• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.5A
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• pp.482-489
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• 2010

In this paper we have proposed a new architecture of DQ-IRM(Double-Quadrature Image Rejection Mixer) for image rejection in the low-IF receiver. It consist of a frequency-tunable RF PPF(Poly Phase Filter) and the quadrature mixers. The conventional DQ-IRM generates the quadrature RF signals for the RF wide band at once. But the proposed DQ-IRM with the frequency-tuable RF PPF generates the quadrature RF signals for the narrow band of 2~3 channels bandwidth, which is partitioned from the RF wide band. We designed the CMOS RF tuner for T-DMB(Terrestrial Digital Multimedia Broadcasting) with the proposed 3rd DQ-IRM using a 0.18um CMOS technology and verified the performances of the designed receiver such as the image rejection ratio, the noise figure and the power consumption. The overall NF of the RF tuner is about 1.26 dB and the image reject ratio is about 51 dB. The power consumption is 55.8 mW at 1.8 V supply voltage. The chip area is $3.0{\times}2.5mm^2$.

• Restorative Dentistry and Endodontics
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• v.36 no.1
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• pp.59-65
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• 2011

Objectives: The purpose of this study is to compare the apical transportation and working length change in curved root canals created in resin blocks, using 3 geometrically different types of Ni-Ti files, K3, NRT, and Profile. Materials and Methods: The curvature of 30 resin blocks was measured by Schneider technique and each groups of Ni-Ti files were allocated with 10 resin blocks at random. The canals were shaped with Ni-Ti files by Crown-down technique. It was analyzed by Double radiograph superimposition method (Backman CA 1992), and for the accuracy and consistency, specially designed jig, digital X-ray, and CAD/CAM software for measurement of apical transportation were used. The amount of apical transportation was measured at 0, 1, 3, 5 mm from 'apical foramen - 0.5 mm' area, and the alteration of the working length before and after canal shaping was also measured. For statistics, Kruskal-Wallis One Way Analysis was used. Results: There was no significant difference between the groups in the amount of working length change and apical transportation at 0, 1, and 3 mm area (p = 0.027), however, the amount of apical transportation at 5 mm area showed significant difference between K3 and Profile system (p = 0.924). Conclusions: As a result of this study, the 3 geometrically different Ni-Ti files showed no significant difference in apical transportation and working length change and maintained the original root canal shape.

• Archives of Plastic Surgery
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• v.34 no.1
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• pp.37-43
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• 2007

Purpose: Photogrammetry has been introduced as an alternative to direct measurement to obtain facial distances for a variety of anthropometric applications. The aim of this study is to establish morphological and functional value of an eye in Korean youths using specially designed computer software with digital photographic images. Methods: Authors measured anthropometry of an eye in Korean youths 1,449 individuals(622 males, 827 females) and analyzed stastically them. Results: The mean measurements are as follows. The diameter of cornea was $11.6{\pm}0.9mm$ in males and $11.3{\pm}0.9mm$ in females. The vertical dimension of palpebral fissure was $7.4{\pm}1.7mm$ in males and $8.2{\pm}1.6mm$ in females. The intercanthal width was $35.8{\pm}3.2mm$ in males and $34.4{\pm}2.9mm$ in females. The biocular width was $90.4{\pm}5.7mm$ in males and $87.4{\pm}5.3mm$ in females. The endocantion-superior margin of palpebral fissure distance was $12.7{\pm}1.4mm$ in males and $11.6{\pm}1.4mm$ in females. The horizontal dimension of palpebral fissure was $28.5{\pm}2.2mm$ in males and $27.4{\pm}1.9mm$ in females. The slant of palpebral fissure was $10.7{\pm}2.6^{\circ}$ in males and $11.3{\pm}3.0^{\circ}$ in females. The height of upper eyelid was $10.6{\pm}2.3mm$ in males and $10.7{\pm}2.3mm$ in females. The width of double fold was $2.0{\pm}0.7mm$ in males and $1.9{\pm}0.6mm$ in females. A double fold was seen in 21.9% of males and 44.9% of females. The most frequent shape of the double fold was type IV. The most common type of epicanthal fold was type III in both males and females. Conclusion: Photogrammetic measurement of large population using specially designed software could offer reliable data and these data could be useful reference for preoperative consultation, surgical planning and anthropometic study of eye.

• Korean Journal of Food Science and Technology
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• v.48 no.5
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• pp.454-460
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• 2016

In this study, we investigated the possibility of Droplet digital PCR (ddPCR) for detection of foodborne pathogens. ddPCR combines partitioning of PCR reactions into several thousands or millions of individual droplets in a water-oil emulsion, and counting of positive PCR reaction using flow cytometry. Four species of foodborne pathogens, Bacillus cereus, Staphylococcus aureus, Salmonella Typhimurium and Escherichia coli O157:H7, were used to quantify the target sequence with each of the designed primers and double stranded DNA-binding Evagreen dye. All tested foodborne pathogens showed a detection limit ranging from $100fg/{\mu}L$ to $10ng/{\mu}L$. It was concluded that ddPCR could be used to detect very low concentrations of foodborne pathogens from complex food matrices. For multi-detection of target pathogens, we also tested the samples using multiplex ddPCR and obtained successful results.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.456-466
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• 2019

