• Journal of the Korean Society for Nondestructive Testing
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• v.20 no.3
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• pp.221-230
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• 2000

The usefulness and limitations of the impact-resonance method, which is a nondestructive evaluation (NDE) method for concrete, are studied by both experimental and theoretical methods. For the experimental study, several concrete slab specimens with various inclusions embedded were fabricated, and tested by the impact-resonance method. Some of the inclusions have been detected and accurately located, but some have not. The reasons for the failure in the latter cases have been investigated theoretically by using finite element analyses, from which the primary factors determining the success of the method have also been identified. This study will serve to enhance the understanding of the underlying physics and to improve the usefulness of the impact-resonance method as applied to concrete NDE.

• Imaging Science in Dentistry
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• v.46 no.4
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• pp.285-290
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• 2016

In this report, we describe the incidental finding of an oropharyngeal mass in a patient who presented with a chief complaint of temporomandibular pain. The patient was initially evaluated by an otorhinolaryngologist for complaints of headaches, earache, and sinus congestion. Due to worsening headaches and trismus, he was further referred for the management of temporomandibular disorder. The clinical evaluation was uneventful except for limited mouth opening (trismus). An advanced radiological evaluation using magnetic resonance imaging revealed a mass in the nasopharyngeal/oropharyngeal region. The mass occupied the masticatory space and extended superioinferiorly from the skull base to the mandible. A diagnostic biopsy of the lesion revealed a long­standing human papilloma virus (HPV­16)­positive squamous cell carcinoma of the oropharynx. This case illustrates the need for the timely radiological evaluation of seemingly innocuous orofacial pain.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.3
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• pp.59-66
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• 2006

In this paper, we suggested an evaluation method of cracks in a ceramic product by resonant ultrasound spectroscopy. For experiment, we manufactured nondestructive measurement system by resonant ultrasound spectroscopy and measured resonance frequencies of acceptable and cracked ferrules. The evaluation criterion of ferrule is based on the comparison of resonance frequencies between acceptable and cracked-ferrule. The criterion value that defined by suggested formula is 2. By using the criterion, it is possible to evaluate both acceptable and cracked-ferrule.

• Journal of the Korea Concrete Institute
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• v.11 no.4
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• pp.157-167
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• 1999

Among several non-destructive testing methods, ultrasonic pulse velocity method and rebound index method have been widely used for the evaluation of concrete strength. However, such methods might not provide accurate estimated results since factors influencing the relationship between strength and either ultrasonic pulse velocity or rebound index are not considered. In this paper, the evaluation method of concrete strength using rod-wave velocity measured by impact-resonance method is proposed. A basic equation is obtained by the linear regression of velocity vs, strength data at specific age and then, aging factor is employed in the equation to consider the difference of the increasing rate between wave velocity and strength. Strengths predicted by the proposed equation agree well with test results. Furthermore, the combined method of rod-wave velocity and rebound index is proposed.

• Progress in Superconductivity and Cryogenics
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• v.20 no.1
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• pp.23-27
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• 2018

As the wireless power transfer (WPT) technology based on strongly resonance coupled method realizes large power charging without any wires through the air, there are advantages compared with the wired counterparts, such as convenient, safety and fearless transmission of power. From this reason, the WPT systems have started to be applied to the wireless charging for various power applications such as train, underwater ship, electric vehicle. This study aims for the effect and characteristics of different inserted resonance coil between Tx and Rx coils for charging system of superconducting magnetic levitation (MAGLEV) train. The transfer efficiency and effect are evaluated with helix type, rectangular type copper resonance coil, and HTS resonance coil under bulb and HTS magnet load, respectively. The input power is adapted with radio frequency (RF) power of 370 kHz below 500 W.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.7
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• pp.603-611
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• 2021

