• Journal of the Korean Society for Precision Engineering
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• v.17 no.6
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• pp.76-82
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• 2000

This paper describes the machining characteristics of cylindrical plunge grinding. The study investigates the process using the current signals of a spindle motor through a hall sensor. Grinding experiments were conducted under various conditions such as wheel speeds, workpiece speeds and infeed rates with a conventional vitrified bonded wheel. Analyzing the current signal of the spindle motor, a relationship between current signals and the metal removal rate in terms of the in(red rate is induced. It was also shown that a hall sensor has similar capabilities in evaluation of grinding behavior compared to the AE signals, which are useful far monitoring the grinding process.

• Journal of the Korean Electrochemical Society
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• v.11 no.4
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• pp.309-312
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• 2008

In an attempt to achieve high rate capability of cell, a new composite cathode was prepared by mixing host compounds with MWCNTs and Super P carbon. Because MWCNTs generally have bundle-type morphologies, it is not easy to get completely separated form. Successful dispersion of divided small bundles between the host particles keeps electrochemical contacts among the particles and plays a significant role in the buffer action as a volume-change absorber. Relative amounts and distributions of the additives are important for design of the electrode for high power application of lithium ion batteries.

• Communications for Statistical Applications and Methods
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• v.31 no.5
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• pp.535-556
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• 2024

Measuring stock market volatility and its determinants is critical for stock market participants, as volatility spillover effects affect corporate performance. This study adopted a novel approach to analysing and implementing GARCH-MIDAS modelling methods. The classical GARCH as a benchmark and the univariate GARCH-MIDAS framework are the GARCH family models whose forecasting outcomes are examined. The outcome of GARCH-MIDAS analyses suggests that inflation, interest rate, exchange rate, and oil price are significant determinants of the volatility of the Johannesburg Stock Market All Share Index. While for Nigeria, the volatility reacts significantly to the exchange rate and oil price. Furthermore, inflation, exchange rate, interest rate, and oil price significantly influence Ghanaian equity volatility, especially for the long-term volatility component. The significant shock of the oil price and exchange rate to volatility is present in all three markets using the generalized autoregressive conditional heteroscedastic-mixed data sampling (GARCH-MIDAS) framework. The GARCH-MIDAS, with a powerful fusion of the GARCH model's volatility-capturing capabilities and the MIDAS approach's ability to handle mixed-frequency data, predicts the volatility for all variables better than the traditional GARCH framework. Incorporating these two techniques provides an innovative and comprehensive approach to modelling stock returns, making it an extremely useful tool for researchers, financial analysts, and investors.

• Journal of Korea Port Economic Association
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• v.22 no.3
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• pp.141-160
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• 2006

In order to obtain and maintain competitive advantage, under rapidly changing maritime environment, liners should make efforts to reinforce their logistics service capabilities. Most of all, for this, shipping lines should accurately recognize and evaluate their logistics service attributes. In the present research, various logistics service attributes for ocean carriers were selected from previous studies and the observed data for 6 main service attributes were collected through a questionnaire survey to 31 maritime experts. Moreover, shipping lines' relative logistics service capabilities were measured by an additional survey process. The comparative gravity between core evaluation factors were measured by AHP technique and the relative capability levels of 2 Korean liners and 5 foreign shipping companies were assessed by utilizing a fuzzy model. The empirical result presents that Korean liners are superior at customer service capability but inferior at freight rate competitiveness. This research shows that Korean liners are ranked at high position for overall logistics service capabilities and focusing on the differentiation strategy but not on the cost related strategy.

• International Area Studies Review
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• v.16 no.1
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• pp.197-220
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• 2012

This study is to understand those determinants of performance differences of Korean small and medium firm's subsidiaries in Vietnam based on the resource based view. We have visited 21 Korean SME's subsidiaries in Hochiminh city area in Vietnam and interviewed CEO of those subsidiaries for 1-2 hours to make each case. Based on case content analysis, we can get those results that eight management capabilities such as securing competent local managers, clear and smooth communication with local employees, establishing good labor-management relations, raising the rate of factory operation and subcontracting, firm specific quality control system, timely financing, establishing good relationships with local communities, and fostering friendly relations with local public officers are major determinants of performance differences. Also we can know that various factors including local experiences in Vietnam have influenced those management capabilities. To be a high performer in Vietnam, foreign subsidiaries of Korean SMEs have to build and develop major management capabilities continuously.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.8
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• pp.1055-1061
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• 2002

A numerical and experimental study on the flow fields behind the fan outlet was carried out to improve the performance of a conventional fan-sink(fan and heat sink). Conventional fan-sinks have a heat sink of which fin configurations tend to increase the flow resistance, thus decreasing the performance and the cooling capabilities of a fan-sink. Lifting surface method is used for the prediction of flow fields behind the fan outlet. Oil-dot flow visualization technique is applied for the validation of numerical results. The numerical results and experimental data show agreement each other. A conventional heat sink is modified and redesigned using flow patterns behind the fan outlet. The newly designed heat sink has the configuration of curved fins which minimize flow resistance. It showed improvements in both cooling: capabilities and volumetric flow rate compared to the conventional one.

