• 한국산학기술학회논문지
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• 제13권8호
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• pp.3578-3585
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• 2012

유탕면류의 HACCP(Hazard Analysis Critical Control Point) 시스템 구축을 위하여 유탕 공정-CCP(Critical Control Point)에 대한 미생물학적(Biological hazards)과 화학적(Chemical hazards) 한계 기준 설정을 위한 목적으로 수행하였으며, 경기도 이천 소재의 P사에서 실행하였다. 유탕공정은 각각의 시간과 온도 측정에 따라 미생물학적, 화학적 위해요소를 제거하거나 감소에 대해 실험하였다. 실험결과 Standard plate count와 식중독균은 유탕공정(Temperature : $145{\pm}10^{\circ}C$, Time : $75{\pm}30$ sec)에 의해 검출되지 않았다. 유탕공정에 의해 생성되는 화학적 위해 기준의 산가는 법적 기준치인 0.6보다 낮은 0.2 이하였다. 증숙실과 유탕실의 공중낙하균을 측정한 결과 3 CFU/mL, 3 CFU/mL 검출되었다. 따라서 유탕공정의 CCP-BC는 일반세균과 식중독균, 산화생성물 생성을 예방, 제거하는데 좋은 대안책이 될 것이다. 결론적으로 HACCP을 위해 유탕공정에 대한 한계기준설정, 모니터링방법, 개선조치, 검증방법, 교육, 기록관리가 필요하다고 생각된다.

• 한국시뮬레이션학회논문지
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• 제13권4호
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• pp.17-29
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• 2004

The focus of this study is to represent a methodology of analysis for integrated logistic system by means of the Evolution Strategies and Data Envelopment Analysis(DEA). The integrated logistic system is composed of AS/RS (Automated Storages and Retrieval System), AGVs(Automated Guided Vehicle System) and Conveyor System. We design the simulation alternatives with choosing the qualitative critical factors for the each subsystem. Evolution Strategies is used to optimize the quantitative critical factors and responses of each alternative. DEA is applied to measure the efficiency of the alternatives in order to select the optimal operation efficiency scheme. The method of analysis which combines Evolution Strategies with DEA can be used to analyze the qualitative and quantitative critical factors in the integrated logistic systems.

• 한국철도학회논문집
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• 제7권4호
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• pp.356-359
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• 2004

In this paper, as the first step to assess and enhance the reliability of Korea High Speed Train, auxiliary power system is selected and reliability analysis is carried out. The auxiliary power system is classified into subsystems and functional analysis is conducted. Reliability block diagrams are drawn and reliability parametric analysis is performed. Analysis results show that the reliability of auxiliary power system depends on critical items. To grow the system reliability, activities should be concentrated on improvement of critical items.

• 한국농공학회지
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• 제28권2호
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• pp.87-92
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• 1986

The differential equation, which can determine the dynamic critical loads for low parabcoic arches, is derived in this study. The dynamic critical loads of the parabolic arches subjected to a concentrated step load are nummerically analyzed for the changes of load positions. In cases of arches with different end conditions (both hinged, fixed hinged, both fixed), the effect of end conditions and that of the rises are investigated in detail. The summary of the results are the following: 1)The snapthrough does not occur when the rise of arch is very low, and the bifurcation appears clearly as the rise of arch increases. 2)The regions in which the dynamic critical loads are not defined for the both ends fixed are broader than that for the both ends hinged. 3)For all case, the load positions of minimum dynamic critical loads exsit at the near position from the end hinged. Thus, the results obtained in present study show that the magnitude of dynamic critical loads, the load positions of minimum dynamic critical loads and the regions in which the dynamic critical loads are not defined depend on end conditions of arches.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1358-1361
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• 2003

In this study, intrinsic static/dynamic fracture toughness of Al 7175-T74 are evaluated from the apparent static/dynamic toughness of notched specimen. The notch/crack critical average stress fracture model is suggested to establish the relationship to predict the intrinsic fracture toughness from the apparent fracture toughness of a notched specimen. The notch/crack critical average stress fracture model is established using the relation between the notch root radius and the effective distance calculated by finite element analysis. It is conclude that the true fracture toughness can be estimated from test results of apparent fracture toughness measured by using a notched specimen. Also, critical notch root radius can be predicted by notch/crack critical average stress fracture model.

