• Journal of the Korean Society for Nondestructive Testing
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• v.25 no.2
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• pp.67-73
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• 2005

The thickness of a Si3N4 thin film with a 100m nominal thickness was measured by use of a Mach-Zehnder interferometer. The map of the phase-delay through the thin film was obtained by an interframe intensity-correlation-matrix method that could elliminate phase-shifting errors. After the spatial phase-shifting errors were treated with a least-squares method, the reference to surface of the phase map was estimated. The overall accuracy of the method was found to be 5nm.

• Biomedical Science Letters
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• v.7 no.4
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• pp.167-172
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• 2001

Nebulin is an approximately 700 kDa filamentous protein in vertebrate skeletal muscle. It binds to the Z line and also binds side-by-side to the entire thin actin filament in a sarcomere. The correlation of nebulin size with thin filament length have led to the suggestion that nebulin acts as a molecular ruler for the length of thin filaments. The C-terminal part of human nebulin is anchored in the sarcomeric Z-disk and contains an SH3 domain. SH3 domains have been identified in an ever-increasing number of proteins important for a wide range of cellular processes, from signal transduction to cytoskeleton assembly and membrane localization. However, the exact physiological role of SH3 domains remains, in many cases, unclear. To explore the role of nebulin SH3 in the cytoskeletal rearrangement that accompanies myoblast differentiation, we transfected sense and antisense nebulin SH3 domain fused to enhanced green fluorescent protein in myoblast. Cells expressing nebulin SH3 fragment showed decrease of cell-cell adhesion, and cells transfected with antisense nebulin SH3 gene showed a rounded cell morphology and loss of cell-matrix adhesion. No alteration in cell shape and differentiation were observed in control cells expressing enhanced green fluorescent protein. Perturbation of nebulin altered the cell shape and disrupted cell adhesion in myoblast, demonstrating that nebulin can affect cytoskeleton rearrangement.

• Interaction and multiscale mechanics
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• v.2 no.1
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• pp.69-89
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• 2009

Reinforced and prestressed concrete (RC and PC) thin walls are crucial to the safety and serviceability of structures subjected to shear. The shear strengths of elements in walls depend strongly on the softening of concrete struts in the principal compression direction due to the principal tension in the perpendicular direction. The past three decades have seen a rapid development of knowledge in shear of reinforced concrete structures. Various rational models have been proposed that are based on the smeared-crack concept and can satisfy Navier's three principles of mechanics of materials (i.e., stress equilibrium, strain compatibility and constitutive laws). The Cyclic Softened Membrane Model (CSMM) is one such rational model developed at the University of Houston, which is being efficiently used to predict the behavior of RC/PC structures critical in shear. CSMM for RC has already been implemented into finite element framework of OpenSees (Fenves 2005) to come up with a finite element program called Simulation of Reinforced Concrete Structures (SRCS) (Zhong 2005, Mo et al. 2008). CSMM for PC is being currently implemented into SRCS to make the program applicable to reinforced as well as prestressed concrete. The generalized program is called Simulation of Concrete Structures (SCS). In this paper, the CSMM for RC/PC in material scale is first introduced. Basically, the constitutive relationships of the materials, including uniaxial constitutive relationship of concrete, uniaxial constitutive relationships of reinforcements embedded in concrete and constitutive relationship of concrete in shear, are determined by testing RC/PC full-scale panels in a Universal Panel Tester available at the University of Houston. The formulation in element scale is then derived, including equilibrium and compatibility equations, relationship between biaxial strains and uniaxial strains, material stiffness matrix and RC plane stress element. Finally the formulated results with RC/PC plane stress elements are implemented in structure scale into a finite element program based on the framework of OpenSees to predict the structural behavior of RC/PC thin-walled structures subjected to earthquake-type loading. The accuracy of the multiscale modeling technique is validated by comparing the simulated responses of RC shear walls subjected to reversed cyclic loading and shake table excitations with test data. The response of a post tensioned precast column under reversed cyclic loads has also been simulated to check the accuracy of SCS which is currently under development. This multiscale modeling technique greatly improves the simulation capability of RC thin-walled structures available to researchers and engineers.

• Bulletin of the Korean Chemical Society
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• v.33 no.2
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• pp.426-432
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• 2012

The activity of an antimicrobial peptide, protegrin-1 (PG-1), on lipid membranes was investigated using solidstate NMR and a new sampling method that employed mechanically aligned bilayers between thin glass plates. At 95% hydration and full hydration, the peptide respectively disrupted 25% and 86% of the aligned 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphotidylcholine (POPC) bilayers at a P/L (peptide-to-lipid) ratio of 1/20 under the new experimental conditions. The kinetics of the POPC bilayers disruption appeared to be diffusioncontrolled. The presence of cholesterol at 95% hydration and full hydration reduced the peptide disruption of the aligned POPC bilayers to less than 10% and 35%, respectively. A comparison of the equilibrium states of heterogeneously and homogeneously mixed peptides and lipids demonstrated the importance of peptide binding to the biomembrane for whole membrane disruption.

