• Electrical & Electronic Materials
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• v.6 no.2
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• pp.109-114
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• 1993

본 논문에서는 0.05Pb(Sn$_{1}$2/Sb$_{1}$2/)-0.35PbTiO$_{3}$-0.60PbZrO $_{3}$+0.4[wt%] MnO$_{2}$ 조성을 갖는 3성분계 압전세라믹스에 Cr$_{2}$O$_{3}$ 의 첨가량을 변화시켜서 지연선을 제작하고 탄성표면파를 여기시켜 전파속도를 측정하였으며 EMMAS 기준에 따라 각 시편의 재료정수를 측정하고 이를 압전방정식에 적용하여 매질에 따라 여기되는 탄성표면파의 계산속도를 이론적으로 산출한 후 이를 지연선에서 측정된 실험속도와 비교하여 재료의 특성이 탄성표면파의 전파특성에 미치는 영향을 조사하였다. 그 결과 SAW 지연선에서 측정된 탄성표면파는 Generalized Rayleigh Wave였으며 재료의 특성이 우수한 시편일 수록 계산속도와 측정속도와의 차가 적었던 것으로 나타났고 오차한도는 평균 99.39[%]였으므로 실험속도 측정방법이 feed through 현상없이 우수한 측정방법이었음을 알 수 있었다.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.256-263
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• 1993

The integration of deburring robots into product quality and productivity impact the industrial. In this paper the intelligent system of robotic deburring is proposed integrated with robot system, image processing system, force sensor system and host PC. The size, position, recognition of burr is determined by the information that the image processing system processed. The feed velocity of cutting tool is controlled by the information that the force sensor system processed. The integration of these information can remove the uncertainty of the information of deburring on the cutting path. The result of these technologies is useful for the development of the factory automation and automatic inspection equipments.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.538-541
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• 2003

Ultra-precision machining was carried out on a electroless nickel materials using single crystal diamond tools. The effects of the cutting velocity, the tool length, the tool nose radius, the feed rate and depth of cut on the surface roughness were studied. In this paper, the cutting condition for getting nano order smooth surface of electroless nickel have been examined experimentally by the ultra-precision machine and single crystal diamond tools. And also. the surface roughness was measured by the three dimension

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.6 no.3
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• pp.9-15
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• 2007

Three methods for grinding: cross grinding, slanted tool axis grinding and parallel grinding, were carried out to study the machinability of tungsten carbide mold for glass formed aspherics lens. In our research, the optimum grinding conditions were investigated in terms of feed-rate, relative velocity of wheel and work piece, tool marks and surface roughness. It is shown that cross grinding are most effective in removal ratio but poor in surface roughness. In addition, tool marks of each method were differentiated on direction and shape.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.3
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• pp.76-82
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• 1999

This study was carried out to verify finding performance of dental diamond bur and investigate the possibility of AE application in density field. Work pieces were made of acryl and bovine respectively for the experiments in this study. Grinding test was conducted to get the data of grinding resistance and specific finding energy of low different types of diamond bur by using tool dynamometer. AE signal was acquired to verify grinding process in the AE measuring system. AErms value was increased as the grinding velocity and depth were increasing, but it decreased as the feed rate was increasing. The case of the small value of AE signal is due to abnormal grinding in D type diamond bur. By analyzing AErms start and finish time of grinding working, abnormal grinding state can be confined. Abnormal state can be found through the behavior of AE signal in the finding working. As a result, it is expected that forecast of abnormal state is possible using AE equipments under real time process.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.844-847
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• 2003

This thesis suggests design considerations and solutions for cam type transfer unit in which feed, lift, and clamp motions are occurred by cams. For fast transferring and avoiding cam breakage, each designed cam must satisfy the given specifications such like velocity, acceleration, jerk, pressure angle, ram thickness, and torque. To reduce absolute torque magnitude, conjugate cam is suggested. Conjugate cam eliminates the redundant pre-load by using complementary cam and follower to avoid jumping between them. The result from the prototype shows the reductions of the absolute torque value, and it indicates that conjugate cam could enhance the working speed of cam type transfer unit and extend of the life span of cam type transfer unit.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1780-1783
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• 2003

Burrs formed in micro drilling with Ø 1.0 and 0.5 are observed. The changes of burr geometry are compared when feed rate and velocity changes. Characteristics of burr formation in 4 different workpiece materials are analyzed. The coefficient of burr geometry, CB is introduced to classify burrs according to burr height and burr types. Finally control charts are produced using the coefficient of burr geometry and burr types in each workpiece material. Data base is constructed to be used for burr expert system.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2002.05a
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• pp.95-100
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• 2002

This study was experimentally performed to investigate flow characteristics of spray droplets in the wind tunnel. Behavior of the spray droplets in the pipe was observed and the deposition rate of droplets on the surface of pipe as liquid film was measured. The experiments were carried out for a variety of parameter, such as velocity of feed air, spray angle of nozzle, and diameter of droplet. From the visual observation of the spray droplets in the pipe and the measurement of deposition rate on the pipe, the general understanding of droplets behavior for desuperheater was provided.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.10
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• pp.20-25
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• 2004

Using the multiple regression analysis cutting forces of turning processes have been predicted based on the cutting conditions such as feed rate(f), depth of cut(d), and cutting velocity(v). The statistical inference of the equation was checked by ANOVA test. The validity of the proposed regression analysis was verified by two sets of cutting tests of 27 cutting conditions and the additional cutting tests of 18 cutting conditions. From the results of analytical and experimental studies, it was found that there was no significant difference between the measured and predicted cutting forces. Also, the shear and friction characteristics of turning processes were analyzed with predicted cutting forces.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.03a
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• pp.59-64
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• 1998

We need to achieve th mass product through methods of higher efficient, higher precise manufacturing process than those of existing precision abrasive machining. Thus, this study is to develop mirror-like surface machining technique of outer diameter of the piston pin by the compound magneto-electrolytic abrasive polishing system. The procedure of machining is followed as first, fulfill the pre-processing by cylindrical grinder, second, complete mirror-like surface by the method of magneto-electrolytic abrasive polishing used CBN non-woven abrasive pads. In this study, it was found that the best suitable conditions of mirror-like surface polishing were that the electrode density was 0.1A/$\textrm{cm}^2$, the applied pressure 1.5kgf/$\textrm{cm}^2$, the feed rate 0.5mm/rev, and the rotoation velocity of workpiece 80rpm, and that the surface roughness was reduced in this conditions.