• 한국IT서비스학회:학술대회논문집
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• 2006.11a
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• pp.261-270
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• 2006

The present study analyzes the social equilibrium of wireless internet platform market before and after the adoption of WIPI(Wireless Internet Platform for Interoperability). When market prevails operator ownership, as opposed to manufacturer ownership, with heterogenous platforms becomes a more likely and desirable solution. After the adoption of WIPI, social equilibrium is achieved only if operators perceive that the cost reduction and the interoperability effects from investing in WIPI fully offset the appropriation effect from investing in heterogenous platforms.

• The Journal of Asian Finance, Economics and Business
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• v.6 no.1
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• pp.281-288
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• 2019

This study examines the relationship between R&D intensity and disclosure. R&D activities are essential in bringing innovation to companies. However, R&D activities are naturally uncertain and increase information asymmetry. Thus, firms with high R&D activities are more likely to have the incentive to communicate the potential of R&D investment to the market through voluntary disclosure and, concurrently, resolve information asymmetry. Meanwhile, incentives to less voluntary disclosure exist because of the proprietary cost and the risk of competitiveness loss. Furthermore, the uncertainties inherent in R&D activities caused the possible decrease in the information accuracy. For the two opposing views, this study investigates the relationship between R&D intensity and disclosure frequency using the Regulation Fair Disclosure data in Korea. Moreover, the relationship between R&D intensity and usefulness of the information disclosed is also examined. Using firm sample listed in the 2011-2016 Korea Stock Market, results show that firms with high R&D intensity make disclosures more frequent. Subsequently, the analysis using forecast sample shows that management forecast error is higher in firms with high R&D intensity. This research contributes to the existing literature by presenting evidence that R&D intensity is a significant factor affecting manager's disclosure behavior and information usefulness.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.12
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• pp.63-73
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• 2021

This study investigates the key determinants of exchange rate (RER) misalignment for the period 1991 to 2020. The BEER technique has been used to estimate the degree of the equilibrium exchange rate. To explore the actual exchange rate misalignment and to assess the behavior of variables that are different in different regimes of undervaluation and overvaluation, the nonlinear technique of Markov regime-switching (MSM) was applied. The mean and variance of each regime are highly significant and show that undervaluation episodes have a low mean (116.139) and more volatility (1.229) while overvaluation episodes have a high mean (126.732) with less volatility (0.871). The findings show that MSM accurately identifies exchange rate misalignment in both regimes as separate incidents of overvaluation and undervaluation. Results further depict that misalignment of the RER is affected by terms of trade, net foreign assets, interest differential, government investment, and consumption decision. Results recommend that if policymakers want to use the exchange rate as a policy tool, they must first consider the drivers of the equilibrium exchange rate. As a result, any deliberate actions to address exchange rate misalignment must focus on the underlying fundamentals that drive the exchange rate.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.3
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• pp.373-380
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• 2019

In this paper, a pico hydro turbine employing low head circulation water at fish farms is designed and evaluated. Due to the advantages of simple structures, small head requirements, and low-cost investment, the constant thickness propeller turbine is considered as a feasible solution. The design process based on the free vortex method is presented in full detail, and a 4-blade runner is built using BladeGen. The turbine performance is analyzed both numerically and via experimental methods. Despite slight differences, the results show similar trends between CFD simulations and experiments carried out on factory test-rigs in a wide range of working conditions. At the design flow rate, the turbine achieves the best efficiency of 70 %, generating 3.5 kW power when rotating at 420 rpm. The internal flow field, as well as the turbine's behavior, are investigated through the distribution of blade streamlines, pressure, and velocity around the runner. Moreover, the pressure coefficient on the blade surface at 3 span positions is plotted while the head loss for each simulation domain is calculated and displayed by charts.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.1
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• pp.117-125
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• 2019

The purpose of this study is to examine urban built environments associated with the walking behavior in order to identify the problem of urban infrastructure from the perspective of Universal design theory. Using the walkability criteria developed based on the findings of previous studies on Universal design theory and walking environment, the urban built environments in old town area of Seoul were evaluated. The results of the evaluation indicated that the pedestrian infrastructure in the study area had several shortcomings to improve in order to provide walking-friendly environments. First, the pedestrian infrastructure for visually impaired people were severely limited. Second, walking traffics in large portion of the street networks were interrupted by a variety of obstacles such as parked cars, signboards, and illegal street shops. Third, there were certain areas where the quality of pavement was not properly managed. In summary, this study provides an empirical data to understand the current situation of pedestrian infrastructure in the urban areas. Improvement of pedestrian infrastructure is needed to address the issues related to the mobility of the disabled people. It is also recommended to construct the GIS data on walking environment in order to develop and mange a long-term public investment plan for walking-friendly urban environments.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.11
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• pp.81-87
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• 2018