• Journal of Ubiquitous Convergence Technology
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• v.2 no.1
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• pp.51-55
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• 2008

A digital home is a ubiquitous environment that is expected to be realized in the near future. All information appliances in a house are connected to each other through wired and/or wireless home networks. Authenticated user can access the various services provided by the digital home, and the access is not restricted by equipment, time, or location. The technologies that form the digital home can be grouped into two categories: wired networking technologies and wireless networking technologies. For the purpose of ubiquitous environments, wireless-networks offer suitable and seamless high-quality services. A wireless LAN can be created simply by equipping a single access point. For that reason, the cost of establishing such a network is low and using it is easy. Of course, there is an exciting new wireless technology. It is the Ultra Wide Band (UWB). However, it is not enough to bring wireless convenience, although offering a broad range of high-speed data transfer capabilities, Because of unstable. Thus, of the wireless-networking systems, we focus on the wireless LAN. We quantitatively analyze its capabilities. The dynamic and adaptive wireless LAN provides a foundation for the evolution toward the next generation of wireless and adaptive networks. The difference between wired LAN and wireless LAN in upload and download rates is small. Although the wireless LAN experiences a greater loss rate than the wired LAN, the difference is minimal. We conclude that a wireless LAN is suitable for use in an apartment environment.

• Journal of the Korean Home Economics Association
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• v.45 no.1
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• pp.91-99
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• 2007

The purpose of this study was to determine a is finding the process for the development of professionals in the foodservice industry. The Questionnaire used in this study was designed to measure the capabilities of professional foodservice employees, investigate the importance and accomplishments of curriculum of the major subject, and determine areas matters of the for improvement in the of field. It was distributed to 101 professors (include lecturers) of foodservice departments, from February 1 to 28, 2006. A total of 101 usable questionnaires were received amounting to a 100 percent response rate. Statistical data analysis was completed using SPSS Win(11.0) for frequency, t-test, one sample t-test, and IPA(importance performance analysis). The results were as is follows. Regarding the As regard capabilities of professional foodservice employees, they remarked that the fair values and creative thinking are the most important. Regarding the curriculum of the major subject, generally the importance degree is higher than the accomplishment degree. The areas improvement are as follows: development of curriculum, securing the excellent faculty, academic-industrial cooperation, expanding and improving the university facilities in university, and increasing the experience during the term.

• Korean Journal of Organic Agriculture
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• v.29 no.1
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• pp.1-23
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• 2021

The form of agri-food transaction has taken a rapid change from the existing method since Covid-19. In response to changes in the market environment such as Covid-19, the integrated marketing organization in Jeollabuk-do was diagnosed from the point of view of innovation, and the future direction was examined. In order to improve the distribution structure of the production area, an integrated marketing organization was fostered, and both quantitative and qualitative growth were brought about. However, some regions still lack willingness to participate and lack of expertise. In particular, there is no infrastructure and strategy to prepare for the increase in non-face-to-face transactions post Covid-19. Online transactions also require economies of scale, so non-face-to-face transaction capabilities must be reinforced by adding a separate organization and experts in charge of online transaction functions within the integrated marketing organization. In the future, online sales are highly likely to expand not only to transactions between producers and individual consumers (C to C), but also to mass consumer (B to B) transactions. It will be an opportunity. In addition, it is necessary to efficiently use production area distribution facilities such as sorting and packaging. Since the non-contact transaction method will increase after Corona 19, it is necessary to strengthen marketing capabilities such as expansion of utilization rate, order placement, settlement, and customer management, and reorganization of specialized organizations.

• Journal of Information Technology Services
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• v.21 no.1
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• pp.61-79
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• 2022

In the rapidly changing era of knowledge revolution, user-centered IT services are emerging as a very important component of modern business. However, in order to lead IT services into success, traditional capabilities and competences are not good enough. Development of IT services involve service planners and designers as well as traditional systems developers. This detailed segmentation of job and corresponding competences among involved in IT service development brings in new type of conflicts and contradictions that may require special attention for IT services to be properly development and implemented. This study aims to explore and define competences and roles of newly emerging job groups in IT services: planners, designers, and developers. In order to identify underlying competences of these emergeing groups, two stage interviews were conducted. At the first stage, general competence framework is developed across these groups with different skills for similar competence catogories. Using the categories developed at the first stage, members of each groups were asked to rate and assess the competences of other groups. Comparisons of these reciprocal assessment revealed the conceptual differences and biases across these groups. Detail differences are discussed and implications are discussed.