• Journal of the Institute of Convergence Signal Processing
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• v.21 no.2
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• pp.61-66
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• 2020

Recently, a variety of electric anesthetics devices have been developed and used in clinical practice to reduce the fatigue of the operator during local anesthesia for dental procedures and to compensate for the disadvantages of manual anesthesia device. In this electric anesthesia injection device, the accurate and constant delivery of pressure for drug infusion is a very important performance factor. In order to evaluate the accuracy of the transfer pressure, a small pressure gauge using a load cell is often used, but since the elastic body inside the load cell may not be able to accommodate a sufficient displacement, an error may occur when evaluating pressure performance. For these reasons, in this study, we proposed and evaluated a silicon-chrome steel (Si-Cr steel) spring jig that can accommodate relatively large displacements that can be used when evaluating the performance of a pressure-controlled pressure application device using a load cell type pressure gauge. As a result of the pressure transmissibility test and repeated measurement results using a commercial dental anesthesia injection device, a more stable result was obtained when using a spring jig, and it was confirmed that the frequency of abnormally high measurement was reduced.

• Journal of the Microelectronics and Packaging Society
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• v.26 no.4
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• pp.69-74
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• 2019

The influence of measuring fixtures on the measurement of dielectric and piezoelectric properties of PMN-PT single crystal specimens was investigated. As the pressure of the jig pin which applied the AC electrical signal to the sample decreased, the lower resonance resistance was measured and the higher mechanical quality factor was calculated. The mechanical quality factor was 418 when the spring tension of the jig pin was 20grf, and the value of the quality factor was reduced by half when the spring tension was 200grf. The 4-probe fixture method is unsuitable for measuring piezoelectric properties, but it was suitable for the measurement of dielectric loss. In order to accurately evaluate the piezoelectric properties of PMN-PT, it is necessary to lower the spring tension of the jig pin as much as possible.

• Korean Journal of Materials Research
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• v.12 no.12
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• pp.935-940
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• 2002

Magnesium-3, 6wt% Nickel alloys were fabricated by Rotation-Cylinder Method(RCM) in ambient atmosphere. The alloys were divided into two different heat-treating conditions, as-cast and thixotropic treated. Thixotropic heat treatment enhances the separation of primary hydride former of Mg and the catalytic phase of $Mg_2$Ni. Hydrogenation properties of the each alloy were evaluated and compared by PCI(Pressure-Composition Isotherm) measurement. The maximum hydrogen capacity and the reversible capacity of as -cast Mg-6wt% Ni alloy were 5.2wt% and 3.8wt% at 623k, respectively.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.192-197
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• 2004

The anisotropy in coefficient of thermal expansion (CTE) between the in-plane and out-of-plane of 3-dimensional thick composite structures induces residual stresses and the large void content due to insufficient compaction of fabric composites, which results in low interlaminar strengths. In order to reduce the through thickness CTE and the void content, in this work, carbon fabric phenolic laminates were compacted by pressure generated by autoclave and a compressive jig, from which the through-thickness CTEs and the void contents were measured. From the measurement, it was found that the through-thickness CTE and the void content had different characteristics from ordinary composites due to gas produced during the cure reaction of phenolic resin.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.766-773
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• 2021

Chemicals, such as ammunition, are disposable items that cannot be reused because of their operational characteristics. The reliability of the test process and test results are important factors in evaluating the performance of guns and ammunition. The pressure after firing is a crucial value in an acceptance test of guns and ammunition performance; hence, accurate measurements are required. The pressure in the artillery is measured using the copper crusher gauge. The compression amount of copper is converted into a pressure by either a length-pressure conversion table or conversion formula. Therefore, the exact measurement of the squeeze of the copper crusher is related directly to the correct estimate of the pressure. Currently, the pressure is measured manually by the operator, which always includes some human error. In this study, the cause of the measurement error was analyzed, and the automatic measuring system for copper crusher deformation was developed to minimize the error elements. A copper crusher could be measured using the probe sensor and CCD camera, and the Jig for stable positioning was also designed. A designated SW was also developed for the system operating and measurement-analysis. This measuring system through this study may be used for an ammunition stockpile reliability test and gun/ammunition acceptance test.

• Design & Manufacturing
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• v.15 no.2
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• pp.23-29
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• 2021

The specific strength of magnesium alloy is four times that of iron and 1.5 times that of aluminum. For this reason, its use is increasing in the transportation industry which is promoting weight reduction. At room temperature, magnesium alloy has low formability due to Hexagonal closed packed (HCP) structure with relatively little slip plane. However, as the molding temperature increases, the formability of the magnesium alloy is greatly improved due to the activation of other additional slip systems, and the flow stress and elongation vary greatly depending on the temperature. In addition, magnesium alloys exhibit asymmetrical behavior, which is different from tensile and compression behavior. In this study, a jig was developed that can measure the plane deformation behavior on the surface of a material in tensile and compression tests of magnesium alloys in warm temperature. A jig was designed to prevent buckling occurring in the compression test by applying a certain pressure to apply it to the tensile and compression tests. And the tensile and compressive behavior of magnesium at each temperature was investigated with the developed jig and DIC equipment. In each experiment, the strain rate condition was set to a quasi-static strain rate of 0.01/s. The transformation temperature is room temperature, 100℃. 150℃, 200℃, 250℃. As a result of the experiment, the flow stress tended to decrease as the temperature increased. The maximum stress decreased by 60% at 250 degrees compared to room temperature. Particularly, work softening occurred above 150 degrees, which is the recrystallization temperature of the magnesium alloy. The elongation also tended to increase as the deformation temperature increased and increased by 60% at 250 degrees compared to room temperature. In the compression experiment, it was confirmed that the maximum stress decreased as the temperature increased.

• Journal of the Korean Society for Heat Treatment
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• v.34 no.1
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• pp.25-30
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• 2021

The differential gear system is a device designed to distribute the driving force of both vehicle wheels and control the rotational speed when the vehicle turns on a curve. The differential device consists of a differential gear case, a ring gear, and a pressure ring. A differential pinion gear and side gear are mounted on the differential pinion shaft inside the differential gear case. In this study, a pin press-fitting device that mounts the pinier gear and side gear to the differential pinion shaft in the differential gear case was designed, and a jig device for pin press-fitting using servo press was developed. In addition, by precisely measuring the pin press-in load and press-in distance according to the pin hole diameter of the differential gear shaft, the optimization of the pin pressin process was established.