• Journal of the Korean Society of Clothing and Textiles
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• v.26 no.2
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• pp.263-269
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• 2002

This research was conducted to establish the efficient use of the colored rice bran fur dyeing textiles. To investigate the fabric dyeability of the colored rice bran extract, the anthocyanin pigments were extracted with water of different temperature ranges of 40 ~ 8$0^{\circ}C$ and were dyed on silk fabrics with different dyeing temperature $25^{\circ}C$~6$0^{\circ}C$, at acidic pH and neutral pH, respectively. Aluminum chloride was preheated with mordant K/S value and dyeing fastness of dyed silk fabrics were examined. The anthocyanins of the colored rice bran were stable and red color at acidic pH, red purple or purple blue at neutral pH, but unstable, blue color at alkaline pH. If extracting temperature and dyeing temperature of dyeing solution were higher, the dyeability was high, but the color of dyed fabric showed red tone. When extracting temperature was 8$0^{\circ}C$ and dyeing temperature of dyeing solution was 6$0^{\circ}C$, the dyeability was best. Without mordant, the dyeability of silk fabrics was higher in acidic pH than in neutral pH solution. With mordant, the dyeability was higher than without mordant, and also higher in acidic pH. Pretreatment of aluminum chloride resulted in the increase of color intensity and stability. The laundering fastness of dyed fabrics was good from grade 5 to grade 3-4. Because of the anthocyanins sensitivity on light radiation, the light fastness of dyed fabrics was poor from grade 3 to grade 1-2.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.227-232
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• 2003

Non-intrusive methods based on active remote IR illumination for eye tracking is important for many applications of vision-based man-machine interaction. One problem that has plagued those methods is their sensitivity to lighting condition change. This tends to significantly limit their scope of application. In this paper, we present a new real-time eye detection and tracking methodology that works under variable and realistic lighting conditions. eased on combining the bright-pupil effect resulted from IR light and the conventional appearance-based object recognition technique, our method can robustly track eyes when the pupils are not very bright due to significant external illumination interferences. The appearance model is incorporated in both eyes detection and tracking via the use of support vector machine and the mean shift tracking. Additional improvement is achieved from modifying the image acquisition apparatus including the illuminator and the camera.

• Current Optics and Photonics
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• v.1 no.4
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• pp.284-288
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• 2017

In order to investigate the ultraviolet-excited photoluminescence properties of phosphor coatings and their relationship to thickness, Lumogen coatings with different thicknesses were deposited on quartz substrates and charge-coupled device chips by thermal evaporation. The variation of the film thickness affected the crystallite size, surface roughness and fluorescence signal. It was found that the Lumogen coating with the thickness of 420 nm has the largest luminescent signal and conversion efficiency, and the corresponding coated charge-coupled devices had the maximum quantum efficiency in the ultraviolet. These results provided one key parameter for improving the sensitivity of Lumogen coated charge-coupled devices to ultraviolet light.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.04a
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• pp.78-80
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• 2006

The hybrid thin-film (HTF) passivation layer composed of the Ultra Violet (UV) curable acrylate layer and MS-31 (MgO:$SiO_2$=3:1wt%) layer was adopted in organic light emitting device (OLEO) to protect organic light emitting materials from penetrations of oxygen and water vapors. The results showed that the HTF layer possessed a very low WVTR value of lower than $0.007gm/m^{2+}day$ at $37.8^{\circ}C$ and 100% RH. This value was within the limited range of the sensitivity of WVTR measurements. And the lifetime of the HTF passivated device became almost three times longer than that of the bare device. The HTF on the OLEO was found to be very effective in protect what from the penetrations of oxygen and moisture.

• Korean Journal of Optics and Photonics
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• v.1 no.2
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• pp.198-203
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• 1990

In this paper, a system has been proposed for the measurement of the spectral characteristic of semiconductor light sources driven by very short pulse currents. This system has been constituted a monochrometer of 600 groovedmm grating and of 275 mm focal length, X-Y recorder, scanning motor which enables the system to get the analog data, and amplifier coupled with peak detector. Especially, peak detector was used to convert the short pulse signal to continuous one. In order to verify the resolution with slit width, several slits were made by the hands. By using this system, the spectra of commercial LEDs, AlGaAdGaAs LD, and InGaAsPIInP BH-LD which were driven with pulse current (duty cy$e = 0.01) were measured. From these measurements, it has been shown that the proposed system has about 1 A1$\AA$ resolution and 10$\mu$W sensitivity.

• Journal of Korean Society of Transportation
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• v.27 no.5
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• pp.113-124
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• 2009

This paper suggests a new approach for providing information for driver safety at signalized intersections. Particularly dangerous situations at signalized intersections such as red-light violations, accelerating through yellow intervals, red-light running, and stopping abruptly due to the dilemma zone problem are considered in this study. This paper presents the development of a dangerous vehicle determination algorithm by collecting real-time vehicle speeds and times from multiple point detectors when the vehicles are traveling during phase-change. For an evaluation of this algorithm, VISSIM is used to perform a real-time multiple detection situation by changing the input data such as various inflow-volume, design speed change, driver perception, and response time. As a result the correct-classification rate is approximately 98.5% and the prediction rate of the algorithm is approximately 88.5%. This paper shows the sensitivity results by changing the input data. This result showed that the new approach can be used to improve safety for signalized intersections.

