• Journal of Microbiology and Biotechnology
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• v.15 no.3
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• pp.626-632
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• 2005

A new bacterium BL-2 excreting a novel cationic polyglucosamine biopolymer was isolated from the spoiled leaves of Chinese cabbage and identified as Enterobacter sp. BL-2. The isolated Enterobacter sp. BL-2 was cultivated in pH-stat fed-batch culture using acetic acid as the feeding stock at pH 8.0, resulting in 17.11 g/l of cells and 1.53 g/l of an extracellular biopolymer after 72 h. The excreted biopolymer was purified by a three-step procedure, involving ethanol precipitation and deproteinizations, to a nearly homogeneous state, and its molecular weight was found to be 106 kDa. It was composed of glucosamine, rhamnose, and galactose at a molar ratio of 86.4:1.6:1.0, respectively, indicating a rarely found novel high-glucosamine-containing biopolymer. The FT-IR and $^{13}C-NMR$ spectra of the novel cationic polyglucosamine biopolymer PGB-l revealed a close identity with chitosan from crab shell. It can effectively flocculate various suspended solids, including kaolin clay, $Ca(OH)_2,\;Al_{2}O_3$, active carbon, microbial cells, and acidic dyes.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11c
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• pp.2435-2438
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• 2002

본 논문은 다양한 표준의 제어 미들웨어가 설치된 환경에서 흠내의 정보기기간의 정보 전달 및 제어물 위해서 단일한 서비스를 개발, 실행하기 위한 구조를 설명한다. 기존의 가전제품에 다양한 통신 미디어(예: IEEE1394, IrDA, LAM, PLC, Bluetooth 등)이 추가되어 새로운 부가가치를 지원하는 정보가전제품들이 소개되고 있고 이에 적합한 통신 환경이 개발, 보급되고 있다. 또한, 정보기기간의 제어, 데이터 전송, 서비스 개발을 목적으로 다양한 제어 미들웨어(Jini, HAVi, LonWorks, UpnP 등) 이 제시되고 발전해가고 있다. 이러한 추세에 의하면 향후 수년안에 홈네트워크 서비스 플랫폼의 요구사항이 높아지며 특히, 다중 제어 미들웨어를 지원하는 서비스 플랫폼의 등장이 필요한 시점이다. 본 논문에서 설계, 구현한 홈네트워크 통합미들웨어는 서비스 프로바이더(서비스 제공자 및 운용자)에게 서비스개발, 보급 운용의 단일 환경을 제공한다. 이의 한 예제인 홈네트워크 미들웨어 연동 서비스는 서로 다른 제어 미들웨어를 따르는 정보기기간의 연동 서비스를 다양한 매체를 수용하는 홈서버에서 가능하도록 구축하였다.

• BMB Reports
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• v.39 no.5
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• pp.546-555
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• 2006

An acidic polysaccharide fraction that had high anti-complementary activity was isolated from the stems of Grey Mangrove in 0.15% yield. The final fractions was designated HAM-3-IIb-II. The polysaccharide fraction appeared to be homogenous by high performance size exclusion chromatography with an estimated molecular weight of 105 kDa. The isolated polysaccharide is more effective than polysaccharide K (PSK) in its anti-complementary activity at 58 ${\mu}g/ml$ of PSK and 23 ${\mu}g/ml$ of HAM-3-IIb-II that inhibit 50% of complement activity in the complement fixation assay. Structural studies indicated that HAM-3-IIb-II was rich in galacturonic acid along with arabinose, galactose and rhamnose, characterizing a pectin-type polysaccharide, which was also confirmed by FT-IR spectrum. The presence of rich neutral sugar side chains of arabinogalactans may have contributed to the expression of high activity. Traditionally, this mangrove plant is used for medicinal purposes and it appears to have some scientific applications.

• Journal of Microbiology and Biotechnology
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• v.9 no.6
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• pp.820-825
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• 1999

A bacterial strain WN9, which produced a new type of extracellular polysaccharide, was isolated from soil samples. By morphological, physiological, biochemical, and phylogenetic studies, strain WN9 was identified as a Paenibacillus sp. and it was named as Paenibacillus sp. WN9, which produced a high molecular extracellular polysaccharide from glucose. The molecular weight of the exopolysaccharide (EPS-WN9) was estimated to be about 31.5 mega-Da. The FT-IR spectrum of EPS-WN9 revealed typical characteristics of polysaccharides. EPS- WN9 consisted of D-glucose and D-mannose with a molar ratio of 1:1.4 being identified as a neutral sugar component. The acidic component of EPS- WN9 was tyrosine. Rheological analysis of EPS- WN9 revealed that the pseudoplastic property and its apparent viscosity remained stable at various temperatures and pHs.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.303.2-303.2
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• 2014

The oxides of group IV transition metals such as titanium, zirconium, hafnium have many important current and future application, including protective coatings, sensors and dielectric layers in thin film electroluminescent (TFEL) devices. Recently, group IV transition metal oxide films have been intensively investigated as replacements for SiO2. Due to high permittivities (k~14-25) compared with SiO2 (k~3.9), large band-gaps, large band offsets and high thermodynamic stability on silicon. Herein, we report the synthesis of new group IV transition metal complexes as useful precursors to deposit their oxide thin films using chemical vapor deposition technique. The complexes were characterized by FT-IR, 1H NMR, 13C NMR and thermogravimetric analysis (TGA). Newly synthesised compounds show high volatility and thermal stability, so we are trying to deposit metal oxide thin films using the complexes by Atomic Layer Deposition (ALD).

