• 대한통합의학회지
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• 제9권1호
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• pp.109-121
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• 2021

Purpose : The first case of coronavirus disease-2019 (COVID-19) disease outbreak in Korea occurred in January 2020, and the cumulative number of confirmed cases by the Central Defense Response Headquarters of the Quality Management Administration as of November 30 was 34,201. Looking at the incidence trend of domestic confirmed cases by age, the incidence rate of COVID-19 in the age group of 20-29 years, which corresponds to college students, was 27.4 %, the highest compared by age group. Considering the current status of the infection rate, universities will become the centers of new COVID-19 cases if face-to-face lectures are recommenced without preparatory measures and analysis of infection prevention (e.g., infection awareness and education for university students). Thus, this study intended to investigate the level of knowledge, educational needs, and preventive behavior performance of college students about COVID-19 and provide basic data for the development of an education program for the prevention of COVID-19 for college students. Methods : This study is a descriptive correlational study aimed to investigate the correlation between knowledge about COVID-19, educational needs, and degree of preventive behavior performance in 407 college students attending one University in Gyeonggi-do. Results : The subjects' knowledge score about COVID-19 was 12.46±1.39 points, average educational needs score was 29.16±3.14 points, and prevention behavior performance survey result was 35.50±3.61 points. Moreover, positive correlation was observed between the knowledge about COVID-19 and educational needs (r=.203, p<.001) and knowledge and preventive behavior performance (r=.140, p=.005). Further, educational needs and preventive behavior performance demonstrated a statistically significant positive relationship (r=.311, p<.001). Conclusion : Therefore, organizing an educational program to acquire accurate knowledge is necessary to make it a habit for college students to practice preventive behavior against COVID-19.

• Asian Journal of Innovation and Policy
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• 제4권2호
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• pp.200-216
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• 2015

This paper empirically investigates the role of R&D intensity on market concentration of firms using four key market valuation variables, namely (1) market share, (2) labor intensity, (3) firm age and, (4) firm's market value. The empirical tests use database at firm level for the Indian IT sector from 1999 to 2013 from the CMIE Prowess database. The results of the regression analyses partially support our hypothesis that R&D intensity positively influences firm's market value measure by the H-index. The test results are consistent with the hypotheses that R&D spending is more valuable for firms with larger market shares, higher labor intensity, and firms that are diversified.

• 대한산업공학회지
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• 제30권3호
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• pp.250-260
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• 2004

This study considers a linear connected-(r,s)-out-of-(m,n):F lattice system whose components are ordered like the elements of a linear (m,n )-matrix. We assume that all components are in the state 1 (operating) or 0 (failed) and identical and s-independent. The system fails whenever at least one connected (r,s)-submatrix of failed components occurs. The purpose of this paper is to present an optimization scheme that aims at minimizing the expected cost per unit time. To find the optimal threshold of maintenance intervention, we use a genetic algorithm for the cost optimization procedure. The expected cost per unit time is obtained by Monte Carlo simulation. The sensitivity analysis to the different cost parameters has also been made.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 추계 학술논문 발표대회
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• pp.7-8
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• 2014

Latex-modified concrete using ready mix concrete (R-LMC) was developed for application of building construction project (specifically, the rooftop of a parking garage unable to use heavy equipments for bridge deck overlay) due to three major outstanding properties of R-LMC; bond strength, resistance of cracks at early age, and resistance of freezing and thawing. However, R-LMC at the placement stage is required to be sufficiently cured because R-LMC is very sensitive to rate of evaporation of surface moisture. This study focused on effects of different curing methods and climate condition on cracks on the surface of hardened R-LMC considering the chart of rate of evaporation of surface moisture from concrete provided by American Concrete Institute in manual for placement of latex modified concrete.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.201.3-201.3
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• 2003

The ethanol extract from the fruit of Terminalia chebula (Combretaceae) and the hook of Uncaria sinensis (Rubiaceae) exhibited significant inhibitory activity on oxidative stress and the age-dependent shortening of the telomeric DNA length. In the peroxidation model using t-BuOOH, human epidermal keratinocytes-neonatal foreskin (HEK-N/F) cells were treated with the T. chebula and U. sinensis extracts. The results showed a notable enhancing effect on the cell viability of 60.5 ${\pm}$ 3.8 and 65.0 ${\pm}$ 3.0%, respectively, by 50 $\mu\textrm{g}$/ml of the extracts. (omitted)

• Anatomy and Cell Biology
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• 제51권4호
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• pp.251-259
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• 2018

The aim of this study is to examine the correlation between tooth wear and age by quantitatively measuring maxillary first molar wear in children. A total of 150 maxillary dental models were analyzed in 30 subjects (male, 11; female, 19) with an age range of 6-14 years. Maxillary first molar wear were assessed based on area, volume and the shortest distance from the buccal occlusal plane to the central pit point (BCPH). The area and volume of the tooth cusps were measured at four different offset-plane heights (0.2, 0.4, 0.6, and 0.8 mm). Relationship between age and the amount of wear or BCPH were statistically analyzed. Correlation and regression analyses were also performed, and age estimation was obtained with linear regression analysis. Repeated measures analysis of variance (ANOVA) revealed significant differences between age and the amount of wear based on area, volume, and offset-plane height. Except age of 8 and 10, 12 and 14's 0.2-mm offset-plane-measured volume, all area and volume measurement of all ages and offset-plane height showed a significant amount of increase. Wear speeds were calculated using the BCPH. Among age and measurement variables, the correlation coefficient was strongest when the volume was measured from the 0.4-mm offset-plane. As age increases, the amount of wear, as quantified by area and volume measurements, also increases. According to this study, a regression equation that can be used for age estimation is follows: Age $(y)=0.16{\times}0.4V+0.85$ ($R^2=0.490$) using volume.

