• Journal of the Mineralogical Society of Korea
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• v.11 no.1
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• pp.13-19
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• 1998

Textures of claystones of the Cheonunsan Formation in the Hwasoon area have been studied using optical microscope and electron microprobe. Microscopic images were observed under the optical microscope using the transmitted polarizing light from thin sections and under the electron microprobe using the back-scattered electron beam from the polished sections. Identification of minerals were made using X-ray diffraction analysis and chemical analysis by electon microprobe. Textural analyses show that the original sedimentary claystones rich in aluminium were subjected to metamorphism by which they changed to the metamorphosed claystone consisting mainly of chloritoid, quartz, andalusite and illite. Later intensive hydrothermal kaolinization of this metamorhosed claystones resulted in the formation of high-aluminous claystones rich in kaolinite exhibiting various complicated replacement textures.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1118-1120
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• 2003

In MSC(Multi-spectral camera ), the incoming light is converted to electronic analog signals by the CCD(charge coupled device) detectors. The analog signals are amplified, biased and converted into digital signals (pixel data stream) in the FPE(Focal plane electronics ). The digital data is transmitted to the PMU for pre-processing to correct for nonuniformity, to partially reorder the pixel stream and to add header data for identification and synchronization In this paper, the video data streams is described in terms of hardware.

• Journal of Magnetics
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• v.12 no.2
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• pp.77-80
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• 2007

Recently there was a proposal for a spin filter by using the spin superlattice structure. In a certain energy range, the proposed structure exhibits a high spin filtering efficiency close to 100%. Unfortunately such energy range turns out to be narrow. In this paper, we report a method to widen the energy range by using an analogy to optical anti-reflection coating. In optics, it is well known that a stack of alternating layers of two dielectric materials can function as a highly transmissive or reflective filter for wide range of wavelength. Since electrons also have wave character as light, it would be possible to make an electronic analog of an optical filter. We demonstrate that alternating layers of two materials with different g-factors can function as a spin filter that allows electrons to be transmitted only when their spins point towards a certain particular direction. This spin-superlattice-based spin filter operates in wide energy ranges, curing the problem in the previous proposal.

• Journal of the Korean Society of Radiology
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• v.13 no.6
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• pp.831-840
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• 2019

The X-ray detector by liquid crystal with front light was proposed and verified by a X-ray image. The proposed detector utilizes the visible light instead of the electric signal by transistor. Therefore, it shows low noise and can be fabricated at low cost. The liquid crystal detector uses the orientation change of the liquid crystal molecule by conductivity change of the photoconductive layer. We can get the X-ray image from the transmitted light through the liquid crystal. The X-ray dose was calibrated from the measured transmittance of the visible light after comparison to the reference transmittance curve of the liquid crystal. The amorphous Se was used for photo con ducting layer and parylene was used for the liquid crystal alignment instead of the conventional alignment layer which needs high-temperature process over 200℃. The proposed X-ray detector can decrease the X-ray dose by high sensitivity which was verified by simulation. After the fabrication of the X-ray detector, the X-ray image was obtained as a function of the bias voltage to the liquid crystal. 10 lines/mm resolution was obtained from the line pattern and we will apply it to the 17inch diagonal liquid crystal X-ray detector with 3π retardation.

• The korean journal of orthodontics
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• v.24 no.4 s.47
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• pp.969-982
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• 1994

This study was designed to investigate the stress distribution, intensity and force mechanism derived from the MEAW by photoelastic stress analysis of the artificial teeth and surrounding bone composed of photoelastic material(PL-3) The findings of this study were as follows, 1. In case of no elastic on the MEAW with tip back, the moderate stress was observed on the molar and canine area, and the light stress was observed on the other area. 2. In case of the vertical elastic on the plain A.W, and the MEAW without tip back, the great stress was observed on the lateral incisor area, but on the MEAW with tip back, the moderate stress was observed on the anterior area and molar area. 3. In case of the C III elastic on plain A.W., the stress was concentrated on the anterior area hanged by elastic but on the MEAW without tip back, the stress was transmitted equally from the anterior area to the posterior teeth area. On the MEAW with tip back, the great stress was observed on the anterior and molar area. 4. In case of the C III elastic on the plain A.W., the stress was concentrated on the posterior area hanged by elastic but on the MEAW without tip back, the stress was transmitted equally from the posterior area to the anterior area. On the MEAW with tip back, the great stress was observed on the posterior area and the moderate stress was observed on the anterior area.

• Korean Journal of Veterinary Service
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• v.26 no.2
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• pp.135-144
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• 2003

Fowl typhoid is a septicemic disease of turkeys and chickens. The antigen is Salmonella(S) gallinarum, which cross-reacts with S pullorum because of common antigen. The organism is maintained in the ovary of carrier birds and transmitted vertically in the york. It is also transmitted horizontally through feces and broken eggs. The symptoms are weakness, drowsiness, wing drooping, hyperexcitability, paresis and diarrhea. In the many cases, the birds are found dead in the morning before any symptoms have been noticed. this experiment was carried out to investigate the characteristics of S gallanarum and scrutinized about the control systems. 1. Fowl typhoid was came about in the winter than the other seasons. The average of mortality was 46.3%. And it was came about not only adult poultry but also chicks. 2. S gallinarum was isolated from liver and spleen in infected chickens. Total isolated strains were 60. 3. The organisms were all extinct at 60$^{\circ}C$, 30mins. 4. A survival rate was higher in underground water than a secondary distilled water. It was detected in underground water until 30 days. 5. When being exposed to the solar light, it became extinct almost within 24 hours. 6. It was survived in a refrigerator until 12 months. 7. It was extinct among 5 mins in 0.1% phenol and 2% formalin. 8. When the cultured organism fluid was inoculated in SD-rat abdominal cavity, rat died within 24 hours. 9. Pullorum-typhoid related program must disciplines in order to destroy the fowl typhoid, and breeding system must be converted to cage system.

