• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.4A
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• pp.245-253
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• 2012

In the longway tunnel and underground traffic road, the structure of transverse ventilation system is constructed by the airpit slab. In this study, the full scale specimens of the PSC airpit slab that attached fire resistance panel are performed the static and dynamic loading tests for evaluation of bending capacity. The first of all, it confirmed the evaluations about the fundamental efficiency of the fire resistance panel and PSC slab by the 3-point bending test and pull-off test. The tests are performed for evaluation of the bending resistance under ultimate static load and the bonded capacity under dynamic fatigue load. A fatigue test is performed for an investigation of the effect on wind pressure that is developed by transit of traffic. The damage or debonding on surface between fire resistance panel and PSC slab was not developed in dynamic fatigue load test, also the behavior of the specimens is very stable and the debonding of the fire resistance panel attached at the bottom surface of PSC slab was not developed in static load test, too. Therefore, the crack or debonding of the fire resistance panel will be not developed by external loads during the construction or completion of the precast fire resistance system.

• The Journal of the Korea Contents Association
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• v.10 no.5
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• pp.210-219
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• 2010

Consumers differ in both horizontally and vertically. Market segmentation aims to divide horizontally different (or heterogeneous) consumers into more similar (or homogeneous) small segments. A specific consumer, however, may differ in vertically. He (or she) may belong to a different market segment from another one where he (or she) belonged to before. In consumer panel data, the vertical difference can be observed by his (or her) choice among brand alternatives are changing over time. The consumer's vertical difference has been defined as 'dynamics'. In this research, we have developed a binary probit model with random-walk coefficients to capture the consumer's dynamics. With an application to a consumer panel data, we have examined how have the random-walk coefficients changed over time.

• Journal of Energy Engineering
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• v.26 no.2
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• pp.80-92
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• 2017

This paper attempts to estimate the diesel fuel demand function in Korea using panel data panel data of 16 major cities or provinces which consist of diesel demands, diesel market prices and gross value added from the year 1998 to 2015. I apply panel GLS(generalized least square) model, fixed effect model, random effect model and dynamic panel model to estimating the parameters of the diesel fuel demand function. The results show that short-run price elasticities of the diesel fuel demand are estimated to be -0.2146(panel GLS), -0.2886(fixed effect), -0.2854(random effect), -0.1905(dynamic panel) respectively. And short-run income elasticities of the diesel fuel demand are estimated to be 0.7379(panel GLS), 0.4119(fixed effect), 0.7260(random effect), 0.4166(dynamic panel) respectively. The short-run price and income elasticities explain that demand for diesel fuel is price- and income-inelastic. The long-run price and income elasticities are estimated to be -0.4784, 1.0461 by dynamic panel model, which means that demand for diesel fuel is price-inelastic but income-elastic in the long run. In addition I apply dummy variable model to estimate the effect of 16 major cities or provinces on diesel demands. The results show that diesel demands is affected 10 regions on the basis of Seoul.

• Environmental and Resource Economics Review
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• v.25 no.2
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• pp.229-253
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• 2016

To achieve the socially optimum level of renewable generation, governments should design renewable policies to induce renewable technologies competitive with conventional generation technologies. And to do that, it is needed to understand how each policy has been effective in promoting renewables for power sector. In most of the literatures, there are two key limitations that they did not considered autocorrelation problem using the amount of generation from renewables as a dependent variable and technology innovation which needs to be preceded technology adoption. In this study, I try to overcome these two problems by using dynamic panel model and adding an additional variable for technology innovation. According to the result, FIT has been effective rather than RPS in promoting renewables for generation and I found the possibility that the counterintuitive results which commonly appeared in existing studies might be due to the two limitations mentioned above.

• Land and Housing Review
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• v.14 no.4
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• pp.47-62
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• 2023

Using the dynamic panel model, this study investigates rent determinants for small and medium-sized office buildings in Korea's CBD and Gangnam areas, key business districts. The results reveal that rents for small and medium-sized office buildings in CBD and Gangnam areas are influenced by macroeconomic fluctuations and characteristics of buildings and locations, suggesting a market with both spatial consumer and investment goods attributes. There are several investment implications as follows. First, even if the location in the CBD area is advantageous, the practical limitations in renovating aging small and medium-sized office buildings must be taken into account when investing. Second, parking conditions are a key factor influencing rent prices in CBD areas, so evaluating the parking facilities and improvement potential of small and medium-sized office buildings is essential for investors. Finally, due to the high sensitivity of Gangnam's small and medium-sized office market to macroeconomic trends, it's vital to prioritize monetary policy shifts as a key factor in investment decisions.

