• KDI Journal of Economic Policy
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• v.29 no.2
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• pp.135-157
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• 2007

The goal of this paper is to examine the validity of nonlinear Taylor rules in Korea. To perform our tests, we utilize new IV ECM threshold cointegration tests that are invariant to nuisance parameters. The new tests have a standard chi-square distribution and the same critical values can be used throughout. This is in contrast to OLS ECM threshold cointegration tests, which depend on nuisance parameters and have nonstandard distributions. After finding significant support for nonlinear cointegration, we find that the Bank of Korea raises the call rate of interest only when inflation is above a threshold rate. We additionally find that the Bank of Korea increases the call rate of interest to possibly counter domestic currency deprecation only when the rate of currency deprecation exceeds a threshold.

• Journal of Navigation and Port Research
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• v.46 no.4
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• pp.385-391
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• 2022

In this study, a multivariate time series analysis was conducted to identify various variables that impact ocean freight rates in addition to supply and demand factors. First, we used the ClarkSea Index, Clarksons Average Bulker Earnings, and Clarksons Average Tanker Earnings provided by the Shipping Intelligence as substitute variables for the dependent variable, ocean freight. The following ndependent variables were selected: World Seaborne Trade, World Fleet, Brent Crude Oil Price, World GDP Growth Rate, Industrial Production (IP OECD) Growth Rate, Interest Rate (US$ LIBOR 6 Months), and Inflation (CP I OECD) through previous studies. The time series data comprise annual data (1992-2020), and a regression analysis was conducted. Results of the regression analysis show that the World Seaborne Trade and Brent Crude Oil P rice impacted the ClarkSea Index. Only the World Seaborne Dry Bulk Trade impacted the Clarksons Average Bulker Earnings, World Seaborne Oil Trade, Brent Crude Oil Price, IP, and CP I on the Clarksons Average Tanker Earnings.

• The Journal of the Convergence on Culture Technology
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• v.9 no.5
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• pp.119-124
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• 2023

This study analyzed the impact of the real estate changes on the unemployment rate in Korea. Using monthly data from January 2013 to February 2023, the study employed a multiple regression analysis model. The key findings are as follows: First, there was a significant causal relationship between the real estate changes and the unemployment rate. Specifically, an increase in the real estate market led to a significant decrease in the unemployment rate, while a decrease in the real estate market resulted in a significant increase in the unemployment rate. Second, an increase in the loan interest rate was found to significantly reduce the unemployment rate, while a rise in interest rates had positive effects on the employment. Furthermore, an increase in inflation was associated with a significant rise in the unemployment rate. Moreover, an increase in the number of permits issued for housing construction significantly reduced the unemployment rate. Lastly, conducting robustness tests by substituting variables did not significantly alter the analysis results, indicating the robustness of the impact of the real estate changes on the unemployment rate. Based on the above analysis, it can be inferred that the fluctuations in real estate prices in South Korea are linked to fluctuations in the unemployment rate, and stable management of the real estate market may contribute to the stability of the unemployment rate.

• Fisheries and Aquatic Sciences
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• v.16 no.4
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• pp.253-260
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• 2013

We investigated the toxicological effects of Aroclor 1254 on the fertilized eggs, embryos and larvae of the olive flounder Paralichthys olivaceus. The survival rate and hatching success of the embryos decreased significantly in treated groups in an Aroclor 1254-dose-dependent manner. Significant differences were found at ${\geq}5{\mu}g/L$ Aroclor 1254 compared to the control group. Hatching success occurred at ${{\leq}}10{\mu}g/L$ Aroclor 1254, which was not significantly different to the control. Embryo malformation increased significantly at ${\geq}1{\mu}g/L$, and included yolk-sac and tail-flexure abnormalities. There was a significant decrease in the survival rate of the larvae at ${\geq}5{\mu}g/L$, which was accompanied by the malformations described above. Notably, concentrations as low as $1{\mu}g/L$ caused a significant increase in abnormalities in the larvae, including incidences of multi-focal hemorrhages, pericardial and yolk-sac edema, inhibition of swim bladder inflation and severe developmental delay. The responses to Aroclor 1254-induced toxicity were generally similar among fertilized eggs, embryos and larvae from three separate flounder hatcheries: Cheju Island, Yeosu and Chungnam, South Korea. These results indicate the high acute toxicity of Arolcor 1254 concentrations of which as low as $1{\mu}g/L$ in olive flounder larvae can affect unhatched embryos. To conclude, the average $LC_{50}$ values for Aroclor 1254 in the embryos and larvae were 50.92 and $3.08{\mu}g/L$, respectively. Additionally, the average $EC_{50}$ values, based on the rate of damage were 14.72 and 5.6$1{\mu}g/L$, respectively.

• Journal of Labour Economics
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• v.43 no.4
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• pp.1-34
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• 2020

After the global financial crisis, doubts have been raised about the usefulness of traditional unemployment rate for the labor market slackness, hence, this study provides alternative indicators that can help estimate the labor market slackness in Korea, and investigates the degree of biasness of traditional indices of Korean labor market. In particular, this study intends to focus on the possibility of employing the labor underutilization index officially announced by Statistics Korea (KOSIS) from 2015. To do this, we first define the labor underutilization indices from 2003 to 2014 by applying current definitions of labor underutilization indices retrospectively to these periods. Based on these indices, the empirical analysis shows that the employment gap using labor underutilization indices is highly correlated with total output gap, and has significantly improved the performance of forecasting inflation rate compared to other labor market slackness indicators.

