• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.2
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• pp.1201-1216
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• 2017

In this study, we described the development of a methodology to measure tip-pinch strength on the paretic hand rehabilitation device and aimed to investigate reliability of the device. FSR sensors were embedded on the device, and tip pinch strength was estimated with data collected from the sensors using a developed equation while participants were demonstrating tip pinch. Reliability tests included inter-rater, test-retest, and inter-instrument reliability. B&L Engineering pinch gauge was utilized for the comparison. Thirty-seven healthy students participated in the experiment. Both inter-rater and test-retest reliability were excellent as Intraclass Correlation Coefficients (ICCs) were greater than 0.9 (p<0.01). There were no statistically significant differences in tip-pinch strengths. Inter-instrument reliability analysis confirmed good correlation between the two instruments (r = 0.88, p < 0.01). The findings of this study suggest that the two instruments are not interchangeable. However, the tip-pinch mechanism used in the paretic hand rehabilitation device is reliable that can be used to evaluate tip pinch strength in clinical environment and can provides a parameter that monitors changes in the hand functions.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.7
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• pp.1340-1347
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• 2002

Finite element simulations are being widely used to increase the efficiency and effectiveness of design of bulk metal forming processes. In such simulations, proper consideration of friction condition is crucial in obtaining reliable results. For this purpose, tip test based on backward extrusion was proposed recently. In this lest, a cylindrical billet is positioned in a shallow groove of a counter punch for centering purpose and formation of a radial tip is induced on the extruded end of the workpiece. In this study, the effect of centering groove on tip test was investigated. The quantitative ratio of the shear friction factors between the punch and die was numerically determined depending on the shape of centering groove. Also, surface expansion and pressure distribution along the punch and die were considered in order to better understand the reason that friction condition at the punch compared to the one of die was more severe.

• Journal of the Korean Society for Heat Treatment
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• v.3 no.2
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• pp.32-36
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• 1990

For the accurate measurements of hardness in a material, it is necessary to have a thorough understanding of the effects of test variables on the accuracy of hardness value. For the rebound hardness test, major test variables are the radius of hammer ball tip, type of backing materials, size and roughness of the specimen. In this study, effects of these variables on Equo-Tip hardness value were investigated. Hardness measurements were carried out using WC balls with various sizes of worn-ot zone. The sample materials chosen for the experiments were commercial standard hardness blocks and SM45C steel bars subjected to either normalization or quench and temper treatments. As backing materials, aluminum, steel and rubber plates were used in all the experiments. Experimental results show that for the accurate measurements of Equo-tip hardness, it is necessary to use the hammer ball with a worn-out zone parameter of less than 0.23, and the recommended minimum thickness and width of the specimen are 25mm and 70mm, respectively. Further for the surface preparation, the specimens need to be polished with an emery paper of No. 400 or finer, and for the backing matrials, it is recommended to use steels or rubbers.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.4 no.3
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• pp.245-253
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• 2006

A test of the 1/3 scale model was conducted to verify the tip-over analysis of a dry. concrete storage cask under a hypothetical accident condition. The tip-over analysis was executed using the velocity at each point as the initial conditions of the model just before the impact. The initial velocity was determined from the initial angular velocity, which would make the equivalent kinetic energy to the potential energy. To confirm the structural integrity of the canister, the visual testing and the non-detective testings such as Liquid Penetrant testing and Ultrasonic Testing were conducted. The lid of a storage cask was plastically deformed near the impact point. The structural integrity of storage cask was maintained. To verify the tip-over analysis the strains and the accelerations acquired by the tip-over test were compared with those by the analyses. The results of the analysis were larger than the test results about two times.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.540-545
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• 2001

In this paper dynamic responses of an engine, which is supported by hydraulic mount, to throttle tip-in/tip out are analyzed. Because the hydraulic mounts have non-linearity which the characteristics of stiffness and damping vary with frequencies, it is difficult to analyze the dynamic behavior of an engine using general integral algorithms. Convolution integrals and relationships between unit impulse response functions and frequency response functions are therefore used to simulate the transient behavior of an engine indirectly. In time domain, impulse response functions are calculated by two-side discrete inverse Fourier transform of frequency response function achieved by Laplace transform of equations of motion. Considering the fact that the shapes of behavior of an engine simulated by the proposed method are in good agreement with test results, it is confirmed that the proposed method is very effective for the analysis of transient response to throttle tip-in/out of an engine with hydraulic mounts.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.5
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• pp.403-409
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• 2014

