• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.24 no.4 s.175
• /
• pp.982-990
• /
• 2000

The finite element alternating method is extended further for general three dimensional cracks in an isotropic body subjected to the mode I loading. The required analytical solution for a dime dimensional crack in an infinite isotropic body is obtained by solving the integral equations. In order to remove the high singularity in integration, the technique suggested by Keat et al. was used. With the proposed method several example problems are solved in order to check the accuracy and efficiency of the method.

• The Korean Journal of Food And Nutrition
• /
• v.14 no.4
• /
• pp.329-332
• /
• 2001

The antimutagenic activity of resveratrol on the mutagenicity induced by Trp P-1 (3-amino-1,4-dime-thyl-5H-pyrido{4,3-b}indole) was studied using the Ames test with Salmonella typhimurium TA98 and 100. Trp P-1 showed strong mutagenecity in S. typhimurium TA98, but was higly decreased mutagenecity in S. typhimurium TA100. This result suggests that the mutagenecity of Trp P-1 can be mainly induced by the DNA lesions causing frame shift. Resveratrol itself did not show antibacterial effect upon 300 $\mu\textrm{g}$/assay. Resveratrol showed the strongest inhibitory effect with dose dependent manner on the mutagenicity induced by Trp P-1. The inhibition rates of resveratrol at concentration of 2, 10, 25, 50, 100, 300 $\mu\textrm{g}$/assay were 13%, 37%, 52%, 65%, 81%, 89%, respectively.

• Microbiology and Biotechnology Letters
• /
• v.28 no.6
• /
• pp.322-328
• /
• 2000

To screen agent for the treat-ment of Alzhimers Disease several strains of bacteria producing acetylcholinesterase inhibitor ware isolated from soil. Strain 960903 showed strong acetylcholinesteras inhibitory activity and low butyrylcholinesterse inhibitory activity. The strain 960903 was identified as Pseudomonas sp. Acetylcholinesterase inhibitor ws highly achieved in fermentation medium containing soluble starch 3.0%, glycerol 1.0%, pharmamedia 0.5%, KCI 0.3%, $CaCO_3$ 0.2%, MgS $O_4$..$7H_2$O 0.05%, $KH_2$$PO_4$ 0.05%(pH6.5) at $30^{\circ}C$ for 4 days. Acetylcholinesterase inhibitor was purified by Diaion WA-30($OH^{-}$) column charomatography and cellulose column chromatography. Acetylcholinesterase inhibi-tor showd the maximum wavelength at 205 nm and was soluble in water, acetic acid, ethanol, methanol and dime-thyl sulfoxide. The concentration of 50% inhibition($IC_{50}$) of inhibitor against acetylcholinesterase was 25$\mu\textrm{g}$/ml. The inhibitor was inactivated on heating ar $100^{\circ}C$ fro 15 min and more stable in acidic region than alkaline region.n.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.16 no.1
• /
• pp.1-8
• /
• 1979

This paper describes a simple asynchronous time dime division multiplexing system developed by means of a synchronous delta modulation. In realizing asynchronous multlplexlng system time author deals with a technique of multiplexing communication channels by reversing the polarity of output pulse and superimposing the channels at a certain time Interval. The results of experiments on the number of error pulses, signal-to-noise ratio and frequency characteristics have shown fair agreements with the theoretically predicted ones related to the system.

• Journal of Biomedical Engineering Research
• /
• v.8 no.1
• /
• pp.13-28
• /
• 1987

Crosslinked poly(2-hydroxyethylmethacrylate) has been prepared by polymerizing 2-hydroxyethyl methacrylate(HEMA) with crosslinkers such as ehyleng glycol dime- thacrylate(EGDMA), tetraethylene glycol dimethacrylate(TEGDMA), tetraethylene glycol diacrylate(TEGDA), divinyl benzene(DVB), and N, N-methylenebisacry- lamide(MAB) in the presence of initiator $\alpha$ , $\alpha$ -azobisisobutyronitrile at 60。C, The synthesized copolymers were identified by FT-lR spectrophotomether. The swelling properties of the crosslinked copolymers in various solvents such as water, methanol, ethanol, n-propanol, and n-butanol were investigated at different temperatures. The thermal properties of the crosslinked coplymers were also measured by differential scanning calorimetry(DSC) and thermogravimetry(TG)

• Journal of the Korean Electrochemical Society
• /
• v.2 no.1
• /
• pp.27-30
• /
• 1999

