• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1343-1347
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• 2006

Non-contact modal testing for longitudinal modes of a pipe is discussed in this work. The suggested method can generate and measure longitudinal vibrations without mechanical contact by using the coupling phenomenon between deformation and magnetic field, known as the magnetostrictive effect. This effect has been used to generate and measure ultrasonic waves, but seldom used to deal with audible vibrations. In this investigation, the validity of the developed method in a typical vibration frequency range is checked with an inconel pipe being used in nuclear power plants.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.4
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• pp.592-597
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• 2015

3D-IC is a novel semiconductor packaging technique stacking dies to improve the performance as well as the overall size. TSV is ideal for 3D-IC because it is convenient for stacking and excellent in electrical characteristics. However, due to high-density and micro-size of TSVs, they should be tested with a non-invasive manner. Thus, we introduce a TSV test method on test prober without a direct contact in this paper. A capacitive coupling effect between a probe tip and TSV is used to discriminate small TSV faults like voids and pin-holes. Through EM simulation, we can verify the size of eye-patterns with various frequencies is good for TSV test tools and non-contact test will be promising.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.511-513
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• 2005

In this paper, the electrical characteristics of the non-contact transformer is presented using conventional coupled inductor theory. In high power applications, the non-contact transformer is so bulky and heavy that it poses some maintenance problems. Therefore it should be divided into some light transformer modules. This paper shows the analytic method of how to measure the parameters of the multiple connected non-contact transformer The analytical results are verified through measurement.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.540-543
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• 2003

This paper presents design and manufacture of RF type non-contact radiological dosage measuring device. It also concerns on the broad out-line and the ways of improvement about RF type non-contact radiation measuring device. Measuring radiological dosage with non-contact RF, the stability and efficiency of the measure have been improved by reforming constant current circuit. Furthermore, applying communication protocol in process makes it possible to achieve faster and more accurate communication than old circuit. On the base of those, RF type non-contact radiological dosage measuring device which consists of radiological dosage measuring module and Reader module has been designed and manufactured. While testing communication against embodied device, the possibility of the field application could be confirmed.

• Journal of Information Processing Systems
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• v.17 no.3
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• pp.505-517
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• 2021

This research presented an implementation of autostereoscopic virtual three-dimensional (3D) button device as non-contact style. The proposed device has several characteristics about visible feature, non-contact use and artificial intelligence (AI) engine. The device was designed to be contactless to prevent virus contamination and consists of 3D buttons in a virtual stereoscopic view. To specify the button pressed virtually by fingertip pointing, a simple deep learning network having two stages without convolution filters was designed. As confirmed in the experiment, if the input data composition is clearly designed, the deep learning network does not need to be configured so complexly. As the results of testing and evaluation by the certification institute, the proposed button device shows high reliability and stability.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.08a
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• pp.293-300
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• 1999

A mathematical model for the analysis of roll gap phenomena in strip temper rolling process is described. The mechanical peculiarities of temper rolling process, such as high friction value and non-circular contact arc, low reduction and non-negligible entry and exit elastic zones as well as central restricted deformation (preliminary displacement or sticking) zone etc., are all taken into account. The deformation of work rolls is calculated with the influence function method and arbitrary contact arc shape is permitted. The strip deformation is modeled by slab method and the entry and exit elastic deformation zones are included. The restricted deformation zone near the neutral point is also considered. The concept and the calculation method of limiting preliminary displacement are used to determine the length of the central restricted deformation zone. The comparison of the model results with the measured mill data is also made.

• Nuclear Engineering and Technology
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• v.33 no.6
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• pp.585-595
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• 2001

A series of experiments have been carried out to investigate the effects of non-condensable gas on the direct contact film condensation of vapor mixture under an adiabatic wall condition. The average heat transfer coefficient of the direct contact condensation was obtained at the atmospheric pressure with four main parameters ; air-mass fraction, mixture velocity, film Reynolds number, and the degree of water film subcooling having an influence on the condensation heat transfer coefficient. With the analysis of 88 experiments, a correlation of the average Nusselt number for direct contact film condensation of steam/air mixture at an adiabatic vertical wall was proposed as functions of film Reynolds number, mixture Reynolds number, air mass fraction, and Jacob number. The average heat transfer coefficient for steam/air mixture condensation decreased significantly while air mass fraction increased. The average heat transfer coefficients also decreased as the Jacob number increased, and were scarcely affected by the film Reynolds number below a mixture Reynolds number of about 245,000.

• Communications of the Korean Mathematical Society
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• v.27 no.2
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• pp.327-339
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• 2012

In this paper we study $h$-projectively semisymmetric, ${\phi}$-pro-jectively semisymmetric, $h$-Weyl semisymmetric and ${\phi}$-Weyl semisym- metric non-Sasakian ($k$, ${\mu}$)-contact metric manifolds. In all the cases the manifold becomes an ${\eta}$-Einstein manifold. As a consequence of these results we obtain that if a 3-dimensional non-Sasakian ($k$, ${\mu}$)-contact metric manifold satisfies such curvature conditions, then the manifold reduces to an N($k$)-contact metric manifold.

• Structural Engineering and Mechanics
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• v.23 no.4
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• pp.431-447
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• 2006

A new incremental finite element model is developed to simulate the frictional contact of elastic bodies. The incremental convex programming method is exploited, in the framework of finite element approach, to recast the variational inequality principle of contact problem in a discretized form. The non-classical friction model of Oden and Pires is adopted, however, the friction effect is represented by an equivalent non-linear stiffness rather than additional constraints. Different parametric studies are worked out to address the versatility of the proposed model.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.1
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• pp.67-74
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• 2000

One of the important application of a contact melting process is a latent thermal energy storage owing to its high heat flux. In some previous works, the split fins have been employed in order to enhance the melting speed. In the present work, the close contact melting was experimentally investigated using an ice as specimen for both split and non-split fins. It was shown that the contact melting by split fins increases the melting rate compared to that of non-split ones.