• Tribology and Lubricants
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• v.37 no.1
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• pp.7-13
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• 2021

Ball bearing is a device that supports and transmits a load acting on a rotating shaft, and it is a type of rolling bearings that uses the rolling friction of the balls by inserting balls between the inner ring and the outer ring. Grease, which is prepared by mixing a thickener with a base oil, is a lubricant commonly used in bearings and has the advantage of a simple structure and easy handling. Bearings are increasingly being used in high value-added products such as semiconductors, aviation, and robots in the era of the 4th industrial revolution. Accordingly, there is an increasing demand for bearing grease. The selection of grease is an important factor in the bearing design. Therefore, a study must be conducted on the grease life evaluation to select an appropriate grease according to operating conditions such as a high temperature, high rotational speed, and high load. In this study, we evaluate the life of ball-bearing grease according to various operating conditions, namely, temperature, speed, and load changes. For this, we develop and theoretically verify a grease life test machine for ball bearings. We conduct a life test of grease according to various operating conditions of bearings and predict the grease life with a 10% and 50% failure probability using the Weibull analysis. In addition, we analyze the oxide characteristics of the grease over time using the Fourier transform infrared spectroscopy and the deterioration characteristics of the grease using the carbonyl index.

• Journal of The Korean Society of Agricultural Engineers
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• v.60 no.1
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• pp.37-45
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• 2018

This study is aims to voluntary participation in rural development projects, voluntary participation by analyzing the individual competence factors, how the what and how much influence affect the continued involvement and participation as a concept of strengthening community capacity the plan for it to present. The results of survey, through factor analysis and reliability analysis for extracting the components of individual competence areas and life satisfaction, self acting capacity, was extracted with recognized competence, was the factor analysis and reliability analysis for ongoing involvement and participation. Personal competence was a multiple regression analysis, the participation of three elements as independent variables as dependent variables to evaluate the impact of continuing involvement, and the resulting Regional and life satisfaction (${\beta}=0.301$) have the greatest impact It showed. In addition, regional analysis and life satisfaction (${\beta}=0.247$) on the impact of enlargement on the individual capabilities showed the highest participation. The elements of local life satisfaction and personal competencies exerts the greatest influence on the continued involvement and participation in the study was obtained. It based on the results in rural development for the voluntary participation and participation of the population should be considered with a plan to enhance the regional and life satisfaction, "the software business, which is carried out in rural areas developed for them by local residents the measures to increase life satisfaction will be provided.

• Journal of Korea Entertainment Industry Association
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• v.14 no.6
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• pp.77-89
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• 2020

The film "Parasite" portrays Korea's history and its present in a space that clearly represents the real world's hierarchy as a vertical structure. It demonstrates the problems of an insurmountable reality and the elements of various conflicts occurring below the surface of Korean society through a complex mix of human emotions and relationships. The most realistic yet unrealistic characters cross boundaries between being victims and perpetrators, defamiliarizing ordinary scenes from everyday life through their small mistakes, strange obsessions, bizarre behavior, anxious psychology, and desperate struggles. This study analyzes the expression of the film "Parasite" through its characters with the belief that the film expresses director Bong Joon-ho's consistent cinematic philosophy of taking reality beyond the traditional rules of film genres. By doing so, Bong creates a feature of the expression that shifts genres as the characters' personalities amplify related behaviors, conflicts and questions, and that this is the core of the unique nuance and distinct humor of this film. In addition, the personalities of the characters interact with all the film's elements (cinematic techniques, space, props, etc.), evoking effects of various meanings, which are transmitted through the actors'images and acting. In this respect, the study analyzes how the actors were cast in order to realistically reproduce the characters of the actors, how their acting was harmonized with the film's elements, and its features as well as how they were expressed.

• Journal of Korean Academy of Nursing
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• v.47 no.4
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• pp.562-574
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• 2017

Purpose: This study attempts to explore the subjective experience of frailty among elderly individuals in Korea. Methods: From June to August in 2014, 11 elderly persons who had experienced frailty in a community were interviewed. For data analysis, the method suggested by Colaizzi was applied as a phenomenological method. Results: According to the analysis, the study participants' frailty process was structured in seven categories: (a) 'natural phenomenon with ageing,' (b) 'life force comes to an end,' (c) 'the light in my heart turns off,' (d) 'unavoidable situation,' (e) 'continuous and connected vicious cycle,' (f) 'the limit of recovery energy already passes,' and (g) 'life is supported by someone's help.' Conclusion: The frailty experience in the participants is a natural process of aging, which cause vicious cycle acting with each other among physical, psychological, and social health. It is said that the cycle of frailty was started from weight loss and insufficient sleep, and boostered by pain. The participants from repetition of the vicious cycle become exhausted and pass the threshold of their recovery energy at some points. If they meet with sudden accidents such as falling, traffic accident and so on, they become to live a dependent life supported by someone's help in a moment. To prevent frailty and worsening conditions in Korean elderly individuals, it is recommended to provide a interventional programs using this study's results.

