• The Korean Journal of Applied Statistics
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• v.30 no.5
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• pp.681-690
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• 2017

Various imbalanced binary classification problems exist such as fraud detection in banking operations, detecting spam mail and predicting defective products. Several sampling methods such as over sampling, under sampling, SMOTE have been developed to overcome the poor prediction performance of binary classifiers when the proportion of one group is dominant. In order to overcome this problem, several sampling methods such as over-sampling, under-sampling, SMOTE have been developed. In this study, we investigate prediction performance of logistic regression, Lasso, random forest, boosting and support vector machine in combination with the sampling methods for binary imbalanced data. Four real data sets are analyzed to see if there is a substantial improvement in prediction performance. We also emphasize some precautions when the sampling methods are implemented.

• Journal of the Economic Geographical Society of Korea
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• v.15 no.1
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• pp.131-145
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• 2012

During the 1980s and 1990s, most of the old industrial cities of advanced countries have experienced serious de-industrialisation. This has caused many problems, such as economic decline, increasing unemployment, environmental degradation and social unrests. Since the mid-1980s, some of these cities have started to tackle the problems by urban regeneration programs with cultural and artistic activities, new industries, and implementing housing projects. The cities of Newcastle and Gateshead in Northeastern England were the examples of the ones which have created major development projects, such as building condominiums, renovating old factory building, and promoting cultural and art activities. This paper introduces policies and programs of the cities' urban regeneration, analyses their governance structure, and articulates factors contributing to the success of the policies and programs.

• Korean Journal of Social Welfare Studies
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• v.48 no.2
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• pp.173-201
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• 2017

This study examined the degree of socioeconomic deprivation in the areas of material hardship, health, housing, employment, and social network among people using debt relief programs. The sample, 209 individuals, was recruited from major agencies offering debt relief programs, including Seoul Bankruptcy Court, Credit Counseling and Recovery Service, and Seoul Welfare Foundation. Data were collected through in-person interviews in 2016. The sample was compared in terms of the level of deprivation with the general population and the low-income group, extracted from the Korea Welfare Panel Study. The debtors group demonstrated a substantially higher level of deprivation on all the dimensions examined. For example, the proportion of people who suffered from hunger was 37.8% in the debtors group compared to 6.7% in the low-income group. The proportion of people who had suicidal ideation in the last 12 months was 57.9% compared to 19.2% in the low-income group and 2.7% in the general population. The level of deprivation was different by chapter choice of consumer bankruptcy. Policy and practice implications of the results were discussed.

• Korean Security Journal
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• no.56
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• pp.165-185
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• 2018

Because financial industry is closely related to the daily lives of people, internal fraud such as embezzlement by the employees can cause serious damage to the national economy, including credit crunch and contagious bankruptcy, as once demonstrated in the Savings Bank Scandal in 2011. Therefore, the importance of financial industry security is being emphasized and developed into converged security that combines physical, human and cyber security. In this study, to prevent fraud caused by internal employees in Korean financial sector, in-depth semi-structured interviews were conducted with a total of 16 participants including bankers, officials of financial regulators, and security experts, who were in charge of risk management in the industry. The collected data were analyzed at three stratification levels such as individual, organization, and socio-cultural factor. Based on this analysis, policy recommendations were suggested for the development of financial industry security and reducing internal fraud in banking institutions.

• Journal of Internet of Things and Convergence
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• v.6 no.4
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• pp.59-64
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• 2020

Recently, many difficulties have been faced in all parts of the world due to the impact of COVID-19. Personally, household income is decreasing sharply as many jobs disappear, and economically, many SMEs are increasingly going bankrupt. It is known that this phenomenon is highly likely to continue for the time being. In such a situation, the smart factory support project provides opportunities for difficult SMEs to improve productivity and change the corporate structure. In this study, the current status of smart factory promotion was examined, and problems occurring in the process of promoting smart factory support projects were identified. The improvement plans were derived so that more efficient projects could be promoted in the future.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.469-474
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• 2020

This study explains the characteristics of micro-insurance based on the theoretical model of health insurance, such as the low demand of low-income people and the lower demand of higher risk aversion. In particular, these characteristics contradict the existing insurance theory which states that the lower the income, the higher the risk aversion, and the higher the demand for insurance. This study postulates a two-period model focusing on health insurance, contrary to a one-period model assumed in existing studies. As a result, first, we show that the decrease in income leads to a decrease in the preventive effort for illness. Second, we offer a model for micro-insurance in which the individual chooses a partial insurance under an actuarially fair insurance premium, while full insurance is optimal in existing studies. Third, we also show that the insurance demand decreases when the outlook for the future improves. Fourth, we finally show that the lack of trust and default risk of the insurer decrease the insurance demand as risk aversion increases.

