• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.3
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• pp.105-109
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• 2001

In this paper, the windmill type ultrasonic motors with 11.35 mm diameter, 2.87 mm thickness of metal endcap and 1.47 g weight were fabricated. Effects of slots and thickness on torque characteristic in the windmill type ultrasonic motor were investigated, when stator's slots were changed from 4, 6, 8 and thickness 0.15 mm, respectively. Specially designed metal endcaps with windmill shaped cutting can provide longitudinal and torsional displacements simultaneously as the ceramic disk vibrates radically. The windmill type ultrasonic motor has only three components: a stator element with windmill shape slotted metal endcap, a rotor and bearing. Ultrasonic motor stimulated to ultrasonic oscillations by piezoelectrics to drive a rotor via friction contact. The ultrasonic motor fabricated here was the windmill type ultrasonic motor operated by single-phase AC source. Bidirectional revolution using single-phase high frequency for driving the ultrasonic motor was presented.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.181-183
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• 2000

Ultrasonic Motors of Wind-Mill type(diameter in 11.35mm, thickness in 2.8mm, and 1.44g weight) using Piezoelectric Ceramics have been developed. In recent study, Maximum torque in 100$V_{max}$, 105.8kHz was 7.2 ${\mu}$N$.$m, and bidirectional revolution using single-phase AC was presented. However, it is difficult to use because of small torque. Thus, in present study, new type of Wind -Mill Type Ultrasonic Motor of was designed as stator' structure was changed

• The Journal of Asian Finance, Economics and Business
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• v.7 no.12
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• pp.21-31
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• 2020

This study investigates the dynamic effects of economic development, international cooperation, electricity consumption, and political risk on the escalation of CO₂ emission in Vietnam. We adopted autoregressive distributed lag model and Granger causality method to examine the interaction between CO₂ and various economic and political factors, including foreign direct investment, trade openness, economic growth, manufacture, electricity consumption, and political risk in Vietnam since the economic revolution in 1986. The findings reflect opposite influence between these factors and the level of CO₂ in the intermediate and long-term durations. Accordingly, foreign direct investment and CO₂ emission have a bidirectional relationship, in which foreign direct investment accelerates short-term CO₂ emission, but reduces it in the long run through an interactive mechanism. Moreover, economic development increases the volume of CO₂ emission in both short and long run. There was also evidence that political risk has a negative effect on the environment. Overall, the findings confirm lasting negative environmental effects of economic growth, trade liberalization, and increased electricity consumption. These factors, with Granger causality, mutually affect the escalation of CO₂ in Vietnam. In order to control the level of CO₂, more efforts are required to improve administrative transparency, attract high-quality foreign investment, and decouple the environment from economic development.

• Journal of Information Science Theory and Practice
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• v.10 no.spc
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• pp.39-45
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• 2022

For national industrial development in the Fourth Industrial Revolution, it is necessary to provide researchers with appropriate job information. This can be achieved by interconnecting the National Science and Technology Standard Classification System used for management of research activity with the Korean Employment Classification of Occupations used for job information management. In the present study, an automatic linkage model of classification systems is introduced based on a pre-trained language model for interconnecting science and technology information with job information. We propose for the first time an automatic model for linkage of classification systems. Our model effectively maps similar classes between the National Science & Technology Standard Classification System and Korean Employment Classification of Occupations. Moreover, the model increases interconnection performance by considering hierarchical features of classification systems. Experimental results show that precision and recall of the proposed model are about 0.82 and 0.84, respectively.

• Journal of Service Research and Studies
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• v.7 no.1
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• pp.15-26
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• 2017

The current research investigates the strategies for fostering service industries from the service's nature perspectives. Because the service industry is broad and heterogeneous in nature, if service's nature is not considered in building strategies for developing service industries, it would have a limited perspective, and thus, it would be difficult to foster large growth in service industries. In addition, not considering service's nature would not encourage synergy among service sectors nor encourage innovative development among individual sectors. Therefore, we need to understand that different service sectors are all under the umbrella for service industries, and consider the service's nature. The current research considers the service's relational, bidirectional, horizontality, and harmonization nature of services, and also, intangibility, inseparability, heterogeneity, perishability were considered in suggesting strategies for fostering service industries. These results can be used to developing governmental policies for developing service industries.

• Journal of Science of Art and Design
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• v.8
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• pp.241-266
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• 2005

Current information-oriented society is expanding rapidly with the huge change to our society from the information revolution emerged in mid '50s. Information technique such as computer, communication satellite and cable technology play their in this information-oriented society, and in 1980s, digital technique was adopted to media, inviting new phenomenon in communication of overall society. Expectations and hope for new trends and changes from digital era flourished when we entered into new Millenium, the 21st century. Since then we have gone through changes in years from analogue to digital. Now the word 'digital' is conceived in unified manner in almost every fields and influences overall society, changing our life pattern rapidly. Modern society had demanded some speedy and bidirectional communication tool in shifting digital era, and resulted from that was a new culture, Now the society changes more and more quickly under the speedy information sharing. From that perspective we need to establish the aspects of sensibility expression, which is one feature of the communication. The sensibility-oriented digital was originated from the human nature, which counts emotion and composure much. To satisfy the human nature a new cultural value which transcend a traditional one is needed. And the sensitivity expression to meet the need is one communication tendency in digital era. Digital era has totally different social qualities from that of analogue era. In digital era, prompt respond to rapid change and creativity combined with sensitivity are needed. Therefore a man with sensitivity would be more outstanding than a man of intelligence. The picture of digital and analogue in our society consists of two axis one is analogue axis like retrospective trend, admiration for nature , oriental thought etc. , and the other is the digital axis of internet and information technology. Sensibility can be widely interpreted as analogue thinking. It is surely different from the plain retrospective trend or nostalgia for past. It is a tendency that digital technology is used and cooperated with the emotion in human nature, In this paper we suggest the sensitivity expressions in detail through the study cases including both sides of digital and sensitivity expressions such as 'Bravo your life' advertising campaign of Samsung Insurance, MP3 advertising campaign, and 'Mini-homepage' of Cyworld. Under the circumstances the main direction of communication is oriented to human. This study's purpose is to think the true meaning of this digital era, to overcoming its weaknesses, such as over-dependency on technique and selfish individualism and to harmonize digital and sensitivity expression. The sensitivity-oriented expression than the reason-oriented one is expected to be put forth in whole media, and this is a more efficient tendency under the shifting digital era.