• The Journal of Korean Society of Virology
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• v.30 no.2
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• pp.131-139
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• 2000

Bovine leukemia virus (BLV) is an etiological agent of chronic diseases in cows worldwide. The BLV is one of retroviruses that contain a multi-functional enzyme, reverse transcriptase produced from the pol gene in its genome. We have sequenced some regions in the pol gene of BLV proviruses found in the Southern province of Korea from samples that turned out to be BL V positives by a PCR analysis. On the 5' side of the BLV pol gene (polymerase region), it was found that there were four leucines located at every 7 amino acids. They can form a leucine zipper motif that was not same as the pol gene of Japanese BLV isolate. The sequencing result of the proviral pol gene in Korean-type BLV also revealed some mutations leading to amino acid changes such as $CCT(Pro){\to}CTC(Leu)$, $AAT(Asn){\to}AAA(Lys)$, and non-sensible variations i.e., $TCT(Ser){\to}TCC(Ser)$, $ATT(Ile){\to}ATC(I1e)$ and $ACG(Thr){\to}ACA(Thr)$. On the 3' side of the pol gene (integrase region), some nucleotide sequences were mutated and led to amino acid changes. Among them, a mutation, $GAA(Glu){\to}GAC(Asp)$ occurred in many Korean-type BLV proviruses was very interesting because the amino acid was regarded as one of the most conserved amino acids in the retroviral integrase. It was also notable that the mutation on any leucine residue did not occur, in spite of its frequent appearance.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.16 no.2
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• pp.152-157
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• 2005

Background and Objectives : 10 normal Korean native speakers participated subjects to investigate the acoustic and aerodynamic study of Korean fricatives, affricates, and plosives and to make good use of the results for the patients with articulation problems. Materials and Method Their productions of [asa], [as'a], [aca], $[ac^ha]$, (ac'a), (ata) , $[at^ha]$, and [at'a] were analyzed with Lx Speech Studio Program (Laryngogrtaph Ltd, UK) for acoustic analysis and Phonatory Function Analyze. (Nagashima Ltd. Model PS 77H, Tokyo, Japan) for aerodynamic analysis. Results : The results are as follows : 1) Plosives showed higher Qx1 in vocal folds closure ratio than fricatives and affricates. 2) Tense fricatives, affricates, and plosives showed higher Qx2 in vocal folds closure ratio than asperated and 1ax. 3) Asperated showed higher Qx1 in vocal folds closure ratio than tense and 1ax. 4) Asperated showed higer peak flow rate than tense and 1ax. Conclusion This results may be helpful for treatment in articulation disorders.

• Journal of the Korean institute of surface engineering
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• v.43 no.5
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• pp.230-237
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• 2010

FTMP(friction thermo-mechanical process) is an adaptation of friction stir welding, and can be used as a generic process to modify the microstructure at selective locations. In this study, in order to analyze characteristics of surface modification of ACA4 castings by FTMP, change of rotating speed(R/S) and traveling speed(T/S) of tool were applied as conditional parameter. Analysis of microstructure, hardness, surface roughness and depth of modified zone(MZ) were searched. The best condition were obtained at R/S 600 rpm and T/S 100 mm/min. At this time, hardness was 82 HV, the surface roughness was 0.07 mm and the depth at MZ was 1.72 mm. Free defects microstructure and fine Si particles formation and strong forging effects were analyzed at MZ.

• Textile Coloration and Finishing
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• v.3 no.1
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• pp.17-24
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• 1991

Polyesteramide(PEA) has been synthesized with different molar ratio of 6-aminocaproic acid(ACA) and oligo butylene terephthalate(OBT) prepared from Dimethyl terephthalate(DMT) and 1, 4-butanediol(BD) by the melt polymerization. Oligomer and polymer molecular structure were characterized by IR spectra, H'-NMR spectra. Also the thermal properties were examined by thermogravimetric analysis(TGA) and differential scanning calorimetry(DSC). DSC and TGA results exhibited that the$ T_m$ s were detectable in the vicinity of $170-220^{\circ}C$ and the Ta's were detectable in the vicinity of $380-390^{\circ}C$ . X-ray diffraction analysis results show that the synthesized polyesteramide has high degree of crystallinity.