• Molecules and Cells
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• v.40 no.10
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• pp.697-705
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• 2017

The maintenance of inorganic phosphate (Pi) homeostasis is essential for plant growth and yield. Plants have evolved strategies to cope with Pi starvation at the transcriptional, post-transcriptional, and post-translational levels, which maximizes its availability. Many transcription factors, miRNAs, and transporters participate in the Pi starvation signaling pathway where their activities are modulated by sugar and phytohormone signaling. Environmental stresses significantly affect the uptake and utilization of nutrients by plants, but their effects on the Pi starvation response remain unclear. Recently, we reported that Pi starvation signaling is affected by abiotic stresses such as salt, abscisic acid, and drought. In this review, we identified transcription factors, such as MYB, WRKY, and zinc finger transcription factors with functions in Pi starvation and other environmental stress signaling. In silico analysis of the promoter regions of Pi starvation-responsive genes, including phosphate transporters, microRNAs, and phosphate starvation-induced genes, suggest that their expression may be regulated by other environmental stresses, such as hormones, drought, cold, heat, and pathogens as well as by Pi starvation. Thus, we suggest the possibility of cross-talk between Pi starvation signaling and other environmental stress signaling pathways.

• Journal of the Korea Fashion and Costume Design Association
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• v.14 no.2
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• pp.199-214
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• 2012

$21^{st}$ century customer is voluntary actor, who has hegemony of communication based on digital surrounding. They are co-creator dismantling boundary between production and spending, and digital homonarrance of digital storyteller acting on the emotion. What is more, they prove the utility of 5 sense, value, experience, and story in market. 20th century Me generation is changing into We generation, who overcomes a sense of alienation and aim at smart life style for harmonious symbiosis with earth environments. Customer cultural trends are as follow as that 1) personalization of taste and experience, 2) spreading and sharing about personal use and experience, 3) consumption centered the value, 4) retreat and healthcare, 5) counter trend comes into the reaction about the forceful major trend. Contemporary customer changes essence of the life on the ground of emotion, symbol, image, and value not a commodity, function, and logos, and demands into change about direction of business to mostly enterprises. Customer's need and desire are on the increase as various emotion and value. Therefore, change of customer cultural trend is barometers for the growth and development of new fashion industry in $21^{st}$ century.

• Mycobiology
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• v.39 no.4
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• pp.283-289
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• 2011

The wild edible mushroom, Lentinus lepideus has recently been cultivated for commercial use in Korea. While the mushroom has been widely used for nutritional and medicinal purposes, the possible anti-hyperlipidemic action is unclear. The effects of dietary L. lepideus on plasma and feces biochemical and on the liver histological status were investigated in hypercholesterolemic rats. Six-wk-old female Sprague-Dawley albino rats were divided into three groups of 10 rats each. Biochemical and histological examinations were performed. A diet containing 5% L. lepideus fruiting bodies reduced plasma total cholesterol, triglyceride, low-density lipoprotein, total lipid, phospholipids, and the ratio of low-density to high-density lipoprotein. Body weight was reduced. The diet did not adversely affect plasma biochemical and enzyme profiles. L. lepideus reduced significantly plasma ${\beta}$- and pre-${\beta}$-lipoprotein, while ${\alpha}$-lipoprotein content was increased. A histological study of hepatic cells by conventional hematoxylin-eosin and oil red O staining revealed normal findings for mushroom-fed hypercholesterolemic rats. The present study suggests that a diet supplemented with L. lepideus can provide health benefits by acting on the atherogenic lipid profile in hypercholesterolemic rats.

• Journal of Life Science
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• v.11 no.1
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• pp.1-6
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• 2001

In order to determine the role of the carboxyl terminal amino acid residues of unacetylated ${\alpha}$-tropomyosin in actin affinity two mutant tropomyosins were constructed by site-directed mutagenesis. TM16 was identical to the striated tropomyosin except that three amino acids in the carboxyl terminal end were altered to $^{282}TNM^{284}$ while in TM17 $^{282}TSI^{284}$ of the striated was replaced with$^{282}NSM^{284}$. TM16 and TM17 were overproduced in Escherichia coli and analyzed for actin affinity by comparing actin affinities of the striated and TM11 $^{282}NNM^{284}$). The apparent binding constants (Kapp) of unacetylated tropomyosins to actin were $5.1{\times}10^4M^{-1}$ for the striated, $1.1{\times}10^5M^{-1}$ for TM11, $1.09{\times}10^5M^{-1}$ for TM16, and $1.03{\times}10^5M^{-1}$ for TM17, respectively. Since the actin affinities of TM11, TM16, and TM17 were very similar, this result suggested that amino acid residues 282 and 283 were insignificant for acting affinity of unacetylated $\alpha$-tropomyosin. However, they all exhibited higher actin affinities than that of the striated, suggesting that Met residue at the carboxyl terminus of unacetylated smooth tropomyosin was rather important for actin affinity, presumably due to the nucleophilic nature of sulfur atom in Met residue.

• The KSFM Journal of Fluid Machinery
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• v.9 no.2 s.35
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• pp.39-43
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• 2006

The magnitude of the axial force acting on turbopump bearings has a great influence on the operational reliability and service life of a turbopump. In the turbopump under current investigation the cavity vanes are introduced to the pump shroud casing to control the axial thrust of the turbopump. To investigate the effect of the cavity vanes, 3D computational flow analyses for a propellant pump stage including an inducer, impeller, volute and secondary flow passages are performed with and without the vanes. The results show that the cavity vanes are very effective in reducing the magnitude of axial thrust without notable changes on the overall performance of the turbopump.

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.354-358
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• 2005

The magnitude of the axial force acting on turbopump bearings has a great influence on the operational reliability and service life of a turbopump. In the turbopump under current investigation the cavity vanes are introduced to the pump shroud casing to control the axial thrust of the turbopump. To investigate the effect of the cavity vanes, 3D computational flow analyses for a propellant pump stage including an inducer, impeller, volute and secondary flow passages are performed with and without the vanes. The results show that the cavity vanes are very effective in reducing the magnitude of axial thrust without notable changes on the overall performance of the turbopump.