• The Research Journal of the Costume Culture
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• v.18 no.1
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• pp.118-132
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• 2010

The purpose of this study is to understand factors of risk perception and purchase obstruction by consumer characteristics and purchase experience of clothing in online. The collection of the research materials was progressed by online and offline. Out of 374 usable questionnaires used for examining this study, 278 questionnaires were collected from offline and 107 questionnaires were collected from online. Frequency analysis, factor analysis, reliability analysis, t-test, One-way ANOVA and multiple regression analysis using SPSS WIN 12.0 were conducted. Three factors of perceived risk were extracted: harmonic/image, quality/shopping process, payments. Based on these dimensions, ANOVA was conducted. The results indicated that the more purchasing experience people had, the less the extent of perceived risk they got, and quality/shopping process risk mostly among them. As the factors which obstruct purchasing decision, a security obstruction, a reliability obstruction, a convenient obstruction and an information insufficient obstruction are extracted. Also, the factors have got the result of same aspects as the perceived risk recognized by the Internet shopping experience. Meaningful differences between groups appear at security obstruction, reliability obstruction, and convenient obstruction. Perceived risk almost influenced on purchase obstruction when purchasing clothes in Internet shopping mall. When consumers perceiving harmony/image risk highly make decisions, they usually hesitate or abandon due to reliability obstruction, convenient obstruction. All the factors: including security obstruction, reliability obstruction, convenient obstruction and information insufficient obstruction made consumers perceiving quality/shopping process risk highly obstruct purchase decision.

• Journal of the Korea Society of Computer and Information
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• v.11 no.1 s.39
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• pp.139-145
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• 2006

Feature extraction technique in digital images has many applications such as robot vision, medical diagnostic system, and motion video transmission, etc. There are several methods for extracting features in digital images for example nonlinear gradient, nonlinear laplacian, and entropy convolutional filter. However, conventional convolutional filters are usually not efficient to extract features in an image because image feature formation in eyes is more sensitive to dark regions than to bright regions. A few nonlinear filters using difference between arithmetic mean and harmonic mean in a window for extracting sketch features are described in this paper They have some advantages, for example simple computation, dependence on local intensities and less sensitive to small intensity changes in very dark regions. Experimental results demonstrate more successful features extraction than other conventional filters over a wide variety of intensity variations.

• Korean journal of food and cookery science
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• v.26 no.4
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• pp.347-357
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• 2010

This study was assessed the menu satisfaction and preferences of high school boarding students in Gyeongggido. Data collection was carried out through surveys given to 300 high school boarding students; a total of 274 were usable. Statistical analyses were done using the SAS package program (version 8.2 for Windows). The results of this study are summarized as follows: 54.0% of respondents were freshman and 46.0% were sophomores: and 52.9% of respondents were male and 47.1% were female. According to the results of the menu satisfaction survey, males and females significantly differed on appropriate food temperature, freshness of food, harmonic combination of menu, menu variety, quality of ingredients, appearance of food, and frequency of supplied nutrition information. A significant difference regarding menu satisfaction was also found between grade level. First grade students were more satisfied than second grade students. Moreover, menu preferences were significantly high for omelet-rice, fried rice, pork-on-the-bone soup, deep-fried chicken, fruit salad, spicy chinese cabbage salad kimchi, chinese cabbage kimchi, and all desserts. On the other hand, pumpkin and rice porridge, beef and rice porridge, barley rice, soft tofu stew, soybean paste soup, braised japanese spanish mackerel, and sauteed squash were not significantly preferred. The results showed that high school boarding students' menu preferences differed depending on gender, grade, and boarding period. In conclusion, the results of this study should provide dieticians information for improving menu planning. In addition, foodservice satisfaction of the boarding school students can be improved by continuous menu improvement.

• Journal of the Korean Data and Information Science Society
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• v.21 no.2
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• pp.279-289
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• 2010

In this study, we propose a simple statistical model for determining the admission or discharge of 668 patients with a chief complaint of dyspnea. For this, we use 11 explanatory variables which are chosen to be important by clinical experts among 55 variables. As a modification process, we determine the discharge interval of each variable by the kernel density functions of the admitted and discharged patients. We then choose the optimal model for determining the discharge of patients based on the number of explanatory variables belonging to the corresponding discharge intervals. Since the numbers of the admitted and discharged patients are not balanced, we use, as the criteria for selecting the optimal model, the arithmetic mean of sensitivity and specificity and the harmonic mean of sensitivity and precision. The selected optimal model predicts the discharge if 7 or more explanatory variables belong to the corresponding discharge intervals.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.12
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• pp.2489-2497
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• 1994

