• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 하계종합학술대회 논문집
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• pp.94-97
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• 1989

This work describes the imortance of the load run back control of a thermal power plant which has a serious effect on a power system, and shows the load run back tests results which was carried out at BORONG Thermal Power Plant, finally suggests what control circuits should be modified in the plant control system in order to prevent plant trip in case of auxiliary machine failure.

• Asia Pacific Journal of Business Review
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• 제1권2호
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• pp.1-16
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• 2017

The fundamental goal of the research was to verify if the Twin Deficits Hypothesis holds for the economy of Zambia using time series data from 1980-2014. The current account and budget deficit were employed as key variables. The exchange rate was also used as a transmission mechanism to see how it contributes in the nexus. Cointegration tests confirmed a long run association of the variables. After fitting the VECM model, Granger causality tests confirmed the existence of twin deficits for Zambia. The results supported uni-directional reverse causality. The exchange rate was shown to be more significant in the long run than in the short run. The implosion of the time series as shown by the predicted cointegration equation implies that unless drastic measures are taken to cure the deficits, using the current account as the major target variable, twin deficits will persist for some time. The major policy implication of this research is that given that Zambia is a primary commodity-dependent developing country subsisting largely on copper revenues to sustain the economy, there is a need to move away from "copper addiction," given the recent volatility of earnings of primary commodities (e.g. through diversification of the economy, import substitution, and other strategies).

• 자원ㆍ환경경제연구
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• 제9권2호
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• pp.373-391
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• 2000

This paper investigates the existence of a long-run relationship between world oil price and consumer price index for Korea during 1983~1999. The cointegration and error correction modelling approaches have been applied. Empirical results suggest that there exists a long-run relationship among world oil prices. consumer prices, M2 and a production gap variable. The dynamic behavior of the relationship has been investigated by estimating a error correction model, in which the error correction term have been found significant. The error correction model has also been found to be robust as it satisfy almost all relevant diagnostic tests.

• The Journal of Asian Finance, Economics and Business
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• 제3권3호
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• pp.27-37
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• 2016

This study uses an endogenous economic growth model to determine the long run relationship between trade openness and economic growth in China by using the data 1975-2009.It contributes to the literature by developing trade openness index. An autoregressive distributed lag approach to cointegration and rolling regression method are employed. This study tests the link between trade openness and economic growth in the case of China by using the framework of endogenous economic growth model. This study also employs the rolling window regression method in order to examine the stability of coefficients throughout the sample span. The autoregressive distributed lag (ARDL) cointegration technique and rolling regression method are used. The empirical findings indicate that trade openness (i.e. Both individual trade indicator and composite trade openness index) are positively related to economic growth in the long run and short run. Our results indicate that trade openness as measured by individual trade indicator and composite trade openness index are positively related to economic growth in the long run and short run. However, results from the rolling window suggest that trade openness is negatively linked to economic growth only for a number of years.

• The Journal of Asian Finance, Economics and Business
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• 제9권4호
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• pp.173-183
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• 2022

The objective of this research is to examine the influence of the COVID-19 pandemic on stock markets in a few developing and developed countries. This study uses daily data from January 2020 to May 2021 and obtained from World Health Organization and Thomson Reuters. The secondary data was evaluated through panel econometric methodology that includes different unit root tests, and to analyze the long-run relationship between variables, panel cointegration techniques were applied. The long-run causality among variables was examined through Panel Vector Error Correction Model. The overall findings of this study suggest a long-run association exists between several cases and death with the stock returns of the GCC and other stock markets. Furthermore, the VECM model also identified a long-run causality running from COVID cases and death towards the stock rerun of both sets of stock markets. However, a subsequent Wald test yielded mixed results, indicating no short-run causality between cases and deaths and stock returns in both groups; however, in the case of GCC, several COVID-19 cases are having a causal impact on stock markets, which is notable in light of the fact that the death rate in GCC is significantly lower than in many developed and developing countries.

• 한국해양공학회지
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• 제28권1호
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• pp.6-11
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• 2014

This paper presents the results of an experimental study of wave run-ups on a semi-submersible offshore structure. A series of model tests with a 1:80 scale ratio were carried out in the two-dimensional wave basin of MOERI/KIOST. The experimental model had two columns and one pontoon. The model was fixed and wave elevations were measured at five points per column. Two different draft (operational & survival) conditions and three wave heights were considered under regular wave conditions. First, the nonlinear characteristics of wave run-ups are discussed by using the time series data. Then, the wave heights are compared with numerical results based on the potential flow model. The comparison shows fairly good correlation between the experiments and computations. Finally, wave run-ups under the operational and survival conditions are suggested.

