• Bulletin of the Korean Chemical Society
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• v.22 no.4
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• pp.372-374
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• 2001

Three simple carboxamides incorporating the phenethylamine moiety have been isolated from strain XR-NC of a symbiotic bacterium Xenorhabdus nematophilus. Their structures were identified by spectroscopic data and synthesis. The compounds exhibited significant cytotoxicities against human cancer-cell line, viz. the gastric adenocarcinoma, colon adenocarcinoma and lung adenocarcinoma.

• Broadcasting and Media Magazine
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• v.24 no.2
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• pp.73-82
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• 2019

국제 표준화 기구 ISO/IEC JCT1/SC29/WG1 JPEG(Joint Photographic Experts Group)에서는 지난 30여년간 JPEG, JPEG 2000, JPEG XR, JPEG XT, JPEG XS 등 다양한 2D 이미지 압축 관련 표준을 제정해왔다. 지난 2014년 10월에는 JPEG Pleno라는 이름으로 2D 이미지가 아닌 3차원 영상 정보 압축을 위한 새로운 표준화 과제를 시작했다. JPEG Pleno에서 다루는 3차원 영상 정보는 라이트 필드, 포인트 클라우드, 홀로그램이다. 본 원고에서는 현재 JPEG Pleno 홀로그래피에서 다뤄지는 디지털 홀로그램 영상 압축에 대한 국제 표준화 현황을 소개하고, 향후 나아갈 방향을 전망해 본다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2022.06a
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• pp.1272-1274
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• 2022

COVID-19 펜데믹으로 인한 비대면 문화 확산과함께 사회 관계망 서비스 등 비대면 수단들을 사용하게 되면서 비대면 기술적 환경의 대안으로 '메타버스(Metaverse)'가 부각되었다. 이에 본 논문은 메타버스의 다양한 개념과, XR, 홀로그램, UI, VR 컨트롤러, NFT 등 메타버스 기반 기술 및 메타버스 기술의 ICT 표준화 현황 및 전략에 대해 살펴보았다.

• Journal of the Korean Association of Geographic Information Studies
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• v.15 no.4
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• pp.55-64
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• 2012

This study developed a mobile application system for serving cadastral information needed to propel diverse cadastral works including cadastral resurvey efficiently. First, BlackPoint-Xr was selected as a spatial client engine to embody the cadastral information system based on mobile device including smart phone and tablet PC. The mobile cadastral information system contains functions such as finding location with GPS based on spatial information such as aerial photo, cadastral map, administrative map, and digital map, parcel search with address and lot number, finding land register including land address, the classification of land, and land price. Especially, this study developed functions which can analyze the measurement of distance, area, slope and cross-section elevation of land to apply construction work and land maintenance project. This system can support efficiently cadastral work and construction project by serving diverse cadastral information to users in field and can be also applied to the field of digital cadastral information.

• Microbiology and Biotechnology Letters
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• v.47 no.4
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• pp.530-535
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• 2019

Diverse types of nuruks (traditional Korean fermentation initiators) were examined in order to isolate thermotolerant yeast strains capable of utilizing xylose as a carbon source. Among twenty yeast strains that grew at 46℃, MBY/L1597 showed a notably higher specific growth rate than other strains. This strain was identified as Millerozyma farinosa. While the control strain M. farinosa KCTC27412 (= CBS7064) did not show xylose reductase (XR) activity and apparent growth at 46℃, M. farinosa MBY/L1597 exhibited XR activity of 4.98 ± 0.49 U/mg protein when NADPH was used as a cofactor. M. farinosa MBY/L1597 cultured at 46℃ produced (9.87 ± 1.00 g/l) xylitol from 20 g/l xylose, corresponding to approximately 50% yield. M. farinosa MBY/L1597 was deposited at the Korean Collection for Type Cultures as KCTC27797.

• Journal of Microbiology and Biotechnology
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• v.9 no.2
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• pp.140-146
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• 1999