Self-Assembled monolayers of carboxyl-terminated alkanethiols, which is negatively charged in pH 7.0, were usually used to facilitate the electron transfer between the positively charged protein and the electrode. In case of L-cysteine, as it has both positive and negative group, it can be a candidate for a new modifier to facilitate positively charged protein or negatively charged protein. Our investigation of L-cysteine shows that the electron transfer occurs successfully to both cytochrome c (cyt. c) and pyrroloquinoline quinone (PQQ). By using 1-ethyl-3-(3-dime-thlyaminopropyl) carbodiimide (EDC), we made a covalent bond between cyt. c and monolayer. Then PQQ was electrostatically adsorbed to the same monolayer. Cyclic voltammograms show that both molecules do not interfere each other and electron transfer is appreciable.

• Proceedings of the Korea Society of Information Technology Applications Conference
• /
• 2006.06a
• /
• pp.700-709
• /
• 2006

본 논문에서는 PDA에서 지문 이미지를 전송하여 인식할 수 있는 지문인식 웹 서비스 시스템을 구현하였다. 본 시스템은 모바일 클라이언트와 지문인식 웹 서비스 제공자로 구성된다. 모바일 클라이언트는 채취된 지문 이미지를 DIME(Direct Internet Message Encapsulation)을 이용하여 지문인식 웹 서비스 제공자를 요청함으로써 저장 공간이 제약적인 PDA에 대용량의 지문 데이터베이스를 설치할 필요 없이 지문인식 결과를 받아 올 수 있다. 지문인식 웹 서비스 제공자는 지문 이미지를 수신 받아 지문인식시스템을 호출하여 인식을 수행한 후 인식결과를 반환하는 서비스를 제공한다. 인식 결과는 XML형태로 데이터를 교환함으로써 무선 인터넷을 이용하는 PDA뿐만 아니라 유선 인터넷을 이용한 클라이언트에게도 동일한 서비스를 제공할 수 있다.

• YAKHAK HOEJI
• /
• v.38 no.5
• /
• pp.516-519
• /
• 1994

The derivatives of methyl 5-hydroxy-dinaphtho[1,2-2',3']furan-7,12-dione-6-carboxylate (MHDDC) were synthesized by condensing alkyl sulfate or alkyl halide with MHDDC in organic solvent, and their structures were identified by NMR, MS, UV, IR etc. We also investigated the physico-chemical properties, physiological activities, and set up the micro-analytical method of the compounds.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2009.04a
• /
• pp.122-125
• /
• 2009

기존의 인터넷 익스플로러는 높은 보급률의 이점을 지니고 있지만 인터넷을 이용하기 위한 기본지식의 필요성과 키보드, 마우스와 같은 장치를 이용한 입력방식은 장애인 및 고령층의 사용자들이 이용하기에는 불편하다. 이와 같은 문제점을 해결하고자 본 논문에서는 웹 서비스 기술을 이용하여 기존의 음성인식 시스템을 웹 서비스로 재구성하고 클라이언트가 음성인식 웹 서비스를 요청하고 음성명령이 가능하도록 인터넷 익스플로러에 음성명령이 가능한 Navigaotr를 Toolbar 형태의 프로그램을 구현하였다. 본 시스템은 클라이언트가 사용하는 음성 Navigator Toolbar와 웹 서비스를 통해서 음성 서비스를 제공하는 음성 서비스 프로바이더로 구성된다. 음성 Navigator Toolbar는 인터넷 환경에서 음성데이터를 바이너리 포맷형식인 DIME을 이용하여 음성 서비스 프로바이더로 전송하고 반환 결과를 가지고 URL Navigator를 통해 인터넷 페이지를 이동시킨다. 음성 서비스 프로바이더는 사용자가 전송한 음성데이터를 인식기를 통해 인식하고 결과를 가지고 정보 Database를 검색하여 실제 인터넷 주소를 사용자에게 반환한다.

• Environmental Mutagens and Carcinogens
• /
• v.18 no.1
• /
• pp.37-42
• /
• 1998

In the present study, we have evaluated cytotoxic effects of the chloroform soluble fraction of the methanolic extract of Perilla frutescens in human oral epitheloid carcinoma cells. The light microscopic study showed morphological changes of the treated cells. Cell membrane damaging activity was measured by the lactate dehydrogenase (LDH) assay and disruptions in cell organelles were determined by 3-(4,5-dime-thylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT), neutral red (NR) and sulforhodamine protein B (SRB) of colorimetric assay. These results suggest that Perilla frutescens retains a potential antitumor activity.