• Tribology and Lubricants
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• v.39 no.3
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• pp.87-93
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• 2023

Nanofluids are dispersions of particles smaller than 100 nm (nanoparticles) in base fluids. They exhibit high thermal conductivity and are mainly applied in cooling applications. Nanolubricants use nanoparticles in base oils as lubricant additives, and have recently started gathering increased attention owing to their potential to improve the tribological and thermal performances of various machinery. Nanolubricants reduce friction and wear, mainly by the action of nanoparticles; however, only a few studies have considered the rheological properties of lubricants. In this study, we adopt a parallel slider bearing model that does not generate geometrical wedge effects, and conduct thermohydrodynamic (THD) analyses to evaluate the effect of higher thermal conductivity and viscosity, which are the main rheological properties of nanolubricants, on the lubrication performances. We use a commercial computational fluid dynamics code, FLUENT, to numerically analyze the continuity, Navier-Stokes, energy equations with temperature-viscosity-density relations, and thermal conductivity and viscosity models of the nanolubricant. The results show the temperature and pressure distributions, load-carrying capacity (LCC), and friction force for three film-temperature boundary conditions (FTBCs). The effects of the higher thermal conductivity and viscosity of the nanolubricant on the LCC and friction force differ significantly, according to the FTBC. The thermal conductivity increases with temperature, improving the cooling performance, reducing LCC, and slightly increasing the friction. The increase in viscosity increases both the LCC and friction. The analysis method in this study can be applied to develop nanolubricants that can improve the tribological and cooling performances of various equipment; however, additional research is required on this topic.

• Journal of Distribution Science
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• v.14 no.6
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• pp.81-87
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• 2016

Purpose - In recent, a research finds that advanced selling can influence a consumer's choice(Kim et al., 2013). Advanced selling is defined as the new product launching strategy which company allows consumers to preorder new product before its release(Chu & Zhang, 2011). Prior researches have focused on the benefits of advanced selling(e.g., information gathering for demand prediction, an advantage for pricing strategy, and so on) for companies using this strategy(Chen, 2001; Chu & Zhang, 2011; Li & Zhang, 2013; Tang et al., 2004; Xie & Shugan, 2009). However, Kim et al.(2013) find it can also influence a consumer's choice. In detail, they suggest that when consumers use advanced selling, they are likely to prefer high-performance options rather than low-price options based on construal level theory(Trope & Liberman, 2003). In this paper, we tried to expand the prior researches for finding the mechanism of the influence of advanced selling on a consumer's choice. The purpose of this research is to test the mediating effect on the influence of advanced selling. Research design, data, and methodology - To find the mechanism of the influence of advanced selling, we designed an experiment for testing mediation effect. we recruited 93 students from a university. We assigned participants into one of two groups using randomization method. The participants with each group were given a scenario describing the sales strategy. Finally, they made a choice between high-performance option and low-price option. Sequentially, they also responded some questions for testing mediation effect. Results - First, we replicated prior research to test the influence of advanced selling. As a result, we could find that consumers prefer the high-performance option when they preorder it to purchase at the time of consumption. Thus, the replication result is the same as prior research. Second, we tested that advanced selling can influence the perception of temporal distance. The results confirmed that consumers perceived longer temporal distance in advanced selling condition(β = 1.575, SE = 0.272, p < 0.001). Third, we predicted that temporal distance can increase the importance of desirable attributes and decrease the importance of feasible attributes. The results suggested that temporal distance decreased significantly the importance of attributes related to feasibility(β = -0.19, SE = 0.07, p < 0.01), however, it had non-significant effect on increasing the importance of desirable attributes. Finally, we used Sobel-test for testing mediation effect, and it confirmed that the importance of feasible attributes had mediating role of the influence of advanced selling(Sobel test statistic = -2.110, SE = 0.111, p < 0.05). Conclusions - In this paper, we tried to find the mechanism of the influence on advanced selling from a consumer's choice. With an experiment, we confirmed that the importance of feasible attributes could mediate the effect on advanced selling. Therefore, we suggested some theoretical and practical contributions from this research. Finally, we discussed research limitations and suggested future research topics.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.490-498
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• 2016

