• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.310-313
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• 2008

Recently, study on the weak interaction energy between the soft polymer surface and liquid crystals has been a primary topic for new LC device applications. In this paper, to understand the switching property of nematic liquid crystals (LCs) at the interface with a weak anchoring boundary, we investigate experimentally the rotation property of surface nematic director by electric field on non-treated Poly-Methylmethacrylate (PMMA, $T_g=110^{\circ}C$, Sigma Aldrich) film observed under various temperatures including the glass transition temperature ($T_g$) of the polymer layer.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.51.2-51
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• 2001

A vehicle driving simulator is a virtual reality device which makes a human being feel as if the one drives a vehicle actually. The driving simulator is effectively used for studying interaction of a driver-vehicle and developing the vehicle system of new concepts. The driving simulator consists of a motion platform, a motion controller, a visual and audio system, a vehicle dynamic analysis system, a vehicle operation system and etc. The vehicle dynamic analysis system supervises overall operation of the simulator and also simulates dynamic motion of a multi-body vehicle model in real-time. In this paper, the main procedures to develop the driving simulator are classified by 4 parts. First, a vehicle motion platform and a motion controller, which generates realistic motion using a six degree of freedom Stewart platform driven hydraulically. Secondly, a visual system generates high fidelity visual scenes which are displayed on a screen ...

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.7
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• pp.1270-1279
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• 2002

Residual stress is a dominant obstacle to efficient production and safe usage of device by deteriorating the mechanical strength and failure properties. Therefore, we proposed a new thin film stress-analyzing technique using a nanoindentation method. For this aim, the shape change in the indentation load-depth curve during the stress-relief in film was theoretically modeled. The change in indentation depth by load-controlled stress relaxation process was related to the increase or decrease in the applied load using the elastic flat punch theory. Finally, the residual stress in thin film was calculated from the changed applied load based on the equivalent stress interaction model. The evaluated stresses for diamond-like carbon films from this nanoindentation analysis were consistent with the results from the conventional curvature method.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.8
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• pp.710-720
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• 2016

The Floating Wave Energy Convertor (FWEC) mooring design has an important requirement associated with the fact that, for a wave energy converter, the mooring connections may interact with their oscillations, possibly modifying its energy absorption significantly. It is therefore important to investigate what might be the most suitable mooring design according to the converter specifications and take into account the demands placed on the moorings in order to assure their survivability. The objective of this study is to identify a computational fluid dynamics method for investigating the effects of coupling a wave energy device with a mooring system. Using the commercial software ANSYS AQWA and ANSYS FLUENT, a configuration was studied for different displacements from the equilibrium position, load demands on the moorings, and internal fluid motion. These results and findings form a basis for future efforts in computational model development, design refinement, and investigation of station keeping for FWEC units.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.10
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• pp.760-766
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• 2003

This paper is concerned with the eddy current damper which can be used to enhance the damping of the host structure. The operating principle of the eddy current damper is first explained in detail. The dynamic interaction between the magnets and the copper plate produces eddy current thus resulting in the damping force. By attaching the eddy current damper to the host structure, the damping of the total structure can be increased so that vibrations can be suppressed. The advantage of the eddy current damper is that it doesn't require any electronic devices and power supply The effect of the eddy current damper on the global dynamic characteristics of the structure is investigated by considering the cantilever with the eddy current damper. Experimental results show that the eddy current damper is an effective device for vibration suppression.

• Smart Structures and Systems
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• v.4 no.4
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• pp.439-448
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• 2008

Optical fiber sensors are by now broadly accepted as an innovative and reliable device for structural health monitoring, to be used either embedded into or bonded on structures. The accuracy of the strain measurement achievable by optical fiber sensors is critically dependent on the characteristics of the bonding of the various interface layers involved in the sensor bonding/embedding (structure material and gluing agent, fiber coating and gluing agent, fiber coating and fiber core). In fact, the signal of the bonded/embedded optical fiber sensor must correspond to the strain experienced by the monitored structure, but the quality of each involved interface can affect the strain transfer. This paper faces the characterization, carried on by both mechanical tests and morphological analysis, of the strain transfer function resulting with epoxidic and vinylester gluing agent on polyimide and acrylate coated optical fibers.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.891-894
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• 1999

ICP reactor produces high-density and high-uniformity plasma in large area, are has excellent characteristic of direction in the case of etching. Until now, many algorithms used one mesh method. These algorithms are not appropriate for sub 0.1 ${\mu}{\textrm}{m}$ device technologies which should deal with each ion. These algorithms could not present exactly straggle and interaction between projectile ions and could not consider reflection effects due to interactions among next projectile ions, reflected ions and sputtering ions, simultaneously. And difficult consider am-bipolar drift effect.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.597-602
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• 2006

Many researches have been studied several vibration control device such as TMD and TLD to reduce the influence of wind or seismic waves for high-rise buildings. TLD provides some advantages such as easy installation and low maintenance cost. However, because of the difficulties in evaluating the characteristics of TLD, the dynamic characteristics of TLD must be investigated by experiment or analysis. In this study, the dynamic response analysis of structure with TLD was carried out to verify the vibration control ability of the proposed TLD for high-rise building with about 60 stories. A real seismic wave was used, and the parameter of interest was chosen by the height of water level in the same shape of water tank. From the numerical results, the responses of structure with water tank were confirmed to be safer than those of structure without water tank.

• The Journal of Korean Association of Computer Education
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• v.11 no.6
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• pp.95-102
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• 2008

In this paper through the implementation of cooperative learning using SDG, education puzzle actually applies to computer training. SDG(Single Display Groupware) which one computer display have a multi-input devices can work as a collaborative system. Learners are performing together through SDG-based cooperative learning system. SDG cooperative learning with a multi-input device is superior to traditional learning with individual. We have implementation of the puzzle game with this fact. This system through effective education and raising their children's education participation rate will be able to do.

• Transactions on Electrical and Electronic Materials
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• v.18 no.6
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• pp.320-322
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• 2017

In this paper, a high-performance, low-area gradient-magnitude calculator architecture is proposed, based on approximate image processing. To reduce the computational complexity of the gradient-magnitude calculation, vector properties, the symmetry axis, and common terms were applied in a hardware-resource-shared architec-ture. The proposed gradient-magnitude calculator was implemented using an Altera Cyclone IV FPGA (EP4CE115F29) and the Quartus II v.16 device software. It satisfied the output-data quality while reducing the logic elements by 23% and the embedded multipliers by 76%, compared with previous work.