• Journal of Life Science
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• v.22 no.5
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• pp.621-626
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• 2012

$Drosophila$ $melanogaster$ has been used as a useful model to study development and disease. In this study, we established the primary culture method of $Drosophila$ in the intestine to understand how intestinal stem cells (ISCs) mediate tissue repair during infection and disease. To obtain intestinal cells, we separated intestines from adult flies and isolated single cells by enzymatic treatment. The survival of cultured cells was measured using MTS-analysis. The maximum growth rate of the cells was observed on the 9th day after seeding. In addition, the presence of ISCs and enteroendocrine cells was confirmed by delta and prospero staining. Accordingly, we supposed that $Drosophila$ $melanogaster$ gut cells established in this study are probably useful in studies about intestinal stem cell regulation and various diseases occurring in the intestine.

• The Journal of Korean Association of Computer Education
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• v.20 no.4
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• pp.27-36
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• 2017

The purpose of this study is to design and implement an instructional model for flipped learning of programming class. Because a programming process requires a high level of abstract thinking with a good understanding of a programming language, many students have difficulty in programming. For this characteristic of programming, it is not easy to effectively achieve learning goals of programming lesson by lecturing grammatical elements of a programming language and the following examples in a limited class time. In order to overcome these problems and to make effective programming lessons, we designed an instructional model based on flipped learning. Especially, in this study, we analyzed learners' difficulties in programming learning and errors that occurred in actual programming process for designing the instructional model. As a result of applying this model to the class, it was found that the students were generally satisfied with the lesson by having positive communication with other students in the classroom and actively participating in the learning.

• Journal of the Korean Wood Science and Technology
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• v.23 no.4
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• pp.27-32
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• 1995

To understand whether ligninolytic enzyme catalyze polymerization or depolymerization of the high molecular weight (HMW) lignin, the action of laccase and Mn-peroxidase (MnP) towards commercial ligninsulfonates (LS) was examined in various conditions of pH and cosubstrates. Polymerization occurred when LS was incubated with laccase at pH 6.0. In contrast, the high molecular weight portions were significant1y reduced at pH 4.5, especially when glucose was added. When LS was treated with MnP at pH 4.5, compounds of low molecular weight were produced. In particular, when cellobiose was added to Mn-P reaction mixture, the breakdown of LS was observed. In conclusion, degradation of LS by laccase and MnP occurred primarily at pH 4.5 where-as polymerization of LS was dominant at pH 6.0. Color index, however, was not greatly changed in the degradation mixtures of LS.

• Magazine of the Korea Concrete Institute
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• v.11 no.1
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• pp.173-181
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• 1999

To deepen the understanding of shear behaviour in beams without transverse reinforcement, the relative importance of five contributing factors to concrete shear resistance($v_c$), which are i)flexural compression zone, ii)friction at crack faces, iii)dowel action, iv)arch action and recently identified, v)residual tensile stresses across cracks, was explained physically using two analytical methods based on the truss concept. One is called "Modified Compression Field Theory(MCFT)" considering ii) and v) explicitly, and the other "Crack Friction Truss Model(CFTM)" more dominantly ii) in determining concrete resistance. To verify their effectiveness, the predictions using MCFT and CFTM were also made for twenty KAIST beam tests($f'_c$=53.7Mpa), designated more likely to the development of the size effect law based on the fracture mechanics concept. Experimental findings with varying of a/d, longitudinal reinforcement ratios, and obtained from MCFT enabled additional explanations for some phenomena which were difficult to measure in tests. However, MCFT seemed somewhat conservative for beams with higher longitudinal reinforcement, while somewhat unsafe for beams with larger depths. More tests are necessary leading to firm conclusions in these areas.

• The Journal of Korean Association of Computer Education
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• v.19 no.4
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• pp.21-31
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• 2016

As the science and technology advances, the side effects of information and communications technology use become a social issue and the social demands to strengthen the informatics ethics in the curriculum of elementary and secondary schools becomes great. The contents of informatics ethics education is included in the current curriculum for elementary and secondary school, but they are embedded in multiple subjects without the holistic guidelines for the informatics ethics curriculum. Therefore it can have duplications of the contents or missing among subjects as those subjects are elective in the secondary school. In this study, we proposed a holistic curriculum for informatics ethics education and developed the education program based on subject integrated curriculum model and the cyber internet ethics education model to solve problems of informatics ethics education. The program was practised for 291 students of $10^{th}$ graders for 5 months and effectiveness was proven by the high attainment of ethics understanding. This subject integrated education program is proposed to solve the structural problems of informatics ethics education in 2015 curriculum.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.2
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• pp.70-77
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• 2003