• Environmental and Resource Economics Review
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• v.31 no.4
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• pp.733-753
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• 2022

Korean government established the Nationally Determined Contribution (NDC) in 2015. After revising in 2019, the government updated an enhanced target at the end of last year. When the NDC is addressed, the emission targets of each sector, such as power generation, industry, and buildings, are also set. This paper analyzes the emission target of each sector by applying a claims problem or bankruptcy problem developed from cooperative game theory. The five allocation rules from a claims problem are introduced and the properties of each rule are considered axiomatically. This study applies the five rules on allocating carbon emission by sector under the NDC target and compares the results with the announced government target. For the power generation sector, the government target is set lower than the emissions allocated by the five rules. On the other hand, the government target for the industry sector is higher than the results of the five rules. In other sectors, the government's targets are similar to the results of the rule that allocates emissions in proportion to each claim.

• Journal of the Korea Society of Computer and Information
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• v.28 no.7
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• pp.179-187
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• 2023

Consumer trust plays a crucial role in the development of the sharing economy. This study primarily focuses on the factors influencing consumer trust and examines the case of ofo, a former leader in China's bike-sharing industry. This paper analyzes the decline in consumer trust in ofo, which can be attributed to internal management issues and the near-bankruptcy situation. The "difficulty in refunds" issue faced by ofo since December 2018 has been growing continuously, and this study explores the factors influencing trust and distrust in this context. By considering product factors (quality), platform factors (payment security, privacy protection, reputation), and social factors (social norms, government regulation) as independent variables, the study analyzes the factors affecting consumer trust. The analysis results revealed that as consumers' distrust towards shared bikes increases, their switching intention also increases. The company's reputation and social norms were found to influence both trust and distrust, while government regulation was found to influence trust. The research findings provide insights relevant to sharing economy platforms and offer guidance for future studies.

• The Korean Journal of Financial Management
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• v.24 no.1
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• pp.109-147
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• 2007

According to the perspective of capital structure theory, we analyzed the dynamism of the capital structure determinants by using panel data of 244 KOSDAQ firms based on two-step GMM system methodology suggested by Blundell Bond(1998). This dynamic methodology had not been used to analyse capital structure determinants in Korea. In the dynamic model of capital structure, profit had negative effect on the book leverage and market leverage, which meant supporting pecking order theory. Growth opportunity (MBR) affected negatively to the market leverage. For the determinants of leverage, earnings volatility had significantly positive effect on KOSDAQ 50 firms. KOSDAQ and KOSDAQ 50 firms had the target leverage. The adjustment speed in KOSDAQ firms was 0.4958 on the book leverage, it was faster than in KOSDAQ 50 firm's 0.2863 on the book leverage and the adjustment speeds for the market leverage were 0.7651 for KOSDAQ firms and 0.5643 for KOSDAQ 50 firms. There was difference in adjustment cost between KOSDAQ firms and KOSDAQ 50 firms.

• Journal of Technology Innovation
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• v.24 no.2
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• pp.21-56
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• 2016

Despite many previous studies on catch-up, understanding on the effect of product architecture developed by latecomers on the catch-up performance remains limited. On the other hands, in contrast to the semiconductor, ship building, and automotive industry, even if Korean industry and government have invested the development of numerical controllers for machine tools in the past four decades, the industry and government have failed to achieve catch-up. Therefore, we newly examine the effect of product architecture on the catch-up performance of the Korea by implementing comparative research with periods on the evolution of product architecture of Fanuc's numerical controllers, which have achieved the largest market share in the world. We found that Fanuc developed open modular architecture based numerical controllers and provided product with customization of user requirements as well as cost effectiveness. Consequently, Fanuc has sustained market leader position since the mid-1980s. However, despite all the efforts of the industry and government, we found that the Korea failed to develop open modular architecture based numerical controllers and could not achieve significant catch-up performance. Our findings provide important theoretical backgrounds for examining the catch-up performance as well as investigating the reason why latecomers failed to achieve market catch-up even if they accomplished technological catch-up.