• Journal of the Korean Society of Tobacco Science
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• v.16 no.1
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• pp.26-33
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• 1994

A tobacco ripeness grading meter was designed and constructed using the color sensor, its performance was evaluated. A degree of ripeness grading of a leaf is very closely related to the measured tobacco leaf color. Measuring the small amount of the reflectance precisely depends on the apparatus including color sensor, light source, detector sensitivity, and geometric characteristics of appratus. To analyze and minimize the variational effects, experiments to select the proper condition were performed. Because of the combined effect mentioned above, the system has some variation on its response. Basis on the results of the experiments, prototype was developed and interfaced to a computer system. The main components of prototype included a tungsten lamp as a light source, Amorphous full color sensor with three filters, regulated D.C. power supply, OP - AMP(741 TC) for amplification, AR - B3001 board for interfacing to a computer with analog to digital conversion, and a compatible IBM PC XT computer. The experimental results of the developed ripeness tobacco leaf measurement system are summarized as following: [1] The output readings of ripeness grade meter for tobacco leaf, which is based on harvesting time, showed the apparent difference in variety of different quality. It was considered suitable that three filters(red, green, blue) in Amorphous full color sensor could be used in four different ripeness degree measurement of tobacco leaf. [2] The output readings of ripeness grade meter for tobacco leaf, which is based on government procurement, showed apparent difference in variety of different quality. Tobacco leaf varieties to stalk position are divided into tips, leaf, cutters, and primings, It is considered suitable that only red filter in the sensor could be used to classify the grade of tobacco leaf within the same kind tobacco stalk. However, the ripeness grade meter was not adequate to classify all the tobacco grades in the four different tobacco leaves.

• Nuclear Engineering and Technology
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• v.56 no.1
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• pp.195-206
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• 2024

Shenzhen Innovation Light source Facility (SILF) is a 3.0 GeV fourth generation diffraction limited synchrotron light source currently under construction in Shenzhen. The SILF storage ring is proposed to use two 500 MHz single cell superconducting radio frequency (SRF) cavities to provide 2.4 MV RF voltage. In this study, we examined the geometric structure of mature CESR superconducting cavities and adopted a beam-pipe-type extraction scheme for high-order modes (HOM). One of the objectives of SRF cavity design and optimization in this study is to reduce E_p/E_acc and B_p/E_acc as much as possible to reduce power loss and ensure stable operation of the cavity. To reduce the risk of beam instability and thermal breakdown, the HOM and Multipacting (MP) are simulated. Moreover, the mechanical properties of the cavity are analyzed, including frequency sensitivity from pressure of liquid helium (LHe), stress, tuning, Lorentz force detuning (LFD), the microphone effect, and buckling. By comprehensive design and optimization of 500 MHz single-cell SRF cavities, a superconducting cavity for SILF storage ring was developed. This paper will detailed present the design and simulation.

• Progress in Medical Physics
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• v.21 no.1
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• pp.93-98
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• 2010

The aim of this work was to establish the methodology for event positioning by measuring depth of interaction (DOI) information and to evaluate the system sensitivity and spatial resolution of the new detector for I-125 and Tc-99m imaging. For this purpose, a Monte Carlo simulation tool, DETECT2000 and GATE were used to model the energy deposition and light distribution in the detector and to validate this approach. Our proposed detector module consists of a monolithic CsI(Tl) crystal with dimensions of $50.0{\times}50.0{\times}3.0\;mm^3$. The results of simulation demonstrated that the resolution is less than 1.5 mm for both I-125 and Tc-99m. The main advantage of the proposed detector module is that by using 3 mm thick CsI(Tl) with maximum-likelihood position-estimation (MLPE) method, high resolution I-125 imaging and high sensitivity Tc-99m imaging are possible. In this paper, we proved that our new detector to be a reliable design as a detector for a multi-energy SPECT.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.2
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• pp.161-167
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• 2010

Purpose: The aim of this study was to help the rapid and effective eye-tests of old patients by developing an optometric questionnaire for the elderly suitable for optical shops in Korea. Methods: We surveyed several previous studies about the age-related changes of the eye, and deduced 10 items which were appropriate for optometric eye-tests. Excluding the items that could be easily found in a routine eye-test and that was just physiological changes, we principally chose anomaly items which could be catched by simple oral questions. The questionnaire was mainly composed of clinically important items that were frequently observed. Results: To diagnose optometric symptoms related to eye-aging, we listed 15 questions on the questionnaire for the elderly. Each of the 15 questions was respectively about the decline in the amplitude of accommodation (no.1), anisometropia (no.2), xerophthalmia (no.3), muscae volitantes (no.4-5), dark adaptation (no.6) light and dark adaptation (no.7), contrast sensitivity (no.8), contrast sensitivity and anisometropia (no.9), contrast sensitivity and colour vision (no.10), the field of view (no.11), stereoscopic vision (no.12), colour vision (no.13), cataract (no.14), and presbyopia (no.15). Each question was easy to understand and related to the generally observed symptoms. Conclusions: Our optometric questionnaire for the elderly, which was developed by the procedure mentioned above, was expected to be a help for examining the aging eye and offer the basis of eye-tests of older patients in Korean optical shops.