• Industrial Engineering and Management Systems
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• 제10권1호
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• pp.34-42
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• 2011

Many companies open multiple projects simultaneously due to market trends, which results in a crowding out effect because of limited resources. R&D engineers become overloaded and scheduling of product development is delayed resulting in timing misses and lost sales leads. The company in this case study (Company A), often opens up many projects simultaneously in order to respond to market needs quickly. The engineers are overloaded and, of course, the schedule is delayed. In order to identify problems, Company A began using Dr. Goldratt's Thinking Processes (TP) during new product development (NPD). When the analysis phase of TP was completed, Company A's core problem was identified as "the quantity of kick-off projects." Consequently, new rules and conditions and procedures were proposed for the opening, suspending, stopping, and closing of projects. Finally, the "Future Reality Tree" ensured that the proposed rules, conditions and procedures were set up as an available solution approved for practical application by executives. After a one-year trial run, the results showed that the Project Duration Rate was reduced by 53%, the Project Closed Rate was increased by 140% and the Project on Time Rate was increased from 10% to 68%. The above results give significant evidence of the benefits of the proposed methodology.

• 대한기계학회논문집
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• 제9권6호
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• pp.714-724
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• 1985

본 논문에서는 입자가 부상된 2상유동의 해석에서 여러유동조건의 유동을 공 통적으로 해석할 수 있고 또 유동의 난류구조를 규명할 수 있도록 하기 위해서 2-방정 식 난류모델을 적용하였고 또 지배방정식들 속에 나타나는 1유체와 2유체의 2차 상관 관계들을 모형화 할 때 Taweel and Landau의 스펙트럼 이론을 확장발전시켜 적용하였 다.

• 한국미생물·생명공학회지
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• 제8권1호
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• pp.19-25
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• 1980

난산균의 효율적인 보존문제로서 Lactobacillus bulgaricus NLS-4를 사용하여 동결 및 동결건조법이 이 균주의 생존도 및 활성도에 미치는 영향을 조사하였다. 동결 및 동결건조처리 후 전반적인 생존도 및 활성도는 저하되나 초발미생물농도를 높여준 경우 모두 증대되어 동결시에는 최고 생존도 및 활성도가 각각 46％ 및 0.25％ lactic acid였고 동결건조 시에는 22％ 및 0.29％ lactic acid였다. 동결 및 동결건조 처리전 보호물질로서 각각 10％ glycerol과 G. C. G. S. 현탁용액을 첨가한 경우 대조군인 10% skim milk를 첨가한 경우보다 생존도 및 활성도가 증가하여 동결시에는 최고 생존도 62％, 최고 비교활성도 95％를 나타냈고 동결건조시에는 각각 79％, 126%를 나타냈다. 결론적으로는 미생물농도가 생존도 및 활성도를 높이기 위한 가장 중한 인자임을 알 수 있었고 보호물질의 첨가도 효과적임을 알 수 있었다.

• Advances in Traditional Medicine
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• 제5권1호
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• pp.29-36
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• 2005

Polysaccharide hydrogels constitute a structurally diverse class of biological macromolecules with a wide range of physicochemical properties. They also constitute important members of the family of industrial water-soluble polymers. They find application in Pharmacy as binders, disintegrants, suspending, emulsifying and sustaining agents. According to the International Pharmaceutical Excipients Council (IPEC), an excipient must have an established safety profile. Hence, in the present study, in vitro cytotoxicity on Vero and HEp-2 cell lines, and in vivo acute toxicity in rats were carried out to establish the safety of polysaccharide hydrogels from the seeds of Plantago ovata and Ocimum basilicum. The in vitro cytotoxicity was determined by MTT and SRB assays. In the in vivo acute toxicity, the effects of three different doses of hydrogels (100, 200 and 400 mg/kg body weight) on food and water intake, body weight, biochemical and hematological parameters were studied. The results of in vitro did not show any cytotoxicity on both the cell lines used. In the in vivo acute toxicity, the hydrogels did not show any toxic symptoms in all three dose levels. This establishes the safety of the selected hydrogels. Hence, they can be used as excipients in pharmaceutical dosage forms.

• 한국해양공학회지
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• 제28권2호
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• pp.111-118
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• 2014

In drilling process of oil wells, the drilling fluid such as mud keeps the drill bit cool and clean during drilling, with suspending drill cuttings and lubricating a drill bit. In this paper, a commercial CFD package(ANSYS Fluent 15.0) was used to solve the hydrodynamic force and evaluate mud mixing time in the mud mixing tank on offshore drilling platforms. Prediction of power consumption in co-rotating and counter-rotating models has been compared with results of Nagata's correlation equation. This research shows the hydrodynamic effect inside the two phase mud mixing tank according to rotating directions(co-rotating and counter-rotating). These results, we can conclude that the co-rotating direction of the two shafts with mixing blade in the mud mixing tank can be a preferable in power consumption and mixing time reduction.

