• Korean Journal of Social Welfare Studies
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• v.43 no.2
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• pp.61-85
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• 2012

The purpose of this study is to examine whether the national pension affects the life satisfaction of old age, using the first and third-wave data from the Korean Retirement and Income Study. The study analyzes the relationship between the national pension and life satisfaction, using several operational definitions of these two variables. This study utilizes the Difference-in-Difference(2D) models and panel data analysis. The main results are : First, the result of simple 2D shows that there is not significantly difference between the pensioner and that of non-pensioner. Second, the result of 2D regression also shows that pension is not significantly associated with life satisfaction of the old age. Lastly, the result of fixed-effect model confirms that the national pension does not have a statistically meaningful effect on the life satisfaction, controling for the unobserved characteristics of the old age. This study also conducts sensitivity analysis and discusses policy implications.

• Journal of the Korean Society of Radiology
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• v.17 no.6
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• pp.835-841
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• 2023

The aim of this study is to evaluate the diagnostic ability of dual-energy computed tomography (DECT) for Composition determination of urinary stones in phantom model. Seventeen cases with urinary stones who underwent DECT were enrolled in the study. The composition of the urinary stones was extracted from the seventeen patients were analyzed with DECT in phantom model with fresh pork. The volume scan method using Dual-energy software was used and the scanned image sets were assessed. All 17 urinary stones of the phantom model were analyzed according to the stone composition using DE stone Analysis were divided into uric acid stones (n=6, 35.29%) and non-uric acid stones (n=11, 64.71%). These urinary stones were pathologically confirmed. The mean attenuation values of uric acid stones at 135 kV, 100 kV and 80 kV was 348.87 ± 166.37 HU, 345.33 ± 151.18 HU and 337.94 ± 172.77 HU, respectively. The mean attenuation values of non-uric acid stones at 135 kV, 100 kV and 80 kV was 551.93 ± 297.09 HU, 747.04 ± 351.31 HU and 958.19 ± 424.72 HU, respectively. At 80 kV, uric acid stones and non-uric acid stones showed significant difference in the attenuation values(P<0.05). The attenuation values of DECT could differentiate the compositions of urinary stones between uric acid and non-uric acid stones at 80 kV in phantom model.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.10a
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• pp.429-436
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• 1997

운전원 훈련용 시뮬레이터의 국산화 개발계획에 따라 영광 원자력 3,4호기 발전소 운전원 훈련용 시뮬레이터가 국내 최초로 개발되었다. STK(space and time kinetics)와 RETACT (Real Time Advanced Core and Thermohydraulics)코드를 이용하여 영광 3,4호기 시뮬레이터의 실시간 NSSS 모델을 생성하였다. 생성된 모델의 검증(Verification Validation)을 위해 정상상태(Steady State)에서의 주요인자들이 ANS3.5의 오차범위이내임을 확인하였다. 과도상태(Transient)의 검증을 위해 터빈정지 과도상태와 주증기 관파열(Main Steam Line Rupture)사고를 실제 발전소 시험 데이터 및 성능해석 코드(NPA)를 이용하여 분석한 결과와 비교하였다. 비교 결과 기준발전소의 반응과 큰 차이 없이 운전원 훈련용 시뮬레이터의 규격인 ANS 3.5를 잘 만족함을 확인 할 수 있었다.

• Journal of the Korea Convergence Society
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• v.12 no.12
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• pp.331-338
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• 2021

This study used data from the 10rd and 15th year of the Korean Welfare Panel to evaluate the effects of the Energy Voucher Program(EVP) on the consumption and expenditure of EVP users' households. The study consisted of program group using EVP and control group not using. Chi-square and t-test were used for the characteristic differences among the groups, and the difference of consumption expenditure was identified by multiple regression analysis. As a result, EVP had a statistically significant effect on the health care costs of EVP users' households, resulting in an increase in health care costs(𝛽=3.06). However, there was no statistically significant effect on the total cost of living, basic cost, education cost, and recreation/entertainment cost. Therefore, in order to increase the effectiveness of the EVP system, it is required to improve the EVP system by expanding the level of benefits and easing the qualification standards for the eligibility for benefits.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.10
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• pp.856-867
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• 2018

This paper presents the applicability of MIMO joint decoding to dual-contact satellite systems in which two LEO satellites using X-band frequency band are transmitting each image data to two ground station antennas, simultaneously. When two satellites are closely positioned within the looking angle of the two antennas, each satellite interferes with each other by the relative antenna gain corresponding to an offset angle and this might cause the performance degradation without interference mitigation. To mitigate the performance degradation, SM MIMO techniques for joint decoding are applied. Especially, the relative antenna gain of ground station depending on the angle difference between two satellites in ground station antenna plays an important role in modelling the dual-contact satellite systems. The condition number of MIMO channel including the antenna gain calculated from the mathematical gain pattern model was primarily analyzed. Simulation results showed that the SM MIMO techniques using detection schemes such as ZF-SIC, MMSE-SIC, and ML can be applicable to dual-contact satellite systems.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.10a
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• pp.817-819
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• 2019

