• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제50권3호
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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.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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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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• 제7권12호
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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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• 제10권spc호
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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.

• 서비스연구
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• 제7권1호
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• pp.15-26
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• 2017

본 연구는 서비스산업 육성정책의 방향을 서비스의 본질 관점에서 연구하였다. 서비스산업의 범위가 넓고 업종이 다양하기 때문에, 서비스의 본질과 특성을 고려하지 않고 개별적인 산업의 특성을 중심으로 발전전략을 수립하면 한정된 시각을 가지게 되어 큰 발전을 추구하기 어렵다. 더구나 산업간 경계가 해체되는 현대 경제에서 중요한 변화를 간과할 수 있다. 또한 서비스산업간의 시너지를 추구하기 어렵고 개별산업의 혁신적 발전을 추구하기도 어렵다. 따라서, 각 개별서비스산업은 모두 서비스라는 공통적인 재화를 가진 산업임을 인식하여, 서비스의 본질 차원을 고려하여 발전전략을 설계할 필요가 있다. 본 연구는 서비스의 관계성, 쌍방향성, 수평성, 조화성 본질과 서비스의 무형성, 비분리성, 비일관성, 무재고성 특성을 반영하여 개별 서비스산업의 육성 전략을 도출해내는 시범연구로 수행되었다. 개별 서비스산업에서의 향상된 발전전략 수립과 정부의 발전정책 개발에 활용될 수 있을 것이다.

• 조형예술학연구
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• 제8권
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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.