• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
• /
• pp.1754-1757
• /
• 1997

Three-dimensional optimum design of coat-hanger die is performed using power-law and Carreau models. It is found that the three-dimensional optimum design algorithm shows good convergence with the non-Newtonian fludis. the nore realistic optimum design is accomplished by employing Carreau model with the three-dimensional design method. The effect of vixcosity modles is investigated by comparing the optimum manifold profiles and flow rate distributions of power-law and Carreau modles. Through the accurated viscosity representation of Carreau model, the effect of total flow rate on the optimum manifold profile is investigated.

• 한국초전도저온공학회:학술대회논문집
• /
• 한국초전도저온공학회 2001년도 학술대회 논문집
• /
• pp.84-88
• /
• 2001

The optimum cross-sectional area Profile of gas-cooled high-temperature superconductor (HTS) current lead is analyzed to have minimum helium boil-off rate. The conventional constant area HTS lead has much higher helium consumption than the optimum HTS lead considered in this study. The optimum HTS lead has variable cross-sectional area to have constant safety factor. An analytical formula of optimum shape of lead and temperature profile are obtained. For multi-step HTS current leads, the optimum tape lengths and minimum heat dissipation rate are also formulated. The developed formulations are applied to the Bi-2223 material, and the differences between constant area, constant safety-factor, and multi-step current leads are discussed.

• 한국기계가공학회지
• /
• 제2권3호
• /
• pp.20-25
• /
• 2003

The End-milling has been widely used in the industrial world because it is effective to cutting working with various shape. Recently the end-milling is demanded the high-precise technique with good surface roughness and rapid manufacturing time for precision machine and electronic elements. The cutting working of end-milling such as, cutting direction, revolution of spindle, feed rate and depth of cut have an effect on optimum surface roughness. This study was carried out to decide the working condition for optimum surface roughness and rapid manufacturing time by design of experiment and ANOVA. From the results of this study, the optimum working condition for end milling is upward cutting in cutting direction, 600rpm in revolution of spindle, 240mm/mm in feed rate, 2mm in axial depth of cut and 0 25mm in radial depth of cut. The design of experiment has become an useful method to select optimum working condition mend-milling.

• 한국작물학회지
• /
• 제32권3호
• /
• pp.287-293
• /
• 1987

호밀 적ㆍ만기 파종에서 종자성숙 및 파종량이 출아, 생육, 청예 건물수량 및 종실수량에 미치는 영향을 구명하고저 경북 경산군 영남대학교 농장에서 재래종(팔당호밀)을 공시하여 파종기 10월 28 일(적기) 및 11월 11일(만기)로 하고 파종기별로 출수후 45일 및 30일에 수확한 종자를 파종량을 달리하여 ( 1$m^2$당 300입, 450입, 600입, 750입, 900입) 시험을 실시하였다. 출아수 및 분얼수는 적기파종에서 출수후 30일과 45일 종자간에 차이가 없었고, 파종량을 증가할 때 출아수가 증가하고 분얼수는 감소하는 경향이 있었고, 만기파종에서는 출수후 45일 종자에서 30일 종자보다 출아수와 분얼수가 많았으며 파종량 증가에 따른 차이는 인정되지 않았다. 만파에서 출수후 30일 종자는 파종량 증가로서 적정주수 확보가 어렵다. 출수기는 적ㆍ만파에서 출수후 30일 종자가 2~3 일 늦었다. 청예수양은 만파에서 크게 감소하였고 적ㆍ만파모두 파종량을 높일 때 청예수량도 증대되어 적기파종에서 750립 / $m^2$( 15kg/ 10a)의 파종량에서 최대가 되었고, 출수후 30일 종자는 만파에서 현저하게 낮았다. 수수 및 1000입중은 적기파종에서 만기파종보다, 그리고 만기파종에서는 출수후 45일 종자로서 파종량 750립/$m^2$ ( 15kg/10a) 이상에서는 적기파종의 종실수량 수준까지 접근할 수 있었다. 출수후 30일 종자는 만기파종에서 파종량을 증가하여도 출아율이 낮고 청예 및 종실수량이 심하게 감소되어 종자로 이용하기는 불안정하다.