• YAKHAK HOEJI
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• v.42 no.4
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• pp.364-369
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• 1998

New cephalosporin antibiotics. 7-[(1H-tetrazolyl)acetamidol]-3-[(4-carboxy-3-hydroxyisothiazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid trisodium salt 2,7-[(5-ethylthio-3-hydroxyisothiazol-4-yl)carbox-amidol-3-[(4-carboxy-3-hydroxyisothiazo1-5-yl)thiomethyl)-3-cephem-4-carboxylic acid 3,7-[(2-aminothiazol-4-yl)acetamido]-3-[(4-carboxy-3-hydroxyisothiazol-5-yl]thiomethyl]-3-cephem-4-caboxylic acid 4,7-[(Z)-2-(2-aminothiazol-4-yl)-2-(alkoxyimino)acetamido)-3-[(4-carboxy-3-hydroxyisothiazol-5-yl)thiomethyl)-3-cephem-4-carboxylic acid 5-9 were synthesized. Antibacterial activities of these new cephalosporin derivatives and the relationship between their structures and activities were examined. Among them, 7-((Z)-2-(2-aminothiazol-4-yl)-2-(carboxymethoxyimino)acetamido)-3-[(4-carboxy-3-hydroxyisothiazol-5-yl)thiomethyl)-3-cephem-4-carboxylic acid 8 and 7-[(Z)-2-(2-aminothiazol-4-yl)-2-(l-carboxy-1-methylethoxyimino)acetamido]-3-[(4-carboxy-3-hydroxyisothiazol-5-yl)thiomethyl)-3-cephem-4-carboxylic acid 9 exhibited good antibacterial activities compared with those of cefotaxime and ceftriaxone.

• Journal of Adhesion and Interface
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• v.12 no.2
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• pp.67-72
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• 2011

Acrylic pressure-sensitive adhesives are used in many different parts in the world. But acrylic acid in PSAs may occur unexpected results such as corroding adherends or producing by-products when applied within electronic devices. This study employed acrylic PSAs based on 2-ethylhexyl acrylate (2-EHA), 2-hydroxyethyl acrylate (2-HEA) and butyl acrylate (BA) with different coating thickness. There are two types of curing agents. One is methylaziridine derivative (MAZ) and the other is aluminum acetylacetonate (AlACA). This study examined the adhesion performance and curing behaviors using peel strength, probe tack and gel fraction. Also, the viscoelastic properties of acrylic PSAs were investigated from Advanced rheometric expansion system (ARES).

• International Journal of Quality Innovation
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• v.3 no.2
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• pp.159-173
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• 2002

Any organization's Six Sigma program may be at high risk without heeding the lessons learned from the past and that tries to operate without a robust business foundation. A foundation that preferably should consist of stepping-stones such as a 5-S house-keeping program, an effective Integrated Management System (IMS), which includes a strong focus on planning for quality to fully capture the Voice of the Customer (VOC), and an organization-wide training scheme, as well as a reliable Cost of Poor Quality (COPQ) system. That's the best advise I can give to any organization that wishes to embark on a Six Sigma improvement program and hope to be successful. The paper will elaborate on the above issues and provide suggested solutions based on the review of published historical information and the experiences encountered over the last four decades by the author, as a quality practitioner and consultant, in industries that produced safety-critical product. This author maintains that few fundamentally new or useful things have been created in the field of Quality during the last couple of decades. Nevertheless, this paper deliberates on a number of relatively “newer” issues including the concept of “three types of customers”, the CTC, “Critical To Customer” term, the eight Quality Management Principles of the new ISO 9000 family, the growth of industry-specific standards, the adoption of Integrated Management Systems, the rebirth of AS2561 COQ standard, the spread of Six Sigma as well as related ASQ certification and the need for a robust business foundation to ensure Six Sigma survival.

