• Journal of the Korean Regional Science Association
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• v.36 no.3
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• pp.41-52
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• 2020

A new town attracts a large population in the short period due to its excellent residential conditions, and forms a local economy. However, if the new town is constructed in an inferior area, it would cause a negative effect to neighboring areas by absorbing population and firms from them. Nevertheless, the relocation of Chungnam provincial office from Daejeon, a metropolitan area to Naepo belongs to the key project of constructing Naepo. If the officers and their family members move to Naepo following the relocation and form a new consumer group of a local economy, the construction of Naepo would cause a positive effect to its neighboring areas. This paper empirically analyzes the effect of Naepo on the local economy through the change in differences of the new openings of restaurants between areas (defined either by donut-shaped area with 500-meter width or by Eup, Myun, and Dong) inside and those outside of 10km from the border of Naepo. The results from regression equation estimation where difference-in-differences framework is applied imply that the construction of Naepo new town caused a positive economic effect to its neighboring areas.

• Journal of Digital Convergence
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• v.18 no.1
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• pp.1-10
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• 2020

In this study, an empirical analysis using Difference-in-Difference(DID) methods was conducted based on the data of domestic defense companies to look at the impact of government support on the performance of these defense industries. As a result, we found that the volume of sales and assets of defense enterprises does not increase or decrease solely on the benefit of government support. In addition, government support for net profit to total sales ratio and net profit to total assets ratio improved significantly, but the effect was only seen in the short term. Unlike previous studies that focused on identifying the existence of differences between industries, our research is different in that it is the first to analyze empirically within the Korean defense industry. It is also theoretically meaningful in that it looked at the effects of government support, especially in industries with unique characteristics that have yet to be known.

• Environmental and Resource Economics Review
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• v.31 no.3
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• pp.319-342
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• 2022

This study analyzed the effect of pay-as-you-throw bag prices on domestic waste through the natural experiment difference in difference with synthetic control method using cases of price cuts in some districts in Busan in 2019. In order to consider the endogenous problem when estimating demand and price elasticity, the price-invariant district was set as a synthetic control group and the price-cutting district was set as a treatment group. As a result of the analysis, the price elasticity of demand was 0.05~0.11, and the price of the pay-as-you-throw bag had little effect in sales. This seems to be because pay-as-you-throw bag is necessities and account for a very small proportion of household income. This suggests that a policy that can shift the demand curve will be more effective than a price policy to achieve the waste reduction goal because the demand curve is almost vertical.

• Journal of Technology Innovation
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• v.31 no.3
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• pp.201-230
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• 2023

The Innovation Procurement Policy was introduced as part of the strategic public procurement policy to improve firms' innovation capabilities and enhance the public sector's ability to solve social problems by designating and purchasing so-called 'innovative products.' The pilot procurement project for innovative products was first introduced in 2019, and the policy system for designating and discovering innovative products by government departments, as well as the priority purchase system, was established in 2020. Hence, this study conducted a quantitative analysis focusing on the effectiveness of the innovation procurement system in supporting firms after it was fully implemented. For this purpose, corporate financial and employment data from 2017 to 2021 were used, and propensity score matching(PSM) and difference-in-difference(DID) methods were utilized as analytical tools. The study found that the innovation procurement system contributed to corporate growth and employment and created additional public and private sales channels. Moreover, it is necessary to enhance the innovation procurement system, such as matching innovative product-producing companies with existing SME support policies, for companies to become self-sustaining after the innovative product designation ends.

• Journal of Labour Economics
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• v.34 no.3
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• pp.81-117
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• 2011

This study examined how firms responded to the articles regarding the prohibition or correction of discrimination against fixed-term workers in the 'fixed-term worker protection law', which has been effective since July of 2007 in Korea. Data used cone from the Korean Workplace Survey, and a difference-in-differences method was employed for the identification of the causal effect, noting that the 'discrimination prohibition law' has been applied to firms over stages based on their sizes. The empirical results show no strong evidence that the law played a positive role in reducing differentials between permanent workers and fixed-term workers in the areas of wage and various employee benefits, including the provision of severance pay, annual leave, and 4 major social insurances for fixed-term workers. A more thorough future analysis on the causes of the insignificant impact of the law in some employee welfare benefits, along with supplemental policies, is needed to have the law achieve the desired goal of removing discrimination at the workplace.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.6
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• pp.651-657
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• 2011

