• Title/Summary/Keyword: Lee Sam

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Sulfate Resistance of Concrete using Ground Granulated Blast-furnace Slag for Recycling

  • Moon, Han-Young;Lee, Seung-Tae;Kim, Hong-Sam
    • Proceedings of the IEEK Conference
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    • 2001.10a
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    • pp.508-513
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    • 2001
  • Recently, ground granulated blast-furnace slag (GGBFS) has been increasingly used as additive for concrete. Many researchers reported that concrete using GGBFS had a better resistance under severe environments, such as marine or sulfate-rich soils, than Portland type cement concrete. The aim, therefore, of this study is to evaluate on the effectiveness of concrete using GGBFS when the concrete exposes to sulfate-rich environment. The detailed items for experiments show 2 series consisted of sulfate immersion test with mortar and sulfate diffusion test with concrete. The sulfate immersion test was performed for 400 days and contained reduction of compressive strength, length change and XRD analysis. For sulfate diffusion test, sulfate ions diffusivity was calculated on tile consideration of electrochemical theory by the diffusion cell test. As the results of this study, it was found that the concrete using GGBFS as additive was superior to portland type cement concrete. Consequently, the use of concrete with GGBFS for recycling may expect the durable and economical benefits.

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A Study on the Fabrication of Fe-Co Magnetic Fluid from the Waste Pickling Liquor of Steel

  • Kim, Young-Sam;Lee, Jong-Heon
    • Proceedings of the IEEK Conference
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    • 2001.10a
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    • pp.149-153
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    • 2001
  • This paper describes on the fabrication of Fe-Co hydrophilic magnetic fluids from the waste pickling liquor of steel. By adding with HNO$_3$in the waste liquor oxidation is proceeded from Fe$^{3+}$ion at 6$0^{\circ}C$ with air blowing. Ultra-fine Co-ferrite particles with the mean particle size of 50 $\AA$ were produced at pH 12 after adjusting the ratio of Fe$^{3+}$Co$^{2+}$=7/3(wt%) and Fe-Co particles with the mean particle size of 94 $\AA$ were produced by reducing the Co-ferrite particle with H$_2$at the temperature of 50$0^{\circ}C$. After triple adsorption of oleic acid dodecyl benzene sulfonate(D.B.S.) and tetra methyl ammonium(T.M.A.) ions on the surface of Fe-Co particles Fe-Co hydrophilic magnetic fluid was produced by dispersing the Fe-Co particles in ethylene glycol solution. The magnetization of the Fe-Co hydrophilic magnetic fluid increased with increasing the Fe-Co concentration. The magnetic fluid containing 70% (g/cc) Fe-Co showed 73 emu/g in magnetization at the magnetic intensity of 10 kOe.kOe.e.

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Optical Add/Drop multiplkexer for WDM system using fiber bragg grating (광섬유 격자 소자를 이용한 WDM 시스템용 전광 분기 결합 장치의 구조 연구)

  • Kim, Se-Yoon;Lee, Sang-Bae;Choi, Sang-Sam;Chung, Joon;Kim, Sang-Yong;Park, Il-Jong;Jeong, Ji-Chai
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.34D no.4
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    • pp.106-112
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    • 1997
  • We demonstrate a novel wavelength -division add/drop multiplexer employing fiber bragg gratings and polarization beam splitters. the multiplexer is easy to fbricate without any special technique such as UV trimming, and yet shows very stable performance with less than 0.3-dB crosstalk power penalty in a 0.8-nm-spaced, 2.5Gbps-per-channel WDM transmission system. We find that the rejection of adjacent channels is more than -6dB, and the signal leakage through output port is less than -34dB.

