• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.8 no.7
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• pp.475-484
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• 2018

The propulsion control device of an electric railway vehicle is a key main component corresponding to an engine of an automobile, and a device for controlling this is a device called a GDU (Gate Drive Unit). Also, when the frequency of failure of the propulsion control system was analyzed, the nonconformity ratio of GDU was the highest. GDU was not able to access core technologies due to the introduction of foreign products, and there were general problems with overall maintenance activities due to discontinuation of GDU of the manufacturer. The GDU has reached the end of its life with 23 to 14 years of long-term use.In order to solve these problems, this study was designed to identify the proper life span by analyzing compatible GDU's acquisition and failure, and to improve the existing system of maintenance focusing on health inspection. Maintenance of the components with a short life span compared to the entire service life is essential. Most foreign parts introduced at the beginning of the construction are not replaced due to technical problems or long-term operation. However, due to the characteristics of railway vehicles with a long life span of more than 25 years, it is necessary to maintain them for a long period of time. The study should be more concrete and empirical. The replacement type GDU of capacitors was able to easily measure the life of the capacitance by removing the capacitor modules, measure the life span of each unit test, and accurately perform preventive maintenance of the capacitor.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.6 no.5
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• pp.367-377
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• 2016

The purpose of the projects for strengthening the Service Business Competitiveness, which had been sponsored by the Ministry of Trade, Industry and Energy, and managed by the NIPA, is to support for combining the whole business process of the SMEs with the business model considering the scientific aspects of the services, to enhance the productivity of them and to add the values of their activities. 5 organizations are selected in 2014, and 4 in 2015 as leading organizations for these projects. This study analyzed the efficiency of these projects using DEA. Throughout the analysis of the prior researches, this study used the amount of government-sponsored money as the input variable, and the number of new customer business, the sales revenue, and the number of new employment as the output variables. And the result of this analysis showed that the decision making unit 12, 15, and 21 was efficient. And from this study, we found out two more performance indicators such as, the number of new employment and the amount of sales revenue, besides the number of new customer businesses.

• Journal of Korea Trade
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• v.27 no.1
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• pp.139-158
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• 2023

Purpose - The study of co-movements between stock markets is a crucial area of finance and has recently received much interest in a variety of studies, especially in international finance. Stock market co-movements are a major phenomenon in financial markets, but they are not necessarily independent of the real market. Several studies support the idea that bilateral trade linkages significantly impact stock market correlations. Motivated by this perspective, this study investigates whether real market integration due to trade agreements brings about financial market integration in terms of stock market co-movement. Design/methodology - Over the 10 free trade agreements (FTAs) signed by the United States, using a dynamic conditional correlations (DCC) multivariate GARCH (MGRACH) model, we empirically measure the degree of integration by finding DCCs between the US market and the partner country's market. We then track how these correlations evolve over time and compare the results before and after trade agreements. Findings - According to the empirical results, there are positive return spillover effects from the US market to eight counterpart equity markets, except Jordan, Morocco, and Singapore. Especially Mexico, Canada, and Chile have large return spillover effects at the 1% significance level. All partner countries of FTAs generally have positive correlations with the US over the entire period, but the size and variance are somewhat different by country. Meanwhile, not all countries that signed trade agreements with the United States showed the same pattern of stock market co-movement after the agreement. Korea, Mexico, Chile, Colombia, Peru, and Singapore show increasing DCC patterns after trade agreements with the US. However, Canada, Australia, Bahrain, Jordan, and Morocco do not show different patterns before and after trade agreements in DCCs. These countries generally have the characteristic of relatively lower or higher co-movements in stock markets with the US before the signing of the FTAs. Originality/value - To our knowledge, few studies have directly examined the linkages between trade agreements and stock markets. Our approach is novel as it considers the problem of conditional heteroscedasticity and visualizes the change of correlations with time variations. Moreover, analyzing several trade agreements based on the United States enables the results of cross-country pairs to be compared. Hence, this study provides information on the degree of stock market integration with countries with which the United States has trade agreements, while simultaneously allowing us to track whether there have been changes in stock market integration patterns before and after trade agreements.

• Knowledge Management Research
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• v.24 no.2
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• pp.27-48
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• 2023

The COVID-19 pandemic has highlighted the importance of firm resilience, particularly for small and medium-sized enterprises (SMEs). This study aimed to investigate the concept of SME resilience, the role of entrepreneurial orientation in enhancing firm resilience, and the impact of top management networking capability on this relationship. The study defined firm resilience as consisting of adaptation capacity and recovery capacity and conducted a survey of 187 domestic SMEs for empirical verification. The findings indicate that entrepreneurial orientation is a critical factor in enhancing firm resilience. Furthermore, the networking capability of top management may also contribute to firm resilience, but it weakens the relationship between entrepreneurial orientation and firm resilience as a moderating variable. In crisis situations, SMEs tend to rely more strongly on existing networks, rather than engaging in new network to acquire new resources, information, and knowledge, which can hinder their ability to adapt and recover. This study contributes to the further development and understanding of SME resilience, which is essential for enterprises to overcome crises and return to pre-shock levels.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.6B
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• pp.503-512
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• 2009

Watershed models, which are a tool for water cycle mechanism, are classified as the distributed model and the lumped model. Currently, the distributed models have been more widely used than lumped model for many researches and applications. The lumped model estimates the parameters in the conceptual and empirical sense, on the other hand, in the case of distributed model the first-guess value is estimated from the grid-based watershed characteristics and rainfall data. Therefore, the distributed model needs more detailed parameter adjustment in its calibration and also one should precisely understand the model parameters' characteristics and sensitivity. This study uses Jungnang basin as a study area and $Vflo^{TM}$ model, which is a physics-based distributed hydrologic model, is used to analyze its parameters' sensitivity. To begin with, 100 years frequency-design rainfall is derived from Huff's method for rainfall duration of 6 hours, then the discharge is simulated using the calibrated parameters of $Vflo^{TM}$ model. As a result, hydraulic conductivity and overland's roughness have an effect on runoff depth and peak discharge, respectively, while channel's roughness have influence on travel time and peak discharge.