This study aimed to investigate the relation between self-esteem and satisfaction. After gathering study subjects (exercise participants) and deciding the population in 2014 in Jeonbuk city area, convenience sampling method was used to analyze the date from 278 subjects. The retrieved questionnaire in the research was analyzed in Window SPSS version 21 statistical program. Frequency analysis, exploratory factor analysis, reliability analysis, and correlation analysis were used to find correlations between test values. Multiple regression analysis was used to find the effects of the test values. The study results are as follows. First, the exercise participants' positive self-esteem exhibited a positive relationship with competence, relatedness, and autonomy, which are sub factors of basic psychological needs satisfaction. Also, negative self-esteem had a negative relationship with competence, relatedness, and autonomy. Second, exercise participants' self-esteem had a positive effect on competence and autonomy in positive self-esteem and a negative effect on negative self-esteem. Relatedness had a positive effect in positive self-esteem but not in negative self-esteem. Thus it is necessary to increase positive self-esteem and make various exercise programs about basic psychological needs satisfaction of the exercise participants and strategic activity guide for exercise participants participating in exercise consistently.

• Journal of Venture Innovation
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• v.3 no.2
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• pp.129-145
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• 2020

The purpose of this study was to examine the effects of the job characteristics of the PR practitioner on flourishing and to identify the mediating effect of the meaning of work and job engagement. This study used a survey of 353 PR practitioners from PR firms and the hypothesis was verified by gathering the data of the job characteristics, the meaning of work, the job engagement and the flourishing by conducting hierarchical regression analysis and SPSS Process Macro bootstrapping analysis. The results showed that the job characteristics of the PR practitioner were found to influence the flourishing with the double-mediation effect, the meaning of the work and job engagement. The more PR practitioners regard their work affects their surroundings, the higher the degree of autonomy is, and the more they get feedbacks they engaged more, as they valued their job more thereby experience flourish more. Moreover, when PR practitioners valued their job more, they more engaged in their work and experience flourish. The meaning of work revealed to be the important factor to affect flourish regardless of the job characteristics and the job engagement so that gained the results that PR firms' effort to elevate the meaning of work of PR practitioners has is important. The study findings suggest that PR practitioners' flourishing is manageable in the organization by paying attention to oneself in the aspect of the organization, not leaving in individual areas. Limitaions and implications for future studies were discussed.

• Journal of Environmental Impact Assessment
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• v.17 no.1
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• pp.1-9
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• 2008

Non-point pollution is caused by many diffusive sources, unlike a point pollution derived from industrial wastewater treatment plants or sewage treatment plants. Runoff of non-point pollutants is originated from rainfall or thawing in short period of time moving over and through the a ground surface. They cause ill effect on the quality of neighboring aquatic environment. To prevent effectively the wash off from non-point pollutant, it should be immediately reduced at the source or be treated after gathering of runoff water. This study has been carried out for the best width of riparian buffer zone. So we implemented the experiment in terms of its depth, width and kind of vegetations and calculated the reduction of pollutants loading. The experimental zone encompasses the watershed of Namhan River (Kyunggido Yangpyunggun Byungsanri). The region was divided into 5 land cover sectors : grass, reed, pussy willow, mixed(grass+pussy willow) and natural zone to compare effectiveness of vegetation. Water samples from four points have been collected in different depths. And the pollutant removal efficiency by sectors with different plant species was yielded through influent with one of each sample. And we obtained the correlation between the width of riparian buffer zone and the removal efficiency of pollutants. Using correlation result, the width of riparian buffer zones which needs to improve the water quality of river could be derived.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.1
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• pp.61-71
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• 2014

Recently social shopping, combining e-Commerce with Social Network Service, become a brand-new eBusiness model. In this paper, we aim to identify the structural relationship of the factors affecting the intention of using social shopping. Reviewing the previous works of social shopping, internet shopping and TAM (Technology Acceptance Model), we extract factors affecting the intention of using social shopping and build a structural research model among these factors. To analyze the structural relationship among theses factors, we perform an empirical study - gathering data from a survey and analyzing gathered data using EFA (Exploratory Factor Analysis) and SEM (Structural Equation Model) to identify the structural relationship. We also analyze moderating effect of past experience of social shopping and gender. As a result, We also can find that two factors - Perceived usefulness and Expected enjoyment - are the key factors influencing acceptance of social shopping and that more segmented strategies are required to attract customers since factors affecting Intention to use are somewhat different according to past experience and gender of respondents.

