• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.5
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• pp.672-683
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• 1990

The line code for ISDN subscriber loops is a critical choice in designing U-interface transceiver, since it affects system performance in a crucial way. This paper provides the performance analysis of U-interface transceiver systems employing four different line codes AMI, MMS43, VMDB5, and 2B1Q. The codes are compared using computer simulation studies, and three performance parameters of the four codes such as power spectrum, eye width, and error probability are used for the comparison. The simulation model consists of the encoder, transmit filter (root-raised cosine filter), channel, receive filter, zero-forcing equalizer, sampler, and decoder. The near-end crosstalk and addive white gaussian noise are considered as teh principal impediments.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.8 no.4
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• pp.201-206
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• 2009

The third generation mobile communications system requiring the reliable multimedia data transmission has provided with the reliable voice, data and video services over the variable propagation environment. However the broadband wireless multiple access technologies cause Inter Symbol Interference (ISI) or Multiple Access Interference (MAI) to degrade the performance of W-CDMA (Code Division Multiple Access) system. Constant Modulus Algorithm (CMA) which is frequently used as the adaptive blind equalizers to remove the interfering signal has ill-convergence phenomenon without proper initialization. In this paper, new blind equalization method based on conventional CMA is proposed to improve the channel efficiency, and through computer simulation this is tested over the time varying fading environment of mobile communication system. Consequently, new blind equalization method into concatenated Kalman filter with CMA is verified better than conventional CMA through adopting minimum mean square errors and eye-pattern obtained from algorithm are compared.

• Journal of the Korean Institute of Telematics and Electronics
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• v.23 no.4
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• pp.419-428
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• 1986

While three most important aspects of line codes are the de-free, the minimum-bandwidth, and the self-clocking properties, the only TIBr, VMDBr, RMD3r, RMD4r codes possess all of these properties. This paper is to report the results of an experimental performance study of VMDB5. The encoder and decoder of VMDB5 and the pulse shaper have been inplemented. Power spectra, eye patterns, and error probabilities are experimentally measured, confirming the theoreticla performance predictions. It has been observed that the NRZ pulse shaping reliable transmission is possible with no extra equalization even in teh case when the -3dB channel bandwith is only half the Nyquist bandwidth.

• The Korea Journal of Herbology
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• v.30 no.5
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• pp.29-43
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• 2015

Objectives : This study was aimed to analyze the correlation between the Herbology and contemporary research results, KCD-codes.Methods : Papers were searched in OASIS and PubMed, then they were categorized. Medicine or pharmacy articles about Menthae Herba were matched with the Herbology treatment and KCD-codes. Other articles were analyzed by abstract of the papers. KCD-codes and terms were arranged by the Herbology treatment. The Degree of Herbology research (HDR) was calculated by numbers of papers, study method, citation rates.Results : There were 97 articles about Menthae Herba. Among these there were 47 medicine and pharmacy articles about Menthae Herba, and 15 articles were matched to the Herbology treatment. Studies about Headache and Wind-warmth was more active than others. Analysis of other articles showed that studies about contraceptive and anti-oxidative effect, plant growth, protective effect from insect, component extraction technics were active, too. In HDR, headache was scored by 136, Wind-warmth by 104, Eye hemorrhage by 51, Discomport in the throat by 50, Distention and fullness in the chest and hypochondrium by 15, Rubella and Measles by 0.Conclusions : 97 articles about Menthae Herba were analyzed and 15 articles were matched to the Herbology treatment. Studies about headache, wind-warmth, eye-hemorrhage were more active than others of the Herbology treatment. And studies about contraceptive and anti-oxidative effect, plant growth, protective effect from insect, component extraction technics could be a new subject of the Herbology.

• Journal of the Korea Fashion and Costume Design Association
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• v.14 no.3
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• pp.147-160
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• 2012

The costumes as an expression system in film are inserted intentionally for a particular purpose. Costumes in film, namely the cinematic dress code, and that in reality are dissimilar in meaning structure. The costumes in film perform a role of a complicated eye-catcher in correlation with the other filmic factors. But the previous studies on the costumes in film are focused on the keywords 'fashion style', 'fashion trend', or 'PPL (product placement)'. In film studies, however, the costumes should be observed from the point of view as semiosis, not as fashion, in other words, from the angle of symbol, icon and index. And the meaning and the process of the communication, which that produce, should be pointed out. It could expose, that costumes play one of the key roles for the developing of narratives and the creating of characters in film. Therefore, this study's aim is to examine the semiosis of costumes in film and to analyse the dress code, dress plot, and dress message in (1990) by Garry Marshall. But this work does not try to indicate the problems of the film-semiotics or to intensify the concept of the semiotic terminology. Thus, this study attempts to approach the theme of costumes in film from the perspective of the semiosis and its meaning process. With this, it has been proved, that semiotic systems are in hiding beyond the conventional forms of cinematic costumes and its natural harmony with characters.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.7
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• pp.1044-1049
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• 1993

In this paper, it is shown that B-CDMA systems inherently reduce the effects of Multi Path fading phenomena which causes to degrade the performance of mobile communication systems. B-COMA systems use PN codes of high chip rates ( > 10 Mbps) and evaluate autocorrelation with the same code in the receiver. Therefore, it is possible that multipath signals, whose delay time is longer than one chip duration compared to the first signal, are removed. We model the wideband fading channel as a suitable linear filter, and perform computer simulation of signal transmission and reception. Graphic comparison of eye diagrams between the narrowband and wideband systems is shown.

