• Food Science and Biotechnology
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• 제16권3호
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• pp.361-366
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• 2007

As the application of quantitative risk assessment (QRA) to food safety becomes widespread, it is now being questioned whether experimental results and simulated results coincide. Therefore, this paper comparatively analyzed experimental data and simulated data of the cross contamination, which needs summation of the simplest calculations in QRA, of chicken by Monte Carlo simulation and fuzzy math computation. In order to verify summation, the following basic operation was performed. For the experiment, thigh, breast, and a mixture of both parts were preserved for 24 hr at $20^{\circ}C$, and then the cell number of Salmonella spp. was measured. In order to examine the differences between experimental results and simulated results, we applied the descriptive statistics. The result was that mean value by fuzzy math computation was more similar to the experimental than that by Monte Carlo simulation, whereas other statistical descriptors by Monte Carlo simulation were more similar.

• 실천공학교육논문지
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• 제15권3호
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• pp.605-614
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• 2023

디지털 대전환 시대를 맞아 개인 맞춤형 교육을 실현하기 위해 교육 분야에서 인공지능 기반 학습 서비스들이 등장하고 있다. 본 연구에서는 인공지능 기반 학습 서비스를 학교 현장에 적용하기 위한 개발 방향을 살펴보고자 하였다. 인공지능 기반 수학학습 서비스로 아이스크림에듀에서 개발한 '수학의 세포들'을 선택하여 교수자 관점에서 기능별 요구를 조사하였다. 그 결과를 IPA를 활용하여 중요도와 적합도로 분석하면서 전문가 의견을 조사하여 서비스의 구체적인 개발 방향을 탐색하였다. 연구결과, 진단, 학습, 평가, 관리 등 모든 영역에서의 중요도는 평균 4.82, 적합도는 평균 4.56로 대부분의 문항에서 우수한 결과가 나타났으며, 특히 중요도가 적합도보다 높게 나타났다. 세부적인 일부 기능 중 개념 학습, 맞춤형 과제 제시, 평가 결과 분석 기능, 대시보드 관련 기능과 대시보드 내 학습 자료가 학생들이 이해하기에 직관적이지 않아 보완이 필요하다는 의견을 확인하였다. 본 연구는 교수자의 관점에서 인공지능 기반 수학학습 서비스에 대한 요구 및 전문가 의견을 정리하여 '수학의 세포들'의 방향을 탐색하는데 유의미한 정보를 제공하였다는 의의가 있다.

• 대한기계학회논문집A
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• 제34권12호
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• pp.1837-1842
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• 2010

화석에너지의 고갈로 인한 대체 에너지 연구는 최근 수십 년 동안 계속 행해지고 있다. 원자력 에너지와 비교해서 낮은 전기발생 효율에도 불구하고, 환경친화적이며 태양이라는 영구성으로 태양에너지는 주목 받고 있다. 본 논문에서는 태양전지의 효율에 가장 영향을 미치는 인자로 햇빛 입사각의 변화와 Top Connector 형상이라 가정하고 MATLAB 과 MathCAD 를 이용하여 모사하였다. 실험모사 결과 상용화 제품인 500um 선폭, 5um 높이 Top Connector 형상과 비교하여, 최고 10%의 태양전지 효율증가는 Top Connector 후막 두께가 25~50 um, 선폭 두께가 50~100um 영역에서 찾을 수 있었다. 10 만 cps 의 점도를 갖는 은페이스를 500um 의 MDDW (Micro-Dispensing Deposition Writing) 직접분사 노즐을 이용하여 성공적으로 25 um 후막을 형성하였다.

• 한국수소및신에너지학회논문집
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• 제32권6호
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• pp.497-505
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• 2021

Water management is essential to improve the performance of proton exchange membrane fuel cells. This study targets to understand the characteristics of water concentration in proton exchange membrane fuel cells at a dynamic load variable environment. The fuel cell model was developed to simulate nonlinear water transport in membrane by the MATLAB/Simulink^® (MathWorks, Natick, MA, USA) platform, and it calculates water content in membrane, ionic conductivity, and predicts fuel cell performance through one-dimensional analysis.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제27권2호
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• pp.121-134
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• 2013

대학 수학교육에서 선형대수학은 가장 중요한 과목 중 하나이다. 21세기 향상된 정보 기술이 선형대수학 수업에 적용된다면, 학생들의 선형대수학 내용에 대한 이해는 한층 더 향상될 것이다. 우리는 학생들의 관심을 높이고 보다 효율적으로 학습 목표에 도달하는데 기여하고자 웹상의 무료 수학 프로그램인 'Sage'(http://sagemath.org)를 활용한 교수학습 환경을 구축하고 그 콘텐츠를 개발하였다. 특히, 2009년 저자는 PC 환경 외에 휴대폰의 인터넷 기능을 통하여 Sage 명령어를 사용할 수 있는 단순모듈 콘텐츠를 개발하였다. 본 논문에서는 스마트폰을 이용하여 대부분의 Sage 기능을 활용할 수 있도록 개발한 모바일 Sage를 소개하고, 학생들의 자기주도적인 선형대수학 학습을 위해 개발한 모바일 선형대수학 스마트폰 콘텐츠(강의록, 동영상강의, 문제와 풀이, 공학적 도구)를 소개한다.

