• Bulletin of the Korean Chemical Society
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• 제34권5호
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• pp.1435-1440
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• 2013

To investigate the influence of the carbon matrix on the electrochemical performance of Si/C composites, four types of Si/C composites were prepared using graphite, petroleum coke, pitch and sucrose as carbon precursors. A ball mill was used to prepare Si/C blends from graphite and petroleum coke, whereas a dispersion technique was used to fabricate Si/C composites where Si was embedded in disordered carbon matrix derived from pitch or sucrose. The Si/pitch-based carbon composite showed superior Si utilization (96% in the first cycle) and excellent cycle retention (70% after 40 cycles), which was attributed to the effective encapsulation of Si and the buffering effect of the surrounding carbon matrix on the silicon particles.

• Asia pacific journal of information systems
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• 제30권1호
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• pp.167-187
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• 2020

College students experience more cyber bullying than youth and cyber bullying on college students may be more harmful than youth. But many studies of cyber bullying have been conducted in youth, but little has been studied for college students. Therefore, this study investigated the negative effects of college students' cyber bullying experience on cognitive processing ability and emotional states. The social support of friends has a buffering effect that prevents stress and reduces the influence on external damage in stressful situations. But the impact of parental social support is controversial. Traditionally, the social support of parents has been claimed to mitigate the negative effects of external damage. Recently, however, it has been argued that parental social support, without considering the independence and autonomy needs of college students, does not alleviate the negative effects. Therefore, this study examined how the social support of friends and parents moderate the negative impact of cyber bullying. The results show that the more college students experience cyber bullying, the lower their cognitive processing ability and emotional states. And, the higher the social support of friends, the lower the harmful impacts of cyber bullying on cognitive processing ability and emotional states. But, the higher the social support of parents, the higher the harmful impacts of cyber bullying on cognitive processing ability and emotional states.

• 스트레스연구
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• 제26권4호
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• pp.340-349
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• 2018

본 연구의 목적은 콜센터 상담원의 감정노동과 소진의 관계에서 회복 탄력성과 사회적 지지의 조절효과를 확인하는 것이다. 콜센터 상담원을 대상으로 한 설문조사를 통해 총 444명의 자료를 수집하였으며, 감정노동이 소진을 예측하는지 확인하였고, 회복 탄력성과 사회적 지지의 조절효과를 탐색하였다. 연구 결과, 감정노동의 하위요인 중 내면 행위는 소진을 감소시켰고, 반대로 표면행위, 감정표현의 빈도, 다양성, 주의 정도는 소진을 증가시켰다. 조절변인인 회복 탄력성과 상사의 사회적 지지는 부분적으로 감정노동과 소진의 관계에서 완충효과가 나타났으나, 동료의 지지는 조절효과가 나타나지 않았다. 감정노동으로 야기되는 소진에 대한 예방 및 치료를 위해 본 연구에서 확인된 조절변인을 활용할 수 있을 것으로 기대된다.

• 농업생명과학연구
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• 제44권1호
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• pp.25-32
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• 2010

본 연구는 수분함량에 따른 보리와 호밀 silage의 발효특성을 평가하기 위하여 수행하였다. 보리와 호밀의 수분함량은 수분첨가 또는 예건을 통해 50%, 65% 및 80%로 조절하였다. 보리 silage의 pH와 Lactate:Acetate 비율은 저수분 처리구 (4.54와 6.23), 호밀 silage에서는 중수분 처리구 (4.33과 9.24)가 가장 높았다. 보리 silage의 propionate 함량은 저수분 처리구가 고수분 처리구에 비해 높았으나, 보리와 호밀 silage의 lactate, 총휘발성지방산 및 acetate 함량은 고수분 처리구가 저수분 처리구에 비해 높았다. 보리 silage의 total-N 함량은 중수분 처리구가 저수분 처리구에 비해 높게 나타났으며, 호밀 silage는 저수분 처리구가 타 처리구에 비해 높았다. 보리 silage의 $NH_3-N$ 함량과 total-N:$NH_3-N$ 비율은 고수분 처리구가 높게 나타났다. 보리와 호밀 silage의 buffering capacity는 수분함량이 높을수록 증가하였으나, pH가 높을수록 감소하였다. 보리와 호밀 silage의 수분 함량은 pH와는 부(-)의 상관관계를 나타내었으나, 휘발성지방산과 $NH_3-N$ 함량 및 total-N중 $NH_3-N$ 비율과는 정 (+)의 상관관계를 나타내었다. 이상의 결과에서 보리와 호밀 silage 제조를 위한 적정 수분함량은 70~80%로 확인되었으며, 사료작물의 수분을 60%까지로 예건하는 것은 silage 품질 저하를 초래할 수 있는 것으로 사료된다.