• 한국산학기술학회논문지
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• 제21권1호
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• pp.103-111
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• 2020

본 연구는 간호대학생의 결혼관, 자녀관, 출산양육동기, 출산의지의 정도를 알아보고, 출산의지에 영향을 미치는 요인을 확인하여 출산의지를 높이기 위한 기초자료를 제공하기 위하여 시도된 서술적 조사연구이다. 연구대상자는 B시의 2개 대학교 간호대학생을 대상으로 자료수집은 2019년 5월 1일부터 30일까지 였고, 최종 248부를 분석에 사용하였다. 수집된 자료는 SPSS 22.0 프로그램을 이용하여 실수, 백분율, 평균, 표준편차, 독립 t-검증, 일원분산분석, 피어슨 상관계수, 다중회귀분석으로 분석하였다. 연구결과 연구대상자의 결혼관, 자녀관, 출산양육동기, 출산의지의 정도는 결혼관 평균 3.39±.38점, 자녀관 평균 2.72±0.39점, 출산양육동기 평균 2.73±0.78점, 출산의지 평균 3.12±0.48점으로 나타났다. 일반적 특성에 따른 출산의지의 차이에서 연령(F=6.002, p=.003)에서 유의한 차이를 나타냈다. 연구대상자의 결혼관, 자녀관, 출산양육동기와 출산의지와의 상관관계에서 출산의지는 결혼관 중 보수적 결혼관(r=.207, p=.001), 적극적 결혼관(r=.226, p<.001), 도구적 결혼관(r=.181, p=.004), 양육동기(r=.283, p<.001)와 정적 상관관계를 나타냈다. 출산의지는 결혼관 중 소극적 결혼관(r=-.292, p<.001), 자녀관(r=-.226, p<.001)과는 부적상관관계를 나타냈다. 연구대상자의 출산의지에 영향을 미치는 요인은 연령(β=.212, p<.001), 결혼관(β=-.318, p<.001), 출산양육동기(β=.227, p=.006)로 나타났고, 설명력은 20.2%였다. 본 연구를 통하여 간호대학생의 출산의지에 영향을 미치는 다양한 요인을 확인하기 위한 반복연구가 필요하다.

• 대한간호학회지
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• 제23권4호
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• pp.678-693
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• 1993

The purposes of this study were to describe the level of vision and hearing impairments, depression and functional capacity, among Korean institutionalized elderly and to examine the relation-ship between sensory impairments, depression, and functional capacity in these people. The final pupose was to test the cognitive function path model using sensory competencies as predictors. A convenience sample of thirty nine male and 90 female subjects with a mean age of 80.5 were the subjects of this study. The subjects were tested for cognitive function, and vision and hearing impairments. Physical function and social function were measured by observation of designated task performance by the subjects. Their level of de-pression was measured using a Geriatric Depression Scale administered through an interview. Individual subjective ratings of hearing and vision were marked by the subjects, on a ladder scale. The results of the study showed that 48.8% of the subjects had a hearing impairment, 63.5% had a vision impairement, and 36.4% had both a vision and hearing impairement. The four sensory groups (no sensory impairement, hearing impairement, vision impairement, hearing and vision impairement) were tested for differences in depression, physical function, social behavior and cognitive function. The only significant difference that was found was in cognitive function, between the no sensory impairement group and the hearing and vision impairement group(F=3.25, P<.05), Subjective ratings of hearing showed a significant correlation with cognitive function(r=.34, p<.001) and with social behavior(r=.31, p<.001). There was no correlation between subjective vision ratings and cognitive function or social behavior. However there was a significant correlation between vision and hearing(r=.49, p<.001). There was also a significant negative correlation between age and vision(r=-.21, p<.01) and between age and hear-ing(r=-.34, p<.001). There was a significant correlation between depression and physical function (r=-.32, p<.001) but there was no correlation between depression and cognitive function or social behavior. Based on the literature review and the result, this study, a path model of sensory competence-> cognitive function- >social behavior was developed and tested : Perceived vision and perceived hearing were the exogenous variahles and cognitive function and social behavior were the endogeneous variables in the model. The path analysis result demonstrated an accept-able fit (GFI=.997, AGFI=.972, X$^2$=.72 (p=.396), RMSR=.019) between the data and the model. There was a significant direct effect($\beta$=.38) of perceived hearing on cognitive function. There was a significant direct effect ($\beta$=.32) of cognitive function on social behavior. The total effect of hearing on social behavior was $\beta$=.32 including the indirect effect ($\beta$=.12) . However perceived vsion had little effect ($\beta$=-.08) on cognitive function. The result of path analysis confirms that hearing levels influence cognitive function, and both hearing and cognitive function levels influence social behavior. However, vision has little effect on cognitive function or on social behavior. For the next study, a combined model of the pre viously developed environment - >depression- > physical and social function model, and the present cognitive function model, should be tested to further refine the functional capacity model. There also a need for longitudinal study of functional capacity and sencory competence in order to better understand how declining sensory competence influences functional capacity and how it effects in-creasing dependency and nursing needs in the elderly.