In this paper, analysis and measurement on coaxial connecter designed for packaging of microwave and micro strip transition structure are carried out. Even though researches on optimization of various kinds of transition structures have been conducted actively; however, the range of the application was very limited since they have been focused mainly on improvement of specific transmission line. Therefore, in this paper, we tried to analyze three kinds of substrates of which dielectric constants are 2,5,10 and are commercially used nowadays. Besides, we have confirmed reliability of FEM analysis, extracted equivalent circuit of transition area, found out factors determining extracted physical values, and made proof of electromagnetic variations for optimum characteristics. In addition, transition structure showing optimized characteristics on the basis of dielectric and microstrip structure was proposed. We reckon that the result of this research will apply with effect to transition design in microwave packaging development.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.8
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• pp.807-815
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• 2013

A numerical study on soot formation in a laminar ethylene diffusion flame at atmospheric pressure was conducted to obtain a better understanding of the effects of buoyancy on sooting flames under 0g and 1g using a gas-phase reaction mechanism and thermal and transport properties. A simple model was employed to predict soot formation, growth and oxidation with interactions between the gas phase chemistry and the soot chemistry taken into account. Results showed that the flames in 0g are much wider than that of 1g because of the thicker diffusion layer and reduction in axial velocity. The reduction in the axial velocity in 0g results in longer residence times, and resulting in greatly enhanced soot volume fraction. And, under zero-gravity, due to the lack of a buoyancy-induced instability, flame instability disappears.

• Journal of Advanced Navigation Technology
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• v.18 no.6
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• pp.609-618
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• 2014

Information system audit, by checking overall matters about constructing and managing information system, has to contribute to improvement of information system's quality and improving performance of projects. For this, an auditor has to present objective corroborative facts which back up result of audit and ways of improvement, but in reality, general(especially businessmen's) cognition is that audit is biased by way too subjective opinions. Local experience and theoretical research until now propose that tools of automating audit will be an active means of systematically collecting and proposing these objective evidences of audit. This research not only verified that in the field of audit, phenomenon of technology application can be explained and predicted by applying TAM, but it also contributed in extending theoretical base on information technology and audit by distinguishing several characteristics which appear in the process of the model's application and analysis.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.6 no.3
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• pp.131-146
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• 2011

This dissertation analyzed the satisfaction of corrective counseling programs for Korean domestic violence offenders. I conducted a survey of Korean domestic violence offenders scattered throughout the country. The survey period was between Mar Feb. 20, 2006 and Apr. 29, 2006. The specific objects of the survey are the 250 domestic violence offenders who got counseling in the Goyang branch office of the Justice Ministry-affiliated Uijeongbu Probation & Parole Center, Ansan Citizen Welfare Society's domestic violence counseling center, Korea Domestic Violence Counseling Center Association, Korea Women's Hot Line, Korea Family Law Counseling Center and its branch offices throughout the country, and the counseling centers commissioned by the court for domestic violence offenders. The study was based on a poll on 182 of the 250 offenders. The research result includes: First, the satisfaction of corrective counseling programs for offenders varies depending upon the age, educational background, location, job, income, and childhood abuse of offenders. In particular, the less experience of childhood abuse leads to greater effect of education. Second, of the types of corrective counseling programs for offenders, the satisfaction for those in couple counseling is the greatest. This is because couple counseling is more influential than individual in the professional education that helps to share and understand couple problems.

• Korean Journal of Microbiology
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• v.45 no.1
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• pp.10-16
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• 2009

A diverse range of stresses such as heat, cold, salt, ethanol, oxygen starvation or nutrient starvation induces same stress-responsive proteins. This general stress response enhances bacterial survival significantly. In Bacillus subtilis and closely related Gram-positive bacteria Listeria monocytogenes, the general stress response is controlled by the alternative transcription factor ${\sigma}^B$. The activity of ${\sigma}^B$ is regulated post-translationally by a signal transduction network that has been extensively studied in B. subtilis, and serve as a model for L. monocytogenes. The proposed model of L. monocytogenes signal transduction network is similar to that of B. subtilis, but the energy stress pathway is missing. More than 150 general stress proteins belong to ${\sigma}^B$ regulon of B. subtilis and L. monocytogenes. In both bacteria, ${\sigma}^B$ function is primarily important for resistance to diverse stresses. In addition, ${\sigma}^B$ function contributes to the control of important virulence genes in food-borne pathogen L. monocytogenes. Therefore, understanding of the general stress response is important not only for bacterial physiology, but also for pathogenicity.