• 한국정밀공학회지
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• 제17권6호
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• pp.210-217
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• 2000

Noncontact measuring methodology of 3-dimensional profile using CCD camera are very attractive because of it's high measuring speed and it's high sensitivity. Especially when projecting a grid pattern over the object, the captured image have 3 dimensional information of the object. Projection moire extract 3-D information with another grid pattern in front of CCD camera. However phase measuring profilometry(PMP) obtain similar results without additional grid pattern. In this paper, the projection moire are compared with the PMP mathematically, and it is shown that PMP can generate moire image with simple mathematical computations. Experimental works are also carried out showing the same results. It is shown that using a single gird pattern, moire image can be obtained directly without any mathematical operation when some conditions are satisfied.

• 한국안전학회지
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• 제7권4호
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• pp.23-32
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• 1992

Surface treatment and chemiluminescence characteristics of the polymer film. It was studied that the Intensities and rates of treatments are in proportional to condition of the treatment, considering the results of study on treatments to polymer film with discharge and ultraviolet irradiation through the methods such as surface resistance, contact angle, dyeing method, solace ten-sion and so on. It was also studied that the said has a nice correlation with the concerned result studied by chemiluminescence. Since the chemiluminescence will enable the Investigators to grasp a eertain condition caused by quitely slight deterioration with high sensitivity, it can be also used as a way for getting an information regarding the decision for degradation-condition and life-estimating of insulation material basically related to some security matters as well as surface condition of treatments through the above method.

• 미생물학회지
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• 제17권2호
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• pp.49-57
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• 1979

Cadimium ion-resistant microorganism was isolated from the sludge of wastewater. The physiological, morphological and other cultural data showed that this strain belonged to Citrobacter freudii. A clearcut distinction of growth among nutrient broth, typtic soy broth and synthetic medium was demonstrated. The resistant cells showed only slight mutagenic action. During the growth of bacterial population in resting state, the organisms reduced the initial level of resistance to cadmium ions when they were not kept in contact with cadmium ions in bacteral multiplication. And cadmium ion-resistant and cadmium ion-sensitive strain were found to show equal, lower or higher sensitivity to other heave metals.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.215-217
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• 2004

This paper shows the analysis of the inductive power transfer system in conjunction with series resonant converter operating variable high frequency. Of particular interest is the sensitivity of the complete system to variations in operational frequency and parameters. In inductive power transfer system, electrical power is transferred from a primary winding in the form of a coil or track, to one or more isolated pick-up coils that may relative to the primary. The ability to transmit power without contact enables high reliability and easy maintenance that allows inductive power transfer system to be implemented in hostile environments. This technology has found application in many fields such as electric vehicles, PRT(Personal Rapid Transit) etc. The coupling between the primary and secondary is then presented to include the effects of parameter and operational frequency variation.

• International Journal of Precision Engineering and Manufacturing
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• 제4권1호
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• pp.30-36
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• 2003

Brittle materials such as glasses and ceramics, which are very weak under impact loading, show fragile failure mode due to their low fracture toughness and crack sensitivity. When brittle materials are subjected to impact by small spheres, high contact pressure occurs at the impacted surface causing local damage on the specimen. This damage is a dangerous factor in causing the final fracture of structures. In this research, the crack propagation process of soda-lime glass by the impact of small spheres is explained and the effects of several constraint conditions for impact damage were studied by using soda-lime glass; that is, the effects for the materials and sizes of impact ball, thickness of specimen and residual strength were evaluated. Especially, this research has focused on the damage behavior of ring cracks, cone cracks and several other kinds of cracks.

• 한국농공학회지
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• 제39권4호
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• pp.82-89
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• 1997

A physically-based soil-water erosion model with simple hydrology and Rose & Hairsine's erosion concept is described, and was implemented in the form of computer program. The model derived from the concept of stream power(Bagnold, 1977) considers settling velocity characteristics of the soil and distinguishes between the processes of entrainment and re-entrainment. It deals separately with rill flow and sheet flow, handles vegetation in terms of soil contact cover, and has the ability to simulate soil movement on nonuniform slopes. The model predicted sediment concentrations reasonably with the results of Mclsaac et al. (1990). It showed a capability to quantitatively predict the movement of soil on uniform and nonuniform slopes. Among the model parameters, soil depositability $({\phi})$ was the most sensitive from the sensitivity analysis.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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• pp.265-266
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• 2006

It was well known that thermopile was quiet a competent sensor using to probe the temperature of "hot point" where the temperature can be off the temperature-limitation for normal operation of the main electrical power equipment. In the present work, we aimed for developing new Ge-thermopile materials which can be using a non-contact temperature sensors at various hot-point of the power equipment and evaluation of its output property. As a results of the present works, a new thermopile which were composed Ga-poded p-type and Sb-doped n-type in Ge-semiconductor were designed and manufactured by MBE(Molecular Beam Epitaxy) process and showed superior sensitivity at room temperature.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 D
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• pp.2167-2169
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• 2004

The main concern for a displacement measurement is the performance of a sensor such as speed, resolution, accuracy and so on. The mainly used sensors are a linear CCD(charge coupled device) and a PSD(position sensitive detection) as a non-contact type. The output value of a linear CCD is so sensitive to a temperature change that it needs a cooling device. Additionally, because of its structural problem, there are some limits in resolution and speed, and it needs a complex image processing algorithm. Also, PSD has some disadvantages like sensitivity to environmental lights and nonlinearities. Like this, a linear CCD and PSD have their own characteristics and if we know them well, we can choose the one of the two sensors properly in some applications according to purposes. In this paper, I performed which one is superior to the other among the two sensors in terms of accuracy, resolution, measurement speed, signal to noise ratio.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 추계학술발표대회 논문집
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• pp.268-271
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• 2004

Non-contact technique should be developed for receiving ultrasonic wave for on-line monitoring of processing defects of fiber reinforced composites, since couplant must be applied on composite materials when conventional ultrasonic testing technique was used. Restriction of conventional ultrasonic testing technique was proven by transmitting and receiving ultrasonic wave on CFRP in various direction of wave propagation with various incident angle of ultrasonic beam. Air-coupled transducer and laser interferometer were applied for non-contacting reception of ultrasonic wave in fiber reinforced composite materials. Air-coupled transducer has optimal sensitivity and frequency band of 300kHz has homogeneous characteristics on direction of wave propagation.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.140-143
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• 2001

Digital shearography, a speckle pattern method is based on the superposition of two laterally sheared images. Therefore, object points which are positioned in some distance from each other are superposed in the image plane. This shearography, one of NDT methods without contact, is able to inspect defects in pipelines and pressure vessels that are used in nuclear power plants. This is can inspect whole fields and has a low sensitivity to environmental noise. Because optical setting is very simple, it has a little exhaustion of time, cost and man power. And also it can find a defect position through real time monitoring of a part. This paper, finds out the relationship among shearing quantity image quality and defect size with this method.