• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.2
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• pp.115-121
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• 2012

Exploration in microelectromechanical systems(MEMS) and nanotechnology requires evaluation techniques suitable for sub-micron length scale so that thermal and mechanical properties of novel materials can be investigated for optimal design of miro/nanostructures. The ultrafast optical pump-probe technique provides a contact-free and non-destructive way to characterize nanoscale thin-films, and its ultrahigh temporal resolution enables the study of heat-transport phenomena down to a sub-picosecond regime. This paper reviews the principle of optical pump-probe technique and introduces its application to the area of micro/nano-NDE.

• Journal of the Korea Institute of Military Science and Technology
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• v.7 no.4 s.19
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• pp.114-124
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• 2004

In this paper, we have proposed a novel method which can analysis a rotating elastically restrained blade with concentrated masses located in an arbitrary position. 1:he equations of motion are derived and transformed into a dimensionless form to investigate general phenomena. For the modeling of the multi-concentrated masses, the Dirac delta function is used for the mass density function. Simulation results show that the vibration characteristics of elastic restrained blade of according to dimensionless variables for example, multiple masses magnitude and mass location ratio. This method can be applied to an practical rotating blade system required to more accurate results.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.11a
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• pp.81-84
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• 1995

A reliable bonding between two silicon wafers, regularly grooved and non-grooved, was done by the direct boning technology, It is Presented that high structural duality was realized not only at the bended interface but in the bulk, commensurate with the filling of artificial grooves, which would be attributed to the dislocation-gettering capability of groove free-surfaces during annealing. The groove filling would be explained with mass-transport phenomena assisted by the dislocation movement from initial contact boundaries toward groove surfaces. Intrinsic voids can be easily removed by aid of the grooves. The proposed method yielded also an intimate bonding not only between {111} wafers strongly misoriented and slightly inclined to {111} basal plane but even between {111} and {100} orientation wafers.

• International Journal of Control, Automation, and Systems
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• v.4 no.4
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• pp.428-437
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• 2006

Many physical systems are hybrid in the sense that they have continuous behaviors and discrete phenomena. In control system with multiple models, switching strategy and stability of the closed-loop system under switching are very important issues. In this paper, a novel adaptive control scheme based on multiple parameter models is proposed to cope with a change in Parameters. Switching strategy guarantees the non-increase in the global control Lyapunov function if the estimation of Lyapunov function value converges. Least-square estimation is used to find the estimated value of the Lyapunov function. Switching and adaptation law guarantees the stability of closed-loop system in the sense of Lyapunov. Simulation results on anti-lock brake system are shown to verify the effectiveness of the proposed controller in view of a large change in system parameters.

• Proceedings of the KIEE Conference
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• 1993.11a
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• pp.240-242
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• 1993

A novel structure, which can suppress latch-up phenomena, is proposed and verified by the PISCESIIB simulation. It is shown that this structure employing the selective N+ buffer layer increases latch-up current density due to suppression of the current flowing through the p-body. The width of the N+ buffer layer is optimized considering the trade-off between the latch-up current density and the forward voltage drop. The selective buffer layer results in an improved trade-off relationship compared with the uniform buffer layer.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1178-1181
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• 2003

Nanotechnology is the creation and utilization of materials, devices, and systems through the control of matter on the nanometer-length scale, that is, at the level of atoms, molecules, and supramolecular structures. The essence of nanotechnology is the ability to work at these levels to generate larger structures with fundamentally new molecular organization. These nanostructures, made with building blocks understood from first principles, are the smallest human-made objects, and they exhibit novel physical, chemical, and biological properties and phenomena. The aim of nanotechnology is to learn to exploit these properties and efficiently manufacture and employ the structures. Control of matter on the nanoscale already plays an important role in scientific disciplines as diverse as physics, chemistry, materials science, biology, medicine, engineering, and computer simulation. This paper describes the superprecision nano separator to productive particle size of nano powder. this separator system is very important in the industrial area for other high technology parts.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.04a
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• pp.27-32
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• 2003

Nanotechnology is the creation and utilization of materials, devices, and systems through the control of matter on the nanometer-length scale, that is, at the level of atoms, molecules, and supramolecular structures. The essence of nanotechnology is the ability to work at these levels to generate larger structures with fundamentally new molecular organization. These nanostructures, made with building blocks understood from first principles, are the smallest human-made objects, and they exhibit novel physical, chemical, and biological properties and phenomena. The aim of nanotechnology is to loam to exploit these properties and efficiently manufacture and employ the structures. Control of matter on the nanoscale already plays an important role in scientific disciplines as diverse as physics, chemistry, materials science, biology, medicine, engineering, and computer simulation. This paper describes the superprecision nano separator to productive particle size of nano powder. this separator system is very important in the industrial area for other high technology parts.

• Journal of the Korea Furniture Society
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• v.25 no.2
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• pp.87-95
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• 2014

Since 1990s the concern on essence and inside has transferred onto the surface and its style. The longing for plastic surgery and skin beauty might prove this fervent tendency. Furthermore the development of digital media and technology as well as high-tech material enabled this hope to be real in the realm of design. All these progresses and transitions toward the surface introduced more creative and novel phenomena of furniture design arena around its surface. The rising of surface has evolved through architecture, interior design and furniture. The surface of furniture can be easily transposed into the human skin. And it acquires the aspects of skin's metaphoric and symbolic meaning. The characteristics of skin effect in furniture design can be summarized as material aspects, relational aspects, and formal aspects. Material aspects shows skin's elasticity and smooth plane. Relational aspects express the reactive functions of skin. Formal aspects represent organic power through surface.

• 한국초전도학회:학술대회논문집
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• v.10
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• pp.9-14
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• 2000

We report on the novel nonequilibrium nlicrowave emission from quasiparticle-injected high-Tc superconductors. The phenomena have been observed for the current-injected YBCO/I/Au or BSCCO/I/Au thin-film tunnel junctions and BSCCO single-crystal intrinsic Josephson mesa junction samples. For the thin-film tunnel junctions, the emitted radiation appears as broadband. For the intrinsic BSCCO mesa samples, the radiation appears as three different modes of emissions depending on the bias point in the hysteretic current-voltage characteristics; Josephson-emission, nonequilibrium broad emission and sharp coherent microwave emission. The results were interpreted by the Josephson plasma excitation model due to quasiparticle injection.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.197-199
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• 2006

The Proton Exchange Membrane Fuel Cells (PEMFCs) are being used in a variety of applications including portable power generation, transportation and back-up power systems. In this paper presents a novel circuit model for a PEMFC that can be used to design and analyze fuel-cell power system. The Pspice-based model uses BJTs, L and C elements available in the Pspice library with some modification. The model includes the phenomena like activation polarization, ohmic polarization and mass transport effect present in a PEM fuel cell. Simulated characteristics of the fuel cell were compared with the experimental results obtained on a commercial fuel cell.