• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제23권2호
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• pp.49-56
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• 2012

Methylphenidate is a widely used stimulant for treatment of attention-deficit hyperactivity disorder (ADHD). In addition to core symptoms of attention and behavioral symptoms, methylphenidate is even effective for executive functions. However, abuse and misuse of stimulants, including methylphenidate, for the purpose of cognitive enhancement is an issue of concern worldwide. Some prejudices and misunderstandings against methylphenidate are popular ; however, little attention has been given to the neuropsychiatric evidence of methylphenidate for enhancement of cognitive function among healthy populations. In this article, our aim was to conduct a review of previous studies investigating the effect of methylphenidate in healthy populations. Findings from several recent studies have demonstrated the effectiveness of methylphenidate for enhancement of cognitive function in healthy populations. The mechanisms of cognitive enhancement are thought to be associated with motivation and the reward circuit in the brain. However, when considering the risk to benefit, an official discussion of the use of methylphenidate among healthy members of the population would be premature. Instead, investigation of epidemiological studies of the prevalence of misuse of stimulants among healthy members of the population, particularly adolescents and college students, is needed. In addition, based on achievements reported in previous studies, investigation of the effect of an approach using non-pharmacological enhancing motivation, which will in turn result in increased cognitive function would be helpful.

• 동아시아식생활학회지
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• 제27권4호
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• pp.431-441
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• 2017

The purpose of this study was to analyze the effect of consumers' perceived brand benefits toward brand coffee shops on continuous purchase intentions as well as the mediating effect of brand trust. The survey was conducted on coffee consumers aged 20~40 years living in Seoul and who visited brand coffee shops exposed as product placement (PPL) in TV dramas. Out of 400 questionnaires distributed to consumers, 381 questionnaires (95.3%) were analyzed. Consumers were more interested in places (60.1%) than the products (39.9%) of the coffee shops exposed as PPL. Over half (54.6%) of the respondents showed a positive attitude towards coffee shop PPLs. All three brand benefits perceived by consumers (functional, symbolic, and empirical) had significant positive effects on brand trust and continuous purchase intention. In particular, symbolic benefit has the greatest impact on continuous purchase intention towards the brand. Brand trust had a mediating effect between perceived brand benefits and continuous purchase intentions. Therefore, it is necessary to focus on enhancing the perceived symbolic benefit of the brand to effectively maintain customer relationships. The results suggest that when planning positioning concepts, considering the importance of brand benefits is the best way to increase the competitiveness of coffee shop brands.

• 간호행정학회지
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• 제19권3호
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• pp.361-371
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• 2013

Purpose: This study was done to investigate the factors affecting organizational commitment and turnover intention of hospital nurses. Empirical analysis on the mediating effect of the person-environment fit of organizational commitment and turnover intention and factors affecting this relationship were also examined. Methods: Participants were nurses working in 4 university hospitals in Seoul or Busan. Data were collected between July 27 and Aug. 10, 2012 and for the final analysis, 393 data sets were used. The fitness of models were tested using AMOS 19.0. Results: The fitness of the modified model showed high compatibility with the empirical data. In the modified model, organizational climate, professional self-concepts and person-organization fit were found to have significant effects on hospital nurses' organizational commitment. Professional self-concepts, personality, person-organization fit and person-job fit significantly affected hospital nurses' turnover intention. There was the mediating effect of person-organization fit between organizational commitment and turnover intention and factors affecting the relationship. But person-job fit was not found to have a mediating effect. Organizational commitment accounted for 49.8% and turnover intention for 39.9% of covariance in these factors. Conclusion: Nursing strategy for enhancing professional self-concepts and person-organizational fit should be planned by nursing managers.

