• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.369-372
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• 2000

ESO(Evolutionary Structural Optimization) method is known that elements involved low stress value are removed from the previous model or that elements are added around elements involved high stress level on it and then the optimized model is obtained with required weight. Rejection ratio/addition ratio and evolutionary ratio are predefined and elements having lower/higher stress than reference stress, which average Mises stress on edge elements times rejection ratio, are deleted/added. In this study, when the plate having a cutout is subjected various in-plane load, a cutout shape is optimized using ESO method. ANSYS is used to analyse a finite element model and optimization procedure is made by APDL (ANSYS Parametric Design Language). ESO method is useful in rather than a complex structure optimization as well as a cutout shape optimization.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.752-757
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• 2001

To reduce stress concentration around the intersection between a spherical pressure vessel and a cylindrical nozzle under various load conditions using less material, the optimization for the distribution of reinforcement has researched. The ranked bidirectional evolutionary structural optimization(R-BESO) method is developed recently, which adds elements based on a rank, and the performance indicator which can estimate a fully stressed model. The R-BESO method can obtain the optimum design using less iteration number than iteration number of the BESO. In this paper, the optimized intersection shape is sought using R-BESO method for a flush and a protruding nozzle. The considered load cases are a radial compression, torque and shear force.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2003.05a
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• pp.23-28
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• 2003

본 논문에서는 MEMS 공정기술을 이용하는 압저항(piezoresistive) 압력센서용 다이아프램의 최적구조 제작을 위한 TMAH(Tetramethyl Ammonium Hydroxide)의 식각특성을 연구하였다. KOH, EDP 등 기존의 공정 수행에 있어서 부딪치게 되는 환경적 요인을 개선하고, 생산성 향상을 위해 독성이 없고 CMOS 집적회로 공정과 호환성이 높은 TMAH를 사용하여, 식각온도와 TMAH 농도 및 식각시간에 따른 에칭률 변화를 측정하였다. 식각온도가 증가 함에 따라, 그리고 TMAH 농도가 감소함에 따라, Si 에칭률은 증가하였으나 hillock 발생률이 증가하여 식각표면의 평탄화 정도가 나빠졌다. 이러한 단점을 AP(Ammonium Persulfate) 첨가제를 이용하여 해결하였다. l5wt% 농도의 TMAH 800ml 용액을 가지고 매 10분당 같은 양의 AP를 1시간당 5g이 되도록 첨가하여, 한변의 길이가 100~400 $\mu\textrm{m}$인 정사각형 모양을 가진 우수한 이방성 다이아프램을 성공적으로 제작하였다.

• Culinary science and hospitality research
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• v.20 no.3
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• pp.100-112
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• 2014

This study investigates the characteristics of cookies added with yacon. The addition of yacon powder did not affect the density of the cookies and decreased pH level. The moisture content was the highest in the cookies with 12% of yacon. Spread ratio was the highest in the cookies containing yacon powder. The loss rate and leavening rate of the cookies decreased with increasing amounts of yacon powder. Lightness and yellowness decreased significantly while redness increased significantly with a high content of yacon powder in the formulation. The hardness of the control group was higher than that of the cookies prepared with different levels of yacon powder. The antioxidant activity was estimated by DPPH free radical scavenging activity and the total phenolic acid content in yacon powder and cookies. The consumer acceptability score for the 6% yacon cookie group ranked significantly higher than the other groups in overall preference, appearance, flavor, taste and color. Through this experiment, this study exhibited both the functional and health based benefits of yacon when it is added to cookies and confirmed the development feasibility of yacon cookies considering consumer satisfaction.

• Korean Journal of Plant Tissue Culture
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• v.27 no.6
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• pp.429-434
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• 2000

Isolated protoplasts from ginseng (Panax ginseng C. A. Meyer) callus tissue were cultured in modified MS media supplemented with various concentrations of dimethylsulfoxide (DMSO). The cell wall regeneration rate and cell division efficiency of the protoplasts were increased significantly by 1% DMSO treatment. However, there was no difference in the viability of protoplasts between the DMSO treatment and non-treatment. Transmission electron microscopy revealed that the microtubules were oriented in parallel manner to the plasmalemma after 3 days of culture in medium with 1% DMSO. Further, interconnected cellulose microfibrils were observed on the outer surface of the 3-day-cultured protoplasts by scanning electron microscopy These structures shown by electron microscopy were not observed in protoplasts cultured on DMSO-free media. This studies indicates that DMSO supplemented in culture media seemed to stimulate the cell wall regeneration and cell divisions of protoplasts by forming microtubule organizing centers (MTOC).

• Fire Science and Engineering
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• v.29 no.6
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• pp.13-19
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• 2015

This study was performed to test the combustive properties of Pinus rigida specimens treated with phosphorus (P) and nitrogen (N) additives. Each Pinus rigida specimen was painted three times with 15 wt% P-N additive solutions at room temperature. After drying the treated specimens, the combustion properties were examined using a cone calorimeter (ISO 5660-1). The time to ignition (TTI) for the treated specimens was 90 to 148 s except for the specimen treated with PP/$4NH_4^+$, and the time to flameout (TF) was 556 to 633 s, which was longer than that of virgin plate. While the The specimens treated with P-N additives showed 12.5 to 43.4% higher mean heat release rate ($HRR_{mean}$) and 11.8 to 43.1% higher total heat release (THR) than virgin plate. The effective heat of combustion (EHC) was by 2.9 to 17.5% lower than that of virgin plate. It can thus be concluded that the combustion-retardation properties were partially improved compared to those of virgin plate.