• Smart Structures and Systems
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• v.6 no.5_6
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• pp.749-765
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• 2010

There are on-going efforts to utilize guided waves for structural damage detection. Active sensing devices such as lead zirconate titanate (PZT) have been widely used for guided wave generation and sensing. In addition, there has been increasing interest in adopting wireless sensing to structural health monitoring (SHM) applications. One of major challenges in wireless SHM is to secure power necessary to operate the wireless sensors. However, because active sensing devices demand relatively high electric power compared to conventional passive sensors such as accelerometers and strain gauges, existing battery technologies may not be suitable for long-term operation of the active sensing devices. To tackle this problem, a new wireless power transmission paradigm has been developed in this study. The proposed technique wirelessly transmits power necessary for PZT-based guided wave generation using laser and optoelectronic devices. First, a desired waveform is generated and the intensity of the laser source is modulated accordingly using an electro-optic modulator (EOM). Next, the modulated laser is wirelessly transmitted to a photodiode connected to a PZT. Then, the photodiode converts the transmitted light into an electric signal and excites the PZT to generate guided waves on the structure where the PZT is attached to. Finally, the corresponding response from the sensing PZT is measured. The feasibility of the proposed method for wireless guided wave generation has been experimentally demonstrated.

• Journal of Conservation Science
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• v.26 no.4
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• pp.371-376
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• 2010

The great jar estimated in Proto-Three Kingdoms period was found at the site from Pyeongtaek Daechuri and the bonding traces from pieces destroyed when they were excavated are observed. Therefore this study would figure out the components of bonding material used in great jars by optical microscope, FT-IR, py-GC/MS and the kind of textile attaching to great jar by transmitted light microscope. As a result of optical microscope for the cross-section, black material is uniformly applied between a piece of jar and the part of bonding and the textile line are observed. Black bonding material is resulted in korean rhus lacquer by FT-IR and py-GC/MS and the kind of textile is identified as hemp by transmitted light microscope. Materials for repairing archaeological objects are hardly known causing little information, but this study proves that the bonding material had used lacquer for great jars before Proto-Three Kingdoms period. Therefore if ancient bonding materials are systematically analysed in the further studies, it would be significant help for studying bonding and restoration materials of ancient objects.

• Korean Journal of Dental Materials
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• v.44 no.2
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• pp.151-161
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• 2017

The purpose of this study was to examine the effect of shade and thickness of resin-nanoceramic CAD-CAM block (RNB) on the microhardness of dual-cured resin cement, as well as to measure the number of photons transmitted through RNBs of different thicknesses and colors. One dual-cured resin cement was used to prepare resin cement specimens. Resin cement specimens were light-cured for 40 seconds through 3 shades (A1, A2, A3 in HT (high translucency) and LT (low translucency) respectively) and four thicknesses (1, 2, 3, 4 mm) of RNB specimens. Vickers microhardness measurements of resin cement specimens were performed using a Vickers hardness tester. The light transmission of RNB specimens was measured using a spectrometer (SpectroPro-500, Acton Research, Acton, MA, U.S.A.), and the translucency parameter was calculated using the CIEL*a*b* system. Data were statistically analyzed by ANOVA and Tukey's test. There was a significant decrease of microhardness of resin cement specimen with an overlay of 4 mm of RNB thickness and A3 shade in comparison to A1 and 1 mm, respectively (p<0.05). The translucency parameter values and light transmission of RNBs tested differed significantly, according to the thicknesses of the specimen (p<0.05). Light transmission is decreased with increase in the thicknesses of RNBs. Shade A1 transmitted more light than darker blocks. A decrease in microhardness of resin cement specimens was observed with increasing thickness and shade (A1 to A3) of RNBs.

• Journal of the Korean Society for Nondestructive Testing
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• v.36 no.5
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• pp.399-405
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• 2016

Recently, fiber optic sensors, which have many advantages are being applied in various fields by replacing conventional electric sensors. To transmit the light signals between an interrogator and a sensor head, optical components such as an optical adaptor and optical jumper cords are generally used. When signals are transmitted using an adaptor, the end surface of each jumper cord is faced together. If alien substances exist on the core surface of an optical fiber, those can cause light transmission loss and signal disappearance. For this reason, non-contact fiber jumper cords are developed to overcome the problems that require continual attention. The light transmission performance of non-contact fiber jumper cords are also evaluated. From the test results, conventional fiber jumper cords are unable to transmit the signals over 2 mm cavity between the ends of both cords. Otherwise, non-contact fiber jumper cords can transmit the signals with stability up to the cavity of 7 mm though they have more transmission loss than the conventional ones. Consequently, non-contact fiber jumper cords that have better signal stability than conventional ones in environments are highly recommended in field applications, especially if they play a role as a cable for signal transmission between fiber optic sensors.