• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.296-297
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• 2007

PMN-PZT 단층 및 다층 후막을 알루미나 기판위에 켄티레버 형태로 제작하여, 외부의 미소 진동에 의한 마이크로 발전 특성을 고찰하였다. 미소 변위에 의한 마이크로 발전 특성은 켄티레버의 무게(load), 진동수, 켄티레버의 길이 등에 밀접한 영향을 미치므로 이에 준한 요소를 고려하여 여러 가지 변수로 실험하였다. 연구 결과 서로 다른 소재의 기판과 발전체의 계면 분리 현상, 전극과 발전체의 분리 현상, 소결 온도 등이 소재 측면의 문제점으로 크게 대두되었으며, $5{\times}20mm$ 기판위에 형성된 발전체의 특성은 $1.1k{\Omega}{\sim}1M{\Omega}$의 부하에 따른 전압변동이 0.01V에서 3.6V로 큰 차이가 났다. 켄티레버의 로드의 변화에 대한 피크 전압은 $1.9{\sim}{\pm}2.8V$로 조사되었으며, 출력은 $0.45{\sim}4{\mu}W$로 측정되었다. 그러나 이런 외부 조건 보다 압전체의 공진 특성과 진동수는 가장 중요한 요인으로 나타났으며, 몇몇 문제가 해결될 경우 마이크로 발전소자로의 활용 가능성이 있는 것으로 조사되었다.

• 대한치과보철학회:학술대회논문집
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• 1997.11a
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• pp.27-27
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• 1997

• Proceedings of the Korean Vacuum Society Conference
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• 2001.02a
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• pp.189-190
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• 2001

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.1051-1052
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• 2011

• 대한치과보철학회:학술대회논문집
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• 1995.12a
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• pp.26-26
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• 1995

• Journal of the Korean Society for Precision Engineering
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• v.22 no.2
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• pp.194-201
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• 2005

Nanoscale fabrication of silicon substrate in an aqueous solution based on the use of atomic force microscopy was demonstrated. A specially designed cantilever with diamond tip, allowing the formation of damaged layer on silicon substrate easily by a simple scratching process (Tribo-Nanolithography, TNL), has been applied instead of conventional silicon cantilever for scanning. A slant nanostructure can be fabricated by a process in which a thin damaged layer rapidly forms in the substrate at the diamond tip-sample junction along scanning path of the tip and simultaneously the area uncovered with the damaged layer is being etched. This study demonstrates how the TNL parameters can affect the formation of damaged layer and the shape of 3-D structure, hence introducing a new process of AFM-based nanolithography in aqueous solution.

• Journal of the Korea Institute of Building Construction
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• v.18 no.3
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• pp.243-249
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• 2018

The study for curling control of plain concrete in underground parking lot was conducted in this study. The shrinkage reducing agent(SRA) was used to minimize the curling deformation of plain concrete in underground parking lot. For the quantitative curling control, the simplified prediction method applying the deflection theory of cantilever beam was proposed too, and the validity of prediction method was examined through the comparison between the experimental values and predictive values. In result, the curling of SRA 1.0% concrete was about 30% less than that of SRA 0.0% concrete, and the possibility of curling estimation by the simplified prediction method was confirmed through the comparison between the experimental values and predictive values.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.303-303
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• 2010

국제적으로 에너지 고갈에 대한 문제점과 환경적은 측면에서 대체 에너지 개발에 대한 관심이 뜨거워 지고 있는 지금 그중에서 에너지 하베스팅에 대한 연구가 활발히 이루어지고 있다 에너지 하베스팅 이란 "자연에서 버려지는 에너지를 수확하여 저장하는 기술" 이며 에너지 하베스팅 방법으로는 태양광을 이용한 태양광발전, 기계적인 운동과 전자기적 현상을 이용한 발전 등이 있다. 태양광발전 같은 경우에 흐린날 이나 실내에서는 사용 할 수 없는 반면 날씨와 관계없는 진동의 기계적 에너지를 전기적 에너지로 변환 할 수 있는 압전 세라믹스를 이용한 에너지 하베스팅의 연구가 이루어 지고 있다. 에너지 하베스팅을 하기 위한 여러 가지 type의 소자가 있지만, 본 논문에서는 무연 압전 세라믹스를 이용한 cantilever type의 실험을 진행하였으며 에너지 하베스팅 시스템에서 핵심이 되는 것은 압전 세라믹스의 성능이므로 비교적 높은 $d_{33}$ 와 $g_{33}$를 가진 소자를 선정하였다. 압전 세라믹스를 이용한 에너지 하베스팅의 장점으로 소형 경량으로 이용할 수 있는 범의가 넓으며 진동 또는 충격을 효과적인 방법으로 에너지로 변환할수 있다. 실험 과정으로 KNNS에 CuO를 첨가하여 1차 밀링후 $Ag_2O$를 첨가하여 2차밀링 하여 $900^{\circ}C$ 하소 cantilever type으로 성형 후 $1080^{\circ}C$ 소성을 하여 세라믹스를 제작하여 그에대한 발전 특성을 조사하였다.

• Journal of Korean Society of Steel Construction
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• v.19 no.6
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• pp.655-661
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• 2007

A new steel connection method using wedges known as Self-Locking Connector has been developed. In this study, experimental investigation was conducted to verify the seismic performance of steel beam-to-column joints with Self-Locking Connectors. Cyclic-loading tests were performed on two beam-to-column joints with Self-Locking Connectors. The two beam-to-column joint specimens were of the cantilever-type and had the same details. Test results showed that beam-to-column joints with Self-Locking Connectors were able to developa total rotation capacity of 0.06 radian, which is greater than the 0.04 radian required for Special Moment Frames. Moreover, their energy absorption capacity was much greater than that of conventional joints.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.5
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• pp.724-743
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• 2000

One of the biggest clinical problems of osseointegrated implant prosthesis is the excessive stress caused by bite forces which are transfered directly into the bone through the osseointegrated implant fixtures. So several biodynamic problems occur when there is an excessive fatigue stress. The factors of stress distribution are the number, kind, position, arrangement of the implants, and the distance between the implants, and the kind, quality of superstructure prosthesis and connection type between the rest implant and the superstructure. Recently, a distal short additional implant, socalled rest implant, is employed to reduced the stresses in conventional cantilevered prostheses. This study was undertaken to analyze the stresses transfered by osseointegrated implant cantilevered prostheses depending upon the number and the position of implants, the presence of rest implant, and the type of their connection. Three dimensional finite element analysis was attempted using ANSIS ver. 5.3 program under IBM INDIGO computer. The results were as follows : 1. The rest implant influenced on the pattern of stress distribution on the anterior area of the mandible and the superstructure. 2. In the group employing the rest implants, the fixed type of connection between the rest implant and the superstructure was more stable than the ball attachment type on the stress distribution. 3. In the group employing the ball attachment between the rest implant and the superstructure, the case with 4-implants(on canine, premolar) was little more stable than the case with 6-implants and the case with 4-implants(on incisor, premolar) on the stress distribution. 4. In the cantilevered group, the case with 4-implants(on incisor, premolar) and the case with 6-implants were more stable than the case with 4-implants(on canine, premolar) on the stress distribution. 5. In all of the group, the case with 6-implants and the fixed type of connection was the most stable and the case with 4-implants (on canine, premolar) was the most unstable on the stress distribution.