• 치위생과학회지
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• 제22권1호
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• pp.57-66
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• 2022

Background: This study aimed to investigate the effect of selecting commercially available blending teas and applying them to bovine teeth on color change over time. Methods: After selecting healthy bovine teeth, using a cutting-disc, 105 specimens with a dimension of 5×5×3 mm were prepared, and 15 specimens were distributed to each group. Black tea was used as a positive control, water was used as a negative control, and blended tea of five types was used as an experimental group. First, pH and buffering capacity were measured with a pH meter, and tooth color was determined using a spectrophotometer before immersion in the blending tea solution and 1, 5, 7, 14, and 21 days after immersion. Thereafter, the shape change of the enamel surface was observed using a scanning electron microscope, and SPSS ver.26 was used to analyze the color change. Results: The average pH of the five blending teas in the experimental group was 3.78, and the pH of group 3 (strawberry rhubarb) was the lowest at 3.22. The pH levels of black tea and water were 5.19 and 7.30, respectively. The buffering capacity was the highest in group 3 at both pH levels of 5.5 and 7.0. The L^*a^*b^* color change according to immersion time was the largest in group 4 (rooibos yellow flower), and the amount of color change was large in black tea and group 4. As a result of observing the enamel surface of bovine teeth, changes in the surface shape were noted in all groups immersed in the experimental solution for 21 days, except for water. Conclusion: There was a significant difference between the experimental groups in terms of color change according to the immersion time, and color and enamel surface changes were observed in black tea and all experimental groups, except for water.

• 가족자원경영과 정책
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• 제23권4호
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• pp.23-39
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• 2019

This study aimed to explore the moderating effect of family strengths on the effect of work-family conflict on happiness in dual-income married couples. This study included 316 married employees who live in Seoul and have children attending junior high or lower grade schools. A survey was conducted December 1-30, 2018 by distributing questionnaires to child care centers, kindergartens, schools, companies, religious institutions, and other locations. The results are follows. First, in this study, the degree of family→work conflict was higher than that of work→family conflict in dual-income married couples, indicating that role conflict at work is greater due to family role pressures. Second, among the socio-demographic characteristics of dual-career couples, monthly income, family→work conflict (an independent variable), and family problem-solving skills (a moderating variable; a subcategory of family strengths) had a significant impact. In the analysis of the effect of work-family conflict on happiness, the higher the monthly income, the lower the family→work conflict, and the higher the family problem solving ability, the higher the feeling of happiness among dual-income married couples. When the work role conflicts from family life roles were more highly perceived in dual-income married couples. Moreover, family→work conflict and an interaction term of family problem-solving ability were identified as variables that had significant effects on happiness. Third, family problem-solving ability was identified as a moderator buffering the effect of work-family conflict on happiness.

• 가족자원경영과 정책
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• 제21권3호
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• pp.121-139
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• 2017

This study aimed to explore the moderating effect of social support resources on the life satisfaction and caregiving burden of family caregivers taking care of the elderly in long-term care services. The study participants were selected from among the family caregivers utilizing 30 home care centers in Seoul, Korea. Of the candidates who agreed to participate in the study, 250 caregivers who had supported the elderly at home for at least 6 months were selected. The data collected were analyzed using SPSS ver. 21.0. The study findings were as follows. First, the whole family caregivers' caregiving burden of family caregivers was found to be slightly higher than the median value. More specifically, the physical burden was the heaviest, followed by the family relationship burden, the social activity burden, the emotional burden, and the financial burden. Social support resources and life satisfaction were found to be a little bit higher than the median value. Second, the variables that statistically significantly increased life satisfaction, starting with the strongest effect, were a lower psycho emotional burden, greater informational support resources, a lower economical burden, greater emotional support, a younger caregiver age, a higher monthly income, and a shorter care period. Third, informational support resources were found to have a moderating effect on the relationship between the support burden and life satisfaction. The more the participants used the informational support resource subcategory of the social support resources, the narrower the life satisfaction decrease, even though the caregivers felt a support burden. Informational support resources appear to have a statistically significant buffering effect.

