• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2008년도 추계학술대회A
• /
• pp.1113-1118
• /
• 2008

In the hot forging process, The forging defects that are caused by metal were strain, temperate, and inclusion. In this paper, the computer simulation analyzed the effective plastic strain and temperature behaviors. The quantitative analyses which proposed the effective mold design of S/CAM shaft was executed. The parameters of forging shape that affected on the optimize conditions that was calculated with simple equation were investigated. it is expected that the developed analysis model and design technique would greatly contribute to the drum brake optimal design considering temperature affected and material behaviors. This development could save more than 20% of production cost and reduced failure rate to more than 30%. By improving the life span of mold from 15,000 to 25,000, financial difficulty of company imposed on a mold manufacture could be overcome.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2000년도 춘계학술대회논문집B
• /
• pp.199-204
• /
• 2000

A low temperature differential model stirling engine is manufactured, and its operation characteristics are measured and analyzed by SIMPLE analysis model, in which heat transfer processes are simply considered. The heat transfer coefficients between working fluid and heat sources in the analysis are estimated by comparing the P-V diagrams by experiment and by analysis. This result may be very useful for further design and manufacture of model Stilting engines as well as real engines because it provides a comparatively correct predictions of the operation conditions and power output. It will be also conveniently used as an educational material for mechanical engineering students because it can be a nice example of optimal design process to decide the phase angle and compression ratio of engine design with a simple but realistic simulation.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• 제3권2호
• /
• pp.251-257
• /
• 2003

In this paper, we wish to construct a optimal traffic cycle using wire remote control. if police vehicle or ambulance suddenly enter the traffic Intersection, it will increase the traffic accident. In this paper, wireless traffic light use the radio traffic control signal and research about the hardware manufacture to check special detectors on urgency vehicles may safety and rapidly enter traffic intersection. Also, this paper present a traffic signal control conditions that analyzes different traffic intersection flows in cases of saturated flows, where the real traffic volume demand is large and the capacity constraints of bottlenecks have significant effects on the flow patterns. Through computer simulation this wireless traffic light has been proven to be much more safety and efficient than fixed traffic signal light which does not consider emergency vehicles for safety escort.

• 소성∙가공
• /
• 제17권1호
• /
• pp.9-12
• /
• 2008

Recently, industries and academic institutes have been interested in the rheology forming technology for light weight materials. However, this rheocasting process has advantages such as the high initial investment cost and the lower mechanical properties than thixocasting. In this study, the continuous fabrication of rheological material with a spiral stirring equipment(mechanical stirring system) was newly devised to overcome the disadvantages of rheocasting process. The experimental parameters were stirring time($0{\sim}1200sec$), stirring velocity ($0{\sim}100rpm$) and stirring temperature($650{\sim}680^{\circ}C$). The optimal conditions for fabricated rheological material of A6061 alloy were stirring time at 300sec, stirring velocity at 60rpm and stirring temperature at $650^{\circ}C$. At these results, the equivalent diameter was $45{\sim}65{\mu}m$, mean roundness was $1.4{\sim}1.6$ and Vickers hardness was 60Hv.

• 한국경영과학회지
• /
• 제39권2호
• /
• pp.97-109
• /
• 2014

This paper considers a reverse supply chain with simultaneous recovery of used products and manufacturing of brand-new ones. Recovered products are downgraded and have to be sold in a market different from that of brand-new products at a different price. In case of a shortage of recovered product inventory, a brand-new item, if available, can be offered at the price of a recovered product. In other words, one-way demand substitution is allowed. We address the joint decision of when to manufacture brand-new product, when to recover returned product, and how to control demand substitution to maximize the hybrid production system's profits. To this end, we propose a Markov decision Process model and investigate the structure of the optimal policy. Performance comparison is numerically implemented between the models with and without downward demand substitution option under different operating conditions of the system parameters.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2004년도 ICEIC The International Conference on Electronics Informations and Communications
• /
• pp.365-370
• /
• 2004

In this paper, we wish to construct a optimal traffic cycle using wire remote control. if police vehicle or ambulance suddenly enter the traffic intersection, it will increase the traffic accident. In this paper, wireless traffic light use the radio traffic control signal and research about the hardware manufacture to check special detectors on urgency vehicles may safety and rapidly enter traffic intersection. Also, this paper present a traffic signal control conditions that analyzes different traffic intersection flows in cases of saturated flows, where the real traffic volume demand is large and the capacity constraints of bottlenecks have significant effects on the flow patterns. Through computer simulation this wireless traffic light has been proven to be much more safety and efficient than fixed traffic signal light which does not considering emergency vehicles for safety escort.

