• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.2
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• pp.189-197
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• 2014

This work proposes a 12b 100 MS/s $0.11{\mu}m$ CMOS three-step hybrid pipeline ADC for high-speed communication and mobile display systems requiring high resolution, low power, and small size. The first stage based on time-interleaved dual-channel SAR ADCs properly handles the Nyquist-rate input without a dedicated SHA. An input sampling clock for each SAR ADC is synchronized to a reference clock to minimize a sampling-time mismatch between the channels. Only one residue amplifier is employed and shared in the proposed ADC for the first-stage SAR ADCs as well as the MDAC of back-end pipeline stages. The shared amplifier, in particular, reduces performance degradation caused by offset and gain mismatches between two channels of the SAR ADCs. Two separate reference voltages relieve a reference disturbance due to the different operating frequencies of the front-end SAR ADCs and the back-end pipeline stages. The prototype ADC in a $0.11{\mu}m$ CMOS shows the measured DNL and INL within 0.38 LSB and 1.21 LSB, respectively. The ADC occupies an active die area of $1.34mm^2$ and consumes 25.3 mW with a maximum SNDR and SFDR of 60.2 dB and 69.5 dB, respectively, at 1.1 V and 100 MS/s.

• Journal of IKEEE
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• v.14 no.3
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• pp.232-235
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• 2010

A 60GHz active phase shifter with 65nm CMOS is presented by replacing passive switches in switched-line type phase shifter with active ones. Active-switch phase shifter is composed of active-switch blocks and passive delay network blocks. The active-switch phase shifter design is compact compare with the conventional vector-sum phase shifter. Active-switch blocks are designed to accomplish required input and output impedances whose requirements are different whether the switch is on or off. And passive delay network blocks are composed of lumped L,C instead of normal microstrip line to reduce the size of the circuit. An 1-bit phase shifter is fabricated by TSMC 65nm CMOS technology and measurement results present -4dB average insertion loss and 120 degree phase shift at 65GHz.

• Journal of radiological science and technology
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• v.25 no.1
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• pp.55-62
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• 2002

Aneurysm-mimicking findings were frequently visualized due to hemodynamical causes of dephasing effects around area of A-com artery during magnetic resonance angiography(MRA) and these kind of phenomena have not been clearly known yet. We investigated the hemodynamical patterns of dephasing effect around area of the A-com artery that might be a cause of false intracranial aneurysms on MRA. For experimental study, We used hand-made silicon phantoms of the asymmetric A-com artery as like a bifurcation configuration. In a closed circulatory system with UHDC computer driven cardiac pump system. MRA and fast digital subfraction angiography(DSA) involved the use of these phantoms. Flow patterns were evaluated with axial and coronal imaging of MRA(2D-TOF, 3D-TOF) and DSA of Phantoms constructed from an automated closed-type circulatory system filled with glycerol solution [circulation fluid(glycerol:water = 1:1.4)]. These findings were then compared with those obtained from computational fluid dynamic(CFD) for inter-experimental correlation study. Imaging findings of MRA, DSA and CFD on inflow zone according to the following: a) MRA demonstrated high signal intensity zone as inflow zone on silicon phantom; b) Patterns of DSA were well matched with MRA on trajectory of inflow zone; and c) CFD were well matched with MRA on the pattern of main flow. Imaging findings of MRA. DSA and CFD on turbulent flow zone according to the following: a) MRA demonstrated hyposignal intensity zone at shoulder and axillar zone of main inflow; b) DSA delineated prominent vortex flow at the same area. The hemodynamical causes of signal defect, which could Induce the false aneurysm on MRA, turned out to be dephasing effects at axilla area of bifurcation from turbulent flow as the results of MRA, DSA and CFD.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.10
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• pp.148-158
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• 2012

This paper presents the design of the incremental delta-sigma ADC. The proposed circuit consists of pre-amplifier, S & H circuit, MUX, delta-sigma modulator, and decimation filter. Third-order discrete-time delta-sigma modulator with 1-bit quantization were fabricated by a $0.18{\mu}m$ CMOS technology. The designed circuit show that the modulator achieves 87.8 dB signal-to-noise and distortion ratio (SNDR) over a 5 kHz signal bandwidth and differential nonlinearity (DNL) of ${\pm}0.25$ LSB, integral nonlinearity (INL) of ${\pm}0.2$ LSB. Power consumption of delta-sigma modulator is $941.6{\mu}W$. It was decided that N cycles are 200 clock for 16-bits output.

• Journal of Information Management
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• v.39 no.2
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• pp.1-25
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• 2008

This study is to investigate the user behavior of defense development and test researchers working for A research institute to provide advanced library services. Based on the prior studies about the subject, survey through questionnaires were conducted, and the data analyzed using SPSS 12.0. Results of the analyses are as follows: The researchers generally gathered information 2 to 3 times per month. The major reason for information gathering was to solve problems and do their tasks. They considered accuracy of information as the most important factor when they gather information. Finding and selecting information sources were the most difficult task for them in retrieving, acquiring and using information. They have most frequently used digital materials (67%), printed materials next (26%), and non-book materials (6%). Internet was both the most frequently used and most satisfied information source for the researchers.