There exists a high correlation between the ionospheric delays and the integer ambiguity in GPS observation equation, so that the sufficient time span is required to revolve the integer ambiguity. This means that the ambiguity resolution plays a key role especially in rapid-static positioning mode. To analyze the effect of ionospheric disturbances on the positioning accuracy, 02/19/2011 day of dataset was selected processed in rapid-static positioning mode. The total of 141 30-minute sessions were processed, i.e., the estimation procedure started every 10 minutes, and the time-to-fix information of each data interval is obtained. In this study, the analysis is performed by comparing the time-to-fix with the magnitudes of ionospheric delays. The computed correlation coefficient between the time-to-fix and the magnitudes of ionospheric delays is 0.31, which indicates the ionospheric disturbances affect the positioning accuracy in rapid-static positioning mode. Therefore, it is required to collect and process sufficient data when the GPS surveying is performed in unfavorable ionospheric conditions.

• Geophysics and Geophysical Exploration
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• v.3 no.2
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• pp.48-52
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• 2000

We have calculated and analyzed the electromagnetic responses of buried conductive pipes due to a horizontal magnetic dipole source on the pound using a three-dimensional (3-D) finite element method to provide useful guidelines for designing electromagnetic pipe locator and for field operation of the system. For single buried pipe, the horizontal component and the horizontal difference of the vertical component of magnetic field show peaks above the pipe. When comparing the width of response curves of both cases around the peak, horizontal difference of vertical component of magnetic field shows much narrower peak, 2 times narrower at a half of maximum amplitude, than that of horizontal component of magnetic field. Accordingly, we can pinpoint the horizontal location of pipe on the ground more accurately by measuring the horizontal difference of vertical component of magnetic fold. Moreover, it will have a merit in determining the depth of pipe, because the equation for depth estimation is defined just above the pipe. When there are two buried pipes separated by two meters with each other, the response of horizontal difference of vertical component of magnetic field has two separate peaks each of which is located above the pipe whereas horizontal magnetic field response has only one peak above the pipe just below the transmitter. Thus, when there exist more than a buried pipe, measuring the horizontal difference of vertical magnetic field can effectively detect not only the pipe under transmitter but also adjacent ones. The width of response curves also indicates higher resolving ability of horizontal difference of vertical component of magnetic field.

• Journal of Navigation and Port Research
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• v.36 no.6
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• pp.429-435
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• 2012

Although GNSS hardware and software technologies have been steadily advanced, it is still difficult to obtain reliable positioning results in the area with lots of signal blockage. In this study, algorithms for integrated GPS and GLONASS double difference relative positioning were developed and its performance was validated via simulations of signal blockages. We assumed that signal blockages are caused by high-rise buildings to the east, west, and south directions. And then, GPS-only and integrated GPS/GLONASS positioning accuracy was analysed in terms of 2-dimensional positioning accuracies. Compared with GPS-only positioning, the positioning accuracy of integrated GPS/GLONASS improved by 0.3-13.5 meters.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.2
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• pp.273-279
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• 2022

In a recent decade, university closures have been a critical regional issue as a total of 17 universities have been closed while many more are facing closure in Korea. The local impact of university closures in the regions with declining populations has been far more detrimental and considered as one of the significant factors of the declining local economy, especially in the neighboring residential sectors. This study has taken an empirical approach to investigate the local impact of university closure on the housing market through a case of Dong-Pusan College in Busan, Korea. The study utilized Difference-in-Difference (DiD) to analyze the housing prices in proximity to the university and identified several factors associated with the local decline in the housing market in relation to university closure.

• 지역과문화
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• v.7 no.4
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• pp.21-48
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• 2020

The purpose of this study is to analyze how the integrated heritage conservation actually affected the urban economy of historical cities. To this end, this study examined the trends and meanings of an integrated heritage conservation, and a relationship between sustainable urban development and integrated heritage conservation to find out connectivity with urban economy. Before an empirical analysis of domestic policy of integrated conservation of heritage, this study overlooked the system of the preservation and promotion of ancient cities, which can be called integrated heritage conservation system in Korea, and examined how the historic landscape improving project, which is being implemented as part of the policy of the preservation and promotion of ancient cities, actually affected the urban economy. This study empirically identified the impact of the project through a land price analysis of the region. This study focused on analyzing an impact of the project on a price of land in the proximity of subsidized land lot and analyzed the impact through Difference-In-Difference method. In particular, the project effect was analyzed only for the settlement zones among the preservation and promotion zones where the project was carried out, and as a result, it was confirmed that the average price of lands in the proximity of subsidized land increased more over the same period than in the areas where the project was not intensively implemented.