• Title/Summary/Keyword: Synthetic division

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Chemical Sensors Array Optimization Based on Wilks Lamda Technique (Wilks Lamda 방법을 이용한 화학센서 어레이 최적화)

  • Jeon, Jin-Young;Shin, Jeong-Suk;Yu, Joon-Boo;Byun, Hyung-Gi
    • Journal of Sensor Science and Technology
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    • v.23 no.5
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    • pp.299-304
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    • 2014
  • Optimizing the performance of a composite sensor array is necessary when the number of sensors to choose from is large. In this paper, we present a chemical sensors array optimization method using Wilks Lamda algorithm applicable a device to detect low concentration of alcohol from driver's exhale breath for interlocking engine ignition preventing drink-driving. More than 20 chemical sensors fabricated different synthetic stuffs and heater temperatures by collaborators were nominated, 5 sensors were selected for optimal sensors array using the method, and alcohol samples were well discriminated from the interference gases inside the vehicle. It has been confirmed by Principal Component Analysis (PCA).

Biodegradability and Risk Assessment of Biomass-based Polymeric Materials

  • Han, Song Yi;Park, Chan Woo;Jang, Jae Hyuk;Lee, Seung Hwan
    • Journal of Forest and Environmental Science
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    • v.31 no.4
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    • pp.297-302
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    • 2015
  • With the intention to solve environmental problems caused by synthetic plastics from petroleum resources, biodegradable polyurethane foams and thermosetting moldings were prepared from biomass, such as wood and wheat bran by liquefaction method. Biodegradability of these biomass-based polymeric materials was investigated. In activated sludge, polyurethane foams from liquefied wheat bran and thermosetting molding from phenolated wood were decomposed approximately 14% and 29% for 20 days, respectively. One of the wood fungi, Coriolus versicolor was able to grow without supplemental nutrition, only with distilled water and polyurethane foam as a nutrition source. Risk assessments were also conducted and results showed that estrogenicity, mutagenicity, and carcinogenicity were not observed in the extractives of biomass- based polymeric materials.

Characterization of (Y,Gd) $BO_3$:Eu Phosphors Prepared by Urea Hydrolysis Method

  • Park, Jung-Min;Kim, Chang-Hae;Jung, Ha-Kyun;Park, Hee-Dong;Park, Yoon-Chang
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.792-794
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    • 2002
  • Uniform cylinder-shaped precursors for (Y,Gd)$BO_3$:Eu phosphors were prepared by urea hydrolysis reaction. After heating the precursors at lower temperature than general synthetic methods, the phosphor powders were well dispersed and held their original shapes. Their emissions under vacuum-ultraviolet (VUV) excitation appeared with the peaks at 593nm due to magnetic dipole transition from $^5D_0$ to $^7F_1$, 612nm and 627nm due to electric dipole transition from $^5D_0$ to $^7F_2$

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Bacillus sp. BS061 Suppresses Powdery Mildew and Gray Mold

  • Kim, Young-Sook;Song, Ja-Gyeong;Lee, In-Kyoung;Yeo, Woon-Hyung;Yun, Bong-Sik
    • Mycobiology
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    • v.41 no.2
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    • pp.108-111
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    • 2013
  • The use of a microorganism, or its secretions, to prevent plant disease offers an attractive alternative or supplement to synthetic fungicides for the management of plant disease without the negative effects of chemical control mechanisms. During a screening for microorganisms with the potential to be used as microbial fungicides, Bacillus sp. BS061 was isolated from a plant leaf. The strain BS061 potently inhibited the mycelial growth of Botrytis cinerea, and significantly reduced disease incidence of powdery mildew in cucumber and strawberry. We also found that the culture filtrate of BS061 inhibited the mycelial growth of various plant pathogens.

SAR Processing Software for Ground Station

  • Kwak, Sung-Hee;Lee, Young-Ran;Shin, Dong-Seok;Park, Won-Kyu
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.634-636
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    • 2003
  • Satrec Initiative (Si) is developing a ground processing system for Synthetic Aperture Radar (SAR) data. SAR provides its own illumination and is not dependent on the light from sun, thus permitting continuous day/night operation and all-weather imaging. The system is capable of producing standard level products from SAR signal. Hence, the system should be able to perform matched filtering, range compression, azimuth compression, multi-look image generation, and geocoded image generation. This paper will describe the processing steps including algorithms, design, and accuracy of the Si's SAR processing system by comparing with commercial software.

