• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.111-112
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• 2002

The influence of aerated oil on a high-speed proceeding bearing is examined by using the classical thermohydrodynamic lubrication theory coupled with analytical models for viscosity and density of air-oil mixture in fluid-film bearing including the live surface tension of aerated oil. Convection to the walls and mixing with supply oil and re-circulating oil are considered. The considered parameters for the study of bubbly lubrication are oil aeration level, air bubble size and shaft speed. The results show that, if the live surface tension is considered, the effect of air bubbles on the bearing load capacity is reduced due to temperature engagement comparing with that under the condition of a constant surface tension.

• 한국벤처창업학회:학술대회논문집
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• 2017.08a
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• pp.37-47
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• 2017

The digital multi-sided platform has led the growth of industries. Accelerating this growth, generativity allowed innovation based on boundary-less modularity. Online games are a rich source of research but most of the research is dedicated in examining only the online game itself. However, there is a growing need to understand online games in an ecosystem level for a new phase of evolution is starting based on generativity. With generativity, online game users now make new graphics and quest that can be added and shared to the already existing game environment. The ecosystem is moving towards finding an amicable multi-sided distribution platform for these user generated game contents. Preliminary data suggest the possibility of actual connection between generativity and users' game engagement. Interviews and surveys will be prepared to find out the details of the possible relationship and how the ecosystem will shape accordingly.

• English Language & Literature Teaching
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• v.13 no.4
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• pp.59-85
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• 2007

This study examined patterns of engaging in "reading in connection to writing" (hereafter reading-writing practices) in the context of two ESL college composition classrooms. The purpose of this study was to explore whether the L2 proficiency level could be a key construct in explaining similarities and differences in reading-writing practices which students engaged in during the composing process. Multiple sources of data collected over the semester included interview protocols, written products, and observational notes. The results showed that the three proficiency groups under examination differed widely in the ways reading was connected to writing and in the types of intermediate texts produced during the composing process. The students in the high proficiency group produced more intermediate texts through an engagement in reading-writing practices connected to each other. On the contrary, the students in lower proficiency groups engaged in a limited range of reading-writing practices without support of intermediate texts. This study provides insight into the different ways ESL college students coordinate reading and writing while composing essays.

• Journal of Internet Computing and Services
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• v.19 no.4
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• pp.95-105
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• 2018

As the IT industry has developed, the frequency of mobile communication usage has increased sharply. Mobile communication has many advantages such as improving work performance, communication beyond time and local constraints, and rapid and vast amounts of information exchange. However, mobile communication also allows supervisors to give their subordinates work at any time. Thus, mobile communication may also have a negative impact on workers' stress levels during non-work time. This study examined required time, urgent business, personal engagement, and trivial matters as sub-dimensions of mobile communication messages that workers could receive during non-work time. Further, the nature of the relationship between team leaders and members explains how these messages may increase the stress levels of workers. Supervisors should prohibit the use of such mobile communication, and efforts should be made at the enterprise level. Through this research, we aim to explain the dual nature of mobile communication, and understand how to optimize the usage of this innovative technology

• Journal of the Korea Safety Management & Science
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• v.9 no.4
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• pp.63-70
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• 2007

There are something unreasonable, unsatisfactory on the law system for laboratorial safety enforced by the government from April 2006. Therefore, the system should be reviewed and revised to be satisfactory for current research condition. This study is to analyze research areas for improving laboratorial safety and to show safer ideas. With more detail, more practically improving ideas have been shown for systemizing safety assessment in advance, effective organization of laboratory, safety committee and their regulation. It is expected that better safety level all the concerned engagement, reasonable revision of safety regulation of laboratory, can be made by this research result.

