• Journal of the Korean Society for information Management
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• v.25 no.3
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• pp.377-392
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• 2008

The need for overall assessment of economic effectiveness of library culture program has been suggested, as its importance continues to grow. Our study proposed a new assessment method by applying DM format and IBM format to contingent valuation method that has been used for analyzing the economic value of culture program. This study also illustrates the process through case analysis so that the public library can apply this model. It is meaningful that the study provides basic framework to evaluate the fair value of the public library by minimizing the bias that the contingent valuation method has.

• The Korean Journal of Applied Statistics
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• v.23 no.3
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• pp.533-543
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• 2010

Asking sensitive questions by a direct survey method causes non-response bias and response bias. Non-response bias arises from interviewees refusal to respond and response bias arises from giving incorrect responses. To rectify these biases, Warner (1965) introduced a randomized response model which is an alternative survey method for socially undesirable or incriminating behavior questions. The randomized response model is a procedure for collecting the information on sensitive characteristics without exposing the identity of the respondent. Many survey researchers have proposed diverse variants of the Warner randomized response model and applied their model to collect the information of sensitive questions. Using an optimal allocation, we proposed three-stage stratified randomized response technique which is an extension of the Kim and Elam (2005) two-stage stratified randomized response technique. In this study, we showed that the estimator based on the proposed response model is more efficient than Kim and Elam (2005). But by adding one more survey step to the Kim and Elam (2005), our proposed model may have relatively less privacy protection compared to the Kim and Elam (2005) model.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.11 s.102
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• pp.1114-1122
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• 2005

In this paper, the study of a design, fabrication and measurement of the receiver MMIC LNA, mixer for S-band application is described. The LNA is designed by 2-stage common source. The mixer is composed of active LO and RF balun to integrate on a chip and applied a newly proposed bias circuit to compensate the process variations of active devices. The LNA has 15.51 dB-gain and 1.02dB-Noise Figure at 2.1 GHz. The conversion gain of the mixer is -12 dB, IIP3 is approximately 4.25 dBm and port-to-port isolation is over 25 dB. The newly proposed bias circuit is composed of a few FETs and resistors, and can compensate the variation of the threshold voltage by the process variations, temperature changes and etc. The designed chip size is $1.2[mm]\times1.4[mm]$.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.1
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• pp.32-37
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• 2007

A DMB CMOS power amplifier (PA) with high efficiency and linearity is present. For this work, a 0.13-um standard CMOS process is employed and all components of the proposed PA are fully integrated into one chop including output matching network and adaptive bias control circuit. To improve the efficiency and linearity simultaneously, an adaptive bias control circuit is adopted along with second harmonic termination circuit at the drain node. The PA is shown a $P_{1dB}$ of 16.64 dBm, power added efficiency (PAE) of 38.31 %, and power gain of 24.64 dB, respectively. The third-order intermodulation (IMD3) and the fifth-order intermodulation (IMD5) have been -24.122 dBc and -37.156 dBc, respectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.3A
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• pp.205-210
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• 2002

In a Doppler weather radar, high resolution windspeed profile measurements are needed to provide the reliable detection of hazardous weather conditions. For this purpose, the pulse pair method is generally considered to be the most efficient estimator, However, this estimator has some bias errors due to asymmetric spectra and may yield meaningless results in the case of a multimodal return spectrum. Although the poly-pulse pair method can reduce the bias errors of skewed weather spectra, the modes of spectrum may provide more reliable information than the statistical mean for the case of a multimodal or seriously skewed spectrum. Therefore, the idea of relatively simple mode estimator for a weather radar is developed in this paper, Performance simulations show promising results in the detection of hazardous weather conditions.

• Journal of the Korean Data and Information Science Society
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• v.12 no.2
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• pp.47-55
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• 2001

Usually estimating the means is used for statistical inference. However depending the purpose of survey, sometimes totals will give the better and more meaningful in statistical inference than the means. Here in this study, we dealt with the unemployment population of small areas with using 4 different small area estimation methods: Direct, Synthetic, Composite, Bayes estimation. For all the estimates considered in this study, the average of absolute bias and men square error were obtained in the Monte Carlo Study which was simulated using data from 1998 Economic Active Population Survey in Korea.

