• 전자공학회논문지 IE
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• v.43 no.3
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• pp.22-27
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• 2006

This paper presents the control system of high-efficiency automotive 35W metal-halide lamp ballast using the new control method and planar transformer. In this paper, the electronic ballast is designed so that digital control method by microcontroller can be applied to the electronic ballast for the lamp requirement and peripheral environment in order that metal-halide lamp, which has the complicated transient features, is to be applied to the automobile even if it has superior features in brightness, color rendering, light efficiency, and lifespan compared to the conventional halogen lamp. Also, the efficiency increase of the ballast is devised by being varied the switching frequency of Flyback Converter following the battery input voltage of the automobile. Being designed for high-frequency switching transformer of converter in planar form, reduction of loss, weight, overall size are realized and efficient power control in the automobile that had the limited energy and the limited space of battery is devised. The results of the proposed system is verified through various experiment results.

• Journal of Surface Science and Engineering
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• v.47 no.4
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• pp.192-197
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• 2014

Red-emitting nitride phosphors recently attracted considerable attention because of their high thermal stability and high color rendering index properties. For excellent phosphor of white light-emitting-diode, ternary nitride phosphor of $Sr/SmSi_5N_8:Eu^{2+}$ with different $Eu^{2+}$ ion concentration were synthesized by solid state reaction method. In this work, red-emitting nitride $Sr/SmSi_5N_8:Eu^{2+}$ phosphor was successfully synthesized by using multi-step high frequency induction heat treatment. The effects of molar ratio of component and experimental conditions on luminescence property of prepared phosphors have been investigated. The structure and luminescence properties of prepared $Sr/SmSi_5N_8:Eu^{2+}$ phosphors were investigated by XRD and photoluminescence spectroscopy. The excitation spectra of $Sr/SmSi_5N_8:Eu^{2+}$ phosphors indicated broad excitation wavelength range of 300 - 550 nm, namely from UV to visible area with distinct enhanced emission peaks. With an increase of $Eu^{2+}$ ion concentration, the peak position of emission in spectra was red-shifted from 613 to 671 nm. After via multi-step heat treatment, prepared phosphor showed excellent luminescence properties, such as high emission intensity and low thermal quenching, better than commercial phosphor of $Y_3Al_5O_{12}:Ce^{3+}$. Using $Eu_2O_3$ as a raw material for $Eu^{2+}$ dopant with nitrogen gas flowing instead of using commercial EuN chemical for $Sr/SmSi_5N_8:Eu^{2+}$ synthesis is one of characteristic of this work.

• Korean Journal of Remote Sensing
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• v.32 no.6
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• pp.693-701
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• 2016

To make a mosaicked image, we need to estimate the geometric relationship between individual images. For such estimation, we needs tiepoint information. In general, feature-based methods are used to extract tiepoints. However, in the case of textureless images, feature-based methods are hardly applicable. In this paper, we propose a frequency domain matching method for automated mosaicking of textureless images. There are three steps in the proposed method. The first step is to convert color images to grayscale images, remove noise, and extract edges. The second step is to define a Region Of Interest (ROI). The third step is to perform phase correlation between two images and select the point with best correlation as tiepoints. For experiments, we used GOCI image slots and general frame camera images. After the three steps, we produced reliable tiepoints from textureless as well as textured images. We have proved application possibility of the proposed method.

• Journal of Fashion Business
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• v.4 no.4
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• pp.135-151
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• 2000

The porpose of this research is helping product developments and establishment men's marketing strategies. This contents are divided into two parts; the dress shirt's wearing condition and the dress shirt's buying condition. The subjects of the research were male that aged 25-50 and their company is resided in Seoul. The conclusion of this research is summarized as below ; 1. Many consumers have wrong term recognition of dress shirt. Most of men know their dress shirt's sizing designation as casual method(ex, $\cdots$95, 100$\cdots$). Therefore it is happened fitness complains. Dress shirt's wearing frequency for a week is 1-2 days or 5days mostly. A number of dress shirt’s wearing period for one is 6-12 months. Dress shirt‘s wearing frequency fand wearing period varies according to their age, unmarried or married situation, scholarship, occupation. So the manufacturer of men's dress shirt grasps the factor's for their character. 2. The conclusion of dress shirt's buying motivation is need better than impulse buying. If company planning season event, the selling will be improved. Most of men buy their dress shirt by themselves. It means a lot of men are interested in their clothes comparing to old days. And men's favorite purchase place is a department store and agent. when they purchasing, the color and size is very important factor. But dress shirt's sizing designation is not yet established. Therefore the dress shirt's sizing designation is needed as possible.

• Journal of the Korean Chemical Society
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• v.60 no.1
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• pp.28-33
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• 2016

The spiropyran is a typical material having photodegradation properties in the process of photochromism. The spiropyran has been utilized in various applications such as optical switch, optical memories, and biosensor because of its remarkable stability, fast responsive time, stronger color change, and photo-induced controllability. However, the spriropyran is photodegraded by the repetitive optical irradiation. The photodegradation of spiropyran have been investigated by using UV-Visible spectroscopy, nuclear magnetic resonance (NMR), and Raman spectroscopy. Herein, the properties of spiropyran were characterized by using terahertz time-domain spectroscopy (THz-TDS) in the terahertz frequency region. In terahertz region, the measured absorbance of spiropyran was increased due to the photodegradation induced by the repetitive UV irradiation. The absorbance tendency of spiropyran in the terahertz frequency region was compared with that in the visible region, and they were completely opposite to each other.