• International Journal of Highway Engineering
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• v.16 no.2
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• pp.119-129
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• 2014

PURPOSES : The purpose of this study is to develop the U-turn accident model at 4-legged signalized intersections in urban areas. METHODS : In order to analyze the characteristics of the accidents which are associated with U-turn operation at 4-legged signalized intersections in urban areas and develop an U-turn accident model by regression analysis, the tests of overdispersion and zero-inflation are conducted about the dependent variables of number of accidents and EPDO (Equivalent Property Damage Only). RESULTS : As their results, the Poisson model fits best for number of accident and the ZIP (Zero Inflated Poisson) fits best for EPOD, the variables of conflict traffic, width of opposing road, traffic passing speed are adopted as independent variable for both models. The variables of number of bus berths and rate of U-turn signal time at which the U-turn is permitted are adopted as independent variable only for EPDO. CONCLUSIONS : These study results suggest that U-turn would be permitted at the intersection where the width of opposing road is wider than 11.9 meters, the passing vehicle speed is not high and U-turn operation is not hindered by the buses stopping at bus stops.

• Smart Structures and Systems
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• v.16 no.4
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• pp.743-758
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• 2015

This paper presents an advanced life cycle cost (LCC) analysis of a ground source heat pump (GSHP) system and suggests a smart operation mode with a thermal performance test (TPT) and an energy pile system constructed on the site of the Incheon International Airport (IIA). First, an economic analysis of the GSHP system was conducted for the second passenger terminal of the IIA considering actual influencing factors such as government support and the residual value of the equipment. The analysis results showed that the economic efficiency of the GSHP system could be increased owing to several influential factors. Second, a multiple regression analysis was conducted using different independent variables in order to analyze the influence indices with regard to the LCC results. Every independent index, in this case the initial construction cost, lifespan of the equipment, discount rate and the amount of price inflation can affect the LCC results. Third, a GSHP system using an energy pile was installed on the site of the construction laboratory institute of the IIA. TPTs of W-shape and spiral-coil-type GHEs were conducted in continuous and intermittent operation modes, respectively, prior to system operation of the energy pile. A cooling GSHP system in the energy pile was operated in both the continuous and intermittent modes, and the LCC was calculated. Furthermore, the smart operation mode and LCC were analyzed considering the application of a thermal storage tank.

• KIEAE Journal
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• v.15 no.6
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• pp.5-10
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• 2015

Purpose: To evaluate the economic performance of grid-connected photovoltaic system in residential house, household electricity bill policy of Korea Electric Power Corporation (KEPCO) must be applied precisely, and market tendency and uncertainty of system also need to be considered. In this study, to evaluate the economic feasibility of PV system, we measured PV power generation and electricity consumption of six of Green home in Daejeon through web based remote monitoring system. Method: We applied Monte-Carlo simulation based on life cycle cost analysis, to reflect an uncertainty of main factor in economic feasibility evaluation of photovoltaic system. Result: First, with deterministic analysis, the difference of NPV of cumulative financial savings among households varied from -3,310 ~ 24,170 thousand won, portraying notably big range. Also the possibility of getting the same result was 50% when applying uncertainty. Second, the higher electricity consumption is, the more economic feasibility of photovoltaic system increases because KEPCO uses progressive taxation in household electricity bill policy. Third, The contribution to variance of electricity price increases in NPV varied from 98.5% to 99.9%. While the inflation rate and annual degradation contributed very little to none.

• Fire Science and Engineering
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• v.18 no.4
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• pp.1-15
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• 2004

The following matters were confirmed through the analysis of property losses due to fires in Korea, the U.S., and Japan. 1. Korean statistics on property losses are not the most detailed of the three centuries, and they have a lot of limitations to analyze the actual condition of property losses due to fires. 2. The percentage which takes up property losses due to fires in GDP is on the decrease in the U.S. and Japan, but increase in Korea. In addition, from 1994, it has occupied almost the same rate in Korean ad compared with the U.S. and Japan. 3. When inflation are taken into consideration, property losses due to fires in the U.S. and Japan have decreased, but in Korea, they have increased except for the recent 2 years.

• Journal of Korean Institute of Industrial Engineers
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• v.41 no.2
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• pp.150-161
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• 2015

This paper proposes a new approach to technology valuation, the market-replacement cost approach which integrates the cost-based approach and market-based approach. The proposed approach estimates the market-replacement cost of a target technology using R&D costs of similar R&D projects previously conducted. Similar R&D projects are extracted from project database based on document similarity between project proposals and technology description of the target technology. R&D costs of similar R&D projects are adjusted by mirroring the rate of technological obsolescence and inflation. Market-replacement cost of the technology is then derived by calculating the weighted average of adjusted costs and similarity values of similar R&D projects. A case of "Prevention method and system for the diffusion of mobile malicious code" is presented to illustrate the proposed approach.