• Journal of the Korean Data and Information Science Society
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• 제18권4호
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• pp.1073-1079
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• 2007

The purpose of this study is to present the relationship between the computer learning and the paper and pencil learning through the math learning (simple computation and complex computation) and the cartoon learning and text learning. The canonical correlation and pairwise t-test of the SMR asymmetry brainwaves of the left and the right brain show the brainwaves with the respect to the manner in which they process information during the specified task by identifying the relative activity of the brainwaves of the left and the right brain. SMR brainwave which known as the scientific measure tool for the activity and the function of the neuronal cell were found to predict the level of the awakening to check the readiness of study preparation. Computer education as a medium of the individualized and the repetitive education shows the difference from the paper and the pencil test in the respect of the differences and the relationship of the SMR brainwave of the learning process.

• Asian Pacific Journal of Cancer Prevention
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• 제13권12호
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• pp.6349-6355
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• 2012

Previous studies showed that Math1 homologous to human Hath1 can cause mouse goblet cells to differentiate. In this context it is important that the majority of colon cancers have few goblet cells. In the present study, the potential role of Hath1 in colon carcinogenesis was investigated. Sections of paraffin-embedded tissues were used to investigate the goblet cell population of normal colon mucosa, mucosa adjacent colon cancer and colon cancer samples from 48 patients. Hath1 and Muc2 expression in these samples were tested by immunohistochemistry, quantitative real-time reverse transcription -PCR and Western blotting. After the recombinant plasmid, pcDNA3.1(+)-Hath1 had been transfected into HT29 colon cancer cells, three clones were selected randomly to test the levels of Hath1 mRNA, Muc2 mRNA, Hath1, Muc2, cyclin D1 and p27 by quantitative real-time reverse transcription-PCR and Western blotting. Moreover, the proliferative ability of HT29 cells introduced with Hath1 was assessed by means of colony formation assay and xenografting. Expression of Hath1, Muc2, cyclin D1 and p27 in the xenograft tumors was also detected by Western blotting. No goblet cells were to be found in colon cancer and levels of Hath1 mRNA and Hath1, Muc2 mRNA and Muc2 were significantly down-regulated. Hath1 could decrease cyclin D1, increase p27 and Muc2 in HT29 cells and inhibit their proliferation. Hath1 may be an anti-oncogene in colon carcinogenesis.

• 한국전자통신학회논문지
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• 제14권1호
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• pp.235-242
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• 2019

유한체 상에서 자기상반다항식은 역방향읽기 성질을 갖는 가역 부호를 설계하는 데 유용하다. 본 논문은 자기상반다항식 중 하나인 최대무게 다항식을 특성다항식으로 갖는 90/150 CA에 관한 연구이다. 전이규칙이 <$100{\cdots}0$>인 n-셀 90/150 CA를 이용하여 2n차 최대무게 다항식에 대응하는 90/150 MWCA가 존재하는지에 대한 판정법을 제안한다. 제안하는 방법은 실험을 통하여 검증한다.

• Molecules and Cells
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• 제41권4호
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• pp.290-300
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• 2018

Using an in vitro model of intestinal organoids derived from intestinal crypts, we examined effects of indole-3-carbinol (I3C), a phytochemical that has anticancer and aryl hydrocarbon receptor (AhR)-activating abilities and thus is sold as a dietary supplement, on the development of intestinal organoids and investigated the underlying mechanisms. I3C inhibited the in vitro development of mouse intestinal organoids. Addition of ${\alpha}$-naphthoflavone, an AhR antagonist or AhR siRNA transfection, suppressed I3C function, suggesting that I3C-mediated interference with organoid development is AhR-dependent. I3C increased the expression of Muc2 and lysozyme, lineage-specific genes for goblet cells and Paneth cells, respectively, but inhibits the expression of IAP, a marker gene for enterocytes. In the intestines of mice treated with I3C, the number of goblet cells was reduced, but the number of Paneth cells and the depth and length of crypts and villi were not changed. I3C increased the level of active nonphosphorylated ${\beta}$-catenin, but suppressed the Notch signal. As a result, expression of Hes1, a Notch target gene and a transcriptional repressor that plays a key role in enterocyte differentiation, was reduced, whereas expression of Math1, involved in the differentiation of secretory lineages, was increased. These results provide direct evidence for the role of AhR in the regulation of the development of intestinal stem cells and indicate that such regulation is likely mediated by regulation of Wnt and Notch signals.

• Food Science and Biotechnology
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• 제17권6호
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• pp.1240-1245
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• 2008

Kimbab is the most popular ready-to-eat (RTE) food in Korea. A rapid detection method based on multiplex PCR technique was developed for detection of major food-borne pathogens like Salmonella spp., Shigella spp., Bacillus cereus, Listeria monocytongenes, and Staphylococcus aureus. Specific bands were obtained as 108 bp (Sau, S. aureus), 284 bp (Sal, S. enterica, S. enteritids, and S. typhmurium), 404 bp (Lmo, L. monocytogenes), 475 bp (Bce, B. cereus), and 600 bp (Shi, S. flexineri and S. sonnei). Visible cell numbers varied from 4.14-5.03, 3.61-4.47, and 4.10-5.11 log CFU/g in randomly collected June, July, and August samples, respectively. Among the 30 kimbab samples obtained 83.3% samples were contaminated and 16.7% samples were free from contamination. The highest rate of contamination was with S. aureus (56.7%) followed by B. cereus (43.3%), Salmonella spp. (36.7%), Shigella spp. (13.3%), and L. monocytogenes (6.7%). The identification of the pathogenic species could be faster using one polymerase chain reaction (PCR) and the ability to test for food-borne pathogenic species in kimbab will save time and increase the ability to assure its quality.