• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1987.04a
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• pp.180-183
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• 1987

In this paper mimimm desperaioms of atep index single mode sptical fibers manufzctrured by the phase madulatiem method.From them we find that the caloulated data agree closely with the resulte measured at the wavelength around 1.3 um and that a method to shift sere dispersion wavelength at the wavelenghth around 1.55 um is to control refractive index profile and relative refractive difference

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.684-687
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• 1999

In this paper, a method for controlling a single phase PWM AC/DC converter without any voltage sensors is proposed. In this method, the source voltage is estimated by sliding mode observer and input current is synchronized with the estimated source voltage. The source voltage is estimated by current error between the actul and the estimated current. The experimental results confirm the validity of the proposed control method.

• Proceedings of the KIEE Conference
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• 1993.11a
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• pp.353-355
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• 1993

A single-mode fiber-optic interferometer for measuring small vibrations was constructed. The interferometer is based on the Fabry-Perot configuration that uses a single mode bidirectional fiber coupler as a beam splitter and employs peak detection scheme in the signal processing. The instrument was used to measure the displacement of the translator clamped to a piezo crystal.

• Proceedings of the IEEK Conference
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• 2000.11c
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• pp.5-8
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• 2000

Voltage mode chaotic neuron has been designed in integrated circuit and fabricated by using 0.8$\mu\textrm{m}$ single poly CMOS technology. The fabricated CMOS chaotic neuron consist of chaotic signal generator and sigmoid output function. This paper presents an analysis of the chaotic behavior in the voltage mode CMOS chaotic neuron. From empirical equations of the chaotic neuron, the dynamical responses such as time series, bifurcation, and average firing rate are calculated. And, results of experiments in the single chaotic neuron and chaotic neural networks by two neurons are shown and compared with the simulated results.

• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.324-327
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• 1990

In this paper describes the feasibility study on a single-phase / three-phase voltage-fed inverter using 1GBTs, incorporating voltage-mode quasi-resonant DC Link and the instantaneous Sinusoidal Current tracking adaptive control implementation under zero voltage switching resfriction. The simulation and experimental results are shown here and discussed for single-phase voltage-fed and three-phase voltage-fed inverter in order to verify the new operating principle of the Inverter topology proposed here.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.321-321
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• 2000

This paper presents a sliding mode controller based on variable structure for the tip position control of a single-link flexible manipulator. Dynamic equations of a single-link flexible manipulator are derived from the Euler-Lagrange equation using a Lagrangian assumed modes method based on Bernoulli-Euler Beam theory. Simulation results are presented to show the validity of the system modeling, controller design.

• Journal of the Optical Society of Korea
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• v.12 no.3
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• pp.152-156
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• 2008

This paper reports a fiber-optic temperature sensor using a single mode fused fiber coupler incorporating a thermo-optic external medium. The spectral transmission was altered by changing the refractive index of the external thermo-optic medium. A theoretical and experimental investigation was carried out with the aim of achieving high sensitivity. The measured sensitivity for the environmental temperature was as high as -1.5 $nm/^{\circ}C$.

• Proceedings of the Optical Society of Korea Conference
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• 2008.02a
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• pp.335-336
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• 2008

We observe the distortion of the back scattered Stokes pulse and the complementary distortion of the transmitted pulse by the stimulated Brillouin scattering when a Q-switched Nd:YAG laser pulse injected into a single mode optical fiber. We determine the constant required energy for the SBS by comparing their temporal shapes.

• Proceedings of the KWS Conference
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• 2005.06a
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• pp.94-96
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• 2005

Welding process of ultra thin stainless steel foil was investigated using a single mode Yb-fiber laser with a CW maximum output power 40W. In micro welding, critical power density for keyhole welding was 1 to 2 orders larger higher than in macro-welding due to larger thermal conduction, extremely high speed welding becomes possible.

• Journal of the Korean Institute of Telematics and Electronics
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• v.16 no.2
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• pp.15-18
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• 1979

Deposited film of a transition metal, Ti was diffused into LiNbO3 crystals to form integrated optical waveguides. By suppressing L O out -diffusion, single-mode waveguides could be constructed. Measurements on characteristics were performed by using the prise coupling technique and a He-Ne laser. ( λ = 0.6328 $\mu$m)