• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.10a
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• pp.493-498
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• 1993

This paper proposes a high precision measurement technique to obtain the height of gage block. The proposed technique is consisted of two steps : In the first step, laser position transducer and electric micrometer are adopted to obtain a coarse value of the height of gage block, and then, second, heterodyne laser interferometry is adopted to acquire the precision value. The experiment results show that accuract in the order of a few nanometer is achieved for the gage blacks of as high as a few millimeter.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.304-309
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• 2000

Strain gage method is used to evaluate the mode I dynamic stress intensity factor of marging steel(18Ni) and titanium alloy(Ti-6A1-4V). To decide the best strain gage position on specimen, static fracture toughness test was performed. Then instrumented charpy impact test and dynamic tensile test was performed by using strain gage method for evlauating dynamic stress intensity factor. Strain gage signals on the crack tip region are used to calculate the stress intensity factors. It is found that strain gage method is more useful than method by using load which is obtained from impact tup to assess dynamic characteristics such as dynamic stress intensity factor.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.6
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• pp.128-135
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• 1996

This paper proposes a high precision measurement technique to obtain the height of gage block with a few millimeter height. The proposed technique is consisted of two steps : In the first step, laser position transducer and electric micrometer are adopted to obtain a coarse value of the height of gage block, and then, in the second step, heterodyne laser interferometry is adopted to acquire the precision value. A new kind of phase detector is constructed in the low cost for the heterodyne interferometer and its linearity with ${\pm}1%$ is confirmed by experiment. Also measurement error factors due to enviroments are discussed and methodology to reduce such errors is proposed. Preliminary experiments are carried out for the gage blocks of as high as a few millimeter.

• Journal of the Korean Society of Safety
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• v.17 no.3
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• pp.13-21
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• 2002

The tincture toughness is evaluated by using U(compact tension) and 3PB(three point bending) specimens of AI alloys far propulsive engine. To evaluate the static fracture toughness, strain gage method is used. The static fracture toughness obtained from the strain measurement is compared with the results by ASTM standard and FEM analysis. For the reliable evaluation of fracture toughness, strain gages are attached at various positions.

• Journal of the Korean Society of Propulsion Engineers
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• v.4 no.1
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• pp.53-64
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• 2000

Strain gage method is investigated to evaluate the mode I stress intensity factor. Two types of specimens for CT and three point bend specimen are used. Sharp notch of specimens is manufactured by wiring discharge machining. Strain gages signal from the crack tip region are used to calculate stress intensity factors. The results are compared with those of the ASTM E399 method and finite element analysis. The present experimental results coincide well with the data obtained from finite element analysis. Attached position of strain gage should be seriously considered during the application of this method.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1416-1418
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• 1994

Expressions for the displacement of a bimorph, one end fixed and the other free, has been introduced when sinusoidal inputs were applied to the ceramic plates on a thin metal plate. Maximum displacements at the free end and strains at the position of strain gage attached were measured when various wave forms, voltages, and frequencies were applied to the bimorph whose length is 6.6[cm], width 2.5[cm], and thickness 0.0365[cm]. Under the constant voltage ( $70[V_{peak}]$ ), the strains and the displacements at the free end were larger than the case of the sinusoidal input when the square wave was applied and were smaller when triangular wave. It was shown that the displacements at the free end and the strains of the gage position were increased as the applied voltage in the range of $30-90[V_{peak}]$ and effective length were increased. And it was also found that the resonant frequency of a bimorph was decreased as its effective length was increased, and that the displacements and the strains were maximum at the resonant frequency.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.219-225
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• 2006

This paper studies on the visibility of dashboard in forklift. As part of the real setting devised for this study, 1. Important evaluation by males experience in forklift driving, 2. Icon cognition experiment, 3. Gage cognition experiment, subjects were asked to estimate the important evaluation, sketched to icon and gage position on the screen. Subjective evaluations were carried out by semantic differential method, sketch method, sketch method, then analyzed by consistency test, frequency rate and T-test. I gather the results concerning the relationship between consistent answers and cognition rates of dashboard understand the conditions which create a desired instrument panel.

• Journal of Welding and Joining
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• v.19 no.3
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• pp.317-324
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• 2001

This study deals with high power Nd:YAG laser welding of thin steels for small pressure vessels. Full penetration welding at the overlap joint was performed so as to assure sufficient weld strength. Results showed that mid-depth weld size reduced drastically with increasing the travel speed. Position of focus had little effect on the bead formation even though short focal system was used. However, the shape factor and the bead width had closely related with the position of focus. Based on the microstructural inspection, acceptable weld was obtained when the overlap clearance was controlled up to 20% of the base metal thickness. In the case that the joint contained more clearance than the critical value, both the tensile shear strength and the tear strength were reduced. Results also demonstrated that shielding gases were proved to play a key role as far as the bead formation characteristics was taken into consideration. Blowing dry air through 5mm in diameter nozzle produced narrower bead cross-section than that of argon or nitrogen shielding.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.7 no.2
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• pp.1-5
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• 2013

In this paper, we proposed how to estimate the walking state in the knee disarticulation prosthesis's knee angle control. In control of the knee disarticulation prosthesis, we can estimate walking state that measurement of knee angle using absolute encoder and measurement of load on the soles using strain gage. We suggested a method of estimating the current walking states which can be divided into four cases and showed the effectiveness of the method via a series of experiments.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.28 no.4
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• pp.48-54
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• 2005

Recently, a couple of process capability indices are used to evaluate that the outputs of the process satisfy the specifications. An assumption of those indices is that the specifications of the characteristics are given single constant value. The display panel is a highly precise product and all the specifications of measure points are designed by their locations in the panel. So it is very difficult to locate the measurement facility to the exact position. In this paper, we propose a new process capability index in case of multi specifications and unfixable objects.