Among various types of geothermal heat pump systems, Vertical Closed-Loop Geothermal Heat Pump (VGSHP) has received increasing attention due to a variety of advantages such as the potential to be installed in a relatively small space and improved energy efficiency. In this research, the performance of VGSHP system coupled with heat storage tank was evaluated, by analyzing operational behavior of heat storage tank, the variations of heat pump energy performance due to the connection with heat storage tank, part load ratios characteristics of heat pump and the corresponding energy cost, compared to chiller and boiler based conventional system. The results of this study showed that the VGSHP system coupled with heat storage tank showed an energy saving effect of about 18% for cooling and about 73% for heating, and annual heating/cooling energy cost reduction of 43,000,000 KRW ($ 39,000), compared to the conventional air conditioning system. In addition, after considering both energy cost and initial investment cost including equipment, installation and auxiliary device expenses, payback period of approximately 11.8 years was required.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.3
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• pp.1135-1142
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• 2021

This study aims to examine the factors that determine bond yields in infrastructure companies listed on the Indonesia Stock Exchange. The research sample used 31 bonds issued by the company during the 2015-2019 period. The data analysis method to estimate the determinant of bond yield uses multiple regression models. The results prove that the increase in the coupon rate causes bond yields to increase, while the inflation rate has the opposite effect of decreasing bond yield. Interest rate, exchange rate, duration, and bond rating variables cannot affect the bond yield. The results of this study imply that investors will be interested in investing in bonds with better yields if the company has to set a higher coupon rate, especially in economic conditions that experience low inflation rates. Interest rates and exchange rates as macroeconomic variables have not been considered by investors in purchasing bonds. Bond characteristic factors, namely, the duration and rating of the bonds, are considered less important factors in bond investment decisions because they are more oriented towards getting higher yields. Therefore, further research needs to be explored further related to the behavior of Indonesian bond investors who may have different characters from investors in other countries.

• Nuclear Engineering and Technology
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• v.54 no.3
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• pp.909-916
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• 2022

To study the developments and variations of unsafe behaviors in nuclear power plants thus reduce the possibility of human-related accidents, this paper, based on the Game Theory, focused on the changes in benefits of the Department of Management, Operational and Emergency in a nuclear power plant, and established the expected revenue functions of these departments. Additionally, the preventive measures of unsafe behaviors in nuclear power plants were also presented in terms of these 3 departments. Results showed that the violations of the Operation Department (OD) and the Emergency Department (ED) were not only relevant with the factors such as their own risks, costs, and the responsibility-sharing due to accidents, but also affected by the safety investments from the Management Department (MD). Furthermore, results also showed that the accident-induced responsibility-sharing of both the OD and the ED would rise, if the MD increased the investments in safety. As a result, the probability of violation behaviors of these 3 departments would be attenuated consciously, which would reduce the unsafe behaviors in the nuclear power plants significantly.

• Journal of Distribution Science
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• v.20 no.9
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• pp.73-81
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• 2022

Purpose: This study aimed to examine whether key audit matters (KAMs) readability influences investor reaction. Research design, data, and methodology: The signaling theory was applied to explain the behavior of investors when they receive useful information for their decisions. Data were collected from 1,866 firm-year observations from Thai listed companies in both the Stock Exchange of Thailand (SET) and the Market for Alternative Investment (MAI) for the fiscal years of 2016-2019. The study was based on secondary data, which were collected from the SET Market Analysis and Reporting Tool (SETSMART) database and the Stock Exchange of Thailand's website (www.set.or.th). A statistical regression method was used with panel data analysis to evaluate possible associations between KAMs readability and investor reaction. The study relied on popular readability measures (Fog Index). Moreover, investor reaction was measured by absolute cumulative abnormal return and abnormal trading volume. Results: It was found that the KAMs readability has positive significance on both absolute cumulative abnormal return and abnormal trading volume. Conclusion: This study showed a significant contribution to the implication of KAMs in an emerging economy. The results reveal that more readable KAMs disclosure distributed new insights and useful information to investors and led to reducing the information gap between auditors and investors.

• Asia-Pacific Journal of Business
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• v.13 no.4
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• pp.135-149
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• 2022

Purpose - The primary objective of this article is to investigate the impact of U.S. monetary policy on institutional / individual / foreign investor reactions in the Korean stock market. Design/methodology/approach - This study employs a high frequency event study methodology to identify U.S. monetary policy shocks and quantify the impact of identified shocks on investor reactions. The dependent variable in the regression model is net stock purchase, while the explanatory variables are U.S. monetary policy shocks. The model is estimated for the period 2000-2019, including 156 FOMC meetings. Findings - Foreign investors immediately sell stocks in response to contractionary U.S. monetary shocks. They do not, however, react to anticipated changes in monetary policy rates, confirming the rationality of foreign investors. Individual investors demonstrate the opposite response, indicating that a non-trivial proportion of individual investors are irrational. Research implications or Originality - This study adds to the current literature on the effect of U.S. monetary policy on the Korean stock market. This study demonstrates a heterogeneous response to U.S. monetary policy shocks, validating the rational investment behavior of foreign investors, while individual investors exhibit a certain degree of irrationality. Methodologically, this study adds to the literature by quantifying the impact of U.S. monetary policy employing a sharper identification method allowing a simple and consistent estimation.