• Korean Membrane Journal
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• v.10 no.1
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• pp.33-38
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• 2008

In this study periodic water-back-flushing using permeate water was performed to minimize membrane fouling and to enhance permeate flux in tubular ceramic micro filtration system for Gongji stream water treatment in Chuncheon city. The filtration time (FT) 2 min with periodic 6 sec water-back-flushing showed the highest value of dimensionless permeate flux ($J/J_0$), and the lowest value of resistance of membrane fouling ($R_f$), and we acquired the highest total permeate volume ($V_T$) of 7.44L. Also in the results of BT effect at fixed FT 10 min, BT (back-flushing time) 20 sec showed the lowest value of $R_f$ and the highest value of $J/J_0$, and we could be obtained the highest $V_T$ of 8.04 L. Consequently FT 10 min and BT 20 sec could be the optimal condition in Gongji stream water treatment. Then the average rejection rates of pollutants by our tubular ceramic MF system were 93.8% for Turbidity, 20.7% for $COD_{Mn}$, 39.2% for $NH_3$-N and 31.5% for T-P.

• Journal of the Korean Magnetics Society
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• v.14 no.1
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• pp.7-12
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• 2004

The annealing-temperature dependence of magnetic properties in compressed powder cores being composed of ball-milled F $e_{73.5}$C $u_1$N $b_3$S $i_{15.5}$ $B_{7}$ alloy powders (size 250∼850${\mu}{\textrm}{m}$) and 5 wt% of ceramic insulators has been investigated. When annealed at 5$50^{\circ}C$ for 1 h and so transformed to $\alpha$-Fe phase nanocrystalline structure with the grain size of 11 nm (electrical resistivity : 110 $\mu$Ω$.$cm), the highest effective permeability of 125 and quality factor of 53 were obtained, and the permeability persisted up to about 500 KHz. Further the core loss measured at the frequency of 50 KHz and the induction amplitude of 0.1 T was very low (230 mW/㎤). However the dc bias characteristics was not satisfactory as compared to that of conventional powder core materials(MPP, Sendust etc.). The inferior dc bias property of F $e_{73.5}$C $u_1$N $b_3$S $i_{15.5}$ $B_{7}$ alloy powder cores was attributed to the fact that the size of powder was too large for obtaining the same permeability with that of conventional materials.

• Journal of the Korean Magnetics Society
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• v.3 no.3
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• pp.185-189
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• 1993

급속응고법으로 제작된 비정질 $Fe_{85-x}Co_{x}Zr_{7}B_{7}Cu_{1}$ 합금의 열처리에 따른 구조 및 자기특성이 조사되었다. 비정질 $Fe_{85-x}Co_{x}Zr_{7}B_{7}Cu_{1}$ 합금은 $600^{\circ}C$이하의 열처리온도에서 약 10 nm의 초미세결정립이 형성된다. $600^{\circ}C$이상의 열처리 조건에서는 결정립크기가 급격히 증가하여 자기특성을 열화시킨다. $Fe_{85-x}Co_{x}Zr_{7}B_{7}Cu_{1}$ 합금의 최적열처리온도는 Fe-Zr-B초미세결정립합금에 비하여 낮으며, 결정립크기 또한 감소한다. 이는 Cu의 첨가에 기인하는 것으로 판단된다. 최적열처리조건에서 $Fe_{80}Co_{5}Zr_{7}B_{7}Cu_{1}$ 초미세결정립합금의 포화자화 및 f=50 kHz, $B_{m}=0.2\;T$에서 측정한 투자율 및 철손은 각각 157.3 emu/g(1.5 T), $1.8{\times}10^{4}$ 및 13 W/kg으로 자기특성이 가장 우수하다.