다양한 학습 모델이 발전하고 있는 지금, 학습을 통한 다양한 시도가 진행되고 있다. 이중 에너지 분야에서 많은 연구가 진행 중에 있으며, 대표적으로 BEMS(Building energy Management System)를 볼 수 있다. BEMS의 경우 건물을 기준으로 건물에서 생성되는 다양한 DATA를 이용하여, 에너지 예측 및 제어하는 다양한 기술이 발전해가고 있다. 하지만 FEMS(Factory Energy Management System)에 관련된 연구는 많이 발전하지 못했으며, 이는 BEMS와 FEAMS의 차이에서 비롯된다. 본 연구에서는 실제 공장에서 수집한 DATA를 기반으로 하여, 전력량 예측을 하였으며 예측을 위한 기술로 시계열 DATA 분석 방법인 LSTM 알고리즘을 이용하여 진행하였다.

• Geophysics and Geophysical Exploration
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• v.8 no.1
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• pp.41-49
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• 2005

We have developed a random heterogeneous velocity model with bimodal distribution in methane hydrate-bearing Bones. The P-wave well-log data have a von Karman type autocorrelation function and non-Gaussian distribution. The velocity histogram has two peaks separated by several hundred metres per second. A random heterogeneous medium with bimodal distribution is generated by mapping of a medium with a Gaussian probability distribution, yielded by the normal spectral-based generation method. By using an ellipsoidal autocorrelation function, the random medium also incorporates anisotropy of autocorrelation lengths. A simulated P-wave velocity log reproduces well the features of the field data. This model is applied to two simulations of elastic wane propagation. Synthetic reflection sections with source signals in two different frequency bands imply that the velocity fluctuation of the random model with bimodal distribution causes the frequency dependence of the Bottom Simulating Reflector (BSR) by affecting wave field scattering. A synthetic cross-well section suggests that the strong attenuation observed in field data might be caused by the extrinsic attenuation in scattering. We conclude that random heterogeneity with bimodal distribution is a key issue in modelling hydrate-bearing Bones, and that it can explain the frequency dependence and scattering observed in seismic sections in such areas.

• Journal of the Korea Convergence Society
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• v.10 no.9
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• pp.343-349
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• 2019

This study used data from the 3rd and 11th year of the Korean Welfare Panel to evaluate the effects of the Long-Term Care Insurance(LTCI) system on the consumption and expenditure of LTCI users' households. The study consisted of program group using LTCI and control group not using. Chi-square and t-test were used for the characteristic differences among the groups, and the difference of consumption expenditure was identified by multiple regression analysis. As a result, LTCI had a statistically significant effect on the health care costs of LTCI users' households, resulting in an increase in health care costs(${\beta}=3.06$). However, there was no statistically significant effect on the total cost of living, basic cost, education cost, and recreation/entertainment cost. Therefore, in order to show the effect of LTC system, we should try to reduce of self-pay and improve the contents and quality of the service of the LTC system.

• Journal of the Society of Disaster Information
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• v.19 no.3
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• pp.498-509
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• 2023

Purpose: This paper proposes a method detecting the falling of a maintenance worker in the underground utility tunnel, by applying deep learning techniques using CCTV video, and evaluates the applicability of the proposed method to the worker monitoring of the utility tunnel. Method: Each rule was designed to detect the falling of a maintenance worker by using the inference results from pre-trained YOLOv5 and OpenPose models, respectively. The rules were then integrally applied to detect worker falls within the utility tunnel. Result: Although the worker presence and falling were detected by the proposed model, the inference results were dependent on both the distance between the worker and CCTV and the falling direction of the worker. Additionally, the falling detection system using YOLOv5 shows superior performance, due to its lower dependence on distance and fall direction, compared to the OpenPose-based. Consequently, results from the fall detection using the integrated dual deep learning model were dependent on the YOLOv5 detection performance. Conclusion: The proposed hybrid model shows detecting an abnormal worker in the utility tunnel but the improvement of the model was meaningless compared to the single model based YOLOv5 due to severe differences in detection performance between each deep learning model

• Archives of design research
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• v.16 no.2
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• pp.57-66
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• 2003

In order to develop color image, color simulation based on data processing techniques has been developed and applied to data interpretation tools or product design supporting systems. It has been a commonmethod to use image key words to search for data and provide color coordination samples that determine computer combination in computerized support systems until recently. However, this method does not reflect system designers and users taste or preference on making final choices of color coordination samples because the database was designed based on an assumption of standardized group that was established database from large scaled image evaluation research. In this study, we suggest a color coordination simulator that supports designer's final decision-making procedure on sample groups through the simulation of various color combination. The simulator allows communications with the system to explore a designer's color combination taste and preference, and provides a user for an efficient environment to judge the optimum result. The color coordination simulator was designed based upon Dual mapping model derived from a designer's thought process, and four steps of operations longrightarrowdefining color concept longrightarrowmaking color sample groupslongrightarrow simulation-determining ranking among final combination samples - will be assisting color design process.