• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.5 no.1
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• pp.22-25
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• 1975

The author has studied on the profiles on Korean young male and female by the cephalometric roentgenograms, the subjects were consisted of 104 persons with normal occlusion and the measurements were done on the soft and hard structures. The mean and standard deviations in the subjects were calculated and compared between male and female. The author has obtained the following results: 1. In the linear measurement, male was longer than female in most measuring points. 2. Compared with the angulation of soft tissue, there were no differences between both sexes. 3. In the skeletal patterns, there were some differences between male and female, but there was a similarity to the facial profile. 4. The individual variations on the cephalometric profiles on the subjects were recognized, especially, in the lower facial part.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2000.11a
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• pp.158-161
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• 2000

In this paper, we propose a new technique to compensate for the VCO nonlinearity using only the returned beat signal whose spectrum contains the internal reflections and the targets simultaneously. In the case of a distance measurement system using single antenna, the reflections from the circulator and the antenna are much larger than the return signal from target. The beat signal by these reflections is at much lower frequency than that of the target, and the VCO nonlinearity can be compensated leer using these signals. Indoor experiments were carried out and the results show marked improvement in the shape of range profile arid the range resolution.

• Journal of the Korean Home Economics Association
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• v.44 no.12
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• pp.105-115
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• 2006

The purpose of this study is to apply conjoint analysis to fashion product development. Conjoint measurement was undertaken on the traditional casual market, composed of Polo, Beanpole, Maru and Giordano brands. Product's attributes, such as brand name, price, country of origin and style, were selected as choice factors. Twelve profiles were used for full-profile stimulus cards method. Based on the importance and utility rates of the product attributes, preferences for the products currently in the market and simulated products were calculated. The results increased our understanding of the trends in traditional casual market and assisted in the preparation of marketing strategies for each brand.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.9
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• pp.2909-2915
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• 1996

Precise and accurate pressure measurements are obtained using deadweight piston gauges. Pressure distribution and elastic distortion in the piston-cylinder unit are the leading factors in determination of effective area. The distortion depends upon the pressure distribution in the clearance between piston and cylinder and those are coupled each other. Considering the viscosity pressure relation of oil and governing flow equation in the clearance, a new numerical iterative algorithm is developed. The disagreement between the monotonous and sharp pressure profiles is an indication that the pressure profile will be different for each piston and cylinder unit due to material variances.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.5
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• pp.1333-1339
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• 1995

Recently developed technique of measuring minor species concentration by using the modulation dip in broadband CARS has been applied to the flame structure study of methane/air premixed flames in a counterflow. This method used the modulation dip from the cold band CO Q-branch resonant signal superimposed on the nonresonant background. The measured CO concentration profile in a symmetric and unsymmetric methane/air premixed flames together with the velocity and temperature by using LDV and CARS have been compared with the numerical results adopting detailed chemistry modeling. The results show that there is a satisfactory agreement between the experimental data and numerical results for velocities, temperatures and CO concentrations. And the modulation dip technique of measuring minor species, such as CO is a viable tool for a quantitative measurement in a flame.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.964-967
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• 2001

Aspherical lens with the higher numerical aperture has been needed in the optical storage device to increase the recording density on the disk. However, high numerical aperture means the large slope angle at the clear aperture of the lens. Therefore, the measurement and manufacturing technique including the lens molding process for the slope angle should be developed. In this paper, the evaluation technique was described for the optical performance of the aspherical lens. Aspherical form error brings about the wavefront error and the side lobe of the beam intensity profile. A schematic diagram of the aspherical lens manufacturing was drawn to explain the aspherical form error compensation. Finally, form error of the aspherical lens was defined and plotted using the raw data of the Formtalysurf.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1030-1033
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• 2003

The packing-free piston has become widely distributed in certain branches of instrument making and precision machine building. A large number of the most diversified instruments are now being constructed on the principle of the packing-free piston like piston manometers, vacuum manometers, hydraulic machines, dynamometers. hardness measuring instruments. power indicators, hydraulic scales, and many others. In spite of the widespread application of systems with a packing-free piston, there were practically no special papers to the theory and practice of the application of such systems. This paper describes the theoretical approaching method to get the pressure distribution profile between the piston and cylinder using finite element method.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.5
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• pp.716-723
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• 2002

Heat transfer in linear motor driven stages for surface mounting device applications was investigated. A simple one-dimensional thermal resistance model (TRM) was introduced. In order to reduce three-dimensional nature to one-dimensional, a few assumptions and simplifications were employed suitably. A good agreement with a finite element heat transfer analysis in temperature profile was obtained. For validation, the analysis was compared with the measurement with respect to motor driving power. Overall discrepancy was less than 7$^{\circ}C$. The influence of two high thermal resistance parts, insulation sheet and thermal contact between the coil assembly and the mounting plate, was examined through the analysis. Additionally, the thermal resistance analysis was applied to another stage including an internal cooling-air passage, and was found available for this system as well. After validation, the cooling effect was surveyed in terms of motor power, and cooling-air and -water flow rate.

• Journal of Mechanical Science and Technology
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• v.16 no.5
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• pp.633-638
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• 2002

An approach to enhance dimensional accuracy of the grinding process has been presented, and grinding of a glass material with a metal-bonded diamond wheel has been studied. In this study, a grinding tool is suspended flexibly and controlled by an electromagnetic actuator. During grinding, profile error of a ground surface is indirectly measured and fed back to a control system. A model of grinding error has been suggested on which the indirect measurement has been based. An optimal PID control is adopted and effectiveness of the in-process feedback control has been verified experimentally.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.96-101
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• 2001

Heat transfer in linear motor driven stages for surface mounting device applications was investigated. A simple one-dimensional thermal resistance model was introduced. In order to reduce three-dimensional nature to one-dimensional, a few assumptions and simplifications were employed suitably. A good agreement with a finite element heat transfer analysis in temperature profile was obtained. For validation, the analysis was compared with the measurement with respect to motor driving power. Overall discrepancy was less than $7^{\circ}C$. The influence of two high thermal resistance parts, insulation sheet and thermal contact between the coil assembly and the mounting plate, was examined through the analysis. Additionally, the thermal resistance analysis was applied to another stage including an internal cooling-air passage, and was found available for this system as well. After validation, the cooling effect was surveyed in terms of motor power, and cooling-air flow rate.