• Food Science and Preservation
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• v.21 no.4
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• pp.491-499
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• 2014

Changes in various physicochemical and sensory characteristics of Samgyetang retorted at the $F_0$ values of 4.0 (F4), 7.0 (F7), and 10.0 (F10) were investigated during storage at $25^{\circ}C$ for 12 months. The pH level tended to decrease in all the treatments with the increase of the storage time, but no significant difference in the extent of the decrease was observed among the treatments. The values of volatile basic nitrogen, thiobarbituric reactive substances, and carbonyl contents increased rapidly over the storage period in the order of F4 > F7 > F10. The viscosity decreased most sharply between month 0 and month 2, after which the rate of increase declined. The oxygen concentration in the headspace of the retort pouch of the Samgyetang was higher for the samples retorted at higher $F_0$ values. In the sensory tests, the scores of the samples retorted at higher $F_0$ values tended to be lower, but all the characteristics of the samples, except for the texture of the T10 samples, were evaluated with scores higher than 5.0, the limit of marketability, over the storage time. In conclusion, the quality of the Samgyetang samples treated at higher $F_0$ values deteriorated more noticeably during storage.

• Journal of Digital Convergence
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• v.14 no.12
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• pp.335-344
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• 2016

The purpose of the study was to investigate the effect of stress, social support, and self-esteem on depression in female students. A self-reported questionnaire was completed by 249 females students from November to December 2015. The study instruments comprised stress, social support, self-esteem, and depression. The data were analyzed by descriptive statistics, t-test, ANOVA, Pearson's correlation coefficients, and hierarchial multiple linear regression using SPSS/WIN 18.0 program. Depression was closely related to school year(F=7.03, p<.001), health status(F=15.19, p<.001), major satisfaction(F=18.02, p<.001), and student activity(t=1.98, p=.049). The significant factors influencing depression were stress(${\beta}=.45$, p<.001), self-esteem(${\beta}=-.34$, p<.001), social support(${\beta}=-.14$, p=.004), major satisfaction(${\beta}=-.11$, p=.018). To decrease depression, it is necessary to develop a program coping with stress and increasing the self-esteem and social support. Thus, it will be able to enhance the mental health of female students.

• The Journal of the Convergence on Culture Technology
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• v.7 no.2
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• pp.309-316
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• 2021

The purpose of this study is to investigate the level of adaptation to college life and identity the influencing factors on adaptation to college life of college freshmen's. Data were collected from 2088 college freshmen's in B city and analyzed by t-test, ANOVA, Pearson correlation coefficient, and multiple regression using SPSS/WIN 22.0. The degree of adaptation to college life in college freshman was 3.75±0.73. There were significant differences in college life adaptation with respect to gender(t=3.947, p<.001), age(F=3.445, p=.032), major(F=5.539, p=.001), family type(F=6.958, p<.001). There was negative correlation between adaptation to college life and perceived stress(r=-.696, p<.001), depression(r=-.507, p<.001), positive correlation were found between perceived stress and depression(r=.567, p<.001). The factors affecting the adaptation to college life of the study subjects were perceived stress, depression, age, major, family type with an explanatory power of 50.4%. In conclusion, to enhance adaptation to college life of college freshmen's, it is necessary to develop and adopt various program of adaptation to college life.

• Journal of Korean Society of Water and Wastewater
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• v.37 no.4
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• pp.203-214
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• 2023

In this study, the physical properties and fracture characteristics according to the tensile load are evaluated on the materials of the polymeric filler and carbon fiber-based composite sleeve technique. The polymeric filler and the composite sleeve technique are applied to areas where the pipe body thickness is reduced due to corrosion in large-diameter water pipes. First, the tensile strength of the polymeric filler was 161.48~240.43 kg_f/cm², and the tensile strength of the polyurea polymeric filler was relatively higher than that of the epoxy. However, the tensile strength of the polymeric filler is relatively very low compared to ductile cast iron pipes(4,300 kg_f/cm²<) or steel pipes(4,100 kg_f/cm²). Second, the tensile strength of glass fiber, which is mainly used in composite sleeves, is 3,887.0 kg_f/cm², and that of carbon fiber is up to 5,922.5 kg_f/cm². The tensile strengths of glass and carbon fiber are higher than ductile cast iron pipe or steel pipe. Third, when reinforcing the hemispherical simulated corrosion shape of the ductile cast iron pipe and the steel pipe with a polymeric filler, there was an effect of increasing the ultimate tensile load by 1.04 to 1.06 times, but the ultimate load was 37.7 to 53.7% compared to the ductile cast iron or steel specimen without corrosion damage. It was found that the effect on the reinforcement of the corrosion damaged part was insignificant. Fourth, the composite sleeve using carbon fiber showed an ultimate load of 1.10(0.61T, 1,821.0 kg_f) and 1.02(0.60T, 2,290.7 kg_f) times higher than the ductile cast iron pipe(1,657.83 kg_f) and steel pipe(2,236.8 kg_f), respectively. When using a composite sleeve such as fiber, the corrosion damage part of large-diameter water pipes can be reinforced with same level as the original pipe, and the supply stability can be secured through accident prevention.