• Convergence Security Journal
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• v.10 no.3
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• pp.1-7
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• 2010

One of celebrities using Social media caught public's eye and interest in Korea. Thereby the number of the user has grown rapidly and by last year it had reached to about 770 million. But at the same time, it has brought us social issues such as invasion of privacy, spreading of malicious code, and stealing of ID. To solve these problems, first the government need to establish adequate law and policy. Second, Service provider should remove vulnerability in the security system and filter illegal information. Third, individual user should put more effort to protect their own privacy. This paper will suggest a solution of using the Social media more sound and secure.

• Journal of the Optical Society of Korea
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• v.17 no.4
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• pp.328-335
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• 2013

Due to the rapid advancement of auto-refractor technology, most optometry shops provide refraction services. Despite their speed and convenience, the measurement values provided by auto-refractors include a significant degree of error due to psychological and physical factors. Therefore, there is a need for repetitive testing to obtain a smaller mean error value. However, even repetitive testing itself might not be sufficient to ensure accurate measurements. Therefore, research on a method of measurement that can complement auto-refractor measurements and provide confirmation of refraction results needs to be conducted. The customized optometry model described herein can satisfy the above requirements. With existing technologies, using human eye measurement devices to obtain relevant individual optical feature parameters is no longer difficult, and these parameters allow us to construct an optometry model for individual eyeballs. They also allow us to compute visual images produced from the optometry model using the CODE V macro programming language before recognizing the diffraction effects visual images with the neural network algorithm to obtain the accurate refractive diopter. This study attempts to combine the optometry model with the back-propagation neural network and achieve a double check recognition effect by complementing the auto-refractor. Results show that the accuracy achieved was above 98% and that this application could significantly enhance the service quality of refraction.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.4
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• pp.355-360
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• 2010

Purpose: Analysis performance for spectacle lens which sales in domestic market and optimization design a spectacle lens which is corrected aberration. Methods: Measured center thickness, radius and aspherical surface coefficient for spherical and aspherical lenses which were ${\pm}$5.00D. Refractive index for every lens was 1.6 and they came from 4 different companies. I used 3 types of equipment to measure lenses. ID-F150 (Mitutoyo) : Center Thickness, FOCOVISION (SR-2, Automation Robotics) : Radius, PGI 1240S (Taylor Hobson) : Aspherical surface coefficient. Designed a lens which had 27 mm of distance from lens rear surface to center of eye, 4 mm of pupil diameter and small aberration on center vision $30^{\circ}C$. To shorten axial distance compared with the measured lens rise merits for cosmetic. Lens Design tool was CODE V (Optical Research Associates). Results: -5.00D aspherical lens had somewhat high astigmatism and distortion compared with the spherical lens. But it had a merit for cosmetic because of short axial height and decrease edge thickness. Improved a performance of distortion and ascertain merits for cosmetic due to short axial height and decrease edge thickness same as (-) lens in case of +5.00 aspherical lens. Though an optimization process front surface aspherical lens had a good performance for astigmatism and distortion and the merit for beauty compared with measured spherical lens. Conclusions: Design trend for domestic aspherical lens is decrease axial height and thickness to increase a merit for cosmetic not but increase performance of aberration. From design theory for optimization design front surface aspherical spectacle lens which has improved performance of aberration and merit for cosmetic at the same time compared with the measured lens. Expect an improved performance from design back aspherical lens compared with front aspherical lens.

• KIPS Transactions on Software and Data Engineering
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• v.3 no.10
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• pp.429-440
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• 2014

The iris recognition is a biometrics technology to extract and code an unique iris feature from human eye image. Also, it includes the technology to compare with other's various iris stored in the system. On the other hand, eyelashes in iris image are a external factor to affect to recognition rate of iris. If eyelashes are not removed exactly from iris area, there are two false recognitions that recognize eyelashes to iris features or iris features to eyelashes. Eventually, these false recognitions bring out a lot of loss in iris informations. In this paper, in order to solve that problems, we removed eyelashes by gabor filter that using for analysis of frequency feature and improve preservation rate of iris informations. By novel method to extract various features on iris area using angle, frequency, and gaussian parameter on gabor filter that is one of the filters for analysing frequency feature for an image, we could remove accurately eyelashes with various lengths and shapes. As the result, proposed method represents that improve about 4% than previous methods using GMM or histogram analysis in iris preservation rate.