When methanol was the sole carbon source, Methylobacterium organophilum NCIB 11278, a facultative methylotroph, accumulated Poly-$\beta$-hydroxybutyrate (PHB) as 59% (w/w) of dry cell weight under potassium limitation, 37% under sulfate limitation, and 33% under nitrogen limitation. Based on a stoichiometric analysis of PHB synthesis from methanol, it was suspected that PHB synthesis is accompanied by the overproduction of energy, either 6-10 ATP and 1 $FADH_2$ or 6 ATP and 3 NADPH to balance the NADH requirement, per PHB monomer. This was confirmed by observation of increased intracellular ATP levels during PHB accumulation. The intracellular ATP with limited potassium, sulfate, and ammonium increased to 0.185, 0.452, and 0.390 $\mu$moles ATP/g Xr (residual cell mass) during PHB accumulation, respectively. The intracellular ATP level under potassium limitation was similar to that when there was no nutrient limitation and no PHB accumulation, 0.152- 0.186 $\mu$moles ATP/g Xr. We propose that the maximum PHB accumulation observed when potassium was limited is a result of the energy balance during PHB accumulation. Microorganisms have high energy requirements under potassium limitation. Enhanced PHB accumulation, in ammonium and sulfate limited conditions with the addition of 2,4-dinitrophenol, which dissipates surplus energy, proves this assumption. With the addition of 1 mM of 2,4-dinitrophenol, the PHB content increased from 32.4% to 58.5% of dry cell weight when nitrogen limited and from 15.1 % to 31.0% of dry cell weight when sulfate limited.

• Journal of the Korean Society of Radiology
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• v.14 no.3
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• pp.289-294
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• 2020

In order to control the quality of X-ray images and patient exposure, it is necessary to document the output dose(air absorption dose(mGy)) output from the X-ray unit from the measurement. The purpose of this study is to find an equation that can calculate the output dose from the measurement of the output dose and output factor(Of) of the X-ray Unit. The output dose and output factors of the X-beam irradiated from the X-ray unit were measured using an XR multi-detector. The output dose calculation formula was obtained by fitting the measured output dose divided by the tube current-exposure time product(mAs) and the set tube voltage with Allometric1. The final output dose calculation formula was obtained by multiplying this formula with the output factor. It is considered that the obtained final output dose calculation formula will be useful for all tube voltages, tube currents, exposure times, field sizes, and distances.

• The Journal of Society for e-Business Studies
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• v.10 no.4
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• pp.53-81
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• 2005

Current DRM system has limitation in protection of user's privacy Therefore, many troubles are expected in service providing if it comes into the ubiquitous times of context-aware environment. HKUST Proposed a watermark-based web service DRM system. However, the relevant study does not consider ubiquitous environment and cannot provide service that considered a context. And privacy protection of a user is impossible. On the other hand, Netherlands Phillips laboratory indicated a privacy problem of a DRM system and they proposed an alternative method about this. However, in relevant study, a Sniffing/Replay attack is possible if communicated authentication information are exposed between a user and device. We designed web services adaptable privacy-aware DRM architecture which supplements these disadvantages. Our architecture can secure user authentication mechanism for sniffing/Replay attack and keep anonymity and protect privacy Therefore , we can implement the privacy-aware considered web service DRM system in Context-Aware environment.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.43 no.4
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• pp.321-327
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• 2017

This study was carried out to develop a stable plant-derived natural sunscreen (BHC-S) that replaces the artificially synthesized organic sunscreen agents. The natural sunscreen (BHC-S), which is composed of peanut extract, Centella asiatica extract, and Ecklonia stolonifera extract, has the same level of ultraviolet shielding effect as PARSOL MCX-XR (OMC), which is a synthetic sunscreen. and has safety against skin. MultiFunctional effect such as and anti-wrinkle improvement. Thus, it can be used as raw material for natural cosmetics for ultraviolet ray blocking, and anti-aging.

• Journal of Microbiology and Biotechnology
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• v.13 no.4
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• pp.501-508
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• 2003

Artificial coupling of one enzyme with another can provide an efficient means for the production of industrially important chemicals. Xylose reductase has been recently discovered to be useful in the reductive production of xylitol. However, a limitation of its in vitro or in vivo use is the regeneration of the cofactor NAD(P)H in the enzyme activity. In the present study, an efficient process for the production of xylitol from D-xylose was established by coupling two enzymes. A NADH-dependent xylose reductase (XR) from Pichia stipitis catalyzed the reduction of xylose with a stoichiometric consumption of NADH, and the resulting cofactor $NAD^+$ was continuously re-reduced by formate dehydrogenase (FDH) for regeneration. Using simple kinetic analyses as tools for process optimization, suitable conditions for the performance and yield of the coupled reaction were established. The optimal reaction temperature and pH were determined to be about $30^{\circ}C$ and 7.0, respectively. Formate, as a substrate of FDH, affected the yield and cofactor regeneration, and was, therefore, adjusted to a concentration of 20 mM. When the total activity of FDH was about 1.8-fold higher than that of XR, the performance was better than that by any other activity ratios. As expected, there were no distinct differences in the conversion yields of reactions, when supplied with the oxidized form $NAD^+$ instead of the reduced form NADH, as a starting cofactor for regeneration. Under these conditions, a complete conversion (>99%) could be readily obtained from a small-scale batch reaction.