• Journal of Korean Academy of Nursing Administration
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• v.13 no.4
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• pp.481-491
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• 2007

Purpose: To investigate the influence of organizational justice and commitment on OCB(organizational citizenship behavior) of hospital nurses. Method: The subjects were 352 nurses who have been working in seven university hospitals. The data were collected by structured questionnaire from Feb. 12 to Mar. 5 of 2006. The data were analyzed by SPSS Win version 12.0, including descriptive statistics, t-test, ANOVA, Pearson correlation coefficient, and Stepwise multiple regression. Results: The mean score of OCB was 3.53, distributive justice was 2.74, procedural justice was 2.73, and organizational commitment was 3.28. The OCB had statistically significant differences according to age(F=8.39, p<.000), tenure duration(F=6.53, p<.000), position(F=7.65, p<.000), marital status(t=5.82, p<.000), and religion(t=3.78, p<.000). The OCB was positively correlated with distributive justice(r=.147, p=.006), procedural justice(r=.180, p=.001), and transactional commitment(r=.115, p=.032). The procedural justice(10.6%) and transactional commitment(14.3%) explained 24.9% of the variance for OCB. Conclusion: The findings showed that organizational justice and commitment were important factors for enhancing OCB in nursing organization. Therefore, the nurse manager must establish the strategies to improve the organizational justice and commitment perception of the nurses in order to promote the OCB.

• Journal of Environmental Science International
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• v.20 no.5
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• pp.599-610
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• 2011

Emission of air pollutants such as nitrogen oxides ($NO_x$), hydrocarbons (HC), $SO_2$, and particulate matter (PM) and $CO_2$ from ship during 2009 in Busan port was estimated based on activity-based method. The significant fraction (> 50%) of ship emission resulted from container and general cargo ships. Emission at port operation mode was the most dominant compared to at sea and maneuvering modes. Emission at North port was the largest source of air pollutants among ports. The magnitudes of air pollutants $NO_x$, $SO_2$, HC, $CO_2$, and PM in Busan port were $8.7{\times}10^3$, $8.23{\times}10^3$, $0.35{\times}10^3$, $4.86{\times}10^6$, and $0.67{\times}10^3$ ton/yr, respectively. The ratio of $NO_x$ to VOC is about 25. Our ship emission estimate is 2 times higher than that in CAPSS emission inventory.

• Child Health Nursing Research
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• v.23 no.4
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• pp.449-458
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• 2017

Purpose: The purpose of this study was to identify factors related to level of satisfaction among mothers of preschoolers. Methods: Participants were 359 mothers of firstborn healthy preschoolers. The questionnaires were collected from August 1 to November 21, 2012. Data were analyzed using SPSS 20.0. Results: The mean score for degree of mothers' parenting satisfaction was 5.94 out of 7. There were significant differences in the level of parenting satisfaction according to mother's job (t=2.48, p=.014), planned pregnancy (t=3.07, p=.002), number of children (t=2.22, p=.027), and parenting education (F=4.33, p=.005). The environmental variables of age of spouse (F=3.06, p=.048) and monthly income of the household (F=2.87, p=.036) also seemed to have an influence. Analysis of predictors such as the mother's job, planned pregnancy, parenting education, overall health problems, parenting stress, perception of emotional status and behaviors in children, age of spouse, and spouse's support explained 31.5% of the variance in mother's parenting satisfaction. Conclusion: The results suggest a need to develop nursing intervention programs for parenting stress reduction, and health programs for fathers to support mothers' child rearing.