• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.185-186
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• 2021

In Korea, many buildings are built with underground spaces and cast-in-place pile method is mostly applied in the temporary retaining walls for the underground space construction. A H-shaped steel section is generally embedded in the soldier pile in the C.I.P method. In this study, a new and economical section with high strength steel replacing the H-shaped section was proposed and its flexural capacity was evaluated experimentally. The new section is the concrete-filled composite section with pentagonal thin plate and thick flange plate. Test results showed that the proposed section has an excellent flexural strength and ductility.

• Journal of Broadcast Engineering
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• v.11 no.2 s.31
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• pp.174-180
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• 2006

H.264/MPEG-4 AVC is jointly developed by ITU-T and ISO/IEC. It provides efficient coding efficiency compared with previous video standards. It reduced the bit rate by approximately $30%{\sim}70%$ while providing the same or better image quality. And, H.264/MPEG-4 AVC supports not only lossy coding but also lossless coding. In this paper, we suggest a method to improve lossless coding efficiency. Proposed method is based on Intra residual DPCM, it has same effect with the prediction from spatially nearest pixel. Also, proposed method does not broken decoder pipe-line. Experimental results, the method reduced the bit rate by approximately 12% in comparison with the H.264 Intra lossless coding. As a result, it is adopted into the H.264/MPEG-4 AVC Advanced 4:4:4 profile.

• Korean Journal of Remote Sensing
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• v.34 no.3
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• pp.481-494
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• 2018

The accurate radiative transfer model simulation is essential for an accurate ozone profile retrieval using optimal estimation from backscattered ultraviolet (BUV) measurement. The input parameters of the radiative transfer model are the main factors that determine the model accuracy. In particular, meteorological parameters such as temperature and surface pressure have a direct effect on simulating radiation spectrum as a component for calculating ozone absorption cross section and Rayleigh scattering. Hence, a sensitivity of UV ozone profile retrievals to these parameters has been investigated using radiative transfer model. The surface pressure shows an average error within 100 hPa in the daily / monthly climatological data based on the numerical weather prediction model, and the calculated ozone retrieval error is less than 0.2 DU for each layer. On the other hand, the temperature shows an error of 1-7K depending on the observation station and altitude for the same daily / monthly climatological data, and the calculated ozone retrieval error is about 4 DU for each layer. These results can help to understand the obtained vertical ozone information from satellite. In addition, they are expected to be used effectively in selecting the meteorological input data and establishing the system design direction in the process of applying the algorithm to satellite operation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4780-4785
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• 2012

As many mobile devices such as smart phones and tablets are widely spread, optimized mobile video encoder used during video recording application is needed. In this paper, we implemented H.264/AVC base profile video encoder on a mobile device and empirically optimized control parameters of the encoder. As the experiment, we more than 100 test cases were designed with varying Lagrangian optimization, Hadamard Transform, search range, I-frame period, and reference frames. During the experiment, we measured picture quality, bit-rate, encoding time, motion estimation time, and power consumption. From the result, we can determine optimal values for the H.264 control parameters.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.7
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• pp.47-52
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• 2009

H.264 video coding standard is widely used due to the high compression rate and quality. The motion compensation is the most time-consuming and complex unit in the H.264 decoder. The performance of the motion compensation is determined by the calculation of pixel interpolation and management of the reference pixels. The reference pixels read from external memory using efficient memory management for data reuse is necessary along with the high performance interpolators. We propose the architecture of a motion compensation unit for H.264 decoders. It is composed of 2-dimensional circular register files, a motion vector predictor and high performance interpolators with low complexity. The 2-dimensional circular register files reuse reference pixel data as much as possible, and feed reference pixel data to interpolators without any latency and complex logic circuits. We design a motion compensation unit and a intra-prediction unit and integrate them into a prediction unit and verify the operation and the performance.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.4
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• pp.493-498
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• 2009

Bluetooth is a popular wireless data transmission method with low power consumption, but it has low data transmission rate. Thus, although many video stream players of a local or network file exist, there have been few players of video stream transmitted via Bluetooth. MPEG-4 AVC/H.264 codec is one of video codecs available with best compression rates for a certain quality, so a H.264 encoder seems to be adequate for video stream to be transmitted via Bluetooth. In this paper, we present a DirectShow filter based player of video stream encoded by H.264 codec, which is transmitted via Bluetooth. Details on the design and implementation of this program are described. Experimental results are shown to demonstrate the validity of the implemented program using various video samples.