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Novel synthetic method for the preparation of α-iododaphnetin using benzyltrimethylammonium dichloroiodate

  • Kim, Taek-Soo;Kim, Bo-Ram;Park, Jeong Hoon;Yang, Seung Dae
    • Journal of Radiopharmaceuticals and Molecular Probes
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    • v.2 no.1
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    • pp.56-60
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    • 2016
  • Benzyltrimethylammonium dichloroiodate in the presence of $ZnCl_2$ has been used for aromatic iodination of electron rich aromatic compounds. However, Baylis-Hillman type regioselective ${\alpha}$-iodination was carried out electronically rich coumarin compound under mild reaction condition with excellent chemical yield. Finally, $BBr_3$ demethylation gave ${\alpha}$-iododaphnetin.

Relationships Between the Larval Growth Inhibition of Caenorhabditis elegans by Apigenin Derivatives and Their Structures

  • Yoon, Young-Ah;Kim, Ho-Jung;Lim, Yoong-Ho;Shim, Yhong-Hee
    • Archives of Pharmacal Research
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    • v.29 no.7
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    • pp.582-586
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    • 2006
  • Due to consumer reluctance to take synthetic drugs for nematode infections and the appearance of resistance to anthelminthic drugs, new drugs from natural products must be developed. Caenorhabditis elegans is one of the freely living nematodes and serves as a good model system for screening anthelminthic drugs. In this study, thirteen flavonoid derivatives were tested for anthelminthic activity and the relationships between their activities and structures were investigated. The structural information combined with the data for the larval growth inhibition of C. elegans provided meaningful structural insights in the search for new anthelminthic drugs.

A Comparative Study of Reservoir Surface Area Detection Algorithm Using SAR Image (SAR 영상을 활용한 저수지 수표면적 탐지 알고리즘 비교 연구)

  • Jeong, Hagyu;Park, Jongsoo;Lee, Dalgeun;Lee, Junwoo
    • Korean Journal of Remote Sensing
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    • v.38 no.6_3
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    • pp.1777-1788
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    • 2022
  • The reservoir is a major water supply source in the domestic agricultural environment, and the monitoring of water storage of reservoirs is important for the utilization and management of agricultural water resource. Remote sensing via satellite imagery can be an effective method for regular monitoring of widely distributed objects such as reservoirs, and in this study, image classification and image segmentation algorithms are applied to Sentinel-1 Synthetic Aperture Radar (SAR) imagery for water body detection in 53 reservoirs in South Korea. Six algorithms are used: Neural Network (NN), Support Vector Machine (SVM), Random Forest (RF), Otsu, Watershed (WS), and Chan-Vese (CV), and the results of water body detection are evaluated with in-situ images taken by drones. The correlations between the in-situ water surface area and detected water surface area from each algorithm are NN 0.9941, SVM 0.9942, RF 0.9940, Otsu 0.9922, WS 0.9709, and CV 0.9736, and the larger the scale of reservoir, the higher the linear correlation was. WS showed low recall due to the undetected water bodies, and NN, SVM, and RF showed low precision due to over-detection. For water body detection through SAR imagery, we found that aquatic plants and artificial structures can be the error factors causing undetection of water body.

Efficient Synthetic Method of Z-Selective 2-Halo-1,3-dienes from Reactions of Allenols Possessing Ethoxycarbonyl and Vinyl Group with Indium Trihalide

  • Eom, Da-Han;Kim, Sung-Hong;Lee, Phil-Ho
    • Bulletin of the Korean Chemical Society
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    • v.31 no.3
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    • pp.645-649
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    • 2010
  • An efficient synthetic method of Z-selective 3-ethoxycarbonyl-2-halo-1,3-dienes and 3-vinyl-2-halo-1,3-dienes was developed from the reaction of allenols having ethoxycarbonyl and vinyl group with indium trihalides at room temperature in $CH_2Cl_2$.