• Nuclear Engineering and Technology
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• 제44권7호
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• pp.817-824
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• 2012

The most important component of a nuclear power plant is its nuclear reactor. Studies on the integrity of reactors have become an important part regarding the safety of a nuclear power plant. The US Nuclear Regulatory Commission Regulatory Guide (NRC RG) 1.20 presents a Comprehensive Vibration Assessment Program (CVAP) to be used to verify the structural integrity of the Reactor Vessel Internals (RVI) for flow-induced vibration prior to commercial operation. However, there are few published studies related to the RVI CVAP. We classified the Advanced Power Reactor 1400 (APR1400) RVI CVAP as a non-prototype category-2 reactor as part of an independent validation of its design. The aim of this paper is to present the results of structural response analyses of the Upper Guide Structure (UGS) assembly of the APR1400 reactor. These results show that the UGS and the Inner Barrel Assembly (IBA) meet the specified integrity levels of the design acceptance criteria. The vibration and stress analysis results in this paper will be used as basic information to select measurement locations of the vibration and stress for the APR1400 RVI CVAP.

• Nuclear Engineering and Technology
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• 제44권7호
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• pp.745-754
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• 2012

The correlations between Large Early Release Frequency (LERF) and Early Fatality need to be investigated for risk-informed application and regulation. In Regulatory Guide (RG) -1.174, while there are decision-making criteria using the measures of Core Damage Frequency (CDF) and LERF, there are no specific criteria on LERF. Since there are both huge uncertainties and large costs needed in off-site consequence calculation, a LERF assessment methodology needs to be developed, and its correlation factor needs to be identified, for risk-informed decision-making. A new method for estimating off-site consequence has been presented and performed for assessing health effects caused by radioisotopes released from severe accidents of nuclear power plants in this study. The MACCS2 code is used for validating the source term quantitatively regarding health effects, depending on the release characteristics of radioisotopes during severe accidents. This study developed a method for identifying correlations between LERF and Early Fatality and validates the results of the model using the MACCS2 code. The results of this study may contribute to defining LERF and finding a measure for risk-informed regulations and risk-informed decision-making.

• 생약학회지
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• 제16권3호
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• pp.171-174
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• 1985

Panax ginseng root has been widely used as an important drug for thousands years in China, Korea and Japan. The main effective components of ginseng have been believed to be saponins. However, ginseng cultivation is very difficult and needs many years for growth. It has already been shown that Panax ginseng callus produces a considerable amount of the same kinds of saponins as in intact plants. Various culture conditions were examined for increased production of ginseng saponins by cell culture. The saponin contents and the growth rates in two cell lines of ginseng callus were compared in static and suspension cultures, rotary and reciprocal shaking cultures. It was shown that the growth rate in rotary shaking cultures of D5-B2K-B2K callus was the highest and ginseng saponin production was most effective in reciprocal cultures of D5-B2K-B2K callus. The saponin content per fresh weight of the culture was 1.03 times higher than that of the fresh ginseng root.

• 한국주조공학회지
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• 제29권4호
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• pp.181-186
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• 2009

The interrelationship between new parameter ${\sigma}$ and maximum diameter $D_{max}$ is elaborated and discussed in comparison with four other glass forming ability (GFA) parameters, i.e. (1) super-cooled liquid region ${\Delta}T_x (=T_x - T_g)$, (2) reduced glass transition temperature $T_{rg} (=T_g/T_l)$, (3) K parameter $K (=[T_x-T_g]/[T_l -T_x])$, and (4) gamma parameter ${\gamma}(=[T_x]/[T_l+T_g])$ in Ca-based bulk metallic glass (BMG) systems. The ${\sigma}$ parameter, defined as ${\Delta}T^*{\times}P^'$, has a far better correlation with $D_{max}$ than the GFA parameters suggested so far, clearly indicating that the liquid phase stability and atomic size mismatch dominantly affect the GFA of Ca-based BMGs. Thus, it can be understood that the GFA of BMGs can be properly described by considering structural aspects for glass formation as well as thermodynamic and kinetic aspects for glass formation.

• Journal of Ginseng Research
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• 제33권4호
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• pp.337-342
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• 2009

The extraction conditions for the production of red ginseng polysaccharide were proposed. The crude fiber content of red ginseng marc (RGM) (15.3%) was much higher than that of white ginseng (WG) (2.1%) and red ginseng (RG) (0.5%). Thus, RGM was selected as the raw material for polysaccharide production. The correlation between the particle size of RGM and the polysaccharide extraction was investigated with a correlation analysis using the SPSS package. The two parameters were found to have a significant correlation (p<0.01). The polysaccharide extraction increased as the particle size of RGM decreased. The optimal concentration of RGM was 6.66% (w/v). The extraction yield increased as both the extraction temperature and the extraction time increased. Finally, the extraction temperature and time were selected as $85^{\circ}C$ and 5 hrs, respectively. Consequently, the extraction conditions for polysaccharide production were optimized and statistically confirmed.

