• Journal of the Korean Society for Precision Engineering
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• v.26 no.3
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• pp.113-121
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• 2009

Behavior of a package of a microwave oven under the clamping condition is evaluated by tests and the finite element analyses. PAM-CRASH software is used for the finite element analyses. Results of the analyses are compared with those of the tests and accuracy is shown to be favorable. Under the clamping condition of the original design, severe deformation occurs and an improved design of the outer case and upper EPS(Expandable Poly Styrene) is proposed to reduce it. Face beads of the outer case are introduced and shape of the upper EPS is modified to reduce the deformation resulting from the clamping load. The improved design model is analyzed and its deformation is shown to be satisfactory. A prototype is produced according to the improved design and tests are performed. Results of the clamping test of the prototype show that the plastic deformation is removed totally.

• Proceedings of the KIPE Conference
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• 2001.12a
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• pp.135-138
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• 2001

In order to solve the problem of system efficiency reduced on account of two stage power conversion, we propose a series resonant full bridge inverter circuit for battery-fed microwave oven. This circuit has both a compact size and a light weight. Also, a frequency control adjusts power levels of the microwave oven. Operational principles are explained in detail. A proto-type inverter circuit with 1[kW] power consumption is built and tested for verifying the operation.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.7 s.172
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• pp.177-184
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• 2005

Recently, the engineering designer of injection mould has become more and more dependent on the CAE. In the design factors of injection mould, the shrinkage rate should be considered as one of the important performances to produce the reliable products. therefore the shrinkage rate can be mostly calculated by the MoldFlow and Pro-engineering. in the design process. However it is not easy to predict the shrinkage rate of a plastic injection mold in its design process because the analysis can take minutes to hours, the high computational costs of performing the analysis limit their use in design optimization. In this study, the surrogate models, DACE model, based on the Kriging in order to optimize the shrinkage rate of electric microwave oven window is used in lieu of the original models, facilitating design optimization.

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.205-207
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• 2001

In response to this inverter microwave oven has been developed to improve high speed cooking time & energy saving performance. The voltage resonating inverter has a defect in switching element that works at 5 or 6times higher than input voltage. Especially, it is very difficult to choose the switching device is very high for the 220 (V) commercial voltage. In this paper, it is proposed the optimum method to realize the turbo 1200(W) output power for microwave oven that is employed the 900(V) IGBT with decreasing operating voltage of the switching component by making the 220(V), 1000(W) inverter through the active clamp voltage resonating inverter.

• Korean Journal of Microbiology
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• v.18 no.3
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• pp.148-152
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• 1980

The microwave of 2450 MHz, generated by a household cooking oven, was evaluated for its applicability to melt various rehydrated media and to remove dissolved oxygen from tubed media for anaerobic culture. The effect on the sterilization of E. coli in selective media was also evaluated. The following results were obtained. 10 The microwave oven was useful in saving time for melting media and in eliminating heat and combustion gas from the laboratory, which were inevitable by-products in the conventional flame method. 2) Dissolved oxygen could be removed without boiling over by exposing the tubes of anaerobic culture medium after putting them in a wire basket in a beaker with water. 30 The count of E. coli during the melting of MacConkey and EMB agar were similar to those treated with open flame. The microwave treatment was not considered a possible mean to replace autoclaving even in these selective media.

• Resources Recycling
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• v.2 no.4
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• pp.10-16
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• 1993

Reduction behavior of stainless steelmaking dust by microwave heating process was investigated using coke and charcoal as reducing agents. Pellet dust and stanless steelmaking dust pelletized with reducing agent were reduced by the heating upto $1000^{\circ}C$ in microwave oven. The results showed that charcoal and coke seemed effective in the reduction of metals from stainless steelmaking dust by microwave heating and charocal was found to be better than coke. Degree of reduction seemed similar with the power of 500W and 700W in microwave oven. Dusts were rapidly reduced within 20 minutes. Reducing degree decreased in the order of Fe>Ni>Cr.

• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.882-884
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• 2009

본 연구는 주형의 형상에 관계없이 균일한 건조성능을 가지는 장치의 도입을 목적으로 Microwave를 이용한 주형건조장치 개발을 위한 기초 연구에 관한 것이다. 건조 성능의 검토를 위해 진공건조기와 Lab-scale의 Microwave 출력장치를 가지는 Microwave oven을 이용하여 주물사의 무게별, 건조시간별 건조효율을 검토하였으며, $CO_2$주형법에서 물유리의 양과 $CO_2$통기시간에 따른 주형의 압축강도를 측정하였다.

• Korean journal of food and cookery science
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• v.14 no.2
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• pp.182-187
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• 1998

The changes in weight, reducing sugar content, sugar composition and enzyme activities (${\beta}$-amylase and invertase) of sweet potato were studied with three kinds of cooking methods, microwave oven, gas oven, and steaming. The weights of sweet potato cooked by microwave oven and gas oven were decreased with increasing cooking time, whereas that of steaming was increased with cooking time. Reducing sugar content of sweet potato cooked by microwave oven was increased till 40 seconds, but decreased thereafter. In the cooking methods using gas oven and steaming, reducing sugar content were increased with cooking time. And reducing sugar content were 334.60 mg/g and 381.29 mg/g, respectively at 100$^{\circ}C$ of cold point in sweet potato cooked by gas oven and steaming. Raw sweet potato consisted of fructose (1.56 mg/g), glucose (1.79 mg/g), sucrose (5.58 mg/g), and maltose (2.22 mg/g). The contents of fructose, glucose, and sucrose were decreased during cooking process. But maltose content was increased with cooking time. Especially, maltose contents were 24.81 mg/g and 28.10 mg/g at 100$^{\circ}C$ of cold point in sweet potato cooked by gas oven and steaming. The activities of ${\beta}$-amylase and invertase were decreased with cooking time. Microwave oven-cooked sweet potato did not show on invertase activity.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.584-588
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• 2001

A conventional power supply to drive a microwave oven has ferro-resonant transformer and high voltage Capacitor(HVC). Though it is simple, transformer is bulky, heavy and has low-efficiency. To improve this defect a high frequency inverter type power supply has been investigated and developed in recent years. But, because of additional control circuit and switching device, inverter-type power supply is more expensive than conventional one. In this study, A new pulse power supply for Microwave Oven using novel HVC embedded high frequency transformer is proposed for down-sizing, cost reduction, and efficiency emprovement of Inverter type power supply. Also, equivalent circuit model is derived by impedance measurements. And the operation of proposed pulse power supply is verified by simulations and experimental results.

• Journal of the Korean Ceramic Society
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• v.32 no.8
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• pp.865-872
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• 1995

Ultra-fine $\beta$-SiC powders were fabricated by self-propagating high temperature synthesis process (SHS) using microwave oven. The flexural strength, fracture toughness, and hardness of hot pressed sample at 200$0^{\circ}C$ for 60 min using synthesized SiC powders, which had 2 wt% of Al2O3 and 2.5 wt% of B4C content, showed 438 MPa, 4.15MPa.m1/2 and 28 GPa, respectively. The highest strength, fracture toughness, and hardness of composites containing 4wt% of Al2O3, which had highest relative density of 99.9%, showed 458 MPa, 4.6MPa.m1/2 and 36.2 GPa, respectively.