• International Journal of Oral Biology
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• v.35 no.1
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• pp.21-25
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• 2010

This study was undertaken to develop species-specific forward and universal reverse PCR primers for the detection of Streptococcus sobrinus. These primers target the variable regions of the 16S ribosomal RNA coding gene (rDNA) and their specificity was tested against 10 strains of S. sobrinus strains and 20 different species of oral bacteria using serial dilutions of the purified genomic DNA of S. sobrinus ATCC $33478^T$. Our data show that species-specific amplicons were obtained from all the S. sobrinus strains tested but not from other species. Both direct and nested PCR could detect as little as 400 pg and 4 fg of genomic DNA from S. sobrinus ATCC $33478^T$, respectively. This result suggests that these PCR primers are highly specific and sensitive and applicable to the detection of S. sobrinus.

• Proceedings of the Korea Concrete Institute Conference
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• 1995.10a
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• pp.14-18
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• 1995

Since cement is one of materials of concrete and have an important effect upon physical properties of concrete, the quality characteristics of ordinary portland cement in domestic market are evaluated in this study. For this purpose, eight kinds of cement are selected and tested on the specific gravity, normal consistency, setting time, fincness, and compressive strength of cement ranged from 300kg/$\textrm{m}^3$ to 600kg/$\textrm{m}^3$ are tested for each kind of cement. As a result,ordinary portland cement in domestic market are satisfied with physical performance prescribed by KS L 5201(Portland Cement) and when unit weight of cement is 300~600kg/$\textrm{m}^3$, the maximum compressive strength of concrete cylinder is showed to be about 440-540kgf/$\textrm{cm}^2$.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1717-1723
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• 2003

Experimental study is conducted to investigate the cooling performance of impinging jet from microtube using Joule-Thomson effect to apply practical applications. And also the heat transfer characteristics of a impinging jet itself and the impinging jet with Joule-Thomson effect are tested to make a comparative study of the two different general ideas. For this propose, two kinds of copper microtubes which have 200 tim and 300 tim in inner diameter respectively were tested and $N_2$ was used as a working fluid. In case of impinging jet without Joule-Thomson effect, heat transfer coefficients distributions were similar to those of normal impinging jet. But in impinging jet with Joule-Thomson effect, the heat transfer coefficients decrease as jet-to-surface increases contrary to the case of the normal jet. As a result, much higher heat transfer coefficients are obtained with Joule-Thomson effect than those of the normal jet without J-T effect.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1499-1502
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• 2003

This paper describes the result of carbody and vibration test for freight car. The purpose of the test is to evaluate an safety which carbody structure shall be considered fully sufficient rigidity so as to load a freight car under maximum load and operating condition on line track. The test carbody is constructed by RS korea co., LTD. in accordance with KNR specfication. The test cases of the carbody is tested the vertical load and compressive load to verify the strength and stillness. The vibration test is tested for analysis and evaluation of vibration, to allow for the fact that mechanical vibration in railway vehicles have specific characteristics.

• Asia-Pacific Journal of Business
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• v.7 no.1
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• pp.43-57
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• 2016

This study examined the relationship between determinant factors of FDI and management performance, and tested moderating effects by competitive strategy. Questionnaires were gathered from 113 respondents, but only 92 valid copies were analyzed through SPSS WIN 18.0. The major empirical results are as follows: In hypothesis 1, Firm-Special Advantage impacted on Management Performance strongly, Internal Advantage impacted on Management Performance strongly, and Locational Advantage impacted on Management Performance strongly. In Hypothesis 2, the moderating effects by competitive strategy on the relationship between determinant factors of FDI and management performance were tested through multiple regression. The result of the moderating effects by competitive strategy were found to be insignificant. Implications of the finding as well as the limitations of this study are also discussed.

• Korean Journal of Pharmacognosy
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• v.17 no.2
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• pp.184-188
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• 1986

The preliminary antifertility test of Dictamnus albus(Rutaceae) showed that a methanol extract of root bark decreased fertility in rats when administered orally on days $1{\sim}10$ postcoitum. Hexane, chloroform, butanol and aqueous fractions from the methanol extract, were tested to produce the result that only the hexane fraction exhibited positive activity. The hexane fraction was subfractionated into acidic, alkaloidal and neutral subtractions and tested. Neutral subtraction showed positive activity. From the neutral subtraction, fraxinellone was isolated as an active principle. The timed-dosing experiments revealed that antifertility activity of fraxinellone appeared to be exerted after tubal exit of the ova to prevent implantations.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2005.11a
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• pp.187-196
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• 2005

Newsprint is quantitatively the most important printing paper. The demands for its printability are continuously increasing. It is well known that the relationship between the physically tested paper properties and newspaper printability is unsatisfactory. In order to improve the printing quality of Korean newsprint, the printability coefficients such as maximum ink requirement($Y_{max}$), print through were investigated. Kinds of Korean newspapers and three kinds of news printing inks were tested by IGT printability tester. Experiment condition of IGT printability tester was 14 steps between $0.2{\sim}2.8g/m^2$ of ink requirement, printing pressure was .200 N and printing velocity was 1m/sec. The properties of newspaper samples(basis weight, bulk density, roughness, smoothness, porosity, i. e.) were examined in accordance with KS and TAPPI standard testing methods. The result of this study are respected for usefulness printing quality management of Korean newsprint.

• Journal of Information Technology Services
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• v.12 no.2
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• pp.55-71
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• 2013

Despite the growing interest in technostress phenomenon of employees in organizations, few guidelines exist about how mangers can effectively control their technostress. Accordingly, scholars should pay greater attention to how firms can successfully manage employees' technostress. This study conceptually developed and tested a research model for understanding the influence of technostress on psychological and behavioral strains. In addition, we tested technical support provision as a moderator. We obtained 107 samples through a survey questionnaire, and data were analyzed based on structural equation modeling (SEM). As a result, it was empirically demonstrated technostress decreases job satisfaction and individual productivity. We also found that technical support provision have moderating effects on the relationship of technostress and job satisfaction/individual productivity.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.740-744
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• 2014

In this study, the ${\beta}$-lactamase (VPA0477) gene was used as a new target for the PCR-based detection of Vibrio parahaemolyticus. Primers specific for the ${\beta}$-lactamase (VPA0477) gene of V. parahaemolyticus, were designed and incorporated into a PCR-based assay. The assay was able to specifically detect all of the 191 V. parahaemolyticus strains tested, but did not result in amplification of 39 other Vibrio spp. and non-Vibrio spp. strains tested. The detection limit of the assay was 10 CFU of V. parahaemolyticus RIMD2210633 from pure culture broth. The ${\beta}$-lactamase (VPA0477) gene-based assay developed in this study was sensitive and specific, and has great potential for the accurate detection and identification of V. parahaemolyticus in seawater or seafood samples.

• Progress in Superconductivity and Cryogenics
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• v.15 no.1
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• pp.35-39
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• 2013

The superconducting Homopolar motor is manufactured and tested. Homopolar motor system is simple and solid as the field coil of the motor is fixed near the stator coil without rotating system. In this paper, a 5 kW fully superconducting homopolar motor which has high temperature superconducting armature and field coils is manufactured and tested in liquid nitrogen. The critical current test results of the used 2G superconducting wire, pancake coil for rotor winding and race-track coils for armature winding are reported. Also, the test result of rotating and operating performance is presented. The operating frequency is to be 5 Hz for low-speed rotating. The developed fully superconducting Homopolar motor is the world's first.