• KSBB Journal
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• 제9권1호
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• pp.85-90
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• 1994

Gellan형 미생물 다당류를 생산하는데 관련된 기초 자료를 얻기 위하여 배지조성, 배양온도 및 초기 pH등에 대한 플라스크 실험을 수행하였으며 이를 근거로 회분식, 유가식 및 연속배양을 실시하였다. 또한 배양액의 비뉴우튼성 유체 특성을 조사하였고 이때의 교반동력을 측정하였다. 플라스크 배양을 통하여 얻은 결과를 이용하여 회분식 배양의 최적조건을 확립하였으며 각종 metabolic parameter들을 추정하였다. 유가식과 연속식 배양을 통하여 생산성 향상을 시도한 결과 유가식과 연속식 배양에서 생산성 향상을 꾀할 수 있었다. 고점성 배양액에서의 물질전달 장해현상을 극복하기 위한 일련의 연구가 필요하다고 사료되며 이로부터 생산성 향상을 크게 기대할 수 있을 것으로 보인다.

• 약학회지
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• 제35권4호
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• pp.319-325
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• 1991

Aluminum phosphate gel was synthesized by reacting aluminum sulfate as a soluble aluminum salt to tribasic sodium phosphate in this study. The optimal synthesis conditions based on the yield of product were investigated by applying Box-Wilson experimental design. It was found that optimal synthesis conditions were as follows: Reaction temperature; $61~71^{\circ}C$, concentration of two reactants; 12.27~13.83%, concentration ratio of two reactants; [AI$_{2}$(SO$_{4}$)$_{3}$]/[Na$_{3}$PO$_{4}$]= 0.5, reaction time; 10.9~12.1 minutes, drying temperature of product; $60~72^{\circ}C$. Aluminum phosphate gel prepared by the optimal synthesis conditions was suspended with four types of natural and synthetic gums at the concentration of 0.375~1.5wv%. Their Theological properties of aluminum phosphate gels were examined with Haake-Rotovisco RV 20 rotational viscometer. It showed that the higher concentration of suspending agents and lower temperature, the higher viscosity. Aluminum phosphate gel suspended by pectin and agar showed plastic flow with rheopexy, and their gels suspended by sodium alginate and sod. CMC showed plastic flow with thixotropy.

• Journal of Ginseng Research
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• 제9권1호
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• pp.119-127
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• 1985

The effect of ginseng saponin on acid phosphatase (AP) activity in liver Iysosomes was investigated and the mechanism by which ginseng saponin may function on the integrity of Iysosomes was discussed. The experimental results obtained are summarized as follows; 1, A very marked increase in the AP activity was observed in the supernatant of hypotonic medium, as compared with that of isotonic medium, indicating that the hypoosmotic shock per so results in activation through osmotic Iysis of particles. 2. Ginseng saponin had no effect on the activity of AP if once released from Iysosomes when Iysed in the hypotonic medium, suggesting that ginseng saponin has no effect on the enzyme molecules per se. 3. The AP activity in isotonic medium suspensions was decreased at the concentrations of 10-6, 10-5 and 10-4% of ginseng saponin, but increased at 10-2 and 10-1%. It's suggested that ginseng saponin enhances the integrity of Iysosomes at 10-6, 10-5 and 10-4%, but decreases it at 10-2 and 10-1%. 4. Suspending particles in distilled water resulted in no correlation of AP activity with treatment with ginseng saponin. 5, The AP activity was decreased in the presence of ATP, showing the possible significance of ATP as a Iysosomal stabilizer and the possibility that ginseng saponin may affect a membrane bound ATPase system by which Iysosomal AP release may be controlled.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2002년도 생물공학의 동향 (X)
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• pp.201-204
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• 2002

gellan 생산의 최적 pH 조건을 알아보기 위해 삼각플라스크와 회분식 발효를 이용 하여 실험하였다. 삼각플라스크 내에서 초기 pH 7.0 은 1.66g/ ${\ell}$ 의 gellan 을 생산하였고 , 회분식 발효에서는 pH 5.5-8.5 의 범위에서 pH를 조절하면서 실험한 결과, pH 3.0 에서 균체량 O.48g/ ${\ell}$f) 및 gellan 생산량O.97g/ ${\ell}$) 이 최대값을 나타내었다.

• Journal of Pharmaceutical Investigation
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• 제22권1호
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• pp.49-54
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• 1992

This study was carried out for the purpose of developing an effective temazepam soft elastic gelatin capsule (softgel) which exhibits an excellent bioavailability and of comparing the rate and extent of absorption of temazepam from the marked elixir and prepared softgel using hydrophilic liquid such as polyethylene glycol 400 as a suspending agent by rotary die method. Both softgel and elixir containing 3 mg of temazepam were given to 7 healthy male New Zealand White rabbits in a single oral dose cross-over study. Plasma temazepam concentrations were measured by HPLC. The mean peak concentrations of temazepam following a single oral dosing as softgel and elixir dosage form were 13.84 and 13.25 ng/ml, respectively. And the mean time to peak concentration was 1.29 hr for the softgel and 1.07 hr for the elixir. There was no significant difference in the extent of drug absorption (AUC) for the two different dosage froms (p>0.05). While the softgel exhibited mean lag time of 0.63 hr, the elixir did not show any lag time. Statistical moment parameters such as the mean residence time and variance of the mean residence time did not differ significantly for the two formulations.