• Tribology and Lubricants
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• v.35 no.5
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• pp.274-285
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• 2019

Chemical mechanical polishing (CMP), which is a material removal process involving chemical surface reactions and mechanical abrasive action, is an essential manufacturing process for obtaining high-quality semiconductor surfaces with ultrahigh precision features. Recent rapid growth in the industries of digital devices and semiconductors has accelerated the demands for processing of various substrate and film materials. In addition, to solve many issues and challenges related to high integration such as micro-defects, non-uniformity, and post-process cleaning, it has become increasingly necessary to approach and understand the processing mechanisms for various substrate materials and abrasive particle behaviors from a tribological point of view. Based on these backgrounds, we review recent CMP R&D trends in this study. We examine experimental and analytical studies with a focus on substrate materials and abrasive particles. For the reduction of micro-scratch generation, understanding the correlation between friction and the generation mechanism by abrasive particle behaviors is critical. Furthermore, the contact stiffness at the wafer-particle (slurry)-pad interface should be carefully considered. Regarding substrate materials, recent research trends and technologies have been introduced that focus on sapphire (${\alpha}$-alumina, $Al_2O_3$), silicon carbide (SiC), and gallium nitride (GaN), which are used for organic light emitting devices. High-speed processing technology that does not generate surface defects should be developed for low-cost production of various substrates. For this purpose, effective methods for reducing and removing surface residues and deformed layers should be explored through tribological approaches. Finally, we present future challenges and issues related to the CMP process from a tribological perspective.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.7
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• pp.685-691
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• 2020

In this study, an algorithm that recognizes numbers from 0 to 9 was developed using the data obtained after tracking hand movements using the echo signal of a millimeter-wave radar sensor at 77 GHz. The echo signals obtained from the radar sensor by detecting the motion of a hand gesture revealed a cluster of irregular dots due to the difference in scattering cross-sectional area. A valid center point was obtained from them by applying a K-Means algorithm using 3D coordinate values. In addition, the obtained center points were connected to produce a numeric image. The recognition rate was compared by inputting the obtained image and an image similar to human handwriting by applying the smoothing technique to a CNN (Convolutional Neural Network) model trained with MNIST (Modified National Institute of Standards and Technology database). The experiment was conducted in two ways. First, in the recognition experiments using images with and without smoothing, average recognition rates of 77.0% and 81.0% were obtained, respectively. In the experiment of the CNN model with augmentation of learning data, a recognition rate of 97.5% and 99.0% on average was obtained in the recognition experiment using the image with and without smoothing technique, respectively. This study can be applied to various non-contact recognition technologies using radar sensors.

• Journal of Digital Convergence
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• v.17 no.3
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• pp.235-251
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• 2019

The purpose of this study was to investigate the single-person household's demand for a wearable healthcare system that provides the ischemic heart disease and cardiopulmonary alarm to be developed. In this study, in-depth interviews were conducted with six unmarried individuals in their thirties who were in the workplace and the results were interpreted by Giorgi's phenomenological analysis method. The study results indicated that although the wearable healthcare system was implemented with high-technology functions that serve the intended purpose, it is necessary to comprehensively consider factors such as aesthetics, comfort, and ease of washing. In this study, we found that the variables influencing the interviewees' intent to accept healthcare services are complex and cannot be attributed to one factor alone; this study has also shown a variety of interpersonal correlations. In addition, although health-care research focusing on the elderly has been conducted in the past, it is suggested that younger generations such as those in their thirties can also be studied as health care service adopters.

• Journal of Broadcast Engineering
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• v.22 no.6
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• pp.829-849
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• 2017

Due to the large-scale TV display, the convergence of broadcasting and broadband, and the advancement of signal compression and transmission technology, terrestrial digital broadcasting has evolved into UHD broadcasting capable of providing simultaneous broadcasting of fixed UHD and mobile HD. The Korean standard for terrestrial UHDTV broadcasting is based on ATSC 3.0, the broadcasting standard of North America. The terrestrial UHDTV broadcasting standard chose that as a new AV codec standard, HEVC video codec which can compress with higher efficiency compared to AVC, and MPEG-H 3D audio codec for realistic audio. Also, DASH and MMT are adopted as transmission format instead of MPEG-2 TS to support broadband as well as broadcasting network, and in order to provide 4K UHD/mobile HD service simultaneously ROUTE multiplexing technology is applied. In this paper, we propose an audio/video encoder, which is required to provide HDR/WCG supported high quality video service, 10.2 channel/4 object supporting stereo sound service, fixed UHD and mobile HD simultaneous broadcasting service based on ATSC3.0, also we implemented the ATSC 3.0 LDM system for ROUTE/DASH packager, multiplexing system and physical layer transmission/reception, and verified the service ability by applying it to real time broadcast environment.

• Journal of Korea Technology Innovation Society
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• v.14 no.2
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• pp.343-372
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• 2011

Since the introduction of motion picture in the early 20th century, Korean motion picture industry has gradually evolved as one of the world leaders. However, due to the rapid technological change as exemplified by the emergence of the new digital and 3D cinema technologies, there is a need to re-consider the existing technology policy and strategy designed for the adoption and effective use of new technologies. In this paper, the authors address this issue by emphasizing the technological development side rather than the use/adoption side. In order to provide policy makers with critical information on the current status of the sector, we analyzed the sectoral innovation system of the Korean motion picture industry. In order to conduct this analysis, we re-visited previous literature and interviewed experts in the motion picture sector. Then, the authors attempted to identify the characteristics and problems of the current Korean motion picture industry. Based on the insights gained from this research, we draw policy implications for technological innovation in this sector. However, the implications from this paper are not limited to the motion picture industry. As the motion picture industry is a new case for innovation studies, our paper may provide new research opportunities to the academia.