• 한국환경과학회지
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• 제2권1호
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• pp.37-48
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• 1993

Effect of plant hormones on the leaf senescence of mung bean (Phseoln radiatus) was investigated by measuring the changes of reducing sugar contents and invertase isozyme activities in detached leaves treated with NAA, $GA_3$ or BA. During dark-induced senescence, reducing sugar contents in the detached leaves increased temporarily at 4 6, thereafter decreased rapidly and reached minimum values within 7-14 6. The pattern of soluble acid invertase activity in the senescing leaves kept in the dark was similar to that of reducing sugar accumulation, whereas the activities of alkaline and extracellular invertases were not significantly changed during leaf senescence. Therefore, these results suggest that soluble acid invertase, but not alkaline and extracellular invertases, induces the accumulation of reducing sugar during leaf senescence of Rung bean plants. Exogenous NAA application had little or no effect In the increase of soluble acid invertase activity during dark-induced senescence compared to the control. However, exogenous applications of $GA_3$ and BA led to the increase of soluble acid invertase activity in the senescing leaves. Particularly, BA application was very effective In enhancing the activity of soluble acid invertase as well as in delaying chlorophyll breakdown during dark-induced senescence. These results suggest, therefore, that BA regulates the activity of soluble acid invertase, which leads to the accumulation of reducing sugar, and the stability of photosynthetic apparatus to delay leaf senescence.

• 한국항공운항학회지
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• 제20권3호
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• pp.76-89
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• 2012

The number of foreign cabin crews consist of 7% of total crews in K-airline, of which Chinese crews are of 38%. The number of foreign crews are 433 from 10 countries as of the end of July 2012. The airline has continued to hire foreign cabin crews to increase efficiency of human resourcing qualified flight attendants. This paper tried to do empirical research through SEM(Structural Equation Model) to overview confirmatory factors and course effects integrally. Cultural stress, aggressive coping, social support and job adaption have been chosen to be a factors. Especially, the SEM was set to show indirect effects of cultural stress and aggressive coping through social support to the dependant variable, job adaptation. According to the analysis result, cultural stress has a direct negative effect on job adaptation. Aggressive coping has also a direct positive effect on job adaptation. It has also proven cultural stress and aggressive coping has a indirect effect to job adaptation through social support. This paper is expect to contribute to develop such training and administrative programs as enhancing foreign crews' job adaptability and managing them effectively.

• Molecules and Cells
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• 제21권1호
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• pp.7-20
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• 2006

The major event in human immunodeficiency virus type 1 (HIV-1) infection is the death of many cells related to host immune response. The demise of these cells is normally explained by cell suicide mechanism, apoptosis. Interestingly, the decrease in the number of immune cells, such as non-CD4+ cells as well as CD4+ T cells, in HIV infection usually occurs in uninfected bystander cells, not in directly infected cells. It has, therefore, been suggested that several soluble factors, including viral protein R (Vpr), are released from the infected cells and induce the death of bystander cells. Some studies show that Vpr interacts directly with adenine nucleotide translocator (ANT) to induce mitochondrial membrane permeabilization (MMP). The MMP results in release of some apoptogenic factors such as cytochrome-c (cyt-c) and apoptosis-inducing factor (AIF). Vpr also has indirect effect on mitochondria through enhancing the level of caspase-9 transcription and suppressing nuclear factor-kappa B (NF-${\kappa}B$). The involvement of p53 in Vpr-induced apoptosis remains to be studied. On the other hand, low level of Vpr expression has anti-apoptotic effect, whereas it's high level of expression induces apoptosis. Extracellular Vpr also exhibits cytotoxicity to uninfected bystander cells through apoptotic or necrotic mechanism. The facts that Vpr has cytotoxic effect on both infected cells and bystander cells, and that it exhibits both proand anti-apoptotic activity may explain its role in viral survival and disease progression.