• Journal of the Institute of Convergence Signal Processing
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• v.7 no.4
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• pp.207-213
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• 2006

This paper presents the design and implementation of a video processor for the device of need TV-OUT function. The designed video processor satisfies the standard conditions of ITU-R(International Telecommunication Union-Radiocommunication) BT.470. Also, in order to apply various digital device, we concentrate upon hardware complexity. ITU-R BT.470 can be classified as NTSC, PAL or SECAM. NTSC and PAL use QAM(Quardarature Amplitude Modulation) to transmit color difference signals and SECAM uses FM(Frequency Modulation). FM must have antic-cloche filter but filter recommended by ITU-R BT.470 is not easy to design due to sharpness of the frequency response. So this paper proposes that the special quality of anti-cloche filter is transformed easy to design and the modulation method is modified to be identical with the result required at standard. The processor can control power consumption by output mode to apply portable digital devices. The proposed processor is experimentally demonstrated with ALTERA FPGA APEX20KE EP20K1000EBC652-3 device and SAMSUNG LCD-TV.

• Korean Journal of Health Psychology
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• v.14 no.2
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• pp.277-292
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• 2009

This study investigated the responses of the autonomic nervous system of individuals with Type D personality during an acute stressful situation. Twenty-three female students of Type D personality and 23 female students with non-Type D personality. Stroop Color-Word Task was used to induce a stressful situation, heart rate variability (HRV) was used to measure the responses of the autonomic nervous system during the baseline, acute stress, recovery periods. To analyze the data, the repeated measures analysis of variance was used to compare the autonomic nervous system of the Type D group to that of the non-Type D group. Regression analysis is used to determine if the Type D scale and stress vulnerability predicted the activities of the autonomic nervous system during the baseline period. The results of this study demonstrated that the Type D group's normalized low frequency (LF norm) and ratio of low frequency to high frequency (LF/HF ratio) were higher than those for the non-Type D group, while its normalized high frequency (HF norm) was lower than that for the non-Type D group in all three periods. There were no statistically significant differences among the three periods in terms of LF norm, HF norm, and LF/HF ratio in the Type D group. The study demonstrated that the total scores of the Type DS-14 and scores of social inhibition and negative affect were independent predictors of LF norm and HF norm during the baseline. The Type D group showed increased activation of the sympathetic nervous system and/or decreased activation of the parasympathetic nervous system. These results support the hypothesis that the Type D personality is vulnerable to the stress. Also, the highly activated sympathetic and/or lowly activated parasympathetic nervous systems, which were observed in the Type D group during the baseline, indicated that the Type D individual is susceptible to psychosomatic disorders.

• Journal of Plant Biotechnology
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• v.6 no.1
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• pp.45-50
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• 2004

Somatic embryos were induced from immature cotyledons and cultured on a MS medium containing 40mg/L 2,4-D. The maximum induction of embryos was obtained from immature cotyledons in a size of 3-4mm, and the highest frequency was obtained in the induction medium at pH 7.0. For embryo development, embryogenic tissues were transferred to a MSM6AC and MSM6 media. Developing embryos were placed at 27$^{\circ}C$with dim light (20$\mu$$molm^{-2}$$s^{-1}$) provided by cool fluorescent tubes (3-D wavelength light is better than standard light). Somatic embryos were clearly developed from globular stage to cotyledonary stages. The color of embryo may be a useful parameter for estimation of embryo quality. When the embryo becomes mature, embryo will be ready for desiccation in order to induce roots and shoots of embryos.

• Korean Journal of Human Ecology
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• v.7 no.1
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• pp.129-138
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• 1998

Recently much attention is paid on the interest in putting Korean traditional clothes into practical use with reviewing a traditional culture. Thus, this study was made of clarifying the difference from sex and group by investigating morderns' consciousness, manner, purchasing and wearing state of Korean traditional dress. - It shows that since about the half of the person inquired doesn't wear the clothes once in a year, its frequency of wearing is very low. - The main reason for not wearing that clothes is due to its uneasiness of wearing. - In purchasing the clothes, color, tinning, quality of the clothes are important in order, and bright and luxurious colors are much favored. - About the half of the inquired possess that clothes, with most of them having about one or two dresses. - In a sort of their possession, man has Jeogori and Baji etc. and woman has only Chima, Jeogori and Sochima, or so. - It shows that while their interest in Korean traditional clothes is high, the interest in its practical wearing point of view is low. - In case of adult, interest in that clothes is relatively high in comparison with other group.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.115-118
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• 2000

Voice conversion technology is essential for TTS systems because the construction of speech database takes much effort. In this paper. male-to-female voice conversion technology in Korean LPC TTS system has been studied. In general. the parameters for voice color conversion are categorized into acoustic and prosodic parameters. This paper adopts LSF(Line Spectral Frequency) for acoustic parameter, pitch period and duration for prosodic parameters. In this paper. Pitch period is shortened by the half, duration is shortened by $25\%, and LSFs are shifted linearly for the voice conversion. And the synthesized speech is post-filtered by a bandpass filter. The proposed algorithm is simpler than other algorithms. for example, VQ and Neural Net based methods. And we don't even need to estimate formant information. The MOS(Mean Opinion Socre) test for naturalness shows 2.25 and for female closeness, 3.2. In conclusion, by using the proposed algorithm. male-to-female voice conversion system can be simply implemented with relatively successful results.