• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.220-225
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• 2003

Recent issue of optical actuator is applying to mobile device. It leads actuator to become smaller than conventional type. This paper proposes the design of micro actuator plate spring and analysis of its vibration characteristic. Considering natural frequency of spindle motor, 1st and 2nd eigenfrequency of micro actuator must avoid its natural frequency. First, magnetic circuit is designed by using fine pattern coil and magnetic force is acquired by simulation program. Then, concept design is achieved by topology optimization. From concept design, micro actuator plate spring is embodied through DOE(design of experiment). Finally, considering vibration characteristic simultaneously, optimal plate spring design is determined by RSM(response surface method).

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.407-410
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• 2002

Triangulation method, conoscopic holography method and interferometry method are analyzed for effective measurement of micro burr geometry, which is formed in micro drilling. To select proper sensor, cylinder with 0.5mm diameter is measured and the result shows that conoscopic holography method is effective for measuring highly inclined surface. Burr with 1.0mm height and 30$\mu\textrm{m}$ height are measured by all methods. The conoscopic holography method is probed to be most proper method for measuring micro burr. A Program for 3D display of measured burr is developed.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.3
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• pp.256-264
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• 2012

A general procedure for the optimal design of a micro-channel heat exchanger for heat pump systems is presented. For this design, a performance analysis program that can reflect the various geometric variables of the micro-channel heat exchanger was developed. The deviation between simulated and experiment results of previous research was within 4% for the heat transfer rate. To prove the feasibility of the optimal design process, the performance of the reference heat exchanger was compared to that of the optimized heat exchanger. The $JF_{air}$ and PECv of the optimized heat exchanger were enhanced by 14% and 26%, respectively.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.3
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• pp.182-187
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• 2004

In this paper, we propose a PC based distributed controller for a two axis convey table using real-time micro-kernel. PC, Windows program, gives an easy way to implement wealthy GUI and micro-kernel, ${\mu}$C/OS-II, provides a real-time capability to control devices. We built a real-time distributed control system using ${\mu}$C/OS-II kernel which needs to process the tasks for two motors within the desired time to synchronize the motion. We used both semaphore and message mail box for synchronization. Unlike the previous study where we used step motors for the actuator of two axes convey table, we rebuilt the convey table with DC motors and the dedicated position servo which had built in out lab, and then we implemented a realtime distributed control system by putting the micro-kernel into between PC and position servo. Moreover we developed the PC based graphic user interfaces for generating planar drawing image control. Experimental results also presented to show the Proposed control system is useful.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.143-144
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• 2006

In this paper, we proposed XP KMPR-1050 negative tone resist to replace SU-8 resist for multi-layer micro-structures and thick plating mold fabrication using UV-LIGA process. XP KMPR resist proposed in this paper can be easily striped using a common stripping solution such as NMP without damage of micro-structure. The conditions for the fabrication of XP KMPR micro-structure were optimized by adjustment of exposure and post-exposure bake(PEB). The $140{\mu}m$ -thick and an aspect ratio at least 10 micro-structure and multi-layer structures were successfully fabricated through the process conditions. Through-mold electroplating and PR striping of XP KMPR has been successfully demonstrated.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.5
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• pp.306-313
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• 2015

In this study, the change of optical characteristics was studied according to the micro optical pattern provided by photo lithography followed by thermal reflow process. The shape and luminance variation with micro pattern was evaluated by SEM and spectrometers. Also, we analyzed the luminance characteristics using the 3D-optical simulation (Optis works) program. As a result, we found that the radius of curvature(R) in micro pattern is decreased up to 77%($150^{\circ}C$) compared to the radius of curvature at the condition $100^{\circ}C$, which is caused by efficient reflow of organic material without chemical changes. The highest enhancement of brightness with optimum micro pattern was obtained at the condition of $120^{\circ}C$ reflow process. The brightness gain with optical micro patterns is more than 15% at the condition of R=16.95 um, ${\Theta}=77.14^{\circ}$ compared to original optical source. The results of light simulation with various radius of curvature and side angle of pattern shows the similar result of experiment evaluation of light behavior on optical micro patterns. It is regarded that the more effect on light enhancement was contributed by side angle which is effective factor on light reflection, rather than the curvature of micro-patterns.