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Implementation of Low Cost WiMAX Remote Radio Head with Ethernet (Ethernet을 이용한 저가형 WiMAX RRH 기지국 구현)

  • Seo, Seong-Sam;Lee, Hyun-Seok
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.49 no.1
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    • pp.35-42
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    • 2012
  • This paper is about the implementation of low cost WiMAX remote radio head system with Ethernet instead of optical link. We deployed a simplified frame structure on the data frames transmitted between a basestation and remote radio heads in order to maximize Ethernet link utilization which shows relatively lower maximum throughput compared to that of optical links. In addition, a synchronization mechanism was applied on a basestation and remote radio heads placed on remote sites in order for simultaneous data transmission and reception in all remote radio heads which are essential for proper communication with terminals. These schemes are implemented with FPGA. The results of experiment with a WiMAX Femtocell show that our remote radio head systems efficiently deliver radio frames with proper timing.

Receptor-oriented Pharmacophore-based in silico Screening of Human Catechol O-Methyltransferase for the Design of Antiparkinsonian Drug

  • Lee, Jee-Young;Baek, Sun-Hee;Kim, Yang-Mee
    • Bulletin of the Korean Chemical Society
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    • v.28 no.3
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    • pp.379-385
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    • 2007
  • Receptor-oriented pharmacophore-based in silico screening is a powerful tool for rapidly screening large number of compounds for interactions with a given protein. Inhibition of the enzyme catechol-Omethyltransferase (COMT) offers a novel possibility for treating Parkinson's disease. Bisubstrate inhibitors of COMT containing the adenine of S-adenosylmethionine (SAM) and a catechol moiety are a new class of potent and selective inhibitor. In the present study, we used receptor-oriented pharmacophore-based in silico screening to examine the interactions between the active site of human COMT and bisubstrate inhibitors. We generated 20 pharmacophore maps, of which 4 maps reproduced the docking model of hCOMT and a bisubstrate inhibitor. Only one of these four, pharmacophore map I, effectively described the common features of a series of bisubstrate inhibitors. Pharmacophore map I consisted of one hydrogen bond acceptor (to Mg2+), three hydrogen bond donors (to Glu199, Glu90, and Gln120), and one hydrophobic feature (an active site region surrounded by several aromatic and hydrophobic residues). This map represented the most essential pharmacophore for explaining interactions between hCOMT and a bisubstrate inhibitor. These results revealed a pharmacophore that should help in the development of new drugs for treating Parkinson's disease.

A Proposal of Energy Retrofitting Methods for Small-to-Medium Existing Building (중소규모 기존 건물의 에너지 개수 방법에 관한 실증연구)

  • Jeong, Hee-Gyu;Lee, Young-Jae;Song, Doo-Sam
    • 한국태양에너지학회:학술대회논문집
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    • 2012.03a
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    • pp.286-292
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    • 2012
  • In recent years, building energy has received much attention and there are many support system to reduce building energy consumption. In addition, It is clear that encouraging to energy efficiency investments can be beneficial to our society, because of the energy supply instability and higher energy price in Korea. Nevertheless, ESCO business, represent the existing building energy retrofit business, hardly has not expanded in Korea. besides, in the case of existing building, it is more difficult to achieve the energy retrofit measures than new building, due to the existing buildings have attributes such as a long life and a lots of energy factor, etc. Therefore, for activate ESCO business and expand ESCO bussiness target to small-to-medium building, it is needed to optimization of retrofitting methods for existing small-to medium buildings in Korea. this research was to derive energy retrofit methods through the energy audit and analysis performed for a small-to-medium building located in Suwon, Korea.

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Characterization of the Serotyping and the Plasmid Profile of E. coli Isolated from Foods and Clinical Specimens

  • Hyo-Shun Kwak;Chong-Sam Lee
    • Animal cells and systems
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    • v.3 no.4
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    • pp.399-405
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    • 1999
  • Characteristics of the food isolates and the clinical specimens isolates of E. coli harboring virulence factor and their correlations were analyzed. The predominant serogroup were 08 and 027 in the food isolates and 06 and 018 in the clinical isolates, respectively, showing the different patterns in serogrouping between them. In the test of antibiotic susceptibility, the food isolates were resistant to cephalothin, streptomycin, tetracycline and minocycline, and the clinical isolates were resistant to ampicillin, carbenicillin, streptomycin, cephalothin, trimethoprim/sulfamethoxazole, tetracyclino and minocycline, respectively. It shows that E.coli isolated from food sources and clinical specimens might be correlated. Plasmid profile in the food and clinical isolates showed wide diversity. Especially, large sized plasmid DNA such as 60 MDa, 90 MDa and 120 MDa were observed. The plasmid DNA (60 MDa) containing a gene encoding hemolysin was found in 43% of the food isolates and 35% of the clinical isolates. To study chromosomal homology, PFGE analysis was performed, showing different restriction patterns by Xbal. This result indicates that there were no genetic correlations between the foods and the clinical isolates.