• The Journal of the Korea Contents Association
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• v.15 no.7
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• pp.436-448
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• 2015

This study examined one of the contemporary financial aspects, the level of corporate cash holdings for the firms belonging to the chaebols in the Korean capital markets. Being accompanied by various alternative econometric methodologies such as static and dynamic panel data model, stepwise OLS, and Fama-Macbeth modelm this research extended the preceding Kim's study (2015) in anticipation of validating the results to identify any financial factors which may significantly affect the chaebol firms' cash reserves. Several financial characteristics such as CASHFLOW, MVBV, REINVEST, and AGENCY, were found to be statistically significant factors on the level corporate liquidity, along with CCC as cash conversion cycle in the models. It may be plausible that any outcomes of this study may be applied to enhance the efficiency of financial strategies of the chaebol firms on cash holdings, thereby expediting the development of the domestic capital markets status quo toward the advanced one in the market classification.

• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.2
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• pp.20-41
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• 2023

Recently, urban shrinkage due to low birth rate and aging population and the decline of local cities are causing a new urban problem of empty houses. This study examines the distribution of vacant homes using spatial panel data collected from 2015 to 2019 at local administraitve districts and estimates the factors of vacant house occurrence using a spatial panel model considering spatio-temporal dependency. As a result, the spatio-temporal dependence of vacant houses was identified and it was estimated using spatial panel model not OLS model. Based on the spatial panel model, it was found that the most influential factor in the occurrence of vacant houses was the housing-related factor. This result shows that policy considerations for housing supply are necessary for the management of vacant housing as well as population movement and poor infrastructure.

• Journal of Technology Innovation
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• v.26 no.4
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• pp.173-198
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• 2018

In this paper, we analyze the determinants of the adoption of industrial robots using the data from 42 countries, and thereby examine the factors underlying the rapid expansion of industrial robots in Korea. To this end, the industrial robot data for the years 2001-2016 were drawn from the World Robotics dataset of the International Federation of Robotics (IFR). The explanatory variables included labor market environment variables and innovation capacity variables extracted from the dataset of the relevant international organizations. For data analysis, the Arellano-Bond dynamic panel analysis was performed to control for the endogeneity problem of some explanatory variables. The empirical results confirmed the exceptionally rapid expansion of industrial robots in Korea as compared to other countries, even when considering the national income level, employment cost, and innovation capacity. This phenomenon could be attributed to both the demand-side and supply-side factors. For one thing, changes in the labor market environment, such as an increase in employment costs, have led to an increase of the corporate demand for industrial robots. For another, the supply-side factors, such as an increase in the capital intensity and innovation capacity of companies, have also contributed to the widespread adoption of industrial robots.

• Land and Housing Review
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• v.14 no.1
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• pp.33-46
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• 2023

This study investigated price factors for large apartment complexes in Seoul during the COVID-19 pandemic and compared Gangnam and non-Gangnam areas, which have been recognized as heterogeneous markets. We find that the change in apartment prices in large-scale complexes did not significantly affect the individual characteristics of apartments, unlike previous studies, but was affected by macroeconomic variables such as interest rates and money. On the other hand, considering the units of the interest rate and total monetary volume variables, the effects of two variables on the apartment sales price is significantly high. In addition, the Gangnam area model analysis shows that apartment prices are greatly affected by interest rates and currency volume, and, the non-Gangnam area model analysis shows that apartment prices are greatly affected by interest rates and currency volume, but the degrees are different from the Gangnam area model. Overall, our study shows that interest rates and money supply were the main factors of apartment price changes, but apartment prices in non-Gangnam areas are more sensitive to changes in interest rates and money supply.

• Journal of the Korean Regional Science Association
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• v.33 no.4
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• pp.29-42
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• 2017

This study aims to analyze the effect of local government capacities on the improvement of air pollution. For this purpose, we construct a dynamic panel model using a data set for air pollutants such as $SO_2$, $CO_2$, and particulate matters and the local governments' capacities for Chinese Provinces in the period of 2007 - 2014. The results show that of the three types of capacities, the organizational capacity measured by environmental personnel, environmental expenditures, and average size of environmental institutions is very important, while the institutional capacity and social capacity have a insignificant impact on the air quality improvement. Among the local government capacities, other than the organizational capacity, only the activity of environmental organizations, which is a social capacity, partially affects the improvement of air pollution. Regarding local conditions, vertical dependence of financial resources, GRDP per capita, and population density have a negative impact on improving air pollution. These findings provide implications for local governments in China as to what capacities they should improve to improve air pollution.