• International Journal of Highway Engineering
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• v.5 no.3 s.17
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• pp.21-29
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• 2003

The management of existing airfield pavement information has currently become difficult and the maintenance cost has increased over time due to the long-term performance. It is needed to develop the method for effective budget allocation and systematic airfield pavement management services. The objectives of this paper are to introduce Micro PAVER, one of the popular pavement management systems, into our management system and customize Micro PAVER based on our environment and pavement management level. This study focused on the analysis on logics and structures of Micro PAVER and customization of important parts in the program using the existing pavement evaluation data and survey method. Customized items selected in this study included the pavement deterioration prediction models, critical PCI, maintenance cost by PCI, maintenance or rehabilitation method and unit cost, and PCI rank.

• Imaging Science in Dentistry
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• v.37 no.1
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• pp.27-33
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• 2007

Purpose : The research was done to investigate the effectiveness of 2D bony morphometry and microstructure of micro-computed tomography (micro-CT) on the osteoporotic bony change. We performed the bone morphometric analysis of proximal femur in ovariectomized rabbits with BMD and micro-CT examination. Materials and Methods : Twenty-one female (Newzealand, about 16 weeks old, 2.9-3.4kg) rabbits were used. Three rabbits were sacrificed on the day when experiment began (Baseline). The remaining 18 rabbits were divided into two groups. One group was ovariectomized bilaterally (OVX) and the other animals were subjected to sham operation (Sham). Bone specimens were obtained from the right and left femur of sacrificed rabbits. At intervals of 1, 2, 3, 5, 6 months respectively, BMD tests were performed on the proximal femur by using PIXlmus 2 (GE Lunar Co. USA), 2-dimensional bone morphometric analysis by custome computer program and 2D/3D bone structure analysis by micro-CT (Skyscan 1072, Antwerpen, Belgium). Statistical analysis was carried out for the correlation between bone morphometry, micro-CT and BMD Result : BV/TV, Tb.Th, Tb.N of micro-CT parameters showed higher values in sham group than OVX group. N.Nd/Ar.RI, N.NdNd, N.NdTm, N. TmTm, PmB/Ar.RI, 3-D BoxSlope of 2D morphometric parameters showed higher values in Sham group than OVX group. The micro-CT parameters of Tb.Sp, Tb.N were statistically significant correlated with BMD respectively. Several 2D morphometric parameters were statistically significant correlated with BMD respectively. Conclusion : Several parameters of 2D bony morphometry and micro-CT showed effective aspects on the osteoporotic bony change.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2003.11a
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• pp.259-264
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• 2003

In this paper, web based monitoring systems are implemented using embedded Linux. The external equipment is controlled via HTTP protocol and web browser program. HTTP protocol is ported into Linux. A micro web server program and external equipment control program are installed on-board memory using CGI to be accessed by web browser. Experimental result of the proposed web based monitoring systems can be used in automation systems and remote distributed control via internet using web browser.

• Journal of the korean Society of Automotive Engineers
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• v.5 no.1
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• pp.9-16
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• 1983

흔히 자동차용 belt를 단순한 소모품으로 생각하여 대수롭지 않게 여기는 경향이 있으나 belt slip에 의한 동력의 손실은 매우 큰 것이며 특히 자동차용 belt에 있어서 그 중요성은 상당한 것이다. 왜냐하면 crankshaft에서의 중력이 belt를 통해서 water pump나 air compressor등에 전달되며 이때 동력전달이 제대로 안되는 경우에는 engine은 냉각수와 냉각팬에 의해 냉각이 되지 않아서 금방 고은소착 되기 때문이며, 또한 belt를 너무 조이는 경우에는 water pump bearing의 파손 등을 초래하기 때문에 belt의 정확한 길이 계산이 매우 중요하다. 그러나 이러한 중요성에도 불구하고 belt의 설계계산을 행하는 데는 많은 시간이 걸리며, 간혹 잘못 계산을 하는 경우에는 큰 문제가 발생할 수도 있기 때문에 belt계산의 기본이론식들을 전부 computer program 화하여 시간의 절약과 계산의 오류를 피하고자 한다. Program을 만들기 위해서 사용한 computer는 micro-computer로서 PET (Personal Electric Transactor)2001이며 사용한 언어는 BASIC이다.