• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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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.

• 전기학회논문지
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• 제64권4호
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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.

• 한국정밀공학회지
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• 제12권4호
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• pp.119-126
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• 1995

This paper presents a non-contact measuring system using one point measuring method to measure surface profiles of dies and clay models for practical use in the field of production engineering. The system has a laser beam probe similar to a measuring probe in a contact measuring system and CCD linear sensor used to detect 300mm measurement range, displacement of measured surfaces, from an origin. There is no mechanical interference between this measuring system and a measured surface in this system. In this measuring system, it was needed 500-600ms including data processing time to measure one point. The experiments showed that the standard deviation was 800 .mu.m and the reproducibility was also 100-210 .mu. m.

• Journal of Power Electronics
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• 제4권1호
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• pp.12-17
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• 2004

In this paper, a practical implementation to reduce leakage flux of a high-frequency inverter based non-contact type power transformer composed of EE-shape ferrite cores is presented for key technology of the next generation medical use X-ray CT scanner system. Design consideration for the unique structure of the non-contact power transformer with 900mm in diameter is also introduced. The complete non-contact transformer is actually arranged by several blocks of the magnetic circuit assembled by using 10 small EE shape cores with 120mm in length. It is experimentally and analytically discussed from a reduced leakage flux viewpoint related to its inductively coupling coefficient. A practical method to lower the leakage flux is described based on effective Copper-Sheet- Treatment placed on EE shape ferrite cores of magnetic circuit.

• 한국정밀공학회지
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• 제14권3호
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• pp.15-20
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• 1997

This paper presents the experimental study of the non-contact temperature measurement for the shadow mask of cathode ray tube using InSb sensor. At present, High resolution of CRT(Cathode Ray Tube) is needed broadly; therefore, the measurement of temperature distribution of shadow mask in CRT during operation is important to analyze the thermal deformation of shadow mask. Most of the studies could not measure the temperature distribution of shadow mask precisely. We studied the temperature dis- tribution of shadow mask using InSb photo sensor for 17" cathode ray tube (CRT). Experiments using ther- mocouple are performed to validate the results of non-contact measurement. The results agree well with those results of non-contact method using InSb sensor.nsor.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.375-378
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• 2002

In this paper, the frequency response separation scheme is proposed for high scanning speed and simple structure of non-contact type of AFM. A self-sensing cantilever is attached on the actuator for detect the atomic force between tip and the media surface. VCM or PZT are used for actuator. This paper presents the method to simplify the actuator structure and the performance of each actuator for non-contact type AFM. Based on the frequency response separation scheme, the only one actuator plays roles 1311owing low frequency surface and modulating self-sensing cantilever tip in contrast with convention non-contact type AFM. 10 ${\mu}{\textrm}{m}$ standard grid sample imaged to verify proposed scheme. This result shows the possibility simplifying the actuator structure and reducing cost of non-contact type AFM.

• 한국생산제조학회지
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• 제23권5호
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• pp.435-442
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• 2014

This paper describes an improved design model that can be used to configure a non-contact pneumatic device to turn a large sheet at the in-line system. For rotational moving in the conveyor system, the conventional method is to turn the system itself. The improved non-contact pick-up system mainly uses 8 pairs of L-shaped latches and 12 swirl type heads. It is positioned above the upward air flow table. This system performs the non-contact gripping and side-edge contact support in the vertical and rotational directions to hold the self-weight of a large flat sheet. A non-contact air head can exert a sufficient gripping ability at 4N lower than the standard working pressure. The side latches support 60% of the lifting force required. Through structural and flow analysis, the working conditions were simultaneously considered in accordance with the deflection and flatness of the glass.

• Journal of Electrical Engineering and Technology
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• 제13권4호
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• pp.1732-1739
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• 2018

With the explosion of digital devices, interaction technologies between human and devices are required more than ever. Especially, hand gesture recognition is advantageous in that it can be easily used. It is divided into the two groups: the contact sensor and the non-contact sensor. Compared with non-contact gesture recognition, the advantage of contact gesture recognition is that it is able to classify gestures that disappear from the sensor's sight. Also, since there is direct contacted with the user, relatively accurate information can be acquired. Electromyography (EMG) and force-sensitive resistors (FSRs) are the typical methods used for contact gesture recognition based on muscle activities. The sensors, however, are generally too sensitive to environmental disturbances such as electrical noises, electromagnetic signals and so on. In this paper, we propose a novel contact gesture recognition method based on Flexible Epidermal Tactile Sensor Array (FETSA) that is used to measure electrical signals according to movements of the wrist. To recognize gestures using FETSA, we extracted feature sets, and the gestures were subsequently classified using the support vector machine. The performance of the proposed gesture recognition method is very promising in comparison with two previous non-contact and contact gesture recognition studies.

• Journal of Welding and Joining
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• 제23권5호
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• pp.37-42
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• 2005

The non-destructive Inspection of the fillet weldment has difficulties due to its geometrical complexity and uneasy access. The surface shear horizontal wave (SH-wave), however, has been successfully applied to the detection of cracks on the surface and sub-surface of the filet weldment heel part. The conventional ultrasonic inspection using the surface SH-wave is usually a contact method using piezoelectric transducer. Thus, it is not suitable for a field application because the reliability and repeatability of inspection are significantly affected by test conditions such as couplant, contact pressure and pre-process. In order to overcome this problem, a non-contact SH-wave inspection method using EMAT is propose. The experimental results with this non-contact method are compared with those with a conventional ultrasonic method in fillet weldment with slit type defects. It is shown that the non-contact inspection technique requires simple procedure and less time in the fillet weldment inspection.

• 한국정밀공학회지
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• 제12권9호
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• pp.52-58
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• 1995

Conventional measurement methods for non-destructive testing(NDT) in nuclear power plants and other industrial plants have been performed as the methods of contact with objects to be inspect, but those methods have been taken relatively much time to be inspected. Holographic interferometry which is a non-contact optical measurement method using a coherent light can overcome these demerit, and also has an advantage that the quantitative measurement of small deformation for large areas can be accomplished at a time with high precision. In this paper the comparisons of the experimental results form holographic interferometry with those from the finite element method(FEM) and the analytical solutions of the elastic equation are discussed.