• 한국지구물리탐사학회:학술대회논문집
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• 2007.06a
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• pp.163-166
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• 2007

KMA established short period seismometer, accelerometer, and ocean bottom seismometer network to build the detail earthquake monitoring system and Tsunami monitoring system. KMA also replaced borehole seismometer and wave height meter monitoring system. The purposes of this study are to record the ambient seismic noise levels of short period seismometer and accelerometer installed in 2006 and 2007, and compare their characteristics to present the standard of site selection criteria.

• Korean Journal of Optics and Photonics
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• v.4 no.4
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• pp.452-456
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• 1993

The quantum efficiencies of photomultiplier tubes were measured by counting the coincidence photon pairs generated in the process of spontaneous parametric down-conversion. They were measured within 3% accuracy over the range of wavelength from 560 to 850 nm without any standard light source or detector. The values for 633 nm correspond to those obtained with a calibrated laser power meter within the measurement error.

• Proceedings of the IEEK Conference
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• 2003.11c
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• pp.216-219
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• 2003

In this paper, we present performance analysis of an IEEE P802.15.3a high rate wireless personal area network transceiver. This physical layer standard uses QOSK as its sub-channel modulation scheme and orthogonal frequency domain modulation (OFDM) for sub-bands. OFDM is used for each sub-band so that multi-path effects are absorbed by equalizer and guard, and fading can be approximately modeled as additive white Gaussian noise. In multi-band ultra-wideband system, DAC quantization error is important noise source since high resolution conversion cannot be used due to high power consumption. Simulation result shows that, to get 640-Mbps throughput, at least 5-bits precision is necessary to maintain bit-error rate under 10$\^$-2/, which can be lowered, with channel coding, to 10$\^$-6/ that is the bit-error rate required by IEEE 802.15 upper protocol layer, in 4-meter LOS fading channel.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.700-709
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• 2009

FBG sensor system is applied to the concrete lining structure in Taegu subway. Near the structure, the power cable tunnel construction started. We wanted to measure the deformation of the structure due to the construction by the FBG sensor. The applied sensor has the gauge length of 1 meter to overcome the inhomogeneity of the concrete material with enough length. In order to fix tightly to the structure, the partially stripped parts of the sensor glued to the package and slip phenomenon between fiber and acrylate jacket was prevented. Prestrain of the sensor was imposed by controlling the two fixed points with bolts and nuts in order to measure compressive strain as well as tensile strain. The behavior of subway lining structure could be monitored very well.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.678-680
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• 2000

We designed and manufactured DSPSRM using the usual output power equation of rotating machine. And the sinusoidaly approximated torque characteristics are achieved by 3D finite element analysis. Also, We calculated average torque per rotation using approximated torque data, calculated by 3D finite element analysis. On this paper, We manufacture torque-meter set and measure the torque characteristic of DSPSRM.

• Journal of Electrical Engineering and Technology
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• v.7 no.3
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• pp.281-287
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• 2012

The customer load profile clustering method is used to make the TDLP (Typical Daily Load Profile) to estimate the quarter hourly load profile of non-AMR (Automatic Meter Reading) customers. This study examines how the repeated clustering method improves the ability to discriminate among the TDLPs of each cluster. The k-means algorithm is a well-known clustering technology in data mining. Repeated clustering groups the cluster into sub-clusters with the k-means algorithm and chooses the sub-cluster that has the maximum average error and repeats clustering until the final cluster count is satisfied.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.479-482
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• 2005

본 연구는 알루미늄 단조 라인의 가열로 컨베이어에 적용된 6관절 이송용 로봇에 Machine Vision System을 구축 한 것으로 이송용 로봇이 작업 대상물을 적재하기 위한 위치정보를 획득하고 재처리하여 로봇 컨트롤러에 제공하는 비주얼가이던스 기법을 연구하여 이를 적용하였다. 적용된 Machine Vision System이 실제 구동에 있어서 안정함을 확인하였다. Machine Vision System에 적용된 CCD 센서로는 Sony사의 XC-HR50이 적용되었으며 Frame Grabber는 Matrox Meter II 카드가 적용되었다. Machine Vision System 제어기로는 범용PC(2.4Ghz, Windows 2000)를 사용하였으며 제어Software는 Microsoft 사의 Visual Basic 6.0 version을 사용하였다.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.1091-1093
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• 1998

The BESS has a major advantages such as load leveling, quick response emergency power (spinning reserve), frequency and voltage control, improvement of reliability, and deferred generation and transmission capacity construction. However, the economic feasibility of these systems requires justification from the customer side of meter. In this paper, we proposed the economic evaluation model of BESS which is modified and complemented the SYSPLAN model[2]. In addition, we analyzed a economic evaluation from the economic measures such as payback period, overall benefit, ROI, and ROR.

• Journal of Radiation Protection and Research
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• v.42 no.1
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• pp.21-25
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• 2017

Background: We are developing L-band and S-band microwave dielectric absorption systems aiming novel dosimetry using DNAs, such as plasmid DNA and genomic DNA, and microwave technology. Materials and Methods: Each system is composed of a cavity resonator, analog signal generator, circulator, power meter, and oscilloscope. Since the cavity resonator is sensitive to temperature change, we have made great efforts to prevent the fluctuation of temperature. We have developed software for controlling and measurement. Results and Discussion: By using this system, we can measure the resonance frequency, f, and ${\Delta}Q$ (Q is a dimensionless parameter that describes how under-damped an oscillator or resonator is, and characterizes a resonator's bandwidth relative to its center frequency) within about 3 minutes with high accuracy. Conclusion: This system will be expected to be applicable to DNAs evaluations and to novel dosimetric system.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2588-2590
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• 2001

Distribution ayatems at the final stage of the power supply process are directly and extensively connected to customers. There are growing demands for more efficient operation and higher reliability. This paper describes the embodiment of distribution automation using internet networks. We suggest the large region distribution server system for distribution automation functions in local area network, automated meter reading system and directed load control system with by-directional communication.