• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.04a
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• pp.255-259
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• 2003

Moire topography method isa well-known non-contacting 3-D measurement method as afast non-contact test for three-dimension shape measuring method. Recently, it's important to study the automatic three-dimension measurement by moire topography because it is frequently applied to the reverse engineering , the medical , the entertainment fields. Three-dimension measurement using projection of moire topography is very attractive because of its high measuring speed and high sensitivity. In this paper, the classical moire method is computerized-so called digital moire when a virtual grating pattern is projected on a surface, the captured image by the CCD camera has three-dimension information of the objects. The moire image can be obtained through a simple image processing and a reference grating pattern. and it provides similar results without physical grating pattern. digital projection moire topography turn out to be very effective for the three-dimension measurement of objects. Using different N-bucket algorithm method of digital projection moire topography is tested to measuring object with the 2-ambiguity problem. Experimental results prove that the proposed scheme is capable of finding measurement errors that decreased more by using the four-three step algorithm method instead of the same step in the phase shifting of different pitch.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.3
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• pp.195-203
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• 2002

In the engine room and the aft part areas of the ship, there exist so many tank structures contacting with fresh water or sea water or oil. If these structures exhibit excessive vibrations during the sea trials, it takes a lot of cost, time and effort to improve vibration situation because the reinforcement work requires emptying the fluid out of the tanks, additional welding and special painting. It is therefore very important to predict a precise vibration characteristics of the tank structures at the design stage, however it is not easy to estimate vibration characteristics of the structures because of difficulties for accurate evaluation of the added (or virtual) mass effect due to the fluid inside the tank. In this paper, numerical and experimental approaches have been performed to present same fundamental data necessary for anti-vibration design of tank structures contacting with fluid, by investigating vibration behaviors of rectangular tank structure for various water depths.

• Journal of the Korean Society for Railway
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• v.14 no.5
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• pp.398-403
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• 2011

When a crack exists under a residual stress, for example in welds, the crack can be closed and it shows non symmetric behavior for tension and compression. Ultrasonic detection method for those nonlinear cracks has been developed recently. The method uses the higher order harmonics generating at the crack surface. In this study, parameter study was carried out for the analysis of the harmonics generation at a nonlinear contact interface as a preliminary study for general 3-dimensional cracks. One-dimensional problem with simple bilinear behavior for the contacting surface was considered. The amplitude of second harmonic to the fundamental wave was obtained for various stiffness ratios, incident frequencies, and the contacting layer thicknesses.

• Journal of the Society of Naval Architects of Korea
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• v.47 no.2
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• pp.242-247
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• 2010

To consider effects of essential parameters of water impact pressure on dynamic structural responses of bow bottom structures, a parametric study for a ship bottom panel is carried out. The idealized pressure time history models were assumed by triangular and rectangular shapes in time domain. The main loading parameters are duration time and peak pressure value maintaining the same impulse value. The structural models for local bottom stiffened panels of a container ship are analysed. The natural frequency analysis and transient dynamic response analysis are performed using MSC/NASTRAN. Added mass effects of contacting water are considered and the pressure distributions are assumed to be uniform in the whole water contacting surface. The effects of loading parameters on the structural responses, especially maximum displacements, are considered. Besides the peak pressure value, effects of duration time correlated with natural frequencies are thought to be the important parameters.

• Tribology and Lubricants
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• v.19 no.1
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• pp.26-30
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• 2003

The stresses of surface and substrate under the rough surface contact are irregular. Using rainflow counting method for irregular stresses, the fatigue surface crack initiation lift was calculated. With the surface generated by computer, this paper figures out the random load generated by contacting to the rough surface, analyzes the stress of its subsurface, and calculates the fatigue crack initiation life of the rough surface fatigue theory.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.3
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• pp.93-104
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• 1997

Steady-state I-V characteristics of a resonant tunneling diode (RTD) is calculated by numerical analysis using quantum liouville equation based on wigner function which is derived from density operator. Modifications to the conventional discrete model are made to calculate more accurate quantum correlations. It is pointed out that we must include inelastic processes and the resistivity of the contacting layers to get a much more credible potential which can be theoretically obtained from the simple screening theory. The effects of spatially-varying effective mass is also checked briefly.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.701-707
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• 2000

In this work, we propose to employ magnetostrictive sensors to develop a new non-contacting modal testing method. Specific applications are made in the modal testing of a beam in bending. The role of bias magnetic fields in measuring bending waves is addressed and an approximate analysis to explain the principle to measure bending signals is carried out. The measured modal data by the present method agree well with those by conventional methods using accelerometers.

