• JSTS:Journal of Semiconductor Technology and Science
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• v.2 no.4
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• pp.295-301
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• 2002

In this paper, solenoid-type 3-D passives (inductors and transformers) have been designed, fabricated, and characterized by using electroplating techniques, wire bonding techniques, multi-layer thick photoresist, and low temperature processes which are compatible with semiconductor circuitry fabrication. Two different fabrication approaches are performed to develop the solenoid-type 3-D passives and relationship of performance characteristics and geometry is also deeply investigated such as windings, cross-sectional area of core, spacing between windings, and turn ratio. Fully integrated inductor has a quality factor of 31 at 6 GHz, an inductance of 2.7 nH, and a self resonant frequency of 15.8 GHz. Bonded wire inductor has a quality factor of 120, an inductance of 20 nH, and a self resonant frequency of 8 GHz. Integrated transformers with turn ratios of 1:1 and n:l have the minimum insertion loss of about 0.6 dB and the wide bandwidth of a few GHz.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.5
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• pp.178-182
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• 2007

This study represents the efficient depth measurement for 3-dimensional microsystems using the disparity histogram from stereo images. Implementation of user-friendly Windows program written in C++ involves the various methods for the stereo-image processing in which the minimization of matching-pixel error upon the unique point for stereo images was carried out as a pre-processing method. Even though MPC among various methods was adopted in the present measurement, the resulting measurements seem to require optimizations of the windows sizes and corrections of post-manipulation for stereo images. The present work using Windows program is promising to measure the 3-dimensional depth of micro-system efficiently in implementing the 3-dimensional structure of micro-systems.

• KSTLE International Journal
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• v.7 no.2
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• pp.51-55
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• 2006

In order to design an effective foot surface which can provide adequate friction for a self-propelled medical microrobot moving inside the small intestine, frictional mechanisms between the small intestine inner wall and the foot surface of the robot must be understood. In this paper, mechanical interlocking effect was considered to design the surface of the foot that can generate the desired frictional force. The concept of the design was derived from the hookworm that lives inside the small intestine. Hookwarms are known to adhere to the small intestine wall by interlocking with villi on the surface of the small intestine. The interlocking mechanism was considered as the main frictional mechanism for the design of the microrobot foot surface in this work. 2 mm and 6 mm diameter solid and hollow cylindrical shaped foot specimens were designed and tested to assess the frictional force between the specimens and the porcine small intestine specimen.

• Journal of Sensor Science and Technology
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• v.10 no.6
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• pp.279-285
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• 2001

In this study, we fabricated the microlens array using very simple and economical method which used Si molds made by bulk etching in HNA and spreaded SU-8 on top of the Si mold. And, we developed fabrication conditions for high fill factor microlens array that is $45{\mu}m$ in height and $150{\mu}m$ in diameter. This microlens array can be used for imaging system like IR detector or projection display. It is expected that it can improve the characteristics of these devices.

• Proceedings of the KIEE Conference
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• 2000.11c
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• pp.581-582
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• 2000

본 논문에서는 적외선과 같이 주파수가 Tera Hz 영역인 극초고주파에서 사용할 수 있는 Horn형 안테나의 제조를 위한 독창적인 방법을 제시하고 실험적인 검증을 하였다. 파장이 $10{\mu}m$ 부근인 전자기파에 대응될 수 있는 안테나의 구조에 대한 시뮬레이션을 하였으며 이를 기준으로 안테나 어레이를 제조하기 위한 기초실험을 하였다. 기존에 사용되던 LIGA-like 공정과는 대조적으로 Columnar illumination 방법을 사용하였으며 $300{\mu}m$ 두께의 SU-8에 대하여 수직벽을 제조할 수 있었고 기판 위치에 일정한 각도를 줌으로서 경사면을 갖는 구조를 제조하였으며 기판을 회전시킴으로서 원뿔형의 Horn형 안테나 어레이를 제조할 수 있는 방안을 제시하였다.

