• The Journal of the Korea Contents Association
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• v.6 no.10
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• pp.143-152
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• 2006

JPEG2000, the standard of still image compression based on wavelet, will be widely used. One of the greatest characteristics of JPEG2000 is to offer ROI(Region-Of-Interest) coding. This is to compress with high quality the region that the user wants better than the other region. JPEG2000 and ROI have different parameters, which are tile size and ROI size, wavelet filter type and ROI shape and its location, codeblock size and number of ROI, number of DWT decomposition level and ROI importance, and number of quality layer and low resolution sub-band importance. In this paper, we shows the correlation of the parameters and ROI coding methods through experiments. This helps an application select the parameters and the methods to meet the application.

• Korean Journal of Materials Research
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• v.8 no.7
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• pp.591-595
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• 1998

In this work, the freestanding GaN single crystalline substrates without cracks were grown by hydride vapor phase epitaxy (HVPE) and its some properties were investigated. The GaN substrate, having a current maximum size of 350 $\mu\textrm{m}$-thickness and 100$\textrm{mm}^2$ area, were obtained by HVPE growth of thick film GaN on sapphire substrate and subsequent mechanical removal of the sapphire substrate. A lattice constant of $C_o$= 5.18486 $\AA$ and a FWHM of DCXRD was 650 arcsec for the single crystalline GaN substrate. The low temperature PL spectrum consist of three excitonic emission and a deep D- A pair recombination at 1.8eV. The Raman E, (high) mode frequency was 567$cm^{-1}$ which was the same as that of strain free bulk single crystals. The Hall mobility and carrier concentration was 283$cm^3$<\ulcornerTEX>/ V.sand 1.1$\times$$10^{18}cm^{-3}$, respectively.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.40 no.6
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• pp.106-113
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• 2003

The modified discrete cosine transform (MDCT) and inverse MDCT (IMDCT) are employed in subband/transform coding schemes as the analysis/synthesis filter bank based on time domain aliasing cancellation (TDAC). And the MDCT and IMDCT are the most computational intensive operations in layer III of the MPEG audio coding standard. In this paper, we propose a new efficient algorithm for the MDCT/IMDCT computation in various audio coding systems. It is based on the MDCT/IMDCT computation algorithm using the discrete cosine transforms (DCTs), and It employs two discrete cosine transform of type II (DCT-II) to compute the MDCT/IMDCT In addition, it takes advantage of ability in calculating the MDCT/IMDCT computation, where the length of a data block Is divisible by 4. The Proposed algorithm in this paper requires less calculation complexity than the existing method does. Also, it can be implemented by the parallel structure, therefore its structure is particularly suitable for VLSI realization

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.202-202
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• 2008

실리콘 기판 위에 성장된 세륨 산화막(CeO2)은 고품질의 SOI(Silicon on Insulator)나 혹은 안정한 캐패시터 소자와 같은 반도체 소자에 대한 응용 가능성이 높아 여러 연구가 진행되어 왔다. 세륨 산화막은 형석 구조, 다시 말해서 대칭적인 큐빅 구조이며 화학적으로 안정한 물질이다. 또한, 세륨 산화막의 격자상수 (a = $5.411\AA$)는 실리콘의 격자상수 (a = $5.430\AA$) 와 비슷하며 큰 밴드갭(6eV) 및 높은 유전상수 ($\varepsilon$ = 26), 높은 열적 안전성을 지니고 있어 실리콘 기판에 사용된 기존 절연막인 사파이어나 질코늄 산화막보다 우수한 특성을 지니고 있다. 본 논문에서는 스퍼터링을 이용하여 세륨 산화막을 실리콘 기판 위에 형성하면서 기판가열 온도 조건을 각각 상온, $100^{\circ}C$, $200^{\circ}C$로 설정하였으며, 세륨 산화막의 증착 두께 조건을 각각 80nm, 120nm로 설정한 다음 퍼니스를 이용하여 $1100^{\circ}C$에서 1시간 동안 열처리를 거친 세륨 산화막의 결정화 형태 및 박막의 막질 상태를 각각 X선 회절 장치 (XRD) 및 주사전자현미경 (SEM)으로 관찰하였다.