• 한국식품저장유통학회지
• /
• 제13권3호
• /
• pp.369-374
• /
• 2006

참다래 리큐르 제조를 위한 최적 침출 조건을 설정하기 위하여 참다래를 절편하지 않은 완숙과와 절편구간으로 나누어 45% 주정으로 침출하여 품질을 조사하였다. 그 결과, 절편하지 않은 완숙과는 8주, 절편구간은 4주간 침출시킨 구간에서 가장 좋은 결과를 나타내었다. 침출과정에서 당도, pH 및 총산도의 변화는 거의 없었고, methanol과 acetaldehyde의 함량은 절편하여 8주간 숙성시킨 구간에서 24.92 ppm으로 미량 검출되었다. 관능검사를 실시한 결과 절편하여 8주간 침출시킨 구간이 전반적인 기호도에서 가장 높게 평가되었다. 최적조건에서 대량 침출한 참다래 리큐르의 품질특성을 조사한 결과, 총페놀성 화합물의 함량은 48.90 mg%, 비타민 C 함량은 16.7 mg%로 나타났으며, 유기산은 malic acid가 1.77%로 가장 많이 침출되었다. 침출주의 유리당은 fructose, glucose 및 maltose가 각각 1.18, 1.12 및 0.08% 함유된 것으로 조사되었다. 침출주의 관능적 품질의 향상을 위해서 stevioside, citric acid, 소금을 각각 0.035, 0.0085, 0.005%(w/v)를 침출주에 첨가한 구간이 가장 좋은 관능적 평가를 받았다.

• 한국산학기술학회논문지
• /
• 제18권11호
• /
• pp.118-123
• /
• 2017

다양한 산업에 사용되고 있는 금속급 실리콘(MG-Si, Metallurgical grade silicon)을 제조하기 위해 실리콘 원료 내 가장 많이 함유하고 있는 불순물인 알루미늄(Al) 및 철(Fe)을 제거하고자 산(Acid) 침출 실험을 수행하였다. 5가지 종류의 산(HCl, HF, H2SO4, HNO3, H3PO4)을 1, 2, 4, 6M로 조제하여 실리콘 원료에 반응시킨 결과, 1M 농도의 HF가 가장 우수한 Al 및 Fe 제거율을 나타내었으며 각각 97.9%와 95.2로 나타났다. 그러나 HF는 실리콘 부식 특성으로 인해 18% 가량의 수율 감소가 발생하였으며 이러한 수율감소를 최소화하기 위해 두 번째로 제거율이 우수하게 나타난 2M HCl과 혼합하여 실리콘 원료에 적용하였다. 혼합용액의 최적조건을 선정하기 위해 실험을 수행하여 $80^{\circ}C$, 2시간의 침출 최적조건으로 결정되었으며 이 혼합용액의 적용 결과 Al 및 Fe 잔류농도가 각각 141 ppmw 및 93ppmw로 나타나 3N급의 순도를 갖는 금속급 실리콘을 제조하기에 매우 용이한 것으로 확인되었다.

• 한국식품조리과학회지
• /
• 제28권2호
• /
• pp.133-141
• /
• 2012

$Kochujang$ is a fermented paste originated from in and $Kochujang$ sauce is a nutritionally and functionally improved version of $Kochujang$ with additions of beef and tonic herbal extracts. The optimization of the ingredient ratios in the manufacturing of $Kochujang$ sauce was investigated using central composite design and response surface methodology. The amount of beef ($X_1$) and the amount of tonic herbal extract ($X_2$) were chosen as the independent variables. The dependent variables consisted of the properties and sensory evaluation scores The examined physicochemical properties included water activity, pH, color, viscosity, and soluble solids. The sensory evaluation attributes were color, flavor, taste, texture, and overall acceptability. Among them, the selected dependent variables were the sauce viscosity ($Y_1$) and the overall acceptability ($Y_2$) of the sauce. The optimal conditions for the independent variables were $X_1$= 9.7% and $X_2$= 14.1%. In addition, the predicted values of the multiple response optimal conditions were $Y_1$= 331000 (cP) and $Y_2$= 7.1 (points), and the actual experimental values were $Y_1$= 3316667 (cP) and $Y_2$= 7 (points).

• 한국재료학회지
• /
• 제21권12호
• /
• pp.685-689
• /
• 2011

The goal of this investigation was to produce a zirconia-family black ceramics that has enhanced functionality and reliability. Color zirconia ceramics have been produced by adding pigments. Pigments cause structural defects within zirconia and result in a drop in physical properties. Using environmentally friendly rice husk, we produced a black zirconia that is free of structural defects. In optimal firing conditions for black zirconia the calcining temperatures of the molding product are changed from $400^{\circ}C$ to $1200^{\circ}C$, and the firing temperatures are changed from $1400^{\circ}C$ to $1600^{\circ}C$. Color of testing the specimens was analyzed using Ultraviolet (UV) spectroscopy. Scanning Electron Microscope (SEM), EDAX (EDX), and Fourier transform infrared spectroscopy (FT-IR) analyses were carried out in order to examine impregnation properties and crystal phases. Universial Test Machine (UTM) was used to measure the flexual strength as well as the compressive strength. From experimental results, it was found that in optimal firing conditions the sample was calcined from $1000^{\circ}C$ to $1500^{\circ}C$. Commission internationalde I'Edairage (CIE) values of manufactured black zirconia color were $L^*$ = 29.73, $a^*$ = 0.23, $b^*$ = -2.68. The bending strength was 918 MPa and the compressive strength was 2676 MPa. These strength values are similar to typical strength values of zirconia, which confirms that carbon impregnation did not influence physical properties.