration and an increase in residual saccharide concentration with a increasing dilution rate. Optimum conditions for high ethanol productivity and low residual saccharide output were clarified to be given at a dilution rate of 0.2 h$^{-1}$ and a Jerusalem artichoke medium concentration of 75 g/l. Ethanol productivity of 3.1 g/l-h and saccharide utilization of 62.6% were obtained under the optimum condition. When the fermentation was performed for 3 weeks under these conditions, the effluent medium showed stable ethanol concentrations of 16.3 - 17.9 g/l and viable cells of 6.60-7.16 log cells/ml without contamination. Trace amounts of methyl, n-propyl, iso-butyl, isoamyl alcohols besides ethanol were detected.

• Journal of Microbiology and Biotechnology
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• 제15권1호
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• pp.192-196
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• 2005

Abstract Oligotrophic microbial fuel cells (MFCs) were tested for the continuous monitoring of low biochemical oxygen demand (BOD) by using artificial wastewater, containing glucose and glutamate, as check solution. Ten times diluted trace mineral solution was used to minimize the background current level, which is generated from the oxidation of nitrilotriacetate used as a chelating agent. The feeding rate of 0.53 ml/min could increase the sensitivity from 0.16 to 0.43 ${\mu}$A/(mg BOD/l) at 0.15 ml/min. The dynamic linear range of the calibration curve was between 2.0 and 10.0 mg BOD/l, and the response time to the change of 2 mg BOD/l was about 60 min. The current signal from an oligotroph-type MFCs increased with the increase in salts concentration, and the salt effect could be eliminated by 50 mM phosphate buffer.

• Communications for Statistical Applications and Methods
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• 제21권4호
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• pp.327-334
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• 2014

Various modified GARCH(1, 1) models have been found adequate in many applications. We are interested in their continuous time versions and limiting properties. We first define a stochastic integral that includes useful continuous time versions of modified GARCH(1, 1) processes and give sufficient conditions under which the process is exponentially ergodic and ${\beta}$-mixing. The central limit theorem for the process is also obtained.

• KSBB Journal
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• 제17권2호
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• pp.182-188
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• 2002

푸마르산으로부터 숙신산 생물전환을 위하여 E. faecalis RKY1을 HFBR에 친정화하여 연속생산 공정에 대한 가능성을 모색하였다. E. faecalis RKY1은 실관의 spongy 부분에 효과적으로 고정화되었으며, transverse mode로 HFBR 조업시 실관가닥이 50개 및 200개일 경우 거의 비슷한 경향을 나타냈다. 또한 배지의 공급속도를 0.25, 0.5, 1.0 mL/min로 증가시키면서 조업한 결과, 정상상태에 도달하는 시간이 각각 24, 12, 9시간으로서 유속이 증가할수록 정상상태에 도달하는 시간은 단축되었지만, 반응기 내의 기질 및 생성물 분포는 그 변화가 심하였다. 실관 생물반응기를 이용하여 숙신산 생물 전환시 배지의 공금 유속이 증가할수록 숙신산 생산성은 증가하였지만 전환수율이 감소하여 미반응 푸마르산은 증가하였다. 최대 숙신산 생산성 및 이 때의 수율은 푸마르산염 농도 80 g/L 및 배지 공금 유속 2.0 mL/min일 때 17.1 g/L ·hr 및 0.54 g/g이었으며, 최적 숙신산 생산성 및 이 때의 수율은 푸마르산염 농도 50 g/L 및 배지 공급 유속 1.0 mL/min일때 9.0 g/L · 및 0.90 g/g으로서 회분식 생물전환의 경우보다 더 우수하였다.