• Journal of the Korean Society for Precision Engineering
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• v.23 no.9 s.186
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• pp.156-163
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• 2006

The purpose of this study is to improve the machining of free-formed NURBS surfaces using newly defined G-codes which can directly deal with shapes defined from CAD/CAM programs on a surface basis and specialize in rough and finish cut. To this purpose, a NURBS surface interpolation system is proposed in this paper. The proposed interpolation system includes online tool-path planning, real-time interpolation and feedrate regulation considering an effective machining method and minimum machining time all suitable for unit NURBS surface machining. The corresponding algorithms are simultaneously executed in an online manner. The proposed NURBS surface interpolation system is integrated and implemented with a PC-based 3-axis CNC milling system. A graphic user interface (GUI) and a 3D tool-path viewer which interprets the G-codes for NURBS surfaces and displays whole tool-paths are also developed and included in our real-time control system. The proposed system is evaluated through actual machining in terms of size of NC data, machining time, regulation of feedrate and cutting force focused on finish cut in comparison with the existing method.

• Journal of Information Display
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• v.13 no.3
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• pp.113-118
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• 2012

Metal oxide semiconductors were considered promising materials as backplanes of future displays. Moreover, the adoption of carrier-suppressing metal into indium-zinc oxide (IZO) has become one of the most important themes in the metal oxide research field. In this paper, efforts to realize and optimize IZO with diverse types of carrier suppressors are summarized. Properties such as the band gap of metal in the oxidized form and its electronegativity were examined to confirm their relationship with the metal's carrier-suppressing ability. It was concluded that those two properties could be used as indicators of the carrier-suppressing ability of a material. As predicted by the properties, the alkali earth metals and early transition metals used in the research effectively suppressed the carrier and optimized the electrical properties of the metal oxide semiconductors. With the carrier-suppressing metals, IZO-based thin-film transistors with high (above $1cm^2/V{\cdot}s$) mobility, a lower than 0.6V/dec sub-threshold gate swing, and an over $3{\times}10^6$ on-to-off current ratio could be achieved.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.11_12
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• pp.705-716
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• 2005

There exist many feature point detection algorithms that developed in pattern recognition research . However, interactive applications for the pen-input displays such as Tablet PCs and LCD tablets have set different goals; reliable segmentation for different drawing styles and real-time on-the-fly fieature point defection. This paper presents a curvature estimation method crucial for segmenting freeHand pen input. It considers only local shape descriptors, thus, peforming a novel curvature estimation on-the-fly while drawing on a pen-input display This has been used for pen marking recognition to build a 3D sketch-based modeling application.

• Journal of Broadcast Engineering
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• v.27 no.6
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• pp.848-859
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• 2022

This paper presents a novel 360-degree video streaming system for large-scale immersive displays and its ongoing implementation. Recent VR systems aim to provide a service for a single viewer on HMD. However, the proposed 360-degree video streaming system enables multiple viewers to explore immersive contents on a large-scale immersive display. The proposed 360-degree video streaming system is being developed in 3 research phases, with the final goal of providing 6DoF. Currently, the phase 1: implementation of the 3DoF 360-degree video streaming system prototype is finished. The implemented prototype employs subpicture-based viewport-dependent streaming technique, and it achieved bit-rate saving of about 80% and decoding speed up of 543% compared to the conventional viewport-independent streaming technique. Additionally, this paper demonstrated the implemented prototype on UCSB AlloSphere, the large-scale instrument for immersive media art exhibition.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.388-394
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• 2003

To handle the high level radioactive materials such a spent fuel, the master-slave manipulators (MSM) are widely used as a remote handling device in nuclear facilities such as the hot cell with sealed and shielded space. In this paper, the Digital Mockup which simulates the remote operation of the Advanced Conditioning Process(ACP) is developed. Also, the workspace and the motion of the slave manipulator, as well as, the remote operation task should be analyzed. The process equipment of ACP and Maintenance/Handling Device are drawn in 3D CAD models using IGRIP. Modeling device of manipulator is assigned with various mobile attributes such as a relative position, kinematics constraints, and a range of mobility, The 3D graphic simulator using the external input device of space ball displays the movement of manipulator. To connect the external input device to the graphic simulator, the interface program of external input device with 6 DOF is deigned using the Low Level Tele-operation Interface(LLTI). The experimental result shows that the developed simulation system gives much-improved human interface characteristics and shows satisfactory response characteristics in terms of synchronization speed. This should be useful for the development of work's education system in the virtual environment.

• Journal of Digital Contents Society
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• v.5 no.1
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• pp.22-27
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• 2004

To handle the high level radioactive materials such a spent fuel, the master-slave manipulaters (MSM) are wide1y used as a remote handling device in nuclear facilities such as the hot cell with sealed and shielded space. In this paper, the Digital Mockup which simulates the remote operation of the Advanced Conditioning Process(ACP) is developed. Also, the workspace and the motion of the slave manipulator, as well as, the remote operation task should be analyzed. The process equipment of ACP and Maintenance/Handling Device are drawn in 3D CAD model using IGRIP. Modeling device of manipulator is assigned with various mobile attributes such as a relative position, kinematics constraints, and a range of mobility. The 3D graphic simulator using the extermal input device of spare ball displays the movement of manipulator. To connect the exterral input device to the graphic simulator, the interface program of external input device with 6 DOF is deigned using the Low Level Tele-operation Interface(LLTI). The experimental result show that the developed simulation system gives much-improved human interface characteristics and shows satisfactory reponse characteristics in terms of synchronization speed. This should be useful for the development of work`s education system in the environment.