• Journal of the Korean Institute of Rural Architecture
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• v.21 no.4
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• pp.17-24
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• 2019

It has been long time since the local small-and-medium cities had lost their vitality due to the progress of aging, economic decline in urban areas, the lack of new growth engines, and the declining population in korea. In addition, since the implementation of the local self-governing system, the creation of new urban areas and the transfer of the administrative institutions to the outskirts of a city have accelerated the decline of old downtown. Rather, local small-and-medium cities would have a problem to make urban regeneration impossible. Under the recognition of such problems, individual self-governing entities have come up with numerous policies and implemented various policies for the revitalization of local small-and-medium cities, but it is a condition that the effect of their efforts falls shorts of expectations, such as the space of the similar style, which has been widespread in developed countries, simple restoration, and a few structural changes. In this regard, the part to be realized anew is to enhance the attractiveness of small-and-medium cities. However, is not possible to raise the overall attractiveness in a short time in reality. To select local assets to be utilized in urban regeneration, it is judged that gathering opinions of local residents is more important than any other thing. Accordingly, this study intends to present positive outcome for the purpose of the revitalization of local small-and-medium cities by finding the factors which can remind us of the collective memory of Jinju city and selection the critical factors to determine a detailed project plan from the perspective of urban regeneration.

• International Commerce and Information Review
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• v.14 no.3
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• pp.429-451
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• 2012

The purpose of this paper is to find what factors have an influential effect on motive and intention of using the unethical negotiation tactics. It is interesting to find that opportunism was not related to unethical negotiation tactics such as inappropriate information gathering and competitive bargaining in our Korea's sample. On the other hand, idealism and Machiavellianism had positive impact on managers' perceptions of unethical negotiation tactics within our sample. To explain the environmental perspective, the lower level of legal punishment system encourages them to use the unethical tactics without hesitation. On the other hand, organizational goal might have not a related on the perception of unethical negotiation tactics. To reduce the potential risk of use of unethical negotiation in the international negotiation process, international negotiators should find the counterpart negotiator' character before attending negotiation table, and international managers would be better to employ a local agent who can understand local negotiating counterpart, so they can assist them in early stage of negotiation.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.38
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• pp.5.1-5.5
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• 2016

Background: This study clinically evaluated the effect of botulinum toxin type A (BTX-A) in the temporomandibular disorder (TMD) treatment using Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). Methods: A total of 21 TMD patients were recruited to be treated with BTX-A injections on the bilateral masseter and temporalis muscles and were followed up by an oral and maxillofacial surgeon highly experienced in the TMD treatment. For each patient, diagnostic data gathering were conducted according to the RDC/TMD. Characteristic pain intensity, disability points, chronic pain grade, depression index, and grade of nonspecific physical symptoms were evaluated. Wilcoxon signed-rank test was applied for statistical analysis. Results: The results showed that more than half of the participants (85.7 %) had parafunctional oral habits such as bruxism or clenching. In comparison between pre- and post-treatment results, graded pain score, characteristic pain intensity, disability points, chronic pain grade, and grade of nonspecific physical symptoms showed statistically significant differences after the BTX-A injection therapy (p < 0.05). Most patients experienced collective decrease in clinical manifestations of TMD including pain relief and improved masticatory functions after the treatment. Conclusions: Within the limitation of our study, BTX-A injections in masticatory musculatures of TMD patients could be considered as a useful option for controlling complex TMD and helping its associated symptoms.

• Journal of fish pathology
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• v.23 no.1
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• pp.99-106
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• 2010

Aquatic animal diseases control act which is to assure the prevention of outbreak and spread of aquatic animal diseases in Korea has come into effect since 22 December 2008. In order to prevent outbreak and spread of aquatic animal diseases, risk analysis is newly introduced. The introduction of risk analysis for movement of aquatic animals related to implementation of recommendation of the World Trade Organization (WTO) Agreement on the Application of Sanitary and Phytosanitary Measures and should be conducted in accordance with guidelines of OIE Aquatic Animal Health Code. This report involves gathering and analysing the information of international regulation and situations of risk analysis framework in Korea for movement of aquatic animals.