• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.11
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• pp.42-46
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• 2006

As an application of SDINS/GPS integration for its synergistic results, the SDINS alignments utilizing GPS carrier phase rate measurements. A measurement model of GPS carrier phase rate is derived in order to be used with SDINS alignment process. For in-flight alignment, the performance of the suggested SDINS/GPS integration method is analyzed using the covariance analysis and its results are confirmed by those of van test. Consequently, it is shown that all states of the SDINS integrated system by utilizing GPS carrier phase rate measurements can be estimated more efficiently than a general SDINS/GPS during in-flight alignment.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2002.11a
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• pp.133-138
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• 2002

As Information society has expanded in large scale. In order to improve the reliability and Qos(Qualify of service), domestic IDC(Internet Data Center) has adopted or will adopt the SLAs(Service Level Agreements). The power quality of internet hosting server unit, power system and UPS is very important for better internet service. Therefore, the higher reliability of power system is imperative for satisfying SLAs. This paper presents the status measurement of domestic IDCs harmonics and illustrates the reduction effect of harmonics through the multi-phase.

• Journal of the Korea Computer Industry Society
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• v.2 no.12
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• pp.1609-1616
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• 2001

We present an autostereoscopic 3D display system using volume hologram. In this proposed system, the interference pattern of angular multiplexed plane reference and object beams are recorded into a volume hologram, which plays a role of guiding object beams of multi-view images into the desired perspective directions. For reconstruction, object beams containing the desired multi-view image information, which satisfy Bragg matching condition, are illuminated in the time-division multiplexed manner onto the crystal. Then multiple stereoscopic images are projected to the display plane for autostereoscopic 3D viewing. It is possible to make a high resolution multiview 3D display system independent upon the viewpoint.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.1
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• pp.60-66
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• 2004

In order to analyze voltage, current electrical power, harmonic and so on of electrical load equipments, electrical power analysis by real measurement rather than mathematical modeling is necessary, and plan of countermeasure for efficient management, energy frugality and accident prevention of electrical equipments using it is possible Especially, electrical power analysis by real measurement is indispensable in order to consider countermove of harmonic occurred by nonlinear load So, in this paper, we developed DSP(Digital Signal Processor) based low price date aquisition system, and verified it's ability by performing measurement and analysis of electrical power and harmonic in the real power system.

• Journal of Advanced Navigation Technology
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• v.15 no.1
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• pp.61-68
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• 2011

DVB-T2 system developed by DVB project is the next generation digital terrestrial television broadcasting standard designed for offering HDTV service in a post-Analog Switch Off (AOS) environment. In this paper, the performance of DVB-T2 is evaluated with the help of computer simulation. The bits error rate(BER) performance is studied in both AWGN, Rayleigh, Ricean and 0db-echo channel. Firstly, we will give a brief introduction to DVB-T2 system and then compare its BER performance to that of Implementation Guideline.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.6
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• pp.544-552
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• 2004

This paper deals with the hybrid active filter which can reduce the 11th/13th harmonics in AC network by using the single tuned filter. Since the proposed algorithm uses the detuning compensation capability of the filter, the output voltage of the proposed active power filter is changed according to the capacitance of capacitors, magnitude of harmonic current, resonance frequency and control mode. In this paper, the control characteristics and the design of hybrid active filter is investigated. A new hybrid active filter with new algorithm, which is an active filter with single tuned filter instead of double tuned filter, is proposed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39A no.9
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• pp.497-507
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• 2014

This paper investigates the standard features of Carrier aggregation (CA), the related UE RF requirements in 3GPP release 12 and estimated CA evolution in future. The main CA feature of 3GPP release 12 in WG4 perspectives includes 2Uplink(UL) CA, 3Downlink(DL) CA and TDD-FDD CA. To support these features in UE, UE-to-UE coexistence problem and RF requirements generated by unwanted emissions such as inter-modulation and harmonics are analyzed. Also, future CA technology such as LTE in unlicensed bands is described.

• 한국지구물리탐사학회:학술대회논문집
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• 2005.05a
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• pp.165-180
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• 2005

Impact seismic wave test is a method for nondestructive testing of concrete structure using of stress wave which is propagated and reflected from internal flaws within concrete structure and external surface, In this study, we performed non-destructive testing using impact seismic wave test for safety diagnosis of civil engineering structures. For this, I've compared and analized the result in the way of reflective method mostly using on one-dimension such as tunnel lining, and penetration method using the way of cross hole and tomography.

• Korean Journal of Optics and Photonics
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• v.10 no.5
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• pp.419-423
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• 1999

Optical filters utilizing the evanescent filed coupling between the side polished fiber and polymer planar waveguide were fabricated and optical properties of the devices were measured. A scheme for reducing polarization dependent properties of the device was proposed and demonstrated experimentally. Our measurement results showed that resonance wavelengths and filtering depth of the optical filters can be determined by adjusting thickness of planar waveguide and polishing depth of the fiber. The device fabrication procedure including fiber polishing steps and formation of polymer planar waveguide were described. The optical characteristics of fabricated optical filers were that 3 dB bandwidth was 15 nm, the resonance wavelength difference between the TE and TM polarized response was less then 2 nm, and insertion loss was less then 0.2 dB. The measured resonance wavelength drift dut to the variation of ambient temperature was -0.35 nm/$^{\circ}C$.

• Journal of the Korean Geophysical Society
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• v.5 no.3
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• pp.211-218
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• 2002

The reversed two station method (RSTM) devised by Chun et al. (1987) is widely used to obtain $Q_{Lg}^{-1}$ for Lg wave data with hypocentral distance greater than 90 km. By applying RSTM to the Lg data of central South Korea with hypocentral distance between 95 and 381 km, we obtained high $Q_{Lg}^{-1}$. The value of $Q_{Lg}^{-1}$ is very similar with that of southeastern S. Korea, which is derived from the same method for similar distances. The studied hypocentral range seems to distort $Q_{Lg}^{-1}$ to high value because decay rate in this range is higher than 0.5, which is typical decay rate of surface wave.