• Proceedings of the IEEK Conference
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• 2000.06b
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• pp.107-110
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• 2000

In this experiment, we fabricated pyramid-type silicon tunneling devices in which a tunneling current flow between a micro-tip and Si$_3$N$_4$ thin film membrane. A MEMS process was used for the fabrication of the tunneling devices. The micro-tips were formed on Si wafers by undercutting a differently oriented square of SiO$_2$ with KOH. The stiffness of the Si$_3$N$_4$ films were observed and the model for the stiffness calculation, which is useful in predicting the stiffness even when the stiffness ranges beyond the scope of the normal experimental condition, was suggested.

• Advances in pediatric surgery
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• v.15 no.2
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• pp.166-172
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• 2009

Labial adhesion in prepubertal girls is a common gynecologic problems. The labia minora are fused by thin transparent or thick fibrous membrane in the midline from the clitoris to posterior fourchet. The prevalence of labial adhesion may be even greater because many children with labial fusions are asymptomatic and these cases remain unreported. They are often unrecognized by physician and parents because most of symptomatic children complained urinary symptoms. The authors experienced 2 cases of labial adhesion in girls; one asymptomatic partial fusion and the other symptomatic complete fusion. These lesions were treated successfully by mechanical separation of labial adhesion and petroleum ointment (Vaseline) application without recurrence in follow-ups.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.74-74
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• 2003

적외선 감지기는 냉장고, 에어컨, 자동차용 전자부품 등의 온도측정 및 제어, 과잉 전류의 억제를 위한 소자로 널리 사용되며, 또한 최근에는 온도보상형 수정발진기(TCXO) 또는 RF모듈, 액정 판넬의 온도보상회로 등 정보통신기기의 신뢰성 향상을 위해 그 수요가 날로 증가하고 있다. 현재 상용되는 적외선 감지기의 대부분은 벌크형 또는 후막형으로 제조되고 있으나, 최근 반도체공정 기술의 발달로 인하여 보다 향상된 특성이 요구됨에 따라 박막형 등 새로운 형태의 적외선 감지기 대해 활발한 연구가 이루어지고 있다. 본 연구에서는 열 질량과 전도에 의한 열손실을 최소화하여 소자의 감도 및 응답 특성을 향상시키기 위하여 SiO$_2$Si$_3$N$_4$/SiO$_2$ (ONO)다중층 위에 소자 감지부를 형성하고 bulk-micromachining기술을 이용하여 멤브레인 구조를 갖는 박막형 적외선 감지기를 제작하였다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.7
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• pp.542-548
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• 2008

A thermal mass air flow sensor (MAFS), which consists of a micro-heater and thermo-resistive sensors on the silicon-nitride ($Si_3N_4$) thin membrane structure, is micro-fabricated by MEMS processes. Two thermo-resistive temperature sensors are located at $100{\mu}m$ upstream and downstream from the micro-heater respectively. The thermal characteristics are measured to find the best measurement indicator. The micro-heater is operated under constant power condition, and four flow indicators are investigated. The normalized temperature indicator shows good physical meaning and is easy to use in practice. It is found that the configurations and heating power of thermal-resistive elements are the dominant factors to determine the range of the flow measurement in the MAFS with higher sensitivity and accuracy.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2003.05a
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• pp.135-138
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• 2003

Skin, the complex membrane that holds the body together, also embraces the full spectrum of design today-from product to architecture, fashion, and media. Every object has a skin. thick or thin, smooth or rough, porous or impermeable, the skin is the line between a hidden interior and an exterior we experience. Skin： Surface, Substance and Design is a compendium of products, furniture, fashion, architecture and media that expand the limits of what we understand as surface. Reflecting the convergence of natural and artificial life, this provocative a thesis shows how enhanced and simulated skins appear everywhere in today's world.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.3
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• pp.75-75
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• 2001

Si₃N₄/SiO₂/Si₃N₄ 멤브레인에 의해 실리콘 기판으로부터 열차단된 비냉각 초전형 박막 (Ba,Sr)TiO₃ 적외선 검지기를 제작하고, 적외선 검지기의 특성을 논의하였다. 25℃의 공기중에서 쵸핑주파수가 1 ㎐일 때 적외선 검지기는 약 168.8 V/W의 비교적 높은 전압 감응도를 나타내었으나, 매우 작은 신호대잡음비 때문에 약 2.6×10⁴㎝·㎐/sup 1/2//W의 낮은 비검지도를 나타내었다. 또한 출력파형의 쵸핑주파수 및 온도 의존성에 대한 정성적인 해석으로부터 적외선 검지기의 열잡음전압 및 열시정수가 모두 상당히 크다는 것을 알 수 있었다.