• Journal of the Korean Data Analysis Society
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• 제20권6호
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• pp.3169-3183
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• 2018

본 연구는 정서사건이론을 기반으로 조직 상황에서 직무사건이 직무열의에 영향을 미치는 과정에서 개인차 변수인 조절초점이 어떠한 영향을 미치는지 살펴보는 것을 목적으로 하였다. 이를 위해 금융권 종사자 232명을 대상으로 긍정사건, 긍정정서, 조절초점 및 직무열의에 대한 설문조사를 실시하였다. 연구 결과는 다음과 같다. 첫째, 주효과 검증에서 금융업 종사자들이 경험하는 긍정사건은 긍정정서를 높여 직무열의에 정적인 영향력을 미치는 것으로 나타났다. 둘째, 조절효과 검증에서 긍정정서가 직무열의에 미치는 영향은 조절초점의 수준에 따라 차별적인 영향력을 보였다. 즉, 향상초점 수준이 높을수록 긍정정서의 직무열의에 대한 효과는 강화되었고, 예방초점 수준이 높을수록 긍정정서의 직무열의에 대한 효과는 약화되는 것으로 확인되었다. 셋째, 조절된 매개 효과 검증에서는 향상초점이 아닌 예방초점에서만 조건적 간접효과가 발견되었다. 즉, 긍정사건이 긍정정서를 매개로 하여 직무열의에 미치는 간접효과의 크기는 예방초점이 높을 때 약화되는 것으로 나타났다. 마지막으로 이러한 결과를 바탕으로 연구의 의의와 제한점 및 추후 연구 이슈에 대해서 논의하였다.

• 한국응용과학기술학회지
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• 제40권6호
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• pp.1437-1444
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• 2023

본 연구는 청소년의 스트레스와 범불안 관계에서 행복감의 조절효과를 검증하고자 수행되었다. 연구대상자는 2020년 실시된 제16차 청소년건강행태조사에 참가한 중·고등학생 54,948명이다. 자료는 SPSS 24.0과 Process Macro 4.0을 이용하여 분석하였다. 연구 결과 청소년의 스트레스는 범불안에 유의한 영향을 미치는 것으로 나타났다. 스트레스가 높을수록 범불안 수준이 높았다. 그리고 스트레스와 범불안 간의 관계를 행복감이 조절하는 것으로 나타났다. 즉 행복감은 스트레스가 범불안에 미치는 부정적 영향을 완충하는 효과가 있음을 확인하였다. 그러므로 청소년의 범불안을 완화하기 위해 행복감을 향상시킬 수 있는 다양한 프로그램을 마련하여 시행할 것을 제언한다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제6권2호
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• pp.133-138
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• 2001

In this study, an attempt was made to increase the survival rate of bifidobacteria entrapped in alginate in the gastrointestinal tract, and to investigate the potential industrial applications, for example lyophilized capsules and yogurt. First, the protective effect of various food additives on bifidobacterial survivability was determined after exposure to simulated gastric juices and bile salts. The additives used in this study were skim milk (SM), polydextrose (PD), soy fiber (SF), yeast extract (YE), chitosan (CS), $\kappa$-carageenan ($\kappa$-C) and whey, which were added at 0.6% concentration (w/v) to 3% alginate-bifidobacterial solution. In the simulated gastric juices and bile salts, the protective effect of 0.6% skim milk-3% alginate (SM-A) beads on the survival rate of bifidobacteria proved to be higher than the other additives. Second, the hydrogen ion permeation was detected through SM-A vessel without bifidobacterial cells at different SM concentrations (0.2%, 0.4%, 0.6%, 0.8%, and 1.0%). There were no differences in terms of the pH decrease in SM-A vessels at 0.6%, 0.8%, and 1.0% (w/v) SM concentrations. The survival rate of bifidobacteria in SM-A beads would appear to be related to the SM buffering capacity against hydrogen ions and its tendency to reduce the pore size of bead. In this experiment, the survival rate of bifidobacteria entrapped in beads containing 0.6% SM showed the highest viability after exposure to simulated gastric juices for 3h, thereby indicating that 0.6% SM is the optimum concentration fir 3% alginate bead preparation. Third, the effect of SM-A beads on the freeze-drying and yogurt storage for 10 days was investigated. SM-A beads were found to be more efficient for freeze drying and yogurt storage than untrapped cells and the alginate bead. Consequently, the survival rate of bifidobacteria entrapped in SM-A beads was increased in simulated gastric juices, bile salts and probiotic products, such as lyophilized capsules and yogurt, SM-A beads can be expected to produce high value probiotic products.