• Journal of Fashion Business
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• v.22 no.4
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• pp.20-29
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• 2018

Today, visitors of art galleries like to share their life in their communities than interacting with artwork. Meantime, image sharing of an exhibition on social media has become more important than actual watching of the artwork. Accordingly, most of the galleries have started paying more attention in organizing an exhibition environment for proof-shots to attract more visitors. We initially conducted research about the internet environment from the late 1990s to the recent years and analyzed the changing watching patterns of the exhibition since the advent of social media. Secondly, for empirical case analysis, we selected 'Plastic Fantastic' held in D-Museum as the target of analysis. The analysis targeted 500 recent postings that were discovered on Instagram on March 4, 2018, as 'Plastic-Fantastic'(in Korean). The methods of analysis included classification types of image, hashtag, and text on Instagram and were arranged in an order of relation to the exhibits. Based on the image analysis, 44.2% of the images involved exhibition displays; the others included a person or other goods. Based on the results of the text and hashtag analysis, only 3.6% of posting included information about the exhibition and 56.4% had non-related inflow hashtags only with image. The behavior of these shares is likely to gradually lose the inherent meaning of the exhibition and to the value rather than imparting the artistic thrill that viewers derive from art. Exhibition should try to seek deep interaction between the display, audience, and social media users, rather than encouraging the visitors to take proof-shots.

• Reproductive and Developmental Biology
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• v.29 no.2
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• pp.63-68
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• 2005

Cloned calves derived from somatic cell nuclear transfer (SCNT) have been frequently lost by sudden death at 1 to 3 month following healthy birth. To address whether placental anomalies are responsible for the sudden death of cloned calves, we compared protein patterns of 2 placentae derived from SCNT of Korean Native calves died suddenly at two months after birth and those of 2 normal placentae obtained from AI fetuses. Placental proteins were separated using 2-Dimensional gel electrophoresis. Approximately 800 spots were detected in placental 2-D gel stained with coomassie-blue. Then, image analysis of Malanie III (Swiss Institute for Bioinformatics) was performed to detect variations in protein spots between normal and SCNT placentae. In the comparison of normal and SCNT samples, 8 spots were identified to be up-regulated proteins and 24 spots to be down-regulated proteins in SCNT placentae, among which proteins were high mobility group protein HMG1, apolipoprotein A-1 precursor, bactenecin 1, tropomyosin beta chain, $H^+-transporting$ ATPase, carbonic anhydrase II, peroxiredoxin 2, tyrosine-rich acidic matrix protein, serum albumin precursor and cathepsin D. These results suggested that the sudden death of cloned calves might be related to abnormal protein expression in placenta.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.51 no.7
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• pp.308-316
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• 2002

In this paper, we propose a robust digital copyright-protection technique based on the concept of human auditory system. First, we propose a watermarking technique that accepts the various attacks such as, time scaling, pitch shift, add noise and a lot of lossy compression such as MP3, AAC WMA. Second, we implement audio PD(portable device) for copyright protection using proposed method. The proposed watermarking technique is developed using digital filtering technique. Being designed according to critical band of HAS(human auditory system), the digital filers embed watermark without nearly affecting audio quality. Before processing of digital filtering, wavelet transform decomposes the input audio signal into several signals that are composed of specific frequencies. Then, we embed watermark in the decomposed signal (0kHz~11kHz) by designed band-stop digital filer. Watermarking detection algorithm is implemented on audio PD(portable device). Proposed watermarking technology embeds 2bits information per 15 seconds. If PD detects watermark '11', which means illegal song. PD displays "Illegal Song" message on LCD, skips the song and plays the next song, The implemented detection algorithm in PD requires 19 MHz computational power, 7.9kBytes ROM and 10kBytes RAM. The suggested technique satisfies SDMI(secure digital music initiative) requirements of platform3 based on ARM9E core.

• Journal of Welding and Joining
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• v.32 no.3
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• pp.27-33
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• 2014

This paper presents a brief summary on a relatively new plasma aided electrolytic surface treatment process for light metals. A brief discussion regarding the advantages, principle, process parameters and applications of this process is discussed. The process owes its origin to Sluginov who discovered an arc discharge phenomenon in electrolysis in 1880. A similar process was studied and developed by Markov and coworkers in 1970s who successfully deposited an oxide film on aluminium. Several investigation thereafter lead to the establishment of suitable process parameters for deposition of a crystalline oxide film of more than $100{\mu}m$ thickness on the surface of light metals such as aluminium, titanium and magnesium. This process nowadays goes by several names such as plasma electrolytic oxidation (PEO), micro-arc oxidation (MOA), anodic spark deposition (ASD) etc. Several startups and surface treatment companies have taken up the process and deployed it successfully in a range of products, from military grade rifles to common off road sprockets. However, there are certain limitations to this technology such as the formation of an outer porous oxide layer, especially in case of magnesium which displays a Piling Bedworth ratio of less than one and thus an inherent non protective oxide. This can be treated further but adds to the cost of the process. Overall, it can be said the PEO process offers a better solution than the conventional coating processes. It offers advantages considering the fact that he electrolyte used in PEO process is environmental friendly and the temperature control is not as strict as in case of other surface treatment processes.