• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 추계학술대회논문집 - 한국공작기계학회
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• pp.466-470
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• 2000

Externally pressurized air journal bearing has been widely used in high-speed spindle system and precision machinery because of its characteristics such as substantially low frictional loss, low heat generation and averaging effect leading better running accuracy. But air journal bearing have a disadvantage of the low load capacity due to the low viscosity. In this paper, The air journal bearing design to overcome the defects of air bearing such as low stiffness and dimping coefficients was investigated theoretically.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2006년도 춘계학술발표논문집
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• pp.188-919
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• 2006

금형산업체의 직무능력 요구에 적응하는 산업현장과 연계된 실무능력 향상을 위한 대학의 금형기술 교육이 필요하다. 특히, 취업 후 회사의 사전교육 없이 직능별 업무에 투입 시킬 수 있는 창의력 있는 우수한 전문기술인을 양성하여 교육의 낭비적 요소를 제거하고 산업체 및 국가의 기술경쟁력을 강화시키며 학생은 인력수요자인 산업체로부터 요구하는 현장실무에 접근성 높은 교육을 받아 취업이 보장되어야 한다. 동시에 산업체는 전문인력 수급의 어려움을 해소 시켜주기 바라고 있다. 이상의 요구를 충족시킬 목적으로 금형산업체와 연계된 금형설계공학전공의 교육과정 개발을 수행하였다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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• pp.89-90
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• 2018

The strength of cement mortar is one of the most important factors in design and construction. Strength can vary widely depending on factors such as water cement ratio, aggregate and materials and curing. In the study, it was found that the standardized method of making the cement mrtar was different from the standard method of preparing the cement mortar by the different process of the cement mortar. I wanted to know the difference. Experiments were carried out to investigate the differences in strength, physical properies and performance depending on the points when the sample were made long in vertical form.

• 소성∙가공
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• 제13권3호
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• pp.236-241
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• 2004

UV-molded microlens arrays with high replication quality were fabricated using a parametric design method. It is important to maximize the replication quality, because one can obtain the replicated micro-optical components with desired properties by accurate control of the shape. In the present study, nickel mold inserts for microlens arrays with lenses having diameters between $3\mu\textrm{m}$ and $230\mu\textrm{m}$ were fabricated by electroforming process. An UV-molding system was designed and constructed, a simple technique to avoid micro-air bubbles was first suggested, and the effects of the compression pressure and UV-curing dose on the replication quality of UV-molded microlens arrays with a diameter of $14\mu\textrm{m}$ were examined experimentally. Finally, geometrical and optical properties of the replicated microlens arrays were measured and analyzed.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 춘계학술대회 논문집
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• pp.91-93
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• 2009

A large steel ingot needs to be larger and larger in size and an ultra high clean, no defect in quality with a low hot top ratio for the resent heavy industry. The demands are very difficult to achieve simultaneously because of their contradictive effect to each other in results. In this study, 30ton steel ingot was cast in a foundry with an optimized design parameter of cast mold and cast process conditions for the low hot top ratio, 12%. The cast ingot was analyzed in macro defect, segregations, and cleanness. No macro defect was founded in central surface of the ingot. The degree of segregation and cleanness are in the controlled range with a sound quality.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 A
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• pp.303-305
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• 1997

The advantage of application polymer instead of conventional porcelain as the housing material for arrester is that light weight, shorter section length of arrester would be possible due to the use of an insulated hanger (mold compound). also, polymer arrester has very good characteristics in design versatility as well as excellent resistance to moist ingress and pollution performance. The finite element method is widely used to calculate for electromagnetic devices. In this paper, we perform the each conditional analysis of PC with an advanced graphical user interface(GUI) using the vector fields simulator. And we try to analyze electromagnetic fields through the conventional two dimensional analysis in case of high voltage contamination on the electrode of a arrester.

• 한국주조공학회지
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• 제37권4호
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• pp.108-114
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• 2017

In this study, we investigated the effect of the Si content on the secondary dendrite arm spacing (SDAS) of hypoeutectic Al-Si binary alloys in the range of 4~10 wt% Si. Cooling curves were measured during the solidification of the alloy cast in a step-wise mold. We compared two kinds of solidification time: the first is the total solidification time for both dendritic and eutectic growth, and the second is the solidification time for only dendritic growth. The proportional constant in the relationship between SDAS and cooling rate was estimated, as this constant represents the stability of the cast microstructure. The proportional constant decreased with the Si contents from 4 wt% to 8 wt%, and it remains relatively uniform with up to 10 wt% of Si.

• 대한안전경영과학회지
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• 제13권4호
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• pp.101-108
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• 2011

In this paper deals with strength of glass fiber reinforced plastics produced by shouting machine was investigated by universal testing instrument. We can obtain following results by performing the strength evaluation of polymer composite material according as varied environment temperature. The effect of environmental temperature on Strength properties was more sensitive in the weld specimen than parent. When changed environmental temperature, variation of strength in the parent was much bigger than it of weld specimen, that is, matrix in the parent, orientation in the specimen ware more sensitive to environmental strength. Tensile strength of polycarbonate matrix was similar regardless of mold temperature.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2000년도 추계학술발표대회 논문집
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• pp.253-256
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• 2000

In order to commercialize the low cost composite fabrication technology in the area of domestic aerospace structure field, Resin Transfer Molding process has been considered as an alternative process to replace the high cost autoclave technology. The end part for the development of RTM process is the control rod of flight control system of aircraft. A braided preform was triaxially designed to improve the dimensional stability and mechanical property in the direction of external loads. Through the flow analysis using CVFEM, the resin filling time was calculated and the resin injection method was determined. The results of the flow analysis were directly applied to RTM mold design. The control rod was successfully manufactured by RTM process using internal pressure. The length and outer diameter of the manufactured part are 1148mm and 32mm, respectively.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 1997년도 추계학술발표회논문집
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• pp.70-73
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• 1997

This paper describes the technique for detecting failure symptom of mold transformer. This study uses the vibration signal analysis method and FEM as the technique. A loading back method is constructed for experiment, accelation sensors are adhered for measurement of vibration signal. Vibration signal measured by this method is analyzed into variation trend of measurement variables by control of control variables. Magnetic field distribution of molded winding is also acquired by FEM considering the design specfication and the characteristics of insulation material, in conclusion, he relation of results between vibration signal and FEM is studied by these methods.