• 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 the Korean BIBLIA Society for library and Information Science
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• v.20 no.2
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• pp.17-30
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• 2009

This study is to improve the quality of online reference service which is serviced in the world. For this it suggests the strategic methods for collecting and connecting of internet information resources. It makes information service circumstance for professional librarians to retrieve and service. To achieve the purpose, this study have drawn implications by analysing the theoretical discussions and the cases of online reference resources system. This study suggests some strategies as follows; 1) Collaborative constructing and using of online reference resources, 2) Developing classification scheme and subdividing the subjects of it, 3) Developing the standard format of the data as like metadata, 4) Developing the guidelines to select the proper resources from many internet information resources, 5) Subdividing the 'knowledge DB' by subjects, 6) Connecting as much as possible the DBs as like the National DB and open access resources.

• Journal of Environmental Science International
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• v.31 no.2
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• pp.149-169
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• 2022

Hwapocheon stream is located in Gimhae-si, Gyeongsangnam-do, and a part was declared a protected wetland area in 2017. In 2020 and 2021, we investigated the community structure of benthic macroinvertebrates of the Hwapocheon stream to provide ecological information for the management of the wetland. As a result, 4 phyla, 6 classes, 20 orders, 51 families, 83 species, and 2,621 individuals of benthic macroinvertebrates were identified. The average indices of diversity, richness, and evenness were the highest in the midstream area, whereas the highest average index of dominance was observed upstream. Seven biological water quality evaluations based on the distribution of benthic macroinvertebrates showed that the Biological Monitoring Working Party was an extremely suitable method for environmental evaluation of the Hwapocheon stream. Regarding functional feeding groups, the number of species of predators and gathering-collectors was the highest, and considering habitual dwelling groups, the number of species of clingers and sprawlers was the highest. The species number of Odonata, Hemiptera, and Coleoptera increased toward the downstream area, whereas the community loss index was the highest upstream. We also investigated relative resistance and resilience based on the distribution of aquatic insects and found that community stability was the highest downstream, whereas the lowest upstream.

• International Area Studies Review
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• v.13 no.1
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• pp.417-444
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• 2009

In October 2005, the Russian government started an investigation if safeguard measures against the importation of Korean sodium cyanide products could be taken. With Russia being a non-WTO member country, the Korean side found themselves in different situation from previous negotiation cases with developed or WTO member countries. Although several elements of trade negotiation theories such as goal setting, bargaining power, and relationship could apply, new constraints of limited information access and uncertainty of administrative procedures should be overcome. Combination of the governmental negotiation, assistance of the Russian consumer group, and the application of related laws led the Russian authority to dismiss the case. I suggest that there be some built-in channels for gathering information of non-WTO member countries.

• Journal of English Language & Literature
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• v.58 no.6
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• pp.1041-1061
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• 2012

In the late nineteenth century, British colonial activities became aggressive and annexationist in the tropics, including the Southeast Asian Archipelago, which reflected the historical circumstances of both increasing resistance from the indigenous and severe competition among European powers. Interestingly, the change in English colonial policy toward an annexationist or imperialist vision adopted the motto of a civilizing mission, which was founded on the anthropological assumption that the white English were civilized, while the non-white indigenous were savage. The assumption developed into colonial discourse through systematic gathering of anthropological knowledge about the peripheries of the Empire. The knowledge system was flawed, which stressed the differences of the peripheral populations from the English and served as an inverted discourse on the Imperial Self rather than the description of the Other. Furthermore, the natives were heterogeneous, which rendered indistinct the racial and cultural differences between the English and the natives. Still, the aboriginals called Malays, who were comprised of many ethnic subgroups, needed to be deemed savage or inferior by the English in order to justify the English civilizing work or imperial ambition. Put differently, the representation of the English as civilized necessitated the (mis)representation of the natives as savage. In this context, Clifford's works contribute to systematic misrepresentation of the Malays, on which colonial discourse is founded, though not without self-contradiction. On the other hand, Conrad's novels that are set in the Malay Archipelago resort to a strategic misrepresentation that reveals the relativity of the discourse. Exploring the dilemma of denationalization to various degrees, Conrad's Malay texts problematize the (mis)representation of the indigenous as inferior, which is the basis of English claim to superiority.

• Smart Structures and Systems
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• v.30 no.5
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• pp.545-556
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• 2022

Through the examination of literatures, electronic commerce is a subject which is accepted in enterprises to define e-commerce adoption, trends, and issues that are assisting and obstructing its efficacy. E-commerce offers numerous advantages to consumer satisfaction in any place and helps the company to get a competitive benefit over its competitors. The Internet has expanded the scope of business. Many business information is available by the global network that supports information gathering between organizations, businesses and their clients, while various divisions of a business is increasing at an exponential rate. Meanwhile, there are a few barriers to proper e-commerce usage and adoption, such as reliable internet connections, poor e-commerce supporting infrastructures, logistics systems presenting socio-regulatory and poor transportation barriers and demonstrating the significant improvement of e-commerce reliable and affordable Internet provisions, i.e., Internet cost, intensity, and reasonable level of e-readiness. The operational and strategic significance of information-based virtual value chains for all organizations cannot be emphasized. As a consequence, this study confirms worldwide market elements of e-commerce, such as its issues, benefits, relevance, scope, facilitators and projects prospective obstacles in a developing economy.