• Journal of Life Science
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• v.26 no.10
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• pp.1214-1217
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• 2016

Rebamipide is a mucosal-protective antiulcer drug, but its mechanism of action in gastric cancer remains elusive. CagA, a major virulence factor of Helicobacter pylori (H. pylori), is associated with the risk of gastric cancer. CagA protein is injected into gastric epithelial cells and deregulates a variety of cellular signaling molecules. CagA from H. pylori induces phospholipase D1 (PLD1) expression through NFκB activation in gastric epithelial cells, followed by invasion and proliferation of gastric epithelial cancer cells. Infection with cagA-positive H. pylori and expression of CagA enhances the binding of NFκB to the PLD1 promoter. Rebamipide abolishes H. pylori cagA-induced PLD1 expression via inhibition of binding of NFκB to the PLD1 promoter and also inhibits PLD activity. Moreover, rebamipide abolishes H. pylori CagA-induced β-catenin and the expression of a target cancer stem cell (CSC) marker gene via upregulation of miRNA-320a and -4496, followed by attenuation of self-renewal capacity of H. pylori CagA-infected gastric CSCs. In addition, rebamipide increases the chemosensitivity of CagA-expressed gastric CSCs and suppresses gastric carcinogenesis. Thus, it is speculated that rebamipide might show a potent efficacy as chemotherapeutic drug against gastric cancer cells. In this review, we summarizes recent results regarding the novel insights for the efficacy of rebamipide in gastric cancer cells.

• The KIPS Transactions:PartB
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• v.16B no.4
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• pp.309-318
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• 2009

The researches on the system that automatically records and retrieves one's everyday life is relatively actively worked recently. These systems, called personal memex or life log, usually entail dedicated devices such as SenseCam in MyLifeBits project. This research paid attention to the digital devices such as mobile phones, credit cards, and digital camera that people use everyday. The system enables a person to store everyday life systematically that are saved in the devices or the deviced-related web pages (e.g., phone records in the cellular phone company) and to refer this quickly later. The data collection agent in the proposed system, called MyMemex, collects the personal life log "web data" using the web services that the web sites provide and stores the web data into the server. The "file data" stored in the off-line digital devices are also loaded into the server. Each of the file data or web data is viewed as a memex event that can be described by 4W1H form. The different types of data in different services are transformed into the memex event data in 4W1H form. The memex event ontology is used in this transform. Users can sign in to the web server of this service to view their life logs in the chronological manner. Users can also search the life logs using keywords. Moreover, the life logs can be viewed as a diary or story style by converting the memex events to sentences. The related memex events are grouped to be displayed as an "episode" by a heuristic identification method. A result with high accuracy has been obtained by the experiment for the episode identification using the real life log data of one of the authors.

• Radiation Oncology Journal
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• v.20 no.4
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• pp.375-380
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• 2002

Purpose : To develop a practical film dosimetry system for routine Quality Assurance (QA). Materials and Methods :An One Click Film (OCF) Dosimetry system was designed to perform swift routine QA with functions including automatic fog value elimination, angle adjustment, automatic symmetry calculation, and realtime profile generation with the ability to display realtime three-dimensional dose distributions. Results : The most frequently used functions for routine QA, such as the elimination of the fog value, conversion into an H&D curve, symmetry, and isodose distribution, can be achieved with only one click. Conclusion : Reliable results were achieved with the OCF dosimetry with simpler steps than other commercially available film dosimetry systems for routine QA. More research on the refined user interface will make this system be clinically useful.

• Journal of the Korean Society of Radiology
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• v.12 no.6
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• pp.785-791
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• 2018

Recently, Disk array is widely used as a long term storage device in PACS, but reliability is not enough in relation to annual failure rate of disk. Between October 2016 and February 2017, we scanned the serial port of the hard disk while reading or storing medical images on a PACS reader. The data rate was calculated from the data stored in HDD 99ea that were used in the PCAS image storage device and in HDD 101ea that were used in the Personal Computer. When a CT image was read from a PACS reader, Reading was 87.8% and Writing was 12.2% in units of several tens of megabytes or less. When the CT image was stored in the PACS reader, Reading was 11.4% and Writing was 88.6% in units of several tens of megabytes or less. While reading the excel file on the personal computer, Reading was 75% and Writing was 25% in less than 3 MB, and In the process of storing the excel file on the personal computer, Reading was carried out by 38% and Writing was carreid out 62% in the units of 3 MB or less. The transfer rate of the hard disk used in the PACS image storage device was 10 GB/h, and the transfer rate per hour of the hard disk of the personal computer was 5 GB / h. Annual failure rate of hard disk of image storage system is 0.97 ~ 1.13%, Annual failure rate of Hard Disk of personal computer is 0.97 ~ 1.13%. the higher transfer rate is, the higher annual failure rate is. These results will be used as a basis for predicting the life expectancy of the hard disk and the annual failure rate.