• 한국치위생학회지
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• 제17권6호
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• pp.1171-1182
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• 2017

Objectives: The purpose of the study was to investigate the correlation between critical thinking and problem-solving abilities in dental hygiene students. Methods: This is a cross-sectional study. A self-reported questionnaire was completed by 386 dental hygiene students enrolled in Gwangju Health university from August 30, 2017 to September 2, 2017. The general characteristics of the subjects, their critical thinking and problem-solving abilities were measured for the study. The tool to measure critical thinking was adapted from Yoon which had a Cronbach' alpha of 0.77. The tool for problem-solving ability was adapted from that used in Heppner & Petersen, which had a Cronbach' alpha of 0.77. The collected data are analyzed using ANOVA, Pearson's Correlation analysis, and multiple regression using SPSS/Win 18.0 program. Results: The results show that critical thinking scored 3.45 while problem solving ability scored 3.20. The correlation between critical thinking and problem-solving abilities was found to be strong. The strongest positive correlation in problem-solving ability was critical thinking (p<0.001). The multiple regression analysis suggests that the factors affecting problem solving ability of the subjects was statistically significant. The significant variables included critical thinking (${\beta}=0.440$) (p<0.001), satisfaction with one's major (${\beta}=0.108$) (p<0.05), interpersonal relationships (${\beta}=0.104$) (p<0.05) and academic performance (${\beta}=0.086$) (p<0.05) with an explanatory power of 38.3%. Conclusions: It is necessary to develop a curriculum and learning method for critical thinking and problem-solving abilities in the dental hygiene students.

• 천문학회지
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• 제38권2호
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• pp.279-282
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• 2005

We report the millimeter-wave radio observations of molecular cloud cores in Taurus. The observed line is the $N_2H^+$ emission at 93 GHz, which is known to be less affected by molecular depletion. We have compared starless (IRAS-less) cores with star-forming cores. We found that there is no large difference between starless and star-forming cores, in core radius, linewidth, core mass, and radial intensity profile. Our result is in contrast with the result obtained by using a popular molecular line, in which starless cores are larger and less condensed. We suggest that different results mainly come from whether the employed molecular line is affected by depletion or not. We made a virial analysis, and found that both starless and star-forming cores are not far from the critical equilibrium state, in Taurus. Together with the fact that Taurus cores are almost thermally supported, we conclude that starless Taurus cores evolve to star formation without dissipating turbulence. The critical equilibrium state in the virial analysis corresponds to the critical Bonnor-Ebert sphere in the Bonnor-Ebert analysis (Nakano 1998). It is suggested that the initial condition of the molecular cloud cores/globules for star formation is close to the critical equilibrium state/critical Bonnor-Ebert sphere, in the low-mass star forming region.

• 한국진공학회지
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• 제16권6호
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• pp.458-462
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• 2007

타원편광분석법은 반도체 물질의 광 특성과 전이점 연구에 유용하게 쓰이는 기술이다. 측정된 유전율 함수로부터 전이점을 구하기 위해서 전통적으로 이차 미분스펙트럼을 이용하여 분석하는데, 이 방법은 high frequency 의 잡음을 크게 증폭시키는 단점이 있다. 본 연구에서는 역 공간 푸리에 변환 (Fourier transform)을 이용하여 low-, medium-, high-index 의 푸리에 계수로부터 baseline, 정보, high frequency 잡음을 분리하는 방법을 소개하고자 한다. 이 방법을 이용하여 광전자소자에 폭넓게 사용되는 ZnCdSe 화합물 반도체의 $E_1,\;E_1+{\Delta}_1$ 전이점에 대한 연구를 하여 전통적인 이차 미분법과 비교해 보았다.

• 대한기계학회논문집A
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• 제37권11호
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• pp.1371-1377
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• 2013

본 연구에서는 다물체 동역학 모델을 이용한 철도차량의 임계속도 계산 방법을 제시하였다. 휠과 레일의 접촉 구속조건과 접촉력을 휠셋 단위에서 수식화하였다. 이를 대차모델에 합하여 구속조건을 가진 다물체 동역학 운동방정식으로 철도차량의 동적모델을 표현하였다. 철도차량의 다물체 동역학 모델에 대한 비선형 구속조건식과 운동방정식은 QR 분해법을 이용하여 독립좌표만으로 이루어진 선형방정식으로 유도하였다. 유도된 선형방정식으로부터 휠셋 및 이륜 대차에 대한 고유치 해석결과를 통해 임계속도를 구하였다. 임계속도에 영향을 미치는 차량 파라미터의 영향에 대한 결과를 제시하였다.

• International Journal of Advanced Culture Technology
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• 제8권2호
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• pp.12-17
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• 2020

This study was a similar experimental study that analyzed the effect by applying the learning portfolio completion. The study period lasted from October 1, 2019 to November 20, 2019. A total of 47 people participated in the study, and the effectiveness of the program was analyzed with the SPSS 18.0 program for critical thinking disposition. The statistical analysis method was frequency analysis and paired t-test. As a result of the analysis, the critical thinking disposition increased significantly in the application of the learning portfolio completion (Truth-seeking MD= -0.05, p <0.01), Open-mindness MD= 0.11, p <0.001), Analyticity MD= 0.76, p <0.001), Systematicity MD= -.25, p <0.001), Self-confidence MD=-0.54, p <0.001), Inquisitiveness MD=0.29, p <0.001), Maturity MD=-.0.33, p <0.001). In conclusion, the teaching method applied with the learning portfolio completion actually helped nursing students learn nursing students learn based on critical thinking. Based on these result, further research using learning portfolio is to be done and more systematic and practical application of learning portfolio completion to nursing students. This study would be used as a basic data for the study guideline development for learners.