• Education of Primary School Mathematics
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• v.26 no.4
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• pp.317-332
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• 2023

Mathematical modeling activities hold the potential for diverse applications, involving the transformation of real-life situations into mathematical models to facilitate problem-solving. In order to assess the cognitive, affective, and social dimensions of students' engagement in mathematical modeling activities, this study conducted sessions with ten groups of fifth-grade elementary school students. The ensuing processes and outcomes were thoroughly analyzed. As a result, each group effectively applied mathematical concepts and principles in creating mathematical models and gathering essential information to address real-world tasks. This led to notable shifts in interest, enhanced mathematical proficiency, and altered attitudes towards mathematics, all while promoting increased collaboration and communication among group members. Based on these analytical findings, the study offers valuable pedagogical insights and practical guidance for effectively implementing mathematical modeling activities.

• Industry Promotion Research
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• v.9 no.2
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• pp.1-12
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• 2024

This study examines the role of Environment, Social, and Governance (ESG) activity recognition on job satisfaction, prosocial activities, and job performance among customer representatives working in call center environments. After gathering data from 264 call center workers in major South Korean insurance companies, the analysis w as performed using SmartPLS 4.0. This study's findings reveal that employee recognition of ESG activities significantly enhanced job satisfaction. The impact of ESG activity recognition on prosocial behavior was positive but relatively weak. Job satisfaction influences both prosocial behavior and the job performance of employees. Finally, prosocial behavior positively influences job performance. The most significant finding is that employees' recognition of companies' ESG management practices serves as a job resource. This recognition enhances employees' attitudes, behavior, and performance, signaling the potential benefits of informing employees about corporations' ethical behaviors.

• Journal of Society of Preventive Korean Medicine
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• v.27 no.3
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• pp.47-67
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• 2023

Objectives : The objective of this study is to examine the findings of a survey assessing the treatment and management status of individuals with diabetes and pre-diabetes, along with their inclination to participate in the Korean Medicine Chronic Disease Management Program. Methods : The survey focused on individuals with diabetes and pre-diabetes, gathering information on respondents' demographic details, diabetes diagnosis, duration of diabetes, attitudes and experiences regarding Korean medicine diabetes treatment, and their willingness to participate in the 'Korean Medicine Chronic Disease Management Program'. Results : 33.1% of participants reported prior experience with Korean medicine treatment for diabetes. The intention to actively utilize Korean medicine treatment was positively observed, with a response rate of 61.1% expressing a favorable inclination and 8.9% indicating a negative stance. Furthermore, 75.3% of patients expressed their intention to participate in the 'Korean Medicine Chronic Disease Management Program' in the future. Among those expressing this intention, 81.4% stated a preference for the 'Korean-Western medicine combined management' in the chronic disease management Program. Conclusions : Patients' willingness to participate in 'Korean Medicine Diabetes Management Program' is high, but lack of information about Korean medicine is a factor that deprives people of the opportunity to experience Korean medicine treatment, and non-medical factors such as difficulty in visiting and administrative complexity are factors that impede participation in the 'Korean Medicine Chronic Disease Management Program'. It should be considered for improvement when formulating policies.

• Journal of Environmental Science International
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• v.33 no.2
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• pp.139-160
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• 2024

The community structure of benthic macroinvertebrates in the Madongho Wetland protected area and inflow river located in Goseong-gun, Gyeongsangnam-do, was investigated in 2022 and 2023. We collected and identified 3,582 individuals belonging to 7 classes, 23 orders, 51 families, and 78 species over the 2 years from six sites. Gnorimosphaeroma naktongense was the dominant species with a ratio of 20%, and Caridina denticulata denticulata was the subdominant species with a ratio of 13.32%. Predators and gathering collectors were the most abundant in the functional feeding group, while sprawlers were the most diverse and numerous in the habitual dwelling group. Diversity, richness, dominance, and evenness were calculated as the biological indices. In addition, various biological water quality indices were calculated. Most insects in the inflow rivers belonged to group I in evaluating relative resistance and resilience, showing high colony stability. The results of analyzing the correlation between salinity and substrate particle size with brackish water species showed that Gnorimosphaeroma naktongense and Hediste japonica had a significant positive correlation with salinity, while Assiminea lutea and Neomysis awatschensis had a significant positive correlation with substrate particle size. Additionally, Sinelobus kisui was found to be a new record of Korean Tanaididae in this study.