• 대한토목학회논문집
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• 제7권3호
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• pp.111-119
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• 1987

해안구조물(海岸構造物)의 안정성(安定性)과 사면상(斜面上)의 반사파(反射波), run-up, run-down 등 흐름특성(特性)에 대한 모형(模型)의 축척효과(縮尺効果) 발생(發生) 메카니즘과 그 제어(制御) 방법(方法)을 7종(種)의 축척모형(縮尺模型)에 의해 실험적(實驗的)으로 연구(硏究)하였다. 그 결과(結果), 종래(從來)의 많은 연구자(硏究者)들이 소홀히 해 왔던 구조물(構造物) 내부(內部)의 침투류(浸透流) 특성(特性)의 상사(相似) 여부(如否)가 축척효과(縮尺効果) 발생(發生)의 가장 중요(重要)한 요인(要因)임을 지적(指摘)하였다. 해안구조물(海岸構造物) 가운데서 특히 투과성(透過性) 구조물(構造物)의 축척효과(縮尺効果) 제어(制御)를 위해서는 피복층(被覆層), filter층(層), 피복층(被覆層)에 가까운 core부(部)의 침투류(浸透流) Reynolds수(數)가 각각(各各) Re > $2{\times}10^4$, $Re_f$ > $3{\times}10^3$, $Re_c$ > $1{\times}10^3$인 조건(條件)을 만족하도록 구조물(構造物) 각(各) 층(層)의 축척(縮尺)을 결정(決定)하는 것이 바람직함을 강조(强調)하였다.

• 한국추진공학회지
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• 제27권1호
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• pp.58-67
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• 2023

본 논문에서는 메탄엔진 단일분사기급 연소기의 추력제어를 위해 수행된 드라이런 테스트, 수류시험, 그리고 연소시험 결과를 다루었다. 메탄엔진 연소시험설비의 산화제 및 연료 공급 라인에 유량제어 밸브를 설치한 후, 다수의 드라이런 테스트를 수행하여 밸브가 설정된 스트로크에 빠르고 안정적으로 도달할 수 있도록 하였다. 다음 액체질소와 기체질소를 사용한 수류시험을 진행하여 밸브 제어에 따른 모사 추진제의 안정적인 공급을 확인하였다. 최종적으로 액체산소와 기체메탄을 사용하여 정격 추력 대비 50%~10%의 고정 추력제어 연소시험과 연속 추력제어 연소시험을 성공적으로 수행하였다.

• 유통과학연구
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• 제10권9호
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• pp.5-11
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• 2012

Purpose - The objective of the paper is to explain both the price sensitivity of international tourists to South Korea and the price sensitivity of Korean tourists to international travel. The study examines long-run equilibrium relationships and Granger causal relationships between foreign exchange rates and inbound and outbound tourism demand in South Korea. Research design/ data / methodology - The study employs monthly time series data from January 1990 to September 2010. The paper examines the long-run equilibrium relationship using the Johansen cointegration test approach after unit root tests. The short-run Granger causality was tested using the vector error correction model with the Wald test. Results - Hypothesis 1 testing whether there is a long-run equilibrium relationship between exchange rates, inbound and outbound tourism demand is supported. Hypothesis 2 testing whether exchange rates lead to a change in touristarrivals and expenditure is not supported. Hypothesis 3 testing whether exchange rates lead to a change in tourist departures and expenditure is supported. Conclusions - The findings of this study show that the impacts of tourism price competitiveness are changing quite significantly with regard to destination competitiveness. In other words, the elasticity of tourism price over tourism demand has been moderated.

• Nuclear Engineering and Technology
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• 제54권5호
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• pp.1664-1673
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• 2022

Achieving sustainable development requires an increasing share of green technologies. World energy demand is expected to rise significantly especially in developing economies. The increasing energy demands will be entertained with conventional energy sources at the cost of higher emissions unless eco-friendly technologies are used. This study examines the asymmetric effects of nuclear energy on carbon emissions for Pakistan from 1974 to 2019. Augmented Dickey-Fuller (ADF) and Phillips Perron (PP) unit root tests suggest that variables are integrated of order one and bound test of Autoregressive Distributed Lag (ARDL) and nonlinear ARDL confirm a long-run relationship among selected variables. The ARDL, Fully Modified Ordinary Least Squares (FMOLS), and Dynamic Ordinary Least Squares (DOLS) results show that the coefficient of nuclear energy has a negative and significant impact on emissions in both short and long run. Further, the NARDL finding shows that there exists an asymmetric long-run association between nuclear energy and CO₂ emissions. The vector error correction method (VECM) results indicate that there exists a bidirectional causal relationship between nuclear energy and carbon emissions in both the short and long run. Additionally, the impact of nuclear energy on ecological footprint has been examined and our findings remain robust.