• Applied Chemistry for Engineering
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• v.22 no.4
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• pp.439-443
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• 2011

It was performed to test the combustive properties of low density polyethylene and ethylene vinyl acetate (LDPE-EVA) mixture by the addition of magnesium hydroxide. Flame retardant of natural magnesium hydroxide was added to the mixture of LDPE-EVA in 40 to 80 wt% concentration. The composite was compounded to prepare specimen for combustive analysis by cone calorimeter (ISO 5660-1). Comparing with virgin LDPE-EVA, the specimens including the magnesium hydroxide had lower combustive properties. It is supposed that the combustion-retardation properties in the composites improved due to the endothermic decomposition of magnesium hydroxide. The specimens with magnesium hydroxide showed both the lower peak heat release rate (PHRR) and lower effective heat of combustion (EHC) than those of virgin polymer. As the magnesium hydroxide content increases, time to ignition increased and the peak heat release rate decreased.

• Proceedings of the Korean Society of Food and Cookery Science Conference
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• 2003.10a
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• pp.92-92
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• 2003

맥문동 추출액을 제조하여 그 추출액을 밀가루중량의 2∼6% 첨가한 식빵의 제빵특성을 조사하였다. 맥문동 추출액에는 총가용성분은 100m1 당 10.67g이며, 총당은 9.77g, 환원당은 5.l0g, 회분은 0.40g, 사포닌함량은 0.80g이였다. 식빵제조시 반죽의 pH는 대조군은 4.96이었으며 맥문동 추출액을 2, 4, 6% 첨가한 군은 각각 4.91, 4.87, 4.85로 나타났다. 빵의 무게는 대조군, 2%, 4%첨가군은 모두 404.3g 이었으며 6%첨가군은 407.3g이었다. 굽기손실률은 6% 첨가군이 9.50%로 가장 낮았으며 랑의 부피는 대조군이 1793.ml, 2% 첨가군은 1780.0ml, 4%와 6% 첨가군은 1610.0ml 이었다. (중략)

• Korean Journal of Plant Tissue Culture
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• v.27 no.2
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• pp.101-107
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• 2000

The explants of yacon (Polymnia sonchifolia Poeppig & Endlicher) were cultured to invest th8e dedifferentiation condition, and formative callus from leaf was cultured to find the regeneration and micro-crown bud formation. Basal MS medium was more effective to form callus than 1/2 MS and B$_{5}$ medium. Calli formations from leaf, petiole and lateral bud were more effective on MS medium supplemented with 1.0, 2.0 mg/L 2,4-D and 0.2, 0.4 mg/L kinetin or BA than 1.0, 2.0 mg/L NAA and 0.2, 0.4 mg/L kinetin or BA. Formative callus from leaf was proliferated about 70% on medium supplemented with 1.0 mg/L BA. When callus was proliferated, 63% regeneration rate was shown on medium supplemented with 1.0, 2.0 mg/L BA in case of subculture for 3~4 months but was not shown on medium supplemented with 1.0, 2.0 mg/L kinetin. Micro-crown bud formed as addition of BA at 3~4 months after callus culture and then was obtained many at 5~6 months, it was most formed about 82% on medium supplemented with 5 mg/L BA. Rate of micro-crown bud formation was increased as more over 5 mg/L BA concentration, when this time, however, shoot had thick leaves and short internodes, and then withered before long, Micro-crown bud was formed about 88.0% on medium supplemented with 5% sucrose, that was more increased 28% than with 3% sucrose. The buds of crown bud between harvested in field and formed in vitro were difference only in size, but both were similar in shape according to histological view.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.4
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• pp.283-289
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• 2015

Three experiments were carried out to determine the effect of harvest maturity and management practices on the dry matter losses and morphological changes of round baled rye silage. Rye was harvested at three growing stages (boot, heading and flowering stage) in three different conditions i) with wilting (unwilted, short wilting and long wilting), ii) with inoculant treatment (untreated, inoculant A and inoculant B) and iii) with three different wrap colors (white, black and green). The morphological changes in round bale silage after 2 months was heavy in the early harvest and unwilted silage. However, harvesting after the heading stage did not change the shape, significantly. Inoculant treatment reduced the morphological changes and dry matter (DM) losses of round baled rye silage. DM loss was decreased with a delayed harvesting date and was significantly reduced by the inoculant. Dramatic changes in the shape were observed in all treatment at boot stage. Inoculant treatment resulted in more severe changes in the boot stage compared to untreated silage. Black color wrapping had the greatest impact among the wrap colors and there were no significant difference in the wrap colors. Harvest maturity and wilting periods was highly correlated (p<0.01) with morphological change. Result of these studies indicated that dry matter content is the most important factor that affects the morphological change in round bale silage.