• Korean Journal of Materials Research
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• v.27 no.5
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• pp.255-262
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• 2017

Reactive oxygen species (ROS) can be produced by interactions between sunlight and light-absorbing substances in natural water environments and can completely destroy various organic pollutants in waste water. In this study, we used graphene oxide modified $Ag_2Se$ nanoparticles to enhance photochemically generated oxygen (PGO) species activity. Surface area and pore volumes of the $Ag_2Se-graphene$ ($Ag_2Se-G$) samples showed catastrophic decrease due to deposition of $Ag_2Se$. The generation of reactive oxygen species was detected through the oxidation reaction of DPCI to DPCO. The photocurrent density and the PGO effect increase in the case of the use of modified graphene. The PGO effect of the graphene modified with $Ag_2Se$ composites increased significantly due to a synergetic effect between graphene and the $Ag_2Se$ nanoparticles. The photocatalytic activity of sample was evaluated by measuring the degradation of organic pollutants such as methylene blue (MB) and industrial dyes such as Texbrite BA-L (TBA) under visible light.

• Natural Product Sciences
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• v.20 no.2
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• pp.130-134
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• 2014

An investigation was carried out to identify novel anti-cancer compounds from Korean indigenous plant extracts. Bioassay-guided fractionation and chemical investigation of the EtOAc extract from the leaves and stems of Stauntonia hexaphylla resulted in the isolation of two active compounds, hederagenin 3-O-${\alpha}$-L-arabinoside (1) and quercetin (2). The structures of these compounds were elucidated by spectroscopic methods, including UV, IR, MS, NMR techniques and compared with previous spectroscopic data. The cytotoxic effects of fractions and compounds on HCT116 human colon cancer cells were evaluated using the MTT assay. Quercetin showed a stronger anti-cancer effect when compared to hederagenin 3-O-${\alpha}$-L-arabinoside.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11b
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• pp.574-576
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• 2005

스마트 홈을 구현하기 위한 핸드폰을 이용한 리모트 컨트롤러나 PDA를 통한 통합 리모트 컨트롤러 등의 통합 리모트 컨트롤러에 관한 연구는 활발히 진행되어 오고 있다. 본 논문은 이러한 리모트 컨트롤러에 관한 연구에 대해 두 가지의 새로운 방향을 생각해 보았다. 첫째로 리모트 컨트롤러를 작동시키기 위해서는 핸드폰이나 PDA등의 input 디바이스가 반드시 필요했던 단점을 보완해서 임베디드 보드에 input device 기능을 포함하는 것이다. 그리고 두 번째는 임베디드 리모트 컨트롤러에 user profile을 두어서 단순한 채널 변경의 기능만을 하는 리모트 컨트롤러가 아니라 사용자의 선호도 등의 정보를 가지고 지능적으로 집안 환경을 최적화된 조건으로 만들 수 있도록 설계 했다. 즉 사용자가 가장 좋아하는 TV채널이나 실내온도 등의 정보를 가지고 각 사용자에게 최적화된 환경을 리모트 컨트롤러가 스스로 작동시킬 수 있게 되는 것이다. 그리고 가전을 작동시키기 위해서 임베디드 보드에 있는 IrDA 통신모듈을 통해 일정한 코드 값만 보내주면 되기 때문에 일반적으로 리모트 컨트롤러로 제어가 가능한 거의 모든 전자제품이 쉽게 제어 가능하다.

• The Journal of the Korea Contents Association
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• v.8 no.8
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• pp.147-157
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• 2008

ERP is the general trend of industrial information system and many companies are introducing strategically to strengthen the competitive power. This paper analyzes the efficiency of introducing companies of ERP system using DEA model. We also suggest the introducing of ERP system which can be benchmarked based on analyzed information. We evaluate the CCR, BCC efficiency and RTS of 38 introducing companies of ERP system. The result shows that three enterprises whose values of CCR efficiency are 1, and seven enterprises whose values of BCC efficiency are 1. RTS indicates IRS of 22 companies. DRS of 2 companies and CRS of 4 companies.

• Bulletin of the Korean Chemical Society
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• v.30 no.10
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• pp.2280-2282
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• 2009

Amorphous zinc phosphate nanospheres were prepared via a sonochemical route. Zinc phosphate nanospheres were uniform in shape with an average diameter of 210 nm. The average diameter of nanospheres could be controlled by changing the pH of a precursor solution. This sonochemical method is simple, facile, economical, and environmentally benign. Non-crystalline characteristics of as-prepared zinc phosphate nanospheres were confirmed by X-ray diffraction, transmission electron microscopy, and FT-IR spectroscopy analyses. We believe this technique will be readily adopted in realizing other forms of zinc phosphate nanostructures.