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Automatic Detection of the Middle Tooth Crown Part for Full Automatic Tooth Segmentation in Dental CT Images

  • Lee, Chan-Woo;Chae, Ok-Sam
    • Journal of the Korea Society of Computer and Information
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    • v.23 no.3
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    • pp.17-23
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    • 2018
  • In this paper, we propose the automatic detection method which find the middle part of tooth crown to start individual tooth segmentation. There have been many studies on the automation of individual tooth segmentation, but there are still many problems for full automation. Detection of middle part of tooth crown used as initial information for individual tooth segmentation is closely related to performance, but most studies are based on the assumption that they are already known or they can be represented by using a straight line. In this study, we have found that the jawbone curve is similar to the tooth alignment curve by spatially analyzing the CT image, and propose a method to automatically detect the middle part of tooth crown. The proposed method successfully uses the jawbone curves to successfully create a tooth alignment curve that is difficult to detect. As the middle part of tooth crown is in the form of a tooth alignment curve, the proposed method detects the middle part of tooth crown successfully. It has also been verified by experiments that the proposed method works well on real dental CT images.

Suppressive Effects of Young Radish Cultivated with Sulfur on Growth and Metastasis of B16-F10 Melanoma Cells

  • Kim Soo-Jin;Kim Byung-Sam;Kyung Tae-Wook;Lee Sang-Chul;Rho Chi-Woong;Choi Kyung-Rak;Hwang Hae-Jun;Choi Hye-Seon
    • Archives of Pharmacal Research
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    • v.29 no.3
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    • pp.235-240
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    • 2006
  • The oral administration of extracts of young radishes cultivated with sulfur after intravenous tumor cell injection achieved a marked reduction of pulmonary colonization in mice. Treatment of the mice with extracts of young radish cultivated with sulfur did not show any increase in the number of CD8+ or NK T cells in the spleen, indicating no influence on host immunity. Sulforaphane, which could be a candidate for an active compound from young radishes cultivated with sulfur, inhibited cell growth of B16-F10 melanoma cells. In addition, extracts of the young radish cultivated with sulfur-fed group showed enhanced quinine reductase (QR) activities in the liver and lung and a slight increase of glutathione S-transferase (GST) activity in the liver. These results suggested that the administration of extracts of young radishes cultivated with sulfur suppressed pulmonary tumorigenesis, possibly due to increased activity of detoxification enzymes in the liver and lung, and partly due to cell cytotoxicity.

Counter Plan for Reduction of Elevated Railway Bridge Noise (고가교 철도소음 저감을 위한 대책수립)

  • Kim, Byoung-Sam;Lee, Tae-Keun;Han, Sung-Ik;Yeo, Dae-Yeon;Kim, Hyung-Doo
    • Proceedings of the KSR Conference
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    • 2010.06a
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    • pp.6-12
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    • 2010
  • The source of wayside noise for the train are the aerodynamic noise, wheel/rail noise, and power unit noise. The major source of railway noise is the wheel/rail noise caused by the interaction between the wheels and rails. The Structure borne noise is mainly a low frequency problem. The train noise and vibration nearby the elevated railway make one specific issue. The microphone array method is used to search sound radiation characteristics of elevated structure to predict the noise propagation from an elevated railway. In this paper, the train noise and structure borne noise by train are measured. From the results, we investigated the effect on the sound absorption tunnel for elevated railway.

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