For ground-based telescope application, the performance assessment of tip-tilt actuator is important because the optical quality of telescope depends upon the windshake compensation ability of the fast steering secondary mirror. But it is difficult to measure the performance characteristics of the actuators due to the large size mirror and test facilities including the vacuum support and structural frame. In this paper, the full-scale tip-tilt test bed for the large size secondary mirror with diameter of 1m is built and the several tests are performed including the range, resolution and frequency response function. From the measurement results, it is shown that the tip-tilt actuator can successfully compensate the windshake with frequency of maximum 12 Hz and be a candidate for the Giant Magellan Telescope.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.5
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• pp.189-195
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• 2003

Atomic Force Microscope (AFM) has been widely used in micro/nano-scale studies and applications for. the last few decade. In this work, wear characteristics of silicon-based AFM tip was investigated. AFM tip shape was observed using a high resolution SEM and the wear coefficient was approximately calculated based on Archard's wear equation. It was shown that the wear coefficient of silicon and silicon nitride were in the range of ${10}^{-1}$~${10}^{-3}$ and ${10}^{-3}$~${10}^{-4}$, respectively. Also, the effect of relative humidity and sliding distance on adhesion-induced tip wear was discussed. It was found that the tip wear has more severe for harder test materials. Finally, the probable wear mechanism was analyzed from the adhesive and abrasive interaction point of view.

• Geomechanics and Engineering
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• v.19 no.2
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• pp.115-126
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• 2019

The long-term settlement characteristics for the cast-in-place bored pile in the deep-thick soft soil are investigated by post-grouting field tests. Six cast-in-place bored engineering piles and three cast-in-place bored test piles are installed to study the long-term settlement characteristics. Three post-grouting methods (i.e., post-tip-grouting, post-side-grouting, and tip and side post-grouting) are designed and carried out by field tests. Results of the local test show that decreased settlements for the post-side-grouted pile, the post-tip-grouted pile and the tip and side post-grouted pile are 22.2%~25.8%, 30.10%~35.98% and 32.40%~35.50%, respectively, compared with non-grouted piles. The side friction resistance for non-grouted piles, post-side-grouted pile, post-tip-grouted pile and the tip and side post-grouted pile undertakes 89.6~91.3%, 94.6%, 92.4%~93.0%, 95.7% of the total loading, respectively. At last, the parameters back analysis method and numerical calculation are adopted to predict the long-term settlement characteristics of the cast-in-place bored pile in the deep-thick soft soil. Determined Bulk modulus (K) and a creep parameter (Ks) are used for the back analysis of the long-term settlement of the post-grouted pile. The settlement difference between the back analysis and the measurement data is about 1.11%-7.41%. Long-term settlement of the post-grouted piles are predicted by the back analysis method, and the predicted results show that the settlement of the post-grouted pile are less than 6 mm and will be stable in 30 days.

• Journal of computational fluids engineering
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• v.21 no.2
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• pp.62-69
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• 2016

It has been highly demanded to improve the accuracy of CFD(Computational Fluid Dynamics) methods for the assessment of the hydrodynamic performance of marine propellers in cavitating and non-cavitating flows. This paper presents a validation study on the numerical simulation of the tip vortex flow of a non-cavitating marine propeller SVA VP1304. The calculations are carried out by using the Reynolds averaged Navier-Stokes(RANS) approach, where the Reynolds Stress Model(RSM) is used for turbulence closure. The present paper contains a grid dependence test for the propeller open water simulations and a special emphasis is placed on conducting a local grid adaptation on the blade tip and in the tip vortex to reasonably reproduce the velocity and the pressure in the tip vortex flow field. The numerical results are compared with the experimental validation data, which are published in the second International Symposium on Marine Propulsors 2011(SMP'11). The present numerical results show a reasonable agreement with the experiments.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.42
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• pp.19.1-19.4
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• 2020

Background: The tongue in groove technique (TIG) is a useful technique for the correction of the nasal tip projection and the nasolabial angle. The purpose of this study was to determine the utility of this technique for nasal tip rotation and projection correction in the Iranian society. Methods: This is a retrospective clinical trial study of 20 patients undergoing open septo-rhinoplasty using TIG technique from January 2017 to August 2019 at the oral and maxillofacial unit of Bu Ali Hospital and private sector. Preoperative and postoperative profile view photographs were compared to assess the changes in tip projection and rotation. Results: Fifteen patients (75%) had normal angular size, and 5 of them (25%) were not within the normal range after the surgery. The Fisher exact test showed that this success was statistically significant (P = 0.006). Ten patients (50%) had normal projection size, postoperatively. The Fisher exact test showed that this effect was statistically significant (P < 0.01) Conclusion: The study demonstrated the benefit of TIG on the correction of nasal tip projection and rotation.