• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.161-161
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• 2006

New polymeric and oligomeric OTFT materials containing fused aromatics such as anthracene and naphthalene have been designed, synthesized and characterized. The new OTFT materials were prepared by palladium-catalyzed Suzuki cross-coupling reaction. The obtained materials were characterized by various spectroscopic methods such as UV-vis, PL, cyclovoltametry, and XRD. The obtained OTFT materials containing fused aromatics showed high thermal stability above $350^{\circ}C$ In OTFT devices using new materials, high charge carrier mobility and on/off ratio were observed.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.34-39
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• 1993

Presented in this paper is a complete error covariance analysis for strapdown inertial navigation system(SDINS). We have found that in SDINS the cross-coupling terms in gyrocompass alignment errors can significantly influence the SDINS error propagation. Initial heading error has a close correlation with the east component of gyro bias erro, while initial level tilt errors are closely related to accelerometer bias errors. In addition, pseudo-state variables are introduced in covariance analysis for SDINS utilizing the characteristics of gyrocompass alignment errors. This approach simplifies the covariance analysis because it makes the initial error covariance matrix to a diagonal form. Thus a real implementation becomes easier. The approach is conformed by comparing the results for a simplified case with the covariance analysis obtained from the conventional SDINS error model.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1617-1620
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• 2005

The current control for interior permanent magnet machines is more complicate than surface permanent magnet machine because of its torque characteristic depending on the reluctance. For high performance torque control, it requires state decoupling between the d-current and q-current dynamics. However the variation of the inductances, which couples the state dynamics of the currents, makes the state decoupling difficult. So some decoupling methods have developed to cope this variations and each current can be regulated independently. This paper presents a novel approach for fully decoupling the states cross-coupling using parameter adaptation. The adaptation method is based on the error between reference currents and the currents with state decoupling which have to follow the references. This method is more object-oriented than the other online parameter estimation methods in IPM machine and other electrical machines

• 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.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.4
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• pp.636-644
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• 1999

Experimental and simulation results are presented on the Aperture-Coupled microstrip patch antennal with U-shaped slot. Experiment and simulation results include impedance bandwidth, copolar and crosspolar-pattern characteristics and gain measurements. Simulation results show the advantages of U-slotted patch antenna comparing with the normal patch antenna. More than 35% impedance bandwidth is obtained with reasonably restricted cross-polar radiation pattern. The U-slotted radiation element fed by aperture-coupling method can be more easily extended to array structure, compared with that fed by coaxial cable.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.1139-1140
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• 2008

This paper is designated to introduce the method of reducing stand-by Power of SMPS applied PLC(Power Line Communication) and its implementation. PLC modem consists mainly of PLC Module, Coupling Circuit, ZCP(Zero-Cross Point) Circuit and Power Supply Circuit. By controlling power from Power Supply Circuit to PLC Module and ZCP Circuit, the reduction of Stand-by Power is established. When this method is applied to SMPS used for a low-speed PLC, about 50% power reduction is provided, compared to the other case to which it is not applied.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.499-502
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• 1989

This paper is concerned with the stability analysis and the design of an auto pilot using direct model reference adaptive control for BTT missile with unknown dynamics when subjected to the longitudinal and lateral gusts. A motion of BTT missile can be separated into the longtudinal and lateral motione. The proposed algorithm is introduced different leakage terms about each motion into adaptation so as to prevent drift of the adaptive gain and alleviate gust effects and cross-coupling. The algorithm is applied to the 6DOF motion of an EMRAAT missile.

• 한국전산유체공학회:학술대회논문집
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• 2008.03a
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• pp.19-26
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• 2008

From numerical point of view on flow network system analyses, stagnation properties are not preserved along streamlines across geometric discontinuities. Hence, GJM and DTM using ghost cell and thermodynamic relations are developed to preserve the stagnation enthalpy for the boundaries, such as the interfaces between junction and branches and the interface between two pipes of different cross-sections in serial pipelines. Additionally, the resolving power and efficiencies of the 2nd order Godunov type FV schemes are investigated and estimated by the tracing of the total mechanical energy during calculating rapid transients. Among the approximate Riemann solvers, RoeM is more suitable with the proposed boundary treatments especially for junction than Roe's FDS because of its conservativeness of stagnation enthalpy across geometric discontinuities.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.2
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• pp.342-350
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• 1993

Experiments are performed to determine the dependence of torsional rigidity upon the cross-sectional area for specimens of dense polyurethane foam. Testing equipment was designed and fabricated in the laboratory to satisfy the experimental characteristics. Results show the increase of torsional rigidity compared to the expected value based on the conventional elasticity. And this can be explained that the consideration of the internal motions of constitutive particles predicts the elastic behavior of the material better.

• 한국전산유체공학회:학술대회논문집
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• 2008.10a
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• pp.19-26
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• 2008

From numerical point of view on flow network system analyses, stagnation properties are not preserved along streamlines across geometric discontinuities. Hence, GJM and DTM using ghost cell and thermodynamic relations are developed to preserve the stagnation enthalpy for the boundaries, such as the interfaces between junction and branches and the interface between two pipes of different cross-sections in serial pipelines. Additionally, the resolving power and efficiencies of the 2nd order Godunov type FV schemes are investigated and estimated by the tracing of the total mechanical energy during calculating rapid transients. Among the approximate Riemann solvers, RoeM is more suitable with the proposed boundary treatments especially for junction than Roe's FDS because of its conservativeness of stagnation enthalpy across geometric discontinuities.