• Fashion, Industry and Education
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• v.15 no.1
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• pp.12-28
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• 2017

In the era of social media, marketers have struggled to understand and serve participants' diverse and multifaceted needs in a novel form of online brand community in the social-networking sites such as Facebook. Thus, this study identifies different groups of participants affiliated with Facebook brand pages based on their needs for brand connection. The need-based segments are validated by comparing results across foodservice and consumer goods. Results of cluster analysis reveal three distinct segments (i.e., residents, lurkers, and peepers) based on participants' functional, experiential, and incentive needs. Results of multivariate analysis of variance illustrate significant differences in relational tendencies for a brand of interest among these three groups. The three groups are profiled based on participants' engagement level. Findings of this study are expected to help marketers better understand the needs of diverse participants in their SNS-embedded brand community so they can develop tailored communication strategies for targeted groups.

• Journal of the military operations research society of Korea
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• v.27 no.2
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• pp.134-148
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• 2001

In this paper, air-defense simulation model, called "DADSim", will be introduced. DADSim(Distributed Air Defense Simulation Model) was developed by Modeling&Simulation Lab of K.N.D.U.(Korea National Defence Univ) Weapon Systems Department. This model is an analysis-purpose model in the engagement-level. DADSim can simulate not only the global air-defense or Korean Peninsula but also the local air-defense or a battle field. DADSim uses the DTED(digital terrain elevation data) LeveII it for the representation of peninsula terrain characteristics. The weapon systems cooperated in the model are low/medium-range missile systems such as HAWK, NIKE, SAM. DADSim was designed in the way of object-oriented development method, implemented by C++ language. The simulation view is an event-sequenced object-orientation. For the convenience of input, output analysis, GUI(Graphic User Interface) of menu, window, dialog box, etc. are provided to the user, For the execution of DADSim, Silicon Graphic IRIX 6.3 or high version is required. DADSim can be used for the effectiveness analysis of­defence systems. Some illustrative examples will be shown in this paper.

• Journal of Korea Multimedia Society
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• v.21 no.11
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• pp.1353-1361
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• 2018

With the availability of real-time educational data collection and analysis techniques, the education paradigm is shifting from educator-centric to data-driven lectures. However, most offline and online education frameworks collect students' feedback from question-answering data that can summarize their understanding but requires instructor's attention when students need additional help during lectures. This paper proposes a content restructure recommendation framework based on collected student feedback. We list the types of student feedback and implement a web-based framework that collects both implicit and explicit feedback for content restructuring. With a case study of four-week lectures with 50 students, we analyze the pattern of student feedback and quantitatively validate the effect of the proposed content restructuring measured by the level of student engagement.

• Journal of Information Science Theory and Practice
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• v.9 no.1
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• pp.79-89
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• 2021

This study explores Facebook use in Vietnamese academic libraries by analysing libraries' posts on their Facebook pages and library users' interaction with those posts. A total of 260 posts on four academic libraries' Facebook pages were examined using the content analysis method. The findings reveal that Facebook was mainly used to encourage reading and to transmit announcements. Most of the academic libraries published one post a week. The photo was the most frequent media type of libraries' posts and gained a higher level of interaction than other posts. According to the research results, the user engagement was low, and the user interaction with libraries' posts generally was in the form of reaction. The findings can help better understand Facebook use in Vietnamese academic libraries and may assist libraries in creating a plan for using Facebook more effectively.

• KDI Journal of Economic Policy
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• v.43 no.1
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• pp.1-27
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• 2021

In this paper, we empirically examine how export pioneers emerge and how they are related to product creators/innovators, utilizing a rich plant-product level dataset from the Korean manufacturing sector for the period of 1990-1998. Our analysis covers the process from the appearance of product creators as well as product imitators to the emergence of export pioneers. We find, first, that product imitators are larger, more productive and older than product creators. Second, most export pioneers are nevertheless found to be product creators. This result is largely due to the fact that almost all export pioneers export the products in the same year as product creation. Third, there are similarities as well as differences between product creators and export pioneers. Plants that are more productive or larger are more likely to become product creators as well as export pioneers. However, previous exporting experience positively affects the probability of export pioneering only, while plants' engagement in R&D positively affects the probability of product creation only. We discuss possible explanations for our main empirical results as well as their policy implications.