• Journal of Korean Library and Information Science Society
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• v.40 no.3
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• pp.97-117
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• 2009

Collection Development Policy(CDP) is the master plan for managing libraries and information centers through which the features and categories of collections are defined and sorted. The National Digital Library therefore needs to determine its manifest principles based on CDP regarding the magnitude of acquisition, the acquisition priority and the magnitude of purchases. This paper pertains to the principal model for NDL Collection Development Policy as a primer for establishing NDL Collection Development Policy in order to illustrate essential elements of national collection development policy and provide general guidelines for NDL Collection Development Policy. To propose an independent Collection Development Policy appropriate for NDL by analyzing cases in digital resource development policies. To guide establishing principles for determining the types and magnitude of NDL collection acquisition, prioritizing acquisition, making decisions on purchase magnitude and licensing. To identify the essential elements in systematic development of national digital information resources; and to propose a model for NDL's CDP accordingly.

• Journal of the Earthquake Engineering Society of Korea
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• v.20 no.1
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• pp.45-54
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• 2016

This study suggests a prediction model of ground motion spectral shape considering characteristics of earthquake records in Korea. Based on the Graizer and Kalkan's prediction procedure, a spectral shape model is defined as a continuous function of period in order to improve the complex problems of the conventional models. The approximate spectral shape function is then developed with parameters such as moment magnitude, fault distance, and average shear velocity of independent variables. This paper finally determines estimator coefficients of subfunctions which explain the corelation among the independent variables using the nonlinear optimization. As a result of generating the prediction model of ground motion spectral shape, the ground motion spectral shape well estimates the response spectrum of earthquake recordings in Korea.

• Journal of the Korean Magnetic Resonance Society
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• v.3 no.2
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• pp.127-139
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• 1999

In this paper we discussed how multiple quantum coherences evolve in the presence of anisotropic distribution of dipolar couplings. The magnitude of dipolar couplings were varied by changing the tile angle of crystal axis. The stronger was dipolar coupling, the higher was frequency of multiple quantum coherence. That is, the order of multiple quantum coherence varies in proportion to the magnitude of dipolar couplings. The theoretical prediction for the multiple quantum coherence at magic angle 54.7$^{\circ}$ in solid NMR spectroscopy was verified in this study. The excitation pattern of n-quantum coherence, which can induce the effective size to characterize spin system, is expected in a larger and more complicated spin system for understanding of the relation of dipolar coupling and multiple quantum coherence.

• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.1007-1009
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• 1998

In this paper, the effects of the drive-in process parameters on the residual stress profile of the p+ silicon film has been investigated. All the residual stress profile has been estimated by the second-order polynomial. All the coefficients of the polynomial have been determined from the measurement of the deflections of cantilevers and a rotating beam by using a surface profiler meter and by means of focusing a calibrated microscope. As the drive-in temperature or the drive-in time increases, the boron concentration decreases and the magnitude of the average residual stress decreases. If the boron concentration decreases the tensile residual stress decreases except near the surface where the magnitude of compressive residual stress increases.

• Journal of the Optical Society of Korea
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• v.18 no.6
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• pp.646-649
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• 2014

Performances of spectrum-sliced channels are strongly affected by their relative intensity noise (RIN). We use polarization-independent optical modulators (PIOMs) for spectrum-sliced channels to suppress their RIN. The PIOM driven by a high sinusoidal voltage signal evenly redistributes optical frequency components in the spectral domain and reduces the RIN. It can be used at a broadband light source (BLS) output to produce spectrum-sliced channels having lower RIN values. Also, it can be used for each spectrum-sliced channel within each optical network unit (ONU). In our experiment, where 12.5-GHz-spaced spectrum-sliced channels are used in 1-GbE speed, the use of PIOM at the BLS output reduces the bit error rate (BER) of the spectrum-sliced channel by more than an order of magnitude. The use of PIOM within the ONU reduces the BER by approximately 3 orders of magnitude.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.691-696
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• 1997

In recent years, stengthening of beam by steel plate, carbon fiber sheets, and carbon fiber laminate is spotlighted in order to repair and rehabilitation of R/C structures. In this study, 3 method of rehabilitation technic are analyzed from the tests. Test parameters are the width of cracks, the method of repair and rehabilitation, the magnitude of existing load. Deflection, failure load, strains of reinforcing bar, strains of sheet and plates are measured during tests. The failure mode and ultimate load are analyzed from these measured data. Test result shows that the width of cracks and the magnitude of existing load do not make any difference of ultimate flexural capacity.

• Journal of Power Electronics
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• v.12 no.3
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• pp.448-457
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• 2012

This paper proposes a carrier-based pulse width modulation (PWM) method to control an indirect matrix converter (IMC) by analyzing the relationship between the space vector PWM (SVPWM) and the carrier-based PWM. The complexity of the SVPWM method for an IMC can be reduced by using an equivalent carrier-based PWM method. The advantage of the proposed algorithm is its ability use only one symmetrical triangular carrier signal to generate the gate signals for all of the power switches in both the rectifier and inverter stages as compared to the conventional method where the carrier signal used in the rectifier stage is different from that of the inverter stage. In addition, by using a suitable offset voltage component in the modulation signals, the output voltage magnitude reaches 0.866 of the input voltage magnitude. Simulation and experimental results are provided in order to validate the proposed method.

• Journal of Korean Society on Water Environment
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• v.20 no.4
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• pp.352-356
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• 2004

Variations of water quality parameters were investigated for last 13 years in Han river. Deviation from 3 month moving average was suggested for the variation analysis. Many parameters of mainstream and tributaries showed similar monthly fluctuations. Suspended solid of mainstream showed higher fluctuation than that of tributaries due to summer flood. Contrarily, the organic parameters such as BOD, COD, and TN showed lower fluctuations in the mainstreams. The magnitude of deviation was in the order of pH < DO, COD, temp. < BOD, TN < TP, SS. Strong correlation was found in BOD data of adjacent sites. Main sites showed low deviation in comparison to adjacent common sites of mainstream (1:2.4). Mainstream showed low deviation in comparison to tributaries (1:1.7). Seasonal tendency of monthly BOD was confirmed using autocorrelation function. The deviation was in inverse proportion to the magnitude of BOD.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.51 no.9
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• pp.451-459
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• 2002

This paper presents a method for modelling of the impedance locus in order to test the protective relay with dynamic. This paper has the two parts, the first part is the configuration of impedance locus with voltage magnitude, total impedance magnitude and angle. And the second part is the control of the locus speed with deviation of two frequencies. The proposed method is applied to two machine equivalent system with PSCAD/EMTDC to show its effectiveness.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.10a
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• pp.72-82
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• 1999

The microearthquake and explosion events recorded in the seismic KNUE(Korea National University of Education) network were analyzed. The seismic data were recorded from Dec. 1997 to Dec. 1998. Total of 118 records consisted of 24 earthquake and 4 explosion events were instrumented at 6 stations. Spectral values increases as magnitude increases and the predominant frequency band expands to low frequency. zone as magnitude increases. Three-dimensional spectrograms(time frequency. amplitude) were also synthesized in order to discriminate microearthquakes and artificial underground explosions. The waves from microearthquakes show that frequency content of dominant amplitude appeared above 10 Hz and the discrimination can be performed in almost all the frequency domain of 3-d spectrogram.