This paper presents the development of a 10 W solid-state hybrid power amplifier(SSPA). operating over $7.7\sim8.5GHz$. The fabrication and measurement of this amplifier are performed with 3 sections, such as the front one for high gain, the middle one for driving, and high power one, to minimize the risk of failure and to increase the easiness of development. and then the final amplifier is realized by connecting 3 sections above mentioned, DC bias circuit, and temperature compensation circuit on one housing. Total small signal gain obtained is about $45\pm1dB$, the input and output return losses are 25 and 27 dB respectively. The output power measured at 1 dB gain compression point for 3 frequencies at 7.7, 8.1, and 8.5 GHz are $39.8\sim40.4dBm$, which is about 10 W. and the 3rd-order harmonic powers of 2 tones test are 13.34 dBc at output power 37.5 dBm. These obtained results satisfies the initially required specification. and the realized SSPA can be installed as a subsystem of the microwave transponder for telecommunication.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.2A
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• pp.167-173
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• 2008

In this paper, the flexible narrow bandpass filters (BPFs) with ${\lambda}$g/4 short and ${\lambda}$g/2 open stubs by microstrip line on duroid substrate are suggested. These BPFs with narrow bandwidth show flexible bandwidth with variation of the position of the stubs using the Qe (external quality factor) without changing the impedance value at microwave range. On the other hand, by replacing the series quarter-wavelength connecting lines with the equivalent T-shaped line of bandstop filter(BSF), the compact stub bandpass filter with harmonics suppression can be realized. The BPF with ${\lambda}$g/4 short stubs shows the insertion loss of 2.1 dB and the return loss of 18 dB and BPF with ${\lambda}$g/2 open stubs shows the insertion loss of 1.2 dB and the return loss of 21.9 dB at the center frequency of 5.8 GHz and the bandwidth of 10 %.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.8A
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• pp.620-625
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• 2003

The coplanar waveguide bandpass filter using folded-line stepped-impedance resonators(SIRs) is proposed. The folded-line SIR has about λ/8 length using the short-circuited end on coplanar waveguide. It make that the bandpass filter has the half size in comparison with general λ/4 SIR filter. In this paper, we derive the equivalent circuit and design the bandpass filter by using that. We design and fabricate the bandpass filter which has 5 GHz center frequency and 3 % fractional bandwidth. The measurement results fur 4-pole folded SIR bandpass filter agreed well with full-wave simulation and equivalent circuit results. The fabricated bandpass filter has a good spurious characteristic, which the harmonic frequency appeared at 2.5f$\_$0/). The proposed folded-line SIR bandpass filter are applicable for MMIC and High-Tc superconducting filters. bandwidth.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.1A
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• pp.85-90
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• 2008

Effects of the emitter degeneration on linearity have been investigated in SiGe HBT double-balanced up-converters with the Gilbert-cell structure. The emitter-coupled degeneration resistors have been optimized for high P1-dB and IP3 through the nonlinear harmonic-balance simulation. Two types of up-converter MMICs fabricated in $0.35{\mu}m$ Si-BiCMOS process were measured to verify the simulation results. The up-converter without the degeneration resistors produces a P1-dB of -13 dBm with an OIP3 of 3.7 dBm, while the up-converter with the degeneration resistors produces a P1-dB of -10 dBm with an OIP3 of 8.7 dBm.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.12
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• pp.2618-2624
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• 2009

Harmonics (or distortion in wave form) has always existed in electrical power systems. It is harmless as long as its level is not substantial. However, with the recent rapid advancement of power electronics technology, so-called nonlinear loads, such as variable frequency drives for motor power/speed control, are increasingly finding their way to shipboard or offshore applications. In this paper a new approach to direct torque control (DTC) of induction motor drive is presented. In comparison with the conventional DTC methods the inverter switching frequency is constant and is dramatically increased, requiring neither any increase of the sampling frequency, nor any high frequency dither signal. The well-developed space vector modulation technique is applied to inverter control in the proposed DTC-based induction motor drive system, thereby dramatically reducing the current harmonics. As compared to the existing DTC approach with constant inverter switching frequency, the presented new approach does not invoke any concept of deadbeat control, thereby dramatically reducing the computations.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.8A
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• pp.846-851
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• 2008

With rapid development of communication industry, the kinds of communication service vary. According to the increasing use of radio waves, the intelligent and effective radio monitoring system needs to be developed, which is replaced for previous radio monitoring system. Next-generation intelligent radio monitoring system based on ITU-R, Rule of wireless facilities, and Radio Waves Act is used, and which can accurately and effectively function as effective radio monitoring system through spectrum analysis of channel power, frequency deviation, offset, and an occupied frequency bandwidth(99% or x-dB), about the analog and digital signal in On-Air of V/UHF bandwidth. Main function of the system has an radio quality measurement, unwanted electromagnetic signals (spurious, harmonic) measurement, high-speed spectrum measurement, frequency usage efficiency investigation, illegal radio exploration, working monitoring, In this paper, we proposes radio quality measurement, high-speed spectrum measurement of next-generation intelligent radio monitoring system.