• 한국가족관계학회지
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• 제22권1호
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• pp.3-22
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• 2017

Objectives: The purpose of this study was to identify the mediating effects of family resilience and depression in a relation between family stress and psychological well-being among middle-aged. Method: The subjects were 409 of men and women between 40 to 59 living in D and G province. They completed the questionnaire on family stress, family resilience, depression, and psychological well-being. Correlation and structural equation models of SPSS 23.0 and AMOS 22.0 were used to examine the relations between the variables. Results: The results are as follows. First, family stress had no significant effect on psychological well-being of middle age men and women, while it directly influenced on family resilience and depression. Second, family resilience and depression had direct influence on psychological well-being. Third, there were significant mediating effects of family resilience and depression in a relationship between family stress and psychological well-being. Conclusions: Family stress has an indirect effect on psychological well-being among middle age men and women mediated by family resilience and depression. The result suggest that psychological well-being influenced by family stress can be improved by enhancing Family Resilience and reducing Depression.

• 품질경영학회지
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• 제47권2호
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• pp.295-314
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• 2019

Purpose: This study aims to investigate the factors affecting productivity performance for Korean SMEs of manufacturing which had obtained the certification of Productivity Management System(PMS) that is a Korean assessment program for enhancing maturity of company's management systems. Methods: The proposed model is based on the PMS model. The valid 759 data registered from 2010 to 2018 year was analyzed using SEM analysis for testing hypotheses. Results: The results are as follows. First, Leadership affects the five core sub-system processes positively, but doesn't a significant Business Performance directly. Secondly, HRM, Customer & Market Analysis, and Process Management excluding Productivity Development and Measurement Analysis and Knowledge Management have a significant effect on Business Performance. Lastly, when examining the mediation effect, Process Development, Customer & Market Analysis, and HRM have indirectly effect between Leadership and Business Performance. Conclusion: This study results suggest not only the role of leadership to improve productivity performance of SME, but also which core processes are focused and differentiated.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2019년도 추계학술대회
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• pp.106-106
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• 2019

The leaves of Phaleria nisidai Kaneh. have been used as a beverage for tonic and immune-enhancing effect in Palau. Recently, extract of the plants showed anti-diabetic effect in clinical trial and possibility could be used as a medicine for diabetes. However, in vitro and in vivo experiments which elucidate cytotoxicity and biological mechanism have not been studied yet. To begin the series of in vitro and in vivo anti-diabetic studies, we evaluated cell viability of pancreatic beta cell lines to figure it out toxicity of the extract. The leaves of Phaleria nisidai were extracted with distilled water and 70% EtOH, and followed by evaporation and lyophilization. And, MIN6 and RIN-m5F cell lines were used for assessment of cell viability. MTT assay was adopted to evaluated a toxicity. Any of extract and concentration used in this study did not show cytotoxicity in the cell lines. Furthermore, morphological change was not observed. These results means Phaleria nisidai might be a medicinal resource when further biological and safety studies would be performed.

• The Journal of Asian Finance, Economics and Business
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• 제8권8호
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• pp.47-56
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• 2021

ASEAN Economic Community (AEC) was established in 2015 from 10 countries to realize the ultimate (adopted in 1997), which aimed to transform ASEAN into a stable, prosperous, and highly competitive region with equitable economic development, reduced poverty, and socioeconomic disparities. The purpose of this paper is to examine the effect of knowledge level on the AEC of Vietnamese small and medium enterprises (SMEs) in the textile and apparel industry towards attitudes, readiness, and performance. This study uses convenience sampling to get questionnaires from 150 SMEs in Hanoi, Vietnam. Then, the paper applies SPSS-AMOS 24 to process data. The empirical results show that AEC's implementation only has a small impact on improving SME performance. However, SMEs have adequate knowledge, attitude, and readiness about AEC. The structural modeling findings indicate that the knowledge factor has an indirect effect on SMEs' performance. This finding is to provide new insight into the roles of attitude and readiness in the case of Vietnam. These factors are needed to mediate the effect of attitudes and readiness in the relationship between knowledge and business performance, a framework strategy of business organizations, and can be used as a conceptual model to improve SMEs' performance.