• The Journal of Bigdata
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• v.8 no.1
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• pp.11-22
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• 2023

This research aimed to examine the public's perception of the "rate of sentence reduction for reasons of mental and physical weakness" and investigate if it aligns with the actual practice. Various sources, such as the Supreme Court's Courtnet search system, the number of mental evaluation requests, and the number of articles and comments related to "mental weakness" on Naver News were utilized for the analysis. The findings indicate that the public has a negative opinion on reducing sentences due to mental and physical weakness, and they are dissatisfied with the vagueness of the standards. However, this study also confirms that the court strictly applies the reduction of responsibility for individuals with mental disabilities specified in Article 10 of the Criminal Act based on the analysis of actual judgments and the number of requests for psychiatric evaluation. In other words, even though the recognition of perpetrators' mental disorders is declining, the public does not seem to recognize this trend. This creates a negative impact on the public's trust in state institutions. Therefore, law enforcement agencies, such as the police and prosecutors, need to enforce the law according to clear standards to gain public trust. The judiciary also needs to make a firm decision on commuting sentences for mentally and physically infirm individuals and inform the public of the outcomes of its application.

• Industry Promotion Research
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• v.8 no.1
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• pp.103-110
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• 2023

This study targeted KakaoTalk app users, mainly in Seoul and the metropolitan area, and verified the factors that had a significant impact on the intention to continuously use the app through KakaoTalk contents. Among various content characteristics, five variables were used to verify the variables that had the greatest influence on the intention to continue using, and the ones that did not. As a result of testing the five hypotheses, it was found that convenience, enjoyment, informativeness, and perceived usefulness had a significant positive(+) effect on the intention to continue using, but intimacy did not. From this, it can be determined that the majority of users use the app content because it is useful and informative, rather than because they have a sense of familiarity. In this way, the purpose of this study is to provide empirical help to factors closely related to the intention of continuous use in deriving priorities to be considered in the service planning stage as well as in terms of technical design of contents when developing mobile apps in the mobile app industry as a whole and in the field in the future. I want to provide it, but there is a meaning.

• The Journal of the Convergence on Culture Technology
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• v.9 no.2
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• pp.553-560
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• 2023

The study is about domestic industries following the migration of hubs (innovation, manufacturing) to other countries and the hub-oriented US industries (batteries, semiconductors, electric vehicles). Additionally, the ongoing trade tensions between the United States and China may have also played a role in companies moving their operations to the United States. The result of such a move could potentially include job creation in the United States, as well as increased investment in the U.S. manufacturing sector. However, it is also possible that there could be negative consequences, such as higher prices for consumers or disruptions to supply chains during the relocation process. However, such IRA, Chips Act scenario would likely also have negative consequences (Inflation in the home country) for the countries whose industries moved to the US, as they would lose jobs, investment, and possibly face economic difficulties as a result. As the result of the empirical analysis of the export scale of Korea and the United States, changes in the movement of global supply hubs are related to factors such as geopolitical price increases and consumption declines. In order to respond to these changes, this paper emphasizes the need to prevent the result of de-advantage by moving the production area of the scale.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3C
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• pp.179-186
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• 2008

Pressuremeter test estimates the deformational properties of soil from the relationship between applied pressure and the displacement of cavity wall. It is general to utilize the reloading curve for the estimation of deformational properties of soil because the initial loading curve can be affected by the disturbance caused by boring. On the other hand, the instrumental resolution or the variation of measured data makes it hard to estimate the maximum shear modulus from pressuremeter test results. This study suggested the methodology estimating the maximum shear modulus from pressuremeter test directly, based on the curve fitting of reloading curve. In addition, the difference was taken into account between the stress state around the probe in reloading and that of the in-situ state. Pressuremeter tests were conducted for 15 cases using a large calibration chamber, together with a number of reference tests. The maximum shear moduli taken from suggested method were compared with those from empirical correlation and bender element test.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1D
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• pp.67-72
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• 2006

Temperature prediction in asphalt pavements is the one of most important factors for estimating the pavement response and predicting the pavement performance in the mechanistic-empirical pavement design. A study on temperature prediction procedure with variation of time and depth in asphalt pavements was conducted using field monitoring data. After selecting the temperature monitoring sections, the temperature sensors have been installed in different depths and the temperature data have been collected in every one hour. The developed pavement temperature prediction model was calibrated using field monitoring temperature data. The predicted temperatures were compared with measured temperatures at different seasons in selected sections. The results showed that the solar absorptivity and emissivity values in the fall is different from the values in other seasons. The predicted temperatures agree well with the measured temperatures at a wide range of temperatures. The temperature differences between each other fall in the range of ${\pm}3^{\circ}C$. It is also found that the regional characteristics did not affect the temperature prediction procedure.