• Korean Journal of Remote Sensing
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• v.37 no.5_1
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• pp.861-870
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• 2021

In this study, fused Aerosol Optical Depth (AOD) data were produced using AOD products from the Geostationary Ocean Color Imager (GOCI) onboard Communication, Oceanography and Meteorology Satellite (COMS)satellite and the Advanced Himawari Imager (AHI) onboard Himawari-8. Since the spatial resolution and the coordinate system between the satellite sensors are different, a preprocessing was first preceded. After that, using the level 1.5 AOD dataset of AErosol RObotic NETwork (AERONET), which is ground-based observation, correlations and trends between each satellite AOD and AERONET AOD were utilized to produce more accurate satellite AOD data than the originalsatellite AODs. The fused AOD were found to be more accurate than the originalsatellite AODs. Root Mean Square Error (RMSE) and mean bias of the fused AODs were calculated to be 0.13 and 0.05, respectively. We also compared errors of the fused AODs against those of the original GOCI AOD (RMSE: 0.15, mean bias: 0.11) and the original AHI AOD (RMSE: 0.15, mean bias: 0.05). It was confirmed that the fused AODs have betterspatial coverage than the original AODsin areas where there are no observations due to the presence of cloud from a single satellite.

• Korean journal of communication and information
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• v.71
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• pp.274-298
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• 2015

Doctoral Candidate, Department of Communication, Pusan National University This study analyzed the political and social significance of the disaster accident news with the frame and bias concept. In particular, this study confirmed theoretically how domestic media biased frame when it presents problem definition, causing interpretation, moral evaluation, and post-prescription on the ferry Sewol accident, In addition, the bias of the frame was analyzed comparing what is the difference between the conservative newspapers and liberal newspapers. Findings are as follows. First, in diagnosis of ferry Sewol accident, news slanted fragmentation frame>personalization frame>authority-disorder frame. The Chosun Ilbo focus on fragmentation bias, meanwhile Hankyoreh focus on the authority disorder relatively. Second, in accident evaluation, responsibility frame> moral frame> problem-solution frame. The Chosun Ilbo focus on responsibility frame and moral frame. But Hankyoreh focus on responsibility frame and problem-solution frame. Third, in the matter of responsibility, government frame>personal frame>organizational frame. Chosun Ilbo biased responsibility of the government and individuals, while the Hankyoreh is relatively more emphasis on government responsibility and the responsibility of the organization also showed. Fourth, in problem solving, thematic frame and episodic frame bias appeared as rough and level. Chosun Ilbo showed episodic frame, Hankyoreh showed thematic frame. News frame and bias as well as ideological differences of media on ferry Sewol accident was discussed in the context of the social dimension.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.6
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• pp.372-376
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• 2018

The effects of off-state bias stress on the characteristics of p-type poly-Si TFT were investigated. To reduce the gate-induced drain leakage (GIDL) current, the off-state bias stress was changed by varying Vgs and Vds. After application of the off-state bias stress, the Vgs causing GIDL current was dramatically increased from 1 to 10 V, and thus, the Vgs margin to turn off the TFT was improved. The on-current and subthreshold swing in the aged TFT was maintained. We performed a technology computer-aided design (TCAD) simulation to describe the aged characteristics. The aged-transfer characteristics were well described by the local charge trapping. The activation energy of the GIDL current was measured for the pristine and aged characteristics. The reduced GIDL current was mainly a thermionic field-emission current.

• The Journal of the Convergence on Culture Technology
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• v.4 no.3
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• pp.299-303
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• 2018

Generally, when predicting the accuracy of the anti-air artillery system, the error is classified as fixed bias, variable bias, and random error. Then the standard deviation on the target is expressed as the square root of the squared sum of each error value which comes from the random error and variable bias and in the case of fixed bias, the mean value is shifted as the sum of errors from the fixed bias. At this time, the variables indicating the displacement of the direction of azimuth and elevation direction with regard to the change of the unit value of each error are weighted. These errors are then used to predict the system's delivery accuracy through a normally distributed integral. This paper presents a method of predicting system accuracy by considering the correlation of errors. This approach shows that it helps to predict the delivery accuracy of the system, precisely.