• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.86-89
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• 2002

A new design approach for realising low-power low-voltage high-Q high-order RE bandpass filter is proposed. Based on the gyrator-C inductor topology, a 2$\^$nd/-order biquadratic bandpass filter can be realised by adding a series capacitor to the input port of the gyrator. High-Q 2$\^$nd/-order and 4$\^$th/-order fully differential RF bandpass filters operating in the 2.4-㎓ ISM (Industrial, scientific and medical) frequency band under a 2-V single power supply voltage with low power dissipation are reported.

• Journal of the Optical Society of Korea
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• v.13 no.1
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• pp.15-21
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• 2009

High-order harmonic generation from a solid surface affected by the contrast of a laser pulse was studied using an oscillating mirror model. High-order harmonics generated from solid surfaces have unusual properties such as spectral redshift, and an intensity difference between even- and odd-order harmonics which is not reported for high-order harmonics generated by a gas medium. We confirmed that high-order harmonics from solid surfaces have selectivity of polarization as well as cut-off extension and the enhancement of conversion efficiency proportional to laser intensity. And the principle of operation and the characteristics of a plasma mirror system developed for achieving high contrast laser pulses to pursue the experimental realization of high-harmonic generation from solid surfaces are reported. Energy fluence on the plasma mirrors is tunable between $10\;J/cm^2$ and $1000\;J/cm^2$ and around 1000 shots are available before the plasma mirrors require replacement.

• Journal of the Korean earth science society
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• v.36 no.5
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• pp.476-483
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• 2015

The high-order Laplacian-type filter, which is capable of providing isotropic and sharp cut-off filtering on the spherical domain, is essential in processing geophysical data. In this study, a spherical high-order filter was designed by combining the Fourier method with finite difference-method in the longitude and latitude, respectively. The regular grid system was employed in the filter, which has uniform angular spacing including the poles. The singularity at poles was eliminated by incorporating variable transforms and continuity-matching boundary conditions across poles. The high-order filter was assessed using the Rossby-Haurwitz wave, the observed geopotential, and observed wind field. The performance of the filter was found comparable to the filter based on the Galerkin procedure. The filter, employing the finite difference method, can be designed to give any target order of accuracy, which is an important advantage being unavailable in other methods. The computational complexity is represented with 2n-1 diagonal matrices solver with n being the target order of accuracy. Along with the availability of arbitrary target-order, it is also advantageous that the filter can adopt the reduced grid to increase computational efficiency.

• Journal of Korean Clinical Health Science
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• v.3 no.2
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• pp.372-377
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• 2015

Purpose: The aim of this study is to compare total high order aberrations between surgery which uses TransPRK and general laser assisted sub-epithelial keratomileusis. Methods: The patients who had general laser assisted sub-epithelial and TransPRK laser assisted sub-epithelial by visiting ophthalmic clinic in Ulsan from January 2014 to August 2014 was researched. Results: When comparing total high order aberrations before and after operation, it was found that total high order aberration in general laser assisted sub-epithelial group increased to $0.222{\pm}0.078{\mu}m$ from $0.074{\pm}0.019{\mu}m$ while that in TransPRK assisted sub-epithelial group increased to $0.179{\pm}0.045{\mu}m$ from $0.076{\pm}0.032{\mu}m$. When comparing the increment in total high order aberrations between two groups after surgery, it was found that the increments of TransPRK assisted sub-epithelial group were statistically smaller than that of general laser assisted sub-epithelial group (p<0.05). Conclusions: This study made a comparative analysis of total high order aberrations between general laser assisted sub-epithelial and TransPRK assisted sub-epithelial which was introduced recently and the result showed a significant difference. The findings of this study suggest that TransPRK assisted sub-epithelial can be used widely in simply improving eye sight and quality of vision by reducing an increase in high order aberration caused by orthokeratology surgery. It is expected that TransPRK assisted sub-epithelial will be helpful for improving the understanding quality of eye sight which occurs by several methods of vision correction surgery.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.11
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• pp.650-653
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• 2005

In this paper, adaptive high-order neural network controller(AHONNC) is adopted to control an induction servomotor. A algorithm is developed by combining compensation control and high-order neural networks. Moreover, an adaptive bound estimation algorithm was proposed to estimate the bound of approximation error. The weight of the high-order neural network can be online tuned in the sense of the Lyapunov stability theorem; thus, the stability of the closed-loop system can be guaranteed. Simulation results for induction servomotor drive system are shown to confirm the validity of the proposed controller.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.4
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• pp.455-461
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• 2007

In this paper a state steering strategy for high order chained system is presented. High order chained system can be derived from the acceleration constraints that cannot be integrable. The system classified as a nonholonomic system cannot be controlled to its equilibrium points by continuous and time-invariant controller. Using variable transformation two sub system can be obtained from the high order chained system. Deadbeat control and iterative state steering methods are proposed to control the system. Simulation results are given to show the effectiveness of the proposed control scheme.

• Structural Engineering and Mechanics
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• v.56 no.3
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• pp.423-442
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• 2015

This study examines the wavelet transform for output-only system identification of ambient excited engineering structures with emphasis on its utilization for modal parameter estimation of high-order and closely-spaced modes. Sophisticated time-frequency resolution analysis has been carried out by employing the modified complex Morlet wavelet function for better adaption and flexibility of the time-frequency resolution to extract two closely-spaced frequencies. Furthermore, bandwidth refinement techniques such as a bandwidth resolution adaptation, a broadband filtering technique and a narrowband filtering one have been proposed in the study for the special treatments of high-order and closely-spaced modal parameter estimation. Ambient responses of a 5-story steel frame building have been used in the numerical example, using the proposed bandwidth refinement techniques, for estimating the modal parameters of the high-order and closely-spaced modes. The first five natural frequencies and damping ratios of the structure have been estimated; furthermore, the comparison among the various proposed bandwidth refinement techniques has also been examined.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.903-905
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• 2003

In this paper, adaptive high-order neural network controller(AHONNC) is adopted to control of an induction servomotor. A algorithm is developed by combining compensation control and high-order neural networks. Moreover, an adaptive bound estimation algorithm was proposed to estimate the bound of approximation error. The weight of the high-order neural network can be online tuned in the sense of the Lyapunov stability theorem; thus, the stability of the closed-loop system can be guaranteed. Simulation results for induction servomotor drive system are shown to confirm the validity of the proposed controller.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.880_881
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• 2009

This paper improves the calculating method about the inductance with the high order frequency coreloss. It is different in which the analyzed inductance for calculating IPMSM and the measured thing for experiment. Due to this phenomenon, the expected input voltage differs from the inquired input voltage for operating the motor. This results from the coreloss margin which have both the 1st order and high order frequency value. For reducing the inductance error, after calculating the equivalence coreloss resistance with having the 1st order frequency Back_EMF and coreloss, designing the inductance with the high order frequency which occurred by the coreloss of high order frequency, and comparing the renovated inductance analysis value with the measured thing.

• Journal of IKEEE
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• v.19 no.4
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• pp.520-525
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• 2015

This paper investigates the consensus problem for high-order integrators with an arbitrary large communication delay. In order to solve this problem, new consensus controller with an additional design parameter that can eliminate the effect of a communication delay on the consensus problem is proposed. Also, it is proved that the proposed consensus controller can always solve the consensus problem of high-order integrators even in the presence of an arbitrarily large communication delay. Finally, an illustrative example is given in order to show the effectiveness of our design method.