• Magazine of the Korea Concrete Institute
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• v.3 no.2
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• pp.115-121
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• 1991

Slippage of beam longitudinal reinforcement at beam-column connections is an important cause of damage to reinforced concrete frames under static and dynamic loads, This paper summarizes the results of an experimen¬tal study on the effects of confinements and compressive strength of concrete on the local bond stress-slip cha¬racteristics of deformed bars. I t is concluded from experimental results that, as far as the bond splittmg cracks are restrained by the vertical column reinforcement, confinement of concrete by transverse reinforcement has insignigicant direct effect on the local bond behavior. The ultimate bond strength, however, Increases pro¬portionally with the square root of concrete compressive strength. An empirical model was developed for local bond st ressslip relationslip of deformed bars in confined concrete of different compressive strengths.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.12
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• pp.991-997
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• 2013

A new frequency tuning scheme and a transconductor with a wide tuning range and low harmonic distortion is presented. This frequency tuning technique is based on the relationship between the time-constant and the elapsed times in charging a capacitor up to a certain level. Its structure is as simple as that of a conventional tuning scheme using a VCF(Voltage-Controlled Filter) and it does not need a pure sine wave but uses a CLK(Clock) pulse as a reference signal, which is easily obtained from on-chip system clocks or external X-tal oscillators. When a certain reference CLK is given, without complex capacitor arrays the pole frequency of the filter can be controlled continuously in the frequency domain. Simulation results are presented to confirm the operation of the proposed approach.

• Journal of the Korean Society of Safety
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• v.9 no.3
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• pp.13-21
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• 1994

Effects of tensile and compression residual stresses in the welded SS41 and A17075-76 on fatigue crack propagation behavior are investigated when a crack propagates from residual stresses region. We propose the fatigue crack growth equation on tensile and compression residual stresses in welded metal. The results obtained in this experimental study are summarized as follows . 1 ) A fatigue crack growth equation which applied fatigue fracture behavior of the welded metal is proposed. (equation omitted) where, $\alpha$, $\beta$, ${\gamma}$ and $\delta$ are constants, and R$_{eff}$ is effective stress ratio [R$_{eff}$=(Kmin+Kres)/(Kmax+Kres)], Kcf is critical fatigue stress intensity factor. The constants are obtained from nonlinear least square method. The relation between crack length and number of cycles obtained by integrating the fatigue crack growth rate equation is in agreement with the experimental data. 2) The experimental results confirmed that the cause of crack extension and retardation by residual stresses has relation to the phenomenon of crack closure. 3) The relaxing trend of residual stresses by the crack propagation was greater In case of compressive residual stress than that of tensile residual stress in the welded metal.tal.

• Journal of Chest Surgery
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• v.29 no.1
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• pp.63-66
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• 1996

Postoperative empyema thoracis with bronchopleural fistula (BPF) Is uncommon but serious complication. The management remains troublesome area in the field of the general thoracic surgery During the period of October 1993 to December 1994, four patients with postresectional empyema thoracic with BPF were treated consecutively in Ewha Womans University Mokdong Hosp tal. The treatment procedures include irrigation and debridement of the empyema cavity and muscle flap transposition. Follow-up periods after surgery were 4-12 months. Three patients were thought successful, one patient failed. We think that the cause of failure is muscle necrosis of rectos abdominis muscle flap due to vascular injury and infection of muscle due to residual infected debridement of empyema cavity.

• Journal of the Korean Ceramic Society
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• v.33 no.5
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• pp.514-518
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• 1996

Sb doped SnO2(ATO: Antinomy doped Tin Oxide) thin films were prepared by a DC magnetron spttuering method using an oxide target and the electrical characteristics of ATO films were investigated. The experimen-tal conditions are as follows :Ar flow rate ; 0~100 sccm deposition tempera-ture ; 250~40$0^{\circ}C$ DC sputter powder ; 150~550W and sputteing pressure ; 2~7 mTorr, The thickness of depositied ATO films were 600$\AA$~1100 $\AA$ ranges. The resistivity of ATO films was decreased due to the increase of the crystallinity of ATO films with deposition temperature. The decrease of carrier concentration of films with the increase of oxygen flow rate and working pressure is responsible for the increase of resistivity. Increasing of sputtering power raised the resistivity of films by decreasing the carrier mobility.

• Journal of Plant Biotechnology
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• v.42 no.3
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• pp.154-160
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• 2015

The plant breeding technology was developed with genetic engineering. Many researchers and breeders have turned from traditional breeding to molecular breeding. Genetically modified organisms (GMO) were developed via molecular breeding technology. Currently, molecular breeding technologies facilitate efficient plant breeding without introducing foreign genes, in virtue by of gene editing technology. Gene targeting (GT) via homologous recombination (HR) is one of the best gene editing methods available to modify specific DNA sequences in genomes. GT utilizes DNA repair pathways. Thus, DNA repair systems are controlled to enhance HR processing. Engineered sequence specific endonucleases were applied to improve GT efficiency. Engineered sequence specific endonucleases like the zinc finger nuclease (ZFN), TAL effector nuclease (TALEN), and CRISPR-Cas9 create DNA double-strand breaks (DSB) that can stimulate HR at a target site. RecQl4, Exo1 and Rad51 are effectors that enhance DSB repair via the HR pathway. This review focuses on recent developments in engineered sequence specific endonucleases and ways to improve the efficiency of GT via HR effectors in plants.