• Journal of the Korean Society for Library and Information Science
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• v.38 no.1
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• pp.51-75
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• 2004

The purpose of this study is to analyze the performance of contracting out public libraries. in order to contribute to the promotion of their effective operation in Korea. Three public libraries which are currently operated by 'contracting out' are selected to be reviewed for this study. Their performance are analyzed by means of literature search, questionnaires, and on-the-spot-survey. Investigated in detail are the following issues: First, the need for and background of 'contracting out' public library services, and their present state in Korea: Second. the pros and cons of 'contracting out' public library services; Third, the outcomes of public library services which have been currently contracted out. Finally, based on the aforementioned findings, a future model of 'contracting out' public library services is proposed, Also suggested are the strategies for furthering the effective management of public libraries.

• Journal of Technologic Dentistry
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• v.30 no.2
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• pp.71-77
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• 2008

Acrylic resin has been widely used for dental care since it requires relatively simple equipment for treatment and less time and cost are needed to make it and, furthermore, proper strength, dimensional stability as well as durability are ensured after treatment. A survey of denture users showed, however, that more than 60% of dentures installed need repair each year, $22{\sim}30%$ of which are due to falling out of teeth. This study is aimed at exploring the means to increase bonding strength of denture by reducing the causes for falling out of teeth during the processing of dentures. For this aim, the bonding strength of dentures was compares and analyzed before and after the glazed surface of teeth contacting denture was eliminated. From the analysis, it was revealed that there was a difference of 4.3MPa in average in bonding strength between 20MPa for the glazed surface not eliminated and 24.3MPa for the glazed surface eliminated.

• Journal of the Korean Home Economics Association
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• v.28 no.2
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• pp.91-106
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• 1990

This study focuses on consumers' advertising discriminatory competencies and the influencing facors. So the objects of this study are as follows : 1) to identify the overall level of advertising discriminatory competencies. 2) to examine if consumer attitude variables have significant effects on the ads. discriminatory competenceis. 3) to examine if the frequencies of contacting advertising variable have significant effects on the ads. discriminatory competencies. 4) to examine if socio-economics variables-age, educational level, monthly family income, occupational status-have significant effects on the ads. discriminatory competencies. 5) to find out the independent influence of variables related to the ads. discriminatory competencies. For this purpose, a survey was conducted using questionaires and advertisement papers. The data used in this study included 194 Homemakers living in Seoul. The ads. used in this study included ads. of diary products like foods, drinks, medicine, cosmetic, detergent in TV, radio, newspaper and magagine. Statistics were Frequency Distribution, Mean, percentile, ANOVA, Scheff -test, Pearsons' Correlation, Multiple Regrassion Analysis. Major findings were as follows : First, in 26 items(70%) of 37 items measured consumers' ads. discriminatory competencies, the rate of right answer was below 50%, so over the half of consumers were misleaded by the deceptive ads. Second, consumers' ads. discriminatory competencies differed significantly according to consumer attitude variables but no according to the frequency of contacting advertising. Third, according to socio-demographic variables-age, educational level, monthly family income, occupational status-advertising discriminatory competencies differed significantly. In group of lower age, higher educational level, higher income and professional occupation status, the level of ads. discriminatory competencies were high. Forth, the most influencing variabel on ads. disciriminatory competencies were eudcational level and in turn general attitude toward ads., attitude toward consumerism. This three variables explain 22.9% of dependent variable's variance. From these findings, the following suggestions are made, First, the consumer education offering informations and learing practical ads. discriminatory competencies should be conducted for all consumers wheather they are educated or not. Also the education to improve the consumer attitude must be. Second, considering misleading level, the business must make the regulatory standards and reinforce the regulation voluntarily, and by enforcing the regulation of ads. and deciding more diverse, objective and exact standards, the government should keep the consumer's right to know.