• The Optical Journal
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• s.120
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• pp.66-68
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• 2009

일찍부터 휴대폰에 들어가는 부품중심으로 사업영역을 키워오며 'Shield Can'을 주력제품으로 갖고 있는 성우전자(대표 조성면, www.swei.co.kr)는 2007년 1월 서울 수서에 제품양산 및 신규 사업을 위해 R&D센터(센터장 임대순)를 설립하고 메커니컬 셔터 개발에 집중하여 지난해는 세계 초소형 휴대폰용 8M 셔터 개발 및 양산에 성공한데 이어, 오토포커스, 오토아이리스 엑츄에이터 등의 성과물을 쏟아내며 기업의 '아이디어 뱅크'로 적극 활용하고 있다. 원고센터를 통해 세계 수준의 정밀프레스 부품전문기업으로 발돋움하기 위한 성우전자의 노력과 노하우를 엿보았다.

• The Journal of the Acoustical Society of Korea
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• v.29 no.1E
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• pp.1-10
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• 2010

The difference in echogenicity between cancerous and normal tissues is not quite distinguishable in ultrasound B-mode imaging. However, tumor or cancer in breast or prostate tends to be stiffer than the surrounding normal tissue. Thus, imaging the stiffness contrast between the two different tissue types is helpful for quantitative diagnosis, and such a method of imaging the elasticity of human tissue is collectively referred to as ultrasound elasticity imaging. Recently, elasticity imaging has established itself as an effective diagnostic modality in addition to ultrasound B-mode imaging. The purpose of this paper is to present various elasticity imaging methods that have been reported up to now and to describe their principles of operation and characteristics.

• Structural Engineering and Mechanics
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• v.6 no.1
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• pp.77-93
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• 1998

Some design formulas and design procedures for single and multiple tuned liquid column dampers (TLCDs) are proposed in this study. Previous studies show that if the properties of the TLCD system are properly selected then the TLCD could be as effective as the traditional tuned mass dampers. In addition, the TLCD system offers advantages such as flexibility in terms of installation, little maintenance required, and potentials for multiple usage, etc., which are incomparable by other mechanical types of dampers. In this paper, a set of optimal properties such as length and head loss of a TLCD system are derived under the assumption that the building vibrates in a dominate mode and is subjected to Gaussian white noise excitation. A design procedure for a single TLCD system will be illustrated and discussed. Due to the nonlinearity in the damping term, the TLCD system is sensitive to the loading intensity. This loading sensitivity could limit the application range of the TLCD system. It will be shown in this paper that such a nonlinear effect can be reduced by using multiple TLCDs. As a demonstrative example, the control effects on a flexible building modeled as a single degree-of-freedom system subjected to white noise excitation will be analyzed and discussed using single or multiple TLCDs.