• Proceedings of the KSPS conference
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• 1996.10a
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• pp.343-348
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• 1996

This paper examines the contribution of vocalic information (after the onset of voicing) to the perception of Korean alveolar stops: the aspirated /$t^{h}$/, the lenis /t/, and the fortis /$t^{*}$/. These stops have been analyzed as differing in VOT (Abramson & Lisker, 1964), the glottal width or aspiration (Kim, 1970), and F0 and intensity build-up (Han & Weitzman, 1970). These studies focused on the articulatory and acoustic qualities of the consonants and often assumed that the consonantal portion before the onset of voicing plays the main role in maintaining the three-way distinction. In contrast, the role of the following vowels was given less attention. In order to investigate the contribution of the following vowels, a perceptual study was conducted using stimuli cross-spliced from three naturally produced syllables [$t^{h}al$] 'mask', [tal] 'moon', and [$t^{*}al$]) 'daughter'. Stimuli were presented to 12 Korean listeners for identification. Each subject responded to a total of 486 tokens. The results show that vowels play the primary role when the cut occurs at the star of voicing. Even with cuts at 10 ms and 40 ms into voicing, the following vowel still plays a clear role. This suggests that vowels carry the important information for distinguishing the three stops.

• BMB Reports
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• v.44 no.3
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• pp.170-175
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• 2011

We identified a bovine $B_{12}$ trafficking chaperone bCblC in Bos taurus that showed 88% amino acid sequence identity with a human homologue. The protein bCblC was purified from E. coli by over-expression of the encoding gene. bCblC bound cyanocobalamin (CNCbl), methylcobalamin (MeCbl) and adenosylcobalamin (AdoCbl) in the base-off states and eliminated the upper axial ligands forming aquo/hydroxocobalamin ($OH_2$/OHCbl) under aerobic conditions. A transition of $OH_2$/OHCbl was induced upon binding to bCblC. Interestingly, bCblC-bound $OH_2$/OHCbl did not react with reduced glutathione (GSH), while the reaction of free$OH_2$/OHCbl with GSH resulted in the formation of glutathionylcobalamin (GSCbl) and glutathione disulfide (GSSG). Furthermore we found that bCblC eliminates the GSH ligand of GSCbl forming $OH_2$/OHCbl. The results demonstrated that bCblC is a $B_{12}$ trafficking chaperone that binds cobalamins and protects $OH_2$/OHCbl from GSH, which could be oxidized to GSSG by free $OH_2$/OHCbl.

• Herbal Formula Science
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• v.14 no.1
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• pp.141-167
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• 2006

The genotoxicity of water extract of Bojungikkeehapdaechilki-tang was tested by In Vitro Chromosome Aberration Test. Bacterial Reverse Mutation Assay and Micronucleus test according to OECD Guidelines and KFDA Guidelines. The obtained results were as follows : 1. Chromosome Aberration Test: In Vitro Chromosome Aberration Test of Bojungikkeehapdaechilki-tang extracts was carried out using cultured Chinese hamster lung cells in the presence and absence of metabolic activation system(S-9 mix). No significant changes in the number of aberrant metaphases having structural and number of aberrations were detected in Bojungikkeehapdaechilki-tang extracts treated groups. 2. Bacterial Reveres Mutation Assay: Bojungikkeehapdaechilki-tang extracts was evaluated for its potential to induce reverse mutation in the histidine auxotroph strains of Salmonella typhimurium such as TA100, TA1535, TA98 and TAl537 and the tryptophan auxotroph strain of Escherichia coli WP2 uvrA. No significant changes in the number of revertant colonies compared to its negative control were detected in Bojungikkeehapdaechilki-tang extracts treated groups against all 5 strains. 3. Micronucleus test: Micronucleus test of Bojungikkeehapdaechilki-tang extracts were performed using specific pathogen free 7-week old male ICR mouse. No significant changes in the number of micronucleated polychromatic erythrocytes among 2000 polychromatic erythrocytes compared to negative control were detected in all Bojungikkeehapdaechilki-tang extracts treated groups. In summarized above-mentioned results, it is concluded that Bojungikkeehapdaechilki-tang extracts have not genotoxicity against In Vitro Chromosome Aberration Test, Bacterial Reverse Mutation Assay and Micronucleus test.

• Korean Journal of Community Nutrition
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• v.2 no.2
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• pp.232-245
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• 1997

This study was carried out to investigate relationships between characteristics of foodservice and job satisfaction of Korean dietitians. The subjects were 2987 dietitians who responded to the questionnaire distributed at the annual education program of the Korean Dietetic As-sociation in 1995. The results were followings; 1)The level of jov satisfaction of Korean dietitians was low for payment work environment and value achievement as a dietitian while it was relatively high for the relationship with col-leagues. The other parts of job satissatisfaction such as work load work contents supervision by the superiors participation of policy decision and selp disccertion were just below average. 2)The type of operating style menu style and serving time in foodservise were not sig-nificantly related to all fields of job satisfaction but the kinds of meals served a day and the to-tal number of persons served a day were significantly correlated. 3) The dietitians who had to provide meal plans such as breakfast+dinner and + snack or all day serving had significantly lower job satisfaction in all fields. 4)Job satisfaction was significantly higher when the total number of persons served a day was between 500-700.(Korean J Community Nutrition 2(2) : 232~245, 1997)