• YAKHAK HOEJI
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• v.44 no.2
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• pp.155-161
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• 2000

New cephalosporin antibiotics , 3-[(4-carboxy-5-ethylthioisothiazol-3-yl)oxymethyl]-7-[(1H-tetra-zol-1-yl)acetamido]-3-cephem-4-carboxylic acid 2, 3-[(4-carboxy-5-ethylthioisothiazol-3-yl) oxymethyl]-7-[(2-aminothiazol-4-yl)acetamido]-3-cephem-4-carboxylic acid 3, 3-[(4-carb oxy-5-ethylthioisothiazol-3-yl)-oxymethyl]-7-[5-(ethylthio-3-hydroxyisothiazol-4-yl)carboxamido]-3-cephem-4-carboxylic acid 4, 3-[(4-car-boxy-5-ethylthioisothiazo1-3-yl)oxymethy1]-7-[(Z)-2-(fur-2-yl)-2-(methoxyimino)acetamido]-3-cephem-4-carboxylic acid 5, 7-[(Z)-2-(2-aminothiazol-4-yl)-2-[(alkoxyimino)acetamido]-3-[(4-carboxy-5-ethylthioisothiazol-3-yl)oxymethyl]-3-cephem-4-carboxylic acid 6-8 were synthesized. Antibacterial activities and structure-activity relationships of these new cephalosporin derivatives were examined. Among them, 7-[(Z)-2-(2-aminothiazol-4-yl)-2-(1-carboxy-1-methylethoxyimino)acetamido]-3-[(4-carboxy-5-ethylthylth-ioisothiazol-3-yl)oxymethyl]-3-cephem-4-carboxylic acid 7 exhibited good antibacterial activities compared to cefotaxime and ceftriaxone.

• YAKHAK HOEJI
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• v.41 no.4
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• pp.473-479
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• 1997

New cephalosporin antibiotics, 7-[(3,4-dihydro-6-methoxycarbonyl-2,2-dimethyl-2H-1,4-thiazin-3-yl)acetamido]-3-substituted-3-cephem-4-carboxylic acid derivatives 2a-2d, 7 -[(3,4-dihydro-6-ethoxycarbonyl-2,2-dimethyl-2H-1,4-thiazin-3-yl)acetamido] -3-substituted-3-cephem-4-carboxylic acid derivatives 3a-3d and 7-[(3,4-dihydro-6-methoxycarbonyl-2,2-dimethyl-2H-1,4-thiazin-3-yl-1-(S)-oxide)acetamido]-3-substituted-3-cephem-4-carboxylic acid derivatives 4a-4d were synthesized. Antibacterial activities of these new cephalosporin derivatives and the relationship between their structures and their activities were examined. Among them, 7-[(3,4-dihydro-6-methoxycaronyl-2,2-dimethyl-2H-1,4-thiazin-3-yl-1-(S)oxide)-acetamido]-3-[(1,2,3-triazol-5-yl)thiomethyl]-3-cephem-4-carboxylic acid 4d exhibited the antibacterial activities against Gram(+)and Gram(-) bacteria.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.4
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• pp.1187-1208
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• 2022

One of the main goals of wireless sensor networks (WSNs) is to utilize the energy of sensor nodes effectively and maximize the network lifetime. Thus, this paper proposed a routing protocol for WSNs based on virtual force disturbing mobile Sink node (VFMSR). According to the number of sensor nodes in the cluster, the average energy and the centroid factor of the cluster, a new cluster head (CH) election fitness function was designed. At the same time, a hexagonal fixed-point moving trajectory model with the best radius was constructed, and the virtual force was introduced to interfere with it, so as to avoid the frequent propagation of sink node position information, and reduce the energy consumption of CH. Combined with the improved ant colony algorithm (ACA), the shortest transmission path to Sink node was constructed to reduce the energy consumption of long-distance data transmission of CHs. The simulation results showed that, compared with LEACH, EIP-LEACH, ANT-LEACH and MECA protocols, VFMSR protocol was superior to the existing routing protocols in terms of network energy consumption and network lifetime, and compared with LEACH protocol, the network lifetime was increased by more than three times.