• Journal of Biosystems Engineering
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• v.26 no.5
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• pp.409-414
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• 2001

This paper reports a technique for measuring a three-dimensional soil deformation and a simplified method to determine the three-dimensional contact area of agricultural tires in a soil bin. A Pirelli 12.4R28 radial-ply tire was used on soft soil. Effects of dynamic load and inflation pressure were determined using the equipment for measuring soil deformation on the soil surface. Soil deformation measurements were made under three conditions of over-load (59kPa-14.2kN), rated-load (108kPa-11.8kN) and under-load (157kPa-9.3kN) in the combinations of the inflation pressures (kPa) and the tire load (kN). The results from three conditions were shown that the contact area of the over-load increased considerably bigger than those of the rated-load and the under-load. Therefore, to regulate soil deformation, the inflation pressure and the tire load should be set according to the soil conditions.

• Macromolecular Research
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• v.17 no.8
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• pp.585-590
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• 2009

The cure behaviors, dielectric characteristics and fracture toughness of diglycidylether of bisphenol-A (DGEBA)/poly(ethylene terephthalate) (PET) blend system were investigated. The degree of conversion for the DGEBA/PET blend system was measured using Fourier transform infrared (FTIR) spectroscopy. The cure kinetics were investigated by measuring the cure activation energies ($E_a$) with dynamic differential scanning calorimetry (DSC). The dielectric characteristic was examined by dielectric analysis (DEA). The mechanical properties were investigated by measuring the critical stress intensity factor ($K_{IC}$), critical strain energy release rate ($G_{IC}$), and impact strength test. As a result, DGEBAIPET was successfully blended. The Ea of the blend system was increased with increasing PET content to a maximum at 10 phr PET. The dielectric constant was decreased with increasing PET content. The mechanical properties of the blend system were also superior to those of the neat DGEBA. These results were attributed to the increased cross-linking density of the blend system, resulting from the interaction between the epoxy group of DGEBA and the carboxyl group of PET.

• Proceedings of the Acoustical Society of Korea Conference
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• 1994.06a
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• pp.867-872
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• 1994

The transfer function of an acoustic system, in general, often exhibits a wide dynamic range and a very long impulse response. The time-stretched pulse (TSP) proposed by Aoshima (ATSP) has a small peak-factor and is accordingly suitable for the measuring impulse responses. The pulse is not so suitable, however, for the measurement of impulse responses over a wide frequency range. In this paper, we try to generalize and optimize this method (OATSP). This makes the method applicable for measuring of impulse responses longer than the length of the TSP. An analysis of error in such a case is also shown. Finally, we discuss how to implement this technique in specific measurement conditins.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.3
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• pp.168-174
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• 1993

A new digital image processing method for measuring of the flank wear of cutting tool is presented. The method is based on computer vision technology in which the tool is illuminated by two halogen lamps and the wear zone is visualized using a CCD camera. The image is converted into digital pixel and processed to detect the wearland width. As a conclusion, it has been proved that the average wearland area and mzximum peak values of the flank wear width can monitored effectively to a measuring resolution of 0.01mm.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.12 s.148
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• pp.1595-1607
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• 2005

Three-dimensional(3-D) body scanners used to capture anthropometric measurements are now becoming a common research tool far apparel. This study had two goals, to test the accuracy and reliability of 3-D measurements of dynamic postures, and !o analyze the change in upper body surface measurements between the standard anthropometric position and various dynamic positions. A comparison of body surface measurements using two different measuring methods, 3-D scan measurements using virtual tools on the computer screen and traditional manual measurements for a standard anthropometric posture and for a posture with shoulder flexion were $-2\~20mm$. Girth items showed some disagreement of values between the two methods. None of the measurements were significantly different except f3r the neckbase girth for any of the measuring methods or postures. Scan measurements of the upper body items showed significant linear surface change in the dynamic postures. Shoulder length, interscye front and back, and biacromion length were the items most affected in the dynamic postures. Changes of linear body surface were very similar for the two measuring methods within the same posture. The repeatability of data taken from the 3-D scans using virtual tools showed satisfactory results. Three times repeated scan measurements f3r the scapula protraction and scapula elevation posture were proven to be statistically the same for all measurement items. Measurements from automatic measuring software that measured the 3-D scan with no manual intervention were compared with the measurements using virtual tools. Many measurements from the automatic program were larger and showed quite different values.