• 한국식품위생안전성학회지
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• 제8권4호
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• pp.231-240
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• 1993

This study was carried out to find out the content of injurious heavy metals, such as mercury, lead, cadmium and arsenic of marine fish which had been captured in adjacent sea of Korea. From March, 1 to April, 30 in 1993. 60 sample of fishes were collected the adult fish and young fish. These samples were analyzed by the Mercury Analyzer and Inductively Coupled Plasma Emission Spectro Analyzer. The results of the study were summarized as follows: (1) The content of mercury in Therafra chalcograma was 0.112$\pm$0.034 ppm which was higher than other fishes, but Pseudosciaena manchurica and Pampus argenteus had lower (P<0.05). Although lead content of Trichiurus lepturus was 0.359$\pm$0.056 ppm, which was higher than other fishes. The lead content of Theragra chalcograma had lower to the almost same level. The cadmium content of the Theragra chalcograma was 0.069$\pm$0.010 ppm which was higher than other samples, but Pseudosciaena manchurica had 0.039$\pm$0.020 ppm to lower level. Though there was some fluctuation in the arsenic content which was 0.433~3.752 ppm, the arsenic content of Therafra chalcograma was 3.752$\pm$2.873 ppm which was the higher than any other fishes. But there are not statistical significances. (2) Heavy metal content by the maturity of the fishes: Mercury content of the old Pseudosciaena manchurica was 0.055$\pm$0.15 ppm comparing to the young's result of 0.030$\pm$0.009 ppm (P<0.05). Though there were some differences according to the maturity, but thee was no statistical significance. (3) In view of the correlation of the heavy metal content, for Pseudosciaena manchurica, high correlation was founded to r=0.6437 between mercury and cadmium (P<0.05). Though the content of mercury, arsenic cadmium and lead had positive correlation (r=0.2725) and negative correlation (r=-0.3958), but there was no significance at all. The other fishes were not found correlation between the heavy metal content. Positive correlation was found between age with mercury in Pseudociaena manchurica (r=0.7018, P<0.05). The negative correlation of age with lead content in the Pseudociaena Manchurica was signigicant (P<0.05). The correlation coefficient was r=-0.7623. The age with mercury content in Coloabis saira had high correlation (r=0.7201, P<0.05). Through the above analysis, it can get conclusion that injurious heavy metal content of the fishes in Korea such a mercury, lead, cadmium and arsenic were at the level of natural content. At present, guidelines of maximum residue level allowed at foreign countries about the injurious heavy metal have been used according to the kinds of fish but our government guideline for the marine fishes in only total mercury below 0.7 ppm and lead below 2 ppm. So more aggressive guidelines for the allowance level of heavy metals in marine fishes are required for the safety of foods.

• 한국패류학회지
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• 제23권1호
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• pp.17-23
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• 2007

2004년 10월부터 2005년 11월까지 전라북도 고창군 주진천에 서식하는 쇄방사늑조개의 서식지 환경과 성장을 조사하였다. 서식지의 월별 수온은 $4.6-29.3^{\circ}C$로 나타났으며, 1월에 가 장 낮았고, 8월에 가장 높았다. 지온은 $2.6-29.4^{\circ}C$로 나타났으며 수온과 비슷하게 1월과 2월에 낮았고 8월에 가장 높았다. 월별 염분은 2.3-20.2 psu로 평균 $8.21\;{\pm}\;4.77\;psu$였다. 쇄방사늑조개의 패각에 나타나는 윤문은 년 1회 형성되며, 주된 윤문 형성 시기는 10-12월임을 확연할 수 있었다. 초륜의 형성 기간은 약 5개월 (0.42년) 으로 나타났으며, 각장 (SL) 과 각고 (SH) 간의 관계는 SH = 0.4352 SL + 0.5642 ($R^2\;=\;0.978$) 이고, 각장과 각폭 (SW) 간의 관계는 SW = 0.4352 SL - 0.5675 ($R^2\;=\;0.957$) 이며, 각장과 전중량 (TW) 간의 관계는 $TW\;=\;6.999\;{\times}\;10^{-5}\;SL^{3.2542}\;(R^2\;=\;0.975)$ 로 나타났다. 연령 (t) 에 대한 각장 (SL) 의 Bertalanffy 성장식은 $SL_t\;=\;30.77\;[1-e^{-0.4572(t+0.7371)}]$였으며, 전중량 (TW) 의 Bertalanffy 성장식은 $TW_t\;=\;4.87\;[1-e^{-0.4572(t+0.7371)}]^{3.2542}$로 추정되었다.