This study aims to analyze the mediating influences of resonance-based self-attitude and brand credibility in a relationship between celebrity endorser credibility and celebrity endorser congruity toward brand purchase intention in the current dynamic business environment. It employs a quantitative research method and reports on a survey, using a questionnaire, including the population of consumers of various instant coffee brands in several cities in Indonesia. The number of respondents in this study was 432 people. The analysis was performed using Partial Least Square Structural Equation Modeling and SmartPLS software. The analysis consisted of descriptive statistics, evaluation of the measurement model, evaluation of the structural model, and hypothesis testing. The results partially support the model developed. The findings suggest that the instant coffee product advertising in Indonesia needs to create brand messages focusing on the formation of resonance-based self-attitude from consumers to increase the influence of celebrity endorser credibility and celebrity endorser congruity, as well as the brand credibility towards the brand purchase intention. This study contributes to the marketing literature and the theory of planned behavior by providing empirical evidence on the relationship between celebrity endorser credibility, celebrity endorser congruity, resonance-based self-attitude, brand credibility, and brand purchase intention.

• Journal of the Korean Wood Science and Technology
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• v.42 no.2
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• pp.130-137
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• 2014

Nondestructive evaluation (NDE) method by using a resonance frequency mode was carried out for ceramics made from particle boards with different phenol resin impregnation ratios (30, 40, 50, 60%) at carbonizing temperature of $800^{\circ}C$. The material for ceramics was Miscanthus sinensis var. purpurascens board. Dynamic modulus of elasticity increased with increasing impregnation ratio. There was a close relationship of dynamic modulus of elasticity and static bending modulus of elasticity to modulus of rupture (MOR). However, the result indicated that correlation coefficient is higher in dynamic modulus of elasticity to MOR than that in static modulus of elasticity to MOR. Therefore, the dynamic modulus of elasticity using resonance frequency by free vibration mode is more useful as a nondestructive evaluation method for predicting the MOR of ceramics made from Miscanthus sinensis var. purpurascens particle boards by different phenol resin impregnation ratios.

• Journal of the Korean Wood Science and Technology
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• v.41 no.5
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• pp.466-473
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• 2013

Nondestructive evaluation (NDE) technique method using a resonance frequency mode was carried out for heat-treated wood under different conditions. The effect of heat treatment on the bending strength and NDE technique using the resonance frequency by impact hammer and force transducer mode for Korean paulownia, Pinus densiflora, Lidiodendron tulipifera and Betula costata were measured. The heat treatment temperature has been investigated at $175^{\circ}C$ and $200^{\circ}C$, respectively. There were a close relationship of dynamic modulus of elasticity and static bending modulus of elasticity to MOR. In all conditions, It was found that there were a high correlation at 1% level between dynamic modulus of elasticity and MOR, and static modulus of elasticity and MOR. However, the result indicated that correlation coefficient is higher in dynamic modulus of elasticity to MOR than that in static modulus of elasticity to MOR. Therefore, the dynamic modulus of elasticity using resonance frequency by impact hammer mode is more useful as a nondestructive evaluation method for predicting the MOR of heat-treated wood under different temperature and species conditions.

• Proceedings of the Korean Nuclear Society Conference
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• 2005.05a
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• pp.119-120
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• 2005

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.314-324
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• 1996

A high speed NMR quality evaluation sensor was designed , constructed and tested . The device consists of an NMR spectrometer coupled to a conveyor system. The conveyor was run at speeds ranging from 0 to 250 mm/s. Spectral of avocado fruits and one-dimensional magnetic resonance images of pickled olives were acquired while the samples were moving on a conveyor belt mounted through a 20Tesla NMR magnet with a 20 mm diameter surface coil and a 150 mm diameter imaging coil respectively. Fro a magnetic resonance spectrum analysis, motion through variations in the magnetic field tends to narrow spectral line width just like using sample rotation in high resolution NMR to narrow spectral line width. Spectrum analysis was used to detect the dry weight of avocado fruits using the ratio oil and water resonance peaks. Good correlations maximum r=0.970@ 50 mm/s and minimum r=0.894@250mm/s ) between oil and water resonance peak ratio and dry weight of avocados were observed at speeds ra ging from0 to 250mm/s. For the application of magnetic resonance imaging (MRI) method, the projections were used to distinguish between pitted and non-pitted olives . Effect of fruit position in the coil was tested and coil degree effects were noticed when projects were generated under dynamic conditions. Various belt speeds (up to 250mm/s) were tested and detection results were compared to static measurements. Higher classification errors were occurred at dynamic conditions compared to errors while olives were at rest.