• 공학교육연구
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• 제23권1호
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• pp.26-36
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• 2020

This study aims to investigate the effect of college choice factors on withdrawal intention of first-year undergraduates in STEM majors. The data for this study were collected from a national sample of 4-year institutions that participated in Collegiate Longitudinal Study funded by the National Research Foundation of Korea during 2013-2014. The data included 1,484 students in STEM majors from 30 institutions, and this study used bivariate and multivariate analytic methods to answer the research questions. This study found that while the internal dimensions of college choice showed a negative effect on the intention to dropout, external dimensions of college choice such as college environment, financial accessibility, admission possibility had a positive effect on the intention. The findings indicate that it is necessary to pay attention to college choice for enrollment management to prevent first-year undergraduates in STEM majors from dropping out.

• Bulletin of the Korean Chemical Society
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• 제35권12호
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• pp.3495-3501
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• 2014

A novel crystal, the mono-protonated metformin acetate (1), was obtained and characterized by elemental analysis, IR spectroscopy and X-ray crystallography. It was found that one of the imino group in the metformin cation was protonated along with the proton transfer from the secondary amino group to the other imino group. Its crystal structure was then compared with the previously reported diprotonated metformin oxalate (2). The difference between them is that the mono-protonated metformin cations can be linked by hydrogen bonding to form dimers while the diprotonated metformin cations cannot. Both of them are stabilized by intermolecular hydrogen bonds to assemble a 3-D supermolecular structure. The four potential tautomer of the mono-protonated metformin cation (tautomers 1a, 1b, 1c and 1d) were optimized and their single point energies were calculated by Density Functional Theory (DFT) B3LYP method based on the Polarized Continuum Model (PCM) in water, which shows that the most likely existed tautomer in human cells is the same in the crystal structure. Based on the optimized structure, their Wiberg bond orders, Natural Population Analysis (NPA) atomic charges, molecular electrostatic potential (MEP) maps were calculated to analyze their electronic structures, which were then compared with the corresponding values of the diprotonated metformin cation (cation 2) and the neutral metformin (compound 3). Finally, the possible tautomeric mechanism of the mono-protonated metformin cation was discussed based on the observed phenomena.

• Smart Structures and Systems
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• 제32권2호
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• pp.101-109
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• 2023

In order to improve the measurement accuracy of the 6-dimensional accelerometer, the cross coupling compensation method of the accelerometer needs to be studied. In this paper, the non-linear error caused by cross coupling of piezoelectric six-dimensional accelerometer is compensated online. The cross coupling filter is obtained by analyzing the cross coupling principle of a piezoelectric six-dimensional accelerometer. Linear and non-linear fitting methods are designed. A two-level calibration hybrid compensation algorithm is proposed. An experimental prototype of a piezoelectric six-dimensional accelerometer is fabricated. Calibration and test experiments of accelerometer were carried out. The measured results show that the average non-linearity of the proposed algorithm is 2.2628% lower than that of the least square method, the solution time is 0.019382 seconds, and the proposed algorithm can realize the real-time measurement in six dimensions while improving the measurement accuracy. The proposed algorithm combines real-time and high precision. The research results provide theoretical and technical support for the calibration method and online compensation technology of the 6-dimensional accelerometer.

• 공학교육연구
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• 제20권4호
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• pp.67-72
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• 2017

It was only 2010 when start-up education spread to undergraduate education in South Korea. Start-up education was conducted so late that there are insufficient studies of evaluation and feedback on the effectiveness of start-up education. Education is a complex concept of teaching people in a desirable direction and developing their inherent abilities. Based on this, start-up education can be defined as cultivating students' entrepreneurial spirit internally and making them exhibit start-up competence externally by teaching them the knowledge, skills and attitudes necessary for business start-up and developing abilities such as creativity, challenge spirit and problem-solving skills. This study conducted pre and post survey to check if the education camp for the technology start-up, which is a practice-oriented start-up education, has an effect on the change of the participating students' perceptions about the business start-up. This study would analyze various factors of college students' business start-up through a factorial analysis so that the quantitative accumulation of start-up education can lead to a qualitative change and propose measures for the management of the quality of the education.

• 대한환경공학회지
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• 제34권6호
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• pp.365-372
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• 2012

최근의 사회는 엔지니어에게 국제사회와 미래를 이해할 수 있고, 리더십을 갖춘 전문기술자가 될 것을 요구하고 있다. 전문교양교육은 이러한 요구를 만족시켜 주어야 하며, 글로벌형 인재를 양성할 수 있도록 강화돼야 한다. 7차 교육과정 이후 소홀해진 과학교육으로 인해 저하된 이공계기초 교양교육을 강화시켜 공과대학 학생들의 전공수학능력을 향상시켜야 한다. 엔지니어의 인성 및 기초교양 교육은 2009 교육과정을 통하여 초 중 고부터 대학으로 이어지는 연속적이고 체계적인 교육과정으로 완성될 수 있다. 아울러 대학 및 학과특성화 과정을 통하여 다양한 교육의 기회를 제공해주고, 사회가 요구하는 필요한 인재를 양성하도록 해야 한다. 환경공학은 학제간 융복합적 성격이 강하기 때문에 다전공제도를 적극 활용하는 것이 바람직하고, 이공계기초 과목의 이수기준을 강화시킬 필요가 있으며, 환경공학 맞춤형 교양교육컨텐츠를 개발할 필요가 있다.

