• 한국산학기술학회논문지
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• 제18권8호
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• pp.378-385
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• 2017

본 연구는 플라스틱 부품의 체결에 널리 활용되고 있는 스냅핏의 설계에 관하여 연구하였다. 이탈방지 기능이 우수한 이탈방지 스냅핏은 형상과 체결 메카니즘이 복잡하여 기존의 이론식에 기반한 체결력과 이탈력을 해석적으로 구할 수가 없다. 따라서 본 연구에서는 이탈방지 스냅핏에 대하여 체결 메커니즘을 분석하고, 실험계획법에 기반하여 체결력 및 이탈력을 측정하고, 분산분석을 통하여 회귀식을 도출하였다. 실험계획은 중심합성계획을 사용하였다. Polybutylene terephthalate를 이용하여 시편을 제작하여 미소인장시험기를 이용하여 체결력과 이탈력을 측정하였다. 설계인자는 Length, Width, Thickness, Interference 등 4개를 선정하였으며, 2차 회귀모형을 이용하여 체결력과 이탈력에 대한 회귀식을 도출하였다. Length와 Width가 증가할수록 체결력은 낮아졌으며, Thickness와 Interference는 증가할수록 체결력이 증가하였다. 이탈력은 체결력과 반대의 결과를 나타내었다. 유한요소법을 이용하여 체결 역학에 대하여 분석하였다. Width는 체결단계에서 단면관성모멘트의 증가를 통한 보의 강성 증가 효과 보다는, 오히려 길이 증가에 따른 연성증대로 인하여 체결력을 감소시키는 것으로 나타났다. 낮은 체결력과 높은 이탈력을 위한 인자들의 영향도는 서로 상반되는 것으로 나타났다. 적정 수준의 이탈력을 유지하면서 체결력을 최소화하는 설계가 필요한 것으로 나타났다.

• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2005년도 추계학술대회 논문집
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• pp.89-92
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• 2005

A microcapsule for drug delivery was successfully produced by utilizing the flow-through droplet-based supramolecular self-assembly in a crossed microchannel network. The PS-b-PMMA block copolymer synthesized atom transfer radical polymerization (ATRP) was initially formed as microdroplets and after the evaporation process it turned to spherical capsule by polymer self-assembly of the micro domains. The characteristics were studied using various analysis methods.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.570-575
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• 2002

Servo performance of a disk drive is greatly affected by the mechanical resonance frequencies of the head gimbal assembly (HSA). It is important factor to allow broader bandwidths for servo system in improving overall drive performance. In this paper, an optimal design for ODD suspension is attempted to increase resonance frequencies in tracking direction. Initial model was designed and the design parameter was defined to the model. The mode frequency variation for the change of design parameter was observed by modal analysis using the finite element method(FEM). The sensitivity matrix was calculated from the observed data and so through sensitivity analysis, an optimized ODD suspension was designed to have the higher resonant frequency than the initial model.

• KIEE International Transactions on Electrophysics and Applications
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• 제11C권2호
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• pp.23-27
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• 2001

Microarray-based DNA chips provide an architecture for multi-analyte sensing. In this paper, we report a new approach for DNA chip microarray fabrication. Multifunctional DNA chip microarrays were made by immobilizing many kinds if DNAs on transducers (particles). DNA chip microarrays were prepared by randomly distributing a mixture of the particles on a chip pattern containing thousands of micro meter-scale sites. The particles occupied different sites from array to array. Each particle cam be distinguished by a tag that is established on the particle. The particles were arranged on the chip pattern by the random fluidic self-assembly (RFSA) method, using hydrophobic interaction.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.359.1-359
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• 2002

Servo performance of a disk drive is greatly affected by the mechanical resonance frequencies of the head gimbal assembly(HGA). It is important (actor to allow broader bandwidth for servo system in improving overall drive performance. In this paper, an optimal design for ODD suspension is attempted to increase resonance frequencies. It was decided that the first resonant frequency in tracking direction was higher than 5㎑. (omitted)

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2006년도 춘계 학술대회 개요집
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• pp.39-41
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• 2006

The weld quality of spacer grids in Pressurized Water Reactors(PWR) fuel is extremely important for the fuel assembly performance in the nuclear renter. The spacer grid welds are currently evaluated mainly by the metallographic examination although it reveals only cross-points which are welded by the laser beam. This experiment is also to compare the weldability of Zircaloy-4 spacer grids using by the GTA and laser beam. The effect of node geometries of spacer grids for GTAW and LBW has been studied and optimum conditions of spacer grid welding have been found. Microstructures and micro-hardness of GTA and laser beam welded zones have been also compared.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1455-1457
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• 2008

Cell adhesion is a coordinated process involving initial binding of integrin receptors to extracellular matrix (ECM), recruitment of adhesion proteins, and focal adhesion assembly. The formation of mechanically stable focal adhesion assembly of cells within surrounding ECM is a key parameter to direct numerous cellular functions including cell migration, differentiation, and apotosis. With current cell adhesion assays, it is difficult to understand contributions of each coordinated event on evolution of cell adhesion strengthening since cells spontaneously spread upon their adhesion to the substrate, thus remodeling their cytoskeletal structure. In this presentation, novel approaches for analysis of cell adhesion strengthening process based on the combination of mechanical device, micro-patterned substrates, and molecular biological techniques will be discussed.

• International Journal of Precision Engineering and Manufacturing
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• 제6권2호
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• pp.34-39
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• 2005

The precision stage is an essential device for optic fiber assembly systems, micro machines and semiconductor equipments. A new piezoelectric inchworm type actuator is proposed to implement an actuator-integrated long-stroke linear stage. An in-and-quadrature phase (I/Q) heterodyne interferometer is developed as a feedback sensor of a servo system, and a synchronized counting method is proposed. The proposed measurement system can measure the accurate position of fast moving object with robustness to external sensing noise from actuator vibration. The developed servo stage will be applied to optic fiber device assembly system.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2002년도 학술대회지
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• pp.423-426
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• 2002

A custom micro-PIV optics assembly has been used to measure the flow field inside a T-shaped microchannel. The micro-PIV system consists of microscope objectives of various magnifications, a dichroic cube, and an 8-bit CCD camera. Fluorescent particles of diameters 620nm have been used with a Nd:YAG laser and color filters. A programmable syringe pump with Teflon tubings were used to inject particle-seeded distilled water into the channel at flow rates of $420,\;40,\;60{\mu}L/hr$. The microchannels are fabricated with PDMS with a silicon mold, then $O_2-ion$ bonded onto a slide glass. Results show differences in flow characteristics and resolution according to fluid injection rates, and magnifications, respectively. The results show PIV results with vector-to-vector distances of $2{\mu}m$ with 32 pixel-square interrogation windows at $50{\%}$ overlap.

• 대한기계학회논문집A
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• 제29권6호
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• pp.809-814
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• 2005

The goal of this paper is to minimize the weight of the T-structure supporting steering system in reducing the vibration level on steering wheel which could be amplified by the resonance. Presently, requirements for reducing noise, vibration and harshness (NVH) in automotive area are more stringent than ever. One of them is the vibration of steering system which occurs sometimes at high speeds or when the engine is idling. Besides, the reduction of weight is also one of requirements for improvement of vehicle performance. This paper used the micro genetic algorithm as an optimization method to satisfy above two requirements. The whole T-structure assembly including steering column was used for frequency analysis.