• 한국수산과학회지
• /
• 제47권4호
• /
• pp.399-405
• /
• 2014

We investigated the effects of feeding rate on the growth performance, blood components, and histology of growing olive flounder Paralichthys olivaceus. Optimum feeding rate (initial fish mean weight : $316.7{\pm}6.18g$) was determined under the optimum water temperature. Two replicated groups of fish were fed a commercial diet at rates of 0%, 0.4%, 0.6%, and 0.8% of body weight (BW) per day, and to satiation. Feeding trial was conducted using a flow-through system with 10 1.2-metric ton aquaria receiving filtered seawater at $21-24^{\circ}C$ for 3 weeks. Weight gain (WG) and specific growth rate (SGR) were significantly higher in fish fed to satiation (1.0% BW/day) than in those in other treatments. These parameters were negative and significantly lower in the starved fish than in fish fed the experimental diet at all feeding rates. There were no significant differences in WG and SGR among fish fed at 0.4%, 0.6%, and 0.8% BW/day. Hematocrit and hemoglobin in fish fed to satiation were significantly lower than those in other treatments. Histological changes of fish fed at 0.6% BW/day indicated that this group was in the best condition; differences were not found in tissues of fish fed at 0%, 0.6% and 1.0% BW/day. Broken-line regression analysis of weight gain showed that the optimum feeding rate of olive flounder weighing 317 g was 0.99% BW per day at the optimum water temperature.

• 한국수산과학회지
• /
• 제47권5호
• /
• pp.582-587
• /
• 2014

We investigated the effects of feeding rate on the growth, blood components, and histology of sub-adult olive flounder Paralichthys olivaceus. Optimum feeding rate (initial fish mean weight : $384.2{\pm}5.91g$) was determined under the optimum water temperature. Two replicated groups of fish were fed a commercial diet at rates of 0%, 0.3%, 0.5%, and 0.7% body weight (BW) per day, and to satiation. The feeding trial was conducted using a flow-through system with ten 1.2-metric ton aquaria receiving filtered seawater at $20-24.5^{\circ}C$ for 3 weeks. After the feeding trial, the weight gain (WG) and specific growth rate (SGR) were significantly higher in fish fed at 0.7% BW/day and those fed to satiation (0.9% BW/day) than in fish fed at other feeding rates or in the unfed fish. These parameters were negative and significantly lower in the unfed fish than in those fed the experimental diet at all feeding rates. There were no significant differences in WG and SGR among fish fed at 0.3 and 0.5% BW/day and among those fed at 0.7% BW/day and to satiation. The histological changes in the hepatopancreas, kidney, and anterior intestine of fish fed at 0, 0.5, and 0.9 % BW/day did not differ much. Broken-line regression analysis of weight gain showed that the optimum feeding rate of olive flounder weighing 384 g was 0.74% BW per day at the optimum water temperatures.

• Archives of Pharmacal Research
• /
• 제16권1호
• /
• pp.43-49
• /
• 1993

The polyvinyl alcohol (PVA) hydrogel containing 1-methy-2-pymolidinone (MP) and sorbitol was preapred by the freeze and thaw method. The release rate of indomethacin from PVA hydrogel was used as a criterion for deciding the optimum formula of hydrogel using the computer optimization technique. The hydrogel of optimum formula was composed of PVA (10 w/v%), MP (0 w/v%) and sorbitol (40 w/v%) and the release rate of indomethacin was 1.981$\mu$g/ml$\cdot{min}^{1/2}$.

• KSBB Journal
• /
• 제14권5호
• /
• pp.561-565
• /
• 1999

Optimum conditions for vacuum-drying ad cultivation of yeast cells for the production of active dry yeast were examined. At lower temperature, more drying time was required to dry the yeast pellet to reach the desirable water content(8%). Optimum temperature of vaccum oven and time for drying was 63$^{\circ}C$ and 90 min, respectively. Optimum medium composition for flask culture using cane molasses as the substrate were 0.25% sugar, 0.013% $K_2$HPO$_4$, 0.1% $K_2$HPO$_4$. and 0.125% (NH$_4$)$_2$SO$_4$. Culture temperature $25^{\circ}C$ gave the highest survival rate of dired yeast. After finishing fed-batch culture and the culture was left in the fermentor without adding any sugar or nutrient, survival of the dried yeast harvested from the fermentor increased to 86.0% after 36 hr. It was also observed that the yeast cells with higher budding rates showed lower survival rate.

• International Journal of Reliability and Applications
• /
• 제9권2호
• /
• pp.141-152
• /
• 2008

This paper presents equations, which can be used to evaluate the failure frequency and the failure rate of a two identical component parallel redundant system in which each component can operate in its wear out period, and the failure rate of each component is exponential power distribution. The optimum maintenance interval for a two identical component parallel redundant system can be obtained using these equations. The proposed approach is presented and illustrated using several numerical examples. The optimum maintenance interval for each component in a two identical parallel redundant system will depend on factors such as: failure rate, repair and maintenance times of each component in the parallel redundant systems.

• 품질경영학회지
• /
• 제9권2호
• /
• pp.10-14
• /
• 1981

Products are assumed to be spoiled and not recoverable when the raw material below the prescribed weight level is charged in the mold. The raw material is autoscaled and their weight is normally distributed with a given variance. This paper describes an appropriate stochastic model of determining the optimum weight allowance and the associated defective rate for auto scale system. The optimum weight allowance and the defective rate which minimizes the total loss of defective and the excess weight allowance is obtained. A numerical example for the existing rubber company is also presented and evaluated.