• Journal of the Korean Society of Clothing and Textiles
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• v.43 no.4
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• pp.579-591
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• 2019

This research investigated the needs analysis on consumers of fine dust masks to effectively develop a design prototype. Data were collected through focus group interviews on 32 individuals who have used fine dust masks. As a result, there is a new demand by consumers for technology based design changes that better fit the nose and face. Consumers preferred the smell and feel of traditional Korean paper. Young adults expressed the importance of masks that can be used for protection as well as fashion. The prototype improved the drawbacks of existing models using an origami-inspired design in a variety of colors, patterns and in sizes that are customized to fit the wearer. The proposed prototype is made of Dak felt fibers and jersey materials. It is characterized by downward-facing ear bands made of polyurethane to improve the fit around the ears and chin to more effectively block incoming air. The mask is foldable and has a crease that goes along the chin to increase the amount of enclosed space against the face making it easier to breathe compared to existing mask designs.

• Korean Journal of Remote Sensing
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• v.26 no.2
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• pp.251-262
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• 2010

In order to provide quantitative control of the standard products of Geostationary Ocean Color Imager (GOCI), on-board radiometric correction, atmospheric correction, and bio-optical algorithm are obtained continuously by comprehensive and consistent calibration and validation procedures. The calibration/validation for radiometric, atmospheric, and bio-optical data of GOCI uses temperature, salinity, ocean optics, fluorescence, and turbidity data sets from buoy and platform systems, and periodic oceanic environmental data. For calibration and validation of GOCI, we compared radiometric data between in-situ measurement and HyperSAS data installed in the Ieodo ocean research station, and between HyperSAS and SeaWiFS radiance. HyperSAS data were slightly different in in-situ radiance and irradiance, but they did not have spectral shift in absorption bands. Although all radiance bands measured between HyperSAS and SeaWiFS had an average 25% error, the 11% absolute error was relatively lower when atmospheric correction bands were omitted. This error is related to the SeaWiFS standard atmospheric correction process. We have to consider and improve this error rate for calibration and validation of GOCI. A reference target site around Dokdo Island was used for studying calibration and validation of GOCI. In-situ ocean- and bio-optical data were collected during August and October, 2009. Reflectance spectra around Dokdo Island showed optical characteristic of Case-1 Water. Absorption spectra of chlorophyll, suspended matter, and dissolved organic matter also showed their spectral characteristics. MODIS Aqua-derived chlorophyll-a concentration was well correlated with in-situ fluorometer value, which installed in Dokdo buoy. As we strive to solv the problems of radiometric, atmospheric, and bio-optical correction, it is important to be able to progress and improve the future quality of calibration and validation of GOCI.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.43 no.3 s.309
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• pp.76-83
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• 2006

A main objective of audio equalizer is for user to tailor acoustic frequency response to increase sound comfort and example applications of audio equalizer includes large-scale audio system to portable audio such as mobile MP3 player. Up to now, all the audio equalizer requires manual setting to equalize frequency bands to create suitable sound quality for each genre of music. In this paper, we propose an intelligent audio graphic equalizer system that automatically classifies the music genre using music content analysis and then the music sound is boosted with the given frequency gains according to the classified musical genre when playback. In order to reproduce comfort sound, the musical genre is determined based on two-step hierarchical algorithm - coarse-level and fine-level classification. It can prevent annoying sound reproduction due to the sudden change of the equalizer gains at the beginning of the music playback. Each stage of the music classification experiments shows at least 80% of success with complete genre classification and equalizer operation within 2 sec. Simple S/W graphical user interface of 3-band automatic equalizer is implemented using visual C on personal computer.