As digital dentistry technology is being developed, it is being used in various ways. This case covers how digital dentistry technology is being applied on the treatment of patients with loss of vertical dimension due to worn dentition and multiple loss of teeth. The loss of vertical dimension was carefully assessed and recovered, and implants were placed with surgical guides, designed considering the final restoration. The movement of the mandibular was measured with the electronic instrument for recording mandibular movement. Wax-up process was done with Naturgemäße Aufwachs-Technik (N.A.T.) and Natural functional reconstruction (N.F.R.). It was scanned, and the provisional restoration was fabricated using Computer-Aided-Design/Computer-Aided-Manufacturing (CAD/CAM) technology, and the adjustment process was done at the clinic to meet with the satisfaction both functionally and esthetically, and then, using double scanning and CAD/CAM technology, it was carried out as a final restoration. As a result, the patient obtained satisfying results, utilizing the benefits of digital dentistry technology and traditional methods.

• Journal of Digital Contents Society
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• v.9 no.1
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• pp.61-67
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• 2008

In this paper, MAC algorithm for the IEEE 802.11 DCF improving the performance is proposed and analyzed by simulation. The MAC of IEEE 802.11 WLAN to control data transmission uses two control methods called DCF(Distributed Coordination Function) and PCF(Point Coordination Function). The DCF controls the transmission based on CSMA/CA(Carrier Sense Multiple Access with Collision Avoidance), that decides a random backoff time with the range of CW(Contention Window) for each station. Normally, each station increase the CW to double after collision, and reduces the CW to the minimum after successful transmission. The DCF shows excellent performance relatively in situation that competition station is less but has a problem that performance is fallen from throughput and delay viewpoint in situation that competition station is increased. This paper proposes an enhanced DCF algorithm that increases the CW to maximal CW after collision and decreases the CW smoothly after successful transmission in order to reduce the collision probability by utilizing the current status information of WLAN. To prove efficiency of proposed algorithm, a lots of simulations are conducted and analyzed.

• Journal of Broadcast Engineering
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• v.23 no.1
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• pp.86-92
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• 2018

In this paper, we propose a method for coding history detection of digital speech signal. In digital speech communication and storage, the signal is encoded to reduce the number of bits. Therefore, when a speech signal waveform is given, we need to detect its coding history so that we can determine whether the signal is an original or an coded one, and if coded, determine the number of times of coding. In this paper, we propose a coding history detection method for 12.2kbps AMR codec in terms of original, single coding, and double coding. The proposed method extracts a speech-specific feature vector from the given speech, and models the feature vector using a deep neural network. We confirm that the proposed feature vector provides better performance in coding history detection than the feature vector computed from the general spectrogram.

• Journal of Digital Contents Society
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• v.18 no.6
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• pp.1091-1099
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• 2017

This study used movies to improve the students' immersion and interest in political classes. Movie is one of the most common and most powerful means of disseminating information that occur among humans. And it is the most easily accessible to the public. Especially, the recognition of visual images proceeds more easily and faster than the perception of thought. Understanding the political happening through movie can get double effect because of the high understanding and immersion. Above all, movies can penetrate into people's minds because they become a ideological. Therefore, it is publicized and also historical events are reproduced in movies. Likewise, politics is also based on the role of the thought or dominant beliefs, and public opinion is formed to justify various groups of human activities. It shows that today's political happening is not a new, but the historical phenomenon of the past are reproduced. Based on this, to discuss modern Korean political history through movies.

• Journal of the Korea Fashion and Costume Design Association
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• v.18 no.2
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• pp.221-236
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• 2016

The purpose of this study is to make a contribution to the development of creative fashion culture through the expansion of creative fields in the fashion design area and also the combination of fashion and art techniques, by classifying the cases of Trompe $L{\oe}il$ expressed in modern fashion, and also analyzing its aesthetic characteristics. Conducting the qualitative research through the literature study and the analysis of design cases, it targeted the women's wear collections of Paris, Milan, London, and New York, limiting its range from S/S 2010 to F/W 2015. The results are as follows: First, based on the preceding research, the types of Trompe $L{\oe}il$ expressed in modern fashion were shown as realistic expression of clothing, movement of daily objects, double images, and application of human body. Second, the aesthetic characteristics of Trompe $L{\oe}il$ based on its expression types were deconstruction, avant-garde, and amusements. The deconstruction was expressed in the expression type of Trompe $L{\oe}il$ such as freedom of materials using digital printing technique, change in the position of clothes, and movement of daily items using collage technique by collecting objets like daily items or waste. The avant-garde was expressed by switching/overlapping in and out of clothes, intentionally exposing some body parts like breast or torso, displacing body parts, and moving daily items. The amusements was shown by realistically expressing accessories or details of clothes using digital printing technique, or moving daily items such as book and fork.

• Korean Journal of Optics and Photonics
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• v.20 no.1
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• pp.23-28
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• 2009

In this study, we propose an image stitching method for large-area holographic photo lithography. In this method, a hologram medium become a hologram mask for lithography. And the mask has information for stitched images. These images are recorded by signal images which are controlled with DMD (digital micro-mirror device), and serial hologram recording is achieved with a motorized linear stage. Using this method, fringe seams appear on the stitching area. To remove these fringe seams, double exposure holographic lithography is tried. Each stitched image is recorded and reconstructed with a different reference beam. The experiments confirm that fringe seams are removed.