• 한국항공운항학회지
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• 제4권1호
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• pp.63-85
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• 1996

의사 결정의 문제는 기본적으로 다수의 상충되는 기준(Criteria)하에서 최적의 대안을 선택하는 문제이며, 특히 국가나 항공사 또는 어느 기관에서 항공기의 구입시 기종 선정의 문제는 항공기 자체의 높은 가격 및 기술 파급효과, 안전성, 경쟁성 등 다수의 요인들을 심도 있게 고려하여야만 한다. 따라서 다수의 전문가 집단의 의견을 종합할 수 있다면 실패의 확률을 줄일 수 있을 것이다. 본 논문은 한국항공대학교의 훈련용 항공기의 도입 필요성이 제기됨에 따라 대상 기종인 Mooney MSE와 Cessna 172RG 기종에 대하여 현재 한국항공대학교에서 비행 교육을 담당하고 있는 운항학과 전임교수와 비행교육원 비행 교관들의 설문을 통하여 계층화 의사결정법을 이용하여 전문가 의견을 종합하였다. 계층화 의사결정법(AHP; Analytic Heirarchy Process)은 1970년대 초 T. L. Saaty에 의해 개발된 기법으로 다수의 목표, 다수의 기준, 다수의 의사결정 주체가 포함되어 있는 의사결정 문제를 계층화한 후, 상위 계층의 한 기준의 관점에서 직하위 계층의 요소들의 상대적 중요도(Relative Importance) 또는 가중치(Weight)를 쌍별비교(Pairwise Comparison)에 의해 측정하여 궁극적으로 최하위 계층의 대안의 우선순위를 구하는 기법으로 앞으로 항공기의 기종선 정시(특히 훈련용 항공기) 계층화 의사결정법(AHP)을 활용할 수 있도록 모델을 제시하고자 하였다.

• 한국식품조리과학회지
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• 제30권6호
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• pp.800-805
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• 2014

The purpose of this research was to prepare Yackwa by addition of red ginseng marc powder to enhance its functional properties. For this purpose, ginsenosides composition of red ginseng marc powder was analyzed and red ginseng marc powder was added at different levels (1 to 15%) for Yackwa preparation. Also, their quality characteristics such as texture and color were measured and sensory evaluation was performed. Four ginsenosides including Rg3, Rc, Rb2, and Rd were the most abundant forms in red ginseng marc powder. With the increase of red ginseng marc powder, the properties of hardness, cohesiveness, and gumminess of samples decreased. The $a^*$ value of sample was highest when 10% of red ginseng marc powder was added. With the addition of red ginseng marc powder, the $L^*$-and $b^*$-values of samples decreased significantly (p<0.05). Based on the results of sensory evaluation, we recommended 10% addition to prepare Yackwa with red ginseng marc powder.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 2002년도 학술대회지
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• pp.227-237
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• 2002

One prominent characteristic of2,3,7,8-tetrachlorodibenzop-dioxin (TCDD) toxicity in rats is a reduction of body weight accompanied by an altered serum lipid profile such as hyperlipidemia. A single administration of TCDD (50 ug/kg) resulted in a decrease of body weight and increase of serum cholesterol in rats. TCDD-induced weight loss and serum cholesterol elevation was reduced in rats administered with water extract (100 mg/kg) or saponin fraction (40 mg/kg) of Panax ginseng C.A.Meyer. In contrast, the administration of Panax quinquefolium did not inhibit the TCDD-induced weight loss and serum cholesterol elevation. Histological examinations of liver and testis revealed the administration of saponin fraction of Panax ginseng attenuated the TCDD-induced hispathologicallesions whereas the administration of saponin fraction of Panax quinquefolium did not. High performance liquid chromatographic analysis demonstrated high percentiles of ginsenoside Rg and ginsenoside $Rh_1$ were evident in saponin fraction of Panax ginseng. Results indicate that the protective effects of Panax ginseng, not Panax quinquefolium, on the TCDD-induced toxicity might be resulted from different compositions of saponins in Panax ginseng.

• 한국의류학회지
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• 제44권5호
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• pp.824-836
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• 2020

This study investigated the effects of textile attachments on electroencephalogram using 20 persons (10 males and 10 females). Four types of attachment cushions were manufactured by changing the shell fabric (cotton and microfiber) and interlining (synthetic loose fiber and buckwheat). This was done using BIOS-S8 (BioBrain Inc., Korea), an 8-channel polygraph for multi-body signal measurement, to measure EEG. Data were analyzed using the SPSS 24.0 statistical program. EEG values were significantly activated according to gender, particularly when the subjects' eyes were open. For the male cases, 'RT', 'RAHB' values were highly activated and for the female cases, 'RA', 'RB', 'RG', 'RFA', 'RST', 'RLB', 'RMB', 'RST', 'RMT' values were highly activated. Examining the differences in EEG according to type of attachment indicated no significant difference in both sexes. However, in cases of females with their eyes closed, the 'RSA' index was quite different in the left occipital lobe (O1), and when their eyes were open, the 'RFA' in the right frontal lobe (F4) showed a significant difference. However, there was no obvious correlation between the activation of EEG and the subjective preference of textile attachments.

• Nuclear Engineering and Technology
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• 제55권1호
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• pp.25-36
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• 2023

Nuclear power plants have recognized the importance of nuclear cybersecurity. Based on regulatory guidelines and security-related standards issued by regulatory agencies around the world including IAEA, NRC, and KINAC, nuclear operating organizations and related systems manufacturing organizations, design companies, and regulatory agencies are considering methods to prepare for nuclear cybersecurity. Cryptographic algorithms have to be developed and applied in order to meet nuclear cybersecurity requirements. This paper presents methodologies for validating cryptographic algorithms that should be continuously applied at the critical control system of I&C in NPPs. Through the proposed schemes, validation programs are developed in the PLC, which is a critical system of a NPP's I&C, and the validation program is verified through simulation results. Since the development of a cryptographic algorithm validation program for critical digital systems of NPPs has not been carried out, the methodologies proposed in this paper could provide guidelines for Cryptographic Module Validation Modeling for Control Systems in NPPs. In particular, among several CMVP, specific testing techniques for ECB mode-based block ciphers are introduced with program codes and validation models.