• Journal of Digital Convergence
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• v.11 no.8
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• pp.265-272
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• 2013

The purpose of this study was to provide a foundation for the methods of stretching in sports activities. The subjects were normal adults, the applied exercise was dynamic and static stretching and the research methods were measuring the jump height and muscle activity during jumping with subsequent data comparison and analysis. Twenty normal adults were randomly divided into 2 groups, and each group performed dynamic or static stretching. Jump height and the vastus lateralis and gastrocnemius muscle activities were measured during jumping, which was performed immediately before and after stretching. Statistical analysis was performed using an analysis of covariance. The results indicated that dynamic stretching was more effective than static stretching with respect to both jump height (p<.05) and muscle activity of the vastus lateralis (p<.05). Consequently, it was believed that dynamic stretching should be applied as a warm-up exercise for athletes who need to build and maintain high muscle strength.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.10
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• pp.813-820
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• 2021

In this study, a low-velocity impact test was performed to obtain the dynamic properties of solid propellants. The dynamic behavior of the solid propellant was examined by measuring the force and displacement of the impactor during the low-velocity impact test. The bending displacement was calculated by compensating for the local displacement caused by the low-velocity impact test in the form of three point bending and the shear displacement caused by using a short and thick solid propellant specimen. Stress and strain were calculated using compensated displacements and measured force, and dynamic properties of solid propellants were obtained from the stress-strain curve and compared with static bending test. The dynamic properties of solid propellant under the low-velocity impact loading at various operating temperature conditions such as room temperature(20 ℃), high temperature(63 ℃), and low temperature(-32 ℃) were compared and investigated.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.2
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• pp.35-43
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• 1999

The paper describes an approach for measuring delivery flow ripple generated by oil hydraulic axial piston pumps. In order to reduce pressure ripple which cause to undesirable noise. vibration and fatigue in hydraulic systems it is indispensible measure a delivery flow ripple from pumps. Since the flow ripple measurement of flow pumps is independent of the dynamic characteristics of the connected hydraulic circuit the measurement of flow ripple is most suitable for pump fluid-borne noise rating. The measurement of flow ripple with high frequencies from axial piston pumps is made by applying the remote instantaneous flow rate measurement method which is based on the dynamic characteristics between pressure and flow rate in hydraulic pipeline. The measured flow ripple waveforms are influenced by the configuration of V-shaped triangular relief groove in the valve plate. It can be seen that the appropriate relief groove in valve plate reduces the pressure and flow ripple amplitude and frequency spectrum for high harmonics.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.1
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• pp.64-72
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• 2004

In this paper. we analyse and present electro-mechanical dynamic characteristics of a micro-machined vibrating silicon ring gyroscope which can measure angular velocities about three orthogonal axes. The ring gyroscope has a ring connected to the gyroscope main body by support-ligaments which are arranged with cyclic symmetry. The natural modes of its vibration can be distinguished into the in-plane motion and the out-of-plane motion which are coupled by the gyro-effect due to the rotation of the gyroscope main body. The motions of the ring are electro-statically derived. sensed and balanced by electrodes. The equations of motion are formulated. The measuring method of angular velocities by force-to-rebalance is presented. The dynamic characteristics of a ring gyroscope are calculated and compared.

• Journal of KSNVE
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• v.7 no.6
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• pp.937-943
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• 1997

Viscoelastic materials have the characteristics of elasticity and viscosity. Unlike the metals which show negligible damping characteristics, the damping characteristic of viscoelastic materials like rubber mounts is very important in the analysis of the dynamic system. So there has been a great interest in measuring the damping characteristics of the material can be measured. One is the resonant method which loss factor can be measured only in the resonant frequency. The other is the nonresonant method. In this paper, the test procedure and the physical meaning of the impedance method are introduced. The impedance test results, the loss factor by the impedance method, are compared to the results of the resonant method including some recommendations in the experimental setup.