• Proceedings of the KSR Conference
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• 2006.11b
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• pp.1017-1028
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• 2006

Japanese railroad companies continued growing by developing diversification based on a railroad enterprise. However, after entering in the 1990s, the diversification model of a railroad company reached the management limit. Under economic depression, A decrease in the birthrate and aging progressed and passenger transport changed to the downward tendency. Nevertheless, since railroad investment was expanded, railroad achievements got worse and price competitiveness with JR East Japan became weak. But the achievements of a diversification section got worse compared with the railroad enterprise. Therefore, group management was thought as important and enterprise reorganization was developed.

• Korean Journal of Legislative Studies
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• v.23 no.1
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• pp.113-149
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• 2017

This study aims to identify the micro-level, social psychological foundation of regionalism and analyze its change and continuity by comparing 1988, 2003, and 2016 survey results. Drawing on the theory of prejudice and social identity, it clarifies the concept of regionalism and examines its affective, behavioral, cognitive implications. In the empirical analysis, where it takes advantage of relevant questions of the same or similar wording in three nationally representative surveys, the study identifies the changes in regionalism at the individual level focusing on anti-Honam prejudice and discrimination and attribution of regional conflict. First, anti-Honam prejudice has been in decline nationally as well as regardless of where one has grown up, except for Daegu/Kyungpook area. Second, anti-Honam prejudice has been weakened among younger generations while regional party identification now affects the sentiment in the direction of regional cleavage overlapped with ideological leanings. Third, while most respondents do not experience explicit discrimination, Honam natives are still more likely to experience discrimination, especially identity and self-esteem related, due to his or her home town. Fourth, Honam natives have been more likely to attribute regional conflict to an external, structural factor like government economic policy and less likely to a subjective one like regional sentiment, which seems to be consistent with attributional attitudes of the victims of prejudice. The study ends with the discussion of how to reduce further anti-Honam prejudice, which includes contact hypothesis, recategorization, cross-categorization, and de-categorization.

• The Journal of the Acoustical Society of Korea
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• v.38 no.5
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• pp.593-600
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• 2019

The similarity in tones between speakers can lower the performance of speaker verification. To improve the performance of speaker verification systems, we propose a multi-task learning technique using deep neural network to learn speaker information and age information. Multi-task learning can improve generalization performances, because it helps deep neural networks to prevent hidden layers from overfitting into one task. However, we found in experiments that learning of age information does not work well in the process of learning the deep neural network. In order to improve the learning, we propose a method to dynamically change the objective function weights of speaker identification and age estimation in the learning process. Results show the equal error rate based on RSR2015 evaluation data set, 6.91 % for the speaker verification system without using age information, 6.77 % using age information only, and 4.73 % using age information when weight change technique was applied.

• Journal of Digital Convergence
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• v.19 no.12
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• pp.21-28
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• 2021

The purpose of this study is to analyze the efficiency of the policy direction to see if the government's purpose of relocating public institutions was achieved by analyzing the case of the Korea Housing Finance Corporation, which moved to Busan Metropolitan City in 2014. Based on the Korea Housing Finance Corporation's settlement management disclosure and public institution performance evaluation report from 2009 to 2019, efficiency was compared and analyzed using DEA analysis, work efficiency in management performance evaluation report, and financial ratio. The analysis results are as follows. First, in the case of DEA analysis, the difference in efficiency before and after fat transfer was not noticeable. Second, the efficiency analysis using the performance evaluation report and the financial ratio showed that the efficiency decreased after local relocation. Taken together, in the case of the Korea Housing Finance Corporation, efficiency decreased after local relocation, which can be attributed to sluggish business performance and inefficiency related to financial ratios. However, this study has limitations because it conducted an analysis on the Korea Housing Finance Corporation. To compensate for this, it is necessary to diversify the scope of research targeting all fund-managed quasi-governmental institutions in Korea. Nevertheless, this study is the first study to analyze before and after the relocation of fund-managed quasi-governmental institutions, and is expected to provide significant implications for future policies to be discussed.

• Korean Chemical Engineering Research
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• v.57 no.4
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• pp.575-583
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• 2019

The results of the catalytic reaction by pulsed injection of reactants are useful for studying the initial reaction characteristics in the case of many coke invloved reactions. The dehydrogenation characteristics of alumina supported platinum tin catalysts were investigated by pulsed injection of propane. The yield of propylene was maximized when the reduction time of propane injection catalyst was $550^{\circ}C$. Raman analysis showed that the amount of coke was very small when PtSn (4.5) catalyst was used and the short contact time was simulated by propane pulse injection. n order to differentiate the degree of dispersion of platinum, PtSn (4.5) catalyst was sintered at $900^{\circ}C$ with hydrogen, and then the temperature of air - redispersion was varied and propane pulse was injected. As a result, conversione and yield were the highest when air-redispersion temperature is $600^{\circ}C$. The lower the air-redispersion temperature, the higher the selectivity. As the tin content in the platinum catalyst increased, the propane conversion was lowered, but the selectivity to propylene increased and the yield increased. From this, it can be seen that the tin-added platinum catalyst is less active than the platinum catalyst from the beginning of the reaction, which is less affected by coke. The dehydrogenation reaction by the propane pulse injection shows a higher conversion rate than the result of continuous injection due to the formation of COx, and the amount of coke is very small. Decrease in selectivity due to the formation of COx can be reduced by increasing the reduction temperature and time.

