• The Journal of Korean Academy of Prosthodontics
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• v.16 no.1
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• pp.32-37
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• 1978

The purpose of this study was to apply the position, the form and the angle of the attrition in the natural maxillary central incisors shown on the labial surface to the artificial teeth in the field of prosthetic dentistry. So we should exactly alter the molds of artificial teeth in individual cases in order to make artificial teeth more natural. 226 extracted teeth of the maxillary central incisors were chosen as materials. I have exactly examined the teeth with a magnifying glass and a circular graduator under concentrated light. The observation brought me the following results: 1) The attrition was most prevailing at the range from the mesial angle to the middle part of cutting edge in the left maxillary central incisor, and distal angle of cutting edge in the right maxillary central incisor. 2) On the attrite form of both angles, the angulated form was more than 4 times as frequent as rounded form in the mesial angle, and almost equal in the distal angle. 3) On the attrite form of cutting edge, mesial attrite form including mesial angle was most frequent in the left maxillary central incisor, and distal attrite form including distal angle in the right maxillary central incisor. 4) The angle made by the labial surface and the attrite surface was about $39^{\circ}$, and more than 70% of the total examined teeth were included at the range from $31^{\circ}\;to\;50^{\circ}$. 5) None attrite form at the cutting edge was about 12% and completely attrite form at the cutting edge was about 27% of examined teeth.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.3
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• pp.146-153
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• 2012

RP system which is widely used to reduce the time of product development is to resolve the problem of cutting work. It is a method using laminated thin films to produce many forms. The RP equipment used for this experiment is FDM system. This can produce 3D model with using 3D CAD designed file within a relatively short time. Not only this, this system also through 3D file preparation, 3D product manufacture, removal support these 3 step operating process can easily produce goods, but product can be different from original design. This research has been conducted to minimize this error. To apply to the circular product made a circular specimen and measured several times with 3D scanner and find out average 99.622% of accuracy. This result is applied to RP system, and with this changed design produced a specimen, and found out the accuracy is increased to 99.958%. If this is applied to circular products, we can produce more precise products with less process.

• Bulletin of the Society of Naval Architects of Korea
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• v.12 no.1
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• pp.1-8
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• 1975

As a first step of a thermal stress analysis in a watertight bulkhead plate during welding of a spool type penetration piece, the bulkhead plate has been idealized as infinite plate with a circular hole. The exact solution for the transient temperature distribution and the associated quasi-static thermal stress which arise in a infinite plate subjected to an instantaneous point source of heat acting on the periphery of the circular hole. And the solutions have been extended to the case of a moving heat source with the aid of the Duhamel's superposition integral. The solutions can be applied to the problems such as a circular cutting or welding of a plate.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.1
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• pp.22-30
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• 1992

The free vibrations of the outer-clamped spinning annular disk which simulates a wafer cutting machine are investigated. The effects of the initial tension, the centrifugal force and outer-fixture extension caused by spinning on the vibration characteristics of the disk are considered. The modal parameters of the disk are calculated by using Galerkin's method as the rotating speed and initial tension are varied. Laboratory experiments are also performed with a rotating and stationary disk, and, it is found that experimental and simulation results are in good agreement.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1040-1043
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• 1996

The accuracy of the servo control in CNC system has a great influence on the duality of machine product. Tracking performance of the servo control is deteriorated mainly by the time delay of the servo system and the inertia of the work table or bed. Contouring errors occur in every interpolation steps by the effect of the tracking performance. In this paper, $H_{\infty}$ two-degree-of-freedom(TDF) controller is designed for improvement to improve the tracking performance. The designed controller is applied 3-axis machining center model and the cutting accuracy is simulated in case of corner cutting, circular and involute interpolation. Simulation results show that $H_{\infty}$ TDF controller designed in this paper has a good effect to improve tracking performance in CNC system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.276-280
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• 1996

This paper presents an indirect method for on-line measuring the cutting forces in contour NC milling processes by using the current signals of the servo drive motors. A Kaluman filler is used for estimating each of the load torques to the x, y-axis servo motors of a horizontal machining center. Then, the load torque induced by the friction force in the guidewayis estimated and subtracted from the total extermal torque, thus resulting in the load torque induced by the cutting force. A series of experimental works on the circular interpolated contour milling process shows good agrement between the cutting forces measured by the dynamometer and those estimated by the method presented in the paper.

• Journal of Biosystems Engineering
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• v.27 no.4
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• pp.301-310
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• 2002

With a purpose to manufacture an onion peeler, the root cutting equipment of the onion could be attached to a prototype onion peeler was developed. Before the experiment, the distribution of the dimensions of the Korean native onion were measured. And some types of the blades to cut and remove the root of the onion were designed and such characteristics as feasible revolution, conveying speed, and power requirement were investigated. From the result of the test, the selected one among the various cutters was the wing type blade with the round blade to cut out the root and with the vertical blade to cut a circular line. The optimum operating conditions of the wing type blade were revealed the revolution with no load was at 630 rpm, and the conveying speed was 0.08 m/s. Under these conditions, the maximum torque was 5.25 kg·m and the power requirement was 33 W, respectively.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.7
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• pp.42-47
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• 2019

In this research, we try to study the change of squareness in the cutting process while changing cutting conditions such as feed rate and spindle rotational speed with chromium molybdenum steel (SCM415) material and TiCN, TiAlN coated end mill tool. The TiCN coating tool had the best straightness at 4,000 rpm at a feed rate of 200 mm/min. The TiAlN coating tool was best measured at 3,000 rpm at a feed rate of 200 mm/min. TiAlN coated tools had excellent dimensional tolerance when comparing the coating tool specifics.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.7
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• pp.77-82
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• 2019

In this study, we study the change of surface roughness during cutting machining by changing the cutting conditions such as feed rate and spindle velocity with chromium molybdenum steel (SCM415) material and TiCN and TiAlN coated end mill tools. The surface roughness value of the test specimen for SCM415, was found to be 3,000 rpm in TiCN coated end mill and $0.634{\mu}m$ in surface roughness at a feed rate of 100 mm/min. In the TiAlN coated end mill, 300 mm/min, the surface roughness was the best at $0.699{\mu}m$. The overall average surface roughness of each coating tool was better than that of TiAlN.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.2
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• pp.149-155
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• 2016

The purpose of this study is to develop special tools used to extend the tool life for the boom of heavy equipment. The boom of heavy equipment is manufactured by cutting the inner and outer surface with respect to the assembly site essential. In particular, when cutting the inner surface, entry of the tool is difficult owing to the limited size of the inner diameter and non circular cutting. In addition, the productivity is poor because the use of the cutting tool made of the SKH material. Therefore, it is necessary to develop a special tool for machining heavy equipment boom to extend tool life and to improve productivity. The special tool developed this study has the form of a holder and tip. The tip was created by applying a commercially available tungsten carbide insert.