• 한국세라믹학회지
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• 제47권4호
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• pp.290-295
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• 2010

This study has been focused on properties of mirror surface grinding technology by ELID(Electrolytic In-process Dressing) for structural ceramics using in high precision structural parts as like semi-conductor manufacturing processes. The experimental studies have been carried out to get mirror surface for grinding of structural ceramics, SiC, $Al_2O_3$ and AlN. Grinding process of the ceramics is carried out with varying mesh type, depth of cut and feed rate using diamond wheel. The machining result of the surface roughness and condition of ground surface, have been analyzed by use of surface roughness tester, SEM, AFM and three dimensional surface profiler measurement system.

• 항공우주기술
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• 제6권2호
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• pp.60-65
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• 2007

우주환경시험팀에서는 인위적으로 발사 환경 시 음향 환경을 구현하여 시험 대상물의 성능을 검증하는 음향 챔버를 개발하였으며, 이를 운용 중에 여다. 그러나 점차적으로 요구되는 대형 위성의 성능 시험 및 발사체 페어링의 내부 구조에 따른 특성의 평가 시험을 수행하기에는 기존 음향 챔버의 음향 에너지 구현 능력으로는 한계가 존재한다. 본 연구에서는 음향 챔버의 성능 확장을 위해 요구되는 각 요소의 설계 및 제작 과정 둥에 대한 연구 결과를 소개하고자 한다. 그리고 개선된 시스템을 이용하여 위성 부품을 대상으로 수행한 시험 결과를 제시하고자 한다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
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• pp.264-269
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• 2000

Nickel-based heat resisting alloys are commonly used for high temperature applications such as in aircraft engines and gas turbines. In this paper, the machinability of Nickel-based heat resisting alloy was investigated with respect to the wear and the chip formation by tool type and cutting condition. Relationship between three types of tool and chip formation was experimentally investigated. Among the three types of tool tested, coated tools(CVD, PVD) are available for the difficult-to-cut-materials such as Nickel-based heat resisting alloy and etc..

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
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• pp.326-331
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• 2000

In this study, residual stress was investigated experimentally to evaluate damaged layer in high-sped machining. In machining difficult-to-cut material, residual stress remaining in machined surface was mainly speared as compressive stress. The scale of this damaged layer depends upon cutting speed, feed per tooth and radial cutting depth. Damaged layer was measured by optical microscope. The micro-structure of damaged layer was a mixed maternsite and austenite. depth of damaged layer is increased with increasing of cutting temperature, cutting force and radial depth. On the other hand, that is slightly decreased with decreasing of cutting force. The increase of tool wear causes a shift of the maximum residual stress in machined surface layer.

• Journal of Nutrition and Health
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• 제22권2호
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• pp.108-117
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• 1989

The purpose of this study was aimed to investigate the historical tends of population growth which has reflected direct effect of the ratio of food self sufficiency in Korea between the year of 1910 and 1980. Author divided the whole years between 1910 and 1980 into five different periods ; colonial period from 1910 to 1945, post colonial period from 1945 to 1950, Korean war period from 1950 to 1955, post Korean war period from 1955 to 1960, fast economic growing period 1960~1980. The ratio of national food self sufficiency has been profoundlly affected by dual factors ; rate of population group and increment of GNP which reflect the national economic development. Total food production never reached the level of population growth ratio in Korea. As a result food demand and supply has shown imbalaced condition which leads to import foods from outside contury to compensate food shortage. The increment of GNP sharply cut down the cereal consumption. The consumption of fish, milk, eggs and meat reflected to increase since 1970.

• 한국기계가공학회지
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• 제19권3호
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• pp.71-76
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• 2020

Various machining methods are being studied to improve the processing quality of the spherical R shape in press die. In this paper, we confirmed that changes in machining quality were associated with changes in cutting direction, path, and cutting angle, which are commonly used in the machining of molds. We obtained a surface roughness graph with each condition change in one specimen using an instrument that measured geometry and surface roughness simultaneously. The results of the study showed that the best surface roughness in the finish cut of the spherical surface was obtained using upward pick feed machining.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.249-250
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• 2006

Recently FPD(Flat Panel Display) is used in various field to display enormous information. So cutting technique of flat panel display is needed for producing variety display merchandises. In present, cutting methods of flat panel glass includes breaking process. But this process occurs many glass particles. This glass particles are directly related badness of merchandise and falling productivity. In this paper, to cut front substrate glass of LCD and to get optimized cutting condition are tried fur eliminating breaking process with developed glass cutting machine using a Piezoelectric ceramics actuator. It is known that the vibration of Piezoelectric Ceramic have effect in crack proceeding through the analysis of fracture section.

• 한국생산제조학회지
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• 제21권6호
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• pp.982-987
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• 2012

Inconel 718 alloy has been widely used in the aerospace, heavy industry and electronic industry. However, the machinability of this alloy is very poor, which is attributed to their inherent high strength that is maintained at elevated temperatures. The tool life is dominant problem in machining difficult-to-cut materials, so it is necessary to select the efficient cutting conditions for the improvement of tool life. In this study, the cutting force, tool wear and surface roughness are investigated in end milling machining under various cutting conditions. By this experiment, the efficient machining condition of this alloy is suggested to adopt in various industries.

• 대한안전경영과학회지
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• 제3권1호
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• pp.35-44
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• 2001

Today's environment of enterprise is changing. They have to face customers' demands with the right product, the right service and supply them at the right time. And aIso cut down logistics and inventory cost and bring up the Profit as much as they can. This means the change of putting enterprise first in importance to putting customer first in importance. therefore to correspond to customer's demand, shorting lead time is becoming a essential condition. The answer to this changes of environment is supply chain management In this study, we use Goldratt's drum-buffer-rope scheduling in between manufacturer and supplier. And when shortage of inventory occur, search for the supply chain's CCR. Pressing CCR for more production, and supply Inventory from logistic center to guide for inventory buffing. using logistic warehouse between manufacturer and supplier, can execute function of buffer.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2002년도 춘계학술대회
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• pp.115-120
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• 2002

Today's environment of enterprise is changing. They have to face customer' demands with the right product, the right service and supply them at the right time. And also cut down logistics and inventory cost and bring up the profit as much as they can. This means the change of putting enterprise first in importance to putting customer first importance. therefore to correspond to customer's demand, shorting lead time is becoming a essential condition. The answer to this changes of environment is supply chain management. In this paper, It consolidates the necessity on a LTV(Life Time Value) and analyzes data which is concerned of Customer Value. Under the these environments, defines the LTV(Life Time Value) rule that can improve the customer value.