• Journal of Environmental Impact Assessment
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• v.28 no.2
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• pp.141-151
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• 2019

Korea has passed the Act on the Integrated Control of Pollutant-Discharging Facilities in 2015, and the integrated environmental management under the BAT standard is underway. To summarize the nature of integrated environmental management, it is the regulation by the integration of the management of the multi-pollutant source and the technical standard of BATs. In general, in environmental economics, regulation-based on technical standards are known to be inefficient. This paper attempts to evaluate the efficiency of BAT standards from an economic point of view. A simple multi-pollutant model demonstrates that the inefficiency of the environmental tax with imperfect information in a single pollutant situation is amplified under multi-pollutant conditions. The simultaneous introduction of BAT and IPPC can be partially explained by this logic. It is also highlighted by the strengthening of BAT standards by EU, as a countermeasure to the potential deterioration of air quality caused by the change of effective environmental taxes accompanying the fuel and emission price changes.

• Journal of the Korean Society of Radiology
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• v.14 no.7
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• pp.899-906
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• 2020

The WSS lateral examination is important for diagnosing spinal disorders. Recently, long-length detectors for large-area diagnose have been popularized to effectively reduce the exposure dose and examination time. It can be applied very efficiently to examinations of patients with high risk of falls, children, and adolescents. However, since the image is acquired through a single irradiation, the volume of cervical vertebra is relatively smaller than the lumbar due to the geometrical anatomy of the spine. Therefore, this study intends to fabricate an additional filter using 3D printing technology and copper filament to obtain uniform image quality in the WSS lateral examination and to analyze the results. 3D printing technology is able to easily print a desired shape, so it is widely used in the entire industrial field, and recently, a copper filament has been developed to confirm the possibility as an additional filter. In the WSS lateral examination, CNR and SNR were excellently measured when the additional filter was applied, confirming the possibility of using the additional filter.

• The Journal of the Convergence on Culture Technology
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• v.7 no.4
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• pp.1-7
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• 2021

The purpose of this study was to analyze the effect of household loan share on bank management soundness. The results of the empirical analysis are summarized as follows. First, as a result of estimating coefficient of the mortgage loan ratio shows a significant negative relationship with the BIS equity capital ratio of banks. In addition, it was found that the mortgage loan ratio had a significant positive (+) effect on Eunhae's BIS and equity capital ratio after the financial crisis. Second, as a result of the estimation coefficient of the mortgage ratio showed a significant positive (+) relationship with the NPL of the bank and below. In addition, it is estimated that the bank's secured loan ratio changed significantly before and after the financial crisis in the effect of banks' NPL and substandard-and-below loans. It is expected to make implication to financial policy and banking regulation and supervision. We believe that more efforts should be made to increase the soundness of household loans in preparation for risk factors that may arise from exogenous factors such as changes in the international financial environment and falling property prices.

• Environmental and Resource Economics Review
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• v.31 no.4
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• pp.645-668
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• 2022

Hydrogen energy is emerging as an important means of carbon neutrality in the various sectors including power, transportation, storage, and industrial processes. Fuel cell power plants are the fastest spreading in the hydrogen ecosystem and are one of the key power sources among means of implementing carbon neutrality in 2050. However, high volatility in system marginal price (SMP) and renewable energy certificate (REC) prices, which affect the profits of fuel cell power plants, delay the investment timing and deployment. This study applied the real option methodology to analyze how the dual uncertainties in both SMP and REC prices affect the investment trigger price level in the irreversible investment decision of fuel cell power plants. The analysis is summarized into the following three. First, under the current Renewable Portfolio Standard (RPS), dual price uncertainties passed on to plant owners has significantly increased the investment trigger price relative to one under the deterministic price case. Second, reducing the volatility of REC price by half of the current level caused a significant drop in investment trigger prices and its investment trigger price is similar to one caused by offering one additional REC multiplier. Third, investment trigger price based on gray hydrogen and green hydrogen were analyzed along with the existing byproduct hydrogen-based fuel cells, and in the case of gray hydrogen, economic feasibility were narrowed significantly with green hydrogen when carbon costs were applied. The results of this study suggest that the current RPS system works as an obstacle to the deployment of fuel cell power plants, and policy that provides more stable revenue to plants is needed to build a more cost-effective and stable hydrogen ecosystem.

• The Journal of the Convergence on Culture Technology
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• v.9 no.2
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• pp.533-543
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• 2023

This study explores the influence of the COVID-19 pandemic on the Korean art market and contrasts the classic hedonic method of art price prediction with the Artificial Neural Network technique. The empirical analysis of this paper utilizes 14,639 observations of Korean art auction data from 2015 to 2021. There are three types of variables in this study: artist-related, artwork-related, and sales-related. Previous studies have suggested that these three types of variables influence art prices. The empirical findings in this research are in twofold. First, in terms of RMSE and R², the Artificial Neural Network outperforms the hedonic model. Both techniques discover that sales and artwork variables have a greater impact than artist-related attributes. Second, when the primary factors of art price are controlled, Korean art prices are found to fall dramatically in 2020, shortly following the onset of COVID-19, but to rebound in 2021. The main lesson in this study is that the Artificial Neural Network enhances art price prediction and reduces information asymmetry in the Korean art market even in the face of unanticipated turmoil such as the COVID-19 outbreak.