• 산업경영시스템학회지
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• 제18권36호
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• pp.349-363
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• 1995

The purpose of the study was to estimate and analyze the rates of return to educational investment. The study was designed to estimate the social and private rates of return to educational investment by school level and sex in order to measure education's economic value with a viewpoint of human capital theory. The produced result of this study are as follows. The social rates of return to education turned out to be male high school 7.94%, male junior college 3.74%, male university 8.50% female high school 4.30%, female junior college 10.11%, female university 6.92%. The private rates of return to education turned out to be male high school 8.41%, male junior college 3.39%, male university 8.38%, female high school 7.90%, female junior college 10.34%, female university 7.33%, In order to measure economic value of educational investment, rates of return to education were compared with those to physical capital investment. Social rates of return to education turned out to be profitable for female junior college, while for private rates of return to education turned out to be profitable in all school levels except for male junior college.

• Journal of Microbiology and Biotechnology
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• 제30권4호
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• pp.515-525
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• 2020

Interferon (IFN)-λ plays an essential role in mucosal cells which exhibit strong antiviral activity. Lactobacillus plantarum (L. plantarum) has substantial application potential in the food and medical industries because of its probiotic properties. Alphacoronaviruses, especially porcine epidemic diarrhea virus (PEDV) and transmissible gastroenteritis virus (TGEV), cause high morbidity and mortality in piglets resulting in economic loss. Co-infection by these two viruses is becoming increasingly frequent. Therefore, it is particularly important to develop a new drug to prevent diarrhea infected with mixed viruses in piglets. In this study, we first constructed an anchored expression vector with CWA (C-terminal cell wall anchor) on L. plantarum. Second, we constructed two recombinant L. plantarum strains that anchored IFN-λ3 via pgsA (N-terminal transmembrane anchor) and CWA. Third, we demonstrated that both recombinant strains possess strong antiviral effects against coronavirus infection in the intestinal porcine epithelial cell line J2 (IPEC-J2). However, recombinant L. plantarum with the CWA anchor exhibited a more powerful antiviral effect than recombinant L. plantarum with pgsA. Consistent with this finding, Lb.plantarum-pSIP-409-IFN-λ3-CWA enhanced the expression levels of IFN-stimulated genes (ISGs) (ISG15, OASL, and Mx1) in IPEC-J2 cells more than did recombinant Lb.plantarum-pSIP-409-pgsA'-IFN-λ3. Our study verifies that recombinant L. plantarum inhibits PEDV and TGEV infection in IPEC-J2 cells, which may offer great potential for use as a novel oral antiviral agent in therapeutic applications for combating porcine epidemic diarrhea and transmissible gastroenteritis. This study is the first to show that recombinant L. plantarum suppresses PEDV and TGEV infection of IPEC-J2 cells.

• 공학교육연구
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• 제23권3호
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• pp.66-75
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• 2020

The purpose of this study is to norm the engineering design competency test. To achieve the purpose of the study, a survey was conducted on engineering college students nationwide using engineering design competency test developed in the precedent study, and a total of 2,859 questionnaires were analyzed. The main results are as follows. First, the national average of engineering design competency scores was 158 out of 240 points. Second, there was no significant difference between genders in engineering design competency by background variables. On the other hand, there was a significant difference by major. It was found that mechanical and construction majors have higher engineering design competency than IT and chemical/material engineering majors. Also, the scores of engineering design competency increased as the grade went up. Third, the number of courses related to engineering design did not affect by engineering design competency, but the actual number of times of experience in engineering design was affected by engineering design competency.

• 대한안전경영과학회지
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• 제15권1호
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• pp.231-239
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• 2013

This intensity is now on a global scale with countless universities across the globe competing for better services, programs and diplomas. For to counteract such a considerable change, in this paper CTQ(Critical to Quality) is extracted for the improvement of the education quality using QFD(Quality Function Development) in college. QFD is a structured approach to seek out voice of customers, understanding their needs, and ensure that their needs are met. First of all, the requirements of the customer are surveyed and analyzed, and then with these results the strategic alternatives are decided. In sequence, the importance and assessment ratings on the requirement of customers are surveyed. Finally, from the relation between the requirement of customers and the strategic alternatives the CTQ is extracted. The derived CTQ is reviewed and analyzed in detail. It'll have major positive effects on the competitiveness of college as well as the education quality of departments.

• Mass Spectrometry Letters
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• 제6권1호
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• pp.1-6
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• 2015

Direct analysis in real time mass spectrometry (DART-MS) is one of the variants of ambient mass spectrometry. The ionization process of DART-MS is in open environment and only takes few seconds, so it is suitable for fast analysis. Actually, since its introduction in 2005, more and more attentions have been drawn to its various applications due to its excellent properties, e.g., fast analysis, and no or less sample preparation, high salt tolerance and so on. This review summarized the promising features of DART-MS, including its ionization mechanism, equipment modification, wide applications, coupling techniques and extraction strategies before analysis.