• Korea Multimedia Society
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• v.12 no.1
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• pp.32-42
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• 2008

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2003.04a
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• pp.68-68
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• 2003

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2451-2456
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• 2003

In biological cell manipulation, manual thrust or penetration of an injection pipette into an egg is currently performed by a skilled operator, relying only on visual feedback information. Massive load of various micro injection of either genes, fluid or cells in the postgenomic era calls a more reliable and automatic micro injection system that can test hundreds of genes or cell types at a single experiment. We initiated to study cellular force sensing in zebrafish eggs as the first step for the development of a more controllable micro injection system by any inexperienced operator. Zebrafish eggs at different developmental stages were collected and an integrated biomanipulation system was employed to measure cellular force during penetrating the egg envelope, the chorion. First of all, the biomanipulation system integrated with cellular force sensing instrument is implemented to measure the penetration force of cell membranes and characterize mechanical properties of zebrafish embryo cells. Furthermore, implementation of cellular force sensing system and calibration are presented. Finally, the cellular force sensing of penetrating cell membranes at each developmental stages was experimentally performed. The results demonstrated that the biomanipulation system with force sensing capability can measure cellular force at real-time while the injection operation is undergoing. The magnitude of the measured force was in the range of several hundreds of uN. The precise real-time measurement should provide the first step forwards for the development of an automatic and reliable injection system of various materials into biological cells.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.2
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• pp.206-214
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• 2017

In this study, measurement of thermophysical properties of materials at high temperatures was performed. This experiment employed a heater device to heat the material to a high temperature. The images of the specimen surface due to thermal load at various temperatures were recorded using charge-coupled device (CCD) cameras. Afterwards, the full-field thermal deformation of the specimen was determined using the digital image correlation (DIC) method. The capability and accuracy of the proposed technique are verified by two experiments: (1) thermal deformation and strain measurement of a stainless steel specimen that was heated to $590^{\circ}C$ and (2) thermal expansion and thermal contraction measurements of specimen in the process of heating and cooling. This research focused on two goals: first, obtaining the temperature dependence of the coefficient of thermal expansion, which can be used as data input for finite element simulation; and second, investigating the capability of the DIC method in measuring full-field thermal deformation and strain. The results of the measured coefficient of thermal expansion were close to the values available in the handbook. The measurement results were in good agreement with finite element method simulation results. The results reveal that DIC is an effective and accurate technique for measuring full-field high-temperature thermal strain in engineering fields such as aerospace engineering.

• Research in Community and Public Health Nursing
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• v.30 no.1
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• pp.11-24
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• 2019

Purpose: This study tries to systematically understand factors that explain levels of happiness among pregnant women in the Ecological systems theory. Methods: A descriptive, cross-sectional study was conducted with 169 pregnant women in Korea. Collected data from self-report questionnaires were analyzed by hierarchical regression analysis using the SPSS statistics 23 program. Results: A total of 5 models were examined according to individual, microsystem, mesosystem, exosystem, and macrosystem in the Ecological systems theory. In the first model including individual factors, extraversion, neuroticism, and physical and psychological change constitute significant factors explaining happiness. In the second model with microsystem factors and in the third one with mesosystem factors, marital intimacy appears to be a significant factor. In the fourth model including exosystem factors, community service is a significant factor. In the final model with social atmosphere, personality (${\beta}=.15$ for extraversion; ${\beta}=-.30$ for neuroticism), physical and psychological change (${\beta}=-.15$), marital intimacy (${\beta}=.35$), and community service (${\beta}=.18$) turn out to be significant. These factors explain 59% of the variance of happiness in the pregnant women in Korea. Conclusion: Considering the fact that pregnant women's happiness is explained by microsystem and exosystem factors as well as individual factors, developing intervention programs that can promote influencing factors such as marital intimacy and community service is necessary to improve levels of happiness among pregnant women in Korea.